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Circulation Research. 1999;84:633-646

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(Circulation Research. 1999;84:633-646.)
© 1999 American Heart Association, Inc.


Point/Counterpoint

Signaling in Myocardial Hypertrophy

Life After Calcineurin?

Peter H. Sugden

From the National Heart and Lung Institute (NHLI) Division, Imperial College School of Medicine, London, United Kingdom.

Correspondence to Peter H. Sugden, DPhil, NHLI Division (Cardiac Medicine), Imperial College School of Medicine, Dovehouse St, London SW3 6LY, United Kingdom. E-mail p.sugden{at}ic.ac.uk


Key Words: myocardial hypertrophy and failure • mitogen-activated protein kinase cascade • calcineurin • calcium movement • transcription


*    Introduction
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*Introduction
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Cardiac (ventricular) hypertrophy is an important adaptive response in vivo that (at least in the shorter term) allows the organism to maintain or increase its cardiac output. Global ventricular hypertrophy is a recognized response to increased pressure or volume work (reviewed in Reference 11 ), with increased myofibrillogenesis and sarcomere deposition being cardinal features. Although global hypertrophy is clinically important, probably the most significant form of cardiac hypertrophy in terms of patient numbers is the localized hypertrophy of the ventricular wall that may follow loss of myocardium after a survivable myocardial infarct. In the early stages, both global and localized hypertrophy may resemble the readily reversible, nonfibrotic "physiological" hypertrophy that develops after repeated endurance exercise. In the longer term, beneficial, "compensated" hypertrophy may decay into maladaptive "decompensated" hypertrophy and heart failure (reviewed in References 2 and 32 3 ) with diminished coronary flow reserve and increased risk of lethal arrhythmias. Although some aspects of the maladapted state are probably intrinsic to the myocyte [eg, prolongation of the action potential and Ca2+ transient (reviewed in References 4 and 54 5 )], other factors (increased fibrosis and mismatch between O2 supply and demand) are also probably involved in decompensation.

The predominating view is that mammalian ventricular myocytes lose their capacity for cell division during the perinatal period and are thus terminally differentiated cells, although this is still a matter of some dispute (reviewed in References 6 and 76 7 ). In contrast, other cells in the heart (endothelial cells, fibroblasts, and smooth muscle cells) retain their mitotic capacity. Although ventricular myocytes are not the only cell type involved in the overall hypertrophic response, much of the ventricular enlargement or remodeling is attributable to their hypertrophy. The identities of signaling pathways that couple the demand for increased contractile power to increased myocyte growth and altered gene expression have been actively investigated for many years. Protein phosphorylation (catalyzed principally by Ser-/Thr- or Tyr-specific protein kinases) and phosphoprotein dephosphorylation (catalyzed by phosphoprotein phosphatases) play central roles in the regulation of many cellular events, including growth and cell division, and it is widely believed that these processes participate in myocyte hypertrophy.

From the broad point of view, 2 hypotheses of hypertrophy have been proposed, which are the extrinsic and the intrinsic hypotheses. The former maintains that myocyte hypertrophy results from extracellular factors (Table 1Down) that are either of a neuroendocrine origin (eg, the catecholamines) or are synthesized and released locally by the myocytes and nonmyocytes in the heart (eg, endothelin-1 [ET-1] and angiotensin II [Ang II]). The intrinsic hypothesis maintains that changes originating within the myocyte are responsible for hypertrophy. Because of its well-established role in excitation-contraction coupling, increased [Ca2+]i concentration has been suggested to be an intrinsic mediator. The 2 hypotheses are not mutually exclusive because, in the hands of some workers, extrinsic agonists such as ET-1 increase [Ca2+]i concentrations in myocytes (reviewed in References 8 and 98 9 ) and, conversely, [Ca2+]i is known to be involved in the secretion of peptide hormones (eg, secretion of atrial natriuretic factor [ANF] from myocytes10 ). The problem with the Ca2+ hypothesis is that, although [Ca2+]i has been implicated in the hypertrophic response,11 12 no clearly defined coupling mechanism has been substantiated until recently. As discussed in the accompanying article,13 the recent elegant studies of Molkentin et al14 have provided evidence that the Ca2+/calmodulin (CaM)–dependent phosphoprotein phosphatase calcineurin (also known as protein phosphatase 2B) plays a significant role in myocyte hypertrophy. The excitement generated by this finding was demonstrated by the rapid appearance of editorials in Science15 and Nature Medicine.16 The problem is that there will be an inevitable temptation to believe that the biochemical mechanisms underlying myocyte hypertrophy and heart failure have been elucidated in all but detail and that therapeutic intervention is now readily at hand. Indeed, in a review of a recent manuscript that we submitted, one reviewer made the following comment: "The authors talk a lot about the mitogen-activated protein kinase (MAPK) pathway and hypertrophy and omit any mention of the recent and exciting observations about the role of Ca2+ and calcineurin-dependent activation of NFAT [nuclear factor of activated T lymphocytes] transcription factors in hypertrophy. At this point, it seems likely that many of the hypertrophic effects of the agonists used here are mediated by the calcineurin–NFAT pathway rather than the MAPK pathway." In my opinion, this comment crystallizes the dangers that Molkentin et al14 have unintentionally created, and I am convinced that the issue is far from settled. There are 3 main points that I wish to cover. First, is there evidence for the involvement of other (possibly interacting) signaling pathways leading to hypertrophy? Second, how convincing is the evidence for involvement of calcineurin? Third, if calcineurin is involved, how convincing is the mechanism proposed by Molkentin et al,14 namely dephosphorylation of the transcription factor nuclear factor of activated T-lymphocytes-3 (NFAT3)?


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Table 1. Extracellular Stimuli of Ventricular Myocyte Hypertrophy


*    Experimental Investigation of Myocardial Hypertrophy
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*Experimental Investigation of...
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Hypertrophy in Vitro
The most commonly used in vitro model involves primary culture of neonatal rat ventricular myocytes, and this has allowed the biochemical and molecular characteristics of hypertrophy to be studied in detail under controlled conditions (reviewed in References 17 through 1917 18 19 ). A plethora of hypertrophic factors and interventions has been identified (Table 1Up). It is invidious to attempt to identify a single hypertrophic agonist, and many may participate in vivo. Although there is concern about the fidelity of simulation of the adult hypertrophic response, many of the changes seen in the cultured neonatal cells have also been detected in adult animals in vivo (reviewed in Reference 1717 ). When exposed to hypertrophic stimuli, myocytes in culture show increased myofibrillogenesis, and the cells enlarge. From a biological standpoint, accumulation of sarcomeres is perhaps the most important feature of cardiac hypertrophy, because, above all other manifestations, this allows the myocyte to increase its contractile power. In addition, there are alterations (both upregulation and downregulation) in gene expression. Immediate-early genes that encode transcription factors (c-fos, c-jun, and Egr-1) are rapidly (within 1 hour) and transiently upregulated, and these may be important in the regulation of genes encoding myofibrillar proteins. B-type natriuretic peptide (BNP) is expressed at this early stage, and this is maintained.20 In the medium term (12 to 24 hours), the "fetal" pattern of gene expression is recapitulated with reexpression of ANF, skeletal muscle {alpha}-actin, and ß-myosin heavy chain (ß-MHC). Although now being superseded by BNP, reexpression of ANF has been widely used as an index of hypertrophy. Over 24 to 48 hours, other genes are upregulated (ventricular myosin light chain 2, cardiac muscle {alpha}-actin). Expression of some genes is downregulated (eg, sarcoplasmic/endoplasmic reticulum Ca2+-ATPase 2 [SERCA2], reviewed in Reference 2121 ), whereas the expression of others is relatively unchanged.

Gene expression is regulated by the binding of trans-acting transcription factors and other cooperating proteins (eg, RNA polymerases) to cis-acting consensus recognition sequences that lie upstream (5') from the transcriptional initiation sites in genes (the promoter region) or to more distant enhancer regions. For most genes, these regions contain multiple sequences recognized by a variety of transcription factors (for a review on the heart, see Reference 2222 ), and interactions between the various DNA-bound transcription factors occur. Gene expression is most commonly studied by transient transfection of expression plasmids containing fusion genes of the 5'-upstream regulatory sequences of hypertrophic "marker" genes (eg, ANF) coupled to suitable reporter genes. This has allowed the identification of regulatory elements within the promoter regions. By cotransfecting/coinfecting suitable reporters with plasmids or adenoviral vectors encoding signaling proteins, this approach has been used to identify putative participants in the induction of hypertrophy.

One frequently ignored fact is that hypertrophy requires increased accumulation of protein (particularly of myofibrillar proteins) and increased myofibrillogenesis. Control at the level of protein turnover and sarcomeric assembly is necessary. As reviewed in Reference 1919 , hypertrophic agonists generally increase the rate of protein synthesis in the short term by increasing the peptide chain initiation (the rate-controlling step). In the longer term, ribosomal synthesis also increases. Because of the experimental difficulties in measuring protein degradation (particularly of specific proteins) with accuracy, it is not clear whether this process is also regulated. In addition, the regulation of myofibrillogenesis is also poorly understood.

Hypertrophy In Vivo
In vivo, probably the most commonly used surgical intervention involves coarctation of the aorta, which induces a pressure-overload hypertrophy. It is important to note that although the aorta can be coarcted at a variety of levels to induce pressure overload, the models may not be necessarily equivalent.23 A variety of transgenic mouse models of cardiac hypertrophy or failure have been developed (reviewed in References 24 through 2624 25 26 ). Although transgenic "knockouts" have been used, most studies have involved expression of a wild-type transgene or one encoding a constitutively active form of a protein. The transgene is cardiospecifically expressed by placing it under the regulation of a constitutive cardiomyocyte promoter (often the {alpha}-MHC promoter sequence). One problem is that transgene expression is difficult to control. In the mouse, mRNA for both {alpha}-MHC and ß-MHC is expressed from the onset of cardiogenesis, with ß-MHC mRNA predominating during fetal development.27 This is reversed during the perinatal period, with a switch occurring in relative abundances of transcripts ({alpha}-MHC mRNA:ß-MHC mRNA, {approx}16:1). This pattern is maintained during adult life in control mice. There are several points here. First, because of the leakiness of the {alpha}-MHC promoter, placing a transgene under its control may still allow transgene expression at critical stages in cardiac development. Second, the recapitulation of ß-MHC expression and the decline in {alpha}-MHC expression during hypertrophy should lead to down-regulation of transgene expression at this stage. Third, transgenesis may modify expression of other genes through obscure mechanisms (see, eg, References 28 and 2928 29 ). Fourth, there may be considerable variability in phenotype and penetrance between individuals expressing any single transgene.30 Fifth, the phenotype is often influenced by the strain of mouse used. In the future, it is likely that use of inducible systems will allow more highly regulated expression of heterologous transgenes, but, even here, transgene expression may be difficult to control uniformly.


*    Before Calcineurin: Myocardial Hypertrophy and Signaling Through Protein Kinase C (PKC) and MAPK Cascades
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up arrowExperimental Investigation of...
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Despite differences in emphasis, there has been relatively general agreement that activation of PKC and 1 or more of the MAPK cascades (Figure 1Down) by G protein–coupled receptor (GPCR) agonists induces many of the features of hypertrophy (see also Table 2Down). Since we have reviewed this topic in depth recently,19 31 32 only the salient features will be outlined. I do not wish to exclude involvement of other protein kinases (eg, the Janus kinases,33 34 35 Ca2+/CaM kinase II,36 and most recently myosin light chain kinase,37 ), but work on these has been less extensive. MAPK cascades consist of 3-member protein kinase "modules" (Figure 1Down). The MAPK kinase kinases (MKKKs) are Ser-/Thr-specific kinases that phosphorylate and activate MAPK kinases (MKKs), and the MKKs in turn phosphorylate and activate the MAPKs, the cascade thus allowing signal integration and amplification. MAPKs are unusual in that they require phosphorylation of a Tyr and a Thr residue in a Thr-Xaa-Tyr motif that lies on their surface in a regulatory loop of varying length, and the sequence of this tripeptide represents 1 criterion for MAPK classification. After their activation, MAPKs phosphorylate a broad range of substrates (including nuclear transcription factors, other protein kinases, and various signaling molecules), thereby modifying their biological activities. Although MAPKs preferentially phosphorylate (Ser/Thr)–Pro sequences (or, even better, Pro-Xaa-[Ser/Thr]–Pro38 ; reviewed in Reference 3939 ), this dipeptidyl sequence is relatively common in proteins, and other factors also contribute to specificity (reviewed in Reference 4040 ).



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Figure 1. MAPK cascades. Exposure of myocytes and whole hearts to GPCR agonists leads to activation of the ERKs, JNKs, and p38-MAPKs. GPCR agonists activate the small G protein Ras through a PKC-dependent mechanism and may also activate Rho subfamily small G proteins. Ras activates the ERK cascade and, either directly or indirectly, may activate JNKs and p38-MAPKs though poorly understood mechanisms, possibly involving protein kinases such as MEKKs, p21-activated kinases (PAKs), germinal center kinases (GCKs), or mixed-lineage kinases (MLKs). The ERKs are activated by MKK1 and MKK2, the JNKs are activated by MKK4 and MKK7, and the p38-MAPKs are activated by MKK3 and MKK6. The MAPKs then phosphorylate other kinases (MAPKAPK1, -2, and -3) and transcription factors (thus regulating transcription). MAPKAPK1 is also known as p90 ribosomal protein S6 kinase (p90RSK) and may also be involved in transcriptional regulation. In addition, MAPKAPK2 and -3 phosphorylate the small heat shock proteins (Hsp25/27) and may thereby confer cytoprotection.


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Table 2. Examples of Transient Transfection of Ventricular Myocytes With MAPK Cascade Members

GTP-binding proteins (G proteins) participate in the activation of MAPK cascades, and these can be broadly divided into 2 types: the heterotrimeric (GPCR-associated) group and the p21 small G protein superfamily, of which there are 5 subgroups (prototypically Ras, but also Rho, ADP ribosylation factors, Rab, and Ran). Of the heterotrimeric G proteins, the Gq/G11 subfamily (Gq for simplicity) has been shown most convincingly to be associated with hypertrophy. From the p21 small G protein superfamily, only the Ras and Rho subgroups (reviewed in References 41 and 4241 42 , respectively) have been examined from this standpoint. All G proteins are biologically inactive in their GDP-ligated form and become activated on exchange of GDP for GTP. Their innate GTPase activity returns them to the inactive state (the GDP/GTP cycle), but this process can be stimulated by ancillary proteins. A number of proteins also affect GDP/GTP exchange (the GPCRs in the case of heterotrimeric G proteins, stimulatory guanine nucleotide exchange factors such as Sos, and inhibitory factors for the small G proteins).

I will use ET-1 as my principal example of a hypertrophic GPCR agonist, as there is unanimity that it is strongly hypertrophic. By binding to heptahelical transmembrane GPCRs, agonists such as ET-1 stimulate the dissociation of membrane-bound inactive heterotrimeric Gq proteins [({alpha}q · GDP) · ß{gamma}] into {alpha}q · GTP and ß{gamma} dimers. Both {alpha}q · GTP and ß{gamma} dimers are potentially capable of activating phospholipase Cß isoforms leading to the hydrolysis of membrane phosphatidylinositol 4,5-bisphosphate (PtdInsP2) to inositol 1,4,5-trisphosphate (InsP3) and diacylglycerols (DGs). DGs are retained in the plane of the membrane, and the DG-sensitive isoforms of PKC (principally nPKC{delta} and nPKC{epsilon} in the rat ventricular myocyte43 44 ) translocate to the particulate fraction (and presumably become activated). Phorbol esters such as phorbol 12-myristate 13-acetate (PMA) act as DG analogs and also translocate myocytic nPKC{delta} and nPKC{epsilon},45 46 and they are also strongly hypertrophic.47 48 The next step(s) in the signaling pathway is unclear, but the end result is that both ET-1 and PMA activate membrane-bound Ras (Ras · GDP->Ras · GTP) (A. Chiloeches, P.H. Sugden, unpublished data, 1998).

One of the best-defined roles of Ras · GTP is its activation of the extracellular signal–regulated protein kinase (ERK) cascade (Figure 1Up), which is particularly involved in cell growth, division, and differentiation. The ERK cascade MKKKs are members of the Raf family (c-Raf, A-Raf, and B-Raf), the MKKs are MKK1 and MKK2, and the MAPKs (phosphorylation motif Tyr-Glu-Thr) are ERK1 (p44-MAPK) and ERK2 (p42-MAPK). ET-1 and PMA strongly activate all 3 stages of the ERK cascade (Raf,49 MKK1 and -2,50 and ERKs43 50 51 ) in myocytes. Activation of Raf involves its binding to membrane-localized Ras · GTP and its translocation to this fraction. It is not clear whether this interaction is sufficient to activate Raf or whether other events such as Ser/Thr phosphorylation and/or Tyr phosphorylation (possibly involving nonreceptor protein Tyr kinases of the Src family52 53 ) are additionally required. The potential for ERKs to regulate gene transcription in the myocyte is demonstrated by the rapid appearance (within 4 minutes) of active phospho-ERKs in nuclei of myocytes exposed to PMA (H.F. Paterson, P.H. Sugden, unpublished data, 1998).

Depending on the criteria used, there are an additional 2 (see, eg, Reference 3232 ) or 5 (see, eg, Reference 5454 ) subgroups of the MAPK superfamily. The simpler classification based on the sequences of the tripeptide phosphorylation motif will be used here. The c-Jun N-terminal kinases (JNKs; phosphorylation motif Thr-Pro-Tyr) and the p38-MAPKs (phosphorylation motif Thr-Gly-Tyr) were first identified as being activated by cellular stresses (eg, protein synthesis inhibitors, hyperosmotic shock, and reactive oxygen species), and this is certainly true in myocytes.55 56 57 It has also emerged that Gq protein–coupled receptor (GqPCR) agonists such as ET-1 are moderately effective in activating JNKs55 and p38-MAPK57 in these cells but that PMA is a poor activator.55 57 The upstream signaling pathways are not as clear as in the ERK cascade, although MKKs, MKKKs, other protein kinases, and small G proteins (particularly Rac and Cdc42, 2 members of the Rho subfamily) are likely to be involved. As with the ERKs, activation of JNKs and p38-MAPKs leads to phosphorylation of transcription factors (Figure 1Up) and other signaling molecules. Generally speaking, the biological roles of the JNKs and p38-MAPKs are less clear than those of the ERKs. In addition to their hypertrophic actions in myocytes (Table 2Up), activation of JNKs has been associated with apoptosis in nonmyocytes and myocytes,58 59 whereas the p38-MAPKs have been associated with both apoptosis60 and cytoprotection/cell survival57 59 61 in myocytes (and other cells).

There is considerable evidence that activation of any of the 3 MAPK cascades can lead to a hypertrophic response in myocytes. All 3 MAPK subfamilies are activated by ET-1 and other hypertrophic GPCR agonists,43 50 51 55 57 and the novel hypertrophic agonist prostaglandin F2{alpha}62 63 has recently been shown to activate JNKs.64 Transfection/infection of suitably constitutively activated components of the cascades (Table 2Up) leads to induction of many features of the hypertrophic response, although myofibrillogenesis is not always observed. Transfection/infection of "dominant-negative" (inhibitory) mutant components of the cascades opposes the hypertrophic actions of GPCR agonists, as does downregulation of ERKs by antisense oligodeoxynucleotides65 or transfection of phospho-MAPK phosphatases.66 67 It is evident from Table 2Up that there is still considerable confusion in this area, and the reasons for the variations between experimental groups are unclear (reviewed in Reference 3232 ). Two points should be borne in mind. First, the degree of overexpression may mean that the experiments have little relation to the physiological situation. Second, the regulation of transcription from genomic DNA may be quite different from that from episomal (plasmid) DNA because of the influence of chromatin proteins. In the hands of some (but not all68 69 ) investigators, selective inhibitors of the ERK and p38-MAPK cascades (PD98059 for the ERK cascade57 and SB203580 or SB202190 for the p38-MAPK cascade60 61 70 ) diminish the hypertrophic response to GPCR agonists, although the interpretation of these studies may not be simple.57 The overall conclusion is that MAPK cascades participate in the hypertrophic response. The ensuing steps are unclear, but it is presumed that transcription factor phosphorylation and transcriptional activation follow, and ET-1 certainly induces phosphorylation and upregulation of c-Jun protein in myocytes.71 Furthermore, the interaction of the novel transcription factor ATF6 with the ANF promoter region, which may be responsible for inducible expression of ANF, may be stimulated by p38-MAPK–dependent phosphorylation of ATF6.72 Despite some anomalies,66 68 73 I personally still favor a predominating role for the ERKs, and I regard the hypertrophic response as an attempt at "transformation" in a terminally differentiated cell.

In addition, activation of participating signaling molecules proximal to the MAPK cascades leads to a hypertrophic phenotype. With particular reference to the ERK cascade, it is clear that transient transfection of myocytes with constitutively activated forms of the G{alpha}q subunit,69 74 PKC isoforms,75 76 77 Ras,78 or Src79 80 leads to a hypertrophic response. Inhibition of G{alpha}q signaling in transgenic mice by disruption of coupling between the GqPCR and Gq protein diminishes the hypertrophy associated with pressure overload and diminishes the activation of ERKs by GqPCR agonists.81 Except for Src (which has not been tested), cardiospecific overexpression of each of these signaling molecules leads to the development of cardiac hypertrophy and heart failure in transgenic mouse models,30 82 83 84 85 86 although some investigators have interpreted their results as indicating that the hypertrophy is independent of ERKs (see, eg, Reference 8484 ). One problem with this interpretation is that ERK was only examined at the heart failure end stage. Activation of ERKs by hypertrophic agonists is transient,50 and they probably trigger responses. Prolonged activation would therefore not be anticipated.

Participation of the Rho family of small G proteins (Rho isoforms themselves [eg, RhoA], Rac, and Cdc42, reviewed in Reference 4242 ) in hypertrophy has also been examined. In a variety of nonmyocytic cell lines, the Rho family regulates cell morphology and actin stress fiber assembly. In addition, Rac and Cdc42 appear to be involved in activation of the JNK and p38-MAPK cascades, but Rho isoforms are not thought to activate these cascades. Although less effective than constitutively activated Ras, constitutively activated Rac is hypertrophic.70 Signaling through Rho itself is poorly understood. Two groups of Rho-activated protein kinases (Rho kinase/ROK{alpha} and PRK/PKN groups) have been identified (reviewed in Reference 8787 ), the PRK/PKN group being related to PKC (reviewed in Reference 8888 ). Recent evidence suggests that, in addition to Ras, hypertrophy induced by or mediated through G{alpha}q may also require signaling through RhoA69 89 90 91 92 and that Rho kinase/ROK{alpha} may mediate this effect.92 However, it is not clear whether hypertrophic agonists activate Rho or the various Rho-dependent kinases.


*    An Involvement of Calcineurin in Myocardial Hypertrophy and Heart Failure?
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up arrowExperimental Investigation of...
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Calcineurin (reviewed in References 93 and 9493 94 ) is a ubiquitously expressed phosphatase that is activated by micromolar Ca2+ concentrations. It is a heterodimer of a 60- to 65-kDa calcineurin A subunit and a 19-kDa calcineurin B subunit. All calcineurin A isoforms contain N-terminal and C-terminal variable domains, a catalytic domain, and a regulatory domain. The regulatory domain contains a calcineurin B-binding helix, a CaM-binding domain, and an autoinhibitory region that binds to the active site preventing enzymic activity at low Ca2+ concentrations. A constitutively activated mutant calcineurin A (calcineurin A[1->398]) has been described in which about two thirds of the N-terminal region of the regulatory domain has been deleted.95 The deleted region includes most of the CaM-binding domain, the autoinhibitory domain, and the C-terminal variable region, but the calcineurin B and immunophilin (see below) binding sites are intact. Increasing the Ca2+ concentration into the micromolar range causes a small activation in the absence of CaM, but in the presence of CaM, there is a highly cooperative activation of calcineurin. The role of calcineurin B in the regulation of enzymic activity by Ca2+ is obscure. It is essential for enzymic activity (perhaps more so than CaM), but the suggestion is that it fulfils a structural role.

One exciting function of calcineurin is its involvement in NFAT-mediated T-lymphocyte activation (reviewed in References 94, 96, and 9794 96 97 ). NFATs (reviewed in References 94 and 9794 97 ) are a family of Rel homology transcription factors, a group that also includes nuclear factor {kappa}B. In the inactive state, NFATs are phosphorylated and (like nuclear factor {kappa}B) are retained in the cytoplasm. NFATs are tightly associated with calcineurin, and this association is apparently independent of the phosphorylation state of NFAT. When T lymphocytes bind to antigen-presenting cells through T-lymphocyte receptors, cytoplasmic Ca2+ concentrations increase and activate calcineurin, leading to NFAT dephosphorylation (Figure 2Down). This allows NFAT to migrate into the nucleus (still complexed to calcineurin98 ), where it upregulates the transcription of a number of genes, including those for interleukin-2 (an autocrine growth factor in T lymphocytes) and other lymphocyte growth factors. The increase in cytoplasmic Ca2+ is mediated by phospholipase C{gamma}–catalyzed hydrolysis of PtdInsP2 to InsP3, with concomitant release of Ca2+ from intracellular stores. In addition, muscarinic GqPCR-mediated activation of NFATs has been described in lymphocytes and other cells.99 100 It is not clear which protein kinases maintain NFAT in its inactive state in the cytoplasm in any cell type, and this remains an important question. Candidates include JNKs,101 casein kinase I{alpha} in conjunction with MAPK/ERK kinase kinase (MEKK1, an MKKK),102 and glycogen synthase kinase 3.103 104 Calcineurin is the target of the immunosuppressants cyclosporin A (CsA) and FK-506 in T lymphocytes (reviewed in References 94 and 9794 97 ). These bind to their respective binding proteins, the immunophilins cyclophilin A and 12- and 12.6-kDa FK-506 binding proteins (FKBP12 and FKBP12.6, respectively). The CsA-cyclophilin and FK506-FKBP12 complexes bind to the calcineurin heterodimer and prevent its activation. In T cells, CsA inhibits the activation of the JNK and p38-MAPK cascades by an unknown mechanism.105 This observation may be relevant to hypertrophy, in which (as described above) both of these cascades have been implicated.



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Figure 2. Putative interactions between the MAPK and calcineurin signaling pathways. As shown in Figure 1Up, GPCR agonists activate MAPKs, with at least the ERKs being activated by a mechanism involving hydrolysis of membrane PtdInsP2 and PKC. MAPKs then mediate the phosphorylation of nuclear transcription factors. In addition, activation of PKC leads to changes in Ca2+ handling (through phosphorylation of channels and pumps) and increases in pHi [possibly mediated by the Na+/H+ exchanger 1 (NHE1)]. The significance of InsP3 (from PtdInsP2 hydrolysis) in cardiac Ca2+ handling is unclear. Increases in Ca2+ concentrations or pHi lead to increased binding of Ca2+ to effector proteins such as calcineurin and CaM. Activation of calcineurin dephosphorylates NFAT, which translocates into the nucleus to interact with other transcription factors to regulate transcription. Poorly characterized NFAT kinases phosphorylate NFAT, causing its return to or retention in the cytoplasm. Furthermore, small increases in pHi stimulate protein synthesis at the level of translation by a poorly understood mechanism.

Calcineurin and Cardiac Hypertrophy/Heart Failure
The transcription factor GATA4106 (reviewed in Reference 107107 ) is present in adult heart (and a limited number of other tissues) and is involved in the positive regulation of a variety of hypertrophic marker genes, including ANF, BNP, and ß-MHC.108 109 GATA4 interacts with other transcription factors, and recent work has suggested that ANF expression may be regulated by cooperative interaction of cis elements with GATA4 and Csx/Nkx2.5.110 Csx/Nkx2.5 is a homeodomain transcription factor that is cardiospecifically expressed into adulthood.111 112

The recent findings of Molkentin et al14 (summarized in Reference 1313 ) implicating a [Ca2+]i->calcineurin->NFAT3 pathway in cardiac hypertrophy that is analogous to T-cell activation have caused a great deal of excitement. Using a yeast 2-hybrid screen and a mouse whole-embryo cDNA library, numerous clones encoding proteins interacting with GATA4 were isolated. The only clone of which the identity was reported encoded NFAT3, and details of the identities of the other proteins are eagerly awaited. However, given that a whole embryo library was used, these species may not be relevant to the heart. Myocytes transiently transfected with plasmids encoding calcineurin A(1->398), NFAT3, and GATA4 dramatically increased expression of a BNP reporter. Transfection of any 1 plasmid, or of any 2 plasmids, was much less effective. It is somewhat surprising that calcineurin A(1->398) alone did not stimulate the BNP reporter, and this might suggest that NFAT3 and/or GATA4 are limiting. The expression of ANF and cardiac troponin I genes was examined, but no quantitative details were presented. It is not clear whether myofibrillar assembly was increased in the transfected myocytes. CsA or FK-506 reduced the increases in cell size and myofibrillar assembly of myocytes exposed to Ang II or phenylephrine for 72 hours, as well as the Ang II–induced increase in ANF mRNA expression. This result appears to differ from that of Boluyt et al,113 who showed that FK-506 was ineffective in reducing phenylephrine-induced increases in myocyte size.

Molkentin et al14 suggested that Ang II and phenylephrine (and, inferentially, ET-1) increase [Ca2+]i concentrations, and indeed some workers have found this to be the case. This is by no means universally accepted, especially in adult cardiac myocytes.114 115 116 However, there is good evidence that these agonists induce alkalosis in myocytes (reviewed in References 9, 117, and 1189 117 118 ) probably by activating the sarcolemmal Na+/H+ exchanger (reviewed in Reference 119119 ), a process known to be regulated by PKCs and MAPKs. Given that Ca2+ binding to regulatory "EF hands" proteins such as CaM and troponin C is mediated by deprotonated acidic amino acids,120 121 alkalinization will favor increased Ca2+ binding to its effector proteins even in the absence of detectable increases in free [Ca2+]i concentrations.122 Thus, hypertrophic agonists could activate calcineurin by raising [Ca2+]i concentrations, pHi, or both (Figure 2Up). This is rather a satisfying hypothesis from another point of view, because small increases in pHi potently stimulate cardiac protein synthesis,123 another cardinal feature of the hypertrophic response. Myocardial hypertrophy could be mediated through changes in the concentrations of simple ions (Ca2+ and H+).

Transgenic Mice
Cardiomyocytic ({alpha}-MHC promoter–controlled) expression of calcineurin A(1->398) in a number of founder lines induced a cardiac enlargement viewed by the authors as corresponding principally to "concentric" hypertrophy,14 the type often found in association with pressure overload. Somewhat surprisingly, given that the active phosphatase was targeted to myocytes, increased cardiac fibrosis was also detected. This implies that alterations within myocytes might induce remodeling and synthesis of the extracellular matrix, presumably by communicating with fibroblasts and smooth muscle cells. Details of the contractile properties of the transgenic hearts and hemodynamic measurements were not presented, nor were details of Ca2+ transients in single myocytes. In lymphocytes, activation of calcineurin and translocation of NFAT is favored both by sustained plateaux of [Ca2+]i124 and by more rapid (1 per 1 minute) [Ca2+]i oscillations.125 This is quite different from the situation in the mouse heart, in which the rate of beating is {approx}400 per 1 minute. It is not clear whether such rapid transients lead to activation of calcineurin, and, unfortunately, it is not feasible to measure calcineurin activity in situ. Nor is it clear to what extent the myocardial hypertrophy and failure in these transgenic animals represents an accurate analog of the human disease, given the possible disturbances in development that could occur because of "leaky" {alpha}-MHC promoter activation (see above) with activation of calcineurin during embryogenesis and fetal life. Furthermore, it is not known whether pure myocyte hypertrophy alone contributed to the cardiac enlargement, or whether there was coexisting myocyte hyperplasia, as seen in transgenic mice that overexpress CaM developmentally.126 It is interesting that myocytes from calcineurin A(1->398) transgenic animals showed alterations in nuclear morphology,14 suggesting that the protein may interfere with the cell cycle.

Cardiospecific expression of constitutively activated NFAT3 (NFAT3{Delta}317, in which the N-terminal third of the molecule encompassing the sites of phosphorylation and calcineurin interaction is deleted) caused hypertrophy in transgenic mice.14 In cultured myocytes, NFAT3{Delta}317 protein was localized to the nucleus, whereas the full-length protein remained in the cytoplasm. To my mind, this represents some of the strongest evidence that the calcineurin/NFAT3 pathway induces myocardial hypertrophy. However, it is not clear whether hearts from the NFAT3{Delta}317 transgenic mice were similar to those from calcineurin A(1->398) transgenic animals, nor whether transfection of NFAT3{Delta}317 induced a hypertrophic phenotype in cultured myocytes. Again, the possible involvement of NFAT in cardiac development127 should be borne in mind.

Interaction of Calcineurin, Ca2+, and MAPK Signaling Pathways
There is clear evidence that the calcineurin/NFAT pathway interacts with other signaling pathways. In the nucleus, NFATs interact with the activator protein-1 (AP-1) transcription factor complex (c-Fos/c-Jun heterodimers) to bind to the 5'-regulatory region of the interleukin-2 gene (reviewed in References 96 and 12896 128 ), and the crystal structure of this complex has recently been determined.129 Since AP-1 transactivating activity is under the control of signals emerging from the Ras superfamily and the MAPK cascades (eg, through phosphorylation of c-Jun, reviewed in References 130 and 131130 131 ), these signaling pathways cooperate with the calcineurin pathway (reviewed in References 128 and 132128 132 ). Although currently there is no experimental evidence to suggest the existence of regulatory interaction, the promoter region of the ANF gene contains 2 AP-1–related cAMP responsive element (CRE)-like consensus sequences (TGAGCTCA, at –555 to –549 bp and at –603 to –596 bp on the sense strand) in close apposition to 2 NFAT sequences (consensus [A/T]GGAAA, at –541 to –536 bp on the sense strand and at –612 to –607 bp on the antisense strand). The CRE-like sequence binds c-Jun/ATF2 heterodimers, and (as with c-Jun) ATF2 transactivating activity is increased by MAPK-catalyzed phosphorylation.133 134 135 The interaction of calcineurin signaling pathways with MAPK pathways in hypertrophy is thus a distinct possibility (Figure 2Up). In addition, there are already examples of interaction of [Ca2+]i with the ERK and JNK cascades in myocytes,12 136 137 and a recent article has even suggested that the PKC->Ras->Raf->MKK1/-2->ERK pathway may induce changes in Ca2+ transients similar to those seen in myocardial hypertrophy and heart failure.138 The mechanisms of these interactions remain relatively ill defined.

Might CsA and FK-506 Be Used to Treat Cardiac Hypertrophy and Heart Failure?
CsA has been reported to diminish the hypertrophy or dilated cardiomyopathy seen in 3 transgenic models involving mutations in myofibrillar proteins.139 In addition, prophylactic administration of CsA inhibited the development of cardiac hypertrophy after suprarenal banding of the abdominal aorta in the rat.139 In contrast, CsA does not prevent the cardiac hypertrophy induced by cardiospecific expression of an activated retinoic acid receptor,139 implying that some forms of myocardial hypertrophy may be mediated by calcineurin-independent signaling pathways. However, 2 separate groups have subsequently been unable to detect any inhibitory effect of CsA or FK-506 on pressure-overload hypertrophy induced by constriction of the abdominal aorta in the rat140 or the transverse aorta in the mouse.141 Although these differences may be attributable to variations in experimental technique or to the time course of hypertrophy in pressure-overload models,142 they do indicate that the involvement of calcineurin in hypertrophy in vivo has not been unambiguously established. More importantly, from the point of view of therapy, it is not clear whether administration of CsA during the "decompensated" phase of hypertrophy/heart failure (rather than prophylactic administration) is beneficial.

CsA is a relatively toxic drug that is used clinically to counteract rejection after transplantation. In addition to problems of immunosuppression (increased opportunistic infection and skin malignancies), the drug is nephrotoxic, and this may be caused by its interference with the calcineurin-dependent regulation of convoluted tubule Na+/K+-ATPase.143 Its use is also associated with hypertension (possibly because of the nephrotoxic side effects involving renal vasoconstriction144 ), neural effects (tremor and fits), hepatotoxicity, and gingival hypertrophy/hyperplasia. A number of studies in transplant patients have examined the association of cardiac hypertrophy with the use of CsA. Although some studies have failed to detect a convincing association (eg, Reference 145145 ), others have shown that CsA may actually induce cardiac hypertrophy through its hypertensive side effects.146 147 In addition, at least 1 study has found that CsA has hypertrophic effects that are independent of its hypertensive effects.148 Although FK-506 may cause fewer side effects,144 it is more expensive than CsA. There is thus relatively little evidence that administration of immunosuppressants to human beings is antihypertrophic, and, in my view, it would be ill advised to administer them prophylactically.

Calcineurin and Specification of Skeletal Muscle Fiber Type
Transfection of calcineurin A(1->398) into C2C12 myotubes increases transcription of slow fiber type-specific genes through NFATs and interacting transcription factors, and administration of CsA in intact rats increases the proportion of fast muscle fibers in the slow-twitch postural soleus muscle.149 Characterization of muscle fiber composition in a suitable calcineurin A(1->398) transgenic mouse is eagerly awaited. At first sight, the studies might seem irrelevant to myocardial disease. However, in a canine model of chronic heart failure, the proportion of slow-twitch fibers is decreased.150 This could not be attributed to changes in capillary density or muscle fiber destruction. Similar changes in fiber type (combined with exercise intolerance) are seen in human heart failure, although here there may also be fiber loss and changes in capillary density (reviewed in Reference 151151 ). A therapeutic regime that increases calcineurin activity and the content of slow-twitch fiber type in skeletal muscle might therefore be beneficial in heart failure patients. However, if calcineurin is involved in cardiac hypertrophy, such a regimen could be detrimental to the heart.


*    Do Derangements in Excitation-Contraction Coupling Contribute to Cardiac Hypertrophy?
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[Ca2+]i uptake and release are of major importance in the regulation of excitation-contraction coupling in the cardiac myocyte (reviewed in Reference 152152 ), and (as originally shown by Gwathmey et al153 154 ) altered Ca2+ "handling" is frequently encountered in hypertrophy and heart failure (reviewed in References 4 and 54 5 ). In the resting state, [Ca2+]i is sequestered in the sarcoplasmic reticulum (SR) by the Ca2+ binding protein, calsequestrin. After excitation, influx of small amounts of [Ca2+]o through sarcolemmal L-type Ca2+ channels activates SR Ca2+ release through the tetrameric SR Ca2+ release channel or ryanodine receptor (RyR), a process known as Ca2+-induced Ca2+-release (CICR). The type 2 RyR predominates in cardiac muscle (where CICR is very important), and the type 1 RyR predominates in skeletal muscle (where CICR is less important). Reuptake of [Ca2+]i into the SR involves SERCA2, whereas the sarcolemmal Na+/Ca2+ exchanger and sarcolemmal Ca2+ pumps are involved in the removal of [Ca2+]i from the myocyte. Could the hypertrophy/failure associated with activation of calcineurin be a manifestation of a generalized perturbation in excitation-contraction coupling that the heart interprets as representing a contractile deficit?

A number of transgenic mouse lines in which proteins that participate in [Ca2+]i handling are overexpressed or "knocked out" have been developed. CaM plays a role in the regulation of cell growth and division in eukaryotic calls (reviewed in Reference 155155 ). Developmental overexpression of CaM induces myocyte hypertrophy and hyperplasia,126 with calcineurin and CaM kinase II suggested as possible targets. The excitation-contraction characteristics of these myocytes have not been investigated. Cardiospecific overexpression of calsequestrin also induces hypertrophy.29 156 Myocytes from these mice show reduced CICR from the SR, increased storage of Ca2+ in the SR, and depressed contractility. In contrast, the phospholamban knockout mouse shows positive inotropism and lusitropism (presumably because of release of the phospholamban-mediated inhibition of SERCA2 activity), but hearts are not hypertrophied.157 Equally, overexpression of SERCA2 increases cardiac contraction and relaxation but does not cause hypertrophy.28 However, reductions in cytoplasmic Ca2+ concentrations do not appear to account for the hypertrophy and hyperplasia seen in the CaM transgenic mice, since overexpression of a mutant CaM that binds Ca2+ normally but is defective in signaling to CaM targets/effectors does not induce growth responses.126 Obviously, it would be desirable to characterize Ca2+ handling in all of these transgenic models under uniform conditions, but it is unlikely that this will ever be achieved.

Is there any evidence of interaction between calcineurin, the immunophilins, and proteins involved in excitation-contraction coupling? It is believed that FKBP12 interacts with RyR1, whereas the closely related protein FKBP12.6 interacts with cardiac RyR2 (reviewed in Reference 158158 ). FKBPs may mediate anchoring of calcineurin to the RyR, and this interaction may be involved in the regulation of channel activity through phosphorylation/dephosphorylation (reviewed in Reference 9494 ). FK-506 disrupts this interaction. Interestingly, single RyR2 opening probability was increased in transgenic FKBP12 knockout mice,159 although it is not clear whether increased RyR2 opening results from the absence of FKBP12 alone or the (presumed) absence of interaction of RyR2 with calcineurin. Although the FKBP12 knockout was frequently embryonically lethal, with mice displaying severe cardiac defects, 1 mouse that survived to adulthood showed signs of heart failure and cardiomyopathy.

In addition to release through the RyR, release of [Ca2+]i from stores in the endoplasmic reticulum is regulated by the InsP3 receptor (InsP3R), which is closely related to the RyR. Although the InsP3R was initially thought to be of little importance in the cardiac myocyte (and this is probably true for regulation of contraction), more detailed studies have established the presence of InsP3R species in cardiac myocytes, and at least in the ferret myocyte, the type 2 InsP3R predominates.160 FKBP12 interacts with the InsP3R1 subtype, but it is not known whether InsP3R2 (or the InsP3R3) interacts with FKBP. However, the amino acid residues thought to be most important in binding of FKBP to InsP3R are conserved.161 These results suggest that chronic activation of calcineurin could perturb Ca2+ handling, and, if these perturbations led to defects in contraction, hypertrophy might indirectly ensue.


*    Mitochondrial Permeability Transition (MPT) Pore, Calcineurin, and Cell Necrosis/Apoptosis
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Massive influx of [Ca2+]o has long been known to be associated with death of the cardiac myocyte, a highly aerobic cell containing abundant mitochondria. The MPT is a phenomenon that leads to increased mitochondrial membrane permeability and collapse of the inner mitochondrial membrane electrochemical gradient (vital for regeneration of ATP from ADP and Pi). It can be attributed to the opening of nonspecific high-conductance pores (MPT pores) in the inner mitochondrial membrane that allow passage of small molecules of <=1.5 kDa (reviewed in References 162 through 164162 163 164 ). The structure of the MPT pore is not understood, but it is associated with inner-membrane adenine nucleotide translocase,165 which exchanges intramitochondrial ATP for cytoplasmic ADP. In the heart, opening of the MPT pore is increased by oxidative stress and adenine nucleotide depletion, conditions that are encountered during ischemia/reperfusion. These situations enhance the sensitivity of the pore to Ca2+ and increase binding of mitochondrial matrix cyclophilin to the mitochondrial membrane in a CsA-sensitive manner. Indeed, administration of CsA preserves mitochondrial integrity and cardiac function under adverse conditions (see, eg, References 166 through 168166 167 168 ; reviewed in Reference 162162 ), possibly through inhibition of MPT pore opening.

Mitochondrial permeability is intimately related to necrosis and to the mitochondrial pathway of apoptosis (reviewed in References 162 through 164162 163 164 ). Apoptosis of the cardiac myocyte (reviewed in References 169 and 170169 170 ) is an area arousing a great deal of interest currently because of the putative role of the process in the development of heart failure. In the mitochondrial pathway of apoptosis, release of cytochrome c from mitochondria allows formation of a complex between cytochrome c, apoptotic protease activating factor 1, ATP/dATP, and procaspase 9. This causes aggregation of procaspase 9 and its activation through cleavage to produce active caspase 9, which in turn leads to activation of caspases 3, 6, and 7. These caspases then cleave key substrates, leading to apoptosis. The mitochondrial pathway of apoptosis is inhibited by antiapoptotic members of the Bcl-2 family (Bcl-2 itself and Bcl-XL) and is promoted by proapoptotic Bcl-2 family members (Bax and Bad). Although it does not directly allow escape of cytochrome c as such, opening of the MPT pore may be an initiating event in the mitochondrial apoptotic pathway. However, apoptotic situations involving the mitochondrial pathway that do not involve the MPT pore have been identified, and these may be related to the ability of proteins such as Bax to form membrane channels/pores.

Expression of wild-type calcineurin A and B, or of constitutively activated calcineurin A, promotes apoptosis in BHK cells (particularly in association with Ca2+ influx), and this could be opposed by coexpression of Bcl-2,171 with which calcineurin interacts.172 Although calcineurin bound to Bcl-2 retains its phosphatase activity, formation of the complex is thought to localize calcineurin to an intracellular membrane fraction at which it is unable to dephosphorylate NFATs.172 In agreement with the foregoing, CsA and FK-506 inhibit apoptosis in a lymphoma cell line.173 The mechanisms underlying the proapoptotic function of calcineurin have not been elucidated, although it is possible that dephosphorylation of Bad (Bad phosphorylation suppresses its proapoptotic function) could be important (reviewed in Reference 174174 ).

The preceding discussion suggests that some of the findings of Molkentin et al14 could be related to the ability of calcineurin and the MPT pore to promote cell death/apoptosis. Postmortem hearts from calcineurin A(1->398) transgenic mice showed signs of heart failure with dilatation and gross fibrosis.14 Although the subject of much current debate, it has been suggested that human heart failure might be associated with apoptosis of the cardiac myocyte.175 176 Hypothetically, it could be argued that cardiospecific activation of calcineurin could promote apoptosis of myocytes, and it is this that leads to heart failure. CsA could prevent calcineurin-dependent apoptosis and the MPT. Indeed, in endothelial cells, CsA inhibits apoptosis by preventing mitochondrial efflux of cytochrome c.177 One major problem with this hypothesis is that cardiomyocytic expression of NFAT3{Delta}317 leads to hypertrophy.14 However, it is not clear whether the phenotype was as severe as in the calcineurin A(1->398) transgenic animals, and NFATs are known to play a role in cardiac development.127 More details of the NFAT3{Delta}317 model would be of interest.


*    General Comments and Future Directions
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*General Comments and Future...
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In addition to more detailed work in experimental animals, there is clearly a need to extend the work to humans. This is never easy, as prospective studies are not feasible. By the time samples of hypertrophied myocardium are available, the initiating signals may no longer be detectable. It is not clear whether the calcineurin pathway can stimulate protein synthesis in myocytes, and this should be examined. Several of the studies cited in this review have made use of transgenic mouse models, and some of the problems associated with this approach have been discussed. Inducible transgenic animals may help. In some transgenic mice, cardiac defects and disturbances in excitation-contraction coupling coexist. By interacting with RyR2 or other proteins, calcineurin A(1->398) might perturb excitation-contraction coupling, indirectly leading to cardiac hypertrophy and heart failure. The effects of calcineurin A(1->398) on Ca2+ transients and contractility in transiently transfected myocytes or in myocytes from the calcineurin A(1->398) transgenic animal would be of interest. Calcineurin and the immunophilins also interact with signaling systems that have not been discussed here. These include the transforming growth factor ß receptor (reviewed in Reference 178178 ) and the protein kinase A anchoring proteins, which are involved in targeting protein kinase A to specific cellular locations (reviewed in Reference 179179 ). Given the importance of protein kinase A in regulating myocardial contractility through modulation of L-type Ca2+ channel activity (reviewed in Reference 44 ), this is another potential point of interaction between calcineurin and Ca2+ handling.

It is unlikely that a single signaling pathway is responsible for the overall hypertrophic response. Interaction of the calcineurin pathway with other signaling pathways, such as the MAPK pathways, should be examined. Intuitively, in the absence of more complex regulation, these 2 pathways would appear to be in opposition, 1 (MAPKs) promoting phosphorylation and the other (calcineurin) promoting dephosphorylation. Examination of MAPK involvement in the regulation of the transactivating activity of transcription factors that associate with NFAT would be worthwhile, and in this regard, GATA4 contains 1 strong MAPK recognition sequence at residues 102 to 105 (Pro-Val-Ser-Pro), as well as several (Ser/Thr)–Pro sequences.106 With these thoughts in mind, I suggest that the involvement of calcineurin in myocardial hypertrophy has not been unambiguously established and that there is life after calcineurin for those of us working in this area.

Note Added in Proof
Transgenic mice cardiospecifically expressing constitutively activated G{alpha}q develop cardiac hypertrophy, then dilated cardiomyopathy and heart failure.202 The effects of CsA in this model were equivocal. It did not diminish hypertrophy when heart weight was expressed relative to body weight, but did so when heart weight was expressed relative to tibial length. There was also an indication that CsA prevented some (but not all) of the changes in gene expression associated with hypertrophy in this model.

Received October 28, 1998; accepted January 25, 1999.


*    References
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up arrowIntroduction
up arrowExperimental Investigation of...
up arrowBefore Calcineurin: Myocardial...
up arrowAn Involvement of Calcineurin...
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up arrowMitochondrial Permeability...
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*References
 
1. Frohlich ED, Apstein C, Chobanian AV, Devereux RB, Dustan HP, Dzau V, Fauad-Tarazi F, Horan MJ, Marcus M, Massie B, Pfeffer MA, Re RN, Roccella EJ, Savage D, Shub C. The heart in hypertension. N Engl J Med. 1992;327:998–1008.[Medline] [Order article via Infotrieve]

2. Eichhorn E, Bristow MR. Medical therapy can improve the biological properties of the chronically failing heart: a new era in the treatment of heart failure. Circulation. 1996;94:2285–2296.[Abstract/Free Full Text]

3. Wagoner LE, Walsh RA. The cellular pathophysiology of progression to heart failure. Curr Opin Cardiol. 1996;11:237–244.[Medline] [Order article via Infotrieve]

4. Richard S, Leclercq F, Lemaire S, Piot C, Nargeot J. Ca2+ currents in compensated hypertrophy and heart failure. Cardiovasc Res. 1998;37:300–311.[Abstract/Free Full Text]

5. Wickenden AD, Kaprielian R, Kassiri Z, Tsoporis JN, Tsushima R, Fishman GI, Backx PH. The role of action potential elongation and altered intracellular calcium handling in the pathogenesis of heart failure. Cardiovasc Res. 1998;37:312–323.[Abstract/Free Full Text]

6. Anversa P, Kajstura J. Ventricular myocytes are not terminally differentiated cells in the adult mammalian heart. Circ Res. 1998;83:1–14.[Free Full Text]

7. Soonpaa MH, Field LJ. Survey of studies examining cardiomyocyte DNA synthesis. Circ Res. 1998;83:15–26.[Free Full Text]

8. Krämer BK, Nishida M, Kelly RA, Smith TW. Endothelins: myocardial actions of a new class of cytokines. Circulation. 1992;85:350–356.[Abstract/Free Full Text]

9. Sugden PH, Bogoyevitch MA. Endothelin-1-dependent signaling pathways in the myocardium. Trends Cardiovasc Med. 1996;6:87–94.

10. Sei CA, Glembotski CC. Calcium dependence of phenylephrine-, endothelin-, and potassium chloride-stimulated atrial natriuretic factor secretion from long term primary neonatal rat atrial cardiocytes. J Biol Chem. 1990;265:7166–7172.[Abstract/Free Full Text]

11. Sadoshima J, Izumo S. Signal transduction pathways of angiotensin II-induced c-fos gene expression in cardiac myocytes in vitro. Circ Res. 1993;73:424–438.[Abstract/Free Full Text]

12. Sadoshima J, Qiu Z, Morgan JP, Izumo S. Angiotensin II and other hypertrophic stimuli mediated by G protein-coupled receptors activate tyrosine kinase, mitogen-activated protein kinase, and 90-kD S6 kinase in cardiac myocytes: the critical role of Ca2+-dependent signaling. Circ Res. 1995;76:1–15.[Abstract/Free Full Text]

13. Olson EN, Molkentin JD. Prevention of cardiac hypertrophy by calcineurin inhibition: hope or hype? Circ Res. 1999;84:623–632.[Free Full Text]

14. Molkentin JD, Lu J-R, Antos C, Markham B, Richardson J, Robbins J, Grant SR, Olson EN. A calcineurin-dependent transcriptional pathway for cardiac hypertrophy. Cell. 1998;93:215–228.[Medline] [Order article via Infotrieve]

15. Barinaga M. Signaling pathways may lead to better heart-failure therapies. Science. 1998;280:383.[Free Full Text]

16. Izumo S, Aoki H. Calcineurin: the missing link in cardiac hypertrophy. Nat Med. 1998;4:661–662.[Medline] [Order article via Infotrieve]

17. Chien KR, Knowlton KU, Zhu H, Chien S. Regulation of cardiac gene expression during myocardial growth and hypertrophy: molecular studies of an adaptive physiologic response. FASEB J. 1991;5:3037–3046.[Abstract]

18. Komuro I, Yazaki Y. Control of cardiac gene expression by mechanical stress. Annu Rev Physiol. 1993;55:55–75.[Medline] [Order article via Infotrieve]

19. Sugden PH, Clerk A. Cellular mechanisms of cardiac hypertrophy. J Mol Med. 1998;76:725–746.[Medline] [Order article via Infotrieve]

20. Hanford DS, Thuerauf DJ, Murray SF, Glembotski CC. Brain natriuretic peptide is induced by {alpha}1-adrenergic agonists as a primary response gene in cultured rat cardiac myocytes. J Biol Chem. 1994;269:26227–26233.[Abstract/Free Full Text]

21. Hasenfuss G. Alterations of calcium-regulatory proteins in heart failure. Cardiovasc Res. 1998;37:279–289.[Free Full Text]

22. Mably JD, Liew CC. Factors involved in cardiogenesis and the regulation of cardiac-specific gene expression. Circ Res. 1996;79:4–13.[Abstract/Free Full Text]

23. Wiesner RJ, Ehmke H, Faulhaber J, Zak R, Rüegg JC. Dissociation of left ventricular hypertrophy, ß-myosin heavy chain gene expression, and myosin isoform switch in rats, after ascending aortic stenosis. Circulation. 1997;95:1253–1259.[Abstract/Free Full Text]

24. Chien KR. Cardiac muscle diseases in genetically engineered mice: evolution of molecular physiology. Am J Physiol. 1995;269:H755–H766.[Abstract/Free Full Text]

25. Becker KD, Gottshall KR, Chien KR. Strategies for studying cardiovascular phenotypes in genetically manipulated mice. Hypertension. 1996;27:495–501.[Abstract/Free Full Text]

26. MacLellan WR, Schneider MD. Success in failure: modeling cardiac decompensation in transgenic mice. Circulation. 1998;97:1433–1435.[Free Full Text]

27. Ng WA, Grupp IL, Subramaniam A, Robbins J. Cardiac myosin heavy chain mRNA expression and myocardial function in the mouse heart. Circ Res. 1991;68:1742–1750.[Abstract/Free Full Text]

28. He H, Giordano FJ, Hilal-Dandan R, Choi DJ, Rockman HA, McDonough PM, Bluhm WF, Meyer M, Sayen MR, Swanson E, Dillmann WH. Overexpression of the rat sarcoplasmic reticulum Ca2+ ATPase gene in hearts of transgenic mice accelerates calcium transients and cardiac relaxation. J Clin Invest. 1997;100:380–389.[Medline] [Order article via Infotrieve]

29. Jones LR, Suzuki YJ, Wang W, Kobayashi YM, Ramesh V, Franzini-Armstrong C, Cleeman L, Morad M. Regulation of Ca2+ signaling in transgenic mouse cardiac myocytes overexpressing calsequestrin. J Clin Invest. 1998;101:1385–1393.[Medline] [Order article via Infotrieve]

30. Gottshall KR, Hunter JJ, Tanaka N, Dalton N, Becker KD, Ross J Jr, Chien KR. Ras-dependent pathways induce obstructive hypertrophy in echo-selected transgenic mice. Proc Natl Acad Sci U S A. 1997;94:4710–4715.[Abstract/Free Full Text]

31. Sugden PH, Clerk A. Regulation of the ERK subgroup of MAP kinase cascades through G protein-coupled receptors. Cell Signal. 1997;9:337–351.[Medline] [Order article via Infotrieve]

32. Sugden PH, Clerk A. "Stress-responsive" mitogen-activated protein kinases in the myocardium. Circ Res. 1998;83:345–352.[Free Full Text]

33. Sheng Z, Knowlton K, Chen J, Hoshijama M, Brown JH, Chien KR. Cardiotrophin 1 (CT-1) inhibition of cardiac myocyte apoptosis via a mitogen-activated protein kinase-dependent pathway: divergence from downstream CT-1 signals for myocardial cell hypertrophy. J Biol Chem. 1997;272:5783–5791.[Abstract/Free Full Text]

34. Kodama H, Fukuda K, Pan J, Makino S, Sano M, Takahashi T, Hori S, Ogawa S. Biphasic activation of the JAK/STAT pathway by angiotensin II in rat cardiomyocytes. Circ Res. 1998;82:244–250.[Abstract/Free Full Text]

35. McWhinney CD, Dostal D, Baker K. Angiotensin II activates Stat5 through Jak2 kinase in cardiac myocytes. J Mol Cell Cardiol. 1998;30:751–761.[Medline] [Order article via Infotrieve]

36. Ramirez MT, Zhao XL, Schulman H, Brown JH. The nuclear {delta}B isoform of Ca2+/calmodulin-dependent protein kinase II regulates atrial natriuretic factor gene expression in ventricular myocytes. J Biol Chem. 1997;272:31203–31208.[Abstract/Free Full Text]

37. Aoki H, Sadoshima J, Izumo S. The critical role of myosin light chain phosphorylation in cardiac myofibrillogenesis in cardiac hypertrophy in vitro. Circulation. 1998;98(suppl I):I-839. Abstract.

38. Alvarez E, Northwood IC, Gonzalez FA, Latour DA, Seth A, Abate C, Curran T, Davis RJ. Pro-Leu-Ser/Thr-Pro is a consensus primary sequence for substrate protein phosphorylation. J Biol Chem. 1991;266:15277–15285.[Abstract/Free Full Text]

39. Davis RJ. The mitogen-activated protein kinase signal transduction pathway. J Biol Chem. 1993;268:14553–14556.[Free Full Text]

40. Madhani HD, Fink GR. The riddle of MAP kinase signaling specificity. Trends Genet. 1998;14:151–155.[Medline] [Order article via Infotrieve]

41. Vojtek AB, Der CJ. Increasing complexity of the Ras signaling pathway. J Biol Chem. 1998;273:19925–19928.[Free Full Text]

42. Mackay DJG, Hall A. Rho GTPases. J Biol Chem. 1998;273:20685–20688.[Free Full Text]

43. Clerk A, Bogoyevitch MA, Andersson MB, Sugden PH. Differential activation of protein kinase C isoforms by endothelin-1 and phenylephrine, and subsequent stimulation of p42 and p44 mitogen-activated protein kinases in ventricular myocytes cultured from neonatal rat hearts. J Biol Chem. 1994;269:32848–32857.[Abstract/Free Full Text]

44. Pucéat M, Hilal-Dandan R, Strulovici B, Brunton LL, Brown JH. Differential regulation of protein kinase C isoforms in isolated neonatal and adult rat cardiomyocytes. J Biol Chem. 1994;269:16938–16944.[Abstract/Free Full Text]

45. Rybin VO, Steinberg SF. Protein kinase C isoform expression and regulation in the developing heart. Circ Res. 1994;74:299–309.[Abstract/Free Full Text]

46. Clerk A, Bogoyevitch MA, Fuller SJ, Lazou A, Parker PJ, Sugden PH. Expression of protein kinase C isoforms during cardiac ventricular development. Am J Physiol. 1995;269:H1087–H1097.[Abstract/Free Full Text]

47. Henrich CJ, Simpson PC. Differential acute and chronic response of protein kinase C in cultured neonatal rat heart myocytes to {alpha}1 adrenergic and phorbol ester stimulation. J Mol Cell Cardiol. 1988;20:1081–1085.[Medline] [Order article via Infotrieve]

48. Dunnmon PM, Iwaki K, Henderson SA, Sen A, Chien KR. Phorbol esters induce immediate-early genes and activate cardiac gene transcription in neonatal rat myocardial cells. J Mol Cell Cardiol. 1990;22:901–910.[Medline] [Order article via Infotrieve]

49. Bogoyevitch MA, Marshall CJ, Sugden PH. Hypertrophic agonists stimulate the activities of the protein kinases c-Raf and A-Raf in cultured ventricular myocytes. J Biol Chem. 1995;270:26303–26310.[Abstract/Free Full Text]

50. Bogoyevitch MA, Glennon PE, Andersson MB, Clerk A, Lazou A, Marshall CJ, Parker PJ, Sugden PH. Endothelin-1 and fibroblast growth factors stimulate the mitogen-activated protein kinase signaling cascade in cardiac myocytes: the potential role of the cascade in the integration of two signaling pathways leading to myocyte hypertrophy. J Biol Chem. 1994;269:1110–1119.[Abstract/Free Full Text]

51. Bogoyevitch MA, Glennon PE, Sugden PH. Endothelin-1, phorbol esters and phenylephrine stimulate MAP kinase activities in ventricular cardiomyocytes. FEBS Lett. 1993;317:271–275.[Medline] [Order article via Infotrieve]

52. Marais R, Light Y, Paterson HF, Marshall CJ. Ras recruits Raf-1 to the plasma membrane for activation by tyrosine phosphorylation. EMBO J. 1995;14:3136–3145.[Medline] [Order article via Infotrieve]

53. Marais R, Light Y, Paterson HF, Mason CS, Marshall CJ. Differential regulation of Raf-1, A-Raf, and B-Raf by oncogenic Ras and tyrosine kinases. J Biol Chem. 1997;272:4378–4383.[Abstract/Free Full Text]

54. Cohen P. The search for physiological substrates of MAP and SAP kinases in mammalian cells. Trends Cell Biol. 1997;7:353–361.

55. Bogoyevitch MA, Ketterman AJ, Sugden PH. Cellular stresses differentially activate the c-Jun N-terminal protein kinases and the extracellular signal-regulated protein kinases in cultured ventricular myocytes. J Biol Chem. 1995;270:29710–29717.[Abstract/Free Full Text]

56. Clerk A, Michael A, Sugden PH. Stimulation of multiple mitogen-activated protein kinase sub-families by oxidative stress and phosphorylation of the small heat shock protein, HSP25/27, in neonatal ventricular myocytes. Biochem J. 1998;333:581–589.

57. Clerk A, Michael A, Sugden PH. The G protein coupled receptor agonists, endothelin-1 and phenylephrine, stimulate p38 mitogen-activated protein kinase pathway in neonatal rat ventricular myocytes. J Cell Biol. 1998;142:523–535.[Abstract/Free Full Text]

58. Johnson NL, Gardner AM, Diener KM, Lange-Carter CA, Gleavy J, Jarpe MB, Minden A, Karin M, Zon LI, Johnson GL. Signal transduction pathways regulated by mitogen-activated/extracellular response kinase kinase kinase induce cell death. J Biol Chem. 1996;271:3229–3237.[Abstract/Free Full Text]

59. Zechner D, Craig R, Hanford DS, McDonough PM, Sabbadini RA, Glembotski CC. MKK6 activates myocardial cell NF-{kappa}B and inhibits apoptosis in a p38 mitogen-activated protein kinase-dependent manner. J Biol Chem. 1998;273:8232–8239.[Abstract/Free Full Text]

60. Wang Y, Huang S, Sah VP, Ross J, Brown JH, Han J, Chien KR. Cardiac muscle cell hypertrophy and apoptosis induced by distinct members of the p38 mitogen-activated protein kinase family. J Biol Chem. 1998;273:2161–2168.[Abstract/Free Full Text]

61. Nemoto S, Sheng Z, Lin A. Opposing effects of Jun kinase and p38 mitogen-activated protein kinases on cardiomyocyte hypertrophy. Mol Cell Biol. 1998;18:3518–3526.[Abstract/Free Full Text]

62. Adams JW, Migita DS, Yu MK, Young R, Hellickson MS, Domingo JD, Lee PH, Bui JS, Henderson SA. Prostaglandin F2{alpha} stimulates hypertrophic growth of cultured neonatal rat ventricular myocytes. J Biol Chem. 1996;271:1179–1186.[Abstract/Free Full Text]

63. Lai J, Jin H, Yang R, Winer J, Li W, Yen R, King KL, Zeigler F, Ko A, Cheng J, Bunting S, Paoni NF. Prostaglandin F2{alpha} induces cardiac myocyte hypertrophy in vitro and cardiac growth in vivo. Am J Physiol. 1996;271:H2197–H2208.[Abstract/Free Full Text]

64. Adams JW, Sah VP, Henderson SA, Brown JH. Tyrosine kinase and c-Jun NH2-terminal kinase mediate hypertrophic responses to prostaglandin F2{alpha} in cultured neonatal rat ventricular myocytes. Circ Res. 1998;83:167–178.[Abstract/Free Full Text]

65. Glennon PE, Kaddoura S, Sale EM, Sale GJ, Fuller SJ, Sugden PH. Depletion of mitogen-activated protein kinase using an antisense oligodeoxynucleotide approach down-regulates the phenylephrine-induced hypertrophic response in rat cardiac myocytes. Circ Res. 1996;78:954–961.[Abstract/Free Full Text]

66. Thorburn J, Carlson M, Mansour SJ, Chien KR, Ahn NG, Thorburn A. Inhibition of a signaling pathway in cardiac muscle cells by active mitogen-activated protein kinase kinase. Mol Biol Cell. 1995;6:1479–1490.[Abstract]

67. Fuller SJ, Davies EL, Gillespie-Brown J, Sun H, Tonks NK. Mitogen-activated protein kinase phosphatase 1 inhibits the stimulation of gene expression by hypertrophic agonists in cardiac myocytes. Biochem J. 1997;323:313–319.

68. Post GR, Goldstein D, Thuerauf DJ, Glembotski CC, Brown JH. Dissociation of p42 and p44 mitogen-activated protein kinase activation from receptor-induced hypertrophy in neonatal rat ventricular myocytes. J Biol Chem. 1996;271:8452–8457.[Abstract/Free Full Text]

69. Hines WA, Thorburn A. Ras and Rho are required for G{alpha}q-induced hypertrophic gene expression in neonatal rat cardiac myocytes. J Mol Cell Cardiol. 1998;30:485–494.[Medline] [Order article via Infotrieve]

70. Zechner D, Thuerauf DJ, Hanford DS, McDonough PM, Glembotski CC. A role for the p38 mitogen-activated protein kinase pathway in myocardial cell growth, sarcomeric organization, and cardiac-specific gene expression. J Cell Biol. 1997;139:115–127.[Abstract/Free Full Text]

71. Clerk A, Sugden PH. Phosphorylation of c-Jun and ATF2 in ventricular myocytes by endothelin and phenylephrine. Biochem Soc Trans. 1997;25:222S.[Medline] [Order article via Infotrieve]

72. Thuerauf DJ, Arnold ND, Zechner D, Hanford DS, DeMartin KM, McDonough PM, Prywes R, Glembotski CC. p38-mitogen-activated protein kinase mediates the transcriptional induction of the atrial natriuretic factor gene through a serum response element: a potential role for the transcription factor ATF6. J Biol Chem. 1998;273:20636–20643.[Abstract/Free Full Text]

73. Clerk A, Gillespie-Brown J, Fuller SJ, Sugden PH. Stimulation of phosphatidylinositol hydrolysis, protein kinase C translocation, and mitogen-activated protein kinase activation by bradykinin in rat ventricular myocytes: dissociation from the hypertrophic response. Biochem J. 1996;317:109–118.

74. LaMorte VJ, Thorburn J, Absher D, Spiegel A, Brown JH, Chien KR, Feramisco JR, Knowlton KU. Gq- and ras-dependent pathways mediate hypertrophy of neonatal rat ventricular myocytes following {alpha}1-adrenergic stimulation. J Biol Chem. 1994;269:13490–13496.[Abstract/Free Full Text]

75. Kariya K, Karns LR, Simpson PC. Expression of a constitutively activated mutant of the ß-isozyme of protein kinase C in cardiac myocytes stimulates the promoter of the ß-myosin heavy chain isogene. J Biol Chem. 1991;266:10023–10026.[Abstract/Free Full Text]

76. Shubeita HE, Martinson EA, van Bilsen M, Chien KR, Brown JH. Transcriptional activation of the cardiac myosin light chain 2 and atrial natriuretic factor genes by protein kinase C in neonatal rat ventricular myocytes. Proc Natl Acad Sci U S A. 1992;89:1305–1309.[Abstract/Free Full Text]

77. Decock JB, Gillespie-Brown J, Parker PJ, Sugden PH, Fuller SJ. Classical, novel and atypical isoforms of PKC stimulate ANF- and TRE/AP-1-regulated-promoter activity in ventricular cardiomyocytes. FEBS Lett. 1994;356:275–278.[Medline] [Order article via Infotrieve]

78. Thorburn A, Thorburn J, Chen S-Y, Powers S, Shubeita HE, Feramisco JR, Chien KR. HRas-dependent pathways can activate morphological and genetic markers of cardiac muscle cell hypertrophy. J Biol Chem. 1993;268:2244–2249.[Abstract/Free Full Text]

79. Fuller SJ, Gillespie-Brown J, Sugden PH. Oncogenic raf, src, and ras stimulate a hypertrophic pattern of gene expression and increase cell size in neonatal rat ventricular myocytes. J Biol Chem. 1998;273:18146–18152.[Abstract/Free Full Text]

80. Kovacic B, Ilic D, Damsky CH, Gardner DG. c-Src plays a role in endothelin-dependent hypertrophy of the cardiac myocyte. J Biol Chem. 1998;273:35185–35193.[Abstract/Free Full Text]

81. Akhter SA, Luttrell LM, Rockman HA, Iaccarino G, Lefkowitz RJ, Koch WJ. Targeting the receptor-Gq interface to inhibit in vivo pressure overload hypertrophy. Science. 1998;280:574–577.[Abstract/Free Full Text]

82. Hunter JJ, Tanaka N, Rockman HA, Ross J Jr, Chien KR. Ventricular expression of a MLC-2-v-ras fusion gene induces cardiac hypertrophy and selective diastolic dysfunction in transgenic mice. J Biol Chem. 1995;270:23173–23178.[Abstract/Free Full Text]

83. Bowman JC, Steinberg SF, Jiang T, Geenan DL, Fishman GI, Buttrick PM. Expression of protein kinase C ß in the heart causes hypertrophy in adult mice and sudden death in neonates. J Clin Invest. 1997;100:2189–2195.[Medline] [Order article via Infotrieve]

84. D'Angelo DD, Sakata Y, Lorenz JN, Boivin GP, Walsh RA, Liggett SB, Dorn GW, II. Transgenic G{alpha}q overexpression induces cardiac contractile failure in mice. Proc Natl Acad Sci U S A. 1997;94:8121–8126.[Abstract/Free Full Text]

85. Wakasaki H, Koya D, Schoen FJ, Jirousek MR, Ways DK, Hoit BD, Walsh RA, King GL. Targeted overexpression of protein kinase C ß2 isoform in myocardium causes cardiomyopathy. Proc Natl Acad Sci U S A. 1997;94:9320–9325.[Abstract/Free Full Text]

86. Sakata Y, Hoit BD, Liggett SB, Walsh RA, Dorn GW II. Decompensation of pressure-overload hypertrophy in G{alpha}q-overexpressing mice. Circulation. 1998;97:1488–1495.[Abstract/Free Full Text]

87. Amano M, Fukata Y, Kaibuchi K. Regulation of cytoskeleton and cell adhesions by the small GTPase Rho and its targets. Trends Cardiovasc Med. 1998;8:162–168.

88. Mellor H, Parker PJ. The extended PKC superfamily. Biochem J. 1998;332:281–292.

89. Sah VP, Hoshijima M, Chien KR, Brown JH. Rho is required for G{alpha}q and {alpha}1-adrenergic receptor signaling in cardiomyocytes: dissociation of Ras and Rho pathways. J Biol Chem. 1996;271:31185–31190.[Abstract/Free Full Text]

90. Thorburn J, Xu S, Thorburn A. MAP kinase and Rho-dependent signals interact to regulate gene expression but not actin morphology in cardiac muscle cells. EMBO J. 1997;16:1888–1900.[Medline] [Order article via Infotrieve]

91. Aoki H, Izumo S, Sadoshima J. Angiotensin II activates RhoA in cardiac myocytes: a critical role of RhoA in angiotensin II–induced premyofibril formation. Circ Res. 1998;82:666–676.[Abstract/Free Full Text]

92. Hoshijima M, Sah VP, Wang Y, Chien KR, Brown JH. The low molecular weight GTPase Rho regulates myofibril formation and organization in neonatal rat ventricular myocytes: involvement of Rho kinase. J Biol Chem. 1998;273:7725–7730.[Abstract/Free Full Text]

93. Guerini D. Calcineurin: not just a simple protein phosphatase. Biochem Biophys Res Commun. 1997;235:271–275.[Medline] [Order article via Infotrieve]

94. Klee CB, Ren H, Wang X. Regulation of the calmodulin-stimulated protein phosphatase, calcineurin. J Biol Chem. 1998;273:13367–13370.[Free Full Text]

95. O'Keefe SJ, Tamura J, Kincaid RL, Tocci MJ, O'Neill EA. FK-506- and CsA-sensitive activation of the interleukin-2 promoter by calcineurin. Nature. 1992;357:692–694.[Medline] [Order article via Infotrieve]

96. Rao A. NF-ATp: a transcription factor required for the co-ordinate induction of several cytokine genes. Immunol Today. 1994;15:274–281.[Medline] [Order article via Infotrieve]

97. Rao A, Luo C, Hogan PG. Transcription factors of the NFAT family: regulation and function. Annu Rev Immunol. 1997;15:707–747.[Medline] [Order article via Infotrieve]

98. Shibasaki F, Price ER, Milan D, McKeon F. Role of kinases and the phosphatase calcineurin in the nuclear shuttling of transcription factor NF-AT4. Nature. 1996;382:370–373.[Medline] [Order article via Infotrieve]

99. Boss V, Talpade DJ, Murphy TJ. Induction of NFAT-mediated transcription by Gq-coupled receptors in lymphoid and non-lymphoid cells. J Biol Chem. 1996;271:10429–10432.[Abstract/Free Full Text]

100. Boss V, Abbott KL, Wang X-F, Pavlath GK, Murphy TJ. The cyclosporin A-sensitive nuclear factor of activated T cells (NFAT) proteins are expressed in vascular smooth muscle cells: differential localization of NFAT isoforms and induction of NFAT-mediated transcription by phospholipase C-coupled cell surface receptors. J Biol Chem. 1998;273:19664–19671.[Abstract/Free Full Text]

101. Chow C-W, Rincón M, Cavanagh J, Dickens M, Davis RJ. Nuclear accumulation of NFAT4 opposed by the JNK signal transduction pathway. Science. 1997;278:1638–1641.[Abstract/Free Full Text]

102. Zhu J, Shibasaki F, Price R, Guillemot JC, Yano T, Dotsch V, Wagner G, Ferrara P, McKeon F. Intramolecular masking of nuclear import signal on NF-AT4 by casein kinase I and MEKK1. Cell. 1998;93:851–861.[Medline] [Order article via Infotrieve]

103. Beals CR, Sheridan CR, Turck CW, Gardner P, Crabtree GR. Nuclear export of NF-ATc enhanced by glycogen synthase kinase-3. Science. 1997;275:1930–1933.[Abstract/Free Full Text]

104. Klemm JD, Beals CR, Crabtree GR. Rapid targeting of nuclear protein to the cytoplasm. Curr Biol. 1997;7:638–644.[Medline] [Order article via Infotrieve]

105. Matsuda S, Moriguchi T, Koyasu S, Nishida E. T lymphocyte activation signals for interleukin-2 production involve activation of MKK6–p38 and MKK7-SAPK/JNK signaling pathways sensitive to cyclosporin. J Biol Chem. 1998;273:12378–12382.[Abstract/Free Full Text]

106. Arceci RJ, King AA, Simon MC, Orkin SH, Wilson DB. Mouse GATA-4: a retinoic acid-inducible GATA-binding transcription factor expressed in endodermally derived tissues and heart. Mol Cell Biol. 1993;13:2235–2246.[Abstract/Free Full Text]

107. Molkentin JD, Olson EN. GATA4: a novel transcriptional regulator of cardiac hypertrophy? Circulation. 1997;96:3833–3835.

108. Grépin C, Dagnino L, Robitaille L, Haberstroh L, Antakly T, Nemer M. A hormone-encoding gene identifies a pathway for cardiac but not skeletal muscle gene transcription. Mol Cell Biol. 1994;14:3115–3129.[Abstract/Free Full Text]

109. Hasegawa K, Lee SJ, Jobe SM, Markham BE, Kitsis RN. cis-acting sequences that mediate induction of ß-myosin heavy chain expression during left ventricular hypertrophy due to aortic constriction. Circulation. 1997;96:3943–3953.[Abstract/Free Full Text]

110. Lee Y, Shioi T, Kasahar H, Jobe SM, Wiese RJ, Markham BE, Izumo S. The cardiac tissue-restricted homeobox protein Csx/Nkx2.5 physically associates with the zinc finger protein GATA4 and cooperatively activates atrial natriuretic factor gene expression. Mol Cell Biol. 1998;18:3120–3129.[Abstract/Free Full Text]

111. Komuro I, Izumo S. Csx: a murine homeobox-containing gene specifically expressed in the developing heart. Proc Natl Acad Sci U S A. 1993;90:8145–8149.[Abstract/Free Full Text]

112. Lints TJ, Parsons LM, Hartley L, Lyons I, Harvey RP. Nkx-2.5: a novel murine homeobox gene expressed in early heart progenitor cells and their myogenic descendants. Development. 1993;119:419–431.[Abstract]

113. Boluyt MO, Zheng J-S, Younes A, Long X, O'Neill L, Silverman H, Lakatta EG, Crow MT. Rapamycin inhibits {alpha}1-adrenergic receptor-stimulated cardiac myocyte hypertrophy but not activation of hypertrophy-associated genes: evidence for involvement of p70 S6 kinase. Circ Res. 1997;81:176–186.[Abstract/Free Full Text]

114. Kohmoto O, Ikenouchi H, Hirata Y, Momomura S, Serizawa T, Barry WH. Variable effects of endothelin-1 on [Ca2+]i transients, pHi, and contraction in ventricular myocytes. Am J Physiol. 1993;265:H793–H800.[Abstract/Free Full Text]

115. Ikenouchi H, Barry WH, Bridge JHB, Weinberg EO, Apstein CS, Lorell BH. Effects of angiotensin II on intracellular Ca2+ and pH in isolated beating rabbit hearts and in myocytes loaded with the indicator indo-1. J Physiol (Cambr). 1994;480:203–215.[Abstract/Free Full Text]

116. Ito N, Kagaya Y, Weinberg EO, Barry WH, Lorell BH. Endothelin and angiotensin II stimulation of Na+/H+ exchanger is impaired in cardiac hypertrophy. J Clin Invest. 1997;99:123–135.

117. Terzic A, Pucéat M, Vassort G, Vogel SM. Cardiac {alpha}1-adrenoceptors: an overview. Pharmacol Rev. 1993;45:147–175.[Medline] [Order article via Infotrieve]

118. Pucéat M, Vassort G. Neurohumoral modulation of intracellular pH in the heart. Cardiovasc Res. 1995;29:178–183.[Medline] [Order article via Infotrieve]

119. Orlowski J, Grinstein S. Na+/H+ exchangers of mammalian cells. J Biol Chem. 1997;272:22373–22376.[Free Full Text]

120. Kretsinger RH. Calcium-binding proteins. Annu Rev Biochem. 1976;45:239–266.[Medline] [Order article via Infotrieve]

121. Kretsinger RH. Structure and evolution of calcium-modulated proteins. CRC Crit Rev Biochem. 1980;8:119–174.[Medline] [Order article via Infotrieve]

122. Vaughan-Jones RD, Lederer WJ, Eisner DA. Ca2+ ions can affect intracellular pH in mammalian cardiac muscle. Nature. 1983;301:522–524.[Medline] [Order article via Infotrieve]

123. Sugden PH, Fuller SJ. Correlations between cardiac protein synthesis rates, intracellular pH and the concentrations of creatine metabolites. Biochem J. 1991;273:339–346.

124. Dolmetsch RE, Lewis RS, Goodnow CC, Healy JI. Differential activation of transcription factors induced by Ca2+ response amplitude and duration. Nature. 1997;386:855–858.[Medline] [Order article via Infotrieve]

125. Dolmetsch RE, Xu K, Lewis RS. Calcium oscillations increase the efficiency and specificity of gene transcription. Nature. 1998;392:933–936.[Medline] [Order article via Infotrieve]

126. Gruver CL, DeMayo F, Goldstein MA, Means AR. Targeted developmental overexpression of calmodulin induces proliferative and hypertrophic growth of cardiomyocytes in transgenic mice. Endocrinology. 1993;133:376–388.[Abstract/Free Full Text]

127. de la Pompa JL, Timmerman LA, Takimoto H, Yoshida H, Elia AJ, Samper E, Potter J, Wakeham A, Marengere L, Langille BL, Crabtree GR, Mak TW. Role of the NF-ATc transcription factor in the morphogenesis of cardiac valves and septum. Nature. 1998;392:182–186.[Medline] [Order article via Infotrieve]

128. Henning SW, Cantrell DA. GTPases in antigen receptor signalling. Curr Opin Immunol. 1998;10:322–329.[Medline] [Order article via Infotrieve]

129. Chen L, Glover JNM, Hogan PG, Rao S, Harrison SC. Structure of the DNA-binding domains from NFAT, Fos and Jun bound specifically to DNA. Nature. 1998;392:42–48.[Medline] [Order article via Infotrieve]

130. Karin M. The regulation of AP-1 activity by mitogen-activated protein kinases. J Biol Chem. 1995;270:16483–16486.[Free Full Text]

131. Minden A, Karin M. Regulation and function of the JNK subgroup of MAP kinases. Biochim Biophys Acta. 1997;1333:F85–F104.[Medline] [Order article via Infotrieve]

132. Reif K, Cantrell DA. Networking Rho family GTPase in lymphocytes. Immunity. 1998;8:395–401.[Medline] [Order article via Infotrieve]

133. Livingstone C, Patel G, Jones N. ATF-2 contains a phosphorylation-dependent transcriptional activation domain. EMBO J. 1995;14:1785–1797.[Medline] [Order article via Infotrieve]

134. Van Dam H, Wilhelm D, Herr I, Steffen A, Herrlich P, Angel P. ATF-2 is preferentially activated by stress-activated protein kinases to mediate c-jun induction in response to genotoxic agents. EMBO J. 1995;14:1798–1811.[Medline] [Order article via Infotrieve]

135. Whitmarsh AJ, Shore P, Sharrocks AD, Davis RJ. Integration of MAP kinase signal transduction pathways at the serum response element. Science. 1995;269:403–407.[Abstract/Free Full Text]

136. Bogoyevitch MA, Andersson MB, Gillespie-Brown J, Clerk A, Glennon PE, Fuller SJ, Sugden PH. Adrenergic receptor stimulation of the mitogen-activated protein kinase cascade and cardiac hypertrophy. Biochem J. 1996;314:115–121.

137. McDonough PM, Hanford DS, Sprenkle AB, Mellon NR, Glembotski CC. Collaborative roles for c-Jun N-terminal kinase, c-Jun, serum response factor, and Sp1 in calcium-regulated myocardial gene expression. J Biol Chem. 1997;272:24046–24053.[Abstract/Free Full Text]

138. Ho PD, Zechner DK, He H, Dillmann WH, Glembotski CC, McDonough PM. The Raf-MEK-ERK cascade represents a common pathway for the alteration of intracellular calcium by Ras and protein kinase C in cardiac myocytes. J Biol Chem. 1998;273:21730–21735.[Abstract/Free Full Text]

139. Sussman MA, Lim HW, Gude N, Taigen T, Olson EN, Robbins J, Colbert MC, Gualberto A, Wieczorek DF, Molkentin JD. Prevention of cardiac hypertrophy in mice by calcineurin inhibition. Science. 1998;281:1690–1693.[Abstract/Free Full Text]

140. Luo X, Shyu K-G, Gualberto A, Walsh K. Calcineurin inhibitors and cardiac hypertrophy. Nat Med. 1998;4:1092–1093.[Medline] [Order article via Infotrieve]

141. Müller JG, Nemoto S, Laser M, Carabello BA, Menick DR. Calcineurin inhibition and cardiac hypertrophy. Science. 1998;282:1007. Available at: http://www.sciencemag.org/cgi/content/full/282/5391/1007a. Accessed November 13, 1998.

142. Molkentin JD. Calcineurin inhibition and cardiac hypertrophy: response. Science. 1998;282:1007. Available at: http://www.sciencemag.org/cgi/content/full/282/5391/1007a. Accessed November 13, 1998.

143. Aperia A, Ibarra F, Svensson LB, Klee C, Greengard P. Calcineurin mediates {alpha}-adrenergic stimulation of Na+,K+-ATPase activity in renal tubule cells. Proc Natl Acad Sci U S A. 1992;89:7394–7397.[Abstract/Free Full Text]

144. Radermacher J, Meiners M, Bramlage C, Kliem V, Behrend M, Schlitt HJ, Pichlmayr R, Koch KM, Brunkhorst R. Pronounced renal vasoconstriction and systemic hypertension in renal transplant patients treated with cyclosporin versus FK-506. Transpl Int. 1998;11:3–10.[Medline] [Order article via Infotrieve]

145. Rowan RA, Billingham ME. Pathologic changes in the long-term transplanted heart: a morphometric study of myocardial hypertrophy, vascularity, and fibrosis. Hum Pathol. 1990;21:767–772.[Medline] [Order article via Infotrieve]

146. Lipkin GW, Tucker B, Giles M, Raine AE. Ambulatory blood pressure and left ventricular mass in cyclosporin- and non-cyclosporin-treated renal transplant patients. J Hypertens. 1993;11:439–442.[Medline] [Order article via Infotrieve]

147. Ventura HO, Lavie CJ, Messerli FH, Smart FW, Stapleton DD, Ochsner JL. Cardiovascular adaptation to cyclosporine-induced hypertension. J Hum Hypertens. 1994;8:233–237.[Medline] [Order article via Infotrieve]

148. Globits S, De Marco T, Schwitter J, Sakuma H, O'Sullivan M, Rifkin C, Keith F, Chatterjee K, Parmley WW, Higgins CB. Assessment of early left ventricular remodeling in orthotopic heart transplant recipients with cine magnetic resonance imaging: potential mechanisms. J Heart Lung Transplant. 1997;16:504–510.[Medline] [Order article via Infotrieve]

149. Chin ER, Olson EN, Richardson JA, Yang Q, Humphries C, Shelton JM, Wu H, Zhu W, Bassel-Duby R, Williams RS. A calcineurin-dependent transcriptional pathway controls skeletal muscle fiber type. Genes Dev. 1998;12:2499–2509.[Abstract/Free Full Text]

150. Sabbah HN, Hansen-Smith F, Sharov VG, Kono T, Lesch M, Gengo PJ, Steffen RP, Levine TB, Goldstein S. Decreased proportion of type I myofibers in skeletal muscle of dogs with chronic heart failure. Circulation. 1993;87:1729–1737.[Abstract/Free Full Text]

151. Harrington D, Coats AJS. Skeletal muscle abnormalities and evidence for their role in symptom generation in chronic heart failure. Eur Heart J. 1997;18:1865–1872.[Free Full Text]

152. Stern MD. Theory of excitation-contraction coupling in cardiac muscle. Biophys J. 1992;63:497–517.[Medline] [Order article via Infotrieve]

153. Gwathmey JK, Morgan JP. Altered calcium handling in pressure-overload hypertrophy in the ferret. Circ Res. 1985;57:836–843.[Abstract/Free Full Text]

154. Gwathmey JK, Copelas L, McKinnin R, Schoen FJ, Feldman MD, Grossman W, Morgan JP. Altered intracellular calcium handling in myocardium from patients with end-stage heart failure. Circ Res. 1987;61:70–76.[Abstract/Free Full Text]

155. Santella L, Carafoli E. Calcium signaling in the cell nucleus. FASEB J. 1997;11:1091–1109.[Abstract]

156. Sato Y, Ferguson DG, Sako H, Dorn GW, II, Kadambi VJ, Yatani A, Hoit BD, Walsh RA, Kranias EG. Cardiac-specific overexpression of mouse cardiac calsequestrin is associated with depressed cardiovascular function and hypertrophy in transgenic mice. J Biol Chem. 1998;273:28470–28477.[Abstract/Free Full Text]

157. Luo W, Grupp IL, Harrer J, Ponniah S, Grupp G, Duffy JJ, Doetschman T, Kranias EG. Targeted ablation of the phospholamban gene is associated with markedly enhanced cardiac contractility and loss of ß agonist stimulation. Circ Res. 1994;75:401–409.[Abstract/Free Full Text]

158. Valdivia HH. Modulation of intracellular Ca2+ levels in the heart by sorcin and FKBP12, two accessory proteins of ryanodine receptors. Trends Pharmacol Sci. 1998;19:479–482.[Medline] [Order article via Infotrieve]

159. Shou W, Aghdasi B, Armstrong DL, Guo Q, Bao S, Charng MJ, Mathews LM, Schneider MD, Hamilton SL, Matzuk MM. Cardiac defects and altered ryanodine receptor function in mice lacking FKBP12. Nature. 1998;391:489–492.[Medline] [Order article via Infotrieve]

160. Perez PJ, Ramos-Franco J, Fill M, Mignery GA. Identification and functional reconstitution of the type 2 inositol 1,4,5-trisphosphate receptor from ventricular cardiac myocytes. J Biol Chem. 1997;272:23961–23969.[Abstract/Free Full Text]

161. Cameron AM, Nucifora NC Jr, Fung ET, Livingston DJ, Aldape RA, Ross CA, Snyder SH. FKBP12 binds the inositol 1,4,5-trisphosphate receptor at leucine-proline (1400–1401) and anchors calcineurin to this FK-506-like domain. J Biol Chem. 1997;272:27582–27588.[Abstract/Free Full Text]

162. Halestrap AP, Connern CP, Griffiths EJ, Kerr PM. Cyclosporin A binding to mitochondrial cyclophilin inhibits the permeability transition pore and protects hearts from ischaemia/reperfusion injury. Mol Cell Biochem. 1997;174:167–172.[Medline] [Order article via Infotrieve]

163. Bernardi P. The permeability transition pore: control points of a cyclosporin A-sensitive mitochondrial channel involved in cell death. Biochim Biophys Acta. 1998;1275:5–9.

164. Halestrap AP, Kerr PM, Javadov S, Woodfield KY. Elucidating the molecular mechanism of the permeability transition pore and its role in reperfusion injury of the heart. Biochim Biophys Acta. 1998;1366:79–94.[Medline] [Order article via Infotrieve]

165. Halestrap AP, Woodfield KY, Connern CP. Oxidative stress, thiol reagents, and membrane potential modulate the mitochondrial permeability transition by affecting nucleotide binding to adenine nucleotide translocase. J Biol Chem. 1997;272:3346–3354.[Abstract/Free Full Text]

166. Griffiths EJ, Halestrap AP. Protection by cyclosporin A of ischemia/reperfusion-induced damage in isolated rat hearts. J Mol Cell Cardiol. 1993;25:1461–1469.[Medline] [Order article via Infotrieve]

167. Massoudy P, Zahler S, Kupatt C, Reder E, Becker BF, Gerlach E. Cardioprotection by cyclosporine A in experimental ischemia and reperfusion: evidence for a nitric oxide-dependent mechanism mediated by endothelin. J Mol Cell Cardiol. 1997;29:535–544.[Medline] [Order article via Infotrieve]

168. Weinbrenner C, Liu GS, Downey JM, Cohen MV. Cyclosporine A limits myocardial infarct size even when administered after onset of ischemia. Cardiovasc Res. 1998;38:676–684.[Abstract/Free Full Text]

169. MacLellan WR, Schneider MD. Death by design. Circ Res. 1997;81:137–144.[Abstract/Free Full Text]

170. Haunstetter A, Izumo S. Apoptosis, basic mechanisms and implications for cardiovascular disease. Circ Res. 1998;82:1111–1129.[Free Full Text]

171. Shibasaki F, McKeon F. Calcineurin functions in Ca2+-activated cell death in mammalian cells. J Cell Biol. 1995;131:735–743.[Abstract/Free Full Text]

172. Shibasaki F, Kondo E, Akagi T, McKeon F. Suppression of signalling through transcription factor NF-AT by interactions between calcineurin and Bcl-2. Nature. 1997;386:728–731.[Medline] [Order article via Infotrieve]

173. Genestier L, Dearden-Badet MT, Bonnefoy-Berard N, Lizard G, Revillard JP. Cyclosporin A and FK-506 inhibit activation-induced cell death in the murine WEHI-231 B cell line. Cell Immunol. 1994;155:283–291.[Medline] [Order article via Infotrieve]

174. Reed JC. Double identity for proteins of the Bcl-2 family. Nature. 1997;387:773–776.[Medline] [Order article via Infotrieve]

175. Narula J, Haider N, Virmani R, DiSalvo TG, Kolodgie FD, Hajjar RJ, Schmidt U, Semigran MJ, Dec GW, Khaw BA. Apoptosis in myocytes in end-stage heart failure. N Engl J Med. 1996;335:1182–1189.[Abstract/Free Full Text]

176. Olivetti G, Abbi R, Quaini F, Kajstura J, Cheng W, Nitahara JA, Quaini E, Di Loreto C, Beltrami CA, Krajewski S, Reed JC, Anversa P. Apoptosis in the failing human heart. N Engl J Med. 1997;336:1131–1141.[Abstract/Free Full Text]

177. Walter DH, Haendele J, Galle J, Zeiher AM, Dimmeler S. Cyclosporin A inhibits apoptosis of human endothelial cells by preventing release of cytochrome c from mitochondria. Circulation. 1998;98:1153–1157.[Abstract/Free Full Text]

178. Massagué J. TGF-ß signal transduction. Annu Rev Biochem. 1998;67:753–791.[Medline] [Order article via Infotrieve]

179. Dell'Acqua ML, Scott JD. Protein kinase A anchoring. J Biol Chem. 1997;272:12881–12884.[Free Full Text]

180. Shubeita HE, McDonough PM, Harris AN, Knowlton KU, Glembotski CC, Brown JH, Chien KR. Endothelin induction of inositol phospholipid hydrolysis, sarcomere assembly, and cardiac gene expression in ventricular myocytes: a paracrine mechanism for myocardial cell hypertrophy. J Biol Chem. 1990;265:20555–20562.[Abstract/Free Full Text]

181. Ito H, Hirata Y, Hiroe M, Tsujino M, Adachi S, Takamoto T, Nitta M, Taniguchi K, Marumo F. Endothelin-1 induces hypertrophy with enhanced expression of muscle-specific genes in cultured neonatal rat cardiomyocytes. Circ Res. 1991;69:209–215.[Abstract/Free Full Text]

182. Sadoshima J, Izumo S. Molecular characterization of angiotensin II-induced hypertrophy of cardiac myocytes and hyperplasia of cardiac fibroblasts: critical role of the AT1 receptor subtype. Circ Res. 1993;73:413–423.[Abstract/Free Full Text]

183. Simpson P. Stimulation of hypertrophy of cultured neonatal rat heart cells through an {alpha}1-adrenergic receptor and induction of beating through an {alpha}1- and ß1-adrenergic receptor interaction: evidence for independent regulation of growth and beating. Circ Res. 1985;56:884–894.[Abstract/Free Full Text]

184. Knowlton KU, Baracchini E, Ross RS, Harris AN, Henderson SA, Evans SM, Glembotski CC, Chien KR. Co-regulation of the atrial natriuretic factor and cardiac myosin light chain-2 genes during {alpha}-adrenergic stimulation of neonatal rat ventricular cells: identification of cis sequences within an embryonic and a constitutive contractile protein gene which mediate inducible expression. J Biol Chem. 1991;266:7759–7768.[Abstract/Free Full Text]

185. Parker TG, Packer SE, Schneider MD. Peptide growth factors can provoke "fetal" contractile protein gene expression in rat cardiac myocytes. J Clin Invest. 1990;85:507–514.

186. Ito H, Hiroe M, Hirata Y, Tsujino M, Adachi S, Shichiri M, Koike A, Nogami A, Marumo F. Insulin-like growth factor-1 induces hypertrophy with enhanced expression of muscle-specific genes in cultured rat cardiomyocytes. Circulation. 1993;87:1715–1721.[Abstract/Free Full Text]

187. Pennica D, King KL, Shaw KJ, Luis E, Rullamas J, Luoh S-M, Darbonne WC, Knutzon DS, Yen R, Chien KR, Baker JB, Wood WI. Expression cloning of cardiotrophin 1, a cytokine that induces cardiac myocyte hypertrophy. Proc Natl Acad Sci U S A. 1995;92:1142–1146.[Abstract/Free Full Text]

188. Komuro I, Kaida T, Shibazaki Y, Kurabayashi M, Katoh Y, Hoh E, Takaku F, Yazaki Y. Stretching cardiac myocytes stimulates protooncogene expression. J Biol Chem. 1990;265:3595–3598.[Abstract/Free Full Text]

189. Komuro I, Katoh Y, Kaida T, Shibazaki Y, Kurabayashi M, Hoh E, Takaku F, Yazaki Y. Mechanical loading stimulates cell hypertrophy and specific gene expression in cultured rat cardiac myocytes: possible role of protein kinase C activation. J Biol Chem. 1991;266:1265–1268.[Abstract/Free Full Text]

190. Sadoshima J, Jahn L, Takahashi T, Kulik TJ, Izumo S. Molecular characterization of stretch-induced adaptation of cultured cardiac cells: an in vitro model of load induced cardiac hypertrophy. J Biol Chem. 1992;267:10551–10560.[Abstract/Free Full Text]

191. Sadoshima J, Izumo S. Mechanical stretch rapidly activates multiple signal transduction pathways in cardiac myocytes: potential involvement of an autocrine/paracrine mechanism. EMBO J. 1993;12:1681–1692.[Medline] [Order article via Infotrieve]

192. Yamazaki T, Komuro I, Kudoh S, Zou Y, Shiojima I, Hiroi Y, Mizuno T, Maemura K, Kurihara H, Aikawa R, Takano H, Yazaki Y. Endothelin-1 is involved in mechanical stress-induced cardiomyocyte hypertrophy. J Biol Chem. 1996;271:3221–3228.[Abstract/Free Full Text]

193. Liang F, Gardner DG. Autocrine/paracrine determinants of strain-activated brain natriuretic peptide gene expression in cultured cardiac myocytes. J Biol Chem. 1998;273:14612–14619.[Abstract/Free Full Text]

194. Sadoshima J, Xu Y, Slayter HS, Izumo S. Autocrine release of angiotensin II mediates stretch-induced hypertrophy of cardiac myocytes in vitro. Cell. 1993;75:977–984.[Medline] [Order article via Infotrieve]

195. Clark WA, Decker ML, Behnke-Barclay M, Janes DM, Decker RS. Cell contact as an independent factor modulating cardiac myocyte hypertrophy and survival in long-term primary culture. J Mol Cell Cardiol. 1998;30:139–155.[Medline] [Order article via Infotrieve]

196. Thorburn J, Frost JA, Thorburn A. Mitogen-activated protein kinases mediate changes in gene expression, but not cytoskeletal organization associated with cardiac muscle hypertrophy. J Cell Biol. 1994;126:1565–1572.[Abstract/Free Full Text]

197. Thorburn J, McMahon M, Thorburn A. Raf-1 kinase activity is necessary and sufficient for gene expression changes but not sufficient for cellular morphology changes associated with cardiac myocyte hypertrophy. J Biol Chem. 1994;269:30580–30586.[Abstract/Free Full Text]

198. Gillespie-Brown J, Fuller SJ, Bogoyevitch MA, Cowley S, Sugden PH. The mitogen-activated protein kinase kinase MEK1 stimulates a pattern of gene expression typical of the hypertrophic phenotype in rat ventricular cardiomyocytes. J Biol Chem. 1995;270:28092–28096.[Abstract/Free Full Text]

199. Ramirez MT, Sah VP, Zhao X-L, Hunter JJ, Chien KR, Brown JH. The MEKK-JNK pathway is stimulated by {alpha}1-adrenergic receptor and ras activation and is associated with in vitro and in vivo cardiac hypertrophy. J Biol Chem. 1997;272:14057–14061.[Abstract/Free Full Text]

200. Choukroun G, Hajjar R, Kyriakis JM, Bonventre JV, Rosenzweig A, Force T. Role of the stress-activated protein kinases in endothelin-induced cardiomyocyte hypertrophy. J Clin Invest. 1998;102:1311–1320.[Medline] [Order article via Infotrieve]

201. Wang Y, Su B, Sah VP, Brown JH, Han J, Chien KR. Cardiac hypertrophy induced by mitogen-activated protein kinase kinase 7, a specific activator for c-Jun NH2-terminal kinase in ventricular muscle cells. J Biol Chem. 1998;273:5423–5426.[Abstract/Free Full Text]

202. Mende U, Kagen A, Cohen J, Aramburu J, Schoen FJ, Neer EJ. Transient cardiac expression of constitutively activated G{alpha}q leads to cardiac hypertrophy and dilated cardiomyopathy by calcineurin-dependent and independent pathways. Proc Natl Acad Sci U S A. 1998;95:13893–13898.[Abstract/Free Full Text]




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[Abstract] [Full Text] [PDF]


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[Abstract] [Full Text] [PDF]


Home page
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Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2001; 281(3): R699 - R705.
[Abstract] [Full Text] [PDF]


Home page
J. Immunol.Home page
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J. Immunol., September 1, 2001; 167(5): 2677 - 2687.
[Abstract] [Full Text] [PDF]


Home page
J. Lipid Res.Home page
A. Zahabi and C. F. Deschepper
Long-chain fatty acids modify hypertrophic responses of cultured primary neonatal cardiomyocytes
J. Lipid Res., August 1, 2001; 42(8): 1325 - 1330.
[Abstract] [Full Text] [PDF]


Home page
Eur Heart JHome page
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A novel strategy to maximize the efficacy of left ventricular assist devices as a bridge to recovery
Eur. Heart J., April 1, 2001; 22(7): 534 - 540.
[PDF]


Home page
Journal of Renin-Angiotensin-Aldosterone SystemHome page
D. Lebeche, Zhao Bin Kang, and R. Hajjar
Candesartan abrogates G protein-coupled receptors agonist-induced MAPK activation and cardiac myocyte hypertrophy
Journal of Renin-Angiotensin-Aldosterone System, March 1, 2001; 2(1_suppl): S154 - S161.
[Abstract] [PDF]


Home page
Mol. Cell. Biol.Home page
A. Clerk, F. H. Pham, S. J. Fuller, E. Sahai, K. Aktories, R. Marais, C. Marshall, and P. H. Sugden
Regulation of Mitogen-Activated Protein Kinases in Cardiac Myocytes through the Small G Protein Rac1
Mol. Cell. Biol., February 15, 2001; 21(4): 1173 - 1184.
[Abstract] [Full Text]


Home page
CirculationHome page
S. Haq, G. Choukroun, H. Lim, K. M. Tymitz, F. del Monte, J. Gwathmey, L. Grazette, A. Michael, R. Hajjar, T. Force, et al.
Differential Activation of Signal Transduction Pathways in Human Hearts With Hypertrophy Versus Advanced Heart Failure
Circulation, February 6, 2001; 103(5): 670 - 677.
[Abstract] [Full Text] [PDF]


Home page
CirculationHome page
N. Hautala, H. Tokola, M. Luodonpaa, J. Puhakka, H. Romppanen, O. Vuolteenaho, and H. Ruskoaho
Pressure Overload Increases GATA4 Binding Activity via Endothelin-1
Circulation, February 6, 2001; 103(5): 730 - 735.
[Abstract] [Full Text] [PDF]


Home page
HypertensionHome page
H. Romppanen, J. Puhakka, G. Foldes, I. Szokodi, O. Vuolteenaho, H. Tokola, M. Toth, and H. Ruskoaho
Endothelin-1-Independent and Angiotensin II-Independent Induction of Adrenomedullin Gene Expression
Hypertension, January 1, 2001; 37(1): 84 - 90.
[Abstract] [Full Text] [PDF]


Home page
JCBHome page
S. Haq, G. Choukroun, Z. B. Kang, H. Ranu, T. Matsui, A. Rosenzweig, J. D. Molkentin, A. Alessandrini, J. Woodgett, R. Hajjar, et al.
Glycogen Synthase Kinase-3{beta} Is a Negative Regulator of Cardiomyocyte Hypertrophy
J. Cell Biol., October 2, 2000; 151(1): 117 - 130.
[Abstract] [Full Text] [PDF]


Home page
Physiol. Rev.Home page
F. Rusnak and P. Mertz
Calcineurin: Form and Function
Physiol Rev, October 1, 2000; 80(4): 1483 - 1521.
[Abstract] [Full Text] [PDF]


Home page
CirculationHome page
B. H. Lorell and B. A. Carabello
Left Ventricular Hypertrophy : Pathogenesis, Detection, and Prognosis
Circulation, July 25, 2000; 102(4): 470 - 479.
[Full Text] [PDF]


Home page
Cardiovasc ResHome page
V. J Owen
A depressing future for cyclosporine?
Cardiovasc Res, July 1, 2000; 47(1): 4 - 5.
[Full Text] [PDF]


Home page
Circ. Res.Home page
A. Sabri, E. Pak, S. A. Alcott, B. A. Wilson, and S. F. Steinberg
Coupling Function of Endogenous {alpha}1- and {beta}-Adrenergic Receptors in Mouse Cardiomyocytes
Circ. Res., May 26, 2000; 86(10): 1047 - 1053.
[Abstract] [Full Text] [PDF]


Home page
Circ. Res.Home page
A. Sabri, G. Muske, H. Zhang, E. Pak, A. Darrow, P. Andrade-Gordon, and S. F. Steinberg
Signaling Properties and Functions of Two Distinct Cardiomyocyte Protease-Activated Receptors
Circ. Res., May 26, 2000; 86(10): 1054 - 1061.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
L. J. De Windt, H. W. Lim, S. Haq, T. Force, and J. D. Molkentin
Calcineurin Promotes Protein Kinase C and c-Jun NH2-terminal Kinase Activation in the Heart. CROSS-TALK BETWEEN CARDIAC HYPERTROPHIC SIGNALING PATHWAYS
J. Biol. Chem., April 28, 2000; 275(18): 13571 - 13579.
[Abstract] [Full Text] [PDF]


Home page
Cardiovasc ResHome page
S. Baudet
Hypertrophy and dilation: a TOTally new story?
Cardiovasc Res, April 1, 2000; 46(1): 17 - 19.
[Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
T. Taigen, L. J. De Windt, H. W. Lim, and J. D. Molkentin
Targeted inhibition of calcineurin prevents agonist-induced cardiomyocyte hypertrophy
PNAS, February 1, 2000; 97(3): 1196 - 1201.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
Y. Xia, J. B. McMillin, A. Lewis, M. Moore, W. G. Zhu, R. S. Williams, and R. E. Kellems
Electrical Stimulation of Neonatal Cardiac Myocytes Activates the NFAT3 and GATA4 Pathways and Up-regulates the Adenylosuccinate Synthetase 1 Gene
J. Biol. Chem., January 21, 2000; 275(3): 1855 - 1863.
[Abstract] [Full Text] [PDF]


Home page
J CARDIOVASC PHARMACOL THERHome page
R. J. Henning, J. Silva, V. Reddy, S. Kamat, M. B. Morgan, Yong Xiang Li, and S. Chiou
Cocaine Increases {beta}-Myosin Heavy-Chain Protein Expression in Cardiac Myocytes
Journal of Cardiovascular Pharmacology and Therapeutics, January 1, 2000; 5(4): 313 - 322.
[Abstract] [PDF]


Home page
HeartHome page
Z R Yousef, S R Redwood, and M S Marber
Postinfarction left ventricular remodelling: where are the theories and trials leading us?
Heart, January 1, 2000; 83(1): 76 - 80.
[Full Text] [PDF]


Home page
HypertensionHome page
Q. He and M. C. LaPointe
Interleukin-1{beta} Regulates the Human Brain Natriuretic Peptide Promoter via Ca2+-Dependent Protein Kinase Pathways
Hypertension, January 1, 2000; 35(1): 292 - 296.
[Abstract] [Full Text] [PDF]


Home page
HypertensionHome page
E. Mervaala, D. N. Muller, J.-K. Park, R. Dechend, F. Schmidt, A. Fiebeler, M. Bieringer, V. Breu, D. Ganten, H. Haller, et al.
Cyclosporin A Protects Against Angiotensin II-Induced End-Organ Damage in Double Transgenic Rats Harboring Human Renin and Angiotensinogen Genes
Hypertension, January 1, 2000; 35(1): 360 - 366.
[Abstract] [Full Text] [PDF]


Home page
Pharmacol. Rev.Home page
O.-E. Brodde and M. C. Michel
Adrenergic and Muscarinic Receptors in the Human Heart
Pharmacol. Rev., December 1, 1999; 51(4): 651 - 690.
[Abstract] [Full Text] [PDF]


Home page
Circ. Res.Home page
R. A. Walsh
Calcineurin Inhibition as Therapy for Cardiac Hypertrophy and Heart Failure : Requiescat in Pace?
Circ. Res., April 2, 1999; 84(6): 741 - 743.
[Full Text] [PDF]


Home page
J. Biol. Chem.Home page
T.-L. Yue, J.-L. Gu, C. Wang, A. D. Reith, J. C. Lee, R. C. Mirabile, R. Kreutz, Y. Wang, B. Maleeff, A. A. Parsons, et al.
Extracellular Signal-regulated Kinase Plays an Essential Role in Hypertrophic Agonists, Endothelin-1 and Phenylephrine-induced Cardiomyocyte Hypertrophy
J. Biol. Chem., November 22, 2000; 275(48): 37895 - 37901.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
Z. Wang, B. Nolan, W. Kutschke, and J. A. Hill
Na+-Ca2+ Exchanger Remodeling in Pressure Overload Cardiac Hypertrophy
J. Biol. Chem., May 18, 2001; 276(21): 17706 - 17711.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
D. C. H. Ng, C. S. Long, and M. A. Bogoyevitch
A Role for the Extracellular Signal-regulated Kinase and p38 Mitogen-activated Protein Kinases in Interleukin-1beta -stimulated Delayed Signal Tranducer and Activator of Transcription 3 Activation, Atrial Natriuretic Factor Expression, and Cardiac Myocyte Morphology
J. Biol. Chem., July 27, 2001; 276(31): 29490 - 29498.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
C. Morisco, K. Seta, S. E. Hardt, Y. Lee, S. F. Vatner, and J. Sadoshima
Glycogen Synthase Kinase 3beta Regulates GATA4 in Cardiac Myocytes
J. Biol. Chem., July 20, 2001; 276(30): 28586 - 28597.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
P. M. Barger, A. C. Browning, A. N. Garner, and D. P. Kelly
p38 Mitogen-activated Protein Kinase Activates Peroxisome Proliferator-activated Receptor alpha . A POTENTIAL ROLE IN THE CARDIAC METABOLIC STRESS RESPONSE
J. Biol. Chem., November 21, 2001; 276(48): 44495 - 44501.
[Abstract] [Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
N. H. Purcell, G. Tang, C. Yu, F. Mercurio, J. A. DiDonato, and A. Lin
Activation of NF-kappa B is required for hypertrophic growth of primary rat neonatal ventricular cardiomyocytes
PNAS, June 5, 2001; 98(12): 6668 - 6673.
[Abstract] [Full Text] [PDF]


Home page
Circ. Res.Home page
W. G. Thomas, Y. Brandenburger, D. J. Autelitano, T. Pham, H. Qian, and R. D. Hannan
Adenoviral-Directed Expression of the Type 1A Angiotensin Receptor Promotes Cardiomyocyte Hypertrophy via Transactivation of the Epidermal Growth Factor Receptor
Circ. Res., February 8, 2002; 90(2): 135 - 142.
[Abstract] [Full Text] [PDF]


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