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(Circulation Research. 2000;86:1173.)
© 2000 American Heart Association, Inc.

Integrative Physiology

Cardiotrophic Effects of Protein Kinase C

Analysis by In Vivo Modulation of PKC Translocation

Daria Mochly-Rosen¹, Guangyu Wu¹, Harvey Hahn, Hanna Osinska, Tamar Liron, John N. Lorenz, Atsuko Yatani, Jeffrey Robbins, Gerald W. Dorn, II

From the Department of Molecular Pharmacology (D.M.-R., T.L.), Stanford University School of Medicine, Stanford, Calif; Departments of Medicine (G.W., H.H., G.W.D.), Physiology (J.N.L.), and Pharmacology (H.O., J.R.), University of Cincinnati Medical Center, Cincinnati, Ohio; and Department of Pediatrics (A.K.), Children’s Hospital Medical Center, Cincinnati, Ohio.

Correspondence to G.W. Dorn II, Division of Cardiology, University of Cincinnati Medical Center, 231 Bethesda Ave, Cincinnati, Ohio 45267-0542. E-mail dorngw{at}ucmail.uc.edu

	Abstract

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Abstract—Protein kinase C (PKC) is a key mediator of many diverse physiological and pathological responses. Although little is known about the specific in vivo roles of the various cardiac PKC isozymes, activation-induced translocation of PKC is believed to be the primary determinant of isozyme-specific functions. Recently, we have identified a catalytically inactive peptide translocation inhibitor (V1) and translocation activator (RACK [receptors for activated C kinase]) specifically targeting PKC. Using cardiomyocyte-specific transgenic expression of these peptides, we combined loss- and gain-of-function approaches to elucidate the in vivo consequences of myocardial PKC signaling. As expected for a PKC RACK binding peptide, confocal microscopy showed that V1 decorated cross-striated elements and intercalated disks of cardiac myocytes. Inhibition of cardiomyocyte PKC by V1 at lower expression levels upregulated –skeletal actin gene expression, increased cardiomyocyte cell size, and modestly impaired left ventricular fractional shortening. At high expression levels, V1 caused a lethal dilated cardiomyopathy. In contrast, enhancement of PKC translocation with RACK resulted in selectively increased ß myosin heavy chain gene expression and normally functioning concentric ventricular remodeling with decreased cardiomyocyte size. These results identify for the first time a role for PKC signaling in normal postnatal maturational myocardial development and suggest the potential for PKC activators to stimulate "physiological" cardiomyocyte growth.

Key Words: protein kinase C • transgenic mouse • cardiac hypertrophy • cardiomyopathy

	Introduction

Top Abstract Introduction Materials and Methods Results Discussion References

 
Protein kinase Cs (PKCs) constitute a large family of phospholipid-dependent serine-threonine kinases with pleiotropic effects. In the heart, clinical and experimental studies have identified a number of conditions such as pathological cardiac hypertrophy, heart failure, and ischemic preconditioning in which PKCs are activated.^{1 2 3 4 5} Despite these known associations and the importance of PKCs as essential and ubiquitous signaling molecules, their physiological or pathophysiological roles in the heart and other tissues have yet to be established.

In defining the consequences of cardiac PKC activation, one is confronted with the existence of multiple PKC isozymes, each with the potential for distinct physiological and pathological effects. A functional characteristic that distinguishes between different PKC isozymes is the pattern of subcellular redistribution on activation.⁶ This subcellular redistribution of activated PKC isozymes is a critical determinant of substrate specificity by enforcing proximity of activated isozymes to select substrates. The mechanism for PKC translocation involves recognition and binding of activated PKCs to isozyme-specific anchor proteins collectively termed receptors for activated C kinases, or RACKs.⁷ Recently, PKC peptides derived from PKC RACK binding or pseudo-RACK sites have been introduced into cardiomyocytes and other cell types, where they act as isozyme-specific translocation inhibitors and activators, respectively.^{7 8 9 10} In light of these developments, we reasoned that biological roles for individual PKC isozymes could be established by targeted in vivo activation or inhibition of selected endogenous PKCs using peptide translocation modifiers expressed as transgenes. An advantage of this approach is that PKC activity is modified in an isozyme-specific manner, without experimentally altering the stoichiometry of PKC, its upstream activators, or downstream effectors. We recently utilized this approach to create transgenic mice in which endogenous cardiomyocyte PKC was modestly activated by transgenically expressing the novel PKC-specific translocation enhancer peptide RACK.¹⁰ Ten-week-old mice expressing the RACK octopeptide in cardiac myocytes exhibited increased PKC partitioning to subcellular particulates (translocation) associated with profound resistance to transient ischemic injury. In the current studies, we have used an opposite approach, that of selectively inhibiting PKC translocation in vivo with the V1 peptide, to explore the necessity for PKC activity in normal physiological postnatal cardiac development. Our results indicate that in vivo inhibition of PKC translocation blocks an essential cardiomyotrophic function that can result in fatal cardiac insufficiency. In contrast, RACK transgenic mice, in which PKC is intrinsically activated, undergo hypertrophic cardiac remodeling while retaining normal contractile function.

	Materials and Methods

Top Abstract Introduction Materials and Methods Results Discussion References

 
All experiments were performed under a protocol approved by the Institutional Animal Care and Use Committee.

Creation of Transgenic Mice
The PKC antagonist, corresponding to the first variable region (V1 fragment) of rat PKC (V1, amino acids 2 to 144), was previously described.⁸ An octopeptide corresponding to the pseudo-RACK sequence of rat PKC (RACK, amino acids 85 to 92) was recently identified as a selective PKC translocation activator.¹⁰ For transgenic expression, the cDNA for each peptide, preceded by an 8–amino acid FLAG epitope,¹⁰ was directionally cloned into exon 3 of the full-length mouse myosin heavy chain (MHC) promoter.¹¹ After separation from vector backbone, transgene constructs were injected into male pronuclei of fertilized FVB/N mouse oocytes. MHC-FLAG-V1 (V1) and MHC-FLAG-RACK founders were identified by genomic Southern analysis of tail clip DNA.

PKC Studies
PKC isozyme expression and translocation were measured by quantitative immunoblot analysis with anti-PKC (Santa Cruz Biotechnology) and anti-PKC (Transduction Laboratories) as previously described⁵ using recombinant human PKC and PKC (Calbiochem) as quantitative standards. Western blots were developed using chemifluorescence (Amersham) and quantified on a STORM phosphor imager system.

Detection of Transgenic Peptides
Western blot analysis of V1 using Sigma anti-FLAG M-2 antibodies was performed using standard techniques. Immunofluorescence studies were carried out with the same monoclonal anti-FLAG antibody and detected with biotinylated anti-mouse antibody (Vector) labeled with avidin D/Texas red (Vector). Phalloidin/Oregon green was from Molecular Probes. Images were analyzed using confocal microscopy.

Assessment of Cardiac Hypertrophy and Function
Morphometric, physiological, and pathological studies utilized standard techniques exactly as previously described.^{5 12} Cardiac gene expression was assayed by RNA dot–Northern blot analysis of total ventricular RNA (3 µg/dot) using ³²P-labeled oligonucleotide probes as described.^{5 12}

Whole-cell currents were recorded by patch-clamp techniques as previously described.^{13 14} Membrane capacitance was measured using voltage ramps of 0.8 V/s from a holding potential of –50 mV. L-type Ca²⁺ currents (I_Ca) were recorded using external and pipette solutions that provided isolation of Ca²⁺ currents from Na⁺ and K⁺ channel currents and Ca²⁺ flux through the Na⁺/Ca²⁺ exchanger.

Statistical Analysis
Transgenic mice and their age-matched nontransgenic (NTG) controls were compared by Student test or ANOVA as appropriate, with P<0.05 considered as significant.

	Results

Top Abstract Introduction Materials and Methods Results Discussion References

 
An initial characterization of RACK-overexpressing mice was previously reported.¹⁰ At 10 weeks of age, these animals had normal-appearing hearts, with normal contractile function and 20% increase in particulate-associated PKC. Mice expressing the V1 inhibitory peptide were created using the same full-length MHC promoter and cloning strategy, and 2 lines were successfully propagated, designated V1_low and V1_med on the basis of transgene copy number and transgenic peptide expression. Expression of the RACK and V1 peptides was assessed by immunologic techniques using an antibody that recognizes the amino-terminal FLAG epitope. The V1 peptide migrated at 15 kDa, and immunoreactive peptide expression was 83% higher in V1_med (40 copies) than in V1_low (8 copies), with no detectable immunoreactivity in NTG siblings (Figure 1, top). Three additional V1 founders and 5 first-generation mice from 2 other V1 founders had >200 copies of the transgene; all were designated V1_high. Each of these animals died of heart failure, as described below. In 5 individual lines of mice expressing the RACK peptide, transgene copy number ranged from 10 to 100 copies, but comparative immunoblotting was not possible because of the small size of the peptide (<2 kDa). Peptide expression was, however, demonstrated by confocal immunostaining using anti-FLAG antibody (Figure 1, bottom). The irregular staining pattern for RACK is presumably due to its affinity for unanchored endogenous PKC.¹⁰

View larger version (45K): [in this window] [in a new window]   Figure 1. Expression and subcellular localization of PKC translocation modifiers in the mouse heart. Top, Immunoblot analysis (anti-FLAG) of V1 peptide (arrow) in low- and medium-expressing lines. Each lane is an individual heart. Bottom, Confocal microscopy of FLAG epitope–tagged peptides in isolated ventricular cardiomyocytes. Left (NTG), Anti-FLAG. Right (NTG), Phalloidin (x100). For V1 and RACK, anti-FLAG: left x40, right x200.

The mechanism for inhibition of PKC by V1 is predicted to be competition with endogenous PKC for binding to its RACK.^{7 8 9} It was anticipated, therefore, that the V1 fragment should itself bind to RACK in the hearts of transgenic mice. Subcellular localization, assayed in V1_low and V1_med cardiac myocytes by anti-FLAG confocal immunomicroscopy, showed that V1 decorated cell-cell contact areas and intracellular cross-striated structures (Figure 1), recapitulating the pattern of subcellular translocation for activated PKC reported in cultured neonatal cardiomyocytes⁶ and adult guinea pig hearts.⁴

Chronic expression of either PKC translocation–modifying peptide did not affect the overall amount of PKC or PKC in transgenic mouse hearts (Figures 2A and 2D, respectively). Compared with NTG siblings, however, the amount of PKC (Figures 2B and 2C), but not PKC (Figures 2E and 2F), associated with the particulate fraction was increased by 20±4% (n=10, P<0.05) in RACK expressors, consistent with the known activity of this peptide as a facilitator of PKC translocation.¹⁰ V1 had the opposite effect; the amount of PKC (Figures 2B and 2C), but not PKC (Figures 2E and 2F), in the cardiac particulate fraction decreased by 15±3% compared with NTG siblings (n=10, P<0.05). Neither peptide affected the expression or subcellular partitioning of PKC or PKC (data not shown).

View larger version (49K): [in this window] [in a new window]   Figure 2. Biochemical activity of PKC translocation activator ( RACK) and inhibitor (V1) peptides in transgenic mouse hearts. Shown are expression and particulate partitioning of PKC (A through C) and PKC (D through F) in transgenic mouse hearts. C indicates cytosolic fraction; P, particulate fraction. n=10 each. *P<0.05 vs NTG.

If PKC plays a role in normal myocardial development, then chronic reduction in PKC translocation and activity by V1 should alter this function. Because transgenes under control of the full-length MHC promoter are only transiently expressed in the embryonic ventricle,¹¹ it was expected that phenotypic consequences of inhibiting PKC translocation would evolve during postnatal development. As noted above, of 7 lines of V1 transgenic mice generated, first-generation mice from 2 lines with an excess of 200 transgene copies had 100% mortality from cardiac insufficiency at an age of 27±2 days (n=5). Before death, these mice became lethargic and developed rapid respirations and cyanosis. Necropsy showed large, thin-walled ventricles (Figure 3A), pulmonary congestion, and ascites. In contrast to typical models of murine dilated cardiomyopathy,^{15 16} histological examination revealed no evidence of cardiomyocyte dropout or fibrotic replacement but did suggest cardiomyocyte enlargement (Figure 3B). These pathological characteristics and early death were also observed in 3 additional founder mice with >200 copies of the transgene. In contrast, heart size and weight of V1_low and V1_med mice were normal at an age of 15 weeks (or before), as was catheterization-derived peak rate of pressure development (dP/dt_max) and responsiveness to ß-adrenergic receptor agonists (Figure 3C). However, echocardiographic left ventricular fractional shortening was slightly, but significantly, depressed in V1_med mice, suggesting mild cardiac dysfunction in this line (Figure 3C, Table).

View larger version (62K): [in this window] [in a new window]   Figure 3. Cardiomyopathy in V1-expressing hearts. A, Representative 30-day-old NTG, V1low, and V1high mouse hearts. B, Representative histological sections (Masson’s trichrome) from full thickness of left ventricular apex of NTG (top) and V1high (bottom). C, Morphometric (n=8) and functional (n=6) features of 15-week-old V1low and V1med mice (black) and NTG siblings (white). D, Ventricular mRNA quantification. Left, Representative RNA dot blots from 3 NTG, 3 V1low, and 3 V1med mice. Right, Quantitative data, indexed to GAPDH, of 5 such experiments. *P<0.05 vs NTG.

View this table: [in this window] [in a new window]   Table 1. Echocardiographic Left Ventricular Function and Morphometry in 15-Week-Old Mice

The above observations suggested a transgene dose effect, wherein a lower copy number of V1 was well tolerated, an intermediate copy number was associated with subtle cardiac dysfunction, but high copy numbers were lethal at a young age because of inadequate myocardial growth in the perinatal period. It was also possible, however, that 1 or more transgene insertional events were responsible for early lethality, rather than transgene dosage effects of V1. To distinguish between these 2 possibilities, V1_low and V1_med mice were crossbred to generate dual-transgenic mice with increased levels of V1 peptide, but without multiplying the effects of transgene insertion. All such dual-transgenic V1 mouse pups died of heart failure between 25 and 33 days of age with dilated, thin-walled hearts appearing identical to those of V1_high mice (n=6). These studies therefore establish a transgene dose-dependent inhibitory effect of V1 on normal postnatal myocardial development, the extreme consequence of which can be cardiac failure from myocardial insufficiency.

A common feature of many forms of heart failure is ventricular expression of embryonic cardiac genes.^{5 17 18 19} Activation of this molecular program is a highly sensitive indicator of myocardial disease and may actually anticipate physiological deterioration. Therefore, levels of these genes were quantified from ventricular RNA of V1_low and V1_med mice. Expression of –skeletal actin mRNA increased in proportion to the level of expressed V1 peptide (Figure 3D). No significant change in expression of atrial natriuretic factor (ANF) or a number of other cardiac genes known to be regulated in heart failure was seen in V1_low. ßMHC mRNA expression was, however, modestly increased in V1_med hearts, possibly representing a compensatory response to diminished ventricular function (Figure 3C). Taken together, the morphometric, molecular, and functional characteristics of V1_high/med/low and V1_medxlow mice are consistent with the notion that a threshold level of PKC activity is required for normal postnatal myocardial growth.

The antithesis of cardiac PKC inhibition with V1 is increased PKC translocation and activity by RACK.¹⁰ Five independent lines of RACK mice displaying essentially identical characteristics were studied. As illustrated in Figure 4B, 8-week-old RACK hearts were normal in size, weight, and function. At 15 weeks, however, RACK hearts were significantly larger than their NTG littermates (Figures 4A and 4B and Table). Unlike other forms of cardiac hypertrophy caused by transgenic modification of this signaling pathway,^{5 20 21} left ventricular systolic and diastolic function measured in RACK mice by echocardiography or in vivo using microminiaturized catheterization techniques were normal (Figure 4B). In a small cohort of RACK mice followed for 6 months, echocardiographic function remained normal (data not shown). Cardiac response to ß-adrenergic stimulation was also normal in RACK mice (Figure 4B).

View larger version (46K): [in this window] [in a new window]   Figure 4. Normally functioning hypertrophy in RACK-expressing hearts. A, Representative 15-week-old NTG and RACK hearts. B, Functional and morphometric features of 8- and 15-week-old RACK and NTG sibling mice (black and white columns, respectively; n=6 to 8). C, Ventricular mRNA quantification. Left, Representative RNA dot blots from 3 control and 3 RACK mice. Right, Quantitative data, indexed to GAPDH, of 5 such experiments. SERCA indicates sarcoplasmic/endoplasmic reticulum Ca2+ ATPase. *P<0.05 vs NTG.

A molecular characteristic of RACK mice that distinguishes it from previously reported forms of murine cardiac hypertrophy caused by activation of endogenous signaling pathways^{5 17 18 19 20 22} is that ANF gene expression was not increased in RACK hearts. Furthermore, and in contrast to V1 hearts, –skeletal actin gene expression was not increased in RACK hearts. Instead, ßMHC gene expression was dramatically increased in RACK hearts (Figure 4C).

To examine the effects of PKC translocation inhibition and activation on individual ventricular cardiac myocytes, independent of chamber geometry and in vivo neurohormonal status, whole-cell patch-clamp studies were performed. Myocyte size, measured as cell capacitance, was significantly smaller than NTG in RACK ventricles, but larger in V1 ventricles (Figure 5A). In the context of the observed increase in cardiac mass and ventricular wall thickness of RACK mice (Figure 4 and Table), decreased myocyte size suggests an increase in ventricular myocyte number. In contrast, increased cell size of V1 myocytes is consistent with decreased myocyte number, given that cardiac mass and wall thickness are normal (Figure 3 and Table).

View larger version (33K): [in this window] [in a new window]   Figure 5. Myocyte-specific effects of PKC translocation modifiers. Shown are bar plots of average cell capacitance (A) (ie, cell size) and ICa density (B). Representative whole-cell ICa-depolarizing steps to +10 mV were applied from a holding potential of -50 mV (C). Calibrations apply to all traces. Numbers correspond to total number of cells measured. *Mean values are significantly different (P<0.01) from NTG cells; #mean values are significantly different (P<0.01) from V1 cells.

Because previous studies have suggested that PKC activity could regulate Ca²⁺ channel activity in the heart, we examined L-type Ca²⁺ current, I_Ca. Figure 5C shows representative I_Ca from NTG, RACK, and V1_med. myocytes. RACK cells had a significantly decreased I_Ca compared with NTG (Figures 5B and 5C). In contrast, robust I_Ca was present in V1 (Figures 5B and 5C). There was no change in the current-voltage relationships among the 3 groups (not shown). In all groups, I_Ca activated around –30 mV and reached its maximum near +10 mV. At the maximum potential, I_Ca inactivated rapidly during maintained depolarization, but in RACK cells the time to half-decay of the current was prolonged (NTG=18.4±0.6 ms [n=87] versus 21.3±1.1 ms [n=53] RACK; P<0.05); there was no significant change in V1 myocytes (17.1±1.1 ms, n=29). These differences may, however, reflect the size of Ca²⁺ influx rather than any change in sarcoplasmic reticulum Ca²⁺ release, given that the small Ca²⁺ current amplitude could induce smaller Ca²⁺-induced Ca²⁺ inactivation. In either case, these studies demonstrate additional opposing effects of myocardial PKC translocation activation and inhibition on cardiomyocyte size and function.

	Discussion

Top Abstract Introduction Materials and Methods Results Discussion References

 
The current studies utilized small, catalytically inactive PKC-derived peptides to selectively modify PKC subcellular localization, and hence activity in the in vivo mouse heart. The most significant finding is demonstration of a necessary and sufficient role for PKC during myocardial growth of the normally developing postnatal mouse. Importantly, although transgenic techniques were used to deliver the V1 and RACK peptides specifically to cardiac myocytes, these are not transgenic studies in the conventional sense, as no active enzyme was overexpressed. Rather, the interaction between PKC and its membrane anchor proteins, RACKs, was modulated. This had the effect of altering PKC subcellular trafficking, and hence access to substrates, without affecting its expression level. The resulting changes in basal cardiac PKC activity were relatively subtle, ie, a 20% increase or 15% decrease in particulate-associated enzyme, and perhaps therefore more physiological than brute force overexpression. This approach of using transgenesis to express an inactive peptide that specifically modifies the activity of a particular signaling pathway without altering the expression of component signaling transducers was previously used by Akhter et al²³ to demonstrate that inhibition of receptor-Gq interactions prevented pressure-overload hypertrophy, thus establishing a necessary role for Gq signaling in cardiac hypertrophy even though ablation of the Gq gene has no cardiac phenotype.²⁴ Likewise, the current study establishes a requirement for PKC activity in cardiomyocyte growth. Consistent with this notion, RACK mice in which enhanced PKC activity was achieved while the natural stoichiometric relationships between PKC isozymes were maintained, developed increased myocardial mass.

Although it is formally possible that V1 and RACK modified cardiac growth in our studies through a mechanism(s) other than the predicted alteration of subcellular PKC trafficking, there is compelling evidence supporting the biochemical activity and isozyme selectivity of these peptides. We have previously shown that V1 introduced into neonatal cardiac myocytes selectively competes with PKC for binding to its RACK.⁸ Under these conditions, V1 also inhibits phorbol 12-myristate 13-acetate–induced translocation of PKC, but not PKC or PKCß. The opposite effects were induced by the RACK peptide, which facilitates PKC translocation to the cardiomyocyte particulate fraction, but does not translocate PKCß, PKC, or PKC.¹⁰ Moreover, the biological effects of RACK were prevented by inhibition of PKC catalytic activity as well as by selectively inhibiting translocation of PKC translocation, but not by inhibiting the classical PKCs.¹⁰

Increased myocardial growth and ventricular remodeling in RACK mice differs in important aspects from the cardiac hypertrophy of transgenic mice overexpressing Gq, in which PKC is also activated.^{5 25} Most striking is normal left ventricular systolic function measured in RACK hearts in vivo or in vitro. This may in part be a consequence of normal responsiveness to ß-adrenergic agonists in RACK mice, which contrasts with impaired ß-adrenergic receptor signaling in Gq overexpressors. Indeed, we recently found that modestly increasing cardiac ß₂-adrenergic receptor expression in Gq mice improved cardiac function, diminished hypertrophy, and normalized ANF and –skeletal actin but not ßMHC gene expression.²² It is therefore of interest that the "normalized" pattern of gene expression in Gq/ß₂AR overexpressors (isolated increase of ßMHC without increased ANF or –skeletal actin) is the same pattern we observed in RACK mice. These data, together with the current studies, suggest that ßMHC expression is not the sole determinant of contractile depression in cardiac hypertrophy and support a role for altered Ca²⁺ signaling²⁶ or ßAR responsiveness^{5 22} in ventricular dysfunction caused by activation of proximal signaling effectors, such as Gq.

The cellular consequences of PKC translocation modification confirmed opposing effects of PKC activation and inhibition on L-type Ca²⁺ channel function and support the proposition that PKC signaling can acutely regulate cardiomyocyte function. Perhaps of more relevance to the cardiac phenotypes of these transgenic animals, however, is the indication of smaller ventricular myocyte size in the "hypertrophied" RACK hearts, and larger myocytes in the "hypotrophied" V1 hearts. A likely explanation is that PKC signaling contributes to the normal increase in cardiomyocyte number that occurs during early postnatal development, ie, that the RACK "hypertrophy" phenotype is really a consequence of cardiomyocyte hyperplasia. Conversely, ventricular dysfunction and dilated cardiomyopathy in V1 mice may be a result of inadequate developmental cardiomyocyte hyperplasia. Consistent with this notion is the histological appearance of massively enlarge cardiomyocytes in failing V1_high hearts (Figure 3B). However, further studies are necessary to make a definitive determination.

A fundamental difference in the RACK phenotype and previously described forms of PKC-induced cardiac hypertrophy becomes apparent by comparison with transgenic mice overexpressing PKCß₂, in which pathological hypertrophy is associated with depressed echocardiographic fractional shortening, impaired ß-adrenergic receptor function, and myocyte replacement fibrosis.²⁰ Activation of endogenous PKC by RACK clearly results in a more physiological type of myocardial growth. Differences in experimental design make it impossible to conclude, however, that the distinct phenotypes of PKCß₂ and RACK mice result solely from unique, isozyme-specific PKC functions. PKCß₂ overexpression increased PKC activity 500% to 1000%, compared with a 20% increase in active PKC in RACK mice. Furthermore, PKCß₂ expression upregulated PKC, whereas no such collateral effect on this PKC isozyme was seen in RACK mice. Thus, different phenotypes in these 2 models may simply be a consequence of vastly different PKC signaling activities resulting from overexpression versus modulated translocation.

Prior reports of increased PKC translocation in pressure overload and Gq-mediated hypertrophy have concluded that PKC, rather than acting as an agent of "physiological" cardiac growth as reported herein, mediates "pathological" hypertrophy.^{5 27} We propose that activation of PKC in these latter cases is indeed a compensatory mechanism that increases muscle mass, but is accompanied by deleterious events (possibly mediated by other PKC isozymes) that ultimately cause cardiac failure. On the basis of current results, it should be feasible to selectively augment the activity of myocardial PKC in cardiac diseases, such as dilated or ischemic cardiomyopathy, where cardiac insufficiency could be reversed by an increase in healthy myocardial mass. In this regard, a PKC translocation activator might be used in addition to chronic exercise training or growth hormone to increase cardiac muscle in heart failure.^{28 29 30} It remains to be determined whether the broad paradigm of altering PKC isozyme function by modulating PKC translocation will also have therapeutic potential in other diseases and organ systems in which specific PKC isozymes are pathological mediators.

	Acknowledgments

 
This study was supported by National Institutes of Health Grants HL58010 and HL52318 to G.W.D. and HL52141 to D.M.-R.

	Footnotes

 
¹ Both authors contributed equally to this study.

Received March 17, 2000; accepted April 17, 2000.

	References

Top Abstract Introduction Materials and Methods Results Discussion References

 
1. Bowling N, Walsh RA, Song G, Estridge T, Sandusky GE, Fouts RL, Mintze K, Pickard T, Roden R, Bristow MR, Sabbah HN, Mizrahi JI, Gromo G, King GL, Vlahos CJ. Increased protein kinase C activity and expression of Ca²⁺-sensitive isoforms in the failing human heart. Circulation. 1999;99:384–391.[Abstract/Free Full Text]

2. 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]

3. Qiu Y, Ping P, Tang X-L, Manchikalapudi S, Rizvi A, Zhang J, Takano H, Wu WJ, Teschner S, Bolli R. Direct evidence that protein kinase C plays an essential role in the development of late preconditioning against myocardial stunning in conscious rabbits and that epsilon is the isoform involved. J Clin Invest. 1998;101:2182–2198.[Medline] [Order article via Infotrieve]

4. Miyamae M, Rodriguez MM, Camacho SA, Diamond I, Mochly-Rosen D, Figueredo VM. Activation of protein kinase C correlates with a cardioprotective effect of regular ethanol consumption. Proc Natl Acad Sci U S A. 1998;95:8262–8267.[Abstract/Free Full Text]

5. D’Angelo DD, Sakata Y, Lorenz JN, Boivin G, Walsh RA, Liggett SB, Dorn GW II. Transgenic Gq overexpression induces cardiac contractile function in mice. Proc Natl Acad Sci U S A. 1997;94:8121–8126.[Abstract/Free Full Text]

6. Disatnik MH, Buraggi G, Mochly-Rosen D. Localization of protein kinase C isozymes in cardiac myocytes. Exp Cell Res. 1994;210:287–297.[Medline] [Order article via Infotrieve]

7. Mochly-Rosen D. Localization of protein kinases by anchoring proteins: a theme in signal transduction. Science. 1995;268:247–251.[Abstract/Free Full Text]

8. Johnson JA, Gray MO, Chen C-H, Mochly-Rosen D. A protein kinase C translocation inhibitor as an isozyme-selective antagonist of cardiac function. J Biol Chem. 1996;271:24962–24966.[Abstract/Free Full Text]

9. Ron D, Mochly-Rosen D. An autoregulatory region in protein kinase C: the pseudoanchoring site. Proc Natl Acad Sci U S A. 1995;92:492–496.[Abstract/Free Full Text]

10. Dorn GW II, Souroujon MC, Liron T, Chen C-H, Gray MO, Zhou HZ, Csukai M, Wu G, Lorenz JN, Mochly-Rosen D. Sustained in vivo cardiac protection by a rationally designed peptide that causes protein kinase C translocation. Proc Natl Acad Sci U S A. 1999;96:12798–12803.[Abstract/Free Full Text]

11. Subramaniam A, Jones WK, Gulick J, Wert S, Neuman J, Robbins J. Tissue-specific regulation of the -myosin heavy chain gene promoter in transgenic mice. J Biol Chem. 1991;266:24613–24620.[Abstract/Free Full Text]

12. Sakata Y, Lorenz JN, Hoit BD, Liggett SB, Walsh RA, Dorn GW II. Decompensation of pressure overload hypertrophy in Gq overexpressing mice. Circulation. 1998;97:1488–1495.[Abstract/Free Full Text]

13. Masaki H, Sato Y, Luo W, Kranias EG, Yatani A. Phospholamban deficiency alters inactivation kinetics of L-type Ca²⁺ channels in mouse ventricular myocytes. Am J Physiol. 1997;273:C1666–C1672.[Abstract/Free Full Text]

14. Yatani A, Wakamori M, Niidome T, Yamamoto S, Tanaka I, Mori Y, Katayama K, Green S. Stable expression and coupling of cardiac L-type Ca²⁺ channels with ß₁-adrenoceptors. Circ Res. 1995;76:335–342.[Abstract/Free Full Text]

15. Arber S, Hunter JJ, Ross J Jr, Hongo M, Sansig G, Borg J, Perriard JC, Chien KR, Caroni P. MLP-deficient mice exhibit a disruption of cardiac cytoarchitectural organization, dilated cardiomyopathy, and heart failure. Cell. 1997;88:393–403.[Medline] [Order article via Infotrieve]

16. Liggett SB, Tepe NM, Lorenz JN, Canning AM, Jantz TD, Mitarai S, Yatani A, Dorn GW II. Early and delayed consequences of ß₂ adrenergic receptor overexpression in mouse hearts: critical role for expression level. Circulation. 2000;101:1707–1714.[Abstract/Free Full Text]

17. 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]

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

19. 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]

20. 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]

21. Bowman JC, Steinberg SF, Jiang T, Geenen DL, Fishman GI, Buttrick PM. Expression of protein kinase Cß 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]

22. Dorn GW II, Tepe NM, Lorenz JN, Koch WJ, Liggett SB. Low- and high-level transgenic expression of ß₂-adrenergic receptors differentially affects cardiac hypertrophy and function in Gq overexpressing mice. Proc Natl Acad Sci U S A. 1999;96:6400–6405.[Abstract/Free Full Text]

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

24. Offermanns S, Toombs CF, Hu Y-H, Simon MI. Defective platelet activation in Gq deficient mice. Nature. 1997;389:183–186.[Medline] [Order article via Infotrieve]

25. Dorn GW II, Tepe NM, Wu G, Yatani A, Liggett SB. Mechanisms of impaired ß-adrenergic receptor signalling in G_q-mediated cardiac hypertrophy and ventricular dysfunction. Mol Pharmacol. 2000;57:278–287.[Abstract/Free Full Text]

26. Yatani A, Frank K, Sako H, Kranias EG, Dorn GW II. Cardiac-specific overexpression of Gq alters excitation-contraction coupling in isolated cardiac myocytes. J Mol Cell Cardiol. 1999;7:1327–1326.

27. Gu X, Bishop SP. Increased protein kinase C and isozyme redistribution in pressure-overload cardiac hypertrophy in the rat. Circ Res. 1994;75:926–931.[Abstract/Free Full Text]

28. Schaible TF, Ciambrone GJ, Capasso JM, Scheuer J. Cardiac conditioning ameliorates cardiac dysfunction associated with renal hypertension in rats. J Clin Invest. 1984;73:1086–1094.

29. Fazio S, Sabatini D, Capaldo B, Vigorito C, Giobdano A, Guida R, Pardo F, Biondi B, Sacca L. A preliminary study of growth hormone in the treatment of dilated cardiomyopathy. N Engl J Med. 1996;334:809–814.[Abstract/Free Full Text]

30. Hongo M, Sentianin EM, Tanaka N, Mao L, McKirnan MD, Clark RG, Won W, Chien KR, Ross J Jr. Angiotensin II blockade followed by growth hormone as adjunctive therapy after experimental myocardial infarction. J Card Fail. 1998;4:213–224.[Medline] [Order article via Infotrieve]

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