Integrative Physiology |
From the Institut National de la Santé et de la Recherche Médicale (E.L., J.P., A.B., L.M., J.-P.H., L.B.), U702, Paris; Université Pierre et Marie Curie-Paris6 (E.L., J.P., A.B., L.M., J.-P.H., L.B.), UMRS702, Paris; Assistance Publique-Hôpitaux de Paris (E.L., A.B., J.-P.H., L.B.), Tenon Hospital, Department of Physiology, Paris; and Centre National de la Recherche Scientifique (A.d.C.K.), UMR8147, Paris, France.
Correspondence to Laurent Baud, MD, PhD, INSERM U702, Hôpital Tenon, 4 rue de la Chine, 75020 Paris, France. E-mail laurent.baud{at}tnn ap-hop-paris.fr
| Abstract |
|---|
|
|
|---|
Key Words: angiotensin calpain remodeling nuclear factor-
-B
| Introduction |
|---|
|
|
|---|
B activation through the activation of different pathways including protein kinase C, mitogen-activated protein kinase, receptor tyrosine kinases (eg, EGF receptor [EGFR]), and nonreceptor tyrosine kinases (eg, Src).4
Calpains are calcium-activated neutral cysteine proteases involved in the activation of NF-
B.5,6 Two major isoforms, calpain µ (or 1) and calpain m (or 2), are ubiquitously expressed, whereas the other isoforms are tissue-specific forms. All calpain isoforms are present in the cytosol as inactive proenzymes. Binding of calcium to µ- or m-calpain induces the release of constraints imposed by domain interactions and results in a 2-stage activation process, with the first involving the release of an
30-kDa regulatory subunit and second involving the rearrangement of the active site cleft in an
80-kDa catalytic subunit.7 In the absence of cytosolic calcium flux, calpain can be activated by EGFR engagement, via direct phosphorylation by mitogen-activated protein kinase.8
Calpain activity, which is tightly controlled by calpastatin, a specific endogenous inhibitor,5 plays an important role in acute inflammatory process.9–11 Indeed, these enzymes are involved in the activation of NF-
B12 and thereby in the NF-
B–dependent expression of proinflammatory cytokines and adhesion molecules. Thus, because of the parallels between Ang II– and calpain-dependent NF-
B activation, we wondered whether calpains could contribute to mechanisms underlying Ang II–dependent cardiovascular remodeling in vivo.
To answer this question, we took advantage of the availability of mice expressing high levels of calpastatin recently generated in our laboratory.13 Using these transgenic mice, we ascertained the functions of calpains in Ang II–mediated vascular remodeling, with special focus on the role of Ang II on hypertrophy, inflammation and fibrosis processes.
| Materials and Methods |
|---|
|
|
|---|
Calpastatin transgenic (CalpTG) mice were created and characterized in the laboratory.13 Ang II was infused subcutaneously (1.8 µg/kg per min) using osmotic minipumps for 4 weeks. Systolic blood pressure (SBP) was measured twice per week in conscious animals by tail plethysmography via a tail cuff apparatus. Specimens of kidney, heart, and aorta were cut for histochemistry and immunohistochemistry studies. Calpain, myeloperoxidase, and gelatinase activities were determined in tissue samples as described previously.11,13 Nuclear proteins were extracted from these tissue samples, and the amounts of activated NF-
B p65 subunit and nuclear factor of activated T cells (NFAT)c3 were measured with a commercial kit and Western blot assay, respectively. VSMCs were isolated from digested aorta, as previously described.14 These cells were pulsed with [3H]leucine and [3H]proline to determine protein and collagen synthesis, respectively. Peritoneal mononuclear cells were isolated as described previously15 to analyze their capacity to generate chemokines and to migrate in response to chemokine gradient.
| Results |
|---|
|
|
|---|
|
To assess the role of calpains in Ang II–dependent hypertension and cardiovascular remodeling, osmotic minipumps were implanted subcutaneously into both WT and CalpTG mice. They infused Ang II (1800 ng/kg per min) or vehicle (0.9% saline) continuously for 4 weeks. In WT mice, Ang II perfusion resulted in a significant increase in calpain activity, together with a significant decrease in calpastatin expression, suggesting a degradation of calpastatin by calpains within the kidney (Figure 1b). In contrast, in CalpTG mice, Ang II perfusion did not increase calpain activity.
Thus, calpastatin transgene expression results in an impairment in the Ang II–dependent calpain activation.
Ang II–Dependent Hypertension in WT and CalpTG Mice
SBP values were identical in WT, heterozygous CalpTG, and homozygous CalpTG control mice (Figure 2). On initiation of Ang II delivery, SBP values rose progressively to almost 170 mm Hg and remained elevated throughout the study period (4 weeks). The degree of SBP increase was similar in WT and CalpTG mice. In spite of this increase in SBP, glomerular filtration rate did not decrease significantly, as determined by measuring either plasma creatinine (15.5±2.4, 14.5±2.0, 27.0±2.4, and 21.9±2.7 µmol/L in WT, TG, WT Ang II, and TG Ang II, respectively; N=4 to 9) or plasma urea (12.0±0.9, 10.9±0.4, 12.4±1.1, and 10.9±1.1 mmol/L in WT, TG, WT Ang II, and TG Ang II, respectively; N=4 to 9). Thus, Ang II causes hypertension through calpain-independent mechanisms.
|
Ang II–Dependent Cardiovascular Hypertrophy in WT and CalpTG Mice
Ang II, by signaling through AT1 receptor, induces vascular wall thickening that involves hypertrophy, hyperplasia, and migration of VSMCs. To assess the role of calpains in this process, media cross-sectional area of aorta and kidney interlobular arteries were determined (Figure 3a and 3b). Ang II infusion promoted a medial wall thickening that was, in large part, prevented in CalpTG mice. To determine whether calpastatin transgene expression directly affects Ang II–induced hypertrophic response in VSMCs, we measured [3H]leucine incorporation in mouse aortic VSMCs in primary culture. The presence of the transgene completely suppressed their response to Ang II (Figure 3c). To gain mechanistic insight, we examined the direct effect of Ang II on VSMC calpain activity. Aortic VSMCs derived from WT type mice showed a time-dependent increase in calpain activity on exposure to Ang II, whereas those from CalpTG mice showed a limited response (Figure 3d). Binding of Ang II to AT1 receptor is thought to cause a transactivation of the EGFR.4 Because EGFR engagement is associated with calpain activation,18 we analyzed the effects of both an AT1 receptor antagonist (losartan) and an EGFR tyrosine kinase inhibitor (AG1478) on VSMC response to Ang II. The 2 drugs prevented completely the Ang II–dependent increase in calpain activity (Figure 3e). Finally, an identical increase in Ang II–induced EGFR phosphorylation was observed in VSMCs from WT and CalpTG mice (Figure 3f), indicating that calpastatin transgene expression affected calpain activity downstream of EGFR transactivation. Collectively, our data suggest that Ang II perfusion results in a vascular wall thickening that would require calpain activation through both Ang II binding to AT1 receptor and EGFR transactivation.
|
In addition to vascular hypertrophy, chronic hypertension causes left ventricular hypertrophy.17 Thus, we compared the heart weight/body weight ratios in WT and CalpTG mice. After 4 weeks of Ang II infusion, WT mice developed a robust cardiac hypertrophy, the extent of which was reduced in CalpTG mice in proportion to transgene expression (Figure 4a). To further document cardiac hypertrophy, we performed morphometric analyses by counting the number of cardiomyocyte nuclei per surface of heart section and by measuring cardiomyocyte cross-sectional areas.19,20 The 2 quantifications confirmed that Ang II infusion induced a stronger hypertrophy in WT mice than in CalpTG mice (Figure 4b and 4c).
|
Ang II–Dependent Perivascular Inflammation in WT and CalpTG Mice
Ang II induces vascular inflammatory response through both blood pressure–dependent and –independent mechanisms.21 Infiltration of monocytes/macrophages, lymphocytes, and, to a lesser extent, neutrophils was indeed markedly increased in the adventitia of aorta (data not shown) and kidney interlobular arteries (Figure 5a) of mice receiving Ang II. Inflammatory cells were activated, as evidenced by the appearance of a myeloperoxidase activity in the kidney cortex (Figure 5b). All of these changes were dramatically attenuated in CalpTG mice (Figure 5a and 5b). Because Ang II directly increases leukocyte infiltration by upregulating the expression of chemokines and adhesion molecules in vascular cells and by activating blood inflammatory cells,21 we next examined in vitro the capacity of vascular cells and blood mononuclear cells to generate chemokines and to migrate in response to chemokine gradient, respectively. Aortic VSMCs derived from WT type mice showed a dose-dependent increase in monocyte chemoattractant protein (MCP)-1 expression on exposure to Ang II, whereas those from CalpTG mice did not (Figure 5c). In addition, mononuclear cells from the peritoneum of WT mice migrated in response to MCP-1 gradient, whereas those from CalpTG mice did not (Figure 5d).
|
To confirm the mechanisms by which calpain inactivation regulates inflammatory cell recruitment, we used the in vivo inflammation model induced by the intraperitoneal injection of thioglycollate. Inflammatory challenge into the abdominal cavity of WT mice led to a time-dependent recruitment of neutrophils, monocytes, and lymphocytes that peaked at 4, 16, and 48 hours, respectively (Figure 5e). Again, CalpTG mice had an impaired (neutrophils) and delayed (monocytes and lymphocytes) ability to recruit inflammatory cells. However, WT and CalpTG mice showed no difference in peritoneal lymphocyte subpopulations (supplemental Table I). Defective recruitment of leukocytes into thioglycollate-induced peritonitis was not attributable to a failure in lymphohematopoiesis, because circulating leukocytes were present at normal abundance in both WT and CalpTG mice (supplemental Table II). Rather, it was related to a defect in chemotaxis, as reflected by the lack of MCP-1 release into the abdominal cavity of CalpTG mice (Figure 5e). These results demonstrate that Ang II–dependent perivascular inflammation is strongly reduced in CalpTG mice because of a defect in leukocyte recruitment, which is attributable to a decrease in both the release of and the response to MCP-1.
Prevention of Ang II–Dependent Perivascular Inflammation and Cardiovascular Hypertrophy in CalpTG Mice Is Associated With an Inhibition of NF-
B but Not NFAT
NF-
B is a central transcription factor involved in Ang II–mediated vascular inflammation/remodeling and cardiac hypertrophy.21,22 Because calpain activity participates in NF-
B activation process,12 we considered the possibility that transgene-dependent decrease in calpain activity may result in a reduction of NF-
B activation. Infusion of Ang II led to a marked increase in the nuclear expression of NF-
B p65 subunit within both kidney cortex and heart of WT mice, and significant blunting of these Ang II–mediated effects was observed in CalpTG mice (Figure 6).
|
Similarly, because Ang II–induced cardiac hypertrophy is attenuated in NFAT4 (NFATc3)-null mice23 and because calpains have been shown to activate the calcineurin/NFAT pathway, we compared the nuclear translocation of NFATc3 in the heart of WT and CalpTG mice. Ang II–induced NFATc3 translocation was not modified by the calpastatin transgene (Figure 6). These data suggest that calpain activity is essential for Ang II–induced cardiovascular remodeling through the activation of NF-
B but not NFATc3.
Ang II–Dependent Perivascular Fibrosis in WT and CalpTG Mice
Ang II promotes perivascular fibrosis in addition to media hypertrophy and infiltration of mononuclear cells.24 Infusion of Ang II for 4 weeks indeed resulted in robust fibrosis around aorta and kidney interlobular arteries of WT mice, as evidenced by polarized light microscopy analysis of Sirius red staining25 and immunohistochemical analysis of type I collagen. Significant blunting of these Ang II–mediated effects were observed in CalpTG mice (Figure 7a, and 7b, 7e, and 7f). The mechanism by which calpastatin-dependent protection occurs could involve an increase in collagen degradation by MMPs and/or a decrease in collagen deposition. A paradoxical decrease of MMP activity (determined by in situ zymography and quantitative zymography: 3.83±0.89 versus 19.93±1.97 optical density units; N=3; P<0.005) in aortic media of CalpTG mice as compared with WT mice excluded the first hypothesis (Figure 7a and 7d). In contrast, a significant decrease in Ang II–induced synthesis and secretion of collagen in VSMCs from CalpTG mice as compared with WT mice (Figure 7c and supplemental Figure II) indicated that calpain activity promotes perivascular fibrosis partly through a direct effect on collagen production.
|
In addition to perivascular fibrosis, kidney interstitial fibrosis was observed after 4 weeks of Ang II infusion in WT mice and, to a much lesser extent, in CalpTG mice (Figure 7g), suggesting that the calpain/calpastatin system is involved in this tissue fibrosis process as well.
| Discussion |
|---|
|
|
|---|
We found that after 4 weeks of infusion with Ang II, WT mice developed a more severe hypertrophy of vascular media than CalpTG mice, the extent of blood pressure elevation being similar in the 2 groups of mice. These results validate the novel concept that calpains are involved in local or tissue renin–angiotensin systems (which cause cardiovascular remodeling) rather than in the circulating renin–angiotensin system (which induces hypertension through vasoconstriction and aldosterone release from the adrenal cortex).29
Vascular remodeling occurs in response to increased arterial blood pressure and/or activation of the renin–angiotensin–aldosterone system.2,3 According to the law of Laplace, 1 option for a vessel to normalize its wall stress in hypertension is to undergo hypertrophy. This hypertrophic remodeling is the consequence of alterations in the growth and/or size of VSMCs and accumulation of extracellular matrix proteins. Our in vivo data show that Ang II–dependent vascular remodeling is limited in both large arteries (aorta) and small kidney arteries from CalpTG mice as compared with WT mice. The difference between the 2 groups of mice reflects differences in the hypertrophic response of VSMCs to Ang II, as demonstrated in vitro by measuring [3H]leucine incorporation. Further pharmacological studies have provided evidence for the molecular mechanisms underlying the response to Ang II. After binding to AT1 receptors, Ang II promoted the transactivation of EGFR, which, in turn, would activate a mitogen-activated protein kinase cascade, resulting in phosphorylation and activation of calpain 2.18,30
Cardiac hypertrophy was also limited in CalpTG mice given Ang II. Basically, transcription factors that are both activated by calpains and responsible for Ang II–dependent left ventricular hypertrophy (reviewed elsewhere31) are potentially involved in this response. Among them, the most important is NF-
B. Calpains degrade the inhibitor I
B
, a key step in nuclear translocation of NF-
B,12 and mice lacking the p50 subunit of NF-
B or expressing an NF-
B super-repressor show limited cardiac hypertrophy in response to chronic Ang II infusion.22 It is likely that NF-
B signaling controls the expression of genes involved in cardiomyocyte hypertrophy (eg, the interleukin-6 receptor gp130). Similarly, calpains activate the serine/threonine protein phosphatase calcineurin via the proteolysis of its autoinihibitory domain, leading to the nuclear translocation of dephosphorylated NFAT in tissues, including heart,32 and NFATc3-null mice have blunted cardiac hypertrophy following Ang II infusion.23 However, based on our results, calpain activity mediates Ang II–dependent left ventricular hypertrophy through a NFATc3-independent process.
In hypertension, small foci of inflammatory cells consisting mainly of lymphocytes and macrophages have been described in both perivascular and tissue interstitial regions, where they precede fibrosis process.33 Calpains may contribute to these events by at least 3 different mechanisms. First, by promoting NF-
B activation, calpains may induce both the expression of and the cell response to MCP-1, which recruits lymphocytes and macrophages. Second, by the cleavage of cytoskeletal linkage molecules such as talin and ezrin, calpains are responsible for the extravasation and the migration of leukocytes.9,34 Third, by promoting NF-
B activation, calpains may induce the expression of endothelin-1,35 which, in turn, induces vascular inflammatory response through increased oxidative stress and stimulation of proinflammatory cytokines.21 The results reported here suggest an involvement of the first mechanism. The latter mechanism is unlikely, because endothelin-1 gene and protein expression were not altered after 4 weeks of Ang II infusion in CalpTG mice as compared with WT mice (data not shown).
There is evidence of a causal relationship between inflammatory cells and fibrosis, because anti–MCP-1 therapy prevents macrophage accumulation and limits perivascular and interstitial fibrosis in hypertension.36 With regard to the exact mechanisms involved, infiltrating inflammatory cells are capable of releasing numerous cytokines, which may regulate fibroblast recruitment and proliferation. Among them, interleukin-13 and transforming growth factor-β generated by mononuclear cells preferentially stimulate the macrophage activity of arginase-1, which is crucial for fibroblast growth and collagen synthesis.37,38 Thus, calpains may participate in fibrosis process mainly by recruiting inflammatory cells.
Calpain-induced cardiovascular and tissue fibrosis also may result from changes in matrix protein turnover. We observed that calpastatin transgene expression was mirrored paradoxically by a decrease in MMP activity. Thus, the antifibrotic action of calpastatin would be explained by a decrease in collagen deposition rather than an increase in collagen degradation. This hypothesis is consistent with our observation that VSMCs derived from the aorta of CalpTG mice produce much less collagen in response to Ang II.
In summary, the present studies demonstrate that calpains contribute to the development of Ang II–induced cardiovascular remodeling. Specifically, the loss of calpain activation prevents myocardial and vascular hypertrophy, perivascular inflammation, and perivascular or tissue fibrosis. It is interesting to note that this protection is observed even though hypertension remains unchanged. Therefore, our studies have important clinical significance in providing evidence for an alternative strategy in the treatment of cardiovascular remodeling. In support of this option, loss of calpain activation appears to prevent overall consequences of Ang II–induced hypertension, and this protective role is tremendous. Further work is needed to assess the clinical efficacy of available calpain inhibitors, focusing on drugs that increase calpastatin expression, because this strategy appears to limit calpain activation without interfering with basal calpain activity.
| Acknowledgments |
|---|
This work was supported by the Institut National de la Santé et de la Recherche Médicale and by the Faculté de Médecine Saint-Antoine. Additional support was provided by grants from the Association pour la Recherche sur le Cancer (grant 9946), the Ligue Nationale contre le Cancer (Comité de Paris), and the Baxter Extramural Grant Program.
Disclosures
None.
| Footnotes |
|---|
| References |
|---|
|
|
|---|
2. Touyz RM. Molecular and cellular mechanisms in vascular injury in hypertension: role of angiotensin II. Curr Opin Nephrol Hypertens. 2005; 14: 125–131.[Medline] [Order article via Infotrieve]
3. Duprez DA. Role of the renin-angiotensin-aldosterone system in vascular remodeling and inflammation: a clinical review. J Hypertens. 2006; 24: 983–991.[Medline] [Order article via Infotrieve]
4. Mehta PK, Griendling KK. Angiotensin II cell signaling: physiological and pathological effects in the cardiovascular system. Am J Physiol Cell Physiol. 2007; 292: C82–C97.
5. Goll DE, Thompson VF, Li H, Wei W, Cong J. The calpain system. Physiol Rev. 2003; 83: 731–801.
6. Zatz M, Starling A. Calpains and disease. N Engl J Med. 2005; 352: 2413–2423.
7. Moldoveanu T, Hosfield CM, Lim D, Elce JS, Jia Z, Davies PL. A Ca2+ switch aligns the active site of calpain. Cell. 2002; 108: 649–660.[CrossRef][Medline] [Order article via Infotrieve]
8. Glading A, Bodnar RJ, Reynolds IJ, Shiraha H, Satish L, Potter DA, Blair HC, Wells A. Epidermal growth factor activates m-calpain (calpain II), at least in part, by extracellular signal-regulated kinase-mediated phosphorylation. Mol Cell Biol. 2004; 24: 2499–2512.
9. Lokuta MA, Nuzzi PA, Huttenlocher A. Calpain regulates neutrophil chemotaxis. Proc Natl Acad Sci U S A. 2003; 100: 4006–4011.
10. Kavita U, Mizel SB. Differential sensitivity of interleukin-1-alpha and -beta precursor proteins to cleavage by calpain, a calcium-dependent protease. J Biol Chem. 1995; 270: 27758–27765.
11. Bellocq A, Doublier S, Suberville S, Perez J, Escoubet B, Fouqueray B, Rodriguez Puyol D, Baud L. Somatostatin increases glucocorticoid binding and signaling in macrophages by blocking the calpain-specific cleavage of hsp 90. J Biol Chem. 1999; 274: 36891–36896.
12. Shumway SD, Maki M, Miyamoto S. The PEST domain of I
B
is necessary and sufficient for in vitro degradation by µ-calpain. J Biol Chem. 1999; 274: 30874–30881.
13. Peltier J, Bellocq A, Perez J, Doublier S, Xu Dubois Y-C, Haymann J-P, Camussi G, Baud L. Calpain activation and secretion promote glomerular injury in experimental glomerulonephritis: evidence from calpastatin-transgenic mice. J Am Soc Nephrol. 2006; 17: 3415–3423.
14. Chansel D, Ciroldi M, Vandermeersch S, Jackson LF, Gomez AM, Henrion D, Lee DC, Coffman TM, Richard S, Dussaule J-C, Tharaux PL. Heparin binding EGF is necessary for vasospastic response to endothelin. FASEB J. 2006; 20: 1936–1938.
15. Perez J, Viollet C, Doublier S, Videau C, Epelbaum J, Baud L. Somatostatin binds to murine macrophages through two distinct subsets of receptors. J Neuroimmunol. 2003; 138: 38–44.[CrossRef][Medline] [Order article via Infotrieve]
16. Schiffrin EL. Small artery remodeling in hypertension: can it be corrected? Am J Med Sci. 2001; 322: 7–11.[CrossRef][Medline] [Order article via Infotrieve]
17. Crowley SD, Gurley SB, Herrera MJ, Ruiz P, Griffiths R, Kumar AP, Kim H-S, Smithies O, Le TH, Coffman TM. Angiotensin II causes hypertension and cardiac hypertrophy through its receptors in the kidney. Proc Natl Acad Sci U S A. 2006; 103: 17985–17990.
18. Franco SJ, Huttenlocher A. Regulating cell migration: calpains make the cut. J Cell Sci. 2005; 118: 3829–3838.
19. Gross V, Obst M, Kiss E, Janke J, Mazak I, Shagdarsuren E, Müller DN, Langenickel TH, Gröne H-J, Luft FC. Cardiac hypertrophy and fibrosis in chronic L-NAME-treated AT2 receptor-deficient mice. J Hypertens. 2004; 22: 997–1005.[CrossRef][Medline] [Order article via Infotrieve]
20. Ford CM, Li S, Pickering JG. Angiotensin II stimulates collagen synthesis in human vascular smooth muscle cells. Involvement of the AT1 receptor, transforming growth factor-β, and tyrosine phosphorylation. Arterioscler Thromb Vasc Biol. 1999; 19: 1843–1851.
21. Cheng ZJ, Vapaatalo H, Mervaala E. Angiotensin II and vascular inflammation. Med Sci Monit. 2005; 11: RA194–RA205.[Medline] [Order article via Infotrieve]
22. Freund C, Schmidt-Ullrich R, Baurand A, Dunger S, Schneider W, Loser P, El-Jamali A, Dietz R, Scheidereit C, Bergmann MW. Requirement of nuclear factor-
B in angiotensin II- and isoproterenol-induced cardiac hypertrophy in vivo. Circulation. 2005; 111: 2319–2325.
23. Wilkins BJ, De Windt LJ, Bueno OF, Braz JC, Glascock BJ, Kimball TF, Molkentin JD. Targeted disruption of NFATc3, but not NFATc4, reveals an intrinsic defect in calcineurin-mediated cardiac hypertrophic growth. Mol Cell Biol. 2002; 22: 7603–7613.
24. Zhan Y, Brown C, Maynard E, Anshelevich A, Ni W, Ho I-C, Oettgen P. Ets-1 is a critical regulator of Ang II-mediated vascular inflammation and remodeling. J Clin Invest. 2005; 115: 2508–2516.[CrossRef][Medline] [Order article via Infotrieve]
25. Matsuo S, Lopez-Guisa JM, Cai X, Okamura DM, Alpers CE, Bumgarner RE, Peters MA, Zhang G, Eddy AA. Multifunctionality of PAI-1 in fibrogenesis: evidence from obstructive nephropathy in PAI-1-overexpressing mice. Kidney Int. 2005; 67: 2221–2238.[CrossRef][Medline] [Order article via Infotrieve]
26. Galvez AS, Diwan A, Odley AM, Hahn HS, Osinska H, Melendez JG, Robbins J, Lynch RA, Marreez Y, Dorn GW. Cardiomyocyte degeneration with calpain deficiency reveals a critical role in protein homeostasis. Circ Res. 2007; 100: 1071–1078.
27. Takano J, Tomioka M, Tsubuki S, Higuchi M, Iwata N, Itohara S, Maki M, Saido TC. Calpain mediates excitotoxic DNA fragmentation via mitochondrial pathways in adult brains. Evidence from calpastatin mutant mice. J Biol Chem. 2005; 280: 16175–16184.
28. De Tullio R, Passalacqua M, Averna M, Salamino F, Melloni E, Pontremoli S. Changes in intracellular localization of calpastatin during calpain activation. Biochem J. 1999; 343: 467–472.[CrossRef][Medline] [Order article via Infotrieve]
29. Paul M, Mehr AP, Kreutz R. Physiology of local renin-angiotensin systems. Physiol Rev. 2006; 86: 747–803.
30. Shah BH, Catt KJ. TACE-dependent EGF receptor activation in angiotensin-II-induced kidney disease. Trends Pharmacol Sci. 2006; 27: 235–237.[CrossRef][Medline] [Order article via Infotrieve]
31. Heineke J, Molkentin JD. Regulation of cardiac hypertrophy by intracellular signalling pathways. Nature Rev Mol Cell Biol. 2006; 7: 589–600.[CrossRef][Medline] [Order article via Infotrieve]
32. Burkard N, Becher J, Heindl C, Neyses L, Schuh K, Ritter O. Targeted proteolysis sustains calcineurin activation. Circulation. 2005; 111: 1045–1053.
33. Hinglais N, Heudes D, Nicoletti A, Mandet C, Laurent M, Bariety J, Michel JB. Colocalization of myocardial fibrosis and inflammatory cells in rats. Lab Invest. 1994; 70: 286–294.[Medline] [Order article via Infotrieve]
34. Dewitt S, Hallett M. Leukocyte membrane "expansion": a central mechanism for leukocyte extravasation. J Leukoc Biol. 2007; 81: 1160–1164.
35. Duffy JY, Schwartz SM, Lyons JM, Bell JH, Wagner CJ, Zingarelli B, Pearl JM. Calpain inhibition decreases endothelin-1 levels and pulmonary hypertension after cardiopulmonary bypass with deep hypothermic circulatory arrest. Crit Care Med. 2005; 33: 623–628.[CrossRef][Medline] [Order article via Infotrieve]
36. Kuwahara F, Kai H, Tokuda K, Takeya M, Takeshita A, Egashira A, Imaizumi T. Hypertensive myocardial fibrosis and diastolic dysfunction: another model of inflammation? Hypertension. 2004; 43: 739–745.
37. Wynn TA. Fibrotic disease and the TH1/TH2 paradigm. Nat Rev Immunol. 2004; 4: 583–594.[CrossRef][Medline] [Order article via Infotrieve]
38. Boutard V, Havouis R, Fouqueray B, Philippe C, Moulinoux J-P, Baud L. Transforming growth factor-β stimulates arginase activity in macrophages. Implications for the regulation of macrophage cytotoxicity. J Immunol. 1995; 155: 2077–2084.[Abstract]
This article has been cited by other articles:
![]() |
Y. Li, Y. Li, Q. Feng, M. Arnold, and T. Peng Calpain activation contributes to hyperglycaemia-induced apoptosis in cardiomyocytes Cardiovasc Res, October 1, 2009; 84(1): 100 - 110. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Pilop, F. Aregger, R. C. Gorman, R. Brunisholz, B. Gerrits, T. Schaffner, J. H. Gorman III, G. Matyas, T. Carrel, and B. M. Frey Proteomic Analysis in Aortic Media of Patients With Marfan Syndrome Reveals Increased Activity of Calpain 2 in Aortic Aneurysms Circulation, September 15, 2009; 120(11): 983 - 991. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Li, Y. Li, L. Shan, E Shen, R. Chen, and T. Peng Over-expression of calpastatin inhibits calpain activation and attenuates myocardial dysfunction during endotoxaemia Cardiovasc Res, July 1, 2009; 83(1): 72 - 79. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Yogi, G. E. Callera, R. Tostes, and R. M. Touyz Bradykinin regulates calpain and proinflammatory signaling through TRPM7-sensitive pathways in vascular smooth muscle cells Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2009; 296(2): R201 - R207. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. M. Heidrich and B. E. Ehrlich Calcium, Calpains, and Cardiac Hypertrophy: A New Link Circ. Res., January 30, 2009; 104(2): e19 - e20. [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Circulation Research Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 2008 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |