Calpain inhibition decreases myocardial apoptosis in a swine model of chronic myocardial ischemia (original) (raw)
Related papers
Surgery, 2016
Introduction-Emerging data suggests a link between calpain activation and the enhanced inflammatory response of the cardiovascular system. We hypothesize that calpain activation associates with altered inflammatory protein expression in correlation with the pro-inflammatory profile of the myocardium. Our pig hypercholesterolemic model with chronic myocardial ischemia will be treated with calpain inhibitors (CI) to establish their potentials to improve cardiac function. Methods-Yorkshire swine, fed a high cholesterol diet (HC) for four weeks, underwent placement of an ameroid constrictor on the left circumflex artery. Three weeks later animals received either: no drug, high cholesterol control group (CON; n= 8); a low dose CI (0.12 mg/kg; LCI, n= 9); or a high dose CI (0.25 mg/kg; HCI, n= 8). The HC and CI were continued for five weeks, after which the pig was euthanized. The left ventricular myocardial tissue (ischemic and non-ischemic) was harvested and analyzed for inflammatory proteins expression. Data was statistically analyzed via the Kruskal-Wallis and Dunn's post hoc test. Results-CI treatment coincides with increased expression of IKB-α and decreased expression of macrophages, NFkB, IL-1 and TNF-α in the ischemic myocardial tissue as compared to the control group. NFkB array revealed decreased expression of IRF5, JNK1/2, JNK2, CD18, NFkB p65, c-Rel, Sharpin, TNF R1, TNF R2 and DR5 in the ischemic myocardium of the HCI treated group compared to the control. Conclusions-Calpain activation in metabolic syndrome is a potential contributor to cardiac dysfunction in metabolic disorders with ischemic background. We suggest calpain inhibition down regulates NFkB signaling in the vessel walls which might be useful for improving myocardial blood flow in ischemic conditions.
Calpain inhibition preserves myocardial structure and function following myocardial infarction
AJP: Heart and Circulatory Physiology, 2009
Mani SK, Balasubramanian S, Zavadzkas JA, Jeffords LB, Rivers WT, Zile MR, Mukherjee R, Spinale FG, Kuppuswamy D. Calpain inhibition preserves myocardial structure and function following myocardial infarction. Cardiac pathology, such as myocardial infarction (MI), activates intracellular proteases that often trigger programmed cell death and contribute to maladaptive changes in myocardial structure and function. To test whether inhibition of calpain, a Ca 2ϩ -dependent cysteine protease, would prevent these changes, we used a mouse MI model. Calpeptin, an aldehydic inhibitor of calpain, was intravenously administered at 0.5 mg/kg body wt before MI induction and then at the same dose subcutaneously once per day. Both calpeptin-treated (n ϭ 6) and untreated (n ϭ 6) MI mice were used to study changes in myocardial structure and function after 4 days of MI, where end-diastolic volume (EDV) and left ventricular ejection fraction (EF) were measured by echocardiography. Calpain activation and programmed cell death were measured by immunohistochemistry, Western blotting, and TdT-mediated dUTP nick-end labeling (TUNEL). In MI mice, calpeptin treatment resulted in a significant improvement in EF [EF decreased from 67 Ϯ 2% pre-MI to 30 Ϯ 4% with MI only vs. 41 Ϯ 2% with MI ϩ calpeptin] and attenuated the increase in EDV [EDV increased from 42 Ϯ 2 l pre-MI to 73 Ϯ 4 l with MI only vs. 55 Ϯ 4 l with MI ϩ calpeptin]. Furthermore, calpeptin treatment resulted in marked reduction in calpain-and caspase-3-associated changes and TUNEL staining. These studies indicate that calpain contributes to MI-induced alterations in myocardial structure and function and that it could be a potential therapeutic target in treating MI patients. cardiomyocytes; cell death * S. K. Mani and S. Balasubramanian contributed equally to this work.
Calpains and Coronary Vascular Disease
Circulation Journal, 2016
Despite many advances in percutaneous and surgical interventions in the treatment of coronary artery disease (CAD), up to one-third of patients are still either not candidates or receive suboptimal revascularization. Calpains are a class of calcium-activated non-lysosomal cysteine proteases that serve as a proteolytic unit for cellular homeostasis. Uncontrolled activation of calpain has been found to be involved in the pathogenesis of myocardial reperfusion injury, cardiac hypertrophy, myocardial stunning and cardiac ischemia. Inhibition of calpains has been shown to significantly attenuate myocardial stunning and reduced infarct size after ischemia-reperfusion. Calpain inhibition therefore serves as a potential medical therapy for patients suffering from a number of diseases, including CAD.
British Journal of Pharmacology, 2002
The calpains have been proposed to be activated following cardiac ischaemia and to contribute to myocyte damage after myocardial infarction (MI). In this study, the activity of calpains I and II in the infarcted and non-infarcted rat myocardium and the action of the selective calpain inhibitor, CAL 9961, has been investigated.MI was induced by permanent ligation of the left coronary artery. One, 3, 7 and 14 days post MI, the enzymes calpain I and II were separated from homogenates of the interventricular septum (IS) and left ventricular free wall (LVFW) by chromatography on DEAE-Sepharose. The activity of the calpains was measured in sham-operated and MI animals chronically treated with placebo or CAL 9961 (15 mg kg−1 d−1 s.c.) in a synthetic substrate assay. Treatment was started 3 days before MI induction.Calpain I activity reached highest values in IS 14 days post MI, whereas maximum activity of calpain II was measured in LVFW 3 days post MI. In experiments in vitro, CAL 9961 completely inhibited both calpains. In vivo, chronic treatment of MI animals with CAL 9961 partially prevented the increase in calpain I activity in IS and reduced calpain II activity in LVFW to sham levels.Our findings demonstrate that calpains I and II are activated after MI, however, both enzymes differ in their regional and temporal activation within the infarcted myocardium. Chronic inhibition of these enzymes with CAL 9961 might limit the calpain-induced myocardial damage and preserve cardiac structural integrity post MI.The calpains have been proposed to be activated following cardiac ischaemia and to contribute to myocyte damage after myocardial infarction (MI). In this study, the activity of calpains I and II in the infarcted and non-infarcted rat myocardium and the action of the selective calpain inhibitor, CAL 9961, has been investigated.MI was induced by permanent ligation of the left coronary artery. One, 3, 7 and 14 days post MI, the enzymes calpain I and II were separated from homogenates of the interventricular septum (IS) and left ventricular free wall (LVFW) by chromatography on DEAE-Sepharose. The activity of the calpains was measured in sham-operated and MI animals chronically treated with placebo or CAL 9961 (15 mg kg−1 d−1 s.c.) in a synthetic substrate assay. Treatment was started 3 days before MI induction.Calpain I activity reached highest values in IS 14 days post MI, whereas maximum activity of calpain II was measured in LVFW 3 days post MI. In experiments in vitro, CAL 9961 completely inhibited both calpains. In vivo, chronic treatment of MI animals with CAL 9961 partially prevented the increase in calpain I activity in IS and reduced calpain II activity in LVFW to sham levels.Our findings demonstrate that calpains I and II are activated after MI, however, both enzymes differ in their regional and temporal activation within the infarcted myocardium. Chronic inhibition of these enzymes with CAL 9961 might limit the calpain-induced myocardial damage and preserve cardiac structural integrity post MI.British Journal of Pharmacology (2002) 135, 1951–1958; doi:10.1038/sj.bjp.0704661
Calpain activation contributes to hyperglycaemia-induced apoptosis in cardiomyocytes
Cardiovascular Research, 2009
Time for primary review: 23 days Aims Cardiomyocyte apoptosis contributes to cardiac complications of diabetes. The aim of this study was to investigate the role of calpain in cardiomyocyte apoptosis induced by hyperglycaemia. Methods and results In cultured adult rat ventricular cardiomyocytes, high glucose (33 mM) increased calpain activity and induced apoptosis, concomitant with the impairment of Na þ /K þ ATPase activity. These effects of high glucose on cardiomyocytes were abolished by various pharmacological calpain inhibitors, knockdown of calpain-1 but not calpain-2 using siRNA, or over-expression of calpastatin, a specific endogenous calpain inhibitor. The effect of calpain inhibition on cardiomyocyte apoptosis was abrogated by ouabain, a selective inhibitor of Na þ /K þ ATPase. Furthermore, blocking gp91 phox-NADPH oxidase activation, L-type calcium channels, or ryanodine receptors prevented calpain activation and apoptosis in high glucose-stimulated cardiomyocytes. In a mouse model of streptozotocin-induced diabetes, administration of different calpain inhibitors blocked calpain activation, increased the Na þ /K þ ATPase activity, and decreased apoptosis in the heart. Conclusion Calpain-1 activation induces apoptosis through down-regulation of the Na þ /K þ ATPase activity in high glucose-stimulated cardiomyocytes and in vivo hyperglycaemic hearts. High glucoseinduced calpain-1 activation is mediated through the NADPH oxidase-dependent pathway and associated with activation of L-type calcium channels and ryanodine receptors. Our data suggest that calpain activation may be important in the development of diabetic cardiomyopathy and thus may represent a potential therapeutic target for diabetic heart diseases.
British Journal of Pharmacology, 2003
Hypercholesterolaemia has been shown to be associated with greater myocardial ischaemiareperfusion injury, in which apoptosis and in¯ammation-mediated necrosis both play a key role. 2 Caspase-1 is involved in the activation of both apoptosis and in¯ammation, through the intermediate of interleukin-1b (IL-1b). We herein examined whether pharmacological inhibition of the caspase-1 cascade, using Ac-Tyr-Val-Ala-Asp-CH 2 Cl (Ac-YVAD.cmk), after myocardial ischaemia have greater protective eects on myocardial ischaemia-reperfusion injury in diet-induced hypercholesterolaemic rabbits. 3 Male rabbits fed with standard chow or chow supplemented with 0.5% cholesterol and 10% coconut oil for 8 weeks were subjected to 30 min of left circum¯ex artery occlusion followed by 4 h of reperfusion. An intravenous bolus of Ac-YVAD.cmk (1.6 mg kg 71) or vehicle was given 20 min after coronary occlusion. 4 Postischaemic administration of Ac-YVAD.cmk markedly decreased infarct size from 26+3% to 12+2% in normally fed rabbits (P=0.005) and from 41+6% to 14+2% in cholesterol-fed rabbits (P50.001). 5 In the ischaemic non-necrotic area, treatment with Ac-YVAD.cmk markedly reduced the percentage of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL)-positive cardiomyocytes from 15.5+0.8% to 2.2+0.1% in normally fed rabbits (P50.001) and from 39.0+2.3% to 2.2+0.1% in cholesterol-fed rabbits (P50.001). 6 Ac-YVAD.cmk treatment resulted in a reduction not only of IL-1b and caspase-1, but also of caspase-3 in the ischaemic myocardium in both normally fed and cholesterol-fed rabbits. 7 No dierences in infarct size, the percentage of TUNEL-positive cardiomyocytes, IL-1b levels or activity of caspase-1 and caspase-3 were observed between Ac-YVAD.cmk-treated normally fed and cholesterol-fed rabbits. 8 This study demonstrates that injection of a selective caspase-1 inhibitor after myocardial ischaemia markedly reduced the detrimental eect conferred by hypercholesterolaemia on myocardial ischaemia-reperfusion injury by attenuating both necrotic as well as apoptotic cell death pathways through inhibition of IL-1b production and activation of caspase-1 and caspase-3.
2010
Background. Recent studies have shown that angiogenesis is regulated by a balance between activators and inhibitors. We investigated the effects of hypercholesterolemia on the functional angiogenic response and collateral formation induced by chronic myocardial ischemia and the expression of angiogenic mediators. Methods. Twelve Yucatan miniswine, fed either a normal (NORM, n ؍ 6) or high cholesterol (HCHO, n ؍ 6) diet for 13 weeks, underwent ameroid constrictor placement around the circumflex artery. Three weeks later, myocardial perfusion was quantified using isotope-labeled microspheres. Seven weeks after ameroid placement, coronary microvascular responses and myocardial perfusion were assessed. Vascular density was evaluated by PECAM-1 (CD-31) staining, and vascular endothelial growth factor, endothelial nitric oxide synthase, endostatin, and angiostatin protein levels were determined. Myocardial protein oxidation was quantified. Results. Coronary microvessels from HCHO pigs showed significant endothelial dysfunction. Baseline-adjusted myocardial flow at 7 weeks was significantly reduced in the HCHO animals (؊0.002 ؎ 0.06 versus ؉0.23 ؎ 0.09 mL/min/g, HCHO versus NORM, p ؍ 0.04). Endostatin expression was significantly increased in the HCHO pigs (2.2-fold, p ؍ 0.001 versus NORM). There was a mild reduction in myocardial vascular endothelial growth factor expression (؊29% ؎ 14%, p ؍ 0.09) in HCHO animals, but no difference in expression of endothelial nitric oxide synthase and angiostatin. The HCHO animals demonstrated increased myocardial protein oxidation compared with the NORM group (؉155% ؎ 21%, p ؍ 0.03 versus NORM). Conclusions. Ischemia-induced angiogenesis is inhibited in hypercholesterolemic pigs with a concomitant increase in endostatin expression and oxidative stress. These findings suggest that under conditions of hypercholesterolemia, coronary collateral development may be regulated by endogenous angiogenesis inhibitors such as endostatin as well as reactive oxygen species.
Diabetes, 2011
OBJECTIVE-Recently we have shown that calpain-1 activation contributes to cardiomyocyte apoptosis induced by hyperglycemia. This study was undertaken to investigate whether targeted disruption of calpain would reduce myocardial hypertrophy and fibrosis in mouse models of type 1 diabetes. RESEARCH DESIGN AND METHODS-Diabetes in mice was induced by injection of streptozotocin (STZ), and OVE26 mice were also used as a type 1 diabetic model. The function of calpain was genetically manipulated by cardiomyocyte-specific knockout Capn4 in mice and the use of calpastatin transgenic mice. Myocardial hypertrophy and fibrosis were investigated 2 and 5 months after STZ injection or in OVE26 diabetic mice at the age of 5 months. Cultured isolated adult mouse cardiac fibroblast cells were also investigated under high glucose conditions.