BACKGROUND: Matrix metalloproteinase-2 (MMP-2) contributes to cardiac dysfunction resulting from ischemia-reperfusion (I/R) injury. MMP-2 not only remodels the extracellular matrix but also acts intracellularly in I/R by degrading troponin I. Whether other intracellular targets exist for MMP-2 during I/R is unknown. METHODS AND RESULTS: Isolated rat hearts were subjected to 20 minutes of ischemia and 30 minutes of reperfusion. The impaired recovery of mechanical function of the heart was attenuated by the MMP inhibitors o-phenanthroline or doxycycline. Quantitative 2D electrophoresis of homogenates of aerobically perfused hearts (control) or those subjected to I/R injury (in the presence or absence of MMP inhibitors) showed 3 low-molecular-weight proteins with levels that were significantly increased upon I/R injury and normalized to control levels by MMP inhibitors. Mass spectrometry analysis identified all 3 proteins as fragments of myosin light chain 1, which possesses theoretical cleavage recognition sequences for MMP-2 and is rapidly degraded by it in vitro. The association of MMP-2 with the thick myofilament in fractions prepared from I/R hearts was observed with immunogold electron microscopy, gelatin zymography for MMP-2 activity, and immunoprecipitation. MMP-2 was found to cleave myosin light chain 1 between tyrosine 189 and glutamine 190 at the C terminus. CONCLUSIONS: Our results demonstrate that myosin light chain 1 is another novel substrate for MMP-2 in the cardiomyocyte and that its degradation may contribute to contractile dysfunction resulting from I/R injury to the heart.
BACKGROUND:Matrix metalloproteinase-2 (MMP-2) contributes to cardiac dysfunction resulting from ischemia-reperfusion (I/R) injury. MMP-2 not only remodels the extracellular matrix but also acts intracellularly in I/R by degrading troponin I. Whether other intracellular targets exist for MMP-2 during I/R is unknown. METHODS AND RESULTS: Isolated rat hearts were subjected to 20 minutes of ischemia and 30 minutes of reperfusion. The impaired recovery of mechanical function of the heart was attenuated by the MMP inhibitors o-phenanthroline or doxycycline. Quantitative 2D electrophoresis of homogenates of aerobically perfused hearts (control) or those subjected to I/R injury (in the presence or absence of MMP inhibitors) showed 3 low-molecular-weight proteins with levels that were significantly increased upon I/R injury and normalized to control levels by MMP inhibitors. Mass spectrometry analysis identified all 3 proteins as fragments of myosin light chain 1, which possesses theoretical cleavage recognition sequences for MMP-2 and is rapidly degraded by it in vitro. The association of MMP-2 with the thick myofilament in fractions prepared from I/R hearts was observed with immunogold electron microscopy, gelatin zymography for MMP-2 activity, and immunoprecipitation. MMP-2 was found to cleave myosin light chain 1 between tyrosine 189 and glutamine 190 at the C terminus. CONCLUSIONS: Our results demonstrate that myosin light chain 1 is another novel substrate for MMP-2 in the cardiomyocyte and that its degradation may contribute to contractile dysfunction resulting from I/R injury to the heart.
Authors: Darrell Wu; Pingping Ren; Yanqiu Zheng; Lin Zhang; Gaiping Xu; Wanmu Xie; Eric E Lloyd; Sui Zhang; Qianzi Zhang; John A Curci; Joseph S Coselli; Dianna M Milewicz; Ying H Shen; Scott A LeMaire Journal: Arterioscler Thromb Vasc Biol Date: 2017-02-02 Impact factor: 8.311
Authors: Kay Sun; Zhihong Zhang; Takamaro Suzuki; Jonathan F Wenk; Nielen Stander; Daniel R Einstein; David A Saloner; Arthur W Wallace; Julius M Guccione; Mark B Ratcliffe Journal: J Thorac Cardiovasc Surg Date: 2010-03-17 Impact factor: 5.209
Authors: Rafael Shimkunas; Zhihong Zhang; Jonathan F Wenk; Mehrdad Soleimani; Michael Khazalpour; Gabriel Acevedo-Bolton; Guanying Wang; David Saloner; Rakesh Mishra; Arthur W Wallace; Liang Ge; Anthony J Baker; Julius M Guccione; Mark B Ratcliffe Journal: Ann Thorac Surg Date: 2013-03-21 Impact factor: 4.330