MMP2 involved in Ischemic reperfusion injury and Troponin diminution

Catching upon my catching up this was uncovered. Notice that only AMIE entry included journal vol and page due to incomplete copy.

subject: Ischemia-Reperfusion Injury I/R/MMP2 MMP2/Matrix Metalloproteinase-2 target
object_opposite: Myosin light chain troponin diminishes
misc: A New Intracellular Target for MMP2/Matrix Metalloproteinase-2 richard.schulz@ualberta.ca
author_year: Grzegorz Sawicki PhD*/Hernando Leon, MD*/Jolanta Sawicka/MSc;Meltem Sariahmetoglu, PhD/ Costas J. Schulze, MD/Paul G. Scott, PhD/Danuta Szczesna-Cordary, PhD; Richard Schulz, PhD/2004
journal_volume_page: Circulation/112/554

Actual article appeared in circulation as abstract

Degradation of Myosin Light Chain in Isolated Rat Hearts Subjected to Ischemia-Reperfusion Injury

A New Intracellular Target for Matrix Metalloproteinase-2

1.      Grzegorz Sawicki, PhD*; 

2.      Hernando Leon, MD*; 

3.      Jolanta Sawicka, MSc;

4.      Meltem Sariahmetoglu, PhD; 

5.      Costas J. Schulze, MD; 

6.      Paul G. Scott, PhD;

7.      Danuta Szczesna-Cordary, PhD; 

8.      Richard Schulz, PhD

+Author Affiliations

1.      From the Departments of Pharmacology (G.S., J.S., M.S., C.J.S., R.S.), Pediatrics (H.L., R.S.), and Biochemistry (P.G.S.), Cardiovascular Research Group, University of Alberta, Edmonton, Alberta, Canada, and Department of Molecular and Cellular Pharmacology (D.S.-C.), University of Miami School of Medicine, Miami, Fla.

1.      Correspondence to Dr Richard Schulz, Cardiovascular Research Group, 4-62 Heritage Medical Research Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2S2. E-mail richard.schulz@ualberta.ca

Abstract

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.

Key Words:

subject: Ischemia-Reperfusion Injury I/R/MMP2 MMP2/Matrix Metalloproteinase-2 target
object_opposite: Myosin light chain troponin diminishes
misc: A New Intracellular Target for MMP2/Matrix Metalloproteinase-2 richard.schulz@ualberta.ca
author_year: Grzegorz Sawicki PhD*/Hernando Leon, MD*/Jolanta Sawicka/MSc;Meltem Sariahmetoglu, PhD/ Costas J. Schulze, MD/Paul G. Scott, PhD/Danuta Szczesna-Cordary, PhD; Richard Schulz, PhD/2004
journal_volume_page: Circulation/112/554