Alterations in mouse cardiac proteome after in vivo myocardial infarction: permanent ischaemia versus ischaemia–reperfusion

Abstract

Mice are increasingly used to study the early molecular mechanisms inducing injury to the heart following myocardial infarction. To date, two-dimensional gel electrophoresis combined with mass spectrometry has not been applied to identify changes in protein expression in myocardial tissue of mice subjected in vivo to permanent ischaemia (PI) or ischaemia-reperfusion (IR). In the PI group, ischaemia was induced for 210 min by ligation of the left anterior descending coronary artery while in the IR group, ischaemia was maintained for 30 min and reperfusion was allowed for 180 min. In both groups, the area of the left ventricle at risk was processed for 2-dimensional gel electrophoresis. By comparing protein density changes in cytosolic as well as membrane fractions, we found a total of 32 protein spots that were differentially expressed. Twenty spots changed in expression level after PI alone, four spots after IR alone, and eight spots changed in both models. Identified proteins with MALDI TOF-TOF and LC-MS/MS can be classified into functional groups of anticoagulant proteins, structural proteins, inflammatory-related proteins, transcription-and translation-related proteins, heat shock proteins (HSPs), metabolism-related proteins and miscellaneous. A remarkable finding was the IR-specific translocation of annexins (A3 and A5) from the cytosolic to the membrane compartment, a phenomenon that was verified by Western blotting. Four proteins were changed in expression level at multiple spot locations, characterized by a difference in isoelectric point. In the case of cardiac troponin T and HSP-20, these changes were also dependent on the model. In addition, one spot for the proteins adenylate kinase 1, cardiac troponin T and HSP-20 was uniquely present in the IR and/or PI groups and not in the respective sham groups. The specific alterations in protein expression that took place after PI and IR may stimulate the search for new tools to diagnoze myocardial infarction and to characterize specific pathology-related changes in protein expression.

Human Mutation in the Anti-apoptotic Heat Shock Protein 20 Abrogates Its Cardioprotective Effects

“…Thus, the need for increased Hsp20 expression becomes more important in the pathophysiological setting of heart failure. Indeed, previous studies have shown that the levels of Hsp20 as well as its phosphorylation levels at Ser 16 increase in the diseased myocardium (7,10,12,16,18) as a protective mechanism (7, 13, 14 -17). Consistent with these findings, we observed that the extent of apoptosis was reduced significantly in cells infected with Ad.WT-Hsp20 after simulated I/R compared with the control group.…”

“…At basal levels, no phosphorylated Hsp20 could be detected, consistent with the low activity of PKA in isolated myocytes. To test the specificity of this antibody, peptide competition was performed with the anti- [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] in human, dog, rat, and mouse shows that proline 20 is fully conserved. B, secondary structure predictions revealed alterations in the helical content around the Ser 16 phosphorylation site as well as around the site of the mutation.…”

“…Importantly, our data show that the phosphorylation of Hsp20 at Ser 16 may be instrumental to its anti-apoptotic properties. In particular, it has been reported that the phosphorylation of Hsp20 at Ser 16 increased after prolonged exposure to ␤-agonist stimulation (7), during I/R (16,18), as well as in congestive heart failure (12). To assess the role of enhanced phosphorylation at this site, a constitutively phosphorylated form of Hsp20 (S16D) was expressed in cardiomyocytes (7).…”

Atrial natriuretic peptide increases inflammation, infarct size, and mortality after experimental coronary occlusion

“…Brief ischemia with reperfusion and prolonged ischemia elicit different patterns of protein and gene expression, thereby activating different pathways in the heart (8). In addition, ANP like other molecules (e.g., P-selectin; see Ref.…”

Experimental Models of Acute Renal Failure and Erythropoietin: What Evidence of a Direct Effect?

“…[3][4][5] In organs with a weaker repairing ability, such as heart and brain, the ischemic injury rapidly leads to infarction and fibrosis. [6][7][8][9][10][11] On the other hand, the fibroid involution of the renal parenchyma is mainly observed as a result of a chronic ischemic-hypoxic or inflammatory injury. [12] The ability of the kidney to repair the ischemic damage is due to several factors that are still not completely known.…”