Abstract 17724: Myocardial Extracellular Matrix Proteins Involved in the Overloaded and Unloaded Heart After Myocardial Infarction

• Published in: Circulation (New York, N.Y.) N.Y.), 2023-11, Vol.148 (Suppl_1)
• Main Authors: Mavropoulos, Spyros Archimedes, Sakata, Tomoki, Mazurek, Renata, Marx, Jonas, Ravichandran, Anjali, Ishikawa, Kiyotake
• Format: Article
• Language: English
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/circ.148.suppl_1.17724

Abstract only Introduction: The cardiac extracellular matrix (ECM) is a dynamic scaffold that transmits and responds to forces that act on the heart during the cardiac cycle. While acute left ventricle (LV) unloading by catheter-based LV assist device (pLVAD) is now a therapeutic option, its impact on ECM is unknown. Hypothesis: The composition of LV ECM proteins changes in response to wall stress. Methods: Ten Yorkshire pigs underwent the protocol in figure 1. Non-ischemic remote myocardium was processed for ECM specific proteomics. Volcano plots were constructed to determine proteins of interest and differential expression was considered as (-log10(p)>1.3 and |log2(fold-change)| >0.5). Gene ontology (GO) analysis was performed to identify associated molecular processes and biological functions. A group of age-matched pigs (n=6) that did not undergo MI induction served as reference. Immunofluorescence microscopy was performed to validate differential expression. Results: Of the 986 proteins analyzed, 39 were significantly differentially expressed between overloaded and unloaded hearts. GO analysis by molecular function revealed that differences tending towards RNA binding and lipid binding proteins. Analysis by biological process showed that cell differentiation, vesicle transport, and programmed cell death were the processes most favored. Staining for three of the identified differentially expressed proteins (figure 2) had results congruent with proteomic analysis. Conclusions: There were significant differences in the protein composition of the cardiac ECM between acutely unloaded and overloaded myocardium, suggesting that it actively responds to altered LV load.