Reproducing extracellular matrix adverse remodelling of non-ST myocardialinfarction in a large animal model

Abstract

The rising incidence of non-ST-segment elevation myocardial infarction (NSTEMI) and associated long-term high mortality constitutes an urgent clinical issue. Unfortunately, the study of possible interventions to treat this pathology lacks a reproducible pre-clinical model. Indeed, currently adopted small and large animal models of MI mimic only full-thickness, ST-segment-elevation (STEMI) infarcts, and hence cater only for investigation into therapeutics and interventions directed at this subset of MI. Thus, we developed an ovine model of NSTEMI by ligating the myocardial muscle at precise intervals parallel to the left anterior descending coronary artery. After validating the presented model both by histology and functional analysis with clinical data, further omics analyses highlighted the distinctive features of post-NSTEMI tissue remodelling. Here, by looking at the transcriptome and proteome-derived pathways emerging at acute (7 days) and late (28 days) post-surgery timepoints, we discovered specific alterations in cardiac post-ischaemic extracellular matrix (ECM). Together with the rise of well-known markers of inflammation and fibrosis, NSTEMI ischaemic regions showed distinctive patterns in the expression of complex N-glycans and glycosaminoglycans in cellular membranes and ECM. Identifying such changes in molecular moieties accessible to infusible and intra-myocardial injectable drugs sheds light on the development of targeted pharmacological solutions to contrast adverse fibrotic remodelling.