Cardiac Gene Expression Post-Myocardial Infarction

The LV was collected from anaesthetised mice in Cohorts 3 (following 8 days of permanent LAD ligation to induce MI) and 4 (4 weeks of permanent LAD ligation) and were dissected, blotted dry, and weighed. The infarcted area from cohort 3 mice was separated and snap-frozen for gene expression analysis. Hearts from cohort 4 mice were pinned out and photographed prior to snap-freezing for gene expression analysis. RNA was extracted from infarcted LV using TRIzol®, prior to reverse-transcription and real time PCR as described above. The expression of inflammatory genes (TNF-α, IL-1β, NLRP3, CD68, CD11c, C-C chemokine receptor type 1 [CCR2]), as well as M1 macrophage marker [S100A9], M2 macrophage marker (macrophage scavenger receptor, SRA; Arginase1, Arg1), the FPR system (ANX-A1, FPR1, FPR2), fibrotic genes (connective tissue growth factor CTGF, periostin, fibronectin, MMP-9), and a hypertrophic gene (atrial natriuretic peptide, ANP), using the Applied Biosystems ABI Prism 7700 Sequence Detection System^{20 (link)}, using sequences in Supplementary Table S1. Plasma levels of MCP-1 were also determined after 8 days and 4 weeks permanent LAD occlusion (cohorts 3 and 4), using a commercially available, high-sensitivity mouse MCP-1 ELISA Kit (RayBiotech Inc., Georgia, USA), as per the manufacturer’s instructions.