Abstract P3086: Aldose Reductase Deletion Protects Ischemic Murine Hearts By Modulating Immune Cell Dynamics

Abstract

Cardiac injury remains a major cause of death worldwide. Previous studies have demonstrated that chronic unchecked inflammation, during post ischemic reperfusion, adversely affects adaptive repair and augments tissue damage. Nature of the infiltrating immune cells determines the extent of repair vs exacerbation of tissue damage during post myocardial ischemia. Understanding mechanisms by which ischemia-mediated inflammatory responses exacerbate tissue damage and mitigate repair pathways are vital to discover therapeutics for myocardial infarction. Our earlier studies demonstrated that aldose reductase (AR) is a key mediator of myocardial ischemia-reperfusion (I/R) injury. Specifically, it established that cardio myocyte AR drives metabolic and signalling mechanisms leads to injury and impaired function in hearts. In this study we investigated the role of AR in influencing time dependent changes in recruitment of immune cells, during in vivo myocardial I/R injury. AR knockout (ARKO) and littermate controls (WT) mice were subjected to LAD sugery followed by reperfusion ( In vivo I/R) and the temporal changes in recruitment of immune cells were determined at earlier (day 3) and later (day 7) time points. We found ablation of AR leads to significant (p<0.0001) cardiac protection during post I/R in mice. Cardiac function measurements revealed greater recovery of ejection fraction and fractional shortening after I/R in ARKO vs WT hearts (p<0.05). Deletion of AR leads to a significant (p =0.0053) reduction in T cells infiltration post I/R in the heart. We observed 2-fold reduction in CD8+ cells, and 2-fold increase in CD4+ cells in ARKO vs WT mice hearts post I/R injury. Specifically, 2-fold reduction in pro-inflammatory Th1, Th2 and Th17 cells and 3-fold increases in anti-inflammatory Treg cells (p = 0.0091) were observed in ARKO vs WT hearts at post I/R injury. In addition, we observed reduction in infiltration of pro-inflammatory macrophages, dendritic cells, and B cells in ARKO vs WT hearts post I/R. Taken together, our data suggests that deletion of AR protects I/R hearts by promoting increases in anti-inflammatory immune cells and paves the way for addressing immune cell-cardiomyocyte crosstalk mechanisms by which AR deletion protects from I/R injury.