PNA5, a Novel Glycosylated Angiotensin 1-7 Treatment Improves Infarct Size and Fibrotic Remodeling in Ischemic Reperfusion Injury

Abstract

Background: Reperfusion during an acute ischemic event is of paramount importance to rescue cardiac tissue. Paradoxically, reperfusion of the ischemic tissue promotes further cardiac injury. Increased reactive oxidative species (ROS) and inflammation contribute to ischemic reperfusion injury (IR). PNA5, a glycosylated analog of angiotensin-(1-7), decreases ROS and inflammation. The purpose of this study is to indicate if PNA5 treatment has the ability to reduce infarct (IN) size and improve cardiac remodeling in IR. We hypothesize that PNA5 will improve fibrosis and diminish IN size in IR. Methods: 3-month-old male mice (C57BI/6J) underwent IR surgery. Mice were anesthetized and the left anterior descending artery was litigated for 45 minutes. Ischemic areas were then reperfused. Mice were immediately injected with PNA5 (subcutaneously s.c. at 100μg/kg, n=11) or with saline as control (n=11). Injections were continued daily with PNA5 or saline for 8-weeks. At the end of treatment, mice were sacrificed. Upon sacrifice, hearts were re-ligated and perfused with Evans Blue to identify the areas at risk (AAR). Hearts were stained with 2-3-4-triphenyltetrazolium chloride to show IN area. IN size and AAR were determined using Image J. Paraffn-embedded hearts were stained with Picrosirius Red for fibrosis. Fibrosis was measured as a ratio of collagen to total tissue area for 17 regions in the left ventricle (LV). Values are represented as mean ± standard error of mean. Results: PNA5-treated mice IN size was significantly decreased compared to saline-treated mice. (IN/AAR: IR-Saline 0.17± 0.02; PNA5 0.10± 0.01, p=0.005; IN/LV: IR-Saline 0.08± 0.01; PNA5 0.05±0.01; p=0.002, student’s T-test). PNA5 reduced fibrosis in the LV compared to IR-saline mice Conclusions: These results indicate PNA5 as a potential therapeutic treatment for IR as it improves IN size and fibrotic remodeling in IR. [Formula: see text] Supported by NIA U01AG066623 to MH. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.