The wound-healing response of the human body to injuries involves induction of fibrosis, which is a dynamic scarring process. When fibrosis occurs in internal organs, it is indisputably a major cause of morbidity and mortality worldwide. The overall goal of the proposed research is to develop an inhibitor of galectin-3 as a drug that will limit excess fibrosis and adverse remodeling of the heart after myocardial infarction (heart attack) and, thereby, improve patient outcomes and reduce mortality. In the Phase I project, we will test the feasibility of using a dominant-negative galectin-3 inhibitor, termed galectin-3C (Ga-3C), to limit adverse remodeling and improve cardiac function after myocardial infarction (MI). MI is the most common cause of cardiac morbidity and mortality in the western world, and is responsible for 1 in 6 deaths (~400,000) in the US per year. Galectin- 3 is one of the galectin family of lectins that has homologous carbohydrate recognition domains and characteristic affinity for ?-galactosides. There are compelling in vitro and animal data showing that galectin-3 is critical for organ fibrosis and specifically fibrosis in the heart. In humans, plasma levels of galectin-3 are approved by the US FDA and in Europe as a biomarker for risk of mortality in those with chronic heart failure (www.galectin-3.com) that is independent of severity of heart failure or renal dysfunction. The Phase I Specific Aims are as follows: 1. To determine the effect of Gal-3C on the TGF- ?1-induced differentiation of primary cardiac fibroblasts to myofibroblasts and on their resulting collagen secretion. 2. To determine an effective dose of Gal-3C to reduce fibrosis in a rat ischemia/reperfusion model of MI.
Sub aim 2 A. We will perform an initial dose-range finding study using osmotic pumps to deliver Gal-3C to rats after surgical induction of MI. Levels of collagen in the heart wil be analyzed as the main endpoint.
Sub aim 2 B. We will test two different doses of Gal-3C administered over days 1-7 post-MI to determine its effect on 1 month post-MI cardiac function. 3. To determine if immediate or delayed treatment with Gal-3C leads to better cardiac function.
Sub aim 3 A. We will assay serum collected at different times from the rats in Subaim 2B to establish the time-course of galectin-3 appearance, to determine the time window for Gal-3C delivery.
Sub aim 3 B. We will repeat the Gal-3C delivery experiment from Aim 2 with delayed treatment timing based on what we learn in Subaim 3A. In Phase II, we plan to test a sustained-release form or a Gal-3C construct with a longer circulating half-life, conduct studies to refine post-MI treatment in animal models, and focus on toxicology, pharmacokinetics, and GMP production towards filing an IND application with the FDA and initiation of Phase I human clinical trials.
Myocardial infarction (MI) is the most common cause of cardiac morbidity and mortality in the western world, and is responsible for 1 out of 6 deaths (~400,000) in the US per year. Currently, the main mortality associated with coronary events is due to subsequent heart failure. This project aims to limit excess fibrosis and adverse remodeling after MI and is expected to lead to improved outcomes and have a major impact on the mortality associated with cardiovascular disease.