Chagasic cardiomyopathy (CCM) is caused by the protozoan Trypanosoma cruzi, and represents the third greatest tropical disease burden globally. There are an estimated >300,000 patients in the US and >10 million patients in endemic countries, and total annual cost of Chagas disease management is estimated at >8 billion US dollars. A common feature of chagasic and other cardiovascular diseases is the functional changes in mitochondria as an outcome of changes in expression of genes/proteins involved in maintaining the oxidative phosphorylation (OXPHOS) pathway and mitochondrial biogenesis. In this proposal, we will develop tools to capture the mitochondrial alterations as an indicator of cardiac disease susceptibility and efficacy (or toxicity) of a particular treatment in chagasic patients. For this, we will utilize microparticles (MPs) that are released as fragments from the plasma membrane of eukaryotic cells, and play selective roles in intercellular communication;and peripheral blood mononuclear cells (i.e. PBMCs) that carry the inherent genetic signature of the host, and reflect the in vivo state of the body. Using these easily available patient samples, we will test a novel hypothesis that MPs and PBMCs carry the specific signature of CCM progression and the treatment efficacy, and these signatures can be captured via changes in mitochondrial physiology and biogenesis in high-throughput in vitro screening assays. The major preliminary observations supporting our hypothesis include (1) DNA damage in cardiomyocytes and heart biopsies of chagasic patients is associated with compromised mitochondrial biogenesis and gene expression for OXPHOS pathway, (2) MPs from chagasic patients influenced the mitochondrial function and cell viability in in vitro assays, and (3) mitochondrial sensitivity to drugs is integrated within the context of whole cells. We will employ cutting edge experimental and high-throughput methodologies, established in the PI's laboratory, to determine (1) whether MPs carry the signature of in vivo changes in mt physiology and biogenesis and predict the molecular processes associated with CCM progression, and (2) whether mt-based high-throughput screening will capture the drugs'effects and will be useful in designing the patient-oriented treatment for CCM. The knowledge gained from the coordinated analysis and modeling of MP-induced mitochondrial responses in aim 1 and mitochondrial toxicity of drugs in aim 2 will lead to improved control and therapeutic treatment strategies for chagasic (and other cardiomyopathy) patients. Relevance and innovation: The innovation lies in the idea that our high-throughput approach will look at mitochondria at the DNA, RNA, protein and functional levels and develop a compendium of biomarkers valuable in personalized medicine, for first predicting the risk of cardiac disease progression, and then determining if a particular treatment will have adverse effects or be inefficacious for an individual. Importantly, the tools we will develop will be applicable to other chronic diseases where mitochondria plays a role (e.g., diabetes, Alzheimer, Parkinson, Huntington) and to testing the toxicity of environmental pollutants.
We will use iterative and complementary experimental and high-throughput methodologies to analyze, identify, quantify, model, and, ultimately, predict the mitochondrial processes that are prognostic of cardiovascular disease progression and drug efficacy.
|Tanowitz, Herbert B; Machado, Fabiana S; Spray, David C et al. (2015) Developments in the management of Chagas cardiomyopathy. Expert Rev Cardiovasc Ther 13:1393-409|