Serum Proteomic Signature of Human Chagasic Patients for the Identification of Novel Potential Protein Biomarkers of Disease

Abstract

Chagas disease is initiated upon infection by Trypanosoma cruzi. Among the health consequences is a decline in heart function, and the pathophysiological mechanisms underlying this manifestation are not well understood. To explore the possible mechanisms, we employed IgY LC10 affinity chromatography in conjunction with ProteomeLab PF2D and two-dimensional gel electrophoresis (2D-GE) to resolve the proteome signature of high-abundance and low-abundance serum proteins in chagasic patients. MALDI-TOF MS/MS analysis yielded 80 and 14 differentially expressed proteins associated with cardiomyopathy of chagasic and other etiologies, respectively. The extent of oxidative stress-induced carbonyl modifications of the differentially expressed proteins (n=26) was increased and coupled with a depression of antioxidant proteins. Functional annotation of the top networks developed by Ingenuity Pathway Analysis of proteome database identified dysregulation of inflammation/acute phase response signaling and lipid metabolism relevant to production of prostaglandins and arachidonic acid in chagasic patients. Overlay of the major networks identified prothrombin and plasminogen at a nodal position with connectivity to proteome signature indicative of heart disease (i.e. thrombosis, angiogenesis, vasodilatation of blood vessels or the aorta, increased permeability of blood vessel and endothelial tubes), and inflammatory responses (e.g., platelet aggregation, complement activation, phagocytes activation and migration). The detection of cardiac proteins (myosin light chain 2, myosin heavy chain 11) and increased levels of vinculin and plasminogen provided a comprehensive set of biomarkers of cardiac muscle injury and development of clinical Chagas disease in human patients. These results provide an impetus for biomarker validation in large cohorts of clinically characterized chagasic patients