Comparative iTRAQ Proteomics Identified Myocardium Proteins Associated with Hypoxia of Yak

摘要

Background: Yaks inhabit high-altitude are well-adapted to the hypoxic environments.Though, the mechanisms involved in regulatory myocardial protein expression at high-altitude werenot completely understood.Objective: To revel the molecular mechanism of hypoxic adaptation in yak, here we have applied comparativemyocardial proteomics in between yak and cattle by isobaric Tag for Relative and AbsoluteQuantitation (iTRAQ) labelling.Method: To understand the systematic protein expression variations in myocardial tissues that explainthe hypoxic adaptation in yak, we have performed iTRAQ analysis combined with Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). Bioinformatics analysis was performed to find theassociation of these Differentially Expressed Proteins (DEPs) in different functions and pathways. Proteinto protein interaction was analyzed by using STRING database.Result: 686 Differentially Expressed Proteins (DEPs) were identified in yak with respect to cattle.From which, 480 DEPs were up-regulated and 206 were down-regulated in yak. Upregulated expressionof ASB4, STAT, HRG, RHO and TSP4 in yak may be associated with angiogenesis, cardiovasculardevelopment, response to pressure overload to heart and regulation of myocardial contraction in responseto increased oxygen tension. The up-regulation of mitochondrial proteins, ACAD8, GPDH-M,PTPMT1, and ALDH2, may have contributed to oxidation within mitochondria, hypoxia-induced cellmetabolism and protection of heart against cardiac ischemic injuries. Further, the upregulated expressionof SAA1, PTX, HP and MBL2 involved in immune response potentially helpful in myocardialprotection against ischemic injuries, extracellular matrix remodeling and free heme neutralization/clearance in oxygen-deficient environment.Conclusion: Therefore, the identification of these myocardial proteins in will be conducive to investigationof the molecular mechanisms involved in hypoxic adaptations of yaks at high-altitude condition.