Abstract 17078: Proteome-wide Turnover Dynamics Analyses in Human and Mouse Models of Heart Failure
Protein quality control is increasingly recognized as a key regulatory mechanism in cardiac remodeling, but the kinetics of the protein synthesis degradation cycle remains poorly understood due to the lack of technology. Accordingly, we devised a technological platform that integrates stable isotope labeling by D2O, mass spectrometry, and software to investigate proteome-wide turnover kinetics in vivo. We demonstrate that direct interrogation of protein turnover kinetics reveals drivers of cardiac remodeling in mice, and apply the approach to human studies.
We first utilized our platform to examine the dynamically changing proteome in cardiac remodeling in mice. Our method deduced the in vivo turnover rates of >1500 proteins in normal mouse hearts and those having undergone cardiac remodeling following an established model of isoproterenol administration. Among those with the most drastically increased turnover in the diseased hearts are proteins implicated in cardiac remodeling, hypertrophy, and heart failure, including annexin II/V, connexin 43, and proteins in the ERK signaling pathway; as well as novel protein targets. We detected only minute changes in their protein abundance, suggesting changes in protein kinetics underpin the inner workings of cardiac myocytes in a physiologically relevant setting.
We have also successfully translated this methodology to human studies. The clinical procedure encompasses a safe and effective labeling scheme, tissue procurement, analysis by high-resolution mass spectrometry, and mathematical modeling. Two healthy human subjects were enrolled in a phase I study and were administered D2O daily for a duration of 14 days to achieve an enrichment of ~2% deuterium in body water as determined by GC-MS. For the first time, we obtained in a single study the turnover rates of 134 plasma proteins including indicators of cardiovascular functions, constituting to our knowledge the largest human protein turnover dataset to-date. Taken together, we created a new approach that integrates analytical chemistry with computational modeling to examine protein dynamics in an in vivo mouse model of heart disease and in human, laying foundations for kinetics studies in human pathogenesis.
- © 2013 by American Heart Association, Inc.