Rationale—Cardiac progenitor cells are an attractive cell type for tissue regeneration but their mechanism for myocardial remodeling is still unclear.

Objective—This investigation determines how chronological age influences the phenotypic characteristics and the secretome of human cardiac progenitor cells (CPCs), as well as their potential to recover injured myocardium.

Methods and Results—Adult (aCPCs) and neonatal (nCPCs) cells were derived from patients more than 40 years or less than one month of age, respectively, and their functional potential was determined in a rodent myocardial infarction (MI) model. A more robust in vitro proliferative capacity of nCPCs, compared to aCPCs, correlated with significantly greater myocardial recovery mediated by nCPCs in vivo. Strikingly, a single injection of nCPC-derived total conditioned media (nTCM) was significantly more effective than nCPCs, aCPC-derived TCM (aTCM), or nCPC-derived exosomes in recovering cardiac function, stimulating neovascularization, and promoting myocardial remodeling. High resolution accurate mass spectrometry (HRAMS) with reverse phase liquid chromatography fractionation and mass spectrometry (LC-MS/MS) was employed to identify proteins in the secretome of aCPCs and nCPCs, and literature-based networking software identified specific pathways affected by the secretome of CPCs in the setting of MI. Examining the TCM, we quantified changes in the expression pattern of 804 proteins in nTCM and 513 proteins in aTCM. Literature-based proteomic network analysis identified that 46 and 6 canonical signaling pathways were significantly targeted by nTCM and aTCM, respectively. One leading candidate pathway is heat shock factor-1 (HSF-1), potentially affecting 8 identified pathways for nTCM but none for aTCM. To validate this prediction, we demonstrated that modulation of HSF-1 by knockdown in nCPCs or overexpression in aCPCs significantly altered the quality of their secretome.

Conclusions—In conclusion, a deep proteomic analysis revealed both detailed and global mechanisms underlying the chronological age-based differences in the ability of CPCs to promote myocardial recovery via the components of their secretome.

Sudhish Sharma1, Rachana Mishra1, Grace E Bigham1, Brody Wehman1, Mohd M. Khan2, Huichun Xu3, Progyaparamita Saha1, Young Ah Goo2, Srinivasa Raju Datla1, Ling Chen4, Mohan E. Tulapurkar7, Bradley S Taylor1, Peixin Yang5, Sotirios Karathanasis6, David R. Goodlett2, and Sunjay Kaushal11Division of Cardiac Surgery, School of Medicine, University of Maryland Baltimore, Maryland 2Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland’ 3Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine 4Department of Physiology and Medicine, School of Medicine, University of Maryland Baltimore, Maryland 5Department of OB/GYN & Reproductive Science, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine 6Cardiovascular and Metabolic Diseases, Innovative Medicines Biotech Unit MedImmune, Inc. Gaithersburg, Maryland 7Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD

Published in final edited form as:Circ Res. 2017 March 03; 120(5): 816–834. doi:10.1161/CIRCRESAHA.116.309782.