Limited Regeneration Potential with Minimal Epicardial Progenitor Conversions in the Neonatal Mouse Heart after Injury

• Published in: Cell reports (Cambridge) Vol. 28; no. 1; pp. 190 - 201.e3
• Main Authors: Cai, Weibin, Tan, Jing, Yan, Jianyun, Zhang, Lu, Cai, Xiaoqiang, Wang, Haiping, Liu, Fang, Ye, Maoqing, Cai, Chen-Leng
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 02.07.2019; Elsevier
• Subjects: Animals; Animals, Newborn; Cell Differentiation - genetics; Cell Differentiation - physiology; Cell Lineage; cell lineage tracing; Coronary Vessels - cytology; Coronary Vessels - metabolism; Endothelial Cells - cytology; Endothelial Cells - metabolism; epicardial cells; Gene Knock-In Techniques; Heart - physiology; Heart Injuries - genetics; Heart Injuries - metabolism; heart regeneration; Mice; Myocytes, Cardiac - cytology; Myocytes, Cardiac - metabolism; neonatal mouse; Neovascularization, Physiologic; Pericardium - cytology; Pericardium - metabolism; Regeneration - genetics; Regeneration - physiology; Stem Cells - cytology; Stem Cells - metabolism; T-Box Domain Proteins - genetics; T-Box Domain Proteins - metabolism; epicardial cells; cell lineage tracing; neonatal mouse; heart regeneration
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2019.06.003

The regeneration capacity of neonatal mouse heart is controversial. In addition, whether epicardial cells provide a progenitor pool for de novo heart regeneration is incompletely defined. Following apical resection of the neonatal mouse heart, we observed limited regeneration potential. Fate-mapping of Tbx18MerCreMer mice revealed that newly formed coronary vessels and a limited number of cardiomyocytes were derived from the T-box transcription factor 18 (Tbx18) lineage. However, further lineage tracing with SM-MHCCreERT2 and Nfactc1Cre mice revealed that the new smooth muscle and endothelial cells are in fact derivatives of pre-existing coronary vessels. Our data show that neonatal mouse heart can regenerate but that its potential is limited. Moreover, although epicardial cells are multipotent during embryogenesis, their contribution to heart repair through “stem” or “progenitor” cell conversion is minimal after birth. These observations suggest that early embryonic heart development and postnatal heart regeneration are distinct biological processes. Multipotency of epicardial cells is significantly decreased after birth. [Display omitted] •Limited regeneration occurs in the neonatal mouse heart upon ventricular apex amputation•Progenitor cell differentiation from epicardium is very minimal during heart repair•New coronary vessels are generated through angiogenesis after injury The regeneration potential of the newborn mouse heart is controversial, and whether epicardial cells provide progenitors for coronary vascular regeneration is unclear. Cai et al. demonstrate a limited regeneration capacity of the neonatal heart upon injury. Epicardial cells do not convert into functional cardiac cells, including coronary vessels, during repair.