期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2012
卷号：109
期号：33
页码：13380-13385
DOI：10.1073/pnas.1208114109
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We examined the myogenic response to infarction in neonatal and adult mice to determine the role of c-kit+ cardiovascular precursor cells (CPC) that are known to be present in early heart development. Infarction of postnatal day 1-3 c-kitBAC-EGFP mouse hearts induced the localized expansion of (c-kit)EGFP+ cells within the infarct, expression of the c-kit and Nkx2.5 mRNA, myogenesis, and partial regeneration of the infarction, with (c-kit)EGFP+ cells adopting myogenic and vascular fates. Conversely, infarction of adult mice resulted in a modest induction of (c-kit)EGFP+ cells within the infarct, which did not express Nkx2.5 or undergo myogenic differentiation, but adopted a vascular fate within the infarction, indicating a lack of authentic CPC. Explantation of infarcted neonatal and adult heart tissue to scid mice, and adoptive transfer of labeled bone marrow, confirmed the cardiac source of myogenic (neonate) and angiogenic (neonate and adult) cells. FACS-purified (c-kit)EGFP+/(MHC)mCherry- (noncardiac) cells from microdissected infarcts within 6 h of infarction underwent cardiac differentiation, forming spontaneously beating myocytes in vitro; cre/LoxP fate mapping identified a noncardiac population of (c-kit)EGFP+ myocytes within infarctions, indicating that the induction of undifferentiated precursors contributes to localized myogenesis. Thus, adult postinfarct myogenic failure is likely not due to a context-dependent restriction of precursor differentiation, and c-kit induction following injury of the adult heart does not define precursor status.
