Soonpaa, Mark H.Lafontant, Pascal J.Reuter, SeanScherschel, John A.Srour, Edward F.Zaruba, Marc-MichaelRubart-von der Lohe, MichaelField, Loren J.2020-03-182020-03-182018-12-18Soonpaa, M. H., Lafontant, P. J., Reuter, S., Scherschel, J. A., Srour, E. F., Zaruba, M. M., ... & Field, L. J. (2018). Absence of cardiomyocyte differentiation following transplantation of adult cardiac-resident Sca-1+ cells into infarcted mouse hearts. Circulation, 138(25), 2963-2966. 10.1161/CIRCULATIONAHA.118.0353910009-7322https://hdl.handle.net/1805/22352Although several lines of evidence suggest that the glycosyl phosphatidylinositol-anchored cell surface protein Sca-1 marks cardiac-resident stem cells, a critical analysis of the literature raises some concerns regarding their cardiomyogenic potential.1 Here, isolated adult cardiac-resident Sca-1+ cells were engrafted into infarcted hearts and monitored for cardiomyogenic differentiation. Donor cells were prepared from ACT-EGFP; MHC-nLAC double-transgenic mice ([C57/Bl6J x DBA/2J]F1 genetic background; all procedures followed were in accordance with Institutional Guidelines). The ACT-EGFP transgene targets ubiquitous expression of an enhanced green fluorescent protein reporter, and the MHC-nLAC transgene targets cardiomyocyte-restricted expression of a nuclear-localized β-galactosidase reporter. Donor cell survival was monitored via EGFP fluorescence, while cardiomyogenic differentiation was monitored by reacting with the chromogenic β-galactosidase substrate 5-bromo-4-chloro-3-indolyl-β-D-galactoside (X-GAL), which gives rise to a blue product.2 Double-transgenic hearts were dispersed with Blendzyme and the resulting cells reacted with an APC-conjugated anti-Sca-1 antibody and a PE-conjugated cocktail of antibodies recognizing hematopoietic lineage markers.3 Sca-1+, EGFP+, lineage- cells were then isolated via fluorescence-activated cell sorting (FACS; characterization of the donor cells is provided in Figure 1A), and 100,000 cells were injected into the infarct border zone of non-transgenic [C57/Bl6J x DBA/2J]F1 mice immediately following permanent coronary artery occlusion.en-USPublisher PolicyStem cellsMyocardial infarctionMiceTransgenicCardiacMyocytesArticle