BACKGROUND AIMS: This study investigated whether neonatal rat cardiomyocytes (NRCM), when co-cultured, can induce transdifferentiation of either human mesenchymal stromal cells (MSC) or hematopoietic stem cells (HSC) into cardiomyocytes. Stem cells were obtained from patients with ischemic heart disease. METHODS: Ex vivo-expanded MSC or freshly isolated HSC were used to set-up a co-culture system between NRCM and MSC or HSC. 5-azacytidin (5-aza) or dimethylsulfoxide (DMSO) was used as differentiation-inducing factor. Co-cultured stem cells were separated from NRCM by flow sorting, and cardiac gene expression was analyzed by reverse transcriptase-polymerase chain reaction. Cellular morphology was analyzed by immunofluorescence and transmission electron microscopy (TEM). RESULTS: Co-culturing MSC induced expression of troponin T and GATA-4. However, no expression of alpha-actinin, myosin heavy chain or troponin I was detected. In the case of HSC, only expression of troponin T could be induced. Immunofluorescence and TEM confirmed the absence of sarcomeric organization in co-cultured MSC and HSC. Adding 5-aza or DMSO to the co-cultures did not influence differentiation. CONCLUSIONS: This in vitro co-culture study obtained no convincing evidence of transdifferentiation of either MSC or HSC into functional cardiomyocytes. Nevertheless, induction of troponin T was observed in MSC and HSC, and GATA-4 in MSC. However, no morphologic changes could be detected by immunofluorescence or by TEM. These data could explain why only limited functional improvement was reported in clinical stem cell trials.
BACKGROUND AIMS: This study investigated whether neonatal rat cardiomyocytes (NRCM), when co-cultured, can induce transdifferentiation of either human mesenchymal stromal cells (MSC) or hematopoietic stem cells (HSC) into cardiomyocytes. Stem cells were obtained from patients with ischemic heart disease. METHODS: Ex vivo-expanded MSC or freshly isolated HSC were used to set-up a co-culture system between NRCM and MSC or HSC. 5-azacytidin (5-aza) or dimethylsulfoxide (DMSO) was used as differentiation-inducing factor. Co-cultured stem cells were separated from NRCM by flow sorting, and cardiac gene expression was analyzed by reverse transcriptase-polymerase chain reaction. Cellular morphology was analyzed by immunofluorescence and transmission electron microscopy (TEM). RESULTS: Co-culturing MSC induced expression of troponin T and GATA-4. However, no expression of alpha-actinin, myosin heavy chain or troponin I was detected. In the case of HSC, only expression of troponin T could be induced. Immunofluorescence and TEM confirmed the absence of sarcomeric organization in co-cultured MSC and HSC. Adding 5-aza or DMSO to the co-cultures did not influence differentiation. CONCLUSIONS: This in vitro co-culture study obtained no convincing evidence of transdifferentiation of either MSC or HSC into functional cardiomyocytes. Nevertheless, induction of troponin T was observed in MSC and HSC, and GATA-4 in MSC. However, no morphologic changes could be detected by immunofluorescence or by TEM. These data could explain why only limited functional improvement was reported in clinical stem cell trials.
Authors: James D Richardson; Adam J Nelson; Andrew C W Zannettino; Stan Gronthos; Stephen G Worthley; Peter J Psaltis Journal: Stem Cell Rev Rep Date: 2013-06 Impact factor: 5.739
Authors: Georg Siegel; Petra Krause; Stefanie Wöhrle; Patrick Nowak; Miriam Ayturan; Torsten Kluba; Bernhard R Brehm; Birgid Neumeister; David Köhler; Peter Rosenberger; Lothar Just; Hinnak Northoff; Richard Schäfer Journal: Stem Cells Dev Date: 2012-03-13 Impact factor: 3.272
Authors: Mani T Valarmathi; John W Fuseler; Richard L Goodwin; Jeffrey M Davis; Jay D Potts Journal: Biomaterials Date: 2011-02-01 Impact factor: 12.479
Authors: S Windmolders; L Willems; A Daniëls; L Linsen; Y Fanton; M Hendrikx; R Koninckx; J-L Rummens; K Hensen Journal: Cell Prolif Date: 2015-01-29 Impact factor: 6.831