title: Generation of functional cardiomyocytes from adult mouse spermatogonial stem cells.
abstract: Stem cell-based therapy is a promising approach for the treatment of heart failure. Adult stem cells with the pluripotency of embryonic stem cells (ESCs) would be an ideal cell source. Recently, we reported the successful establishment of multipotent adult germline stem cells (maGSCs) from mouse testis. These cultured maGSCs show phenotypic characteristics similar to ESCs and can spontaneously differentiate into cells from all 3 germ layers. In the present study, we used the hanging drop method to differentiate maGSCs into cardiomyocytes and analyzed their functional properties. Differentiation efficiency of beating cardiomyocytes from maGSCs was similar to that from ESCs. The maGSC-derived cardiomyocytes expressed cardiac-specific L-type Ca(2+) channels and responded to Ca(2+) channel-modulating drugs. Cx43 was expressed at cell-to-cell contacts in cardiac clusters, and fluorescence recovery after photobleaching assay showed the presence of functional gap junctions among cardiomyocytes. Action potential analyses demonstrated the presence of pacemaker-, ventricle-, atrial-, and Purkinje-like cardiomyocytes. Stimulation with isoproterenol resulted in a significant increase in beating frequency, whereas the addition of cadmium chloride abolished spontaneous electrical activity. Confocal microscopy analysis of intracellular Ca(2+) in maGSC-derived cardiomyocytes showed that calcium increased periodically throughout the cell in a homogenous fashion, pointing to a fine regulated Ca(2+) release from intracellular Ca(2+) stores. By using line-scan mode, we found rhythmic Ca(2+) transients. Furthermore, we transplanted maGSCs into normal hearts of mice and found that maGSCs were able to proliferate and differentiate. No tumor formation was found up to 1 month after cell transplantation. Taken together, we believe that maGSCs provide a new source of distinct types of cardiomyocytes for basic research and potential therapeutic application.
authors.affiliation: Department of Cardiology and Pneumology, Georg-August-University of Göttingen, Göttingen, Germany.
authors.forename: Kaomei
authors.initials: K
authors.lastname: Guan
authors.forename: Stefan
authors.initials: S
authors.lastname: Wagner
authors.forename: Bernhard
authors.initials: B
authors.lastname: Unsöld
authors.forename: Lars S
authors.initials: LS
authors.lastname: Maier
authors.forename: Diana
authors.initials: D
authors.lastname: Kaiser
authors.forename: Bernhard
authors.initials: B
authors.lastname: Hemmerlein
authors.forename: Karim
authors.initials: K
authors.lastname: Nayernia
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Engel
authors.forename: Gerd
authors.initials: G
authors.lastname: Hasenfuss
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000096:biosynthesis / Q000187:drug effects; D020013:Calcium Signaling / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D018031:Connexin 43 / Q000096:biosynthesis; D005260:Female; D036681:Fluorescence Recovery After Photobleaching; D017629:Gap Junctions / Q000378:metabolism; D006085:Graft Survival; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D039902:Multipotent Stem Cells / Q000166:cytology* / Q000637:transplantation; D009206:Myocardium / Q000166:cytology; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D013093:Spermatogonia / Q000166:cytology* / Q000637:transplantation; D033581:Stem Cell Transplantation
chemical_list: D000318:Adrenergic beta-Agonists; D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D018031:Connexin 43