title: Lost in transdifferentiation.
abstract: What are the true origins of the smooth muscle cells (SMCs) present in the intimal lesions of transplant arteriosclerosis? A new study in the JCI shows that Sca-1(+) cells purified from the mouse aortic root can migrate through an irradiated vein graft to the neointima of the vessel and transdifferentiate to express the early SMC differentiation marker gene SM22. Do Sca-1(+) cells transdifferentiate into SMC-like cells, or is activation of SMC marker genes a consequence of fusion of these cells with preexisting SMCs, a possibility raised by results of studies of adult stem cells in animal models of liver regeneration ? Or could this be bona fide transdifferentiation that recapitulates the pathologic processes in humans?
authors.affiliation: Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908, USA.
authors.forename: Mark H
authors.initials: MH
authors.lastname: Hoofnagle
authors.forename: Brian R
authors.initials: BR
authors.lastname: Wamhoff
authors.forename: Gary K
authors.initials: GK
authors.lastname: Owens
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D001161:Arteriosclerosis / Q000473:pathology; D001854:Bone Marrow Cells / Q000166:cytology; D002454:Cell Differentiation; D002459:Cell Fusion; D019070:Cell Lineage; D002465:Cell Movement; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005819:Genetic Markers; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D009124:Muscle Proteins / Q000235:genetics; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism / Q000637:transplantation*; D014019:Tissue Donors; D014184:Transplantation, Homologous; D017539:Tunica Intima / Q000473:pathology; D014680:Veins / Q000528:radiation effects / Q000637:transplantation*
chemical_list: D005819:Genetic Markers; D009124:Muscle Proteins