title: Progenitor cells of the testosterone-producing Leydig cells revealed.
abstract: The cells responsible for production of the male sex hormone testosterone, the Leydig cells of the testis, are post-mitotic cells with neuroendocrine characteristics. Their origin during ontogeny and regeneration processes is still a matter of debate. Here, we show that cells of testicular blood vessels, namely vascular smooth muscle cells and pericytes, are the progenitors of Leydig cells. Resembling stem cells of the nervous system, the Leydig cell progenitors are characterized by the expression of nestin. Using an in vivo model to induce and monitor the synchronized generation of a completely new Leydig cell population in adult rats, we demonstrate specific proliferation of vascular progenitors and their subsequent transdifferentiation into steroidogenic Leydig cells which, in addition, rapidly acquire neuronal and glial properties. These findings, shown to be representative also for ontogenetic Leydig cell formation and for the human testis, provide further evidence that cellular components of blood vessels can act as progenitor cells for organogenesis and repair.
authors.affiliation: Institute of Anatomy, University of Hamburg, Germany. davidoff@uke.uni-hamburg.de
authors.forename: Michail S
authors.initials: MS
authors.lastname: Davidoff
authors.forename: Ralf
authors.initials: R
authors.lastname: Middendorff
authors.forename: Grigori
authors.initials: G
authors.lastname: Enikolopov
authors.forename: Dieter
authors.initials: D
authors.lastname: Riethmacher
authors.forename: Adolf F
authors.initials: AF
authors.lastname: Holstein
authors.forename: Dieter
authors.initials: D
authors.lastname: Müller
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D019070:Cell Lineage / Q000502:physiology; D007381:Intermediate Filament Proteins / Q000378:metabolism; D007985:Leydig Cells / Q000166:cytology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D009457:Neuroglia / Q000166:cytology / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D038081:Organogenesis / Q000502:physiology; D020286:Pericytes / Q000166:cytology / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D013737:Testis / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D013739:Testosterone / Q000096:biosynthesis*; D013997:Time Factors; D014945:Wound Healing / Q000502:physiology
chemical_list: D007381:Intermediate Filament Proteins; C577484:NES protein, human; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; C577486:Nes protein, rat; D064231:Nestin; D013739:Testosterone