title: Regulation of seminiferous tubule-associated stem Leydig cells in adult rat testes.
abstract: Testicular Leydig cells are the primary source of testosterone in males. Adult Leydig cells have been shown to arise from stem cells present in the neonatal testis. Once established, adult Leydig cells turn over only slowly during adult life, but when these cells are eliminated experimentally from the adult testis, new Leydig cells rapidly reappear. As in the neonatal testis, stem cells in the adult testis are presumed to be the source of the new Leydig cells. As yet, the mechanisms involved in regulating the proliferation and differentiation of these stem cells remain unknown. We developed a unique in vitro system of cultured seminiferous tubules to assess the ability of factors from the seminiferous tubules to regulate the proliferation of the tubule-associated stem cells, and their subsequent entry into the Leydig cell lineage. The proliferation of the stem Leydig cells was stimulated by paracrine factors including Desert hedgehog (DHH), basic fibroblast growth factor (FGF2), platelet-derived growth factor (PDGF), and activin. Suppression of proliferation occurred with transforming growth factor β (TGF-β). The differentiation of the stem cells was regulated positively by DHH, lithium- induced signaling, and activin, and negatively by TGF-β, PDGFBB, and FGF2. DHH functioned as a commitment factor, inducing the transition of stem cells to the progenitor stage and thus into the Leydig cell lineage. Additionally, CD90 (Thy1) was found to be a unique stem cell surface marker that was used to obtain purified stem cells by flow cytometry.
authors.affiliation: Center for Scientific Research, Institute of Reproductive Biomedicine, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China;
authors.forename: Xiaoheng
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205; Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Jiamusi University, Jiamusi, Heilongjiang 154000, China;
authors.forename: Zhao
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205; Department of Urology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, China.
authors.forename: Zhenming
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Center for Scientific Research, Institute of Reproductive Biomedicine, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China; Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205;
authors.forename: Jingjing
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205; Department of Urology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, China.
authors.forename: Yuxi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205;
authors.forename: Chenhao
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205;
authors.forename: Jinyong
authors.initials: J
authors.lastname: Chung
authors.affiliation: Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205;
authors.forename: Janet
authors.initials: J
authors.lastname: Folmer
authors.affiliation: Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205;
authors.forename: June
authors.initials: J
authors.lastname: Liu
authors.affiliation: Center for Scientific Research, Institute of Reproductive Biomedicine, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China; hchen13@jhu.edu r_ge@yahoo.com lianqingquanmz@163.com.
authors.forename: Qingquan
authors.initials: Q
authors.lastname: Lian
authors.affiliation: Center for Scientific Research, Institute of Reproductive Biomedicine, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China; hchen13@jhu.edu r_ge@yahoo.com lianqingquanmz@163.com.
authors.forename: Renshan
authors.initials: R
authors.lastname: Ge
authors.affiliation: Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205;
authors.forename: Barry R
authors.initials: BR
authors.lastname: Zirkin
authors.affiliation: Center for Scientific Research, Institute of Reproductive Biomedicine, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China; Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205; hchen13@jhu.edu r_ge@yahoo.com lianqingquanmz@163.com.
authors.forename: Haolin
authors.initials: H
authors.lastname: Chen
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000818:Animals; D000077214:Becaplermin; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002469:Cell Separation; D002478:Cells, Cultured; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000378:metabolism; D003893:Desmin / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005434:Flow Cytometry; D007985:Leydig Cells / Q000378:metabolism*; D008297:Male; D008856:Microscopy, Fluorescence; D020574:Proto-Oncogene Proteins c-sis / Q000494:pharmacology; D011914:Rats, Inbred BN; D012671:Seminiferous Tubules / Q000378:metabolism*; D013234:Stem Cells / Q000378:metabolism*; D013737:Testis / Q000166:cytology / Q000378:metabolism*; D018800:Thy-1 Antigens / Q000378:metabolism; D046509:Tissue Culture Techniques
chemical_list: D015096:3-Hydroxysteroid Dehydrogenases; D000199:Actins; D000077214:Becaplermin; D002786:Cholesterol Side-Chain Cleavage Enzyme; D003893:Desmin; D016222:Fibroblast Growth Factor 2; D020574:Proto-Oncogene Proteins c-sis; D018800:Thy-1 Antigens; C498862:Acta2 protein, rat
keywords: CD90; DHH; Leydig cell; stem cell; testosterone