UvA-DARE (Digital Academic Repository) The potency of human testicular stem cells Chikhovskaya, J.V. Link to publication

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1 UvA-DARE (Digital Academic Repository) The potency of human testicular stem cells Chikhovskaya, J.V. Link to publication Citation for published version (APA): Chikhovskaya, J. V. (2013). The potency of human testicular stem cells. General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. UvA-DARE is a service provided by the library of the University of Amsterdam ( Download date: 20 Apr 2019

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4 In this thesis, we evaluate the stem cell state of cells present in primary human testicular cell cultures as well as their origin and relation to germ or somatic lineages within testicular tissue. We conclude that human testis-derived embryonic stem celllike (htes-like) colonies arising in primary testicular cell cultures do not have pluripotent characteristics and do not arise due to spontaneous in vitro transition of propagated spermatogonia, but are multipotent mesenchymal somatic progenitors originated from the testis during isolation. Furthermore, we focused on somatic progenitors present in the primary testicular cell cultures and described for first time a method to isolate the uncommitted human LC stem cell based on their surface markers expression profile. Although the methods of expansion and differentiation of these isolated uncommitted LC stem cells need further improvement, the described method could provide the basis for stem cell therapy implying autotransplantation of autologus LC progenitors to overcome hypogonadism occurring after high dose chemotherapy and other conditions requiring androgen replacement. Chapter I of this thesis provides an overview of the main stem cell types present in testicular tissue and introduces the main questions and aim of the study. In Chapter II, the basic features of propagated htes-like cells in accordance with general guidelines of human ESCs culture are described. The differentiation abilities of these cells are compared with the differentiation potential of human blastocyst-derived ESCs and ips cells. The obtained results suggested that htes-like cells expanded from colonies spontaneously arising in primary testicular stem cells do not possess the main features typical for pluripotent stem cells i.e. human blastocyst-derived ESC and ips. The inability to form teratomas allowed to define the htes-like cells as a multipotent rather than a pluripotent stem cell population. Chapter III represents further investigation of htes-like cell properties in order to elucidate their exact stem cell state. Irrespective from conditions chosen for propagation, htes-like cells showed consistent global gene expression profiles, surface markers expression and efficient differentiation towards mesodermal lineages. We conclude that htes-like cells are a multipotent cell population with characteristics closely resembling mesenchymal stem cells, so called multipotent stromal cells (MSCs). 151

5 Chapter IV focuses on the origin of multipotent progenitors derived from human testicular tissue and designates them as multipotent human testis derived stem cells (mhtscs) rather than ES-like progenitors. The origin of mhtscs in relation to germ or somatic lineages present in adult human testicular tissue was investigated on testis tissues of individuals with normal complete spermatogenesis and with Sertoli cell only syndrome. MhtSCs originate from the subpopulation of somatic uncommitted MSC-like progenitors present in primary testicular cultures and not from germline stem cells. Therefore, these mhtscs are not formed by incomplete reprogramming of SSCs in vitro. In Chapter V we explore the properties of somatic stem cell derived from human testicular tissue and investigated the isolation, propagation and differentiation of adult LC progenitors. We conclude that the population of testicular MSCs harbors the subset of adult LC stem cell which could be isolated on base of their surface markers expression profile, propagated and differentiated in vitro. The Chapter VI represents the general discussion and proposes possible research lines for further studies required for potential clinical application. 152