DOCSLIB.ORG

Regulation of Germ Line Stem Cell Homeostasis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Regulation of Germ Line Stem Cell Homeostasis Anim. Reprod., v.12, n.1, p.35-45, Jan./Mar. 2015 Regulation of germ line stem cell homeostasis T.X. Garcia, M.C. Hofmann1 Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas MD Anderson Cancer Center, Houston, TX, USA. Abstract Blanpain and Fuchs, 2009; Rossi et al.., 2011; Arwert et al.., 2012). Proper regulation of stem cell fate is Mammalian spermatogenesis is a complex therefore critical to maintain adequate cell numbers in process in which spermatogonial stem cells of the testis health and diseases. Accumulating evidence suggests (SSCs) develop to ultimately form spermatozoa. In the that stem cells behavior is regulated by both seminiferous epithelium, SSCs self-renew to maintain extracellular signals from their microenvironment, or the pool of stem cells throughout life, or they niche, and intrinsic signals within the cells. Using differentiate to generate a large number of germ cells. A diverse model organisms, much work has been done to balance between SSC self-renewal and differentiation is understand how the niche controls stem cell self- therefore essential to maintain normal spermatogenesis renewal and differentiation and how in turn stem cells and fertility. Stem cell homeostasis is tightly regulated influence their environment. This mini-review focuses by signals from the surrounding microenvironment, or on recent findings pertaining to germ cell development SSC niche. By physically supporting the SSCs and and the relationship between spermatogonial stem cells providing them with these extrinsic molecules, the of the testis and their niche. Sertoli cell is the main component of the niche. Earlier studies have demonstrated that GDNF and CYP26B1, Development of the male germ line produced by Sertoli cells, are crucial for self-renewal of the SSC pool and maintenance of the undifferentiated In the mouse, the germ line originates from a state. Down-regulating the production of these small population of primordial germ cells (PGCs), molecules is therefore equally important to allow germ which arise from the pluripotent epiblast during cell differentiation. We propose that NOTCH signaling gastrulation and are specified by BMP signaling at in Sertoli cells is a crucial regulator of germ cell fate by embryonic day 6.5 (E6.5; Ewen and Koopman, 2010). counteracting these stimulatory factors to maintain stem PGCs proliferate, migrate through the hindgut and cell homeostasis. Dysregulation of this essential niche colonize the genital ridges between E7.5 and E11. Once component can lead by itself to sterility or facilitate in the developing gonads, PGCs stop proliferating and testicular cancer development. initially develop according to cues based on the surrounding somatic cells. For example, studies have Keywords: germ cell homeostasis, NOTCH signaling, shown that irrespectively of their sex, germ cells will Sertoli cells, spermatogonial stem cell niche, enter meiosis if they reside in a developing ovary, but spermatogonial stem cells. not in a developing testis (Evans et al., 1977; Adams and McLaren, 2002), and that only subsequent gamete Introduction differentiation depends on the sex of the germ cells. In the developing ovary, between E12.5 and E14.5, Stem cells are immature, undifferentiated cells meiosis entry is signaled by retinoic acid (RA), a that are able to self-renew to maintain their own pool, powerful morphogen provided by the mesonephros but also to differentiate into specialized cell types that (Rhinn and Dolle, 2012; Feng et al., 2014). In the will ultimately perform a biological function. In the developing testis, meiosis cannot proceed because of the embryo and fetus, stem cell activity is critical for organ activity of the enzyme CYP26B1, produced by Sertoli development and growth. In adults, stem cells are and interstitial cells, which catalyzes the oxidization of essential for the maintenance, repair and regeneration of RA into inactive metabolites (White et al., 2000). many tissues. In particular, a pool of actively self- Therefore once in the gonads, male PGCs, now called renewing stem cells is necessary to sustain prospermatogonia, or gonocytes, do not further hematopoiesis in the bone marrow, to regenerate the differentiate due to depleted levels of RA and instead intestinal epithelium and to maintain spermatogenesis in undergo mitotic arrest. They re-enter the cell cycle at the seminiferous tubules, since in all these tissues postnatal day 3 (P3), then migrate to the basement differentiated cells are eliminated and must be membrane of the seminiferous epithelium to become replenished throughout life (Oatley and Brinster, 2008; spermatogonial stem cells (SSCs). _________________________________________ 1Corresponding author: [email protected] Phone: +1-713-745-2009; Fax: +1-713-563-7755 Received: August 19, 2014 Accepted: September 8, 2014 Garcia and Hofmann. Germ line stem cell homeostasis. SSCs self-renew throughout life to maintain a This step is considered an amplification step that pool of undifferentiated cells that are at the origin of increases the number of progenitors, and Asingle, Apaired spermatogenesis and ensure the permanent production of and Aaligned are often referred to as undifferentiated sperm (de Rooij and Griswold, 2012; Fig. 1). SSCs are spermatogonia (de Rooij and Russell, 2000). Aaligned cells single cells (Asingle spermatogonia, As) that are not will further differentiate into type A1-A4 spermatogonia connected by intercellular bridges like the other more and B spermatogonia, which finally divide to form mature germ cells (Dym and Fawcett, 1971; Huckins, primary spermatocytes. Throughout this postnatal germ 1971; de Rooij and Russell, 2000). SSCs self-renew cell development period, the levels of CYP26B1 in under the influence of glial cell line-derived neurotrophic Sertoli cells gradually decrease (Gaido and Lehmann, factor (GDNF), which is produced by Sertoli cells and 2006), allowing the levels of retinoic acid to rise, which binds to the membrane receptor complex GFRA1/RET drives Stra8 expression in germ cells, meiosis entry and (Meng et al., 2000; Kubota et al., 2004; Hofmann et al.., spermatocyte differentiation into haploid spermatids and 2005; Naughton et al., 2006). When rodent SSCs spermatozoa (Anderson et al., 2008). The molecular differentiate, they divide into two daughter cells called events underlying the regulation of CYP26B1 are not Apaired spermatogonia (Apr), which will in turn divide to completely understood, nor are the cause and function of form chains of 4, 8 or 16 Aaligned spermatogonia (Aal). mitotic arrest in prospermatogonia. Figure 1. Intrinsic markers essential for SSC self-renewal and differentiation. The transcription factor ID4 identifies a small population of Asingle spermatogonia that are believed to be the true stem cells (Chan et al., 2014). The membrane receptors GFRA1 and RET bind the ligand GDNF, which is crucial for stem cell self-renewal (Meng et al., 2000; Hofmann et al., 2005; Naughton et al., 2006). ZBTB16 and POU5F1 are transcription factors expressed by SSCs and undifferentiated spermatogonia (Ohbo et al., 2003; Buaas et al., 2004; Costoya et al., 2004; Dann et al., 2008). Upon downregulation of CYP26B1, increased retinoic acid levels will stimulate germ cell expression of STRA8, which will induce them to differentiate and enter meiosis (Anderson et al., 2008). SOHLH1/2 and NGN3 are expressed at the boundary between Aaligned and A1-A4 differentiating spermatogonia, while KIT is a known marker of differentiating spermatogonia (Schrans-Stassen et al., 1999; Yoshida et al., 2006; Suzuki et al., 2012). ZBTB16 is an inhibitor of KIT, which therefore contributes in maintaining the undifferentiated state (Filipponi et al., 2007). Molecules discussed more in depth in the present review are marked in blue. 36 Anim. Reprod., v.12, n.1, p.35-45, Jan./Mar. 2015 Garcia and Hofmann. Germ line stem cell homeostasis. The germline stem cell microenvironment seminiferous tubules, also contribute to the niche by producing growth factors such as LIF (Piquet-Pellorce Stem cell behavior is regulated by specialized et al., 2000), and the CC-chemokine MCP-1 (Aubry et microenvironments, or niches, which maintain the size al., 2000). Together with Sertoli cells, peritubular and homeostasis of the stem cell population. The role of myoid cells produce components of the basement the niche has been demonstrated in several tissues, in membrane onto which they reside together with particular intestinal epithelium, bone marrow and undifferentiated spermatogonia (Richardson et al., epidermis (Singh, 2012). Many of the events 1995; Siu and Cheng, 2008). determining germ cell development in the perinatal Other cellular components of the testicular testis, including development of prospermatogonia into niche are found in the interstitial space between the stem cells, and spermatogonial stem cell fate throughout seminiferous tubules. Leydig cells, which are known to life, are also orchestrated by their microenvironment, synthesize testosterone, also produce growth factors which is composed of several types of somatic cells crucial for SSC self-renewal such as CSF-1 (Dirami et (Fig. 2). Within the seminiferous epithelium, the Sertoli al., 1999; Kokkinaki et al., 2009; Oatley et al., 2009) cell is an important cellular component of the testicular and VEGF (Collin and Bergh, 1996; Ergun et al., 1997; niche and is responsible for the production of several Korpelainen et al., 1998; Anand et al., 2003; Caires et growth factors that
Load more

Recommended publications
  • Cellular Therapy Via Spermatogonial Stem Cells for Treating Impaired Spermatogenesis, Non-Obstructive Azoospermia
    cells Review Cellular Therapy via Spermatogonial Stem Cells for Treating Impaired Spermatogenesis, Non-Obstructive Azoospermia Nesma E. Abdelaal 1, Bereket Molla Tanga 2,3, Mai Abdelgawad 4, Sahar Allam 5 , Mostafa Fathi 6, Islam M. Saadeldin 7 , Seonggyu Bang 2 and Jongki Cho 2,* 1 Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Universite Paris-Saclay/Île-de-France, 91198 Gif-sur-Yvette, France; [email protected] 2 College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea; [email protected] (B.M.T.); [email protected] (S.B.) 3 Faculty of Veterinary Medicine, Hawassa University, P.O. Box 05 Hawassa, Ethiopia 4 Biotechnology and Life Sciences Department, Faculty of Postgraduate Studies for Advanced Sciences (PSAS), Beni-Suef University, Beni-Suef 62521, Egypt; [email protected] 5 Faculty of Medicine, Tanta University, Tanta 31527, Egypt; [email protected] 6 Biotechnology Program, Faculty of Agriculture, Ain Shams University, Giza 11566, Egypt; [email protected] 7 Department of Physiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt; [email protected] * Correspondence: [email protected]; Tel.: +82-42-821-6788 Abstract: Male infertility is a major health problem affecting about 8–12% of couples worldwide. Spermatogenesis starts in the early fetus and completes after puberty, passing through different stages. Male infertility can result from primary or congenital, acquired, or idiopathic causes. The Citation: Abdelaal, N.E.; Tanga, absence of sperm in semen, or azoospermia, results from non-obstructive causes (pretesticular and B.M.; Abdelgawad, M.; Allam, S.; testicular), and post-testicular obstructive causes.
    [Show full text]
  • Approaches and Technologies in Male Fertility Preservation
    International Journal of Molecular Sciences Review Approaches and Technologies in Male Fertility Preservation Mahmoud Huleihel 1,2,* and Eitan Lunenfeld 2,3,4 1 The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel 2 The Center of Advanced Research and Education in Reproduction (CARER), Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; lunenfl[email protected] 3 Department of OB/GYN, Soroka Medical Center, Beer Sheva 8410501, Israel 4 Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel * Correspondence: [email protected]; Tel.: +972-86479959 Received: 28 May 2020; Accepted: 29 July 2020; Published: 31 July 2020 Abstract: Male fertility preservation is required when treatment with an aggressive chemo-/-radiotherapy, which may lead to irreversible sterility. Due to new and efficient protocols of cancer treatments, surviving rates are more than 80%. Thus, these patients are looking forward to family life and fathering their own biological children after treatments. Whereas adult men can cryopreserve their sperm for future use in assistance reproductive technologies (ART), this is not an option in prepubertal boys who cannot produce sperm at this age. In this review, we summarize the different technologies for male fertility preservation with emphasize on prepubertal, which have already been examined and/or demonstrated in vivo and/or in vitro using animal models and, in some cases, using human tissues. We discuss the limitation of these technologies for use in human fertility preservation. This update review can assist physicians and patients who are scheduled for aggressive chemo-/radiotherapy, specifically prepubertal males and their parents who need to know about the risks of the treatment on their future fertility and the possible present option of fertility preservation.
    [Show full text]
  • Triggers of Spermatogenesis Moses Bibi Moses D
    Triggers of Spermatogenesis Moses Bibi Moses D. Bibi will graduate in January 2020 with a Bachelor of Science Honors degree in Biology, is accepted in the Touro Medical Honors Pathway with New York Medical College and will attend medical school beginning fall 2020. Abstract Of the 7% of men affected with infertility, about 54% suffer from pre-testicular and/or testicular factor induced azoospermia/ oligospermia .This agenesis of spermatozoa has been the subject of much andrology research over the past 50 years, with a par- ticular focus in the triggers of spermatogenesis .While much of their work is limited to murine populations, researchers have put a lot of emphasis on the spermatogonial stem cell (SSC) niche as the source of the trigger(s) . By following physiological patterns exhibited in the seminiferous epithelium, researchers have been able to detect distinct morphological stages that correlate with spermatogonial germ-line action . Different niche cells appear to release different concentrations of active compounds, androgens, and receptors during different stages. Specifically, in the steps leading up to and during SSC differentiation, Sertoli cells and germ line cells release retinoic acid and retinoic acid receptors . Retinoic acid appears to trigger SSCs in vitro as well .Testosterone, re- leased by Leydig cells and potentially testicular macrophages, appears to play an essential role in a spermiation-SSC differentiation axis, as well as a role in GDNF production by peritubular myoid cells, both required for proper maintenance of SSC populations and commitment to meiosis .With new and promising research being done on the whole of the SSC niche, as opposed to just Sertoli cells, scientists are closer than ever to uncovering the secrets of male fertility .
    [Show full text]
  • Spermatogonial Stem Cells in Fish: Characterization, Isolation, Enrichment, and Recent Advances of in Vitro Culture Systems
    biomolecules Review Spermatogonial Stem Cells in Fish: Characterization, Isolation, Enrichment, and Recent Advances of In Vitro Culture Systems Xuan Xie 1,* , Rafael Nóbrega 2 and Martin Pšeniˇcka 1 1 Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in Ceske Budejovice, Zátiší 728/II, 389 25 Vodˇnany, Czech Republic; [email protected] 2 Reproductive and Molecular Biology Group, Department of Morphology, Institute of Biosciences, São Paulo State University, Botucatu, SP 18618-970, Brazil; [email protected] * Correspondence: [email protected]; Tel.: +420-606-286-138 Received: 9 March 2020; Accepted: 14 April 2020; Published: 22 April 2020 Abstract: Spermatogenesis is a continuous and dynamic developmental process, in which a single diploid spermatogonial stem cell (SSC) proliferates and differentiates to form a mature spermatozoon. Herein, we summarize the accumulated knowledge of SSCs and their distribution in the testes of teleosts. We also reviewed the primary endocrine and paracrine influence on spermatogonium self-renewal vs. differentiation in fish. To provide insight into techniques and research related to SSCs, we review available protocols and advances in enriching undifferentiated spermatogonia based on their unique physiochemical and biochemical properties, such as size, density, and differential expression of specific surface markers. We summarize in vitro germ cell culture conditions developed to maintain proliferation and survival of spermatogonia in selected fish species. In traditional culture systems, sera and feeder cells were considered to be essential for SSC self-renewal, in contrast to recently developed systems with well-defined media and growth factors to induce either SSC self-renewal or differentiation in long-term cultures.
    [Show full text]
  • Derivation and Propagation of Spermatogonial Stem Cells From
    Xu et al. Stem Cell Research & Therapy (2020) 11:408 https://doi.org/10.1186/s13287-020-01896-0 RESEARCH Open Access Derivation and propagation of spermatogonial stem cells from human pluripotent cells Huiming Xu1,2* , Mengbo Yang1, Ruhui Tian3, Yonghui Wang1, Linhong Liu1, Zijue Zhu3, Shi Yang4, Qingqing Yuan1, Minghui Niu1, Chencheng Yao3, Erlei Zhi3, Peng Li3, Chenhao Zhou3, Zuping He1, Zheng Li3* and Wei-Qiang Gao1,2* Abstract Objectives: This study is designed to generate and propagate human spermatogonial stem cells (SSCs) derived from human pluripotent stem cells (hPSCs). Methods: hPSCs were differentiated into SSC-like cells (SSCLCs) by a three-step strategy. The biological characteristics of SSCLCs were detected by immunostaining with antibodies against SSC markers. The ability of self- renewal was measured by propagating for a long time and still maintaining SSCs morphological property. The differentiation potential of SSCLCs was determined by the generation of spermatocytes and haploid cells, which were identified by immunostaining and flow cytometry. The transcriptome analysis of SSCLCs was performed by RNA sequencing. The biological function of SSCLCs was assessed by xeno-transplantation into busulfan-treated mouse testes. Results: SSCLCs were efficiently generated by a 3-step strategy. The SSCLCs displayed a grape-like morphology and expressed SSC markers. Moreover, SSCLCs could be propagated for approximately 4 months and still maintained their morphological properties. Furthermore, SSCLCs could differentiate into spermatocytes and haploid cells. In addition, SSCLCs displayed a similar gene expression pattern as human GPR125+ spermatogonia derived from human testicular tissues. And more, SSCLCs could survive and home at the base membrane of seminiferous tubules.
    [Show full text]
  • Spermatogonial Stem Cells: Implications for Genetic Disorders and Prevention
    STEM CELLS AND DEVELOPMENT Volume 25, Number 20, 2016 Mary Ann Liebert, Inc. DOI: 10.1089/scd.2016.0210 Spermatogonial Stem Cells: Implications for Genetic Disorders and Prevention Makiko Yamada, Letizia De Chiara, and Marco Seandel Spermatogonial stem cells (SSCs) propagate mammalian spermatogenesis throughout male reproductive life by continuously self-renewing and differentiating, ultimately, into sperm. SSCs can be cultured for long periods and restore spermatogenesis upon transplantation back into the native microenvironment in vivo. Con- ventionally, SSC research has been focused mainly on male infertility and, to a lesser extent, on cell repro- gramming. With the advent of genome-wide sequencing technology, however, human studies have uncovered a wide range of pathogenic alleles that arise in the male germ line. A subset of de novo point mutations was shown to originate in SSCs and cause congenital disorders in children. This review describes both monogenic diseases (eg, Apert syndrome) and complex disorders that are either known or suspected to be driven by mutations in SSCs. We propose that SSC culture is a suitable model for studying the origin and mechanisms of these diseases. Lastly, we discuss strategies for future clinical implementation of SSC-based technology, from detecting mutation burden by sperm screening to gene correction in vitro. Introduction sumes within the first week after birth [4,5]. Prospermatogonia migrate to the basement membrane and the spermatogenesis tem cells play a pivotal role in maintaining homeo- phase begins [6]. The differentiation of PGCs into prosper- Sstasis in adult tissues; they self-renew, differentiate, matogonia in humans is not well understood, but there seem to and regenerate tissues upon injury.
    [Show full text]
  • Biological Therapy for Non-Obstructive Azoospermia Sarah C
    EXPERT OPINION ON BIOLOGICAL THERAPY, 2018 VOL. 18, NO. 1, 19–23 https://doi.org/10.1080/14712598.2018.1380622 REVIEW Biological therapy for non-obstructive azoospermia Sarah C. Vija, Edmund Sabanegh Jrb and Ashok Agarwalc aGlickman Urologic and Kidney Institute, Cleveland Clinic Foundation, Cleveland, OH, USA; bDepartment of Urology, Glickman Urologic and Kidney Institute, Cleveland Clinic Foundation, Cleveland, OH, USA; cAndrology Laboratory, Glickman Urologic and Kidney Institute, Cleveland Clinic Foundation, Cleveland, OH, USA ABSTRACT ARTICLE HISTORY Introduction: Most male patients with non-obstructive azoospermia (NOA) have no therapeutic options Received 26 June 2017 outside of assisted reproductive techniques to conceive a biological child. If mature sperm cannot be Accepted 13 September 2017 obtained from the testes, these patients must rely on options of donor sperm or adoption. Several KEYWORDS techniques are in the experimental stage to provide this patient population alternatives for conceiving. Gene therapy; Areas covered: This review discusses three of the experimental techniques for restoring fertility in men non-obstructive with NOA: spermatogonial stem cell transplantation, the use of adult and embryonic stem cells to azoospermia; develop mature gametes and gene therapy. After this discussion, the authors give their expert opinion spermatogonial stem cell and provide the reader with their perspectives for the future. transplantation; pluripotent Expert opinion: Several limitations, both technical and ethical, exist for spermatogonial stem cell stem cell transplantation, the use of stem cells and gene therapy. Well-defined reproducible protocols are necessary. Furthermore, several technical barriers exist for all protocols. And while success has been achieved in animal models, future research is still required in human models.
    [Show full text]
  • Testicular Organoids to Study Cell-Cell Interactions in the Mammalian Testis
    HHS Public Access Author manuscript Author ManuscriptAuthor Manuscript Author Andrology Manuscript Author . Author manuscript; Manuscript Author available in PMC 2021 July 01. Published in final edited form as: Andrology. 2020 July ; 8(4): 835–841. doi:10.1111/andr.12680. Testicular organoids to study cell-cell interactions in the mammalian testis Sadman Sakib1,2, Taylor Goldsmith1,2, Anna Voigt2, Ina Dobrinski1,2 1Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary 2Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary Abstract Background: Over the last ten years, three-dimensional organoid culture has garnered renewed interest, as organoids generated from primary cells or stem cells with cell associations and functions similar to organs in vivo can be a powerful tool to study tissue-specific cell-cell interactions in vitro. Very recently, a few interesting approaches have been put forth for generating testicular organoids for studying the germ cell niche microenvironment. Aim: To review different model systems that have been employed to study germ cell biology and testicular cell-cell interactions and discuss how the organoid approach can address some of the shortcomings of those systems. Results and Conclusion: Testicular organoids that bear architectural and functional similarities to their in vivo counterparts, are a powerful model system to study cell-cell interactions in the germ cell niche. Organoids enable studying samples in humans and other large animals where in vivo experiments are not possible, allow modeling of testicular disease and malignancies and may provide a platform to design more precise therapeutic interventions. Keywords Testicular organoids; morphogenesis; germ cell niche; cell-cell interaction Introduction Historically the term “organoid” has been used to describe different three-dimensional (3D) cell culture systems such as organ cultures (Barcellos-Hoff et al.
    [Show full text]
  • Development and Function of Smooth Muscle Cells Is Modulated by Hic1 in Mouse Testis Aya Uchida1,2, Sadman Sakib1, Elodie Labit1, Sepideh Abbasi1, R
    © 2020. Published by The Company of Biologists Ltd | Development (2020) 147, dev185884. doi:10.1242/dev.185884 RESEARCH ARTICLE Development and function of smooth muscle cells is modulated by Hic1 in mouse testis Aya Uchida1,2, Sadman Sakib1, Elodie Labit1, Sepideh Abbasi1, R. Wilder Scott3, T. Michael Underhill3, Jeff Biernaskie1 and Ina Dobrinski1,* ABSTRACT (Yoshida et al., 2007). It is traditionally accepted that Sertoli cells In mammalian testis, contractile peritubular myoid cells (PMCs) support the spermatogonial stem cell (SSC) niche by secreting regulate the transport of sperm and luminal fluid, while secreting several growth factors (Meng et al., 2000; Takashima et al., 2015; growth factors and extracellular matrix proteins to support the Takase and Nusse, 2016), whereas the importance of testicular spermatogonial stem cell niche. However, little is known about the smooth muscle cells in supporting the SSC niche is only beginning role of testicular smooth muscle cells during postnatal testicular to be appreciated (Chen et al., 2014; de Rooij, 2017). Testicular development. Here we report age-dependent expression of smooth muscle cells secret trophic factors, such as glial cell line- hypermethylated in cancer 1 (Hic1; also known as ZBTB29)in derived neurotrophic factor (GDNF), colony stimulating factor 1 testicular smooth muscle cells, including PMCs and vascular smooth (CSF1) and chemokine (C-X-C motif) ligand 12 (CXCL12), to muscle cells, in the mouse. Postnatal deletion of Hic1 in smooth support the maintenance and self-renewal of SSCs (Oatley et al., muscle cells led to their increased proliferation and resulted in 2009; Chen et al., 2016; Mayer et al., 2018), while regulating the dilatation of seminiferous tubules, with increased numbers of PMCs.
    [Show full text]
  • Targeting the Gdnf Gene in Peritubular Myoid Cells Disrupts Undifferentiated Spermatogonial Cell Development
    Targeting the Gdnf Gene in peritubular myoid cells disrupts undifferentiated spermatogonial cell development Liang-Yu Chena, William D. Willisa, and Edward M. Eddya,1 aGamete Biology Group, Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709 Edited by John J. Eppig, The Jackson Laboratory, Bar Harbor, ME, and approved December 16, 2015 (received for review September 9, 2015) Spermatogonial stem cells (SSCs) are a subpopulation of undiffer- type A-aligned (Aal) spermatogonia, and these in turn divide to entiated spermatogonia located in a niche at the base of the sem- form longer chains of differentiating (type A1,A2,A3, intermedi- iniferous epithelium delimited by Sertoli cells and peritubular myoid ate, and B) spermatogonia. (PM) cells. SSCs self-renew or differentiate into spermatogonia that Although SSCs are single cells, not all As spermatogonia are ∼ proliferate to give rise to spermatocytes and maintain spermato- likely to be SSCs. There are 35,000 As spermatogonia in the genesis. Glial cell line-derived neurotrophic factor (GDNF) is essential testes of adult mice (8), but only about 3,000 of these have the for this process. Sertoli cells produce GDNF and other growth factors ability to regenerate spermatogenesis when transplanted to and are commonly thought to be responsible for regulating SSC germ cell-depleted testes (9). Although there are no generally development, but limited attention has been paid to the role of PM accepted molecular markers specific for SSCs, potential candidates cells in this process. A conditional knockout (cKO) of the androgen are inhibitor of DNA binding 4 (ID4) and paired box 7 (PAX7), – receptor gene in PM cells resulted in male infertility.
    [Show full text]
  • Mammalian Gonocyte and Spermatogonia Differentiation: Recent Advances and Remaining Challenges
    REPRODUCTIONREVIEW Mammalian gonocyte and spermatogonia differentiation: recent advances and remaining challenges Gurpreet Manku1,2,3 and Martine Culty1,2,3 1The Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Avenue, Montreal, Quebec, Canada H3G 1A4, Departments of 2Medicine and 3Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada Correspondence should be addressed to M Culty; Email: [email protected] Abstract The production of spermatozoa relies on a pool of spermatogonial stem cells (SSCs), formed in infancy from the differentiation of their precursor cells, the gonocytes. Throughout adult life, SSCs will either self-renew or differentiate, in order to maintain a stem cell reserve while providing cells to the spermatogenic cycle. By contrast, gonocytes represent a transient and finite phase of development leading to the formation of SSCs or spermatogonia of the first spermatogenic wave. Gonocyte development involves phases of quiescence, cell proliferation, migration, and differentiation. Spermatogonia, on the other hand, remain located at the basement membrane of the seminiferous tubules throughout their successive phases of proliferation and differentiation. Apoptosis is an integral part of both developmental phases, allowing for the removal of defective cells and the maintenance of proper germ–Sertoli cell ratios. While gonocytes and spermatogonia mitosis are regulated by distinct factors, they both undergo differentiation in response to retinoic acid. In contrast to postpubertal spermatogenesis, the early steps of germ cell development have only recently attracted attention, unveiling genes and pathways regulating SSC self-renewal and proliferation. Yet, less is known on the mechanisms regulating differentiation. The processes leading from gonocytes to spermatogonia have been seldom investigated.
    [Show full text]
  • Self Renewal of Spermatogonial Stem Cells the Most Promising Multipotent Cells
    Veterinary World, 2011, Vol.4(5): 234-240 REVIEW Self Renewal of Spermatogonial Stem Cells: the Most Promising Multipotent Cells - A Review J. Tokas 1, C. S. Mukhopadhyay 2* and Archana Verma3 1. Department of Biochemistry, COBS & H, CCS-Haryana Agricultural University, Hisar 2. Department of Animal Biotechnology, GADVASU, Ludhiana, Punjab, India. 3. Dairy Cattle Breeding Division, N.D.R.I., Karnal, Haryana * Corresponding author. Tel.: +91-161-2414023, E-mail : [email protected] Published online at www.veterinaryworld.org on 25-03-2011 Abstract Germ cells are endowed with unique properties like the ability to undergo meiosis and differentiate into gametes in order to perpetuate the genetic material. Spermatogonial stem cells (SSC) are considered as the best suited undifferentiated germ cells and are being consistently studied to reveal the basic physiology, genomics and transcriptomics of those cells. SSC provide an excellent model system to understand the differentiation, development and functioning of gonads and further use of these cells in transplantation-cell based therapies. In the present article, basic aspects of spermatogonial multiplication, regulation of stem cell renewal and differentiation would be discussed. Keywords: Spermatogonial stem cells, spermatogenesis, testis, self-renewal. Introduction found in a living organism. These cells have more restricted options to select a differentiation program In the current scenario, stem cells have egressed as one of the most fascinating areas of biological from a few possible pathways only. Adult and science. Stem cells are subject of increasing interest embryonic stem cells differ in the number and type of because of their biological properties and potential differentiated cell types they can form.
    [Show full text]