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Schrenk D, Bignami M, Bodin L, Chipman JK, del Mazo J, Grasl‐Kraupp B, Hogstrand C, Hoogenboom L(R, Leblanc J, Nebbia CS, Ntzani E, Petersen A, Sand S, Schwerdtle T, Vleminckx C, Wallace H, Falandysz J, Hart A, Rose M, Anastassiadou M, Eskes C, Gergelova P, Innocenti M, Rovesti E, Whitty B, Nielsen E. Risks for animal and human health related to the presence of polychlorinated naphthalenes (PCNs) in feed and food. EFSA J 2024; 22:e8640. [PMID: 38476320 PMCID: PMC10928787 DOI: 10.2903/j.efsa.2024.8640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024] Open
Abstract
EFSA was asked for a scientific opinion on the risks for animal and human health related to the presence of polychlorinated naphthalenes (PCNs) in feed and food. The assessment focused on hexaCNs due to very limited data on other PCN congeners. For hexaCNs in feed, 217 analytical results were used to estimate dietary exposures for food-producing and non-food-producing animals; however, a risk characterisation could not be performed because none of the toxicological studies allowed identification of reference points. The oral repeated dose toxicity studies performed in rats with a hexaCN mixture containing all 10 hexaCNs indicated that the critical target was the haematological system. A BMDL20 of 0.05 mg/kg body weight (bw) per day was identified for a considerable decrease in the platelet count. For hexaCNs in food, 2317 analytical results were used to estimate dietary exposures across dietary surveys and age groups. The highest exposure ranged from 0.91 to 29.8 pg/kg bw per day in general population and from 220 to 559 pg/kg bw per day for breast-fed infants with the highest consumption of breast milk. Applying a margin of exposure (MOE) approach, the estimated MOEs for the high dietary exposures ranged from 1,700,000 to 55,000,000 for the general population and from 90,000 to 230,000 for breast-fed infants with the highest consumption of breast milk. These MOEs are far above the minimum MOE of 2000 that does not raise a health concern. Taking account of the uncertainties affecting the assessment, the Panel concluded with at least 99% certainty that dietary exposure to hexaCNs does not raise a health concern for any of the population groups considered. Due to major limitations in the available data, no assessment was possible for genotoxic effects or for health risks of PCNs other than hexaCNs.
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Pasquariello R, Anipchenko P, Pennarossa G, Crociati M, Zerani M, Brevini TA, Gandolfi F, Maranesi M. Carotenoids in female and male reproduction. PHYTOCHEMISTRY 2022; 204:113459. [PMID: 36183866 DOI: 10.1016/j.phytochem.2022.113459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/21/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Carotenoids are among the best-known pigments in nature, confer color to plants and animals, and are mainly derived from photosynthetic bacteria, fungi, algae, plants. Mammals cannot synthesize carotenoids. Carotenoids' source is only alimentary and after their assumption, they are mainly converted in retinal, retinol and retinoic acid, collectively known also as pro-vitamins and vitamin A, which play an essential role in tissue growth and regulate different aspects of the reproductive functions. However, their mechanisms of action and potential therapeutic effects are still unclear. This review aims to clarify the role of carotenoids in the male and female reproductive functions in species of veterinary interest. In female, carotenoids and their derivatives regulate not only folliculogenesis and oogenesis but also steroidogenesis. Moreover, they improve fertility by decreasing the risk of embryonic mortality. In male, retinol and retinoic acids activate molecular pathways related to spermatogenesis. Deficiencies of these vitamins have been correlated with degeneration of testis parenchyma with consequent absence of the mature sperm. Carotenoids have also been considered anti-antioxidants as they ameliorate the effect of free radicals. The mechanisms of action seem to be exerted by activating Kit and Stra8 pathways in both female and male. In conclusion, carotenoids have potentially beneficial effects for ameliorating ovarian and testes function.
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Affiliation(s)
- Rolando Pasquariello
- Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, Università Degli Studi di Milano, 20133, Milan, Italy
| | - Polina Anipchenko
- Department of Veterinary Medicine, University of Perugia, Via S. Costanzo 4, 06126, Perugia, Italy
| | - Georgia Pennarossa
- Laboratory of Biomedical Embryology, Department of Veterinary Medicine and Animal Sciences, Università Degli Studi di Milano, 26900, Lodi, Italy.
| | - Martina Crociati
- Department of Veterinary Medicine, University of Perugia, Via S. Costanzo 4, 06126, Perugia, Italy; Centre for Perinatal and Reproductive Medicine, University of Perugia, 06129, Perugia, Italy
| | - Massimo Zerani
- Department of Veterinary Medicine, University of Perugia, Via S. Costanzo 4, 06126, Perugia, Italy
| | - Tiziana Al Brevini
- Laboratory of Biomedical Embryology, Department of Veterinary Medicine and Animal Sciences, Università Degli Studi di Milano, 26900, Lodi, Italy
| | - Fulvio Gandolfi
- Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, Università Degli Studi di Milano, 20133, Milan, Italy
| | - Margherita Maranesi
- Department of Veterinary Medicine, University of Perugia, Via S. Costanzo 4, 06126, Perugia, Italy
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3
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Griswold MD. Cellular and molecular basis for the action of retinoic acid in spermatogenesis. J Mol Endocrinol 2022; 69:T51-T57. [PMID: 35670629 DOI: 10.1530/jme-22-0067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 06/07/2022] [Indexed: 11/08/2022]
Abstract
Spermatogenesis is a highly organized and regulated process that requires the constant production of millions of gametes over the reproductive lifetime of the mammalian male. This is possible because of an active stem cell pool and an ordered entry into the germ cell developmental sequence. The ordered entry is a result of the synthesis and action of retinoic acid allowing for the onset of spermatogonial differentiation and an irreversible commitment to spermatogenesis. The periodic appearance and actions of retinoic acid along the seminiferous tubules is a result of the interactions between germ cells and Sertoli cells that result in the generation and maintenance of the cycle of the seminiferous epithelium and is the subject of this review.
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Affiliation(s)
- Michael D Griswold
- School of Molecular Biosciences, Center for Reproductive Biology, Washington State University, Pullman, Washington, USA
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Awang-Junaidi AH, Fayaz MA, Goldstein S, Honaramooz A. Using a testis regeneration model, FGF9, LIF, and SCF improve testis cord formation while RA enhances gonocyte survival. Cell Tissue Res 2022; 389:351-370. [PMID: 35596812 DOI: 10.1007/s00441-022-03641-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 05/09/2022] [Indexed: 11/30/2022]
Abstract
Implantation of testis cell aggregates from various donors under the back skin of recipient mice results in de novo formation of testis tissue. We used this implantation model to study the putative in vivo effects of six different growth factors on testis cord development. Recipient mice (n = 7/group) were implanted with eight neonatal porcine testis cell aggregates that were first exposed to a designated growth factor: FGF2 at 1 µg/mL, FGF9 at 5 µg/mL, VEGF at 3.5 µg/mL, LIF at 5 µg/mL, SCF at 3.5 µg/mL, retinoic acid (RA) at 3.5 × 10-5 M, or no growth factors (control). The newly developed seminiferous cords (SC) were classified based on their morphology into regular, irregular, enlarged, or aberrant. Certain treatments enhanced implant weight (LIF), implant cross-sectional area (SCF) or the relative cross-sectional area covered by SC within implants (FGF2). RA promoted the formation of enlarged SC and FGF2 led to the highest ratio of regular SC and the lowest ratio of aberrant SC. Rete testis-like structures appeared earlier in implants treated with FGF2, FGF9, or LIF. These results show that even brief pre-implantation exposure of testis cells to these growth factors can have profound effects on morphogenesis of testis cords using this implantation model.
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Affiliation(s)
- Awang Hazmi Awang-Junaidi
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada.,Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia
| | - Mohammad Amin Fayaz
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada
| | - Savannah Goldstein
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada
| | - Ali Honaramooz
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada.
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Yokota S, Takeda K, Oshio S. Spatiotemporal Small Non-coding RNAs Expressed in the Germline as an Early Biomarker of Testicular Toxicity and Transgenerational Effects Caused by Prenatal Exposure to Nanosized Particles. FRONTIERS IN TOXICOLOGY 2022; 3:691070. [PMID: 35295114 PMCID: PMC8915876 DOI: 10.3389/ftox.2021.691070] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/01/2021] [Indexed: 12/28/2022] Open
Abstract
In recent years, an apparent decline in human sperm quality has been observed worldwide. One in every 5.5 couples suffers from infertility, with male reproductive problems contributing to nearly 40% of all infertility cases. Although the reasons for the increasing number of infertility cases are largely unknown, both genetic and environmental factors can be contributing factors. In particular, exposure to chemical substances during mammalian male germ cell development has been linked to an increased risk of infertility in later life owing to defective sperm production, reproductive tract obstruction, inflammation, and sexual disorders. Prenatal exposure to nanomaterials (NMs) is no exception. In animal experiments, maternal exposure to NMs has been reported to affect the reproductive health of male offspring. Male germ cells require multiple epigenetic reprogramming events during their lifespan to acquire reproductive capacity. Given that spermatozoa deliver the paternal genome to oocytes upon fertilization, we hypothesized that maternal exposure to NMs negatively affects male germ cells by altering epigenetic regulation, which may in turn affect embryo development. Small non-coding RNAs (including microRNAs, PIWI-interacting RNAs, tRNA-derived small RNAs, and rRNA-derived small RNAs), which are differentially expressed in mammalian male germ cells in a spatiotemporal manner, could play important regulatory roles in spermatogenesis and embryogenesis. Thus, the evaluation of RNAs responsible for sperm fertility is of great interest in reproductive toxicology and medicine. However, whether the effect of maternal exposure to NMs on spermatogenesis in the offspring (intergenerational effects) really triggers multigenerational effects remains unclear, and infertility biomarkers for evaluating paternal inheritance have not been identified to date. In this review, existing lines of evidence on the effects of prenatal exposure to NMs on male reproduction are summarized. A working hypothesis of the transgenerational effects of sperm-derived epigenomic changes in the F1 generation is presented, in that such maternal exposure could affect early embryonic development followed by deficits in neurodevelopment and male reproduction in the F2 generation.
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Affiliation(s)
- Satoshi Yokota
- Division of Cellular and Molecular Toxicology, Center for Biological Safety and Research, National Institute of Health Sciences, Kawasaki, Japan
| | - Ken Takeda
- Division of Toxicology and Health Science, Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, Yamaguchi, Japan
| | - Shigeru Oshio
- Department of Hygiene Chemistry, School of Pharmaceutical Sciences, Ohu University, Koriyama, Japan
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6
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Action and Interaction between Retinoic Acid Signaling and Blood–Testis Barrier Function in the Spermatogenesis Cycle. Cells 2022; 11:cells11030352. [PMID: 35159162 PMCID: PMC8834282 DOI: 10.3390/cells11030352] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/12/2021] [Accepted: 11/20/2021] [Indexed: 02/04/2023] Open
Abstract
Spermatogenesis is a complex process occurring in mammalian testes, and constant sperm production depends on the exact regulation of the microenvironment in the testes. Many studies have indicated the crucial role of blood–testis barrier (BTB) junctions and retinoic acid (RA) signaling in the spermatogenesis process. The BTB consists of junctions between adjacent Sertoli cells, comprised mainly of tight junctions and gap junctions. In vitamin A-deficient mice, halted spermatogenesis could be rebooted by RA or vitamin A administration, indicating that RA is absolutely required for spermatogenesis. Accordingly, this manuscript will review and discuss how RA and the BTB regulate spermatogenesis and the interaction between RA signaling and BTB function.
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Hofmann MC, McBeath E. Sertoli Cell-Germ Cell Interactions Within the Niche: Paracrine and Juxtacrine Molecular Communications. Front Endocrinol (Lausanne) 2022; 13:897062. [PMID: 35757413 PMCID: PMC9226676 DOI: 10.3389/fendo.2022.897062] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/25/2022] [Indexed: 12/22/2022] Open
Abstract
Male germ cell development depends on multiple biological events that combine epigenetic reprogramming, cell cycle regulation, and cell migration in a spatio-temporal manner. Sertoli cells are a crucial component of the spermatogonial stem cell niche and provide essential growth factors and chemokines to developing germ cells. This review focuses mainly on the activation of master regulators of the niche in Sertoli cells and their targets, as well as on novel molecular mechanisms underlying the regulation of growth and differentiation factors such as GDNF and retinoic acid by NOTCH signaling and other pathways.
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Rosario R, Stewart HL, Walshe E, Anderson RA. Reduced retinoic acid synthesis accelerates prophase I and follicle activation. Reproduction 2021; 160:331-341. [PMID: 32520724 PMCID: PMC7424351 DOI: 10.1530/rep-20-0221] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 06/08/2020] [Indexed: 12/16/2022]
Abstract
In female mammals, reproductive potential is determined during fetal life by the formation of a non-renewable pool of primordial follicles. Initiation of meiosis is one of the defining features of germ cell differentiation and is well established to commence in response to retinoic acid. WIN 18,446 inhibits the conversion of retinol to retinoic acid, and therefore it was used to explore the impact of reduced retinoic acid synthesis on meiotic progression and thus germ cell development and subsequent primordial follicle formation. e13.5 mouse fetal ovaries were cultured in vitro and treated with WIN 18,446 for the first 3 days of a total of up to 12 days. Doses as low as 0.01 µM reduced transcript levels of the retinoic acid response genes Stra8 and Rarβ without affecting germ cell number. Higher doses resulted in germ cell loss, rescued with the addition of retinoic acid. WIN 18,446 significantly accelerated the progression of prophase I; this was seen as early as 48 h post treatment using meiotic chromosome spreads and was still evident after 12 days of culture using Tra98/Msy2 immunostaining. Furthermore, ovaries treated with WIN 18,446 at e13.5 but not at P0 had a higher proportion of growing follicles compared to vehicle controls, thus showing evidence of increased follicle activation. These data therefore indicate that retinoic acid is not necessary for meiotic progression but may have a role in the regulation of its progression and germ cell survival at that time and provide evidence for a link between meiotic arrest and follicle growth initiation.
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Affiliation(s)
- Roseanne Rosario
- MRC Centre for Reproductive Health, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Hazel L Stewart
- MRC Centre for Reproductive Health, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Emily Walshe
- MRC Centre for Reproductive Health, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Richard A Anderson
- MRC Centre for Reproductive Health, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
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9
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Khanehzad M, Abbaszadeh R, Holakuyee M, Modarressi MH, Nourashrafeddin SM. FSH regulates RA signaling to commit spermatogonia into differentiation pathway and meiosis. Reprod Biol Endocrinol 2021; 19:4. [PMID: 33407539 PMCID: PMC7789255 DOI: 10.1186/s12958-020-00686-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 12/17/2020] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Spermatogenesis is a complex process that is controlled by interactions between germ cells and somatic cells. The commitment of undifferentiated spermatogonia to differentiating spermatogonia and normal spermatogenesis requires the action of gonadotropins. Additionally, numerous studies revealed the role of retinoic acid signaling in induction of germ cell differentiation and meiosis entry. MAIN TEXT Recent studies have shown that expression of several RA signaling molecules including Rdh10, Aldh1a2, Crabp1/2 are influenced by changes in gonadotropin levels. Components of signaling pathways that are regulated by FSH signaling such as GDNF, Sohlh1/2, c-Kit, DMRT, BMP4 and NRGs along with transcription factors that are important for proliferation and differentiation of spermatogonia are also affected by retinoic acid signaling. CONCLUSION According to all studies that demonstrate the interface between FSH and RA signaling, we suggest that RA may trigger spermatogonia differentiation and initiation of meiosis through regulation by FSH signaling in testis. Therefore, to the best of our knowledge, this is the first time that the correlation between FSH and RA signaling in spermatogenesis is highlighted.
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Affiliation(s)
- Maryam Khanehzad
- Department of Anatomy, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Roya Abbaszadeh
- Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | | | | | - Seyed Mehdi Nourashrafeddin
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of Pittsburgh, Pittsburgh, USA.
- School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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10
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Beedle MT, Stevison F, Zhong G, Topping T, Hogarth C, Isoherranen N, Griswold MD. Sources of all-trans retinal oxidation independent of the aldehyde dehydrogenase 1A isozymes exist in the postnatal testis†. Biol Reprod 2020; 100:547-560. [PMID: 30247516 DOI: 10.1093/biolre/ioy200] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/01/2018] [Accepted: 09/11/2018] [Indexed: 02/06/2023] Open
Abstract
Despite the essential role of the active metabolite of vitamin A, all-trans retinoic acid (atRA) in spermatogenesis, the enzymes, and cellular populations responsible for its synthesis in the postnatal testis remain largely unknown. The aldehyde dehydrogenase 1A (ALDH1A) family of enzymes residing within Sertoli cells is responsible for the synthesis of atRA, driving the first round of spermatogenesis. Those studies also revealed that the atRA required to drive subsequent rounds of spermatogenesis is possibly derived from the ALDH1A enzymes residing within the meiotic and post-meiotic germ cells. Three ALDH1A isozymes (ALDH1A1, ALDH1A2, and ALDH1A3) are present in the testis. Although, ALDH1A1 is expressed in adult Sertoli cells and is suggested to contribute to the atRA required for the pre-meiotic transitions, ALDH1A2 is proposed to be the essential isomer involved in testicular atRA biosynthesis. In this report, we first examine the requirement for ALDH1A2 via the generation and analysis of a conditional Aldh1a2 germ cell knockout and a tamoxifen-induced Aldh1a2 knockout model. We then utilized the pan-ALDH1A inhibitor (WIN 18446) to test the collective contribution of the ALDH1A enzymes to atRA biosynthesis following the first round of spermatogenesis. Collectively, our data provide the first in vivo evidence demonstrating that animals severely deficient in ALDH1A2 postnatally proceed normally through spermatogenesis. Our studies with a pan-ALDH1A inhibitor (WIN 18446) also suggest that an alternative source of atRA biosynthesis independent of the ALDH1A enzymes becomes available to maintain atRA levels for several spermatogenic cycles following an initial atRA injection.
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Affiliation(s)
- My-Thanh Beedle
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, Washington, USA
| | - Faith Stevison
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Guo Zhong
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Traci Topping
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, Washington, USA
| | - Cathryn Hogarth
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, Washington, USA
| | - Nina Isoherranen
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Michael D Griswold
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, Washington, USA
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11
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Edelsztein NY, Kashimada K, Schteingart HF, Rey RA. CYP26B1 declines postnatally in Sertoli cells independently of androgen action in the mouse testis. Mol Reprod Dev 2019; 87:66-77. [DOI: 10.1002/mrd.23302] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 11/11/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Nadia Y. Edelsztein
- Centro de Investigaciones Endocrinológicas “Dr. César Bergadá” (CEDIE), CONICET – FEI – División de EndocrinologíaHospital de Niños Ricardo Gutiérrez Buenos Aires Argentina
| | - Kenichi Kashimada
- Department of Pediatrics and Developmental BiologyTokyo Medical and Dental University (TMDU) Tokyo Japan
| | - Helena F. Schteingart
- Centro de Investigaciones Endocrinológicas “Dr. César Bergadá” (CEDIE), CONICET – FEI – División de EndocrinologíaHospital de Niños Ricardo Gutiérrez Buenos Aires Argentina
| | - Rodolfo A. Rey
- Centro de Investigaciones Endocrinológicas “Dr. César Bergadá” (CEDIE), CONICET – FEI – División de EndocrinologíaHospital de Niños Ricardo Gutiérrez Buenos Aires Argentina
- Departamento de Biología Celular, Histología, Embriología y Genética, Facultad de MedicinaUniversidad de Buenos Aires Buenos Aires Argentina
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12
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Abstract
Macrophages are a heterogeneous group of cells that are capable of carrying out distinct functions in different tissues, as well as in different locations within a given tissue. Some of these tissue macrophages lie on, or close to, the outer (abluminal) surface of blood vessels and perform several crucial activities at this interface between the tissue and the blood. In steady-state tissues, these perivascular macrophages maintain tight junctions between endothelial cells and limit vessel permeability, phagocytose potential pathogens before they enter tissues from the blood and restrict inappropriate inflammation. They also have a multifaceted role in diseases such as cancer, Alzheimer disease, multiple sclerosis and type 1 diabetes. Here, we examine the important functions of perivascular macrophages in various adult tissues and describe how these functions are perturbed in a broad array of pathological conditions.
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13
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Li X, Long XY, Xie YJ, Zeng X, Chen X, Mo ZC. The roles of retinoic acid in the differentiation of spermatogonia and spermatogenic disorders. Clin Chim Acta 2019; 497:54-60. [PMID: 31302099 DOI: 10.1016/j.cca.2019.07.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/20/2019] [Accepted: 07/10/2019] [Indexed: 12/21/2022]
Abstract
Male fertility depends on the regulatory balance between germ cell self-renewal and differentiation, and the spatial and temporal patterns of this balance must be maintained throughout the life cycle. Retinoic acid and its receptors are important factors in spermatogenesis. Spermatogonia cells can self-proliferate and differentiate and have unique meiotic capabilities; they halve their genetic material and produce monomorphic sperm to pass genetic material to the next generation. A number of studies have found that the spermatogenesis process is halted in animals with vitamin A deficiency and that most germ cells are degraded, but they tend to recover after treatment with RA or vitamin A. This literature review discusses our understanding of how RA regulates sperm cell differentiation and meiosis and also reviews the functional information and details of RA.
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Affiliation(s)
- Xuan Li
- Clinical Anatomy & Reproductive Medicine Application Institute, Department of Histology and Embryology, Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Xiang-Yang Long
- Department of Urology, The Second Affiliated Hospital, University of South China, Hengyang 421001, China
| | - Yuan-Jie Xie
- Clinical Anatomy & Reproductive Medicine Application Institute, Department of Histology and Embryology, Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Xin Zeng
- Clinical Anatomy & Reproductive Medicine Application Institute, Department of Histology and Embryology, Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Xi Chen
- Clinical Anatomy & Reproductive Medicine Application Institute, Department of Histology and Embryology, Hengyang Medical School, University of South China, Hengyang 421001, China.
| | - Zhong-Cheng Mo
- Clinical Anatomy & Reproductive Medicine Application Institute, Department of Histology and Embryology, Hengyang Medical School, University of South China, Hengyang 421001, China.
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14
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Parekh PA, Garcia TX, Waheeb R, Jain V, Gandhi P, Meistrich ML, Shetty G, Hofmann MC. Undifferentiated spermatogonia regulate Cyp26b1 expression through NOTCH signaling and drive germ cell differentiation. FASEB J 2019; 33:8423-8435. [PMID: 30991836 DOI: 10.1096/fj.201802361r] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cytochrome P450 family 26 subfamily B member 1 (CYP26B1) regulates the concentration of all-trans retinoic acid (RA) and plays a key role in germ cell differentiation by controlling local distribution of RA. The mechanisms regulating Cyp26b1 expression in postnatal Sertoli cells, the main components of the stem cell niche, are so far unknown. During gonad development, expression of Cyp26b1 is maintained by Steroidogenic Factor 1 (SF-1) and Sex-Determining Region Y Box-9 (SOX9), which ensure that RA is degraded and germ cell differentiation is blocked. Here, we show that the NOTCH target Hairy/Enhancer-of-Split Related with YRPW Motif 1 (HEY1), a transcriptional repressor, regulates germ cell differentiation via direct binding to the Cyp26b1 promoter and thus inhibits its expression in Sertoli cells. Further, using in vivo germ cell ablation, we demonstrate that undifferentiated type A spermatogonia are the cells that activate NOTCH signaling in Sertoli cells through their expression of the NOTCH ligand JAGGED-1 (JAG1) at stage VIII of the seminiferous epithelium cycle, therefore mediating germ cell differentiation by a ligand concentration-dependent process. These data therefore provide more insights into the mechanisms of germ cell differentiation after birth and potentially explain the spatiotemporal RA pulses driving the transition between undifferentiated to differentiating spermatogonia.-Parekh, P. A., Garcia, T. X., Waheeb, R., Jain, V., Gandhi, P., Meistrich, M. L., Shetty, G., Hofmann, M.-C. Undifferentiated spermatogonia regulate Cyp26b1 expression through NOTCH signaling and drive germ cell differentiation.
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Affiliation(s)
- Parag A Parekh
- Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Thomas X Garcia
- Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA.,Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, USA.,Department of Biology and Biotechnology, University of Houston-Clear Lake, Houston, Texas, USA
| | - Reham Waheeb
- Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA.,Department of Theriogenology, University of Alexandria, Alexandria, Egypt
| | - Vivek Jain
- Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA.,Department of Biology and Biotechnology, University of Houston-Clear Lake, Houston, Texas, USA
| | - Pooja Gandhi
- Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Marvin L Meistrich
- Department of Experimental Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Gunapala Shetty
- Department of Experimental Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Marie-Claude Hofmann
- Department of Endocrine Neoplasia and Hormonal Disorders, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
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15
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Peer NR, Law SM, Murdoch B, Goulding EH, Eddy EM, Kim K. Germ Cell-Specific Retinoic Acid Receptor α Functions in Germ Cell Organization, Meiotic Integrity, and Spermatogonia. Endocrinology 2018; 159:3403-3420. [PMID: 30099545 PMCID: PMC6112597 DOI: 10.1210/en.2018-00533] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 08/01/2018] [Indexed: 12/20/2022]
Abstract
Retinoic acid receptor α (RARA), a retinoic acid-dependent transcription factor, is expressed in both somatic and germ cells of the testis. Rara-null male mice with global Rara mutations displayed severely degenerated testis and infertility phenotypes. To elucidate the specific responsibility of germ cell RARA in spermatogenesis, Rara was deleted in germ cells, generating germ cell-specific Rara conditional knockout (cKO) mice. These Rara cKO animals exhibited phenotypes of quantitatively reduced epididymal sperm counts and disorganized germ cell layers in the seminiferous tubules, which worsened with aging. Abnormal tubules lacked lumen, contained vacuoles, and showed massive germ cell sloughing, all characteristics similar to those observed in Rara-null tubules. Spermatocyte chromosomal spreads revealed a novel role for germ cell RARA in modulating the integrity of synaptonemal complexes and meiotic progression. Furthermore, the initiation of spermatogenesis from spermatogonial stem cells was decreased in Rara cKO testes following busulfan treatment, supporting a role of germ cell RARA in spermatogonial proliferation. Collectively, the evidence in this study indicates that RARA produced in male germ cells has a broad spectrum of functions throughout spermatogenesis, which includes the maintenance of seminiferous epithelium organization, the integrity of the meiotic genome, and spermatogonial proliferation and differentiation. The results further suggest that germ cell RARA has dual functions: intrinsically in germ cells, balancing proliferation and differentiation of spermatogonia, and controlling genome integrity during meiosis; and extrinsically in the crosstalks with Sertoli cells, controlling the cell junctional physiology for coordinating proper spatial and temporal development of germ cells during spermatogenesis.
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Affiliation(s)
- Natalie R Peer
- School of Molecular Biosciences, Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Sze Ming Law
- School of Molecular Biosciences, Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Brenda Murdoch
- School of Molecular Biosciences, Center for Reproductive Biology, Washington State University, Pullman, Washington
- Department of Animal and Veterinary Science, University of Idaho, Moscow, Idaho
| | - Eugenia H Goulding
- Laboratory of Reproductive and Developmental Biology, Gamete Biology Section, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Edward M Eddy
- Laboratory of Reproductive and Developmental Biology, Gamete Biology Section, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Kwanhee Kim
- School of Molecular Biosciences, Center for Reproductive Biology, Washington State University, Pullman, Washington
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16
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Jauregui EJ, Mitchell D, Topping T, Hogarth CA, Griswold MD. Retinoic acid receptor signaling is necessary in steroidogenic cells for normal spermatogenesis and epididymal function. Development 2018; 145:dev160465. [PMID: 29899137 PMCID: PMC6053667 DOI: 10.1242/dev.160465] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 05/31/2018] [Indexed: 12/24/2022]
Abstract
Spermatogenesis in mammals is a very complex, highly organized process, regulated in part by testosterone and retinoic acid (RA). Much is known about how RA and testosterone signaling pathways independently regulate this process, but there is almost no information regarding whether these two signaling pathways directly interact and whether RA is crucial for steroidogenic cell function. This study uses a transgenic mouse line that expresses a dominant-negative form of RA receptor α (RAR-DN) and the steroidogenic cell-specific Cre mouse line, Cyp17iCre, to generate male mice with steroidogenic cells unable to perform RA signaling. Testes of mutant mice displayed increased apoptosis of pachytene spermatocytes, an increased number of macrophages in the interstitium and a loss of advanced germ cells. Additionally, blocking RA signaling in Leydig cells resulted in increased permeability of the blood-testis barrier, decreased levels of the steroidogenic enzyme cytochrome P450 17a1 and decreased testosterone levels. Surprisingly, the epididymides of the mutant mice also displayed an abnormal phenotype. This study demonstrates that RA signaling is required in steroidogenic cells for their normal function and, thus, for male fertility.
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Affiliation(s)
- Estela J Jauregui
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA 99164, Washington, USA
| | - Debra Mitchell
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA 99164, Washington, USA
| | - Traci Topping
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA 99164, Washington, USA
| | - Cathryn A Hogarth
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA 99164, Washington, USA
| | - Michael D Griswold
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA 99164, Washington, USA
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17
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Griswold MD. 50 years of spermatogenesis: Sertoli cells and their interactions with germ cells. Biol Reprod 2018; 99:87-100. [PMID: 29462262 PMCID: PMC7328471 DOI: 10.1093/biolre/ioy027] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 01/22/2018] [Accepted: 02/02/2018] [Indexed: 01/15/2023] Open
Abstract
The complex morphology of the Sertoli cells and their interactions with germ cells has been a focus of investigators since they were first described by Enrico Sertoli. In the past 50 years, information on Sertoli cells has transcended morphology alone to become increasingly more focused on molecular questions. The goal of investigators has been to understand the role of the Sertoli cells in spermatogenesis and to apply that information to problems relating to male fertility. Sertoli cells are unique in that they are a nondividing cell population that is active for the reproductive lifetime of the animal and cyclically change morphology and gene expression. The numerous and distinctive junctional complexes and membrane specializations made by Sertoli cells provide a scaffold and environment for germ cell development. The increased focus of investigators on the molecular components and putative functions of testicular cells has resulted primarily from procedures that isolate specific cell types from the testicular milieu. Products of Sertoli cells that influence germ cell development and vice versa have been characterized from cultured cells and from the application of transgenic technologies. Germ cell transplantation has shown that the Sertoli cells respond to cues from germ cells with regard to developmental timing and has furthered a focus on spermatogenic stem cells and the stem cell niche. Very basic and universal features of spermatogenesis such as the cycle of the seminiferous epithelium and the spermatogenic wave are initiated by Sertoli cells and maintained by Sertoli-germ cell cooperation.
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Affiliation(s)
- Michael D Griswold
- Center for Reproductive Biology, Washington State University, Pullman, Washington, USA
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18
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Agrimson KS, Oatley MJ, Mitchell D, Oatley JM, Griswold MD, Hogarth CA. Retinoic acid deficiency leads to an increase in spermatogonial stem number in the neonatal mouse testis, but excess retinoic acid results in no change. Dev Biol 2017; 432:229-236. [PMID: 29037932 DOI: 10.1016/j.ydbio.2017.10.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 10/02/2017] [Accepted: 10/03/2017] [Indexed: 01/04/2023]
Abstract
The onset of spermatogenesis occurs in response to retinoic acid (RA), the active metabolite of vitamin A. However, whether RA plays any role during establishment of the spermatogonial stem cell (SSC) pool is unknown. Because designation of the SSC population and the onset of RA signaling in the testis that induces differentiation have similar timing, this study asked whether RA influenced SSC establishment. Whole mount immunofluorescence and flow cytometric analysis using the Id4-eGfp transgenic reporter mouse line revealed an enrichment for ID4-EGFP+ cells within the testis following inhibition of RA synthesis by WIN 18,446 treatment. Transplantation analyses confirmed a significant increase in the number of SSCs in testes from RA-deficient animals. Conversely, no difference in the ID4-EGFP+ population or change in SSC number were detected following exposure to an excess of RA. Collectively, reduced RA altered the number of SSCs present in the neonatal testis but precocious RA exposure in the neonatal testis did not, suggesting that RA deficiency causes a greater proportion of progenitor undifferentiated spermatogonia to retain their SSC state past the age when the pool is thought to be determined.
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Affiliation(s)
- Kellie S Agrimson
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA, USA
| | - Melissa J Oatley
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA, USA
| | - Debra Mitchell
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA, USA
| | - Jon M Oatley
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA, USA
| | - Michael D Griswold
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA, USA
| | - Cathryn A Hogarth
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA, USA.
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19
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Potter SJ, DeFalco T. Role of the testis interstitial compartment in spermatogonial stem cell function. Reproduction 2017; 153:R151-R162. [PMID: 28115580 DOI: 10.1530/rep-16-0588] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/22/2016] [Accepted: 01/23/2017] [Indexed: 01/15/2023]
Abstract
Intricate cellular and molecular interactions ensure that spermatogonial stem cells (SSCs) proceed in a step-wise differentiation process through spermatogenesis and spermiogenesis to produce sperm. SSCs lie within the seminiferous tubule compartment, which provides a nurturing environment for the development of sperm. Cells outside of the tubules, such as interstitial and peritubular cells, also help direct SSC activity. This review focuses on interstitial (interstitial macrophages, Leydig cells and vasculature) and peritubular (peritubular macrophages and peritubular myoid cells) cells and their role in regulating the SSC self-renewal and differentiation in mammals. Leydig cells, the major steroidogenic cells in the testis, influence SSCs through secreted factors, such as insulin growth factor 1 (IGF1) and colony-stimulating factor 1 (CSF1). Macrophages interact with SSCs through various potential mechanisms, such as CSF1 and retinoic acid (RA), to induce the proliferation or differentiation of SSCs respectively. Vasculature influences SSC dynamics through CSF1 and vascular endothelial growth factor (VEGF) and by regulating oxygen levels. Lastly, peritubular myoid cells produce one of the most well-known factors that is required for SSC self-renewal, glial cell line-derived neurotrophic factor (GDNF), as well as CSF1. Overall, SSC interactions with interstitial and peritubular cells are critical for SSC function and are an important underlying factor promoting male fertility.
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Affiliation(s)
- Sarah J Potter
- Division of Reproductive SciencesCincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Tony DeFalco
- Division of Reproductive SciencesCincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
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20
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Dumont L, Oblette A, Rondanino C, Jumeau F, Bironneau A, Liot D, Duchesne V, Wils J, Rives N. Vitamin A prevents round spermatid nuclear damage and promotes the production of motile sperm during in vitro maturation of vitrified pre-pubertal mouse testicular tissue. Mol Hum Reprod 2016; 22:819-832. [PMID: 27671755 DOI: 10.1093/molehr/gaw063] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 08/06/2016] [Accepted: 08/31/2016] [Indexed: 11/14/2022] Open
Abstract
STUDY QUESTION Does vitamin A (retinol, Rol) prevent round spermatid nuclear damage and increase the production of motile sperm during in vitro maturation of vitrified pre-pubertal mouse testicular tissue? SUMMARY ANSWER The supplementation of an in vitro culture of ~0.75 mm3 testicular explants from pre-pubertal mice with Rol enhances spermatogenesis progression during the first spermatogenic wave. WHAT IS KNOWN ALREADY The production of functional spermatozoa in vitro has only been achieved in the mouse model and remains a rare event. Establishing an efficient culture medium for vitrified pre-pubertal testicular tissue is now a crucial step to improve the spermatic yield obtained in vitro. The role of Rol in promoting the differentiation of spermatogonia and their entry into meiosis is well established; however, it has been postulated that Rol is also required to support their full development into elongated spermatids. STUDY DESIGN, SIZE, DURATION A total of 60 testes from 6.5 days post-partum (dpp) mice were vitrified/warmed, cut into fragments and cultured for 30 days: 20 testes were used for light microscopy and histological analyses, 20 testes for DNA fragmentation assessment in round spermatids and 20 testes for induced sperm motility assessment. Overall, 16 testes of 6.5 dpp were used as in vitro fresh tissue controls and 12 testes of 36.5 dpp mice as in vivo controls. Testes were vitrified with the optimal solid surface vitrification procedure and cultured with an in vitro organ culture system until Day 30 (D30). Histological analysis, cell death, degenerating round spermatids, DNA fragmentation in round spermatids and induced sperm motility were assessed. Testosterone levels were measured in media throughout the culture by radioimmunoassay. MAIN RESULTS AND THE ROLE OF CHANCE At D30, better tissue development together with higher differentiation of spermatogonial stem cells, and higher global cell division ability were observed for vitrified/warmed testicular fragments of ~0.75 mm3 with a culture medium supplemented with Rol compared to controls. During in vitro culture of vitrified pre-pubertal testicular tissue, Rol enhanced and maintained the entry of spermatogonia into meiosis and promoted a higher spermatic yield. Furthermore, decreased round spermatid nuclear alterations and DNA damage combined with induced sperm motility comparable to in vivo highlight the crucial role of Rol in the progression of spermatogenesis during the first wave. LIMITATIONS, REASONS FOR CAUTION Despite our promising results, the culture media will have to be further improved and adapted within the context of a human application. WIDER IMPLICATIONS OF THE FINDINGS The results have potential implications for the handling of human pre-pubertal testicular tissues cryopreserved for fertility preservation. However, because some alterations in round spermatids persist after in vitro culture with Rol, the procedure needs to be optimized before human application, bearing in mind that the murine and human spermatogenic processes differ in many respects. LARGE SCALE DATA None. STUDY FUNDING AND COMPETING INTERESTS This study was supported by a Ph.D. grant from the Normandy University and a financial support from 'la Ligue nationale contre le cancer' (both awarded to L.D.), funding from Rouen University Hospital, Institute for Research and Innovation in Biomedicine (IRIB) and Agence de la Biomédecine. The authors declare that there is no conflict of interest.
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Affiliation(s)
- L Dumont
- EA 4308 'Gametogenesis and Gamete Quality', Reproductive Biology Laboratory-CECOS, Rouen University Hospital, Institute for Biomedical Research, Pavillon Derocque, Hôpital Charles Nicolle, 1 Rue de Germont, 76031 Rouen Cedex, France.,Normandy University, Ed 497 Normande de Biologie Intégrative, Santé et Environnement (EdNBISE), Bâtiment Principal UFR Sciences, Place Emilie Blondel, 76821 Mont-Saint-Aignan Cedex, France.,Institute for Research and Innovation in Biomedicine (IRIB) , IRIB Normandy, 22 Boulevard Gambetta, 76183 Rouen Cedex, France
| | - A Oblette
- EA 4308 'Gametogenesis and Gamete Quality', Reproductive Biology Laboratory-CECOS, Rouen University Hospital, Institute for Biomedical Research, Pavillon Derocque, Hôpital Charles Nicolle, 1 Rue de Germont, 76031 Rouen Cedex, France.,Normandy University, Ed 497 Normande de Biologie Intégrative, Santé et Environnement (EdNBISE), Bâtiment Principal UFR Sciences, Place Emilie Blondel, 76821 Mont-Saint-Aignan Cedex, France.,Institute for Research and Innovation in Biomedicine (IRIB) , IRIB Normandy, 22 Boulevard Gambetta, 76183 Rouen Cedex, France
| | - C Rondanino
- EA 4308 'Gametogenesis and Gamete Quality', Reproductive Biology Laboratory-CECOS, Rouen University Hospital, Institute for Biomedical Research, Pavillon Derocque, Hôpital Charles Nicolle, 1 Rue de Germont, 76031 Rouen Cedex, France.,Institute for Research and Innovation in Biomedicine (IRIB) , IRIB Normandy, 22 Boulevard Gambetta, 76183 Rouen Cedex, France
| | - F Jumeau
- EA 4308 'Gametogenesis and Gamete Quality', Reproductive Biology Laboratory-CECOS, Rouen University Hospital, Institute for Biomedical Research, Pavillon Derocque, Hôpital Charles Nicolle, 1 Rue de Germont, 76031 Rouen Cedex, France.,Institute for Research and Innovation in Biomedicine (IRIB) , IRIB Normandy, 22 Boulevard Gambetta, 76183 Rouen Cedex, France
| | - A Bironneau
- EA 4308 'Gametogenesis and Gamete Quality', Reproductive Biology Laboratory-CECOS, Rouen University Hospital, Institute for Biomedical Research, Pavillon Derocque, Hôpital Charles Nicolle, 1 Rue de Germont, 76031 Rouen Cedex, France
| | - D Liot
- EA 4308 'Gametogenesis and Gamete Quality', Reproductive Biology Laboratory-CECOS, Rouen University Hospital, Institute for Biomedical Research, Pavillon Derocque, Hôpital Charles Nicolle, 1 Rue de Germont, 76031 Rouen Cedex, France
| | - V Duchesne
- EA 4308 'Gametogenesis and Gamete Quality', Reproductive Biology Laboratory-CECOS, Rouen University Hospital, Institute for Biomedical Research, Pavillon Derocque, Hôpital Charles Nicolle, 1 Rue de Germont, 76031 Rouen Cedex, France
| | - J Wils
- Biochemistry Laboratory, Rouen University Hospital, Institute for Biomedical Research , Pavillon Derocque, Hôpital Charles Nicolle, 1 Rue de Germont, 76031 Rouen Cedex, France
| | - N Rives
- EA 4308 'Gametogenesis and Gamete Quality', Reproductive Biology Laboratory-CECOS, Rouen University Hospital, Institute for Biomedical Research, Pavillon Derocque, Hôpital Charles Nicolle, 1 Rue de Germont, 76031 Rouen Cedex, France .,Institute for Research and Innovation in Biomedicine (IRIB) , IRIB Normandy, 22 Boulevard Gambetta, 76183 Rouen Cedex, France
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21
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Chen Y, Ma L, Hogarth C, Wei G, Griswold MD, Tong MH. Retinoid signaling controls spermatogonial differentiation by regulating expression of replication-dependent core histone genes. Development 2016; 143:1502-11. [PMID: 26965368 DOI: 10.1242/dev.135939] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/02/2016] [Indexed: 12/14/2022]
Abstract
Retinoic acid (RA) signaling is crucial for spermatogonial differentiation, which is a key step for spermatogenesis. We explored the mechanisms underlying spermatogonial differentiation by targeting expression of a dominant-negative mutant of retinoic acid receptor α (RARα) specifically to the germ cells of transgenic mice to subvert the activity of endogenous receptors. Here we show that: (1) inhibition of retinoid signaling in germ cells completely blocked spermatogonial differentiation identical to vitamin A-deficient (VAD) mice; (2) the blockage of spermatogonial differentiation by impaired retinoid signaling resulted from an arrest of entry of the undifferentiated spermatogonia into S phase; and (3) retinoid signaling regulated spermatogonial differentiation through controlling expression of its direct target genes, including replication-dependent core histone genes. Taken together, our results demonstrate that the action of retinoid signaling on spermatogonial differentiation in vivo is direct through the spermatogonia itself, and provide the first evidence that this is mediated by regulation of expression of replication-dependent core histone genes.
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Affiliation(s)
- Yao Chen
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Li Ma
- CAS-MPG Partner Institute for Computational Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Cathryn Hogarth
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA
| | - Gang Wei
- CAS-MPG Partner Institute for Computational Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Michael D Griswold
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA
| | - Ming-Han Tong
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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22
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Abstract
Mammalian spermatogenesis requires a stem cell pool, a period of amplification of cell numbers, the completion of reduction division to haploid cells (meiosis), and the morphological transformation of the haploid cells into spermatozoa (spermiogenesis). The net result of these processes is the production of massive numbers of spermatozoa over the reproductive lifetime of the animal. One study that utilized homogenization-resistant spermatids as the standard determined that human daily sperm production (dsp) was at 45 million per day per testis (60). For each human that means ∼1,000 sperm are produced per second. A key to this level of gamete production is the organization and architecture of the mammalian testes that results in continuous sperm production. The seemingly complex repetitious relationship of cells termed the "cycle of the seminiferous epithelium" is driven by the continuous commitment of undifferentiated spermatogonia to meiosis and the period of time required to form spermatozoa. This commitment termed the A to A1 transition requires the action of retinoic acid (RA) on the undifferentiated spermatogonia or prospermatogonia. In stages VII to IX of the cycle of the seminiferous epithelium, Sertoli cells and germ cells are influenced by pulses of RA. These pulses of RA move along the seminiferous tubules coincident with the spermatogenic wave, presumably undergoing constant synthesis and degradation. The RA pulse then serves as a trigger to commit undifferentiated progenitor cells to the rigidly timed pathway into meiosis and spermatid differentiation.
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Affiliation(s)
- Michael D Griswold
- School of Molecular Biosciences, Center for Reproductive Biology, College of Veterinary Medicine, Washington State University, Pullman, Washington
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23
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Yoshida S. From cyst to tubule: innovations in vertebrate spermatogenesis. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2016; 5:119-31. [PMID: 26305780 PMCID: PMC5049625 DOI: 10.1002/wdev.204] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 06/20/2015] [Accepted: 07/05/2015] [Indexed: 12/15/2022]
Abstract
Although vertebrates share many common traits, their germline development and function exhibit significant divergence. In particular, this article focuses on their spermatogenesis. The fundamental elements that constitute vertebrate spermatogenesis and the evolutionary changes that occurred upon transition from water to land will be discussed. The life-long continuity of spermatogenesis is supported by the function of stem cells. Series of mitotic and meiotic germ cell divisions are 'incomplete' due to incomplete cytokinesis, forming syncytia interconnected via intercellular bridges (ICBs). Throughout this process, germ cells are supported by appropriate microenvironments established primarily by somatic Sertoli cells. In anamniotes (fish and amphibians) spermatogenesis progresses in cysts, in which developing germ cell syncytia are individually encapsulated by Sertoli cells. Accordingly, Sertoli cells undergo turnover with germ cells that they nourish. This mode of cystic spermatogenesis is also observed in nonvertebrates as insects. In amniotes (reptiles, birds, and mammals), however, Sertoli cells do not turn over but comprise a persistent structure of seminiferous tubules. Sertoli cells nourish different stages of germ cells simultaneously in distinct regions of their surface. This function of Sertoli cells is spatiotemporally orchestrated, and the seminiferous epithelial cycle and spermatogenic wave make the seminiferous tubules a high-throughput factory for sperm production. Furthermore, contrary to the organized differentiating cells, undifferentiated spermatogonia that comprise the stem cell compartment exhibit active motion over the basal layer of seminiferous tubules and the frequent breakdown of ICBs. Thus, amniote seminiferous tubules represent a typical facultative (or open) niche environment without a stem cell tethering anatomically defined niche. WIREs Dev Biol 2016, 5:119-131. doi: 10.1002/wdev.204 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Shosei Yoshida
- Division of Germ Cell Biology, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
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24
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Liu XR, Wang YY, Dan XG, Kumar A, Ye TZ, Yu YY, Yang LG. Anti-inflammatory potential of β-cryptoxanthin against LPS-induced inflammation in mouse Sertoli cells. Reprod Toxicol 2015; 60:148-55. [PMID: 26686910 DOI: 10.1016/j.reprotox.2015.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 11/04/2015] [Accepted: 11/10/2015] [Indexed: 10/22/2022]
Abstract
β-cryptoxanthin (CX), a major carotenoid pigment, can inhibit inflammatory gene expression in mice with nonalcoholic steatohepatitis. In the present study, we examined the anti-inflammatory effects of CX on lipopolysaccharide (LPS)-induced inflammation in mouse primary Sertoli cells and the possible molecular mechanisms behind its effects. The results showed that CX significantly inhibited LPS-induced decreases in cell viability and in the percentage of apoptotic cells. Moreover, CX inhibited the LPS-induced up-regulation of tumor necrosis factor α (TNF-α), interleukin-10 (IL-10), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in Sertoli cells. In addition, CX significantly limited the LPS-induced down-regulation of AR, HSF2, CREB, FSHR, INHBB and ABP in Sertoli cells. Western blot analysis showed that CX significantly suppressed NF-κB (p65) activation as well as MAPK phosphorylation. All the results suggested that CX suppressed inflammation, possibly associated with the NF-κB activation and MAPK of phosphorylation. Thus, CX may possess therapeutic potential against inflammation-related diseases.
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Affiliation(s)
- Xiao-Ran Liu
- Key Laboratory of China Education Ministry in Agricultural Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, P.R. China, 430070
| | - Yue-Ying Wang
- Key Laboratory of China Education Ministry in Agricultural Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, P.R. China, 430070
| | - Xin-Gang Dan
- Key Laboratory of China Education Ministry in Agricultural Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, P.R. China, 430070
| | - Ashok Kumar
- College of Life Science and Technology, State Key laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, P.R. China, 430070
| | - Ting-Zhu Ye
- Key Laboratory of China Education Ministry in Agricultural Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, P.R. China, 430070
| | - Yao-Yao Yu
- Key Laboratory of China Education Ministry in Agricultural Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, P.R. China, 430070
| | - Li-Guo Yang
- Key Laboratory of China Education Ministry in Agricultural Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, P.R. China, 430070.
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Kent T, Arnold SL, Fasnacht R, Rowsey R, Mitchell D, Hogarth CA, Isoherranen N, Griswold MD. ALDH Enzyme Expression Is Independent of the Spermatogenic Cycle, and Their Inhibition Causes Misregulation of Murine Spermatogenic Processes. Biol Reprod 2015; 94:12. [PMID: 26632609 PMCID: PMC4809557 DOI: 10.1095/biolreprod.115.131458] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 11/13/2015] [Indexed: 01/14/2023] Open
Abstract
Perturbations in the vitamin A metabolism pathway could be a significant cause of male infertility, as well as a target toward the development of a male contraceptive, necessitating the need for a better understanding of how testicular retinoic acid (RA) concentrations are regulated. Quantitative analyses have recently demonstrated that RA is present in a pulsatile manner along testis tubules. However, it is unclear if the aldehyde dehydrogenase (ALDH) enzymes, which are responsible for RA synthesis, contribute to the regulation of these RA concentration gradients. Previous studies have alluded to fluctuations in ALDH enzymes across the spermatogenic cycle, but these inferences have been based primarily on qualitative transcript localization experiments. Here, we show via various quantitative methods that the three well-known ALDH enzymes (ALDH1A1, ALDH1A2, and ALDH1A3), and an ALDH enzyme previously unreported in the murine testis (ALDH8A1), are not expressed in a stage-specific manner in the adult testis, but do fluctuate throughout juvenile development in perfect agreement with the first appearance of each advancing germ cell type. We also show, via treatments with a known ALDH inhibitor, that lowered testicular RA levels result in an increase in blood-testis barrier permeability, meiotic recombination, and meiotic defects. Taken together, these data further our understanding of the complex regulatory actions of RA on various spermatogenic events and, in contrast with previous studies, also suggest that the ALDH enzymes are not responsible for regulating the recently measured RA pulse.
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Affiliation(s)
- Travis Kent
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Samuel L Arnold
- Department of Pharmaceutics, University of Washington, Seattle, Washington
| | - Rachael Fasnacht
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Ross Rowsey
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Debra Mitchell
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Cathryn A Hogarth
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Nina Isoherranen
- Department of Pharmaceutics, University of Washington, Seattle, Washington
| | - Michael D Griswold
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, Washington
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Macrophages Contribute to the Spermatogonial Niche in the Adult Testis. Cell Rep 2015; 12:1107-19. [PMID: 26257171 DOI: 10.1016/j.celrep.2015.07.015] [Citation(s) in RCA: 199] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 05/02/2015] [Accepted: 07/08/2015] [Indexed: 02/07/2023] Open
Abstract
The testis produces sperm throughout the male reproductive lifespan by balancing self-renewal and differentiation of spermatogonial stem cells (SSCs). Part of the SSC niche is thought to lie outside the seminiferous tubules of the testis; however, specific interstitial components of the niche that regulate spermatogonial divisions and differentiation remain undefined. We identified distinct populations of testicular macrophages, one of which lies on the surface of seminiferous tubules, in close apposition to areas of tubules enriched for undifferentiated spermatogonia. These macrophages express spermatogonial proliferation- and differentiation-inducing factors, such as colony-stimulating factor 1 (CSF1) and enzymes involved in retinoic acid (RA) biosynthesis. We show that transient depletion of macrophages leads to a disruption in spermatogonial differentiation. These findings reveal an unexpected role for macrophages in the spermatogonial niche in the testis and raise the possibility that macrophages play previously unappreciated roles in stem/progenitor cell regulation in other tissues.
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Nourashrafeddin S. Potential roles of gonadotropins to control pulsatile retinoic acid signaling during spermatogenesis. Med Hypotheses 2015; 85:303-4. [PMID: 26141633 DOI: 10.1016/j.mehy.2015.05.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 05/30/2015] [Indexed: 12/27/2022]
Abstract
Spermatogenesis is a highly regulated process that takes place in the seminiferous tubules of testis. This process initiates at puberty with differentiation of spermatogonia and their meiotic entry. The initiation of spermatogenesis depends on gonadotropins secreted by the pituitary gland; i.e., follicle-stimulating hormone (FSH) and luteinizing hormone (LH). In the absence of FSH and LH only premeiotic germ cells are present in the testis. The prepubertal development phase in juvenile testis is characterized by a protracted hypogonadotropic state, which only consists of Sertoli and undifferentiated germ cells in the seminiferous epithelium. All germ cells in the juvenile testis are undifferentiated spermatogonia, which are proliferating in a relatively gonadotropin-independent manner. It has been revealed that vitamin A deficient (VAD) animals are also infertile, and only premeiotic germ cells (undifferentiated spermatogonia) are present in their seminiferous tubules. The developmental block in VAD animal can be removed by administration of retinol and germ cell differentiation reinitiates in a synchronous manner. Recent studies have revealed that the biologically active form of vitamin A, retinoic acid (RA), regulates germ cell differentiation and lead to the generation of the cycle of the seminiferous epithelium and normal spermatogenic wave. Recent study has shown that synchronous spermatogenesis at neonatal mouse, but not after initiation of meiosis, can be induced by treating vitamin A sufficient males with RA. The treatment of neonatal males at different ages with exogenous RA has revealed that although RA is sufficient to induce differentiation of spermatogonial at 4 dpp and earlier, it fails to alter asynchrony and it does not irreversibly cause a spermatogonial differentiation. These observations led us to suggest that gonadotropins trigger differentiation of spermatogonia and spermatogenesis through regulation of RA signaling in the seminiferous epithelium of the adult testis.
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Hogarth CA, Evans E, Onken J, Kent T, Mitchell D, Petkovich M, Griswold MD. CYP26 Enzymes Are Necessary Within the Postnatal Seminiferous Epithelium for Normal Murine Spermatogenesis. Biol Reprod 2015; 93:19. [PMID: 26040672 DOI: 10.1095/biolreprod.115.129718] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/28/2015] [Indexed: 12/11/2022] Open
Abstract
The active metabolite of vitamin A, retinoic acid (RA), is known to be essential for spermatogenesis. Changes to RA levels within the seminiferous epithelium can alter the development of male germ cells, including blocking their differentiation completely. Excess RA has been shown to cause germ cell death in both neonatal and adult animals, yet the cells capable of degrading RA within the testis have yet to be investigated. One previous study alluded to a requirement for one of the RA degrading enzymes, CYP26B1, in Sertoli cells but no data exist to determine whether germ cells possess the ability to degrade RA. To bridge this gap, the roles of CYP26A1 and CYP26B1 within the seminiferous epithelium were investigated by creating single and dual conditional knockouts of these enzymes in either Sertoli or germ cells. Analysis of these knockout models revealed that deletion of both Cyp26a1 and Cyp26b1 in either cell type resulted in increased vacuolization within the seminiferous tubules, delayed spermatid release, and an increase in the number of STRA8-positive spermatogonia, but spermatozoa were still produced and the animals were found to be fertile. However, elimination of CYP26B1 activity within both germ and Sertoli cells resulted in severe male subfertility, with a loss of advanced germ cells from the seminiferous epithelium. These data indicate that CYP26 activity within either Sertoli or germ cells is essential for the normal progression of spermatogenesis and that its loss can result in reduced male fertility.
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Affiliation(s)
- Cathryn A Hogarth
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Elizabeth Evans
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Jennifer Onken
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Travis Kent
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Debra Mitchell
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Martin Petkovich
- Cancer Research Institute, Queen's University, Kingston Ontario, Canada
| | - Michael D Griswold
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, Washington
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29
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Pradhan A, Olsson PE. Inhibition of retinoic acid synthesis disrupts spermatogenesis and fecundity in zebrafish. Gen Comp Endocrinol 2015; 217-218:81-91. [PMID: 25687389 DOI: 10.1016/j.ygcen.2015.02.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 01/31/2015] [Accepted: 02/06/2015] [Indexed: 01/03/2023]
Abstract
Timing of germ cell entry into meiosis is sexually dimorphic in mammals. However it was recently shown that germ cells initiate meiosis at the same time in male and female zebrafish. Retinoic acid (RA) has been shown to be critical for mammalian spermatogenesis. Inhibition of RA synthesis by WIN 18,446 has been reported to inhibit spermatogenesis in a wide variety of animals including humans and was once used as a contraceptive in humans. In this study we explored the role of RA in zebrafish spermatogenesis. In silico analysis with Internal coordinate mechanics docking software showed that WIN 18,446 can bind to the rat, human and zebrafish Aldh1a2 catalytic domain with equivalent potency. RA exposure resulted in up-regulation of the RA metabolizing enzyme genes cyp26a1, cyp26b1 and cyp26c1 in vitro and in vivo. Exposure to WIN 18,446 resulted in down-regulation of Aldh1a2, cyp26a1 and cyp26b1 in vivo. WIN 18,446 was effective in disrupting spermatogenesis and fecundity in zebrafish but the reduction in sperm count and fecundity was only observed when zebrafish were maintained on a strict Artemia nauplii diet which is known to contain low levels of vitamin A. This study shows that RA is involved in spermatogenesis as well as oocyte development in zebrafish. As the zebrafish Aldh1a2 structure and function is similar to the mammalian counterpart, Aldh1a2 inhibitor screening using zebrafish as a model system may be beneficial in the discovery and development of new and safe contraceptives for humans.
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Affiliation(s)
- Ajay Pradhan
- Biology, The Life Science Center, School of Science and Technology, Örebro University, SE-701 82 Örebro, Sweden
| | - Per-Erik Olsson
- Biology, The Life Science Center, School of Science and Technology, Örebro University, SE-701 82 Örebro, Sweden.
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30
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Manku G, Culty M. Mammalian gonocyte and spermatogonia differentiation: recent advances and remaining challenges. Reproduction 2015; 149:R139-57. [DOI: 10.1530/rep-14-0431] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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. While the formation of abnormal gonocytes or SSCs could lead to infertility, defective gonocyte differentiation might be at the origin of testicular germ cell tumors. Thus, it is important to better understand the molecular mechanisms regulating these processes. This review summarizes and compares the present knowledge on the mechanisms regulating mammalian gonocyte and spermatogonial differentiation.
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31
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Zhang T, Murphy MW, Gearhart MD, Bardwell VJ, Zarkower D. The mammalian Doublesex homolog DMRT6 coordinates the transition between mitotic and meiotic developmental programs during spermatogenesis. Development 2014; 141:3662-71. [PMID: 25249458 DOI: 10.1242/dev.113936] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In mammals, a key transition in spermatogenesis is the exit from spermatogonial differentiation and mitotic proliferation and the entry into spermatocyte differentiation and meiosis. Although several genes that regulate this transition have been identified, how it is controlled and coordinated remains poorly understood. Here, we examine the role in male gametogenesis of the Doublesex-related gene Dmrt6 (Dmrtb1) in mice and find that Dmrt6 plays a crucial role in directing germ cells through the mitotic-to-meiotic germ cell transition. DMRT6 protein is expressed in late mitotic spermatogonia. In mice of the C57BL/6J strain, a null mutation in Dmrt6 disrupts spermatogonial differentiation, causing inappropriate expression of spermatogonial differentiation factors, including SOHLH1, SOHLH2 and DMRT1 as well as the meiotic initiation factor STRA8, and causing most late spermatogonia to undergo apoptosis. In mice of the 129Sv background, most Dmrt6 mutant germ cells can complete spermatogonial differentiation and enter meiosis, but they show defects in meiotic chromosome pairing, establishment of the XY body and processing of recombination foci, and they mainly arrest in mid-pachynema. mRNA profiling of Dmrt6 mutant testes together with DMRT6 chromatin immunoprecipitation sequencing suggest that DMRT6 represses genes involved in spermatogonial differentiation and activates genes required for meiotic prophase. Our results indicate that Dmrt6 plays a key role in coordinating the transition in gametogenic programs from spermatogonial differentiation and mitosis to spermatocyte development and meiosis.
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Affiliation(s)
- Teng Zhang
- Developmental Biology Center, Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA Molecular, Cellular, Developmental Biology and Genetics Graduate Program, University of Minnesota, Minneapolis, MN 55455, USA
| | - Mark W Murphy
- Developmental Biology Center, Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Micah D Gearhart
- Developmental Biology Center, Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Vivian J Bardwell
- Developmental Biology Center, Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA University of Minnesota Masonic Cancer Center, Minneapolis, MN 55455, USA
| | - David Zarkower
- Developmental Biology Center, Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA University of Minnesota Masonic Cancer Center, Minneapolis, MN 55455, USA
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32
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Davis JC, Snyder EM, Hogarth CA, Small C, Griswold MD. Induction of spermatogenic synchrony by retinoic acid in neonatal mice. SPERMATOGENESIS 2014; 3:e23180. [PMID: 23687613 PMCID: PMC3644044 DOI: 10.4161/spmg.23180] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Retinoic acid (RA) is required for the successful differentiation and meiotic entry of germ cells in the murine testis. The availability of RA to undifferentiated germ cells begins in a variable, uneven pattern during the first few days after birth and establishes the asynchronous pattern of germ cell differentiation in adulthood. It has been shown that synchronous spermatogenesis can be induced in 2 d postpartum mice, but not in adult mice, by treating vitamin A sufficient males with RA. In this study, neonatal males were treated at different ages with a single dose of RA and spermatogenesis was examined after recovery to adulthood. The failure of exogenous RA to alter asynchrony correlates with the appearance of meiotic preleptotene spermatocytes within the seminiferous epithelium.
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Affiliation(s)
- Jeffrey C Davis
- School of Molecular Biosciences; Washington State University; Pullman, WA USA
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33
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Evans E, Hogarth C, Mitchell D, Griswold M. Riding the spermatogenic wave: profiling gene expression within neonatal germ and sertoli cells during a synchronized initial wave of spermatogenesis in mice. Biol Reprod 2014; 90:108. [PMID: 24719255 DOI: 10.1095/biolreprod.114.118034] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Continual sperm production relies on germ cells undergoing spermatogenesis asynchronously. As a result, the testis always contains a mixed population of germ cells at different stages of their differentiation process. The heterogeneous nature of the testis makes profiling gene expression within Sertoli cells or specific populations of germ cells impossible when a wild-type testis is assessed. We recently reported a unique method for synchronizing spermatogenesis without affecting fertility by manipulating RA levels within the neonatal testis. Using this protocol, combined with the RiboTag transgenic mouse line, we have mapped the Sertoli and germ cell translatome during the initial synchronized wave of spermatogenesis. Using microarray analysis, we identified 392 and 194 germ cell and Sertoli cells transcripts, respectively, that dynamically change during spermatogonial differentiation, division, and the onset of meiosis. Functional annotation clustering revealed that transcripts enriched in germ cells were mostly associated with meiosis (21 transcripts), chromatin organization (12 transcripts), and cell cycle (3 transcripts). In addition, glycoproteins (65 transcripts), cell adhesion (15 transcripts), and cell junction (13 transcripts) transcripts were overrepresented in the Sertoli cell-enriched list. These datasets represent the first transcriptional analysis of spermatogonial differentiation, division, and meiotic onset. These data suggest that several of the genes encoding meiotic proteins are expressed and are actively being translated well before germ cells enter meiosis. In addition, this study provides novel candidate genes, Asf1b and Esyt3, that may be involved in the regulation of spermatogonial chromatin reorganization, germ-Sertoli cell interactions, and/or blood-testis barrier formation.
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Affiliation(s)
- Elizabeth Evans
- School of Molecular Biosciences and The Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Cathryn Hogarth
- School of Molecular Biosciences and The Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Debra Mitchell
- School of Molecular Biosciences and The Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Michael Griswold
- School of Molecular Biosciences and The Center for Reproductive Biology, Washington State University, Pullman, Washington
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34
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Khillan JS. Vitamin A/retinol and maintenance of pluripotency of stem cells. Nutrients 2014; 6:1209-22. [PMID: 24662164 PMCID: PMC3967188 DOI: 10.3390/nu6031209] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 02/21/2014] [Accepted: 02/24/2014] [Indexed: 12/22/2022] Open
Abstract
Retinol, the alcohol form of vitamin A is a key dietary component that plays a critical role in vertebrate development, cell differentiation, reproduction, vision and immune system. Natural and synthetic analogs of retinol, called retinoids, have generally been associated with the cell differentiation via retinoic acid which is the most potent metabolite of retinol. However, a direct function of retinol has not been fully investigated. New evidence has now emerged that retinol supports the self-renewal of stem cells including embryonic stem cells (ESCs), germ line stem cells (GSCs) and cancer stem cells (CSCs) by activating the endogenous machinery for self-renewal by a retinoic acid independent mechanism. The studies have also revealed that stem cells do not contain enzymes that are responsible for metabolizing retinol into retinoic acid. This new function of retinol may have important implications for stem cell biology which can be exploited for quantitative production of pure population of pluripotent stem cells for regenerative medicine as well as clinical applications for cancer therapeutics.
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Affiliation(s)
- Jaspal S Khillan
- Department of Immunology, University of Pittsburgh, 3501 Fifth Ave, Pittsburgh, PA 15261, USA.
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35
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Checking the Pulse of Vitamin A Metabolism and Signaling during Mammalian Spermatogenesis. J Dev Biol 2014. [DOI: 10.3390/jdb2010034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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36
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Lucas TF, Nascimento AR, Pisolato R, Pimenta MT, Lazari MFM, Porto CS. Receptors and signaling pathways involved in proliferation and differentiation of Sertoli cells. SPERMATOGENESIS 2014; 4:e28138. [PMID: 25225624 DOI: 10.4161/spmg.28138] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/05/2014] [Accepted: 02/06/2014] [Indexed: 12/11/2022]
Abstract
The identification of the hormones and other factors regulating Sertoli cell survival, proliferation, and maturation in neonatal, peripubertal, and pubertal life remains one of the most critical questions in testicular biology. The regulation of Sertoli cell proliferation and differentiation is thought to be controlled by cell-cell junctions and a set of circulating and local hormones and growth factors. In this review, we will focus on receptors and intracellular signaling pathways activated by androgen, follicle-stimulating hormone, thyroid hormone, activin, retinoids, insulin, insulin-like growth factor, relaxin, and estrogen, with special emphasis on estrogen receptors. Estrogen receptors activate intracellular signaling pathways that converge on cell cycle and transcription factors and play a role in the regulation of Sertoli cell proliferation and differentiation.
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Affiliation(s)
- Thaís Fg Lucas
- Section of Experimental Endocrinology; Department of Pharmacology; Escola Paulista de Medicina; Universidade Federal de São Paulo; INFAR; Vila Clementino; São Paulo, SP Brazil
| | - Aline R Nascimento
- Section of Experimental Endocrinology; Department of Pharmacology; Escola Paulista de Medicina; Universidade Federal de São Paulo; INFAR; Vila Clementino; São Paulo, SP Brazil
| | - Raisa Pisolato
- Section of Experimental Endocrinology; Department of Pharmacology; Escola Paulista de Medicina; Universidade Federal de São Paulo; INFAR; Vila Clementino; São Paulo, SP Brazil
| | - Maristela T Pimenta
- Section of Experimental Endocrinology; Department of Pharmacology; Escola Paulista de Medicina; Universidade Federal de São Paulo; INFAR; Vila Clementino; São Paulo, SP Brazil
| | - Maria Fatima M Lazari
- Section of Experimental Endocrinology; Department of Pharmacology; Escola Paulista de Medicina; Universidade Federal de São Paulo; INFAR; Vila Clementino; São Paulo, SP Brazil
| | - Catarina S Porto
- Section of Experimental Endocrinology; Department of Pharmacology; Escola Paulista de Medicina; Universidade Federal de São Paulo; INFAR; Vila Clementino; São Paulo, SP Brazil
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37
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Nicholls PK, Harrison CA, Rainczuk KE, Wayne Vogl A, Stanton PG. Retinoic acid promotes Sertoli cell differentiation and antagonises activin-induced proliferation. Mol Cell Endocrinol 2013; 377:33-43. [PMID: 23831638 DOI: 10.1016/j.mce.2013.06.034] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 05/25/2013] [Accepted: 06/26/2013] [Indexed: 12/12/2022]
Abstract
From puberty and throughout adult spermatogenesis, retinoid signalling is essential for germ cell differentiation and male fertility. The initiation of spermatogonial differentiation and germ cell meiosis occurs under the direction of local retinoid signalling in the testis, and corresponds with the final phase of somatic Sertoli cell differentiation at puberty. Here, we consider the cellular and molecular basis of retinoid actions upon Sertoli cell differentiation. Primary rat Sertoli cells were isolated during the pubertal proliferative and quiescent phases at postnatal days 10- and 20- respectively, and cultured with all-trans-retinoic acid. We show that retinoid signalling can potently suppress activin-induced proliferation by antagonising G1 phase progression and entry into the cell cycle. Retinoid signalling was also found to initiate tight junction formation in primary Sertoli cells, consistent with a pro-differentiative role. This study implicates retinoid signalling in the differentiation of both somatic and germ cells in the testis at puberty.
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Affiliation(s)
- Peter K Nicholls
- Prince Henry's Institute of Medical Research, Clayton, Victoria 3168, Australia
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38
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Kawaguchi R, Zhong M, Kassai M, Ter-Stepanian M, Sun H. Differential and isomer-specific modulation of vitamin A transport and the catalytic activities of the RBP receptor by retinoids. J Membr Biol 2013; 246:647-660. [PMID: 23811822 DOI: 10.1007/s00232-013-9578-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 06/12/2013] [Indexed: 12/20/2022]
Abstract
Retinoids are vitamin A derivatives with diverse biological functions. Both natural and artificial retinoids have been used as therapeutic reagents to treat human diseases, but not all retinoid actions are understood mechanistically. Plasma retinol binding protein (RBP) is the principal and specific carrier of vitamin A in the blood. STRA6 is the membrane receptor for RBP that mediates cellular vitamin A uptake. The effects of retinoids or related compounds on the receptor's vitamin A uptake activity and its catalytic activities are not well understood. In this study, we dissected the membrane receptor-mediated vitamin A uptake mechanism using various retinoids. We show that a subset of retinoids strongly stimulates STRA6-mediated vitamin A release from holo-RBP. STRA6 also catalyzes the exchange of retinol in RBP with certain retinoids. The effect of retinoids on STRA6 is highly isomer-specific. This study provides unique insights into the RBP receptor's mechanism and reveals that the vitamin A transport machinery can be a target of retinoid-based drugs.
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Affiliation(s)
- Riki Kawaguchi
- Department of Physiology, Jules Stein Eye Institute, and Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Ming Zhong
- Department of Physiology, Jules Stein Eye Institute, and Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Miki Kassai
- Department of Physiology, Jules Stein Eye Institute, and Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Mariam Ter-Stepanian
- Department of Physiology, Jules Stein Eye Institute, and Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Hui Sun
- Department of Physiology, Jules Stein Eye Institute, and Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
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39
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Abstract
PURPOSE OF REVIEW Description of new evidence to support the model for how retinoic acid regulates spermatogonial differentiation, male meiosis and the cycle of the seminiferous epithelium. RECENT FINDINGS It has been known since the 1920s that vitamin A is essential for spermatogenesis. However, only recently has significant progress been made toward understanding how the active metabolite of vitamin A, retinoic acid, regulates spermatogenesis at multiple different differentiation steps, including the onset of meiosis. Current publications suggest that the initiation and maintenance of the cycle of the seminiferous epithelium is linked to retinoic-acid-driving spermatogonial differentiation and meiotic onset. SUMMARY Retinoic acid appears to act in a pulsatile manner, periodically driving spermatogonial differentiation and meiotic onset at discrete points along testis tubules, and as a result, is likely to be responsible for generating and maintaining the cycle of the seminiferous epithelium.
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Affiliation(s)
- Cathryn A Hogarth
- School of Molecular Biosciences, Center for Reproductive Biology, Washington State University, Pullman, WA 99164, USA
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40
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Yefimova MG, Messaddeq N, Harnois T, Meunier AC, Clarhaut J, Noblanc A, Weickert JL, Cantereau A, Philippe M, Bourmeyster N, Benzakour O. A chimerical phagocytosis model reveals the recruitment by Sertoli cells of autophagy for the degradation of ingested illegitimate substrates. Autophagy 2013; 9:653-66. [PMID: 23439251 PMCID: PMC3669177 DOI: 10.4161/auto.23839] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Phagocytosis and autophagy are typically dedicated to degradation of substrates of extrinsic and intrinsic origins respectively. Although overlaps between phagocytosis and autophagy were reported, the use of autophagy for ingested substrate degradation by nonprofessional phagocytes has not been described. Blood-separated tissues use their tissue-specific nonprofessional phagocytes for homeostatic phagocytosis. In the testis, Sertoli cells phagocytose spermatid residual bodies produced during germ cell differentiation. In the retina, pigmented epithelium phagocytoses shed photoreceptor tips produced during photoreceptor renewal. Spermatid residual bodies and shed photoreceptor tips are phosphatidylserine-exposing substrates. Activation of the tyrosine kinase receptor MERTK, which is implicated in phagocytosis of phosphatidylserine-exposing substrates, is a common feature of Sertoli and retinal pigmented epithelial cell phagocytosis. The major aim of our study was to investigate to what extent phagocytosis by Sertoli cells may be tissue specific. We analyzed in Sertoli cell cultures that were exposed to either spermatid residual bodies (legitimate substrates) or retina photoreceptor outer segments (illegitimate substrates) the course of the main phagocytosis stages. We show that whereas substrate binding and ingestion stages occur similarly for legitimate or illegitimate substrates, the degradation of illegitimate but not of legitimate substrates triggers autophagy as evidenced by the formation of double-membrane wrapping, MAP1LC3A-II/LC3-II clustering, SQSTM1/p62 degradation, and by marked changes in ATG5, ATG9 and BECN1/Beclin 1 protein expression profiles. The recruitment by nonprofessional phagocytes of autophagy for the degradation of ingested cell-derived substrates is a novel feature that may be of major importance for fundamentals of both apoptotic substrate clearance and tissue homeostasis.
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Affiliation(s)
- Marina G Yefimova
- Institut de Physiologie et Biologie Cellulaires, CNRS-FRE 3511, Université de Poitiers, Poitiers, France
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Hogarth CA, Evanoff R, Mitchell D, Kent T, Small C, Amory JK, Griswold MD. Turning a spermatogenic wave into a tsunami: synchronizing murine spermatogenesis using WIN 18,446. Biol Reprod 2013; 88:40. [PMID: 23284139 DOI: 10.1095/biolreprod.112.105346] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The BDADs (bis-[dichloroacetyl]-diamines) are compounds that can inhibit spermatogenesis via blocking the metabolism of vitamin A. We utilized one specific BDAD, WIN 18,446, to manipulate the endogenous production of retinoic acid (RA) in the testis to further investigate the action of this compound on mammalian sperm production. Transient treatment of adult male mice with WIN 18,446 blocked spermatogonial differentiation and induced significant changes in the cycle of the seminiferous epithelium. WIN 18,446 treatment of neonatal mice also blocked spermatogonial differentiation and, followed by injection of RA, induced synchronous spermatogenesis in adulthood. The net result was pulsatile, rather than normal continuous, release of sperm from the seminiferous epithelium. This study describes a novel technique that can enrich for specific germ cell populations within the testis, representing a valuable new tool for studying spermatogenesis.
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Affiliation(s)
- Cathryn A Hogarth
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA 99164, USA
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Retinol dehydrogenase 10 is indispensible for spermatogenesis in juvenile males. Proc Natl Acad Sci U S A 2012; 110:543-8. [PMID: 23267101 DOI: 10.1073/pnas.1214883110] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Retinoic acid (RA), an active vitamin A derivative, is essential for mammalian spermatogenesis. Genetic studies have revealed that oxidation of vitamin A to retinal by retinol dehydrogenase 10 (RDH10) is critical for embryonic RA biosynthesis. However, physiological roles of RDH10 in postnatal RA synthesis remain unclear, given that Rdh10 loss-of-function mutations lead to early embryonic lethality. We conducted in vivo genetic studies of Rdh10 in postnatal mouse testes and found that an RDH10 deficiency in Sertoli cells, but not in germ cells, results in a mild germ cell depletion phenotype. A deficiency of RDH10 in both Sertoli and germ cells in juvenile mice results in a blockage of spermatogonial differentiation, similar to that seen in vitamin A-deficient animals. This defect in spermatogenesis arises from a complete deficiency in juvenile testicular RA synthesis and can be rescued by retinoid administration. Thus, in juvenile mice, the primary, but not exclusive, source of RA in the testes is Sertoli cells. In contrast, adult Rdh10-deficient mice exhibit phenotypically normal spermatogenesis, indicating that during development a change occurs in either the cellular source of RA or the retinaldehyde dehydrogenase involved in RA synthesis.
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Evans EB, Hogarth C, Evanoff RM, Mitchell D, Small C, Griswold MD. Localization and regulation of murine Esco2 during male and female meiosis. Biol Reprod 2012; 87:61. [PMID: 22699483 DOI: 10.1095/biolreprod.112.099978] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Meiosis is essential for generation of healthy gametes in both sexes and involves recombination and segregation of homologous chromosomes to produce haploid gametes. The initiation of meiosis in both sexes relies upon retinoic acid (RA) (Griswold MD, Hogarth CA, Bowles J, Koopman P. Initiating Meiosis: The Case for Retinoic Acid. Biol Reprod 2012; 86(35):1-7). Previous studies have demonstrated that the stimulated by retinoic acid gene 8 (Stra8) was required for meiotic progression in both the mouse ovary and postnatal testis. To identify additional candidates that may play a role during meiosis, we used microarray databases to generate lists of transcripts with expression profiles similar to that of Stra8 in the embryonic ovary and postnatal testis. One such gene, establishment of cohesion 1 homolog 2 (Saccharomyces cerevisiae) (Esco2), has been described as a regulator of sister chromatid cohesion during mitosis. This study describes the first in-depth analysis of ESCO2 localization and regulation during meiosis in both males and females. ESCO2 colocalized with the gamma H2A histone family member X (H2AFX) in pachytene spermatocytes, indicating that ESCO2 is a component of the XY body. In pachytene cells of the embryonic ovary, ESCO2 colocalized with H2AFX, which is consistent with the presence of ESCO2 in areas of double-stranded breaks. In addition, the expression of Esco2 was found to be regulated by RA in the postnatal testis. These data indicate that ESCO2 may play a vital role in meiosis in both males and females.
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Affiliation(s)
- Elizabeth B Evans
- School of Molecular Biosciences and The Center for Reproductive Biology, Washington State University, Pullman, Washington, USA
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Tong MH, Mitchell DA, McGowan SD, Evanoff R, Griswold MD. Two miRNA clusters, Mir-17-92 (Mirc1) and Mir-106b-25 (Mirc3), are involved in the regulation of spermatogonial differentiation in mice. Biol Reprod 2012; 86:72. [PMID: 22116806 DOI: 10.1095/biolreprod.111.096313] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Increasing evidence indicates that microRNAs (miRNAs) may be critical players in spermatogenesis. The miRNA expression profiles of THY1(+)-enriched undifferentiated spermatogonia were characterized, and members of Mir-17-92 (Mirc1) and its paralog Mir-106b-25 (Mirc3) clusters are significantly downregulated during retinoic acid-induced spermatogonial differentiation, both in vitro and in vivo. The repression of microRNA clusters Mir-17-92 (Mirc1) and Mir-106b-25 (Mirc3) by retinoic acid in turn potentially upregulates the expression of Bim, Kit, Socs3, and Stat3. The male germ cell-specific Mir-17-92 (Mirc1) knockout mice exhibit small testes, a lower number of epididymal sperm, and mild defect in spermatogenesis. Absence of Mir-17-92 (Mirc1) in male germ cells dramatically increases expression of Mir-106b-25 (Mirc3) cluster miRNAs in the germ cells. These results suggest that Mir-17-92 (Mirc1) cluster and Mir-106b-25 (Mirc3) cluster miRNAs possibly functionally cooperate in regulating spermatogonial development.
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Affiliation(s)
- Ming-Han Tong
- School of Molecular Biosciences, Washington State University, Pullman, Washington 99164, USA
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Griswold MD, Hogarth CA, Bowles J, Koopman P. Initiating meiosis: the case for retinoic acid. Biol Reprod 2012; 86:35. [PMID: 22075477 DOI: 10.1095/biolreprod.111.096610] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The requirement for vitamin A in reproduction and development was first determined from studies of nutritional deficiencies. Subsequent research has shown that embryonic development and both male and female reproduction are modulated by retinoic acid (RA), the active form of vitamin A. Because RA is active in multiple developmental systems, its synthesis, transport, and degradation are tightly regulated in different tissues. A growing body of evidence implicates RA as a requirement for the initiation of meiosis in both male and female mammals, resulting in a mechanistic model involving the interplay of RA, RA synthesis enzymes, RA receptors, and degradative cytochrome P450 enzymes in this system. Recently, that model has been challenged, prompting a review of the established paradigm. While it remains possible that additional molecules may be involved in regulating entry into meiosis, the weight of evidence supporting a key role for RA is incontrovertible.
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Affiliation(s)
- Michael D Griswold
- School of Molecular Biosciences, Washington State University, Pullman, 99164, USA.
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Tong MH, Mitchell D, Evanoff R, Griswold MD. Expression of Mirlet7 family microRNAs in response to retinoic acid-induced spermatogonial differentiation in mice. Biol Reprod 2011; 85:189-97. [PMID: 21430230 DOI: 10.1095/biolreprod.110.089458] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Spermatogonial differentiation is orchestrated by the precise control of gene expression involving retinoic acid signaling. MicroRNAs have emerged as important regulators of spermatogenesis, and here we show that the Mirlet7 family miRNAs are expressed in mouse spermatogonia and spermatocytes. Retinoic acid significantly leads to the induction of Mirlet7 miRNAs through suppression of Lin28. We further confirmed both in vitro and in vivo that expressions of Mycn, Ccnd1, and Col1a2, which are targets of Mirlet7, were downregulated during spermatogonial differentiation. These results suggest that Mirlet7 family miRNAs play a role in retinoic acid-induced spermatogonial differentiation.
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Affiliation(s)
- Ming-Han Tong
- School of Molecular Biosciences, Washington State University, Pullman, Washington 99164, USA
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Snyder EM, Davis JC, Zhou Q, Evanoff R, Griswold MD. Exposure to retinoic acid in the neonatal but not adult mouse results in synchronous spermatogenesis. Biol Reprod 2011; 84:886-93. [PMID: 21228214 DOI: 10.1095/biolreprod.110.089755] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Retinoic acid (RA) is required for germ cell differentiation, the regulation of which gives rise to a constant production of mature sperm. In testes from 3-day postpartum (dpp) RARE-hsplacZ mice, periodic regions positive for beta-galactosidase activity were observed along the length of the seminiferous tubules. Periodicity was abolished by treatment of neonates with exogenous RA at 2 dpp. To assess the consequences, 2-dpp mice were treated with RA, and the long- and short-term effects were assessed. Long-term effects of neonatal RA exposure included a delay in the appearance of advanced germ cells and the absence of a spermatogenic wave (synchronous spermatogenesis) in the adult. In contrast, RA exposure in vitamin A-sufficient adults did not result in synchronous spermatogenesis but rather induced apoptosis in a subset of spermatogonia. Shortly after (24 h) neonates were exposed, altered expression of known germ cell differentiation and the (Stra8, Kit, Sycp3, and Rec8) meiosis markers and an increase in the number of STRA8 and SYCP3 immunopositive cells were observed relative to those of vehicle controls. However, 48 and 72 h after exposure, a significant reduction in the number of STRA8 and SYCP3 immunopositive cells occurred. Immunohistochemical analysis of a marker for apoptosis demonstrated neonatal exposure resulted in increased germ cell apoptosis, as observed in the adult. Additionally, RA exposure resulted in increased Cyp26a1 expression of the RA-degrading enzyme. Thus, while RA treatment of neonatal and adult mice resulted in apoptosis of spermatogonia, synchronous spermatogenesis occurred only after neonatal RA exposure.
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Affiliation(s)
- Elizabeth M Snyder
- School of Molecular Biosciences, Washington State University, Pullman, WA, USA
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Hogarth CA, Evanoff R, Snyder E, Kent T, Mitchell D, Small C, Amory JK, Griswold MD. Suppression of Stra8 expression in the mouse gonad by WIN 18,446. Biol Reprod 2011; 84:957-65. [PMID: 21209416 DOI: 10.1095/biolreprod.110.088575] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Bis-(dichloroacetyl)-diamines (BDADs) are compounds that inhibit spermatogenesis and function as male contraceptives in many species; however, their mechanism of action has yet to be fully investigated. It has been proposed that BDADs may function via inhibition of testicular retinoic acid (RA) biosynthesis. We employed an organ culture technique and the expression of a marker for RA activity, Stra8 (stimulated by retinoic acid gene 8), to investigate if the BDAD WIN 18,446 inhibited the biosynthesis of RA from retinol (ROL) in neonatal and adult murine testis and in the embryonic murine gonad. After culturing either whole testes or germ cells isolated from mice at 2 days postpartum (dpp) with WIN 18,446 or with WIN 18,446 plus ROL, Stra8 expression was suppressed, demonstrating that WIN 18,446 inhibited the conversion of ROL to RA in both systems. We also utilized a transgenic mouse containing an RA-responsive LacZ reporter gene to demonstrate limited RA induction of LacZ expression in 2-dpp testes cultured with WIN 18,446 plus ROL. The expression of Stra8 was downregulated in adult mouse testis tubules cultured with WIN 18,446 when compared to tubules cultured with the vehicle control. WIN 18,446 also inhibited the conversion of ROL to RA in embryonic ovaries and testes cultured for 48 h. These murine results provide critical insights regarding how the BDADs can inhibit spermatogenesis by blocking the ability of vitamin A to drive germ cell development. In addition, these techniques will be useful for screening novel inhibitors of RA biosynthesis as potential male contraceptives.
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Affiliation(s)
- Cathryn A Hogarth
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA
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Sun H, Kawaguchi R. The membrane receptor for plasma retinol-binding protein, a new type of cell-surface receptor. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2011; 288:1-41. [PMID: 21482409 DOI: 10.1016/b978-0-12-386041-5.00001-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Vitamin A is essential for diverse aspects of life ranging from embryogenesis to the proper functioning of most adult organs. Its derivatives (retinoids) have potent biological activities such as regulating cell growth and differentiation. Plasma retinol-binding protein (RBP) is the specific vitamin A carrier protein in the blood that binds to vitamin A with high affinity and delivers it to target organs. A large amount of evidence has accumulated over the past decades supporting the existence of a cell-surface receptor for RBP that mediates cellular vitamin A uptake. Using an unbiased strategy, this specific cell-surface RBP receptor has been identified as STRA6, a multitransmembrane domain protein with previously unknown function. STRA6 is not homologous to any protein of known function and represents a new type of cell-surface receptor. Consistent with the diverse functions of vitamin A, STRA6 is widely expressed in embryonic development and in adult organ systems. Mutations in human STRA6 are associated with severe pathological phenotypes in many organs such as the eye, brain, heart, and lung. STRA6 binds to RBP with high affinity and mediates vitamin A uptake into cells. This review summarizes the history of the RBP receptor research, its expression in the context of known functions of vitamin A in distinct human organs, structure/function analysis of this new type of membrane receptor, pertinent questions regarding its very existence, and its potential implication in treating human diseases.
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Affiliation(s)
- Hui Sun
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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Li H, Palczewski K, Baehr W, Clagett-Dame M. Vitamin A deficiency results in meiotic failure and accumulation of undifferentiated spermatogonia in prepubertal mouse testis. Biol Reprod 2010; 84:336-41. [PMID: 20881313 DOI: 10.1095/biolreprod.110.086157] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Vitamin A (retinol) is required for maintenance of adult mammalian spermatogenesis. In adult rodents, vitamin A withdrawal is followed by a loss of differentiated germ cells within the seminiferous epithelium and disrupted spermatogenesis that can be restored by vitamin A replacement. However, whether vitamin A plays a role in the differentiation and meiotic initiation of germ cells during the first round of mouse spermatogenesis is unknown. In the present study, we found that vitamin A depletion markedly decreased testicular expression of the all-trans retinoic acid-responsive gene, Stra8, and caused meiotic failure in prepubertal male mice lacking lecithin:retinol acyltransferase (Lrat), encoding for the major enzyme in liver responsible for the formation of retinyl esters. Rather than undergoing normal differentiation, germ cells accumulated in the testes of Lrat(-/-) mice maintained on a vitamin A-deficient diet. These results, together with our previous observations that germ cells fail to enter meiosis and remain undifferentiated in embryonic vitamin A-deficient ovaries, support the hypothesis that vitamin A regulates the initiation of meiosis I of both oogenesis and spermatogenesis in mammals.
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Affiliation(s)
- Hui Li
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706-1544, USA
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