1
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Cheng Z, Yang C, Zhao Q, Zhong J, Zhang J, Jin R, Li Y, Ta N, Wu D, Yuan Z, Sun W, Wang R. Efficacy and predictors of immune checkpoint inhibitors in patients with gallbladder cancer. Cancer Sci 2024; 115:1979-1988. [PMID: 38487949 PMCID: PMC11145113 DOI: 10.1111/cas.16142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 02/03/2024] [Accepted: 02/25/2024] [Indexed: 06/04/2024] Open
Abstract
Immune checkpoint inhibitors (ICIs) have shown promising efficacy in multiple cancers including biliary tract cancers (BTCs). However, the data focusing on the efficacy of ICIs in patients with gallbladder cancer (GBC) is still limited. In this study, we aim to assess the efficacy of ICIs in GBC and explore the clinicopathologic and molecular markers associated with ICI benefit. We retrospective analyzed 69 GBC patients who had received ICI therapy between January 2016 and December 2020. Tumor samples were obtained for genomic sequencing and immunohistochemical analysis. The median progression-free survival (PFS) and overall survival (OS) was 4.4 months and 8.5 months, respectively. Multivariate analysis indicated that alcohol intake history, carcinoma embryonic antigen (CEA) level ≥100 U/mL, and cutaneous immune-related adverse events (irAEs) were independent prognostic factors for PFS. CEA level ≥100 U/mL and cutaneous irAEs were independent prognostic factors for OS. The objective response rate and disease control rate (DCR) were 15.9% and 37.7%, respectively. Patients with cutaneous irAEs, high CD8+ T cell infiltrated or immune inflamed GBCs had higher DCR. Patients with high CD8+ T cell infiltrated or immune inflamed GBCs also had a notably improved prognosis. These results suggest that ICIs were effective in patients with GBC. High CEA level, cutaneous irAEs, high CD8+ T cell infiltration, and immune inflamed phenotype could be useful for predicting the efficacy of ICIs in GBC.
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Affiliation(s)
- Zhuo Cheng
- Department of Oncology, Eastern Hepatobiliary Surgery HospitalNaval Medical UniversityShanghaiChina
| | - Cheng Yang
- Department of Special Treatment I and Liver Transplantation, Eastern Hepatobiliary Surgery HospitalNaval Medical UniversityShanghaiChina
| | - Qian Zhao
- Department of PathologyShanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
| | - Jingjiao Zhong
- Department of RadiologyChanghai Hospital, Naval Medical UniversityShanghaiChina
| | - Jin Zhang
- The First Department of Hepatic Surgery, Eastern Hepatobiliary Surgery HospitalNaval Medical UniversityShanghaiChina
| | - Riming Jin
- The First Department of Hepatic Surgery, Eastern Hepatobiliary Surgery HospitalNaval Medical UniversityShanghaiChina
| | - Yao Li
- The First Department of Hepatic Surgery, Eastern Hepatobiliary Surgery HospitalNaval Medical UniversityShanghaiChina
| | - Na Ta
- Department of Pathology, Changhai HospitalNaval Medical UniversityShanghaiChina
| | - Dong Wu
- The First Department of Hepatic Surgery, Eastern Hepatobiliary Surgery HospitalNaval Medical UniversityShanghaiChina
| | - Zhengang Yuan
- Department of Oncology, Eastern Hepatobiliary Surgery HospitalNaval Medical UniversityShanghaiChina
| | - Wen Sun
- National Center for Liver CancerNaval Medical UniversityShanghaiChina
| | - Ruoyu Wang
- The First Department of Hepatic Surgery, Eastern Hepatobiliary Surgery HospitalNaval Medical UniversityShanghaiChina
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2
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Ebrahimi S, Shams A, Maghami P, Hekmat A. Investigation of Signals and Transcription Factors for The Generation of Female Germ-Like Cells. CELL JOURNAL 2022; 24:458-464. [PMID: 36093805 PMCID: PMC9468721 DOI: 10.22074/cellj.2022.8303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Indexed: 11/04/2022]
Abstract
<strong>Objective:</strong> Primordial germ cell (PGCs) lines are a source of a highly specialized type of cells, characteristically oocytes,<br />during female germline development in vivo. The oocyte growth begins in the transition from the primary follicle. It is<br />associated with dynamic changes in gene expression, but the gene-regulating signals and transcription factors that control oocyte growth remain unknown. We aim to investigate the differentiation potential of mouse bone marrow mesenchymal stem cells (mMSCs) into female germ-like cells by testing several signals and transcription factors.<br /><strong>Materials and Methods:</strong> In this experimental study, mMSCs were extracted from mice femur bone using the flushing<br />technique. The cluster-differentiation (CD) of superficial mesenchymal markers was determined with flow cytometric analysis. We applied a set of transcription factors including retinoic acid (RA), titanium nanotubes (TNTs), and fibrin such as TNT-coated fibrin (F+TNT) formation and (RA+F+TNT) induction, and investigated the changes in gene, MVH/ DDX4, expression and functional screening using an in vitro mouse oocyte development condition. Germ cell markers expression, (MVH / DDX4), was analyzed with Immunocytochemistry staining, quantitative transcription-polymerase chain reaction (RT-qPCR) analysis, and Western blots.<br /><strong>Results:</strong> The expression of CD was confirmed by flow cytometry. The phase determination of the TNTs and F+TNT were confirmed using x-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. Remarkably, applying these transcription factors quickly induced pluripotent stem cells into oocyte-like cells that were sufficient to generate female germlike cells, growth, and maturation from mMSCs differentiation. These transcription factors formed oocyte-like cells specification of stem cells, epigenetic reprogramming, or meiosis and indicate that oocyte meiosis initiation and oocyte growth are not separable from the previous epigenetic reprogramming in stem cells in vitro.<br /><strong>Conclusion:</strong> Results suggested several transcription factors may apply for arranging oocyte-like cell growth and supplies an alternative source of in vitro maturation (IVM).
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Affiliation(s)
- Saman Ebrahimi
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Alireza Shams
- Department of Anatomy, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran,P.O.Box: 3149969415Department of AnatomySchool of MedicineAlborz University of Medical SciencesKarajIran
| | - Parvaneh Maghami
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Azadeh Hekmat
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
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3
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Chassot AA, Le Rolle M, Jolivet G, Stevant I, Guigonis JM, Da Silva F, Nef S, Pailhoux E, Schedl A, Ghyselinck NB, Chaboissier MC. Retinoic acid synthesis by ALDH1A proteins is dispensable for meiosis initiation in the mouse fetal ovary. SCIENCE ADVANCES 2020; 6:eaaz1261. [PMID: 32494737 PMCID: PMC7244317 DOI: 10.1126/sciadv.aaz1261] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 03/13/2020] [Indexed: 06/11/2023]
Abstract
In mammals, the timing of meiosis entry is regulated by signals from the gonadal environment. All-trans retinoic acid (ATRA) signaling is considered the key pathway that promotes Stra8 (stimulated by retinoic acid 8) expression and, in turn, meiosis entry. This model, however, is debated because it is based on analyzing the effects of exogenous ATRA on ex vivo gonadal cultures, which not accurately reflects the role of endogenous ATRA. Aldh1a1 and Aldh1a2, two retinaldehyde dehydrogenases synthesizing ATRA, are expressed in the mouse ovaries when meiosis initiates. Contrary to the present view, here, we demonstrate that ATRA-responsive cells are scarce in the ovary. Using three distinct gene deletion models for Aldh1a1;Aldh1a2;Aldh1a3, we show that Stra8 expression is independent of ATRA production by ALDH1A proteins and that germ cells progress through meiosis. Together, these data demonstrate that ATRA signaling is dispensable for instructing meiosis initiation in female germ cells.
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Affiliation(s)
| | | | - Geneviève Jolivet
- Université Paris-Saclay, INRAE, ENVA, BREED, 78350, Jouy-en-Josas, France
| | - Isabelle Stevant
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland
| | - Jean-Marie Guigonis
- Université Côte d’Azur, UMR E4320, CEA, F-06107 Nice, France
- Plateforme “Bernard Rossi”, Faculté de Médecine, Université Côte d’Azur, F-06107 Nice, France
| | - Fabio Da Silva
- Université Côte d'Azur, CNRS, Inserm, iBV, Nice, France
- Division of Molecular Embryology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Serge Nef
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland
| | - Eric Pailhoux
- Université Paris-Saclay, INRAE, ENVA, BREED, 78350, Jouy-en-Josas, France
| | | | - Norbert B. Ghyselinck
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Département de Génétique Fonctionnelle et Cancer, CNRS UMR7104, Inserm U1258, Université de Strasbourg (UNISTRA), 1 rue Laurent Fries, F-67404 Illkirch CEDEX, France
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4
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Tang F, Richardson N, Albina A, Chaboissier MC, Perea-Gomez A. Mouse Gonad Development in the Absence of the Pro-Ovary Factor WNT4 and the Pro-Testis Factor SOX9. Cells 2020; 9:cells9051103. [PMID: 32365547 PMCID: PMC7291083 DOI: 10.3390/cells9051103] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 04/25/2020] [Accepted: 04/28/2020] [Indexed: 12/03/2022] Open
Abstract
The transcription factors SRY and SOX9 and RSPO1/WNT4/β-Catenin signaling act as antagonistic pathways to drive testis and ovary development respectively, from a common gonadal primordium in mouse embryos. In this work, we took advantage of a double knockout mouse model to study gonadal development when Sox9 and Wnt4 are both mutated. We show that the XX gonad mutant for Wnt4 or for both Wnt4 and Sox9 develop as ovotestes, demonstrating that ectopic SOX9 function is not required for the partial female-to-male sex reversal caused by a Wnt4 mutation. Sox9 deletion in XY gonads leads to ovarian development accompanied by ectopic WNT/β-catenin signaling. In XY Sox9 mutant gonads, SRY-positive supporting precursors adopt a female-like identity and develop as pre-granulosa-like cells. This phenotype cannot be fully prevented by the deletion of Wnt4 or Rspo1, indicating that SOX9 is required for the early determination of the male supporting cell identity independently of repressing RSPO1/WNT4/β-Catenin signaling. However, in XY Sox9 Wnt4 double mutant gonads, pre-granulosa cells are not maintained, as they prematurely differentiate as mature granulosa cells and then trans-differentiate into Sertoli-like cells. Together, our results reveal the dynamics of the specific and independent actions of SOX9 and WNT4 during gonadal differentiation: SOX9 is essential in the testis for early specification of male-supporting cells whereas WNT4 functions in the ovary to maintain female-supporting cell identity and inhibit male-specific vascular and steroidogenic cell differentiation.
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5
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Li Y, Talotta-Altenburg LM, Silimperi KA, Ciabattoni GO, Lowe-Krentz LJ. Endothelial nitric oxide synthase activation is required for heparin receptor effects on vascular smooth muscle cells. Am J Physiol Cell Physiol 2019; 318:C463-C475. [PMID: 31891520 DOI: 10.1152/ajpcell.00284.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Published studies indicate that TMEM184A is a heparin receptor that interacts with and transduces stimulation from heparin in vascular cells. Previous studies have indicated that heparin increases endothelial nitric oxide synthase (eNOS) activity in bovine endothelial cells. However, the precise mechanism remains unknown. In this study, we investigated the impact of heparin treatment and TMEM184A on eNOS's activation and the role of eNOS in heparin signaling in the cloned A7r5 rat vascular smooth muscle cell line and confirmed results in endothelial cells. We employed a combination of TMEM184A knockdown A7r5 cells along with transient eNOS knockdown and enzyme inhibitor strategies. The results indicate that heparin induces phosphorylation of eNOS. eNOS can be immunoprecipitated with TMEM184A and is internalized to the perinuclear region in a TMEM184A-dependent manner in response to heparin. We also examined how heparin treatment leads to phosphorylation of eNOS and confirmed that TMEM184A and Ca2+ were required to mediate heparin-elicited eNOS phosphorylation. Evidence supporting the involvement of transient receptor potential cation channel subfamily V member 4 with TMEM184A in this eNOS activation process is also presented.
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Affiliation(s)
- Yaqiu Li
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania
| | | | - Kayli A Silimperi
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania
| | - Grace O Ciabattoni
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania
| | - Linda J Lowe-Krentz
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania
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6
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Divergent Roles of CYP26B1 and Endogenous Retinoic Acid in Mouse Fetal Gonads. Biomolecules 2019; 9:biom9100536. [PMID: 31561560 PMCID: PMC6843241 DOI: 10.3390/biom9100536] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/17/2019] [Accepted: 09/24/2019] [Indexed: 11/19/2022] Open
Abstract
In female mammals, germ cells enter meiosis in the fetal ovaries, while in males, meiosis is prevented until postnatal development. Retinoic acid (RA) is considered the main inducer of meiotic entry, as it stimulates Stra8 which is required for the mitotic/meiotic switch. In fetal testes, the RA-degrading enzyme CYP26B1 prevents meiosis initiation. However, the role of endogenous RA in female meiosis entry has never been demonstrated in vivo. In this study, we demonstrate that some effects of RA in mouse fetal gonads are not recapitulated by the invalidation or up-regulation of CYP26B1. In organ culture of fetal testes, RA stimulates testosterone production and inhibits Sertoli cell proliferation. In the ovaries, short-term inhibition of RA-signaling does not decrease Stra8 expression. We develop a gain-of-function model to express CYP26A1 or CYP26B1. Only CYP26B1 fully prevents STRA8 induction in female germ cells, confirming its role as part of the meiotic prevention machinery. CYP26A1, a very potent RA degrading enzyme, does not impair the formation of STRA8-positive cells, but decreases Stra8 transcription. Collectively, our data reveal that CYP26B1 has other activities apart from metabolizing RA in fetal gonads and suggest a role of endogenous RA in amplifying Stra8, rather than being the initial inducer of Stra8. These findings should reactivate the quest to identify meiotic preventing or inducing substances.
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7
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Abstract
Germ cells are the stem cells of the species. Thus, it is critical that we have a good understanding of how they are specified, how the somatic cells instruct and support them, how they commit to one or other sex, and how they ultimately develop into functional gametes. Here, we focus on specifics of how sexual fate is determined during fetal life. Because the majority of relevant experimental work has been done using the mouse model, we focus on that species. We review evidence regarding the identity of instructive signals from the somatic cells, and the molecular responses that occur in germ cells in response to those extrinsic signals. In this way we aim to clarify progress to date regarding the mechanisms underlying the mitotic to meiosis switch in germ cells of the fetal ovary, and those involved in adopting and securing male fate in germ cells of the fetal testis.
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Affiliation(s)
- Cassy Spiller
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Josephine Bowles
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.
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8
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Liu XM, Yamasaki A, Du XM, Coffman VC, Ohsumi Y, Nakatogawa H, Wu JQ, Noda NN, Du LL. Lipidation-independent vacuolar functions of Atg8 rely on its noncanonical interaction with a vacuole membrane protein. eLife 2018; 7:41237. [PMID: 30451685 PMCID: PMC6279349 DOI: 10.7554/elife.41237] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 11/18/2018] [Indexed: 11/18/2022] Open
Abstract
The ubiquitin-like protein Atg8, in its lipidated form, plays central roles in autophagy. Yet, remarkably, Atg8 also carries out lipidation-independent functions in non-autophagic processes. How Atg8 performs its moonlighting roles is unclear. Here we report that in the fission yeast Schizosaccharomyces pombe and the budding yeast Saccharomyces cerevisiae, the lipidation-independent roles of Atg8 in maintaining normal morphology and functions of the vacuole require its interaction with a vacuole membrane protein Hfl1 (homolog of human TMEM184 proteins). Crystal structures revealed that the Atg8-Hfl1 interaction is not mediated by the typical Atg8-family-interacting motif (AIM) that forms an intermolecular β-sheet with Atg8. Instead, the Atg8-binding regions in Hfl1 proteins adopt a helical conformation, thus representing a new type of AIMs (termed helical AIMs here). These results deepen our understanding of both the functional versatility of Atg8 and the mechanistic diversity of Atg8 binding.
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Affiliation(s)
- Xiao-Man Liu
- National Institute of Biological Sciences, Beijing, China
| | | | - Xiao-Min Du
- National Institute of Biological Sciences, Beijing, China.,College of Life Sciences, Beijing Normal University, Beijing, China
| | | | - Yoshinori Ohsumi
- Unit for Cell Biology, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Hitoshi Nakatogawa
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Jian-Qiu Wu
- The Ohio State University, Columbus, United States
| | | | - Li-Lin Du
- National Institute of Biological Sciences, Beijing, China
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9
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Farwell SLN, Reylander KG, Iovine MK, Lowe-Krentz LJ. Novel Heparin Receptor Transmembrane Protein 184a Regulates Angiogenesis in the Adult Zebrafish Caudal Fin. Front Physiol 2017; 8:671. [PMID: 28936181 PMCID: PMC5594097 DOI: 10.3389/fphys.2017.00671] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 08/23/2017] [Indexed: 12/22/2022] Open
Abstract
Transmembrane protein 184A (TMEM184A) was recently identified as the heparin receptor in vascular cells. Heparin binds specifically to TMEM184A and induces anti-proliferative signaling in vitro. Though it is highly conserved, the physiological function of TMEM184A remains unknown. The objective of this study was to investigate the expression and effects on vascular regeneration of TMEM184A using the adult zebrafish regenerating caudal fin as an in vivo model. Here, we show that Tmem184a is expressed in vascular endothelial cells (ECs) of mature and regenerating zebrafish fins. Transient morpholino (MO)-mediated knockdown of Tmem184a using two validated MOs results in tangled regenerating vessels that do not grow outward and limit normal overall fin regeneration. A significant increase in EC proliferation is observed. Consistent with in vitro work with tissue culture vascular cells, heparin has the opposite effect and decreases EC proliferation which also hinders overall fin regeneration. Collectively, our study suggests that Tmem184a is a novel regulator of angiogenesis.
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Affiliation(s)
- Sara Lynn N Farwell
- Department of Biological Sciences, Lehigh UniversityBethlehem, PA, United States
| | - Kimberly G Reylander
- Department of Biological Sciences, Lehigh UniversityBethlehem, PA, United States
| | - M Kathryn Iovine
- Department of Biological Sciences, Lehigh UniversityBethlehem, PA, United States
| | - Linda J Lowe-Krentz
- Department of Biological Sciences, Lehigh UniversityBethlehem, PA, United States
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10
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Hickford DE, Wong SFL, Frankenberg SR, Shaw G, Yu H, Chew KY, Renfree MB. Expression of STRA8 is conserved in therian mammals but expression of CYP26B1 differs between marsupials and mice. Biol Reprod 2017; 97:217-229. [DOI: 10.1093/biolre/iox083] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 07/28/2017] [Indexed: 11/13/2022] Open
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11
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Chassot AA, Le Rolle M, Jourden M, Taketo MM, Ghyselinck NB, Chaboissier MC. Constitutive WNT/CTNNB1 activation triggers spermatogonial stem cell proliferation and germ cell depletion. Dev Biol 2017; 426:17-27. [PMID: 28456466 DOI: 10.1016/j.ydbio.2017.04.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 03/27/2017] [Accepted: 04/18/2017] [Indexed: 01/01/2023]
Abstract
The differentiation of germ cells into oogonia or spermatogonia is the first step that eventually gives rise to fully mature gametes. In the female fetal gonad, the RSPO1/WNT/CTNNB1 signalling pathway is involved in primordial germ cell proliferation and differentiation into female germ cells, which are able to enter meiosis. In the postnatal testis, the WNT/CTNNB1 pathway also mediates proliferation of spermatogonial stem cells and progenitor cells. Here we show that forced activation of the WNT/CTNNB1 pathway in fetal gonocytes using transgenic mice leads to deregulated spermatogonial proliferation, and exhaustion of the spermatocytes by apoptosis, resulting in a hypoplastic testis. These findings demonstrate that a finely tuned timing in WNT/CTNNB1 signalling activity is required for spermatogenesis.
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Affiliation(s)
| | | | | | - Maketo M Taketo
- Department of Pharmacology, Graduate School of Medicine, Kyoto University Yoshida-Konoe-cho, Sakyo, Kyoto, Japan
| | - Norbert B Ghyselinck
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moleculaire et Cellulaire (IGBMC), CNRS UMR7104, INSERM U964, Université de Strasbourg, F-67404 Illkirch, France
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12
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Pugh RJ, Slee JB, Farwell SLN, Li Y, Barthol T, Patton WA, Lowe-Krentz LJ. Transmembrane Protein 184A Is a Receptor Required for Vascular Smooth Muscle Cell Responses to Heparin. J Biol Chem 2016; 291:5326-41. [PMID: 26769966 DOI: 10.1074/jbc.m115.681122] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Indexed: 11/06/2022] Open
Abstract
Vascular cell responses to exogenous heparin have been documented to include decreased vascular smooth muscle cell proliferation following decreased ERK pathway signaling. However, the molecular mechanism(s) by which heparin interacts with cells to induce those responses has remained unclear. Previously characterized monoclonal antibodies that block heparin binding to vascular cells have been found to mimic heparin effects. In this study, those antibodies were employed to isolate a heparin binding protein. MALDI mass spectrometry data provide evidence that the protein isolated is transmembrane protein 184A (TMEM184A). Commercial antibodies against three separate regions of the TMEM184A human protein were used to identify the TMEM184A protein in vascular smooth muscle cells and endothelial cells. A GFP-TMEM184A construct was employed to determine colocalization with heparin after endocytosis. Knockdown of TMEM184A eliminated the physiological responses to heparin, including effects on ERK pathway activity and BrdU incorporation. Isolated GFP-TMEM184A binds heparin, and overexpression results in additional heparin uptake. Together, these data support the identification of TMEM184A as a heparin receptor in vascular cells.
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Affiliation(s)
- Raymond J Pugh
- Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015
| | - Joshua B Slee
- From the Departments of Biological Sciences and the Department of Natural Sciences, DeSales University, Center Valley, Pennsylvania 18034
| | | | - Yaqiu Li
- From the Departments of Biological Sciences and
| | | | - Walter A Patton
- the Department of Chemistry, Lebanon Valley College, Annville, Pennsylvania 17003, and
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13
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Abstract
Current knowledge on gonadal development and sex determination is the product of many decades of research involving a variety of scientific methods from different biological disciplines such as histology, genetics, biochemistry, and molecular biology. The earliest embryological investigations, followed by the invention of microscopy and staining methods, were based on histological examinations. The most robust development of histological staining techniques occurred in the second half of the nineteenth century and resulted in structural descriptions of gonadogenesis. These first studies on gonadal development were conducted on domesticated animals; however, currently the mouse is the most extensively studied species. The next key point in the study of gonadogenesis was the advancement of methods allowing for the in vitro culture of fetal gonads. For instance, this led to the description of the origin of cell lines forming the gonads. Protein detection using antibodies and immunolabeling methods and the use of reporter genes were also invaluable for developmental studies, enabling the visualization of the formation of gonadal structure. Recently, genetic and molecular biology techniques, especially gene expression analysis, have revolutionized studies on gonadogenesis and have provided insight into the molecular mechanisms that govern this process. The successive invention of new methods is reflected in the progress of research on gonadal development.
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Affiliation(s)
- Rafal P Piprek
- Department of Comparative Anatomy, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland.
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14
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Zhang LJ, Chen B, Feng XL, Ma HG, Sun LL, Feng YM, Liang GJ, Cheng SF, Li L, Shen W. Exposure to Brefeldin A promotes initiation of meiosis in murine female germ cells. Reprod Fertil Dev 2015; 27:294-303. [PMID: 24209976 DOI: 10.1071/rd13281] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 10/10/2013] [Indexed: 12/13/2022] Open
Abstract
In mammals, ontogenesis starts from a fusion of spermatozoon and oocyte, which are produced by reductive nuclear division of a diploid germ cell in a specialised but complex biological process known as meiosis. However, little is known about the mechanism of meiotic initiation in germ cells, although many factors may be responsible for meiosis both in male and female gonads. In this study, 11.5 days post coitum (dpc) female fetal mouse genital ridges were cultured in vitro with exposure to Brefeldin A (BFA) for 6h, and the changes in meiosis were detected. Synaptonemal-complex analysis implied that BFA played a positive role in meiosis initiation and this hypothesis was confirmed by quantitative PCR of meiosis-specific genes: stimulated by retinoic acid gene 8 (Stra8) and deleted in a zoospermia-like (DAZL). At the same time, mRNA expression of retinoic acid synthetase (Raldh2) and retinoic acid (RA) receptors increased in female gonads with in vitro exposure to BFA. Transplanting genital ridges treated with BFA into the kidney capsule of immunodeficient mice demonstrated that the development capacity of female germ cells was normal, while formation of primordial follicles was seen to be a result of accelerated meiosis after exposure to BFA. In conclusion, the study indicated that BFA stimulated meiosis initiation partly by RA signalling and then promoted the development of follicles.
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Affiliation(s)
- Lian-Jun Zhang
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, Qingdao Agricultural University, Qingdao, 266109, China
| | - Bo Chen
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xin-Lei Feng
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, Qingdao Agricultural University, Qingdao, 266109, China
| | - Hua-Gang Ma
- Center for Reproductive Biology, Weifang People's Hospital, Weifang, 261041, China
| | - Li-Lan Sun
- Center for Reproductive Biology, Weifang People's Hospital, Weifang, 261041, China
| | - Yan-Min Feng
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, Qingdao Agricultural University, Qingdao, 266109, China
| | - Gui-Jin Liang
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, Qingdao Agricultural University, Qingdao, 266109, China
| | - Shun-Feng Cheng
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, Qingdao Agricultural University, Qingdao, 266109, China
| | - Lan Li
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, Qingdao Agricultural University, Qingdao, 266109, China
| | - Wei Shen
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, Qingdao Agricultural University, Qingdao, 266109, China
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15
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Rossitto M, Philibert P, Poulat F, Boizet-Bonhoure B. Molecular events and signalling pathways of male germ cell differentiation in mouse. Semin Cell Dev Biol 2015; 45:84-93. [PMID: 26454096 DOI: 10.1016/j.semcdb.2015.09.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 09/22/2015] [Indexed: 12/15/2022]
Abstract
Germ cells, the precursors of gametes, represent a unique cell lineage that is able to differentiate into spermatozoa or oocytes depending on the chromosomal sex of the organism. In the mammalian embryonic gonad, commitment to oogenesis involves pre-meiotic DNA replication and entry into the first meiotic division; whereas, commitment to spermatogenesis involves inhibition of meiotic initiation, suppression of pluripotency, mitotic arrest and expression of specific markers that will control the development of the male germ cells. The crucial decision made by the germ line to commit to either a male or a female fate has been partially explained by genetic and ex vivo studies in mice which have implicated a complex network of regulatory genes, numerous factors and pathways. Besides the reproductive failure that may follow a deregulation of this complex network, the germ cells may, in view of their proliferative and pluripotent nature, act as precursors of potential malignant transformation and as putative targets for exogenous environmental compounds. Our review summarizes and discusses recent developments that have improved our understanding on how germ cell precursors are committed to a male or a female cell fate in the mouse gonad.
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Affiliation(s)
- Moïra Rossitto
- Genetic and Development Department, Institute of Human Genetics, CNRS UPR1142, Montpellier, France.
| | - Pascal Philibert
- Genetic and Development Department, Institute of Human Genetics, CNRS UPR1142, Montpellier, France.
| | - Francis Poulat
- Genetic and Development Department, Institute of Human Genetics, CNRS UPR1142, Montpellier, France.
| | - Brigitte Boizet-Bonhoure
- Genetic and Development Department, Institute of Human Genetics, CNRS UPR1142, Montpellier, France.
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16
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Röhrig T, Pihlajoki M, Ziegler R, Cochran RS, Schrade A, Schillebeeckx M, Mitra RD, Heikinheimo M, Wilson DB. Toying with fate: Redirecting the differentiation of adrenocortical progenitor cells into gonadal-like tissue. Mol Cell Endocrinol 2015; 408:165-77. [PMID: 25498963 PMCID: PMC4417465 DOI: 10.1016/j.mce.2014.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 11/30/2014] [Accepted: 12/01/2014] [Indexed: 01/07/2023]
Abstract
Cell fate decisions are integral to zonation and remodeling of the adrenal cortex. Animal models exhibiting ectopic differentiation of gonadal-like cells in the adrenal cortex can shed light on the molecular mechanisms regulating steroidogenic cell fate. In one such model, prepubertal gonadectomy (GDX) of mice triggers the formation of adrenocortical neoplasms that resemble luteinized ovarian stroma. Transcriptomic analysis and genome-wide DNA methylation mapping have identified genetic and epigenetic markers of GDX-induced adrenocortical neoplasia. Members of the GATA transcription factor family have emerged as key regulators of cell fate in this model. Expression of Gata4 is pivotal for the accumulation of gonadal-like cells in the adrenal glands of gonadectomized mice, whereas expression of Gata6 limits the spontaneous and GDX-induced differentiation of gonadal-like cells in the adrenal cortex. Additionally, Gata6 is essential for proper development of the adrenal X-zone, a layer analogous to the fetal zone of the human adrenal cortex. The relevance of these observations to developmental signaling pathways in the adrenal cortex, to other animal models of altered adrenocortical cell fate, and to human diseases is discussed.
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Affiliation(s)
- Theresa Röhrig
- Department of Pediatrics, Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA; Hochschule Mannheim - University of Applied Sciences, Mannheim 68163, Germany
| | - Marjut Pihlajoki
- Department of Pediatrics, Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA; Children's Hospital, University of Helsinki and Helsinki University Central Hospital, Helsinki 00290, Finland
| | - Ricarda Ziegler
- Department of Pediatrics, Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA; Hochschule Mannheim - University of Applied Sciences, Mannheim 68163, Germany
| | - Rebecca S Cochran
- Department of Pediatrics, Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA
| | - Anja Schrade
- Department of Pediatrics, Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA; Children's Hospital, University of Helsinki and Helsinki University Central Hospital, Helsinki 00290, Finland
| | - Maximiliaan Schillebeeckx
- Department of Genetics, Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA
| | - Robi D Mitra
- Department of Genetics, Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA
| | - Markku Heikinheimo
- Department of Pediatrics, Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA; Children's Hospital, University of Helsinki and Helsinki University Central Hospital, Helsinki 00290, Finland
| | - David B Wilson
- Department of Pediatrics, Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA; Department of Developmental Biology, Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA.
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17
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Moniot B, Ujjan S, Champagne J, Hirai H, Aritake K, Nagata K, Dubois E, Nidelet S, Nakamura M, Urade Y, Poulat F, Boizet-Bonhoure B. Prostaglandin D2 acts through the Dp2 receptor to influence male germ cell differentiation in the foetal mouse testis. Development 2014; 141:3561-71. [DOI: 10.1242/dev.103408] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Through intercellular signalling, the somatic compartment of the foetal testis is able to program primordial germ cells to undergo spermatogenesis. Fibroblast growth factor 9 and several members of the transforming growth factor β superfamily are involved in this process in the foetal testis, counteracting the induction of meiosis by retinoic acid and activating germinal mitotic arrest. Here, using in vitro and in vivo approaches, we show that prostaglandin D2 (PGD2), which is produced through both L-Pgds and H-Pgds enzymatic activities in the somatic and germ cell compartments of the foetal testis, plays a role in mitotic arrest in male germ cells by activating the expression and nuclear localization of the CDK inhibitor p21Cip1 and by repressing pluripotency markers. We show that PGD2 acts through its Dp2 receptor, at least in part through direct effects in germ cells, and contributes to the proper differentiation of male germ cells through the upregulation of the master gene Nanos2. Our data identify PGD2 signalling as an early pathway that acts in both paracrine and autocrine manners, and contributes to the differentiation of germ cells in the foetal testis.
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Affiliation(s)
- Brigitte Moniot
- Genetic and Development department, Institute of Human Genetics, CNRS UPR1142, Montpellier 34094, Cedex 05, France
| | - Safdar Ujjan
- Genetic and Development department, Institute of Human Genetics, CNRS UPR1142, Montpellier 34094, Cedex 05, France
| | - Julien Champagne
- Genetic and Development department, Institute of Human Genetics, CNRS UPR1142, Montpellier 34094, Cedex 05, France
| | - Hiroyuki Hirai
- Department of Advanced Technology and Development, BML, Matoba, Kawagoe, Saitama 350-1101, Japan
| | - Kosuke Aritake
- Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka 565-0874, Japan
| | - Kinya Nagata
- Department of Advanced Technology and Development, BML, Matoba, Kawagoe, Saitama 350-1101, Japan
| | - Emeric Dubois
- Plateforme MGX, Functional Genomic Institute, CNRS UMR 5203 – INSERM U 661, Montpellier 34094, Cedex 05, France
| | - Sabine Nidelet
- Plateforme MGX, Functional Genomic Institute, CNRS UMR 5203 – INSERM U 661, Montpellier 34094, Cedex 05, France
| | - Masataka Nakamura
- Human Gene Sciences Center, Tokyo Medical and Dental University, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
| | - Yoshihiro Urade
- Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka 565-0874, Japan
| | - Francis Poulat
- Genetic and Development department, Institute of Human Genetics, CNRS UPR1142, Montpellier 34094, Cedex 05, France
| | - Brigitte Boizet-Bonhoure
- Genetic and Development department, Institute of Human Genetics, CNRS UPR1142, Montpellier 34094, Cedex 05, France
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18
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Rogon C, Ulbricht A, Hesse M, Alberti S, Vijayaraj P, Best D, Adams IR, Magin TM, Fleischmann BK, Höhfeld J. HSP70-binding protein HSPBP1 regulates chaperone expression at a posttranslational level and is essential for spermatogenesis. Mol Biol Cell 2014; 25:2260-71. [PMID: 24899640 PMCID: PMC4116300 DOI: 10.1091/mbc.e14-02-0742] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 05/12/2014] [Accepted: 05/23/2014] [Indexed: 11/11/2022] Open
Abstract
Molecular chaperones play key roles during growth, development, and stress survival. The ability to induce chaperone expression enables cells to cope with the accumulation of nonnative proteins under stress and complete developmental processes with an increased requirement for chaperone assistance. Here we generate and analyze transgenic mice that lack the cochaperone HSPBP1, a nucleotide-exchange factor of HSP70 proteins and inhibitor of chaperone-assisted protein degradation. Male HSPBP1(-/-) mice are sterile because of impaired meiosis and massive apoptosis of spermatocytes. HSPBP1 deficiency in testes strongly reduces the expression of the inducible, antiapoptotic HSP70 family members HSPA1L and HSPA2, the latter of which is essential for synaptonemal complex disassembly during meiosis. We demonstrate that HSPBP1 affects chaperone expression at a posttranslational level by inhibiting the ubiquitylation and proteasomal degradation of inducible HSP70 proteins. We further provide evidence that the cochaperone BAG2 contributes to HSP70 stabilization in tissues other than testes. Our findings reveal that chaperone expression is determined not only by regulated transcription, but also by controlled degradation, with degradation-inhibiting cochaperones exerting essential prosurvival functions.
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Affiliation(s)
- Christian Rogon
- Institut für Zellbiologie and Bonner Forum Biomedizin, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53121 Bonn, Germany
| | - Anna Ulbricht
- Institut für Zellbiologie and Bonner Forum Biomedizin, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53121 Bonn, Germany
| | - Michael Hesse
- Institut für Physiologie I, Life and Brain Centre, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53105 Bonn, Germany
| | - Simon Alberti
- Institut für Zellbiologie and Bonner Forum Biomedizin, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53121 Bonn, Germany
| | - Preethi Vijayaraj
- Abteilung für Zellbiochemie, Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53115 Bonn, Germany
| | - Diana Best
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, United Kingdom
| | - Ian R Adams
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, United Kingdom
| | - Thomas M Magin
- Abteilung für Zellbiochemie, Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53115 Bonn, Germany
| | - Bernd K Fleischmann
- Institut für Physiologie I, Life and Brain Centre, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53105 Bonn, Germany
| | - Jörg Höhfeld
- Institut für Zellbiologie and Bonner Forum Biomedizin, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53121 Bonn, Germany
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19
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Feng CW, Bowles J, Koopman P. Control of mammalian germ cell entry into meiosis. Mol Cell Endocrinol 2014; 382:488-497. [PMID: 24076097 DOI: 10.1016/j.mce.2013.09.026] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 08/24/2013] [Accepted: 09/20/2013] [Indexed: 11/21/2022]
Abstract
Germ cells are unique in undergoing meiosis to generate oocytes and sperm. In mammals, meiosis onset is before birth in females, or at puberty in males, and recent studies have uncovered several regulatory steps involved in initiating meiosis in each sex. Evidence suggests that retinoic acid (RA) induces expression of the critical pre-meiosis gene Stra8 in germ cells of the fetal ovary, pubertal testis and adult testis. In the fetal testis, CYP26B1 degrades RA, while FGF9 further antagonises RA signalling to suppress meiosis. Failsafe mechanisms involving Nanos2 may further suppress meiosis in the fetal testis. Here, we draw together the growing knowledge relating to these meiotic control mechanisms, and present evidence that they are co-ordinately regulated and that additional factors remain to be identified. Understanding this regulatory network will illuminate not only how the foundations of mammalian reproduction are laid, but also how mis-regulation of these steps can result in infertility or germline tumours.
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Affiliation(s)
- Chun-Wei Feng
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Josephine Bowles
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Peter Koopman
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.
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20
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Tanaka M. Vertebrate female germline--the acquisition of femaleness. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2013; 3:231-8. [PMID: 24896659 DOI: 10.1002/wdev.131] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 08/29/2013] [Accepted: 10/09/2013] [Indexed: 01/16/2023]
Abstract
The cellular and molecular characteristics of female germ cells have primarily been studied in the mammalian ovary. In most female mammals, all primordial germ cells (PGCs) develop into oocytes early during ovary formation, and germline stem cells are few in number or absent in postnatal ovaries (Lei L, Spradling AC. Female mice lack adult germ-line stem cells but sustain oogenesis using stable primordial follicles. Proc Natl Acad Sci USA 2013, 110:8585-8590). Research efforts in the field have largely focused on meiosis and follicular development, but a fundamental question regarding establishment of femaleness, which is very important to understand the 'female' germline, has not been discussed sufficiently. Recent work has revealed the presence of germline stem cells in the vertebrate ovary, using the teleost fish, medaka (Oryzias latipes) (Nakamura S, Kobayashi K, Nishimura T, Higashijima S, Tanaka, M. Identification of germline stem cells in the ovary of teleost medaka. Science 2010, 328:1561-1563). This discovery allows direct comparison between female and male germline stem cells and raises an interesting and heretofore unaddressed issue regarding femaleness of germline stem cells. In this article, the germ cell behavior in the ovaries of different species is reviewed and compared, the molecular mechanisms underlying the generation of female germ cells are discussed, and the relationship between female germ cells and the surrounding somatic cells is examined.
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Affiliation(s)
- Minoru Tanaka
- Laboratory of Molecular Genetics for Reproduction, National Institute for Basic Biology, Okazaki, Japan
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21
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Olivier-Mason A, Wojtyniak M, Bowie RV, Nechipurenko IV, Blacque OE, Sengupta P. Transmembrane protein OSTA-1 shapes sensory cilia morphology via regulation of intracellular membrane trafficking in C. elegans. Development 2013; 140:1560-72. [PMID: 23482491 DOI: 10.1242/dev.086249] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The structure and function of primary cilia are critically dependent on intracellular trafficking pathways that transport ciliary membrane and protein components. The mechanisms by which these trafficking pathways are regulated are not fully characterized. Here we identify the transmembrane protein OSTA-1 as a new regulator of the trafficking pathways that shape the morphology and protein composition of sensory cilia in C. elegans. osta-1 encodes an organic solute transporter alpha-like protein, mammalian homologs of which have been implicated in membrane trafficking and solute transport, although a role in regulating cilia structure has not previously been demonstrated. We show that mutations in osta-1 result in altered ciliary membrane volume, branch length and complexity, as well as defects in localization of a subset of ciliary transmembrane proteins in different sensory cilia types. OSTA-1 is associated with transport vesicles, localizes to a ciliary compartment shown to house trafficking proteins, and regulates both retrograde and anterograde flux of the endosome-associated RAB-5 small GTPase. Genetic epistasis experiments with sensory signaling, exocytic and endocytic proteins further implicate OSTA-1 as a crucial regulator of ciliary architecture via regulation of cilia-destined trafficking. Our findings suggest that regulation of transport pathways in a cell type-specific manner contributes to diversity in sensory cilia structure and might allow dynamic remodeling of ciliary architecture via multiple inputs.
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Affiliation(s)
- Anique Olivier-Mason
- Department of Biology and National Center for Behavioral Genomics, Brandeis University, Waltham, MA 02454, USA
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22
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Schillebeeckx M, Schrade A, Löbs AK, Pihlajoki M, Wilson DB, Mitra RD. Laser capture microdissection-reduced representation bisulfite sequencing (LCM-RRBS) maps changes in DNA methylation associated with gonadectomy-induced adrenocortical neoplasia in the mouse. Nucleic Acids Res 2013; 41:e116. [PMID: 23589626 PMCID: PMC3675465 DOI: 10.1093/nar/gkt230] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
DNA methylation is a mechanism for long-term transcriptional regulation and is required for normal cellular differentiation. Failure to properly establish or maintain DNA methylation patterns leads to cell dysfunction and diseases such as cancer. Identifying DNA methylation signatures in complex tissues can be challenging owing to inaccurate cell enrichment methods and low DNA yields. We have developed a technique called laser capture microdissection-reduced representation bisulfite sequencing (LCM-RRBS) for the multiplexed interrogation of the DNA methylation status of cytosine–guanine dinucleotide islands and promoters. LCM-RRBS accurately and reproducibly profiles genome-wide methylation of DNA extracted from microdissected fresh frozen or formalin-fixed paraffin-embedded tissue samples. To demonstrate the utility of LCM-RRBS, we characterized changes in DNA methylation associated with gonadectomy-induced adrenocortical neoplasia in the mouse. Compared with adjacent normal tissue, the adrenocortical tumors showed reproducible gains and losses of DNA methylation at genes involved in cell differentiation and organ development. LCM-RRBS is a rapid, cost-effective, and sensitive technique for analyzing DNA methylation in heterogeneous tissues and will facilitate the investigation of DNA methylation in cancer and organ development.
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Affiliation(s)
- Maximiliaan Schillebeeckx
- Department of Genetics, Center for Genome Sciences, Washington University School of Medicine, 4444 Forest Park Parkway, St. Louis, Missouri 63110, USA
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23
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Miles DC, Wakeling SI, Stringer JM, van den Bergen JA, Wilhelm D, Sinclair AH, Western PS. Signaling through the TGF beta-activin receptors ALK4/5/7 regulates testis formation and male germ cell development. PLoS One 2013; 8:e54606. [PMID: 23342175 PMCID: PMC3546992 DOI: 10.1371/journal.pone.0054606] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 12/14/2012] [Indexed: 01/19/2023] Open
Abstract
The developing testis provides an environment that nurtures germ cell development, ultimately ensuring spermatogenesis and fertility. Impacts on this environment are considered to underlie aberrant germ cell development and formation of germ cell tumour precursors. The signaling events involved in testis formation and male fetal germ cell development remain largely unknown. Analysis of knockout mice lacking single Tgfβ family members has indicated that Tgfβ's are not required for sex determination. However, due to functional redundancy, it is possible that additional functions for these ligands in gonad development remain to be discovered. Using FACS purified gonadal cells, in this study we show that the genes encoding Activin's, TGFβ's, Nodal and their respective receptors, are expressed in sex and cell type specific patterns suggesting particular roles in testis and germ cell development. Inhibition of signaling through the receptors ALK4, ALK5 and ALK7, and ALK5 alone, demonstrated that TGFβ signaling is required for testis cord formation during the critical testis-determining period. We also show that signaling through the Activin/NODAL receptors, ALK4 and ALK7 is required for promoting differentiation of male germ cells and their entry into mitotic arrest. Finally, our data demonstrate that Nodal is specifically expressed in male germ cells and expression of the key pluripotency gene, Nanog was significantly reduced when signaling through ALK4/5/7 was blocked. Our strategy of inhibiting multiple Activin/NODAL/TGFβ receptors reduces the functional redundancy between these signaling pathways, thereby revealing new and essential roles for TGFβ and Activin signaling during testis formation and male germ cell development.
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Affiliation(s)
- Denise C. Miles
- Centre for Reproduction and Development, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Stephanie I. Wakeling
- Centre for Reproduction and Development, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Jessica M. Stringer
- Centre for Reproduction and Development, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Jocelyn A. van den Bergen
- Department of Paediatrics, University of Melbourne, Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Dagmar Wilhelm
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
| | - Andrew H. Sinclair
- Department of Paediatrics, University of Melbourne, Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Patrick S. Western
- Centre for Reproduction and Development, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
- * E-mail:
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24
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Bowles J, Koopman P. Precious Cargo: Regulation of Sex-Specific Germ Cell Development in Mice. Sex Dev 2013; 7:46-60. [DOI: 10.1159/000342072] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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25
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Retinoic acid induces Sertoli cell paracrine signals for spermatogonia differentiation but cell autonomously drives spermatocyte meiosis. Proc Natl Acad Sci U S A 2012; 109:16582-7. [PMID: 23012458 DOI: 10.1073/pnas.1214936109] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Direct evidence for a role of endogenous retinoic acid (RA), the active metabolite of vitamin A in the initial differentiation and meiotic entry of spermatogonia, and thus in the initiation of spermatogenesis is still lacking. RA is synthesized by dedicated enzymes, the retinaldehyde dehydrogenases (RALDH), and binds to and activates nuclear RA receptors (RARA, RARB, and RARG) either within the RA-synthesizing cells or in the neighboring cells. In the present study, we have used a combination of somatic genetic ablations and pharmacological approaches in vivo to show that during the first, prepubertal, spermatogenic cycle (i) RALDH-dependent synthesis of RA by Sertoli cells (SC), the supporting cells of the germ cell (GC) lineage, is indispensable to initiate differentiation of A aligned into A1 spermatogonia; (ii) RARA in SC mediates the effects of RA, possibly through activating Mafb expression, a gene whose Drosophila homolog is mandatory to GC differentiation; (iii) RA synthesized by premeiotic spermatocytes cell autonomously induces meiotic initiation through controlling the RAR-dependent expression of Stra8. Furthermore, we show that RA of SC origin is no longer necessary for the subsequent spermatogenic cycles but essential to spermiation. Altogether, our data establish that the effects of RA in vivo on spermatogonia differentiation are indirect, via SC, but direct on meiotic initiation in spermatocytes, supporting thereby the notion that, contrary to the situation in the female, RA is necessary to induce meiosis in the male.
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26
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Baillet A, Mandon-Pepin B. Mammalian ovary differentiation - a focus on female meiosis. Mol Cell Endocrinol 2012; 356:13-23. [PMID: 21964319 DOI: 10.1016/j.mce.2011.09.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 09/01/2011] [Accepted: 09/13/2011] [Indexed: 02/03/2023]
Abstract
Over the past 50 years, the ovary development has been subject of fewer studies as compare to the male pathway. Nevertheless due to the advancement of genetics, mouse ES cells and the development of genetic models, studies of ovarian differentiation was boosted. This review emphasizes some of new progresses in the research field of the mammalian ovary differentiation that have occurred in recent years with focuses of the period around prophase I of meiosis and of recent roles of small non-RNAs in the ovarian gene expression.
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Affiliation(s)
- Adrienne Baillet
- Laboratoire de Génétique et Biologie Cellulaire, EA 4589 Université de Versailles Saint-Quentin-en-Yvelines, Ecole Pratique des Hautes Etudes, F-78035 Versailles cedex, France.
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27
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Reichmann J, Crichton JH, Madej MJ, Taggart M, Gautier P, Garcia-Perez JL, Meehan RR, Adams IR. Microarray analysis of LTR retrotransposon silencing identifies Hdac1 as a regulator of retrotransposon expression in mouse embryonic stem cells. PLoS Comput Biol 2012; 8:e1002486. [PMID: 22570599 PMCID: PMC3343110 DOI: 10.1371/journal.pcbi.1002486] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 03/07/2012] [Indexed: 12/24/2022] Open
Abstract
Retrotransposons are highly prevalent in mammalian genomes due to their ability to amplify in pluripotent cells or developing germ cells. Host mechanisms that silence retrotransposons in germ cells and pluripotent cells are important for limiting the accumulation of the repetitive elements in the genome during evolution. However, although silencing of selected individual retrotransposons can be relatively well-studied, many mammalian retrotransposons are seldom analysed and their silencing in germ cells, pluripotent cells or somatic cells remains poorly understood. Here we show, and experimentally verify, that cryptic repetitive element probes present in Illumina and Affymetrix gene expression microarray platforms can accurately and sensitively monitor repetitive element expression data. This computational approach to genome-wide retrotransposon expression has allowed us to identify the histone deacetylase Hdac1 as a component of the retrotransposon silencing machinery in mouse embryonic stem cells, and to determine the retrotransposon targets of Hdac1 in these cells. We also identify retrotransposons that are targets of other retrotransposon silencing mechanisms such as DNA methylation, Eset-mediated histone modification, and Ring1B/Eed-containing polycomb repressive complexes in mouse embryonic stem cells. Furthermore, our computational analysis of retrotransposon silencing suggests that multiple silencing mechanisms are independently targeted to retrotransposons in embryonic stem cells, that different genomic copies of the same retrotransposon can be differentially sensitive to these silencing mechanisms, and helps define retrotransposon sequence elements that are targeted by silencing machineries. Thus repeat annotation of gene expression microarray data suggests that a complex interplay between silencing mechanisms represses retrotransposon loci in germ cells and embryonic stem cells.
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Affiliation(s)
- Judith Reichmann
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - James H. Crichton
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Monika J. Madej
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Mary Taggart
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Philippe Gautier
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Jose Luis Garcia-Perez
- GENYO, Pfizer-University of Granada-Andalusian Government-Centre for Genomics and Oncological Research, Granada, Spain
| | - Richard R. Meehan
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Ian R. Adams
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
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Ohta K, Yamamoto M, Lin Y, Hogg N, Akiyama H, Behringer RR, Yamazaki Y. Male differentiation of germ cells induced by embryonic age-specific Sertoli cells in mice. Biol Reprod 2012; 86:112. [PMID: 22262692 PMCID: PMC3338658 DOI: 10.1095/biolreprod.111.095943] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 09/13/2011] [Accepted: 01/05/2012] [Indexed: 11/01/2022] Open
Abstract
Retinoic acid (RA) is a meiosis-inducing factor. Primordial germ cells (PGCs) in the developing ovary are exposed to RA, resulting in entry into meiosis. In contrast, PGCs in the developing testis enter mitotic arrest to differentiate into prospermatogonia. Sertoli cells express CYP26B1, an RA-metabolizing enzyme, providing a simple explanation for why XY PGCs do not initiate meios/is. However, regulation of entry into mitotic arrest is likely more complex. To investigate the mechanisms that regulate male germ cell differentiation, we cultured XX and XY germ cells at 11.5 and 12.5 days postcoitus (dpc) with an RA receptor inhibitor. Expression of Stra8, a meiosis initiation gene, was suppressed in all groups. However, expression of Dnmt3l, a male-specific gene, during embryogenesis was elevated but only in 12.5-dpc XY germ cells. This suggests that inhibiting RA signaling is not sufficient for male germ cell differentiation but that the male gonadal environment also contributes to this pathway. To define the influence of Sertoli cells on male germ cell differentiation, Sertoli cells at 12.5, 15.5, and 18.5 dpc were aggregated with 11.5 dpc PGCs, respectively. After culture, PGCs aggregated with 12.5 dpc Sertoli cells increased Nanos2 and Dnmt3l expression. Furthermore, these PGCs established male-specific methylation imprints of the H19 differentially methylated domains. In contrast, PGCs aggregated with Sertoli cells at late embryonic ages did not commit to the male pathway. These findings suggest that male germ cell differentiation is induced both by inhibition of RA signaling and by molecule(s) production by embryonic age-specific Sertoli cells.
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Affiliation(s)
- Kohei Ohta
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, Hawaii, USA.
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29
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Jameson SA, Natarajan A, Cool J, DeFalco T, Maatouk DM, Mork L, Munger SC, Capel B. Temporal transcriptional profiling of somatic and germ cells reveals biased lineage priming of sexual fate in the fetal mouse gonad. PLoS Genet 2012; 8:e1002575. [PMID: 22438826 PMCID: PMC3305395 DOI: 10.1371/journal.pgen.1002575] [Citation(s) in RCA: 215] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 01/17/2012] [Indexed: 11/18/2022] Open
Abstract
The divergence of distinct cell populations from multipotent progenitors is poorly understood, particularly in vivo. The gonad is an ideal place to study this process, because it originates as a bipotential primordium where multiple distinct lineages acquire sex-specific fates as the organ differentiates as a testis or an ovary. To gain a more detailed understanding of the process of gonadal differentiation at the level of the individual cell populations, we conducted microarrays on sorted cells from XX and XY mouse gonads at three time points spanning the period when the gonadal cells transition from sexually undifferentiated progenitors to their respective sex-specific fates. We analyzed supporting cells, interstitial/stromal cells, germ cells, and endothelial cells. This work identified genes specifically depleted and enriched in each lineage as it underwent sex-specific differentiation. We determined that the sexually undifferentiated germ cell and supporting cell progenitors showed lineage priming. We found that germ cell progenitors were primed with a bias toward the male fate. In contrast, supporting cells were primed with a female bias, indicative of the robust repression program involved in the commitment to XY supporting cell fate. This study provides a molecular explanation reconciling the female default and balanced models of sex determination and represents a rich resource for the field. More importantly, it yields new insights into the mechanisms by which different cell types in a single organ adopt their respective fates.
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Affiliation(s)
| | | | | | | | | | | | | | - Blanche Capel
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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30
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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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31
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Auguste A, Chassot AA, Grégoire EP, Renault L, Pannetier M, Treier M, Pailhoux E, Chaboissier MC. Loss of R-spondin1 and Foxl2 amplifies female-to-male sex reversal in XX mice. Sex Dev 2011; 5:304-17. [PMID: 22116255 DOI: 10.1159/000334517] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2011] [Indexed: 11/19/2022] Open
Abstract
In vertebrates, 2 main genetic pathways have been shown to regulate ovarian development. Indeed, a loss of function mutations in Rspo1 and Foxl2 promote partial female-to-male sex reversal. In mice, it has been shown that the secreted protein RSPO1 is involved in ovarian differentiation and the transcription factor FOXL2 is required for follicular formation. Here, we analysed the potential interactions between these 2 genetic pathways and have shown that while Rspo1 expression seems to be independent of Foxl2 up-regulation, Foxl2 expression partly depends of Rspo1 signalisation. This suggests that different Foxl2-positive somatic cell lineages exist within the ovaries. In addition, a combination of both mutated genes in XX Foxl2(-/-)/Rspo1(-/-) gonads promotes sex reversal, detectable at earlier stages than in XX Rspo1(-/-) mutants. Ectopic development of the steroidogenic lineage is more pronounced in XX Foxl2(-/-)/Rspo1(-/-) gonads than in XX Rspo1(-/-) embryos, suggesting that Foxl2 is involved in preventing ectopic steroidogenesis in foetal ovaries.
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Affiliation(s)
- A Auguste
- INRA, UMR 1198, Biologie du Développement et de la Reproduction, Jouy-en-Josas, France
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32
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Chassot AA, Gregoire EP, Lavery R, Taketo MM, de Rooij DG, Adams IR, Chaboissier MC. RSPO1/β-catenin signaling pathway regulates oogonia differentiation and entry into meiosis in the mouse fetal ovary. PLoS One 2011; 6:e25641. [PMID: 21991325 PMCID: PMC3185015 DOI: 10.1371/journal.pone.0025641] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 09/08/2011] [Indexed: 11/19/2022] Open
Abstract
Differentiation of germ cells into male gonocytes or female oocytes is a central event in sexual reproduction. Proliferation and differentiation of fetal germ cells depend on the sex of the embryo. In male mouse embryos, germ cell proliferation is regulated by the RNA helicase Mouse Vasa homolog gene and factors synthesized by the somatic Sertoli cells promote gonocyte differentiation. In the female, ovarian differentiation requires activation of the WNT/β-catenin signaling pathway in the somatic cells by the secreted protein RSPO1. Using mouse models, we now show that Rspo1 also activates the WNT/β-catenin signaling pathway in germ cells. In XX Rspo1−/− gonads, germ cell proliferation, expression of the early meiotic marker Stra8, and entry into meiosis are all impaired. In these gonads, impaired entry into meiosis and germ cell sex reversal occur prior to detectable Sertoli cell differentiation, suggesting that β-catenin signaling acts within the germ cells to promote oogonial differentiation and entry into meiosis. Our results demonstrate that RSPO1/β-catenin signaling is involved in meiosis in fetal germ cells and contributes to the cellular decision of germ cells to differentiate into oocyte or sperm.
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Affiliation(s)
- Anne-Amandine Chassot
- INSERM, U636, Nice, France
- Université de Nice-Sophia Antipolis, Laboratoire de Génétique du Développement Normal et Pathologique, Nice, France
| | - Elodie P. Gregoire
- INSERM, U636, Nice, France
- Université de Nice-Sophia Antipolis, Laboratoire de Génétique du Développement Normal et Pathologique, Nice, France
| | - Rowena Lavery
- INSERM, U636, Nice, France
- Université de Nice-Sophia Antipolis, Laboratoire de Génétique du Développement Normal et Pathologique, Nice, France
| | - Makoto M. Taketo
- Department of Pharmacology, Graduate School of Medicine, Kyoto University Yoshida-Konoé-cho, Sakyo, Kyoto, Japan
| | - Dirk G. de Rooij
- Center for Reproductive Medicine, Academic Medical Center, Amsterdam, The Netherlands
- Department of Endocrinology and Metabolism, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Ian R. Adams
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, Scotland
| | - Marie-Christine Chaboissier
- INSERM, U636, Nice, France
- Université de Nice-Sophia Antipolis, Laboratoire de Génétique du Développement Normal et Pathologique, Nice, France
- * E-mail:
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33
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Madsen L, Kriegenburg F, Vala A, Best D, Prag S, Hofmann K, Seeger M, Adams IR, Hartmann-Petersen R. The tissue-specific Rep8/UBXD6 tethers p97 to the endoplasmic reticulum membrane for degradation of misfolded proteins. PLoS One 2011; 6:e25061. [PMID: 21949850 PMCID: PMC3174242 DOI: 10.1371/journal.pone.0025061] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Accepted: 08/23/2011] [Indexed: 11/18/2022] Open
Abstract
The protein known as p97 or VCP in mammals and Cdc48 in yeast is a versatile ATPase complex involved in several biological functions including membrane fusion, protein folding, and activation of membrane-bound transcription factors. In addition, p97 plays a central role in degradation of misfolded secretory proteins via the ER-associated degradation pathway. This functional diversity of p97 depends on its association with various cofactors, and to further our understanding of p97 function it is important that these cofactors are identified and analyzed. Here, we isolate and characterize the human protein named Rep8 or Ubxd6 as a new cofactor of p97. Mouse Rep8 is highly tissue-specific and abundant in gonads. In testes, Rep8 is expressed in post-meiotic round spermatids, whereas in ovaries Rep8 is expressed in granulosa cells. Rep8 associates directly with p97 via its UBX domain. We show that Rep8 is a transmembrane protein that localizes to the ER membrane with its UBX domain facing the cytoplasm. Knock-down of Rep8 expression in human cells leads to a decreased association of p97 with the ER membrane and concomitantly a retarded degradation of misfolded ER-derived proteasome substrates. Thus, Rep8 tethers p97 to the ER membrane for efficient ER-associated degradation.
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Affiliation(s)
- Louise Madsen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Andrea Vala
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Diana Best
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, Scotland
| | - Søren Prag
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Kay Hofmann
- Bioinformatics Department, Miltenyi Biotec GmbH, Bergisch-Gladbach, Germany
| | - Michael Seeger
- Institut für Biochemie, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Ian R. Adams
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, Scotland
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34
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Childs AJ, Cowan G, Kinnell HL, Anderson RA, Saunders PTK. Retinoic Acid signalling and the control of meiotic entry in the human fetal gonad. PLoS One 2011; 6:e20249. [PMID: 21674038 PMCID: PMC3108594 DOI: 10.1371/journal.pone.0020249] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 04/28/2011] [Indexed: 12/24/2022] Open
Abstract
The development of mammalian fetal germ cells along oogenic or spermatogenic fate trajectories is dictated by signals from the surrounding gonadal environment. Germ cells in the fetal testis enter mitotic arrest, whilst those in the fetal ovary undergo sex-specific entry into meiosis, the initiation of which is thought to be mediated by selective exposure of fetal ovarian germ cells to mesonephros-derived retinoic acid (RA). Aspects of this model are hard to reconcile with the spatiotemporal pattern of germ cell differentiation in the human fetal ovary, however. We have therefore examined the expression of components of the RA synthesis, metabolism and signalling pathways, and their downstream effectors and inhibitors in germ cells around the time of the initiation of meiosis in the human fetal gonad. Expression of the three RA-synthesising enzymes, ALDH1A1, 2 and 3 in the fetal ovary and testis was equal to or greater than that in the mesonephros at 8–9 weeks gestation, indicating an intrinsic capacity within the gonad to synthesise RA. Using immunohistochemistry to detect RA receptors RARα, β and RXRα, we find germ cells to be the predominant target of RA signalling in the fetal human ovary, but also reveal widespread receptor nuclear localization indicative of signalling in the testis, suggesting that human fetal testicular germ cells are not efficiently shielded from RA by the action of the RA-metabolising enzyme CYP26B1. Consistent with this, expression of CYP26B1 was greater in the human fetal ovary than testis, although the sexually-dimorphic expression patterns of the germ cell-intrinsic regulators of meiotic initiation, STRA8 and NANOS2, appear conserved. Finally, we demonstrate that RA induces a two-fold increase in STRA8 expression in cultures of human fetal testis, but is not sufficient to cause widespread meiosis-associated gene expression. Together, these data indicate that while local production of RA within the fetal ovary may be important in regulating the onset of meiosis in the human fetal ovary, mechanisms other than CYP26B1-mediated metabolism of RA may exist to inhibit the entry of germ cells into meiosis in the human fetal testis.
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Affiliation(s)
- Andrew J Childs
- Medical Research Council Human Reproductive Sciences Unit, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom.
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35
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Western PS, Ralli RA, Wakeling SI, Lo C, van den Bergen JA, Miles DC, Sinclair AH. Mitotic arrest in teratoma susceptible fetal male germ cells. PLoS One 2011; 6:e20736. [PMID: 21674058 PMCID: PMC3107236 DOI: 10.1371/journal.pone.0020736] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Accepted: 05/08/2011] [Indexed: 12/11/2022] Open
Abstract
Formation of germ cell derived teratomas occurs in mice of the 129/SvJ strain, but not in C57Bl/6 inbred or CD1 outbred mice. Despite this, there have been few comparative studies aimed at determining the similarities and differences between teratoma susceptible and non-susceptible mouse strains. This study examines the entry of fetal germ cells into the male pathway and mitotic arrest in 129T2/SvJ mice. We find that although the entry of fetal germ cells into mitotic arrest is similar between 129T2/SvJ, C57Bl/6 and CD1 mice, there were significant differences in the size and germ cell content of the testis cords in these strains. In 129T2/SvJ mice germ cell mitotic arrest involves upregulation of p27KIP1, p15INK4B, activation of RB, the expression of male germ cell differentiation markers NANOS2, DNMT3L and MILI and repression of the pluripotency network. The germ-line markers DPPA2 and DPPA4 show reciprocal repression and upregulation, respectively, while FGFR3 is substantially enriched in the nucleus of differentiating male germ cells. Further understanding of fetal male germ cell differentiation promises to provide insight into disorders of the testis and germ cell lineage, such as testis tumour formation and infertility.
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Affiliation(s)
- Patrick S Western
- Centre for Reproduction and Development, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia.
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36
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Lavery R, Lardenois A, Ranc-Jianmotamedi F, Pauper E, Gregoire EP, Vigier C, Moreilhon C, Primig M, Chaboissier MC. XY Sox9 embryonic loss-of-function mouse mutants show complete sex reversal and produce partially fertile XY oocytes. Dev Biol 2011; 354:111-22. [DOI: 10.1016/j.ydbio.2011.03.029] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 03/18/2011] [Accepted: 03/28/2011] [Indexed: 10/18/2022]
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37
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Kumar S, Chatzi C, Brade T, Cunningham TJ, Zhao X, Duester G. Sex-specific timing of meiotic initiation is regulated by Cyp26b1 independent of retinoic acid signalling. Nat Commun 2011; 2:151. [PMID: 21224842 DOI: 10.1038/ncomms1136] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Accepted: 11/15/2010] [Indexed: 01/26/2023] Open
Abstract
Sex-specific initiation of meiosis in the fetal ovary has been suggested to require retinoic acid (RA) for induction of Stra8, with expression of the RA-degrading enzyme Cyp26b1 in fetal testis delaying meiosis until postnatal development. In this study, we investigate Raldh2(-/-) mice lacking RA synthesis and signalling in mesonephros and adjacent gonad and reveal that Stra8 expression in the fetal ovary does not require RA signalling. In contrast to previous observations, we find that Stra8 is expressed in the absence of physiologically detectable levels of RA. Ketoconazole inhibition of Cyp26b1 in Raldh2(-/-) testis allows RA-independent induction of Stra8, but only when the mesonephros remains attached, pointing to a non-RA signal from the mesonephros that induces Stra8 in the adjacent gonad. These findings demonstrate that Cyp26b1 prevents the onset of meiosis by metabolizing a substrate other than RA that controls Stra8 expression, thus changing the paradigm for how studies on Cyp26 function are conducted.
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Affiliation(s)
- Sandeep Kumar
- Sanford-Burnham Medical Research Institute, Development and Aging Program, 10901 North Torrey Pines Road, La Jolla, California 92037, USA
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38
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Ewen K, Jackson A, Wilhelm D, Koopman P. A Male-Specific Role for p38 Mitogen-Activated Protein Kinase in Germ Cell Sex Differentiation in Mice1. Biol Reprod 2010; 83:1005-14. [DOI: 10.1095/biolreprod.110.086801] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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39
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Yang S, Wang W, Lei C, Liu Q, Xu F, Xing X, Chen H, Liu J, Wu S, Wang M. Localization and characterization of rat transmembrane protein 225 specifically expressed in testis. DNA Cell Biol 2010; 30:9-16. [PMID: 20979528 DOI: 10.1089/dna.2010.1048] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Testis is the one and only location of spermatogenesis and sexual hormone production. Spermatogenesis is a complicated physiological process regulated by many genes specifically and differentially expressed in the testis. In this study, Transmembrane Protein 225 (TMEM225), which is specifically expressed in rat testis, has been identified. TMEM225 was cloned from the testis cDNA library and was mapped to chromosome 8q22 by browsing the University of California Santa Cruz genomic database. It contains an open reading frame with a length of 696 bp, encoding a protein with four putative transmembrane helices. TMEM225 mRNA expression was evaluated by reverse transcription-polymerase chain reaction and in situ hybridization. In addition, the subcellular location of TMEM225 was evaluated. The results obtained highlighted age related specific expression of TMEM225 in testis, specifically during the adult period after age of 13 months. In situ hybridization analysis indicated that TMEM225 mRNA was mainly expressed in spermatocyte cells and round spermatids. Green fluorescence protein localization analysis showed that rat TMEM225 mainly surrounded the nuclear membrane, with a minority distribution in the cytoplasm, and the distribution of TMEM225 was affected by the deletion of N-terminal transmembrane domain. As the expression phase is not related to the first wave of spermatozoon development, our data presented here suggest that TMEM225 may play an important role in sperm degeneration but not in spermatogenesis.
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Affiliation(s)
- Shirui Yang
- Department of Biochemistry and Molecular Biology, Medical School, Soochow University, Suzhou, China
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40
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Gregoire EP, Lavery R, Chassot AA, Akiyama H, Treier M, Behringer RR, Chaboissier MC. Transient development of ovotestes in XX Sox9 transgenic mice. Dev Biol 2010; 349:65-77. [PMID: 20965161 DOI: 10.1016/j.ydbio.2010.10.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 09/16/2010] [Accepted: 10/05/2010] [Indexed: 12/20/2022]
Abstract
The sex of an individual results from the paternal transmission of the SRY gene located on the Y chromosome. In turn, SRY initiates Sox9 expression, a transcription factor required for testicular differentiation. Ectopic activation of SOX9 in XX Wt1:Sox9 transgenic mice induces female-to-male sex reversal in adult mice. Here we show that complete sex reversal is preceded by a transient phase of ovotestis differentiation with XX Wt1:Sox9 transgenic gonads containing a testicular central region and one or both ovarian poles indicating that Wt1:Sox9 is not as efficient as Sry to induce male development. In XX Wt1:Sox9(Tg/+) gonads, transgenic Sox9 is expressed earlier than Sox9 in XY gonads and is able to induce the expression of EGFP, knocked into the 3' UTR of Sox9 indicating that SOX9 is involved in the initiation and maintenance of its own expression. However, the delayed onset of expression of endogenous Sox9-EGFP suggests that this activation requires other factors, whose expression depends on SOX9. In the testicular regions of the XX Wt1:Sox9 ovotestes, proliferation of the XX fetal germ cells is hampered and they differentiate as pro-spermatogonia. This indicates that XX germ cells are not competent to respond to proliferative signals released from a testicular environment. In the ovarian regions, despite the continuous mRNA expression of the WT1:Sox9 transgene, the SOX9 protein does not accumulate suggesting that regulation of this gene in ovarian cells involves post-transcriptional mechanisms. Finally, ovarian cells of the XX Wt1:Sox9 ovotestis undergo apoptosis during late embryogenesis leading to complete female-to-male sex reversal of the transgenic mice at birth.
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41
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Bowles J, Feng CW, Spiller C, Davidson TL, Jackson A, Koopman P. FGF9 suppresses meiosis and promotes male germ cell fate in mice. Dev Cell 2010; 19:440-9. [PMID: 20833365 DOI: 10.1016/j.devcel.2010.08.010] [Citation(s) in RCA: 175] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 08/12/2010] [Accepted: 08/17/2010] [Indexed: 11/25/2022]
Abstract
Sex determination of mammalian germ cells occurs during fetal development and depends on signals from gonadal somatic cells. Previous studies have established that retinoic acid (RA) triggers ovarian germ cells to enter meiosis and thereby commit to oogenesis, whereas in the developing testis, the enzyme CYP26B1 degrades RA and germ cells are not induced to enter meiosis. Using in vitro and in vivo models, we demonstrate that fibroblast growth factor 9 (FGF9) produced in the fetal testis acts directly on germ cells to inhibit meiosis; in addition, FGF9 maintains expression of pluripotency-related genes and upregulates markers associated with male germ cell fate. We conclude that two independent and mutually antagonistic pathways involving RA and FGF9 act in concert to determine mammalian germ cell sexual fate commitment and support a model in which the mitosis/meiosis switch is robustly controlled by both positive and negative regulatory factors.
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Affiliation(s)
- Josephine Bowles
- Division of Molecular Genetics and Development, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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42
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Ohta K, Lin Y, Hogg N, Yamamoto M, Yamazaki Y. Direct effects of retinoic acid on entry of fetal male germ cells into meiosis in mice. Biol Reprod 2010; 83:1056-63. [PMID: 20826729 DOI: 10.1095/biolreprod.110.085787] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In both male and female germ cells of mice, retinoic acid (RA) is a meiosis-inducing factor. In the present study, we used a germ cell culture system to examine the direct effects of RA on meiotic initiation in male germ cells at the stage when they normally enter mitotic arrest to determine the extent to which fetal male germ cells can respond to exogenous RA to alter their sex-specific pathway. Male germ cells between 13.5 and 15.5 days postcoitum (dpc) were isolated from Pou5fl-green fluorescent protein transgenic fetuses and cultured with or without RA for up to 6 days. In the absence of RA, male germ cells did not undergo DNA replication and did not enter meiosis in culture. However, in the presence of RA, male germ cells isolated at 13.5 dpc expressed Stra8 and initiated the meiotic process. The ratio of cells entering meiosis gradually decreased as cells were isolated progressively at later stages. By 15.5 dpc, isolated male germ cells lost their ability to respond to RA signaling. These cells remained dispersed as single cells and progressed along the male differentiation pathway, as evidenced by the establishment of male-specific methylation imprints regardless of the presence or absence of RA. We conclude that male germ cells maintain sexual bipotency until 14.5 dpc that can be reversed by the addition of RA. Once male germ cells enter mitotic arrest, however, they appear to be committed irreversibly to the male-specific differentiation pathway even in the presence of exogenously added RA.
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Affiliation(s)
- Kohei Ohta
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813, USA
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43
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Lazarus1, a DUF300 protein, contributes to programmed cell death associated with Arabidopsis acd11 and the hypersensitive response. PLoS One 2010; 5:e12586. [PMID: 20830211 PMCID: PMC2935358 DOI: 10.1371/journal.pone.0012586] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Accepted: 08/16/2010] [Indexed: 02/01/2023] Open
Abstract
Background Programmed cell death (PCD) is a necessary part of the life of multi-cellular organisms. A type of plant PCD is the defensive hypersensitive response (HR) elicited via recognition of a pathogen by host resistance (R) proteins. The lethal, recessive accelerated cell death 11 (acd11) mutant exhibits HR-like accelerated cell death, and cell death execution in acd11 shares genetic requirements for HR execution triggered by one subclass of R proteins. Methodology/Principal Findings To identify genes required for this PCD pathway, we conducted a genetic screen for suppressors of acd11, here called lazarus (laz) mutants. In addition to known suppressors of R protein-mediated HR, we isolated 13 novel complementation groups of dominant and recessive laz mutants. Here we describe laz1, which encodes a protein with a domain of unknown function (DUF300), and demonstrate that LAZ1 contributes to HR PCD conditioned by the Toll/interleukin-1 (TIR)-type R protein RPS4 and by the coiled-coil (CC)-type R protein RPM1. Using a yeast-based topology assay, we also provide evidence that LAZ1 is a six transmembrane protein with structural similarities to the human tumor suppressor TMEM34. Finally, we demonstrate by transient expression of reporter fusions in protoplasts that localization of LAZ1 is distributed between the cytosol, the plasma membrane and FM4–64 stained vesicles. Conclusions/Significance Our findings indicate that LAZ1 functions as a regulator or effector of plant PCD associated with the HR, in addition to its role in acd11-related death. Furthermore, the similar topology of a plant and human DUF300 proteins suggests similar functions in PCD across the eukaryotic kingdoms, although a direct role for TMEM34 in cell death control remains to be established. Finally, the subcellular localization pattern of LAZ1 suggests that it may have transport functions for yet unknown, death-related signaling molecules at the plasma membrane and/or endosomal compartments. In summary, our results validate the utility of the large-scale suppressor screen to identify novel components with functions in plant PCD, which may also have implications for deciphering cell death mechanisms in other organisms.
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Guerquin MJ, Duquenne C, Lahaye JB, Tourpin S, Habert R, Livera G. New testicular mechanisms involved in the prevention of fetal meiotic initiation in mice. Dev Biol 2010; 346:320-30. [PMID: 20707993 DOI: 10.1016/j.ydbio.2010.08.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 07/30/2010] [Accepted: 08/03/2010] [Indexed: 11/28/2022]
Abstract
In mammals, early fetal germ cells are unique in their ability to initiate the spermatogenesis or oogenesis programs dependent of their somatic environment. In mice, female germ cells enter into meiosis at 13.5 dpc whereas in the male, germ cells undergo mitotic arrest. Recent findings indicate that Cyp26b1, a RA-degrading enzyme, is a key factor preventing initiation of meiosis in the fetal testis. Here, we report evidence for additional testicular pathways involved in the prevention of fetal meiosis. Using a co-culture model in which an undifferentiated XX gonad is cultured with a fetal or neonatal testis, we demonstrated that the testis prevented the initiation of meiosis and induced male germ cell differentiation in the XX gonad. This testicular effect disappeared when male meiosis starts in the neonatal testis and was not directly due to Cyp26b1 expression. Moreover, neither RA nor ketoconazole, an inhibitor of Cyp26b1, completely prevented testicular inhibition of meiosis in co-cultured ovary. We found that secreted factor(s), with molecular weight greater than 10 kDa contained in conditioned media from cultured fetal testes, inhibited meiosis in the XX gonad. Lastly, although both Sertoli and interstitial cells inhibited meiosis in XX germ cells, only interstitial cells induced mitotic arrest in germ cell. In conclusion, our results demonstrate that male germ cell determination is supported by additional non-retinoid secreted factors inhibiting both meiosis and mitosis and produced by the testicular somatic cells during fetal and neonatal life.
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Affiliation(s)
- Marie-Justine Guerquin
- aboratory of Differentiation and Radiobiology ofGonads, Unit of Gametogenesis and Genotoxicity, UMR-U566, INSERM, U566, F_92265 Fontenay-aux-roses, France
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Abstract
Primordial germ cells (PGCs) are embryonic progenitors for the gametes. In the gastrulating mouse embryo, a small group of cells begin expressing a unique set of genes and so commit to the germline. Over the next 3-5 days, these PGCs migrate anteriorly and increase rapidly in number via mitotic division before colonizing the newly formed gonads. PGCs then express a different set of unique genes, their inherited epigenetic imprint is erased and an individual methylation imprint is established, and for female PGCs, the silent X chromosome is reactivated. At this point, germ cells (GCs) commit to either a female or male sexual lineage, denoted by meiosis entry and mitotic arrest, respectively. This developmental program is determined by cues emanating from the somatic environment.
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Affiliation(s)
- Katherine A Ewen
- Division of Molecular Genetics and Development, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
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Bowles J, Koopman P. Sex determination in mammalian germ cells: extrinsic versus intrinsic factors. Reproduction 2010; 139:943-58. [DOI: 10.1530/rep-10-0075] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mammalian germ cells do not determine their sexual fate based on their XX or XY chromosomal constitution. Instead, sexual fate is dependent on the gonadal environment in which they develop. In a fetal testis, germ cells commit to the spermatogenic programme of development during fetal life, although they do not enter meiosis until puberty. In a fetal ovary, germ cells commit to oogenesis by entering prophase of meiosis I. Although it was believed previously that germ cells are pre-programmed to enter meiosis unless they are actively prevented from doing so, recent results indicate that meiosis is triggered by a signaling molecule, retinoic acid (RA). Meiosis is avoided in the fetal testis because a male-specifically expressed enzyme actively degrades RA during the critical time period. Additional extrinsic factors are likely to influence sexual fate of the germ cells, and in particular, we postulate that an additional male-specific fate-determining factor or factors is involved. The full complement of intrinsic factors that underlie the competence of gonadal germ cells to respond to RA and other extrinsic factors is yet to be defined.
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Svingen T, Wilhelm D, Combes AN, Hosking B, Harley VR, Sinclair AH, Koopman P. Ex vivo magnetofection: a novel strategy for the study of gene function in mouse organogenesis. Dev Dyn 2009; 238:956-64. [PMID: 19301396 DOI: 10.1002/dvdy.21919] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Gene function during mouse development is often studied through the production and analysis of transgenic and knockout models. However, these techniques are time- and resource-consuming, and require specialized equipment and expertise. We have established a new protocol for functional studies that combines organ culture of explanted fetal tissues with microinjection and magnetically induced transfection ("magnetofection") of gene expression constructs. As proof-of-principle, we magnetofected cDNA constructs into genital ridge tissue as a means of gain-of-function analysis, and shRNA constructs for loss-of-function analysis. Ectopic expression of Sry induced female-to-male sex-reversal, whereas knockdown of Sox9 expression caused male-to-female sex-reversal, consistent with the known functions of these genes. Furthermore, ectopic expression of Tmem184a, a gene of unknown function, in female genital ridges, resulted in failure of gonocytes to enter meiosis. This technique will likely be applicable to the study of gene function in a broader range of developing organs and tissues.
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Affiliation(s)
- Terje Svingen
- Division of Molecular Genetics and Development, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
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Wallacides A, Chesnel A, Chardard D, Flament S, Dumond H. Evidence for a conserved role of retinoic acid in urodele amphibian meiosis onset. Dev Dyn 2009; 238:1389-98. [DOI: 10.1002/dvdy.21948] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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van den Bergen JA, Miles DC, Sinclair AH, Western PS. Normalizing gene expression levels in mouse fetal germ cells. Biol Reprod 2009; 81:362-70. [PMID: 19403927 DOI: 10.1095/biolreprod.109.076224] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Real-time PCR has become a popular method to analyze transcription of genes that are developmentally regulated during organogenesis of the testes and ovaries. However, the heterogenous cell populations and commitment to strikingly different developmental pathways of the germ and somatic cells in these organs complicate analysis of this process. The selection of suitable reference genes for quantifying gene expression in this system is essential, but to date it has not been sufficiently addressed. To rectify this problem, we have used fluorescence-activated cell sorting to purify germ cells from mouse fetal testes and ovaries and examined 16 common housekeeping genes for their suitability as reference genes. In pure populations of germ cells isolated from Embryonic Day 12.5 (E12.5) to E15.5 male and female gonads, Mapk1 and Sdha were identified as the most stable reference genes. Analysis of the heterogenous fraction of gonadal somatic cells revealed that Canx and Top1 were stable in both sexes, whereas a comparative analysis of germ and somatic cell populations identified Canx and Mapk1 as suitable reference genes through these developmental stages. Application of these reference genes to quantification of gene expression in developing gonads revealed that past assays, which employed nonverified reference genes, have in some cases provided misleading gene expression profiles. This study has identified suitable reference genes to directly compare expression profiles of genes expressed in germ and somatic cells of male and female fetal gonads. Application of these reference genes to expression analysis in fetal germ and somatic cells provides a more accurate system in which to profile gene expression in these tissues.
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Affiliation(s)
- Jocelyn A van den Bergen
- Department of Paediatrics, Murdoch Children's Research Institute, Australian Research Council Centre of Excellence in Biotechnology and Development, University of Melbourne, Royal Children's Hospital, Melbourne, Victoria, Australia
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Kocer A, Reichmann J, Best D, Adams IR. Germ cell sex determination in mammals. Mol Hum Reprod 2009; 15:205-13. [PMID: 19218284 PMCID: PMC2657314 DOI: 10.1093/molehr/gap008] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 01/20/2009] [Accepted: 01/26/2009] [Indexed: 12/14/2022] Open
Abstract
One of the major decisions that germ cells make during their development is whether to differentiate into oocytes or sperm. In mice, the germ cells' decision to develop as male or female depends on sex-determining signalling molecules in the embryonic gonadal environment rather than the sex chromosome constitution of the germ cells themselves. In response to these sex-determining cues, germ cells in female embryos initiate oogenesis and enter meiosis, whereas germ cells in male embryos initiate spermatogenesis and inhibit meiosis until after birth. However, it is not clear whether the signalling molecules that mediate germ cell sex determination act in the developing testis or the developing ovary, or what these signalling molecules might be. Here, we review the evidence for the existence of meiosis-inducing and meiosis-preventing substances in the developing gonad, and more recent studies aimed at identifying these molecules in mice. In addition, we discuss the possibility that some of the reported effects of these factors on germ cell development may be indirect consequences of impairing sexual differentiation of gonadal somatic cells or germ cell survival. Understanding the molecular mechanisms of germ cell sex determination may provide candidate genes for susceptibility to germ cell tumours and infertility in humans.
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Affiliation(s)
| | | | | | - Ian R. Adams
- MRC Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
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