1
|
Wanjari UR, Gopalakrishnan AV. Blood-testis barrier: a review on regulators in maintaining cell junction integrity between Sertoli cells. Cell Tissue Res 2024; 396:157-175. [PMID: 38564020 DOI: 10.1007/s00441-024-03894-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 03/20/2024] [Indexed: 04/04/2024]
Abstract
The blood-testis barrier (BTB) is formed adjacent to the seminiferous basement membrane. It is a distinct ultrastructure, partitioning testicular seminiferous epithelium into apical (adluminal) and basal compartments. It plays a vital role in developing and maturing spermatocytes into spermatozoa via reorganizing its structure. This enables the transportation of preleptotene spermatocytes across the BTB, from basal to adluminal compartments in the seminiferous tubules. Several bioactive peptides and biomolecules secreted by testicular cells regulate the BTB function and support spermatogenesis. These peptides activate various downstream signaling proteins and can also be the target themself, which could improve the diffusion of drugs across the BTB. The gap junction (GJ) and its coexisting junctions at the BTB maintain the immunological barrier integrity and can be the "gateway" during spermatocyte transition. These junctions are the possible route for toxicant entry, causing male reproductive dysfunction. Herein, we summarize the detailed mechanism of all the regulators playing an essential role in the maintenance of the BTB, which will help researchers to understand and find targets for drug delivery inside the testis.
Collapse
Affiliation(s)
- Uddesh Ramesh Wanjari
- Department of Biomedical Sciences, School of Bio-Sciences and Technology, Vellore Institute of Technology, Tamil Nadu, Vellore, PIN 632014, India
| | - Abilash Valsala Gopalakrishnan
- Department of Biomedical Sciences, School of Bio-Sciences and Technology, Vellore Institute of Technology, Tamil Nadu, Vellore, PIN 632014, India.
| |
Collapse
|
2
|
Li L, Gao S, Wang L, Bu T, Chu J, Lv L, Tahir A, Mao B, Li H, Li X, Wang Y, Wu X, Ge R, Cheng CY. PCP Protein Inversin Regulates Testis Function Through Changes in Cytoskeletal Organization of Actin and Microtubules. Endocrinology 2022; 163:6519617. [PMID: 35106541 PMCID: PMC8870424 DOI: 10.1210/endocr/bqac009] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Indexed: 02/03/2023]
Abstract
Inversin is an integrated component of the Frizzled (Fzd)/Dishevelled (Dvl)/Diversin planar cell polarity (PCP) complex that is known to work in concert with the Van Gogh-like protein (eg, Vangl2)/Prickle PCP complex to support tissue and organ development including the brain, kidney, pancreas, and others. These PCP protein complexes are also recently shown to confer developing haploid spermatid PCP to support spermatogenesis in adult rat testes. However, with the exception of Dvl3 and Vangl2, other PCP proteins have not been investigated in the testis. Herein, we used the technique of RNA interference (RNAi) to examine the role of inversin (Invs) in Sertoli cell (SC) and testis function by corresponding studies in vitro and in vivo. When inversin was silenced by RNAi using specific small interfering RNA duplexes by transfecting primary cultures of SCs in vitro or testes in vivo, it was shown that inversin knockdown (KD) perturbed the SC tight junction-barrier function in vitro and in vivo using corresponding physiological and integrity assays. More important, inversin exerted its regulatory effects through changes in the organization of the actin and microtubule cytoskeletons, including reducing the ability of their polymerization. These changes, in turn, induced defects in spermatogenesis by loss of spermatid polarity, disruptive distribution of blood-testis barrier-associated proteins at the SC-cell interface, appearance of multinucleated round spermatids, and defects in the release of sperm at spermiation.
Collapse
Affiliation(s)
- Linxi Li
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- Correspondence: Linxi Li, PhD, The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China.
| | - Sheng Gao
- Institute of Reproductive Medicine, Nantong University School of Medicine, Nantong, Jiangsu 226001, China
| | - Lingling Wang
- Institute of Reproductive Medicine, Nantong University School of Medicine, Nantong, Jiangsu 226001, China
| | - Tiao Bu
- Institute of Reproductive Medicine, Nantong University School of Medicine, Nantong, Jiangsu 226001, China
| | - Jinjin Chu
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Lixiu Lv
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Anam Tahir
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Baiping Mao
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Huitao Li
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Xiaoheng Li
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Yiyan Wang
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Xiaolong Wu
- Institute of Reproductive Medicine, Nantong University School of Medicine, Nantong, Jiangsu 226001, China
| | - Renshan Ge
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - C Yan Cheng
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- Institute of Reproductive Medicine, Nantong University School of Medicine, Nantong, Jiangsu 226001, China
- Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310016, China
- Correspondence: C. Yan Cheng, PhD, Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310016, China. ;
| |
Collapse
|
3
|
Panner Selvam MK, Sikka SC. Role of endocrine disruptors in male infertility and impact of COVID-19 on male reproduction. REPRODUCTIVE AND DEVELOPMENTAL TOXICOLOGY 2022. [PMCID: PMC8864147 DOI: 10.1016/b978-0-323-89773-0.00059-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Several epidemiological studies suggest strong association of endocrine disruptors (EDs) with impaired male reproduction. High levels of polychlorinated biphenyls in serum are associated with low sperm count and poor fertility. A high dichloro diphenyl trichloroethane (DDT) concentration results in low serum testosterone (T) and poor semen quality. DDT stimulates estrogen production by acting as estrogen receptor agonist and potent androgen receptor antagonist. Phthalates, another group of EDs, induce seminiferous tubule degeneration with impaired spermatogenesis via disruption of gene expression that regulates cholesterol and lipid homeostasis resulting in low T. Bisphenol A, a strong exogenous estrogen with antiandrogen effect, lowers serum follicle-stimulating hormone, luteinizing hormone, and T, resulting in impaired development of seminiferous tubules and spermatogenesis. Di(2-ethylhexyl) phthalates can exert their antiandrogenic action by directly inhibiting testosterone biosynthesis via cytochrome P-450 dysfunction. Since these EDs are commonly found in plastic bottles, cosmetics, pesticides, some metal food cans, etc., and accumulate in the environment, it is very important to observe caution and avoid their exposure. This updated chapter also reviews the impact of COVID-19-related infection on male reproduction.
Collapse
|
4
|
Abstract
Organoids are 3-dimensional (3D) structures grown in vitro that emulate the cytoarchitecture and functions of true organs. Therefore, testicular organoids arise as an important model for research on male reproductive biology. These organoids can be generated from different sources of testicular cells, but most studies to date have used immature primary cells for this purpose. The complexity of the mammalian testicular cytoarchitecture and regulation poses a challenge for working with testicular organoids, because, ideally, these 3D models should mimic the organization observed in vivo. In this review, we explore the characteristics of the most important cell types present in the testicular organoid models reported to date and discuss how different factors influence the regulation of these cells inside the organoids and their outcomes. Factors such as the developmental or maturational stage of the Sertoli cells, for example, influence organoid generation and structure, which affect the use of these 3D models for research. Spermatogonial stem cells have been a focus recently, especially in regard to male fertility preservation. The regulation of the spermatogonial stem cell niche inside testicular organoids is discussed in the present review, as this research area may be positively affected by recent progress in organoid generation and tissue engineering. Therefore, the testicular organoid approach is a very promising model for male reproductive biology research, but more studies and improvements are necessary to achieve its full potential.
Collapse
Affiliation(s)
- Nathalia de Lima e Martins Lara
- Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Sadman Sakib
- Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
- Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ina Dobrinski
- Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
- Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Correspondence: Ina Dobrinski, DrMedVet, MVSc, PhD, Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, 404 HMRB, 3300 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada.
| |
Collapse
|
5
|
Liu SW, Li HT, Ge RS, Cheng CY. NC1-peptide derived from collagen α3 (IV) chain is a blood-tissue barrier regulator: lesson from the testis. Asian J Androl 2021; 23:123-128. [PMID: 32896837 PMCID: PMC7991810 DOI: 10.4103/aja.aja_44_20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Collagen α3 (IV) chains are one of the major constituent components of the basement membrane in the mammalian testis. Studies have shown that biologically active fragments, such as noncollagenase domain (NC1)-peptide, can be released from the C-terminal region of collagen α3 (IV) chains, possibly through the proteolytic action of metalloproteinase 9 (MMP9). NC1-peptide was shown to promote blood–testis barrier (BTB) remodeling and fully developed spermatid (e.g., sperm) release from the seminiferous epithelium because this bioactive peptide was capable of perturbing the organization of both actin- and microtubule (MT)-based cytoskeletons at the Sertoli cell–cell and also Sertoli–spermatid interface, the ultrastructure known as the basal ectoplasmic specialization (ES) and apical ES, respectively. More importantly, recent studies have shown that this NC1-peptide-induced effects on cytoskeletal organization in the testis are mediated through an activation of mammalian target of rapamycin complex 1/ribosomal protein S6/transforming retrovirus Akt1/2 protein (mTORC1/rpS6/Akt1/2) signaling cascade, involving an activation of cell division control protein 42 homolog (Cdc42) GTPase, but not Ras homolog family member A GTPase (RhoA), and the participation of end-binding protein 1 (EB1), a microtubule plus (+) end tracking protein (+TIP), downstream. Herein, we critically evaluate these findings, providing a critical discussion by which the basement membrane modulates spermatogenesis through one of its locally generated regulatory peptides in the testis.
Collapse
Affiliation(s)
- Shi-Wen Liu
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou 325027, China.,The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York, NY 10065, USA
| | - Hui-Tao Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou 325027, China.,The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York, NY 10065, USA
| | - Ren-Shan Ge
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou 325027, China
| | - C Yan Cheng
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou 325027, China.,The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York, NY 10065, USA
| |
Collapse
|
6
|
Rho GTPases Signaling in Zebrafish Development and Disease. Cells 2020; 9:cells9122634. [PMID: 33302361 PMCID: PMC7762611 DOI: 10.3390/cells9122634] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/30/2020] [Accepted: 12/07/2020] [Indexed: 02/08/2023] Open
Abstract
Cells encounter countless external cues and the specificity of their responses is translated through a myriad of tightly regulated intracellular signals. For this, Rho GTPases play a central role and transduce signals that contribute to fundamental cell dynamic and survival events. Here, we review our knowledge on how zebrafish helped us understand the role of some of these proteins in a multitude of in vivo cellular behaviors. Zebrafish studies offer a unique opportunity to explore the role and more specifically the spatial and temporal dynamic of Rho GTPases activities within a complex environment at a level of details unachievable in any other vertebrate organism.
Collapse
|
7
|
Lara NDLEM, Costa GMJ, Figueiredo AFA, de França LR. The Sertoli cell: what can we learn from different vertebrate models? Anim Reprod 2020; 16:81-92. [PMID: 33299481 PMCID: PMC7720927 DOI: 10.21451/1984-3143-ar2018-125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Besides having medical applications, comparative studies on reproductive biology are very useful, providing, for instance, essential knowledge for basic, conservation and biotechnological research. In order to maintain the reproductive potential and the survival of all vertebrate species, both sperm and steroid production need to occur inside the testis. From the approximately fifty thousand vertebrate species still alive, very few species are already investigated; however, our knowledge regarding Sertoli cell biology is quite good. In this regard, it is already known that since testis differentiation the Sertoli cells are the somatic cells in charge of supporting and orchestrating germ cells during development and full spermatogenesis in adult animals. In the present review, we highlight key aspects related to Sertoli cell biology in vertebrates and show that this key testis somatic cell presents huge and intrinsic plasticity, particularly when cystic (fish and amphibians) and non-cystic (reptiles, birds and mammals) spermatogenesis is compared. In particular, we briefly discuss the main aspects related to Sertoli cells functions, interactions with germ cells, Sertoli cells proliferation and efficiency, as well as those regarding spermatogonial stem cell niche regulation, which are crucial aspects responsible for the magnitude of sperm production. Most importantly, we show that we could greatly benefit from investigations using different vertebrate experimental models, mainly now that there is a big concern regarding the decline in human sperm counts caused by a multitude of factors.
Collapse
Affiliation(s)
| | - Guilherme Mattos Jardim Costa
- Laboratory of Cellular Biology, Department of Morphology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Luiz Renato de França
- Laboratory of Cellular Biology, Department of Morphology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| |
Collapse
|
8
|
Li L, Li H, Wang L, Wu S, Lv L, Tahir A, Xiao X, Wong CKC, Sun F, Ge R, Cheng CY. Role of cell polarity and planar cell polarity (PCP) proteins in spermatogenesis. Crit Rev Biochem Mol Biol 2020; 55:71-87. [PMID: 32207344 DOI: 10.1080/10409238.2020.1742091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Studies on cell polarity proteins and planar cell polarity (PCP) proteins date back to almost 40 years ago in Drosophila and C. elegans when these proteins were shown to be crucial to support apico-basal polarity and also directional alignment of polarity cells across the plane of an epithelium during morphogenesis. In adult mammals, cell polarity and PCP are most notable in cochlear hair cells. However, the role of these two groups of proteins to support spermatogenesis was not explored until a decade earlier when several proteins that confer cell polarity and PCP proteins were identified in the rat testis. Since then, there are several reports appearing in the literature to examine the role of both cell polarity and PCP in supporting spermatogenesis. Herein, we provide an overview regarding the role of cell polarity and PCP proteins in the testis, evaluating these findings in light of studies in other mammalian epithelial cells/tissues. Our goal is to provide a timely evaluation of these findings, and provide some thought provoking remarks to guide future studies based on an evolving concept in the field.
Collapse
Affiliation(s)
- Linxi Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,Center for Biomedical Research, The Mary M. Wohlford Laboratory for Male Contraceptive Research, Population Council, New York, USA
| | - Huitao Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,Center for Biomedical Research, The Mary M. Wohlford Laboratory for Male Contraceptive Research, Population Council, New York, USA
| | - Lingling Wang
- Center for Biomedical Research, The Mary M. Wohlford Laboratory for Male Contraceptive Research, Population Council, New York, USA
| | - Siwen Wu
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,Center for Biomedical Research, The Mary M. Wohlford Laboratory for Male Contraceptive Research, Population Council, New York, USA
| | - Lixiu Lv
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China
| | - Anam Tahir
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xiang Xiao
- Department of Reproductive Physiology, Zhejiang Academy of Medical Sciences, Hangzhou, China
| | - Chris K C Wong
- Department of Biology, Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Hong Kong, China
| | - Fei Sun
- Institute of Reproductive Medicine, Nantong University School of Medicine, Nantong, China
| | - Renshan Ge
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China
| | - C Yan Cheng
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,Center for Biomedical Research, The Mary M. Wohlford Laboratory for Male Contraceptive Research, Population Council, New York, USA
| |
Collapse
|
9
|
Mao BP, Li L, Yan M, Lian Q, Ge R, Cheng CY. Environmental toxicants and cell polarity in the testis. Reprod Toxicol 2018; 81:253-258. [DOI: 10.1016/j.reprotox.2018.08.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 08/17/2018] [Accepted: 08/23/2018] [Indexed: 12/13/2022]
|
10
|
Xiao X, Ni Y, Yu C, Li L, Mao B, Yang Y, Zheng D, Silvestrini B, Cheng CY. Src family kinases (SFKs) and cell polarity in the testis. Semin Cell Dev Biol 2018; 81:46-53. [PMID: 29174914 PMCID: PMC5988912 DOI: 10.1016/j.semcdb.2017.11.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 11/20/2017] [Indexed: 01/02/2023]
Abstract
Non-receptor Src family kinases (SFKs), most notably c-Src and c-Yes, are recently shown to be expressed by Sertoli and/or germ cells in adult rat testes. Studies have shown that SFKs are involved in modulating the cell cytoskeletal function, and involved in endocytic vesicle-mediated protein endocytosis, transcytosis and/or recycling as well as intracellular protein degradation events. Furthermore, a knockdown to SFKs, in particular c-Yes, has shown to induce defects in spermatid polarity. These findings, coupled with emerging evidence in the field, thus prompt us to critically evaluate them to put forth a developing concept regarding the role of SFKs and cell polarity, which will become a basis to design experiments for future investigations.
Collapse
Affiliation(s)
- Xiang Xiao
- Zhejiang Academy of Medical Sciences, Hangzhou, Zhejiang 310013, China
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York, New York 10065
| | - Ya Ni
- Zhejiang Academy of Medical Sciences, Hangzhou, Zhejiang 310013, China
| | - Chenhuan Yu
- Zhejiang Academy of Medical Sciences, Hangzhou, Zhejiang 310013, China
| | - Linxi Li
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York, New York 10065
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzho, Zhejiang 325035, China
| | - Baiping Mao
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York, New York 10065
- The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzho, Zhejiang 325035, China
| | - Yue Yang
- Zhejiang Academy of Medical Sciences, Hangzhou, Zhejiang 310013, China
| | - Dongwang Zheng
- Zhejiang Academy of Medical Sciences, Hangzhou, Zhejiang 310013, China
| | | | - C. Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York, New York 10065
| |
Collapse
|
11
|
Wen Q, Mruk D, Tang EI, Wong CK, Lui WY, Lee WM, Xiao X, Silvestrini B, Cheng CY. Cell polarity and cytoskeletons-Lesson from the testis. Semin Cell Dev Biol 2018; 81:21-32. [PMID: 28965865 PMCID: PMC5889362 DOI: 10.1016/j.semcdb.2017.09.037] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 09/28/2017] [Indexed: 12/23/2022]
Abstract
Cell polarity in the adult mammalian testis refers to the polarized alignment of developing spermatids during spermiogenesis and the polarized organization of organelles (e.g., phagosomes, endocytic vesicles, Sertoli cell nuclei, Golgi apparatus) in Sertoli cells and germ cells to support spermatogenesis. Without these distinctive features of cell polarity in the seminiferous epithelium, it is not possible to support the daily production of millions of sperm in the limited space provided by the seminiferous tubules in either rodent or human males through the adulthood. In short, cell polarity provides a novel mean to align spermatids and the supporting organelles (e.g., phagosomes, Golgi apparatus, endocytic vesicles) in a highly organized fashion spatially in the seminiferous epithelium during the epithelial cycle of spermatogenesis. This is analogous to different assembling units in a manufacturing plant such that as developing spermatids move along the "assembly line" conferred by Sertoli cells, different structural/functional components can be added to (or removed from) the developing spermatids during spermiogenesis, so that functional spermatozoa are produced at the end of the assembly line. Herein, we briefly review findings regarding the regulation of cell polarity in the testis with specific emphasis on developing spermatids, supported by an intriguing network of regulatory proteins along a local functional axis. Emerging evidence has suggested that cell cytoskeletons provide the tracks which in turn confer the unique assembly lines in the seminiferous epithelium. We also provide some thought-provoking concepts based on which functional experiments can be designed in future studies.
Collapse
Affiliation(s)
- Qing Wen
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, 1230 York Ave, New York, New York 10065
| | - Dolores Mruk
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, 1230 York Ave, New York, New York 10065
| | - Elizabeth I. Tang
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, 1230 York Ave, New York, New York 10065
| | - Chris K.C. Wong
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Wing-yee Lui
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Will M. Lee
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Xiang Xiao
- Department of Reproductive Physiology, Zhejiang Academy of Medical Sciences, Hangzhou, Zhejiang, China
| | | | - C. Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, 1230 York Ave, New York, New York 10065
| |
Collapse
|
12
|
Chen N, Su P, Wang M, Li YM. Ascorbic acid inhibits cadmium-induced disruption of the blood-testis barrier by regulating oxidative stress-mediated p38 MAPK pathways. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:21713-21720. [PMID: 29790047 DOI: 10.1007/s11356-018-2138-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 04/25/2018] [Indexed: 06/08/2023]
Abstract
Ascorbic acid (AA), one of the best-known reactive oxygen species (ROS) scavengers, exhibits numerous functions such as antioxidant, anti-cancer, and anti-inflammatory effects. Increasing evidence demonstrates that oxidative stress plays an important role in testicular toxicity. In the present study, we investigated the protective effect of AA against cadmium (Cd)-induced blood-testis barrier (BTB) disruption. Sprague-Dawley (SD) rats were divided into four groups: the Cd-treated group received a single dose (s.c.) of 2 mg/kg BW cadmium chloride; the AA antagonism group received an injection of AA at a dose of 400 mg/kg BW (200 mg 24 h prior to Cd treatment and 200 mg 24 h following Cd treatment); and the control groups received an equal volume of saline or an equal dose of AA. As expected, ROS expression was upregulated in the Cd-treated rats, accompanied by an increase in malondialdehyde (MDA). Interestingly, AA suppressed Cd-induced oxidative stress by decreasing the levels of ROS and MDA and increasing the activity of superoxide dismutase (SOD) and catalase (CAT). In addition, AA also reduced BTB disruption by inhibiting TGF-β3 activation and p38 MAPK phosphorylation. Significant decreases in occludin and claudin-11 expression were observed in the Cd-treated rats, whereas AA administration attenuated this effect. Moreover, testicular histopathology and transmission electron microscopy further demonstrated the protective effects of AA against Cd-induced BTB damage. In conclusion, the results of the present study suggest that AA protects BTB destruction via the inhibition of oxidative stress and the TGF-β3/p38 MAPK signalling pathway in the testis of Cd-exposed rats.
Collapse
Affiliation(s)
- Na Chen
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Ping Su
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Mei Wang
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Ya-Min Li
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| |
Collapse
|
13
|
Li L, Gao Y, Chen H, Jesus T, Tang E, Li N, Lian Q, Ge RS, Cheng CY. Cell polarity, cell adhesion, and spermatogenesis: role of cytoskeletons. F1000Res 2017; 6:1565. [PMID: 28928959 PMCID: PMC5580414 DOI: 10.12688/f1000research.11421.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/21/2017] [Indexed: 01/13/2023] Open
Abstract
In the rat testis, studies have shown that cell polarity, in particular spermatid polarity, to support spermatogenesis is conferred by the coordinated efforts of the Par-, Crumbs-, and Scribble-based polarity complexes in the seminiferous epithelium. Furthermore, planar cell polarity (PCP) is conferred by PCP proteins such as Van Gogh-like 2 (Vangl2) in the testis. On the other hand, cell junctions at the Sertoli cell–spermatid (steps 8–19) interface are exclusively supported by adhesion protein complexes (for example, α6β1-integrin-laminin-α3,β3,γ3 and nectin-3-afadin) at the actin-rich apical ectoplasmic specialization (ES) since the apical ES is the only anchoring device in step 8–19 spermatids. For cell junctions at the Sertoli cell–cell interface, they are supported by adhesion complexes at the actin-based basal ES (for example, N-cadherin-β-catenin and nectin-2-afadin), tight junction (occludin-ZO-1 and claudin 11-ZO-1), and gap junction (connexin 43-plakophilin-2) and also intermediate filament-based desmosome (for example, desmoglein-2-desmocollin-2). In short, the testis-specific actin-rich anchoring device known as ES is crucial to support spermatid and Sertoli cell adhesion. Accumulating evidence has shown that the Par-, Crumbs-, and Scribble-based polarity complexes and the PCP Vangl2 are working in concert with actin- or microtubule-based cytoskeletons (or both) and these polarity (or PCP) protein complexes exert their effects through changes in the organization of the cytoskeletal elements across the seminiferous epithelium of adult rat testes. As such, there is an intimate relationship between cell polarity, cell adhesion, and cytoskeletal function in the testis. Herein, we critically evaluate these recent findings based on studies on different animal models. We also suggest some crucial future studies to be performed.
Collapse
Affiliation(s)
- Linxi Li
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, New York, USA.,The Second Affiliated Hospital & Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ying Gao
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, New York, USA
| | - Haiqi Chen
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, New York, USA
| | - Tito Jesus
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, New York, USA
| | - Elizabeth Tang
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, New York, USA
| | - Nan Li
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, New York, USA
| | - Qingquan Lian
- The Second Affiliated Hospital & Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ren-Shan Ge
- The Second Affiliated Hospital & Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, New York, USA
| |
Collapse
|
14
|
Wu D, Huang CJ, Khan FA, Jiao XF, Liu XM, Pandupuspitasari NS, Brohi RD, Huo LJ. SENP3 grants tight junction integrity and cytoskeleton architecture in mouse Sertoli cells. Oncotarget 2017; 8:58430-58442. [PMID: 28938568 PMCID: PMC5601664 DOI: 10.18632/oncotarget.16915] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 03/14/2017] [Indexed: 11/25/2022] Open
Abstract
Germ cells develop in a sophisticated immune privileged microenvironment provided by specialized junctions contiguous the basement membrane of the adjacent Sertoli cells that constituted the blood-testis barrier (BTB) in seminiferous epithelium of testis in mammals. Deciphering the molecular regulatory machinery of BTB activity is central to improve male fertility and the role of post-translational modification including SUMOylation pathway is one of the key factors. Herein, we unveiled the mystery of the SUMO-2/3 specific protease SENP3 (Sentrin-specific protease 3) in BTB dynamics regulation. SENP3 is predominantly expressed in the nucleus of Sertoli and spermatocyte cells in adult mouse testis, and knockdown of SENP3 compromises tight junction in Sertoli cells by destructing the permeability function with a concomitant decline in trans-epithelial electrical resistance in primary Sertoli cells, which could attribute to the conspicuous dysfunction of tight junction (TJ) proteins (e.g., ZO-1, occludin) at the cell-cell interface due to the inactivation of STAT3. Moreover, SENP3 knockdown disrupts F-actin architecture in Sertoli cells through intervening Rac1/CDC42-N-WASP-Arp2/3 signaling pathway and Profilin-1 abundance. Our study pinpoints SENP3 might be a novel determinant of multiple pathways governing BTB dynamics in testis to support germ cells development in mammals.
Collapse
Affiliation(s)
- Di Wu
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Chun-Jie Huang
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Faheem Ahmed Khan
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Xiao-Fei Jiao
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Xiao-Ming Liu
- Second Affiliated Hospital and Center of Reproductive Medicine, The Second Affiliated Hospital & Yuying Children's Hospital, Wenzhou Medical University, Wenzhou 325000, Zhejiang, China
| | - Nuruliarizki Shinta Pandupuspitasari
- The Center for Biomedical Research, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430070, Hubei, China
| | - Rahim Dad Brohi
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Li-Jun Huo
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| |
Collapse
|
15
|
Li N, Wong CK, Cheng CY. Plastins regulate ectoplasmic specialization via its actin bundling activity on microfilaments in the rat testis. Asian J Androl 2017; 18:716-22. [PMID: 26608945 PMCID: PMC5000794 DOI: 10.4103/1008-682x.166583] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Plastins are a family of actin binding proteins (ABPs) known to cross-link actin microfilaments in mammalian cells, creating actin microfilament bundles necessary to confer cell polarity and cell shape. Plastins also support cell movement in response to changes in environment, involved in cell/tissue growth and development. They also confer plasticity to cells and tissues in response to infection or other pathological conditions (e.g., inflammation). In the testis, the cell-cell anchoring junction unique to the testis that is found at the Sertoli cell-cell interface at the blood-testis barrier (BTB) and at the Sertoli-spermatid (e.g., 8–19 spermatids in the rat testis) is the basal and the apical ectoplasmic specialization (ES), respectively. The ES is an F-actin-rich anchoring junction constituted most notably by actin microfilament bundles. A recent report using RNAi that specifically knocks down plastin 3 has yielded some insightful information regarding the mechanism by which plastin 3 regulates the status of actin microfilament bundles at the ES via its intrinsic actin filament bundling activity. Herein, we provide a brief review on the role of plastins in the testis in light of this report, which together with recent findings in the field, we propose a likely model by which plastins regulate ES function during the epithelial cycle of spermatogenesis via their intrinsic activity on actin microfilament organization in the rat testis.
Collapse
Affiliation(s)
- Nan Li
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Avenue, New York 10065, USA
| | - Chris Kc Wong
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Avenue, New York 10065, USA
| |
Collapse
|
16
|
Abstract
Drebrin is a family of actin-binding proteins with two known members called drebrin A and E. Apart from the ability to stabilize F-actin microfilaments via their actin-binding domains near the N-terminus, drebrin also regulates multiple cellular functions due to its unique ability to recruit multiple binding partners to a specific cellular domain, such as the seminiferous epithelium during the epithelial cycle of spermatogenesis. Recent studies have illustrated the role of drebrin E in the testis during spermatogenesis in particular via its ability to recruit branched actin polymerization protein known as actin-related protein 3 (Arp3), illustrating its involvement in modifying the organization of actin microfilaments at the ectoplasmic specialization (ES) which includes the testis-specific anchoring junction at the Sertoli-spermatid (apical ES) interface and at the Sertoli cell-cell (basal ES) interface. These data are carefully evaluated in light of other recent findings herein regarding the role of drebrin in actin filament organization at the ES. We also provide the hypothetical model regarding its involvement in germ cell transport during the epithelial cycle in the seminiferous epithelium to support spermatogenesis.
Collapse
Affiliation(s)
- Haiqi Chen
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave., New York, NY, 10065, USA
| | - Michelle W M Li
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave., New York, NY, 10065, USA
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave., New York, NY, 10065, USA.
| |
Collapse
|
17
|
Angeles-Floriano T, Roa-Espitia AL, Baltiérrez-Hoyos R, Cordero-Martínez J, Elizondo G, Hernández-González EO. Absence of aryl hydrocarbon receptor alters CDC42 expression and prevents actin polymerization during capacitation. Mol Reprod Dev 2016; 83:1015-1026. [DOI: 10.1002/mrd.22736] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 09/12/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Tania Angeles-Floriano
- Departamento de Biología Celular; CINVESTAV-IPN; Av. Instituto Politécnico Nacional 2508; CP 07360; México DF México
| | - Ana L. Roa-Espitia
- Departamento de Biología Celular; CINVESTAV-IPN; Av. Instituto Politécnico Nacional 2508; CP 07360; México DF México
| | - Rafael Baltiérrez-Hoyos
- Facultad de Medicina y Cirugía; Universidad Autónoma Benito Juárez de Oaxaca; Oaxaca; Cátedras CONACYT
| | - Joaquin Cordero-Martínez
- Departamento de Biología Celular; CINVESTAV-IPN; Av. Instituto Politécnico Nacional 2508; CP 07360; México DF México
| | - Guillermo Elizondo
- Departamento de Biología Celular; CINVESTAV-IPN; Av. Instituto Politécnico Nacional 2508; CP 07360; México DF México
| | - Enrique O. Hernández-González
- Departamento de Biología Celular; CINVESTAV-IPN; Av. Instituto Politécnico Nacional 2508; CP 07360; México DF México
| |
Collapse
|
18
|
Chen H, Cheng CY. Planar cell polarity (PCP) proteins and spermatogenesis. Semin Cell Dev Biol 2016; 59:99-109. [PMID: 27108805 PMCID: PMC5071175 DOI: 10.1016/j.semcdb.2016.04.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 04/18/2016] [Indexed: 11/24/2022]
Abstract
In adult mammalian testes, spermatogenesis is comprised of several discrete cellular events that work in tandem to support the transformation and differentiation of diploid spermatogonia to haploid spermatids in the seminiferous epithelium during the seminiferous epithelial cycle. These include: self-renewal of spermatogonial stem cells via mitosis and their transformation into differentiated spermatogonia, meiosis I/II, spermiogenesis and the release of sperms at spermiation. Studies have shown that these cellular events are under precise and coordinated controls of multiple proteins and signaling pathways. These events are also regulated by polarity proteins that are known to confer classical apico-basal (A/B) polarity in other epithelia. Furthermore, spermatid development is likely supported by planar cell polarity (PCP) proteins since polarized spermatids are aligned across the plane of seminiferous epithelium in an orderly fashion, analogous to hair cells in the cochlea of the inner ear. Thus, the maximal number of spermatids can be packed and supported by a fixed population of differentiated Sertoli cells in the limited space of the seminiferous epithelium in adult testes. In this review, we briefly summarize recent findings regarding the role of PCP proteins in the testis. This information should be helpful in future studies to better understand the role of PCP proteins in spermatogenesis.
Collapse
Affiliation(s)
- Haiqi Chen
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York, NY 10065, United States
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York, NY 10065, United States.
| |
Collapse
|
19
|
Gao Y, Cheng CY. Does cell polarity matter during spermatogenesis? SPERMATOGENESIS 2016; 6:e1218408. [PMID: 27635303 DOI: 10.1080/21565562.2016.1218408] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 07/19/2016] [Accepted: 07/26/2016] [Indexed: 12/21/2022]
Abstract
Cell polarity is crucial to development since apico-basal polarity conferred by the 3 polarity protein modules (or complexes) is essential during embryogenesis, namely the Par (partition defective)-, the CRB (Crumbs)-, and the Scribble-based polarity protein modules. While these protein complexes and their component proteins have been extensively studied in Drosophila and C. elegans and also other mammalian tissues and/or cells, their presence and physiological significance in the testis remain unexplored until the first paper on the Par-based protein published in 2008. Since then, the Par-, the Scribble- and the CRB-based protein complexes and their component proteins in the testis have been studied. These proteins are known to confer Sertoli and spermatid polarity in the seminiferous epithelium, and they are also integrated components of the tight junction (TJ) and the basal ectoplasmic specialization (ES) at the Sertoli cell-cell interface near the basement membrane, which in turn constitute the blood-testis barrier (BTB). These proteins are also found at the apical ES at the Sertoli-spermatid interface. Thus, these polarity proteins also play a significant role in regulating Sertoli and spermatid adhesion in the testis through their actions on actin-based cytoskeletal function. Recent studies have shown that these polarity proteins are having antagonistic effects on the BTB integrity in which the Par6- and CRB3-based polarity complexes promotes the integrity of the Sertoli cell TJ-permeability barrier, whereas the Scribble-based complex promotes restructuring/remodeling of the Sertoli TJ-barrier function. Herein, we carefully evaluate these findings and provide a hypothetic model regarding their role in the testis in the context of the functions of these polarity proteins in other epithelia, so that better experiments can be designed in future studies to explore their significance in spermatogenesis.
Collapse
Affiliation(s)
- Ying Gao
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council , New York, NY, USA
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council , New York, NY, USA
| |
Collapse
|
20
|
Gao Y, Lui WY, Lee WM, Cheng CY. Polarity protein Crumbs homolog-3 (CRB3) regulates ectoplasmic specialization dynamics through its action on F-actin organization in Sertoli cells. Sci Rep 2016; 6:28589. [PMID: 27358069 PMCID: PMC4928075 DOI: 10.1038/srep28589] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 06/07/2016] [Indexed: 12/24/2022] Open
Abstract
Crumbs homolog 3 (or Crumbs3, CRB3) is a polarity protein expressed by Sertoli and germ cells at the basal compartment in the seminiferous epithelium. CRB3 also expressed at the blood-testis barrier (BTB), co-localized with F-actin, TJ proteins occludin/ZO-1 and basal ES (ectoplasmic specialization) proteins N-cadherin/β-catenin at stages IV-VII only. The binding partners of CRB3 in the testis were the branched actin polymerization protein Arp3, and the barbed end-capping and bundling protein Eps8, illustrating its possible role in actin organization. CRB3 knockdown (KD) by RNAi in Sertoli cells with an established tight junction (TJ)-permeability barrier perturbed the TJ-barrier via changes in the distribution of TJ- and basal ES-proteins at the cell-cell interface. These changes were the result of CRB3 KD-induced re-organization of actin microfilaments, in which actin microfilaments were truncated, and extensively branched, thereby destabilizing F-actin-based adhesion protein complexes at the BTB. Using Polyplus in vivo-jetPEI as a transfection medium with high efficiency for CRB3 KD in the testis, the CRB3 KD testes displayed defects in spermatid and phagosome transport, and also spermatid polarity due to a disruption of F-actin organization. In summary, CRB3 is an actin microfilament regulator, playing a pivotal role in organizing actin filament bundles at the ES.
Collapse
Affiliation(s)
- Ying Gao
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York, 10065, New York, USA
| | - Wing-Yee Lui
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Will M Lee
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York, 10065, New York, USA
| |
Collapse
|
21
|
Gao Y, Xiao X, Lui WY, Lee WM, Mruk D, Cheng CY. Cell polarity proteins and spermatogenesis. Semin Cell Dev Biol 2016; 59:62-70. [PMID: 27292315 DOI: 10.1016/j.semcdb.2016.06.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 06/08/2016] [Indexed: 02/09/2023]
Abstract
When the cross-section of a seminiferous tubule from an adult rat testes is examined microscopically, Sertoli cells and germ cells in the seminiferous epithelium are notably polarized cells. For instance, Sertoli cell nuclei are found near the basement membrane. On the other hand, tight junction (TJ), basal ectoplasmic specialization (basal ES, a testis-specific actin-rich anchoring junction), gap junction (GJ) and desmosome that constitute the blood-testis barrier (BTB) are also located near the basement membrane. The BTB, in turn, divides the epithelium into the basal and the adluminal (apical) compartments. Within the epithelium, undifferentiated spermatogonia and preleptotene spermatocytes restrictively reside in the basal compartment whereas spermatocytes and post-meiotic spermatids reside in the adluminal compartment. Furthermore, the heads of elongating/elongated spermatids point toward the basement membrane with their elongating tails toward the tubule lumen. However, the involvement of polarity proteins in this unique cellular organization, in particular the underlying molecular mechanism(s) by which polarity proteins confer cellular polarity in the seminiferous epithelium is virtually unknown until recent years. Herein, we discuss latest findings regarding the role of different polarity protein complexes or modules and how these protein complexes are working in concert to modulate Sertoli cell and spermatid polarity. These findings also illustrate polarity proteins exert their effects through the actin-based cytoskeleton mediated by actin binding and regulatory proteins, which in turn modulate adhesion protein complexes at the cell-cell interface since TJ, basal ES and GJ utilize F-actin for attachment. We also propose a hypothetical model which illustrates the antagonistic effects of these polarity proteins. This in turn provides a unique mechanism to modulate junction remodeling in the testis to support germ cell transport across the epithelium in particular the BTB during the epithelial cycle of spermatogenesis.
Collapse
Affiliation(s)
- Ying Gao
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave., New York, NY 10065, United States
| | - Xiang Xiao
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave., New York, NY 10065, United States; Department of Reproductive Physiology, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China
| | - Wing-Yee Lui
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Will M Lee
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Dolores Mruk
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave., New York, NY 10065, United States
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave., New York, NY 10065, United States.
| |
Collapse
|
22
|
Chen H, Mruk DD, Lee WM, Cheng CY. Planar Cell Polarity (PCP) Protein Vangl2 Regulates Ectoplasmic Specialization Dynamics via Its Effects on Actin Microfilaments in the Testes of Male Rats. Endocrinology 2016; 157:2140-59. [PMID: 26990065 PMCID: PMC4870864 DOI: 10.1210/en.2015-1987] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Planar cell polarity (PCP) proteins confer polarization of a field of cells (eg, elongating/elongated spermatids) within the plane of an epithelium such as the seminiferous epithelium of the tubule during spermatogenesis. In adult rat testes, Sertoli and germ cells were found to express PCP core proteins (eg, Van Gogh-like 2 [Vangl2]), effectors, ligands, and signaling proteins. Vangl2 expressed predominantly by Sertoli cells was localized at the testis-specific, actin-rich ectoplasmic specialization (ES) at the Sertoli-spermatid interface in the adluminal compartment and also Sertoli-Sertoli interface at the blood-testis barrier (BTB) and structurally interacted with actin, N-cadherin, and another PCP/polarity protein Scribble. Vangl2 knockdown (KD) by RNA interference in Sertoli cells cultured in vitro with an established tight junction-permeability barrier led to BTB tightening, whereas its overexpression using a full-length cDNA construct perturbed the barrier function. These changes were mediated through an alteration on the organization actin microfilaments at the ES in Sertoli cells, involving actin-regulatory proteins, epidermal growth factor receptor pathway substrate 8, actin-related protein 3, and Scribble, which in turn affected the function of adhesion protein complexes at the ES during the epithelial cycle of spermatogenesis. Using Polyplus in vivo-jetPEI reagent as a transfection medium to silence Vangl2 in the testis in vivo by RNA interference with high efficacy, Vangl2 KD led to changes in F-actin organization at the ES in the epithelium, impeding spermatid and phagosome transport and spermatid polarity, meiosis, and BTB dynamics. For instance, step 19 spermatids remained embedded in the epithelium alongside with step 9 and 10 spermatids in stages IX-X tubules. In summary, the PCP protein Vangl2 is an ES regulator through its effects on actin microfilaments in the testis.
Collapse
Affiliation(s)
- Haiqi Chen
- The Mary M. Wohlford Laboratory for Male Contraceptive Research (H.C., D.D.M., C.Y.C.), Center for Biomedical Research, Population Council, New York, New York 10065; and School of Biological Sciences (W.M.L.), University of Hong Kong, Pokfulam, Hong Kong, China
| | - Dolores D Mruk
- The Mary M. Wohlford Laboratory for Male Contraceptive Research (H.C., D.D.M., C.Y.C.), Center for Biomedical Research, Population Council, New York, New York 10065; and School of Biological Sciences (W.M.L.), University of Hong Kong, Pokfulam, Hong Kong, China
| | - Will M Lee
- The Mary M. Wohlford Laboratory for Male Contraceptive Research (H.C., D.D.M., C.Y.C.), Center for Biomedical Research, Population Council, New York, New York 10065; and School of Biological Sciences (W.M.L.), University of Hong Kong, Pokfulam, Hong Kong, China
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research (H.C., D.D.M., C.Y.C.), Center for Biomedical Research, Population Council, New York, New York 10065; and School of Biological Sciences (W.M.L.), University of Hong Kong, Pokfulam, Hong Kong, China
| |
Collapse
|
23
|
França LR, Hess RA, Dufour JM, Hofmann MC, Griswold MD. The Sertoli cell: one hundred fifty years of beauty and plasticity. Andrology 2016; 4:189-212. [PMID: 26846984 DOI: 10.1111/andr.12165] [Citation(s) in RCA: 246] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 12/30/2015] [Accepted: 01/04/2016] [Indexed: 12/18/2022]
Abstract
It has been one and a half centuries since Enrico Sertoli published the seminal discovery of the testicular 'nurse cell', not only a key cell in the testis, but indeed one of the most amazing cells in the vertebrate body. In this review, we begin by examining the three phases of morphological research that have occurred in the study of Sertoli cells, because microscopic anatomy was essentially the only scientific discipline available for about the first 75 years after the discovery. Biochemistry and molecular biology then changed all of biological sciences, including our understanding of the functions of Sertoli cells. Immunology and stem cell biology were not even topics of science in 1865, but they have now become major issues in our appreciation of Sertoli cell's role in spermatogenesis. We end with the universal importance and plasticity of function by comparing Sertoli cells in fish, amphibians, and mammals. In these various classes of vertebrates, Sertoli cells have quite different modes of proliferation and epithelial maintenance, cystic vs. tubular formation, yet accomplish essentially the same function but in strikingly different ways.
Collapse
Affiliation(s)
- L R França
- Laboratory of Cellular Biology, Department of Morphology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.,National Institute for Amazonian Research (INPA), Manaus, Amazonas, Brazil
| | - R A Hess
- Reproductive Biology and Toxicology, Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, Urbana, IL, USA
| | - J M Dufour
- Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - M C Hofmann
- Department of Endocrine Neoplasia and Hormonal Disorders, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - M D Griswold
- Center for Reproductive Biology, School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| |
Collapse
|
24
|
Mizuhashi K, Chaya T, Kanamoto T, Omori Y, Furukawa T. Obif, a Transmembrane Protein, Is Required for Bone Mineralization and Spermatogenesis in Mice. PLoS One 2015. [PMID: 26207632 PMCID: PMC4514473 DOI: 10.1371/journal.pone.0133704] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Various kinds of transmembrane and secreted proteins play pivotal roles in development through cell-cell communication. We previously reported that Obif (Osteoblast induction factor, Tmem119), encoding a single transmembrane protein, is expressed in differentiating osteoblasts, and that Obif-/- mice exhibit significantly reduced bone volume in the femur. In the current study, we characterized the Obif protein and further investigated the biological phenotypes of a variety of tissues in Obif-/- mice. RESULTS First, we found that O-glycosylation of the Obif protein occurs at serine residue 36 in the Obif extracellular domain. Next, we observed that Obif-/- mice exhibit bone dysplasia in association with significantly increased osteoid volume per osteoid surface (OV/OS) and osteoid maturation time (Omt), and significantly decreased mineral apposition rate (MAR) and bone formation rate per bone surface (BFR/BS). In addition, we observed that Obif-/- mice show a significant decrease in testis weight as well as in sperm number. By histological analysis, we found that Obif is expressed in spermatocytes and spermatids in the developing testis and that spermatogenesis is halted at the round spermatid stage in the Obif-/- testis that lacks sperm. However, the number of litters fathered by male mice was slightly reduced in Obif-/- mice compared with wild-type mice, although this was not statistically significant. CONCLUSIONS Our results, taken together with previous observations, indicate that Obif is a type Ia transmembrane protein whose N-terminal region is O-glycosylated. In addition, we found that Obif is required for normal bone mineralization and late testicular differentiation in vivo. These findings suggest that Obif plays essential roles in the development of multiple tissues.
Collapse
Affiliation(s)
- Koji Mizuhashi
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, 3–2 Yamadaoka, Suita, Osaka, Japan
- Department of Developmental Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka, Japan
| | - Taro Chaya
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, 3–2 Yamadaoka, Suita, Osaka, Japan
- Department of Developmental Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, 3–2 Yamadaoka, Suita, Osaka, Japan
| | - Takashi Kanamoto
- Department of Developmental Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka, Japan
- Department of Orthopedic Surgery, Osaka University Graduate School of Medicine, 2–2 Yamadaoka, Suita, Osaka, Japan
| | - Yoshihiro Omori
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, 3–2 Yamadaoka, Suita, Osaka, Japan
- Department of Developmental Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, 3–2 Yamadaoka, Suita, Osaka, Japan
| | - Takahisa Furukawa
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, 3–2 Yamadaoka, Suita, Osaka, Japan
- Department of Developmental Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, 3–2 Yamadaoka, Suita, Osaka, Japan
- * E-mail:
| |
Collapse
|
25
|
Kistler WS, Baas D, Lemeille S, Paschaki M, Seguin-Estevez Q, Barras E, Ma W, Duteyrat JL, Morlé L, Durand B, Reith W. RFX2 Is a Major Transcriptional Regulator of Spermiogenesis. PLoS Genet 2015; 11:e1005368. [PMID: 26162102 PMCID: PMC4498915 DOI: 10.1371/journal.pgen.1005368] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 06/17/2015] [Indexed: 11/21/2022] Open
Abstract
Spermatogenesis consists broadly of three phases: proliferation of diploid germ cells, meiosis, and finally extensive differentiation of the haploid cells into effective delivery vehicles for the paternal genome. Despite detailed characterization of many haploid developmental steps leading to sperm, only fragmentary information exists on the control of gene expression underlying these processes. Here we report that the RFX2 transcription factor is a master regulator of genes required for the haploid phase. A targeted mutation of Rfx2 was created in mice. Rfx2-/- mice are perfectly viable but show complete male sterility. Spermatogenesis appears to progress unperturbed through meiosis. However, haploid cells undergo a complete arrest in spermatid development just prior to spermatid elongation. Arrested cells show altered Golgi apparatus organization, leading to a deficit in the generation of a spreading acrosomal cap from proacrosomal vesicles. Arrested cells ultimately merge to form giant multinucleated cells released to the epididymis. Spermatids also completely fail to form the flagellar axoneme. RNA-Seq analysis and ChIP-Seq analysis identified 139 genes directly controlled by RFX2 during spermiogenesis. Gene ontology analysis revealed that genes required for cilium function are specifically enriched in down- and upregulated genes showing that RFX2 allows precise temporal expression of ciliary genes. Several genes required for cell adhesion and cytoskeleton remodeling are also downregulated. Comparison of RFX2-regulated genes with those controlled by other major transcriptional regulators of spermiogenesis showed that each controls independent gene sets. Altogether, these observations show that RFX2 plays a major and specific function in spermiogenesis. Failure of spermatogenesis, which is presumed to often result from genetic defects, is a common cause of male sterility. Although numerous genes associated with defects in male spermatogenesis have been identified, numerous cases of genetic male infertility remain unelucidated. We report here that the transcription factor RFX2 is a master regulator of gene expression programs required for progression through the haploid phase of spermatogenesis. Male RFX2-deficient mice are completely sterile. Spermatogenesis progresses through meiosis, but haploid cells undergo a complete block in development just prior to spermatid elongation. Gene expression profiling and ChIP-Seq analysis revealed that RFX2 controls key pathways implicated in cilium/flagellum formation, as well as genes implicated in microtubule and vesicle associated transport. The set of genes activated by RFX2 in spermatids exhibits virtually no overlap with those controlled by other known transcriptional regulators of spermiogenesis, establishing RFX2 as an essential new player in this developmental process. RFX2-deficient mice should therefore represent a valuable new model for deciphering the regulatory networks that direct sperm formation, and thereby contribute to the identification of causes of human male infertility.
Collapse
Affiliation(s)
- W. Stephen Kistler
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, United States of America
- * E-mail: (WSK); (BD)
| | - Dominique Baas
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, Villeurbanne, Lyon, France
| | - Sylvain Lemeille
- Department of Pathology and Immunology, University of Geneva Medical School, CMU, Geneva, Switzerland
| | - Marie Paschaki
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, Villeurbanne, Lyon, France
| | - Queralt Seguin-Estevez
- Department of Pathology and Immunology, University of Geneva Medical School, CMU, Geneva, Switzerland
| | - Emmanuèle Barras
- Department of Pathology and Immunology, University of Geneva Medical School, CMU, Geneva, Switzerland
| | - Wenli Ma
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, United States of America
| | - Jean-Luc Duteyrat
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, Villeurbanne, Lyon, France
| | - Laurette Morlé
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, Villeurbanne, Lyon, France
| | - Bénédicte Durand
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534, Université Claude Bernard Lyon-1, Villeurbanne, Lyon, France
- * E-mail: (WSK); (BD)
| | - Walter Reith
- Department of Pathology and Immunology, University of Geneva Medical School, CMU, Geneva, Switzerland
| |
Collapse
|
26
|
Xiao X, Mruk DD, Wong CKC, Cheng CY. Germ cell transport across the seminiferous epithelium during spermatogenesis. Physiology (Bethesda) 2015; 29:286-98. [PMID: 24985332 DOI: 10.1152/physiol.00001.2014] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Transport of germ cells across the seminiferous epithelium is crucial to spermatogenesis. Its disruption causes infertility. Signaling molecules, such as focal adhesion kinase, c-Yes, c-Src, and intercellular adhesion molecules 1 and 2, are involved in these events by regulating actin-based cytoskeleton via their action on actin-regulating proteins, endocytic vesicle-mediated protein trafficking, and adhesion protein complexes. We critically evaluate these findings and provide a hypothetical framework that regulates these events.
Collapse
Affiliation(s)
- Xiang Xiao
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York; and
| | - Dolores D Mruk
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York; and
| | - Chris K C Wong
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York; and
| |
Collapse
|
27
|
Gungor-Ordueri NE, Celik-Ozenci C, Cheng CY. Fascin 1 is an actin filament-bundling protein that regulates ectoplasmic specialization dynamics in the rat testis. Am J Physiol Endocrinol Metab 2014; 307:E738-53. [PMID: 25159326 PMCID: PMC4216949 DOI: 10.1152/ajpendo.00113.2014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In the testis, spermatids are polarized cells, with their heads pointing toward the basement membrane during maturation. This polarity is crucial to pack the maximal number of spermatids in the seminiferous epithelium so that millions of sperms can be produced daily. A loss of spermatid polarity is detected after rodents are exposed to toxicants (e.g., cadmium) or nonhormonal male contraceptives (e.g., adjudin), which is associated with a disruption on the expression and/or localization of polarity proteins. In the rat testis, fascin 1, an actin-bundling protein found in mammalian cells, was expressed by Sertoli and germ cells. Fascin 1 was a component of the ectoplasmic specialization (ES), a testis-specific anchoring junction known to confer spermatid adhesion and polarity. Its expression in the seminiferous epithelium was stage specific. Fascin 1 was localized to the basal ES at the Sertoli cell-cell interface of the blood-testis barrier in all stages of the epithelial cycle, except it diminished considerably at late stage VIII. Fascin 1 was highly expressed at the apical ES at stage VII-early stage VIII and restricted to the step 19 spermatids. Its knockdown by RNAi that silenced fascin 1 by ~70% in Sertoli cells cultured in vitro was found to perturb the tight junction-permeability barrier via a disruption of F-actin organization. Knockdown of fascin 1 in vivo by ~60-70% induced defects in spermatid polarity, which was mediated by a mislocalization and/or downregulation of actin-bundling proteins Eps8 and palladin, thereby impeding F-actin organization and disrupting spermatid polarity. In summary, these findings provide insightful information on spermatid polarity regulation.
Collapse
Affiliation(s)
- N Ece Gungor-Ordueri
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York; and
| | - Ciler Celik-Ozenci
- Department of Histology and Embryology, Faculty of Medicine, Akdeniz University, Antalya, Turkey
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York; and
| |
Collapse
|
28
|
Tang EI, Xiao X, Mruk DD, Qian XJ, Mok KW, Jenardhanan P, Lee WM, Mathur PP, Cheng CY. Microtubule affinity-regulating kinase 4 (MARK4) is a component of the ectoplasmic specialization in the rat testis. SPERMATOGENESIS 2014; 2:117-126. [PMID: 22670221 PMCID: PMC3364792 DOI: 10.4161/spmg.20724] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
During the seminiferous epithelial cycle of spermatogenesis, the ectoplasmic specialization (ES, a testis-specific adherens junction, AJ, type) maintains the polarity of elongating/elongated spermatids and confers adhesion to Sertoli cells in the seminiferous epithelium, and known as the apical ES. On the other hand, the ES is also found at the Sertoli-Sertoli cell interface at the blood-testis barrier (BTB) known as basal ES, which together with the tight junction (TJ), maintains Sertoli cell polarity and adhesion, creating a functional barrier that limits paracellular transport of substances across the BTB. However, the apical and basal ES are segregated and restricted to the adluminal compartment and the BTB, respectively. During the transit of preleptotene spermatocytes across the BTB and the release of sperm at spermiation at stage VIII of the seminiferous epithelial cycle, both the apical and basal ES undergo extensive restructuring to facilitate cell movement at these sites. The regulation of these events, in particular their coordination, remains unclear. Studies in other epithelia have shown that the tubulin cytoskeleton is intimately related to cell movement, and MARK [microtubule-associated protein (MAP)/microtubule affinity-regulating kinase] family kinases are crucial regulators of tubulin cytoskeleton stability. Herein MARK4, the predominant member of the MARK protein family in the testis, was shown to be expressed by both Sertoli and germ cells. MARK4 was also detected at the apical and basal ES, displaying highly restrictive spatiotemporal expression at these sites, as well as co-localizing with markers of the apical and basal ES. The expression of MARK4 was found to be stage-specific during the epithelial cycle, structurally associating with α-tubulin and the desmosomal adaptor plakophilin-2, but not with actin-based BTB proteins occludin, β-catenin and Eps8 (epidermal growth factor receptor pathway substrate 8, an actin bundling and barbed end capping protein). More importantly, it was shown that the expression of MARK4 tightly associated with the integrity of the apical ES because a diminished expression of MARK4 associated with apical ES disruption that led to the detachment of elongating/elongated spermatids from the epithelium. These findings thus illustrate that the integrity of apical ES, an actin-based and testis-specific AJ, is dependent not only on the actin filament network, but also on the tubulin-based cytoskeleton.
Collapse
|
29
|
Wong EWP, Cheng CY. NC1 domain of collagen α3(IV) derived from the basement membrane regulates Sertoli cell blood-testis barrier dynamics. SPERMATOGENESIS 2014; 3:e25465. [PMID: 23885308 PMCID: PMC3710226 DOI: 10.4161/spmg.25465] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 06/13/2013] [Accepted: 06/14/2013] [Indexed: 11/19/2022]
Abstract
The blood-testis barrier (BTB) is an important ultrastructure for spermatogenesis. Delay in BTB formation in neonatal rats or its irreversible damage in adult rats leads to meiotic arrest and failure of spermatogonial differentiation beyond type A. While hormones, such as testosterone and FSH, are crucial to BTB function, little is known if there is a local regulatory mechanism in the seminiferous epithelium that modulates BTB function. Herein, we report that collagen α3(IV) chain, a component of the basement membrane in the rat testis, could generate a noncollagenous (NC1) domain peptide [Colα3(IV) NC1] via limited proteolysis by matrix metalloproteinase-9 (MMP-9), and that the expression of MMP-9 was upregulated by TNFα. While recombinant Colα3(IV) NC1 protein produced in E. coli failed to perturb Sertoli cell tight junction (TJ)-permeability barrier function, possibly due to the lack of glycosylation, Colα3(IV) NC1 recombinant protein produced in mammalian cells and purified to apparent homogeneity by affinity chromatography was found to reversibly perturb the Sertoli cell TJ-barrier function. Interestingly, Colα3(IV) NC1 recombinant protein did not perturb the steady-state levels of several TJ- (e.g., occludin, CAR, JAM-A, ZO-1) and basal ectoplasmic specialization- (e.g., N-cadherin, α-catenin, β-catenin) proteins at the BTB but induced changes in protein localization and/or distribution at the Sertoli cell-cell interface in which these proteins moved from the cell surface into the cell cytosol, thereby destabilizing the TJ function. These findings illustrate the presence of a local regulatory axis known as the BTB-basement membrane axis that regulates BTB restructuring during spermatogenesis.
Collapse
Affiliation(s)
- Elissa W P Wong
- The Mary M. Wohlford Laboratory for Male Contraceptive Research; Center for Biomedical Research; Population Council; New York, NY USA
| | | |
Collapse
|
30
|
Cheng CY, Mruk DD. Actin binding proteins and spermiogenesis: Some unexpected findings. SPERMATOGENESIS 2014; 1:99-104. [PMID: 22319657 DOI: 10.4161/spmg.1.2.16913] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 06/05/2011] [Accepted: 06/07/2011] [Indexed: 12/18/2022]
Abstract
Drebrin E, an actin-binding protein lacking intrinsic activity in the regulation of actin dynamics (e.g., polymerization, capping, nucleation, branching, cross-linking, bundling and severing), is known to recruit actin regulatory proteins to a specific cellular site. Herein, we critically evaluate recent findings in the field which illustrate that drebrin E works together with two other actin-binding proteins, namely Arp3 (actin-related protein 3, a component of the Arp2/3 complex that simultaneously controls actin nucleation for polymerization and branching of actin filaments) and Eps8 (epidermal growth factor receptor pathway substrate 8 that controls capping of the barbed ends of actin filaments, as well as actin filament bundling) to regulate the homeostasis of F-actin filament bundles at the ectoplasmic specialization (ES), a testis-specific atypical adherens junction (AJ) in the seminiferous epithelium. This is mediated by the strict temporal and spatial expression of these three actin-binding proteins at the apical and basal ES at the Sertoli cell-spermatid (step 8-19) and Sertoli-Sertoli cell interface, respectively, during the seminiferous epithelial cycle of spermatogenesis. In this Commentary, we put forth a possible model by which drebrin E may be acting as a platform upon which proteins (e.g., Arp3) that are needed to alter the conformation of actin filament bundles at the ES can be recruited to the site, thus facilitating changes in cell shape and cell position in the epithelium during spermiogenesis and spermiation. In short, drebrin E may be acting as a "logistic" distribution center to manage different regulatory proteins at the apical ES, thereby regulating the dynamics of actin filament bundles and modulating the plasticity of the apical ES. This would allow adhesion to be altered continuously throughout the epithelial cycle to accommodate spermatid movement in the seminiferous epithelium during spermiogenesis and spermiation. We also describe a hypothetical model, upon which functional studies can be designed in the future.
Collapse
Affiliation(s)
- C Yan Cheng
- Center for Biomedical Research; The Population Council; New York, NY USA
| | | |
Collapse
|
31
|
Gómez O, Ballester-Lurbe B, Guasch RM, Pérez-Roger I, García-Roselló E, Terrado J. Analysis of RhoE expression in the testis, epididymis and ductus deferens, and the effects of its deficiency in mice. J Anat 2014; 225:583-90. [PMID: 25270035 DOI: 10.1111/joa.12241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2014] [Indexed: 12/12/2022] Open
Abstract
Rho proteins are a large family of GTPases involved in the control of actin cytoskeleton dynamics, proliferation and survival. Rnd1, Rnd2 and RhoE/Rnd3 form a subfamily of Rho proteins characterized by being constitutively active. The role of these proteins has been studied during the last years in several systems; however, little is known about their expression and functions in the reproductive organs. In this work we analysed the localization and the effect of RhoE deficiency in the testes using mice lacking RhoE expression (RhoE gt/gt), and our research shows some unexpected and relevant results. First, we have observed that RhoE is only expressed in Leydig cells within the testicular parenchyma and it is absent of seminiferous tubules. In addition, RhoE is expressed in the excurrent ducts of the testis, including the ductuli efferentes, epididymis and ductus deferens. Moreover, the testes of postnatal 15-day-old RhoE null mice are smaller, both in absolute values and in relation to the body weight. Furthermore, the dimensions of their seminiferous tubules are also reduced compared with wild-types. In order to study the role of RhoE in the adult, we analysed heterozygous animals as RhoE null mice die early postnatally. Our results show that the testes of adult RhoE heterozygous mice are also smaller than those of the wild-types, with a 17% decrease in the ratio testis weight/body weight. In addition, their seminiferous tubules have reduced tubular diameter (12%) and a thinner epithelial wall (33%) that appears disorganized and with a swollen lumen. Finally, and probably as a consequence of those alterations, the sperm concentration of heterozygous animals was found to be lower than in the wild-types. These results indicate that accurate levels of RhoE in the testes are necessary for a correct development and function of male gonads, and suggest novel and unexpected roles of Rnd GTPases in the reproductive physiology.
Collapse
Affiliation(s)
- Olga Gómez
- Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad CEU Cardenal Herrera, Alfara del Patriarca, Valencia, Spain
| | | | | | | | | | | |
Collapse
|
32
|
Chalmel F, Com E, Lavigne R, Hernio N, Teixeira-Gomes AP, Dacheux JL, Pineau C. An integrative omics strategy to assess the germ cell secretome and to decipher sertoli-germ cell crosstalk in the Mammalian testis. PLoS One 2014; 9:e104418. [PMID: 25111155 PMCID: PMC4128672 DOI: 10.1371/journal.pone.0104418] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 07/08/2014] [Indexed: 12/11/2022] Open
Abstract
Mammalian spermatogenesis, which takes place in complex testicular structures called seminiferous tubules, is a highly specialized process controlled by the integration of juxtacrine, paracrine and endocrine information. Within the seminiferous tubules, the germ cells and Sertoli cells are surrounded by testicular fluid (TF), which probably contains most of the secreted proteins involved in crosstalk between these cells. It has already been established that germ cells can modulate somatic Sertoli cell function through the secretion of diffusible factors. We studied the germ cell secretome, which was previously considered inaccessible, by analyzing the TF collected by microsurgery in an “integrative omics” strategy combining proteomics, transcriptomics, genomics and interactomics data. This approach identified a set of proteins preferentially secreted by Sertoli cells or germ cells. An interaction network analysis revealed complex, interlaced cell-cell dialog between the secretome and membranome of seminiferous cells, mediated via the TF. We then focused on germ cell-secreted candidate proteins, and we identified several potential interacting partners located on the surface of Sertoli cells. Two interactions, APOH/CDC42 and APP/NGFR, were validated in situ, in a proximity ligation assay (PLA). Our results provide new insight into the crosstalk between germ cells and Sertoli cells occurring during spermatogenesis. Our findings also demonstrate that this “integrative omics” strategy is powerful enough for data mining and highlighting meaningful cell-cell communication events between different types of cells in a complex tissue, via a biological fluid. This integrative strategy could be applied more widely, to gain access to secretomes that have proved difficult to study whilst avoiding the limitations of in vitro culture.
Collapse
Affiliation(s)
- Frédéric Chalmel
- IRSET, Inserm U1085, Campus de Beaulieu, Rennes, France
- * E-mail: (CP); (FC)
| | - Emmanuelle Com
- Proteomics Core Facility Biogenouest, Inserm U1085 IRSET, Campus de Beaulieu, Rennes, France
| | - Régis Lavigne
- Proteomics Core Facility Biogenouest, Inserm U1085 IRSET, Campus de Beaulieu, Rennes, France
| | - Nolwen Hernio
- Proteomics Core Facility Biogenouest, Inserm U1085 IRSET, Campus de Beaulieu, Rennes, France
| | - Ana-Paula Teixeira-Gomes
- INRA UMR 1282, Infectiologie et Santé Publique, Nouzilly, France
- INRA Plate-forme d'Analyse Intégrative des Biomolécules (PAIB), Nouzilly, France
| | | | - Charles Pineau
- Proteomics Core Facility Biogenouest, Inserm U1085 IRSET, Campus de Beaulieu, Rennes, France
- * E-mail: (CP); (FC)
| |
Collapse
|
33
|
Xiao X, Wong EWP, Lie PPY, Mruk DD, Wong CKC, Cheng CY. Cytokines, polarity proteins, and endosomal protein trafficking and signaling-the sertoli cell blood-testis barrier system in vitro as a study model. Methods Enzymol 2014; 534:181-94. [PMID: 24359954 DOI: 10.1016/b978-0-12-397926-1.00010-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Endosomal signaling is emerging as one of the most important cellular events that regulate signaling function in mammalian cells or an epithelium in response to changes in environment such as the presence of stimuli mediated by cytokines, toxicants, heat, ions during growth and development, and other cellular processes such as cytokinesis and spermatogenesis. Recent studies have shown that protein endocytosis-the initial step of endosomal signaling-involves the participation of polarity proteins, such as partitioning defective protein 6 (Par6), Cdc42 and 14-3-3 (also known as Par5), which in turn is regulated by cytokines (e.g., TGF-β2, TGF-β3) and testosterone at the Sertoli cell blood-testis barrier (BTB) in the mammalian testis. In this short method paper, we provide a detailed protocol of assessing protein endocytosis, the initial and also the most critical step of endosomal signaling at the Sertoli cell BTB. This biochemical endocytosis assay summarizes our experience for the last decade, which should likely be performed in conjunction with the dual-labeled immunofluorescence analysis to assess protein endocytosis. While we are using a Sertoli cell in vitro system that mimics the BTB in vivo, this approach should be applicable to virtually all mammalian cells.
Collapse
Affiliation(s)
- Xiang Xiao
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, USA; Department of Reproductive Physiology, Zhejiang Academy of Medical Sciences, Hangzhou, Zhejiang, China
| | - Elissa W P Wong
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, USA
| | - Pearl P Y Lie
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, USA
| | - Dolores D Mruk
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, USA
| | - Chris K C Wong
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, USA.
| |
Collapse
|
34
|
Hu Z, Li Z, Yu J, Tong C, Lin Y, Guo X, Lu F, Dong J, Xia Y, Wen Y, Wu H, Li H, Zhu Y, Ping P, Chen X, Dai J, Jiang Y, Pan S, Xu P, Luo K, Du Q, Yao B, Liang M, Gui Y, Weng N, Lu H, Wang Z, Zhang F, Zhu X, Yang X, Zhang Z, Zhao H, Xiong C, Ma H, Jin G, Chen F, Xu J, Wang X, Zhou Z, Chen ZJ, Liu J, Shen H, Sha J. Association analysis identifies new risk loci for non-obstructive azoospermia in Chinese men. Nat Commun 2014; 5:3857. [DOI: 10.1038/ncomms4857] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 04/11/2014] [Indexed: 11/09/2022] Open
|
35
|
Paul C, Robaire B. Impaired function of the blood-testis barrier during aging is preceded by a decline in cell adhesion proteins and GTPases. PLoS One 2013; 8:e84354. [PMID: 24391944 PMCID: PMC3877286 DOI: 10.1371/journal.pone.0084354] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 11/14/2013] [Indexed: 11/21/2022] Open
Abstract
With increasing age comes many changes in the testis, including germ cell loss. Cell junctions in the testis tether both seminiferous epithelial and germ cells together and assist in the formation of the blood-testis barrier (BTB), which limits transport of biomolecules, ions and electrolytes from the basal to the adluminal compartment and protects post-meiotic germ cells. We hypothesize that as male rats age the proteins involved in forming the junctions decrease and that this alters the ability of the BTB to protect the germ cells. Pachytene spermatocytes were isolated from Brown Norway rat testes at 4 (young) and 18 (aged) months of age using STA-PUT velocity sedimentation technique. RNA was extracted and gene expression was assessed using Affymetrix rat 230 2.0 whole rat genome microarrays. Microarray data were confirmed by q-RT-PCR and protein expression by Western blotting. Of the genes that were significantly decreased by at least 1.5 fold, 70 were involved in cell adhesion; of these, at least 20 are known to be specifically involved in junction dynamics within the seminiferous epithelium. The mRNA and protein levels of Jam2, Ocln, cdh2 (N-cadherin), ctnna (α-catenin), and cldn11 (involved in adherens junctions), among others, were decreased by approximately 50% in aged spermatocytes. In addition, the GTPases Rac1 and cdc42, involved in the recruitment of cadherins to the adherens junctions, were similarly decreased. It is therefore not surprising that with lower expression of these proteins that the BTB becomes diminished with age. We saw, using a FITC tracer, a gradual collapse of the BTB between 18 and 24 months. This provides the opportunity for harmful substances and immune cells to cross the BTB and cause the disruption of spermatogenesis that is observed with increasing age.
Collapse
Affiliation(s)
- Catriona Paul
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Canada
| | - Bernard Robaire
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Canada
- Department of Obstetrics and Gynecology, McGill University, Montréal, Canada
- * E-mail:
| |
Collapse
|
36
|
Mok KW, Mruk DD, Cheng CY. Regulation of blood-testis barrier (BTB) dynamics during spermatogenesis via the "Yin" and "Yang" effects of mammalian target of rapamycin complex 1 (mTORC1) and mTORC2. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 301:291-358. [PMID: 23317821 DOI: 10.1016/b978-0-12-407704-1.00006-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In mammalian testes, haploid spermatozoa are formed from diploid spermatogonia during spermatogenesis, which is a complicated cellular process. While these cellular events were reported in the 1960s and 1970s, the underlying molecular mechanism(s) that regulates these events remained unexplored until the past ∼10 years. For instance, adhesion proteins were shown to be integrated components at the Sertoli cell-cell interface and/or the Sertoli-spermatid interface in the late 1980s. But only until recently, studies have demonstrated that some of the adhesion proteins serve as the platform for signal transduction that regulates cell adhesion. In this chapter, a brief summary and critical discussion are provided on the latest findings regarding these cell-adhesion proteins in the testis and their relationship to spermatogenesis. Moreover, antagonistic effects of two mammalian target of rapamycin (mTOR) complexes, known as mTORC1 and mTORC2, on cell-adhesion function in the testis are discussed. Finally, a hypothetic model is presented to depict how these two mTOR-signaling complexes having the "yin" and "yang" antagonistic effects on the Sertoli cell tight junction (TJ)-permeability barrier can maintain the blood-testis barrier (BTB) integrity during the epithelial cycle while preleptotene spermatocytes are crossing the BTB.
Collapse
Affiliation(s)
- Ka Wai Mok
- Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, USA
| | | | | |
Collapse
|
37
|
Wan HT, Mruk DD, Li SYT, Mok KW, Lee WM, Wong CKC, Cheng CY. p-FAK-Tyr(397) regulates spermatid adhesion in the rat testis via its effects on F-actin organization at the ectoplasmic specialization. Am J Physiol Endocrinol Metab 2013; 305:E687-99. [PMID: 23880313 PMCID: PMC4073987 DOI: 10.1152/ajpendo.00254.2013] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During spermatogenesis, the molecular mechanism that confers spermatid adhesion to the Sertoli cell at the apical ectoplasmic specialization (apical ES), a testis-specific F-actin-rich adherens junction, in the rat testis remains elusive. Herein, the activated form of focal adhesion kinase (FAK), p-FAK-Tyr(397), a component of the apical ES that was expressed predominantly and stage specifically in stage VII-early stage VIII tubules, was found to be a crucial apical ES regulator. Using an FAK-Y397E phosphomimetic mutant cloned in a mammalian expression vector for its transfection vs. FAK and vector alone in adult rat testes in vivo, its overexpression was found to cause defects in spermiation. These defects in spermiation were manifested by entrapment of spermatids in the seminiferous epithelium in late stage VIII-X tubules and were mediated by a disruption on the spatiotemporal expression and/or mislocalization of actin regulatory protein actin-related protein 3, which induces branched actin polymerization, epidermal growth factor receptor pathway substrate 8 (an actin barbed end capping and bundling protein), and palladin (an actin cross-linking and bundling protein). This thus perturbed changes of F-actin organization at the apical ES to facilitate spermiation, which also led to a concomitant alteration in the distribution and upregulation of adhesion proteins nectin-2 and nectin-3 at the apical ES. As such, nectin-2 and -3 remained at the apical ES to anchor step 19 spermatids on to the epithelium, delaying spermiation. These findings illustrate a mechanistic pathway mediated by p-FAK-Tyr(397) that regulates spermatid adhesion at the apical ES in vivo.
Collapse
Affiliation(s)
- Hin-Ting Wan
- 1The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York;
| | - Dolores D. Mruk
- 1The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York;
| | - Stephen Y. T. Li
- 1The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York;
| | - Ka-Wai Mok
- 1The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York;
| | - Will M. Lee
- 2School of Biological of Sciences, University of Hong Kong, Hong Kong, China; and
| | - Chris K. C. Wong
- 3Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - C. Yan Cheng
- 1The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York;
| |
Collapse
|
38
|
Li SY, Mruk DD, Cheng CY. Focal adhesion kinase is a regulator of F-actin dynamics: New insights from studies in the testis. SPERMATOGENESIS 2013; 3:e25385. [PMID: 24381802 PMCID: PMC3861170 DOI: 10.4161/spmg.25385] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/27/2013] [Accepted: 06/08/2013] [Indexed: 02/03/2023]
Abstract
During spermatogenesis, spermatogonia (2n, diploid) undergo a series of mitotic divisions as well as differentiation to become spermatocytes, which enter meiosis I to be followed by meiosis II to form round spermatids (1n, haploid), and then differentiate into spermatozoa (1n, haploid) via spermiogenesis. These events take place in the epithelium of the seminiferous tubule, involving extensive junction restructuring at the Sertoli-Sertoli and Sertoli-germ cell interface to allow the transport of developing germ cells across the epithelium. Although structural aspects of these cell-cell junctions have been studied, the underlying mechanism(s) that governs these events has yet to be explored. Earlier studies have shown that a non-receptor protein tyrosine kinase known as focal adhesion kinase (FAK) is a likely regulator of these events due to the stage-specific and spatiotemporal expression of its various phosphorylated/activated forms at the testis-specific anchoring junctions in the testis, as well as its association with actin regulatory proteins. Recent studies have shown that FAK, in particular its two activated phosphorylated forms p-FAK-Tyr407 and p-FAK-Tyr397, are crucial regulators in modulating junction restructuring at the Sertoli cell-cell interface at the blood-testis barrier (BTB) known as the basal ectoplasmic specialization (basal ES), as well as at the Sertoli-spermatid interface called apical ES during spermiogenesis via its effects on the filamentous (F)-actin organization at the ES. We herein summarize and critically evaluate the current knowledge regarding the physiological significance of FAK in regulating BTB and apical ES dynamics by governing the conversion of actin filaments at the ES from a “bundled” to a “de-bundled/branched” configuration and vice versa. We also provide a molecular model on the role of FAK in regulating these events based on the latest findings in the field.
Collapse
Affiliation(s)
- Stephen Yt Li
- The Mary M. Wohlford Laboratory for Male Contraceptive Research; Center for Biomedical Research; Population Council; New York, NY USA
| | - Dolores D Mruk
- The Mary M. Wohlford Laboratory for Male Contraceptive Research; Center for Biomedical Research; Population Council; New York, NY USA
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research; Center for Biomedical Research; Population Council; New York, NY USA
| |
Collapse
|
39
|
Wan HT, Mruk DD, Wong CKC, Cheng CY. The apical ES-BTB-BM functional axis is an emerging target for toxicant-induced infertility. Trends Mol Med 2013; 19:396-405. [PMID: 23643465 DOI: 10.1016/j.molmed.2013.03.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 03/27/2013] [Accepted: 03/29/2013] [Indexed: 02/06/2023]
Abstract
Testes are sensitive to toxicants, such as cadmium and phthalates, which disrupt a local functional axis in the seminiferous epithelium known as the 'apical ectoplasmic specialization (apical ES)-blood-testis barrier (BTB)-basement membrane (BM)'. Following exposure, toxicants contact the basement membrane and activate the Sertoli cell, which perturbs its signaling function. Thus, toxicants can modulate signaling and/or cellular events at the apical ES-BTB-BM axis, perturbing spermatogenesis without entering the epithelium. Toxicants also enter the epithelium via drug transporters to potentiate their damaging effects, and downregulation of efflux transporters by toxicants impedes BTB function such that toxicants remain in the epithelium and efficiently disrupt spermatogenesis. These findings support a novel model of toxicant-induced disruption of spermatogenesis that could be interfered with using small molecules.
Collapse
Affiliation(s)
- Hin-Ting Wan
- Center for Biomedical Research, Population Council, 1230 York Ave, New York, NY 10065, USA
| | | | | | | |
Collapse
|
40
|
Abstract
During spermatogenesis, spermatids derived from meiosis simultaneously undergo extensive morphological transformation, to become highly specialized and metabolically quiescent cells, and transport across the seminiferous epithelium. Spermatids are also transported back-and-forth across the seminiferous epithelium during the epithelial cycle until they line up at the luminal edge of the tubule to prepare for spermiation at stage VIII of the cycle. Spermatid transport thus requires the intricate coordination of the cytoskeletons in Sertoli cells (SCs) as spermatids are nonmotile cells lacking the ultrastructures of lamellipodia and filopodia, as well as the organized components of the cytoskeletons. In the course of preparing this brief review, we were surprised to see that, except for some earlier eminent morphological studies, little is known about the regulation of the microtubule (MT) cytoskeleton and the coordination of MT with the actin-based cytoskeleton to regulate spermatid transport during the epithelia cycle, illustrating that this is a largely neglected area of research in the field. Herein, we summarize recent findings in the field regarding the significance of actin- and tubulin-based cytoskeletons in SCs that support spermatid transport; we also highlight specific areas of research that deserve attention in future studies.
Collapse
Affiliation(s)
- Elizabeth I Tang
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Avenue, New York, New York 10065, USA
| | | | | |
Collapse
|
41
|
Miyaso H, Nakamura N, Matsuno Y, Kawashiro Y, Komiyama M, Mori C. Postnatal exposure to low-dose decabromodiphenyl ether adversely affects mouse testes by increasing thyrosine phosphorylation level of cortactin. J Toxicol Sci 2013; 37:987-99. [PMID: 23038006 DOI: 10.2131/jts.37.987] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Decabromodiphenyl ether (decaBDE) is a brominated flame retardant used in many commercial products such as televisions, computers, and textiles. Recent reports indicate that decaBDE adversely affects male reproductive organs in mice, but the underlying molecular mechanisms remain unknown. We hypothesized that decaBDE affects mouse testes by altering the expression and phosphorylation level of cortactin (CTTN), an F-actin-binding protein that is similar to flutamide, and we performed western blot analyses on testicular samples from mice subcutaneously injected with decaBDE (0.025, 0.25, and 2.5 mg/kg body weight/day) on postnatal days 1 to 5. Mice treated with low-dose decaBDE (0.025 mg/kg) showed reduced testicular weight, sperm count, elongated spermatid and Sertoli cell numbers, as well as induced Tyr phosphorylation of CTTN and reduced the expression level of p60 Src tyrosine kinase (SRC). Further, 0.25 and 2.5 mg/kg decaBDE-exposed groups produced an decrease the expression level of CTTN. High-dose decaBDE (2.5 mg/kg) showed increased abnormal germ cells, as well as induced Ser phosphorylation of CTTN and activated extracellular signal-regulated kinase (ERK1/2); however, high-dose decaBDE did not affect testicular weight and sperm count. These findings suggest that postnatal exposure to low-dose decaBDE inhibits mouse testicular development by increasing Tyr phosphorylation of CTTN, although different mechanisms may be involved depending on the dose of decaBDE.
Collapse
Affiliation(s)
- Hidenobu Miyaso
- Department of Bioenvironmental Medicine, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba-Shi, Chiba, Japan
| | | | | | | | | | | |
Collapse
|
42
|
Su W, Mruk DD, Cheng CY. Regulation of actin dynamics and protein trafficking during spermatogenesis--insights into a complex process. Crit Rev Biochem Mol Biol 2013; 48:153-72. [PMID: 23339542 DOI: 10.3109/10409238.2012.758084] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the mammalian testis, extensive restructuring takes place across the seminiferous epithelium at the Sertoli-Sertoli and Sertoli-germ cell interface during the epithelial cycle of spermatogenesis, which is important to facilitate changes in the cell shape and morphology of developing germ cells. However, precise communications also take place at the cell junctions to coordinate the discrete events pertinent to spermatogenesis, namely spermatogonial renewal via mitosis, cell cycle progression and meiosis, spermiogenesis and spermiation. It is obvious that these cellular events are intimately related to the underlying actin-based cytoskeleton which is being used by different cell junctions for their attachment. However, little is known on the biology and regulation of this cytoskeleton, in particular its possible involvement in endocytic vesicle-mediated trafficking during spermatogenesis, which in turn affects cell adhesive function and communication at the cell-cell interface. Studies in other epithelia in recent years have shed insightful information on the intimate involvement of actin dynamics and protein trafficking in regulating cell adhesion and communications. The goal of this critical review is to provide an updated assessment of the latest findings in the field on how these complex processes are being regulated during spermatogenesis. We also provide a working model based on the latest findings in the field including our laboratory to provide our thoughts on an apparent complicated subject, which also serves as the framework for investigators in the field. It is obvious that this model will be rapidly updated when more data are available in future years.
Collapse
Affiliation(s)
- Wenhui Su
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, NY 10065, USA
| | | | | |
Collapse
|
43
|
Xiao X, Mruk DD, Cheng CY. c-Yes regulates cell adhesion at the apical ectoplasmic specialization-blood-testis barrier axis via its effects on protein recruitment and distribution. Am J Physiol Endocrinol Metab 2013; 304:E145-59. [PMID: 23169788 PMCID: PMC3543571 DOI: 10.1152/ajpendo.00422.2012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
During spermatogenesis, extensive restructuring takes place at the cell-cell interface since developing germ cells migrate progressively from the basal to the adluminal compartment of the seminiferous epithelium. Since germ cells per se are not motile cells, their movement relies almost exclusively on the Sertoli cell. Nonetheless, extensive exchanges in signaling take place between these cells in the seminiferous epithelium. c-Yes, a nonreceptor protein tyrosine kinase belonging to the Src family kinases (SFKs) and a crucial signaling protein, was recently shown to be upregulated at the Sertoli cell-cell interface at the blood-testis barrier (BTB) at stages VIII-IX of the seminiferous epithelial cycle of spermatogenesis. It was also highly expressed at the Sertoli cell-spermatid interface known as apical ectoplasmic specialization (apical ES) at stage V to early stage VIII of the epithelial cycle during spermiogenesis. Herein, it was shown that the knockdown of c-Yes by RNAi in vitro and in vivo affected both Sertoli cell adhesion at the BTB and spermatid adhesion at the apical ES, causing a disruption of the Sertoli cell tight junction-permeability barrier function, germ cell loss from the seminiferous epithelium, and also a loss of spermatid polarity. These effects were shown to be mediated by changes in distribution and/or localization of adhesion proteins at the BTB (e.g., occludin, N-cadherin) and at the apical ES (e.g., nectin-3) and possibly the result of changes in the underlying actin filaments at the BTB and the apical ES. These findings implicate that c-Yes is a likely target of male contraceptive research.
Collapse
Affiliation(s)
- Xiang Xiao
- Center for Biomedical Research, Population Council, New York, NY 10065, USA
| | | | | |
Collapse
|
44
|
Polarity protein complex Scribble/Lgl/Dlg and epithelial cell barriers. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 763:149-70. [PMID: 23397623 DOI: 10.1007/978-1-4614-4711-5_7] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The Scribble polarity complex or module is one of the three polarity modules that regulate cell polarity in multiple epithelia including blood-tissue barriers. This protein complex is composed of Scribble, Lethal giant larvae (Lgl) and Discs large (Dlg), which are well conserved across species from fruitflies and worms to mammals. Originally identified in Drosophila and C. elegans where the Scribble complex was found to work with the Par-based and Crumbs-based polarity modules to regulate apicobasal polarity and asymmetry in cells and tissues during embryogenesis, their mammalian homologs have all been identified in recent years. Components of the Scribble complex are known to regulate multiple cellular functions besides cell polarity, which include cell proliferation, assembly and maintenance of adherens junction (AJ) and tight junction (TJ), and they are also tumor suppressors. Herein, we provide an update on the Scribble polarity complex and how this protein complex modulates cell adhesion with some emphasis on its role in Sertoli cell blood-testis barrier (BTB) function. It should be noted that this is a rapidly developing field, in particular the role of this protein module in blood-tissue barriers, and this short chapter attempts to provide the information necessary for investigators studying reproductive biology and blood-tissue barriers to design future studies. We also include results of recent studies from flies and worms since this information will be helpful in planning experiments for future functional studies in the testis to understand how Scribble-based proteins regulate BTB dynamics and spermatogenesis.
Collapse
|
45
|
França LR, Auharek SA, Hess RA, Dufour JM, Hinton BT. Blood-Tissue Barriers. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013. [DOI: 10.1007/978-1-4614-4711-5_12] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
46
|
Xiao X, Mruk DD, Cheng FL, Cheng CY. C-Src and c-Yes are two unlikely partners of spermatogenesis and their roles in blood-testis barrier dynamics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 763:295-317. [PMID: 23397631 DOI: 10.1007/978-1-4614-4711-5_15] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Src family kinases (SFKs), in particular c-Src and c-Yes, are nonreceptor protein tyrosine kinases that mediate integrin signaling at focal adhesion complex at the cell-extracellular matrix interface to regulate cell adhesion, cell cycle progression, cell survival, proliferation and differentiation, most notably in cancer cells during tumorigenesis and metastasis. Interestingly, recent studies have shown that these two proto-oncogenes are integrated components of the stem cell niche and the cell-cell actin-based anchoring junction known as ectoplasmic specialization (ES) at the: (1) Sertoli cell-spermatid interface known as apical ES and (2) Sertoli-Sertoli cell interface known as basal ES which together with tight junctions (TJ), gap junctions and desmosomes constitute the blood-testis barrier (BTB). At the stem cell niche, these SFKs regulate spermatogonial stem cell (SSC) renewal to maintain the proper population of SSC/spermatogonia for spermatogenesis. At the apical ES and the BTB, c-Src and c-Yes confer cell adhesion either by maintaining the proper phosphorylation status of integral membrane proteins at the site which in turn regulates protein-protein interactions between integral membrane proteins and their adaptors, or by facilitating androgen action on spermatogenesis via a nongenomic pathway which also modulates cell adhesion in the seminiferous epithelium. Herein, we critically evaluate recent findings in the field regarding the roles of these two unlikely partners of spermatogenesis. We also propose a hypothetical model on the mechanistic functions of c-Src and c-Yes in spermatogenesis so that functional experiments can be designed in future studies.
Collapse
Affiliation(s)
- Xiang Xiao
- Center for Biomedical Research, Population Council, New York New York, USA
| | | | | | | |
Collapse
|
47
|
Su W, Wong EWP, Mruk DD, Cheng CY. The Scribble/Lgl/Dlg polarity protein complex is a regulator of blood-testis barrier dynamics and spermatid polarity during spermatogenesis. Endocrinology 2012; 153:6041-53. [PMID: 23038739 PMCID: PMC3512062 DOI: 10.1210/en.2012-1670] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
During spermatogenesis, spermiogenesis that releases sperm into the tubule lumen and restructuring of the blood-testis barrier (BTB) that accommodates the transit of preleptotene spermatocytes take place simultaneously, but at the opposite ends of the seminiferous epithelium. These events are tightly regulated and coordinated; however, neither the underlying mechanism(s) nor the involving molecules are known. Herein, the Scribble/Lgl (Lethal giant larvae)/Dlg (Discs large) polarity complex was shown to regulate spermatid polarity during spermiogenesis and tight junction (TJ)-permeability barrier via changes in protein distribution at the apical ectoplasmic specialization and the BTB during the epithelial cycle, respectively. Scribble, Lgl2, and Dlg1 were found to be expressed by Sertoli and germ cells. Scribble also displayed stage-specific expression at the BTB, being highest at stages VII-VIII, colocalizing with TJ proteins occludin and ZO-1. Unlike components of other polarity complex modules, such as partitioning-defective 6, the knockdown of which by RNA interference was found to impede Sertoli cell TJ barrier, a knockdown of the Scribble complex (i.e. simultaneous knockdown of Scribble, Lgl and Dlg or Lgl alone; but not Scribble or Dlg alone) both in vitro and in vivo promoted the TJ integrity. This was mediated by reorganizing actin filament network at the Sertoli cell-cell interface, which, in turn, affected changes in the localization and/or distribution of occludin and/or β-catenin at the BTB. These knockdowns also perturbed F-actin organization at the Sertoli cell-spermatid interface, thereby modulating spermatid adhesion and polarity at the apical ectoplasmic specialization. In summary, the Scribble/Lgl/Dlg complex participates in the regulation of BTB dynamics and spermatid adhesion/polarity in the testis.
Collapse
Affiliation(s)
- Wenhui Su
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, NY 10065, USA
| | | | | | | |
Collapse
|
48
|
Lie PPY, Cheng CY, Mruk DD. The biology of interleukin-1: emerging concepts in the regulation of the actin cytoskeleton and cell junction dynamics. Cell Mol Life Sci 2012; 69:487-500. [PMID: 21744066 PMCID: PMC3297025 DOI: 10.1007/s00018-011-0760-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 06/14/2011] [Accepted: 06/17/2011] [Indexed: 01/28/2023]
Abstract
Interleukin (IL)-1 is a proinflammatory cytokine with important roles in innate immunity, as well as in normal tissue homeostasis. Interestingly, recent studies have also shown IL-1 to function in the dynamics of the actin cytoskeleton and cell junctions. For example, treatment of different epithelia with IL-1α often results in the restructuring of the actin network and cell junctions, thereby leading to junction disassembly. In this review, we highlight new and interesting findings that show IL-1 to be a critical player of restructuring events in the seminiferous epithelium of the testis during spermatogenesis.
Collapse
Affiliation(s)
- Pearl P. Y. Lie
- Center for Biomedical Research, Population Council, 1230 York Avenue, New York, NY 10065 USA
| | - C. Yan Cheng
- Center for Biomedical Research, Population Council, 1230 York Avenue, New York, NY 10065 USA
| | - Dolores D. Mruk
- Center for Biomedical Research, Population Council, 1230 York Avenue, New York, NY 10065 USA
| |
Collapse
|
49
|
Abstract
The blood-testis barrier (BTB) is one of the tightest blood-tissue barriers in the mammalian body. It divides the seminiferous epithelium into the basal and the apical (adluminal) compartments. Meiosis I and II, spermiogenesis, and spermiation all take place in a specialized microenvironment behind the BTB in the apical compartment, but spermatogonial renewal and differentiation and cell cycle progression up to the preleptotene spermatocyte stage take place outside of the BTB in the basal compartment of the epithelium. However, the BTB is not a static ultrastructure. Instead, it undergoes extensive restructuring during the seminiferous epithelial cycle of spermatogenesis at stage VIII to allow the transit of preleptotene spermatocytes at the BTB. Yet the immunological barrier conferred by the BTB cannot be compromised, even transiently, during the epithelial cycle to avoid the production of antibodies against meiotic and postmeiotic germ cells. Studies have demonstrated that some unlikely partners, namely adhesion protein complexes (e.g., occludin-ZO-1, N-cadherin-β-catenin, claudin-5-ZO-1), steroids (e.g., testosterone, estradiol-17β), nonreceptor protein kinases (e.g., focal adhesion kinase, c-Src, c-Yes), polarity proteins (e.g., PAR6, Cdc42, 14-3-3), endocytic vesicle proteins (e.g., clathrin, caveolin, dynamin 2), and actin regulatory proteins (e.g., Eps8, Arp2/3 complex), are working together, apparently under the overall influence of cytokines (e.g., transforming growth factor-β3, tumor necrosis factor-α, interleukin-1α). In short, a "new" BTB is created behind spermatocytes in transit while the "old" BTB above transiting cells undergoes timely degeneration, so that the immunological barrier can be maintained while spermatocytes are traversing the BTB. We also discuss recent findings regarding the molecular mechanisms by which environmental toxicants (e.g., cadmium, bisphenol A) induce testicular injury via their initial actions at the BTB to elicit subsequent damage to germ-cell adhesion, thereby leading to germ-cell loss, reduced sperm count, and male infertility or subfertility. Moreover, we also critically evaluate findings in the field regarding studies on drug transporters in the testis and discuss how these influx and efflux pumps regulate the entry of potential nonhormonal male contraceptives to the apical compartment to exert their effects. Collectively, these findings illustrate multiple potential targets are present at the BTB for innovative contraceptive development and for better delivery of drugs to alleviate toxicant-induced reproductive dysfunction in men.
Collapse
Affiliation(s)
- C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Avenue, New York, NY 10065, USA.
| | | |
Collapse
|
50
|
Chang YF, Lee-Chang JS, Harris KY, Sinha-Hikim AP, Rao MK. Role of β-catenin in post-meiotic male germ cell differentiation. PLoS One 2011; 6:e28039. [PMID: 22125654 PMCID: PMC3220672 DOI: 10.1371/journal.pone.0028039] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 10/31/2011] [Indexed: 01/13/2023] Open
Abstract
Though roles of β-catenin signaling during testis development have been well established, relatively little is known about its role in postnatal testicular physiology. Even less is known about its role in post-meiotic germ cell development and differentiation. Here, we report that β-catenin is highly expressed in post-meiotic germ cells and plays an important role during spermiogenesis in mice. Spermatid-specific deletion of β-catenin resulted in significantly reduced sperm count, increased germ cell apoptosis and impaired fertility. In addition, ultrastructural studies show that the loss of β-catenin in post-meiotic germ cells led to acrosomal defects, anomalous release of immature spermatids and disruption of adherens junctions between Sertoli cells and elongating spermatids (apical ectoplasmic specialization; ES). These defects are likely due to altered expression of several genes reportedly involved in Sertoli cell-germ cell adhesion and germ cell differentiation, as revealed by gene expression analysis. Taken together, our results suggest that β-catenin is an important molecular link that integrates Sertoli cell-germ cell adhesion with the signaling events essential for post-meiotic germ cell development and maturation. Since β-catenin is also highly expressed in the Sertoli cells, we propose that binding of germ cell β-catenin complex to β-catenin complex on Sertoli cell at the apical ES surface triggers a signaling cascade that regulates post-meiotic germ cell differentiation.
Collapse
Affiliation(s)
- Yao-Fu Chang
- Greehey Children's Cancer Research Institute, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Jennifer S. Lee-Chang
- Greehey Children's Cancer Research Institute, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Krystle Y. Harris
- Greehey Children's Cancer Research Institute, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Amiya P. Sinha-Hikim
- Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Drew University of Medicine and Science, Los Angeles, California, United States of America
| | - Manjeet K. Rao
- Greehey Children's Cancer Research Institute, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- * E-mail:
| |
Collapse
|