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Wanta A, Noguchi K, Sugawara T, Sonoda K, Duangchit S, Wakayama T. Expression of Protein Markers in Spermatogenic and Supporting Sertoli Cells Affected by High Abdominal Temperature in Cryptorchidism Model Mice. J Histochem Cytochem 2023; 71:387-408. [PMID: 37431084 PMCID: PMC10363907 DOI: 10.1369/00221554231185626] [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: 04/26/2023] [Accepted: 06/12/2023] [Indexed: 07/12/2023] Open
Abstract
Cryptorchidism is a congenital abnormality resulting in increased rates of infertility and testicular cancer. We used cryptorchidism model mice that presented with the translocation of the left testis from the scrotum to the abdominal cavity. Mice underwent the surgical procedure of the left testis at day 0 and were sacrificed at days 3, 5, 7, 14, 21, and 28 post-operatively. The weight of the left cryptorchid testis decreased significantly at days 21 and 28. The morphological changes were observed after 5 days and showed detached spermatogenic cells and abnormal formation of acrosome at day 5, multinucleated giant cells at day 7, and atrophy of seminiferous tubules at days 21 and 28. The high abdominal temperature disrupted the normal expression of cell adhesion molecule-1, Nectin-2, and Nectin-3 which are essential for spermatogenesis. In addition, the pattern and alignment of acetylated tubulin in cryptorchid testes were also changed at days 5, 7, 14, 21, and 28. Ultrastructure of cryptorchid testes revealed giant cells that had been formed by spermatogonia, spermatocytes, and round and elongating spermatids. The study's findings reveal that cryptorchidism's duration is linked to abnormal changes in the testis, impacting protein marker expression in spermatogenic and Sertoli cells. These changes stem from the induction of high abdominal temperature.
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Affiliation(s)
- Arunothai Wanta
- Department of Histology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
- School of Medicine, Mae Fah Luang University, Chiang Rai, Thailand
| | - Kazuhiro Noguchi
- Department of Histology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Taichi Sugawara
- Department of Histology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Kayoko Sonoda
- Department of Histology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Suthat Duangchit
- Department of Histology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
- Department of Physiology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Tomohiko Wakayama
- Department of Histology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
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Wang L, Zhang R, Wu B, Yu Y, Li W, Li S, Liu C. Autophagy mediated tubulobulbar complex components degradation is required for spermiation. FUNDAMENTAL RESEARCH 2022. [DOI: 10.1016/j.fmre.2022.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Cervero P, Vrenken K, Klose M, Rehm K, Linder S. Nectin stabilization at adherens junctions is counteracted by Rab5a-dependent endocytosis. Eur J Cell Biol 2021; 100:151184. [PMID: 34826799 DOI: 10.1016/j.ejcb.2021.151184] [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: 06/27/2017] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 11/19/2022] Open
Abstract
Cell-cell junctions undergo constant remodeling, which is crucial for the control of vascular integrity. Indeed, transport of junctional components such as cadherins is understood in increasing depth. However, little is known about the respective pathways regulating localization of nectin at cell-cell junctions. Here, we performed an siRNA-based screen of vesicle regulators of the RabGTPase family, leading to the identification of a novel role for Rab5a in the endocytosis nectin-2 at adherens junctions of primary human endothelial cells (HUVEC). Confocal microscopy experiments revealed disordered nectin-2 localization at adherens junctions upon Rab5a depletion. In addition, internalized nectin-2 was shown to prominently localize to Rab5a-positive vesicles in both fixed and living cells. As shown previously, nectin-2 stabilization at junctions is achieved via drebrin-dependent coupling to the subcortical actin cytoskeleton. Consistently, depletion of drebrin in this study leads to enhanced internalization of nectin-2 from junctions. Strikingly, simultaneous silencing of Rab5a and drebrin restored the junctional localization of nectin-2, pointing to Rab5a as counteracting the drebrin-dependent stabilization of nectin-2 at adherens junctions. This mechanism could be further validated by transendothelial resistance measurements. Collectively, our results identify Rab5a as a key player in the endocytosis of nectin-2 and thus in the regulation of adherens junction integrity in primary human endothelial cells.
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Affiliation(s)
- Pasquale Cervero
- Institut für medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Kirsten Vrenken
- Institut für medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Eppendorf, Martinistr. 52, 20246 Hamburg, Germany; Laboratory of Pediatric Oncology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, P.O.Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Matthias Klose
- Institut für medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Kerstin Rehm
- Institut für medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
| | - Stefan Linder
- Institut für medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
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Palia P, Adams A, Sriram A, Vogl AW. Cortactin knockdown results in disruption of basal TBCs and alters turnover of Sertoli cell ESs in Rattus norvegicus†. Biol Reprod 2021; 105:1330-1343. [PMID: 34426822 DOI: 10.1093/biolre/ioab161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 07/05/2021] [Accepted: 08/17/2021] [Indexed: 11/13/2022] Open
Abstract
Here we explore the prediction that long-term knockdown of cortactin (CTTN), a component of tubulobulbar complexes (TBCs), disrupts TBCs in Sertoli cells and alters the turnover of basal ectoplasmic specializations (ESs). In rats, intratesticular injections of siRNA targeting CTTN (siCTTN) in one testis and nontargeting siRNA (siControl) in the contralateral testis were done on days 0, 2, 4, 6, and 8. The experiment was terminated on day 9 and testes were analyzed by either western blotting, or by stimulated emission depletion (STED), electron and/or conventional fluorescence microscopy. Levels of CTTN were successfully knocked down in experimental testes compared to controls. When cryo-sections were labeled for actin filaments, or CTTN, and oxysterol binding protein-related protein 9 (ORP9) and analyzed by STED microscopy, TBCs were "less distinct" than in tubules of the same stages from control testes. When analyzed by electron microscopy, redundant clumps of basal actin filament containing ESs were observed in experimental sections. Using labeling of actin filaments in ESs, thresholding techniques were used to calculate the number of pixels above threshold per unit length of tubule wall in seminiferous tubules at Stage VII. Median values were higher in experimental testes relative to controls in the four animals analyzed. Although we detected subtle differences in ES turnover, we were unable to demonstrate changes in spermatocyte translocation or in the levels of junction proteins at the sites. Our results are the first to demonstrate that perturbation of basal TBCs alters the turnover of actin-related junctions (ESs).
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Affiliation(s)
- Prunveer Palia
- Life Sciences Institute and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Arlo Adams
- Life Sciences Institute and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aarati Sriram
- Life Sciences Institute and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - A Wayne Vogl
- Life Sciences Institute and Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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Zakrzewski P, Suwińska A, Lenartowski R, Rędowicz MJ, Buss F, Lenartowska M. Myosin VI maintains the actin-dependent organization of the tubulobulbar complexes required for endocytosis during mouse spermiogenesis†‡. Biol Reprod 2021; 102:863-875. [PMID: 31901088 PMCID: PMC7124960 DOI: 10.1093/biolre/ioz232] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 12/16/2019] [Accepted: 12/30/2019] [Indexed: 12/15/2022] Open
Abstract
Myosin VI (MYO6) is an actin-based motor that has been implicated in a wide range of cellular processes, including endocytosis and the regulation of actin dynamics. MYO6 is crucial for actin/membrane remodeling during the final step of Drosophila spermatogenesis, and MYO6-deficient males are sterile. This protein also localizes to actin-rich structures involved in mouse spermiogenesis. Although loss of MYO6 in Snell's waltzer knock-out (KO) mice causes several defects and shows reduced male fertility, no studies have been published to address the role of MYO6 in sperm development in mouse. Here we demonstrate that MYO6 and some of its binding partners are present at highly specialized actin-based structures, the apical tubulobulbar complexes (TBCs), which mediate endocytosis of the intercellular junctions at the Sertoli cell-spermatid interface, an essential process for sperm release. Using electron and light microscopy and biochemical approaches, we show that MYO6, GIPC1 and TOM1/L2 form a complex in testis and localize predominantly to an early endocytic APPL1-positive compartment of the TBCs that is distinct from EEA1-positive early endosomes. These proteins also associate with the TBC actin-free bulbular region. Finally, our studies using testis from Snell's waltzer males show that loss of MYO6 causes disruption of the actin cytoskeleton and disorganization of the TBCs and leads to defects in the distribution of the MYO6-positive early APPL1-endosomes. Taken together, we report here for the first time that lack of MYO6 in mouse testis reduces male fertility and disrupts spatial organization of the TBC-related endocytic compartment during the late phase of spermiogenesis.
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Affiliation(s)
- Przemysław Zakrzewski
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, Torun, Poland.,Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Torun, Torun, Poland
| | - Anna Suwińska
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, Torun, Poland.,Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Torun, Torun, Poland
| | - Robert Lenartowski
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, Torun, Poland.,Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Torun, Torun, Poland
| | - Maria Jolanta Rędowicz
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Folma Buss
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Marta Lenartowska
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, Torun, Poland.,Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Torun, Torun, Poland
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Abstract
Objective To identify dysregulated miRNAs in testicular tissues from animal models and
patients with cryptorchidism. Methods Databases were systematically searched for studies published before 10 May
2020 that had investigated miRNAs in cryptorchidism. Predicted targets of
the identified miRNA biomarkers were obtained by searching TargetScan and
Starbase. Gene ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes
(KEGG) pathway enrichment analyses were subsequently conducted. Results Five publications met the eligibility criteria for the review. 21
differentially expressed miRNAs were the most abundantly reported in 185
animal and human tissue samples. Three miRNAs (miR-210, miR-449a and
miR-34c) were dysregulated in both animal and human testicular tissues. The
top five relevant lncRNAs associated with the miRNAs were NEAT1, KCNQ1OT1,
XIST, AC005154.1, and TUG1. Conclusions Further research is warranted to explore the potential of these dysregulated
miRNAs as biomarkers or therapeutic targets for male infertility associated
with cryptorchidism.
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Affiliation(s)
- Hongshuai Jia
- Department of Urology, Capital Institute of Paediatrics, Beijing, China
| | - Chunsheng Hao
- Department of Urology, Capital Institute of Paediatrics, Beijing, China
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Yan M, Li L, Mao B, Li H, Li SYT, Mruk D, Silvestrini B, Lian Q, Ge R, Cheng CY. mTORC1/rpS6 signaling complex modifies BTB transport function: an in vivo study using the adjudin model. Am J Physiol Endocrinol Metab 2019; 317:E121-E138. [PMID: 31112404 PMCID: PMC6689739 DOI: 10.1152/ajpendo.00553.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/30/2019] [Accepted: 05/05/2019] [Indexed: 12/13/2022]
Abstract
Studies have shown that the mTORC1/rpS6 signaling cascade regulates Sertoli cell blood-testis barrier (BTB) dynamics. For instance, specific inhibition of mTORC1 by treating Sertoli cells with rapamycin promotes the Sertoli cell barrier, making it "tighter." However, activation of mTORC1 by overexpressing a full-length rpS6 cDNA clone (i.e., rpS6-WT, wild type) in Sertoli cells promotes BTB remodeling, making the barrier "leaky." Also, there is an increase in rpS6 and p-rpS6 (phosphorylated and activated rpS6) expression at the BTB in testes at stages VIII-IX of the epithelial cycle, and it coincides with BTB remodeling to support the transport of preleptotene spermatocytes across the barrier, illustrating that rpS6 is a BTB-modifying signaling protein. Herein, we used a constitutively active, quadruple phosphomimetic mutant of rpS6, namely p-rpS6-MT of p-rpS6-S235E/S236E/S240E/S244E, wherein Ser (S) was converted to Glu (E) at amino acid residues 235, 236, 240, and 244 from the NH2 terminus by site-directed mutagenesis, for its overexpression in rat testes in vivo using the Polyplus in vivo jet-PEI transfection reagent with high transfection efficiency. Overexpression of this p-rpS6-MT was capable of inducing BTB remodeling, making the barrier "leaky." This thus promoted the entry of the nonhormonal male contraceptive adjudin into the adluminal compartment in the seminiferous epithelium to induce germ cell exfoliation. Combined overexpression of p-rpS6-MT with a male contraceptive (e.g., adjudin) potentiated the drug bioavailability by modifying the BTB. This approach thus lowers intrinsic drug toxicity due to a reduced drug dose, further characterizing the biology of BTB transport function.
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Affiliation(s)
- Ming Yan
- Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council , New York, New York
| | - Linxi Li
- Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council , New York, New York
- Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University , Wenzhou, Zhejiang , China
| | - Baiping Mao
- Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council , New York, New York
- Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University , Wenzhou, Zhejiang , China
| | - Huitao Li
- Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council , New York, New York
- Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University , Wenzhou, Zhejiang , China
| | - Stephen Y T Li
- Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council , New York, New York
| | - Dolores Mruk
- Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council , New York, New York
| | | | - Qingquan Lian
- Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University , Wenzhou, Zhejiang , China
| | - Renshan Ge
- Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University , Wenzhou, Zhejiang , China
| | - C Yan Cheng
- Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council , New York, New York
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8
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Xiao X, Yang Y, Mao B, Cheng CY, Ni Y. Emerging role for SRC family kinases in junction dynamics during spermatogenesis. Reproduction 2019; 157:R85-R94. [PMID: 30608903 PMCID: PMC6602873 DOI: 10.1530/rep-18-0440] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 01/03/2019] [Indexed: 12/22/2022]
Abstract
SRC family kinases (SFKs) are known regulators of multiple cellular events, including cell movement, differentiation, proliferation, survival and apoptosis. SFKs are expressed virtually by all mammalian cells. They are non-receptor protein kinases that phosphorylate a variety of cellular proteins on tyrosine, leading to the activation of protein targets in response to environmental stimuli. Among SFKs, SRC, YES and FYN are the ubiquitously expressed and best studied members. In fact, SRC, the prototypical SFK, was the first tyrosine kinase identified in mammalian cells. Studies have shown that SFKs are regulators of cell junctions, and function in endocytosis and membrane trafficking to regulate junction restructuring events. Herein, we briefly summarize the recent findings in the field regarding the role of SFKs in the testis in regulating spermatogenesis, particularly in Sertoli-Sertoli and Sertoli-germ cell adhesion. While it is almost 50 years since the identification of the oncogene v-Src encoded by Rous sarcoma transforming virus, the understanding of SFK involvement during spermatogenesis in the testis remains far behind that in other epithelia and tissues. The goal of this review is to bridge this gap.
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Affiliation(s)
- Xiang Xiao
- Department of Reproductive Physiology, Zhejiang Academy of Medical Sciences, Hangzhou 310013, Zhejiang, China
| | - Yue Yang
- Department of Reproductive Physiology, Zhejiang Academy of Medical Sciences, Hangzhou 310013, Zhejiang, China
| | - Baiping Mao
- The Mary M. Woldford 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. Woldford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Ave, New York, NY 10065, United States
| | - Ya Ni
- Department of Reproductive Physiology, Zhejiang Academy of Medical Sciences, Hangzhou 310013, Zhejiang, China
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Adams A, Sriram A, Wayne Vogl A. Internalization of Intact Intercellular Junctions in the Testis by Clathrin/Actin-Mediated Endocytic Structures: Tubulobulbar Complexes. Anat Rec (Hoboken) 2018; 301:2080-2085. [PMID: 30312540 DOI: 10.1002/ar.23963] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/12/2018] [Accepted: 04/17/2018] [Indexed: 02/06/2023]
Abstract
Sertoli cells of the mammalian seminiferous epithelium form unique subcellular actin-related structures at intercellular junctions. The appearance of these so called "tubulobulbar complexes" (TBCs) precedes both sperm release at the apex of the epithelium and the movement of early spermatogenic cells out of the spermatogonial stem cell niche at the base of the epithelium. TBCs are considered to be part of the mechanism of junction endocytosis by Sertoli cells. The structures contain junction proteins and morphologically identifiable junctions, and are associated with markers of endocytosis. Here we review the current state of knowledge about the structure and function of TBCs. As the complexes form, they morphologically resemble and have the molecular signature of clathrin-coated pits with extremely long necks. As they mature, the actin filament networks around the "necks" of the structures progressively disassemble and the membrane cores expand or swell into distinct "bulbs". These bulbs acquire extensive membrane contact sites with associated cisternae of endoplasmic reticulum. Eventually the bulbs undergo scission and continue through endosomal compartments of the Sertoli cells. The morphology and composition of TBC indicates to us that the structures likely evolved from the basic clathrin-mediated endocytosis mechanism common to cells generally, and along the way they incorporated unique features to accommodate the cyclic turnover of massive and "intact" intercellular junctions that occurs during spermatogenesis. Anat Rec, 301:2080-2085, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Arlo Adams
- Department of Cellular and Physiological Sciences, Life Sciences Centre, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aarati Sriram
- Department of Cellular and Physiological Sciences, Life Sciences Centre, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - A Wayne Vogl
- Department of Cellular and Physiological Sciences, Life Sciences Centre, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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10
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Kumar A, Raut S, Balasinor NH. Endocrine regulation of sperm release. Reprod Fertil Dev 2018; 30:1595-1603. [DOI: 10.1071/rd18057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 05/02/2018] [Indexed: 01/11/2023] Open
Abstract
Spermiation (sperm release) is the culmination of a spermatid’s journey in the seminiferous epithelium. After a long association with the Sertoli cell, spermatids have to finally ‘let go’ of the support from Sertoli cells in order to be transported to the epididymis. Spermiation is a multistep process characterised by removal of excess spermatid cytoplasm, recycling of junctional adhesion molecules by endocytosis, extensive cytoskeletal remodelling and final spermatid disengagement. Successful execution of all these events requires coordinated regulation by endocrine and paracrine factors. This review focuses on the endocrine regulation of spermiation. With the aim of delineating how hormones control the various aspects of spermiation, this review provides an analysis of recent advances in research on the hormonal control of molecules associated with the spermiation machinery. Because spermiation is one of the most sensitive phases of spermatogenesis to variations in hormone levels, understanding their molecular control is imperative to advance our knowledge of the nuances of spermatogenesis and male fertility.
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11
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Chen H, Mruk DD, Lui WY, Wong CKC, Lee WM, Cheng CY. Cell polarity and planar cell polarity (PCP) in spermatogenesis. Semin Cell Dev Biol 2017; 81:71-77. [PMID: 28923514 DOI: 10.1016/j.semcdb.2017.09.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 09/04/2017] [Accepted: 09/06/2017] [Indexed: 12/22/2022]
Abstract
In adult mammalian testes, spermatids, most notably step 17-19 spermatids in stage IV-VIII tubules, are aligned with their heads pointing toward the basement membrane and their tails toward the tubule lumen. On the other hand, these polarized spermatids also align across the plane of seminiferous epithelium, mimicking planar cell polarity (PCP) found in other hair cells in cochlea (inner ear). This orderly alignment of developing spermatids during spermiogenesis is important to support spermatogenesis, such that the maximal number of developing 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 provide emerging evidence to demonstrate spermatid PCP in the seminiferous epithelium to support spermatogenesis. We also review findings in the field regarding the biology of spermatid cellular polarity (e.g., head-tail polarity and apico-basal polarity) and its inter-relationship to spermatid PCP. Furthermore, we also provide a hypothetical concept on the importance of PCP proteins in endocytic vesicle-mediated protein trafficking events to support spermatogenesis through protein endocytosis and recycling.
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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
| | - Dolores D 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
| | - Wing-Yee Lui
- School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong, China
| | - Chris K C Wong
- Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong, China
| | - Will M Lee
- School of Biological Sciences, University of Hong Kong, Pokfulam, 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, NY 10065, United States.
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12
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Lyon K, Adams A, Piva M, Asghari P, Moore ED, Vogl AW. Ca2+ signaling machinery is present at intercellular junctions and structures associated with junction turnover in rat Sertoli cells†. Biol Reprod 2017; 96:1288-1302. [DOI: 10.1093/biolre/iox042] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 05/08/2017] [Indexed: 11/13/2022] Open
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13
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Adams A, Wayne Vogl A. High Resolution Localization of Rab5, EEA1, and Nectin-3 to Tubulobulbar Complexes in the Rat Testis. Anat Rec (Hoboken) 2017; 300:1160-1170. [PMID: 28176461 DOI: 10.1002/ar.23563] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 09/27/2016] [Accepted: 10/02/2016] [Indexed: 11/10/2022]
Abstract
Tubulobulbar complexes are clathrin/actin-based structures that internalize intercellular junctions in the testis. They resemble coated pits with extremely long necks that are cuffed by dendritic actin networks. As the structures mature, a swollen region or bulb develops near the end of each complex. The bulbs lack actin cuffs and are closely associated with cisternae of endoplasmic reticulum. The bulbs expand and are internalized and enter endocytic compartments of the Sertoli cell. Previous immunofluorescence studies have demonstrated that markers for early endosomes (Rab5 and EEA1) are associated with tubulobulbar complexes and are localized at or near the ends of the structures. Here we use a pre-embedding immunoelectron microscopic technique to accurately localize these markers to apical tubulobulbar complexes that occur at junctions between Sertoli cells and spermatids. Staining for Rab5 occurs at bulbs, identified by the presence of two plasma membranes and a close association with cisternae of endoplasmic reticulum. EEA1 is associated with large vesicles that lack an association with the endoplasmic reticulum. Labeling for nectin-3, an adhesion junction protein in the spermatid plasma membrane, occurs at junctions, TBC bulbs, and in associated double membrane vesicles. Our results suggest that Rab5 associates with junction protein containing bulbs prior to their internalization and that EEA1 associates with the structures later and after internalization. We conclude that at tubulobulbar complexes in Sertoli cells of the seminiferous epithelium, the identity of 'bulbs' as putative early endosomes begins to be established prior to their undergoing scission or budding from their parent structures. Anat Rec, 300:1160-1170, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Arlo Adams
- Department of Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
| | - A Wayne Vogl
- Department of Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
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Zhang Z, Li W, Zhang Y, Zhang L, Teves ME, Liu H, Strauss JF, Pazour GJ, Foster JA, Hess RA, Zhang Z. Intraflagellar transport protein IFT20 is essential for male fertility and spermiogenesis in mice. Mol Biol Cell 2016; 27:mbc.E16-05-0318. [PMID: 27682589 PMCID: PMC5170554 DOI: 10.1091/mbc.e16-05-0318] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 09/06/2016] [Accepted: 09/20/2016] [Indexed: 12/22/2022] Open
Abstract
Intraflagellar transport (IFT) is a conserved mechanism thought to be essential for the assembly and maintenance of cilia and flagella. However, little is known about its role in mammalian sperm flagella formation. To fill this gap, we disrupted the Ift20 gene in male germ cells. Homozygous mutant mice were infertile with significantly reduced sperm counts and motility. In addition, abnormally shaped elongating spermatid heads and bulbous round spermatids were found in the lumen of the seminiferous tubules. Electron microscopy revealed increased cytoplasmic vesicles, fiber-like structures, abnormal accumulation of mitochondria and a decrease in mature lysosomes. The few developed sperm had disrupted axonemes and some retained cytoplasmic lobe components on the flagella. ODF2 and SPAG16L, two sperm flagella proteins failed to be incorporated into sperm tails of the mutant mice, and in the germ cells, both were assembled into complexes with lighter density in the absence of IFT20. Disrupting IFT20 did not significantly change expression levels of IFT88, a component of IFT-B complex, and IFT140, a component of IFT-A complex. Even though the expression level of an autophagy core protein that associates with IFT20, ATG16, was reduced in the testis of the Ift20 mutant mice, expression levels of other major autophagy markers, including LC3 and ubiquitin were not changed. Our studies suggest that IFT20 is essential for male fertility and spermiogenesis in mice, and its major function is to transport cargo proteins for sperm flagella formation. It also appears to be involved in removing excess cytoplasmic components.
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Affiliation(s)
- Zhengang Zhang
- Department of Gastroenterology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China, 430030 Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Wei Li
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Yong Zhang
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, VA, 23298 Department of Dermatology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China, 430030
| | - Ling Zhang
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, VA, 23298 School of Public Health, Wuhan University of Science and Technology, Wuhan, Hubei, 430065
| | - Maria E Teves
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Hong Liu
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, VA, 23298 School of Public Health, Wuhan University of Science and Technology, Wuhan, Hubei, 430065
| | - Jerome F Strauss
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, VA, 23298
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - James A Foster
- Department of Biology, Randolph-Macon College, Ashland, VA 23005
| | - Rex A Hess
- Comparative Biosciences, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln, Urbana, IL 61802-6199
| | - Zhibing Zhang
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, VA, 23298
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Sriram A, Lyon KRP, Ho CD, Huynh N, Vogl AW. Actin Disruption Results in Altered Morphology of Basal Tubulobulbar Complexes in Rat Seminiferous Epithelium. Anat Rec (Hoboken) 2016; 299:1449-55. [PMID: 27348857 DOI: 10.1002/ar.23394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 05/29/2016] [Indexed: 11/11/2022]
Abstract
Basal tubulobulbar complexes (TBCs) that occur at attachment sites between neighboring Sertoli cells are subcellular machines that internalize intercellular junctions during movement of spermatocytes from basal to adluminal compartments of the seminiferous epithelium. Each complex consists of an elongate tubular extension of two attached plasma membranes, and is capped at its distal end by a clathrin-coated pit. The tubular region is surrounded by a cuff of actin arranged in a dendritic network. Near the end of the complex, a bulbous region forms that lacks the actin cuff but is closely associated with cisternae of endoplasmic reticulum. The bulb eventually buds from the complex and enters endocytic compartments of the Sertoli cell. Previous research has shown that when the actin network is perturbed using the actin filament-disruptor, cytochalasin D, apical tubulobulbar complexes that are associated with spermatids were associated with lower levels of actin, patchy actin networks and swollen tubular regions. Here we explored the effects of actin network perturbation on the morphology of basal tubulobulbar complexes in stage V seminiferous tubules. Isolated rat testes were perfused ex vivo for one hour with oxygenated Krebs-Henseleit buffer (with BSA) containing either 40 μM cytochalasin D or control solution containing DMSO and perfusion-fixed for electron microscopy. Compared to control, actin cuffs in drug-treated TBCs appeared less uniform and patchy. In addition, the tubular regions of the complexes appeared swollen. Our results are consistent with the conclusion that intact networks of actin filaments are required for maintaining the structural integrity of basal TBCs. Anat Rec, 299:1449-1455, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Aarati Sriram
- Department of Cellular and Physiological Sciences Faculty of Medicine, The University of British Columbia, Canada
| | - Kevin R P Lyon
- Department of Obstetrics and Gynaecology Faculty of Medicine, The University of British Columbia, Canada
| | - Clement Dallas Ho
- Department of Cellular and Physiological Sciences Faculty of Medicine, The University of British Columbia, Canada
| | - Nghi Huynh
- Department of Cellular and Physiological Sciences Faculty of Medicine, The University of British Columbia, Canada
| | - A Wayne Vogl
- Department of Cellular and Physiological Sciences Faculty of Medicine, The University of British Columbia, Canada. .,Department of Obstetrics and Gynaecology Faculty of Medicine, The University of British Columbia, Canada.
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16
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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: 259] [Impact Index Per Article: 32.4] [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.
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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
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17
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Li N, Mruk DD, Wong CKC, Han D, Lee WM, Cheng CY. Formin 1 Regulates Ectoplasmic Specialization in the Rat Testis Through Its Actin Nucleation and Bundling Activity. Endocrinology 2015; 156:2969-83. [PMID: 25901598 PMCID: PMC4511136 DOI: 10.1210/en.2015-1161] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
During spermatogenesis, developing spermatids and preleptotene spermatocytes are transported across the adluminal compartment and the blood-testis barrier (BTB), respectively, so that spermatids line up near the luminal edge to prepare for spermiation, whereas preleptotene spermatocytes enter the adluminal compartment to differentiate into late spermatocytes to prepare for meiosis I/II. These cellular events involve actin microfilament reorganization at the testis-specific, actin-rich Sertoli-spermatid and Sertoli-Sertoli cell junction called apical and basal ectoplasmic specialization (ES). Formin 1, an actin nucleation protein known to promote actin microfilament elongation and bundling, was expressed at the apical ES but limited to stage VII of the epithelial cycle, whereas its expression at the basal ES/BTB stretched from stage III to stage VI, diminished in stage VII, and was undetectable in stage VIII tubules. Using an in vitro model of studying Sertoli cell BTB function by RNA interference and biochemical assays to monitor actin bundling and polymerization activity, a knockdown of formin 1 in Sertoli cells by approximately 70% impeded the tight junction-permeability function. This disruptive effect on the tight junction barrier was mediated by a loss of actin microfilament bundling and actin polymerization capability mediated by changes in the localization of branched actin-inducing protein Arp3 (actin-related protein 3), and actin bundling proteins Eps8 (epidermal growth factor receptor pathway substrate 8) and palladin, thereby disrupting cell adhesion. Formin 1 knockdown in vivo was found to impede spermatid adhesion, transport, and polarity, causing defects in spermiation in which elongated spermatids remained embedded into the epithelium in stage IX tubules, mediated by changes in the spatiotemporal expression of Arp3, Eps8, and palladin. In summary, formin 1 is a regulator of ES dynamics.
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Affiliation(s)
- Nan Li
- Center for Biomedical Research (N.L., D.D.M., C.Y.C.), Population Council, New York, New York 10065; Department of Biology (C.K.C.W.), Hong Kong Baptist University, Hong Kong, China; Department of Cell Biology (D.H.), Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China; and School of Biological Sciences (W.M.L.), University of Hong Kong, Hong Kong, China
| | - Dolores D Mruk
- Center for Biomedical Research (N.L., D.D.M., C.Y.C.), Population Council, New York, New York 10065; Department of Biology (C.K.C.W.), Hong Kong Baptist University, Hong Kong, China; Department of Cell Biology (D.H.), Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China; and School of Biological Sciences (W.M.L.), University of Hong Kong, Hong Kong, China
| | - Chris K C Wong
- Center for Biomedical Research (N.L., D.D.M., C.Y.C.), Population Council, New York, New York 10065; Department of Biology (C.K.C.W.), Hong Kong Baptist University, Hong Kong, China; Department of Cell Biology (D.H.), Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China; and School of Biological Sciences (W.M.L.), University of Hong Kong, Hong Kong, China
| | - Daishu Han
- Center for Biomedical Research (N.L., D.D.M., C.Y.C.), Population Council, New York, New York 10065; Department of Biology (C.K.C.W.), Hong Kong Baptist University, Hong Kong, China; Department of Cell Biology (D.H.), Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China; and School of Biological Sciences (W.M.L.), University of Hong Kong, Hong Kong, China
| | - Will M Lee
- Center for Biomedical Research (N.L., D.D.M., C.Y.C.), Population Council, New York, New York 10065; Department of Biology (C.K.C.W.), Hong Kong Baptist University, Hong Kong, China; Department of Cell Biology (D.H.), Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China; and School of Biological Sciences (W.M.L.), University of Hong Kong, Hong Kong, China
| | - C Yan Cheng
- Center for Biomedical Research (N.L., D.D.M., C.Y.C.), Population Council, New York, New York 10065; Department of Biology (C.K.C.W.), Hong Kong Baptist University, Hong Kong, China; Department of Cell Biology (D.H.), Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China; and School of Biological Sciences (W.M.L.), University of Hong Kong, Hong Kong, China
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18
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Cheng CY. Toxicants target cell junctions in the testis: Insights from the indazole-carboxylic acid model. SPERMATOGENESIS 2015; 4:e981485. [PMID: 26413399 PMCID: PMC4581065 DOI: 10.4161/21565562.2014.981485] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 10/23/2014] [Indexed: 12/31/2022]
Abstract
There are numerous types of junctions in the seminiferous epithelium which are integrated with, and critically dependent on the Sertoli cell cytoskeleton. These include the basal tight junctions between Sertoli cells that form the main component of the blood–testis barrier, the basal ectoplasmic specializations (basal ES) and basal tubulobulbar complexes (basal TBC) between Sertoli cells; as well as apical ES and apical TBC between Sertoli cells and the developing spermatids that orchestrate spermiogenesis and spermiation. These junctions, namely TJ, ES, and TBC interact with actin microfilament-based cytoskeleton, which together with the desmosomal junctions that interact with the intermediate filament-based cytoskeleton plus the highly polarized microtubule-based cytoskeleton are working in concert to move spermatocytes and spermatids between the basal and luminal aspect of the seminiferous epithelium. In short, these various junctions are structurally complexed with the actin- and microtubule-based cytoskeleton or intermediate filaments of the Sertoli cell. Studies have shown toxicants (e.g., cadmium, bisphenol A (BPA), perfluorooctanesulfonate (PFOS), phthalates, and glycerol), and some male contraceptives under development (e.g., adjudin, gamendazole), exert their effects, at least in part, by targeting cell junctions in the testis. The disruption of Sertoli–Sertoli cell and Sertoli–germ cell junctions, results in the loss of germ cells from the seminiferous epithelium. Adjudin, a potential male contraceptive under investigation in our laboratory, produces loss of spermatids from the seminiferous tubules through disruption of the Sertoli cell spermatid junctions and disruption of the Sertoli cell cytoskeleton. The molecular and structural changes associated with adjudin administration are described, to provide an example of the profile of changes caused by disturbance of Sertoli-germ cell and also Sertoli cell-cell junctions.
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Affiliation(s)
- C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research; Center for Biomedical Research; Population Council ; New York, NY USA
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19
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Modulation of CD112 by the alphaherpesvirus gD protein suppresses DNAM-1-dependent NK cell-mediated lysis of infected cells. Proc Natl Acad Sci U S A 2014; 111:16118-23. [PMID: 25352670 DOI: 10.1073/pnas.1409485111] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Natural killer (NK) cells are key players in the innate response to viruses, including herpesviruses. In particular, the variety of viral strategies to modulate the recognition of certain herpesviruses witnesses the importance of NK cells in the control of this group of viruses. Still, NK evasion strategies have remained largely elusive for the largest herpesvirus subfamily, the alphaherpesviruses. Here, we report that the gD glycoprotein of the alphaherpesviruses pseudorabies virus (PRV) and herpes simplex virus 2 (HSV-2) displays previously uncharacterized immune evasion properties toward NK cells. Expression of gD during infection or transfection led to degradation and consequent down-regulation of CD112, a ligand for the activating NK receptor DNAX accessory molecule 1 (DNAM-1). CD112 downregulation resulted in a reduced ability of DNAM-1 to bind to the surface of both virus-infected and gD-transfected cells. Consequently, expression of gD suppressed NK cell degranulation and NK cell-mediated lysis of PRV- or HSV-2-infected cells. These data identify an alphaherpesvirus evasion strategy from NK cells and point out that interactions between viral envelope proteins and host cell receptors can have biological consequences that stretch beyond virus entry.
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20
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Abstract
The transport of germ cells across the seminiferous epithelium is composed of a series of cellular events during the epithelial cycle essential to the completion of spermatogenesis. Without the timely transport of spermatids during spermiogenesis, spermatozoa that are transformed from step 19 spermatids in the rat testis fail to reach the luminal edge of the apical compartment and enter the tubule lumen at spermiation, thereby arriving the epididymis for further maturation. Step 19 spermatids and/or sperms that remain in the epithelium beyond stage VIII of the epithelial cycle will be removed by the Sertoli cell via phagocytosis to form phagosomes and be degraded by lysosomes, leading to subfertility and/or infertility. However, the biology of spermatid transport, in particular the final events that lead to spermiation remain elusive. Based on recent data in the field, we critically evaluate the biology of spermiation herein by focusing on the actin binding proteins (ABPs) that regulate the organization of actin microfilaments at the Sertoli-spermatid interface, which is crucial for spermatid transport during this event. The hypothesis we put forth herein also highlights some specific areas of research that can be pursued by investigators in the years to come.
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21
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Cheng CY, Lie PPY, Wong EWP, Mruk DD. Focal adhesion kinase and actin regulatory/binding proteins that modulate F-actin organization at the tissue barrier: Lesson from the testis. Tissue Barriers 2014; 1:e24252. [PMID: 24665388 PMCID: PMC3875635 DOI: 10.4161/tisb.24252] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 03/07/2013] [Accepted: 03/09/2013] [Indexed: 11/28/2022] Open
Abstract
Focal adhesion kinase (FAK), as its name implied, is an important mediator of integrin-based signaling function in mammalian cells at the focal adhesion complex (FAC, also known as focal contact) at the cell-extracellular matrix interface. FAK is intimately related to cell movement, such as in macrophages, fibroblasts and also tumor cells. In the testis, however, FAK and two of its phosphorylated forms, p-FAK-Tyr407 and -Tyr397, are not found at the FAC since there is no ultrastructure analogous or similar to FAC in the mammalian testis vs. other epithelia. Instead, FAK and its two phosphorylated forms are detected along the seminiferous epithelium in the rat testis at the cell-cell interface in a testis-specific adherens junction (AJ) known as the ectoplasmic specialization (ES). ES is an F-actin-rich ultrastructure in which bundles of actin filaments are sandwiched in-between plasma membrane and cisternae of endoplasmic reticulum not found in other mammalian epithelial/endothelial cells. The ES is restricted to the interface of Sertoli cells and spermatids (step 8–19) known as the apical ES, and to the Sertoli cell-cell interface known as the basal ES. Interestingly, the basal ES is also an integrated component of the blood-testis barrier (BTB), coexisting with tight junction (TJ) and gap junction (GJ), and it is conceivable that actin filament bundles at the ES undergo extensive organization, converting from their “bundled” to “de-bundled/branching” configuration to facilitate transport of germ cells across the epithelium and at the BTB during the epithelial cycle. A recent report (Lie et al. PNAS 109:12562–12567, 2012) has demonstrated that the stage-specific and spatiotemporal expression of p-FAK-Tyr407 and -Tyr397 are crucial to the regulation of these events via their stage-specific and spatiotemporal expression during the epithelial cycle mediated by their effects on the organization of the actin filament bundles at the ES, involving actin binding/regulatory proteins. In this Commentary, we will critically evaluate these findings in light of other recent reports in the field. While these ideas are based on studies in the BTB in the rat testis, this information should be applicable and helpful to investigators studying other tissue barriers.
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Affiliation(s)
- C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research; Center for Biomedical Research; Population Council; New York, NY USA
| | - Pearl P Y Lie
- The Mary M. Wohlford Laboratory for Male Contraceptive Research; Center for Biomedical Research; Population Council; New York, NY USA
| | - Elissa W P Wong
- 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
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22
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Vogl AW, Du M, Wang XY, Young JS. Novel clathrin/actin-based endocytic machinery associated with junction turnover in the seminiferous epithelium. Semin Cell Dev Biol 2013; 30:55-64. [PMID: 24280271 DOI: 10.1016/j.semcdb.2013.11.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 11/13/2013] [Accepted: 11/18/2013] [Indexed: 01/25/2023]
Abstract
Tubulobulbar complexes are elaborate clathrin/actin related structures that form at sites of intercellular attachment in the seminiferous epithelium of the mammalian testis. Here we summarize what is currently known about the morphology and molecular composition of these structures and review evidence that the structures internalize intercellular junctions both at apical sites of Sertoli cell attachment to spermatids, and at basal sites where Sertoli cells form the blood-testis barrier. We present updated models of the sperm release and spermatocyte translocation mechanisms that incorporate tubulobulbar complexes into their designs.
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Affiliation(s)
- A Wayne Vogl
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC Canada V6T 1Z3.
| | - Min Du
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC Canada V6T 1Z3.
| | - Xue Ying Wang
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC Canada V6T 1Z3.
| | - J'Nelle S Young
- Department of Radiology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA. J'
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23
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Aristaeus de Asis M, Pires M, Lyon K, Vogl AW. A network of spectrin and plectin surrounds the actin cuffs of apical tubulobulbar complexes in the rat. SPERMATOGENESIS 2013; 3:e25733. [PMID: 24381803 PMCID: PMC3861171 DOI: 10.4161/spmg.25733] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 07/10/2013] [Accepted: 07/11/2013] [Indexed: 11/19/2022]
Abstract
Tubulobulbar complexes (TBCs) are actin-related endocytic structures that internalize intercellular junctions in the seminiferous epithelium. The structures consist of elongate tubular projections of the attached plasma membranes of two adjacent cells that project into Sertoli cells. This double membrane core is cuffed by a dentritic actin network and is capped at its end by a clathrin-coated pit. Here we explore the possibility that elements of the spectrin cytoskeleton are associated with clusters of tubulobulbar complexes that develop at adhesion junctions between late spermatids and Sertoli cells at the apex of the epithelium, and extend what is known about the distribution of plectin at the sites. Cryo-sections of perfusion-fixed testes and apical processes of Sertoli cells mechanically dissociated from perfusion-fixed testes were probed for spectrin, EPB41, and actin and analyzed using conventional fluorescence microscopy and confocal microscopy. Data sets from confocal microscopy were analyzed further in three-dimensional reconstructions using computer software. Additional apical Sertoli cell processes were probed for plectin and analyzed using conventional fluorescence microscopy. Antibodies generated against elements of the spectrin cytoskeleton react with material around and between the actin cuffs of tubulobulbar complexes, but appear excluded from the actin cuffs themselves. A similar staining pattern occurs with a probe for plectin. Immunoelectron microscopy confirmed the staining patterns observed by fluourescence microscopy. Based on our results, we suggest that a network of spectrin and plectin forms a scaffold around tubulobulbar complexes that may provide support for the actin network that cuffs each complex and also link adjacent complexes together.
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Affiliation(s)
| | - Manuel Pires
- Faculte des Sciences Fondamentales et Appliquees; Universite de Poitiers; Poitiers, France
| | - Kevin Lyon
- Department of Cellular and Physiological Sciences; Faculty of Medicine; University of British Columbia; BC Canada
| | - A Wayne Vogl
- Department of Cellular and Physiological Sciences; Faculty of Medicine; University of British Columbia; BC Canada
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24
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Rikitake Y, Mandai K, Takai Y. The role of nectins in different types of cell-cell adhesion. J Cell Sci 2013; 125:3713-22. [PMID: 23027581 DOI: 10.1242/jcs.099572] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Mammalian tissues and organs are composed of different types of cells that adhere to each other homotypically (i.e. interactions between cells of the same cell type) or heterotypically (i.e. interactions between different cell types), forming a variety of cellular patterns, including mosaic patterns. At least three types of cell-cell adhesion have been observed: symmetric homotypic, asymmetric homotypic and heterotypic cell adhesions. Cadherins and nectins, which are known cell-cell adhesion molecules, mediate these cell adhesions. Cadherins comprise a family of more than 100 members, but they are primarily involved in homophilic trans-interactions (i.e. interactions between the same cadherin members) between opposing cells. By contrast, the nectin family comprises only four members, and these proteins form both homophilic and heterophilic trans-interactions (i.e. interactions between the same and different nectin members on opposing cells). In addition, heterophilic trans-interactions between nectins are much stronger than homophilic trans-interactions. Because of these unique properties, nectins have crucial roles in asymmetric homotypic cell-cell adhesion at neuronal synapses and in various types of heterotypic cell-cell adhesions. We summarize recent progress in our understanding of the biology of nectins and discuss their roles in heterotypic cell-cell adhesions, whose formation cannot be solely explained by the action of cadherins.
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Affiliation(s)
- Yoshiyuki Rikitake
- Division of Molecular and Cellular Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
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25
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Qian X, Mruk DD, Cheng CY. Rai14 (retinoic acid induced protein 14) is involved in regulating f-actin dynamics at the ectoplasmic specialization in the rat testis*. PLoS One 2013; 8:e60656. [PMID: 23565266 PMCID: PMC3614988 DOI: 10.1371/journal.pone.0060656] [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: 01/16/2013] [Accepted: 03/01/2013] [Indexed: 01/31/2023] Open
Abstract
Rai14 (retinoic acid induced protein 14) is an actin binding protein first identified in the liver, highly expressed in the placenta, the testis, and the eye. In the course of studying actin binding proteins that regulate the organization of actin filament bundles in the ectoplasmic specialization (ES), a testis-specific actin-rich adherens junction (AJ) type, Rai14 was shown to be one of the regulatory proteins at the ES. In the rat testis, Rai14 was found to be expressed by Sertoli and germ cells, structurally associated with actin and an actin cross-linking protein palladin. Its expression was the highest at the ES in the seminiferous epithelium of adult rat testes, most notably at the apical ES at the Sertoli-spermatid interface, and expressed stage-specifically during the epithelial cycle in stage VII-VIII tubules. However, Rai14 was also found at the basal ES near the basement membrane, associated with the blood-testis barrier (BTB) in stage VIII-IX tubules. A knockdown of Rai14 in Sertoli cells cultured in vitro by RNAi was found to perturb the Sertoli cell tight junction-permeability function in vitro, mediated by a disruption of F-actin, which in turn led to protein mis-localization at the Sertoli cell BTB. When Rai14 in the testis in vivo was knockdown by RNAi, defects in spermatid polarity and adhesion, as well as spermatid transport were noted mediated via changes in F-actin organization and mis-localization of proteins at the apical ES. In short, Rai14 is involved in the re-organization of actin filaments in Sertoli cells during the epithelial cycle, participating in conferring spermatid polarity and cell adhesion in the testis.
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Affiliation(s)
- Xiaojing Qian
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York, United States of America
- Department of Anatomy, Histology and Embryology, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Dolores D. Mruk
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - C. Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York, United States of America
- * E-mail:
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Du M, Young J, De Asis M, Cipollone J, Roskelley C, Takai Y, Nicholls PK, Stanton PG, Deng W, Finlay BB, Vogl AW. A novel subcellular machine contributes to basal junction remodeling in the seminiferous epithelium. Biol Reprod 2013; 88:60. [PMID: 23303684 DOI: 10.1095/biolreprod.112.104851] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Tubulobulbar complexes are cytoskeleton-related membrane structures that develop at sites of intercellular attachment in mammalian seminiferous epithelium. At apical junctions between Sertoli cells and spermatids, the structures internalize adhesion junctions and are a component of the sperm release mechanism. Here we explore the possibility that tubulobulbar complexes that form at the blood-testis barrier are subcellular machines that internalize basal junction complexes. Using electron microscopy, we confirmed that morphologically identifiable tight and gap junctions are present in basal tubulobulbar complexes in rats. In addition, immunological probes for claudin-11 (CLDN11), connexin-43 (GJA1), and nectin-2 (PVRL2) react with linear structures at the light level that we interpret as tubulobulbar complexes, and probes for early endosome antigen 1 (EEA1) and Rab5 (RAB5A) react in similar locations. Significantly, fluorescence patterns for actin and claudin-11 indicate that the amount of junction present is dramatically reduced over the time period that tubulobulbar complexes are known to be most prevalent during spermatogenesis. We also demonstrated, using electron microscopy and fluorescence microscopy, that tubulobulbar complexes develop at basal junctions in primary cultures of Sertoli cells and that like their in vivo counterparts, the structures contain junction proteins. We use this culture system together with transfection techniques to show that junction proteins from one transfected cell occur in structures that project into adjacent nontransfected cells as predicted by the junction internalization hypothesis. On the basis of our findings, we present a new model for basal junction remodeling as it relates to spermatocyte translocation in the seminiferous epithelium.
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Affiliation(s)
- Min Du
- Department of Cellular and Physiological Sciences, Faculty of Medicine, Life Sciences Centre, The University of British Columbia, Vancouver, British Columbia, Canada
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Upadhyay RD, Kumar AV, Sonawane S, Gaonkar R, Balasinor NH. Estrogen Effects on Actin Cytoskeletal and Endocytic Proteins Associated With Tubulobulbar Complex Disruption in Rat Testes. Reprod Sci 2013; 20:1162-74. [DOI: 10.1177/1933719113477491] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Rahul D. Upadhyay
- Department of Neuroendocrinology, National Institute for Research in Reproductive Health, Mumbai, India
| | - Anita V. Kumar
- Department of Neuroendocrinology, National Institute for Research in Reproductive Health, Mumbai, India
| | - Shobha Sonawane
- Department of Neuroendocrinology, National Institute for Research in Reproductive Health, Mumbai, India
| | - Reshma Gaonkar
- Department of Neuroendocrinology, National Institute for Research in Reproductive Health, Mumbai, India
| | - Nafisa H. Balasinor
- Department of Neuroendocrinology, National Institute for Research in Reproductive Health, Mumbai, India
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Xiao X, Mruk DD, Cheng CY. Intercellular adhesion molecules (ICAMs) and spermatogenesis. Hum Reprod Update 2013; 19:167-86. [PMID: 23287428 DOI: 10.1093/humupd/dms049] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND During the seminiferous epithelial cycle, restructuring takes places at the Sertoli-Sertoli and Sertoli-germ cell interface to accommodate spermatogonia/spermatogonial stem cell renewal via mitosis, cell cycle progression and meiosis, spermiogenesis and spermiation since developing germ cells, in particular spermatids, move 'up and down' the seminiferous epithelium. Furthermore, preleptotene spermatocytes differentiated from type B spermatogonia residing at the basal compartment must traverse the blood-testis barrier (BTB) to enter the adluminal compartment to prepare for meiosis at Stage VIII of the epithelial cycle, a process also accompanied by the release of sperm at spermiation. These cellular events that take place at the opposite ends of the epithelium are co-ordinated by a functional axis designated the apical ectoplasmic specialization (ES)-BTB-basement membrane. However, the regulatory molecules that co-ordinate cellular events in this axis are not known. METHODS Literature was searched at http://www.pubmed.org and http://scholar.google.com to identify published findings regarding intercellular adhesion molecules (ICAMs) and the regulation of this axis. RESULTS Members of the ICAM family, namely ICAM-1 and ICAM-2, and the biologically active soluble ICAM-1 (sICAM-1) are the likely regulatory molecules that co-ordinate these events. sICAM-1 and ICAM-1 have antagonistic effects on the Sertoli cell tight junction-permeability barrier, involved in Sertoli cell BTB restructuring, whereas ICAM-2 is restricted to the apical ES, regulating spermatid adhesion during the epithelial cycle. Studies in other epithelia/endothelia on the role of the ICAM family in regulating cell movement are discussed and this information has been evaluated and integrated into studies of these proteins in the testis to create a hypothetical model, depicting how ICAMs regulate junction restructuring events during spermatogenesis. CONCLUSIONS ICAMs are crucial regulatory molecules of spermatogenesis. The proposed hypothetical model serves as a framework in designing functional experiments for future studies.
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Affiliation(s)
- Xiang Xiao
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Avenue, New York, NY 10065, USA
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Vogl AW, Young JS, Du M. New insights into roles of tubulobulbar complexes in sperm release and turnover of blood-testis barrier. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 303:319-55. [PMID: 23445814 DOI: 10.1016/b978-0-12-407697-6.00008-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Tubulobulbar complexes are actin-filament-related structures that form at intercellular junctions in the seminiferous epithelium of mammalian testis. The structures occur both at adhesion junctions between Sertoli cells and the maturing spermatids in apical regions of the epithelium, and at junction complexes between neighboring Sertoli cells near the base of the epithelium. Here, we review the general morphology and molecular composition of tubulobulbar complexes, and also include a description of tubulobulbar complex structure in the human seminiferous epithelium. Although tubulobulbar complexes are unique to the seminiferous epithelium, they have the molecular signature of clathrin-based endocytosis machinery present generally in cells. We review the evidence that tubulobulbar complexes internalize intact intercellular junctions and are significant components of the sperm-release mechanism and the process by which spermatocytes translocate from basal to adluminal compartments of the epithelium.
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Affiliation(s)
- A Wayne Vogl
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada.
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Young JS, De Asis M, Guttman J, Vogl AW. Cortactin depletion results in short tubulobulbar complexes and spermiation failure in rat testes. Biol Open 2012; 1:1069-77. [PMID: 23213386 PMCID: PMC3507196 DOI: 10.1242/bio.20122519] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 07/16/2012] [Indexed: 11/20/2022] Open
Abstract
Tubulobulbar complexes are actin-related endocytic structures that form at sites of intercellular attachment in the seminiferous epithelium and are proposed to internalize intact junctions. In this study, we test the prediction that altering the structure/function of tubulobulbar complexes results in failure to release mature spermatids from Sertoli cells. We used an in vivo knockdown strategy to target cortactin, a component of tubulobulbar complexes, in Sprague Dawley rats. In each animal, one testis was surgically injected with cortactin siRNA reagents and the other testis was injected with non-targeting siRNA. After three days, experimental and control testes were processed for immunoblotting, electron microscopy or immunofluorescence microscopy. In testis sections immunostained for cortactin or labeled for filamentous actin, fluorescence microscopy revealed that tubulobulbar complexes were shorter in siRNA-treated testes relative to controls. Significantly, in the knockdown testes, spermiation was delayed in some tubules and had failed in others. When evaluated by electron microscopy, adhesion complexes (ectoplasmic specializations) remained associated with mature spermatids that failed to be released from Sertoli cells. Immunoblots both of whole testis lysates and of isolated seminiferous epithelial lysates confirmed that cortactin expression was knocked-down in experimental testes and in the seminiferous epithelium respectively, relative to controls. Moreover, in testes injected with siRNA reagents with a dye modification on one of the four targeting siRNA sequences, dye clusters were detected at the base of the epithelium confirming that the reagents entered Sertoli cells. Our results are consistent with the hypothesis that tubulobulbar complexes internalize intercellular junctions and that they are a significant component of the sperm release mechanism.
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Affiliation(s)
- J'nelle S Young
- Department of Cellular and Physiological Sciences, Faculty of Medicine, Life Sciences Centre, 2350 Health Sciences Mall, The University of British Columbia , Vancouver, BC V6T 1Z3 , Canada
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Upadhyay RD, Kumar AV, Ganeshan M, Balasinor NH. Tubulobulbar complex: cytoskeletal remodeling to release spermatozoa. Reprod Biol Endocrinol 2012; 10:27. [PMID: 22510523 PMCID: PMC3442992 DOI: 10.1186/1477-7827-10-27] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 03/30/2012] [Indexed: 11/15/2022] Open
Abstract
Tubulobulbar complexes (TBCs) are actin-based structures that help establish close contact between Sertoli-Sertoli cells or Sertoli-mature germ cells (spermatids) in the seminiferous tubules of the testes. They are actin-rich push-through devices that eliminate excess spermatid cytoplasm and prepare mature spermatids for release into the tubular lumen. Just prior to spermiation, the elongated spermatid interacts with the Sertoli cell via an extensive structure comprising various adhesion molecules called the apical ectoplasmic specialization which is partially replaced by the apical TBC, on the concave surface of the spermatid head. The sperm release process involves extensive restructuring, namely the disassembly and reassembly of junctions at the Sertoli-spermatid interface in the seminiferous epithelium. Based on the presence of different classes of molecules in the TBCs or the defects observed in the absence of TBCs, the main functions attributed to TBCs are elimination of excess spermatid cytoplasm, endocytosis and recycling of junctional molecules, shaping of the spermatid acrosome, and forming transient anchoring devices for mature spermatids before they are released. This review summarizes the recent findings that focus on the role of TBCs in cell cytoskeleton restructuring during sperm release in the testes and the molecular mechanism involved.
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Affiliation(s)
- Rahul D Upadhyay
- Department of Neuroendocrinology, National Institute for Research in Reproductive Health, J.M.Street, Parel, Mumbai, 400012, India
| | - Anita V Kumar
- Department of Neuroendocrinology, National Institute for Research in Reproductive Health, J.M.Street, Parel, Mumbai, 400012, India
| | - Malti Ganeshan
- Department of Neuroendocrinology, National Institute for Research in Reproductive Health, J.M.Street, Parel, Mumbai, 400012, India
| | - Nafisa H Balasinor
- Department of Neuroendocrinology, National Institute for Research in Reproductive Health, J.M.Street, Parel, Mumbai, 400012, India
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