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Peña-Corona SI, Vásquez Aguire WS, Vargas D, Juárez I, Mendoza-Rodríguez CA. Effects of bisphenols on Blood-Testis Barrier protein expression in vitro: A systematic review and meta-analysis. Reprod Toxicol 2021; 103:139-148. [PMID: 34146661 DOI: 10.1016/j.reprotox.2021.06.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 06/04/2021] [Accepted: 06/13/2021] [Indexed: 12/16/2022]
Abstract
Bisphenols are a group of environmental endocrine-disrupting chemicals that produce alterations in the expression of intercellular junction proteins of the Blood-Testis Barrier (BTB) involved in spermatogenesis. The association between bisphenol exposure and BTB protein expression is controversial. Therefore, we performed this systematic review and meta-analysis to clarify bisphenol effects on Sertoli cell BTB protein expression in vitro. The Standardized Mean Difference (SMD) with a 95 % confidence interval (95 % CI) was used to evaluate the association between alterations in the BTB protein expression and bisphenol exposure in vitro. Six articles were included in the meta-analysis. Bisphenol-A (BPA) exposure at 200 μM was associated with significant decrease in BTB protein expression (SMD = -2.70, 95 %CI: -3.59, -1.80, p het = 0.46, p = <0.00001). In the moderate (40-50 μM) and low dose (<25 μM), no significant associations were obtained. We also found a non-monotonic dose-response curve of bisphenol effect in ZO-1 protein expression; low and high doses presented a significant decrease compared to control, while moderate dose presented no change. The current temporary Tolerable Daily Intake (tTDI) of BPA is 4 μg/kg bw/day. The 5-25 μM doses of BPA are equivalent to ∼1-5 mg/kg bw, respectively. Although the low dose group (<25 μM) assessed doses below the previous NOAEL value, these doses are above the current tTDI. Thus, it is necessary to conduct more studies with lower bisphenol concentrations to avoid underestimating the potential adverse effects of bisphenols at doses below tTDI.
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Affiliation(s)
- Sheila Irais Peña-Corona
- Facultad de Química, Departamento de Biología, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Walker Sixto Vásquez Aguire
- Facultad de Ciencias Matemáticas, Escuela Académica de Estadística, Universidad Nacional Mayor de San Marcos 15081, Lima, Peru
| | - Dinorah Vargas
- Facultad de Medicina Veterinaria y Zootecnia, Departamento de Fisiología y Farmacología, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Ivan Juárez
- Facultad de Medicina Veterinaria y Zootecnia, Departamento de Medicina Preventiva y Salud Pública, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - C Adriana Mendoza-Rodríguez
- Facultad de Química, Departamento de Biología, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico.
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Johnson C, Kastelic J, Thundathil J. Role of Akt and mammalian target of rapamycin signalling in insulin-like growth factor 1-mediated cell proliferation in porcine Sertoli cells. Reprod Fertil Dev 2021; 32:929-940. [PMID: 32586423 DOI: 10.1071/rd19460] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 05/04/2020] [Indexed: 12/13/2022] Open
Abstract
The critical role of insulin-like growth factor (IGF) 1 in promoting Sertoli cell proliferation invivo and invitro has been established, but its downstream signalling mechanisms remain unknown. In addition to mitogenic effects, a role for IGF1 in mediating cholesterol biosynthesis within testes has been implied. The aims of this study were to investigate the roles of: (1) phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (mTOR) signalling in IGF1-mediated Sertoli cell proliferation; and (2) IGF1 in mediating cholesterol biosynthesis in Sertoli cells. Primary cultures of Sertoli cells were prepared from 1-week-old porcine testes. On Day 3 of culture, Sertoli cells were treated with 300ng mL-1 IGF1, alone or in combination with inhibitors of IGF1 receptor (2μM picropodophyllotoxin), Akt (1μM wortmannin) or mTOR (200nM rapamycin). Cells were cultured for 30min and phosphorylation levels of Akt, mTOR and p70 ribosomal protein S6 kinase (p70S6K) were determined by immunoblotting. Cell proliferation and quantitative polymerase chain reaction assays were conducted using cells cultured for 24h. IGF1 increased phosphorylation of Akt, mTOR and p70S6K and cell proliferation, and these effects were inhibited by inhibitors of IGF1R, Akt and mTOR. Furthermore, IGF1 upregulated the expression of cholesterol biosynthetic genes (3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS1) and cytochrome P450, family 5, subfamily A, polypeptide 1 (CYP5A1)), but not sterol regulatory element-binding transcription factor 1 (SREBF1). Increased phosphorylation of p70S6K, a major downstream target of mTOR, and upregulated expression of genes involved in cholesterol biosynthesis are indicative of the key role played by IGF1 in regulating the synthesis of cholesterol, the precursor for steroid hormones.
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Affiliation(s)
- Chinju Johnson
- Department of Production Animal Health, Faculty of Veterinary Medicine, 3330 Hospital Drive NW, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - John Kastelic
- Department of Production Animal Health, Faculty of Veterinary Medicine, 3330 Hospital Drive NW, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Jacob Thundathil
- Department of Production Animal Health, Faculty of Veterinary Medicine, 3330 Hospital Drive NW, University of Calgary, Calgary, AB T2N 4N1, Canada; and Corresponding author.
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Washburn RL, Hibler T, Thompson LA, Kaur G, Dufour JM. Therapeutic application of Sertoli cells for treatment of various diseases. Semin Cell Dev Biol 2021; 121:10-23. [PMID: 33910764 DOI: 10.1016/j.semcdb.2021.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 04/07/2021] [Indexed: 12/11/2022]
Abstract
Sertoli cells (SCs) are immune privileged cells found in the testis that function to immunologically protect maturing germ cells from immune destruction. This immune protection is due to the blood-testis-barrier, which prevents infiltration of cytotoxic immune cells and antibodies, and SC production of immunomodulatory factors, that favor a tolerogenic environment. The ability of SCs to create an immune privileged environment has led to the exploration of their potential use in the treatment of various diseases. SCs have been utilized to create a tolerogenic ectopic microenvironment, to protect co-grafted cells, and to deliver therapeutic proteins through gene therapy. To date, numerous studies have reported the potential use of SCs for the treatment of diabetes, neurodegenerative disorders, and restoration of spermatogenesis. Additionally, SCs have been investigated as a delivery vehicle for therapeutic products to treat other diseases like Laron syndrome, muscular dystrophy, and infections. This review will provide an overview of these therapeutic applications.
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Affiliation(s)
- Rachel L Washburn
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Taylor Hibler
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Lea Ann Thompson
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Gurvinder Kaur
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Department of Medical Education, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
| | - Jannette M Dufour
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Department of Medical Education, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
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Bernardino RL, Marinelli RA, Maggio A, Gena P, Cataldo I, Alves MG, Svelto M, Oliveira PF, Calamita G. Hepatocyte and Sertoli Cell Aquaporins, Recent Advances and Research Trends. Int J Mol Sci 2016; 17:ijms17071096. [PMID: 27409609 PMCID: PMC4964472 DOI: 10.3390/ijms17071096] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 06/22/2016] [Accepted: 07/04/2016] [Indexed: 12/30/2022] Open
Abstract
Aquaporins (AQPs) are proteinaceous channels widespread in nature where they allow facilitated permeation of water and uncharged through cellular membranes. AQPs play a number of important roles in both health and disease. This review focuses on the most recent advances and research trends regarding the expression and modulation, as well as physiological and pathophysiological functions of AQPs in hepatocytes and Sertoli cells (SCs). Besides their involvement in bile formation, hepatocyte AQPs are involved in maintaining energy balance acting in hepatic gluconeogenesis and lipid metabolism, and in critical processes such as ammonia detoxification and mitochondrial output of hydrogen peroxide. Roles are played in clinical disorders including fatty liver disease, diabetes, obesity, cholestasis, hepatic cirrhosis and hepatocarcinoma. In the seminiferous tubules, particularly in SCs, AQPs are also widely expressed and seem to be implicated in the various stages of spermatogenesis. Like in hepatocytes, AQPs may be involved in maintaining energy homeostasis in these cells and have a major role in the metabolic cooperation established in the testicular tissue. Altogether, this information represents the mainstay of current and future investigation in an expanding field.
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Affiliation(s)
- Raquel L Bernardino
- Department of Microscopy, Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, 4050-313 Porto, Portugal.
| | - Raul A Marinelli
- Instituto de Fisiología Experimental-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas-Universidad Nacional de Rosario, 531 S2002LRK Rosario, Santa Fe, Argentina.
| | - Anna Maggio
- Department of Biosciences, Biotechnologies and Biopharnaceutics, University of Bari "Aldo Moro", 70125 Bari, Italy.
| | - Patrizia Gena
- Department of Biosciences, Biotechnologies and Biopharnaceutics, University of Bari "Aldo Moro", 70125 Bari, Italy.
| | - Ilaria Cataldo
- Department of Biosciences, Biotechnologies and Biopharnaceutics, University of Bari "Aldo Moro", 70125 Bari, Italy.
| | - Marco G Alves
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, 6201-506 Covilhã, Portugal.
| | - Maria Svelto
- Department of Biosciences, Biotechnologies and Biopharnaceutics, University of Bari "Aldo Moro", 70125 Bari, Italy.
| | - Pedro F Oliveira
- Department of Microscopy, Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, 4050-313 Porto, Portugal.
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.
| | - Giuseppe Calamita
- Department of Biosciences, Biotechnologies and Biopharnaceutics, University of Bari "Aldo Moro", 70125 Bari, Italy.
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Li N, Tang EI, Cheng CY. Regulation of blood-testis barrier by actin binding proteins and protein kinases. Reproduction 2015; 151:R29-41. [PMID: 26628556 DOI: 10.1530/rep-15-0463] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 12/01/2015] [Indexed: 12/13/2022]
Abstract
The blood-testis barrier (BTB) is an important ultrastructure in the testis, since the onset of meiosis and spermiogenesis coincides with the establishment of a functional barrier in rodents and humans. It is also noted that a delay in the assembly of a functional BTB following treatment of neonatal rats with drugs such as diethylstilbestrol or adjudin also delays the first wave of spermiation. While the BTB is one of the tightest blood-tissue barriers, it undergoes extensive remodeling, in particular, at stage VIII of the epithelial cycle to facilitate the transport of preleptotene spermatocytes connected in clones across the immunological barrier. Without this timely transport of preleptotene spermatocytes derived from type B spermatogonia, meiosis will be arrested, causing aspermatogenesis. Yet the biology and regulation of the BTB remains largely unexplored since the morphological studies in the 1970s. Recent studies, however, have shed new light on the biology of the BTB. Herein, we critically evaluate some of these findings, illustrating that the Sertoli cell BTB is regulated by actin-binding proteins (ABPs), likely supported by non-receptor protein kinases, to modulate the organization of actin microfilament bundles at the site. Furthermore, microtubule-based cytoskeleton is also working in concert with the actin-based cytoskeleton to confer BTB dynamics. This timely review provides an update on the unique biology and regulation of the BTB based on the latest findings in the field, focusing on the role of ABPs and non-receptor protein kinases.
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Affiliation(s)
- Nan Li
- The Mary M. Wohlford Laboratory for Male Contraceptive ResearchCenter for Biomedical Research, Population Council, 1230 York Avenue, New York, New York 10065, USA
| | - Elizabeth I Tang
- The Mary M. Wohlford Laboratory for Male Contraceptive ResearchCenter for Biomedical Research, Population Council, 1230 York Avenue, New York, New York 10065, USA
| | - C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive ResearchCenter for Biomedical Research, Population Council, 1230 York Avenue, New York, New York 10065, USA
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Meneguelli De Souza LC, Retamal CA, Rocha GM, Lopez ML. Morphological evidence for a permeability barrier in the testis and spermatic duct of Gymnotus carapo (Teleostei: Gymnotidae). Mol Reprod Dev 2015; 82:663-78. [PMID: 26073744 DOI: 10.1002/mrd.22503] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 05/07/2015] [Indexed: 11/10/2022]
Abstract
Cell-cell interactions play essential roles in the regulation of gametogenesis. The involvement of junctional complexes in permeability barriers, for example, provides structural and physiological support for male germ-cell development. This study describes morphological characteristics of the reproductive system of Gymnotus carapo, a neo-tropical freshwater fish widely distributed in South and Central America, focusing on the detection of permeability barriers using morphological and biochemical approaches. Ultrastructural analysis of testes treated with the lanthanum nitrate exclusion technique showed that the tracer penetrated the interstitial compartment of the testis, surrounding and appearing within cysts containing spermatogonia and spermatocytes in early stages of meiosis, but was not detected in the spermatid cysts or inside the lumen of spermatogenic tubules. These results suggest the presence of a permeability barrier that is stabilized after meiosis is completed and serves to protect the haploid cells from the vascular system. In the spermatic-duct region, the tracer was obstructed near the lumen of the duct. Junctional complexes and focal tight junctions between adjacent cells were observed in the testis and spermatic duct. Freeze-fracture methods indeed confirmed the presence of tight junctions, which were visualized as parallel rows of individual particles between adjacent cells. More evidence supporting the existence of a permeability barrier was gathered from differences observed in the electrophoretic protein profiles of testis and spermatic-duct fluids compared to blood plasma. Together, these observations demonstrate the existence of a permeability barrier formed by tight junctions in the testis and spermatic duct of G. carapo.
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Affiliation(s)
- Lara C Meneguelli De Souza
- Setor Biologia da Reprodução, Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, Brazil
| | | | - Gustavo M Rocha
- Instituto Nacional de Metrologia, Padronização e Qualidade Industrial, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Maria Luisa Lopez
- Setor Biologia da Reprodução, Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, Brazil
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7
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Yauk CL, Aardema MJ, Benthem JV, Bishop JB, Dearfield KL, DeMarini DM, Dubrova YE, Honma M, Lupski JR, Marchetti F, Meistrich ML, Pacchierotti F, Stewart J, Waters MD, Douglas GR. Approaches for identifying germ cell mutagens: Report of the 2013 IWGT workshop on germ cell assays(☆). MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 783:36-54. [PMID: 25953399 DOI: 10.1016/j.mrgentox.2015.01.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 01/23/2015] [Indexed: 01/06/2023]
Abstract
This workshop reviewed the current science to inform and recommend the best evidence-based approaches on the use of germ cell genotoxicity tests. The workshop questions and key outcomes were as follows. (1) Do genotoxicity and mutagenicity assays in somatic cells predict germ cell effects? Limited data suggest that somatic cell tests detect most germ cell mutagens, but there are strong concerns that dictate caution in drawing conclusions. (2) Should germ cell tests be done, and when? If there is evidence that a chemical or its metabolite(s) will not reach target germ cells or gonadal tissue, it is not necessary to conduct germ cell tests, notwithstanding somatic outcomes. However, it was recommended that negative somatic cell mutagens with clear evidence for gonadal exposure and evidence of toxicity in germ cells could be considered for germ cell mutagenicity testing. For somatic mutagens that are known to reach the gonadal compartments and expose germ cells, the chemical could be assumed to be a germ cell mutagen without further testing. Nevertheless, germ cell mutagenicity testing would be needed for quantitative risk assessment. (3) What new assays should be implemented and how? There is an immediate need for research on the application of whole genome sequencing in heritable mutation analysis in humans and animals, and integration of germ cell assays with somatic cell genotoxicity tests. Focus should be on environmental exposures that can cause de novo mutations, particularly newly recognized types of genomic changes. Mutational events, which may occur by exposure of germ cells during embryonic development, should also be investigated. Finally, where there are indications of germ cell toxicity in repeat dose or reproductive toxicology tests, consideration should be given to leveraging those studies to inform of possible germ cell genotoxicity.
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Affiliation(s)
- Carole L Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada.
| | | | - Jan van Benthem
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Jack B Bishop
- National Institute of Environmental Health Sciences, NC, USA
| | | | | | | | | | - James R Lupski
- Department of Molecular and Human Genetics, and Department of Pediatrics, Baylor College of Medicine, USA
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | | | - Francesca Pacchierotti
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Italy
| | | | | | - George R Douglas
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada.
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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.
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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
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9
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Trezza CR, Kashuba ADM. Pharmacokinetics of antiretrovirals in genital secretions and anatomic sites of HIV transmission: implications for HIV prevention. Clin Pharmacokinet 2014; 53:611-24. [PMID: 24859035 PMCID: PMC4094112 DOI: 10.1007/s40262-014-0148-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The incidence of HIV remains alarmingly high in many parts of the world. Prophylactic use of antiretrovirals, capable of concentrating in the anatomical sites of transmission, may reduce the risk of infection after an unprotected sexual exposure. To date, orally and topically administered antiretrovirals have exhibited variable success in preventing HIV transmission in large-scale clinical trials. Antiretroviral mucosal pharmacokinetics may help explain the outcomes of these investigations. Penetration and accumulation of antiretrovirals into sites of transmission can influence dosing strategies and pre-exposure prophylaxis clinical trial design. Antiretroviral tissue distribution varies widely within and between drug classes, attributed in part to their physicochemical properties and tissue-specific drug transporter expression. Nucleoside(-tide) reverse transcriptase inhibitors, the CCR5 antagonist maraviroc, and the integrase inhibitor raltegravir demonstrate the highest penetration into the male and female reproductive tracts and colorectal tissue relative to blood. This review describes antiretroviral exposure in anatomic sites of transmission, and places these findings in context with the prevention of HIV and the efficacy of pre-exposure prophylactic strategies.
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Affiliation(s)
- Christine R. Trezza
- University of North Carolina at Chapel Hill, Eshelman School of Pharmacy, Chapel Hill, NC
| | - Angela D. M. Kashuba
- University of North Carolina at Chapel Hill, Eshelman School of Pharmacy, Chapel Hill, NC
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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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TURNER TT, D'ADDARIO DA, FORREST JB, HOWARDS SS. The Effects of Experimental Cryptorchidism on the Entry of [3H]-Inulin and [3H]-Horseradish Peroxidase into the Lumen of the Rat Seminiferous Tubules. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/j.1939-4640.1982.tb00665.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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12
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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.
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Affiliation(s)
- Xiang Xiao
- Center for Biomedical Research, Population Council, New York New York, USA
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13
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Meeks JJ, Sheinfeld J, Eggener SE. Environmental toxicology of testicular cancer. Urol Oncol 2012; 30:212-5. [PMID: 22385991 DOI: 10.1016/j.urolonc.2011.09.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 09/28/2011] [Accepted: 09/30/2011] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Testicular cancer incidence appears to be increasing. In many regions, industrialization results in the production of potentially carcinogenic environmental toxins. We review the available data linking environmental toxins to testicular germ cell tumors (TGCT). METHODS A PubMed review of the English literature was performed to identify studies evaluating the relationship between environmental toxins and TGCT. RESULTS Many environmental toxins have been implicated in the development of TGCT, including organochlorines, polychlorinated biphenyls, polyvinyl chlorides, phthalates, marijuana, and tobacco. Variable levels of evidence exist and significant study design limitations preclude a definitive etiologic role for individual environmental toxins. CONCLUSION Environmental toxins may play an important but undetermined role in the development of TGCT. Further work is needed to evaluate specific toxins and TGCT carcinogenesis.
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Affiliation(s)
- Joshua J Meeks
- Division of Urology, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
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14
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Abstract
Male factor infertility is increasing in developed countries, and several factors linked to lifestyle have been shown to negatively affect spermatogenesis. Sertoli cells are pivotal to spermatogenesis, providing nutritional support to germ cells throughout their development. Sertoli cells display atypical features in their cellular metabolism; they can metabolize various substrates, preferentially glucose, the majority of which is converted to lactate and not oxidized via the tricarboxylic acid cycle. Why Sertoli cells preferentially export lactate for germ cells is not entirely understood. However, lactate is utilized as the main energy substrate by developing germ cells and has an antiapoptotic effect on these cells. Several biochemical mechanisms contribute to the modulation of lactate secretion by Sertoli cells. These include the transport of glucose through the plasma membrane, mediated by glucose transporters; the interconversion of pyruvate to lactate by lactate dehydrogenase; and the release of lactate mediated by monocarboxylate transporters. Several factors that modulate Sertoli cell metabolism have been identified, including sex steroid hormones, which are crucial for maintenance of energy homeostasis, influencing the metabolic balance of the whole body. In fact, energy status is essential for normal reproductive function, since the reproductive axis has the capacity to respond to metabolic cues.
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15
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Mortensen MS, Gundgaard MG, Daugaard G. Treatment options for carcinoma in situ testis. ACTA ACUST UNITED AC 2011; 34:e32-6. [DOI: 10.1111/j.1365-2605.2011.01178.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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16
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Mital P, Hinton BT, Dufour JM. The blood-testis and blood-epididymis barriers are more than just their tight junctions. Biol Reprod 2011; 84:851-8. [PMID: 21209417 DOI: 10.1095/biolreprod.110.087452] [Citation(s) in RCA: 259] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The terms blood-testis barrier (BTB) or blood-epididymis barrier (BEB), are often described as Sertoli cell-Sertoli cell tight junctions (TJs) or TJs between the epithelial cells in the epididymis, respectively. However, in reality, the BTB and BEB are much more complex than just the TJ. The focus of this minireview is to remind readers that the complete BTB and BEB are comprised of three components: anatomical, physiological, and immunological. The TJs form the anatomical (physical) barrier that restricts passage of molecules and cells from entering or exiting the lumen. The physiological barrier is comprised of transporters that regulate movement of substances in or out of the lumen, thus creating a microenvironment, which is critical for the proper development and maturation of germ cells. The immunological barrier limits access by the immune system and sequesters the majority of the autoantigenic germ cells. Combined with the overall immune-privilege of the testis, this suppresses detrimental immune responses against the autoantigenic germ cells. These three components on their own do not create a complete functional barrier; instead, it is the interaction between all three components that create a barrier of maximal competence.
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Affiliation(s)
- Payal Mital
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
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17
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Adjudin-mediated Sertoli-germ cell junction disassembly affects Sertoli cell barrier function in vitro and in vivo. Int J Biochem Cell Biol 2010; 42:1864-75. [PMID: 20713173 DOI: 10.1016/j.biocel.2010.08.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Revised: 06/29/2010] [Accepted: 08/10/2010] [Indexed: 12/13/2022]
Abstract
Adjudin, an analogue of lonidamine, affects adhesion between Sertoli and most germ cells, resulting in reversible infertility in rats, rabbits and dogs. Previous studies have described the apical ectoplasmic specialization, a hybrid-type of Sertoli cell-elongating/elongated spermatid adhesive junction, as a key target of adjudin. In this study, we ask if the function of the blood-testis barrier which is constituted by co-existing tight junctions, desmosome-gap junctions and basal ectoplasmic specializations can be maintained when the seminiferous epithelium is under assault by adjudin. We report herein that administration of a single oral dose of adjudin to adult rats increased the levels of several tight junction and basal ectoplasmic specialization proteins during germ cell loss from the seminiferous epithelium. These findings were corroborated by a functional in vitro experiment when Sertoli cells were cultured on Matrigel™-coated bicameral units in the presence of adjudin and transepithelial electrical resistance was quantified across the epithelium. Indeed, the Sertoli cell permeability barrier was shown to become tighter after adjudin treatment as evidenced by an increase in transepithelial electrical resistance. Equally important, the blood-testis barrier in adjudin-treated rats was shown to be intact 2 weeks post-treatment when its integrity was monitored following vascular administration of inulin-fluorescein isothiocyanate which failed to permeate past the barrier and enter into the adluminal compartment. These results illustrate that a unique mechanism exists to maintain blood-testis barrier integrity at all costs, irrespective of the presence of germ cells in the seminiferous epithelium of the testis.
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18
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Rato L, Socorro S, Cavaco JEB, Oliveira PF. Tubular Fluid Secretion in the Seminiferous Epithelium: Ion Transporters and Aquaporins in Sertoli Cells. J Membr Biol 2010; 236:215-24. [DOI: 10.1007/s00232-010-9294-x] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2010] [Accepted: 07/20/2010] [Indexed: 01/01/2023]
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19
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Li MWM, Mruk DD, Lee WM, Cheng CY. Disruption of the blood-testis barrier integrity by bisphenol A in vitro: is this a suitable model for studying blood-testis barrier dynamics? Int J Biochem Cell Biol 2009; 41:2302-14. [PMID: 19497385 PMCID: PMC3516449 DOI: 10.1016/j.biocel.2009.05.016] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 05/24/2009] [Accepted: 05/26/2009] [Indexed: 10/20/2022]
Abstract
Bisphenol A, an estrogenic environmental toxicant, has been implicated to have hazardous effects on reproductive health in humans and rodents. However, there are conflicting reports in the literature regarding its effects on male reproductive function. In this study, it was shown that in adult rats treated with acute doses of bisphenol A, a small but statistically insignificant percentage of seminiferous tubules in the testes displayed signs of germ cell loss, consistent with some earlier reports. It also failed to disrupt the blood-testis barrier in vivo. This is possibly due to the low bioavailability of free bisphenol A in the systemic circulation. However, bisphenol A disrupted the blood-testis barrier when administered to immature 20-day-old rats, consistent with earlier reports concerning the higher susceptibility of immature rats towards bisphenol A. This observation was confirmed using primary Sertoli cells cultured in vitro with established tight junction-permeability barrier that mimicked the blood-testis barrier in vivo. The reversible disruption of Sertoli cell tight junction barrier by bisphenol A was associated with an activation of ERK, and a decline in the levels of selected proteins at the tight junction, basal ectoplasmic specialization, and gap junction at the blood-testis barrier. Studies by dual-labeled immunofluorescence analysis and biotinylation techniques also illustrated declining levels of occludin, connexin 43, and N-cadherin at the cell-cell interface following bisphenol A treatment. In summary, bisphenol A reversibly perturbs the integrity of the blood-testis barrier in Sertoli cells in vitro, which can also serve as a suitable model for studying the dynamics of the blood-testis barrier.
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Affiliation(s)
- Michelle W. M. Li
- Center for Biomedical Research, Population Council, 1230 York Avenue, New York, New York 10065
| | - Dolores D. Mruk
- Center for Biomedical Research, Population Council, 1230 York Avenue, New York, New York 10065
| | - Will M. Lee
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - C. Yan Cheng
- Center for Biomedical Research, Population Council, 1230 York Avenue, New York, New York 10065
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20
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Anand-Ivell R, Heng K, Hafen B, Setchell B, Ivell R. Dynamics of INSL3 Peptide Expression in the Rodent Testis1. Biol Reprod 2009; 81:480-7. [DOI: 10.1095/biolreprod.109.077552] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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21
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Setchell BP. Blood-testis barrier, junctional and transport proteins and spermatogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 636:212-33. [PMID: 19856170 DOI: 10.1007/978-0-387-09597-4_12] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Brian P Setchell
- Department of Anatomical Sciences, University of Adelaide, Adelaide, Australia.
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22
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Mruk DD, Silvestrini B, Cheng CY. Anchoring junctions as drug targets: role in contraceptive development. Pharmacol Rev 2008; 60:146-80. [PMID: 18483144 DOI: 10.1124/pr.107.07105] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
In multicellular organisms, cell-cell interactions are mediated in part by cell junctions, which underlie tissue architecture. Throughout spermatogenesis, for instance, preleptotene leptotene spermatocytes residing in the basal compartment of the seminiferous epithelium must traverse the blood-testis barrier to enter the adluminal compartment for continued development. At the same time, germ cells must also remain attached to Sertoli cells, and numerous studies have reported extensive restructuring at the Sertoli-Sertoli and Sertoli-germ cell interface during germ cell movement across the seminiferous epithelium. Furthermore, the proteins and signaling cascades that regulate adhesion between testicular cells have been largely delineated. These findings have unveiled a number of potential "druggable" targets that can be used to induce premature release of germ cells from the seminiferous epithelium, resulting in transient infertility. Herein, we discuss a novel approach with the aim of developing a nonhormonal male contraceptive for future human use, one that involves perturbing adhesion between Sertoli and germ cells in the testis.
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Affiliation(s)
- Dolores D Mruk
- Population Council, Center for Biomedical Research, The Mary M Wohlford Laboratory for Male Contraceptive Research, 1230 York Avenue, New York, NY 10065, USA.
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23
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Wong EWP, Mruk DD, Cheng CY. Biology and regulation of ectoplasmic specialization, an atypical adherens junction type, in the testis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1778:692-708. [PMID: 18068662 DOI: 10.1016/j.bbamem.2007.11.006] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 10/30/2007] [Accepted: 11/09/2007] [Indexed: 12/01/2022]
Abstract
Anchoring junctions are cell adhesion apparatus present in all epithelia and endothelia. They are found at the cell-cell interface (adherens junction (AJ) and desmosome) and cell-matrix interface (focal contact and hemidesmosome). In this review, we focus our discussion on AJ in particular the dynamic changes and regulation of this junction type in normal epithelia using testis as a model. There are extensive restructuring of AJ (e.g., ectoplasmic specialization, ES, a testis-specific AJ) at the Sertoli-Sertoli cell interface (basal ES) and Sertoli-elongating spermatid interface (apical ES) during the seminiferous epithelial cycle of spermatogenesis to facilitate the migration of developing germ cells across the seminiferous epithelium. Furthermore, recent findings have shown that ES also confers cell orientation and polarity in the seminiferous epithelium, illustrating that some of the functions initially ascribed to tight junctions (TJ), such as conferring cell polarity, are also part of the inherent properties of the AJ (e.g., apical ES) in the testis. The biology and regulation based on recent studies in the testis are of interest to cell biologists in the field, in particular their regulation, which perhaps is applicable to tumorigenesis.
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Affiliation(s)
- Elissa W P Wong
- Center for Biomedical Research, Population Council, 1230 York Avenue, New York, NY 10065, USA
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24
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Onaran I, Aydemir B, Kiziler AR, Demiryurek T, Alici B. Relationships between levels of estradiol and testosterone in seminal plasma and GSTM1 polymorphism in infertile men. ACTA ACUST UNITED AC 2007; 53:13-6. [PMID: 17364458 DOI: 10.1080/01485010600889134] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Glutathione S-transferase M1 (GSTM1) enzyme serves as a steroid-binding protein by its ability to bind to testosterone and estradiol. The levels of total estradiol and testosterone were measured by using an electrochemiluminescence immunoassay in serum and seminal plasma from 103 subjects including 62 subfertile patients. GSTM1 polymorphism was examined using polymerase chain reaction. The estradiol and testosterone levels in seminal plasma were not different in control and subfertile subjects. No role for GSTM1 enzyme as a steroid-binding protein seemed likely as there was also no significant difference in seminal plasma estradiol and testosterone levels according to GSTM1 genotype. Significant positive correlations were found between seminal estradiol and serum estradiol in infertile males, and between seminal testosterone and serum testosterone in fertile males, independent of GSTM1 genotype. GSTM1 polymorphism is not a genetic risk factor of seminal estradiol and testosterone levels in infertile males although further studies are warranted.
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Affiliation(s)
- I Onaran
- Department of Medical Biology, Istanbul University, Istanbul, Turkey.
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25
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Wong CH, Mruk DD, Lee WM, Cheng CY. Targeted and reversible disruption of the blood-testis barrier by an FSH mutant-occludin peptide conjugate. FASEB J 2006; 21:438-48. [PMID: 17167075 PMCID: PMC2806095 DOI: 10.1096/fj.05-4144com] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The blood-testis barrier (BTB) is one of the tightest blood-tissue barriers in mammals. As such, it poses a challenge to deliver any drugs to the seminiferous epithelium of the testis, such as a nonhormonal male contraceptive. To circumvent this problem, a genetically engineered follicle-stimulating hormone (FSH) mutant protein was produced in Spodoptera furgiperda (Sf)-9 insect cells to serve as a testis-specific carrier. Subsequently, a 22-amino acid peptide corresponding to the second extracellular loop of occludin, which was known to disrupt BTB integrity in vivo, was inserted to the FSH mutant by polymerase chain reaction (PCR), as well as chemical cross-linking. This molecule was found to have negligible hormonal activity but was still capable of binding to FSH receptors, which are restricted to Sertoli cells in mammals. When this FSH mutant-occludin peptide conjugate was administered to adult rats at 40 microg/adult rat (approximately 300 gm b.w.) via intraperitoneally (i.p.) injection, it induced transient and reversible disruption of the BTB, while at 150 microg/rat, it induced partial germ cell loss from the testis, particularly elongating/elongate spermatids. Most importantly, this effect was limited to the BTB without compromising the TJ-barrier integrity or cell adhesion in epithelia of other organs, such as kidney, liver, and small intestine. In summary, the use of an FSH mutant-occludin peptide conjugate is a feasible nanodevice to transiently compromise the BTB.
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Affiliation(s)
- Ching-Hang Wong
- Center for Biomedical Research, The Population Council, New York, New York, USA
| | - Dolores D. Mruk
- Center for Biomedical Research, The Population Council, New York, New York, USA
| | - Will M. Lee
- Department of Zoology, University of Hong Kong, Hong Kong, China
| | - C. Yan Cheng
- Center for Biomedical Research, The Population Council, New York, New York, USA
- Correspondence: Population Council, 1230 York Ave., New York, NY 10021, USA.
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26
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Wong CH, Cheng CY. Mitogen-activated protein kinases, adherens junction dynamics, and spermatogenesis: a review of recent data. Dev Biol 2005; 286:1-15. [PMID: 16153630 DOI: 10.1016/j.ydbio.2005.08.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Revised: 07/05/2005] [Accepted: 08/02/2005] [Indexed: 11/23/2022]
Abstract
Mitogen-activated protein kinases (MAPKs) are important regulators of many cellular processes. In mammalian testes, these kinases are involved in controlling cell division, differentiation, survival and death, and are therefore critical to spermatogenesis. Recent studies have also illustrated their involvement in junction restructuring in the seminiferous epithelium, especially at the ectoplasmic specialization (ES), a testis-specific adherens junction (AJ) type. ES contributes to the adhesion between Sertoli cells at the blood-testis barrier, as well as between Sertoli and developing spermatids (step 9 and beyond) at the adluminal compartment. MAPKs regulate AJ dynamics in the testis via their effects on the turnover of junction-associated protein complexes, the production of proteases and protease inhibitors, and the cytoskeleton structure. In this review, roles of the three major MAPK members, namely extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK, in ES dynamics are critically discussed. An integrated model of how these three MAPKs regulate adhesion function in the seminiferous epithelium is also presented. This model will serve as the framework for future investigation in the field.
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Affiliation(s)
- Ching-Hang Wong
- Population Council, 1230 York Avenue, New York, NY 10021, USA
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27
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Castillo C, Krygier G, Carzoglio J, Cepellini Magariños R, Cepellini Olmos R, Jubín J, Sabini G. Gastrointestinal bleeding as the first manifestation of a burned-out tumour of the testis. Clin Transl Oncol 2005; 7:458-63. [PMID: 16373055 DOI: 10.1007/bf02716597] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We discuss the clinical presentation and course of the disease of a 25-year-old male who had gastrointestinal (GIT) symptoms secondary to retroperitoneal lymph node proliferation of a germ-cell tumour of the testis. The pathology evaluation of the orchiectomy specimen classified it as a burned-out tumour of the testis, given the lack of tumour elements and the presence of typical scarring tissue. Biological is-sues leading to tumour regression are discussed, as well.
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Affiliation(s)
- Cecilia Castillo
- Clinical Oncology Department, Clínicas Hospital, University of the Republic, School of Medicine, Montevideo, Uruguay
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28
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Xia W, Cheng CY. TGF-beta3 regulates anchoring junction dynamics in the seminiferous epithelium of the rat testis via the Ras/ERK signaling pathway: An in vivo study. Dev Biol 2005; 280:321-43. [PMID: 15882576 DOI: 10.1016/j.ydbio.2004.12.036] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2004] [Revised: 12/16/2004] [Accepted: 12/16/2004] [Indexed: 10/25/2022]
Abstract
Recent studies have shown that transforming growth factor (TGF)-beta3 regulates blood-testis barrier (BTB) dynamics in vivo, plausibly by determining the steady-state levels of occludin and zonula occludens-1 (ZO-1) at the BTB site via the p38 MAP kinase signaling pathway. Since BTB is composed of coexisting TJs and basal ectoplasmic specializations [ES, a testis-specific adherens junction (AJ) type] in the seminiferous epithelium of the rat testis, we sought to examine if TGF-beta3 would also regulate anchoring junction dynamics. Using an in vivo model in which rats were treated with AF-2364 [1-(2,4-dichlorobenzyl)-indazole-3-carbohydrazide] to perturb Sertoli-germ cell AJs without affecting the integrity of TJs at the BTB, it was noted that the event of germ cell loss from the epithelium was associated with a transient surge in TGF-beta3. Furthermore, it was also associated with a surge in the protein levels of Ras, p-ERK, and the intrinsic activity of ERK, illustrating TGF-beta3 apparently regulates Sertoli-germ cell ES function via the Ras/MEK/ERK signaling pathway. Indeed, pretreatment of rats with TbetaRII/Fc chimera, a TGF-beta antagonist, or U0126, a specific MEK inhibitor, could significantly delay and partially block the disruptive effects of AF-2364 in depleting germ cells from the epithelium. While the protein levels of the cadherin/catenin complex were significantly induced during AF-2364-mediated germ cell loss, perhaps being used to retain germ cells in the epithelium, this increase failed to reverse the loss of adhesion function between Sertoli and germ cells because of a loss of protein-protein interactions between cadherins and catenins. Collectively, these results illustrate that the testis has a novel mechanism in place in which an agent that primarily disrupts TJs can induce secondary loss of AJ function, leading to germ cell loss from the seminiferous epithelium. Yet an agent that selectively disrupts AJs (e.g., AF-2364) can limit its effects exclusively at the Sertoli-germ cell adhesive site without perturbing the Sertoli-Sertoli TJs.
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Affiliation(s)
- Weiliang Xia
- Population Council, Center for Biomedical Research, New York, NY 10021, USA
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29
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Wong CH, Cheng CY. The Blood‐Testis Barrier: Its Biology, Regulation, and Physiological Role in Spermatogenesis. Curr Top Dev Biol 2005; 71:263-96. [PMID: 16344108 DOI: 10.1016/s0070-2153(05)71008-5] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The blood-testis barrier (BTB) in mammals, such as rats, is composed of the tight junction (TJ), the basal ectoplasmic specialization (basal ES), the basal tubulobulbar complex (basal TBC) (both are testis-specific actin-based adherens junction [AJ] types), and the desmosome-like junction that are present side-by-side in the seminiferous epithelium. The BTB physically divides the seminiferous epithelium into basal and apical (or adluminal) compartments, and is pivotal to spermatogenesis. Besides its function as an immunological barrier to segregate the postmeiotic germ-cell antigens from the systemic circulation, it creates a unique microenvironment for germ-cell development and confers cell polarity. During spermatogenesis, the BTB in rodents must physically disassemble to permit the passage of preleptotene and leptotene spermatocytes. This occurs at late stage VII through early stage VIII of the epithelial cycle. Studies have shown that this dynamic BTB restructuring to facilitate germ-cell migration is regulated by two cytokines, namely transforming growth factor-beta3 (TGF-beta3) and tumor necrosis factor-alpha (TNFalpha), via downstream mitogen-activated protein kinases. These cytokines determine the homeostasis of TJ- and basal ES-structural proteins, proteases, protease inhibitors, and other extracellular matrix (ECM) proteins (e.g., collagen) in the seminiferous epithelium. Some of these molecules are known regulators of focal contacts between the ECM and other actively migrating cells, such as macrophages, fibroblasts, or malignant cells. These findings also illustrate that cell-cell junction restructuring at the BTB is regulated by mechanisms involved in the junction turnover at the cell-matrix interface. This review critically discusses these latest findings in the field in light of their significance in the biology and regulation of the BTB pertinent to spermatogenesis.
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Mruk DD, Cheng CY. Sertoli-Sertoli and Sertoli-germ cell interactions and their significance in germ cell movement in the seminiferous epithelium during spermatogenesis. Endocr Rev 2004; 25:747-806. [PMID: 15466940 DOI: 10.1210/er.2003-0022] [Citation(s) in RCA: 614] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Spermatogenesis is the process by which a single spermatogonium develops into 256 spermatozoa, one of which will fertilize the ovum. Since the 1950s when the stages of the epithelial cycle were first described, reproductive biologists have been in pursuit of one question: How can a spermatogonium traverse the epithelium, while at the same time differentiating into elongate spermatids that remain attached to the Sertoli cell throughout their development? Although it was generally agreed upon that junction restructuring was involved, at that time the types of junctions present in the testis were not even discerned. Today, it is known that tight, anchoring, and gap junctions are found in the testis. The testis also has two unique anchoring junction types, the ectoplasmic specialization and tubulobulbar complex. However, attention has recently shifted on identifying the regulatory molecules that "open" and "close" junctions, because this information will be useful in elucidating the mechanism of germ cell movement. For instance, cytokines have been shown to induce Sertoli cell tight junction disassembly by shutting down the production of tight junction proteins. Other factors such as proteases, protease inhibitors, GTPases, kinases, and phosphatases also come into play. In this review, we focus on this cellular phenomenon, recapping recent developments in the field.
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Affiliation(s)
- Dolores D Mruk
- Population Council, Center for Biomedical Research, New York, New York 10021, USA.
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31
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Fabre E, Jira H, Izard V, Ferlicot S, Hammoudi Y, Theodore C, Di Palma M, Benoit G, Droupy S. 'Burned-out' primary testicular cancer. BJU Int 2004; 94:74-8. [PMID: 15217435 DOI: 10.1111/j.1464-410x.2004.04904.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To report the natural history of 'burned-out' testicular tumour (a testicular tumour that has regressed spontaneously with no treatment and that generally presents at the stage of metastases). PATIENTS AND METHODS We report five cases of burned-out testicular tumours to illustrate the clinical, radiological and histopathological features, and discuss the hypothesis of natural history of these neoplasms. RESULTS The findings in the five patients tended to indicate that metastatic progression appears to induce spontaneous regression of the previous tumour site. Patients explored for extragonadal germ cell tumour present with various clinical features depending on the site of the metastases. CONCLUSION Despite the controversial hypotheses of the origin of these tumours, extragonadal germ cell tumours should be considered to be metastases of a 'burned-out' primary testicular tumour that must be investigated. When a primary testicular tumour is detected, the testis must be removed, and standard chemotherapy yields good long-term results. The hypothesis of an immunological reaction against the tumour inducing the spontaneous necrosis of the primary tumour and possibly the metastases should be considered. Immunological screening should be proposed in patients to investigate this interesting model of spontaneous tumour regression.
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Affiliation(s)
- Elodie Fabre
- Service d'Urologie, CHU Bicêtre, Bicêtre, France
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32
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Abstract
Various barriers in the testis may prevent hormones from readily reaching the cells they are supposed to stimulate, especially the hydrophilic hormones from the pituitary. For example, LH must pass through or between the endothelial cells lining the blood vessels to reach the surface of the Leydig cells, and FSH has the additional barrier of the peritubular myoid cells before it reaches the Sertoli cells. The specialised junctions between pairs of Sertoli cells would severely restrict the passage of peptides from blood to the luminal fluid and therefore to the cells inside this barrier, such as the later spermatocytes and spermatids. There is evidence in the literature that radioactively labelled LH does not pass readily into the testis from the blood, and the concentration of native LH in the interstitial extracellular fluid surrounding the Leydig cells in rats is only about one-fifth of that in blood plasma. Furthermore, after injection with LHRH, there are large rises in LH in the blood within 15 min, at which time the Leydig cells have already responded by increasing their content of testosterone, but with no significant change in the concentration of LH in the interstitial extracellular fluid. Either the Leydig cells respond to very small changes in LH, or the testicular endothelial cells in some way mediate the response of the Leydig cells to LH, for which there is now some evidence from co-cultures of endothelial and Leydig cells. The lipophilic steroid hormones, such as testosterone, which are produced by the Leydig cells, have actions within the seminiferous tubules in the testis but also in other parts of the body. They should pass more readily through cells than the hydrophilic peptides; however, the concentration of testosterone in the fluid inside the seminiferous tubules is less than in the interstitial extracellular fluid in the testis, especially after stimulation by LH released after injection of LHRH and despite the presence inside the tubules of high concentrations of an androgen-binding protein. The concentration of testosterone in testicular venous blood does not rise to the same extent as that in the interstitial extracellular fluid, suggesting that there may also be some restriction to movement of the steroid across the endothelium. There is a very poor correlation between the concentrations of testosterone in fluids from the various compartments of the testis and in peripheral blood plasma. Determination of the testosterone concentration in the whole testis is also probably of little predictive value, because the high concentrations of lipid in the Leydig cells would tend to concentrate testosterone there, and hormones inside these cells are unlikely to have any direct effect on other cells in the testis. The best predictor of testosterone concentrations around cells in the testis is the level of testosterone in testicular venous blood, the collection of which for testosterone analysis is a reasonably simple procedure in experimental animals and should be substituted for tissue sampling. There seems to be no simple way of determining the concentrations of peptide hormones in the vicinity of the testicular cells.
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Lui WY, Lee WM, Cheng CY. TGF-betas: their role in testicular function and Sertoli cell tight junction dynamics. INTERNATIONAL JOURNAL OF ANDROLOGY 2003; 26:147-60. [PMID: 12755993 DOI: 10.1046/j.1365-2605.2003.00410.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Transforming growth factor-betas (TGF-betas) are known to regulate multiple physiological functions in the testis, which include spermatogenesis, Leydig cell steroidogenesis, extracellular matrix synthesis and testis development. More recent studies have shown that TGF-beta3 also regulates Sertoli cell tight junction (TJ) dynamics in vitro via the p38 mitogen-activated protein (MAP) kinase pathway, suggesting that this cytokine plays a crucial role in regulating the opening and closing of the blood-testis barrier (BTB). This in turn regulates the passage of pre-leptotene and leptotene spermatocytes across the BTB at stages VIII-XI of the seminiferous epithelial cycle. This review summarizes recent advances of studies on TGF-betas in the testis, highlighting their regulatory role in TJ dynamics.
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Affiliation(s)
- Wing-Yee Lui
- Population Council, Center for Biomedical Research, New York, NY 10021, USA
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Cheng CY, Mruk DD. Cell Junction Dynamics in the Testis: Sertoli-Germ Cell Interactions and Male Contraceptive Development. Physiol Rev 2002; 82:825-74. [PMID: 12270945 DOI: 10.1152/physrev.00009.2002] [Citation(s) in RCA: 420] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Spermatogenesis is an intriguing but complicated biological process. However, many studies since the 1960s have focused either on the hormonal events of the hypothalamus-pituitary-testicular axis or morphological events that take place in the seminiferous epithelium. Recent advances in biochemistry, cell biology, and molecular biology have shifted attention to understanding some of the key events that regulate spermatogenesis, such as germ cell apoptosis, cell cycle regulation, Sertoli-germ cell communication, and junction dynamics. In this review, we discuss the physiology and biology of junction dynamics in the testis, in particular how these events affect interactions of Sertoli and germ cells in the seminiferous epithelium behind the blood-testis barrier. We also discuss how these events regulate the opening and closing of the blood-testis barrier to permit the timely passage of preleptotene and leptotene spermatocytes across the blood-testis barrier. This is physiologically important since developing germ cells must translocate across the blood-testis barrier as well as traverse the seminiferous epithelium during their development. We also discuss several available in vitro and in vivo models that can be used to study Sertoli-germ cell anchoring junctions and Sertoli-Sertoli tight junctions. An in-depth survey in this subject has also identified several potential targets to be tackled to perturb spermatogenesis, which will likely lead to the development of novel male contraceptives.
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Affiliation(s)
- C Yan Cheng
- Population Council, Center for Biomedical Research, New York, New York 10021, USA.
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35
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von Ostau C, Krege S, Hartmann M, Rübben H. Metachronous contralateral germ cell tumor 7 years after management of testicular intraepithelial neoplasia by chemotherapy and multiple control biopsies. SCANDINAVIAN JOURNAL OF UROLOGY AND NEPHROLOGY 2001; 35:430-1. [PMID: 11771876 DOI: 10.1080/003655901753224558] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We report about a metachronous germ cell tumor 7 years after chemotherapy of advanced testicular cancer and contralateral testicular intraepithelial neoplasia (TIN). Chemotherapy can not safely eradicate TIN. The safest treatment for TIN remains low dose radiation.
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Affiliation(s)
- C von Ostau
- Department of Urology, University of Essen, Medical School, Germany
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36
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Abul H, Mathew T, Abul F, Al-Sayer H, Dashti H. Trace element levels in the testes of thioacetamide-induced cirrhotic rats. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/jtra.1049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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37
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Christensen TB, Daugaard G, Geertsen PF, von der Maase H. Effect of chemotherapy on carcinoma in situ of the testis. Ann Oncol 1998; 9:657-60. [PMID: 9681081 DOI: 10.1023/a:1008213515649] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Approximately 5% of patients with testicular cancer harbour carcinoma in situ (CIS) in the contralateral testis. CIS will progress into invasive tumour in about 50% of cases within five years. The present study evaluated the effect of platinum containing chemotherapy on CIS. PATIENTS AND METHODS Thirty-three patients with disseminated germ-cell cancer and biopsy proven CIS of the testis were evaluated. RESULTS CIS had disappeared in the first follow-up biopsy in 30 patients. Six patients had a relapse of CIS with or without invasive cancer after 30, 31, 47, 51, 76 and 95 months from start of chemotherapy. Two relapses were among six patients who initially received cisplatin, vinblastine and bleomycine and four among 27 patients who initially received cisplatin, etoposide and bleomycine. The estimated cumulative risk of CIS five and 10 years after chemotherapy was 21% and 42%, respectively. The estimated cumulative incidence of spermatogenesis was 64% and 81% at five and 10 years of follow-up, respectively. CONCLUSION Platinum containing chemotherapy may eradicate CIS. However, patients with CIS may develop invasive cancer in spite of chemotherapy. In the light of the present data, we recommend radiotherapy to the affected testicle in patients with CIS in the contralateral testis and in patients with bilateral testicular CIS. In patients with extragonadal disease and CIS in one testicle, orchiectomy of the affected testicle is recommended. In patients for whom future fertility is an important issue, follow-up including repeated biopsies can be offered for a period of at least 10 years.
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Affiliation(s)
- T B Christensen
- Department of Oncology, Aarhus University Hospital, Denmark.
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38
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Abstract
Scrotal ultrasonography has many indications. Evaluation of testis masses, hydroceles, and extratesticular structures are the most common indications. Color Doppler ultrasound has made assessment of scrotal blood flow possible. This enables the sonographer to make specific diagnoses in cases of acute scrotal pain. Other indications include evaluating infertile men, searching for an undescended testis, and evaluating the traumatized scrotum.
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Affiliation(s)
- W G Horstman
- Department of Radiology, Eastern Virginia Medical School, Norfolk, USA
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39
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Pöllänen P, Cooper TG, Kokk K, Saari T, Setchell BP. Microvascular permeability to the F(ab')2 fragment of IgG in the male rat reproductive tract at puberty. J Reprod Immunol 1997; 32:221-40. [PMID: 9080385 DOI: 10.1016/s0165-0378(96)01003-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Development of contraceptive vaccines has recently raised much interest following the cloning of the sperm and oocyte components involved in the sperm-oocyte interaction. The main difficulty of immunocontraception in the male is the poor access of antibodies to the luminal compartment. As recent literature suggests that many substances are transported to the testis by receptor-mediated or fluid-phase transcytosis, the dependence of the transport of IgG on the Fc receptor was studied in the present investigation by comparing the penetration of whole IgG and the F(ab')2 fragment of IgG to the testis and epididymis. The maximum volume of distribution (Veq) for the F(ab')2 fragment was significantly higher than that for whole IgG in the testis of 30-60-day old rats, in the caput and cauda of 30- and 45-day old rats and the corpus of 45-day old rats. The speeds at which equilibrium between tissue extracellular fluid and serum was reached (K) for the F(ab')2 fragment and whole IgG were significantly different in the testicular capsule of the 60-day old, in the caput and corpus of the 45- and 60-day old and in the cauda of the 45-day old rats. The microvascular permeabilities (PE) to the F(ab')2 fragment were more than 2-fold higher than those to whole IgG in the testis of the 20-, 45- and 60-day old, in the testicular capsule of the 20- and 45-day old, in the caput of 20-, 30- and 60-day old and in the corpus of 20-day old rats. The PE to whole IgG was more than 2-fold higher than that to the F(ab')2 fragment in the cauda of the 45-day-old rats. The PE to the F(ab')2 fragment increased steadily from 20 to 60 days of age in the testis and caput, but in the corpus there was a more abrupt increase between 30 and 45 days of age. In the cauda, PE remained in the same range of magnitude throughout pubertal development. These results suggest that the F(ab')2 fragment reaches the lumen of the reproductive tract more easily than whole IgG from 30 days of age onwards in the testis, whereas in the caput, corpus and cauda epididymidis the rate at which F(ab')2 fragment reaches the lumen increases only temporarily at the time of appearance of spermatozoa in the lumen. Transport of IgG to the male reproductive tract is thus unlikely to be mediated by Fc receptors.
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Affiliation(s)
- P Pöllänen
- Department of Anatomy, University of Turku, Finland.
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40
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41
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42
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43
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Setchell BP, Granholm T, Ritzén EM. Failure of thyroid allografts to function in the testes of cynomolgous monkeys. J Reprod Immunol 1995; 28:75-80. [PMID: 7738917 DOI: 10.1016/0165-0378(94)00897-g] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Allografts of thyroid were placed into one testis of 8 cynomolgous monkeys. None of these had accumulated significant amounts of radioactive iodide 28 days later, whereas autografts of thyroid placed in the other testis of 6 of these monkeys did so in 5 cases out of the 6. Autografts of thyroid placed subcutaneously in these 6 monkeys also accumulated iodide in the same 5 animals, but subcutaneous allografts failed in all 6 monkeys in which these were done. These results suggest that there is no immune privilege for grafts in the primate testis, which in this regard resembles more the testis of the ram, rather than that of rodents.
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Affiliation(s)
- B P Setchell
- Pediatric Endocrinology Unit, Karolinska Hospital, Stockholm, Sweden
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44
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Kerr JB, Savage GN, Millar M, Sharpe RM. Response of the seminiferous epithelium of the rat testis to withdrawal of androgen: evidence for direct effect upon intercellular spaces associated with Sertoli cell junctional complexes. Cell Tissue Res 1993; 274:153-61. [PMID: 8242704 DOI: 10.1007/bf00327996] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The morphological response of the Sertoli cells to partial or complete withdrawal of testosterone was studied in adult rats following hypophysectomy or administration of ethane dimethanesulphonate (EDS), a toxicant known to destroy selectively the Leydig cells of the testis. To assess the role of germ cells in effecting changes to Sertoli cells following withdrawal of testosterone, germ cell-deficient rats with Sertoli-cell-only testes (SCO) were treated with EDS to remove the source of testosterone. At 6 days after hypophysectomy or 4, 6 and 8 days after EDS treatment, stage VII and VIII seminiferous tubules showed degenerating germ cells and numerous basally-located vacuoles approximately 1-15 microns in diameter. Ultrastructural analysis indicated that most of the vacuoles were multiple focal dilations of the intercellular space associated with Sertoli cell junctional complexes. In SCO rats, treatment with EDS resulted in a significant (P < 0.05) increase in the formation of many vacuoles particularly in the base but also in the trunk of the Sertoli cells and again electron microscopic analysis showed multiple, localized expansions of the intercellular space associated with Sertoli cell junctional complexes. The appearance of intercellular spaces in SCO testes following androgen withdrawal cannot be attributed to shrinkage of degenerating germ cells since the seminiferous tubules did not contain germ cells. It is concluded that withdrawal of androgen induces early morphological alterations of the Sertoli cell junctional complexes in which the sites of membrane fusions representing tight junctions remain intact whereas the intercellular spaces exhibit major focal dilations.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J B Kerr
- Department of Anatomy, Monash University, Clayton, Victoria, Australia
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45
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Schulze C. Interaktionen zwischen Leydigzellen — peritubulären Zellen — Sertolizellen und ihre Bedeutung für die Steuerung der Spermatogenese. Ann Anat 1992. [DOI: 10.1016/s0940-9602(11)80312-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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46
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Daugaard G, Rørth M, von der Maase H, Skakkebaek NE. Management of extragonadal germ-cell tumors and the significance of bilateral testicular biopsies. Ann Oncol 1992; 3:283-9. [PMID: 1327076 DOI: 10.1093/oxfordjournals.annonc.a058180] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Forty-nine patients with assumed extragonadal germ-cell tumors (retroperitoneum: 39, mediastinum: 8, CNS: 2) were included in the present study. The patients were treated with 'high' (40 mg cisplatin/m2 and 200 mg etoposide/m2 daily x 5) or 'conventional' (20 mg cisplatin/m2 and 100 mg etoposide/m2 daily x 5) doses of cisplatin and etoposide together with bleomycin, depending on the presence or absence of poor prognosis factors. Forty-six patients were evaluable for response and 3 patients were classified as non-responders (1 early death, 2 toxic deaths). Eighty percent obtained complete remission and 76% are alive without evidence of disease after a median observation time of 41 months (88% of patients with primary tumor in the mediastinum, 72% with tumor in the retroperitoneal area, 87% of patients with seminoma and 71% with non-seminoma, respectively). In 48 patients testicular biopsies were performed. In 42% of patients with primary retroperitoneal tumors, carcinoma in situ testis (CIS) was diagnosed. None of the patients with tumors in mediastinum or CNS had CIS in the testicles. The therapeutic outcome for patients with extragonadal germ-cell tumors is now similar to that of patients with very advanced testicular cancer when considered in relation to the presence of prognostic factors. The coexistence of CIS and retroperitoneal tumor could indicate that these tumors are not truly extragonadal or that these lesions have a common malignant progenitor.
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Affiliation(s)
- G Daugaard
- Department of Oncology ONK, Rigshospitalet, Copenhagen
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47
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Abstract
Examination of the stallion's reproductive tract involves assessments of external and internal anatomy. External examinations are performed by visual inspection, palpation, or ultrasonography and include the scrotum, testes, epididymides, penis, and prepuce. Internal examinations may be performed by rectal palpation, transrectal ultrasonography, or endoscopy and include the accessory sex glands, pelvic urethra, and inguinal rings. A fertile stallion must produce, transport, store, and deliver viable spermatozoa to the mare. The physiologic processes involved include neuroendocrine control, spermatogenesis, sperm maturation, semen delivery, and fertilization.
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Affiliation(s)
- T V Little
- Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington
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48
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Crain TW, Kennon WG, Desmond PM, Dresner ML, Sandberg GD. Extragonadal yolk sac tumor in a superior scrotal mass. J Urol 1992; 147:1087-8. [PMID: 1552591 DOI: 10.1016/s0022-5347(17)37481-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We report a case of an extragonadal yolk sac tumor in a superior scrotal mass. Testicular ultrasonography was normal preoperatively and after chemotherapy. Serum alpha-fetoprotein was initially increased to 344.55 ng./ml. (normal 0 to 15) but it returned to normal after surgery and chemotherapy.
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Affiliation(s)
- T W Crain
- Department of Surgery, Tripler Army Medical Center, Honolulu, Hawaii 96859-5000
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49
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Plöen L, Setchell BP. Blood-testis barriers revisited. A homage to Lennart Nicander. INTERNATIONAL JOURNAL OF ANDROLOGY 1992; 15:1-4. [PMID: 1544694 DOI: 10.1111/j.1365-2605.1992.tb01108.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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50
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Pelletier RM, Byers SW. The blood-testis barrier and Sertoli cell junctions: structural considerations. Microsc Res Tech 1992; 20:3-33. [PMID: 1611148 DOI: 10.1002/jemt.1070200104] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In this review, a few well-established axioms have been challenged while others were viewed from a new perspective. The extensive literature on the blood-testis barrier has been scrutinized to help probe its mechanics and hopefully to promote understanding of the constant adaptation of the barrier function to germ cell development. Our principal conclusions are as follows: (1) Although the barrier zonule is topographically located at the base of the seminiferous epithelium it actually encircles the apex of the Sertoli cell. Consequently the long irregular processes specialized in holding and shaping the developing germ cells should be considered as apical appendages analogous to microvilli. (2) The development of the barrier zonule does not coincide with the appearance of a particular class of germ cells. (3) The barrier compartmentalizes the epithelium into only two cellular compartments: basal and lumenal. (4) Although the blood-testis barrier does sequester germ cells usually considered antigenic, immunoregulator factors other than the physical barrier seem to be involved in preventing autoimmune orchitis. (5) Structurally, a Sertoli cell junctional complex is composed of occluding, gap, close, and adhering junctions. The Sertoli cell membrane segments facing germ cells are presumably included in the continuum of the Sertoli cell junctional complex that extends all over the lateral and apical Sertoli cell membranes. (6) The modulation (i.e., formation and dismantling) of the junctions in a baso-apical direction is characteristic of the seminiferous epithelium and may be dictated by germ cell differentiation. The formation of tubulobulbar complexes and the following internalization of junction vesicles conceivably represent sequential steps of a single intricate junction elimination process that involves junction membrane segments from different cell types as part of a continual cell membrane recycling system. (7) The preferential association of junctional particles with one or the other fracture-face reflect a response to various stimuli including seasonal breeding. Changes in the affinity of the particles are generally coincidental with cytoskeletal changes. However, changes in the cytoskeleton are not necessarily accompanied by permeability changes. The number of strands seems to reflect neither the junctional permeability nor the transepithelial resistance. The diverse orientation of the strands seems to be related to the plasticity of the Sertoli cell occluding zonule. (8) Cooperation between all constituents (Sertoli cells, myoid cells, cell substratum, and germ cells) of the epithelium seems essential for the barrier zonule to function in synchrony with the germ cell differentiation.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- R M Pelletier
- Department of Anatomy, Faculty of Medicine, University of Ottawa, Ontario, Canada
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