Articoli di riviste: "Sertoli cells Physiology"

1

de, Kretser DM. "Germ cell-Sertoli cell interactions". Reproduction, Fertility and Development 2, n. 3 (1990): 225. http://dx.doi.org/10.1071/rd9900225.

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The interactions between the Sertoli cells and germ cells are progressively becoming an important part of testicular physiology. This paper explores the cytological basis for these interactions, detailing the cyclic changes in the Sertoli cells in concert with the stages of the seminiferous cycle and the nature of the blood-testis barrier. These cytological changes are correlated with a number of variations in the function of Sertoli cells. The mechanisms by which germ cells and Sertoli cells interact are explored and can be divided into those using cell-to-cell contact and others utilizing paracrine factors.

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Maqdasy, Salwan, Fatim-Zohra El Hajjaji, Marine Baptissart, Emilie Viennois, Abdelkader Oumeddour, Florence Brugnon, Amalia Trousson et al. "Identification of the Functions of Liver X Receptor-β in Sertoli Cells Using a Targeted Expression-Rescue Model". Endocrinology 156, n. 12 (24 settembre 2015): 4545–57. http://dx.doi.org/10.1210/en.2015-1382.

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Liver X receptors (LXRs) are key regulators of lipid homeostasis and are involved in multiple testicular functions. The Lxrα−/−;Lxrβ−/− mice have illuminated the roles of both isoforms in maintenance of the epithelium in the seminiferous tubules, spermatogenesis, and T production. The requirement for LXRβ in Sertoli cells have been emphasized by early abnormal cholesteryl ester accumulation in the Lxrβ−/− and Lxrα−/−;Lxrβ−/− mice. Other phenotypes, such as germ cell loss and hypogonadism, occur later in life in the Lxrα−/−;Lxrβ−/− mice. Thus, LXRβ expression in Sertoli cells seems to be essential for normal testicular physiology. To decipher the roles of LXRβ within the Sertoli cells, we generated Lxrα−/−;Lxrβ−/−:AMH-Lxrβ transgenic mice, which reexpress Lxrβ in Sertoli cells in the context of Lxrα−/−;Lxrβ−/− mice. In addition to lipid homeostasis, LXRβ is necessary for maintaining the blood-testis barrier and the integrity of the germ cell epithelium. LXRβ is also implicated in the paracrine action of Sertoli cells on Leydig cells to modulate T synthesis. The Lxrα−/−;Lxrβ−/− and Lxrα−/−;Lxrβ−/−:AMH-Lxrβ mice exhibit lipid accumulation in germ cells after the Abcg8 down-regulation, suggesting an intricate LXRβ-dependent cooperation between the Sertoli cells and germ cells to ensure spermiogenesis. Further analysis revealed also peritubular smooth muscle defects (abnormal lipid accumulation and disorganized smooth muscle actin) and spermatozoa stagnation in the seminiferous tubules. Together the present work elucidates specific roles of LXRβ in Sertoli cell physiology in vivo beyond lipid homeostasis.

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Pelletier, R. Marc, Casimir D. Akpovi, Li Chen, Robert Day e María L. Vitale. "CX43 expression, phosphorylation, and distribution in the normal and autoimmune orchitic testis with a look at gap junctions joining germ cell to germ cell". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 300, n. 1 (gennaio 2011): R121—R139. http://dx.doi.org/10.1152/ajpregu.00500.2010.

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Spermatogenesis requires connexin 43 (Cx43).This study examines normal gene transcription, translation, and phosphorylation of Cx43 to define its role on germ cell growth and Sertoli cell's differentiation, and identifies abnormalities arising from spontaneous autoimmune orchitis (AIO) in mink, a seasonal breeder and a natural model for autoimmunity. Northern blot analysis detected 2.8- and a 3.7-kb Cx43 mRNA bands in seminiferous tubule-enriched fractions. Cx43 mRNA increased in seminiferous tubule-enriched fractions throughout development and then seasonally with the completion of spermatogenesis. Cx43 protein levels increased transiently during the colonization of the tubules by the early-stage spermatocytes. Cx43 phosphorylated (PCx43) and nonphosphorylated (NPCx43) in Ser368 decreased during the periods of completion of meiosis and Sertoli cell differentiation, while Cx43 mRNA remained elevated throughout. PCx43 labeled chiefly the plasma membrane except by stage VII when vesicles were also labeled in Sertoli cells. Vesicles and lysosomes in Sertoli cells and the Golgi apparatus in the round spermatids were NPCx43 positive. A decrease in Cx43 gene expression was matched by a Cx43 protein increase in the early, not the late, phase of AIO. Total Cx43 and PCx43 decreased with the advance of orchitis. The study makes a novel finding of gap junctions connecting germ cells. The data indicate that Cx43 protein expression and phosphorylation in Ser368 are stage-specific events that may locally influence the acquisition of meiotic competence and the Sertoli cell differentiation in normal testis. AIO modifies Cx43 levels, suggesting changes in Cx43-mediated intercommunication and spermatogenic activity in response to cytokines imbalances in Sertoli cells.

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4

Benahmed, M., J. Reventos, E. Tabone e J. M. Saez. "Cultured Sertoli cell-mediated FSH stimulatory effect on Leydig cell steroidogenesis". American Journal of Physiology-Endocrinology and Metabolism 248, n. 2 (1 febbraio 1985): E176—E181. http://dx.doi.org/10.1152/ajpendo.1985.248.2.e176.

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To determine the precise role of Sertoli cells in the stimulating effects of follicle stimulating hormone (FSH) on Leydig cell activity, porcine purified Leydig and Sertoli cells were cultured separately or together in a chemically defined medium in the absence or presence of porcine, FSH 50 ng/ml. Leydig cell activity was evaluated using two parameters: human chorionic gonadotropin (hCG) binding sites; and hCG-stimulated cAMP production and testosterone secretion. First, it was found that FSH increases Leydig cell activity in crude Leydig cell preparations (40–60% of Leydig cells), whereas it exerts no effect on purified Leydig cells (greater than 90% of Leydig cells). Second, FSH stimulates the activity of Leydig cells cocultured with Sertoli cells, whereas it remains without effect on purified Leydig cells cultured alone. This stimulating effect of FSH on Leydig cell activity is dependent on the Sertoli cell number in the coculture. These data 1) show that the stimulating effect of FSH on Leydig cell function is mediated by Sertoli cells and 2) support the concept of local control of Leydig cell function originating from Sertoli cells.

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Froment, P., M. Vigier, D. Nègre, I. Fontaine, J. Beghelli, F. L. Cosset, M. Holzenberger e P. Durand. "Inactivation of the IGF-I receptor gene in primary Sertoli cells highlights the autocrine effects of IGF-I". Journal of Endocrinology 194, n. 3 (settembre 2007): 557–68. http://dx.doi.org/10.1677/joe-07-0258.

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IGF-I regulates pituitaryand gonadal functions, and is pivotal for sexual development and fertility in mammalian species. To better understand the function of autocrine IGF-I in Sertoli cell physiology, we established a system for Cre-mediated conditional inactivation of the IGF-I receptor (IGF-IR) in cultured Sertoli cells. We show here that loss of IGF-IR decreased the number of viable Sertoli cells as a consequence of diminished Sertoli cell proliferation and increased Sertoli cell death. Furthermore, the lack of IGF-IR altered the morphology of cultured Sertoli cells and decreased lactate and transferrin secretions. Collectively, our data indicate that autocrine IGF-I contributes significantly to Sertoli cell homeostasis. The described in vitro system for loss-of-function analysis of the IGF-IR can be readily transposed to study the role of other intratesticular growth factors involved in spermatogenesis.

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Renier, G., J. Gaulin, W. Gibb, R. Collu e J. R. Ducharme. "Effect of catecholamines on porcine Sertoli and Leydig cells in primary culture". Canadian Journal of Physiology and Pharmacology 65, n. 10 (1 ottobre 1987): 2053–58. http://dx.doi.org/10.1139/y87-321.

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The accumulation by purified immature porcine Leydig and Sertoli cells of cyclic adenosine 3′,5′-monophosphate in the presence of 1-methyl-3-isobuthylxathine was studied and their respective testosterone and 17β-estradiol production in response to catecholamines was assessed in vitro. These substances increased both basal and FSH-stimulated cyclic adenosine 3′,5′-monophosphate accumulation in Sertoli cells. In contrast, catecholamines slightly enhanced basal cyclic adenosine 3′,5′-monophosphate production but inhibited its human chorionic gonadotropin-stimulated accumulation by Leydig cells. Catecholamines had no effect on basal and stimulated testosterone release by these cells, while dopamine inhibited 17β-estradiol synthesis by Sertoli cells. Using various α- and β-adrenergic agonists and antagonists, β-receptors, likely of the β1-subtype, were shown to be present in both cell lines. Taken together these data suggest the presence of a cyclic adenosine 3′,5′-monophosphate-linked adrenergic receptor in porcine Leydig and Sertoli cells, the role of which remains to be determined.

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Moroi, Seiji, Mitinori Saitou, Kazushi Fujimoto, Akira Sakakibara, Mikio Furuse, Osamu Yoshida e Shoichiro Tsukita. "Occludin is concentrated at tight junctions of mouse/rat but not human/guinea pig Sertoli cells in testes". American Journal of Physiology-Cell Physiology 274, n. 6 (1 giugno 1998): C1708—C1717. http://dx.doi.org/10.1152/ajpcell.1998.274.6.c1708.

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Occludin is the only integral membrane protein identified to date as a component of tight junctions (TJs). Here, we examined the distribution and expression of occludin in murine testis bearing well-developed TJ. In the adult mouse testis, occludin was concentrated at TJ strands, which are located at the most basal regions of lateral membranes of Sertoli cells. In immunoblotting, occludin showed a characteristic multiple banding pattern, suggesting that occludin is highly phosphorylated in the testis. In 1-wk-old mouse testis, occludin was distributed diffusely at the lateral membranes of Sertoli cells, and even at this stage, highly phosphorylated occludin was detected. With development, occludin gradually became concentrated at the most basal regions of Sertoli cells. The same results were obtained in rat, but unexpectedly occludin was not detected in human or guinea pig Sertoli cells by immunofluorescence microscopy as well as by immunoblotting. Inasmuch as TJs are also well developed in Sertoli cells of these species, we concluded that, at least in the testes of these species, there are some Sertoli cell-specific isoforms of occludin or other TJ-associated integral membrane proteins that differ from occludin.

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8

Fantoni, G., P. L. Morris, G. Forti, G. B. Vannelli, C. Orlando, T. Barni, R. Sestini, G. Danza e M. Maggi. "Endothelin-1: a new autocrine/paracrine factor in rat testis". American Journal of Physiology-Endocrinology and Metabolism 265, n. 2 (1 agosto 1993): E267—E274. http://dx.doi.org/10.1152/ajpendo.1993.265.2.e267.

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Cultured Sertoli cells of 20-day-old rats were found to produce and release endothelin-1-like immunoreactivity (ET-1-LI) under follicle-stimulating hormone control. The elution profile of ET-1-LI from extracts of spent Sertoli cell culture medium corresponds to that of synthetic ET-1, suggesting a testicular production of authentic ET-1. In contrast, the conditioned medium from rat Leydig cells did not contain ET-1-LI. Immunohistochemical studies confirmed that, in 20-day-old rats, the positive staining was confined to some Sertoli cells, whereas interstitial cells were negative. In the adult rat testis the positivity was not limited to the tubular compartment (Sertoli cells) but was also present in the interstitium. A high concentration (13 pmol/mg protein) of high-affinity (dissociation constant = 0.6 nM) 125I-labeled ET-1 binding sites was present in Leydig cells. These sites bind ET-1 and ET-2 with 1,000-fold higher affinity than ET-3, suggesting that they correspond to the subtype ETA of the ET receptors. Specific 125I-ET-1 binding sites are present also in Sertoli cells but are 50-fold less concentrated than in Leydig cells. Our results suggest an autocrine/paracrine role for ET-1 in rat testis.

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Allan, Charles M., Patrick Lim, Mathew Robson, Jenny Spaliviero e David J. Handelsman. "Transgenic mutant D567G but not wild-type human FSH receptor overexpression provides FSH-independent and promiscuous glycoprotein hormone Sertoli cell signaling". American Journal of Physiology-Endocrinology and Metabolism 296, n. 5 (maggio 2009): E1022—E1028. http://dx.doi.org/10.1152/ajpendo.90941.2008.

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We have characterized the in vivo actions of human wild-type FSH receptor (FSHR) overexpressed in Sertoli cells of transgenic (Tg) mice ( TgFSHRwt) compared with transgenic overexpression of the human activated mutant FSHR*D567G ( TgFSHR*D567G). Testicular TgFSHRwt expression significantly elevated specific FSH binding (>2-fold, P < 0.01) relative to nontransgenic testes, similar to increased FSH binding in TgFSHR*D567G testes. Isolated TgFSHRwt Sertoli cells exhibited higher FSH-stimulated cAMP levels compared with non- Tg or TgFSHR*D567G cells but did not display the elevated FSH-independent basal cAMP levels found in TgFSHR*D567G Sertoli cells. Furthermore, Sertoli cell overexpression of TgFSHR*D567G but not TgFSHRwt allowed promiscuous cAMP responses to human chorionic gonadotropin (300 IU/ml) and TSH (30 mIU/ml), demonstrating increased constitutive signaling and altered glycoprotein hormone specificity via the intracellular D567G substitution rather than FSHR overexpression. Despite elevating Sertoli cell FSH sensitivity, overexpression of TgFSHRwt had no detectable effect upon normal testis function and did not stimulate Sertoli and germ cell development in testes of gonadotropin-deficient hypogonadal ( hpg) mice, in contrast to the increased meiotic and postmeiotic germ cell development in TgFSHR*D567G hpg testes. Increased steroidogenic potential of TgFSHR*D567G hpg testes was demonstrated by elevated Cyp11a1 and Star expression, which was not detected in TgFSHRwt hpg testes. Androgen-regulated and Sertoli cell-specific Rhox5 gene expression was increased in TgFSHR*D567G but not TgFSHRwt hpg testes, providing evidence of elevated LH-independent androgen activity due to mutant FSHR*D567G. Hence, transgenic FSHR overexpression in Sertoli cells revealed that the D567G mutation confers autonomous signaling and steroidogenic activity in vivo as well as promiscuous glycoprotein hormone receptor activation, independently of FSHR overexpression alone.

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Riera, María F., María N. Galardo, Eliana H. Pellizzari, Silvina B. Meroni e Selva B. Cigorraga. "Molecular mechanisms involved in Sertoli cell adaptation to glucose deprivation". American Journal of Physiology-Endocrinology and Metabolism 297, n. 4 (ottobre 2009): E907—E914. http://dx.doi.org/10.1152/ajpendo.00235.2009.

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Sertoli cells provide the physical support and the necessary environment for germ cell development. Among the products secreted by Sertoli cells, lactate, the preferred energy substrate for spermatocytes and spermatids, is present. Considering the essential role of lactate on germ cell metabolism, it is supposed that Sertoli cells must ensure its production even in adverse conditions, such as those that would result from a decrease in glucose levels in the extracellular milieu. The aim of the present study was to investigate 1) a possible effect of glucose deprivation on glucose uptake and on the expression of glucose transporters in rat Sertoli cells and 2) the participation of different signal transduction pathways in the above-mentioned regulation. Results obtained show that decreasing glucose levels in Sertoli cell culture medium provokes 1) an increase in glucose uptake accompanied by only a slight decrease in lactate production, 2) an increase in GLUT1 and a decrease in GLUT3 expression, and 3) an activation of AMP-activated protein kinase (AMPK)-, phosphatidylinositol 3-kinase (PI3K)/PKB-, and p38 MAPK-dependent pathways. Additionally, by using specific inhibitors of these pathways, a possible participation of AMPK- and p38MAPK-dependent pathways in the regulation of glucose uptake and GLUT1 expression is shown. These results suggest that Sertoli cells adapt to conditions of glucose deprivation to ensure an adequate lactate concentration in the microenvironment where germ cell development occurs.

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Kongmanas, Kessiri, Arpornrad Saewu, Wongsakorn Kiattiburut, Mark A. Baker, Kym F. Faull, Dylan Burger e Nongnuj Tanphaichitr. "Accumulation of Seminolipid in Sertoli Cells Is Associated with Increased Levels of Reactive Oxygen Species and Male Subfertility: Studies in Aging Arsa Null Male Mice". Antioxidants 10, n. 6 (4 giugno 2021): 912. http://dx.doi.org/10.3390/antiox10060912.

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Seminolipid (also known as sulfogalactosylglycerolipid-SGG), present selectively in male germ cells, plays important roles in spermatogenesis and sperm–egg interaction. The proper degradation of SGG in apoptotic germ cells is also as important. Sertoli cells first phagocytose apoptotic germ cells, then Sertoli lysosomal arylsulfatase A (ARSA) desulfates SGG, the first step of SGG degradation. We have reported that aging male Arsa−/− mice become subfertile with SGG accumulation in Sertoli cell lysosomes, typical of a lysosomal storage disorder (LSD). Since reactive oxygen species (ROS) levels are increased in other glycolipid-accumulated LSDs, we quantified ROS in Arsa−/− Sertoli cells. Our analyses indicated increases in superoxide and H2O2 in Arsa−/− Sertoli cells with elevated apoptosis rates, relative to WT counterparts. Excess H2O2 from Arsa−/− Sertoli cells could travel into testicular germ cells (TGCs) to induce ROS production. Our results indeed indicated higher superoxide levels in Arsa−/− TGCs, compared with WT TGCs. Increased ROS levels in Arsa−/− Sertoli cells and TGCs likely caused the decrease in spermatogenesis and increased the abnormal sperm population in aging Arsa−/− mice, including the 50% decrease in sperm SGG with egg binding ability. In summary, our study indicated that increased ROS production was the mechanism through which subfertility manifested following SGG accumulation in Sertoli cells.

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Kato, Ryo, Tomoji Maeda, Toshihiro Akaike e Ikumi Tamai. "Characterization of novel Na+-dependent nucleobase transport systems at the blood-testis barrier". American Journal of Physiology-Endocrinology and Metabolism 290, n. 5 (maggio 2006): E968—E975. http://dx.doi.org/10.1152/ajpendo.00160.2005.

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In the testis, nucleosides and nucleobases are important substrates of the salvage pathway for nucleotide biosynthesis, and one of the roles of Sertoli cells is to provide nutrients and metabolic precursors to spermatogenic cells located within the blood-testis barrier (BTB). We have already shown that concentrative and equilibrative nucleoside transporters are expressed and are functional in primary-cultured rat Sertoli cells as a BTB model, but little is known about nucleobase transport at the BTB or about the genes encoding specific nucleobase transporters in mammalian cells. In the present study, we examined the uptake of purine ([3H]guanine) and pyrimidine ([3H]uracil) nucleobases by primary-cultured rat Sertoli cells. The uptake of both nucleobases was time and concentration dependent. Kinetic analysis showed the involvement of three different transport systems in guanine uptake. In contrast, uracil uptake was mediated by a single Na+-dependent high-affinity transport system. Guanine uptake was inhibited by other purine nucleobases but not by pyrimidine nucleobases, whereas uracil uptake was inhibited only by pyrimidine nucleobases. In conclusion, it was suggested that there might be purine- or pyrimidine-selective nucleobase transporters in rat Sertoli cells.

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Eusebi, Fabrizio, Francesca Grassi, Guiseppe Fratamico, Susanna Dolci, Marco Conti e Mario Stefanini. "Cell-to-cell communication in cultured Sertoli cells". Pfl�gers Archiv European Journal of Physiology 404, n. 4 (agosto 1985): 382–84. http://dx.doi.org/10.1007/bf00585353.

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Domanskyi, Andrii, Fu-Ping Zhang, Mirja Nurmio, Jorma J. Palvimo, Jorma Toppari e Olli A. Jänne. "Expression and localization of androgen receptor-interacting protein-4 in the testis". American Journal of Physiology-Endocrinology and Metabolism 292, n. 2 (febbraio 2007): E513—E522. http://dx.doi.org/10.1152/ajpendo.00287.2006.

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Androgen receptor-interacting protein 4 (ARIP4) belongs to the SNF2 family of proteins involved in chromatin remodeling, DNA excision repair, and homologous recombination. It is a DNA-dependent ATPase, binds to DNA and mononucleosomes, and interacts with androgen receptor (AR) and modulates AR-dependent transactivation. We have examined in this study the expression and cellular localization of ARIP4 during postnatal development of mouse testis. ARIP4 was detected by immunohistochemistry in Sertoli cell nuclei at all ages studied, starting on day 5, and exhibited the highest expression level in adult mice. At the onset of spermatogenesis, ARIP4 expression became evident in spermatogonia, pachytene, and diplotene spermatocytes. Immunoreactive ARIP4 antigen was present in Leydig cell nuclei. In Sertoli cells ARIP4 was expressed in a stage-dependent manner, with high expression levels at stages II–VI and VII–VIII. ARIP4 expression patterns did not differ significantly in testes of wild-type, follicle-stimulating hormone receptor knockout, and luteinizing hormone receptor knockout mice. In testes of hypogonadal mice, ARIP4 was found mainly in interstitial cells and exhibited lower expression in Sertoli and germ cells. In vitro stimulation of rat seminiferous tubule segments with testosterone, FSH, or forskolin did not significantly change stage-specific levels of ARIP4 mRNA. Heterozygous ARIP4+/− mice were haploinsufficient and had reduced levels of Sertoli-cell specific androgen-regulated Rhox5 (also called Pem) mRNA. Collectively, ARIP4 is an AR coregulator in Sertoli cells in vivo, but the expression in the germ cells implies that it has also AR-independent functions in spermatogenesis.

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Veitinger, Sophie, Thomas Veitinger, Silvia Cainarca, Daniela Fluegge, Corinna H. Engelhardt, Stefan Lohmer, Hanns Hatt et al. "Purinergic signalling mobilizes mitochondrial Ca2+in mouse Sertoli cells". Journal of Physiology 589, n. 21 (28 ottobre 2011): 5033–55. http://dx.doi.org/10.1113/jphysiol.2011.216309.

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Cheng, C. Yan, e Dolores D. Mruk. "Cell Junction Dynamics in the Testis: Sertoli-Germ Cell Interactions and Male Contraceptive Development". Physiological Reviews 82, n. 4 (10 gennaio 2002): 825–74. http://dx.doi.org/10.1152/physrev.00009.2002.

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Abstract (sommario):

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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Oliveira, P. F., M. Sousa, A. Barros, T. Moura e A. Rebelo da Costa. "Intracellular pH regulation in human Sertoli cells: role of membrane transporters". REPRODUCTION 137, n. 2 (febbraio 2009): 353–59. http://dx.doi.org/10.1530/rep-08-0363.

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Sertoli cells are responsible for regulating a wide range of processes that lead to the differentiation of male germ cells into spermatozoa. Intracellular pH (pHi) is an important parameter in cell physiology regulating namely cell metabolism and differentiation. However, pHi regulation mechanisms in Sertoli cells have not yet been systematically elucidated. In this work, pHi was determined in primary cultures of human Sertoli cells. Sertoli cells were exposed to weak acids, which caused a rapid acidification of the intracellular milieu. pHi then recovered by a mechanism that was shown to be particularly sensitive to the presence of the inhibitor DIDS (4,4′-diisothiocyanostilbene disulfonic acid). In the presence of amiloride and PSA (picrylsulfonic acid), pHi recovery was also significantly affected. These results indicate that, in the experimental conditions used, pHi is regulated by the action of an Na+-driven HCO3−/Cl−exchanger and an Na+/HCO3−co-transporter and also by the action of the Na+/H+exchanger. On the other hand, pHi recovery was only slightly affected by concanamycin A, suggesting that V-Type ATPases do not have a relevant action on pHi regulation in human Sertoli cells, and was independent of the presence of bumetanide, suggesting that the inhibition of the Na+/K+/Cl−co-transporter does not affect pHi recovery, not even indirectly via the shift of ionic gradients. Finally, pHi was shown to be sensitive to the removal of external Cl−, but not of Na+or K+, evidencing the presence of a membrane Cl−-dependent base extruder, namely the Na+-independent HCO3−/Cl−exchanger, and its role on pHi maintenance on these cells.

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Deng, Qiong, Chihua He, Yong Wu, Jianwen Zhang, Ying Zhang, Zhu Wang, Hui Liang e Fei Yang. "CSN6 and Rab34 Are Involved in Androgen Receptor Trafficking in Mouse Testicular Sertoli Cells". Cellular Physiology and Biochemistry 47, n. 6 (2018): 2360–68. http://dx.doi.org/10.1159/000491608.

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Background/Aims: Androgen and its receptor (AR) play an important role in maintaining spermatogenesis and male fertility. Our previous studies showed that testosterone at a physiological concentration induces cytoplasmic AR translocation to the Sertoli cell plasma membrane of within 5 minutes. Methods: In this study, mass spectrometry (MS) and bioinformatic analyses were applied to identify candidate proteins mediating AR trafficking. The candidate proteins were knocked down by shRNA transfection. Results: Nine candidate proteins were identified by MS. The data was verified by co-immunoprecipitation and Western blot. Of the candidates, CSN6 regulated AR transport through the phosphorylation signaling pathway and Rab34 affected AR trafficking by regulating Ras activity. Conclusions: CSN6 and Rab34 are involved in AR trafficking by regulating the phosphorylation signaling pathway. These findings provide new insights into the testosterone signaling pathway in Sertoli cells that mediates spermatogenesis.

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Trejo, Raquel, Alicia Valadéz-Salazar e Graciela Delhumeau. "Effects of quercetin on rat testis aerobic glycolysis". Canadian Journal of Physiology and Pharmacology 73, n. 11 (1 novembre 1995): 1605–15. http://dx.doi.org/10.1139/y95-722.

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Lactate production by testicular fragments and isolated germinal cells at various stages of spermatogenesis was studied in aerobic and anerobic conditions. Several ATPase inhibitors were used to determine the role of ATPase activities in the control of aerobic lactate production. Aerobic glycolysis reached a high level in spermatogonia plus Sertoli cell and in primary spermatocyte populations. The activity was twice that found in early spermatids. Neither Na+–K+ ATPase nor mitochondrial F1 ATPase seemed to participate directly in the control of aerobic glycolysis. The uncoupling of oxidative phosphorylation revealed the potential role of F1 ATPase in providing ADP and Pi for the glycolytic pathway. Lactate production was inhibited by quercetin in all the experimental conditions tested. Quercetin (100 μM) halted lactate production by the Sertoli cell plus spermatogonia population and by isolated primary spermatocytes. In spermatids, quercetin inhibited aerobic glycolysis only by 40%, even at higher concentrations. Only during the first meiotic prophase did quercetin inhibit the activity of a cytosolic Ca2+–Mg2+ ATPase. This ATPase was also inhibited by erythro-9-[3-3(hydroxynonyl)]adenine (EHNA), suggesting that a cytoplasmic dynein could be involved in the control of glycolysis in Sertoli cells, spermatogonia, and early primary spermatocytes.Key words: quercetin, aerobic glycolysis, germ cells, cytosolic dynein, mitochondrial ATPase.

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Wen, Qing, Elizabeth I. Tang, Wing-yee Lui, Will M. Lee, Chris K. C. Wong, Bruno Silvestrini e C. Yan Cheng. "Dynein 1 supports spermatid transport and spermiation during spermatogenesis in the rat testis". American Journal of Physiology-Endocrinology and Metabolism 315, n. 5 (1 novembre 2018): E924—E948. http://dx.doi.org/10.1152/ajpendo.00114.2018.

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In the mammalian testis, spermatogenesis is dependent on the microtubule (MT)-specific motor proteins, such as dynein 1, that serve as the engine to support germ cell and organelle transport across the seminiferous epithelium at different stages of the epithelial cycle. Yet the underlying molecular mechanism(s) that support this series of cellular events remain unknown. Herein, we used RNAi to knockdown cytoplasmic dynein 1 heavy chain (Dync1h1) and an inhibitor ciliobrevin D to inactivate dynein in Sertoli cells in vitro and the testis in vivo, thereby probing the role of dynein 1 in spermatogenesis. Both treatments were shown to extensively induce disruption of MT organization across Sertoli cells in vitro and the testis in vivo. These changes also perturbed the transport of spermatids and other organelles (such as phagosomes) across the epithelium. These changes thus led to disruption of spermatogenesis. Interestingly, the knockdown of dynein 1 or its inactivation by ciliobrevin D also perturbed gross disruption of F-actin across the Sertoli cells in vitro and the seminiferous epithelium in vivo, illustrating there are cross talks between the two cytoskeletons in the testis. In summary, these findings confirm the role of cytoplasmic dynein 1 to support the transport of spermatids and organelles across the seminiferous epithelium during the epithelial cycle of spermatogenesis.

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PELTO-HUIKKO, M., R. SCHULTZ, J. KOISTINAHO e T. HÖKFELT. "Immunocytochemical demonstratin of c-fos protein in sertoli cells and germ cells in rat testis". Acta Physiologica Scandinavica 141, n. 2 (febbraio 1991): 283–84. http://dx.doi.org/10.1111/j.1748-1716.1991.tb09080.x.

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22

Deng, Qiong, Zeng Zhang, Yong Wu, Wang-yang Yu, Jianwen Zhang, Zhi-mao Jiang, Ying Zhang, Hui Liang e Yao-ting Gui. "Non-Genomic Action of Androgens is Mediated by Rapid Phosphorylation and Regulation of Androgen Receptor Trafficking". Cellular Physiology and Biochemistry 43, n. 1 (2017): 223–36. http://dx.doi.org/10.1159/000480343.

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Abstract (sommario):

Background: Testosterone is critical for maintaining spermatogenesis and male fertility. The accomplishment of these processes requires the synergistic actions of the classical and non-classical signaling pathways of androgens. Methods: A murine testicular Sertoli cell line, TM4 cell was used to examine androgen actions in Sertoli cells. Western blot analysis and immunofluorescence assay were employed to study the testosterone-induced Androgen receptor (AR) translocation. Protein phosphorylation antibody array was applied to identify the phosphorylation sites under testosterone treatment, and these findings were verified by Western blot analysis. Results: We found that a physiological dose of testosterone induced fast membrane association of AR. By using a phosphorylation antibody array, several phosphorylation sites, such as MEK1/2 (Ser217/221), Akt (Ser473), and Erk1/2 (Thr202/Tyr204) were rapidly phosphorylated within 5 min of testosterone treatment. Inhibition of the MEK and Akt signaling pathways prevented AR trafficking. Blocking of AR by flutamide eliminated the stimulation effect of testosterone on kinase phosphorylation. Testosterone induced kinase Src phosphorylation, and inhibition of Src restricted AR translocation to the membrane and the nucleus. Conclusion: Findings suggested that the membrane association of AR was mediated by the MEK and Akt phosphorylation signaling pathways, which resulted in Src activation and was initiated by testosterone binding to the membrane-localized AR. This study provides new insights into the testosterone signaling pathway in Sertoli cells, which mediate spermatogenesis. In addition, the study can be used in the diagnosis and treatment of male infertility caused by disorders in spermatogenesis.

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23

Ko, W. H., H. C. Chan, S. B. Chew e P. Y. D. Wong. "Regulated anion secretion in cultured epithelia from Sertoli cells of immature rats". Journal of Physiology 512, n. 2 (ottobre 1998): 471–80. http://dx.doi.org/10.1111/j.1469-7793.1998.471be.x.

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24

Frungieri, Mónica B., Ricardo S. Calandra, Artur Mayerhofer e María E. Matzkin. "Cyclooxygenase and prostaglandins in somatic cell populations of the testis". REPRODUCTION 149, n. 4 (aprile 2015): R169—R180. http://dx.doi.org/10.1530/rep-14-0392.

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Abstract (sommario):

Prostaglandins (PGs) are synthesized through the action of the rate-limiting enzyme cyclooxygenase (COX) and further specific enzymes. The development ofCox-deficient mice in the 1990s gave insights into the reproductive roles of PGs. FemaleCox-knockout mice were subfertile or infertile. Interestingly, fertility was not affected in male mice deficient inCox, suggesting that PGs may not be critical for the functioning of the testis. However, this conclusion has recently been challenged by observations of important roles for PGs in both physiological and pathological processes in the testis. The two key somatic cell types in the testis, Leydig and Sertoli cells, express the inducible isoenzyme COX2 and produce PGs. Testicular COX2 expression in these somatic cells is regulated by hormonal input (FSH, prolactin (PRL), and testosterone) as well as by IL1β. PGs modulate steroidogenesis in Leydig cells and glucose uptake in Sertoli cells. Hence, the COX2/PG system in Leydig and Sertoli cells acts as a local modulator of testicular activity, and consequently may regulate spermatogenic efficiency. In addition to its expression in Leydig and Sertoli cells, COX2 has been detected in the seminiferous tubule wall, and in testicular macrophages and mast cells of infertile patients. These observations highlight the possible relevance of PGs in testicular inflammation associated with idiopathic infertility. Collectively, these data indicate that the COX2/PG system plays crucial roles not only in testicular physiology (i.e., development, steroidogenesis, and spermatogenesis), but more importantly in the pathogenesis or maintenance of infertility status in the male gonad. Further studies of these actions could lead to new therapeutic approaches to idiopathic male infertility.Free German abstractA German translation of this abstract is freely available athttp://www.reproduction-online.org/content/149/4/R169/suppl/DC1.Free Spanish abstractA Spanish translation of this abstract is freely available athttp://www.reproduction-online.org/content/149/4/R169/suppl/DC2.

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Qian, Xiaojing, Dolores D. Mruk, Elissa W. P. Wong e C. Yan Cheng. "Breast cancer resistance protein regulates apical ectoplasmic specialization dynamics stage specifically in the rat testis". American Journal of Physiology-Endocrinology and Metabolism 304, n. 7 (1 aprile 2013): E757—E769. http://dx.doi.org/10.1152/ajpendo.00645.2012.

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Abstract (sommario):

Drug transporters determine the bioavailability of drugs in the testis behind the blood-testis barrier (BTB). Thus, they are crucial for male contraceptive development if these drugs (e.g., adjudin) exert their effects behind the BTB. Herein breast cancer resistance protein (Bcrp), an efflux drug transporter, was found to be expressed by both Sertoli and germ cells. Interestingly, Bcrp was not a component of the Sertoli cell BTB. Instead, it was highly expressed by peritubular myoid cells at the tunica propria and also endothelial cells of the microvessels in the interstitium at all stages of the epithelial cycle. Unexpectedly, Bcrp was found to be expressed at the Sertoli-step 18–19 spermatid interface but limited to stage VI-early VIII tubules, and an integrated component of the apical ectoplasmic specialization (apical ES). Apparently, Bcrp is being used by late-stage spermatids to safeguard their completion of spermiogenesis by preventing harmful drugs to enter these cells while they transform to spermatozoa. Also, the association of Bcrp with actin, Eps8 (epidermal growth factor receptor pathway substrate 8, an actin barbed end capping and bundling protein), and Arp3 (actin-related protein 3, a component of the Arp2/3 complex known to induce branched actin polymerization) at the apical ES suggest that Bcrp may be involved in regulating the organization of actin filament bundles at the site. Indeed, a knockdown of Bcrp by RNAi in the testis perturbed the apical ES function, disrupting spermatid polarity and adhesion. In summary, Bcrp is a regulator of the F-actin-rich apical ES in the testis.

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Yan, Ming, Linxi Li, Baiping Mao, Huitao Li, Stephen Y. T. Li, Dolores Mruk, Bruno Silvestrini, Qingquan Lian, Renshan Ge e C. Yan Cheng. "mTORC1/rpS6 signaling complex modifies BTB transport function: an in vivo study using the adjudin model". American Journal of Physiology-Endocrinology and Metabolism 317, n. 1 (1 luglio 2019): E121—E138. http://dx.doi.org/10.1152/ajpendo.00553.2018.

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Abstract (sommario):

Studies have shown that the mTORC1/rpS6 signaling cascade regulates Sertoli cell blood-testis barrier (BTB) dynamics. For instance, specific inhibition of mTORC1 by treating Sertoli cells with rapamycin promotes the Sertoli cell barrier, making it “tighter.” However, activation of mTORC1 by overexpressing a full-length rpS6 cDNA clone (i.e., rpS6-WT, wild type) in Sertoli cells promotes BTB remodeling, making the barrier “leaky.” Also, there is an increase in rpS6 and p-rpS6 (phosphorylated and activated rpS6) expression at the BTB in testes at stages VIII–IX of the epithelial cycle, and it coincides with BTB remodeling to support the transport of preleptotene spermatocytes across the barrier, illustrating that rpS6 is a BTB-modifying signaling protein. Herein, we used a constitutively active, quadruple phosphomimetic mutant of rpS6, namely p-rpS6-MT of p-rpS6-S235E/S236E/S240E/S244E, wherein Ser (S) was converted to Glu (E) at amino acid residues 235, 236, 240, and 244 from the NH2 terminus by site-directed mutagenesis, for its overexpression in rat testes in vivo using the Polyplus in vivo jet-PEI transfection reagent with high transfection efficiency. Overexpression of this p-rpS6-MT was capable of inducing BTB remodeling, making the barrier “leaky.” This thus promoted the entry of the nonhormonal male contraceptive adjudin into the adluminal compartment in the seminiferous epithelium to induce germ cell exfoliation. Combined overexpression of p-rpS6-MT with a male contraceptive (e.g., adjudin) potentiated the drug bioavailability by modifying the BTB. This approach thus lowers intrinsic drug toxicity due to a reduced drug dose, further characterizing the biology of BTB transport function.

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Oliveira, P. F., M. Sousa, A. Barros, T. Moura e A. Rebelo da Costa. "Membrane Transporters and Cytoplasmatic pH Regulation on Bovine Sertoli Cells". Journal of Membrane Biology 227, n. 1 (3 dicembre 2008): 49–55. http://dx.doi.org/10.1007/s00232-008-9139-z.

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28

Rocha, A. B., F. C. R. Guma, E. A. Casali, G. S. Scherer, M. A. Elena e E. A. Bernard. "Influence of the Biomatrix on the Response of Sertoli Cells to FSH". Archives of Physiology and Biochemistry 105, n. 5 (gennaio 1997): 473–77. http://dx.doi.org/10.1076/apab.105.5.473.3288.

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29

Pelletier, R. Marc, Suk Ran Yoon, Casimir D. Akpovi, Emil Silvas e María Leiza Vitale. "Defects in the regulatory clearance mechanisms favor the breakdown of self-tolerance during spontaneous autoimmune orchitis". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 296, n. 3 (marzo 2009): R743—R762. http://dx.doi.org/10.1152/ajpregu.90751.2008.

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Abstract (sommario):

We identified aberrations leading to spontaneous autoimmune orchitis (AIO) in mink, a seasonal breeder and natural model for autoimmunity. This study provides evidence favoring the view that a malfunction of the clearance mechanisms for apoptotic cell debris arising from imbalances in phagocyte receptors or cytokines acting on Sertoli cells constitutes a major factor leading to breakdown of self-tolerance during spontaneous AIO. Serum anti-sperm antibody titers measured by ELISA reflected spermatogenic activity without causing immune inflammatory responses. Orchitic mink showed excess antibody production accompanied by spermatogenic arrest, testicular leukocyte infiltration, and infertility. AIO serum labeled the postacrosomal region, the mid and end piece of mink sperm, whereas normal mink serum did not. Normal serum labeled plasma membranes, whereas AIO serum reacted with germ cell nuclei. Western blot analyses revealed that AIO serum reacted specifically to a 23- and 50-kDa protein. The number of apostain-labeled apoptotic cells was significantly higher in orchitic compared with normal tubules. However, apoptosis levels measured by ELISA in seminiferous tubular fractions (STf) were not significantly different in normal and orchitic tubules. The levels of CD36, TNF-α, TNF-α RI, IL-6, and Fas but not Fas-ligand (L), and ATP-binding cassette transporter ABCA1 were changed in AIO STf. TNF-α and IL-6 serum levels were increased during AIO. Fas localized to germ cells, Sertoli cells, and the lamina propria of the tubules and Fas-L, to germ cells. Fas colocalized with Fas-L in residual bodies in normal testis and in giant cells and infiltrating leukocytes in orchitic tubules.

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Vigodner, Margarita, Tomomoto Ishikawa, Peter N. Schlegel e Patricia L. Morris. "SUMO-1, human male germ cell development, and the androgen receptor in the testis of men with normal and abnormal spermatogenesis". American Journal of Physiology-Endocrinology and Metabolism 290, n. 5 (maggio 2006): E1022—E1033. http://dx.doi.org/10.1152/ajpendo.00527.2005.

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Abstract (sommario):

Sumoylation affects multiple cellular events, including chromatin inactivation and transcriptional repression. Our data provide the first characterization of small ubiquitin-related modifier-1 (SUMO-1) expression during human spermatogenesis by the use of high-resolution cellular SUMO-1 bioimaging. During human meiotic prophase, SUMO-1 localizes to sex chromosomes and centromeric and pericentromeric chromatin. As human spermatocytes progress toward the end of prophase in meiosis I, SUMO-1 is no longer detected within the sex body and pericentromeric heterochromatin but localizes exclusively to centromeres. SUMO-1 localization along sex chromosome axes, pseudoautosomal region, and centromeres of both chromosomes supports a role for SUMO-1 sumoylation in epigenetic events occurring over the entire sex body, e.g., meiotic sex chromosome inactivation and chromatin condensation. Centromeric SUMO-1 throughout meiotic prophase suggests a role in centromeric chromatin condensation and/or other centromere/kinetochore functions. SUMO-1 is likely involved in both facultative and constitutive heterochromatin processes in spermatocytes. Haploid round spermatids show a consistent association of SUMO-1 with centromeric clusters. During spermatid elongation, SUMO-1 localizes in the manchette perinuclear ring. Steroidogenic Leydig cells show some cytoplasmic but strong nuclear and perinuclear SUMO-1. Peritubular myoepithelial cell SUMO-1 colocalizes with centromeric heterochromatin. In epithelial Sertoli cells, when associated with centromeric heterochromatin, SUMO-1 is adjacent but not colocalized with the nucleolus. Male germ cells demonstrate no SUMO-1 nucleolar association. Human and rodent Sertoli cells consistently show an inverse correlation between androgen receptor (AR) and SUMO-1 expression and compartmentalization. Sertoli cells from certain infertile patients, however, showed greatly decreased SUMO-1 and AR. Our data suggest that human testicular SUMO-1 has specific functions in heterochromatin organization, meiotic centromere function, and gene expression.

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Lasala, Celina, Helena F. Schteingart, Nassim Arouche, Patricia Bedecarrás, Romina P. Grinspon, Jean-Yves Picard, Nathalie Josso, Nathalie di Clemente e Rodolfo A. Rey. "SOX9 and SF1 are involved in cyclic AMP-mediated upregulation of anti-Müllerian gene expression in the testicular prepubertal Sertoli cell line SMAT1". American Journal of Physiology-Endocrinology and Metabolism 301, n. 3 (settembre 2011): E539—E547. http://dx.doi.org/10.1152/ajpendo.00187.2011.

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Abstract (sommario):

In Sertoli cells, anti-Müllerian hormone (AMH) expression is upregulated by FSH via cyclic AMP (cAMP), although no classical cAMP response elements exist in the AMH promoter. The response to cAMP involves NF-κB and AP2; however, targeted mutagenesis of their binding sites in the AMH promoter do not completely abolish the response. In this work we assessed whether SOX9, SF1, GATA4, and AP1 might represent alternative pathways involved in cAMP-mediated AMH upregulation, using real-time RT-PCR (qPCR), targeted mutagenesis, luciferase assays, and immunocytochemistry in the Sertoli cell line SMAT1. We also explored the signaling cascades potentially involved. In qPCR experiments, Amh, Sox9, Sf1, and Gata4 mRNA levels increased after SMAT1 cells were incubated with cAMP. Blocking PKA abolished the effect of cAMP on Sox9, Sf1, and Gata4 expression, inhibiting PI3K/PKB impaired the effect on Sf1 and Gata4, and reducing MEK1/2 and p38 MAPK activities curtailed Gata4 increase. SOX9 and SF1 translocated to the nucleus after incubation with cAMP. Mutations of the SOX9 or SF1 sites, but not of GAT4 or AP1 sites, precluded the response of a 3,063-bp AMH promoter to cAMP. In conclusion, in the Sertoli cell line SMAT1 cAMP upregulates SOX9, SF1, and GATA4 expression and induces SOX9 and SF1 nuclear translocation mainly through PKA, although other kinases may also participate. SOX9 and SF1 binding to the AMH promoter is essential to increase the activity of the AMH promoter in response to cAMP.

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Brauchi, Sebastian, Maria C. Rauch, Ivan E. Alfaro, Christian Cea, Ilona I. Concha, Dale J. Benos e Juan G. Reyes. "Kinetics, molecular basis, and differentiation of l-lactate transport in spermatogenic cells". American Journal of Physiology-Cell Physiology 288, n. 3 (marzo 2005): C523—C534. http://dx.doi.org/10.1152/ajpcell.00448.2003.

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Abstract (sommario):

Round spermatid energy metabolism is closely dependent on the presence of l-lactate in the external medium. This l-lactate has been proposed to be supplied by Sertoli cells in the seminiferous tubules. l-Lactate, in conjunction with glucose, modulates intracellular Ca2+ concentration in round spermatids and pachytene spermatocytes. In spite of this central role of l-lactate in spermatogenic cell physiology, the mechanism of l-lactate transport, as well as possible differentiation during spermatogenesis, has not been studied in these cells. By measuring radioactive l-lactate transport and intracellular pH (pHi) changes with pHi fluorescent probes, we show that these cells transport l-lactate using monocarboxylate-H+ transport (MCT) systems. RT-PCR, in situ mRNA hybridization, and immunocyto- and immunohistochemistry data show that pachytene spermatocytes express mainly the MCT1 and MCT4 isoforms of the transporter (intermediate- and low-affinity transporters, respectively), while round spermatids, besides MCT1 and MCT4, also show expression of the MCT2 isoform (high-affinity transporter). These molecular data are consistent with the kinetic data of l-lactate transport in these cells demonstrating at least two transport components for l-lactate. These separate transport components reflect the ability of these cells to switch between the generation of glycolytic l-lactate in the presence of external glucose and the use of l-lactate when this substrate is available in the external environment. The supply of these substrates is regulated by the hormonal control of Sertoli cell glycolytic activity.

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Casali, E. A., T. R. da Silva, D. P. Gelain, G. R. R. F. Kaiser, A. M. O. Battastini, J. J. F. Sarkis e E. A. Bernard. "Ectonucleotidase activities in Sertoli cells from immature rats". Brazilian Journal of Medical and Biological Research 34, n. 10 (ottobre 2001): 1247–56. http://dx.doi.org/10.1590/s0100-879x2001001000003.

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34

Fenton, R. A., G. J. Cooper, I. D. Morris e C. P. Smith. "Coordinated expression of UT-A and UT-B urea transporters in rat testis". American Journal of Physiology-Cell Physiology 282, n. 6 (1 giugno 2002): C1492—C1501. http://dx.doi.org/10.1152/ajpcell.00567.2001.

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Abstract (sommario):

The blood-seminiferous tubule barrier is responsible for maintaining the unique microenvironment conducive to spermatogenesis. A key feature of the blood-testis barrier is selective permeability to solutes and water transport, conferred by the Sertoli cells of the seminiferous tubules (SMTs). Movement of fluid into the lumen of the seminiferous tubule is crucial to spermatogenesis. By Northern analysis, we have shown that 4.0-, 3.3-, 2.8-, and ∼1.7-kb UT-A mRNA transcripts and a 3.8-kb UT-B mRNA transcript are detected within rat testis. Western analysis revealed the expression of both characterized and novel UT-A and UT-B proteins within the testis. Immunolocalization studies determined that UT-A and UT-B protein expression are coordinated with the developmental stage of the SMT. UT-A proteins were detected in Sertoli cell nuclei at all stages of tubule development and in residual bodies of stage VIII tubules. UT-B protein was expressed on Sertoli cell membranes of stage II–III tubules. Using in vitro perfusion, we determined that a phloretin-inhibitable urea pathway exists across the SMTs of rat testis and conclude that UT-B is likely to participate in this pathway.

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35

Christiansen, T., B. Korsgaard e A. Jespersen. "Effects of nonylphenol and 17 beta-oestradiol on vitellogenin synthesis, testicular structure and cytology in male eelpout Zoarces viviparus." Journal of Experimental Biology 201, n. 2 (15 gennaio 1998): 179–92. http://dx.doi.org/10.1242/jeb.201.2.179.

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Abstract (sommario):

Nonylphenol has been found to be oestrogenic in fish and may influence the reproductive system of male fish. In the present study, the effects of low (10 microg g-1 week-1) and high (100 microg g-1 week-1) doses of nonylphenol and of 17 beta-oestradiol on the synthesis of vitellogenin and on testicular structure and cytology were investigated in male eelpout Zoarces viviparus during active spermatogenesis (May) and late spermatogenesis (June). Twenty-five days after injection, a significant dose-dependent increase in the plasma vitellogenin concentration, measured by enzyme-linked immunosorbent assay, was observed in the treated groups. A highly significant reduction in the gonadosomatic index was observed concomitant with the increase in the plasma vitellogenin concentration. Macroscopically, milt was observed to be present in the control fish, but was sparse or absent in the treated fish. Histological examination using light microscopy revealed severe effects of nonylphenol as well as of oestradiol treatment on testicular structure. Control fish had seminiferous lobules containing spermatogenic cysts and only a few spermatozoa (May) or had the walls of their seminiferous lobules lined with cuboidal Sertoli cells (June). In the treated fish, the seminiferous lobules were degenerated (May) or were filled with numerous spermatozoa and the Sertoli cells appeared very squamous (June). Electron microscopy revealed greater numbers of phagocytosed spermatozoa in these Sertoli cells. In rats, -glutamyl transpeptidase (-GTP) has been used as a specific marker of Sertoli cell function. In the present study, both nonylphenol and 17 beta-oestradiol treatment resulted in a reduction in the activity of this enzyme. The study provides evidence that nonylphenol is oestrogenic, as indicated by the large increase in vitellogenin synthesis, and that both nonylphenol and oestradiol have marked effects on the testicular structure and cytology of germ cells and Sertoli cells of male Z. viviparus.

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Yoon, Kyung-Ae, Young-Mi Chae e Je-Yoel Cho. "FGF2 stimulates SDF-1 expression through theErmtranscription factor in Sertoli cells". Journal of Cellular Physiology 220, n. 1 (luglio 2009): 245–56. http://dx.doi.org/10.1002/jcp.21759.

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37

Leichtmann-Bardoogo, Yael, Lyora A. Cohen, Avital Weiss, Britta Marohn, Stephanie Schubert, Andreas Meinhardt e Esther G. Meyron-Holtz. "Compartmentalization and regulation of iron metabolism proteins protect male germ cells from iron overload". American Journal of Physiology-Endocrinology and Metabolism 302, n. 12 (15 giugno 2012): E1519—E1530. http://dx.doi.org/10.1152/ajpendo.00007.2012.

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Abstract (sommario):

The universal importance of iron, its high toxicity, and complex chemistry present a challenge to biological systems in general and to protected compartments in particular. The high mitotic rate and avid mitochondriogenesis of developing male germ cells imply high iron requirements. Yet access to germ cells is tightly regulated by the blood-testis barrier that protects the meiotic and postmeiotic germ cells. To elucidate how iron is supplied to developing male germ cells, we analyzed iron deposition and iron transport proteins in testes of mice with iron overload and with genetic ablation of the iron regulators Hfe and iron regulatory protein 2. Iron accumulated mainly around seminiferous tubules, and only small amounts localized within the seminiferous tubules. The localization and regulation of proteins involved in iron import, storage, and export such as transferrin, transferrin receptor, the divalent metal transporter-1, cytosolic ferritin, and ferroportin strongly support a model of a largely autonomous iron cycle within seminiferous tubules. We show evidence that ferritin secretion from Sertoli cells may play an important role in iron acquisition of primary spermatocytes. During spermatogenic development iron is carried along from primary spermatocytes to spermatids, and from spermatids iron is recycled to the apical compartment of Sertoli cells, which traffic it back to a new generation of spermatocytes. Losses are replenished by the peripheral circulation. Such an internal iron cycle essentially detaches the iron homeostasis within the seminiferous tubule from the periphery and protects developing germ cells from iron fluctuations. This model explains how compartmentalization can optimize cellular and systemic nutrient homeostasis.

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Tung, Pierre S., e Irving B. Fritz. "Role of laminin in the Morphogenetic cascade during Coculture of sertoli cells with peritubular cells". Journal of Cellular Physiology 161, n. 1 (ottobre 1994): 77–88. http://dx.doi.org/10.1002/jcp.1041610111.

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39

Akerstrom, V. L., e M. R. Walters. "Physiological effects of 1,25-dihydroxyvitamin D3 in TM4 Sertoli cell line". American Journal of Physiology-Endocrinology and Metabolism 262, n. 6 (1 giugno 1992): E884—E890. http://dx.doi.org/10.1152/ajpendo.1992.262.6.e884.

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Abstract (sommario):

1,25-Dihydroxyvitamin D3 [1,25(OH)2D3] receptors have been previously described in Sertoli cells. This study was performed to assess biological activity of the receptor in the mouse Sertoli cell line TM4. A 2-h preincubation with 0.01-25 nM 1,25(OH)2D3 resulted in a dose-dependent rapid uptake of 45Ca2+ within 5 min of addition of the isotope to the cells (27 +/- 8%, n = 4 experiments; P less than 0.05). This response was specific for 1,25(OH)2D3, in that it was not induced by 25-hydroxyvitamin D3, estradiol, cortisol, R 5020 (promegestone), or testosterone. However, a combination of testosterone and 1,25(OH)2D3 inhibited uptake by 23 +/- 8% (n = 3 experiments, P less than 0.01). That the mechanism responsible for 1,25(OH)2D3-stimulated uptake may involve 1,25(OH)2D3 receptor interaction is supported by the observation that cycloheximide inhibited the response. Conversely, there was no detectable change in uptake by 1,25(OH)2D3-treated cells after 24-h incubation with 0.1-5 nM 1,25(OH)2D3. Increased levels of DNA and protein content also resulted from a 2-h incubation with the steroid and were sustained up to 24 h without a concomitant increase in cell number or a detectable change in cell morphology. The presence of specific 1,25(OH)2D3 receptor-like binding sites was demonstrated by sucrose gradient analysis and hydroxylapatite assay. These data demonstrate that 1,25(OH)2D3 may play an important role in testicular function through regulation of receptor-mediated events.

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Bernardino, Raquel, David Carrageta, Ana Silva, Giuseppe Calamita, Marco Alves, Graça Soveral e Pedro Oliveira. "Estrogen Modulates Glycerol Permeability in Sertoli Cells through Downregulation of Aquaporin-9". Cells 7, n. 10 (28 settembre 2018): 153. http://dx.doi.org/10.3390/cells7100153.

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Abstract (sommario):

High 17β-Estradiol (E2) levels are known to cause alterations of spermatogenesis and environments throughout the male reproductive tract. Sertoli cells (SCs) ensure an adequate environment inside the seminiferous tubule. Glycerol stands as essential for the maintenance of blood–testis barrier created by SCs, however, the role of E2 in this process is not known. Herein, we hypothesized that the effect of E2 on glycerol permeability in mouse SCs (mSCs) could be mediated by aquaglyceroporins. The expression of aquaglyceroporins was assessed by RT-PCR and qRT-PCR. Glycerol permeability was evaluated by stopped-flow light scattering. We were able to identify the expression of AQP3 and AQP9 in mSCs where AQP9 is more abundant than AQP3. Our results show that high E2 levels decrease AQP9 mRNA abundance with no influence on AQP3 in mSCs. Interestingly, high E2 levels decreased mSCs’ permeability to glycerol, while downregulating AQP9 expression, thus suggesting a novel mechanism by which E2 modulates fluid secretion in the testis. In conclusion, E2 is an important regulator of mSCs physiology and secretion through changes in AQP9 expression and function. Thus, alterations in glycerol permeability induced by E2 may be the cause for male infertility in cases associated with the presence of high E2 levels.

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Huynh, S., H. Oulhaj, J. Bocquet e A. Nouvelot. "Metabolic utilization of linoleate and α-linolenate in cultured Sertoli cells". Comparative Biochemistry and Physiology Part B: Comparative Biochemistry 99, n. 2 (gennaio 1991): 265–70. http://dx.doi.org/10.1016/0305-0491(91)90039-g.

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42

Fiorini, Celine, Xavier Decrouy, Norah Defamie, Dominique Segretain e Georges Pointis. "Opposite regulation of connexin33 and connexin43 by LPS and IL-1α in spermatogenesis". American Journal of Physiology-Cell Physiology 290, n. 3 (marzo 2006): C733—C740. http://dx.doi.org/10.1152/ajpcell.00106.2005.

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Abstract (sommario):

The gap junction proteins, connexins (Cxs), are present in the testis, and among them, Cx43 play an essential role in spermatogenesis. In the present study, we investigated the testicular expression and regulation of another Cx, Cx33, previously described as a negative regulator of gap junction communication. Cx33 mRNA was present in testis and undetectable in heart, liver, ovary, and uterus. In the mature testis, Cx33 was specifically immunolocalized in the basal compartment of the seminiferous tubules, whereas Cx43 was present in both seminiferous tubule and interstitial compartments. During stages IX and X of spermatogenesis, characterized by Sertoli cell phagocytosis of residual bodies, Cx43 was poorly expressed within seminiferous tubules, while Cx33 signal was strong. To evaluate the role of phagocytosis in the control of Cx33 and Cx43 expression, the effect of LPS was analyzed in the Sertoli cell line 42GPA9. We show herein that phagocytosis activation by LPS concomitantly stimulated Cx33 and inhibited Cx43 mRNA levels. These effects appear to have been mediated through IL-1α, because the exposure of Sertoli cells to the IL-1 receptor antagonist partly reversed these effects. IL-1α enhanced and reduced, respectively, the levels of Cx33 and Cx43 mRNA in a time- and dose-dependent manner. These data reveal that Cx33 and Cx43 genes are controlled differently within the testis and suggest that these two Cxs may exert opposite and complementary effects on spermatogenesis.

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Cameron, D. F., J. Rountree, R. E. Schultz, D. Repetta e F. T. Murray. "Sustained hyperglycemia results in testicular dysfunction and reduced fertility potential in BBWOR diabetic rats". American Journal of Physiology-Endocrinology and Metabolism 259, n. 6 (1 dicembre 1990): E881—E889. http://dx.doi.org/10.1152/ajpendo.1990.259.6.e881.

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Rats with short-term diabetes show a greater than 50% reduction of serum testosterone and increased lipid in Leydig cells but normal testicular structure. The purpose of this study was to determine the extent of testicular pathology (morphology index), integrity of the blood-testis barrier, daily sperm production (DSP), number of Leydig cells per testis (LC/T), and total trunk testosterone (TTT) in diabetic rats (BBWORdp) with long-term hyperglycemia (300-350 mg/dl for greater than 180 days) and to evaluate its effects on fertility potential. Results were compared with similarly aged normoglycemic rats (BBWORdr) and normal control Wistar rats. After 6 mo of diabetes, testis weights, DSPs, TTTs, and the morphology index were significantly reduced. The LC/T was not different from BBWORdr rats. The blood-testis barrier appeared intact, although structural abnormalities were noted in Sertoli-Sertoli junction complexes. There was a significant reduction in the number of pregnancies per rat and implantations per pregnancy in matings utilizing the diabetic BBWORdp rat and control Wistar female rats. Results indicate that long-term diabetes with sustained hyperglycemia leads to significant testicular dysfunction associated with decreased fertility potential.

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Niu, Qiaoge, Maosheng Cao, Chenfeng Yuan, Yuwen Huang, Zijiao Zhao, Boqi Zhang, Xin Wang et al. "Effect of nerve growth factor on the proliferation in newborn bovine testicular Sertoli cells". Reproduction 160, n. 3 (settembre 2020): 405–15. http://dx.doi.org/10.1530/rep-19-0601.

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Nerve growth factor (NGF) has been proved to play important roles in male reproductive physiology, but the molecular mechanisms of NGF action remain unclear. In this study, the effects of NGF on the growth of newborn bovine testicular Sertoli (NBS) cells and the related signaling pathways were investigated. The NBS cells were treated in vitro with NGF (100 ng/mL) for 18 h. The expression levels of cell proliferation related genes, INHBB, and cytoplasmic specialization related gene were determined using real-time PCR and Western blot. The roles of PI3K/AKT and MAPK/ERK pathways in NGF-induced cell proliferation were investigated. It was found that NGF regulates proliferation and function of NBS cells via its receptor NTRK1 by activating the PI3K/ATK and MAPK/ERK signaling pathways. The study will help to further understand the role of NGF in male reproduction and provide new therapeutic targets for reproductive dysfunctions in male animals.

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Kishi, Hisashi, Mariko Itoh, Sachiko Wada, Yoko Yukinari, Yumiko Tanaka, Natsuko Nagamine, Wanzhu Jin, Gen Watanabe e Kazuyoshi Taya. "Inhibin is an important factor in the regulation of FSH secretion in the adult male hamster". American Journal of Physiology-Endocrinology and Metabolism 278, n. 4 (1 aprile 2000): E744—E751. http://dx.doi.org/10.1152/ajpendo.2000.278.4.e744.

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We investigated the importance of inhibin and testosterone in the regulation of gonadotropin secretion in adult male golden hamsters ( Mesocricetus auratus). After castration, plasma concentrations of inhibin and testosterone were reduced to undetectable, whereas plasma follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were increased. After hemicastration, plasma FSH and LH increased moderately and plasma inhibin decreased to one-half its initial level. Plasma testosterone levels in hemicastrated animals decreased 3 h after hemicastration but returned to those in sham-operated animals at 6 h. Plasma LH in the castrated hamster declined comparably to intact animals with testosterone treatment; plasma FSH also decreased but still remained at levels higher than those in intact animals. After treatment with inhibin in long-term-castrated animals, plasma FSH decreased, whereas plasma LH was not altered. Intact males treated with flutamide, an anti-androgen, showed a significant increase in plasma LH but not in FSH. On the other hand, treatment with anti-inhibin serum induced a significant elevation in plasma FSH, but not in LH. Using immunohistochemistry, we showed that the inhibin α-subunit was localized to both Sertoli and Leydig cells. The present study in adult male hamsters indicates that FSH secretion is regulated mainly by inhibin, presumably from Sertoli and Leydig cells, and that LH secretion is controlled primarily by androgens produced from the Leydig cells. This situation is more similar to that of primates than of rats.

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Dias, Tania Rodrigues, Raquel Lages Bernardino, Marco Gouveia Alves, Joaquina Silva, Alberto Barros, Mário Sousa, Susana Casal, Branca Maria Silva e Pedro Fontes Oliveira. "L-theanine modulates human Sertoli cells metabolic and mitochondrial function while maintaining redox homeostasis". Free Radical Biology and Medicine 120 (maggio 2018): S150. http://dx.doi.org/10.1016/j.freeradbiomed.2018.04.496.

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Michailidis, Georgios, Maria Anastasiadou, Edith Guibert e Pascal Froment. "Activation of innate immune system in response to lipopolysaccharide in chicken Sertoli cells". REPRODUCTION 148, n. 3 (settembre 2014): 259–70. http://dx.doi.org/10.1530/rep-14-0064.

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Abstract (sommario):

Sertoli cells (SCs) play an important physiological role in the testis, as they support, nourish, and protect the germ cells. As protection of the developing spermatozoa is an emerging aspect of reproductive physiology, this study examined the expression pattern of innate immune-related genes, including avian β-defensins (AvBDs), Toll-like receptors (TLRs), and cytokines, and investigated the time course of an inflammatory response in rooster SCs triggered by exposure to the bacterial endotoxin lipopolysaccharide (LPS). SCs were isolated from 6-week-old chicken, culturedin vitro, and stimulated with 1 μg/ml LPS at different time courses (0, 6, 12, 24, and 48 h). Data on expression analysis revealed that all ten members of the chickenTLRfamily, nine members of theAvBDfamily, as well as eight cytokine genes were expressed in SCs. Quantitative real-time PCR analysis revealed that LPS treatment resulted in significant induction of the expression levels of sixTLRs, sixAvBDs, and four cytokine genes, while two cytokine genes were downregulated and two other genes were unchanged. The increasing interleukin 1β (IL1β) production was confirmed in the conditioned medium. Furthermore, the phagocytosis of SCs was increased after LPS treatment. In conclusion, these findings provide evidence that SCs express innate immune-related genes and respond directly to bacterial ligands. These genes represent an important component of the immune system, which could be integrated into semen, and present a distinctive constituent of the protective repertoire of the testis against ascending infections.

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Abdullah, Munir, James A. Crowell, Laura L. Tres e Abraham L. Kierszenbaum. "Fetuin: A serum component associated with rat sertoli and spermatogenic cells in coculture". Journal of Cellular Physiology 127, n. 3 (giugno 1986): 463–72. http://dx.doi.org/10.1002/jcp.1041270317.

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Mitic, Laura L., Christina M. Van Itallie e James M. Anderson. "Molecular Physiology and Pathophysiology of Tight Junctions I. Tight junction structure and function: lessons from mutant animals and proteins". American Journal of Physiology-Gastrointestinal and Liver Physiology 279, n. 2 (1 agosto 2000): G250—G254. http://dx.doi.org/10.1152/ajpgi.2000.279.2.g250.

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Tight junctions form the major paracellular barrier in epithelial tissues. Barrier-sealing properties are quite variable among cell types in terms of electrical resistance, solute and water flux, and charge selectivity. A molecular explanation for this variability appears closer following identification of the transmembrane proteins occludin and members of the claudin multigene family. For example, the human phenotype of mutations in claudin-16 suggests that it creates a channel that allows magnesium to diffuse through renal tight junctions. Similarly, a mouse knockout of claudin-11 reveals its role in formation of tight junctions in myelin and between Sertoli cells in testis. The study of other claudins is expected to elucidate their contributions to creating junction structure and physiology in all epithelial tissues.

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Heindel, JerroldJ, CassandraJ Powell, CarlS Paschall, Akira Arimura e MichaelD Culler. "PACAP stimulates cAMP accumulation and secretory function in cultured rat sertoli cells". Regulatory Peptides 37, n. 3 (febbraio 1992): 333. http://dx.doi.org/10.1016/0167-0115(92)90645-b.

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