scholarly journals Connexin43 in Germ Cells Seems to Be Dispensable for Murine Spermatogenesis

2021 ◽  
Vol 22 (15) ◽  
pp. 7924
Author(s):  
Kristina Rode ◽  
Marion Langeheine ◽  
Bettina Seeger ◽  
Ralph Brehm
Keyword(s):  
Protein Synthesis ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Qrt Pcr ◽  
Successful Termination ◽  
Cx43 Mrna ◽  
Quantitative Western Blot ◽  
Testicular Histology ◽  
Tubular Diameter ◽  
Mouse Lines

Testicular Connexin43 (Cx43) connects adjacent Sertoli cells (SC) and SC to germ cells (GC) in the seminiferous epithelium and plays a crucial role in spermatogenesis. However, the distinction whether this results from impaired inter-SC communication or between GC and SC is not possible, so far. Thus, the question arises, whether a GC-specific Cx43 KO has similar effects on spermatogenesis as it is general or SC-specific KO. Using the Cre/loxP recombinase system, two conditional KO mouse lines lacking Cx43 in premeiotic (pGCCx43KO) or meiotic GC (mGCCx43KO) were generated. It was demonstrated by qRT-PCR that Cx43 mRNA was significantly decreased in adult pGCCx43KO mice, while it was also reduced in mGCCx43KO mice, yet not statistically significant. Body and testis weights, testicular histology, tubular diameter, numbers of intratubular cells and Cx43 protein synthesis and localization did not show any significant differences in semi-quantitative Western blot analysis and immunohistochemistry comparing adult male KO and WT mice of both mouse lines. Male KO mice were fertile. These results indicate that Cx43 in spermatogonia/spermatids does not seem to be essential for successful termination of spermatogenesis and fertility as it is known for Cx43 in somatic SC, but SC-GC communication might rather occur via heterotypic GJ channels.

Freeze-etch observations on the tight junctions of sertoli cells grown in organ culture with FSH

1978 ◽  
Vol 36 (2) ◽  
pp. 340-341
Author(s):  
Rita Meyer ◽  
Zoltan Posalaky ◽  
Dennis Mcginley
Keyword(s):  
Organ Culture ◽  
Tight Junctions ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Barrier Function ◽  
Cell Junction ◽  
Intramembranous Particles ◽  
Junctional Complexes ◽  
Oriented Parallel

The Sertoli cell tight junctional complexes have been shown to be the most important structural counterpart of the physiological blood-testis barrier. In freeze etch replicas they consist of extensive rows of intramembranous particles which are not only oriented parallel to one another, but to the myoid layer as well. Thus the occluding complex has both an internal and an overall orientation. However, this overall orientation to the myoid layer does not seem to be necessary to its barrier function. The 20 day old rat has extensive parallel tight junctions which are not oriented with respect to the myoid layer, and yet they are inpenetrable by lanthanum. The mechanism(s) for the control of Sertoli cell junction development and orientation has not been established, although such factors as the presence or absence of germ cells, and/or hormones, especially FSH have been implicated.

Development of Testis Cords and the Formation of Efferent Ducts in Xenopus laevis: Differences and Similarities with Other Vertebrates

2021 ◽  
pp. 1-14
Author(s):  
Yuanyuan Li ◽  
Jinbo Li ◽  
Man Cai ◽  
Zhanfen Qin
Keyword(s):  
Cell Proliferation ◽  
Xenopus Laevis ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Testis Development ◽  
Larval Stages ◽  
Efferent Ducts ◽  
Steroidogenic Cells ◽  
Testis Cord ◽  
Anterior Posterior

The knowledge of testis development in amphibians relative to amniotes remains limited. Here, we used Xenopus laevis to investigate the process of testis cord development. Morphological observations revealed the presence of segmental gonomeres consisting of medullary knots in male gonads at stages 52–53, with no distinct gonomeres in female gonads. Further observations showed that cell proliferation occurs at specific sites along the anterior-posterior axis of the future testis at stage 50, which contributes to the formation of medullary knots. At stage 53, adjacent gonomeres become close to each other, resulting in fusion; then (pre-)Sertoli cells aggregate and form primitive testis cords, which ultimately become testis cords when germ cells are present inside. The process of testis cord formation in X. laevis appears to be more complex than in amniotes. Strikingly, steroidogenic cells appear earlier than (pre-)Sertoli cells in differentiating testes of X. laevis, which differs from earlier differentiation of (pre-)Sertoli cells in amniotes. Importantly, we found that the mesonephros is connected to the testis gonomere at a specific site at early larval stages and that these connections become efferent ducts after metamorphosis, which challenges the previous concept that the mesonephric side and the gonadal side initially develop in isolation and then connect to each other in amphibians and amniotes.

Defects in the regulatory clearance mechanisms favor the breakdown of self-tolerance during spontaneous autoimmune orchitis

2009 ◽  
Vol 296 (3) ◽  
pp. R743-R762 ◽  
Author(s):  
R.-Marc Pelletier ◽  
Suk Ran Yoon ◽  
Casimir D. Akpovi ◽  
Emil Silvas ◽  
María Leiza Vitale
Keyword(s):  
Germ Cells ◽  
Sertoli Cells ◽  
Plasma Membranes ◽  
Fas Ligand ◽  
Inflammatory Responses ◽  
Apoptotic Cell ◽  
Self Tolerance ◽  
Tnf Α ◽  
Fas L ◽  
Autoimmune Orchitis

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.

Expression and localization of androgen receptor-interacting protein-4 in the testis

2007 ◽  
Vol 292 (2) ◽  
pp. E513-E522 ◽  
Author(s):  
Andrii Domanskyi ◽  
Fu-Ping Zhang ◽  
Mirja Nurmio ◽  
Jorma J. Palvimo ◽  
Jorma Toppari ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Hormone Receptor ◽  
Luteinizing Hormone Receptor ◽  
Dependent Manner ◽  
Cell Nuclei ◽  
Interacting Protein ◽  
Independent Functions

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.

scholarly journals Cell-type-specific regulation of genes involved in testicular lipid metabolism: fatty acid-binding proteins, diacylglycerol acyltransferases, and perilipin 2

Reproduction ◽  
2013 ◽  
Vol 146 (5) ◽  
pp. 471-480 ◽  
Author(s):  
Gerardo M Oresti ◽  
Jesús García-López ◽  
Marta I Aveldaño ◽  
Jesús del Mazo
Keyword(s):  
Fatty Acid ◽  
Cell Differentiation ◽  
Germ Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Fatty Acid Binding Proteins ◽  
Cell Type ◽  
Fatty Acid Binding ◽  
Germ Cell Differentiation ◽  
Perilipin 2

Male germ cell differentiation entails the synthesis and remodeling of membrane polar lipids and the formation of triacylglycerols (TAGs). This requires fatty acid-binding proteins (FABPs) for intracellular fatty acid traffic, a diacylglycerol acyltransferase (DGAT) to catalyze the final step of TAG biosynthesis, and a TAG storage mode. We examined the expression of genes encoding five members of the FABP family and two DGAT proteins, as well as the lipid droplet protein perilipin 2 (PLIN2), during mouse testis development and in specific cells from seminiferous epithelium.Fabp5expression was distinctive of Sertoli cells and consequently was higher in prepubertal than in adult testis. The expression ofFabp3increased in testis during postnatal development, associated with the functional differentiation of interstitial cells, but was low in germ cells.Fabp9, together withFabp12, was prominently expressed in the latter. Their transcripts increased from spermatocytes to spermatids and, interestingly, were highest in spermatid-derived residual bodies (RB). Both Sertoli and germ cells, which produce neutral lipids and store them in lipid droplets, expressedPlin2. Yet, whileDgat1was detected in Sertoli cells,Dgat2accumulated in germ cells with a similar pattern of expression asFabp9. These results correlated with polyunsaturated fatty acid-rich TAG levels also increasing with mouse germ cell differentiation highest in RB, connecting DGAT2 with the biosynthesis of such TAGs. The age- and germ cell type-associated increases inFabp9,Dgat2, andPlin2levels are thus functionally related in the last stages of germ cell differentiation.

scholarly journals Expression of Human Hormone-Sensitive Lipase (HSL) in Postmeiotic Germ Cells Confers Normal Fertility to HSL-Deficient Mice

Endocrinology ◽  
2004 ◽  
Vol 145 (12) ◽  
pp. 5688-5693 ◽  
Author(s):  
Shu Pei Wang ◽  
Shari Chung ◽  
Krishnakant Soni ◽  
Hugo Bourdages ◽  
Louis Hermo ◽  
...  
Keyword(s):  
Germ Cells ◽  
Free Cholesterol ◽  
Fatty Acyl ◽  
Hormone Sensitive Lipase ◽  
Cortical Cells ◽  
Cholesterol Ratio ◽  
Testicular Mass ◽  
Normal Fertility ◽  
Hormone Sensitive ◽  
Testicular Histology

Abstract Hormone-sensitive lipase (HSL, Lipe, E.C.3.1.1.3) is a multifunctional fatty acyl esterase that is essential for male fertility and spermatogenesis and that also plays important roles in the function of adipocytes, pancreatic β-cells, and adrenal cortical cells. Gene-targeted HSL-deficient (HSL−/−) male mice are infertile, have a 2-fold reduction in testicular mass, a 2-fold elevation of the ratio of esterified to free cholesterol in testis, and unique morphological abnormalities in round and elongating spermatids. Postmeiotic germ cells in the testis express a specific HSL isoform. We created transgenic mice expressing a normal human testicular HSL cDNA from the mouse protamine-1 promoter, which mediates expression specifically in postmeiotic germ cells. Testicular cholesteryl esterase activity was undetectable in HSL−/− mice, but in HSL−/− males expressing the testicular transgene, activity was 2-fold greater than normal. HSL transgene mRNA became detectable in testes between 19 and 25 days of age, coinciding with the first wave of postmeiotic transcription in round spermatids. In contrast to nontransgenic HSL−/− mice, HSL−/− males expressing the testicular transgene were normal with respect to fertility, testicular mass, testicular esterified/free cholesterol ratio, and testicular histology. Their cauda epididymides contained abundant, normal-appearing spermatozoa. We conclude that human testicular HSL is functional in mouse testis and that the mechanism of infertility in HSL-deficient males is cell autonomous and resides in postmeiotic germ cells, because HSL expression in these cells is in itself sufficient to restore normal fertility.

scholarly journals Androgens and Postmeiotic Germ Cells Regulate Claudin-11 Expression in Rat Sertoli Cells

Endocrinology ◽  
2005 ◽  
Vol 146 (3) ◽  
pp. 1532-1540 ◽  
Author(s):  
Anne Florin ◽  
Magali Maire ◽  
Aline Bozec ◽  
Ali Hellani ◽  
Sonia Chater ◽  
...  
Keyword(s):  
Germ Cells ◽  
Sertoli Cells ◽  
Inhibitory Effect ◽  
Positive Control ◽  
Maximum Effect ◽  
Dependent Manner ◽  
Adult Age ◽  
Adult Rat ◽  
Protein Levels ◽  
Negative Effect

In the present study we investigated whether fetal exposure to flutamide affected messenger and protein levels of claudin-11, a key Sertoli cell factor in the establishment of the hemotesticular barrier, at the time of two key events of postnatal testis development: 1) before puberty (postnatal d 14) during the establishment of the hemotesticular barrier, and 2) at the adult age (postnatal d 90) at the time of full spermatogenesis. The data obtained show that claudin-11 expression was inhibited in prepubertal rat testes exposed in utero to 2 and 10 mg/kg·d flutamide. However, in adult testes, the inhibition was observed only with 2, and not with 10, mg/kg·d of the antiandrogen. It is shown here that these differences between prepubertal and adult testes could be related to dual and opposed regulation of claudin-11 expression resulting from positive control by androgens and an inhibitory effect of postmeiotic germ cells. Indeed, testosterone is shown to stimulate claudin-11 expression in cultured Sertoli cells in a dose- and time-dependent manner (maximum effect with 0.06 μm after 72 h of treatment). In contrast, postmeiotic germ cells potentially exert a negative effect on claudin-11 expression, because adult rat testes depleted in spermatids (after local irradiation) displayed increased claudin-11 expression, whereas in a model of cocultured Sertoli and germ cells, spermatids, but not spermatocytes, inhibited claudin-11 expression. The apparent absence of claudin-11 expression changes in adult rat testes exposed to 10 mg/kg·d flutamide therefore could result from the antagonistic effects of 1) the inhibitory action of the antiandrogen and 2) the stimulatory effect of the apoptotic germ cells on claudin-11 expression. Together, due to the key role of claudin-11 in the hemotesticular barrier, the present findings suggest that such regulatory mechanisms may potentially affect this barrier (re)modeling during spermatogenesis.

Protein synthesis by isolated pachytene spermatocytes in the absence of sertoli cells

1985 ◽  
Vol 233 (2) ◽  
pp. 285-290 ◽  
Author(s):  
N. H. P. M. Jutte ◽  
R. Jansen ◽  
J. A. Grootegoed ◽  
F. F. G. Rommerts ◽  
H. J. van der Molen
Keyword(s):  
Protein Synthesis ◽  
Sertoli Cells ◽  
Pachytene Spermatocytes

CX43 expression, phosphorylation, and distribution in the normal and autoimmune orchitic testis with a look at gap junctions joining germ cell to germ cell

2011 ◽  
Vol 300 (1) ◽  
pp. R121-R139 ◽  
Author(s):  
R.-Marc Pelletier ◽  
Casimir D. Akpovi ◽  
Li Chen ◽  
Robert Day ◽  
María L. Vitale
Keyword(s):  
Cell Differentiation ◽  
Gap Junctions ◽  
Germ Cell ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Seminiferous Tubule ◽  
Connexin 43 ◽  
Cx43 Expression ◽  
Cx43 Protein ◽  
Cx43 Mrna

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.

scholarly journals Minireview: Transcriptional Regulation of Gonadal Development and Differentiation

Endocrinology ◽  
2005 ◽  
Vol 146 (3) ◽  
pp. 1035-1042 ◽  
Author(s):  
Susan Y. Park ◽  
J. Larry Jameson
Keyword(s):  
Germ Cells ◽  
Sertoli Cells ◽  
Leydig Cells ◽  
Cell Types ◽  
Gonadal Development ◽  
Targeted Mutagenesis ◽  
Seminiferous Tubules ◽  
Molecular Pathways ◽  
Theca Cells ◽  
Main Cell

The embryonic gonad is undifferentiated in males and females until a critical stage when the sex chromosomes dictate its development as a testis or ovary. This binary developmental process provides a unique opportunity to delineate the molecular pathways that lead to distinctly different tissues. The testis comprises three main cell types: Sertoli cells, Leydig cells, and germ cells. The Sertoli cells and germ cells reside in seminiferous tubules where spermatogenesis occurs. The Leydig cells populate the interstitial compartment and produce testosterone. The ovary also comprises three main cell types: granulosa cells, theca cells, and oocytes. The oocytes are surrounded by granulosa and theca cells in follicles that grow and differentiate during characteristic reproductive cycles. In this review, we summarize the molecular pathways that regulate the distinct differentiation of these cell types in the developing testis and ovary. In particular, we focus on the transcription factors that initiate these cascades. Although most of the early insights into the sex determination pathway were based on human mutations, targeted mutagenesis in mouse models has revealed key roles for genes not anticipated to regulate gonadal development. Defining these molecular pathways provides the foundation for understanding this critical developmental event and provides new insight into the causes of gonadal dysgenesis.

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