scholarly journals Vitamin K-dependent γ-glutamyl carboxylase in Sertoli cells is essential for male fertility in mice

Author(s):  
Sachiko Shiba ◽  
Ikeda Kazuhiro ◽  
Kuniko Horie-Inoue ◽  
Kotaro Azuma ◽  
Tomoka Hasegawa ◽  
...  

Gamma-glutamyl carboxylase (GGCX) is a vitamin K (VK)-dependent enzyme that catalyzes γ-carboxylation of glutamic acid residues in VK-dependent proteins. Anticoagulant warfarin is known to reduce GGCX activity by inhibiting VK cycle and is recently shown to disrupt spermatogenesis. To explore GGCX function in testis, we here generated Sertoli cell-specific Ggcx conditional knockout (Ggcx scKO) mice and investigated their testicular phenotype. Ggcx scKO mice exhibited late-onset male infertility. They possessed morphologically abnormal seminiferous tubules containing multinucleated and apoptotic germ cells, and their sperm concentration and motility were substantially reduced. Localization of connexin 43 (Cx43), a gap junction protein abundantly expressed in Sertoli cells and required for spermatogenesis, was distorted in Ggcx scKO testes, and Cx43 overexpression in Sertoli cells rescued the infertility of Ggcx scKO mice. These results highlight GGCX activity within Sertoli cells, which promotes spermatogenesis by regulating the intercellular connection between Sertoli cells and germ cells.

2020 ◽  
Vol 21 (12) ◽  
pp. 4358
Author(s):  
Shuai Wang ◽  
Pengxiang Wang ◽  
Dongli Liang ◽  
Yuan Wang

Sertoli cells are somatic supporting cells in spermatogenic niche and play critical roles in germ cell development, but it is yet to be understood how epigenetic modifiers regulate Sertoli cell development and contribution to spermatogenesis. BRG1 (Brahma related gene 1) is a catalytic subunit of the mammalian SWI/SNF chromatin remodeling complex and participates in transcriptional regulation. The present study aimed to define the functions of BRG1 in mouse Sertoli cells during mouse spermatogenesis. We found that BRG1 protein was localized in the nuclei of both Sertoli cells and germ cells in seminiferous tubules. We further examined the requirement of BRG1 in Sertoli cell development using a Brg1 conditional knockout mouse model and two Amh-Cre mouse strains to specifically delete Brg1 gene from Sertoli cells. We found that the Amh-Cre mice from Jackson Laboratory had inefficient recombinase activities in Sertoli cells, while the other Amh-Cre strain from the European Mouse Mutant Archive achieved complete Brg1 deletion in Sertoli cells. Nevertheless, the conditional knockout of Brg1 from Sertoli cells by neither of Amh-Cre strains led to any detectable abnormalities in the development of either Sertoli cells or germ cells, suggesting that BRG1-SWI/SNF complex is dispensable to the functions of Sertoli cells in spermatogenesis.


1999 ◽  
Vol 276 (2) ◽  
pp. H709-H717 ◽  
Author(s):  
Kevin Petrecca ◽  
Roxana Atanasiu ◽  
Sergio Grinstein ◽  
John Orlowski ◽  
Alvin Shrier

The Na+/H+exchanger NHE1 isoform is an integral component of cardiac intracellular pH homeostasis that is critically important for myocardial contractility. To gain further insight into its physiological significance, we determined its cellular distribution in adult rat heart by using immunohistochemistry and confocal microscopy. NHE1 was localized predominantly at the intercalated disk regions in close proximity to the gap junction protein connexin 43 of atrial and ventricular muscle cells. Significant labeling of NHE1 was also observed along the transverse tubular systems, but not the lateral sarcolemmal membranes, of both cell types. In contrast, the Na+-K+-ATPase α1-subunit was readily labeled by a specific mouse monoclonal antibody (McK1) along the entire ventricular sarcolemma and intercalated disks and, to a lesser extent, in the transverse tubules. These results indicate that NHE1 has a distinct distribution in heart and may fulfill specialized roles by selectively regulating the pH microenvironment of pH-sensitive proteins at the intercalated disks (e.g., connexin 43) and near the cytosolic surface of sarcoplasmic reticulum cisternae (e.g., ryanodine receptor), thereby influencing impulse conduction and excitation-contraction coupling.


2009 ◽  
Vol 30 (7) ◽  
pp. 928-934 ◽  
Author(s):  
Yi Xia ◽  
Kai-zheng Gong ◽  
Ming Xu ◽  
You-yi Zhang ◽  
Ji-hong Guo ◽  
...  

Endocrinology ◽  
2005 ◽  
Vol 146 (3) ◽  
pp. 1035-1042 ◽  
Author(s):  
Susan Y. Park ◽  
J. Larry Jameson

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.


Development ◽  
1991 ◽  
Vol 111 (2) ◽  
pp. 509-522
Author(s):  
R. Minkoff ◽  
S.B. Parker ◽  
E.L. Hertzberg

Gap junction distribution in the facial primordia of chick embryos at the time of primary palate formation was studied employing indirect immunofluorescence localization with antibodies to gap junction proteins initially identified in rat liver (27 × 10(3) Mr, connexin 32) and heart (43 × 10(3) Mr, connexin 43). Immunolocalization with antibodies to the rat liver gap junction protein (27 × 10(3) Mr) demonstrated a ubiquitous and uniform distribution in all regions of the epithelium and mesenchyme except the nasal placode. In the placodal epithelium, a unique non-random distribution was found characterized by two zones: a very heavy concentration of signal in the superficial layer of cells adjacent to the exterior surface and a region devoid of detectable signal in the interior cell layer adjacent to the mesenchyme. This pattern was seen during all stages of placode invagination that were examined. The separation of gap junctions in distinct cell layers was unique to the nasal placode, and was not found in any other region of the developing primary palate. One other tissue was found that exhibited this pattern-the developing neural epithelium of the brain and retina. These observations suggest the presence of region-specific signaling mechanisms and, possibly, an impedance of cell communication among subpopulations of cells in these structures at critical stages of development. Immunolocalization with antibodies to the ‘heart’ 43 × 10(3) Mr gap junction protein also revealed the presence of gap junction protein in facial primordia and neural epithelium. A non-uniform distribution of immunoreactivity was also observed for connexin 43.


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