scholarly journals GATA4 Is a Key Regulator of Steroidogenesis and Glycolysis in Mouse Leydig Cells

Endocrinology ◽  
2015 ◽  
Vol 156 (5) ◽  
pp. 1860-1872 ◽  
Author(s):  
Anja Schrade ◽  
Antti Kyrönlahti ◽  
Oyediran Akinrinade ◽  
Marjut Pihlajoki ◽  
Merja Häkkinen ◽  
...  

Transcription factor GATA4 is expressed in somatic cells of the mammalian testis. Gene targeting studies in mice have shown that GATA4 is essential for proper differentiation and function of Sertoli cells. The role of GATA4 in Leydig cell development, however, remains controversial, because targeted mutagenesis experiments in mice have not shown a consistent phenotype, possibly due to context-dependent effects or compensatory responses. We therefore undertook a reductionist approach to study the function of GATA4 in Leydig cells. Using microarray analysis and quantitative RT-PCR, we identified a set of genes that are down-regulated or up-regulated after small interfering RNA (siRNA)-mediated silencing of Gata4 in the murine Leydig tumor cell line mLTC-1. These same genes were dysregulated when primary cultures of Gata4flox/flox adult Leydig cells were subjected to adenovirus-mediated cre-lox recombination in vitro. Among the down-regulated genes were enzymes of the androgen biosynthetic pathway (Cyp11a1, Hsd3b1, Cyp17a1, and Srd5a). Silencing of Gata4 expression in mLTC-1 cells was accompanied by reduced production of sex steroid precursors, as documented by mass spectrometric analysis. Comprehensive metabolomic analysis of GATA4-deficient mLTC-1 cells showed alteration of other metabolic pathways, notably glycolysis. GATA4-depleted mLTC-1 cells had reduced expression of glycolytic genes (Hk1, Gpi1, Pfkp, and Pgam1), lower intracellular levels of ATP, and increased extracellular levels of glucose. Our findings suggest that GATA4 plays a pivotal role in Leydig cell function and provide novel insights into metabolic regulation in this cell type.

1990 ◽  
Vol 122 (1) ◽  
pp. 101-106 ◽  
Author(s):  
Joseph T. French ◽  
Thomas H. Welsh

Abstract Serum-free primary cultures of neonatal (1-day-old) porcine Leydig cells were used to study the effects of phorbol-12-myristate-13-acetate and 1,2-dioctanoylglycerol on testosterone and pregnenolone production. Phorbol-12-myristate-13-acetate alone from 0.001-10 μmol/l stimulated testosterone and pregnenolone production, whereas 1,2-dioctanoylglycerol alone had no effect on steroid production, relative to control. Phorbol12-myristate-13-acetate and 1,2-dioctanoylglycerol each inhibited pLH-stimulated testosterone and pregnenolone production. To further clarify the influence of these protein kinase C activators on steroidogenesis, cultured Leydig cells were treated with either phorbol-12-myristate-13-acetate or 1,2-dioctanoylglycerol plus forskolin (an adenylate cyclase activator). Both phorbol-12-myristate-13-acetate and 1,2-dioctanoylglycerol inhibited forskolin-stimulated testosterone production. Phorbol-12-myristate-13-acetate had no effect on forskolin-stimulated pregnenolone production and only the highest concentration of 1,2-dioctanoylglycerol (100 μmol/l) inhibited forskolin-stimulated production of pregnenolone. These data demonstrate that porcine Leydig cell steroidogenesis can be modulated by interactions of the protein kinase C and protein kinase A second messenger systems.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Emmanuelle Martinot ◽  
Derek Boerboom

Abstract Background First identified as a regulator of neuronal axon guidance, Slit/Robo signaling has since been implicated in additional physiologic and pathologic processes, such as angiogenesis, organogenesis and cancer progression. However, its roles in the regulation of testis function have been little explored. Methods Immunohistochemistry and RT-qPCR analyses were performed to detect the expression of Slit/Robo signaling effectors in the adult mouse testis. To identify the roles and mechanisms of Slit/Robo signaling in the regulation of steroidogenesis, RT-qPCR, immunoblotting and hormone measurements were carried out using Leydig cells (primary cultures and the MA10 cell line) treated with exogenous SLIT ligands, and testes from Robo1-null mice. Results Slit1, -2 and -3 and Robo1 and -2 expression was detected in the adult mouse testis, particularly in Leydig cells. In vitro treatment of Leydig cells with exogenous SLIT ligands led to a decrease in the expression of the steroidogenic genes Star, Cyp11a1, and Cyp17a1. SLIT2 treatment decreased the phosphorylation of the key steroidogenic gene regulator CREB, possibly in part by suppressing AKT activity. Furthermore, SLIT2 treatment reduced the responsiveness of MA10 cells to luteinizing hormone by decreasing the expression of Lhcgr. Consistent with these in vitro results, an increase in testicular Star mRNA levels and intra-testicular testosterone concentrations were found in Robo1-null mice. Finally, we showed that the expression of the Slit and Robo genes in Leydig cells is enhanced by testosterone treatment in vitro, by an AR-independent mechanism. Conclusion Taken together, these results suggest that Slit/Robo signaling represents a novel mechanism that regulates Leydig cell steroidogenesis. It may act in an autocrine/paracrine manner to mediate negative feedback by testosterone on its own synthesis.


Endocrinology ◽  
2003 ◽  
Vol 144 (8) ◽  
pp. 3279-3284 ◽  
Author(s):  
P. J. O’Shaughnessy ◽  
L. M. Fleming ◽  
G. Jackson ◽  
U. Hochgeschwender ◽  
P. Reed ◽  
...  

Abstract Adult Leydig cell steroidogenesis is dependent on LH but fetal Leydig cells can function independently of gonadotropin stimulation. To identify factors that may be involved in regulation of fetal Leydig cells expressed sequence tag libraries from fetal and adult testes were compared, and fetal-specific genes identified. The ACTH receptor [melanocortin type 2 receptor (Mc2r)] was identified within this fetal-specific group. Subsequent real-time PCR studies confirmed that Mc2r was expressed in the fetal testis at 100-fold higher levels than in the adult testis. Incubation of fetal or neonatal testes with ACTH in vitro stimulated testosterone production more than 10-fold, although ACTH had no effect on testes from animals aged 20 d or older. The steroidogenic response of fetal and neonatal testes to a maximally stimulating dose of human chorionic gonadotropin was similar to the response shown to ACTH. The ED50 for ACTH, measured in isolated fetal and neonatal testicular cells, was 5 × 10−10m and the lowest dose of ACTH eliciting a response was 2 × 10−11m. Circulating ACTH levels in fetal mice were around 8 × 10−11m. Neither α-MSH nor γ-MSH had any effect on androgen production in vitro at any age. Fetal testosterone levels were normal in mice that lack circulating ACTH (proopiomelanocortin-null) indicating that ACTH is not essential for fetal Leydig cell function. Results show that both LH and ACTH can regulate testicular steroidogenesis during fetal development in the mouse and suggest that fetal Leydig cells, but not adult Leydig cells, are sensitive to ACTH stimulation.


Endocrinology ◽  
2021 ◽  
Author(s):  
Pierre-Olivier Hébert-Mercier ◽  
Francis Bergeron ◽  
Nicholas M Robert ◽  
Samir Mehanovic ◽  
Kenley Joule Pierre ◽  
...  

Abstract Leydig cells produce androgens that are essential for male sex differentiation and reproductive function. Leydig cell function is regulated by several hormones and signaling molecules, including growth hormone (GH). Although GH is known to upregulate Star gene expression in Leydig cells, its molecular mechanism of action remains unknown. The STAT5B transcription factor is a downstream effector of GH signaling in other systems. While STAT5B is present in both primary and Leydig cell lines, its function in these cells has yet to be ascertained. Here we report that treatment of MA-10 Leydig cells with GH or overexpression of STAT5B induces Star mRNA levels and increases steroid hormone output. The mouse Star promoter contains a consensus STAT5B element (TTCnnnGAA) at -756 bp to which STAT5B binds in vitro (EMSA and supershift) and in vivo (ChIP) in a GH-induced manner. In functional promoter assays, STAT5B was found to activate a -980 bp mouse Star reporter. Mutating the -756 bp element prevented STAT5B binding but did not abrogate STAT5B-responsiveness. STAT5B was found to functionally cooperate with DNA-bound cJUN. The STAT5B/cJUN cooperation was only observed in Leydig cells and not in Sertoli or fibroblast cells, indicating that additional Leydig cell-enriched transcription factors are required. The STAT5B/cJUN cooperation was lost only when both STAT5B and cJUN elements were mutated. In addition to identifying the Star gene as a novel target for STAT5B in Leydig cells, our data provide important new insights into the mechanism of GH and STAT5B action in the regulation of Leydig cell function.


1989 ◽  
Vol 120 (1) ◽  
pp. 97-NP ◽  
Author(s):  
K. J. Teerds ◽  
J. Closset ◽  
F. F. G. Rommerts ◽  
D. G. de Rooij ◽  
D. M. Stocco ◽  
...  

ABSTRACT The effects of pure FSH and/or LH preparations on the number of Leydig cells and their function in immature hypophysectomized rats have been investigated. As a result of hypophysectomy at the age of 17–18 days, the number of recognizable Leydig cells per testis decreased, as did the steroidogenic capacity in vivo and in vitro. Treatment with 64 μg FSH on both 22 and 23 days of age, did not affect the number of recognizable Leydig cells. In contrast, two injections of LH (10 μg) caused a sixfold increase in the number of Leydig cells, but had a negative effect on spermatogenesis. These stimulatory and inhibitory effects of LH diminished when FSH was added. Treatment with FSH for 7 days caused a twofold increase in the number of Leydig cells when compared with hypophysectomized controls. 3β-Hydroxysteroid dehydrogenase (3β-HSD) and esterase activity in Leydig cells also increased under the influence of FSH. The pregnenolone production per Leydig cell in the presence of 5-cholesten-3β,22(R)-diol (22R-hydroxycholesterol) as substrate showed a sevenfold increase. Plasma testosterone levels 2 h after injection of human chorionic gonadotrophin in intact rats and hypophysectomized FSH-treated rats were the same. Following LH treatment for 7 days, the number of Leydig cells proved to be 11 times higher, and 3β-HSD and esterase activity were not different from intact controls. The testicular pregnenolone production was four- to fivefold higher when compared with untreated hypophysectomized rats. However, pregnenolone production per Leydig cell in LH-treated rats was only slightly different from the hypophysectomized controls. In conclusion, FSH treatment caused an increase in the number and steroidogenic activity of Leydig cells, and LH had a major effect on the number of Leydig cells, but did not stimulate the steroidogenic capacity. Journal of Endocrinology (1989) 120, 97–106


Reproduction ◽  
2006 ◽  
Vol 132 (4) ◽  
pp. 607-616 ◽  
Author(s):  
Caroline N Kahiri ◽  
M Wahid Khalil ◽  
Francis Tekpetey ◽  
Gerald M Kidder

Connexin43 (Cx43) is the most abundantly expressed member of the connexin (gap junction protein) family and the only one so far identified in mouse Leydig cell gap junctions. Mice lacking Cx43 were used to investigate its role in testicular androgen production and regulation. Testes from term fetuses were grafted under the kidney capsules of castrated adult males. After 3 weeks, serum from host mice was analyzed for androgens. In order to test their response to stimulation, the grafted testes were incubated in vitro with varying concentrations of LH and their androgen end products analyzed. Incubation with radiolabeled progesterone was followed by high performance liquid chromatography to quantify the androgen-intermediate metabolites. Radiolabeled testosterone in the presence of NADPH was used to determine the activity of testosterone-metabolizing enzymes 17β-hydroxysteroid dehydrogenase (17βHSD), 5α-reductase (5αR), and 3α-hydroxysteroid dehydrogenase (3α HSD). Serum androgen levels did not differ between hosts carrying wild-type versus null mutant grafts although Cx43-deficient testes had more 17βHSD and 5αR activity than wild-type controls. Furthermore, the genotype of grafted testes did not influence LH-stimulated androgen production in vitro. These results indicate that the steroidogenic function of Leydig cells is not compromised by the absence of Cx43, perhaps because other gap junction proteins are present. Dye transfer experiments demonstrated that Cx43-deficient Leydig cells retain intercellular coupling, indicating that Cx43 is not the only protein contributing to their gap junctions. Thus, despite their prominence in Leydig cells, Cx43 gap junctions are not essential for androgen production.


1985 ◽  
Vol 132 (2) ◽  
pp. 729-734 ◽  
Author(s):  
M. Benahmed ◽  
C. Grenot ◽  
E. Tabone ◽  
P. Sanchez ◽  
A.M. Morera

2021 ◽  
Vol 3 (Supplement_1) ◽  
pp. i15-i16
Author(s):  
Sachin Kumar ◽  
Antony Michealraj ◽  
Leo Kim ◽  
Jeremy Rich ◽  
Michael Taylor

Abstract Ependymomas are malignant glial tumours that occur throughout the central nervous system. Of the nine distinct molecular subgroups of ependymoma, Posterior Fossa A (PFA), is the most prevalent, occurring in the hindbrain of infants and young children. Lacking highly recurrent somatic mutations, PFAs are thought to be a largely epigenetically driven entity, defined by hypomethylation at the histone 3 lysine 27 residue. Previous transcriptional analysis of PFAs revealed an enrichment of hypoxia signaling genes. Thus, we hypothesized that hypoxic signaling, in combination with a unique metabolic milieu, drive PFA oncogenesis through epigenetic regulation. In this study, we identified that PFA cells control the availability of specific metabolites under hypoxic conditions, resulting in diminished H3K27 trimethylation and increased H3K27 acetylation in vitro and in vivo. Unique to PFA cells, transient exposure to ambient oxygen results in irreversible cellular toxicity. Furthermore, perturbation of key metabolic pathways is sufficient to inhibit growth of PFA primary cultures in vitro. PFA cells sequester s-adenosylmethionine while upregulating EZHIP, a polycomb repressive complex 2 (PRC2) inhibitor, resulting in decreased H3K27 trimethylation. Furthermore, hypoxia fine-tunes the abundance of alpha-ketoglutarate and acetyl-CoA to fuel demethylase and acetyltransferase activity. Paradoxically, a genome-wide CRISPR knockout screen identified the core components of PRC2 as uniquely essential in PFAs. Our findings suggest that PFAs thrive in a narrow “Goldilocks” zone, whereby they must maintain a unique epigenome and deviation to increased or decreased H3K27 trimethylation results in diminished cellular fitness. Previously, we showed that PFAs have a putative cell of origin arising in the first trimester of development. Using single-cell RNAseq and metabolomics, we demonstrate that PFAs resemble the natural metabolic-hypoxic milieu of normal development. Therefore, targeting metabolism and/or the epigenome presents a unique opportunity for rational therapy for infants with PFA ependymoma.


Sign in / Sign up

Export Citation Format

Share Document