scholarly journals Uncarboxylated Osteocalcin Stimulates 25-Hydroxy Vitamin D Production in Leydig Cell Line Through a GPRC6a-Dependent Pathway

Endocrinology ◽  
2014 ◽  
Vol 155 (11) ◽  
pp. 4266-4274 ◽  
Author(s):  
Luca De Toni ◽  
Vincenzo De Filippis ◽  
Simone Tescari ◽  
Marco Ferigo ◽  
Alberto Ferlin ◽  
...  
Keyword(s):  
Vitamin D ◽  
Cell Line ◽  
Chorionic Gonadotropin ◽  
Cross Talk ◽  
Leydig Cell ◽  
Human Chorionic Gonadotropin ◽  
Leydig Cells ◽  
Second Messengers ◽  
Dependent Manner ◽  
Key Enzyme

Abstract Recent studies disclosed a cross talk between testis and bone. By the action of LH, Leydig cells are able to modulate bone metabolism through testosterone and insulin-like factor 3. Moreover, LH modulates the Leydig expression of CYP2R1, the key enzyme involved in vitamin D (Vit D) 25-hydroxylation. However, pathways regulating CYP2R1 expression have been poorly investigated. The cross talk from the bone to the testis of the vitamin D 25-hydroxylase CYP2R1 involves osteocalcin (OC), which is produced by the osteoblasts and stimulates the production of testosterone by the Leydig cells through its putative receptor GPRC6A, a cation-sensing G-protein-coupled receptor. The aim of this study was to investigate the possible action of OC on CYP2R1 expression and 25-hydroxy Vit D (25-OH Vit D) production in a mouse Leydig cell line (MA-10). After confirmation of the expression of GPRC6A by MA-10, we found that stimulation with either human chorionic gonadotropin or uncarboxylated-OC (ucOC) increases CYP2R1 protein expression in a dose-dependent manner and, in turn, increases the release of 25-OH Vit D in culture medium. This effect was abolished by receptor blockade with, respectively, anti-LH receptor and anti-GPRC6A antibodies. Moreover, both agonists converged to phosphorylation of Erk1/2 by a likely differential action on second messengers. Human chorionic gonadotropin induced slow “tonic” increase of intercellular calcium and accumulation of cAMP, whereas ucOC mainly induced phasic increase of cell calcium. Supporting these findings, we found that serum ucOC positively correlated with 25-OH Vit D levels in 40 overweight male patients and 21 controls. Altogether, our results suggest that OC contributes with LH to 25-OH Vit D production by Leydig cells.

Inductions of immediate early genes (IEGs) and ref-1 by human chorionic gonadotropin in murine Leydig cell line (MA-10)

IUBMB Life ◽  
1998 ◽  
Vol 44 (2) ◽  
pp. 217-224 ◽  
Author(s):  
Syoji Suzuki ◽  
Takashi Nagaya ◽  
Nobuhiko Suganuma ◽  
Yutaka Tomoda ◽  
Hisao Seo
Keyword(s):  
Cell Line ◽  
Chorionic Gonadotropin ◽  
Leydig Cell ◽  
Human Chorionic Gonadotropin ◽  
Immediate Early Genes ◽  
Immediate Early ◽  
Early Genes

scholarly journals Urocortin 1 Inhibits Rat Leydig Cell Function

Endocrinology ◽  
2008 ◽  
Vol 149 (12) ◽  
pp. 6425-6432 ◽  
Author(s):  
Catherine L. Rivier
Keyword(s):  
Chorionic Gonadotropin ◽  
Leydig Cell ◽  
Human Chorionic Gonadotropin ◽  
Leydig Cells ◽  
Cell Function ◽  
Cell Activity ◽  
Inhibitory Effect ◽  
Urocortin 1 ◽  
Stress Models

Corticotropin-releasing factor (CRF) has previously been reported in rat testes in which it inhibits Leydig cells activity. However, recent studies in our laboratory have suggested that some of the effects originally attributed to CRF were instead due to the related peptide Urocortin 1 (Ucn 1) and that this latter hormone, not CRF, was detectable in Leydig cells. We show here that Ucn 1 [a mixed CRF receptor (CRFR) type 1 and CRFR2 agonist] and the CRFR1-selective peptide Stressin 1, but not Ucn 2 or Ucn 3 (both considered selective CRFR2 ligands), significantly blunt the testosterone response to human chorionic gonadotropin. The effect of Ucn 1 is observed regardless of whether this peptide is injected iv or directly into the testes, and it is reversed by the mixed CRFR1/R2 antagonist Astressin B. Blockade of GnRH receptors with the antagonist Azalin B does not interfere with the influence of Ucn 1, thereby demonstrating that pituitary luteinizing hormone does not appear to be involved in this model. Collectively these results suggest that Ucn 1, not CRF, is present in the rat testes and interferes with Leydig cell activity. However, whereas we previously reported that alcohol up-regulated gonadal Ucn 1 gene expression, CRF receptor antagonists were unable to reverse the inhibitory effect exerted by alcohol on human chorionic gonadotropin-induced testosterone release. The functional role played by testicular Ucn 1 in stress models characterized by blunted androgen levels therefore needs to be further investigated.

Isolation of rat Leydig cells and precursor forms after administration of ethane dimethane sulfonate

1994 ◽  
Vol 266 (6) ◽  
pp. E975-E979 ◽  
Author(s):  
G. P. Risbridger ◽  
A. Davies
Keyword(s):  
Luteinizing Hormone ◽  
Cell Population ◽  
Chorionic Gonadotropin ◽  
Leydig Cell ◽  
Human Chorionic Gonadotropin ◽  
Leydig Cells ◽  
Steroid Production ◽  
Microscopic Appearance ◽  
Rat Testis ◽  
Adult Rat

The cytotoxic drug ethane dimethane sulfonate (EDS) has been extensively used as a means of studying the regeneration of Leydig cells in the adult rat testis. This study used the EDS-treated rat testis as a source of material for the isolation of regenerating Leydig cells and their precursors and describes the procedures required for the isolation of these cell preparations. As early as 13-15 days after EDS, cells in the precursor fraction can bind low, but detectable, levels of iodinated purified human chorionic gonadotropin. However, no luteinizing hormone (LH) response was detected in terms of steroid production. The precursor fraction of cells isolated from the EDS-treated rat testis 17-19 days after the administration of EDS was heterogeneous in light-microscopic appearance, but identifiable Leydig-like cells were present. The cells in this fraction were the first to exhibit the ability to respond to LH with the production of detectable levels of the reduced androgen, 5 alpha-androstane-3 alpha,17 beta-diol. The amount of androgen produced by both the Leydig cell and precursor fractions had increased by 21 days after EDS and reached the levels produced by immature adultlike Leydig cells, which can be isolated from the 20-day-old rat testes. These studies demonstrate that steroidogenically responsive precursor forms of Leydig cells can be isolated from the EDS-treated testes 17-19 days after depletion of the adult Leydig cell population.

scholarly journals Translational Fusion of Two β-Subunits of Human Chorionic Gonadotropin Results in Production of a Novel Antagonist of the Hormone

Endocrinology ◽  
2007 ◽  
Vol 148 (8) ◽  
pp. 3977-3986 ◽  
Author(s):  
Satarupa Roy ◽  
Sunita Setlur ◽  
Rupali A. Gadkari ◽  
H. N. Krishnamurthy ◽  
Rajan R. Dighe
Keyword(s):  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Expression System ◽  
Biologically Active ◽  
Chain Molecule ◽  
Dependent Manner ◽  
Β Subunit ◽  
Single Chain ◽  
Α Subunit ◽  
Lh Receptor

The strategy of translationally fusing the α- and β-subunits of human chorionic gonadotropin (hCG) into a single-chain molecule has been used to produce novel analogs of hCG. Previously we reported expression of a biologically active single-chain analog hCGαβ expressed using Pichia expression system. Using the same expression system, another analog, in which the α-subunit was replaced with the second β-subunit, was expressed (hCGββ) and purified. hCGββ could bind to LH receptor with an affinity three times lower than that of hCG but failed to elicit any response. However, it could inhibit response to the hormone in vitro in a dose-dependent manner. Furthermore, it inhibited response to hCG in vivo indicating the antagonistic nature of the analog. However, it was unable to inhibit human FSH binding or response to human FSH, indicating the specificity of the effect. Characterization of hCGαβ and hCGββ using immunological tools showed alterations in the conformation of some of the epitopes, whereas others were unaltered. Unlike hCG, hCGββ interacts with two LH receptor molecules. These studies demonstrate that the presence of the second β-subunit in the single-chain molecule generated a structure that can be recognized by the receptor. However, due to the absence of α-subunit, the molecule is unable to elicit response. The strategy of fusing two β-subunits of glycoprotein hormones can be used to produce antagonists of these hormones.

Production of Human Chorionic Gonadotropin In Vitro by a Cell Line Derived From a Carcinoma of the Lung2

1973 ◽  
Vol 50 (3) ◽  
pp. 669-674 ◽  
Author(s):  
Alan S. Robson ◽  
Saul W. Rosen ◽  
Armen H. Tashjian ◽  
Bruce D. Weintraub
Keyword(s):  
Cell Line ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
A Cell

Enhancement of Radiosensitivity of the MCF-7 Breast Cancer Cell Line with Human Chorionic Gonadotropin

2002 ◽  
Vol 72 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Sunthorn Pond-Tor ◽  
Ryan G. Rhodes ◽  
Paul E. Dahlberg ◽  
John T. Leith ◽  
John McMichael ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Line ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Chorionic Gonadotropin ◽  
Breast Cancer Cell Line ◽  
Human Chorionic Gonadotropin ◽  
Cancer Cell Line ◽  
Mcf 7

scholarly journals LH/chorionic gonadotropin signaling pathway involves protein tyrosine phosphatase activity downstream of protein kinase A activation: evidence of an obligatory step in steroid production by Leydig cells

2001 ◽  
Vol 170 (2) ◽  
pp. 403-411 ◽  
Author(s):  
FC Maciel ◽  
C Poderoso ◽  
A Gorostizaga ◽  
C Paz ◽  
EJ Podesta
Keyword(s):  
Protein Kinase ◽  
Chorionic Gonadotropin ◽  
Leydig Cell ◽  
Protein Tyrosine Phosphatase ◽  
Leydig Cells ◽  
Tyrosine Phosphatase ◽  
Zona Fasciculata ◽  
Stimulatory Action ◽  
Protein Tyrosine ◽  
Cell Functions

Our recent reports indicate that protein tyrosine phosphorylation is an obligatory component of the mechanism of action of ACTH in its stimulatory action of corticosteroid production in adrenal zona fasciculata (ZF). The role of protein tyrosine phosphatase (PTP) activity in the regulation of steroidogenesis by LH/chorionic gonadotropin (CG) was tested using cell-permeable PTP inhibitors. Thus, PTP inhibition blocks LH- and 8-bromo-cAMP-stimulated testosterone production by Leydig cells without affecting 22(R)OH-cholesterol-supported steroidogenesis, similar results to those obtained in the adrenal ZF/ACTH system, leading us to propose that PTP action is an obligatory and common step in the cascade triggered by both hormones. Then, we continued the study testing whether LH modulates PTP activity in MA-10 cells, a Leydig cell line. In this regard, we observed by an in-gel PTP assay two PTPs of 110 and 50 kDa that are activated by hormone and 8-bromo-cAMP activation of the cells. Moreover, there is a transient increase by the second messenger in total PTP activity that correlates with the higher activity displayed by the 110 and 50 kDa proteins in the in-gel assay. In accordance with these results, analysis of tyrosine phosphorylated proteins showed the LH-induced dephosphorylation of proteins of 120, 68 and 50 kDa. The results of this study indicate that PTPs play an important role in the regulation of Leydig cell functions and that there exists a cross talk between serine/threonine phosphorylation and tyrosine dephosphorylation mediated by hormone-activated cAMP-dependent protein kinase and PTPs. These results are the first evidence of PTP having a role in LH/CG-stimulated steroidogenesis.

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