Role of oxygen in the regulation of Leydig tumor derived MA-10 cell steroid production: the effect of cobalt chloride

Abstract

We have earlier shown that cobalt chloride (CoCl2)-induced hypoxia and second messenger 8-bromoadenosine 3', 5'-cyclic adenosine monophosphate (8-Br-cAMP) stimulates vascular endothelial growth factor (VEGF) production in Leydig tumor cell derived MA-10 cells. Both stimuli follow common signal transduction pathways including protein kinase A (PK-A), extracellular regulated kinase 1/2 (ERK1/2), and phosphatidyl inositol-3 kinase/akt (PI3-K/Akt) pathways in the stimulation of VEGF by MA-10 cells. In the present study we investigated the role of CoCl2 and 8-Br-cAMP on steroid production in MA-10 cells. The MA-10 cells were cultured in Waymouth MB 752/1 medium, supplemented with 15% heat inactivated horse serum. Progesterone was estimated by radioimmunoassay (RIA).We report that 8-Br-cAMP stimulated progesterone production by the MA-10 cells whereas CoCl2 inhibited the same. Also, 8-Br-cAMP stimulated steroidogenic acute regulatory protein (StAR) and cytochrome P450 side-chain cleavage enzyme (P450scc) mRNAs expression. However, CoCl2 had no effect on StAR mRNA. Cobalt chloride directly inhibited the expression of P450scc mRNA. The decrease in progesterone production could be attributed to three different mechanisms, (1) an increase in production of reactive oxygen species (ROS), (2) an increase in HIF-1α activity, and (3) ultimately a decrease in the level of cytochrome P450 side chain cleavage (CYT P450scc). Hypoxia has an action and mechanism of action similar to that of gonadotropins on VEGF production, whereas they have a contrasting effect on steroidogenesis. This study suggests that hypoxia could be as important as gonadotropins in regulating Leydig cell steroidogenesis.

Triiodothyronine stimulates VEGF expression and secretion via steroids and HIF-1α in murine Leydig cells

“…T 3 and 8-Br-cAMP were shown to stimulate steroid secretion and CoCl 2 -induced hypoxia was shown to inhibit steroid secretion in Leydig cell derived lines (Manna et al 1999(Manna et al , 2001Kumar et al 2014). In this study also, T 3 stimulated steroid secretion from MLTC-1 cells ( Figure 3A,B).…”

“…LH and its second messenger, 3ʹ, 5ʹ cyclic adenosine monophosphate (cAMP) are known to stimulate steroid production and secretion from Leydig cells and their derived lines. In contrast, low oxygen tension or hypoxia have been shown to inhibit steroid production and secretion from Leydig cell derived MA-10 cells (Kumar et al 2014).…”

“…In contrast, a stimulatory role of DHT on the HIF-1α protein has been shown in prostate cancer cell line, LNCaP (Mabjeesh et al 2003). Our earlier study on MA-10 cells showed that the inhibitory effect of CoCl 2 on progesterone secretion was mediated partly through HIF-1α (Kumar et al 2014). This could have been because cyclosporine A (CsA), a non-specific inhibitor of HIF-1α with many other functions, was used in that study.…”

HIF 1 inhibits STAR transcription and testosterone synthesis in murine Leydig cells

“…From the synthesis of cholesterol to testosterone, there are three rate-limiting proteins, of which STAR is the first rate-limiting protein, while P450scc and 3b-HSD are the other two (Aspden et al 1998). Previous studies reported that 3b-HSD and P450scc are target genes for HIF1α in murine Leydig cells (Lysiak et al 2009, Kumar et al 2014. But in our work, neither protein nor mRNA levels of P450scc and 3b-HSD were significantly changed under hypoxia, while STAR mRNA and protein levels were significantly reduced.…”

Cobalt in athletes: hypoxia and doping - new crossroads

“…Due to its effect on cytochrome enzymes Co supplements are frequently prescribed to improve the therapeutic effect of hormone replacement therapy in menopausal and post-menopausal women to reduce estrogen hyperexcretion (Wright, 2005). Co inhibited progesterone and increased insulin-like growth factor I in a dose-dependent manner in rat ovarian fragments and Leydig tumor-derived MA-10 cells (Kumar et al, 2014;Roychoudhury et al, 2014). In addition, hypoxia reduced testosterone release in mouse Leydig cells (Wang et al, 2017).…”