Project description:Steroid hormones regulate essential physiological processes and inadequate levels are associated with various pathological conditions. In testosterone-producing Leydig cells, steroidogenesis is strongly stimulated by LH via its receptor leading to increased cAMP production and expression of the steroidogenic acute regulatory (STAR) protein, which is essential for the initiation of steroidogenesis. Leydig cell steroidogenesis then passively decreases following the rapid degradation of cAMP into AMP by phosphodiesterases. In this study, we show that AMP-activated protein kinase (AMPK) is activated following cAMP breakdown in MA-10 and MLTC-1 Leydig cells. Activated AMPK then actively inhibits cAMP-induced steroidogenesis by repressing the expression of key regulators of steroidogenesis including Star and Nr4a1. Similar results were obtained in Y-1 adrenal cells and in the constitutive steroidogenic cell line R2C. Our data identify AMPK as an active repressor of steroid hormone biosynthesis in steroidogenic cells that is essential to preserve cellular energy and prevent excess steroid production. Steroid hormones regulate essential physiological processes and inadequate levels are associated with various pathological conditions. In testosterone-producing Leydig cells, steroidogenesis is strongly stimulated by LH via its receptor leading to increased cAMP production and expression of the steroidogenic acute regulatory (STAR) protein, which is essential for the initiation of steroidogenesis. Leydig cell steroidogenesis then passively decreases following the rapid degradation of cAMP into AMP by phosphodiesterases. In this study, we show that AMP-activated protein kinase (AMPK) is activated following cAMP breakdown in MA-10 and MLTC-1 Leydig cells. Activated AMPK then actively inhibits cAMP-induced steroidogenesis by repressing the expression of key regulators of steroidogenesis including Star and Nr4a1. Similar results were obtained in Y-1 adrenal cells and in the constitutive steroidogenic cell line R2C. Our data identify AMPK as an active repressor of steroid hormone biosynthesis in steroidogenic cells that is essential to preserve cellular energy and prevent excess steroid production. MA-10 Leydig cells were treated with either DMSO (control), 10 uM forskolin or forskolin+Aicar (1 mM) for 1.5 h before total RNA extraction
Project description:In the present study, we have used a quantitative LC-MS/MS approach using total and phosphopeptide-enriched proteins to identify the changes that occur in the proteome and phosphoproteome of MA-10 Leydig cells during both the stimulatory phase (Fsk/cAMP treatment) and inhibitory phase (AICAR-mediated activation of AMPK) of steroidogenesis. The phosphorylation level of several proteins, including some never before described in Leydig cells, was significantly altered during stimulation and inhibition of steroidogenesis. Our data provide new key insights into the finely tuned and dynamic processes that ensure adequate steroid hormone production.
Project description:Steroid hormones regulate essential physiological processes and inadequate levels are associated with various pathological conditions. In testosterone-producing Leydig cells, steroidogenesis is strongly stimulated by LH via its receptor leading to increased cAMP production and expression of the steroidogenic acute regulatory (STAR) protein, which is essential for the initiation of steroidogenesis. Leydig cell steroidogenesis then passively decreases following the rapid degradation of cAMP into AMP by phosphodiesterases. In this study, we show that AMP-activated protein kinase (AMPK) is activated following cAMP breakdown in MA-10 and MLTC-1 Leydig cells. Activated AMPK then actively inhibits cAMP-induced steroidogenesis by repressing the expression of key regulators of steroidogenesis including Star and Nr4a1. Similar results were obtained in Y-1 adrenal cells and in the constitutive steroidogenic cell line R2C. Our data identify AMPK as an active repressor of steroid hormone biosynthesis in steroidogenic cells that is essential to preserve cellular energy and prevent excess steroid production. Steroid hormones regulate essential physiological processes and inadequate levels are associated with various pathological conditions. In testosterone-producing Leydig cells, steroidogenesis is strongly stimulated by LH via its receptor leading to increased cAMP production and expression of the steroidogenic acute regulatory (STAR) protein, which is essential for the initiation of steroidogenesis. Leydig cell steroidogenesis then passively decreases following the rapid degradation of cAMP into AMP by phosphodiesterases. In this study, we show that AMP-activated protein kinase (AMPK) is activated following cAMP breakdown in MA-10 and MLTC-1 Leydig cells. Activated AMPK then actively inhibits cAMP-induced steroidogenesis by repressing the expression of key regulators of steroidogenesis including Star and Nr4a1. Similar results were obtained in Y-1 adrenal cells and in the constitutive steroidogenic cell line R2C. Our data identify AMPK as an active repressor of steroid hormone biosynthesis in steroidogenic cells that is essential to preserve cellular energy and prevent excess steroid production.
Project description:To study the potential tumorigenic effect of two activating mutations of hLHR identified in patients, we generated in vitro cell model using mouse Leydig MA-10 cells. The two mutations, Asp578His and Asp578Gly, were stably transfected to MA-10 cell to create MA-10-Asp578His and MA-10-Asp578Gly line. The profile of expressed genes in cells expressing the mutated hLHR was compared with that of control cells using cDNA microarrays with NIA mouse clone sets. Keywords: Genetic modification analysis
Project description:We investigated the role of AMPK activation in the progression of senescence in HFDPCs. The anti-senescence effects of adenine, a recently identified AMPK activator, were determined in a comparison with AICAR, a pharmacological AMPK activator, in HFDPCs. The results showed that either adenine or AICAR induced phosphorylation of Thr172 of AMPK in HFDPCs. As revealed by microarray analysis, significant changes of gene expression pattern were observed in the high-passage HFDPCs compared with that at lower passage level. A chip study using total RNA recovered from three separate wild-type cultures of Human follicle dermal papilla cells (HFDPCs) and three separate cultures of a triple adenine-treated cells.
Project description:The purpose of this study was to identify differentially-expressed genes between WT MA-10 mouse tumor Leydig cells and MA-10 cells in which the steroidogenic acute regulatory protein (STAR) is knocked out.
Project description:We investigated the role of AMPK activation in the progression of senescence in HFDPCs. The anti-senescence effects of adenine, a recently identified AMPK activator, were determined in a comparison with AICAR, a pharmacological AMPK activator, in HFDPCs. The results showed that either adenine or AICAR induced phosphorylation of Thr172 of AMPK in HFDPCs. As revealed by microarray analysis, significant changes of gene expression pattern were observed in the high-passage HFDPCs compared with that at lower passage level.