Project description:Testosterone production by Leydig cells is a tightly regulated process requiring synchronized expression of several steroidogenic genes by numerous transcription factors. Myocyte enhancer factor 2 (MEF2) is a transcription factor recently identified in somatic cells of the male gonad. In other tissues, MEF2 is an essential regulator of organogenesis and cell differentiation. So far in the testis, MEF2 was found to regulate Leydig cell steroidogenesis by controlling Nr4a1 and Star gene expression. To expand our understanding of the role of MEF2 in Leydig cells, we performed microarray analyses of MA-10 Leydig cells depleted in MEF2 and results were analyzed using the Partek and IPA softwares. Several genes were differentially expressed in MEF2-depleted Leydig cells and 15 were validated by qPCR. A large number of these genes are known to be involved in fertility, gonad morphology and steroidogenesis and include Pde8a, Por, Ahr, Bmal1, Cyp1a1, Cyp1b1, Map2k1, Tsc22d3, Nr0b2, Smad4, and Star, which were all downregulated in the absence of MEF2. In silico analyses revealed the presence of MEF2 binding sites within the first 2 kb upstream the transcription start site of the Por, Bmal1, and Nr0b2 promoters, which suggests a direct regulation by MEF2. Using transient transfections in MA-10 Leydig cells, siRNA knockdown, and a MEF2-Engrailed dominant negative, we found that MEF2 activates the Por, Bmal1 and Nr0b2 promoters and that this requires an intact MEF2 element. Our results identify novel target genes for MEF2 and define MEF2 as an important regulator of Leydig cell function and male reproduction. MA-10 Leydig cells were treated with siRNA MEF2A/2D (siRNA MEF2) or scrambled siRNA as control (siRNA Ctrl) 48h before total RNA extraction.
Project description:Testosterone production by Leydig cells is a tightly regulated process requiring synchronized expression of several steroidogenic genes by numerous transcription factors. Myocyte enhancer factor 2 (MEF2) is a transcription factor recently identified in somatic cells of the male gonad. In other tissues, MEF2 is an essential regulator of organogenesis and cell differentiation. So far in the testis, MEF2 was found to regulate Leydig cell steroidogenesis by controlling Nr4a1 and Star gene expression. To expand our understanding of the role of MEF2 in Leydig cells, we performed microarray analyses of MA-10 Leydig cells depleted in MEF2 and results were analyzed using the Partek and IPA softwares. Several genes were differentially expressed in MEF2-depleted Leydig cells and 15 were validated by qPCR. A large number of these genes are known to be involved in fertility, gonad morphology and steroidogenesis and include Pde8a, Por, Ahr, Bmal1, Cyp1a1, Cyp1b1, Map2k1, Tsc22d3, Nr0b2, Smad4, and Star, which were all downregulated in the absence of MEF2. In silico analyses revealed the presence of MEF2 binding sites within the first 2 kb upstream the transcription start site of the Por, Bmal1, and Nr0b2 promoters, which suggests a direct regulation by MEF2. Using transient transfections in MA-10 Leydig cells, siRNA knockdown, and a MEF2-Engrailed dominant negative, we found that MEF2 activates the Por, Bmal1 and Nr0b2 promoters and that this requires an intact MEF2 element. Our results identify novel target genes for MEF2 and define MEF2 as an important regulator of Leydig cell function and male reproduction.
Project description:In steroidogenic Leydig cells, MEF2A, MEF2C, and MEF2D are key regulators of genes involved in steroid hormone synthesis, reproductive function, and oxidative stress defense. Here we used TurboID proximity-mediated biotinylation to map the protein-protein interaction networks of MEF2A, MEF2C, and MEF2D in mouse MA-10 Leydig cells. Interactions were captured under both basal (unstimulated) and forskolin-stimulated conditions to examine differences in the MEF2 interactomes in relation to steroidogenesis. This dataset provides insights into MEF2-related signalling pathways and the functional landscape of MEF2 transcription factors in Leydig cells.
Project description:In males, Leydig cells are the main producers of testosterone and insulin-like 3, hormones which are both essential for sex differentiation and reproductive functions. Nuclear receptor chicken ovalbumin upstream promoter-transcription factors II (COUP-TFII) is expressed in the cells committed to give rise to the fully functional steroidogenic adult Leydig cells and has a major role in their function and differentiation. Up to date, only handful of COUP-TFII gene targets have been reported. A transcriptomic approach was used to identify additional genes affected by depletion of COUP-TFII in mouse MA-10 Leydig cell line.
Project description:Sex differences in liver gene expression are dictated by sex-differences in circulating growth hormone (GH) profiles. Presently, the pituitary hormone dependence of mouse liver gene expression was investigated on a global scale to discover sex-specific early GH response genes that might contribute to sex-specific regulation of downstream GH targets and to ascertain whether intrinsic sex-differences characterize hepatic responses to plasma GH stimulation. RNA expression analysis using 41,000-feature microarrays revealed two distinct classes of sex-specific mouse liver genes: genes subject to positive regulation (class-I) and genes subject to negative regulation by pituitary hormones (class-II). Genes activated or repressed in hypophysectomized (Hypox) mouse liver within 30-90min of GH pulse treatment at a physiological dose were identified as direct targets of GH action (early response genes). Intrinsic sex-differences in the GH responsiveness of a subset of these early response genes were observed. Notably, 45 male-specific genes, including five encoding transcriptional regulators that may mediate downstream sex-specific transcriptional responses, were rapidly induced by GH (within 30min) in Hypox male but not Hypox female mouse liver. The early GH response genes were enriched in 29 male-specific targets of the transcription factor Mef2, whose activation in hepatic stellate cells is associated with liver fibrosis leading to hepatocellular carcinoma, a male-predominant disease. Thus, the rapid activation by GH pulses of certain sex-specific genes is modulated by intrinsic sex-specific factors, which may be associated with prior hormone exposure (epigenetic mechanisms) or genetic factors that are pituitary-independent, and could contribute to sex-differences in predisposition to liver cancer or other hepatic pathophysiologies.
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:Methoxyacetic acid (MAA) is the active metabolite of the widely used industrial chemical ethylene glycol monomethyl ether, an established testicular toxicant. MAA induces the degradation of testicular germ cells in association with changes in gene expression in both germ cells and Sertoli cells of the testis. This study investigates the impact of MAA on gene expression in testicular Leydig cells, which play a critical role in germ cell survival and male reproductive function. Cultured mouse TM3 Leydig cells were treated with MAA for 3, 8, and 24 h and global gene expression was monitored by microarray analysis. A total of 3,912 MAA-responsive genes were identified. Ingenuity Pathway analysis identified reproductive system disease, inflammatory disease and connective tissue disorder as the top biological functions affected by MAA. The MAA-responsive genes were classified into 1,366 early responders, 1,387 mid-responders, and 1,138 late responders, based on the time required for MAA to elicit a response. Analysis of enriched functional clusters for each subgroup identified 106 MAA early response genes involved in transcription regulation, including 32 genes associated with developmental processes and 60 DNA-binding proteins that responded to MAA rapidly but transiently, and which may contribute to the downstream effects of MAA seen for large numbers of mid and late response genes. Genes within the phosphatidylinositol/phospholipase C/calcium signaling pathway, whose activity is required for potentiation of nuclear receptor signaling by MAA, were also enriched in the set of early MAA response genes. These findings on the progressive changes in gene expression induced by MAA in Leydig cells may help elucidate the signaling pathways perturbed by this testicular toxicant and explain its mechanism of toxicity at the gene level.