The Transcription Factor MEF2 Is a Novel Regulator of Gsta Gene Class in Mouse MA-10 Leydig Cells
The Transcription Factor MEF2 Is a Novel Regulator of Gsta Gene Class in Mouse MA-10 Leydig Cells
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DOI：
10.1210/en.2015-1500
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发表时间：
2015-12-01
期刊：
影响因子：
4.8
通讯作者：
Tremblay, Jacques J.
中科院分区：
文献类型：
--
作者：
Di-Luoffo, Mickael;Brousseau, Catherine;Tremblay, Jacques J.
睾酮对精子发生和男性性征的发育至关重要。然而，类固醇生成产生大量的活性氧（ROS），这可能会破坏睾酮的产生。肌细胞增强因子2（MEF 2）是各种组织中器官发生和细胞分化的重要调节因子。在睾丸中，MEF 2存在于整个胎儿和成人的支持细胞和间质细胞中。MEF 2-缺陷MA-10 Leydig细胞表现出类固醇合成的显著减少，伴随着谷胱甘肽S-转移酶（GST）活性的降低和编码ROS失活酶的4个Gsta成员（GST）的表达。在这里，我们报告了一个新的作用MEF 2在ROS解毒直接调节GSTA在Leydig细胞的表达。MEF 2缺陷MA-10 Leydig细胞中内源性Gsta 1 -4 mRNA水平降低。相反，MEF 2的过度表达增加内源性Gsta 1水平。通过染色质免疫沉淀和DNA沉淀分析证实MEF 2募集到近端Gsta 1启动子和直接结合到-506-bp MEF 2元件上。在MA-10 Leydig细胞中，MEF 2激活Gsta 1启动子，并与Ca 2（+）/钙调蛋白依赖性激酶I合作，进一步增强Gsta 1启动子活性。当-506-bp MEF 2元件突变或当使用MEF 2-Engrailed显性负性蛋白时，这些作用丧失。在Gsta 2、Gsta 3和Gsta 4启动子上获得了类似的结果，表明MEF 2因子在所有4个Gsta基因的调节中具有全局作用。总之，我们的研究结果确定了MEF 2在参与ROS解毒的基因表达中的新作用，ROS解毒是Leydig细胞中足够的睾酮产生所必需的过程。
Testosterone is essential for spermatogenesis and the development of male sexual characteristics. However, steroidogenesis produces a significant amount of reactive oxygen species (ROS), which can disrupt testosterone production. The myocyte enhancer factor 2 (MEF2) is an important regulator of organogenesis and cell differentiation in various tissues. In the testis, MEF2 is present in Sertoli and Leydig cells throughout fetal and adult life. MEF2-deficient MA-10 Leydig cells exhibit a significant decrease in steroidogenesis concomitant with a reduction in glutathione S-transferase (GST) activity and in the expression of the 4 Gsta members (GST) that encode ROS inactivating enzymes. Here, we report a novel role for MEF2 in ROS detoxification by directly regulating Gsta expression in Leydig cells. Endogenous Gsta1-4 mRNA levels were decreased in MEF2-deficient MA-10 Leydig cells. Conversely, overexpression of MEF2 increased endogenous Gsta1 levels. MEF2 recruitment to the proximal Gsta1 promoter and direct binding on the -506-bp MEF2 element were confirmed by chromatin immunoprecipitation and DNA precipitation assays. In MA-10 Leydig cells, MEF2 activates the Gsta1 promoter and cooperates with Ca2(+)/calmodulin-dependent kinases I to further enhance Gsta1 promoter activity. These effects were lost when the -506-bp MEF2 element was mutated or when a MEF2-Engrailed dominant negative protein was used. Similar results were obtained on the Gsta2, Gsta3, and Gsta4 promoters, suggesting a global role for MEF2 factors in the regulation of all 4 Gsta genes. Altogether, our results identify a novel role for MEF2 in the expression of genes involved in ROS detoxification, a process essential for adequate testosterone production in Leydig cells.