Paracrine role of MIS in Steroidogenesis

MIS 在类固醇生成中的旁分泌作用

• 批准号: 6622474
• 负责人: Christopher Houk
• 金额: $ 5.19万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6622474
• 关键词: Leydig cells; Mullerian duct inhibiting substance; biological signal transduction; cytochrome P450; cytochrome b5 reductase; developmental genetics; enzyme inhibitors; gene expression; genetic promoter element; genetically modified animals; hormone regulation /control mechanism; laboratory mouse; male; microarray technology; northern blottings; paracrine; phosphorylation; reproductive development; sex differentiation; steroid biosynthesis; testosterone; tissue /cell culture; transfection

MIS is a glycoprotein in the TGFbeta family of Growth and differentiation factors whose role in fetal Mullerian regression is critical to normal male sexual development. The Sertoli cells begin producing MIS in humans at 7 weeks gestation as a result of the earlier SRY initiated testicular maturational steps. MIS production continues into adulthood in both sexes, which may underlie its role as a regulator of adult gonadal function. Adult transgenic mice over expressing MIS develop severe gonadal abnormalities including Leydig cell hypoplasia, lowered testosterone levels, and subfertility. Mice that are null for MIS or the type II receptor develop the opposite phenotype, showing Leydig cell hyperplasia and elevated testosterone levels. Previous experiments by this lab have shown that MIS inhibits testosterone production at the transcriptional level and may also do this by inhibition of the lyase step. To better delineate the mechanism's of the lyase suppression I plan to investigate MIS's effect using a viral-promoter driven P450c17 gene, and I also plan to examine MIS's effect on the phosphorylation state of the P450c17 enzyme, a potential regulatory of lyase activity. Finally I will perform gene array experiments using recombinant human MIS and MA-10 cells. The results of this effort will allow me to begin to study the molecular pathways involved in MIS signaling and androgen synthesis.

MIS是生长和分化因子TGF β家族中的糖蛋白，其在胎儿苗勒管退化中的作用对正常男性性发育至关重要。由于SRY启动的睾丸成熟步骤较早，因此在妊娠7周时人类的支持细胞开始产生MIS。MIS生产持续到成年期的两性，这可能是其作为成年性腺功能的调节器的作用的基础。过表达MIS的成年转基因小鼠发生严重的性腺异常，包括Leydig细胞发育不全、睾酮水平降低和生育力低下。MIS或II型受体无效的小鼠发展出相反的表型，表现出Leydig细胞增生和睾酮水平升高。该实验室以前的实验表明，MIS在转录水平上抑制睾酮的产生，也可能通过抑制裂解酶步骤来实现这一点。为了更好地描述裂解酶抑制的机制，我计划使用病毒启动子驱动的P450 c17基因来研究MIS的效果，我还计划研究MIS对P450 c17酶的磷酸化状态的影响，这是裂解酶活性的潜在调节。最后，我将使用重组人MIS和MA-10细胞进行基因阵列实验。这项工作的结果将使我开始研究MIS信号和雄激素合成的分子途径。