Regulation of insulins by the Rhox5 homeobox gene supports spermatogenesis

Rhox5 同源框基因对胰岛素的调节支持精子发生

• 批准号: 7844172
• 负责人: JAMES Arthur MACLEAN
• 金额: $ 0.91万
• 依托单位: SOUTHERN ILLINOIS UNIVERSITY CARBONDALE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7844172
• 关键词: 15p; Accounting; Androgens; Apoptosis; Binding; Biological; Biological Models; Biological Process; Breeding; Cell Communication; Cell Cycle Regulation; Cell Death; Cell Line; Cell Maturation; Cell Survival; Complex; Consult; Data; Defect; Development; Elements; Embryo; Epithelial Cells; Event; Exhibits; Failure; Fertility; Gene Expression; Gene Targeting; Genes; Genetic Transcription; Germ Cells; Gonadal structure; Homeobox; Homeobox Genes; Hormonal; Human; IGF1 gene; Insulin; Insulin-Like Growth Factor Receptor; Knockout Mice; Knowledge; Laboratories; Link; Luciferases; Mediating; Metabolic; Metabolism; Microarray Analysis; Molecular; Morphology; Mus; Nuclear Hormone Receptors; Nurses; Organ; Pancreas; Patients; Peroxisome Proliferator-Activated Receptors; Physiology; Plasmids; Principal Investigator; Process; Proteins; Regulation; Regulatory Pathway; Reporter; Reproduction; Reproductive system; Research; Response Elements; Role; Scientist; Seminal fluid; Somatic Cell; Sperm Count Procedure; Sperm Motility; Spermatogenesis; Staging; Supporting Cell; System; Techniques; Testis; Tissues; Transcription factor genes; Transcriptional Activation; Transfection; Work; X Chromosome; adiponectin; asthenospermia; base; cell growth regulation; cell type; cofactor; design; in vivo; insulin signaling; knockout gene; leydig interstitial cell; male; mind control; postnatal; programs; promoter; reproductive; reproductive development; research study; resistin; response; sertoli cell; spermatogenic epithelium structure; stem; transcription factor

Project Summary Homeobox genes encode transcription factors that control a wide variety of biological events. I recently identified a cluster of homeobox genes that are good candidates to regulate male reproductive development and physiology. Many of these reproductive homeobox on the X chromosome (Rhox) genes are androgen regulated and most are expressed in Sertoli cells (the nurse cells that support spermatogenesis), suggesting that they regulate the expression of somatic-cell gene products crucial for germ-cell development. Indeed, targeted deletion of one of these genes, Rhox5 (Pem), results in male subfertility, marked by increased germ-cell apoptosis and abnormal sperm motility. To begin to uncover the molecular events triggered by Rhox5 in Sertoli cells, I used microarray analysis to identify Rhox5-regulated genes, many of which encode proteins that have roles in metabolism, including insulin II (Ins2), resistin, and adiponectin, and the nuclear hormone receptor PPAR. Because insulin-like factors have recently been shown to support germ cell survival, I focused my initial studies on Rhox5 regulation of Ins2. Transient transfection of Rhox5 expression plasmids increased the activity of Ins2 promoter-driven luciferase reporter constructs. This was a breakthrough discovery for our laboratory, as no putative Rhox5-response elements had ever discovered. Rhox5-mediated activation of the Ins2 promoter was Sertoli-cell specific, as it occurred in Sertoli cell lines and Sertoli cells purified from day 12 testes, but not cell lines derived from other tissues. This suggests that a Sertoli-specific cofactor is required for Rhox5-mediated transcriptional activation. In this application, I propose to characterize the mechanism by which Rhox5 regulates target genes in the testes. The experiments are designed to identify cofactors that work with Rhox5 to achieve cell-type specific expression of Rhox5-regulated genes. Because Rhox5 positively regulates metabolic factors that support germ cell survival, elucidation of the transcription control mechanism that leads to subfertility in Rhox5-null mice provides a useful model system for understanding human subfertility. Untreatable subfertility caused by poor semen quality accounts for 75% of patients consulting for fertility problems Project Narrative Untreatable subfertility caused by poor semen quality accounts for 75% of patients consulting for fertility problems. This is due mainly to defects in sperm numbers (oligozoospermia) and sperm motility (asthenozoospermia). My proposed research strives to understand the mechanism by which the Rhox5 homeobox transcription factor controls the expression of genes that support male germ cell development. Mice which lack the Rhox5 gene exhibit abnormalities in sperm number, sperm motility, and breeding efficiency. Thus, the characterization of Rhox5-null mice may also be useful as a model system for understanding human fertility problems.

项目摘要 同型基因编码控制各种生物学的转录因子 事件。我最近确定了一群同源基因，这些基因是调节的好候选者 男性生殖发展和生理学。其中许多在 X染色体（Rhox）基因受雄激素调节，大多数在Sertoli细胞中表达 （支持精子发生的护士细胞），表明它们调节 体细胞基因产物对种系发育至关重要。确实，有针对性的删除 在这些基因Rhox5（PEM）中，导致雄性亚生物，以增加的细菌为特征 凋亡和精子运动异常。开始发现由 Rhox5在Sertoli细胞中，我使用微阵列分析来鉴定Rhox5调节的基因，许多 哪些编码在代谢中具有作用的蛋白质，包括胰岛素II（INS2），抵抗素和 脂联素和核激素受体PPAR。因为胰岛素样因素具有 最近显示以支持生殖细胞的存活，我将初步研究集中在Rhox5上 INS2的调节。 Rhox5表达的瞬时转染质粒增加了活性 INS2启动子驱动的荧光素酶报告基因结构。这是一个突破性的发现 我们的实验室，因为从未发现过的Rhox5响应元素。 Rhox5介导的 INS2启动子的激活是Sertoli细胞的特异性，因为它发生在Sertoli细胞系中，并且 Sertoli细胞从第12天的睾丸纯化，而不是来自其他组织的细胞系。这 表明Rhox5介导的转录需要Sertoli特异性的辅助因子 激活。在此应用中，我建议表征Rhox5的机制 调节睾丸中的靶基因。实验旨在识别辅助因子 与Rhox5一起工作以实现Rhox5调节基因的细胞类型特异性表达。因为 Rhox5积极调节支持生殖细胞存活的代谢因子，阐明 导致Rhox5-null小鼠差的转录控制机制提供了有用的 理解人类差的模型系统。由于差而引起的不可治疗的差异 精液质量占75％的患者咨询生育问题的咨询项目叙述 由于精液质量差占患者的75％而引起的不可治疗的差异性 咨询生育问题。这主要是由于精子数字缺陷 （寡素体）和精子运动（哮喘植物）。我提议的研究努力 了解Rhox5同型转录因子控制的机制 支持男性生殖细胞发育的基因的表达。缺乏Rhox5基因的小鼠 精子数，精子运动和育种效率的异常。因此， Rhox5-Null小鼠的表征也可能是理解模型系统 人类生育问题。