Genetic Effects--Disease-Causing Mutations/LH Receptor

遗传效应--致病突变/LH 受体

• 批准号: 7209177
• 负责人: Owen M Rennert
• 金额: --
• 依托单位: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7209177
• 关键词: behavior disorders; behavioral genetics; cell line; chorionic gonadotropin; developmental genetics; gene mutation; genetic models; green fluorescent proteins; hormone receptor; human tissue; hypogonadism; laboratory rat; leucine; luteinizing hormone; neurogenesis; neurogenetics; precocious puberty; pseudohermaphroditism; receptor binding; reproductive system disorder; testis neoplasms; transfection /expression vector; behavior disorders; behavioral genetics; cell line; chorionic gonadotropin; developmental genetics; gene mutation; genetic models; green fluorescent proteins; hormone receptor; human tissue; hypogonadism; laboratory rat; leucine; luteinizing hormone; neurogenesis; neurogenetics; precocious puberty; pseudohermaphroditism; receptor binding; reproductive system disorder; testis neoplasms; transfection /expression vector

Biochemical Effect of An Inactivating Mutation of the Luteinizing Hormone Receptor Leung, Bear, Wu, Rennert, Chan in collaboration with Steinbach, Fechner. Luteinizing hormone/Chorionic gonadotropin Receptor (LHR) plays a key role in the development of the gonad and in reproductive physiology. In the testis, LHR activation leads to the production of testosterone. Inactivation of the LHR results in reduced production of testosterone and causes hypergonadotrophic hypogonadism in Leydig Cell Hypoplasia (LCH), a form of male pseudohermaphroditism. A novel missense mutation A340T identified in a patient with LCH resulted in substitution of Ile-114 by Phe, which affects one of the Leucine-rich repeats (LRR) in the extracellular domain of the hLHR. The mutant receptor failed to trigger cAMP production upon hCG stimulation in transient expression studies. This mutation did not affect trafficking of the receptor as revealed by fluorescent microscopic study of the green fluorescent protein of this receptor. It affected binding of the hormone by the receptor. A computer model of the LRR was generated to study the effect of this mutation. The model clearly demonstrated the conformational effect of the mutation. This finding may be extended to explain the impact of mutations on the biological activity of other proteins with LRRs. Novel Function of Luteinizing hormone/Chorionic Gonadotropin Receptor (LHR) in the Nervous System Meng, Rennert, Chan Individuals with LHR carrying activating mutations develop familial male-limited precocious puberty (FMPP) and are often shown to have behavioral problems. The cause is unclear. The behavioral problem of FMPP patients may be related to the dysfunction of brain cells caused by the expression of the mutated LHR. Recently LHR was shown to express in several non-gonad tissues including the nervous system. LHR expression level in the brain is developmentally regulated. In the adult rat LHR expression was detected in some neurons of specific brain regions, the ependymal cells of all four ventricles and the choroid plexus. The function of LHR in these cells is unknown. The goal of this study is to investigate the functional activity of LHR in the brain. The rat neuronal cell line, PC12 was transfected with an expression construct with the human LHR cDNA (hLHR) carrying an activating mutation, Asp578His (H mutation), inserted into pIRES2EGFP under the control of CMV promoter. Transfection with the mutated hLHR led to an initiation of neurite outgrowth in 10.8 +/- 1.8 % of cells which was significantly higher than that observed in cells transfected with the vector alone (3.9 +/- 0.8%) or transfected with the wild type hLHR (3.4 +/- 0.7%). Among the neurite-bearing cells, those transfected with the mutated LHR had a significantly higher proportion of cells that had neurites longer than 2x cell body (41.7%) as compared to those transfected with vector (15.5%) or wild type hLHR (19.2%). These results suggested the possible neurotrophic effects of hLHR in the brain. Further experiments are underway to elucidate the mechanism of LHR induced neuronal differentiation.

黄体生成激素受体的灭活突变的生化效应 Leung，Bear，Wu，Rennert，Chan与Fechner的Steinbach合作。 黄体生成激素/绒毛膜性促性腺激素受体（LHR）在性腺发展和生殖生理学中起关键作用。在睾丸中，LHR激活导致睾丸激素的产生。 LHR的失活导致睾丸激素的产生降低，并导致Leydig细胞低质（LCH）（LCH）的过度性营养性性超大型症，这是一种雄性伪耐药性的一种形式。在LCH患者中鉴定出的一种新型的错义突变A340T导致PHE取代ILE-114，这会影响HLHR的细胞外域中的富含亮氨酸的重复量（LRR）之一。在短暂表达研究中，突变受体在HCG刺激后未能触发CAMP产生。这种突变不会影响受体的运输，如该受体的绿色荧光蛋白的荧光微观研究所揭示的那样。它影响了受体对激素的结合。生成了LRR的计算机模型来研究该突变的效果。该模型清楚地证明了突变的构象作用。这一发现可能会扩展以解释突变对其他LRR的生物学活性的影响。 黄体生成激素/绒毛膜促性腺激素受体（LHR）在神经系统中的新功能 Meng，Rennert，Chan LHR携带激活突变的个体会出现家族性男性限制的早熟青春期（FMPP），并且经常被证明存在行为问题。原因尚不清楚。 FMPP患者的行为问题可能与突变的LHR表达引起的脑细胞功能障碍有关。最近显示，LHR在包括神经系统在内的几个非助导组织中表达。大脑中的LHR表达水平受发展调节。在成年大鼠LHR表达中，在特定大脑区域的一些神经元中检测到所有四个心室和脉络膜丛的室心室细胞。 LHR在这些细胞中的功能尚不清楚。这项研究的目的是研究LHR在大脑中的功能活性。大鼠神经元细胞系PC12用携带激活突变ASP578HIS（H突变）的人LHR cDNA（HLHR）的表达构建体转染，并在CMV启动子的控制下插入PIRES2EGFP中。用突变的HLHR转染导致在10.8 +/- 1.8％的细胞中引发神经突生长的启动，这显着高于单独使用载体转染的细胞中观察到的细胞（3.9 +/- 0.8％）（3.9 +/- 0.8％）或用野生型HLHR转染（3.4 +/- 0.7％）。在含神经突的细胞中，与载体（15.5％）或野生型HLHR（19.2％）相比，用突变的LHR转染的神经突的细胞比例明显更高的细胞（41.7％）。这些结果表明HLR在大脑中可能产生的神经营养作用。正在进行进一步的实验，以阐明LHR诱导的神经元分化的机理。