Identification of Relaxin Receptor Antagonists

松弛素受体拮抗剂的鉴定

• 批准号: 6947202
• 负责人: SHEAU-YU Teddy HSU
• 金额: $ 21.54万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-10 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6947202
• 关键词: analog; birth; cell line; cell surface receptors; drug discovery /isolation; gene mutation; hormone receptor; inhibitor /antagonist; nucleic acid sequence; polymerase chain reaction; protein structure function; receptor binding; receptor expression; relaxin; reproductive development; transfection

DESCRIPTION (provided by applicant): Relaxin is a heterodimeric peptide hormone produced by the corpus luteum, decidua, and placenta in pregnant and nonpregnant females attaining the highest plasma levels during pregnancy. Other than its role in the inhibition of uterine contractile activity, relaxin has been shown to effect the induction of collagen remodeling and the consequent softening of the tissues of the birth canal (cervix and vagina), growth and differentiation of the mammary gland, and dilation of the blood vessels. Thus, relaxin plays a significant role in the overall regulation of physiological adaptation during pregnancy. Based on: primary and secondary structural characteristics, relaxin was grouped with insulin and insulin-like growth factors (IGFs) as a structural homolog. Analogous to insulin, prorelaxin, the precursor form of relaxin, has a domain arrangement similar to insulin and IGF precursors; mature relaxin appears to be processed by convertases to generate a two-chain heterodimer from the prorelaxin. In addition to two almost identical relaxin genes in human, there are five additional relaxin family genes including those encoding INSL3/RLF, INSIA/EPIL, INSL5/RIF2, INSL6/RIF1, and relaxin3. Passive immunization with anti-relaxin antibodies during the anteparmm period reduces cervical growth and extensibility as well as disrupts birth in rodents. In addition, numerous studies have shown that serum relaxin is an independent predictor of the risk of preterm delivery at multiple stages of pregnancy in humans. These earlier studies have propelled the proposition that a reduction of relaxin activity through receptor antagonists or immunization could be important for the treatment of preterm labor and birth in conjunction with traditional methods targeting other signaling pathways. Our recent studies have established that relaxin activates two orphan G protein-coupled receptors, LGR7 and LGR8 (Hsu et al., 2002. Science 295:671-4) as well as the cAMP-dependent pathway in target cells, whereas the closely related relaxin3 and INSL3 are selective agonists for LGR7 and LGR8, respectively. To take advantage of these new findings in relaxin signaling for the benefit of reproductive health research, we propose to screen for mutant recombinant relaxin antagonists that retain receptor-binding activity while being devoid of receptor-activation activity. Once mutant peptides with only the receptor binding activity are obtained, the antagonistic effect of these peptides will be tested in co-treatment assays to determine whether the mutant peptides are capable of antagonizing the relaxin-induced cAMP production in LGR7- and LGR8- expressing cells as well as delaying parturition in pregnant rats in vivo. These antagonists could be used to block relaxin action during preterm labor as well as provide a tool for further research on the role of LGR7 and LGR8 in reproductive tract physiology.

描述（由申请人提供）：放松素是一种由黄体，Decidua和胎盘在怀孕期间达到最高血浆水平的杂二肽激素。除了其在抑制子宫收缩活性中的作用外，已证明松弛素还会影响胶原蛋白重塑的诱导以及随之而来的出生管组织（宫颈和阴道）的软化，乳腺的生长和分化以及血管的扩张。因此，放松素在怀孕期间的生理适应性调节中起着重要作用。基于：主要和次要结构特征，将松弛素与胰岛素和胰岛素样生长因子（IGF）分组为结构同源物。类似于胰岛素，前体形式的胰岛素，其结构域的排列类似于胰岛素和IGF前体。成熟的松弛素似乎是通过转化酶处理的，以从prorelaxin产生两链异二聚体。除了人类中的两个几乎相同的松弛素基因外，还有五个其他放松蛋白家族基因，包括编码INSL3/RLF，INSIA/EPIL，INSL5/RIF2，INSL6/RIF1和LASEXIN3的那些基因。 用抗激素抗体的被动免疫在天前时期降低了宫颈的生长和可扩展性，并破坏啮齿动物的出生。此外，许多研究表明，血清松弛素是对人类怀孕多个妊娠阶段的早产风险的独立预测指标。这些早期的研究推动了这样一个主张，即通过受体拮抗剂或免疫降低松弛活性对于对早产和出生的治疗与针对其他信号通路的传统方法可能很重要。我们最近的研究确定，松弛素激活两个孤儿G蛋白偶联受体LGR7和LGR8（Hsu等，2002。Science295：671-4）以及靶细胞中的CAMP依赖性途径，而密切相关的RelaseIn3和Insl3对LGR7和INSL3是针对LGR7和LGR7和LGR8的选择性的。为了利用放松蛋白信号传导中的这些新发现，以促进生殖健康研究的益处，我们建议筛选突变的重组松弛蛋白拮抗剂，这些拮抗剂保留受体结合活性，同时却没有受体激活活性。一旦仅获得了具有受体结合活性的突变肽，这些肽的拮抗作用将在共同处理测定中测试，以确定突变肽是否能够拮抗LGR7和LGR8-表达细胞中的松弛蛋白诱导的CAMP产生，并在Vivo中延迟partection的大鼠。这些拮抗剂可用于阻止早产期间的松弛素作用，并为LGR7和LGR8在生殖道生理学中的作用提供进一步研究的工具。