IMPACT OF MENOPAUSE ON VAGINAL CONNECTIVE TISSUE SUPPORT

描述(申请人提供)：失去阴道结缔组织支持会导致盆腔内脏脱垂进入阴道。脱垂和脱垂的后遗症对数百万妇女的生活产生了深远的负面影响。在美国，11%的女性将接受修复脱垂的大手术，30%的女性因手术失败而需要重新手术。到目前为止，大多数研究都把分娩作为发展脱垂的主要风险因素；然而，大多数妇女直到分娩后几十年才出现脱垂，这表明其他因素起作用(4-6，35-38)。在这次修订的拨款申请中，我们汇集了一个多学科的专家团队，通过全面分析更年期对阴道支持结缔组织的影响来研究更年期作为脱垂的风险因素。在目标I-1和1-2中，我们建议对未接受激素治疗的绝经前和绝经后妇女的阴道支持性结缔组织活检进行比较，以测试未接受激素治疗的绝经后妇女的胶原[I/(III+V)]比率降低是否会导致生物力学性能下降并容易脱垂。此外，我们还确定了弹性蛋白和/或平滑肌相对于胶原的数量变化是否与生物力学的恶化有关。最后，在赠款的这一部分，我们询问绝经后妇女的激素治疗是否改善了未接受激素治疗的绝经后妇女阴道结缔组织中发现的结构和生物力学缺陷。在AIM II-1中，我们将研究阴道结缔组织这些结构成分的变化是否由于结缔组织降解基质金属蛋白酶(MMPs)相对于其内源性抑制物(TIMPs)的表达和活性模式的改变。我们使用生化方法测量单个金属蛋白酶的表达和活性，并使用底物降解实验测量组织中的净蛋白分解活性。同时研究了17-β-雌二醇+/-孕酮对培养的支持性阴道结缔组织来源的细胞中基质金属蛋白酶/组织基质金属蛋白酶/基质金属蛋白酶表达的调节机制。由于人体组织研究固有的局限性，我们在AIMS III-1和111-2中使用了一个大鼠模型，以确定补充17-β-雌二醇、17-β-雌二醇和孕酮或补充基质金属蛋白酶抑制剂-化学修饰的四环素-8是否可以防止中年大鼠手术诱导更年期后阴道结缔组织生物力学性能的恶化。我们有令人兴奋的初步数据来支持研究中概述的每个目标。我们相信，这项修订后的赠款提案的结果将阐明导致女性阴道壁脱垂的重要机制，并最终将有助于制定预防策略，以治疗这种常见的、令人衰弱的、但研究极少的疾病。

DESCRIPTION (provided by applicant): Loss of the vaginal connective tissue support results in prolapse of the pelvic viscera into the vaginal canal. Prolapse and the sequela of prolapse have a profoundly negative impact on the lives of millions of women. Eleven percent of women in the United States will undergo a major surgical procedure to repair prolapse and 30% require re-operation because of failure (4). Until now, most studies have focused on childbirth as the primary risk factor for developing prolapse; however, the majority of women do not develop prolapse until decades following childbirth indicating that other factors play a role (4-6, 35-38). In this revised grant application, we have collected a multidisciplinary team of experts to study menopause as a risk factor for prolapse by performing a comprehensive analysis of the impact of menopause on the supportive connective tissue of the vagina. In Aims I-1 and 1-2, we propose to compare biopsies of vaginal supportive connective tissue in premenopausal and postmenopausal women not on hormone therapy to test whether a decrease in the ratios of collagen [I/(III + V)] in postmenopausal women not on hormone therapy leads to inferior biomechanical properties and predisposes to prolapse. In addition, we determine whether quantitative changes in the amount of elastin and/or smooth muscle relative to collagen correlate with a deterioration in biomechanics. Finally, in this section of the grant, we ask whether hormone therapy in postmenopausal women improves the structural and biomechanical deficiencies identified in the vaginal connective tissue of postmenopausal women not on hormone therapy. In Aim II-1, we will investigate whether the changes in these structural components of the vaginal connective tissue are due to an alteration in the expression and activity pattern of the connective tissue degrading Matrix Metalloproteinases (MMPs) relative to their endogenous inhibitors (Tissue Inhibitors of MMPs, TIMPs). We measure the expression and activity of individual metalloproteinases using biochemical assays and net proteolytic activity in tissue using substrate degradation assays. The mechanism of regulation of MMP/TIMP expression by 17-beta-estradiol +/- progesterone is studied, in parallel, in cells derived from the supportive vaginal connective tissue in culture. Because of the limitations inherent in studies on human tissues, we use a rat model in Aims III-1 and 111-2, to determine whether supplementation with 17-beta-estradiol, 17-beta-estradiol and progesterone or the MMP inhibitor - chemically modified tetracycline-8, prevents the deterioration in the biomechanical properties of the vaginal connective tissue that occur following a surgically induced menopause in middle aged rats. We have exciting preliminary data to support each of the Aims outlined in the study. We believe that the results of this revised grant proposal will elucidate an important mechanism that predisposes women to vaginal wall prolapse and will ultimately contribute to the development of preventative strategies to treat this common and debilitating, yet vastly understudied disease.