MOLECULAR MECHANISMS CONTRIBUTING TO GENDER DISPARITY IN MULTIPLE SCLEROSIS

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。多发性硬化症（MS）影响了大约40万美国人，其中三分之二是女性。MS的病因尚不清楚，但髓磷脂蛋白可能是引发中枢神经系统炎症反应的自身抗原。阐明这些激素影响小胶质细胞功能的机制和理解重要髓磷脂特异性蛋白的调节对于理解多发性硬化症性别差异的基础至关重要。该项目的目标是确定导致多发性硬化症性别偏见的分子机制，女性性类固醇对小胶质细胞功能调节的影响将通过观察表达来评估iNOS的水平和调节，iNOS是炎症分子产生的关键酶，负责随后的髓磷脂降解，这是该疾病的特征。将inos -荧光素酶构建体瞬时转染到小胶质细胞中来检验这一途径，近几个月来，一个有效的转染系统已经在实验室中得到了优化。实验正在进行中，以评估在培养基中添加雌性类固醇后iNOS表达的反应。性类固醇对免疫反应的调节可能导致多发性硬化症的性别差异，但介导疾病易感性的潜在自身抗原的性别特异性表达也可能起作用。现有的数据表明，在成熟的中枢神经系统髓鞘中发现的编码最丰富蛋白的Plp mRNA在小鼠睾丸的间质细胞中表达，以前认为只在中枢神经系统中表达，而在雌性睾丸的外周细胞中没有表达。我们获得的Western blot数据证实了Plp蛋白在睾丸组织中的表达。这种外周表达可能在男性中建立保护性耐受。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Multiple sclerosis (MS) affects approximately 400,000 Americans, two-thirds of whom are female. The causes of MS remain elusive, but a myelin protein is likely to be the autoantigen responsible for initiating the inflammatory response in the CNS, and sex steroids may modulate susceptibility to MS. Elucidation of the mechanisms by which these hormones influence microglial function and an understanding of the regulation of important myelin-specific proteins will be crucial in understanding the basis of gender differences in MS. The goals of this project are to determine molecular mechanisms that result in a gender bias in MS. Effects of female sex steroids upon the regulation of microglia function will be assessed by looking at expression levels and regulation of iNOS, a key enzyme in the production of inflammatory molecules responsible for the subsequent degradation of myelin characteristic of the disease. Transient transfections of iNOS-luciferase constructs into microglial cells will be done to examine this pathway, and an efficient system for these transfections has been optimized in the lab in recent months. Experiments are underway to assess iNOS expression in response to female sex steroids added to culture media. Modulation of the immune response by sex steroids is likely to contribute to the gender disparity of MS, but gender-specific expression of potential autoantigens in mediating susceptibility to the disease may also contribute. Existing data demonstrate expression of Plp mRNA encoding the most abundant protein found in mature CNS myelin, previously thought to be expressed exclusively in the CNS, in Leydig cells of the testes of mice, with no peripheral expression in female counterparts. We have obtained Western blot data confirming expression of Plp protein in testicular tissue. It is possible this peripheral expression could establish protective tolerance in males.