Gene Regulatory Mechanisms that Repress BMP2 in Pathological Calcification

这个项目的目标是了解衰老和慢性肾脏疾病(CKD)是如何促进 骨形态发生蛋白2(BMP2)的合成，进一步促进骨组织的病理性钙化 心脏瓣膜和血管系统。 转录后调控机制抑制BMP2在主动脉和主动脉瓣中的表达。我们 假设(1)这种抑制对于控制成人的BMP2水平是必不可少的，并且 (2)衰老和慢性肾脏病等情况损害了调节这一过程的因素的功能。 在健康的心脏瓣膜和主动脉中的抑制。 我们将在老年正常小鼠(24个月)和Klotho零小鼠身上测试这些假说 它模拟了年龄相关的疾病，包括慢性肾脏病。Klotho基因缺失小鼠早衰 死亡发生在7-8周大的时候。此时，心脏瓣膜广泛钙化， 血管系统等软组织已经出现。 目的1是测试有条件地删除一个强抑制因素对 骨形态发生蛋白2的3‘非翻译区对正常衰老和Klotho Null小鼠钙化的影响 小鼠过早衰老和衰老相关的肾功能障碍。我们最近将使用 开发BMP2等位基因来评估这种有效的转录后抑制物的缺失如何 影响与衰老和肾功能障碍相关的钙化进程。初步 结果表明，骨钙素对钙化有抑制作用。 目标2是识别和比较年轻、健康的主动脉和主动脉特有的miRNA信号 对正常衰老小鼠和Klotho基因缺失小鼠这些组织特征的影响 过早衰老和严重的血管钙化。在这些简介中，我们将重点关注后 靶向BMP2的转录抑制因子(MiRNAs)并参与3‘非编码区 在健康组织中介导的抑制。 目标3是测试选择和验证的miRNAs如何影响BMP2和BMP2的表达 下游成骨事件导致Klotho基因缺失小鼠的钙化，携带我们独特的 转基因。我们的新型BMP2报告小鼠将加快miRNA的临床前测试 防止病理性钙化的疗法。我们新开发的BMP2等位基因(Aim 1)将 区分这些针对BMP2的miRNAs相对于非靶向基因的变化。 拟议研究的结果将是：(1)增加对BMP2如何 对病理性钙化的影响，(2)潜在miRNA的鉴定和分析 生物标志物，以及(3)控制病理性钙化的新的治疗线索。

The goal of this project is to understand how aging and chronic kidney disease (CKD) promote bone morphogenetic protein 2 (BMP2) synthesis that furthers pathological calcification of the heart valves and vasculature. Post-transcriptional regulatory mechanisms repress BMP2 in aorta and aortic valve. We hypothesize that (1) this repression is essential for controlling BMP2 levels in the adult and that (2) conditions such as aging and CKD impair the function of factors that mediate this repression in healthy heart valves and aorta. We will test these hypotheses in aged normal mice (24 months) and in the Klotho null mouse which models age-related disorders, including CKD. Klotho null mice suffer premature aging and death occurs at 7 - 8 weeks of age. At this time, extensive calcification of the heart valves, vasculature, and other soft tissues has occurred. AIM 1 is to test the influence of conditionally deleting a strong repressive element in the 3'untranslated region (UTR) of Bmp2 on calcification in normal aged mice and in Klotho null mice with premature aging and aging associated renal dysfunction. We will use recently developed Bmp2 alleles to assess how the deletion of this potent post-transcriptional repressor influences the course of calcification associated with aging and renal dysfunction. Preliminary results indicate that the UCS inhibits calcification. AIM 2 is to identify and compare miRNA signatures unique to young, healthy aorta and aortic valve to the signatures of these tissues from normal aged mice and in Klotho null mice with premature aging and severe vascular calcification. Within these profiles, we will focus on post- transcriptional repressive factors (miRNAs) that target the Bmp2 UCS and contribute to 3'UTR mediated repression in healthy tissues. AIM 3 is to test how selected and validated miRNAs influence the expression Bmp2 and downstream osteogenic events that lead to calcification in Klotho null mice bearing our unique transgenes. Our novel Bmp2 reporter mouse will expedite pre-clinical testing of miRNA therapies that prevent pathological calcification. Our newly developed Bmp2 allele (Aim 1) will differentiate changes due these miRNAs targeting Bmp2 relative to off-target genes. The outcomes of the proposed research will be (1) increased understanding of how BMP2 influences pathological calcification, (2) the identification and analyses of potential miRNA biomarkers, and (3) new therapeutic leads for controlling pathological calcification.