Gene Regulatory Mechanisms that Repress BMP2 in Pathological Calcification

该项目的目标是了解衰老和慢性肾脏病（CKD）如何促进 骨形态发生蛋白2（BMP 2）的合成，进一步促进了 心脏瓣膜和脉管系统。 转录后调节机制抑制主动脉和主动脉瓣中的BMP 2。我们 假设（1）这种抑制对于控制成人中的BMP 2水平是必需的， (2)诸如衰老和CKD等疾病损害了介导这种疾病的因子的功能， 抑制健康的心脏瓣膜和主动脉。 我们将在老年正常小鼠（24个月）和Klotho基因敲除小鼠中检验这些假设 它模拟了与年龄相关的疾病，包括慢性肾病。Klotho基因敲除小鼠遭受过早衰老 并且在7 - 8周龄时死亡。此时心脏瓣膜广泛钙化 血管系统和其他软组织发生。 目的1是测试有条件地删除一个强抑制因素的影响， Bmp 2的3 '非翻译区（UTR）对正常老年小鼠和Klotho null小鼠钙化的影响 小鼠过早衰老和衰老相关的肾功能不全。我们最近将使用 开发了Bmp 2等位基因，以评估这种有效的转录后抑制因子的缺失 影响与衰老和肾功能不全相关的钙化过程。初步 结果表明，UCS抑制钙化。 目的2是鉴定和比较年轻、健康主动脉和主动脉瘤中独特的miRNA特征， 这些组织的签名来自正常老年小鼠和Klotho基因敲除小鼠， 过早衰老和严重的血管钙化在这些配置文件中，我们将重点放在后- 靶向Bmp 2 UCS并促进3 'UTR的转录抑制因子（miRNA） 在健康组织中介导抑制。 目的3是测试选择和验证的miRNAs如何影响Bmp 2和Bmp 3的表达。 下游成骨事件导致Klotho基因敲除小鼠的钙化， 转基因我们的新型Bmp 2报告小鼠将加快miRNA的临床前测试 预防病理性钙化的疗法。我们新开发的Bmp 2等位基因（Aim 1）将 区分由于这些靶向Bmp 2的miRNA相对于脱靶基因的变化。 拟议研究的结果将是（1）增加对BMP 2 影响病理性钙化，（2）潜在miRNA的鉴定和分析 生物标志物，和（3）控制病理性钙化的新治疗线索。

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.