Switch of Osteogenesis in Vascular Calcification

总结 血管钙化的治疗进展可能具有深远的公共利益。血管钙化是 糖尿病并发症的频繁发生与发病率和死亡率的增加有关。虽然 确切的机制尚未确定，已知血管钙化是一个活跃的过程， 异位骨形成，其中成骨分化发生在从其他细胞转分化的细胞中， 血统以前的研究表明，血管内皮细胞改变细胞命运，分化为 成骨细胞样细胞在血管钙化。然而，不知道是否通过诱导来逆转这种开关， 成骨细胞-内皮细胞转分化改善血管钙化。先进的调查已经 表明小分子能够重新编程和调节细胞命运，还表明， 内皮样细胞可以从其它谱系转分化。在目前的建议中，我们利用 通过高通量技术鉴定的小分子，旨在诱导成骨细胞-内皮细胞 转分化，并探讨糖尿病血管钙化的影响。初步数据显示， 我们使用高通量模型来鉴定GSK 3抑制剂SB 216763将成骨细胞转化为 内皮样细胞我们发现SB 216763或限制性GSK 3 β调节SMAD 1和SMAD 2的蛋白水平。 连环蛋白及其转录活性将成骨细胞命运转变为内皮分化。 此外，SB 216763治疗减少了EC-起源的成骨分化，并减少了钙化。 基质Gla蛋白敲除小鼠主动脉，建立血管钙化模型。治疗 SB 216763还可降低糖尿病Ins 2 Akita/+小鼠的动脉钙化，而不影响其他组织。 因此，我们假设GSK 3抑制诱导成骨细胞-内皮细胞转分化， 改善糖尿病血管钙化。在具体目标1中，我们将阐明其机制 潜在的成骨细胞-内皮细胞转分化诱导的GSK 3抑制。具体目标2： 确定GSK 3抑制是否改善糖尿病小鼠模型中的血管钙化。如果成功，它将 将成骨细胞-内皮细胞转分化作为一个新的概念，而GSK 3抑制剂SB 216763可能 成为治疗获得性血管疾病钙化的一种新的治疗方法。

SUMMARY Therapeutic advances in vascular calcification may have far-reaching public benefits. Vascular calcification is a frequent complication of diabetes mellitus associated with the increase of morbidity and mortality. Although the precise mechanism has not been determined, vascular calcification is known to be an active process involving ectopic bone formation, in which osteogenic differentiation occurs in the cells transdifferentiated from other lineages. Previous studies have shown that vascular endothelial cells switch cell fate to differentiate into osteoblastic-like cells in vascular calcification. However, it is unknown if reversing this switch by inducing osteoblastic-endothelial transdifferentiation ameliorates vascular calcification. Advanced investigations have shown that the small molecules are able to reprogram and modulate cell fates, and also shown that endothelial-like cells can be transdifferentiated from other lineages. In present proposal, we take advantage of a small molecule identified by using high throughput technology, aiming to induce osteoblastic-endothelial transdifferentiation and investigate the effects on vascular calcification in diabetes mellitus. In preliminary data, we use a high throughput model to identify that GSK3 inhibitor SB216763 converts osteoblasts into endothelial-like cells. We show that SB216763 or limiting GSK3ß modulates protein levels of SMAD1 and ß- catenin and their transcriptional activity to switch the osteoblastic fate for endothelial differentiation. Furthermore, SB216763 treatment reduces EC-origin osteogenic differentiation and decreases calcification in aorta of matrix Gla protein null mouse, an established model of vascular calcification. The treatment of SB216763 also decreases arterial calcification in diabetic Ins2Akita/+ mice without affecting other tissues. Therefore, we hypothesize that GSK3 inhibition induces osteoblastic-endothelial transdifferentiation to ameliorate vascular calcification in diabetes mellitus. In specific Aim 1, we will elucidate the mechanism underlying osteoblastic-endothelial transdifferentiation induced by GSK3 inhibition. In specific Aim 2, we will determine if GSK3 inhibition ameliorates vascular calcification in diabetic mouse model. If successful, it will build osteoblastic-endothelial transdifferentiation as a new concept, and GSK3 inhibitor SB216763 may emerge as a new therapeutic approach to treat calcification in acquired vascular diseases.