Sp1通过Hippo-YAP信号通路促进血管钙化的机制及干预研究

Vascular calcification is very common in patients with diabetes and end-stage renal disease. The presence of vascular calcification increases the mortality rate of cardiovascular disease, but there is no effective prevention or treatment. Sp1 acts as a transcription factor and has many functions.. The previous study by the applicant found that Sp1 can increase the release of matrix vesicles and promote vascular calcification, but the mechanisms are still unclear. Recent studies have found that Sp1 can regulate YAP protein expression, and Hippo-YAP signaling pathway can participate in the pathophysiological process of osteogenic differentiation. For the first time, the applicant found that silencing Sp1 can down-regulate the expression of YAP and reduce the release of matrix vesicles, ameliorating calcification. It is speculated that Sp1 may promote vascular calcification by regulating the Hippo-YAP signaling pathway. In addition, the applicant found that metformin can reduce vascular calcification and decrease the expression level of Sp1, and it is speculated that metformin may inhibit vascular calcification with Sp1 as a target. This study intends to use a variety of experimental methods to verify the hypothesis and further explore its underlying mechanisms. If the subject obtains the expected results, it will not only improve our understanding of the regulation mechanisms of vascular calcification, but also provide new ideas and theoretical basis for clinical prevention and treatment of vascular calcification.

临床上糖尿病、终末期肾病患者血管钙化非常普遍，血管钙化的存在使心血管疾病病死率增加，但并没有有效的预防、治疗办法。Sp1作为转录因子作用广泛，申请人前期研究发现Sp1在血管钙化中高表达，增加基质囊泡的释放，促进钙化，但具体机制尚不明确。近期研究发现Sp1可调控YAP的蛋白表达，Hippo-YAP信号通路可参与成骨分化的病理生理过程，申请者前期实验发现沉默Sp1能够下调YAP的表达并减少基质囊泡的释放，延缓钙化的发生发展。据此推测Sp1可能通过调控Hippo-YAP信号通路促进血管钙化。此外，申请者研究发现二甲双胍能够减轻血管钙化且Sp1表达水平下降，据此推测二甲双胍可能以Sp1为靶点抑制血管钙化。本课题拟运用多种实验方法验证假说，并进一步探讨其分子机制。本课题如获得预期结果，不仅能够增进我们对于血管钙化调节机制的了解，更能为临床预防和治疗血管钙化提供新思路及理论依据。

临床上糖尿病、终末期肾病患者血管钙化非常普遍。血管钙化的存在使血管僵硬度增加、脉压增大，造成冠脉灌注减少、心室肥厚，最终增加心血管疾病病死率，目前并没有有效的预防、治疗办法。研究证实转录因子Sp1能够直接促进BMP2转录加速平滑肌细胞表型转化，Sp1的翻译后修饰能明显影响Sp1的转录激活活性及稳定性。因此，我们推测除Sp1表达水平外，其翻译后修饰亦参与调控血管钙化，为靶向抑制Sp1促钙化作用提供了可能。此外YAP参与了血管钙化进程，YAP能够通过与Beclin结合改变Beclin泛素化水平，从而影响血管平滑肌细胞自噬、凋亡水平，进而影响血管钙化的发生发展。此外，二甲双胍能够通过以Sp1为干预靶点抑制血管钙化。