Vascular calcification is a pathological process commonly associated with atherosclerosis, chronic kidney disease, and diabetes. Paraspeckle protein NONO is a multifunctional RNA/DNA binding protein involved in many nuclear biological processes but its role in vascular calcification remains unclear. Here, we observed that NONO expression was decreased in calcified arteries of mice and patients with CKD. We generated smooth muscle-specific NONO-knockout mice and established three different mouse models of vascular calcification by means of 5/6 nephrectomy, adenine diet to induce chronic kidney failure, or vitamin D injection. The knockout mice were more susceptible to the development of vascular calcification relative to control mice, as verified by an increased calcification severity and calcium deposition. Likewise, aortic rings from knockout mice showed more significant vascular calcification than those from control mice . , NONO deficiency aggravated high phosphate–induced vascular smooth muscle cell osteogenic differentiation and apoptosis, whereas NONO overexpression had a protective effect. Mechanistically, we demonstrated that the regulation of vascular calcification by NONO was mediated by bone morphogenetic protein 2 (BMP2). NONO directly bound to the BMP2 promoter using its C-terminal region, exerting an inhibitory effect on the transcription of BMP2. Thus, our study reveals that NONO is a novel negative regulator of vascular calcification, which inhibits osteogenic differentiation of vascular smooth muscle cell and vascular calcification via negatively regulating BMP2 transcription. Hence, NONO may provide a promising target for the prevention and treatment of vascular calcification.

中文翻译：

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Paraspeckle 蛋白 NONO 通过抑制骨形态发生蛋白 2 转录来减轻血管钙化

血管钙化是一种通常与动脉粥样硬化、慢性肾病和糖尿病相关的病理过程。 Paraspeckle 蛋白 NONO 是一种多功能 RNA/DNA 结合蛋白，参与许多核生物学过程，但其在血管钙化中的作用仍不清楚。在这里，我们观察到小鼠和 CKD 患者的钙化动脉中 NONO 表达减少。我们培育了平滑肌特异性 NONO 基因敲除小鼠，并通过 5/6 肾切除、腺嘌呤饮食诱导慢性肾衰竭或注射维生素 D 的方式建立了三种不同的血管钙化小鼠模型。与对照小鼠相比，基因敲除小鼠更容易发生血管钙化，钙化严重程度增加和钙沉积证实了这一点。同样，基因敲除小鼠的主动脉环比对照小鼠的主动脉环显示出更明显的血管钙化。 ，NONO缺乏会加剧高磷酸诱导的血管平滑肌细胞成骨分化和凋亡，而NONO过表达则具有保护作用。从机制上讲，我们证明 NONO 对血管钙化的调节是由骨形态发生蛋白 2 (BMP2) 介导的。 NONO利用其C端区域直接与BMP2启动子结合，对BMP2的转录产生抑制作用。因此，我们的研究表明NONO是一种新型的血管钙化负调节因子，它通过负调节BMP2转录来抑制血管平滑肌细胞的成骨分化和血管钙化。因此，NONO可能为预防和治疗血管钙化提供一个有前景的靶点。