系统性硬化症(SSc)是一种慢性自身免疫性结缔组织疾病。血管损害是SSc的重要特点之一,影响疾病的进展和预后。MiR-126-3p是调节血管结构和功能的重要microRNA(miRNA),可以通过外泌体运输。然而,miR-126-3p在SSc血管损伤中的作用尚不清楚.因此,我们专注于miR-126-3p与SSc血管损伤之间的联系,以及研究miR-126-3p在SSc血管损伤中的潜在作用。首先,这项研究成功地从临床血浆样本中提取了细胞外囊泡,并对其中的外泌体进行了表征。然后,我们通过在线数据库预测并筛选了哺乳动物/机制雷帕霉素靶蛋白(mTOR)的靶途径和miR-126-3p的靶基因SLC7A5。接下来,我们构建了SSc小鼠用于体内研究。结果显示血浆外泌体中miR-126-3p的表达降低,而SLC7A5表达式,自噬,和脂质过氧化在主动脉中增加。荧光素酶报告基因测定表明miR-126-3p可以与SLC7A5结合,导致其表达降低。体外实验表明,外泌体miR-126-3p可以被人脐静脉内皮细胞(HUVEC)内化。miR-126-3p组表现出增强的细胞活力和试管形成能力,随着血管形成标志物CD31的表达增加。此外,miR-126-3p下调HUVECs中SLC7A5和LC3的蛋白表达,在上调mTOR蛋白表达的同时,P62,PPARγ,和CPT-1。然而,miR-126-3p对HUVECs的作用被mTOR抑制剂抵消,被mTOR激活剂增强.结果表明,外泌体miR-126-3p有可能通过调节HUVECs中的SLC7A5/mTOR信号通路来保护SSc免受血管损伤。
Systemic sclerosis (SSc) is a chronic autoimmune connective tissue disease. Vascular damage is one of the important features of SSc, which affects the progression and prognosis of the disease. MiR-126-3p is an important microRNA (miRNA) that regulates vascular structure and function, which can be transported through exosomes. However, the role of miR-126-3p in vascular damage in SSc is still unclear. Therefore, we focused on the connection between miR-126-3p and vascular damage in SSc, as well as investigated the potential role of miR-126-3p in vascular damage in SSc. First, this study successfully extracted extracellular vesicles from clinical plasma samples and characterized the exosomes within them. Then, we predicted and screened the target pathway mammalian/mechanistic target of rapamycin (mTOR) and the target gene SLC7A5 of miR-126-3p through online databases. Next, we constructed SSc mice for in vivo studies. The results showed that the expression of miR-126-3p was decreased in the plasma exosomes, while the SLC7A5 expression, autophagy, and lipid peroxidation were increased in the aorta. Luciferase reporter gene assays demonstrated that miR-126-3p can bind to SLC7A5, resulting in a decrease in its expression. In vitro experiments have shown that exosomal miR-126-3p can be internalized by human umbilical vein endothelial cells (HUVECs). The miR-126-3p group exhibited enhanced cell viability and tube formation ability, along with increased expression of the vascular formation marker CD31. Additionally, miR-126-3p downregulated the protein expression of SLC7A5 and LC3 in HUVECs, while upregulating the protein expression of mTOR, P62, PPARγ, and CPT-1. However, the effects of miR-126-3p on HUVECs were counteracted by mTOR inhibitors and enhanced by mTOR activators. The results indicated that exosomal miR-126-3p has the potential to protect against vascular injury in SSc by regulating the SLC7A5/mTOR signalling pathway in HUVECs.