Wu Yunhui, Yang Binhong, Sun Haoqi, Cheng Meijuan, Jin Jingjing, Zhang Dongxue, Chang Lixin, Zhang Shenglei, Bai Yaling, Xu Jinsheng
Department of Nephrology, The Fourth Hospital of Hebei Medical University, 12 Jiankang Road, Shijiazhuang, 050011, People's Republic of China.
Hebei Key Laboratory of Vascular Calcification in Kidney Disease, Shijiazhuang, People's Republic of China.
Cardiovasc Diabetol. 2025 Jun 3;24(1):236. doi: 10.1186/s12933-025-02797-3.
Vascular calcification (VC) is frequently observed in patients with chronic kidney disease (CKD), which seriously affects the structure and function of blood vessels. Ferroptosis, a type of cell death caused by iron-catalyzed reactive oxygen species (ROS) and lipid peroxidation, has been implicated in cardiovascular diseases, including VC. However, the underlying molecular mechanisms of ferroptosis in VSMCs remain poorly understood.
Bioinformatics analysis was employed to mine the dataset and screen sterol regulatory element-binding protein 1 (SREBP1) related to ferroptosis and VC. Quantitative real-time polymerase chain reaction, western blotting, immunofluorescence, and immunohistochemistry were used to analyze gene expression. Functional experiments were conducted to comprehensively investigate the effects of SREBP1 on ferroptosis and VC. Chromatin immunoprecipitation (ChIP) analysis and dual-luciferase reporter assays were utilized to further elucidate the regulatory effects of SREBP1 on the inhibitor of apoptosis-stimulating protein of p53 (iASPP).
We identified that liproxstatin-1 (Lip-1), as a ferroptosis-specific inhibitor, dose-dependently impeded calcification progression, highlighting the pivotal roles of lipid peroxidation. Furthermore, we obtained clues that SREBP1, a lipid-regulating transcription factor, was associated with calcification and ferroptosis by investigating the GEO and FerrDB databases. Subsequently, we observed that SREBP1 was significantly downregulated in serum and calcified radial arteries of CKD patients, in calcified aortas from CKD mice, and in calcified VSMCs. The low SREBP1 expression was inversely correlated with ferroptosis in vivo and in vitro, respectively. Overexpression of SREBP1 remarkably attenuated osteogenic differentiation and calcium deposition of VSMCs by suppressing ferroptosis. Mechanistically, we demonstrated that SREBP1 bound to the promoter region of iASPP and directly promoted the expression of iASPP. Moreover, iASPP silencing exacerbated ferroptosis and calcification of VSMCs. Rescue experiments revealed that SREBP1 exerted the protective effects on VC that were achieved in part by regulating the activation of iASPP. In vivo experiments further elucidated that artery-specific SREBP1 overexpression alleviated ferroptosis and calcification via the SREBP1/iASPP axis in CKD mice.
These findings report that targeting SREBP1 or iASPP may represent an attractive interventional strategy for VC in CKD.
血管钙化（VC）在慢性肾脏病（CKD）患者中经常出现，严重影响血管的结构和功能。铁死亡是一种由铁催化的活性氧（ROS）和脂质过氧化引起的细胞死亡，已被证明与包括VC在内的心血管疾病有关。然而，血管平滑肌细胞（VSMCs）中铁死亡的潜在分子机制仍知之甚少。
采用生物信息学分析挖掘数据集，筛选与铁死亡和VC相关的固醇调节元件结合蛋白1（SREBP1）。运用定量实时聚合酶链反应、蛋白质免疫印迹法、免疫荧光和免疫组织化学分析基因表达。进行功能实验以全面研究SREBP1对铁死亡和VC的影响。利用染色质免疫沉淀（ChIP）分析和双荧光素酶报告基因检测进一步阐明SREBP1对p53凋亡刺激蛋白抑制剂（iASPP）的调控作用。
我们发现，铁死亡特异性抑制剂liproxstatin-1（Lip-1）能剂量依赖性地抑制钙化进展，突出了脂质过氧化的关键作用。此外，通过研究GEO和FerrDB数据库，我们获得线索表明，脂质调节转录因子SREBP1与钙化和铁死亡有关。随后，我们观察到在CKD患者的血清和钙化桡动脉、CKD小鼠的钙化主动脉以及钙化的VSMCs中，SREBP1显著下调。SREBP1的低表达分别与体内和体外的铁死亡呈负相关。SREBP1的过表达通过抑制铁死亡显著减弱了VSMCs的成骨分化和钙沉积。机制上，我们证明SREBP1与iASPP的启动子区域结合并直接促进iASPP的表达。此外，iASPP沉默加剧了VSMCs的铁死亡和钙化。挽救实验表明，SREBP1对VC的保护作用部分是通过调节iASPP的激活实现的。体内实验进一步阐明，在CKD小鼠中，动脉特异性SREBP1过表达通过SREBP1/iASPP轴减轻了铁死亡和钙化。
这些发现表明，靶向SREBP1或iASPP可能是CKD中VC的一种有吸引力的干预策略。
