2026 年第 10 期 第 21 卷

PALMD缺失通过激活转化生长因子β通路促进主动脉瓣膜间质细胞衰老的机制研究

Mechanism research on PALMD deletion promoting senescence of aortic valve interstitial cells via activating transforming growth factor-β pathway

作者：冯雨张继超韩迎春李玉琳

英文作者：Feng Yu Zhang Jichao Han Yingchun Li Yulin

单位：首都医科大学附属北京安贞医院北京市心肺血管疾病研究所心血管基础与转化医学研究中心，北京101118

英文单位：Center for Basic and Translational Cardiovascular Medicine Beijing Anzhen Hospital Capital Medical University Beijing Institute of Heart Lung and Blood Vessel Diseases Beijing 101118 China

关键词：主动脉瓣狭窄；细胞衰老；PALMD

英文关键词：Aorticvalvestenosis;Cellsenescence;PALMD

• 摘要：

• 目的  探讨PALMD在钙化性主动脉瓣狭窄（CAVS）发生发展中对细胞衰老的调控作用及分子机制。方法 通过基因表达综合数据库分析PALMD与衰老相关基因CDKN1A、CDKN1B的相关性；构建PALMD/载脂蛋白E（ApoE）双基因敲除（DKO）小鼠模型，采用β-半乳糖苷酶染色、CDKN1A免疫荧光染色检测主动脉瓣的衰老细胞；分离人原代瓣膜间质细胞，利用小干扰RNA（siRNA）敲低PALMD表达，通过β-半乳糖苷酶染色及实时荧光定量聚合酶链反应（qPCR）检测细胞衰老状态及衰老相关基因表达；采用蛋白质免疫印迹和qPCR分析SMAD3磷酸化水平及转化生长因子β（TGF-β）通路下游基因表达变化。结果 PALMD表达与CDKN1A、CDKN1B呈显著负相关；在DKO小鼠主动脉瓣中CDKN1A阳性细胞显著增多；体外敲低PALMD可促进瓣膜间质细胞衰老，衰老相关基因CDKN1A、CDKN2B表达上调（均P<0.05）；机制上，PALMD缺失可激活TGF-β通路，表现为SMAD3磷酸化水平升高及下游基因纤溶酶原激活物抑制剂-1、结缔组织生长因子表达增加。结论 PALMD通过抑制TGF-β信号通路活化延缓主动脉瓣膜间质细胞衰老，其缺失可促进细胞衰老并加速主动脉瓣狭窄进程，PALMD可作为CAVS干预的潜在靶点。

• Objective To investigate the regulatory effect and molecular mechanism of PALMD on cell senescence during the initiation and progression of calcific aortic valve stenosis (CAVS). Methods The correlations between PALMD and senescence-related genes CDKN1A and CDKN1B were analyzed based on the gene expression omnibus database. PALMD/apolipoprotein E (ApoE) double knockout (DKO) mouse models were established. Senescent cells in aortic valves were detected by β-galactosidase staining and CDKN1A immunofluorescence staining. Primary human valvular interstitial cells were isolated, and PALMD expression was knocked down by small interfering RNA (siRNA). Cell senescence status and the expression of senescence-related genes were detected via β-galactosidase staining and quantitative real-time polymerase chain reaction (qPCR). Western blot and qPCR were performed to detect the phosphorylation level of SMAD3 and the expression changes of downstream genes of transforming growth factor-β (TGF-β) pathway. Results PALMD expression was significantly negatively correlated with CDKN1A and CDKN1B. The number of CDKN1A-positive senescent cells was markedly increased in aortic valves of DKO mice. In vitro PALMD knockdown accelerated valvular interstitial cell senescence and upregulated the expression of senescence-related genes CDKN1A and CDKN2B (all P<0.05). Mechanistically, PALMD deletion activated the TGF-β pathway, manifested as elevated SMAD3 phosphorylation and increased expression of downstream genes PAI-1 and CTGF. Conclusion PALMD alleviates senescence of aortic valve interstitial cells by suppressing the activation of TGF-β signaling pathway. PALMD deletion accelerates cell senescence and the progression of aortic valve stenosis, and PALMD can serve as a potential therapeutic target for CAVS intervention.