Yang Hanyan, Zhong Yulong, Guo Wenjie, Guo Wenjing, Chen Boliang, Lin Zexuan, Zhang Qin, Zou Rongjun, Cao Xiaolong, Li Fengxian, Feng Wei, Yan Jianyun, Zeng Zhi, Wang Wei, Ouyang Kunfu, Xu Xinjie, Fan Xiaoping, Fang Xi, Ai Shanshan, Liu Canzhao
Department of Cardiology, Southern Medical University, Guangdong, 510282, China (H.Y., Wenjie Guo, Wenjing Guo, B.C., Z.L., X.C., J.Y., Z.Z., S.A., C.L.).
Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, Guangdong Provincial Biomedical Engineering Technology Research Center for Cardiovascular Disease, Guangdong, 510282, China (H.Y., Wenjie Guo, Wenjing Guo, B.C., Z.L., J.Y., Z.Z., C.L.).
Circulation. 2025 Sep 16. doi: 10.1161/CIRCULATIONAHA.124.072525.
Neointimal hyperplasia is the major cause of significant vascular complications after arterial interventions. Despite the advancements in strategies such as drug-eluting stents to minimize neointimal hyperplasia, achieving consistently effective long-term outcomes remains a challenge. Protein-protein interactions mediated by PDZ (PSD-95, Discs-large, and ZO-1) domains are essential for numerous biological processes. However, little is known about the role of PDZ proteins in neointima formation. This study aims to explore the role of TAX1BP3 (Tax1 binding protein 3), a singular PDZ protein, in phenotypic switching of vascular smooth muscle cells (VSMCs) and its implication in neointimal hyperplasia.
Subcellular localization of TAX1BP3 was assessed in isolated VSMCs or arteries obtained from mice with neointima formation. TAX1BP3 mutants were constructed to study the role of SUMOylation on TAX1BP3 nucleocytoplasmic shuttling. VSMC-specific Tax1bp3 knockout mice were generated to determine the relevant phenotypes in a carotid artery wire injury model. RNA sequencing, assays for transposase-accessible chromatin using sequencing, computational prediction of complex structures, and coimmunoprecipitation were performed to elucidate the underlying molecular mechanisms. AAV-mediated Tax1bp3 gene delivery and engineered AIENP-TAX1BP3 were employed to investigate the potential translational relevance.
TAX1BP3 exhibited dynamic nucleocytoplasmic shuttling during phenotypic switching of VSMCs. TAX1BP3 is SUMOylated at K116, and its SUMOylation is essential for maintaining the nuclear localization of TAX1BP3. Deficiency of TAX1BP3 facilitated the transition from a contractile to a synthetic phenotype and aggravated neointima formation after vascular injury in mice. The integration of RNA sequencing and an assay for transposase-accessible chromatin using sequencing unveiled that TAX1BP3 primarily regulated the cell cycle progression and cell proliferation of VSMCs through YAP-TEAD transcription activity. The computational prediction of TAX1BP3/YAP1 complex structures and protein interaction-related experiments revealed that TAX1BP3 and TEAD1 compete for binding to YAP through its TEAD binding domain (BD) in a noncanonical PDZ manner. AAV-mediated Tax1bp3 gene delivery significantly attenuated postinjury neointima formation and the progression of atherosclerosis. AIENP-TAX1BP3 administration effectively reduced VSMC phenotypic switching and neointimal hyperplasia.
These results demonstrate that SUMOylation of TAX1BP3 at K116 enables its nucleocytoplasmic shuttling during phenotypic switching of VSMCs. TAX1BP3 competitively interacts with the YAP-TEAD complex in a noncanonical PDZ manner and exerts its protective role in vascular neointimal hyperplasia primarily through the regulation of cell proliferation.
内膜增生是动脉介入治疗后严重血管并发症的主要原因。尽管在诸如药物洗脱支架等旨在最小化内膜增生的策略方面取得了进展，但实现持续有效的长期疗效仍然是一项挑战。由PDZ（PSD-95、盘状大蛋白和ZO-1）结构域介导的蛋白质-蛋白质相互作用对众多生物学过程至关重要。然而，关于PDZ蛋白在内膜形成中的作用知之甚少。本研究旨在探讨一种独特的PDZ蛋白TAX1BP3（Tax1结合蛋白3）在血管平滑肌细胞（VSMC）表型转换中的作用及其在内膜增生中的意义。
在从内膜形成的小鼠中分离得到的VSMC或动脉中评估TAX1BP3的亚细胞定位。构建TAX1BP3突变体以研究SUMO化对TAX1BP3核质穿梭的作用。生成VSMC特异性Tax1bp3基因敲除小鼠，以确定颈动脉钢丝损伤模型中的相关表型。进行RNA测序、转座酶可及染色质测序分析、复杂结构的计算预测和免疫共沉淀，以阐明潜在的分子机制。采用腺相关病毒介导的Tax1bp3基因递送和工程化的AIENP-TAX1BP3来研究潜在的转化相关性。
TAX1BP3在VSMC表型转换过程中表现出动态核质穿梭。TAX1BP3在K116位点发生SUMO化，其SUMO化对于维持TAX1BP3的核定位至关重要。TAX1BP3的缺失促进了从收缩型到合成型表型的转变，并加重了小鼠血管损伤后的内膜形成。RNA测序与转座酶可及染色质测序分析的整合揭示，TAX1BP3主要通过YAP-TEAD转录活性调节VSMC的细胞周期进程和细胞增殖。TAX1BP3/YAP1复合物结构的计算预测和蛋白质相互作用相关实验表明，TAX1BP3和TEAD1通过其TEAD结合域（BD）以非经典PDZ方式竞争与YAP的结合。腺相关病毒介导的Tax1bp3基因递送显著减轻了损伤后内膜形成和动脉粥样硬化的进展。给予AIENP-TAX1BP3有效减少了VSMC表型转换和内膜增生。
这些结果表明，TAX1BP3在K116位点的SUMO化使其在VSMC表型转换过程中能够进行核质穿梭。TAX1BP3以非经典PDZ方式与YAP-TEAD复合物竞争性相互作用，并主要通过调节细胞增殖在血管内膜增生中发挥保护作用。
