Division of Cardiothoracic and Vascular Surgery, Sino-Swiss Heart-Lung Transplantation Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China.
Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.
Clin Epigenetics. 2022 Aug 13;14(1):101. doi: 10.1186/s13148-022-01321-8.
Vascular smooth muscle cell (VSMC) phenotype switching is critical for neointima formation, which is the major cause of restenosis after stenting or coronary artery bypass grafting. However, the epigenetic mechanisms regulating phenotype switching of VSMCs, especially histone methylation, are not well understood. As a main component of histone lysine demethylases, Jumonji demethylases might be involved in VSMC phenotype switching and neointima formation.
A mouse carotid injury model and VSMC proliferation model were constructed to investigate the relationship between histone methylation of H3K36 (downstream target molecule of Jumonji demethylase) and neointima formation. We found that the methylation levels of H3K36 negatively correlated with VSMC proliferation and neointima formation. Next, we revealed that JIB-04 (a pan-inhibitor of the Jumonji demethylase superfamily) could increase the methylation levels of H3K36. Furthermore, we found that JIB-04 obviously inhibited HASMC proliferation, and a cell cycle assay showed that JIB-04 caused G2/M phase arrest in HASMCs by inhibiting the phosphorylation of RB and CDC2 and promoting the phosphorylation of CHK1. Moreover, JIB-04 inhibited the expression of MMP2 to suppress the migration of HASMCs and repressed the expression of contraction-related genes. RNA sequencing analysis showed that the biological processes associated with the cell cycle and autophagy were enriched by using Gene Ontology analysis after HASMCs were treated with JIB-04. Furthermore, we demonstrated that JIB-04 impairs autophagic flux by downregulating STX17 and RAB7 expression to inhibit the fusion of autophagosomes and lysosomes.
JIB-04 suppresses the proliferation, migration, and contractile phenotype of HASMCs by inhibiting autophagic flux, which indicates that JIB-04 is a promising reagent for the treatment of neointima formation.
血管平滑肌细胞（VSMC）表型转换对于新生内膜形成至关重要，新生内膜形成是支架置入或冠状动脉旁路移植术后再狭窄的主要原因。然而，调节 VSMC 表型转换的表观遗传机制，特别是组蛋白甲基化，尚不完全清楚。作为组蛋白赖氨酸去甲基酶的主要组成部分，Jumonji 去甲基酶可能参与 VSMC 表型转换和新生内膜形成。
构建了小鼠颈动脉损伤模型和 VSMC 增殖模型，以研究 H3K36 组蛋白甲基化（Jumonji 去甲基酶的下游靶分子）与新生内膜形成之间的关系。我们发现 H3K36 组蛋白的甲基化水平与 VSMC 增殖和新生内膜形成呈负相关。接下来，我们揭示了 JIB-04（Jumonji 去甲基酶超家族的泛抑制剂）可以增加 H3K36 的甲基化水平。此外，我们发现 JIB-04 明显抑制 HASMC 增殖，细胞周期检测表明 JIB-04 通过抑制 RB 和 CDC2 的磷酸化并促进 CHK1 的磷酸化，导致 HASMC 发生 G2/M 期阻滞。此外，JIB-04 抑制 MMP2 的表达，抑制 HASMC 的迁移，并抑制收缩相关基因的表达。RNA 测序分析显示，用 JIB-04 处理 HASMC 后，通过基因本体分析，与细胞周期和自噬相关的生物学过程被富集。此外，我们证明 JIB-04 通过下调 STX17 和 RAB7 的表达来抑制自噬体与溶酶体的融合，从而破坏自噬流。
JIB-04 通过抑制自噬流抑制 HASMC 的增殖、迁移和收缩表型，表明 JIB-04 是治疗新生内膜形成的有前途的试剂。
