Fu Hongxue, Gao Bin, Zhou Xin, Hao Yingting, Liu Chang, Lan Ailin, Tang Jingyi, Zhou Fachun
Department of Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.
School of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 400054, China.
Cell Mol Biol Lett. 2025 May 19;30(1):60. doi: 10.1186/s11658-025-00739-1.
Sepsis-induced acute lung injury (ALI) is a clinical condition with high morbidity and mortality, and impaired endothelial function is the main pathological characteristic. As a member of DNA demethylases, ten-eleven translocation protein 2 (TET2) is involved in a variety of biological processes. However, the role of TET2 in endothelial dysfunction of sepsis-induced ALI remains unclear.
We used cecal ligation and puncture (CLP) to establish a sepsis-induced acute lung injury mouse model and screened out Tet2 from TET family proteins. The results suggested that Tet2 was obviously declined. We used lipopolysaccharide (LPS) to stimulate human pulmonary microvascular endothelial cells (HPMECs) as an in vitro model, and we found the expression of TET2 was also decreased. Then we used small interfering RNAs and adenovirus to knockdown or overexpress TET2 to investigate the effect of TET2 on the function of HPMECs. The changes in sepsis-induced ALI symptoms were also analyzed in Tet2-deficient mice generated by adeno-associated virus 6 (AAV6). Next, RNA sequencing and KEGG analysis were used to find the TET2-regulated downstream target genes and signaling pathways under LPS stimulation. Finally, the rescue experiments were performed to analyze the role of target genes and signaling pathways modulated by TET2 in LPS-treated HPMECs.
TET2 and 5-hmC levels were significantly decreased in both in vitro and in vivo models of sepsis-induced ALI. TET2 knockdown exacerbated the dysfunction and apoptosis of HPMECs induced by LPS. Conversely, TET2 overexpression significantly alleviated these dysfunctions and reduced apoptosis. Meanwhile, the lung injury of Tet2-deficient mice was aggravated by increased inflammation and apoptosis. RNA sequencing and subsequent experiments showed that TET2 overexpression could increase the expression of Integrin α10 (ITGA10) by reducing the methylation level of ITGA10 promoter. This, in turn, activated the PI3K-AKT signaling pathway. Knocking down ITGA10 weakened the beneficial effects of TET2 overexpression in LPS-stimulated endothelial cells.
In our study, we demonstrated that TET2 deficiency aggravates endothelial cell dysfunction and promotes acute lung injury by targeting ITGA10 via the PI3K-AKT pathway. These findings indicate that TET2 may be a promising therapeutic target for treating sepsis-induced ALI.
脓毒症诱导的急性肺损伤（ALI）是一种发病率和死亡率均较高的临床病症，内皮功能受损是其主要病理特征。作为DNA去甲基化酶家族的一员，10-11易位蛋白2（TET2）参与多种生物学过程。然而，TET2在脓毒症诱导的ALI内皮功能障碍中的作用尚不清楚。
我们采用盲肠结扎穿孔术（CLP）建立脓毒症诱导的急性肺损伤小鼠模型，并从TET家族蛋白中筛选出Tet2。结果表明Tet2明显下降。我们使用脂多糖（LPS）刺激人肺微血管内皮细胞（HPMECs）作为体外模型，发现TET2的表达也降低。然后我们使用小干扰RNA和腺病毒敲低或过表达TET2，以研究TET2对HPMECs功能的影响。还分析了腺相关病毒6（AAV6）产生的Tet2缺陷小鼠中脓毒症诱导的ALI症状的变化。接下来，使用RNA测序和KEGG分析来寻找LPS刺激下TET2调节的下游靶基因和信号通路。最后，进行挽救实验以分析TET2调节的靶基因和信号通路在LPS处理的HPMECs中的作用。
在脓毒症诱导的ALI的体外和体内模型中，TET2和5-羟甲基胞嘧啶（5-hmC）水平均显著降低。TET2敲低加剧了LPS诱导的HPMECs功能障碍和凋亡。相反，TET2过表达显著减轻了这些功能障碍并减少了凋亡。同时，Tet2缺陷小鼠的肺损伤因炎症和凋亡增加而加重。RNA测序及后续实验表明，TET2过表达可通过降低整合素α10（ITGA10）启动子的甲基化水平来增加ITGA10的表达。这进而激活了PI3K-AKT信号通路。敲低ITGA10减弱了TET2过表达对LPS刺激的内皮细胞的有益作用。
在我们的研究中，我们证明TET2缺陷通过PI3K-AKT途径靶向ITGA10，加重内皮细胞功能障碍并促进急性肺损伤。这些发现表明TET2可能是治疗脓毒症诱导的ALI的一个有前景的治疗靶点。
