Ding Weiguo, Xu Weixing, Lu Di, Sheng Hongfeng, Xu Xinwei, Xu Bin, Zheng Aote
Department of Orthopedics, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang Province, 310012, China.
Open Med (Wars). 2023 Jan 24;18(1):20220619. doi: 10.1515/med-2022-0619. eCollection 2023.
This study investigated the function of telomerase RNA component (TERC) in spinal cord injury (SCI). SCI models were established in rats via laminectomy and PC-12 cells were treated with lipopolysaccharide (LPS). TERC and miR-34a-5p expressions in cells and rat spinal cords were detected by quantitative reverse transcription polymerase chain reaction, followed by overexpression/knockdown of TERC/miR-34a-5p. Spinal cord histopathological changes were examined via hematoxylin-eosin staining. miR-34a-5p' relation with TERC and XBP-1 was predicted by TargetScan and checked by dual-luciferase reporter/RNA immunoprecipitation assays. Cell biological behaviors were assessed by Cell counting kit-8, wound healing, Transwell, and flow cytometry assays. XBP-1 and inflammation/apoptosis-related protein expressions were analyzed by western blot. TERC was upregulated and miR-34a-5p was low-expressed in SCI tissues and LPS-induced PC-12 cells. TERC-knockdown alleviated histopathological abnormalities yet upregulated miR-34a-5p in SCI tissues. In LPS-induced PC-12 cells, TERC knockdown promoted cell viability, migration, invasion, and inhibited apoptosis, while TERC overexpression ran oppositely. TERC knockdown downregulated the XBP-1, IL-6, TNF-α, Bax, p-p38/t-p38, and cleaved caspase-9/-3, but upregulated Bcl-2 and p-Akt/t-Akt. TERC targeted miR-34a-5p, which further targeted XBP-1. miR-34a-5p downregulation exerted effects opposite to and offset TERC knockdown-induced effects. TERC knockdown facilitated the regeneration of neuron tissues yet inhibited inflammation in SCI through Akt activation and p-38 inhibition via the miR-34a-5p/XBP-1 axis.
本研究调查了端粒酶RNA组分（TERC）在脊髓损伤（SCI）中的作用。通过椎板切除术在大鼠中建立SCI模型，并用脂多糖（LPS）处理PC-12细胞。通过定量逆转录聚合酶链反应检测细胞和大鼠脊髓中TERC和miR-34a-5p的表达，随后对TERC/miR-34a-5p进行过表达/敲低。通过苏木精-伊红染色检查脊髓组织病理学变化。通过TargetScan预测miR-34a-5p与TERC和XBP-1的关系，并通过双荧光素酶报告基因/RNA免疫沉淀试验进行验证。通过细胞计数试剂盒-8、伤口愈合、Transwell和流式细胞术试验评估细胞生物学行为。通过蛋白质免疫印迹分析XBP-1和炎症/凋亡相关蛋白的表达。在SCI组织和LPS诱导的PC-12细胞中，TERC上调而miR-34a-5p低表达。敲低TERC可减轻SCI组织的组织病理学异常，但上调miR-34a-5p。在LPS诱导的PC-12细胞中，敲低TERC可促进细胞活力、迁移、侵袭并抑制凋亡，而过表达TERC则产生相反的作用。敲低TERC可下调XBP-1、IL-6、TNF-α、Bax、p-p38/t-p38和裂解的caspase-9/-3，但上调Bcl-2和p-Akt/t-Akt。TERC靶向miR-34a-5p，而miR-34a-5p进一步靶向XBP-1。下调miR-34a-5p产生与敲低TERC诱导的作用相反且抵消其作用的效果。敲低TERC通过miR-34a-5p/XBP-1轴激活Akt并抑制p-38，促进SCI中神经元组织的再生但抑制炎症。
