Department of Neurosurgery, The First People's Hospital of Yunnan Province, the Affiliated Hospital of Kunming University of Science and Technology, Kunming, 650032, Yunnan, China.
Department of Neurosurgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, No. 321 zhongshan Road, Gulou District, Nanjing, 210008, Jiangsu, China.
Inflammation. 2021 Jun;44(3):923-933. doi: 10.1007/s10753-020-01387-7. Epub 2021 Jan 12.
Long non-coding RNAs (lncRNAs) play important roles in various diseases, but the effect of lncRNA CASC9 on spinal cord injury (SCI) remains unclear. Therefore, the present study was conducted to explore the role of this lncRNA in SCI. SCI model was established by laminectomy in rats in vivo or induced by LPS in PC12 cells in vitro. Methylprednisolone (MP) was used for treatment in vivo. Spinal cord tissues were stained with H&E, and the oxidative stress- and inflammation-related factors were detected using their commercial kits. Cell apoptosis was determined using flow cytometry assay. Relative expression of corresponding genes was measured using qRT-PCR and western blotting. Luciferase reporter assay was used to verify binding site between CASC9 and miR-383-5p, as well as miR-383-5p and LDHA. The results showed that lncRNA CASC9 was downregulated and miR-383-5p was upregulated in SCI rats and LPS-induced PC12 cells. Severe histological injury and increased water content were also found in SCI rats. Increased levels of LDH, MDA, lactic acid, TNF-α, and IL-1β were found in SCI rats and LPS-induced PC12 cells. These changes could be reversed by MP treatment in vivo or overexpression of CASC9 in vitro. Besides, overexpression of CASC9 decreased cell apoptosis and protein expression of LDHA and increased protein expression of Nrf2 and HO-1 in LPS-induced PC12 cells. Furthermore, miR-383-5p was a direct target of CASC9 and was negatively regulated by CASC9. LDHA was a direct target of miR-383-5p and was negatively regulated by CASC9. In conclusion, lncRNA CASC9 exerted a protective role against oxidative stress, inflammation, and cell apoptosis in SCI, providing a novel therapeutic target or prognostic factor for SCI.
长链非编码 RNA（lncRNA）在各种疾病中发挥重要作用，但 lncRNA CASC9 对脊髓损伤（SCI）的影响尚不清楚。因此，本研究旨在探讨该 lncRNA 在 SCI 中的作用。通过体内大鼠椎板切除术或体外 LPS 诱导 PC12 细胞建立 SCI 模型。体内采用甲基强的松龙（MP）治疗。用 H&E 染色脊髓组织，用其商业试剂盒检测氧化应激和炎症相关因子。用流式细胞术检测细胞凋亡。用 qRT-PCR 和 Western blot 检测相应基因的相对表达。用荧光素酶报告实验验证 CASC9 与 miR-383-5p 以及 miR-383-5p 与 LDHA 之间的结合位点。结果显示，SCI 大鼠和 LPS 诱导的 PC12 细胞中 lncRNA CASC9 下调，miR-383-5p 上调。SCI 大鼠也出现严重的组织学损伤和含水量增加。SCI 大鼠和 LPS 诱导的 PC12 细胞中 LDH、MDA、乳酸、TNF-α 和 IL-1β 水平升高。体内用 MP 治疗或体外过表达 CASC9 可逆转这些变化。此外，过表达 CASC9 可降低 LPS 诱导的 PC12 细胞中的细胞凋亡和 LDHA 蛋白表达，增加 Nrf2 和 HO-1 蛋白表达。进一步研究发现，miR-383-5p 是 CASC9 的直接靶标，受 CASC9 负调控。LDHA 是 miR-383-5p 的直接靶标，受 CASC9 负调控。综上所述，lncRNA CASC9 对 SCI 中的氧化应激、炎症和细胞凋亡发挥保护作用，为 SCI 提供了新的治疗靶点或预后因子。
