Huang Kun, Zhao Yayu, Lei Wen, Ge Hongran, Zou Tiannan, Li Weichao
Department of Orthopedic Surgery, The First People's Hospital of Yunnan province, Affiliated Hospital of Kunming University of Science and Technology, No. 157, Jinbi Road, Kunming, 650032, China.
Faculty of Medical Science, Kunming University of Science and Technology, Kunming, 650500, China.
Neurochem Res. 2025 Jun 7;50(3):188. doi: 10.1007/s11064-025-04442-7.
This work reported the neuronal protection of low-dose lipopolysaccharide (LD-LPS) after spinal cord injury (SCI). SCI rat model was constructed, after adenovirus-mediated ALKBH5 vectors and shRNA transfection and LD-LPS pre-treatment. Hematoxylin and eosin, Nissl, TUNEL staining of spinal cord tissues were adopted to monitor pathological changes, neuronal survival and apoptosis. PC12 cells transfected with ALKBH5 vectors and ALKBH5/Nrf2 siRNAs were treated by LD-LPS, followed by oxygen and glucose deprivation/reoxygenation (OGD/R). Cell viability and apoptosis were assessed by cell counting kit-8 and TUNEL assays. Neuronal oxidative stress was evaluated by appraising MDA and SOD levels. ALKBH5 and Nrf2 expression was monitored through immunohistochemistry, Western blot and qRT-PCR. Methylated RNA immunoprecipitation assay and Dot-blot experiment were for Nrf2 m6A modification detection, while RNA pull-down assay was for the binding validation between ALKBH5 and Nrf2. In rats with SCI, LD-LPS relieved spinal cord tissue damage and neuronal apoptosis; enhanced neuronal survival; decreased MDA content; elevated SOD activity; down-regulated ALKBH5; up-regulated Nrf2; and facilitated Nrf2 m6A methylation. These above influences by LD-LPS were eliminated by ALKBH5. Similar results were found in the OGD/R-induced PC12 cells after LD-LPS treatment. ALKBH5 significantly blocked Nrf2 m6A methylation, and pulled down Nrf2 protein. In the OGD/R-induced PC12 cells, the repressed oxidative stress and apoptosis by ALKBH5 silencing was abrogated by Nrf2 knockdown. LD-LPS might alleviate neuronal apoptosis and oxidative stress after SCI by facilitating Nrf2 m6A methylation via reducing ALKBH5. It was proposed to be a novel strategy for SCI treatment.
本研究报道了低剂量脂多糖(LD-LPS)对脊髓损伤(SCI)后的神经元保护作用。构建SCI大鼠模型,进行腺病毒介导的ALKBH5载体和shRNA转染以及LD-LPS预处理。采用苏木精-伊红染色、尼氏染色、脊髓组织TUNEL染色来监测病理变化、神经元存活和凋亡情况。用LD-LPS处理转染了ALKBH5载体和ALKBH5/Nrf2小干扰RNA的PC12细胞,随后进行氧糖剥夺/复氧(OGD/R)处理。通过细胞计数试剂盒-8法和TUNEL检测评估细胞活力和凋亡情况。通过评估丙二醛(MDA)和超氧化物歧化酶(SOD)水平来评价神经元氧化应激。通过免疫组织化学、蛋白质印迹法和实时定量聚合酶链反应(qRT-PCR)监测ALKBH5和Nrf2的表达。采用甲基化RNA免疫沉淀测定法和斑点印迹实验检测Nrf2的m6A修饰,而RNA下拉实验用于验证ALKBH5与Nrf2之间的结合。在SCI大鼠中,LD-LPS减轻了脊髓组织损伤和神经元凋亡;增强了神经元存活;降低了MDA含量;提高了SOD活性;下调了ALKBH5;上调了Nrf2;并促进了Nrf2的m6A甲基化。LD-LPS的上述作用被ALKBH5消除。在LD-LPS处理后的OGD/R诱导的PC12细胞中也发现了类似结果。ALKBH5显著阻断了Nrf2的m6A甲基化,并下拉了Nrf2蛋白。在OGD/R诱导的PC12细胞中,Nrf2基因敲低消除了ALKBH5沉默所抑制的氧化应激和凋亡。LD-LPS可能通过降低ALKBH5促进Nrf2的m6A甲基化,从而减轻SCI后的神经元凋亡和氧化应激。这被认为是一种治疗SCI的新策略。
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