Zhang Dehua, Mao Feng, Wang Shaobo, Wu Hongzi, Wang Shun, Liao Yi
Department of Orthopedics, The Central Hospital of Karamay, No.67 Zhun Gaer Road, Karamay, 834000, Xinjiang, China.
Neurochem Res. 2023 Jan;48(1):172-187. doi: 10.1007/s11064-022-03719-5. Epub 2022 Aug 30.
Spinal cord injury (SCI) is a prevalent disease that debilitates millions of people. Nuclear factor E2-related factor 2 (Nrf2) is an important regulator of SCI. The current study sought to elaborate on the effects of Nrf2 on gasdermin D (GSDMD)-mediated microglia pyroptosis to repair SCI. The SCI rat model was established via the percussion of the T10 spinal cord and in vitro SCI model was established on BV-2 cells via lipopolysaccharide (LPS)/adenosine triphosphate (ATP) treatment. Nrf2 expression in SCI rats and BV-2 cells was overexpressed via pcDNA3.1-Nrf2 injection. Functional assays were carried out to evaluate SCI rat pathological injury, BV-2 cell viability, the release of lactate dehydrogenase (LDH), and pyroptotic factors. The binding relations of Nrf2 and microRNA (miR)-146a and miR-146a and GSDMD were verified. BV-2 pyroptosis was analyzed after the combined experiment of miR-146a-inhibitor and pcDNA3.1-GSDMD. Our experiments revealed that Nrf2 was downregulated in SCI, and Nrf2 overexpression relieved SCI pathological injury, promoted BV-2 cell viability, inhibited the release of LDH, and repressed pyroptosis. Mechanically, Nrf2 bound to the miR-146a promoter and promoted miR-146a expression, and miR-146a targeted GSDMD transcription. Rescue experiments revealed that miR-146a knockdown or GSDMD overexpression annulled the inhibitory function of Nrf2 overexpression in LPS/ATP-induced microglia pyroptosis. Overall, our findings initially highlighted that Nrf2 inhibited GSDMD-mediated microglia pyroptosis and accelerated SCI repair by repressing miR-146a.
脊髓损伤（SCI）是一种使数百万人衰弱的常见疾病。核因子E2相关因子2（Nrf2）是SCI的重要调节因子。当前研究旨在阐述Nrf2对gasdermin D（GSDMD）介导的小胶质细胞焦亡的影响，以修复SCI。通过敲击T10脊髓建立SCI大鼠模型，并通过脂多糖（LPS）/三磷酸腺苷（ATP）处理在BV-2细胞上建立体外SCI模型。通过注射pcDNA3.1-Nrf2使SCI大鼠和BV-2细胞中的Nrf2表达过表达。进行功能测定以评估SCI大鼠的病理损伤、BV-2细胞活力、乳酸脱氢酶（LDH）释放和焦亡因子。验证了Nrf2与微小RNA（miR）-146a以及miR-146a与GSDMD的结合关系。在进行miR-146a抑制剂和pcDNA3.1-GSDMD的联合实验后，分析BV-2细胞焦亡情况。我们的实验表明，SCI中Nrf2表达下调，Nrf2过表达可减轻SCI病理损伤，促进BV-2细胞活力，抑制LDH释放，并抑制焦亡。机制上，Nrf2与miR-146a启动子结合并促进miR-146a表达，而miR-146a靶向GSDMD转录。挽救实验表明，miR-146a敲低或GSDMD过表达消除了Nrf2过表达对LPS/ATP诱导的小胶质细胞焦亡的抑制作用。总体而言，我们的研究结果初步表明，Nrf2通过抑制miR-146a来抑制GSDMD介导的小胶质细胞焦亡并加速SCI修复。
