Tian Haozhe, Zheng Juan, Wang Fangli, Zhang Wenjing, Chen Yuqing, Wang Xiangshu, Wang Xiaoxuan, Xi Jin, Hu Jianguo, Zhang Yuxin
School of Laboratory Medicine Bengbu Medical University Bengbu China; Anhui Key Laboratory of Tissue Transplantation at Bengbu Medical University Bengbu China.
Anhui Province Key Laboratory of Basic and Translational Research of Inflammation-related Diseases Bengbu China; Clinical laboratory of The First Affiliated Hospital of Bengbu Medical University Bengbu China.
Int Immunopharmacol. 2025 Mar 6;149:114230. doi: 10.1016/j.intimp.2025.114230. Epub 2025 Feb 7.
Inflammation at the injury site exacerbates tissue cell death following a spinal cord injury (SCI). Studies show that NLRP3 inflammasomes are crucial in the inflammation following Spinal Cord Injury, and NLRP3 inflammasomes have been shown to promote cells to undergo excessive autophagy in other diseases. Moreover, excessive autophagy levels could hinder functional repair post-SCI. In this regard, we hypothesized that inhibiting NLRP3 inflammasomes could reduce autophagy levels at the injury site, thus promoting functional repair post-SCI.
Herein, a mouse SCI model was used for in vivo experiments, and an in vitro neuroinflammatory model created using LPS-activated BV2 cells was used for in vitro experiments. Histopathological staining was used to assess tissue repair. Western Blot (WB) and quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) were used to detect changes in relevant autophagy molecules, macrophage polarization-related markers and downstream inflammatory factors, and Immunofluorescence (IF) was used to detect changes in macrophage polarization.
Following SCI, the inhibition of NLRP3 inflammasomes resulting from intraperitoneal injection of MCC950 significantly reduced autophagy levels at the injury site, resulting in both histological and behavioral improvements. In addition, the phosphorylation of mTOR during inhibition of NLRP3 inflammasomes to reduce autophagy levels further improved the immune microenvironment at the injury site, and M2-type macrophages were significantly upregulated M2-type macrophages. Moreover, in vitro experiments yielded results consistent with those of in vivo experiments regarding changes in autophagy-related indexes and polarization-related markers.
Inhibition of NLRP3 inflammasomes can reduce autophagy level at the injury site to promote functional recovery and play a neuroprotective role. Moreover, phosphorylation of mTOR during the process of inhibition of NLRP3 inflammasomes to reduce autophagy, leading to reduced autophagy levels, could improve the immune microenvironment at the injury site, thus promoting functional recovery and histopathological repair post-SCI.
脊髓损伤（SCI）后损伤部位的炎症会加剧组织细胞死亡。研究表明，NLRP3炎性小体在脊髓损伤后的炎症反应中起关键作用，并且在其他疾病中已显示NLRP3炎性小体可促进细胞发生过度自噬。此外，过度的自噬水平会阻碍脊髓损伤后的功能修复。在这方面，我们假设抑制NLRP3炎性小体可以降低损伤部位的自噬水平，从而促进脊髓损伤后的功能修复。
在此，使用小鼠脊髓损伤模型进行体内实验，并使用脂多糖激活的BV2细胞建立的体外神经炎症模型进行体外实验。采用组织病理学染色评估组织修复情况。采用蛋白质免疫印迹法（WB）和定量实时聚合酶链反应（qRT-PCR）检测相关自噬分子、巨噬细胞极化相关标志物和下游炎症因子的变化，采用免疫荧光法（IF）检测巨噬细胞极化的变化。
脊髓损伤后，腹腔注射MCC950抑制NLRP3炎性小体可显著降低损伤部位的自噬水平，从而在组织学和行为学上均有改善。此外，在抑制NLRP3炎性小体以降低自噬水平的过程中，mTOR的磷酸化进一步改善了损伤部位的免疫微环境，M2型巨噬细胞显著上调。此外，体外实验在自噬相关指标和极化相关标志物变化方面得到了与体内实验一致的结果。
抑制NLRP3炎性小体可降低损伤部位的自噬水平，促进功能恢复并发挥神经保护作用。此外，在抑制NLRP3炎性小体以降低自噬水平的过程中，mTOR的磷酸化导致自噬水平降低，可改善损伤部位的免疫微环境，从而促进脊髓损伤后的功能恢复和组织病理学修复。
