Open AccessZinc provides neuroprotection by regulating NLRP3 inflammasome through autophagy and ubiquitination in a spinal contusion injury model
Author(s) -
Lin Jiaquan,
Tian He,
Zhao Xiaoguang,
Lin Sen,
Li Daoyong,
Liu Yuanye,
Xu Chang,
Mei Xifan
Publication year - 2021
Publication title -
cns neuroscience and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.403
H-Index - 69
eISSN - 1755-5949
pISSN - 1755-5930
DOI - 10.1111/cns.13460
Subject(s) - autophagy , inflammasome , neuroprotection , proinflammatory cytokine , spinal cord injury , in vivo , microbiology and biotechnology , blot , chemistry , pharmacology , medicine , inflammation , biology , apoptosis , immunology , spinal cord , neuroscience , biochemistry , gene
Aim Spinal cord injury (SCI) is a serious disabling injury worldwide, and the excessive inflammatory response it causes plays an important role in secondary injury. Regulating the inflammatory response can be a potential therapeutic strategy for improving the prognosis of SCI. Zinc has been demonstrated to have a neuroprotective effect in experimental spinal cord injury models. In this study, we aimed to explore the neuroprotective effect of zinc through the suppression of the NLRP3 inflammasome. Method Allen's method was used to establish an SCI model in C57BL/6J mice. The Basso Mouse Scale (BMS), Nissl staining were employed to confirm the protective effect of zinc on neuronal survival and functional recovery in vivo. Western blotting (WB), immunofluorescence (IF), and enzyme‐linked immunosorbent assay (ELISA) were used to detect the expression levels of NLRP3 inflammasome and autophagy‐related proteins. Transmission electron microscopy (TEM) was used to confirm the occurrence of zinc‐induced autophagy. In vitro, lipopolysaccharide (LPS) and ATP polarized BV2 cells to a proinflammatory phenotype. 3‐Methyladenine (3‐MA) and bafilomycin A1 (BafA1) were chosen to explore the relationship between the NLRP3 inflammasome and autophagy. A coimmunoprecipitation assay was used to detect the ubiquitination of the NLRP3 protein. Results Our data showed that zinc significantly promoted motor function recovery after SCI. In vivo, zinc treatment inhibited the protein expression level of NLRP3 while increasing the level of autophagy. These effects were fully validated by the polarization of BV2 cells to a proinflammatory phenotype. The results showed that when 3‐MA and BafA1 were applied, the promotion of autophagy by zinc was blocked and that the inhibitory effect of zinc on NLRP3 was reversed. Furthermore, co‐IP confirmed that the promotion of autophagy by zinc also activated the protein expression of ubiquitin and suppressed high levels of NLRP3. Conclusion Zinc provides neuroprotection by regulating NLRP3 inflammasome through autophagy and ubiquitination after SCI.