Affiliation:
1. Department of Orthopaedics Tangdu Hospital Fourth Military Medical University Xi'an 710038 China
2. Department of Pharmaceutical Analysis School of Pharmacy Fourth Military Medical University Xi'an 710032 China
3. State Key Laboratory of Proteomics Beijing Proteome Research Center National Center for Protein Sciences Beijing Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences Institute of Lifeomics Beijing 102206 China
Abstract
AbstractNeuroinflammation is associated with poor outcomes in patients with spinal cord injury (SCI). Recent studies have demonstrated that stimulator of interferon genes (Sting) plays a key role in inflammatory diseases. However, the role of Sting in SCI remains unclear. In the present study, it is found that increased Sting expression is mainly derived from activated microglia after SCI. Interestingly, knockout of Sting in microglia can improve the recovery of neurological function after SCI. Microglial Sting knockout restrains the polarization of microglia toward the M1 phenotype and alleviates neuronal death. Furthermore, it is found that the downregulation of mitofusin 2 (Mfn2) expression in microglial cells leads to an imbalance in mitochondrial fusion and division, inducing the release of mitochondrial DNA (mtDNA), which mediates the activation of the cGas‐Sting signaling pathway and aggravates inflammatory response damage after SCI. A biomimetic microglial nanoparticle strategy to deliver MASM7 (named MSNs‐MASM7@MI) is established. In vitro, MSNs‐MASM7@MI showed no biological toxicity and effectively delivered MASM7. In vivo, MSNs‐MASM7@MI improves nerve function after SCI. The study provides evidence that cGas‐Sting signaling senses Mfn2‐dependent mtDNA release and that its activation may play a key role in SCI. These findings provide new perspectives and potential therapeutic targets for SCI treatment.
Funder
National Natural Science Foundation of China
Subject
General Physics and Astronomy,General Engineering,Biochemistry, Genetics and Molecular Biology (miscellaneous),General Materials Science,General Chemical Engineering,Medicine (miscellaneous)