Research on the role and mechanism of mitochondrial targeting peptide SS-31 in inflammation-in-duced senescence and pyroptosis of nucleus pulposus cells
10.3969/j.issn.1004-406X.2025.04.09
- VernacularTitle:线粒体靶向肽SS-31对炎症诱导髓核细胞衰老和焦亡的作用及机制研究
- Author:
Xin PENG
1
;
Zhiqiang WANG
;
Tong ZHANG
;
Guang YANG
;
Xiaotao WU
;
Yanzheng GAO
Author Information
1. 河南省人民医院脊柱脊髓外科 450003郑州市
- Publication Type:Journal Article
- Keywords:
SS-31;
Nucleus pulposus cells;
Inflammation;
Senescence;
Pyroptosis
- From:
Chinese Journal of Spine and Spinal Cord
2025;35(4):399-407
- CountryChina
- Language:Chinese
-
Abstract:
Objectives:To investigate the effect and mechanism of mitochondrial targeting peptide SS-31 on senescence and pyroptosis of nucleus pulposus(NP)cells induced by inflammation.Methods:NP cells were isolated and cultured in vitro from 6-week-old male SD rats,and were divided into control group,lipopolysaccharide(LPS)group,and LPS+SS-31 group;And the control group of cells received no treatment,LPS group of cells were treated with 100μg/mL LPS for 24h,and LPS+SS-31 group of cells were pre-treated with SS-31 30min before LPS intervention.The levels of cellular senescence and pyroptosis were assessed in each group using β-galactosidase(SA-β-Gal)staining and westem blot(WB)assay;Transmission electron mi-croscopy and oxygen consumption rate(OCR)assay were used to analyze the mitochondrial function of NP cells in each group;The expressions of phosphorylated nuclear factor-κB-p65(p-NF-κB-p65),cyclic GMP-AMP synthase(cGAS),and interferon stimulating gene(STING)in each group were detected by WB and im-munofluorescence;Hematoxylin-eosin(HE)staining,immunohistochemistry(IHC)staining and WB assay were performed to analyze the effects of in vivo injection of SS-31 on intervertebral disc degeneration,senescence,and pyroptosis.Results:The positive SA-β-Gal staining of NP cells,expression of senescence marker pro-teins(p53,p21),and pyroptosis-related molecules(NLRP3,Caspase-1 p20)were significantly lower in the LPS+SS-31 group compared with the LPS group(P＜0.05);Transmission electron microscopy(TEM)showed that the mitochondrial swelling of NP cells was round,the matrix was translucent,and the interstitial lumen of the mitochondrial cristae was dilated in the LPS group,while the mitochondrial swelling was subsided,and the morphology of mitochondria tended to be normalized in the LPS+SS-31 group.Meanwhile,the maximum respi-ration level of NP cells was significantly enhanced in the LPS+SS-31 group compared with the LPS group(P＜0.05).The results of WB and immunofluorescence showed that LPS significantly up-regulated the expression of p-NF-κB-p65,cGAS,and STING(P＜0.05),while SS-31 pretreatment significantly inhibited the expression of p-NF-κB-p65,cGAS and STING in NP cells induced by LPS(P＜0.05).Finally,in vivo experiments con-firmed that local injection of SS-31 reduced the senescence and pyroptosis of NP cells,and alleviated the degeneration of intervertebral disc induced by annulus fibropuncture.Conclusions:SS-31 alleviates inflamma-tion-induced senescence and pyroptosis of NP cells,which is related to the inhibition of NF-κB signaling pathway and cGAS/STING signaling pathway.
