Mechanism of TWEAK/Fn14 regulating glial scar formation after spinal cord injury in rats

LIANG Guangsheng; QIU Ping; FU Xiaoxing; XIONG Liwei; MIN Zhihai; WU Hong

doi:10.13276/j.issn.2097-1656.2025.12.005

Abstract：Objective To investigate how TWEAK/Fn14 regulates JNK signaling and thus plays a role in glial scar formation following acute spinal cord injury(SCI).Methods The improved Allen's percussion method was used to construct the rat SCI model.The experiment was divided into several stages.Firstly,Sham group and SCI group were set up.At 1,3,7,14 and 28 d after SCI modeling,TWEAK/Fn14 signal activation in the spinal cord was detected by Western blotting.Then,the rats were randomly divided into Sham group,SCI group,anti-TWEAK group and Fc-TWEAK group.At 1,3,7,14 and 28 d after modeling,Basso Beattie Bresnahan(BBB)score was used to evaluate the hind limb motor function of the rats.At 28 d after modeling,HE staining was used to observe the pathological changes of spinal cord tissue,TUNEL was used to detect the apoptosis of spinal cord tissue,and ELISA was used to detect the levels of inflammatory factors(IL-1β,IL-6 and TNF-α)in spinal cord tissue.Western blotting was used to detect the protein expression of TWEAK,Fn14,Bcl-2,Bax,JNK,and p-JNK in spinal cord tissue,and immunofluorescence staining was used to detect the expression of Iba-1,GFAP,and vimentin in spinal cord tissue.Results TWEAK and Fn14 protein expression levels in SCI group were significantly higher than those in Sham group at 1,3,7,14,and 28 d following modeling(P＜0.05,P＜0.01).Following SCI modeling,BBB scores in SCI group were significantly lower than those in Sham group at 1,7,14,and 28 d(P＜0.01).The BBB score was significantly higher in anti-TWEAK group(P＜0.05)and significantly lower in Fc-TWEAK group(P＜0.05)as compared to SCI group.In comparison to Sham group,SCI group exhibited degeneration and necrosis in certain gray matter and white matter neurons,a significant increase in the levels of IL-6,TNF-α and IL-1β,as well as a significant increase in apoptosis,a significant decrease in Bcl-2 expression,and a significant increase in the expression of Bax,Iba-1,GFAP,and vimentin(P＜0.05,P＜0.01).In spinal cord tissue,anti-TWEAK intervention inhibited neuronal necrosis and apoptosis,lowered IL-6,TNF-α,IL-1 β,Bax,Iba-1,GFAP,and vimentin levels(P＜0.05),and increased Bcl-2 expression(P＜0.05).Intervention with Fc-TWEAK had the opposite effect as anti-TWEAK.Conclusion Downregulation of TWEAK/Fn14 expression may inhibit neuroinflammation and microglial activation by inhibiting JNK signaling,thus inhibiting glial scar formation.