Change and clinical significance of expressions of cold-inducible RNA-binding protein(CIRP)following acute traumatic brain injuries

Ji Huijun; Cao Yang; Li Ze; Liu Yuanyang; Gao Bingbing; Yu Yang; Liu Jingpeng

doi:10.3969/j.issn.1009-4237.2024.11.004

Abstract：Objective To explore the brain tissue and serum expression levels of extracellular cold-induc-ible RNA-binding protein(eCIRP)in patients with traumatic brain injuries(TBI)and rats of TBI model,and fur-ther to investigate whether CIRP can serve as a biomarker for TBI.Methods Twelve healthy male C57BL/6J mice(24-26 g)were randomly divided into sham operation group and TBI group,with 6 mice in each group.Fluid percus-sion-induced rat TBI was successfully conducted(sham operation group:strike force of 0 atmosphere;TBI group:strike force of 1.1-1.3 atmospheres).HE staining was adopted to observe the pathomorphological changes and size of the cortical tissue on the injured side,western blot to detect the expression levels of CIRP in cortical tissues,and ELISA to assess the serum levels of CIRP,astrocytic S100 calcium-binding protein B(S100B),tumor necrosis factor-α(TNF-α)and interleukin-1 β(IL-1 β).Moreover,a prospective study was conducted on 8 severe TBI patients(GCS 3-12,6 males and 2 females aged 30-66 years,mean 49.1 years)admitted to the Neurosurgery Department of the First Medical Center of Chinese PLA General Hospital from Dec.2022 to Jan.2024 and 10 healthy volunteers(7 males and 3 females aged 26-64 years,mean 45.3 years).Blood sampling of both TBI patients and healthy volun-teers was conducted to detect the serum levels of CIRP,S100B,TNF-α and IL-1β by ELISA.The relationships be-tween CIRP and S100B,TNF-α or IL-1β were analyzed.Results At 24 h after modeling,rats of the TBI group showed significant cortical tissue loss on the injured side,and the hemispheric volume loss was approximately 3.1％±0.5％;moreover,the relative expression level of CIRP in the cortical tissue of TBI group was significantly higher than that in sham operation group(P＜0.001).The serum levels(pg/mL)of CIRP,S100B,TNF-α,and IL-1 β of sham operation group and TBI group were 223.8±38.5 vs.516.5±93.9,34.7±7.7 vs.132.7±34.7,22.9±5.2 vs.41.2±7.3 and 59.5±8.1 vs.114.7±26.4 respectively(all P＜0.01).While for the healthy volunteers and severe TBI patients,the serum levels(pg/mL)of CIRP,S100B,TNF-α,and IL-1β were 11.4±4.7 vs.36.1±8.2,82.3±10.6 vs.120.5±16.3,41.9±7.7 vs.146.0±37.4 and 82.9±17.8 vs.155.3±26.9 respectively(all P＜0.001).In addition,the serum CIRP level was positively associated with S100B,TNF-α and IL-1β in TBI rats(r=0.923,0.958,and 0.984 respectively)and severe TBI patients(r=0.740,0.664,0.662 respectively).Conclusion CIRP is upregulated in the injured cortex and serum after TBI.In addition,there is a positive relationship between serum CIRP and S100B,TNF-α and IL-1β expression levels,and thus CIRP can serve as a biomarker for TBI.