Abstract: Objective  To investigate the expression of microRNA-542-3p (miR-542-3p) and long non-coding RNA taurine up-regulated gene 1 (lncRNA TUG1) in the serum of patients with severe traumatic brain injury (STBI) and their relationship with the prognosis of patients.Methods From January 2020 to July 2022, 128 STBI patients were collected as the severe group and 130 patients with mild or moderate TBI were collected as the control group,retrospectively.The expression levels of miR-542-3p and lncRNA TUG1 in serum were detected and the correlation between them was analyzed.Logistic regression was used to analyze the influencing of serum miR-542-3p and lncRNA TUG1 expression on the poor prognosis of STBI patients,and the predictive efficacy of them on the prognosis of STBI patients was analyzed by receiver operating characteristic (ROC) curve.Results  The serum miR-542-3p and lncRNA TUG1expression level in the severe group were lower and higher than that in the control group,respectively(P＜0.05).The serum miR-542-3p was negatively correlated with lncRNA TUG1 in STBI patients (r=-0.595,P＜0.001).The serum lncRNA TUG1 and miR-542-3p level in poor prognosis group were higher and lower than than that in good prognosis group,respectively(P＜0.05).High lncRNA TUG1 level was risk factor for poor prognosis in STBI patients (P＜0.05),while high miR-542-3p level was a protective factor (P＜0.05).The area under the curve (AUC) (0.939) of serum miR-542-3p and lncRNA TUG1 for predicting the prognosis of STBI patients in combination was higher than that of single prediction (Z=2.410,P=0.016;Z=3.339,P＜0.001).Conclusion  The expression of miR-542-3p in serum of STBI patients is down-regulated,while the expression of lncRNA TUG1 is up-regulated.Both of them can be used for predicting the prognosis of STBI patients,and the combination of the two has higher predictive value.

Key words: severe traumatic brain injury, micro RNA-542-3p, long chain non-coding RNA taurine up-regulated gene 1, prognosis