Expression and molecular mechanism of microRNA and interleukin-1 in peripheral blood of patients with acute severe traumatic brain injury

Abstract

Objective To investigate the expression change of serum interleukin-1α (IL-1α) and interleukin-1β (IL-1β) concentrations and relative expression of microRNA (miRNA) in peripheral blood mononuclear cell (PBMC) of patients with acute severe traumatic brain injury (sTBI) and its molecular mechanism. Methods TargetScan Release 7.1 software was used to analyze miRNA regulating IL-1α and IL-1β genes. Enzyme-linked immunosorbent assay (ELISA) was used to detect expressions of serum IL-1α and IL-1β. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect miRNA relative expression of PBMC. Dual-Luciferase Reporter Assay System was constructed to verify the interaction between genes. Results IL-1α was the target gene regulated by miRNA-24-3p, and IL-1β was the target gene regulated by miRNA-383-3p. Compared with control group, the concentrations of serum IL-1α [(4.09 ± 2.32) ng/L vs. (0.56 ± 0.02) ng/L; t = 124.369, P = 0.030] and IL-1β [(3.99 ± 1.73) ng/L vs. (0.89 ± 0.03) ng/L; t = 163.123, P = 0.010] in sTBI group were significantly higher. In sTBI group, the relative expressions of miRNA-24-3p and miRNA-383-3p in PBMC were 23% and 17%, and the relative expressions of IL-1α and IL-1β were 390% and 420%. Dual-Luciferase Reporter Assay System showed the expressions of IL-1α (F = 40 154.000, P = 0.000) and IL-1β (F = 4015.000, P = 0.003) had significant difference in different groups. The expression of IL-1α in miRNA-24-3p group was significantly lower than that in control group (P = 0.000), miRNA-24-3p inhibitor group (P = 0.023), negative control group (P = 0.023) and negative inhibitor group (P = 0.023). The expression of IL-1β in miRNA-383-3p group was significantly lower than that in control group (P = 0.000), miRNA-383-3p inhibitor group (P = 0.000), negative control group (P = 0.000) and negative inhibitor group (P = 0.000). After transfected with clone IL-1α-mut-3'UTR and IL-1β-mut-3'UTR plamid, there were significant differences in different groups on expressions of IL-1α (F = 72.400, P = 0.001) and IL-1β (F = 37.000, P = 0.000). However, the expression of IL-1α in miRNA-24-3p group had no significant difference with control group, miRNA-24-3p inhibitor group, negative control group and negative inhibitor group (P > 0.05, for all), and the expression of IL-1β in miRNA-383-3p group had no significant difference with control group, miRNA-383-3p inhibitor group, negative control group and negative inhibitor group (P > 0.05, for all). Conclusions The concentrations of IL-1α and IL-1β in serum of sTBI patients are higher than that of normal controls. The mechanism may be that IL-1 α is negatively regulated by miRNA-24-3p and IL-1β is negatively regulated by miRNA-383-3p.

DOI: 10.3969/j.issn.1672-6731.2018.11.012