Temporal Expression MicroRNA-21 in Serum of Patients with Spinal Cord Injury

Objective: To investigate the levels of microRNA-21 (miR-21) in the serum of patients with spinal cord injury (SCI) and to determine whether there was a correlation with degree of injury. Methods: Quantitative real-time reverse transcription-polymerase chain reaction(q-RT-PCR) was used to measure the serum levels ofmiR-21 at 1, 7 and 28 days and 3 months after SCI 42 in male and female SCI patients (n = 48) and compare with age and sex-matched patients with non spinal cord injuries (NSCI, n = 60) and healthy volunteers (n = 70). Correlations between serum miR-21 levels and age, sex and degree of injury were investigated. Results: The data from the present study show that the serum level of miR-21 immediately increased and peaked on day 7 post-SCI and then declined to the control level. There were no differences between NSCI group and normal control group at each time point. The expression level o fmiR-21 was related to the lesion degree of SCI. The age and sex of the patients did not influence miR-21 expression after SCI. Conclusions: These finding might provide reference for diagnosis and treatment and contribute to the identification of selective and temporal drug targeted therapy after SCI.