Expression and significance of neuroglobin in astrocytes after spinal cord injury

MING Chao; ZENG Yun; XIONG Min

doi:10.3969/j.issn.1002-266X.2019.04.009

Abstract：Objective To investigate the expression and significance of neuroglobin (Ngb) in astrocytes (AS) after spinal cord injury (SCI). Methods Thirty SD rats were randomly divided into two groups: the SCI group and the non-operative group. Modified Allen's method was used to prepare the SCI model. HE staining was carried out to observe the pathological changes, and immunofluorescence assay was performed to detect the expression changes of Ngb in AS after SCI. AS incubated with hydrogen peroxide was utilized to mimic the cellular oxidative stress injury. The activity of AS was detected by MTT after 6-hour and 12-hour treatment with different concentrations of H2 O2 (0, 50, 100, 150, 200, and 400 μmol/L). Oxygen free radical (ROS) was measured by flow cytometry after treatment with different concentrations of H2 O2. The Ngb mRNA level after oxidative stress was determined by real-time fluorescent quantitative PCR. Results HE staining showed that the wound repair represented a natural healing process that gradually changed from acute injury to glical scar formation. The immunofluorescence assay demonstrated that Ngb expression in AS first increased, then decreased, and reached the peak at 14 days after SCI. The activity of AS was significantly lower than that of controls after 6-hour and 12-hour treatment with different concentrations of H2 O2 (0, 50, 100, 150, 200, and 400 μmol/L) (P ＜ 0. 05). Different concentrations of H2 O2 promoted ROS production at 6 and 12 h. With the increase of H2 O2 concentration and exposure time, the Ngb mRNA level showed a trend of increasing first and decreasing lately after oxidative stress injury in AS with a time-dose dependent manner (P ＜ 0. 05). Conclusion The expression of Ngb increases in AS after SCI, and Ngb may be involved in the anti-oxidative stress injury in AS after SCI, thereby exerting endogenous cytoprotective effects.