The therapeutic effect of NeuroD on radiation-induced intestinal injury in mice / 中华放射医学与防护杂志

ABSTRACT

Objective To evaluate the therapeutic effect of NeuroD protein on radiation-induced intestinal injuries.Methods The expression and purification of NeuroD-enhanced green fluorescent protein (EGFP) fusion protein was performed in prokaryotic expression system.The efficiency of the fusion protein transduction into cells was monitored under fluorescence microscope.C57BL/6J mice were randomly divided into four groups with 10 mice in each groupnormal control group,PBS group,EGFP group,and NeuroD-EGFP group.Besides the normal control group,the other three groups of mice received 9 Gy γ-ray total body irradiation.Intestinal tissues were collected,frozen sections were prepared to monitor the distribution of NeuroD in mice intestinal tract under fluorescence microscope,and pathological sections were prepared for H&E staining to evaluate the therapeutic effect of NeuroD protein.Results The NeuroD-EGFP fusion protein was purified by Ni-NTA column and verified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).Visible green fluorescence gathered within the cells after NeuroD-EGFP fusion protein was added in the culture medium,suggesting that NeuroD-EGFP could penetrate the cell membrane into the cells.Five hours after intraperitoneal injection of NeuroD-EGFP,visible green fluorescence gathered within the intestinal epithelial cells in villi.At 3.5 d after irradiation,NeuroD-EGFP treated mice showed significantly higher villus (F =49.49,P ＜ 0.01) and crypt depth (F =16.72,P ＜ 0.01) and more crypts per circumference (F =10.32,P ＜ 0.01) compared with PBS and EGFP groups.Conclusion NeuroD protein can accelerate the post-irradiation recovery of injured villi and crypt of intestinal tract and could be used to treat radiation-induced intestinal injuries.