ABSTRACT
Objective To analyze the effect of LncRNA MEG3 on the blood-brain barrier in neonatal mice with hypoxic-ischemic brain injury(HIBD)by regulating miR-17-5p.Methods A total of 90 C57BL mice were randomly grouped into control group,model group,si-NC group,si-LncRNA MEG3 group,si-LncRNA MEG3+anti-miR-NC group and si-LncRNA MEG3+anti-miR-17-5p group,with 15 mice in each group.Except for the control group,the rest of the mice were constructed with HIBD model,and the Longa score was used to evaluate the nerve damage of mice.The ultrastructure of vascular endothelial cells around brain tissue was observed by electron microscope.The permeability of blood-brain barrier in mice was measured by EB method.The levels of LncRNA MEG3 and miR-17-5p in the brain tissue of mice in each group were determined by qRT-PCR.The levels of ZO-1 and Occludin protein in the brain tissue of mice were determined by Western blotting.Results Compared with control group,the vascular endothelium of mice in model group was unevenly thin and thick,and showed edema in many places.Compared with model group,the vascular endothelial cells in the si-LncRNA MEG3 group were gradually tightly connected,the thickness was more uniform,and the edema was reduced.Compared with the si-LncRNA MEG3 group,vascular endothelial cell damage was intensified in the si-LncRNA MEG3+anti-miR-17-5p group.Compared with those in the control group,the neurological deficit score,brain water content,EB content,and LncRNA MEG 3 level in the model group were significantly increased,miR-1 7-5 p level,ZO-1 and Occludin expression were significantly decreased(all P＜0.05).Compared with those in model group,there were no significant differences in neural function deficit score,brain water content,EB content,lncRNA MEG3 level,miR-17-5p level,ZO-1 and Occludin expression in si-NC group(all P＞0.05);the neurological deficit score,brain water content,EB content and LncRNA MEG3 level in si-LncRNA MEG3 group were significantly decreased,miR-17-5p level,ZO-1,and Occludin expression were significantly increased(all P＜0.05).Compared with those in si-LncRNA MEG3 group,there were no significant differences in neural function deficit score,brain water content,EB content,LncRNA MEG3 level,miR-17-5p level,ZO-1 and Occludin expression in si-LncRNA MEG3+anti-miR-NC group(all P＞0.05);the neurological deficit score,brain water content and EB content in si-LncRNA MEG3+anti-miR-17-5p group were significantly increased,miR-17-5p level,ZO-1 and Occludin expression were significantly decreased(all P＜0.05).Conclusion LncRNA MEG3 silencing may reduce the permeability of the blood-brain barrier in neonatal mice with HIBD by up-regulating miR-17-5p,maintaining the protective effect of the blood-brain barrier on the brain,and protecting brain tissue.