Background: Disorders of the blood-brain barrier (BBB) arising from diabetes mellitus are closely related to diabetic encephalopathy. Previous research has suggested that neuron-glia antigen 2 (NG2)-glia plays a key role in maintaining the integrity of the BBB. However, the mechanism by which NG2-glia regulates the diabetic BBB remains unclear. Methods: Type 2 diabetes mellitus (T2DM) db/db mice and db/m mice were used. Evans-Blue BBB permeability tests and transmission electron microscopy techniques were applied. Tight junction proteins were assessed by immunofluorescence and transmission electron microscopy. NG2-glia number and signaling pathways were evaluated by immunofluorescence. Detection of matrix metalloproteinase-9 (MMP-9) in serum was performed using enzyme-linked immunosorbent assay (ELISA). Results: In T2DM db/db mice, BBB permeability in the hippocampus significantly increased from 16 weeks of age, and the structure of tight junction proteins changed. The number of NG2-glia in the hippocampus of db/db mice increased around microvessels from 12 weeks of age. Concurrently, the expression of MMP-9 increased in the hippocampus with no change in serum. Sixteen- week-old db/db mice showed activation of the Wnt/β-catenin signaling in hippocampal NG2-glia. Treatment with XAV-939 improved structural and functional changes in the hippocampal BBB and reduced MMP-9 secretion by hippocampal NG2-glia in db/db mice. It was also found that the upregulation of β-catenin protein in NG2-glia in the hippocampus of 16-week-old db/db mice was significantly alleviated by treatment with XAV-939. Conclusion The results indicate that NG2-glia can lead to structural and functional disruption of the diabetic BBB by activating Wnt/β-catenin signaling, upregulating MMP-9, and degrading tight junction proteins.

Objective To investigate the changes of composition and level of serum free fatty acid (FFA)of children with critical illness.Methods The serum FFAs were measured by gas chromatography in 61 children(27 critically ill eases and 34 healthy controls).The changes in serum FFA was compared between healthy children and critically ill cases.We also evaluated the difference between the data before treatment and those after recovery in children with critical illness.Results Levels of palmitic acid,palmitoleic acid.oleic acid,docosanoic acid.arachidonic acid(AA)and eicosapentaenoic acid(EPA)were evidently higher in the critically ill children than those of healthy control(P＜0.05);children underthe recovery stage showed higher levels of myristic acid,palmitic acid,palmitoleic acid,oleic acid,arechidic acid as compared with healthy controis(P＜0.05).Conclusion Compexed with healthy children,the profile of serum FFA was quite different in critically ill and recovery ones.Critical illness may influence the profile of serum FFA.