Effects of high glucose exposure on permeability of brain microvascular endothelial cells

Objective To investigate the permeability of brain microvascular endothelial cells under the condition of high glucose exposure.

Methods The bEnd.3 cell line was chosen to detect the value of trans- endothelial electrical resistance (TEER), the activity of alkaline phosphatase (ALP) and γ-glutamyl transferase (γ-GT).Hence, the characteristics of blood-brain barrier in cell model were identified.The permeability of brain microvascular endothelial cells on high glucose exposure was evaluated by cell morphology, cell viability, intracellular lactate dehydrogenase activity and relative expression of ZO-1 and Occludin genes.

Results The value of TEER, the activity of ALP and γ-GT increased gradually with increasing incubation time.The observation of cell morphology showed that the number of cells decreased significantly under high glucose exposure, and the adherence was unstable.Cell viability decreased with higher concentration of glucose or longer exposure time under high glucose exposure.The activity of lactate dehydrogenase was also decreased, and there were significant differences among the dose groups (P < 0.05).In addition, the expression levels of tight junction protein ZO-1 and Occludin were further detected.It was found that high glucose exposure inhibited the expression of ZO-1 and Occludin genes in a dose-dependent manner.

Conclusion The bEnd.3 cell line has the characteristics of blood-brain barrier.High glucose exposure inhibited the expression of tight junction protein ZO-1 and Occludin. The results might be related to the change of the permeability in brain microvascular endothelial cells