Effect of γ-Irradiation on Expression of Tight and Adherens Junction Protein mRNA on In Vitro Blood-Brain Barrier Model

We studied the effect of gamma-irradiation on HUVEC endothelial cells co-cultured with allogeneic astrocytes. This 2D in vitro model of the blood-brain barrier has the same parameters as cerebral microvascular endothelial cells forming the blood-brain barrier and allows reproducing its functions in vivo. Dose-dependent changes in cell morphology and violation of monolayer integrity were observed. Real-time PCR and immunocytochemical analysis revealed changes in the expression of tight (ZO-1, claudin-5) and adherens junction protein (vascular endothelial cadherin, beta-catenin) mRNA. Expression of tight and adherens junction proteins mRNA decreased in 2, 24, and 48 h after irradiation in doses of 2, 4, and 6 Gy. Significant dosedependent changes were found only for beta-catenin mRNA expression in 2 h after exposition. This model of blood-brain barrier in vitro can be used for studying the molecular mechanisms regulating permeability of cerebral endothelium under normal conditions and after pathological exposures, e.g. gamma-irradiation.