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 γ-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, β-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 β-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. γ-irradiation.