To Establish The Tight Junction Model Between The Endothelial Cell Of Blood-brain Barrier And Observe The Damage Effect On The Tight Junction

In recent years, lots of studies have been made on the tight junctions (TJs) between the endothelial cells in the blood-brain barrier. The researchers have found that many kinds of proteins joined together and formed the tight junction complex. The structure of TJ is complex and the function of it is also complex. TJs can not only seal the gap between the cerebral vascular endothelial cells, play an important role in the function of blood-brain barrier (BBB), but also take part in the signal transduction in the cell, adjust the cell growth and differentiation. In many nervous system disease processes, the scientists have also observed many changes of the TJs. Therefore, to make more research on the TJs will help us to understand the function of TJs, to know the role of TJs in the pathology and physiology processes of nervous system diseases, so that we can cure the nervous system diseases better. Homocysteine (Hcy) has been regarded as an independent risk factor for cerebrovascular diseases. It can damage the brain vascular endothelial cellsdirectly and leads to the cerebrovascular endothelial cells dysfunction, and so on. But, we still don't know whether the Hcy can damage the TJs between the cerebral vessel endothelial cells or not. Our current research work investigated the damage effects initially.Objectives: The first was to establish the model of TJs between the cerebral vessel endothelial cells and provided a basis for the further research of the damage effects of Hcy to the TJs between the endothelial cells. The second was to observe the effect that Hcy had on the growth of the endothelial cell and the morphology changes of the TJs. The third was to detect the influence of Hcy on the expression of TJ protein occludin.Methods: (1) HUVECs were cultured. And we observed the TJ between the endothelial cells under the transmission electron microscope when the cell contacted and fused into together, just like the slabstones. (2) HUVECs were cultured to the third generation. Then HUVECs were divided into 7 groups. After HUVECs were exposed to Hcy in different concentration (0.01mM, 0.1mM, 0.2mM, 0.5mM, l.0mM, 2.0mM, and control group) for 24hours, by means of HE stain, we observed the endothelial dysfunction. Another 5 group of HUVECs were exposed to Hcy in different concentration for 24 hours (0.01 mM, 0.1mM, 1.0 mM, 0.1mM+flunarizine 100ng/ml, control group). We detected the changes of the TJ between the endothelial cells under the transmission electron microscope. (3) HUVECs were cultured to the third generation, and then divided them into 7 groups. After HUVECs were exposed to Hcy in different concentration for 24 hours, we observed the expression of TJ protein occludin by means of semiquantitative RT-PCR and histochemical method.Results: (1) We successfully established the model of TJ between the...