Effect Of Hypoxic Microenvironment On Cerebral Astrocytes Apoptosis And The Expression Of Bcl-2

Part 1. The astrocyte tolerance to hypoxia microenvironment[Objective] Primary brain injury often leads to local and even the whole brain ischemia brain tissue hypoxia, neurons in ischemic anoxia tolerance is poorer, easy cause neuron death.The repair process often accompanied by the proliferation of glial cells,and proliferation of glial cells gradually filling after the death of neurons.By comparing the growth and apoptosis of normal brain glial cells in hypoxia and oxygen to explore the astrocytes tolerance to hypoxia microenvironment.[Methods] Through three gas incubator build hypoxic microenvironment, to set a cerebral astrocytes normal oxygen control group (21%O2) and low oxygen treatment group (0.1%O2、0.5%O2、1%O2), respectively, to cultivate after 24 h,48 h,72 h microscope macroscopic observation groups of cell growth, and through the determined by MTT method and Annexin V-FITC/PI staining cells after the detection of cell proliferation and apoptosis, using Western blot method to detect alpha HIF-1 expression situation, understand the low oxygen influence on glial cell growth and apoptosis, in order to investigate the glial cells under the condition of low oxygen tolerance ability.[Results] No matter normal oxygen control or low oxygen treatment group, all cells can survive and proliferate, no obvious apoptosis (P> 0.05);With increasing oxygen concentration, the apoptosis rate is not significant change (P< 0.05);Western blot method to detect low oxygen treatment group of HIF-1 alpha expression level was significantly higher than normal oxygen(P< 0.05), and HIF-1 alpha expression level increasing trend with the oxygen concentration decreases gradually (P< 0.05);HIF-1 alpha expression level decreased with time extended time(P< 0.05).[Conclusion] No matter often oxygen control or low oxygen treatment group, all cells can survive and proliferation, low oxygen concentration cannot induce brain glioma cells apoptosis,even if 0.1%, but speed of cell proliferation was slowed than nomal oxygen.Degradation of HIF-1 alpha was inhibited under the condition of low oxygen increasing trend with the oxygen concentration decreases gradually (P< 0.05);HIF-1 alpha expression level decreased with time extended time(P< 0.05).[Conclusion] No matter often oxygen control or low oxygen treatment group, all cells can survive and proliferation, low oxygen concentration cannot induce brain glioma cells apoptosis,even if 0.1%, but speed of cell proliferation was slowed than nomal oxygen.Degradation of HIF-1 alpha was inhibited under the condition of low oxygenPart 2. Protection of Hypoxic microenvironment in sugar-free adversity and the influence of the expression of Bcl-2[Objective] Brain tissue ischemia oxygen while often associated with low sugar or even sugar free environment.By comparing stellate cell growth and apoptosis in he sugar and sugar free conditions, to investigate the effect of glucose on cell growth;By comparing cell growth situation of often oxygen group and hypoxia group in sugar-free adversity, to discuss the protection of glial cells in sugar-free adversity and low oxygen microenvironment.[Methods] By established hypoxic microenvironment through three gas incubator, the normal brain glial cells was respectively set as normal sugar group (21%O2-High G) and sugar-free group (21%O2-NO G), training for 24 h,48 h,72 h,96 h, 120 h, by determined by MTT method and Annexin V-FITC/PI staining cells to detect cell proliferation and apoptosis.Consider cells in ischemia anoxic accompany a sugar-free condition at the same time, sugar-free cells were divided to normal oxygen group (21%O2-NO G) and low oxygen sugar-free group (0.1%O2-NO G), training for 24 h,48 h,72 h,96 h,120 h.By the same method to detect cell proliferation and apoptosis.By Western blot method to detect the BCL-2 expression in normal oxygen and low oxygen group, to show the role in inhibiting apoptosis of BCL-2.[Results] Normal brain glial cells trained after 24 h,48 h,72 h, compared with sugar-free group (21%O2-NO G) and often sugar group (21%O2-High G) by microscope and flow cytometry,we found more obvious apoptosis in sugar-free group(P< 0.05);Determined by MTT method to detect the two groups in certain cell proliferation,and normal sugar group (21%O2-High G) is more. Normal oxygen sugar-free group was detected more obvious apoptosis than ow oxygen sugar-free group by microscope and flow cytometry detection after glial cells was trained 24 h, 48 h,72 h (P< 0.05);and low oxygen sugar-free group was detected more obvious cell proliferation than normal oxygen sugar-free group by MTT method (P< 0.05). Bcl-2 expression of sugar-free group was increased significantly than normal sugar group by western blot method;and Low oxygen sugar-free group also express more Bcl-2 significantly than normal oxygen sugar-free group(P< 0.05)[Conclusion] Sugar-free conditions can induce cell to be apoptosis;Hypoxic microenvironment can inhibit apoptosis of normal brain glial cells in sugar-free adversity,which can further promote cell growth and proliferation.The Bcl-2 can inhibit apoptosis significantly,namely the protection.