The Effect Of ROS In Lanthanum Chloride-induced Astrocyte Apoptosis

PrefaceChina has the largest rare-earth reserves and output is the world,rare earth products continuously into the environment,enter the food chain,with the rapid development of rare earth elements were released into environment,the growth of Accumulation in plants,animals,the environment,human health and the long-term effects has attracted people's attention.Rare Earth may have multiple toxic effects,and rare-earth functional activities of the central nervous system effects of toxicological studies of rare earth has been more active.Animal studies show that the rare-earth can break through the blood-brain barrier into the brain tissue and affect the central nervous system.Rare-earth mining area of the epidemiological investigation showed that rare earth exposure can affect the development of children's IQ.indicating that the brain is not only the accumulation of the Organization of Rare Earth,but the brain is the target organ.A number of in vivo and out vitro experiments show that rare earth exposure on animals with high-dose or cultured cells will enable a variety of antioxidant enzyme activity decreased,suggesting that due to the toxicity of rare earth may be associated with oxidative stress-related.Lanthanum is the representative of light rare earth,Our previous studies also confirmed that with 0.5%lanthanum chloride drinking water in rats can decreased antioxidant enzyme activity, hippocampal neuronal apoptosis rate increased.Glial cells is the large number of central nervous system of a large class of cells,accounting for about 90 percent of the total number of cells,astrocytes are the main components of which,from holders of the neuron to provide nutrition and metabolism,such as assistance role in its function as the constant awareness of the research it has become focus in recent years in neuroscience.The purpose of this study on cultured astrocytes exposed to lanthanum chloride,observation of cells exposed to different doses of the antioxidant enzyme activity,ROS levels and P53,bcl-2,bax protein expression and apoptosis,to explore lanthanum chloride on the central nervous system toxicity mechanism.Methods1.Identification of astrocytes by Immunohistochemical method(GFAP staining)2.Determination of cell viability(MTT)3.Intracellular reactive oxygen species measured by flow cytometry method4.Degradation products of lipid peroxidation and the detection of enzyme content5.P53,bcl-2 and bax protein expression by western-blot method6.Detection of apoptosis by flow cytometry methodResults1.Identification of astrocytesObserved under the microscope mirror and counting statistics of GFAP-positive cells,the positive cells about 90%at least,it can be primary culture cells as a model of glial cells in vitro.2.Determination of cell viability in each groupThe Lanthanum group compared with the control group had significant difference, and with increasing doses of exposure,cell survival rate decreased gradually3.determination of reactive oxygen speciesLanthanum post-exposure level of ROS was increased.Lanthanum exposed cells in each group the average higher and the level significant statistical difference(P <0.05).4.degradation products of lipid peroxidation and the detection of enzyme content.With an increase in exposure,degradation products of lipid peroxidation MDA content increased.(P <0.01).SOD,GSH-Px activity decreased significantly5.P53,bcl-2 and bax protein expression changesWith the dose increase,Bax protein expression gradually increased compared with the control group and there are significant differences(P <0.01),in the other hand bcl-2 and Bax protein expression,a downward trend in their expression.the P53 protein expression group compared with the control group were significantly increased (P <0.05). 6.Apoptosis detected in each groupApoptosis rate of the control group in a very low level,and lanthanum chloride exposure in apoptosis compared with the control group,it is statistically significantly worse(P < 0.05),with the dose increased,the rate of apoptosis in the rapid growth also showed significant correlation.Conclusion1.Lanthanum chloride can vitro astrocytes decreased activity of antioxidant enzymes,increased levels of intracellular ROS,causing oxidative damage2.Lanthanum chloride can vitro astrocyte expression of P53 protein,Bax expression,Bcl-2 reduced the expression level.3.Lanthanum chloride could astrocytes in vitro inhibited cell proliferation and induced apoptosis.