Study On The Apoptosis Of Neurocyte Induced By PbAC

PREFACE Lead (Pb2+), a heavy metal, has been used by humans formany technological purposes, which is the main reason for its presentwidespread distribution. Although various actions have been taken todecrease the use and distribution of lead in the environment, it remains asignificant health hazard. Lead is highly toxic to nerve and can damagelearning and memory of minors. The neuron apoptosis induced by lowconcentration lead relate to the nervers toxicity. Excessive apoptosis ofthe nerve cell will seriously influence the central nervous system normalgrowth and the differentiation. In vivo animal studies have proved theexistence of this phenomenon. We will establish a cell model toinvestigate the molecular and genetic mechanisms of this effect. We willuse glioma cell line U-251 cells in the research.AIM Establish the model of apoptosis in U-251 induced by lead; observethe cell's variation and confirm the apoptosis and investigate the variationof apoptosis related gene.METHODS MTT; DNA LADDER; Cell fluorescent staining; GeneChip.RESULTS1. The growth curve of U-251. Cells were training at 37℃, 5%CO2and saturation humidity incubator and cell count each 24-hour. We got the curve. The curve shows that the double time of U-251 is 24hours, 1st day is detention period, 2nd-6th day is exponential phase ofgrowth, 7th-8th day is platform. In platform, because of contactinhibition, the rate of growth slowed down, the cell began to die andthe number of cells decreased.2. Determine the time-concentration curve of effect of lead acetate onU-251 by MTT. We used SPSS for experimental results variance test.The results shows that lead acetate can significantly inhibit the growthof cells. There was an obviousdose-time response relationshipbetween the lead acetate and inhibition ratio of U-251. IC50 is in thevicinity of 0.2mmol/L. With the time increasing, the differencesbetween dose groups were increasingly obvious.3. Confirm the apoptosis of U-251 and determine the time and dose oflead acetate. In the role of lead acetate, apoptosis occurred in U-251cells. The dose-time response relationship between the lead acetateand apoptosis was evident. We can conclude from result of MTT andexperiment, that in the next experiment, the lead acetate strength is0.5mmol/L and action time is 72hours.4. Analysis of gene arrays. U-251 was deal with the lead acetate, thenthe expression of CCND1 and PARP1 was down regulation and theexpression of TNFRSF10B, GADD45A, PSEN2, HSPA5, Bax andp21 was up regulation. CONCLUSIONLead acetate can promote cell apoptosis through various gene pathwaysand affect learning and memory functions.