Effects Of Magnesium Sulfate On The Molecular Mechanism Of Radiation Injury Of Human Umbilical Vein Endothelial Cells

Objective:Study after 4Gy-X-ray radiation on the human umbilical vein endothelial cells(HUVEC) the effects of magnesium sulfate on cell cycle and apoptosis, and probe the possible mechanism analysis. Study the effect of magnesium sulfate on the expression of anti apoptotic protein Bcl-2 protein and mRNA in HUVEC cells.Methods:1. Select HUVEC cells in the exponential growth phase, use flow cytometry to detect the effect of magnesium sulfate on HUVEC cell cycle distribution after radiation.The expression of cyclin CyclinB1 is detected by flow cytometry and Western blot.2. The apoptosis rate of HUVEC cells was determined by Annexin V/PI double staining method. Bcl-2 and P53 protein is detected by the expression of Western blot;Bcl-2 mRNA is detected by the real time RT-PCR;3. IκB-α protein is detected by western blot; IκB-α mRNA is detected by the expression of RT-PCR;4. Data are expressed by the mean and standard deviation, using SPSS 19 statistical software. T test is used for the group difference. P < 0.05 is statistically significant.Results:1.Preliminary experimental results show that 1.25 mg/ml of magnesium sulfate on human umbilical vein endothelial cells is non-toxic, and can improve the X cell survival rate after irradiation.2.1.25mg/ml magnesium sulfate can alleviate G2/M arrest on HUVEC cells produced by X after irradiation. Flow cytometry and Western blot analysis show:compared to the irradiation alone group, of the radiation plus drug group, cyclinB1 protein expression increased after 24 h.3.Compared with the control group, the apoptosis rate of simple irradiation group had increased. Compared with the simple irradiation, HUVEC apoptosis rate of1.25mg/ml magnesium sulfate treatment group had increased, which suggests1.25mg/ml magnesium sulfate may promote apoptosis of HUVEC cells irradiation after X ray.4.Real time PCR results showed that the X-ray increased expression of anti apoptotic protein Bcl-2 mRNA, but 1.25mg/ml magnesium sulfate can reduce the mRNA expression level. Western blot indicated that irradiation after 48 h, 72 h, the expression of Bcl-2 protein increase, but 1.25mg/ml magnesium sulfate can reduce the expression of Bcl-2; Western blot showed that single irradiation after 72 h, p53 expression increased significantly; compared to the simple irradiation group, the expression of p53 of HUVEC is promoted by magnesium sulfate after 72 h.5.Real time PCR results showed that the X-ray increased the expression of IκB-αmRNA, but 1.25mg/ml magnesium sulfate can reduce the mRNA expression level.Western blot showed that single irradiation after 24 h, 48 h, IκB-α protein expression increased, but decreased expression after 72 h. IκB-α mRNA expression was decreased by 1.25mg/ml magnesium sulfate after X ray irradiation.Conclusions:1.1.25mg/ml magnesium sulfate can alleviate G2/M arrest on HUVEC cells irradiation after X ray;2.1.25mg/ml magnesium sulfate can increase the HUVEC cell apoptosis rate irradiation after X ray;3.Magnesium sulfate may inhibit the expression of IκB-α mRNA, inhibiting activation of NF-κB, thus preventing the NF-κB nuclear translocation to reduce the expression of Bcl-2 mRNA and protein levels, thereby promoting apoptosis on cells that cannot repair.