Study On Shiga Toxin Ⅱ E Variant And Ricin Induced Apoptosis Of Vero Cell

Objective:To investigate whether shiga toxin â…¡ e varriant and ricin induce apoptosis in Africa green monkey kideny cell line Vero, and the expression of gene Caspase-9, Bax, Caspase-3.Methods : The raw Stx2e were isolated in the 40 to 80 fraction of ammoniumsulfate precipitation . ricin were Purified by a Sepharose 4B column and gel filtration on a Sephadex G-100. The Africa green monkey kideny cellline Vero were treated with raw Stx2e and ricin . acridine orange and ethidium bromide flrorescent dye stain method andL adder-like patterns of DNA fragments were usedto detect apoptosis. E xpression of Caspase-9, Bax , and Caspase-3 were assessed by western-blotting.Results: Raw Stx2e induced Vero cell to apoptosis strongly in time-and-dose-dependant manner; Raw Stx2e induced 90% of Vero cell to apoptosis at the concentration above 2ug/ml. ricin induced Vero cell to apoptosis in time-and-dose-dependant manner;ricin induced 18% of Verocell to apoptosis at the concentration above lug/ml. The morphology of Vero changed as nuclear condensation of chromatin and DNA fragmentation after treated with 2ug/ml of raw stx2e for 24h or after treated with lug/ml of raw ricin for 36h .After treated with raw stx2e, compared with the control, the expression of Bax had a increasment,the expression of caspase-3 had a significant increasment, the expression of Caspase-9 did not have a significant difference. After treated with ricin, compared with the control, the expression of caspase-3 had a incre asment, the expression of Bax had a decrease, the expression of Caspase-9 did not have a significant difference.Conclusions: Stx2e and ricin induced Vero cells to apoptosis in time -and-dose-dependent manner. Caspase-3 and Bax involved in Vero...