Effects Of Octreotide On The Apoptosis And Expressions Of Bcl-2 And Bax In Human Hepatic Stellate Cells

objective:To investigate the effects of octreotide on the apoptosis and expressions of Bcl-2 and Bax in human hepatic stellate cells,and explore the possible mechanism of octreotide against hepatic fibrosis.Methods:HSC-LX2 were cultured in DMEM medium which contain 10%fetal bovine serum in 37 ?,5%CO2 incubator.HSC-LX2 were identified by immunocytochemistry of desmin and ?-SMA.HSC-LX2 were incubated with the different concentration of octreotide for 24 and 48 hours.Cell apoptosis were evaluated by Fitc-tunel fluorescence staining.Bcl-2 and Bax protein in HSC-LX2 were detected by immunocytochemistry.Meanwhile,Bcl-2 protein in HSC-LX2 were detected by Western blot.Results:?1?Desmin and a-SMA were found in HSC-LX2 by immunocytochemistry.?2?Apoptosis rates increased in HSC-LX2 when induced by octreotide for 24h.Apoptosis rates for 24h in 10^-5 mmol/L and 10^-2 mmol/L groups were 11.99%�1.89%and 20.12%�2.5%,significantly higher than that in control group?4.92%�0.74%,P<0.05?.Meanwhile,there was significant difference between 10^-5 mmol/L and 10^-2mmol/L groups?P<0.05?.Apoptosis rates also showed significant increase in HSC-LX2 induced by octreotide for 48h.Apoptosis rates for 48h in 10^-5 mmol/L and 10^-2mmol/L groups were 14.62%�1.93%and 23.71%�2.85%,significantly higher than that of control group?6.23%�0.97%,P<0.05?,Meanwhile,there was significant difference between 10^-5 mmol/L and 10^-2 mmol/L groups?P<0.05?.HSC-LX2 were incubated with 10"5 mmol/L octreotide for 24h and 48h.Apoptosis rate of 48h group was significantly higher than that of 24h group?P<0.05?.HSC-LX2 were incubated with 10"2 mmol/L octreotide for 24h and 48h.Apoptosis rate of 48h group was significantly higher than that of 24h group?P<0.05?.These results indicated that octreotide could promote and induce the apoptosis of HSC-LX2.?3?HSC-LX2 were incubated with the different concentration of octreotide for 24h.Bax expression in 10 mmol/L group?0.19�0.04?and 10^-2 mmol/L group?0.26�0.06?were significantly higher than that in control group?0.13�0.04,P<0.05?.There was also significant difference between 0-5 mmol/L group and 10^-2 mmol/L group?P<0.05?.BcL-2 expression in 10^-5 mmol/L group?0.2510.04?and 10^-2 mmol/L group?0.15�0.09?were significantly decreased than that in control group?0.33�0.06,P<0.05?.There was significant difference between 10^-5 mmol/L group and 10^-2mmol/L group?P<0.05?.HSC-LX2 were incubated with the different concentration of ctreotide for 48h.Bax expression in 10^-5 mmol/L group?0.25�0.06?and 10^-2mmol/L group?0.49�0.08?were significantly higher than that in control group?0.14�0.03,P<0.05?.There was also signifncant difference between 10^-5 mmol/L group and 10^-2 mmol/L group?P<0.05?.Bcl-2 expression in 10^-5 mmol/L group?0.21 10.07?and 10^-2mmol/L group?0.11�0.04?were significantly decrease than that in control group?0.34�0.09,P<0.05?.There was significant difference between 10^-5 mmol/L group and 10^-2 mmol/L group?P<0.05?.HSC-LX2 were incubated with 10^-5 mmol/L octreotide for 24h anrd 48h,Bax expression in 48h group were significantly higher than that in 24h group?P<0.05?,Bcl-2 expression in 48h group were ciecreased than that in 24h group?P>0.05?,HSC-LX2 were incubated with 10^-2 mmol/L octreotide for 24h and 48h,Bax expression in 48h group were significantly higher than that in 24h group?P<0.05?,Bcl-2 expression in 48h group were decreased than that in 24h group?P>0.05?.These results indicate that octreotide could upregulate the expression of Bax and down-regulate the expression of Bcl-2.?4?HSC-LX2 were incubated with the different concentration of octreotide for 24h,The result of Western-blot shows that the expression of Bcl-2 in 10^-5 mmol/L group?0.42�0.08?and 10^-2mmol/L group?0.25�0.07?were apparently decreased,eompared with that in control group?0.50�0.06,P<0.05?.Meanwhile,there was significant difference between 10^-5mmol/L group and 10^-2mmol/L group?P<0.05?,HSC-LX2 were incubated with the different concentration of octreotide for 48h.The expression of Bcl-2 in 10^-5mmol/L group?0.34�0.05?and 10^-2mmol/Lgroup?0.20�0.07?were also significantly decreased,compared with that in control group?0.50�0.06,P<0.05?.There was also significant difference between 10^-5mmol/L group and 10^-2mmol/L group?P<0.05?.The results indicate that octreotide could decrease the expression of Bcl-2 in human hepatic stellate cells.Conclusions:?1?Octreotide could induce the apoptosis of human hepatic stellate cells in a dose and time dependent manner.?2?The mechanism of octreotide inducing human hepatic stellate cells apoptosis might be associated with down-regulation of Bcl-2 expression and upregulation of Bax expression in HSC.