ABSTRACT
Objective To investigate the mechanism of HSP70 that inhibits myocardial cell apoptosis in sepsis.Methods Myocardial cells in primary culture were randomly divided into control group,normal serum group,sepsis serum group,transported empty vector group and transported HSP70 group.The myocardial cells in transported HSP70 group have been transported by pcDNA3.1-HSP70 for 36 hours.The myocardial cells in every group have been cultured by respective serum for 2 hours and dyed by Hoechst 33258,and then calculate the rate of myocardial cells apoptosis.Using Western-blot to investigate the effect of overexpression of HSP70 on Caspase-3,8,9's activation and Bid's cracking.Results The rate of myocardial cells apoptosis after dealing in transported HSP70 group [ ( 12.48 ± 2.39 ) ％,( 23.96 ± 3.12 ) ％,( 25.40 ± 3.96) ％ ] is lower than in sepsis serum group [ ( 28.66 ± 2.24 ) ％,( 55.76 ± 5.69 ) ％,( 46.89±8.74)％,t =5.856,5.932,6.027,P ＜0.01,n =3] and lower than in transported empty vector group [(34.25±3.42)％,(50.71±6.38)％,(47.62+5.74)％,t =5.876,5.903,6.122,P ＜0.01,n =3],is higher than in control group,and in normal serum group(3.13％ ～ 6.75％ ,t =6.324,6.578,6.137,5.987,6.032,6.871,P ＜ 0.01,n =3 ).When Caspase-3,8,9 activating,the gray-scale of P11,P20 and P10 in transported HSP70 group( 12.5276 ± 2.1247,9.3481 ± 4.5423,16.1349 ± 6.0641 ) is lighter than that in sepsis serum group ( 27.1324 ± 2.1564,25.5643 ± 4.3018,36.5647 ± 6.7135,t =5.856,5.902,5.891,P ＜ 0.01,n =3 ) and lighter than in transported empty vector group (28.0314 ±2.0367,25.6413 ±4.1356,34.5648 ±5.9473,t =3.861,3.933,4.281,P ＜0.05,n =3),is deeper than in control group(8.0324 ± 1.5234,5.1246 ± 1.3274,2.0314 ±0.6423,t =3.286,3.867,4.031,P＜0.05,n =3) and in normal serum group(8.5649 ± 1.2136,6.0324 ± 1.0214,3.2146 ±0.1325,t =5.898,5.969,6.879,P ＜0.01,n =3).The gray-scale of tBid in transported HSP70 group( 12.0316 ±2.3641 ) is lighter than in sepsis serum group(27.0536 ± 5.3214),t =3.274 ( P ＜ 0.05,n =3 ) and lighter than in transported empty vector group(27.1034 ± 3.6741,t =3.301,P ＜ 0.05,n =3 ),is deeper than in control group ( 6.0347 ± 2.1304,t =5.924,P ＜ 0.01,n =3 ) and in normal serum group ( 7.3121± 1.3021,t =5.871,P ＜ 0.01,n =3 ).Conclusions HSP70 inhibit myocardial cells apoptosis in sepsis by intervened the death receptor pathway and mitochondrial pathway.