Role of telomerase reverse transcriptase on cell apoptosis of neutrophils in rats with acute necrotizing pancreatitis / 中华胰腺病杂志

ABSTRACT

Objective:To investigate the effects of telomerase reverse transcriptase (TERT) on neutrophils apoptosis in rats with acute necrotizing pancreatitis (ANP).Methods:Twenty-four Sprague Dawley (SD) rats were randomly divided into three groups including control group, ANP (3h、6h) group and TERT inhibitor(BIBR1532)group using random number method with 6 in each group. ANP rats were induced by retrograde injection of 5% sodium taurocholate into the pancreaticcobiliary duct. After 3 and 6 hours, the fresh neutrophils were collected and isolated from peripheral blood of ANP rats. Rats were intraperitoneally injected with 2 mg/kg BIBR1532. After ANP modeling for 3 h, rats were killed and peripheral neutrophils were collected. Subsequently, the expression of TERT mRNA in neutrophils was tested by real-time quantitative PCR; the protein levels of TERT, BCL-xL and Bax were determined by Western blotting; neutrophil apoptosis was detected by flow cytometry; TNF-α and IL-6 were assayed by Elisa; the rat pancreatic tissue was pathologically examined.Results:In neutrophils from control group, ANP 3 h group, ANP 6 h group and BIBR1532 group, TERT mRNA was 1.03±0.26, 3.31±1.07, 5.21±0.78 and 1.95±0.49; TERT protein expression was 0.09±0.03, 0.43±0.12, 0.58±0.11 and 0.22±0.07; Bcl-xL protein expression was 0.19±0.05, 0.50±0.07, 0.85±0.04 and 0.40±0.11; Bax protein expression was 0.29±0.08, 0.23±0.03, 0.17±0.02 and 0.43±0.12; apoptosis rate was 10.03±0.74%, 7.99±0.27%, 6.65±0.36% and 22.98±2.86%. TERT mRNA and protein expression and Bcl-xL protein expression in ANP 3 h and 6 h group were higher than those in control group, but Bax preotein expression and apoptosis rate were lower than those in control group; TERT mRNA and protein expression and Bcl-xL protein expression in BIBR1532 group were lower than those in ANP 3 h group, but Bax protein expression and apoptosis rate in BIBR1532 group were higher than those in ANP 3 h group; and all the differences were statistically significant (all P value <0.05). The level of TNF-α was [(96.67±27.12)ng/L, (382.30±46.33)ng/L and (206.88±36.42)ng/L], IL-6 was [(43.34±14.50)ng/L, (134.21±16.13)ng/L and (88.06±13.05)ng/L in control, ANP 3 h and BIBR1532 group; those in ANP 3 h group were all higher than those in control group, but those in BIBR1532 group were lower than those in ANP 3 h group; all the differences were statistically significant (all P value <0.05). Compared with ANP group, the morphology of pancreatic tissue was obviously alleviated in BIBER1532 group. Conclusions:TERT expression is obviously increased in peripheral neutrophils in ANP rats, and apoptosis rate of neutrophils from ANP rats is greatly increased after TERT inhibitor treatment, demonstrating that TERT could inhibit the apoptosis of peripheral neutrophil in ANP rats.