MG-132对雨蛙肽诱导的急性胰腺炎小鼠细胞间黏附分子1表达的影响

Effect of MG-132 upon the expression of intercellular adhesion molecule-1 in cerulein-induced acute pancreatitis in mice

目的研究蛋白酶体抑制剂MG．132对雨蛙肽诱导的急性胰腺炎（AP）小鼠核因子KB（NF．KB）与细胞间黏附分子1（ICAM-1）表达的影响。方法45只BalB／c小鼠按随机数字表法分为9组，即对照3、6、12h组，AP3、6、12h组和MG-1323、6、12h组，每组5只。AP组小鼠雨蛙肽100μg/kg腹腔内注射诱导，1次／h，共6次。对照组则腹腔内注射相同剂量的生理盐水。MG-132组在AP诱导前30min腹腔注射MG．13210mg／kg。检测血清淀粉酶和可溶性ICAM-1（sICAM-1）的浓度变化，观察胰腺的病理学变化，经免疫组化法检测胰腺组织中NF-KB的表达，采用半定量逆转录聚合酶链反应（RT．PCR）检测胰腺组织中ICAM-1mRNA的表达。结果MG-132各组血清淀粉酶（U／L）、血清sICAM-1（pg／m1）的浓度均低于相应时间点AP各组（1629±59、1794±123、2910±152比1282±61、1525±103、1809±117，133±10、157±10、217±43比106±6、135±4、163±19，P〈0．05或P〈0．01），MG-132各组胰腺组织的病理评分均分别低于相应时间点AP各组（5．7±1．0、7．1±1．2、9．6±2．1比3．2±1．0、5．3±1．0、6．9±0．8，P〈0．05或P〈0．01），MG-132组胰腺组织中NF—KB蛋白表达及ICAM-1mRNA的表达均明显低于相应时间点AP各组（3．8±1．1、4．6±1．2．6．7±0．4比1．9±0．6、3．1±1．0、4．7±1．0，0．3±0．1、1．0±0．2、1．2±1．0比0．3±0．2、1．8±0．2、2．1±0．2，P〈0．05或P〈0．01）的表达。结论蛋白酶体抑制剂MG-132对雨蛙肽诱导的AP具有保护作用，其机制可能与抑制NF—KB的活化、下调包括黏附分子在内的细胞因子的表达有关。

Objective To investigate the effects of the proteasome inhibitor MG-132 upnon NF-KB and the expression of intercellular adhesion molecule-1 （ ICAM-1 ） in eerulein-induced acute pancreatitis （AP） in mice. Methods Forty-five BalB/c mice were randomly allocated into nine groups： control 3, 6, 12 h group （n =5） ; AP 3, 6, 12 h group （n =5） and MG-132 3, 6, 12 h group （n =5）. AP group was induced by an ip injection of 100 ±g/kg cerulein six times with a 1 h interval. Control group received physiological saline likewise. MG-132 group was injected ip with 10 mg/kg MG-132 at 30 rain before induction of AP. The levels of serum amylase and soluble ICAM-I （ sICAM-1 ） were tested. The pathological changes of pancreas were observed. The expression of NF-KB proteins was examined by immunohistochemistry and the expression of ICAM-1 mRNA analyzed by reverse transcription-polymerase chain reaction （RT-PCR）. Results In MG-132 group, the levels of serum amylase （U/L） and slCAM-1 （pg/ml） markedly decreased in comparison with AP group （ 1629 ±59, 1794 ＋ 123, 2910 ± 152 vs 1282 ± 61, 1525 ± 103, 1809± 117, 133 ± 10, 157 ± 10, 217 ±43 vs 106 ±6, 135 ±4, 163 ± 19, P 〈0.05 or P 〈0. 01 ） ; the scores of pathologieal changes decreased in pancreas （5. 7 ± 1. O, 7. 1 ± 1.2, 9. 6 ± 2. 1 vs 3.2 ±1.0, 5.3 ± 1.0, 6. 9 ±0. 8, P 〈0.05 or P 〈0. 01） ;the expression of NF-KB protein （3.8 ± 1.1, 4.6±1.2, 6.7 ±0.4 vs 1.9 ±0.6, 3.1 ±1.0, 4.7 ±1.0, P〈0.05 or P〈0.01） were significantly lowered than those in AP group. ICAM-1 mRNA also decreased more than those in AP group （ 0. 3 ± 0. 1, 1.0±0.2, 1.2±1.0vs0.3±0.2, 1.8±0.2,2.1±0.2, P〈0.05orP〈0.01）. Conclusions The proteasome inhibitor MG-132 can obviously improve the outcome of acute panereatitis. And the mechanism may be related to the down-regulated expression of cytokines, including adhesion molecules, through the suppression of NF-KB activation.