β-Catenin在雨蛙肽诱导的胰腺腺泡细胞凋亡中的作用

Role of β-catenin in apoptosis of pancreatic acinar cells induced by caerulein

目的:研究β-连环蛋白(β-catenin)在雨蛙肽诱导的胰腺腺泡细胞凋亡中的作用及机制。方法:用雨蛙肽处理大鼠胰腺腺泡AR42J细胞,real-time PCR和Western blot检测细胞中β-catenin的mRNA和蛋白表达变化。在AR42J细胞中转染β-catenin过表达载体,用雨蛙肽处理后,用real-time PCR和Western blot测定过表达效果,MTT法测定细胞活力的变化,二硝基苯肼法检测乳酸脱氢酶(LDH)漏出率,碘-淀粉比色法检测淀粉酶(AMY)漏出率,流式细胞术测定细胞凋亡,Western blot检测细胞中内质网应激相关蛋白CHOP和cleaved caspase-12的蛋白水平。结果:AR42J细胞经雨蛙肽处理后细胞中β-catenin的mRNA和蛋白水平均降低(P<0.05)。β-Catenin过表达载体转染可明显提高雨蛙肽作用下胰腺腺泡细胞中β-catenin的表达水平。雨蛙肽处理后的AR42J细胞活力降低,LDH和AMY漏出率升高,细胞凋亡率及细胞中CHOP和cleaved caspase-12的蛋白水平升高(P<0.05)。过表达β-catenin可以提高雨蛙肽处理后的AR42J细胞活力,降低LDH和AMY漏出率,减少细胞凋亡,降低细胞中CHOP和cleaved caspase-12的蛋白水平(P<0.05)。结论:β-Catenin可明显抑制雨蛙肽诱导的胰腺腺泡细胞凋亡,作用机制与减少内质网应激有关。

AIM: To study the role of β-catenin in the apoptosis of pancreatic acinar cells induced by caerulein. METHODS: Rat pancreatic acinar AR42 J cells were treated with caerulein. The expression of β-catenin at mRNA and protein levels in the AR42 J cells was determined by real-time PCR and Western blot. The β-catenin over-expression vector was transfected into AR42 J cells. After treatment with caerulein,the over-expression effect was evaluated by realtime PCR and Western blot. The changes of cell viability were measured by MTT assay. The leakage rates of lactate dehydrogenase( LDH) and amylase( AMY) were measured by binitrophenyl hydrazine method and iodine starch colorimetry,respectively. The apoptosis was analyzed by flow cytometry. The protein levels of endoplasmic reticulum stress protein CHOP and cleaved caspase-12 in the AR42 J cells were determined by Western blot. RESULTS: The expression of β-catenin at mRNA and protein levels in the AR42 J cells was decreased after treatment with caerulein( P < 0. 05). The expression of β-catenin in the AR42 J cells was significantly increased by transfection with β-catenin over-expression vector. The viability of AR42 J cells after treatment with caerulein was reduced,while the leakage rates of LDH and AMY,the apoptotic rate and the protein levels of CHOP and cleaved caspase-12 in the cells were increased( P < 0. 05). Over-expression of β-catenin enhanced the viability of AR42 J cells after treatment with caerulein,reduced the leakage rates of LDH and AMY,and decreased the apoptotic rate and the protein levels of CHOP and cleaved caspase-12 in the AR42 J cells. CONCLUSION: β-Catenin significantly inhibits the apoptosis of pancreatic acinar cells induced by caerulein. The mechanism is related to the reduction of endoplasmic reticulum stress.