核桃多酚对皮质酮损伤PC12细胞的作用机制

Mechanism of Walnut Polyphenols on PC12 Cells Injured by Corticosterone

核桃多酚为核桃粕中的生物活性物质,具有重要的开发和应用价值。为探讨核桃多酚的潜在抗抑郁活性,采用皮质酮诱导的大鼠嗜铬瘤(PC12)细胞损伤模型,以细胞活力、细胞凋亡、乳酸脱氢酶(lactate dehydrogenase,LDH)释放量、细胞内钙离子水平评价核桃多酚在皮质酮损伤模型上的作用,并进一步采用蛋白免疫印迹法探讨核桃多酚对皮质酮损伤PC12细胞作用的机制。结果表明:核桃多酚(75、150μg/mL)预处理可显著逆转皮质酮损伤引起PC12细胞活力降低、细胞凋亡、LDH释放量增加和钙超载,发挥细胞保护作用;此外,核桃多酚可显著逆转皮质酮诱导的PC12细胞中cAMP依赖性蛋白激酶A(cAMP-dependent protein kinase A,PKA)活性降低,并下凋cAMP反应原件结合蛋白(cAMP-response element binding protein,CREB)133位丝氨酸的磷酸化和下游靶蛋白脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)的表达量;进一步应用PKA阻断剂H89预处理消除了核桃多酚对皮质酮诱导的PC12细胞的保护作用,说明增加PKA/CREB/BDNF信号通路活性是核桃多酚发挥抗皮质酮损伤作用必需的。研究结果表明,核桃多酚具有潜在的抗抑郁活性,可能是核桃饮食发挥抗抑郁作用的重要物质基础,其对皮质酮损伤的PC12细胞的保护作用与上调PKA/CREB/BDNF信号通路有关。研究结果旨在探明核桃多酚的潜在抗抑郁活性及机制,并为核桃粕的高值化利用提供理论参考。

Walnut polyphenols(WP)is an important bioactive substance in defatted walnut and has important development and application value.In order to evaluate the antidepressant effect of WP on corticosterone-induced damage of rat pheochromocytoma(PC12)cells by cell viability,cell apoptosis,leakage of extracellular lactate dehydrogenase,and intracellular calcium level,and investigated its mechanisms by western blotting.The results showed that WP(75,150μg/mL)pretreatment could protect cell by significantly reversing the cell viability decrease,cell apoptosis,LDH release increase,and overload of intracellular calcium in PC12 cells treated with corticosterone.In addition,WP significantly increased the activity of cAMP-dependent protein kinase A(PKA),reduced the level of Ser133 phosphorylation of cAMP response element binding protein(CREB)and the expression of downstream target protein brain-derived neurotrophic factor(BDNF),which were decreased by corticosterone treatment.Furthermore,pretreatment with PKA inhibitor H89 abolished the protective effects of WP on corticosterone induced PC12 cells,indicating that up-regulation of PKA/CREB/BDNF neurotrophic signaling pathway was required for WP neuroprotective effects against corticosterone.These results suggested that WP might have potential antidepressant activity and be an important material basis in the antidepressant effect of walnut diet.The cytoprotective effect of WP on PC12 cells was related to the up-regulation of PKA/CREB/BDNF neurotrophic signaling pathway.The research results aimed to explore the potential antidepressant activity and mechanism of walnut polyphenols,and provided theoretical reference for the high-value utilization of walnut meal.