雷公藤甲素与地塞米松对哮喘豚鼠不同密度嗜酸粒细胞凋亡及bcl-2 mRNA表达的影响

Effects of Triptolide and Dexamethasone on expression of bcl-2 mRNA and apoptosis in eosinophils

目的观察雷公藤甲素(TP)与地塞米松(DM)对体外不同密度嗜酸粒细胞(Eos)凋亡及bcl-2 mRNA表达的影响,探讨其促进哮喘Eos凋亡的机制.方法卵蛋白激发哮喘豚鼠动物模型48小时后行支气管肺泡灌洗,分离不同密度Eos.TP(10-7～10-4mol/L) 或DM(10-10～10-5mol·L-1)干预24小时,原位杂交检测Eos的bcl-2 mRNA表达,TUNEL法检测细胞凋亡.结果 TP及DM干预24小时,可见Eos凋亡增加,以低密度Eos(HEos)为明显,bcl-2 mRNA表达降低,呈剂量依赖性.bcl-2 mRNA的表达与Eos凋亡呈负相关.结论 TP及DM可抑制bcl-2 mRNA表达,促进Eos凋亡.bcl-2参与了TP及DM对Eos凋亡的调节.TP可能具有激素样促进细胞凋亡的作用.

Objective To investigate the effects of Triptolide(TP) and Dexamethasone (DM) on expression of bcl-2 mRNA and apoptosis in eosinophils(Eos) of bronchalveolar lavage fluid(BALF) in asthmatic guinea pigs,and to inquire into the mechanism of TP and DM promoting Eos apoptosis.Methods Forty-eight hours after giunea pigs were stimulated by ovalbumin(OVA),Hypodense Eos(HEos) and Normodense Eos(NEos) were purified from BALF by gradients of percoll.Twenty-four hours after Eos cultured in PRMI1640 medium containing TP (10 -7～10 -4mol·L -1) or DM (10 -10～10 -5mol/L),the mRNA of bcl-2 in Eos was measured by hybridization,Apoptosis was detected by TdT-mediated dUTP nick end labeling(TUNEL).Results Eos cultured under the condition of TP or DM administration in vitro,apoptotic Eos increased and the expression of bcl-2 mRNA decreased in a dose-dependent manner.The expression of bcl-2 mRNA was inversely correlated with Eos apoptosis.Conclusions TP and DM may promote Eos apoptosis and inhibit expression of bcl-2 in dose-dependent manner in vitro.bcl-2 might be involved in the mechanism that TP and DM promote apoptosis of Eos.