大黄素影响巨噬细胞升高[Ca^(2+)]_i和释放TNF-a的作用特征

THE EFFECT OF EMODIN ON THE INCREASE OF [Ca^(2+)] AND TNF-α PRODUCTION IN LIPOLYSACCHARIDE-STIMULATED RAT MACROPHAGES

为了研究大黄素(emodin)对正常的和细菌脂多糖(LPS)刺激的大鼠腹腔巨噬细胞(PM准)释放肿瘤坏死因子琢(TNF-琢)和升高[Ca2+]i的影响,应用L929细胞系和MTT法检测TNF-琢量,同时用激光共焦扫描显微术检测单细胞[Ca2+]i变化动力学。结果显示大黄素能轻度促进正常PM准释放TNF-琢,并发现大黄素诱发PM准[Ca2+]i变化呈振荡波模式。大黄素显著抑制LPS刺激PM准过度释放TNF-琢和升高[Ca2+]i,10-5mol/L大黄素抑制了10mg/LLPS刺激的TNF-琢峰值的50%和[Ca2+]i峰值的68%。LPS诱发PM准[Ca2+]i变化呈现高幅值的“平台期”,大黄素使之转变为低幅值的波动变化。以上结果说明,大黄素对PM准释放TNF-琢和升高[Ca2+]i表现出的双向调节作用之间有一定的相关性,大黄素对LPS诱发的[Ca2+]i升高的调制,可能是抑制LPS刺激PM准释放TNF-琢的信号传导通路中的重要环节。

To explore the role of emodin on increase in i and TNF-á production in normal and lipopolysaccharide (LPS)-stimulated rat perit oneal macrophages (PM ), TNF- production was determined using TNF- -sensitive L929 cell line and by MTT method and the kinetics of intracellular free Ca 2+ con-centration ( i ) in a single cell were monitored continuously by confocal laser scanning microscope. The results showed that 10 -5 mol/L emodin could elevate TNF- production slightly, and caused forming low amplitude i oscillation in normal single PM . Emodin could inhibit both excessive release of TNF- and increase in i when PM was stimulated by LPS. 10 -5 mol/L emodin inhibited TNF- production by 50% and i increase by 68% respectively. Interestingly, emodin could transform the high amplitude 'plateau-like' i induced by LPS into fluctuation that has low amplitude. These re sults indicate that the biphase characteristics of modulation of Emodin on TNF- production correlate with i changing. The modulation of emodin on i may be a main way that emodin inhibits TNF- production in LPS stimulated PM .