Hsu Ming-Jen, Lee Shiuh-Sheng, Lin Wan-Wan
Department of Pharmacology, College of Medicine, National Taiwan University, No. 1 Sec. 1, Jen-Ai Road, Taipei, Taiwan, ROC.
J Leukoc Biol. 2002 Jul;72(1):207-16.
Ganoderma lucidum has been widely used as a remedy to promote health and longevity in China. The polysaccharide component with a branched (1-->3)-beta-D-glucan moiety from G. lucidum (PS-G) has shown evidence of enhancement of immune responses and of eliciting anti-tumor effects. In this study, we investigated the effect of PS-G on neutrophil viability, which is manifested by spontaneous apoptosis. Annexin V staining and MTT assays reveal that PS-G is able to inhibit spontaneous and Fas-induced neutrophil apoptosis, and this effect of PS-G is enhanced by the presence of zVAD (a caspase inhibitor) and GM-CSF. The antiapoptotic effect of PS-G is diminished by the presence of wortmannin and LY294002 (two PI-3K inhibitors), but is not altered by PD98059 (a MEK inhibitor). Western blotting indicates the stimulating effect of PS-G on Akt phosphorylation and its inhibition of procaspase 3 degradation, which occurs in neutrophils undergoing spontaneous apoptosis or triggered death by Fas. Taken together, PS-G elicitation of antiapoptotic effects on neutrophils primarily relies on activation of Akt-regulated signaling pathways.
在中国，灵芝已被广泛用作促进健康和长寿的药物。来自灵芝的具有分支（1→3）-β-D-葡聚糖部分的多糖成分（PS-G）已显示出增强免疫反应和引发抗肿瘤作用的证据。在本研究中，我们研究了PS-G对以自发凋亡为特征的中性粒细胞活力的影响。膜联蛋白V染色和MTT分析表明，PS-G能够抑制自发的和Fas诱导的中性粒细胞凋亡，并且zVAD（一种半胱天冬酶抑制剂）和GM-CSF的存在增强了PS-G的这种作用。渥曼青霉素和LY294002（两种PI-3K抑制剂）的存在会减弱PS-G的抗凋亡作用，但PD98059（一种MEK抑制剂）不会改变其作用。蛋白质印迹表明，PS-G对Akt磷酸化具有刺激作用，并抑制procaspase 3降解，这发生在经历自发凋亡或由Fas触发死亡的中性粒细胞中。综上所述，PS-G对中性粒细胞的抗凋亡作用主要依赖于Akt调节的信号通路的激活。
