猴头菇多糖对免疫应激小鼠胸腺和脾脏显微结构、免疫功能及细胞增殖和凋亡的影响

Effects of Hericium erinaceu polysaccharide on microstructure,immune function,cell proliferation and apoptosis of thymus and spleen in LPS induced stressed mice

目的研究猴头菇多糖对脂多糖(LPS)诱导免疫应激小鼠胸腺和脾脏显微结构、细胞因子分泌、抗氧化功能及细胞增殖和凋亡的影响,为猴头菇多糖在缓解应激状态中的应用提供参考。方法选用12周龄雄性昆明小鼠50只,随机分为对照组、模型组和试验Ⅰ-Ⅲ组(n=10)。除对照组腹腔注射生理盐水外,其余4组在试验结束前3 d腹腔注射0.6 mL/kg/d的LPS(1次/d)。试验Ⅰ、Ⅱ、Ⅲ组分别灌胃80、160、320 mg/kg的猴头菇多糖,持续2周。测定胸腺和脾脏促炎细胞因子水平、抗氧化功能及细胞增殖和凋亡基因表达,并进行显微结构观察分析。结果与对照组相比,模型组胸腺和脾脏中白细胞介素1β(IL-1β)、白细胞介素4(IL-4)和干扰素γ(IFN-γ)水平显著或极显著升高(P<0.05或P<0.01),总超氧化物歧化酶(T-SOD)和总抗氧化能力(T-AOC)活性显著降低(P<0.05)、谷胱甘肽过氧化物酶(GSH-Px)含量也显著降低(P<0.05),丙二醛(MDA)含量显著升高(P<0.05),脾脏增殖细胞核抗原(PCNA)mRNA表达量显著降低(P<0.05),半胱氨酸蛋白酶-3(Caspase-3)mRNA表达量显著增加(P<0.05)。与模型组相比,试验Ⅲ组小鼠胸腺和脾脏IL-1β、IL-4和IFN-γ水平显著或极显著降低(P<0.05或P<0.01),T-SOD、T-AOC和GSH-Px的活性或含量均显著升高(P<0.05)、MDA含量和Caspase-3 mRNA表达量显著降低(P<0.05)。组织学观测发现,试验Ⅲ组小鼠胸腺和脾脏显微结构与模型组相比明显改善,胸腺皮质厚度增加(P<0.01),脾小结和动脉周围淋巴鞘厚度降低(P<0.05或P<0.01)。结论补充320 mg/kg猴头菇多糖能够明显改善免疫应激对小鼠胸腺和脾脏显微结构的损伤,抑制免疫应激诱导的促炎细胞因子分泌和细胞凋亡基因表达,增强抗氧化酶活性。

Objective To study the effects of Hericium erinaceus polysaccharide on the microstructure,cytokine secretion,antioxidant function,cell proliferation and apoptosis of thymus and spleen in mice with immune stress induced by lipopolysaccharide(LPS),so as to provide reference for the application of Hericium erinaceus polysaccharide in relieving stress.MethodsFifty male Kunming mice of 12-week old were randomly divided into control group,model group and experimental group I-III(n=10).In addition to the control group,the other four groups were intraperitoneally injected with 0.6 mL/kg/d LPS(once a day)three days before the end of the experiment.The experimental groups I,II and III were given 80,160 and 320 mg/kg Hericium erinaceus polysaccharide by gavage for 2 weeks.Results Compared with the control group,the levels of interleukin-1β(IL-1β),interleukin-4(IL-4)and interferonγ(IFN-γ)in thymus and spleen of mice in the model group were significantly increased(P<0.05 or P<0.01),the activities of total superoxide dismutase(T-SOD)and total antioxidant capacity(T-AOC)were significantly decreased(P<0.05),the content of glutathione peroxidase(GSH-Px)was also significantly decreased(P<0.05),and the content of malondialdehyde(MDA)was significantly increased(P<0.05).The expression of proliferating cell nuclear antigen(PCNA)mRNA in spleen of mice was significantly decreased(P<0.05),while the expression of cysteine protease-3(caspase-3)mRNA was significantly increased(P<0.05).Compared with the model group,IL-1β,IL-4 and IFN-γin thymus and spleen of mice in experimental group III was significantly higher,the activity or content of T-SOD,T-AOC and GSH Px were increased significantly(P<0.05),and the content of MDA and the expression of caspase-3 mRNA were significantly decreased(P<0.05).By histological observation,compared with the model group,the microstructure of thymus and spleen in experimental groupⅢwas significantly improved,the thickness of thymic cortex was increased(P<0.01),and the thickness of splenic nodule and periarterial lymphatic sheath was decreased(P<0.05 or P<0.01).Conclusion Supplementation of 320 mg/kg Hericium erinaceus polysaccharide can significantly improve the damage of thymus and spleen microstructure,inhibit the secretion of pro-inflammatory cytokines and the expression of apoptosis genes induced by immune stress,and enhance the activity of antioxidant enzymes.