白术多糖通过线粒体和死亡受体途径缓解脂多糖诱导的雏鹅胸腺细胞凋亡

Polysaccharide of Atractylodes macrocephala Koidz Relieves Lipopolysaccharide-Induced Apoptosis through Mitochondrial and Death Receptor Pathways in Thymus of Goslings

本试验旨在通过研究白术多糖(PAMK)对脂多糖(LPS)处理雏鹅胸腺的氧化应激、炎性因子及细胞凋亡水平的影响,探索PAMK是否通过线粒体途径和死亡受体途径对LPS诱导的胸腺细胞凋亡具有缓解作用。试验选用80只1日龄的马岗鹅,随机分为4组,每组5个重复,每个重复4只。对照组(CON组)和脂多糖组(LPS组)饲喂基础饲粮,白术多糖组(PAMK组)和脂多糖+白术多糖组(LPS+PAMK组)在基础饲粮中添加400 mg/kg PAMK;CON组和PAMK组分别在雏鹅第24、26、28日龄腹腔注射1 mL生理盐水;LPS组和LPS+PAMK组分别在雏鹅第24、26、28日龄腹腔注射2 mg/kg LPS溶液。试验期28 d。结果表明:1)苏木精-伊红染色和超微结构观察结果显示,PAMK缓解了LPS引起的胸腺损伤和凋亡。2)与CON组相比,PAMK组的白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)的mRNA相对表达水平无显著差异(P>0.05),白细胞介素-10(IL-10)的mRNA相对表达水平显著下降(P<0.05)。与LPS组相比,LPS+PAMK组的IL-1β、IL-6、TNF-α、IL-10的mRNA相对表达水平显著降低(P<0.05)。3)与LPS组相比,PAMK+LPS组过氧化氢酶(CAT)、超氧化物歧化酶(SOD)的mRNA相对表达水平显著升高(P<0.05),谷胱甘肽过氧化物酶(GPX)的mRNA相对表达水平显著降低(P>0.05)。4)与CON组相比,PAMK组B细胞白血病/淋巴瘤-2相关X蛋白(Bax)、肿瘤蛋白63(TP63)的mRNA相对表达水平无显著差异(P>0.05),半胱氨酸天冬氨酸特异性蛋白酶-3(Caspase-3)的mRNA相对表达水平显著降低(P<0.05),B细胞白血病/淋巴瘤-2(Bcl-2)、半胱氨酸天冬氨酸特异性蛋白酶-8(Caspase-8)的mRNA相对表达水平显著升高(P<0.05)。与LPS组相比,LPS+PAMK组Bax、Caspase-3的mRNA相对表达水平显著降低(P<0.05),Bcl-2、Caspase-8、TP63的mRNA相对表达水平表达显著升高(P<0.05)。5)与CON组相比,PAMK组Bax、Caspase-8的蛋白相对表达水平无显著差异(P>0.05),Bcl-2的蛋白相对表达水平显著下降(P<0.05)。与LPS组相比,LPS+PAMK组Bax、Caspase-8的蛋白相对表达水平显著下降(P<0.05),Bcl-2的蛋白相对表达水平显著升高(P<0.05)。由此可见,PAMK可抑制LPS引起的氧化应激、炎性因子水平上升,通过线粒体及死亡受体途径缓解雏鹅胸腺细胞凋亡,并维持胸腺组织的结构完整性。

This experiment was conducted to study the effects of polysaccharide of Atractylodes macrocephala Koidz(PAMK)on oxidative stress,inflammatory factors and apoptosis level in thymus of goslings treated with lipopolysaccharide(LPS),to find that whether PAMK relieved LPS-induced apoptosis through the mitochondrial and death receptor pathways in thymus of goslings.A total of 80 one-day-old healthy goslings were selected and randomly divided into 4 groups with 5 replicates per group and 4 goslings per replicate.Goslings in control group(CON group)and lipopolysaccharide group(LPS group)were fed the basal diets,and others in polysaccharide of Atractylodes macrocephala Koidz group(PAMK group)and lipopolysaccharide+polysaccharide of Atractylodes macrocephala Koidz group(LPS+PAMK group)were fed basal diets supplemented with 400 mg/kg PAMK.Goslings in CON group and PAMK group were intraperitoneal injected 1 mL normal saline on days 24,26 and 28,respectively,and goslings in LPS group and LPS+PAMK group were intraperitoneal injected 2 mg/kg LPS solution on days 24,26 and 28,respectively.The experiment lasted for 28 days.The results showed as follows:1)the hematoxylin-eosin staining and ultrastructural observation showed that PAMK relieved the LPS-induced injury and apoptosis in thymus.2)Compared with the CON group,the mRNA relative expression levels of interleukin-1β(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)of PAMK group were no significant difference(P>0.05),and the interleukin-10(IL-10)mRNA relative expression level was significantly decreased(P<0.05).Compared with the LPS group,the mRNA relative expression levels of IL-1β,IL-6,TNF-αand IL-10 of LPS+PAMK group were significantly decreased(P<0.05).3)Compared with the LPS group,the mRNA relative expression levels of catalase(CAT),superoxide dismutase(SOD)of LPS+PAMK group were significantly increased(P<0.05),and the glutathione peroxidase(GPX)mRNA relative expression level was significantly decreased(P<0.05).4)Compared with the CON group,the mRNA relative expression levels of B-cell lymphoma/leukaemia-2-associated X protein(Bax)and tumor protein 63(TP63)of PAMK group were no significant difference(P>0.05),the cysteinyl aspartate specific proteinase-3(Caspase-3)mRNA relative expression level was significantly decreased(P<0.05),and the mRNA relative expression levels of B-cell lymphoma/leukaemia-2(Bcl-2)and cysteinyl aspartate specific proteinase-8(Caspase-8)were significantly increased(P<0.05).Compared with the LPS group,the mRNA relative expression levels of Bax and Caspase-3 of LPS+PAMK group were significantly decreased(P<0.05),and the mRNA relative expression levels of Bcl-2,Caspase-8 and TP 63 were significantly increased(P<0.05).5)Compared with the CON group,the protein relative expression levels of Bax and Caspase-8 of PAMK group were no significant difference(P>0.05),and the Bcl-2 protein relative expression level was significantly decreased(P<0.05).Compared with the LPS group,the protein relative expression levels of Bax and Caspase-8 of LPS+PAMK group were significantly decreased(P<0.05),and the Bcl-2 protein relative expression level was significantly increased(P<0.05).In conclusion,the PAMK can inhibit the increase of oxidative stress and inflammatory factor levels induced by LPS,alleviate the thymus apoptosis of goslings through the mitochondrial and death receptor pathways,and maintain the structural integrity of thymus tissue.