化脓隐秘杆菌自然感染病牛肝脏病理学和细胞凋亡的检测与分析

Detection and Analysis of Pathology and Apoptosis of Cattle Liver with Natural Infection of Arcanobacterium pyogenes

通过研究化脓隐秘杆菌感染牛肝脏组织的病理学变化及检测Caspase-3、Caspase-8、Caspase-9、Bax和Bcl-2的表达,来确定化脓隐秘杆菌感染是否会引起牛肝脏细胞发生凋亡。筛检2头阴性健康对照牛和5头自然感染的化脓隐秘杆菌病牛,采集其肝脏组织样本,进行石蜡制片和H.E.染色,来观察病理组织学变化;采用常规免疫组织化学的方法,对肝脏组织中凋亡相关基因及相关通路蛋白Bax、Bcl-2和Caspase-3、Caspase-8、Capase-9的表达进行检测。结果显示,化脓隐秘杆菌病牛肝脏肿大,有灰黄色病灶;胆汁潴留;肝细胞变性坏死,间质炎细胞浸润;感染组牛肝脏肝细胞、小叶间胆管上皮细胞和汇管区淋巴细胞Caspase-3、Caspase-9和Bax表达阳性,与对照组相比,差异显著(P<0.05);肝脏只有少量细胞Caspase-8和Bcl-2阳性表达,与对照组相比,差异不显著(P>0.05)。结果表明:化脓隐秘杆菌能够引起牛肝脏肝细胞、小叶间胆管上皮细胞和汇管区淋巴细胞发生坏死和凋亡;化脓隐秘杆菌可以通过调节细胞Bcl-2家族的活性,引起其Bax和Bcl-2比率改变,增加线粒体内外膜的通透性,导致和凋亡相关的因子释放,激活Caspase-9,进一步激活Caspase-3,从而引起肝细胞、小叶间胆管上皮细胞和汇管区淋巴细胞发生凋亡。

By studying the pathological changes of bovine liver tissue infected by Arcanobacterium pyogenes and detecting the expressions of Caspase-3,Caspase-8,Caspase-9,Bax and Bcl-2,whether Arcanobacterium pyogenes infection caused the apoptosis of bovine liver cells was determined.Liver tissue samples from 2 negative healthy control cattle and 5 naturally infected Arcanobacteriosis pyogenes were screened for paraffin and H.E.Staining to observe the histopathological changes;The expressions of apoptosis-related genes and related pathway proteins Bax,Bcl-2,Caspase-3,Caspase-8 and Capase-9 in liver tissues were detected by conventional immunohistochemical methods.The results showed that the liver of cattle with Arcanobacteriosis pyogenes was enlarged and there were grayish yellow lesions.Bile retention;Hepatocyte degeneration and necrosis,interstitial inflammation cell infiltration;The expressions of Caspase-3,Caspase-9 and Bax were positive in liver cells,interlobular bile duct epithelial cells and portal lymphocyte in infected group,and the differences were significant compared with those in control group(P<0.05).There were only a small number of Caspase-8 and Bcl-2 positive expressions in liver cells,and the difference was not significant compared with the control group(P<0.05).The results showed that Arcanobacterium pyogenes could cause necrosis and apoptosis of hepatocytes,interlobular bile duct epithelial cells and portal area lymphocytes of bovine liver.Arcanobacterium pyogenes could regulate the activity of the Bcl-2 family of cells,cause changes in the ratio of Bax and Bcl-2,increase the permeability of the inner and outer membranes of mitochondria,lead to the release of apoptosis-related factors,activate Caspase-9,and further activate Caspase-3.The apoptosis of hepatocytes,interlobular bile duct epithelial cells and sink area lymphocytes was induced.