Baicalin mitigated Mycoplasma gallisepticum-induced structural damage and attenuated oxidative stress and apoptosis in chicken thymus through the Nrf2/HO-1 defence pathway
Baicalin mitigated Mycoplasma gallisepticum-induced structural damage and attenuated oxidative stress and apoptosis in chicken thymus through the Nrf2/HO-1 defence pathway
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黄芩苷通过 Nrf2/HO-1 防御途径减轻鸡胸腺中鸡胸腺结构损伤并减轻氧化应激和细胞凋亡
DOI：
10.1186/s13567-019-0703-6
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发表时间：
2019-10-21
影响因子：
4.4
通讯作者：
Ishfaq, Muhammad
中科院分区：
文献类型：
--
作者：
Li, Jichang;Qiao, Zujian;Ishfaq, Muhammad
胸腺是一种主要的淋巴器官，在抵抗感染因子的免疫反应中起着关键作用。黄芩苷是一种天然衍生的黄酮类化合物，以其药理特性而闻名，但黄芩苷对免疫损伤的预防作用尚不清楚。我们在鸡胸腺感染支原体（MG）引起的结构损伤的背景下研究了这种效应。组织病理学检查显示，mg感染组胸腺细胞的致密排列丧失。炎性细胞浸润，核屑堆积，皮层与髓质界限不清。mg感染组与对照组和黄芩苷组相比，凋亡相关基因mRNA和蛋白表达量显著升高。在末端脱氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL）试验中，mg感染组阳性染色细胞核数量增加。电镜检查显示mg感染组出现染色质凝集、线粒体肿胀及凋亡囊泡。黄芩苷处理可显著缓解MG感染引起的氧化应激和细胞凋亡。重要的是，黄芩苷处理能部分改善这种异常形态。与mg感染组相比，黄芩苷处理组细胞凋亡相关基因mRNA和蛋白水平的表达均显著降低。同时，黄芩苷显著上调核因子-红细胞2相关因子2 （Nrf2）信号通路及下游基因，抑制mg诱导的鸡胸腺细胞氧化应激和凋亡。综上所述，这些研究结果表明黄芩苷通过激活Nrf2信号通路有效地减轻了氧化应激和细胞凋亡，可以保护胸腺免受MG感染介导的结构和功能损伤。
The thymus is a primary lymphoid organ and plays a critical role in the immune response against infectious agents. Baicalin is a naturally derived flavonoid famous for its pharmacological properties, but the preventive effects of baicalin against immune impairment remain unclear. We examined this effect in the context ofMycoplasma gallisepticum(MG) infection-induced structural damage in the chicken thymus. Histopathological examination showed that the compact arrangement of cells in the thymus was lost in the MG-infected group. Inflammatory cell infiltration and nuclear debris accumulated, and the boundary between the cortex and medulla was not clearly visible. The mRNA and protein expression of apoptosis-related genes were significantly increased in the MG-infected group compared to the control group and the baicalin group. The number of positively stained nuclei in the terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay were increased in the MG-infected group. In addition, electron microscopic examination showed chromatin condensation, mitochondrial swelling and apoptotic vesicles in the MG-infected group. However, baicalin treatment significantly alleviated the oxidative stress and apoptosis induced by MG infection. Importantly, the abnormal morphology was partially ameliorated by baicalin treatment. Compared to the MG-infected group, the baicalin-treated group showed significantly reduced expression of apoptosis-related genes at both the mRNA and protein levels. Meanwhile, the nuclear factor erythroid 2-related factor 2 (Nrf2) signalling pathway and downstream genes were significantly upregulated by baicalin to counteract MG-induced oxidative stress and apoptosis in the thymocytes of chickens. In summary, these findings suggest that baicalin treatment efficiently attenuated oxidative stress and apoptosis by activating the Nrf2 signalling pathway and could protect the thymus from MG infection-mediated structural and functional damage.