Mo Quan, Hu Liwen, Weng Jiahua, Zhang Yong, Zhou Yancheng, Xu Ruiguang, Zuo Zhicai, Deng Junliang, Ren Zhihua, Zhong Zhijun, Peng Guangneng, Nong Xiang, Wei Yahui, Hu Yanchun
Key laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China (QM, LH, JW, YZ, YCZ, RX, ZCZ, JD, ZR, ZJZ, GP, YH).
College of Life Science, Leshan Normal University, Leshan, China (XN).
J Histochem Cytochem. 2017 Sep;65(9):543-558. doi: 10.1369/0022155417722118. Epub 2017 Jul 26.
Euptox A (9-oxo-10, 11-dehydroageraphorone), the main toxin isolated from Eupatorium adenophorum, is known to induce immunotoxicity in animals. However, the precise mechanism underlying the effects of Euptox A on splenocytes is unclear. Here, we aimed to investigate the molecular mechanisms underlying the effect of Euptox A in mouse spleens after its intragastric administration and found that Euptox A exhibits proautophagic effects in splenocytes. Euptox A markedly arrested the splenocytes in the G0/G1 phase, which was accompanied by inhibition of the expression of the positive regulators CDK4, CDK2, cyclin D1, PCNA, and E2F1, and promotion of the expression of the negative regulators p53, p21 Waf1/Cip1, p27 Kip1, and Chk1. We also found that Euptox A did not markedly induce splenocyte apoptosis, but induced autophagy while increasing the subcellular localization of punctate LC3, ratio of LC3-II/LC3-I, and Beclin 1 levels, and decreasing p62 levels. Euptox A also significantly inhibited p-PI3K, p-p38 MAPK, p-Akt, and p-mTOR expression, but increased PTEN and p-AMPK expression. These results indicated that Euptox A induced splenocyte autophagy by inhibiting the PI3K/Akt/mTOR pathway, suppressing p38 MAPK expression, and activating AMPK. These findings provide new insights into the mechanisms involved in spleen toxicity caused by Euptox A in mice.
泽兰毒素A（9-氧代-10,11-脱氢紫茎泽兰酮）是从紫茎泽兰中分离出的主要毒素，已知可在动物体内诱导免疫毒性。然而，泽兰毒素A对脾细胞作用的精确机制尚不清楚。在此，我们旨在研究泽兰毒素A经胃内给药后对小鼠脾脏作用的分子机制，发现泽兰毒素A在脾细胞中表现出促自噬作用。泽兰毒素A使脾细胞明显停滞于G0/G1期，同时伴随着对阳性调节因子CDK4、CDK2、细胞周期蛋白D1、增殖细胞核抗原（PCNA）和E2F1表达的抑制，以及对阴性调节因子p53、p21 Waf1/Cip1、p27 Kip1和Chk1表达的促进。我们还发现泽兰毒素A并未明显诱导脾细胞凋亡，但诱导了自噬，同时增加了点状LC3的亚细胞定位、LC3-II/LC3-I的比例以及Beclin 1水平，并降低了p62水平。泽兰毒素A还显著抑制p-PI3K、p-p38丝裂原活化蛋白激酶（MAPK）、p-Akt和p-雷帕霉素靶蛋白（mTOR）的表达，但增加了磷酸酶和张力蛋白同源物（PTEN）和p-腺苷酸活化蛋白激酶（AMPK）的表达。这些结果表明，泽兰毒素A通过抑制PI3K/Akt/mTOR途径、抑制p38 MAPK表达和激活AMPK诱导脾细胞自噬。这些发现为泽兰毒素A对小鼠脾脏毒性作用的机制提供了新的见解。
