敌百虫诱导的氧化应激增加仔猪肠道穿透性,损伤线粒体功能，诱导线粒体吞噬

Shuting Cao, Huan Wu, ChunChun Wang, Qianhui Zhang, Lefei Jiao, Fanghui Lin, and Caihong H. Hu

翻译： 吴姝 校对：上海亘泰实业集团

    本试验研究了敌百虫诱导的氧化应激对仔猪肠道屏障、线粒体功能和线粒体吞噬水平的影响。选取12只平均体重为9.6 kg的35d雄性杜洛克×长白猪×约克夏杂交猪（21 d断奶），分为对照组和试验组，每组6只。试验组仔猪按100 mg/kg体重的剂量注射敌百虫，对照组仔猪注射等量生理盐水。

      结果表明：注射敌百虫降低了平均日采食量和日增重。敌百虫显著降低了超氧化物歧化酶和谷胱甘肽过氧化物酶活性 (P < 0.05)，显著增加丙二醛含量 (P < 0.05)。敌百虫注射组仔猪的跨膜电阻显著降低 (P < 0.05)，而荧光素异硫氰酸葡聚糖（4 kDa）的细胞旁通透性显著增加 (P < 0.05)。同时，与对照组相比，敌百虫组空肠中claudin-1、occluding和ZO-1蛋白丰度显著降低（P＜0.05）。敌百虫导致线粒体功能障碍：ROS的生成显著增加 (P < 0.05)、肠道线粒体膜电位显著下降 (P < 0.05)。敌百虫注射组仔猪空肠线粒体的生物合成及功能相关基因、PPARg共激活因子-1α、哺乳动物沉默信息调节因子-1、核呼吸因子-1、mt转录因子A、mt单链DNA结合蛋白、mt聚合酶r、葡萄糖激酶、柠檬酸合成酶、ATP合酶和细胞色素氧化酶Ⅰ和Ⅴ亚基的mRNA丰度都显著降低 (P < 0.05)。敌百虫显著上调线粒体相关蛋白的表达（P＜0.05），导致10号染色体上的磷酸酶、张力素同源基因和肠道线粒体中的Parkin缺失，并增加空肠粘膜的LC3-II/LC3-I。

      这些结果表明，氧化应激破坏了肠道屏障，引起线粒体功能障碍，并触发线粒体自噬。

关键词：肠道屏障功能、线粒体功能、线粒体自噬、氧化应激

Diquat-induced oxidative stress increases intestinal permeability, impairs mitochondrial function, and triggers mitophagy in piglets

Shuting Cao, Huan Wu, ChunChun Wang, Qianhui Zhang, Lefei Jiao, Fanghui Lin, and Caihong H. Hu

ABSTRACT: In the present study, we investigated the influence of diquat-induced oxidative stress on intestinal barrier, mitochondrial function, and the level of mitophagy in piglets. Twelve male Duroc ×Landrace × Yorkshire 35-d-old pigs (weaned at 21 d ofage), with an average body of 9.6 kg, were allotted to two treatments of six piglets each including the challenged group and the control group. The challenged pigs were injected with 100 mg/kg body weight diquat and control pigs injected with 0.9% (w/v) NaCl solution. The results showed that diquat injection decreased ADFI and ADG. Diquat decreased (P < 0.05) the activities of superoxide dismutase and glutathione peroxidase and increased (P < 0.05) the malondialdehyde concentrations. The lower(P < 0.05) transepithelial electrical resistance and higher (P < 0.05) paracellular permeability of fluorescein isothiocyanatedextran 4 kDa were found in diquat challenged piglets. Meanwhile, diquat decreased (P < 0.05) the protein abundance of claudin-1, occluding, and zonula occludens-1 in jejunum compared with the control group. Diquat-induced mitochondrial dysfunction, as demonstrated by increased (P < 0.05) reactive oxygen species production and decreased (P < 0.05) membrane potential of intestinal mitochondria. Diquat-injected pigs revealed a decrease (P < 0.05) of mRNA abundance of genes related to mitochondrial biogenesis and functions,PPARg coactivator-1α, mammalian-silencing information regulator-1, nuclear respiratory factor-1, mt transcription factor A, mtsingle-str and DNA-binding protein, mt polymerase r, glucokinase, citratesynthase, ATP synthase, and cytochrome coxidase subunit I and V in the jejunum. Diquat induced an increase (P < 0.05) in expression of mitophagy-related proteins, phosphatase and tensin homologue deleted on chromosome 10-induced putative kinase, and Parkin in the intestinal mitochondria, as well as an enhancement of the ratio of light chain 3-II (LC3-II) to LC3-I content in the jejunal mucosa. These results suggest that oxidative stress disrupted the intestinal barrier, caused mitochondrial dysfunction, and triggered mitophagy.

Keywords: intestinal barrier function, mitochondrial function, mitophagy, oxidative stress