敵百蟲誘導的氧化應激增加仔豬腸道穿透性,損傷線粒體功能，誘導線粒體吞噬

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

翻譯： 吳姝 校對：上海亙泰實業集團

    本試驗研究了敵百蟲誘導的氧化應激對仔豬腸道屏障、線粒體功能和線粒體吞噬水平的影響。選取12只平均體重為9.6 kg的35d雄性杜洛克×長白豬×約克夏雜交豬（21 d斷奶），分為對照組和試驗組，每組6只。試驗組仔豬按100 mg/kg體重的劑量注射敵百蟲，對照組仔豬注射等量生理鹽水。

      結果表明：注射敵百蟲降低了平均日采食量和日增重。敵百蟲顯著降低了超氧化物歧化酶和谷胱甘肽過氧化物酶活性 (P < 0.05)，顯著增加丙二醛含量 (P < 0.05)。敵百蟲注射組仔豬的跨膜電阻顯著降低 (P < 0.05)，而熒光素異硫氰酸葡聚糖（4 kDa）的細胞旁通透性顯著增加 (P < 0.05)。同時，與對照組相比，敵百蟲組空腸中claudin-1、occluding和ZO-1蛋白豐度顯著降低（P＜0.05）。敵百蟲導致線粒體功能障礙：ROS的生成顯著增加 (P < 0.05)、腸道線粒體膜電位顯著下降 (P < 0.05)。敵百蟲注射組仔豬空腸線粒體的生物合成及功能相關基因、PPARg共激活因子-1α、哺乳動物沉默信息調節因子-1、核呼吸因子-1、mt轉錄因子A、mt單鏈DNA結合蛋白、mt聚合酶r、葡萄糖激酶、檸檬酸合成酶、ATP合酶和細胞色素氧化酶Ⅰ和Ⅴ亞基的mRNA豐度都顯著降低 (P < 0.05)。敵百蟲顯著上調線粒體相關蛋白的表達（P＜0.05），導致10號染色體上的磷酸酶、張力素同源基因和腸道線粒體中的Parkin缺失，并增加空腸粘膜的LC3-II/LC3-I。

      這些結果表明，氧化應激破壞了腸道屏障，引起線粒體功能障礙，并觸發線粒體自噬。

關鍵詞：腸道屏障功能、線粒體功能、線粒體自噬、氧化應激

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