维生素E对H2O2诱导的奶牛乳腺上皮细胞氧化损伤及紧密连接相关基因表达的影响

试验通过研究维生素E （VE）对H₂O₂诱导的奶牛乳腺上皮细胞（MAC-T cells）氧化损伤及紧密连接相关基因表达的影响，旨在揭示维生素E对缓解奶牛乳腺细胞氧化应激的作用。试验设对照组（完全培养基处理组）、H₂O₂组和H₂O₂＋VE组。利用MTT法检测奶牛乳腺细胞存活率，比色法检测奶牛乳腺细胞培养液中超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性、丙二醛（MDA）和活性氧（ROS）含量；通过实时荧光定量PCR检测紧密连接基因ZO-1、occludin、claudin-1的相对表达量。结果显示，与对照组相比，H₂O₂组的奶牛乳腺上皮细胞存活率显著下降（P<0.05），ROS和MDA含量显著增加（P<0.05），SOD和CAT活性显著下降（P<0.05）；与H₂O₂组相比，H₂O₂＋20 μmol/L VE组的细胞存活率显著上升（P<0.05），ROS和MDA含量显著下降（P<0.05），SOD和CAT活性显著增加（P<0.05）。此外，与对照组相比，H₂O₂组极显著抑制了紧密连接基因的相对表达量（P<0.01）；而与H₂O₂组相比，添加维生素E极显著缓解了H₂O₂对紧密连接基因相对表达的抑制作用（P<0.01）。本研究结果证明，维生素E不仅能够减轻H₂O₂诱导的奶牛乳腺上皮细胞氧化损伤，还能缓解H₂O₂对紧密连接基因相对表达的抑制作用。

Effect of Vitamin E on H2O2-Induced Oxidative Damage and Tight Junction Related Gene Expression of MAC-T Cells

This experiment aimed to study the effect of vitamin E (VE) on H₂O₂-induced oxidative damage and tight junction-related gene expression in MAC-T cells.There were three groups in this study,control,H₂O₂ and H₂O₂+VE groups.MTT was used to detect cell survival rate,while colorimetric method was employed to detect the activity of superoxide dismutase (SOD) and catalase (CAT),the content of malondialdehyde (MDA) and reactive oxygen species (ROS) in cell culture medium.The expression levels of tight junction genes ZO-1,occludin and claudin-1 were detected by Real-time PCR.The results showed that compared with the control group,the survival rate of MAC-T cells in the H₂O₂ group decreased significantly (P<0.05),the content of ROS and MDA increased significantly (P<0.05),and the activity of SOD and CAT decreased significantly (P<0.05).Compared with the H₂O₂ group,the cell survival rate of the H₂O₂＋20 μmol/L VE group increased significantly (P<0.05),the content of ROS and MDA decreased significantly (P<0.05),and the activity of SOD and CAT increased significantly (P<0.05).In addition,compared with the control group,the H₂O₂ group extremely significantly inhibited the relative expression of tight junction genes (P<0.01).Compared with the H₂O₂ group,the relative expression of tight junction genes was extremely significantly increased after the addition of vitamin E (P<0.01).This study demonstrated that vitamin E could lessen the oxidative damage induced by H₂O₂ in MAC-T cells,and significantly alleviate the down-regulate tight junction genes expression in MAC-T cells induced by H₂O₂.