Unregulated inflammation during bovine mastitis is characterized by severe mammary tissue damage with systemic involvement. Vascular dysfunction underlies tissue pathology because of concurrent oxidative stress mediated by several inflammatory mediators. We recently demonstrated increased production of 20-hydroxyeicosatetraenoic acid (20-HETE), a cytochrome P450-derived (CYP) oxylipid that correlated with oxidative stress during severe bovine coliform mastitis. The hypothesis for this study was that 20-HETE-induced oxidative stress disrupts barrier function of endothelial cells. Primary endothelial cells from the bovine aorta were utilized to investigate the effects of 20-HETE on barrier integrity in an in-vitro model of oxidative stress. The effects of various antioxidants on modulating the 20-HETE barrier integrity effects also were investigated. Our results showed that 20-HETE decreased endothelial barrier integrity, which was associated with increased reactive metabolite production and decreased total glutathione. The antioxidant, vitamin E, partially delayed the loss of endothelial resistance upon exposure to 20-HETE but did not prevent complete loss of barrier integrity. The decrease in barrier resistance due to 20-HETE was neither associated with oxidative stress as assessed by oxidative protein or lipid damage nor endothelial cell apoptosis; however, selenium supplementation conferred resistance to loss of barrier integrity suggesting a role for shifts in redox status. Specific mechanisms by which 20-HETE alters vascular barrier integrity require further investigation to identify targets for therapy during inflammatory conditions with enhanced CYP450 activity.

中文翻译：

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20-羟基二十碳四烯酸可独立于氧化应激和细胞死亡而改变内皮细胞屏障的完整性。

牛乳腺炎期间炎症失调的特征是乳腺组织严重受损，全身受累。血管功能障碍是组织病理的基础，这是由于几种炎症介质介导的并发氧化应激。我们最近证明了20-羟基二十碳四烯酸（20-HETE）的生产增加，这是一种细胞色素P450衍生（CYP）的脂质，与严重牛大肠菌型乳腺炎期间的氧化应激相关。这项研究的假设是20-HETE诱导的氧化应激会破坏内皮细胞的屏障功能。利用牛主动脉的内皮细胞在体外氧化应激模型中研究20-HETE对屏障完整性的影响。还研究了各种抗氧化剂对20-HETE屏障完整性效应的调节作用。我们的结果表明20-HETE降低了内皮屏障的完整性，这与增加活性代谢产物和减少总谷胱甘肽有关。抗氧化剂维生素E暴露于20-HETE后可部分延迟内皮抵抗力的丧失，但不能阻止屏障完整性的完全丧失。由20-HETE引起的屏障抵抗力的降低与氧化应激（通过氧化蛋白或脂质损伤的评估）或内皮细胞凋亡均无关。然而，硒的补充赋予了对屏障完整性丧失的抵抗力，这暗示着氧化还原状态改变的作用。20-HETE改变血管屏障完整性的特定机制需要进一步研究，以鉴定具有增强的CYP450活性的炎症条件下的治疗目标。