Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824 United States.
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824 United States.
Prostaglandins Other Lipid Mediat. 2020 Aug;149:106425. doi: 10.1016/j.prostaglandins.2020.106425. Epub 2020 Feb 4.
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.
奶牛乳腺炎期间的不受调节的炎症以严重的乳腺组织损伤和全身受累为特征。血管功能障碍是由几种炎症介质介导的氧化应激引起的，是组织病理学的基础。我们最近证明，在严重的牛大肠杆菌乳腺炎期间，20-羟二十碳四烯酸（20-HETE）的产生增加，20-HETE 是一种细胞色素 P450 衍生的（CYP）氧化脂，与氧化应激相关。本研究的假设是，20-HETE 诱导的氧化应激破坏内皮细胞的屏障功能。从牛主动脉中分离的原代内皮细胞用于研究 20-HETE 在氧化应激的体外模型中对屏障完整性的影响。还研究了各种抗氧化剂对调节 20-HETE 屏障完整性的影响。我们的结果表明，20-HETE 降低了内皮屏障的完整性，这与活性代谢物产生增加和总谷胱甘肽减少有关。抗氧化剂维生素 E 部分延迟了内皮抵抗在暴露于 20-HETE 时的丧失，但不能防止屏障完整性的完全丧失。由于 20-HETE 导致的屏障阻力下降与氧化应激（如氧化蛋白或脂质损伤）或内皮细胞凋亡无关；然而，硒补充赋予了对屏障完整性丧失的抗性，表明氧化还原状态的变化起作用。需要进一步研究 20-HETE 改变血管屏障完整性的具体机制，以确定在 CYP450 活性增强的炎症情况下治疗的靶点。
