IFN-γ regulates xanthine oxidase-mediated iNOS-independent oxidative stress in maneb- and paraquat-treated rat polymorphonuclear leukocytes

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• 作者：Deepali Singh ; Vinod Kumar ; Chetna Singh
• 关键词：Maneb ; Paraquat ; Oxidative stress ; Xanthine oxidase ; Cytokines ; Polymorphonuclear leukocytes
• 刊名：Molecular and Cellular Biochemistry
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：427
• 期：1-2
• 页码：133-143
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Biochemistry, general; Medical Biochemistry; Oncology; Cardiology;
• 出版者：Springer US
• ISSN：1573-4919
• 卷排序：427

文摘

Maneb (MB) and paraquat (PQ) provoke oxidative stress-mediated cell damage. Role of xanthine oxidase (XO) in oxidative stress and its association with nitric oxide (NO)/NO synthase (NOS) have been widely reported. While inducible NOS (iNOS) is implicated in MB+PQ-induced toxicity in rat polymorphonuclear leukocytes (PMNs), role of XO and its alliance with iNOS have not yet been established. The study investigated the role of XO in MB+PQ-induced oxidative stress in rat PMNs and its regulation by iNOS and inflammatory cytokines. MB+PQ-augmented reactive oxygen species (ROS), superoxide, nitro-tyrosine, lipid peroxidation (LPO), and nitrite levels along with the catalytic activity of iNOS, superoxide dismutase (SOD), and XO. XO inhibitor, allopurinol (AP), alleviated MB+PQ-induced changes except nitrite content and iNOS activity. Conversely, an iNOS inhibitor, aminoguanidine, mitigated MB+PQ-induced LPO, nitrite, iNOS, and nitro-tyrosine levels; however, no change was observed in ROS, SOD, and XO. Nuclear factor-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), tumor necrosis factor-alpha (TNF-α) inhibitor, pentoxyfylline, and an anti-inflammatory agent, dexamethasone, attenuated MB+PQ-induced increase in XO, superoxide, and ROS with parallel reduction in the expression of interferon-gamma (IFN-γ), TNF-α, and interleukin-1β (IL-1β) in rat PMNs. Exogenous IFN-γ, TNF-α, and IL-1β enhanced superoxide, ROS, and XO in the PMNs of control and MB+PQ-treated rats; however, IFN- γ was found to be the most potent inducer. Moreover, AP ameliorated cytokine-induced free radical generation and restored XO activity towards normalcy. The results thus demonstrate that XO mediates oxidative stress in MB+PQ-treated rat PMNs via iNOS-independent but cytokine (predominantly IFN-γ)-dependent mechanism.