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Peroxiredoxin (Prx) represents a family of sulfhydryl-dependent peroxidases that reduce hydrogen peroxide and organic hydroperoxides to water and alcohols, respectively. There are six known mammalian isozymes (Prx1-6), classified as typical 2-Cys, atypical 2-Cys, or 1-Cys Prxs. In addition to their well-established peroxide-scavenging activity, Prxs also participate in the regulation of various cell signaling pathways. Experimental studies provide substantial evidence for a protective role of Prxs in various neurological disorders involving oxidative and inflammatory stress. There is also evidence suggesting a potential benefit of Prxs in certain neurological diseases in human subjects. This review first describes the biochemical properties and molecular regulation of Prxs, then summarizes the major findings on the neuroprotective functions of Prxs and finally discusses the feasibility of using natural compounds, including those from herbal remedies to augment Prx expression to counteract oxidative neurological disorders.

While it is well known that bacterial infection is the predominant cause of sepsis, the molecular pathophysiology of this clinical syndrome remains ill-defined. In this Research Highlights article, we discuss the recent research findings regarding a protective role for glutathione peroxidase-4 (GPx4) in bacterial infection and polymicrobial sepsis via modulating ferroptosis and pyroptosis, two novel modes of regulated cell death. It is suggested that GPx4, being a requisite gateway to both ferroptosis and pyroptosis, may serve as a critical molecular target for developing effective drugs for controlling infection and sepsis.

To investigate the role of interferon regulatory factor-1 (IRF-1) in the development of lupus nephritis, IRF-1 -/-genotype mice were bred onto the MRL/lpJfas lpr (MRL/lpr) background. We examined kidney mesangial cell function and disease progression. Endpoints evaluated included inflammatory mediators, autoantibody production, immune complex deposition, renal pathology, T cell subset analysis, and duration of survival. Mesangial cells cultured from IRF-1 -/-mice produced significantly lower levels of nitric oxide and IL-12 but not TNF-a when stimulated with LPS + IFN-c. IRF-1 -/-mice showed less aggravated dermatitis compared to the wild-type mice. Anti-doublestranded DNA production and proteinuria were significantly decreased in IRF-1 -/-mice compared to IRF-1 +/+ mice. IgG and C3 deposition as well as glomerulonephritis were decreased in IRF-1 -/-mice at 26 wk of age compared to the IRF-1 +/+ mice. Splenic CD4 -CD8 -CD44 + T cells were decreased while CD4 + CD25 + T cells were increased in the IRF-1 -/-mice when compared to IRF-1 +/+ mice. Survival rates (ED 50 ) were 22 wk for IRF-1 +/+ mice and 45 wk for IRF-1 -/-mice. These findings suggest an important role of IRF-1 in mediating renal disease in MRL/lpr mice. IntroductionThe etiology of systemic lupus erythematosus remains an enigma although genetic factors influenced by environmental agents appear to trigger the disease. Clearly, B cells, T cells, and macrophages play important roles in the development of lupus pathology [1][2][3].Chronic expression of Th1 cytokines secreted by Th cells is particularly harmful due to their influence on the initiation and promotion of tissue destruction [4,5]. Cytokines, including IFN-c, promote inflammation and provide a positive amplification loop responsible for escalating autoimmune kidney damage [6].MRL/lpr mice develop glomerulonephritis and vasculitis at an early age (4-5 months) [7]. Renal disease is characterized by the early influx of activated T cells and macrophages into the kidney. Activated T cells secrete IFN-c, which induces macrophages to express CSF-1, IL-1b, and TNF-a. Macrophages accumulate in the kidney during inflammation and generate IFN-a, TNF-a, and reactive oxygen species. Locally produced chemokines, particularly monocyte chemoattractant protein (MCP)-1, are also instrumental in attracting and maintaining cellular influx [8] -12 [20]. In the IRF-1 -/-NOD mouse, insulitis and diabetes were decreased accompanied by an increased survival [21]. Additional studies have suggested a role of IRF-1 and IFN-regulated genes in mediating human lupus [22][23][24]. Based on the knowledge that IRF-1 modulates inflammatory mediator production, we sought to determine whether IRF-1 gene deletion alters the severity of lupus nephritis in MRL/lpr mice. Results IRF-1 MRL/lpr mouse phenotypeTo determine the role of IRF-1 in autoimmune disease, IRF-1-knockout mice were backcrossed for eight generations to the MRL/lpr mice. After eight backcrosses, the littermates were intercrossed to yield cohorts for these studies....

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