Publications by authors named "J Harkema"

Metabolic reprogramming by the pyruvate kinase M2 isoform is associated with cell proliferation and reactive oxygen species (ROS) defenses. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), an environmental contaminant that induces ROS and hepatotoxicity, dose-dependently induces pyruvate kinase muscle isoform M2 (PKM2) in the liver. To further investigate its role in combating TCDD hepatotoxicity, a Pkm mouse was constructed lacking the dioxin response element mediating aryl hydrocarbon receptor (AHR) induction.

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Epidemiological evidence suggests an association between dioxin and dioxin-like compound (DLC) exposure and human liver disease. The prototypical DLC, 2,3,7,8-tetrachlorodibenzo--dioxin (TCDD), has been shown to induce the progression of reversible hepatic steatosis to steatohepatitis with periportal fibrosis and biliary hyperplasia in mice. Although the effects of TCDD toxicity are mediated by aryl hydrocarbon receptor (AHR) activation, the underlying mechanisms of TCDD-induced hepatotoxicity are unresolved.

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Objective: Acute intranasal (IN) instillation of lupus-prone NZBWF1 mice with crystalline silica (cSiO) triggers robust lung inflammation that drives autoimmunity. Prior studies in other preclinical models show that soluble epoxide hydrolase (sEH) inhibition upregulates pro-resolving lipid metabolites that are protective against pulmonary inflammation. Herein, we assessed in NZBWF1 mice how acute IN cSiO exposure with or without the selective sEH inhibitor TPPU influences lipidomic, transcriptomic, proteomic, and histopathological biomarkers of inflammation, fibrosis, and autoimmunity.

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Lupus, a systemic autoimmune disease shaped by gene-environment interplay, often progresses to endstage renal failure. While subchronic systemic exposure to bacterial lipopolysaccharide (LPS) triggers autoimmunity and glomerulonephritis in lupus-prone mice, it is unknown if inhaling LPS, which is common in certain occupations, can similarly trigger lupus. Here we determined how subchronic intranasal (IN) LPS instillation influences autoimmunity and glomerulonephritis development in lupusprone NZBWF1 female mice.

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Article Synopsis
  • Occupational exposure to respirable crystalline silica (cSiO) may contribute to lupus development, and previous studies indicated that docosahexaenoic acid (DHA) could prevent this autoimmunity, especially in young lupus-prone mice.
  • This study examined the impact of cSiO and DHA on mature lupus-prone mice, simulating the age of workers exposed to silica, and analyzed various health markers after exposure to silica.
  • Results showed that while cSiO exposure in the control group led to significant lung inflammation and autoimmune responses, DHA supplementation effectively reduced these negative effects, indicating its potential as a therapeutic agent against silica-induced autoimmunity.
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