Background: Hexabromocyclododecane (HBCD) is an additive flame retardant used in the textile industry and in polystyrene foam manufacturing. Because of its lipophilicity and persistency, HBCD accumulates in adipose tissue and thus has the potential of causing metabolic disorders through disruption of lipid and glucose homeostasis. However, the association between HBCD and obesity remains unclear.Objectives: We investigated whether exposure to HBCD contributes to initiation and progression of obesity and related metabolic dysfunction in mice fed a normal diet (ND) or a high-fat diet (HFD).Methods: Male C57BL/6J mice were fed a HFD (62.2 kcal% fat) or a ND and treated orally with HBCD (0, 1.75, 35, or 700 μg/kg body weight) weekly from 6 to 20 weeks of age. We examined body weight, liver weight, blood biochemistry, histopathological changes, and gene expression profiles in the liver and adipose tissue.Results: In HFD-fed mice, body and liver weight were markedly increased in mice treated with the high (700 ...

Acute ozone (O₃) exposure causes oxidative stress leading inflammation in the lung. However, its precise mechanisms are not fully elucidated. Here, we examined the role of peroxiredoxin I (PrxI) in O₃-induced pulmonary inflammation using PrxI null (PrxI^−/−) and wild-type (WT) mice. PrxI is known as an antioxidant and also emerged as a potent proinflammatory factor that activates toll-like receptor 4/nuclear factor-kappa B signalling. Both mice were exposed to 2 ppm O₃ for 6 h and their responses to oxidative stress and acute inflammation in the lung were evaluated after 18 h. The O₃ inhalation activated the transcription factor nuclear factor-erythroid 2-related factor 2 and upregulated heme oxygenase-1 mRNA, the typical makers of oxidative stress, to similar extent in both lungs observed after 0 and 4 h, respectively. O₃ exposure induced significantly less pulmonary inflammation in PrxI^−/− than in WT mice judging from the reduced infiltrations of neutrophils into the lung and the suppressed production of proinflammatory mediators, such as interleukin-6 and keratinocyte chemoattractant in the bronchoalveolar lavage fluids. Our results suggest that PrxI is not an effective protector against O₃-induced oxidative damages reportedly caused by harmful lipid metabolites but plays a positive role in the initiation of lung inflammation following O₃ exposure.

Tris (2-butoxyethyl) phosphate (TBEP) is an organophosphate flame retardant and used as a plasticizer in various household products such as plastics, floor polish, varnish, textiles, furniture, and electronic equipment. However, little is known about the effects of TBEP on the brain and behavior. We aimed to examine the effects of dietary exposure of TBEP on memory functions, their-related genes, and inflammatory molecular markers in the brain of allergic asthmatic mouse models. C3H/HeJSlc male mice were given diet containing TBEP (0.02 (TBEP-L), 0.2 (TBEP-M), or 2 (TBEP-H) μg/kg/day) and ovalbumin (OVA) intratracheally every other week from 5 to 11 weeks old. A novel object recognition test was conducted in each mouse at 11 weeks old. The hippocampi were collected to detect neurological, glia, and immunological molecular markers using the real-time RT-PCR method and immunohistochemical analyses. Mast cells and microglia were examined by toluidine blue staining and ionized calcium-binding adapter molecule (Iba)-1 immunoreactivity, respectively. Impaired discrimination ability was observed in TBEP-H-exposed mice with or without allergen. The mRNA expression levels of N-methyl-D aspartate receptor subunits Nr1 and Nr2b, inflammatory molecular markers tumor necrosis factor-α oxidative stress marker heme oxygenase 1, microglia marker Iba1, and astrocyte marker glial fibrillary acidic protein were significantly increased in TBEP-H-exposed mice with or without allergen. Microglia and mast cells activation were remarkable in TBEP-H-exposed allergic asthmatic mice. Our results indicate that chronic exposure to TBEP with or without allergen impaired object recognition ability accompanied with alteration of molecular expression of neuronal and glial markers and inflammatory markers in the hippocampus of mice. Neuron-glia-mast cells interaction may play a role in TBEP-induced neurobehavioral toxicity.