The effects of microbial materials adhered to Asian sand dust on allergic lung inflammation

Asian sand dust (ASD) containing microbiological materials, sulfate (SO(4)(2)), and nitrate (NO(3)(-) ) derived from air pollutants in East China, reportedly cause adverse respiratory health effects. ASD aggravates ovalbumin (OVA)-associated experimental lung eosinophilia. In this study, the toxic materials adsorbed onto ASD were excluded by heat treatment at 360 degrees C for 30 min. The effects of nonheated ASD or heated ASD (H-ASD) toward the allergic lung inflammation were compared in murine lungs. ICR mice were administered intratracheally with normal saline (control), H-ASD, ASD, OVA, OVA + H-ASD, and OVA + ASD, four times at 2-week intervals. ASD only increased neutrophils in bronchoalveolar lavage fluids (BALFs) along with pro-inflammatory mediators, such as keratinocyte chemoattractant (KC). H-ASD and ASD enhanced eosinophil recruitment induced by OVA in the alveoli and in the submucosa of the airway, which has a goblet cell proliferation in the bronchial epithelium. The two ASDs synergistically increased interleukin-5 (IL-5), monocyte chemotactic protein-3 (MCP-3), and eotaxin, which were associated with OVA, in BALF. The enhancing effects were much greater in ASD than in H-ASD. The two ASDs induced the adjuvant effects to specific IgE and IgG1 production by OVA. In the in vitro study using RAW264.7 cells, ASD increased the expression of Toll-like receptor 2 (TLR 2) mRNA but not TLR4 mRNA. H-ASD caused no expression of either TLR mRNA. These results suggest that the aggravated lung eosinophilia by ASD may be due to activation of Th2-associated immune response via the activation of TLR2 by microbial components adhered to ASD.

Synaptic vesicle ultrastructural changes in the rat hippocampus induced by a combination of alpha-linolenate deficiency and a learning task

Rats fed either a safflower oil (alpha-linolenate-deficient) or a perilla oil (alpha-linolenate-sufficient) diet through two generations (F1) showed significant differences in the brightness-discrimination learning task. In this task, correct responses were lever-pressing responses, which were reinforced with dietary pellets, and incorrect responses were those with no reinforcement. The inferior learning performance in the safflower oil group was caused mainly by the inferior ability to rectify the incorrect responses through the learning sessions. In the safflower oil group after the learning task, the average densities of synaptic vesicles in the terminals of the hippocampus CA1 region were decreased by nearly 30% as compared with those in the perilla oil group, and it is notable that this difference was not detected without the learning task. These results suggest that dietary oil-induced morphological changes in synapses in the hippocampus of rats are related to the differential learning performance and that the turnover rate of synaptic vesicles in the hippocampus may be an important factor affecting learning performance.