Vitamin D3 levels and NLRP3 expression in murine models of obese asthma: association with asthma outcomes

Vitamin D (25(OH)D3) is an essential nutrient that plays a role in the immune system. Serum 25(OH)D3 is found to be associated with asthma. However, the role of vitamin D in obese asthma remains unclear. Therefore, we investigated the association between vitamin D levels and asthma outcomes in a murine model of obese asthma. We also evaluated NLRP3 inflammasome activity in the pathogenesis of obese asthma. We divided 20 male Balb/c mice (3-4 weeks old) into 4 groups: normal control, asthma, obese, and obese asthma and developed an obese asthma mouse model. Airway hyperreactivity, cytokine concentrations, 25(OH)D3 levels, NLRP3 mRNA and IL-1β mRNA expressions were measured. Lung histology and bronchoalveolar lavage fluid (BALF) cell count were also determined. Obese asthma mice showed a significant increase in airway hyper-responsiveness, airway inflammation, pro-inflammatory cytokine levels and NLRP3 mRNA, IL-1β mRNA expression. Both asthma and obese groups had lower 25(OH)D3 levels. Vitamin D levels in obese asthma were the lowest among all groups. Vitamin D levels correlated negatively with body weight, lung resistance levels at 25 mg/mL of methacholine, total inflammatory cells, and IL-1β and IL-17 concentrations in BALF. These data demonstrated an association between serum vitamin D levels and outcomes of obese asthma, and indicated that NLRP3 inflammasome may play a role in this disorder.

Construction of three different recombinant scorpion fusion proteins with bifunctional activity.

This is the first report of three different fusion proteins with an antitumor-analgesic peptide obtained from Chinese scorpion Buthus martensii Karsch (BmKAGAP). The fusion proteins were constructed in the form of chimeric toxins, aiming to obtain bifunctional analgesic and antitumor activity. The fusion proteins consisted of luteinizing hormone-releasing hormone (LHRH), three different types of flexible linkers (L1, Ser-Ser-His-His-His-His-His-His-Ser-Ser-Gly-Leu-Val-Pro-Arg-Gly-Ser-His-Met; L2, Gly-Gly-Gly-Ser-Gly-Gly-Gly-Ser; L3, Ser-Gly-Gly-Ser-Gly-Gly-Ser-Gly-Gly-Gly-Ser-Ser-Gly-Gly-Ser-Gly-Gly-Gly-Gly-Ser-Gly-Gly-Gly-Gly-Ser), and BmKAGAP. The genes coding three fusion proteins were cloned and expressed in E. coli in soluble form. Following two successive column chromatographic separations, purified fusion proteins were obtained. These fusion proteins exhibited analgesic activity in mice and were cytotoxic to a hepatocellular carcinoma cell line Hep3B.