Vitamin D constrains inflammation by modulating the expression of key genes on Chr17q12-21.1

Vitamin D possesses immunomodulatory functions and vitamin D deficiency has been associated with the rise in chronic inflammatory diseases, including asthma (Litonjua and Weiss, 2007). Vitamin D supplementation studies do not provide insight into the molecular genetic mechanisms of vitamin D-mediated immunoregulation. Here, we provide evidence for vitamin D regulation of two human chromosomal loci, Chr17q12-21.1 and Chr17q21.2, reliably associated with autoimmune and chronic inflammatory diseases. We demonstrate increased vitamin D receptor (Vdr) expression in mouse lung CD4+ Th2 cells, differential expression of Chr17q12-21.1 and Chr17q21.2 genes in Th2 cells based on vitamin D status and identify the IL-2/Stat5 pathway as a target of vitamin D signaling. Vitamin D deficiency caused severe lung inflammation after allergen challenge in mice that was prevented by long-term prenatal vitamin D supplementation. Mechanistically, vitamin D induced the expression of the Ikzf3-encoded protein Aiolos to suppress IL-2 signaling and ameliorate cytokine production in Th2 cells. These translational findings demonstrate mechanisms for the immune protective effect of vitamin D in allergic lung inflammation with a strong molecular genetic link to the regulation of both Chr17q12-21.1 and Chr17q21.2 genes and suggest further functional studies and interventional strategies for long-term prevention of asthma and other autoimmune disorders.

Aerobic Exercise Decreases Lung Inflammation by IgE Decrement in an OVA Mice Model

Aerobic exercise (AE) reduces lung function decline and risk of exacerbations in asthmatic patients. However, the inflammatory lung response involved in exercise during the sensitization remains unclear. Therefore, we evaluated the effects of exercise for 2 weeks in an experimental model of sensitization and single ovalbumin-challenge. Mice were divided into 4 groups: mice non-sensitized and not submitted to exercise (Sedentary, n=10); mice non-sensitized and submitted to exercise (Exercise, n=10); mice sensitized and exposed to ovalbumin (OVA, n=10); and mice sensitized, submitted to exercise and exposed to OVA (OVA+Exercise, n=10). 24 h after the OVA/saline exposure, we counted inflammatory cells from bronchoalveolar fluid (BALF), lung levels of total IgE, IL-4, IL-5, IL-10 and IL-1ra, measurements of OVA-specific IgG1 and IgE, and VEGF and NOS-2 expression via western blotting. AE reduced cell counts from BALF in the OVA group (p<0.05), total IgE, IL-4 and IL-5 lung levels and OVA-specific IgE and IgG1 titers (p<0.05). There was an increase of NOS-2 expression, IL-10 and IL-1ra lung levels in the OVA groups (p<0.05). Our results showed that AE attenuated the acute lung inflammation, suggesting immunomodulatory properties on the sensitization process in the early phases of antigen presentation in asthma.