Overexpression of Zip-2 mRNA in the leukocytes of asthmatic infants.

The increase in prevalence of asthma is strongly dependent on environmental factors, including foods. Significant decreases in the intake of dietary zinc may be an important contributing factor to the increasing incidence of asthma. As zinc can not passively diffuse across cell membranes, specific zinc transporters are required for zinc influx and efflux. There are two identified gene families involved in zinc homeostasis, ZnT transporters and ZIP transporters. In this study, we aimed to investigate the expression of these zinc transporters mRNA in the leukocytes of asthmatic infants. Asthmatic infants (n = 9) and healthy infants (n = 9) were included in this study. Five zinc transporters were chosen: ZnT-1, ZnT-3, ZnT-5, ZIP-1, and ZIP-2. Levels of zinc were determined in serum and expression of zinc transporters mRNA were measured. Serum zinc levels were significantly lower in asthmatic infants (P < 0.01); Expression of ZnT-1, ZnT-3, ZnT-5, ZIP-1 mRNA were not significantly different between two groups, but expression of ZIP-2 mRNA was significantly higher (P < 0.01) in the asthmatic group than the control group. In conclusion, overexpression of ZIP-2 mRNA was found in the leukocytes of asthmatic infants.