| ObjectiveThe zinc deficiency asthmatic rats'models were established in order to explore effects of dietary zinc and dexamethasone on the zinc transporters expression in rats' lung tissue and leucocytes. Changes of zinc transporters'mRNA expression in peripheral blood leukocytes of normal infants and asthmatic infants in asthmatic disease was preliminary studied.Methods20 male wistar rats were randomly divided into 4 groups:zinc-lower ova group,ova group,control group and dexamethasone treated group. Zinc-lower group was given the low-zinc feed and the other group was given normal feed. The asthmatic rats'models were established according to the literature. The body weight and food intake of the rats were recorded every two days. The animals were killed after 5 weeks, and the content of zinc in the lung and serum was measured, and the mRNA expression of zinc transporter of the lung tissue and peripheral blood leukocytes were tested via RT-PCR method.A routine blood test data,IgE data,serum zinc concentration data as well as fresh blood of 9 normal infants and 9 infants with bronchial asthma were collected. The mRNA expression of zinc transporter of peripheral blood lymphocytes was tested via RT-PCR method.ResultsWeight of zinc deficient asthmatic rats was significantly lower than the control groups', and there was no significant change between asthmatic group and control group, as well as dexamethasone group. Compared with the control group, ZnT-1 mRNA expression of zinc-lower asthmatic rats in lung tissue decreased by 45%, ZnT-1mRNA expression of asthmatic group increased by 67%, ZnT-1mRNA expression of the dexamethasone intervention group increased by 45%. ZIP-8mRNA and ZIP-13mRNA expression in the control group was significantly lower than zinc deficiency asthmatic group, asthmatic group and dexamethasone intervention group. Compared with the asthmatic group, ZnT-1mRNA expression of zinc deficiency asthmatic group significantly decreased by 67%, ZIP-8mRNA and ZIP-13mRNA expression increased. ZnT-1mRNA, ZIP-8mRNA and ZIP-13mRNA expression of the dexamethasone intervention group were not obviously changed.Serum zinc content of asthmatic infants was significantly lower than control group infants (P<0.01);there are no significant differences in peripheral blood lymphocytes ZnT-1, ZnT-3, ZnT-5, ZIP-1 mRNA expression between asthmatic infants and the control group infants; peripheral blood lymphocytes ZIP-2mRNA expression of asthmatic infants was significantly higher than the control infants group (P<0.01).ConclusionZinc is essential to cell growth and is cofactor for more than 300 enzymes, representing over 50 different enzyme classes. Also it is involved in diverse cellular processes, from catalysis to gene expression to cell proliferation. Several proteins and genes involved in cellular zinc transport, which belong to two gene families:ZnT and ZIP. ZnT transporters reduce intracellular zinc by promoting zinc efflux from cells or into intracellular vesicles, while ZIP transporters increase intracellular zinc by promoting intracellular zinc uptake and, perhaps, vesicular zinc release into the cytoplasm. In mammals, inadequate levels of zinc in the diet lead to dermatologic lesions, growth retardation, mental disorders, and compromised function of the immune and reproductive systems. In animals, zinc balance is primarily maintained through a regulated rate of intestinal uptake, fecal elimination of excess zinc, renal reabsorption and distribution to cells, including intracellular storage. A large number of studies documented changes in zinc metabolism in experimental animal models of acute and chronic inflammatory disease, and asthma is one of these chronic inflammatory diseases. Case-control studies found that the combined risk of atopy, bronchial reactivity and allergic-type symptoms were four to five fold higher in individuals with low zinc intake as compared to those with higher zinc intake.Asthmatic patients were shown to have lower plasma zinc than healthy controls. Both asthma and Zn deficiency are thought to favor the T-helper-2 (Th2) inflammatory cytokine profile, and asthmatic individuals with systemic zinc deficiency may have further increases in Th2 proinflammatory cytokines. Asthma is one of chronic inflammatory diseases, which is recognized as one of the world medical problems. According to the survey, there are at least more than 20 million patients with asthma in China; Therefore, it is necessary to explore the zinc transporters'expression and the influences of zinc on zinc transporters in asthma.In this study, we explore the zinc transporters'expression in the leukocytes of asthmatic infants. This is the first report, which detects the zinc transporters expression in asthma infants. At the same time, we explore the expression of zinc transporters after the asthmatic rats treated by zinc and dexamethasone, to make some effect in the study of zinc transporter regulation in asthma.
|
PDF Full Text Request