Decreased renal mRNA expression of TRPM6 is associated with hypomagnesemia in C57BL/6 asthmatic mice.

BACKGROUND AND OBJECTIVES Hypomagnesemia has been reported up to 40% in asthma patients, and a relationship between hypomagnesemia and asthma severity has been previously characterized. However, the mechanism for hypomagnesemia in asthma patients is not clear. Transient receptor potential melastatin 6 (TRPM6) is a newly identified channel that is involved in active epithelial magnesium transport, and downregulation of TRPM6 in the kidney was related to reduced Mg2+ reabsorption in mouse model. The aim of the study was to investigate whether plasma and erythrocyte magnesium levels were correlated with renal expression of TRPM6 mRNA in C57BL/6 asthmatic mice. MATERIALS AND METHODS 48 healthy C57BL/6 mice were randomly divided into asthmatic group and control group with 24 mice in each group. Each group were randomly taken out 8 mice at 1d, 21d, 34d to detect plasma Mg2+, intracellular Mg2+ and renal TRPM6 mRNA expressions. RESULTS There were no significant difference in plasma Mg2+, intracellular Mg2+ and TRPM6 mRNA expression of renal tissues between asthmatic group and control group at 1d. However, plasma Mg2+ and intracellular Mg2+ as well as TRPM6 mRNA of renal tissues in asthmatic group were significantly lower than that of control group at 21d and at 34d. Both plasma Mg2+ and intracellular Mg2+ were positively correlated with TRPM6 mRNA expression in the renal tissues. CONCLUSION This study indicates that the consistently reduced expression of TRPM6 mRNA may play a role in the pathogenesis of hypomagnesemia in C57BL/6 asthmatic mice.