Zinc Deficiency may Accelerate Aging by Inhibiting Klotho mRNA Expression

Summary BackgroundZinc (Zn) is critical for the functional and structural integrity of cells, in which it participates in a number of processes, including gene expression. Z nd eficiency has effects that resemble the symptoms of human aging, including low immunity, dermatitis, delayed wound healing, and impaired taste. In this study, we examined the effect of Zn deficiency on the expression of the aging-related gene Klotho in rats. In mice, Klotho is involved in a murine developmental syndrome that resembles human aging. MethodsMale Sprague-Dawley rats (161�162 g) were fed a diet deficient in Zn or containing 0.01 % Zn for 4 weeks. Kidneys were removed after 0, 1, 2, 3 and 4 weeks, and the expression of Klotho mRNA was determined using real-time polymerase chain reactions. ResultsData were analyzed using the comparative threshold (CT) method. The mean ∆∆CT values for renal Klotho mRNA expression were much lower in the Zn-deficient rats than in the control rats. In the Zn-deficient group, values of ∆∆CT were �1.15 � 0.46 at 2 weeks, �1.69 � 0.33 at 3 weeks, and �2.08 � 0.53 at 4 weeks. ConclusionZn deficiency was associated with decreased Kloth og ene expression, suggesting that Zn deficiency might accelerate aging by inhibiting the expression of Klotho.