Science of NAD
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Hyperglycemia-reduced NAD+ biosynthesis impairs corneal epithelial wound healing in diabetic mice
Metabolism
January 1, 2021
Li, Ya
Summary
Hyperglycemia attenuated NAD+ content and NAMPT expression in the corneal epithelium of both type 1 DM mice and type 2 DM patients. Local knockdown of NAMPT by siRNA or FK866 consistently recapitulated the delayed corneal epithelial wound healing in normal mice. Moreover, NAD+ replenishment recovered the impaired proliferation and migration capacity by either FK866 or high glucose treatment in cultured corneal epithelial cells. Furthermore, in DM mice, NAD+ and its precursors nicotinamide mononucleotide and nicotinamide riboside also facilitated corneal epithelial and nerve regeneration, accompanied with the recovered expression of SIRT1 and phosphorylated EGFR, AKT, and ERK1/2 in epithelium and corneal sensitivity.