Updated project metadata. We discovered that glucose directly bind to DDX21, induced the conformation change of the proteins and inhibit its helicase activity. Glucose also inhibits the dimerization of DDX21, re-localize DDX21 from nucleolus to nucleoplasm and reassemble DDX21 to RNA splicing complex. DDX21 is essential for epidermal differentiation while with normal glucose condition, DDX21 was re-localized from nucleolus to nucleoplasm, bind to splicing factors and mRNA introns more to regulate splicing of key differentiation factors and promote epidermal differentiation.