Characterization of glucose transport system in keratinocytes: insulin and IGF-1 differentially affect specific transporters.

Skin is one of the major tissues displaying chronic diabetic complications. We have studied glucose transport following stimulation with insulin and IGF-1 in cultured mouse keratinocytes. In proliferating cells, acute stimulation with insulin and IGF-1 increased glucose uptake. Insulin translocated glucose transporters 1 and 5, whereas IGF-1 translocated glucose transporters 2 and 3. With differentiation, glucose transporter 3 expression increased and the expression of glucose transporters 1, 2, and 5 decreased. No increase in glucose uptake was observed, however, following stimulation with either hormone. These results indicate that insulin and IGF-1 differentially regulate glucose uptake as well as expression and translocation of specific transporters in skin keratinocytes.