Leptin induces keratinocytes proliferation by JAK2 /STAT3 signal transduction pathway

Objectives The aim of this study was to elucidate the effect of leptin on keratinocytes proliferation,the possible role and the mechanism of leptin on wound healing.Methods Primary cultured and identificated human keratinocytes by CK17 and CK19 immunocytochemistry staining.To observe the dose-and timedependent role of leptin on keratinocytes,and the impact of JAK inhibitor(AG490) on leptin induced keratinocytes proliferation,cells in all groups were collected and examined by MTT assay after 24 h incubation with leptin.Results After 24,48 and 72 h incubation in D-KSFM with 100 ng /mL leptin,cell proliferation in the leptin intervention group was higher than that in the control group.When the therapeutic concentration range of leptin was 0-400 ng /mL,OD value of cells in leptin group is higher than that in control group.When the concentration of leptin was 800 ng /mL,however,there were fewer cells in the leptin intervention group compared with the control group.The results of immunocytochemistry staining showed that the positive expression of CK17 in leptin group was stronger than in the control group and AG490 + leptin group.Conclusions The positive effect of leptin on keratinocytes proliferation showed a tendency of time-dependent.Meanwhile,there was a concentration-dependent proliferation of leptin on keratinocytes when concentration range is from zero to 400 ng /mL.AG490 can effectively inhibit leptin induced keratinocytes proliferation,which suggested that JAK2 /STAT3 signal pathways involved in transmembrane signal transduction of leptin.