Abstract:

To investigate the effect of leptin on the secretion of chemokine in THP1 cells and explore its related  mechanism,and to provide basis for research on the role of leptin in immune response.Methods The expressions of Ob-Rb and Ob-Rt in THP1 cells were detected by RT-PCR and flow cytometry (FCM).The THP1 cells at  logarithm growth phase were selected and randomly divided into blank control group and different concentrations(10,50,100,200  μg•L^-1) of leptin groups.Transwell chamber assay was performed to detect the number of invated THP1 cells.The THP1 cells were divided into blank control group and 100  μg•L^-1 leptin group.Western blotting method was carried out to detect the expressions of p-AKT,p-ERK 1/2,and p-STAT3 in THP1 cells.The THP1 cells were divided into blank control group and 100  μg•L^-1 leptin group,100  μg•L^-1 leptin+ DMSO group,100  μg•L^-1 leptin+50  μmol?L-1 AG490 group,100  μg•L^-1 leptin+10  μmol•L^-1 LY294002 group and 100  μg•L^-1 leptin+ 10 mol•L^-1 PD980590 group.RT-PCR and Western blotting methods were performed to detect the expression of IL-8.Results  Ob-Rb and Ob-Rt were highly expressed in THP1 cells.Compared with blank control group,the number of invated THP1 cells was significantly increased in 50,100, and 200  μg•L^-1 leptin groups (P<0.05).Compared with blank control group,the expressions of p-STAT3,p-ERK 1/2 and p-AKT in THP1 cells were up-regulated in 100 ug•L^-1 leptin group(P<0.05).Compared with blank control group,the mRNA and protein expressions of IL8 in THP1 cells  in 50,100,and 200  μg?L-1 leptin groups were remarkably increased(P<0.05);compared with 100  μg•L^-1 leptin group,the expressions of IL-8 in THP1 cells in 100  μg•L^-1 leptin+10 mol•L^-1 PD980590 group and 100  μg•L^-1 leptin+10  μmol•L^-1 LY2 94002 group were decreased(P<0.05),while the expression of IL-8 in 100  μg?L-1 leptin+ 50  μmol•L^-1 AG490 group had no  change(P>0.05).Conclusion leptin can up-regulate the expression of chemokine in THP1 cells,which might be associated with PI3K-AKT and MAPK/ERK 1/2 signaling pathways.

Key words: leptin, THP1 cells, chemokine, interleukin-8