The Effects Of Acylated Ghrelin Counteracting The Inflammatory Reaction Mediated By Macrophages On Islet Cells In Vitro

Objective:To investigate the potential role of acylated ghrelin to prevent islet β cells from cytotoxic injury by inflammatory cytokines released from macrophage.Methods:Co-culture system for RAW264.7macrophages and MIN6islet cells was established through transwell, RAW264.7macrophages were pretreated with different doses of acylated ghrelin(10、100、500nmol/L) for4hours prior to co-culture. Meanwhile, cultured RAW264.7and MIN6respectively were set up as controls. The expression of TLR4and A-FABP in RAW264.7macrophages was detected by RT-PCR and Western blotting, IL-1β and TNF-α levels in the supernatant were detected by ELISA, Glucose-stimulated insulin level was detected by insulin radioimmuno-assay kits for the function of islet cells after48hours.Results:Compared to macrophages control, co-culture increased significantly the mRNA and protein levels of TLR4and A-FABP as well as the concentrations of TNF-α and IL-1β (P<0.05) in RAW264.7macrophage. Compared to islet cells control, co-culture decreased significantly high glucose-stimulated insulin serection (P<0.05). Compared to co-culture control, acylated ghrelin inhibited markedly the mRNA and protein levels of both TLR4and A-FABP as well as the concentrations of TNF-α and IL-1β(P<0.05) in RAW264.7macrophage in a dose-dependent fashion.Conclusions:This study demonstrated that co-culture of macrophage and islet cells can activate inflammation pathway, stimulate inflammatory cytokine release and decrease insulin secretion from islet cells;acylated ghrelin can decrease the activation of inflammatory pathway and the release of inflammatory factors in response to the co-culture in a dose dependent manner, but it can’t prevent completely the decline of secretion function in islet β cell.