Inhibition of Lipopolysaccharide-Induced Expression of Fractalkine by Methylprednisolone via NF-Κb in Human Renal Tubular Epithelial Cells

Abstract

Objective: to study the effect of the glucocorticoid, methylprednisolone (MP), in lipopolysaccharide (LPS)-induced fractalkine (FKN) expression in HK-2 cells and to determine the role of NF-κB in this signaling pathway. Methods: HK-2 cells were stimulated by LPS to set up an in vitro inflammation model. The concentration of FKN in cell culture supernatant was measured by ELISA. FKN and p65 mRNA expression were detected by RT-PCR. FKN, p65 protein expression and the activity of the NF-κB were detected by immunofluorescence staining and western blotting. The effect of MP and SC-514 (a selective and reversible inhibitor of IKK beta) in FKN expression and NF-κB activation induced by LPS were evaluated. Results: LPS induced FKN expression and secretion in HK-2 cells occurred in a time- and dose-dependent manner and correlated with the activation of NF-κB. MP was able to inhibit FKN expression and secretion as well as the NF-κB induced activation of LPS, whereas SC-514 abolished this effect. Conclusions: MP inhibited FKN expression induced by LPS through the NF-κB pathway in human renal tubular epithelial cells in vitro. Use of HK-2 cells to study the renal inflammatory process will allow the further elucidation of the pathways involved in kidney disease.