The influence of endotoxin tolerance on the expression of IL-6 and IL-8 in normal human prostate epithelial cells

Abstract

Objective Current studies have shown that tissue inflammation plays an important role in the course of development of benign prostate hyperplasia (BPH). Endotoxin tolerance (ET) was found to exist in human tissue cells, such as intestinal epithelial cells and human gingival epithelial cells, and could affect the tissue inflammation and immune responses. Lipopolysaccharide (LPS) generated by G-bacteria such as Escherichia coli, which was considered as the most important pathogen of tissue inflammation of prostate. We intended to analyze the inflammatory cytokines interleukin -6 (IL-6) and interleukin -8 (IL-8) expression of normal human prostate epithelial cells RWPE-1 which were stimulated by LPS repeatedly to find out whether ET exist in human prostate epithelial cells as well. Methods RWPE-1 cells were given stimulation of 1 μg/mL LPS which came from Escherichia coli for 24 hours.After collected the culture supernatant of REWP-1, 1 μg/mL LPS group stimulation was given again to form a model of ET. Expression level of cytokines IL-6 and IL-8 was detected by Millipore human cytokine detection kit instructions, in Luminex platform. Results Expression of IL-6 and IL-8 was significant rising at 6 hours and 12 hours after first LPS stimulation (P<0.05). Compared with first LPS stimulation, expression of IL-6 and IL-8 was significant lower after stimulated by LPS repeatedly (P<0.05). Conclusions Endotoxin tolerance phenomenon exists in normal prostate epithelial cells RWPE-1, and inhibits the expression of IL-6 and IL-8. It may influence the chronic inflammation and immune response of prostate tissue. Key words: Prostate; Endotoxins; Interleukin-6; Interleukin-8