The Stimulation Effect Of Uric Acid On Prostate Epithelial Cells And Its Mechanism

Background:Chronic prostatitis(CP)is commonly encountered in urology,which incidence rate has a tendency to increase by degrees year after year.The mechanism of CP is poorly understood,and there is no effective therapeutic method in clinic.It is particularly challenging to identify the mechanism,and to work out a serial rational treatment for the disease.Some research shows that CP is a disease often associated with abnormal levels of uric acid in serum or prostate secretions(EPS).Uric acid as the end-product of purine metabolism in the human body is elevated when patients have metabolic disorders.Hyperuricemia is highly associated with various human diseases including CP.Previous studies have shown that UA can promote the development of various immune inflammatory responses by regulating TLR4/NF?B and NLRP3/Caspase-1 signaling pathways.However,the molecular functions of high concentration of uric acid in patients with CP remains unclear.Objective:To investigate the stimulation effects and mechanism of uric acid induce response of inflammation in prostatic epithelial cells(RWPE-1 cells).Methods:According to the pre-experiment results,prostatic epithelial cells(RWPE-1 cells)were cultured with uric acid at concentrations of 0,8,12 and 16mg/dl.The proliferation and morphological changes of RWPE-1 cells were observed by an inverted microscope.Western-blotting was used to detect protein expression levels of TLR4,NF?Bp65,IKK?,IKK? and NLRP3 in RWPE-1 cells.Gene expression of IKK?,IKK?,NLRP3 and Caspase-1 was quantified by real-time polymerase chain reaction.Cell culture supernatants were measured for inflammatory IL-1? and TNF-?by ELISA.Results:Morphological changes in RWPE-1 cells were concentration dependent with uric acid from inverted microscope.Compared with untreated RWPE-1 cells,the levels ofTLR4,NF?Bp65,IKK?,IKK? and NLRP3 in the uric acid-stimulated group were elevated,while the levels of TLR4,NF?Bp65,IKK?,IKK? and NLRP3 were significantly correlated with uric acid concentration(P<0.05).Stimulation of soluble uric acid increased the expression of the IKK?,IKK?,NLRP3 and Caspase1 were positively correlated with the increase in uric acid concentration(P<0.05).After uric acid stimulated RWPE-1 cells for 12 h,the TNF-? levels of each group(0,8,12,16mg/dl)were(9.69 ± 0.22),(9.56 ± 0.47),(9.63 ± 0.51),(10.08 ± 0.11)ng/L,and IL-1? were(7.75 ± 0.52),(7.85 ± 0.87),(9.27 ± 1.11),(9.62 ± 0.44)ng/L,the difference was not statistically significant(P>0.05).After 24 h,the TNF-? levels of each group were(24.86 ± 0.61),(25.14 ± 0.83),(30.34 ± 0.61),(30.77 ± 1.84)ng/L,IL-1? were(14.81 ± 0.23),(15.53 ± 0.30),(22.87 ± 0.65),(25.60 ± 0.70)ng/L.After48 h,the TNF-? of each group were(26.72 ± 0.37),(26.80 ± 1.14),(31.60 ± 0.76),(42.98 ± 1.49)ng/L,IL-1? were(25.36 ± 0.70),(30.29 ± 0.62),(38.91 ± 1.52),(40.97± 1.17)ng/L.After 24 and 48 hours of uric acid stimulation,high concentration of uric acid enhance the expression levels of IL-1? and TNF-? in RWPE-1 cells(P<0.05).Conclusion:High concentrations of uric acid can induce inflammatory response in RWPE-1cells,and activation of TLR4/NF?B and NLRP3/Caspase-1 signaling pathways is one of the mechanisms.