title: Glucose-based peritoneal dialysis fluids downregulate toll-like receptors and trigger hyporesponsiveness to pathogen-associated molecular patterns in human peritoneal mesothelial cells.
abstract: The objective of this study was to investigate the effects of glucose-based peritoneal dialysis (PD) fluids and icodextrin-based PD fluids on the expression of Toll-like receptor 2 (TLR2)/TLR4 and subsequent ligand-induced mitogen-activated protein kinase (MAPK) and NF-kappaB signaling and tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) mRNA expression in human peritoneal mesothelial cells (HPMCs). A human peritoneal mesothelial cell line (HMrSV5) was stimulated with glucose-based and icodextrin-based peritoneal dialysis fluids. Cell viability was assessed using MTT [3-(4,5-dimethylthiazolyl)-2,5-diphenyl-2H-tetrazolium bromide]. TLR2/TLR4 expression was determined by real-time PCR, Western blotting, and an immunofluorescence assay. In addition, cells were pretreated with different PD solutions and then incubated with Pam3CSK4 or lipopolysaccharide (LPS), and the degrees of MAPK and NF-kappaB activation were reflected by detecting the phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), p38, and p65, using a Western blot method. TNF-alpha and IL-1beta mRNA expression was measured by real-time PCR. Glucose-based peritoneal dialysis fluids suppressed the expression of TLR2 and TLR4 proteins in HPMCs. Challenge of cells with either Pam3CSK4 or LPS resulted in impaired TNF-alpha and IL-1beta production. Moreover, reduced TLR2 and TLR4 levels in glucose-based peritoneal dialysis solution-treated mesothelial cells were accompanied by reduced p42/44 (ERK1/2), JNK, p38 MAPK, and NF-kappaB p65 phosphorylation upon TLR ligand engagement. No significant changes in MAPK and NF-kappaB signaling and TNF-alpha and IL-1beta mRNA expression were observed in icodextrin-based PD solution-treated mesothelial cells. Glucose-based PD solution, but not icodextrin-based PD solution, downregulates expression of TLR2/TLR4 by human peritoneal mesothelial cells and triggers hyporesponsiveness to pathogen-associated molecular patterns.
authors.affiliation: Department of Nephrology, First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Xiao
authors.initials: X
authors.lastname: Yang
authors.forename: Yun-Fang
authors.initials: YF
authors.lastname: Zhang
authors.forename: Ya-Ning
authors.initials: YN
authors.lastname: Wang
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.forename: Xiu-Qing
authors.initials: XQ
authors.lastname: Dong
authors.forename: Jin-Jin
authors.initials: JJ
authors.lastname: Fan
authors.forename: Xue-Qing
authors.initials: XQ
authors.lastname: Yu
mesh_terms: D015153:Blotting, Western; D002460:Cell Line; D002470:Cell Survival; D002863:Chromogenic Compounds / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis; D015314:Dialysis Solutions / Q000009:adverse effects*; D004847:Epithelial Cells / Q000187:drug effects / Q000276:immunology*; D019085:Fluorescent Antibody Technique, Direct; D005936:Glucans / Q000009:adverse effects*; D005947:Glucose / Q000009:adverse effects*; D006801:Humans; D000077607:Icodextrin; D010530:Peritoneal Dialysis / Q000009:adverse effects; D010537:Peritoneum / Q000166:cytology* / Q000187:drug effects* / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013778:Tetrazolium Salts / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000096:biosynthesis* / Q000187:drug effects / Q000276:immunology; D051197:Toll-Like Receptor 4 / Q000096:biosynthesis* / Q000187:drug effects / Q000276:immunology
chemical_list: D002863:Chromogenic Compounds; D016207:Cytokines; D015314:Dialysis Solutions; D005936:Glucans; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D013778:Tetrazolium Salts; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D000077607:Icodextrin; D005947:Glucose