Glycosaminoglycans reduced inflammatory response by modulating toll-like receptor-4 in LPS-stimulated chondrocytes.
Lipopolysaccharide (LPS)-mediated activation of toll-like receptor-4 (TLR-4) complex induces specific signaling pathways, such as the myeloid differentiation primary response protein-88 (MyD88) and the tumor necrosis factor receptor-associated factor-6 (TRAF-6), involving NF-kappaB activation. As previous data reported that hyaluronan (HA) and heparan sulfate (HS) may interact with TLR-4, the aim of this study was to investigate whether glycosaminoglycans (GAGs) may modulate the TLR-4 receptor in a model of LPS-induced inflammatory cytokines in mouse chondrocytes. LPS stimulation up-regulated all inflammation parameters. The GAG treatment produced various effects: HA reduced MyD88 and TRAF-6 levels and NF-kappaB activation at the higher dose only, and exerted a very low anti-inflammatory effect; chondroitin-4-sulfate (C4S) and chondroitin-6-sulfate significantly inhibited MyD88, TRAF-6 and NF-kappaB activation, the inflammation cytokines, and inducible nitric oxide synthase; HS, like C4S, significantly reduced MyD88, TRAF-6, NF-kappaB and inflammation. Specific TLR-4 blocking antibody confirmed that TLR-4 was the target of GAG action.
Department of Biochemical, Physiological and Nutritional Sciences, Medical Chemistry Section, School of Medicine, University of Messina, Policlinico Universitario, Messina, Italy. gcampo@unime.it
Giuseppe M
GM
Campo
Angela
A
Avenoso
Salvatore
S
Campo
Paola
P
Traina
Angela
A
D'Ascola
Alberto
A
Calatroni
D000818:Animals; D000918:Antibody Specificity; D015153:Blotting, Western; D002417:Cattle; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects* / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D006025:Glycosaminoglycans / Q000494:pharmacology*; D007249:Inflammation / Q000378:metabolism; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D048029:TNF Receptor-Associated Factor 6 / Q000235:genetics / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
D006025:Glycosaminoglycans; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B; D012333:RNA, Messenger; D048029:TNF Receptor-Associated Factor 6; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D052247:Nitric Oxide Synthase Type II; D053509:Matrix Metalloproteinase 13