title: The inhibition of hyaluronan degradation reduced pro-inflammatory cytokines in mouse synovial fibroblasts subjected to collagen-induced arthritis.
abstract: Hyaluronan (HA) degradation produces small oligosaccharides that are able to increase pro-inflammatory cytokines in rheumatoid arthritis synovial fibroblasts (RASF) by activating both CD44 and the toll-like receptor 4 (TLR-4). CD44 and TLR-4 stimulation in turn activate the NF-kB that induces the production of pro-inflammatory cytokines. Degradation of HA occurs via two mechanisms: one exerted by reactive oxygen species (ROS) and one controlled by different enzymes in particular hyaluronidases (HYALs). We aimed to investigate the effects of inhibiting HA degradation (which prevents the formation of small HA fragments) on synovial fibroblasts obtained from normal DBA/J1 mice (NSF) and on synovial fibroblasts (RASF) obtained from mice subjected to collagen induced arthritis (CIA), both fibroblast types stimulated with tumor necrosis factor alpha (TNF-α). TNF-α stimulation produced high mRNA expression and the related protein production of CD44 and TLR-4 in both NSF and RASF, and activation of NF-kB was also found in all fibroblasts. TNF-α also up-regulated the inflammatory cytokines, interleukin-1beta (IL-1beta) and interleukin-6 (IL-6), and other pro-inflammatory mediators, such as matrix metalloprotease-13 (MMP-13), inducible nitric oxide synthase (iNOS), as well as HA levels and small HA fragment production. Treatment of RASF with antioxidants and specific HYAL1, HYAL2, and HYAL3 small interference RNA (siRNAs) significantly reduced TLR-4 and CD44 increase in the mRNA expression and the related protein synthesis, as well as the release of inflammatory mediators up-regulated by TNF-α. These data suggest that the inhibition of HA degradation during arthritis may contribute to reducing TLR-4 and CD44 activation and the inflammatory mediators response.
authors.affiliation: Department of Biochemical, Physiological and Nutritional Sciences, Section of Medical Chemistry, School of Medicine, University of Messina, Policlinico Universitario, 98125-Messina, Italy. gcampo@unime.it
authors.forename: Giuseppe M
authors.initials: GM
authors.lastname: Campo
authors.forename: Angela
authors.initials: A
authors.lastname: Avenoso
authors.forename: Angela
authors.initials: A
authors.lastname: D'Ascola
authors.forename: Michele
authors.initials: M
authors.lastname: Scuruchi
authors.forename: Vera
authors.initials: V
authors.lastname: Prestipino
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Nastasi
authors.forename: Alberto
authors.initials: A
authors.lastname: Calatroni
authors.forename: Salvatore
authors.initials: S
authors.lastname: Campo
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000235:genetics; D002478:Cells, Cultured; D003094:Collagen; D016207:Cytokines / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D058851:GPI-Linked Proteins / Q000235:genetics; D018960:Hyaluronan Receptors / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006820:Hyaluronic Acid / Q000378:metabolism*; D006821:Hyaluronoglucosaminidase / Q000235:genetics; D018836:Inflammation Mediators / Q000378:metabolism*; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008315:Malondialdehyde / Q000032:analysis; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008811:Mice, Inbred DBA; D016328:NF-kappa B / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering; D013583:Synovial Membrane; D051197:Toll-Like Receptor 4 / Q000276:immunology / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000494:pharmacology
chemical_list: D015815:Cell Adhesion Molecules; D016207:Cytokines; D058851:GPI-Linked Proteins; D018960:Hyaluronan Receptors; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D015850:Interleukin-6; D016328:NF-kappa B; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D008315:Malondialdehyde; D006820:Hyaluronic Acid; D003094:Collagen; D052247:Nitric Oxide Synthase Type II; C469220:Hyal1 protein, mouse; C469221:Hyal2 protein, mouse; D006821:Hyaluronoglucosaminidase; C066852:hyaluronidase PH-20; D053509:Matrix Metalloproteinase 13