title: Inhibition of small HA fragment activity and stimulation of A2A adenosine receptor pathway limit apoptosis and reduce cartilage damage in experimental arthritis.
abstract: Recent studies have found that the inactivation of small hyaluronan (HA) fragments originating from native HA during inflammation reduced the inflammatory response in models of experimental arthritis. The stimulation of adenosine receptors A2A reduced inflammation by inhibiting NF-kB activation. The combination of both treatments was significantly more effective than either of the individual treatments. The aim of this study was to further investigate the effects of a combined treatment using the HA inhibitor Pep-1 and a selective A2AR agonist (CV-1808) on the structure and ultrastructure of the articular cartilage and on apoptosis in a model of collagen-induced arthritis (CIA) in mice. Arthritic mice were treated with Pep-1 and/or CV-1808 intraperitoneally daily for 20 days. At day 35, the hind limbs were processed for light microscopy (hematoxylin/eosin and Safranin-O-Fast Green) and for transmission and scanning electron microscopy. CIA increased IL-6, caspase-3 and caspase-7 mRNA expression and the related protein levels in arthritic articular cartilage, and significantly increased concentrations of Bcl-2-associated X protein (Bax), while B cell-lymphoma-2 protein (Bcl-2) was markedly reduced. The combined Pep-1/CV-1808 treatment significantly reduced CIA injury, particularly at the highest doses, demonstrated by the presence of Safranin-O-positive cartilage, with a smooth surface and normal chondrocytes in the superficial, intermediate and deep zones. Morphological data and histological scoring were strongly supported by the reduction in inflammation and apoptotic markers. The results further support the role of HA degradation and A2A receptors in arthritis.
authors.affiliation: Section of Medical Biotechnologies and Preventive Medicine, Department of Biomedical Sciences and Morphofunctional Images, School of Medicine, University of Messina, Policlinico Universitario, Torre Biologica, 5° piano, Via C. Valeria 1, 98125, Messina, Italy, gcampo@unime.it.
authors.forename: Giuseppe M
authors.initials: GM
authors.lastname: Campo
authors.forename: Antonio
authors.initials: A
authors.lastname: Micali
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: Antonina
authors.initials: A
authors.lastname: Pisani
authors.forename: Antongiulio
authors.initials: A
authors.lastname: Bruschetta
authors.forename: Alberto
authors.initials: A
authors.lastname: Calatroni
authors.forename: Domenico
authors.initials: D
authors.lastname: Puzzolo
authors.forename: Salvatore
authors.initials: S
authors.lastname: Campo
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D058908:Adenosine A2 Receptor Agonists / Q000494:pharmacology*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism; D001169:Arthritis, Experimental / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002358:Cartilage, Articular / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D024043:Collagen Type II; D004359:Drug Therapy, Combination; D005620:Freund's Adjuvant; D006820:Hyaluronic Acid / Q000037:antagonists & inhibitors* / Q000378:metabolism; D018836:Inflammation Mediators / Q000378:metabolism; D007596:Joints / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D008811:Mice, Inbred DBA; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010455:Peptides / Q000494:pharmacology*; D043705:Receptor, Adenosine A2A / Q000187:drug effects* / Q000378:metabolism; D012720:Severity of Illness Index; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors
chemical_list: D058908:Adenosine A2 Receptor Agonists; D000893:Anti-Inflammatory Agents; D051017:Apoptosis Regulatory Proteins; D024043:Collagen Type II; D018836:Inflammation Mediators; D010455:Peptides; D043705:Receptor, Adenosine A2A; C575521:glycyl-alanyl-histidyl-tryptophyl-glutaminyl-phenylalanyl-asparagyl-alanyl-leucyl-threonyl-valyl-arginine; D006820:Hyaluronic Acid; D005620:Freund's Adjuvant; C026708:2-phenylaminoadenosine; D000241:Adenosine