The role of aquaporin 1 in knee osteoarthritis: a contemporary review

IntroductionThe aim of this article is to criticallyreview literature about aquaporin 1and its involvement in joint diseases.In particular, we focused our researchon osteoarthritis of the knee.Materials and methodsWe reviewed the literature regardingaquaporin 1 role in joint cavitydisease. We examined the currentliterature through searching PubMedand Scopus using appropriatekeywords in relation to aquaporin1 and osteoarthritis. Main researcharticles were selected for review.ResultsAquaporin 1 is an integral membraneprotein expressed in different normaland pathological tissues, for example,erythrocytes, renal tubule cells andin knee tissues (synoviocytes, articularchondrocytes and fibrochondrocytes).In knee tissues, aquaporin 1is also expressed in human synovitisand in chondrocytes of patients withrheumatoid arthritis and osteoarthritis.The process of developmentand ageing of articular cartilage isrelated to its nutrition and function,which depend mainly on the watermolecular transmembrane transport.Water transport is taken by aquaporins.The regulation of the waterand solute content of chondrocyteswill profoundly affect their anabolicand catabolic functions. The chondrocytesare supplied by diffusion,helped by the pumping action generatedby compression of the articularcartilage or flexion of the elasticcartilage. The water content of cellsis effectively influenced by the abundanceof aquaporin water channels.ConclusionThis review reports recent findingsabout the involvement of aquaporin1 in the function of the articularcartilage and its possible role in kneeosteoarthritis.