title: Modulation of hyaluronan fragmentation by interleukin-1 beta in synovial membrane cells.
abstract: Hyaluronan (HA) plays a crucial role in the lubricating and buffering properties of synovial fluid. The purpose of this study was to examine the effects of interleukin (IL)-1beta on HA degradation in cultured synovial membrane cells. The rabbit synovial membrane cell line HIG-82 was cultured with and without IL-1beta. The amounts of HA of varying molecular weights in the medium were analyzed using high-performance liquid chromatography, the mRNA levels of HA synthase (HAS) and hyaluronidase (HYAL) were analyzed by means of real-time PCR, and HYAL activity was analyzed by HA zymography. The amounts of HA with a molecular weight lower than 300 kDa, and between 300 and 1900 kDa, in the culture medium of HIG-82 cells were significantly higher in the presence of IL-1beta. However, the amount of HA with a molecular weight greater than 1900 kDa was significantly lower in the presence of IL-1beta. Both HAS2 and HAS3 mRNA levels were upregulated by treatment with IL-1beta. So, too, were the levels of HYAL1 and HYAL2 mRNA, which resulted in enhanced HYAL activity. However, HYAL activity was inhibited by transfection of HYAL2-siRNA. Our results suggest that IL-1beta is a crucial factor in the fragmentation of HA in inflammatory joints.
authors.affiliation: Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan. tkotaro@hiroshima-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Tanimoto
authors.forename: T
authors.initials: T
authors.lastname: Yanagida
authors.forename: Y
authors.initials: Y
authors.lastname: Tanne
authors.forename: T
authors.initials: T
authors.lastname: Kamiya
authors.forename: Y C
authors.initials: YC
authors.lastname: Huang
authors.forename: T
authors.initials: T
authors.lastname: Mitsuyoshi
authors.forename: N
authors.initials: N
authors.lastname: Tanaka
authors.forename: E
authors.initials: E
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Tanne
mesh_terms: D000818:Animals; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D006820:Hyaluronic Acid / Q000737:chemistry / Q000378:metabolism*; D007375:Interleukin-1 / Q000008:administration & dosage*; D011817:Rabbits; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013583:Synovial Membrane / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*
chemical_list: D007375:Interleukin-1; D006820:Hyaluronic Acid