title: Reduction of IL-20 Expression in Rheumatoid Arthritis by Linear Polarized Infrared Light Irradiation.
abstract: BACKGROUND
  Low-level laser is being evaluated for treating rheumatoid arthritis (RA). Recently, the linear polarized infrared light (Super Lizer, SL) irradiation may also be useful for RA treatment. However, the molecular mechanism underlying the effectiveness of SL on RA is unclear. It has been IL-20 may involved in RA disease progression.
  
  
  OBJECTIVE
  To understand how SL action, we constructed the experimental model in vitro using human rheumatoid fibroblast-like synoviocyte (MH7A) and collagen induced (CIA) RA rat in vivo. We examined the effect of SL irradiation on IL-20 gene expression in MH7A and IL-20 protein production in CIA) rat joints.
  
  
  METHODS
  MH7A was cultured and challenged with IL-1ß, then examined IL-20 and IL-20R mRNA level by DNA microarray. IL-20 protein expression was examined by immunohistochemistry using a specific antibody against rat IL-20.
  
  
  RESULTS
  Scatter plot analysis demonstrated that an increase in IL-20 gene expression by IL-1ß was reduced by SL irradiation, but IL-20R did not show a significant change. The Immunohistochemical analysis demonstrated a strong IL-20 staining in synovial membrane tissue of CIA rat joint, and SL irradiation significantly reduced the staining.
  
  
  CONCLUSIONS
  Since IL-20 has been identified as an important cytokine in the pathogenesis of RA, the reduction of IL-20 expression by SL irradiation may be one of mechanisms in reduction of inflammation in RA joints by SL irradiation suggesting that SL irradiation may be useful for RA therapy.
authors: Department of Biochemistry, Nihon University School of Dentistry at Matsudo.
authors: Asayo
authors: A
authors: Imaoka
authors: Department of Biochemistry, Nihon University School of Dentistry at Matsudo.
authors: Lin
authors: L
authors: Zhang
authors: Department of Pharmacology, Nihon University School of Dentistry at Matsudo.
authors: Noboru
authors: N
authors: Kuboyama
authors: Department of Biochemistry, Nihon University School of Dentistry at Matsudo.
authors: Yoshimitsu
authors: Y
authors: Abiko
keywords: IL-20; Rheumatoid arthritis; linear polarized infrared light