title: Obesity aggravates the joint inflammation in a collagen-induced arthritis model through deviation to Th17 differentiation.
abstract: White fat cells secrete adipokines that induce inflammation and obesity has been reported to be characterized by high serum levels of inflammatory cytokines such as IL-6 and TNF-α. Rheumatoid arthritis (RA) is a prototype of inflammatory arthritis, but the relationship between RA and obesity is controversial. We made an obese inflammatory arthritis model: obese collagen-induced arthritis (CIA). C57BL/6 mice were fed a 60-kcal high fat diet (HFD) from the age of 4 weeks and they were immunized twice with type II collagen (CII). After immunization, the obese CIA mice showed higher arthritis index scores and histology scores and a more increased incidence of developing arthritis than did the lean CIA mice. After treatment with CII, mixed lymphocyte reaction also showed CII-specific response more intensely in the obese CIA mice than lean CIA. The anti-CII IgG and anti-CII IgG2a levels in the sera of the obese CIA mice were higher than those of the lean CIA mice. The number of Th17 cells was higher and the IL-17 mRNA expression of the splenocytes in the obese CIA mice was higher than that of the lean CIA mice. Obese CIA mice also showed high IL-17 expression on synovium in immunohistochemistry. Although obesity may not play a pathogenic role in initiating arthritis, it could play an important role in amplifying the inflammation of arthritis through the Th1/Th17 response. The obese CIA murine model will be an important tool when we investigate the effect of several therapeutic target molecules to treat RA.
authors.affiliation: The Rheumatism Research Center, Catholic Research Institute of Medical Science, The Catholic University of Korea, Seoul 137-040, Korea.
authors.forename: Joo-Yeon
authors.initials: JY
authors.lastname: Jhun
authors.forename: Bo-Young
authors.initials: BY
authors.lastname: Yoon
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Park
authors.forename: Hye-Joa
authors.initials: HJ
authors.lastname: Oh
authors.forename: Jae-Kyeong
authors.initials: JK
authors.lastname: Byun
authors.forename: Seon-Young
authors.initials: SY
authors.lastname: Lee
authors.forename: Jun-Ki
authors.initials: JK
authors.lastname: Min
authors.forename: Sung-Hwan
authors.initials: SH
authors.lastname: Park
authors.forename: Ho-Youn
authors.initials: HY
authors.lastname: Kim
authors.forename: Mi-La
authors.initials: ML
authors.lastname: Cho
mesh_terms: D054392:Adipokines / Q000276:immunology / Q000378:metabolism; D000818:Animals; D001169:Arthritis, Experimental / Q000235:genetics / Q000276:immunology / Q000473:pathology; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D024043:Collagen Type II / Q000008:administration & dosage / Q000276:immunology; D004195:Disease Models, Animal; D015870:Gene Expression; D006801:Humans; D007249:Inflammation / Q000139:chemically induced / Q000276:immunology*; D020381:Interleukin-17 / Q000378:metabolism; D015850:Interleukin-6 / Q000097:blood; D007596:Joints / Q000276:immunology / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000235:genetics / Q000276:immunology / Q000473:pathology; D058504:Th17 Cells / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D054392:Adipokines; D024043:Collagen Type II; D020381:Interleukin-17; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha