Direct effect of interleukin-6 (IL-6) on growth plate chondrocytes

• Published in: Nihon Rinsho Men'eki Gakkai Sokai Shorokushu Vol. 35; p. 153
• Main Authors: 今川, 智之, 宮前, 多佳子, 森, 雅亮, 成戸, 卓也, 中島, 章子, 横田, 俊平
• Format: Journal Article
• Language: Japanese
• Published: 日本臨床免疫学会 2007; The Japan Society for Clinical Immunology
• Subjects: ATDC5; growth impairment; growth plate chondrocytes; interleukin-6; systemic juvenile idiopathic arthritis (sJIA)
• ISSN: 1880-3296
• DOI: 10.14906/jscisho.35.0.153.0

Background: Growth impairment is a major complication of systemic juvenile idiopathic arthritis (sJIA). Aims: To investigate the cellular-level effect of IL-6 on the growth plate chondrocytes. Materials and Methods: The murine chondrocyte EC cell line, ATDC5 was examined for the expression of IL-6 receptor and gp130 by fluorescence-activated cell sorting (FACS) analysis. Cells were harvested for 14 full days and recombinant murine IL-6 was added to the cultures from day 2 to day 14. To study the effect of IL-6 on cell differentiation, the quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) was performed for the chondrogenic differentiation markers, type II collagen, aggrecan, and type X collagen. To test IL-6 function blocking, MR16-1, the anti-mouse IL-6 receptor monoclonal antibody, was used. Results: FACS analysis revealed the expression of IL-6 receptor and gp130 on the surface of ATDC5 cells. The results of qRT-PCR indicated that IL-6 reduced the expressions of chondrogenic differentiation marker gene. A blocking test showed that the inhibitory effect of IL-6 was abrogated. Conclusion: The results indicate that IL-6 inhibits the early differentiation of growth plate chondrocytes at a cellular level. Growth impairment in sJIA is brought about in part through the direct inhibitory effect of IL-6 on early differentiation of growth plate chondrocytes.