RANKL downregulates cell surface CXCR6 expression through JAK2/STAT3 signaling pathway during osteoclastogenesis

Journal Article · Fri Dec 14 04:00:00 EST 2012 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2012.10.122· OSTI ID:22210357

Li, Changhong; Zhao, Jinxia; Sun, Lin; Yao, Zhongqiang; Liu, Rui ^[1]; Huang, Jiansheng ^[2]; Liu, Xiangyuan ^[1]

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1. Department of Rheumatology and Immunology, Peking University Third Hospital, Beijing 100191 (China)
2. Department of Pediatrics, Washington University School of Medicine, St. Louis, MO (United States)

Highlights: Black-Right-Pointing-Pointer CXCR6 is down-regulated during RANKL-induced osteoclastogenesis in RAW264.7 cells. Black-Right-Pointing-Pointer CXCR6 reduction was nearly reversed by inhibition of JAK2/STAT3 signaling pathway. Black-Right-Pointing-Pointer CXCL16 alone does not positively regulate osteoclastogenesis. -- Abstract: The receptor activator of nuclear factor-{kappa}B ligand (RANKL), as a member of the tumor necrosis factor (TNF) family, plays an essential role in osteoclast differentiation and function. Chemokines and their receptors have recently been shown to play critical roles in osteoclastogenesis, however, whether CXCL16-CXCR6 plays role in RANKL-mediated osteoclastogenesis is unknown. In this study, we first reported that RANKL decreased CXCR6 in a dose-dependent manner, which may be through deactivation of Akt and STAT3 signaling induced by CXCL16. Interestingly, RANKL-mediated CXCR6 reduction may be associated to the activation of STAT3 by phosphorylation. When STAT3 activation was blocked by JAK2/STAT3 inhibitor AG490, RANKL failed to shut down CXCR6 expression during osteoclastogenesis. However, CXCL16 alone did not augment RANKL-mediated osteoclast differentiation and did not alter RANKL-receptor RANK mRNA expression. These results demonstrate that reduction of CXCL16-CXCR6 is critical in RANKL-mediated osteoclastogenesis, which is mainly through the activation of JAK2/STAT3 signaling. CXCL16-CXCR6 axis may become a novel target for the therapeutic intervention of bone resorbing diseases such as rheumatoid arthritis and osteoporosis.

• OSTI ID: 22210357
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 3-4 Vol. 429; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

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60 APPLIED LIFE SCIENCES
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OSTEOPOROSIS
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RECEPTORS
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