Nur77 prevents excessive osteoclastogenesis by inducing ubiquitin ligase Cbl-b to mediate NFATc1 self-limitation
- University of Texas Southwestern Medical Center, United States
Abstract
Osteoclasts are bone-resorbing cells essential for skeletal remodeling. However, over-active osteoclasts can cause bone degenerative disorders. Therefore, the level of NFATc1, the master transcription factor of osteoclast, must be tightly controlled. Although the activation and amplification of NFATc1 have been extensively studied, how NFATc1 signaling is eventually resolved is unclear. Here, we uncover a novel and critical role of the orphan nuclear receptor Nur77 in mediating an NFATc1 self-limiting regulatory loop to prevent excessive osteoclastogenesis. Nur77 deletion leads to low bone mass owing to augmented osteoclast differentiation and bone resorption. Mechanistically, NFATc1 induces Nur77 expression at late stage of osteoclast differentiation; in turn, Nur77 transcriptionally up-regulates E3 ubiquitin ligase Cbl-b, which triggers NFATc1 protein degradation. These findings not only identify Nur77 as a key player in osteoprotection and a new therapeutic target for bone diseases, but also elucidate a previously unrecognized NFATc1→Nur77→Cblb⎯•NFATc1 feedback mechanism that confers NFATc1 signaling autoresolution.
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Author details
Reviewing Editor
- Janet Rossant, University of Toronto, Canada
Ethics
Animal experimentation: All protocols for mouse experiments were approved under number 2008-0324 by the Institutional Animal Care and Use Committee of UTSW.
Version history
- Received: February 26, 2015
- Accepted: July 13, 2015
- Accepted Manuscript published: July 14, 2015 (version 1)
- Version of Record published: July 29, 2015 (version 2)
Copyright
© 2015, Li et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Nur77 prevents excessive osteoclastogenesis by inducing ubiquitin ligase Cbl-b to mediate NFATc1 self-limitation
eLife 4:e07217.
https://doi.org/10.7554/eLife.07217
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