Activation of mTORC1 in B Lymphocytes Promotes Osteoclast Formation via Regulation of β-Catenin and RANKL/OPG
- PMID: 26825871
- DOI: 10.1002/jbmr.2800
Activation of mTORC1 in B Lymphocytes Promotes Osteoclast Formation via Regulation of β-Catenin and RANKL/OPG
Abstract
The cytokine receptor activator of nuclear factor-κB ligand (RANKL) induces osteoclast formation from monocyte/macrophage lineage cells. However, the mechanisms by which RANKL expression is controlled in cells that support osteoclast differentiation are still unclear. We show that deletion of TSC1 (tuberous sclerosis complex 1) in murine B cells causes constitutive activation of mechanistic target of rapamycin complex 1 (mTORC1) and stimulates RANKL but represses osteoprotegerin (OPG) expression and subsequently promotes osteoclast formation and causes osteoporosis in mice. Furthermore, the regulation of RANKL/OPG and stimulation of osteoclastogenesis by mTORC1 was confirmed in a variety of RANKL-expressing cells and in vivo. Mechanistically, mTORC1 controls RANKL/OPG expression through negative feedback inactivation of Akt, destabilization of β-catenin mRNA, and downregulation of β-catenin. Our findings demonstrate that mTORC1 activation-stimulated RANKL expression in B cells is sufficient to induce bone loss and osteoporosis. The study also established a link between mTORC1 and the RANKL/OPG axis via negative regulation of β-catenin. © 2016 American Society for Bone and Mineral Research.
Keywords: B LYMPHOCYTE; OSTEOCLAST FORMATION; RANKL (RECEPTOR ACTIVATOR OF NUCLEAR FACTOR-κB LIGAND); mTORC1 (MECHANISTIC TARGET OF RAPAMYCIN COMPLEX 1); β-CATENIN.
© 2016 American Society for Bone and Mineral Research.
Similar articles
-
Aging increases stromal/osteoblastic cell-induced osteoclastogenesis and alters the osteoclast precursor pool in the mouse.J Bone Miner Res. 2005 Sep;20(9):1659-68. doi: 10.1359/JBMR.050503. Epub 2005 May 2. J Bone Miner Res. 2005. PMID: 16059637
-
Receptor activator of nuclear factor-κB ligand (RANKL)/RANK/osteoprotegerin system in bone and other tissues (review).Mol Med Rep. 2015 May;11(5):3212-8. doi: 10.3892/mmr.2015.3152. Epub 2015 Jan 7. Mol Med Rep. 2015. PMID: 25572286 Review.
-
The differential expression of osteoprotegerin (OPG) and receptor activator of nuclear factor kappaB ligand (RANKL) in human osteoarthritic subchondral bone osteoblasts is an indicator of the metabolic state of these disease cells.Clin Exp Rheumatol. 2008 Mar-Apr;26(2):295-304. Clin Exp Rheumatol. 2008. PMID: 18565252 Free PMC article.
-
Trapidil, a platelet-derived growth factor antagonist, inhibits osteoclastogenesis by down-regulating NFATc1 and suppresses bone loss in mice.Biochem Pharmacol. 2013 Sep 15;86(6):782-90. doi: 10.1016/j.bcp.2013.07.015. Epub 2013 Aug 6. Biochem Pharmacol. 2013. PMID: 23928189
-
Osteoclast differentiation by RANKL and OPG signaling pathways.J Bone Miner Metab. 2021 Jan;39(1):19-26. doi: 10.1007/s00774-020-01162-6. Epub 2020 Oct 20. J Bone Miner Metab. 2021. PMID: 33079279 Review.
Cited by
-
Inactivation of Regulatory-associated Protein of mTOR (Raptor)/Mammalian Target of Rapamycin Complex 1 (mTORC1) Signaling in Osteoclasts Increases Bone Mass by Inhibiting Osteoclast Differentiation in Mice.J Biol Chem. 2017 Jan 6;292(1):196-204. doi: 10.1074/jbc.M116.764761. Epub 2016 Nov 22. J Biol Chem. 2017. PMID: 27879318 Free PMC article.
-
Estrogen-mediated downregulation of HIF-1α signaling in B lymphocytes influences postmenopausal bone loss.Bone Res. 2022 Feb 17;10(1):15. doi: 10.1038/s41413-022-00189-x. Bone Res. 2022. PMID: 35177582 Free PMC article.
-
Prevention and Treatment of Osteoporosis Using Chinese Medicinal Plants: Special Emphasis on Mechanisms of Immune Modulation.J Immunol Res. 2018 Feb 20;2018:6345857. doi: 10.1155/2018/6345857. eCollection 2018. J Immunol Res. 2018. PMID: 29675436 Free PMC article. Review.
-
Supranutritional selenium suppresses ROS-induced generation of RANKL-expressing osteoclastogenic CD4+ T cells and ameliorates rheumatoid arthritis.Clin Transl Immunology. 2021 Sep 20;10(9):e1338. doi: 10.1002/cti2.1338. eCollection 2021. Clin Transl Immunology. 2021. PMID: 34584694 Free PMC article.
-
Osteocyte TSC1 promotes sclerostin secretion to restrain osteogenesis in mice.Open Biol. 2019 May 31;9(5):180262. doi: 10.1098/rsob.180262. Open Biol. 2019. PMID: 31088250 Free PMC article.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Other Literature Sources
Medical
Research Materials