High mobility group box 1 protein regulates osteoclastogenesis through direct actions on osteocytes and osteoclasts in vitro

Hannah M. Davis, Sinai Valdez, Leland Gomez, Peter Malicky, Fletcher A. White, Mark A. Subler, Jolene J. Windle, Joseph Bidwell, Angela Bruzzaniti, Lilian Plotkin

Research output: Contribution to journalArticle

Abstract

Old age and Cx43 deletion in osteocytes are associated with increased osteocyte apoptosis and osteoclastogenesis. We previously demonstrated that apoptotic osteocytes release elevated concentrations of the proinflammatory cytokine, high mobility group box 1 protein (HMGB1) and apoptotic osteocyte conditioned media (CM) promotes osteoclast differentiation. Further, prevention of osteocyte apoptosis blocks osteoclast differentiation and attenuates the extracellular release of HMGB1 and RANKL. Moreover, sequestration of HMGB1, in turn, reduces RANKL production/release by MLO-Y4 osteocytic cells silenced for Cx43 (Cx43def), highlighting the possibility that HMGB1 promotes apoptotic osteocyte-induced osteoclastogenesis. However, the role of HMGB1 signaling in osteocytes has not been well studied. Further, the mechanisms underlying its release and the receptor(s) responsible for its actions is not clear. We now report that a neutralizing HMGB1 antibody reduces osteoclast formation in RANKL/M-CSF treated bone marrow cells. In bone marrow macrophages (BMMs), toll-like receptor 4 (TLR4) inhibition with LPS-RS, but not receptor for advanced glycation end products (RAGE) inhibition with Azeliragon attenuated osteoclast differentiation. Further, inhibition of RAGE but not of TLR4 in osteoclast precursors reduced osteoclast number, suggesting that HGMB1 produced by osteoclasts directly affects differentiation by activating TLR4 in BMMs and RAGE in preosteoclasts. Our findings also suggest that increased osteoclastogenesis induced by apoptotic osteocytes CM is not mediated through HMGB1/RAGE activation and that direct HMGB1 actions in osteocytes stimulate pro-osteoclastogenic signal release from Cx43def osteocytes. Based on these findings, we propose that HMGB1 exerts dual effects on osteoclasts, directly by inducing differentiation through TLR4 and RAGE activation and indirectly by increasing pro-osteoclastogenic cytokine secretion from osteocytes.

Original languageEnglish (US)
Pages (from-to)16741-16749
Number of pages9
JournalJournal of Cellular Biochemistry
Volume120
Issue number10
DOIs
StatePublished - Jan 1 2019

Fingerprint

Rage
HMGB1 Protein
Osteocytes
Osteoclasts
Osteogenesis
Apoptosis
Cytokines
Toll-Like Receptor 4
Connexin 43
Bone
Macrophages
Conditioned Culture Medium
Chemical activation
In Vitro Techniques
Bone Marrow
Macrophage Colony-Stimulating Factor
Bone Marrow Cells
Cells
Advanced Glycosylation End Product-Specific Receptor

Keywords

  • apoptosis
  • cytokine
  • HMGB1
  • osteoclast
  • osteocyte
  • RAGE
  • TLR4

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

High mobility group box 1 protein regulates osteoclastogenesis through direct actions on osteocytes and osteoclasts in vitro. / Davis, Hannah M.; Valdez, Sinai; Gomez, Leland; Malicky, Peter; White, Fletcher A.; Subler, Mark A.; Windle, Jolene J.; Bidwell, Joseph; Bruzzaniti, Angela; Plotkin, Lilian.

In: Journal of Cellular Biochemistry, Vol. 120, No. 10, 01.01.2019, p. 16741-16749.

Research output: Contribution to journalArticle

Davis, Hannah M. ; Valdez, Sinai ; Gomez, Leland ; Malicky, Peter ; White, Fletcher A. ; Subler, Mark A. ; Windle, Jolene J. ; Bidwell, Joseph ; Bruzzaniti, Angela ; Plotkin, Lilian. / High mobility group box 1 protein regulates osteoclastogenesis through direct actions on osteocytes and osteoclasts in vitro. In: Journal of Cellular Biochemistry. 2019 ; Vol. 120, No. 10. pp. 16741-16749.
@article{a2d3e8f660134d709dbe4ed3e09723aa,
title = "High mobility group box 1 protein regulates osteoclastogenesis through direct actions on osteocytes and osteoclasts in vitro",
abstract = "Old age and Cx43 deletion in osteocytes are associated with increased osteocyte apoptosis and osteoclastogenesis. We previously demonstrated that apoptotic osteocytes release elevated concentrations of the proinflammatory cytokine, high mobility group box 1 protein (HMGB1) and apoptotic osteocyte conditioned media (CM) promotes osteoclast differentiation. Further, prevention of osteocyte apoptosis blocks osteoclast differentiation and attenuates the extracellular release of HMGB1 and RANKL. Moreover, sequestration of HMGB1, in turn, reduces RANKL production/release by MLO-Y4 osteocytic cells silenced for Cx43 (Cx43def), highlighting the possibility that HMGB1 promotes apoptotic osteocyte-induced osteoclastogenesis. However, the role of HMGB1 signaling in osteocytes has not been well studied. Further, the mechanisms underlying its release and the receptor(s) responsible for its actions is not clear. We now report that a neutralizing HMGB1 antibody reduces osteoclast formation in RANKL/M-CSF treated bone marrow cells. In bone marrow macrophages (BMMs), toll-like receptor 4 (TLR4) inhibition with LPS-RS, but not receptor for advanced glycation end products (RAGE) inhibition with Azeliragon attenuated osteoclast differentiation. Further, inhibition of RAGE but not of TLR4 in osteoclast precursors reduced osteoclast number, suggesting that HGMB1 produced by osteoclasts directly affects differentiation by activating TLR4 in BMMs and RAGE in preosteoclasts. Our findings also suggest that increased osteoclastogenesis induced by apoptotic osteocytes CM is not mediated through HMGB1/RAGE activation and that direct HMGB1 actions in osteocytes stimulate pro-osteoclastogenic signal release from Cx43def osteocytes. Based on these findings, we propose that HMGB1 exerts dual effects on osteoclasts, directly by inducing differentiation through TLR4 and RAGE activation and indirectly by increasing pro-osteoclastogenic cytokine secretion from osteocytes.",
keywords = "apoptosis, cytokine, HMGB1, osteoclast, osteocyte, RAGE, TLR4",
author = "Davis, {Hannah M.} and Sinai Valdez and Leland Gomez and Peter Malicky and White, {Fletcher A.} and Subler, {Mark A.} and Windle, {Jolene J.} and Joseph Bidwell and Angela Bruzzaniti and Lilian Plotkin",
year = "2019",
month = "1",
day = "1",
doi = "10.1002/jcb.28932",
language = "English (US)",
volume = "120",
pages = "16741--16749",
journal = "Journal of Cellular Biochemistry",
issn = "0730-2312",
publisher = "Wiley-Liss Inc.",
number = "10",

}

TY - JOUR

T1 - High mobility group box 1 protein regulates osteoclastogenesis through direct actions on osteocytes and osteoclasts in vitro

AU - Davis, Hannah M.

AU - Valdez, Sinai

AU - Gomez, Leland

AU - Malicky, Peter

AU - White, Fletcher A.

AU - Subler, Mark A.

AU - Windle, Jolene J.

AU - Bidwell, Joseph

AU - Bruzzaniti, Angela

AU - Plotkin, Lilian

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Old age and Cx43 deletion in osteocytes are associated with increased osteocyte apoptosis and osteoclastogenesis. We previously demonstrated that apoptotic osteocytes release elevated concentrations of the proinflammatory cytokine, high mobility group box 1 protein (HMGB1) and apoptotic osteocyte conditioned media (CM) promotes osteoclast differentiation. Further, prevention of osteocyte apoptosis blocks osteoclast differentiation and attenuates the extracellular release of HMGB1 and RANKL. Moreover, sequestration of HMGB1, in turn, reduces RANKL production/release by MLO-Y4 osteocytic cells silenced for Cx43 (Cx43def), highlighting the possibility that HMGB1 promotes apoptotic osteocyte-induced osteoclastogenesis. However, the role of HMGB1 signaling in osteocytes has not been well studied. Further, the mechanisms underlying its release and the receptor(s) responsible for its actions is not clear. We now report that a neutralizing HMGB1 antibody reduces osteoclast formation in RANKL/M-CSF treated bone marrow cells. In bone marrow macrophages (BMMs), toll-like receptor 4 (TLR4) inhibition with LPS-RS, but not receptor for advanced glycation end products (RAGE) inhibition with Azeliragon attenuated osteoclast differentiation. Further, inhibition of RAGE but not of TLR4 in osteoclast precursors reduced osteoclast number, suggesting that HGMB1 produced by osteoclasts directly affects differentiation by activating TLR4 in BMMs and RAGE in preosteoclasts. Our findings also suggest that increased osteoclastogenesis induced by apoptotic osteocytes CM is not mediated through HMGB1/RAGE activation and that direct HMGB1 actions in osteocytes stimulate pro-osteoclastogenic signal release from Cx43def osteocytes. Based on these findings, we propose that HMGB1 exerts dual effects on osteoclasts, directly by inducing differentiation through TLR4 and RAGE activation and indirectly by increasing pro-osteoclastogenic cytokine secretion from osteocytes.

AB - Old age and Cx43 deletion in osteocytes are associated with increased osteocyte apoptosis and osteoclastogenesis. We previously demonstrated that apoptotic osteocytes release elevated concentrations of the proinflammatory cytokine, high mobility group box 1 protein (HMGB1) and apoptotic osteocyte conditioned media (CM) promotes osteoclast differentiation. Further, prevention of osteocyte apoptosis blocks osteoclast differentiation and attenuates the extracellular release of HMGB1 and RANKL. Moreover, sequestration of HMGB1, in turn, reduces RANKL production/release by MLO-Y4 osteocytic cells silenced for Cx43 (Cx43def), highlighting the possibility that HMGB1 promotes apoptotic osteocyte-induced osteoclastogenesis. However, the role of HMGB1 signaling in osteocytes has not been well studied. Further, the mechanisms underlying its release and the receptor(s) responsible for its actions is not clear. We now report that a neutralizing HMGB1 antibody reduces osteoclast formation in RANKL/M-CSF treated bone marrow cells. In bone marrow macrophages (BMMs), toll-like receptor 4 (TLR4) inhibition with LPS-RS, but not receptor for advanced glycation end products (RAGE) inhibition with Azeliragon attenuated osteoclast differentiation. Further, inhibition of RAGE but not of TLR4 in osteoclast precursors reduced osteoclast number, suggesting that HGMB1 produced by osteoclasts directly affects differentiation by activating TLR4 in BMMs and RAGE in preosteoclasts. Our findings also suggest that increased osteoclastogenesis induced by apoptotic osteocytes CM is not mediated through HMGB1/RAGE activation and that direct HMGB1 actions in osteocytes stimulate pro-osteoclastogenic signal release from Cx43def osteocytes. Based on these findings, we propose that HMGB1 exerts dual effects on osteoclasts, directly by inducing differentiation through TLR4 and RAGE activation and indirectly by increasing pro-osteoclastogenic cytokine secretion from osteocytes.

KW - apoptosis

KW - cytokine

KW - HMGB1

KW - osteoclast

KW - osteocyte

KW - RAGE

KW - TLR4

UR - http://www.scopus.com/inward/record.url?scp=85070106791&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85070106791&partnerID=8YFLogxK

U2 - 10.1002/jcb.28932

DO - 10.1002/jcb.28932

M3 - Article

C2 - 31106449

AN - SCOPUS:85070106791

VL - 120

SP - 16741

EP - 16749

JO - Journal of Cellular Biochemistry

JF - Journal of Cellular Biochemistry

SN - 0730-2312

IS - 10

ER -