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A transmembrane osteoclastic protein-tyrosine phosphatase regulates osteoclast activity in part by promoting osteoclast survival through c-Src-dependent activation of NFκB and JNK2

Research output: Contribution to journalArticlepeer-review

Abstract

This study evaluated the effects of overexpression of wild-type (WT) or phosphatase-deficient (PD) mutant of an osteoclastic protein-tyrosine phosphatase (PTP-oc) in RAW/C4 cells. Osteoclast-like cells derived from WT-PTP-oc overexpressing clones increased, while those derived from PD-PTP-oc expressing clones decreased, their resorption activity. WT-PTP-oc clones had lower apoptosis, lower caspase 3/7 activity, reduced c-Src tyr-527 phosphorylation (PY527) and IκBα cellular levels, and increased NFκB activation and JNK phosphorylation. Overexpression of PD-PTP-oc or PTP-oc siRNA treatment increased apoptosis, caspase 3/7 activity, PY527 and IκBα levels, and decreased NFκB and JNK2 activation. Inhibition of the c-Src kinase blocked the PTP-oc-mediated NFκB and JNK2 activation. Blocking the NFκB activation had no effect on the JNK2 activation. Inhibiting the NFκB and/or JNK2 pathway prevented the PTP-oc-mediated reduction in apoptosis. In conclusion, PTP-oc activates osteoclast activity in part by promoting osteoclast survival through the PTP-oc-mediated c-Src-dependent activation of NFκB and JNK2. © 2007 Elsevier Inc. All rights reserved.
Original languageEnglish
Pages (from-to)47-59
Number of pages13
JournalArchives of Biochemistry and Biophysics
Volume463
Issue number1
DOIs
StatePublished - Jul 1 2007

ASJC Scopus Subject Areas

  • Biophysics
  • Biochemistry
  • Molecular Biology

Keywords

  • Apoptosis
  • JNK
  • Osteoclasts
  • Protein-tyrosine phosphatase
  • Survival
  • c-Src
  • Cell Survival/physiology
  • Mitogen-Activated Protein Kinase 9/physiology
  • NF-kappa B/physiology
  • Proto-Oncogene Proteins pp60(c-src)/physiology
  • Protein Tyrosine Phosphatases/physiology
  • Bone Resorption/physiopathology
  • Animals
  • Apoptosis/physiology
  • Phosphotyrosine/metabolism
  • Cell Differentiation
  • Mice
  • RNA, Small Interfering/pharmacology
  • Osteoclasts/physiology

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