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Stimulation of Notch Signaling in Mouse Osteoclast Precursors
08:01

Stimulation of Notch Signaling in Mouse Osteoclast Precursors

Published on: February 28, 2017

Lyn inhibits osteoclast differentiation by interfering with PLCgamma1-mediated Ca2+ signaling

Soo-Hyun Yoon1, Youngkyun Lee, Hyung-Joon Kim

  • 1Department of Cell and Developmental Biology, Seoul National University, Seoul, Republic of Korea.

FEBS Letters
|March 17, 2009
PubMed

Insights

Lyn negatively regulates osteoclastogenesis, the process of bone resorption. Reducing Lyn enhances signaling pathways crucial for osteoclast differentiation, leading to increased bone loss.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Immunology

Background:

  • Osteoclasts are specialized cells derived from macrophages responsible for bone resorption.
  • Osteoclast differentiation is tightly regulated by signaling pathways, including those initiated by the receptor activator of NF-kappaB ligand (RANKL).

Purpose of the Study:

  • To investigate the role of Lyn, a protein tyrosine kinase, in osteoclast differentiation.
  • To elucidate the molecular mechanisms by which Lyn influences RANKL-mediated signaling.

Main Methods:

  • Proteomics analysis to identify proteins affected by osteoclast differentiation factor RANKL.
  • Experimental manipulation of Lyn expression (forced reduction) in osteoclast precursors.
  • Assessment of downstream signaling molecules, including PLCgamma1, intracellular calcium (Ca2+), and NFATc1 activation.
  • In vivo studies using siRNA to inhibit Lyn in mouse calvariae models.

Main Results:

  • Lyn protein levels were found to be down-regulated by RANKL during osteoclast differentiation.
  • Forced reduction of Lyn significantly amplified RANKL-induced signaling, including PLCgamma1 activation, Ca2+ influx, and NFATc1 nuclear translocation.
  • Inhibition of Lyn in vivo resulted in pronounced bone resorption in mouse calvariae.

Conclusions:

  • Lyn acts as a negative regulator of osteoclastogenesis.
  • Lyn interferes with RANKL-induced PLCgamma1-mediated Ca2+ signaling, thereby inhibiting NFATc1 activation and osteoclast differentiation.
  • These findings reveal a novel mechanism for the control of bone resorption by Lyn.

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