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Antiapoptotic molecule Bcl-2 is essential for the anabolic activity of parathyroid hormone in bone

Yuichi Nagase1, Mitsuyasu Iwasawa, Toru Akiyama

  • 1Department of Orthopaedic Surgery, University of Tokyo, Tokyo, Japan.

Annals of the New York Academy of Sciences
|April 16, 2010
PubMed

Insights

The antiapoptotic molecule B-cell lymphoma 2 (Bcl-2) is essential for bone health and parathyroid hormone (PTH) anabolic activity. Loss of Bcl-2 function impairs osteoblast activity, leading to reduced bone mass.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Skeletal Biology

Background:

  • The antiapoptotic protein Bcl-2 regulates mitochondrial integrity and cell survival.
  • Bcl-2 is implicated in skeletal integrity, but its precise role and mechanisms are unclear.
  • Genetic models to study Bcl-2 in adult bone are limited due to early lethality.

Purpose of the Study:

  • To investigate the role of Bcl-2 in bone mass regulation and osteoblast function.
  • To determine if Bcl-2 is required for the anabolic effects of parathyroid hormone (PTH).

Main Methods:

  • Generated and analyzed Bcl-2(-/-)Bim(+/-) mice, which survive to adulthood.
  • Compared bone mass, osteoblast function, and response to PTH in Bcl-2(-/-)Bim(+/-) mice and Bcl-2(+/-)Bim(+/-) littermates.

Main Results:

  • Bcl-2(-/-)Bim(+/-) mice exhibited reduced bone mass compared to controls.
  • Impaired osteoblast function was identified as the cause of decreased bone mass.
  • The anabolic effect of PTH on bone was abolished in Bcl-2(-/-)Bim(+/-) mice.

Conclusions:

  • Bcl-2 is crucial for maintaining bone mass by supporting osteoblast function.
  • Bcl-2 is indispensable for mediating the bone-building effects of PTH.
  • Targeting Bcl-2 may offer therapeutic strategies for bone diseases.

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