Lhx2 regulates bone remodeling in mice by modulating RANKL signaling in osteoclasts

Area of Science:

• Molecular Biology
• Cell Biology
• Bone Biology

Background:

• The LIM homeobox 2 (Lhx2) transcription factor is involved in various cellular processes, including neural induction, morphogenesis, and hematopoiesis.
• Osteoclast differentiation is a critical process in bone remodeling and is implicated in bone diseases.

Purpose of the Study:

• To investigate the role of Lhx2 in osteoclast differentiation.
• To elucidate the molecular mechanisms by which Lhx2 influences osteoclast formation.
• To evaluate the in vivo relevance of Lhx2 in bone homeostasis.

Main Methods:

• Quantitative analysis of Lhx2 expression during receptor activator of nuclear factor-κB ligand (RANKL)-mediated osteoclastogenesis.
• Overexpression studies of Lhx2 in bone marrow-derived monocyte/macrophage lineage cells (BMMs).
• Assessment of nuclear factor of activated T cells c1 (NFATc1) induction and c-Fos interaction with Lhx2.
• Phenotypic analysis of Lhx2 conditional knockout mice.

Main Results:

• Lhx2 expression decreased during RANKL-induced osteoclast differentiation.
• Overexpression of Lhx2 in BMMs inhibited RANKL-induced osteoclast differentiation by suppressing NFATc1 induction.
• Lhx2 interacted with c-Fos, attenuating its DNA-binding ability and inhibiting NFATc1 transactivation.
• Lhx2 conditional knockout mice displayed an osteoporotic bone phenotype with increased in vivo osteoclast formation.

Conclusions:

• Lhx2 functions as a negative regulator of osteoclast formation both in vitro and in vivo.
• The anti-osteoclastogenic activity of Lhx2 suggests its potential as a therapeutic target for bone diseases.
• Understanding Lhx2's role in osteoclastogenesis provides insights into bone disease pathogenesis and treatment strategies.