Blocking circadian clock factor Rev-erbα inhibits growth plate chondrogenesis via up-regulating MAPK-ERK1/2 pathway

Area of Science:

• Endocrinology
• Developmental Biology
• Molecular Biology

Background:

• Circadian clock genes regulate various physiological processes.
• Rev-erbα (NR1D1) is implicated in cartilage metabolism.
• The role of Rev-erbα in growth plate chondrogenesis is not well understood.

Purpose of the Study:

• To investigate the function of Rev-erbα in growth plate development and chondrogenesis.
• To elucidate the underlying molecular mechanisms.

Main Methods:

• Spatiotemporal expression analysis of Rev-erbα in growth plates.
• Ex vivo studies using Rev-erbα antagonist SR8278 on metatarsal bones.
• In vitro studies involving primary chondrocyte culture and Rev-erbα knockdown.
• Western blot analysis to assess MAPK-ERK1/2 pathway activation.

Main Results:

• Rev-erbα is expressed in a spatiotemporal pattern within the growth plate.
• SR8278 treatment reduced longitudinal bone elongation, growth plate height, and hypertrophic zone.
• Rev-erbα inhibition suppressed chondrocyte proliferation and hypertrophic differentiation.
• Rev-erbα knockdown upregulated the MAPK-ERK1/2 pathway.
• Inhibition of MAPK-ERK1/2 partially rescued SR8278-induced growth plate defects.

Conclusions:

• Rev-erbα is essential for normal growth plate chondrogenesis.
• Rev-erbα influences chondrocyte proliferation and differentiation.
• The MAPK-ERK1/2 pathway is involved in Rev-erbα-mediated growth plate development.