Runx1 up-regulates chondrocyte to osteoblast lineage commitment and promotes bone formation by enhancing both chondrogenesis and osteogenesis.

Runx1 up-regulates chondrocyte to osteoblast lineage commitment and promotes bone formation by enhancing both chondrogenesis and osteogenesis. Biochem J. 2020 May 11;: Authors: Tang C, Chen W, Luo Y, Wu J, Zhang Y, McVicar A, McConnell M, Liu Y, Zhou HD, Li YP Abstract One of the fundamental questions in bone biology is where osteoblasts originate and how osteoblast differentiation is regulated. The mechanism underlying which factors regulate chondrocyte to osteoblast lineage commitment remains unknown. Our data showed that Runt-related transcription factor 1 (Runx1) is expressed at different stages of both chondrocyte and osteoblast differentiation. Runx1 chondrocyte-specific knockout (Runx1f/fCol2α1-cre) mice exhibited impaired cartilage formation, decreased bone density, and an osteoporotic phenotype. The expressions of chondrocyte differentiation regulation genes, including Sox9, Ihh, CyclinD1, PTH1R, and hypertrophic chondrocyte marker genes including Col2α1, Runx2, MMP13, Col10α1 in the growth plate were significantly decreased in Runx1f/fCol2α1-cre mice chondrocytes.  Importantly, the expressions of osteoblast differentiation regulation genes including Osx, Runx2, ATF4, and osteoblast marker genes including OCN and OPN were significantly decreased in the osteoblasts of Runx1f/fCol2α1-cre mice.  Notably, our data showed that osteoblast differentiation regulation genes and marker genes are also expressed in chondrocytes ...
Source: The Biochemical Journal - Category: Biochemistry Authors: Tags: Biochem J Source Type: research