Effects of epidermal growth factor receptor on endochondral ossification and recruitment of osteoclasts in mice / 吉林大学学报(医学版)

ABSTRACT

Objective To determine the role of epidermal growth factor receptor(EGFR) signaling in endochondral ossification.Methods Long bones,from EGFR knockout mice(EGFR-/-),wild type(EGFR+/+) and(or) heterozygous mice(EGFR+/-) were collected and Trichrome Masson staining,in situ hybridization and tartrate-resistant acid phosphatase(TRAP) staining were used to observe endochondral ossification and recruitment of osteoclasts;Osteoclast formation was observed by addition of EGFR tyrosine kinase inhibitor AG1478 to the cultured osteoclasts from bone marrow cells.Results Due to the same phenotype of EGFR+/+ and EGFR+/-,they were regarded as EGFR+/+ in our study.EGFR deficiency caused delayed primary endochondral ossification of cartilage anlage and delayed osteoclast recruitment.The hypertrophic cartilage area in EGFR-/-mice was about 5 times longer than that in EGFR+/+ mice.There was different distribution of MMP-9 between EGFR+/+ and EGFR-/-in E16.5,but there was no difference about the quantity of MMP-9 in osteoclasts between EGFR-/-and EGFR+/+.However,inhibition of EGFR signaling with AG1478 significantly decreased osteoclast formation compared with control group with DMSO(P