The study of the mechanism in the endochondral ossification of bone mesenchymal stem cells in mice by continued enhanced function of fibroblast growth factor type Ⅱ receptor mutation / 重庆医学

ABSTRACT

Objective To study the role of ERK signal pathway in the endochondral ossification of bone mesenchymal stem cells ,and to explore the mechanism of ERK signal pathway in persistent enhanced FGFR2 function on development of mice BMSCs by a knock‐in mouse model with the FGFR2S252W/+ .Methods Mice with neo‐FGFR2 gain‐of‐function mutation were mated with EII‐Cre mice .The genotype of generation mice were identified by PCR and divided into wild type group and mutant type group ac‐cording to their genotype .6 week‐old mice were sacrificed to receive bone mesenchymal stem cells .The western blot was used to compare the level of P‐ERK and ERK and the RT‐PCR was applied to detect the genes of Col2 ,Col10 ,OC ,OP in chondrogenic dif‐ferentiation medium of BMSCs .Then ,treatment of cultured BMSCs with PD98059 ,compare the changes of genes and utilize the in vitro culture of long bones detect the role of ERK signal pathway in the endochondral ossification by FGFR2 mutant .Results We successfully derive BMSCs from FGFR2S252W/+ mutant mice and found the activity of ERK signal pathway of FGFR2S252W/+ was en‐hanced .After been cultured in chondrogenic differentiation medium ,the expressions of the BMSCs mRNA of Col2 ,Col10 from mu‐tant group were decreased ,while the expressions of OC ,OP were increased .Those OC ,OP genes levels showed an increased treated by PD98059 .Using in vitro culture of long bones ,we found the retardation of total length growth of long bones has been rescued by PD98059 treatment ,suggesting that ERK signal pathways was responsible for the retarded long bone development in FGFRS252W/+mice .Conclusion The results indicate these effects are mediated by the ERK signal pathway .Furthermore ,the retardation of long bones has been recued by PD98059 treatment ,suggesting that ERK signal pathway is responsible for the retarded long bone devel‐opment in FGFR2S252W/+ mice .