Laurence Legeai-Mallet et Valérie Cormier-Daire

Genetic disorders of the skeletal system may affect bone and/or cartilage formation from early embryo-fetal development up to childhood. Skeletal development is a temporally-regulated non-linear process orchestrated by a complex genetic network that proceeds via two distinct ossification mechanisms, namely membranous and endochondral. An impairment of this process is responsible for a group of rare and often severe disorders: the osteochondrodysplasia.

Our research aims to contribute to the understanding of the ossification process by:

1. Identifying the molecular basis of osteochondrodyplasias, studying large cohort of patients clinically well characterized through the reference center for skeletal dysplasia.

2. Developing novel therapeutic approaches in bone fragility disorders using human osteoblasts and mouse models.

3. Deciphering proteoglycan synthesis impairment, in chondrodysplasia with multiple dislocations, using cellular and mouse models.

4. Understanding the link between of ADAMTS(L) proteins and the related microfibrillar network, TGFb signaling, and ossification processes, using cellular and mouse models with short and tall stature phenotypes.

5. Elucidating the molecular and cellular mechanisms involved in craniofacial development using Fgfr3 zebrafish lines.

6. Providing an in-depth understanding of FGFR3 signalling in axial skeleton formation.

7. Evaluating the relationships between FGFR3 gain-of-function mutations and signalling pathways involved in primary cilia and in cartilage and bone lineage cells.

8. Conducting pre-clinical studies to test and identify drugs able to correct long bone growth plate, craniofacial and spine anomalies in achondroplasia and hypochondroplasia mouse models.