From mesenchymal stem cells to biomineralisation

The development of the skeleton represents a pioneering step during evolution essential for the success of vertebrates. The skeleton mediates motility, protects the nervous system as well as vital organs, and acts in the adult as the site of haematopoiesis crucial for an efficient immune defence. To fulfill all these functions soft tissue has to be transformed into calcified, stiff and stable skeletal elements. This highly coordinated developmental process called endochondral ossification mediates the transformation of a mesenchymal stem cell into a specialized calcifying cell and finally forms the skeleton. However, in the adult the same process can result in severe chronic diseases like osteoarthritis and atherosclerosis, which affects most people in their life - they just have to get old enough (L.Fischer).

We want to define mechanisms that initiate calcification in both in normal and pathological biomineralization. What mechanisms are initiating biomineralization of cartilage? What underlying cellular programs are driving a mesenchymal stem cell into hypertrophy and calcification and do these processes represent a common mechanism in skeletal and pathological calcification (ostheoarthritis, atherosclerosis)?

To address these questions we are currently focusing on two strategies:

1. Studying biomineralization in lack of function mouse models
   
2. Using mesenchymal stem cell systems of chondrogenic and vascular origin to analyze their differentiation and calcification capabilities.