ANALISI DELL’ESPRESSIONE GENICA DI RUNX-2 E DELLADENSITA’ MINERALE OSSEA IN UNA POPOLAZIONEDI GIOVANI E ADULTI SANI

Bone mineral density (BMD) and peak bone mass (PBM) are important determinants of skeletal resistance. The development of bone densitometry improved the possibility of studying BMD and the influence of genetic and environmental factors on bone. Heredity factors are important for BMD and Runx-2 is accepted as a regulator of osteoblasts and bone formation. The aim of our study was to evaluate the behaviour of Runx-2 during skeletal maturity in the healthy young-adult population. We analyzed spine and hip BMD in 153 volunteers, 98 women and 55 men using dual energy x-ray absorptiometry (DXA). In a subgroup of them, a sample of peripheral blood was taken in order to perform gene expression analysis of Runx-2 both in peripheral mesenchimal stem cells (MSCs; 28 subjects) and peripheral mononuclear cells (PBMC; 140 subjects). In our work BMD was comparable in both genders after puberty, while it became higher in men than women during the third and fourth decade. PBM was achieved in the third decade in women and in the fourth in men. More interestingly Runx-2 gene expression highly correlated with BMD in both genders. MSCs and PBMC showed the same gene expression profile of Runx-2. In conclusion PBM is reached earlier in females, BMD becomes higher in men later and BMD and PBM are strictly associated with Runx-2. In addition, PBMC should be considered an important source for gene expression analysis in bone diseases.