Bone sialoprotein as a potential key factor implicated in the pathophysiology of osteoarthritis.

Objective: We previously identified an association between bone sialoprotein (BSP) and osteoarthritic (OA) chondrocyte hypertrophy but the precise role of BSP in ostearthritis (OA) has not been extensively studied. This study aimed to confirm the association between BSP and OA chondrocyte hypertrophy, to define its effect on molecules produced by chondrocytes and to analyse its association with cartilage degradation and vascular density at the osteochondral junction.

Method: Human OA chondrocytes were cultivated in order to increase hypertrophic differentiation.

Development and organization of human stratum corneum after birth: electron microscopy isotropy score and immunocytochemical corneocyte labelling as epidermal maturation's markers in infancy.

Background: There is growing evidence for the ongoing structural and functional adaptation of the skin after birth.

Objectives: The aim of this study was the definition of scanning electron microscopy markers of skin maturation in different age groups (birth to adulthood). We propose a semiquantitative score to analyse the maturation of the skin surface and a complementary evaluation of the distribution of corneodesmosin and corneodesmosomes.

Consequences of chondrocyte hypertrophy on osteoarthritic cartilage: potential effect on angiogenesis.

Objective: The aim of this study was to investigate the link between the hypertrophic phenotype of chondrocytes and angiogenesis in osteoarthritis (OA) and more particularly to demonstrate that OA hypertrophic chondrocytes potentially express a phenotype promoting angiogenesis through the expression of factors controlling endothelial cells migration, invasion and adhesion.

Method: Human OA chondrocytes were cultivated in alginate beads in medium supplemented with 10% fetal bovine serum (FBS) to induce chondrocyte hypertrophy. The hypertrophic phenotype was characterized throughout 28 days of culture by measuring the expression of specific genes and by a microscopic observation of cellular morphology.