Mesenchymal stem cells from adipose tissue differentiated in chondrocytes express hyaline cartilage markers.

Lubricin is a proteoglycan synthesized and expressed by articular chondrocytes of the superficial zone. It is known to play an important role in articular joint pathophysiology. This study focused on the isolation, cultivation and characterization of human mesenchymal stem cells (MSCs) from adipose tissue and on their differentiation into chondrocytes. The main aim was to investigate some markers of biomechanical quality of cartilage, such as lubricin, and collagen type I, and II. Adipose tissue is an alternative source for the isolation of multipotent MSCs, which allows them to be obtained by a less invasive method and in larger quantities than from other sources. These cells can be isolated from cosmetic liposuctions in large numbers and easily grown under standard tissue culture conditions. Three-dimensional chondrocytes were assessed by histology and histochemistry. Collagen type I, II and lubricin expression was determined through immunohistochemistry, immunofluorescenc e and Western blot. The results showed that, compared to control cartilage, showing just collagen type I, chondrocytes from MSCs (CD44, CD90 and CD105 positive; CD45, CD14 and CD34 negative) were able to express lubricin, collagen type I, and II, indicative of hyaline cartilage formation. Based on the function of lubricin in the joint cavity and disease and as a potential therapeutic agent, our results suggest that MSCs from adipose tissue are a promising cell source for tissue engineering of cartilage.