Adipogenic potential of stem cells derived from rabbit subcutaneous and visceral adipose tissue in vitro.

Rabbits are considered as appropriate animal models to study some obesity-associated abnormalities because of the similarity of their blood lipid profile and metabolism to humans. The current study was focused on comparison of adipose differentiation ability in rabbit adipose-derived stem cells (ADSC) in vitro. Subcutaneous and visceral stromal vascular fractions (SVF) were isolated from three 28-d-old New Zealand rabbits by collagenase digestion. Supernatants from both isolates were collected 24 h after the initial plating. On the fourth passage, all isolated cell types undergo triplicate adipogenic induction. The adipose induction potential was calculated as percentage of increasing optical density (OD) values. The data revealed that with increasing the number of induction cycles, the induction tendency in visceral ADSC decreased in contrast to the subcutaneous ones. Although the supernatants did not reach induction levels of their relevant precursors, they follow the same pattern in both subcutaneous and visceral ADSC. All cell types successfully passed osteogenic and chondrogenic differentiation. In conclusion, the best adipose induction ability was observed in directly plated subcutaneous cell population. The increase of induction numbers depressed adipose induction ability in cell populations derived from visceral fat depots.

Biological properties of allogenic articular chondrocytes on the surface of bovine cartilage explants in vitro.

Bovine cartilage explants were co-cultured with or without allogenic chondrocytes for 4 weeks. The attachment of the applied chondrocytes to cartilage after labelling with fluorescence was assessed using a confocal laser microscope. Morphological changes and the production of extracellular matrix (ECM) of co-cultured chondrocytes on intact and damaged surfaces of cartilage were evaluated by histological and immunohistochemical methods. Co-cultured chondrocytes attached to and proliferated on the intact and damaged areas of cartilage, and a new layer was created there. The defects were also filled with ECM produced by the co-cultured chondrocytes. Glycosaminoglycans and collagen type II were detected in the newly formed ECM, and large numbers of rounded chondrocytes were observed at primitive lacunae in this matrix at 4 weeks of culture. The results suggest that chondrocytes have the ability to attach to, to proliferate on and to establish a new matrix on the intact and damaged surfaces of cartilage explants.