Immunophenotypic analysis of human articular chondrocytes: changes in surface markers associated with cell expansion in monolayer culture.

Cartilage tissue engineering relies on in vitro expansion of primary chondrocytes. Monolayer is the chosen culture model for chondrocyte expansion because in this system the proliferative capacity of chondrocytes is substantially higher compared to non-adherent systems. However, human articular chondrocytes (HACs) cultured as monolayers undergo changes in phenotype and gene expression known as "dedifferentiation.

A suppressive effect of the adenovirus 5 protein E1B 55K on apoptosis induced by IL-3 deprivation and gamma-irradiation.

The murine IL-3-dependent myeloid cell line 32D undergoes a rapid death when deprived of interleukin-3 (IL-3), a process that is suppressed or delayed by the constitutive expression of Bcl-2 or the Bcl-2-related Bcl-xL survival protein. The adenovirus type 5 E1B region encodes an E1B 55K protein, that has been reported to bind and inactivate the p53 protein that plays an important role in the induction of apoptosis. In order to explore the potential effect of the E1B 55K protein on IL-3 deprival-induced cell death, we have established 32D cell lines overexpressing the adenovirus E1B 55K protein and compared its ability to modulate the cell death with that of the human Bcl-2 protein.