Subpopulation of Rabbit Articular Chondrocytes Separated by Percoll Density Gradient / 대한정형외과연구학회지

ABSTRACT

Articular chondrocytes have been known to have heterogeneity in articular cartilage. Four layers are generally recognized from the articular surface to the subchondral bone. We have used Percoll density gradients to separate chondrocytes from articular cartilage into distinct subpopulations. Non-fibrillated articular cartilage was obtained from rabbit knee. The cells were carefully layered on the top of the preformed gradient and spun. After centrifugation, we obtained four fractions Fraction A referred boundary between 0% and 10%, fraction B from between 10% and 20%, fraction C from between 20% and 30%, and fraction D from between 40% and 50%. In the A fraction, cells are relatively larger and round in shape, while their nuclei are relatively smaller. In the cytoplasm many lipid droplets were found and rough endoplasmic reticulum were disrupted. In the D fraction, chondrocyte is small, with large nucleus which surrounded by well-developed rough endoplasmic reticulum. The type II collagen proteins were expressed strongly and more proteoglycans synthesized in fractions A and B. And chondrocytes from the fraction D divided more slowly than those from the fractions A, B, and C. We have succeeded in separating chondrocytes from articular cartilage into distinct subpopulations by Percoll density gradients, as well as characterized growth rate, histological appearances and phenotypic expression. This study is the first report about the Percoll density gradients to separate articular chondrocytes.