Comparison of CD44 and CD14 Surface Markers in Adipose-Derived Stem Cells and Differentiated Chondrocytes during Chondrogenesis

Nowadays, adipose-derived stem cells (ADSCs) are widely used for cartilage tissue engineering. However, most studies are in the field of scaffolds, growth factors and mechanical stimulation methods. But, few studies have been conducted regarding changes in surface markers during chondrogenesis. Accordingly, this study aimed to assess the changes in surface markers CD14 and CD44 during chondrogenesis.

Human subcutaneous adipose tissue were isolated and cultured from 3 persons influenced by collagenase enzyme and stem cells. The cells of second passage were used for flow cytometry analysis of CD14 and CD44 surface markers. Second passage cells were cultured in alginate scaffolds under the influence of chondrogenic medium. Differentiated cells at the days 7 and 14 were used to evaluate CD14 and CD44 surface markers.

The mean expression of CD44 in ADSCs was 96.8% but CD14 did not expressed in 98.6% of the cells. In stem cells, the mean expression of CD44 differentiated in alginate scaffolds on the day 7 was 96.3%; but on the day 14, it fell to 52.8%. The mean expression of CD14 at the days 7 and 14 was 99.7% and 99.9%, respectively.

Our investigation revealed that the stem cells and differentiated cells at the day 7 express CD44 at high level, but at day 14, the expression of CD44 in differentiated cells is reduced. CD14 is not expressed on stem cells but in differentiated cells is expressed in high level. Due to these changes in surface markers during chondrogenesis, using them can be offered to determine chondrogenesis and to compare differentiated and normal chondrocytes.