Long Term Exposure to Myrtucommulone-A Changes CD105 Expression and Differentiation Potential of Mesenchymal Stem Cells.

Mesenchymal stem cells (MSCs) represent a heterogeneous group of multipotent stem cells that could be found in various somatic tissues. MSCs are defined by molecular and functional features including spindle-shape morphology, adherence to plastic surfaces, expression of specific surface markers and differentiation potential to chondrocytes, adipocytes and osteocytes. The surface markers were proposed to affect the differentiation potential of MSCs by a limited number of studies. Endoglin (CD105) is defined to be a significant marker for osteogenic and chondrogenic differentiation ability of MSCs. Low CD105 expression is associated with increased osteogenic potential while high CD105 expression is correlated with strong chondrogenic potential. Myrtucommulone-A (MC-A) is an active compound with various biological effects on different cell types but its effect on MSC differentiation has not been described yet. In the present study we aimed at investigating the long-term effects of MC-A on hMSCs. MC-A-treatment reduced CD105 expression in distinct human mesenchymal stem cell (hMSC) lines and gave rise to CD105 population but did not change CD44, CD90 or CD73 expression. The decrease in CD105 expression reduced the chondrogenic potential of hMSCs subsequently while adipogenic or osteogenic differentiation was not affected dramatically. MC-A-treatment also suppressed the NF-κB p65 activation which might be responsible for the reduced chondrogenic potential. Our findings suggest that MC-A could be used to enrich CD105 hMSCs without the need for cell sorting or changing culture conditions which could be utilised in targeted differentiation studies.