Cell Surface Markers and Exogenously Induced PpIX in Synovial Mesenchymal Stem Cells

To assess the expression of surface markers and the accumulation of protoporphyrin IX in synovial mesenchymal stem cells.
Conclusion:
The expression of majority of the twenty four tested synovial mesenchymal stem cells (SMSC) surface markers varied from low to high levels without statistically significant difference between RA and OA groups. However, the levels of the immunologically active CD47 and the grow factor receptor CD271 were significantly lower, while the expression of the cell membrane zinc-dependent metalloproteinase CD10 was more intensive in the RA group of SMSC. No direct association between the expression levels of the three markers (CD47, CD271 and CD10) and the protoporphyrin IX (PpIX) fluorescence was observed, and comparison of the mean intensities of PpIX fluorescence revealed no statistically significant differences between the RA and OA groups. Noteworthy, some conspicuous distinction in PpIX accumulation was observed in certain specimens within these groups at initial hours of incubation with the lower (0.1mM) 5-ALA concentration, suggesting possibilities of this method application for the characterization of individual SMSC populations. Samples of synovium were obtained as postoperative tissues during articular replacement surgery from patients with osteoarthritis (OA group, n = 6) and rheumatoid arthritis (RA group, n = 5). The specimens of patients with OA were collected from the knee joint and those of patients with RA – from the small joints of the hand. The specimens of patients with OA were used as a control group.