Phospho-protein array of Healthy-MSCs and OA-MSCs during osteogenesis.

<p>(a) Phospho-protein array of MSCs from two healthy (FS28 and FS29) and two OA individuals (CX1 and CX25) during osteogenic differentiation measured at days 1, 10 and 21. Image shows the phosphorylation status of 28 spotted duplicates for receptor tyrosine kinases (RTKs) and 11 signaling nodes where signal generated at each array spot is proportional to the amount of phospho-protein bound by each capture antibody. (b) Representation of the averaged pixel intensity values for the most prominent signals after background correction and further transformation as relative signal compared with the maximum signal of 10 positive controls (darker spots). 1: Ret Pan-Tyr. 2: Pan-Tyr ALK. 3: Akt/PKB/Rac at Thr308. 4: Akt/PKB/Rac at Ser473, 5. p44/42 MAPK (ERK1/2) at Thr202/Tyr204. 6: S6 Ribosomal Protein at Ser235/236 and 7: c-Abl (Pan-Tyr). (c) Significant differences in signal intensities between Healthy and OA MSCs were detected for phosphorylation signals of Ret Pan-Tyr at day 10 and p44/42 MAPK (ERK1/2) at day 21.