Fig. 1

Pharmacological inhibition of CD45-specific phosphatase activity restores the differentiation potential of aged MSCs. A Adipogenic differentiation of young, aged, and PTP inhibitor-treated aged MSCs after Oil Red O staining is depicted. B Absorbance of Oil red O dye eluates from young, aged, and PTP inhibitor-treated aged MSCs in comparison to young counterpart measured at 540 nm is graphically represented. C The panel shows osteoblastic differentiation in young, aged, and PTP inhibitor-treated aged MSCs after alizarin Red staining. D Absorbance of Alizarin Red dye eluates from young, aged, and PTP inhibitor-treated aged MSCs in comparison to young counterpart measured at 570 nm is graphically represented. E Chondrogenic differentiation of young, aged, and PTP inhibitor-treated aged MSCs after Safronin O staining is depicted. Microscopic scoring of Safranin O positive patches is graphically represented on the right-hand side of E. F ALP activity normalized to the DNA content in young, aged, and PTP inhibitor-treated aged MSCs is depicted. G Immunofluorescence staining of young (a), aged (b), and PTP inhibitor-treated aged MSCs (c) with an antibody against PPARG. MFI of PPARG in the nuclear region in the aged MSCs is significantly high as compared to that in the young MSCs, whereas in the PTP inhibitor-treated aged MSCs it is significantly decreased (G d). H Immunofluorescence staining of young, aged, and PTP inhibitor-treated aged MSCs with an antibody against RUNX2 (H a–c). MFI for RUNX2 showed a significant increase in PTP inhibitor-treated aged MSCs than their aged counterparts (H d). Error bars in the graph indicate the standard deviation (SD). Statistical significance shown by *, where *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001, ns not significant. compared to young. I qRT-PCR analysis for the relative expression of Pparg (a), Rankl (b), Runx-2 (c), OPG (d), Alp2 (e), Col2A (f), and Sox9 (g) in young, aged and PTP inhibitor-treated aged MSCs, respectively. Data represent relative expression of transcripts normalized to that of GAPDH and expressed as the Mean ± SEM for three biologically independent experiments (n = 3). For statistical significance, one-way ANOVA followed by Bonferroni post hoc test in Graph pad prism 6 version 6.0 (GraphPad Software Inc, La Jolla, CA) was used. All the data are represented as mean ± SD. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001, ns not significant. MSCs mesenchymal stem cells, PTP protein tyrosine phosphatase, MFI mean fluorescence intensity