Figure 4.

PDGF Signaling in C-AdMSCs and D-AdMSCs

(A) PDGF-BB levels detected in the serum of healthy (C-serum) and diabetic (D-serum) donors by ELISA, showing an increased concentration of PDGF-BB in D-serum. (B) Flow cytometry analysis determining the percentage of AdMSCs expressing PDGFRβ. (C) Quantification of PDGFRβ fluorescence intensity did not reveal significant differences between D-AdMSCs and C-AdMSCs. (D) Representative western blot for PDGFRβ protein levels in AdMSCs. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as an internal control. (E) Densitometry analysis of western blots for PDGFRβ levels. (F) Densitometry analysis of western blots for phosphorylated PDGFRβ levels following PDGF stimulation. (G) Densitometry analysis of western blots for phosphorylated ERK1/2 levels following PDGF stimulation. (H) Densitometry analysis of western blots for phosphorylated SMAD2 levels following PDGF stimulation. (I) Representative western blot showing the expression levels of total and phosphorylated PDGFRβ, ERK1/2 and SMAD2/3 in AdMSCs. GAPDH was used as an internal control. (J) Immunocytochemistry staining for pSMAD2 (red) and TF (green) in AdMSCs. Cell nuclei were stained with Hoechst dye (blue). (K) Quantification of pSMAD2 fluorescence intensity in (J), revealing a significant increase in D-AdMSCs. (L) Quantification of TF fluorescence intensity in (J), revealing a significant increase in D-AdMSCs. Scale bar: 100 μm in (J). Data are represented as mean ± SEM. *p < 0.05, **p < 0.001 (two-tailed t test, two-way ANOVA).