Fig. 1

Culture, identification, and endothelial differentiation of PMSCs. A PMSCs morphology was detected by an inverted microscope. Three and seven days after isolation, small fibroblast-like MSC colonies were visible. Cell culture was enriched in a population of cells characterized by a fibroblast-like spike appearance. Scale bar: 200 μm. B Successfully differentiated PMSCs were stained with Alizarin Red for osteogenic differentiation, Oil Red O for adipocytes, and Alcian blue, in which red calcium nodules, orange lipid droplets, and blue cartilage could be observed. Scale bar: 200 μm. C PMSCs surface markers. Flow cytometry demonstrated that the cells expressed CD44, CD73, CD90, and CD105 but not CD31, CD34, and CD45. D, E Identification of induced PMSCs by flow cytometry and quantitative analyses were also performed. The fractions of CD31⁺ CD34⁺ double-positive cells were about 10%, 50%, 60%, and 70%, at 3, 7, 10, and 14 days, respectively. F–H Dil-Ac-LDL uptake assay was to identify the induced PMSCs through immunofluorescence and flow cytometry, and quantitative analyses were also performed. Scale bar: 100 μm. I Morphological characteristics of cells after cultivated in the inducing and non-inducing groups. The cells developed into short spindle shapes in the inducing group. The cells in the non-inducing medium retained the typical spindle-shaped morphology. Scale bar: 200 μm. J Immunofluorescence staining of vWF and VEGFR-2 was performed in different groups. Scale bar: 100 μm. Data are shown as the mean ± SD from three independent experiments and the representative result is shown. *P < 0.05, **P < 0.01, ***P < 0.001 by Student’s t test. SD: standard deviation. EC-differentiated PMSC: the induced PMSCs group for endothelial differentiation