Figure 1.

Stem cell identification and proliferation and differentiation tests

(A) Cell morphology under a light microscope. Magnification: 40×. Scale bar: 50 μm.

(B) Cell surface markers (CD90, CD105, CD73, CD34, CD45, and HLA-DR) of NPMSCs were detected by flow cytometry.

(C) The cell proliferation rate was measured by CCK-8 assay. The number of cells gradually increased and was significantly higher on day 5 than on days 3 and 1. The value-added rate (CCK-8 signal ratio) was used to assess the number of cells. The value-added rate reached a peak on day 5 and was slightly decreased on day 7; however, the rate remained significantly higher than that on days 1 and 3. Results are presented as the mean ± SD of three independent experiments (∗p<0.05).

(D) Levels of COL 2A1 and ACAN mRNA expression under the normal and MCDM culture conditions were detected by quantitative RT–PCR. Under the MCDM conditions, the levels of COL 2A1 and ACAN mRNA expression were effectively increased. Results are presented as the mean ± SD of three independent experiments (∗∗p<0.01).

(E–G) The protein levels of COL 2A1 and ACAN were analyzed by western blotting (E), and the relative quantitative data (F, G) were calculated. GAPDH was used as an internal control. Results are presented as the mean ± SD of three independent experiments (∗p < 0.05).