Fig. 1

Polydeoxyribonucleotide (PDRN) rescued IL-1β-induced inhibition of chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). (A) hBMSCs were treated with different doses (50 and 100 µg/mL) of PDRN or left untreated, and cell viability was determined using the CCK-8 reagent. (B) hBMSCs were treated with vehicle, IL-1β (10 ng/mL) and different doses (50 and 100 µg/mL) of PDRN, and cell viability was determined using the CCK-8 reagent. (C) hBMSCs were treated with different doses (50 and 100 µg/mL) of PDRN or left untreated, and then cultured with chondrogenic differentiation medium for 14 days. Thereafter, protein levels of SOX9 and COL2A1 were investigated by western blot analysis. (D) The western blot images were quantified using ImageJ. (E) hBMSCs were treated with vehicle, IL-1β (10 ng/mL), or IL-1β (10 ng/mL) with PDRN (100 µg/mL) and then subjected to chondrogenic differentiation for 14 days. Thereafter, alcian blue and safranin O staining of hBMSCs was performed. (F) Absorbance quantification of alcian blue and safranin O staining. (G) mRNA levels of chondrogenesis-related genes were analyzed using qRT-PCR; GAPDH used for normalization. (H) Expression levels of SOX9 and COL2A1 were determined using western blot analysis. (I) Densitometry of the protein bands shown in (H), using the ImageJ software. Results are means ± SDs. n = 3; *P < 0.05, **P < 0.01, and ***P < 0.001. (A, B, D, F, G, and I) P-values were determined using a one-way analysis of variance with Bonferroni post hoc tests.