Fig 2: TNFa does not significantly affect proliferation and extracellular molecule expression in OA chondrocytes. (A) CD34, CD44, CD59, CD74, CD90, CD105, CD146 and CD164 surface markers of chondrocytes were evaluated by flow cytometry. (B) Chondrocytes were exposed to TNFa and assessed by water-soluble tetrazolium salt assay. n=5, one-way ANOVA with Tukey's post hoc test. (C) Chondrocytes were exposed to 25 ng/ml TNFa for 24 h and assessed by flow cytometry. IgG was used as a control. OA, osteoarthritis; TNFa, tumor necrosis factor a; ACAN, aggrecan; SOX9, SRY-box transcription factor 9.

Fig 3: Characterization of GMSCs. (A) Morphology of primary GMSCs. (B) Expression of green fluorescent protein in transfected GMSCs. (C) CFU-F assay at day 14 and colonies were stained with 1% crystal violet. (D) Cell colonies formed in a CFU-F assay. (E) Lipid droplets were observed after cells were cultured under adipogenic conditions for 2 weeks. (F) Lipid droplets were not detected in the control group following Oil Red O staining. (G) Mineralized nodules were observed after cells were cultured under osteogenic conditions for 4 weeks following Alizarin Red S staining. (H) Mineralized nodules were not detected in the control group following Alizarin Red S staining. Scale bars, 200 µm. (I) Flow cytometry analysis demonstrated GMSCs were positive for CD73, CD90 and CD105 and negative for CD45. GMSCs, gingival mesenchymal stem cells; CFU-F, colony forming units-fibroblast; FITC, fluorescein isothiocyanate; PE, phycoerythrin.

Fig 4: Characterization of control-MSCs and IPF-MSCs. a Surface markers of control-MSCs and IPF-MSCs were evaluated by flow cytometry. Both control-MSCs and IPF-MSCs expressed CD73, CD90, and CD105 but not CD34 or CD45. b Adipogenic differentiation evaluated by Oil Red staining and quantification of adipogenic efficiency in control-MSCs and IPF-MSCs. c Osteogenic differentiation determined by Alizarin red staining and quantification of osteogenic efficiency in control-MSCs and IPF-MSCs. d Chondrogenic differentiation determined by Alcian blue staining and quantification of chondrogenic efficiency in control-MSCs and IPF-MSCs. All data were obtained from at least three independent experiments and each error bar represents the mean ± SEM. Scale bar = 200 µm. ***p < 0 .001

Fig 5: Traits of the GMSCs. (A) Morphology of primary GMSCs. (B) Expression of GFP in the transfected GMSCs. (C) CFU-F assay at day 14 and colonies were stained by 1% crystal violet. (D) Cell colonies formed in the CFU-F assay. (E) Lipid droplets were observed in cells cultured under adipogenic condition for 2 weeks after Oil Red O staining. (F) Lipid droplets were not detected in the control group. (G) Mineralized nodules were observed in cells cultured under osteogenic condition for 4 weeks after Alizarin Red S staining. (H) Mineralized nodules were not detected in the control group. (I) Flow cytometric analysis demonstrated that GMSCs were positive for CD73, CD90, CD105 and STRO-1 and negative for CD31 and CD45. GMSCs, gingiva-derived mesenchymal stem cells; GFP, green fluorescent protein.