Fibroblast growth factor-4 maintains cellular viability while enhancing osteogenic differentiation of stem cell spheroids in part by regulating RUNX2 and BGLAP expression.

ABSTRACT: Fibroblast growth factors (FGFs) are growth factors that were initially identified as proteins that stimulate fibroblast proliferation. The aim of the present study was to examine the effects of FGF-4 on the morphology, cellular viability and osteogenic differentiation of stem cell spheroids. Stem cell spheroids were generated using concave microwells in the presence of FGF-4 at concentrations of 0, 50, 100 and 200 ng/ml. Cellular viability was qualitatively assessed by a fluorometric live/dead assay using a microscope and quantitatively determined by using Cell Counting Kit-8. Furthermore, alkaline phosphatase activity and calcium deposition were determined to assess osteogenic differentiation. Reverse transcription-quantitative PCR (RT-qPCR) was performed to evaluate the mRNA expression levels of Runt-related transcription factor 2 (RUNX2) and bone ?-carboxyglutamate protein (BGLAP). Spheroidal shapes were achieved in the microwells on day 1 and a significant increase in the spheroid diameter was observed in the 200 ng/ml FGF-4 group compared with the control group on day 1 (P<0.05). The results regarding viability using Cell Counting Kit-8 in the presence of FGF-4 at 50, 100 and 200 ng/ml at day 1 were 98.0±2.5, 106.2±17.6 and 99.5±6.0%, respectively, when normalized to the control group (P>0.05). Furthermore, the alkaline phosphatase activity was significantly elevated in the 200 ng/ml group, when compared with the control group. The RT-qPCR results demonstrated that the mRNA expression levels of RUNX2 and BGLAP were significantly increased at 200 ng/ml. Therefore, the present results suggested that the application of FGF-4 maintained cellular viability while enhancing the osteogenic differentiation of stem cell spheroids, at least partially by regulating RUNX2 and BGLAP expression levels.

SUBMITTER: Son J 

PROVIDER: S-EPMC7401302 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature