Genetic expression and functional characterization of the RUNX2 gene in human adult bone marrow mesenchymal stem cells

Abstract

ABSTRACT. Past studies have revealed the critical role of runt-related transcription factor 2 (RUNX2) in the proliferation and differentiation of mesenchymal stem cells (MSCs). This study therefore aimed to investigate the expression profile of the RUNX2 gene in human bone marrow MSCs and its biological characteristics. Bone marrow MSCs were separated from 12 patients who had received hip joint replacement surgery. After purification and culture, the MSCs were subjected to the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, the alkaline phosphatase assay, reverse transcription polymerase chain reaction, and RUNX2 protein quantification. The cell growth curve, staining images, and information on the membrane antigens and the levels of RUNX2 mRNA and protein were obtained based on the results. The growth curve showed, after a 2-day lag period, cultured MSCs entered into the log phase between d3 (Day 3) and d6, when they reached a plateau. Flow cytometry data suggested 94.38% of MSCs were CD90-positive, while only 3.99 and 1.71% of total cells were positive for CD35 and CD45, respectively. With the elongated induction period, cultured MSCs were polygonal in shape. After a 14-day induction, cell fusion occurred in the center of the cell nodule accompanied by the disappearance of cellular structure to form the calcium nodule, which was stained red. There was also a statistically significant increase in the level of RUNX2 protein at d7 and d14. An osteogenic medium is required for the differentiation of adult MSCs, which is also under RUNX2 regulation. These findings are potentially valuable for clinical practice.

Therapeutic abortion and ectopic pregnancy: alternative sources for fetal stem cell research and therapy in Iran as an Islamic country

“…The population of MSCs in fetal tissues is significantly greater than adult tissues. For example, in a newborn marrow, there is one MSC among 10,000 nucleated cells while it is one per 250,000 adult bone marrow (Caplan 1994;Baker et al 2015;Zhang and Li 2015).…”

Reciprocal Effect of Environmental Stimuli to Regulate the Adipogenesis and Osteogenesis Fate Decision in Bone Marrow-Derived Mesenchymal Stem Cells (BM-MSCs)

“…Upregulation of PPARγ activity promotes bone marrow adiposity, while its downregulation is associated with bone mass elevation. Activation of RUNX2 and BMPs, on the other hand, biases BM-MSCs toward osteogenic lineage while suppressing differentiation of BM-MSCs toward adipogenic lineage [3,4,8,14].…”