Barium Stimulates the Expression of Osteogenic Genes in Human Mesenchymal Stem Cells into Osteoblasts in vitro

Abstract

Objectives: The purpose of this study was to determine the effect of barium on gene expression in differentiation of human mesenchymal stem cells into osteoblasts in vitro. Methods: Human bone marrow stem cells were cultured for 0∼14 days in osteogenic differentiation medium with strontium chloride (SrCl₂) and barium chloride (BaCl₂). Alkaline phosphatase (ALP) activity staining was the method selected for measuring osteoblast differentiation. Total ribonucleic acid (RNA) was extracted after 1, 3, 7, and 14 days, and analysis of runt-related transcription factor 2/core-binding factor alpha 1 (Runx2/Cbfa1), bone morphogenetic protein-2 (BMP-2), and bone sialoprotein (BSP) gene expression was performed by real-time reverse transcriptase (RT)-polymerase chain reaction (PCR). Results: Barium and strontium had a superior enhancing effect on cell proliferation when compared to cells cultured in media without strontium or barium. BaCl2 produced a 2-fold increase in the expression of Runx2/Cbfa1 at 14 days. SrCl₂(0.1∼0.3 mM) produced a 2-fold increase in the expression of Runx2/Cbfa1 at 14 days. Barium produced a 1.5-fold increase in the expression of BMP-2 on days 1 or 3. Expression of BSP was increased 1.5∼1.7- and 2-fold on days 1 and 14 by barium and strontium, respectively. Conclusion: Barium-like strontium is considered one of the important factors in inducing mesenchymal stem cells to differentiate into osteoblasts with further enhancement on bone formation.