Effect of excess iron culturing on the proliferation and osteogenic differentiation of rat bone mesenchymal stem cells

Objective To investigate the proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs) in the culture with excess iron. Methods Four-week old female Sprague-Dawley (SD) rats were used for BMSCs isolation from bone marrow. BMSCs were identified by flow cytometry and exposed to ammonium iron citrate (FAC) (50, 100 and 200 μmol/L) under osteogenic medium for 1 to 2 weeks. The proliferation and differentiation of BMSCs were analyzed by cell counting kit-8 (CCK-8), Alizarin Red S staining and real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) tests. Results The proliferation activity of BMSCs decreased with the increase of FAC concentration. The formation of calcium nodules decreased with the increase of FAC concentration (P=0.000). The expression of osteogenic differentiation genes runt related transcription factor-2 (Runx2) decreased with the increase of FAC concentration (sham group: 1.000±0.229; 100 μmol/L FAC group: 0.198±0.044; 200 μmol/L FAC group: 0.149±0.009, P=0.001). The mRNA expression of ALP decreased with the increase of FAC concentration (sham group: 0.980±0.063; 50 μmol/L FAC group: 0.018±0.001; 100 μmol/L FAC group: 0.014±0.002; 200 μmol/L FAC group: 0.008±0.001, P=0.001). The mRNA expression of OPN decreased with the increase of FAC concentration (sham group: 0.999±0.001; 50 μmol/L FAC group: 0.170±0.072; 100 μmol/L FAC group: 0.142±0.008; 200 μmol/L FAC group: 0.117±0.028, P=0.003). Conclusion The ammonium iron citrate significantly inhibit the proliferation of rat BMSCs, and simultaneously suppress osteogenic differentiation of rat BMSCs dose-dependently. Key words: Bone marrow mesenchymal stem cells; Iron citrate; Osteogenic differentiation; Rat