Effects of azathioprine and infliximab on mesenchymal stem cells derived from the bone marrow of rats in vitro

Mesenchymal stem cell (MSC) transplantation has been demonstrated to be promising in the treatment of inflammatory bowel disease (IBD). Azathioprine (AZA) is widely used in IBD patients. Infliximab, as a representative of biological therapy for IBD, is important in the treatment regimen. In the present study we investigated the effects of AZA and infliximab on the cell proliferation, cell cycle and apoptosis of the MSCs derived from the bone marrow of Sprague-Dawley (SD) rats in vitro in order to provide preliminary data for optimizing the treatment of IBD. MSCs derived from the bone marrow of rats were either cultured in various concentrations of AZA- or infliximab-supplemented medium for 24, 48 and 72 h, respectively. The growth curves of MSCs were obtained. The apoptosis and the cell cycle of the MSCs were analyzed by flow cytometry. AZA decreased the proliferation of MSCs by 66% and increased apoptosis at 0.20 mg/ml for 72 h (P<0.05). The percentage of necrotic cells increased markedly in MSCs treated with 0.30 mg/ml AZA for 72 h (P<0.05). As the exposure time increased, the percentage of MSCs in phase G0-G1 increased and that in phase S decreased in AZA groups exceeding 0.20 mg/ml (P<0.05). However, infliximab had a minimal impact on the cell proliferation, apoptosis and cell cycle of the MSCs. AZA was able to inhibit cell proliferation and induce apoptosis of the MSCs in vitro. Infliximab did not affect the cell proliferation, apoptosis and cell cycle of the MSCs derived from rats.