Chidamide Promotes Osteogenic Differentiation of Bone Marrow Mesenchymal Stromal Cells from Patients with Myelodysplastic Syndromes

Abstract

To explore the effects and mechanisms of chidamide on the osteogenic differentiation of bone marrow mesenchymal stromal cells (MSC) from myelodysplastic syndromes (MDS). MSC were isolated and cultured from bone marrow of MDS patients and healthy donors. CCK-8 assay was used to detect the effects of chidamide on the proliferation of MSC. The effects of chidamide on the activity of histone deacetylase (HDAC) in MSC was measured by a fluorescence assay kit and Western blot. Alkaline phosphatase (ALP) activity was detected on day 3 and calcium nodule formation was observed by Alizarin Red staining on day 21 after osteogenic differentiation. The expression of early and late osteogenic genes was detected on day 7 and day 21, respectively. RT-PCR and Western blot were used to detect the effects of chidamide on mRNA and protein expression of RUNX2 which is the key transcription factor during osteogenesis. As the concentration of chidamide increased, the proliferation of MSC was inhibited. However, at a low concentration (1 μmol/L), chidamide had no significant inhibitory effect on MSC proliferation but significantly inhibited HDAC activity. In MSC from both MDS patients and healthy donors, chidamide (1 μmol/L) significantly increased ALP activity, calcium nodule formation, thereby mRNA expression of osteogenic genes, and restored the reduced osteogenic differentiation ability of MDS-MSC compared to normal MSC. Mechanistic studies showed that the osteogenic-promoting effect of chidamide may be related to the upregulation of RUNX2 . Chidamide can inhibit HDAC activity in MSC, upregulate the expression of the osteogenic transcription factor RUNX2, and promote the osteogenic differentiation of MDS-MSC.