The pathogenesis of MDS has not been completely understood, and insufficiency of the hematopoietic microenvironment can be an important factor. MSCs and osteoblasts are key components of the hematopoietic microenvironment. Studying osteoblastic differentiation of MSCs quantitatively may help to understand the pathogenesis of MDS.
38 patients with MDS and 15 normal donors were investigated in this study. Osteoblastic differentiation assays were performed in 16 MDS cases and 8 controls. The expression of osteogenic differentiation markers were measured by real-time PCR. Alkaline phosphatase staining was performed with Alkaline Phosphatase staining kit after 3,7,14 days of incubation. ALP activity was assessed at 3, 7, and 10 days after osteogenic differentiation. Mineralization analysis was performed at 7, 14 and 21 days of osteogenic induction. The areas of mineralization were measured by Image-Pro Plus 6.0 software.
Both MDS-MSCs and normal cells displayed same fibroblast-like morphology and similar antigen expression. The expression level of RUNX2 was significantly decreased in MSCs from MDS, compaired with normal controls, especially in lower-risk MDS. After osteogenic induction, lower-risk MDS showed lower alkaline phosphatase activity, less intense alizarin red S staining, and lower gene expression of osteogenic differentiation markers, however, higher-risk MDS was normal.
We concluded that impaired osteogenic differentiation of MSCs was seen mainly in patients with lower-risk MDS. It may contribute to the ineffective hamatopoiesis of MDS.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.