Figure 5
From: Identification of Meflin as a Potential Marker for Mesenchymal Stromal Cells
Meflin regulated undifferentiated state of C3H10T1/2 cells and BM-MSCs.
(A) Forced exogenous expression of Meflin suppressed the expression of Sox9 protein in chondrogenic differentiation (left panel) and Runx2 and osteopontin proteins in osteogenic differentiation (right panel) in C3H10T1/2 cells. (B) Forced expression of Meflin, but not Decorin (control), led to the downregulation of basal expression of the Sox9 gene in undifferentiated C3H10T1/2 cells (left panel). In cells that underwent osteogenic differentiation (right panel), Meflin suppressed alkaline phosphatase (ALP) activity and calcium deposit as determined by Alizarin red staining. (C) Meflin-depletion led to the upregulation of the basal expression of Sox9 protein in BM-MSCs (top panel) and C3H10T1/2 cells (lower panel). (D) Meflin-depletion upregulated the activity of the human Sox9 promoter in BM-MSCs, as determined by luciferase reporter assay. *P < 0.05 compared with control. A.U., arbitrary units. (E) qPCR assay showed that Meflin-depletion led to the upregulation of Aggrecan and Collagen IIa, the hallmarks of chondrogenic differentiation, in C3H10T1/2 cells. *P < 0.05 compared with control. (F) No apparent effect of Meflin-depletion on adipogenic differentiation in 3T3-L1 cells. Note that Meflin expression was specifically detected in superconfluent (SC) cells that underwent rapid downregulation by adipogenic differentiation. (G) Schematic illustration of our preliminary hypothesis on the role of Meflin in determining the undifferentiated state of cultured MSCs. Meflin is expressed in undifferentiated MSCs to suppress the induction of Sox9 and Runx2 expression. At present, the role of Meflin in adipogenic differentiation remains undetermined. (H) Gradual decrease of Meflin expression depending on the passage number in BM-MSCs.
