MicroRNA expression profiling of human bone marrow mesenchymal stem cells during osteogenic differentiation reveals Osterix
regulation by miR-31.
Runx2 regulates the expression of bone-related proteins such as osteocalcin, osteopontin, as well as receptor activator of nuclear factor kappa-B ligand (RANKL), and alkaline phosphatase (ALP). Osterix
is located downstream of Runx2, and its main role is to increase the expression of osteopontin and ALP. Thus, VSMCs undergo phenotypic transformation and downregulation of expression of the contractile proteins smooth muscle (SM) 22 and alpha-smooth muscle actin (a-SMA).
Roehl, "Expression of osterix
is regulated by FGF and Wnt/[beta]-catenin signalling during osteoblast differentiation," PLoS ONE, vol.
Runx2 and Osterix
are key transcription factors in osteogenic differentiation.
hMSC did not express osterix
(transcription factor) or osteopontin (extracellular matrix protein) at the start of the experiment.
To verify osteogenic differentiation of AD-MSCs after 21 days of cultivation in osteogenic medium, we performed relative quantification of gene transcripts of osterix
(OSX), bone sialoprotein (BSP), and osteocalcin (OC) by real time RT-PCR using the [2.sup.-delta delta CT] method.
Este medio de cultivo permite sintesis de colageno tipo I, formacion de moleculas inductoras y senalizadores para formacion de minerales de hidroxiapatita, expresando marcadores diferenciadores como Osterix
, Runx2, osteocalcina y sialoproteina osea.
For immunohistochemistry, primary antibodies against osterix
(ab22552, Abcam UK, 1: 80, no antigen retrieval) and CD31 (ab32457, Abcam UK, 1:50, heat enhanced antigen retrieval using a pressure cooker) were used.
Osteoblasts responsible for bone formation are derived from mesenchymal stem cells expressing transcription factors runt-related factor 2 and osterix
. Osteoclasts in command of bone resorption are derived from haematopoietic stem cells and they expressed unique markers such as calcitonin receptor (CTR), tartrateresistant acid phosphatase (TRAP), and cathepsin-K (CTSK).
The expression levels of osteogenic markers including ALP, OPN, and Osterix
as well as Alizarin Red S staining intensity were significantly increased after in vitro induction of osteogenic differentiation (Figures 1(a) and 1(b)).
Tambien se ha descrito la presencia del gen Osterix
(Osx) como un factor necesario en la osificacion y mineralizacion (Kierszenbaum & Tres; Glynn et al., 2013; Carlson).
According to the results of qRT-PCR, mRNA expression of runt-related transcription factor 2 (Runx2) and Osterix
gene, which are characteristic early markers of osteogenesis, was hindered by GC treatment (Figure 3(a)).