Tyrosine kinase receptor c-ros-oncogene 1 mediates TWIST-1 regulation of human mesenchymal stem cell lineage commitment.
The TWIST-1 gene encodes a basic helix-loop-helix (bHLH) transcription factor important in mediating skeletal and head mesodermal tissue development. Bone marrow-derived mesenchymal stem/stromal cells (BMSC), express high levels of TWIST-1, which is down regulated during ex vivo expansion. Cultured BMSC over-expressing TWIST-1 display decreased capacity for osteogenic differentiation and an enhanced capacity to undergo adipogenesis, suggesting that TWIST-1 is a mediator of lineage commitment. However, little is known regarding the mechanism(s) by which TWIST-1 mediates cell fate determination. In this study, microarray analysis was used to identify a novel downstream TWIST-1 target, tyrosine kinase receptor c-ros-oncogene 1 (C-ROS-1), which was down regulated in TWIST-1 over-expressing BMSC. Chromatin immunoprecipitation analysis showed that TWIST-1 directly bound to two E-box binding sites on the proximal C-ROS-1 promoter. Knock-down of C-ROS-1 in human BMSC and cranial bone cells resulted in a decreased capacity for osteogenic differentiation in vitro. Conversely, suppression of C-ROS-1 in BMSC resulted in an enhanced capacity to undergo adipogenesis. Furthermore, reduced C-ROS-1 levels led to activation of different components of the PI3K/AKT/mTORC1 signalling pathway during osteogenic and adipogenic differentiation. Collectively, these data suggest that C-ROS-1 is involved in BMSC fate switching between osteogenesis and adipogenesis, mediated via PI3K/AKT/mTORC1 signalling.
Mesenchymal Stem Cell Laboratory, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia; Cancer Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.
Esther
E
Camp
Australian Craniofacial Unit, Women's and Children's Hospital, North Adelaide, South Australia, Australia.
Peter J
PJ
Anderson
Cancer Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia; Myeloma Research Laboratory, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia.
Andrew C W
ACW
Zannettino
Mesenchymal Stem Cell Laboratory, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia; Cancer Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia. Electronic address: stan.gronthos@adelaide.edu.au.
Stan
S
Gronthos
D050156:Adipogenesis / Q000235:genetics; D000328:Adult; D019070:Cell Lineage; D015536:Down-Regulation / Q000235:genetics; D055785:Gene Knockdown Techniques; D006801:Humans; D000076222:Mechanistic Target of Rapamycin Complex 1 / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D010012:Osteogenesis / Q000235:genetics; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D012886:Skull / Q000166:cytology; D051879:Twist-Related Protein 1 / Q000378:metabolism*
D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; C103173:TWIST1 protein, human; D051879:Twist-Related Protein 1; D019869:Phosphatidylinositol 3-Kinases; D011505:Protein-Tyrosine Kinases; C062333:ROS1 protein, human; D000076222:Mechanistic Target of Rapamycin Complex 1; D051057:Proto-Oncogene Proteins c-akt
Bone marrow stromal cells; C-ROS-1; Mesenchymal stem cells; PI3K/AKT/mTOR signalling; TWIST-1