title: Higher BMP receptor expression and BMP-2-induced osteogenic differentiation in tendon-derived stem cells compared with bone-marrow-derived mesenchymal stem cells.
abstract: OBJECTIVE
  Surgical reattachment of tendon to bone often fails due to regeneration failure of the specialised tendon-bone junction (TBJ). The use of mesenchymal stem cells for TBJ regeneration has been reported with promising results. Tendon-derived stem cells (TDSCs) with high proliferative and multi-lineage differentiation potential have been isolated. As stem cells residing in tendons, TDSCs can be considered a new cell source for TBJ repair. Bone morphogenic protein 2 (BMP-2) is a potent osteogenic factor with roles in normal bone healing and pathological ectopic bone formation in soft tissues. The use of BMP-2 to promote TBJ repair has been well reported. This study aimed to compare TDSCs to the gold standard bone-marrow-derived mesenchymal stem cells (BMSCs) with respect to osteogenic response to BMP-2 in vitro.
  
  
  METHODS
  The clonogenicity and multi-differentiation potential of TDSCs and BMSCs were identified by colony-forming-unit assay, osteogenic, adipogenic and chondrogenic differentiation assays. Their osteogenic response to BMP-2 in vitro was examined by alkaline phosphatase (ALP) cytochemical staining, ALP activity assay and Alizarin red S staining of calcium nodule formation. Messenger RNA (mRNA) and BMP receptor (types IA, IB and II) protein expression were examined by quantitative real-time reverse-transcriptase polymerase chain reaction (qRT-PCR) and Western blotting.
  
  
  RESULTS
  Our results showed that both TDSCs and BMSCs exhibited stem cell properties, including clonogenicity and multi-differentiation potential. TDSCs expressed higher mRNA and protein levels of BMP receptors IA, IB and II. They also exhibited higher osteogenic differentiation with and without BMP-2 stimulation compared with BMSCs.
  
  
  CONCLUSIONS
  TDSCs with/without BMP-2 might be an attractive source for TBJ repair compared with BMSCs.
authors: Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Rm. 74025, 5/F, Clinical Sciences Building, Prince of Wales Hospital, Shatin, Hong Kong SAR, China. ruiyunfeng@126.com
authors: Yun Feng
authors: YF
authors: Rui
authors: Pauline Po Yee
authors: PP
authors: Lui
authors: Yuk Wai
authors: YW
authors: Lee
authors: Kai Ming
authors: KM
authors: Chan
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism*; D052004:Bone Morphogenetic Protein Receptors / Q000378:metabolism*; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D015870:Gene Expression; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D010012:Osteogenesis / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D013234:Stem Cells / Q000378:metabolism*; D013710:Tendons / Q000166:cytology* / Q000378:metabolism
chemical_list: D055396:Bone Morphogenetic Protein 2; D052004:Bone Morphogenetic Protein Receptors; D000469:Alkaline Phosphatase