title: Conversion of human bone marrow-derived mesenchymal stem cells into tendon progenitor cells by ectopic expression of scleraxis.
abstract: Tendons and ligaments (T/L) are dense connective tissues of mesodermal origin. During embryonic development, the tendon-specific cells descend from a sub-set of mesenchymal progenitors condensed in the syndetome, a dorsolateral domain of the sclerotome. These cells are defined by the expression of the transcription factor scleraxis (Scx), which regulates tendon formation and several other characteristic genes, such as collagen type I, decorin, fibromodulin, and tenomodulin (Tnmd). In contrast to other mesenchymal progenitors, the genealogy and biology of the tenogenic lineage is not yet fully understood due to the lack of simple and efficient protocols enabling generation of progenitors in vitro. Here, we investigated whether the expression of Scx can lead to the direct commitment of mesenchymal stem cells (MSCs) into tendon progenitors. First, MSC derived from human bone marrow (hMSC) were lentivirally transduced with FLAG-Scx cDNA to establish 2 clonal cell lines, hMSC-Scx and hMSC-Mock. Subsequent to Scx transduction, hMSC underwent cell morphology change and had significantly reduced proliferation and clonogenicity. Gene expression analysis demonstrated that collagen type I and several T/L-related proteoglycans were upregulated in hMSC-Scx cells. When stimulated toward 3 different mesenchymal lineages, hMSC-Scx cells failed to differentiate into chondrocytes and osteoblasts, whereas adipogenic differentiation still occurred. Lastly, we detected a remarkable upregulation of the T/L differentiation gene Tnmd in hMSC-Scx. From these results, we conclude that Scx delivery results in the direct programming of hMSC into tendon progenitors and that the newly generated hMSC-Scx cell line can be a powerful and useful tool in T/L research.
authors: Experimental Surgery and Regenerative Medicine, Department of Surgery, Ludwig-Maximilians-University (LMU), Munich, Germany.
authors: Paolo
authors: P
authors: Alberton
authors: Cvetan
authors: C
authors: Popov
authors: Markus
authors: M
authors: Prägert
authors: Julia
authors: J
authors: Kohler
authors: Chisa
authors: C
authors: Shukunami
authors: Matthias
authors: M
authors: Schieker
authors: Denitsa
authors: D
authors: Docheva
mesh_terms: D050156:Adipogenesis; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics* / Q000502:physiology; D001854:Bone Marrow Cells / Q000166:cytology*; D002454:Cell Differentiation; D015870:Gene Expression; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D010012:Osteogenesis; D013710:Tendons / Q000166:cytology*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; C093504:SCX protein, human