title: COMP-Ang1 promotes chondrogenic and osteogenic differentiation of multipotent mesenchymal stem cells through the Ang1/Tie2 signaling pathway.
abstract: Mesenchymal stem cells (MSCs) are pleiotrophic cells that differentiate to chondrocytes, osteoblasts, or adipocytes, as a result of crosstalk by specific signaling pathways including MAPK pathway. Recently cartilage oligomeric matrix protein angiopoietin1 (COMP-Ang1), an Ang1 variant which is more potent than native Ang1 in phosphorylating Tie2 receptor was developed. The Ang1/Tie2 signaling system not only plays a pivotal role in vessel growth, remodeling, and maturation, but also protective and recruit effect on MSCs. Thus, the aim of the present study was to investigate the differentiate effect of Ang1/Tie2 signaling on MSCs in the presence of chondrogenic, osteogenic and adipogenic induction medium, and to determine the possible mechanisms. Our results clearly demonstrated that MSCs cultured in each induction medium with COMP-Ang1 revealed strongly chondrogenic and osteogenic morphological change (3.5- and 2-fold, respectively) as well as up-regulate each gene, except for adipogenic differentiation. Accordingly, we found that phosphorylation of Tie2 expression lead to phosphorylation of p38 and AKT and then accelerating each differentiation of MSCs to chondrocytes and osteoblasts. Therefore, our findings suggest that COMP-Ang1 present a portal to promote MSCs differentiation to chondrocytes and osteoblasts through Ang1/Tie2 signaling pathway and provide insights into novel therapies for bone diseases.
authors.affiliation: Department of Laboratory Animal Medicine, College of Veterinary Medicine, Jeonju, 561-156, Republic of Korea.
authors.forename: Sokho
authors.initials: S
authors.lastname: Kim
authors.forename: Jeong-Chae
authors.initials: JC
authors.lastname: Lee
authors.forename: Eui-Sic
authors.initials: ES
authors.lastname: Cho
authors.forename: Jungkee
authors.initials: J
authors.lastname: Kwon
mesh_terms: D050156:Adipogenesis / Q000187:drug effects; D042683:Angiopoietin-1 / Q000502:physiology*; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D020219:Chondrogenesis / Q000187:drug effects*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects*; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D051057:Proto-Oncogene Proteins c-akt / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D042787:Receptor, TIE-2 / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000494:pharmacology*; D015398:Signal Transduction / Q000502:physiology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000502:physiology
chemical_list: D042683:Angiopoietin-1; C515576:COMP-Ang1 fusion protein; D011993:Recombinant Fusion Proteins; D019869:Phosphatidylinositol 3-Kinases; D042787:Receptor, TIE-2; D051057:Proto-Oncogene Proteins c-akt; D048051:p38 Mitogen-Activated Protein Kinases
keywords: COMP-Ang1; MAPK; MSCs; Tie2; differentiation