title: Transforming growth factor-beta-mediated chondrogenesis of human mesenchymal progenitor cells involves N-cadherin and mitogen-activated protein kinase and Wnt signaling cross-talk.
abstract: The multilineage differentiation potential of adult tissue-derived mesenchymal progenitor cells (MPCs), such as those from bone marrow and trabecular bone, makes them a useful model to investigate mechanisms regulating tissue development and regeneration, such as cartilage. Treatment with transforming growth factor-beta (TGF-beta) superfamily members is a key requirement for the in vitro chondrogenic differentiation of MPCs. Intracellular signaling cascades, particularly those involving the mitogen-activated protein (MAP) kinases, p38, ERK-1, and JNK, have been shown to be activated by TGF-betas in promoting cartilage-specific gene expression. MPC chondrogenesis in vitro also requires high cell seeding density, reminiscent of the cellular condensation requirements for embryonic mesenchymal chondrogenesis, suggesting common chondro-regulatory mechanisms. Prompted by recent findings of the crucial role of the cell adhesion protein, N-cadherin, and Wnt signaling in condensation and chondrogenesis, we have examined here their involvement, as well as MAP kinase signaling, in TGF-beta1-induced chondrogenesis of trabecular bone-derived MPCs. Our results showed that TGF-beta1 treatment initiates and maintains chondrogenesis of MPCs through the differential chondro-stimulatory activities of p38, ERK-1, and to a lesser extent, JNK. This regulation of MPC chondrogenic differentiation by the MAP kinases involves the modulation of N-cadherin expression levels, thereby likely controlling condensation-like cell-cell interaction and progression to chondrogenic differentiation, by the sequential up-regulation and progressive down-regulation of N-cadherin. TGF-beta1-mediated MAP kinase activation also controls WNT-7A gene expression and Wnt-mediated signaling through the intracellular beta-catenin-TCF pathway, which likely regulates N-cadherin expression and subsequent N-cadherin-mediated cell-adhesion complexes during the early steps of MPC chondrogenesis.
authors.affiliation: Cartilage Biology and Orthopaedics Branch, NIAMS, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Tuli
authors.forename: Suraj
authors.initials: S
authors.lastname: Tuli
authors.forename: Sumon
authors.initials: S
authors.lastname: Nandi
authors.forename: Xiaoxue
authors.initials: X
authors.lastname: Huang
authors.forename: Paul A
authors.initials: PA
authors.lastname: Manner
authors.forename: William J
authors.initials: WJ
authors.lastname: Hozack
authors.forename: Keith G
authors.initials: KG
authors.lastname: Danielson
authors.forename: David J
authors.initials: DJ
authors.lastname: Hall
authors.forename: Rocky S
authors.initials: RS
authors.lastname: Tuan
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001842:Bone and Bones / Q000166:cytology; D015820:Cadherins / Q000378:metabolism*; D002448:Cell Adhesion; D002454:Cell Differentiation; D019070:Cell Lineage; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006801:Humans; D007150:Immunohistochemistry; D020935:MAP Kinase Signaling System; D051379:Mice; D008809:Mice, Inbred C3H; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013234:Stem Cells / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D015854:Up-Regulation; D051153:Wnt Proteins; D029961:Zebrafish Proteins; D051176:beta Catenin; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: C495270:CTNNB1 protein, human; C495267:CTNNB1 protein, mouse; D015820:Cadherins; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D011506:Proteins; D011518:Proto-Oncogene Proteins; D013431:Sulfates; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; C092778:WNT7A protein, human; D051153:Wnt Proteins; C490508:Wnt7a protein, mouse; D029961:Zebrafish Proteins; D051176:beta Catenin; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases