title: Chondrogenic differentiation of mesenchymal progenitor cells encapsulated in ultrahigh-viscosity alginate.
abstract: One major problem of current cartilage repair techniques is that three-dimensional encapsulated mesenchymal progenitor cells frequently differentiate into hypertrophic cells that express type X collagen and osteogenic marker genes. Studies on wild-type cells of murine mesenchymal C3H10T1/2 progenitor cells as well as on cells transfected with cDNA encoding for bone morphogenetic protein (BMP)-2 or -4 in alginate revealed that the formation of markers for osteogenesis and chondrogenic hypertrophy apparently depended on the BMP-transfection. Cells were encapsulated in ultrahigh-viscosity, clinical grade alginate and differentiation was studied over a period of 17 days. Consistent with results published previously staining with haematoxylin-eosin or Alcian blue, immunohistochemical analysis, and quantitative RT-PCR confirmed the expression of chondrogenic markers (chondroitin-4- and -6-sulfate as well as type II collagen). Production of chondrogenic markers was particularly high in BMP-4 transfected cells. Hypertrophic chondrogenesis did not occur in BMP-4 transfected cells, as revealed by measurement of type X collagen, but could be demonstrated for wild-type cells and to some extent for BMP-2 transfected cells. The osteogenic markers, type I collagen, alkaline phosphatase, and Cbfa1 were upregulated in all cell lines even though the levels and the time of upregulation differed significantly. In any case, the markers were less and only very shortly expressed in BMP-4 transfected cells as revealed quantitatively by real time RT-PCR. Thus, the in vitro results suggested that BMP-4 is a very promising candidate for suppressing chondrogenic hypertrophy, while simultaneously enhancing the production of chondrogenic components.
authors.affiliation: Department of Orthopaedic Surgery, König-Ludwig-Haus, Julius Maximilian University, Brettreichstrasse 11, D-97074 Würzburg, Germany.
authors.forename: Andre
authors.initials: A
authors.lastname: Steinert
authors.forename: Meike
authors.initials: M
authors.lastname: Weber
authors.forename: Arno
authors.initials: A
authors.lastname: Dimmler
authors.forename: Conrad
authors.initials: C
authors.lastname: Julius
authors.forename: Norbert
authors.initials: N
authors.lastname: Schütze
authors.forename: Ulrich
authors.initials: U
authors.lastname: Nöth
authors.forename: Hubert
authors.initials: H
authors.lastname: Cramer
authors.forename: Jochen
authors.initials: J
authors.lastname: Eulert
authors.forename: Ulrich
authors.initials: U
authors.lastname: Zimmermann
authors.forename: Christian
authors.initials: C
authors.lastname: Hendrich
mesh_terms: D000464:Alginates / Q000737:chemistry; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D020219:Chondrogenesis / Q000502:physiology*; D002809:Chondroitin Sulfates / Q000235:genetics / Q000378:metabolism; D024043:Collagen Type II / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D007150:Immunohistochemistry; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D014162:Transfection; D014783:Viscosity
chemical_list: D000464:Alginates; D015415:Biomarkers; D019485:Bone Morphogenetic Proteins; D024043:Collagen Type II; D006603:Hexuronic Acids; D012333:RNA, Messenger; D020723:Glucuronic Acid; D002809:Chondroitin Sulfates