title: Changes in the endogenous BMP expression during redifferentiation of chondrocytes in 3D cultures.
abstract: Engineering cartilage tissue is challenging, mainly because chondrocytes lose their differentiated phenotype when cultured in monolayer. The aim of this study was to analyse the influence of 3D-culture conditions on the redifferentiation of chondrocytes, devoting special attention to BMPs. Dedifferentiated chondrocytes were seeded onto two different scaffolds (Bio-Gide and HYAFF-11) and were then cultured for 38 days. Every week, samples were taken for gene expression analysis and immunohistochemistry. In both scaffolds an increasing differentiation was observed caused by an increase in Col2 and a reduction in Col1 expression. The various BMPs were regulated, albeit differently by the changing culture conditions. While GDF-5 and BMP-4 expression increased in the monolayer culture in comparison with native cartilage and decreased again in the 3D culture, the BMP-2 and BMP-6 expression decreased dramatically in the monolayer as well as in the 3D culture. BMP-7 was not detectable in any probe. Scaffold cultivation appears to stimulate the induction of redifferentiation, but is not sufficient to induce expression of BMP-2 -6 or -7. Since, in comparison to cartilage development, there is a lack of surrounding signal centres, external stimuli seem to be required to obtain complete redifferentiation. Our data indicate that a combination of BMP-2, -6 and -7 may be promising for this purpose.
authors.affiliation: Department of Traumatology, Center for Joint and Cartilage, Medical University of Vienna, Vienna, Austria. christian.albrecht@meduniwien.ac.at
authors.forename: Christian
authors.initials: C
authors.lastname: Albrecht
authors.forename: Werner
authors.initials: W
authors.lastname: Schlegel
authors.forename: Philipp
authors.initials: P
authors.lastname: Bartko
authors.forename: Peter
authors.initials: P
authors.lastname: Eckl
authors.forename: Tamara
authors.initials: T
authors.lastname: Jagersberger
authors.forename: Vilmos
authors.initials: V
authors.lastname: Vécsei
authors.forename: Stefan
authors.initials: S
authors.lastname: Marlovits
mesh_terms: D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002358:Cartilage, Articular / Q000166:cytology; D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000502:physiology*; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D024043:Collagen Type II / Q000235:genetics / Q000378:metabolism; D018031:Connexin 43 / Q000235:genetics / Q000378:metabolism; D006801:Humans; D012313:RNA / Q000378:metabolism; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry; D000099176:Noggin Protein
chemical_list: D019485:Bone Morphogenetic Proteins; D002352:Carrier Proteins; D024042:Collagen Type I; D024043:Collagen Type II; D018031:Connexin 43; D012313:RNA; D000099176:Noggin Protein; C500216:GJA1 protein, human