title: Human chondrocytes differentially express matrix modulators during in vitro expansion for tissue engineering.
abstract: Cartilage tissue engineering plays an important role in the generation of grafts for reconstructive surgery. In cultured chondrocytes, the dedifferentiation of cells seems unavoidable for multiplication. Dedifferentiated cells produce matrix of less quality, and the molecular basis is still not well understood. Therefore, the aim of our study was to investigate the expression of matrix modulators in human chondrocytes during expansion. Human chondrocytes were isolated from septal cartilage (n=32) and held in primary cell culture. Cells were harvested after 1, 6 and 21 days. The differentiation of cells using light microscopy, the expression patterns of various proteins (MMPs, BMPs, and TIMPs) using immunohistochemistry, and the expression of distinct genes using microarray technique, were investigated. The chondrocytes showed strong in vitro proliferation. After 6 and 21 days, BMP-5 and -8 were up-regulated, BMP-2 was down-regulated and BMP-6 was inactivated. Other BMPs were not expressed. The expression of MMP-2, -3 and -13 was up-regulated from day 1 to 21, and MMP-12 and -20 were down-regulated. Other MMPs were not expressed. TIMP-1 was up-regulated and TIMP-3 was down-regulated during expansion. Differential expression of matrix modulators might influence the matrix composition of engineered cartilage. Improving the basic knowledge in this area may ultimately help clinicians to identify and proactively intervene in an attempt to prevent bioartificial cartilage from losing stability.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Ruprecht-Karls-University Heidelberg, Germany. ugoessler@web.de
authors.forename: Ulrich Reinhart
authors.initials: UR
authors.lastname: Goessler
authors.forename: Karen
authors.initials: K
authors.lastname: Bieback
authors.forename: Peter
authors.initials: P
authors.lastname: Bugert
authors.forename: Ramin
authors.initials: R
authors.lastname: Naim
authors.forename: Carsten
authors.initials: C
authors.lastname: Schafer
authors.forename: Haneen
authors.initials: H
authors.lastname: Sadick
authors.forename: Karl
authors.initials: K
authors.lastname: Hormann
authors.forename: Frank
authors.initials: F
authors.lastname: Riedel
mesh_terms: D055396:Bone Morphogenetic Protein 2; D055417:Bone Morphogenetic Protein 5; D019485:Bone Morphogenetic Proteins / Q000032:analysis / Q000235:genetics; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D005109:Extracellular Matrix / Q000737:chemistry / Q000378:metabolism*; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D020782:Matrix Metalloproteinases / Q000032:analysis / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D019714:Tissue Inhibitor of Metalloproteinases / Q000032:analysis / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000032:analysis / Q000235:genetics
chemical_list: C525718:BMP2 protein, human; C525814:BMP5 protein, human; C405632:BMP8B protein, human; D055396:Bone Morphogenetic Protein 2; D055417:Bone Morphogenetic Protein 5; D019485:Bone Morphogenetic Proteins; D019714:Tissue Inhibitor of Metalloproteinases; D016212:Transforming Growth Factor beta; D020782:Matrix Metalloproteinases