title: Chondrogenic differentiation potential of osteoarthritic chondrocytes and their possible use in matrix-associated autologous chondrocyte transplantation.
abstract: BACKGROUND
  Autologous chondrocyte transplantation (ACT) is a routine technique to regenerate focal cartilage lesions. However, patients with osteoarthritis (OA) are lacking an appropriate long-lasting treatment alternative, partly since it is not known if chondrocytes from OA patients have the same chondrogenic differentiation potential as chondrocytes from donors not affected by OA.
  
  
  METHODS
  Articular chondrocytes from patients with OA undergoing total knee replacement (Mankin Score > 3, Ahlbäck Score > 2) and from patients undergoing ACT, here referred to as normal donors (ND), were isolated applying protocols used for ACT. Their chondrogenic differentiation potential was evaluated both in high-density pellet and scaffold (Hyaff-11) cultures by histological proteoglycan assessment (Bern Score) and immunohistochemistry for collagen types I and II. Chondrocytes cultured in monolayer and scaffolds were subjected to gene expression profiling using genome-wide oligonucleotide microarrays. Expression data were verified by using real-time PCR.
  
  
  RESULTS
  Chondrocytes from ND and OA donors demonstrated accumulation of comparable amounts of cartilage matrix components, including sulphated proteoglycans and collagen types I and II. The mRNA expression of cartilage markers (ACAN, COL2A1, COMP, CRTL1, SOX9) and genes involved in matrix synthesis (BGN, CILP2, COL9A2, COL11A1, TIMP4) was highly induced in 3D cultures of chondrocytes from both donor groups. Genes associated with hypertrophic or OA cartilage (ALPL, COL1A1, COL3A1, COL10A1, MMP13, POSTN, PTH1R, RUNX2) were not significantly regulated between the two groups of donors. The expression of 661 genes, including COMP, FN1, and SOX9, was differentially regulated between OA and ND chondrocytes cultured in monolayer. During scaffold culture, the differences diminished between the OA and ND chondrocytes, and only 184 genes were differentially regulated.
  
  
  CONCLUSIONS
  Only few genes were differentially expressed between OA and ND chondrocytes in Hyaff-11 culture. The risk of differentiation into hypertrophic cartilage does not seem to be increased for OA chondrocytes. Our findings suggest that the chondrogenic capacity is not significantly affected by OA, and OA chondrocytes fulfill the requirements for matrix-associated ACT.
authors.affiliation: Tissue Engineering Laboratory and Berlin-Brandenburg Center for Regenerative Therapies, Department of Rheumatology and Clinical Immunology, Charité-Universitätsmedizin Berlin, Tucholskystrasse 2, Berlin, 10117, Germany. tilo.dehne@charite.de
authors.forename: Tilo
authors.initials: T
authors.lastname: Dehne
authors.forename: Camilla
authors.initials: C
authors.lastname: Karlsson
authors.forename: Jochen
authors.initials: J
authors.lastname: Ringe
authors.forename: Michael
authors.initials: M
authors.lastname: Sittinger
authors.forename: Anders
authors.initials: A
authors.lastname: Lindahl
mesh_terms: D015415:Biomarkers / Q000032:analysis; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation; D019902:Chondrocytes / Q000166:cytology* / Q000637:transplantation*; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D010003:Osteoarthritis / Q000235:genetics* / Q000378:metabolism*; D011509:Proteoglycans / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054457:Tissue Scaffolds
chemical_list: D015415:Biomarkers; D011509:Proteoglycans; D012333:RNA, Messenger