title: Physiological normoxia and chondrogenic potential of chondrocytes.
abstract: Cartilage is poorly vascularised with a limited capacity for repair following damage. The poor vascularisation results in cartilage tissue having a low normoxic value. This study examined and compared the effects of physiological cartilage normoxia (2% O2), hypoxia (0.2% O2), and hyperoxia (21% O2) on human articular chondrocytes (hAC) during similar time courses to those prior to transplant in cell therapy procedures. hAC were isolated and maintained at 0.2% O2, 2% O2, or 21% O2. Population doublings (PDs), cell surface area, chondrogenic differentiation potential, RT-PCR, quantitative RT-PCR and immunohistochemistry (Collagen Type II) were used to confirm chondrogenic differentiation of micromass pellets in different O2. Isolation and maintenance of hAC at =2% O2 resulted in significant alterations in surface area (smaller), rate of proliferation (reduced), and chondrogenic differentiation potential (enhanced). Chondrogenic gene expression appeared largely insensitive to O2 concentration. A relationship was apparent between collagen type II protein presence and O2 concentration. Oxygen concentrations of 2% O2 or less promoted retention of a dedifferentiated hAC phenotype and enhanced stability of hAC chondrogenesis.
authors.affiliation: Guy Hilton Research Centre, Institute of Science and Technology in Medicine, Keele University, Stoke-On-Trent, UK.
authors.forename: Alasdair
authors.initials: A
authors.lastname: Kay
authors.forename: James
authors.initials: J
authors.lastname: Richardson
authors.forename: Nicholas R
authors.initials: NR
authors.lastname: Forsyth
mesh_terms: D000368:Aged; D001483:Base Sequence; D002454:Cell Differentiation; D019902:Chondrocytes / Q000166:cytology / Q000502:physiology*; D017931:DNA Primers; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D010100:Oxygen