RRC ID 45011
Author Hatta T, Kishimoto KN, Okuno H, Itoi E.
Title Oxygen tension affects lubricin expression in chondrocytes.
Journal Tissue Eng Part A
Abstract We assessed the effects of oxygen tension on lubricin expression in bovine chondrocytes and cartilage explants and a role for hypoxia-inducible transcription factor (HIF)-1α in regulating lubricin expression was investigated using a murine chondroprogenitor cell line, ATDC5, and bovine chondrocytes isolated from superficial and middle/deep zones of femoral cartilage. ATDC5 cells and bovine chondrocytes were cultured in micromass under different oxygen tensions (21%, 5%, and 1%). ATDC5 cells and middle/deep zone chondrocytes that initially had low lubricin expression levels were also cultured with or without transforming growth factor (TGF)-β1. Quantitative reverse transcription (RT)-PCR was used to determine lubricin and chondrogenic marker gene mRNA levels and immunohistochemistry was used to assess lubricin protein expression. Explant cartilage plugs cultured under different oxygen tensions were also subjected to immunohistological analysis for lubricin. HIF-1α gene silencing was achieved by electroporatic transfer into ATDC5 cells. A low oxygen tension reduced lubricin gene expression levels in bovine superficial chondrocytes, TGF-β1-treated middle/deep zone chondrocytes, and TGF-β1-treated ATDC5 cells. Lubricin expression in explant cartilage was also suppressed under hypoxia. HIF-1α gene silencing in ATDC5 cells attenuated the lubricin expression response to the oxygen tension. These results corroborate with previous studies that the oxygen tension regulates lubricin gene expression and suggest that HIF-1α plays an important role in this regulation. The normal distribution of lubricin in articular cartilage may be due to the hypoxic oxygen environment of cartilage as it is an avascular tissue. An oxygen tension gradient may be a key factor for engineering cartilage tissue with a layered morphology.
Volume 20(19-20)
Pages 2720-7
Published 2014-10-1
DOI 10.1089/ten.TEA.2013.0353
PMID 24712343
MeSH Animals Antigens, Differentiation / biosynthesis Antigens, Differentiation / genetics Cattle Cell Hypoxia / genetics Cell Line Chondrocytes / cytology Chondrocytes / metabolism* Gene Expression Regulation / physiology* Gene Silencing Glycoproteins / biosynthesis* Glycoproteins / genetics Hypoxia-Inducible Factor 1, alpha Subunit / genetics Hypoxia-Inducible Factor 1, alpha Subunit / metabolism Oxygen / metabolism* Transforming Growth Factor beta1 / genetics Transforming Growth Factor beta1 / metabolism
IF 3.508
Times Cited 4
Human and Animal Cells ATDC5(RCB0565)