Immune Netw.  2002 Mar;2(1):25-34. 10.4110/in.2002.2.1.25.

Effects of Antioxidant on the Hypoxia-induced Expression of ICAM-1 in Cultured Human Synovial Fibroblasts

• Kim JR
• Yoo WH

• KMID: 1571389
• DOI: http://doi.org/10.4110/in.2002.2.1.25

Abstract

BACKGROUND: Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovial hyperplasia and joint destruction. The synovial fibroblasts express cell adhesion molecules and have a role in adhesive interation with inflammatory cells in synovial tissue. It has been suggested that hypoxic conditioins are thought to exist in arthritic joints, and several studies indicate that reactive oxygen species (ROS) produced in hypoxic condition can initiate events that lead to pro-adhesive changes via increased expression of adhesion molecules. So, this study wsa designed to examine whether antioxidant can inhibit hypoxia-induced expression of ICAM-1 in cultured human synovial fibroblasts.
METHODS
Synovial fibroblasts were isolated from synovial tissue in patients with RA and cultured at hypoxic condition. Antioxidant, PDTC (pyrrolidine dithiocarbamate) were pre-treated for an hour before the hypoxic culture and synovial fibroblasts were harvested at 0, 6, 12, 24, 48 hours time points. Cell surface ICAM-1 expression in synovial fibroblasts was examined by the flow cytometric analysis. To analyse the expression of ICAM-1 mRNA, reverse-transcriptase polymerase chain reaction (RT-PCR) was performed. The levels of cytokines in culture supernatants were measured by ELISA, and activation of NF-kB was analysed by electrophoretic mobility shift assay. The adhesive reaction between synovial fibroblasts and lymphocytes was assayed by measurement of fluorescent intensity of BCECF-AM in lymphocytes.
RESULTS
Hypoxic stimuli up-regulated the ICAM-1 expression as well as the adhesive interaction of human synvial fibroblasts to lymphocytes in a time-dependent manner, and PDTC inhibited hpyoxia-induced ICAM-1 expression and cell-cell interaction. PDTC also inhibited the hypoxia-induced activation of intracellular transcription factor, NF-kB. PDTC decreased the amount of hypoxia-induced production of IL-1beta and TNF-alpha.
CONCLUSION
These studies demonstrate that PDTC inhibit the hypoxia-induced expression of the adhesion molecule, ICAM-1 and activation of NF-kB in cultured human synovial fibroblasts.

Keyword

antioxidants; hypoxia; ICAM-1; rheumatoid arthritis; synovial fibroblasts

MeSH Terms

Adhesives
Anoxia
Antioxidants
Arthritis, Rheumatoid
Cell Adhesion Molecules
Cytokines
Electrophoretic Mobility Shift Assay
Enzyme-Linked Immunosorbent Assay
Fibroblasts*
Humans*
Hyperplasia
Intercellular Adhesion Molecule-1*
Joints
Lymphocytes
NF-kappa B
Polymerase Chain Reaction
Reactive Oxygen Species
RNA, Messenger
Transcription Factors
Tumor Necrosis Factor-alpha
Adhesives
Antioxidants
Cell Adhesion Molecules
Cytokines
Intercellular Adhesion Molecule-1
NF-kappa B
RNA, Messenger
Reactive Oxygen Species
Transcription Factors
Tumor Necrosis Factor-alpha