Effects of cytokines on the production of nitric oxide in a chondrogenic cell line established from human osteogenic sarcoma.
OBJECTIVE
The purpose of this study was to examine the effects of various cytokines and/or lipopolysaccharide (LPS) on nitric oxide (NO) production from USAC, a newly established clonal cell line derived from human osteogenic sarcoma that expressed chondrocytic phenotypes.


METHODS
No production was measured by Griess method. Inducible nitric oxide synthase (iNOS) mRNA was detected by PCR analysis. Western blotting analysis and immunocytochemistry was used to detect iNOS protein.


RESULTS
Although USAC cells treated without any stimulants produced only small amounts of NO, exposure to cytokines and/or LPS induced iNOS in USAC cells and produced high levels of NO. The stimulatory effects of cytokines and/or LPS on NO production required TNF-alpha. TNF-alpha alone neither induced iNOS in USAC cells nor caused production of NO, but addition of TNF-alpha to USAC cells pretreated with LPS and IFN-gamma enhanced the expression of iNOS mRNA, induced iNOS protein and produced NO. Dexamethasone inhibited the stimulatory effect of TNF-alpha.


CONCLUSIONS
The responsiveness of USAC cells to cytokines and/or LPS and steroid hormone on NO production was quite different from that reported for rabbit and human articular cartilaginous cells. The differences in responsiveness between articular cartilaginous chondrocytes and USAC cells might have been because USAC cells were established from a malignant tumor.
Tachibana
H
H
Second Department of Oral and Maxillofacial Surgery, School of Dentistry, Showa University, Ohtaku, Tokyo, Japan. hideharu@senzoku.showa-u.ac.jp
Kakuta
S
S
Yagami
K
K
Nagumo
M
M
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D001859:Bone Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D019902:Chondrocytes / Q000378:metabolism*; D002999:Clone Cells; D016207:Cytokines / Q000494:pharmacology*; D003907:Dexamethasone / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008819:Mice, Nude; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D012516:Osteosarcoma / Q000473:pathology*; D011817:Rabbits; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019323:omega-N-Methylarginine / Q000494:pharmacology
D000893:Anti-Inflammatory Agents; D016207:Cytokines; D004791:Enzyme Inhibitors; D007375:Interleukin-1; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D003907:Dexamethasone; D007371:Interferon-gamma; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse