Expression of cyclooxygenase-1 and -2 in IL-1beta-induced synovitis of the temporomandibular joint.
BACKGROUND
In this study, we analyzed the gene expression profile of fibroblast-like synoviocyte (FLS) cultures from the temporomandibular joint (TMJ) to identify candidate genes associated with intracapsular pathologic conditions of TMJ. Cyclooxygenase (COX)-2 was one of the genes in FLS upregulated following stimulation by interleukin (IL)-1beta, a cytokine thought to play a key role in several pathological conditions. This study investigated the expression of COX-1 and COX-2 in cultured human FLS and rat TMJ synovium following stimulation with IL-1beta.


METHODS
RNA was isolated from human FLS after IL-1beta treatment. COX-1 and -2 expression was examined using a GeneChip and real-time polymerase chain reaction. Prostaglandin E(2) (PGE(2)) levels in conditioned media from FLS were measured using enzyme-linked immunosorbent assay. Synovial tissues from TMJs of IL-1beta-injected rats were examined for COX-1 and COX-2 expression by immunohistochemical staining.


RESULTS
Following treatment of FLS with IL-1beta, expression of the COX-2 gene increased up to 8 h and peaked at 4 h, whereas COX-1 expression did not change. Stimulation with IL-1beta increased the level of PGE(2) in conditioned media of cultured FLS in a time-dependent manner up to 48 h. Immunohistochemistry showed a strong positive staining for COX-2 in the lining and sub-lining synovial tissues of the TMJ of IL-1beta-injected rats. In contrast, staining for COX-1 was the same in synovial tissues with and without IL-1beta injection.


CONCLUSIONS
These data suggest that COX-2 expression stimulated by IL-1beta stimulates the production of PGE(2) in FLS and plays important roles in the progression of inflammation in TMJ.
Satoh
K
K
Department of Maxillofacial Surgery, Nihon University School of Dentistry, Matsudo, Chiba 271-8587, Japan.
Ogura
N
N
Akutsu
M
M
Kuboyama
N
N
Kuyama
K
K
Yamamoto
H
H
Kondoh
T
T
D000328:Adult; D000818:Animals; D002478:Cells, Cultured; D051545:Cyclooxygenase 1 / Q000235:genetics / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D053583:Interleukin-1beta / Q000378:metabolism; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D012313:RNA / Q000032:analysis; D051381:Rats; D013583:Synovial Membrane / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D013585:Synovitis / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D013704:Temporomandibular Joint / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D013705:Temporomandibular Joint Disorders / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D055815:Young Adult
D053583:Interleukin-1beta; D012313:RNA; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2