Effects of advanced glycation end products on the expression of COX-2, PGE2 and NO in human osteoarthritic chondrocytes.
OBJECTIVE
Advanced glycation end products (AGE) accumulate in articular cartilage with age. We investigated the effects of AGE in primary-cultured human OA chondrocytes.


METHODS
Chondrocytes were cultured with/or without AGE-bovine serum albumin (AGE-BSA) and the expression levels of inducible nitric oxide (iNOS), cyclooxygenase (COX)-2 microsomal prostaglandin E synthase-1 (mPGES-1) were evaluated using RT-PCR and western blot analysis. Prostaglandin E(2) (PGE(2)) was analysed by ELISA and nitric oxide (NO) was analysed by Griess reaction assay. Pharmacological studies to elucidate the involved pathway were executed using specific inhibitors of MAPK and receptor for AGE (RAGE).


RESULTS
We found that treatment of OA chondrocytes with AGE-BSA increased COX-2, mPGES-1 and iNOS mRNA and protein, as well as elevating production of PGE(2) and NO. Pre-treatment with the MAPK inhibitors SP600125 (JNK inhibitor), SB202190 (p38 inhibitor) or PD98059 (ERK inhibitor) significantly inhibited AGE-BSA induction of COX-2 expression and production of PGE(2). In contrast, SN50, a nuclear factor-kappaB (NF-kappaB) inhibitor, had no effect on levels of COX-2 and PGE(2). SB202190 and SN50, but not SP600125 and PD98059, decreased AGE-BSA-induced production of NO. Pre-treatment with soluble receptor for AGE (sRAGE) also reduced AGE-stimulated COX-2, iNOS and PGE(2), implicating the involvement of RAGE.


CONCLUSIONS
These results show that AGE may augment inflammatory responses in OA chondrocytes by increasing PGE(2) and NO levels, possibly via the MAPK pathway for PGE(2) and the NF-kappaB pathway for NO.
Nah
S-S
SS
Division of Allergy and Rheumatology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, 388-1, Pungnap-dong, Songpa-gu, Seoul 138-736, Korea.
Choi
I-Y
IY
Lee
C K
CK
Oh
J S
JS
Kim
Y G
YG
Moon
H-B
HB
Yoo
B
B
D000368:Aged; D002358:Cartilage, Articular / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects* / Q000378:metabolism; D051545:Cyclooxygenase 1 / Q000096:biosynthesis / Q000235:genetics; D051546:Cyclooxygenase 2 / Q000096:biosynthesis / Q000235:genetics; D015232:Dinoprostone / Q000096:biosynthesis / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects; D017127:Glycation End Products, Advanced / Q000494:pharmacology*; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D019746:Intramolecular Oxidoreductases / Q000096:biosynthesis / Q000235:genetics; D020935:MAP Kinase Signaling System; D008875:Middle Aged; D009569:Nitric Oxide / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis / Q000235:genetics; D020370:Osteoarthritis, Knee / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000071876:Prostaglandin-E Synthases; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012710:Serum Albumin, Bovine / Q000494:pharmacology*; D015398:Signal Transduction
D017127:Glycation End Products, Advanced; D018836:Inflammation Mediators; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic; C081628:advanced glycation end products-bovine serum albumin; D012710:Serum Albumin, Bovine; D009569:Nitric Oxide; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D019746:Intramolecular Oxidoreductases; C000605862:PTGES protein, human; D000071876:Prostaglandin-E Synthases; D015232:Dinoprostone