Uric acid stimulates monocyte chemoattractant protein-1 production in vascular smooth muscle cells via mitogen-activated protein kinase and cyclooxygenase-2.
Previous studies have reported that uric acid stimulates vascular smooth muscle cell (VSMC) proliferation in vitro. We hypothesized that uric acid may also have direct proinflammatory effects on VSMCs. Crystal- and endotoxin-free uric acid was found to increase VSMC monocyte chemoattractant protein-1 (MCP-1) expression in a time- and dose-dependent manner, peaking at 24 hours. Increased mRNA and protein expression occurred as early as 3 hours after uric acid incubation and was partially dependent on posttranscriptional modification of MCP-1 mRNA. In addition, uric acid activated the transcription factors nuclear factor-kappaB and activator protein-1, as well as the MAPK signaling molecules ERK p44/42 and p38, and increased cyclooxygenase-2 (COX-2) mRNA expression. Inhibition of p38 (with SB 203580), ERK 44/42 (with UO126 or PD 98059), or COX-2 (with NS398) each significantly suppressed uric acid-induced MCP-1 expression at 24 hours, implicating these pathways in the response to uric acid. The ability of both n-acetyl-cysteine and diphenyleneionium (antioxidants) to inhibit uric acid-induced MCP-1 production suggested involvement of intracellular redox pathways. Uric acid regulates critical proinflammatory pathways in VSMCs, suggesting it may have a role in the vascular changes associated with hypertension and vascular disease.
Division of Nephrology, Baylor College of Medicine, SM-1273, 6550 Fannin St, Houston TX 77030. rjohnson@bcm.tmc.edu
John
J
Kanellis
Susumu
S
Watanabe
Jin H
JH
Li
Duk Hee
DH
Kang
Ping
P
Li
Takahiko
T
Nakagawa
Ann
A
Wamsley
David
D
Sheikh-Hamad
Hui Y
HY
Lan
Lili
L
Feng
Richard J
RJ
Johnson
D000818:Animals; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000096:biosynthesis* / Q000235:genetics; D051546:Cyclooxygenase 2; D005786:Gene Expression Regulation; D007527:Isoenzymes / Q000235:genetics / Q000502:physiology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000502:physiology; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D010084:Oxidation-Reduction; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D018808:Transcription Factor AP-1 / Q000378:metabolism; D015854:Up-Regulation; D014527:Uric Acid / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases
D018932:Chemokine CCL2; D007527:Isoenzymes; D016328:NF-kappa B; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D014527:Uric Acid; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases