C-reactive protein induces NF-kappaB activation through intracellular calcium and ROS in human mesangial cells.
BACKGROUND
C-reactive protein (CRP) is known to have a direct proinflammatory effect in endothelial cells. However, little is known about the effect of CRP in intrinsic renal cells. We investigated the effects of CRP on the nuclear factor-kappaB (NF-kappaB) activation and monocyte chemoattractant protein-1 (MCP-1) gene expression in human mesangial cells and also examined whether intracellular calcium and reactive oxygen species (ROS) were involved in the CRP- induced NF-kappaB activation.


METHODS
NF-kappaB binding activity and MCP-1 mRNA expression were measured by electrophoretic mobility shift assay and Northern blot analysis, respectively. Intracellular calcium was monitored by confocal microscopy using calcium sensitive dye, Fluo-3 and intracellular ROS production was determined, using 2',7'-dichlorofluorescin diacetate.


RESULTS
CRP increased NF-kappaB binding activity in a dose-dependent manner (12.5-100 microg/ml), which was induced within 1 h after incubation and peaked around 3 h. CRP also increased the MCP-1 mRNA expression via activation of NF-kappaB. Both intracellular calcium and ROS was induced by CRP. Calcium chelator, BAPTA-AM and anti-oxidants such as N-acetylcysteine and tiron suppressed CRP-induced NF-kappaB activation.


CONCLUSIONS
CRP exerted a proinflammatory effect in human mesangial cells by inducing MCP-1 gene expression via NF-kappaB activation, which was mediated, at least in part, through intracellular calcium and ROS.
Chang
Jai Won
JW
Department of Internal Medicine, Urology, Asan Institute for Life Sciences, College of Medicine, University of Ulsan, Seoul, South Korea.
Kim
Choung Soo
CS
Kim
Soon Bae
SB
Park
Su Kil
SK
Park
Jung Sik
JS
Lee
Sang Koo
SK
D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt / Q000494:pharmacology; D000111:Acetylcysteine / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D015152:Blotting, Northern; D002097:C-Reactive Protein / Q000494:pharmacology* / Q000502:physiology*; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation; D050527:Mesangial Cells / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D018613:Microscopy, Confocal; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D013997:Time Factors
D000975:Antioxidants; D002614:Chelating Agents; D018932:Chemokine CCL2; D016328:NF-kappa B; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt; D004533:Egtazic Acid; D002097:C-Reactive Protein; D002118:Calcium; D000111:Acetylcysteine