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Nitric oxide induces MIP‐2 transcription in rat renal mesangial cells and in a rat model of glomerulonephritis
Author(s) -
Walpen Sebastian,
Beck KarlFriedrich,
Schaefer Liliana,
Raslik Igor,
Eberhardt Wolfgang,
Schaefer Roland M.,
Pfeilschifter Josef
Publication year - 2001
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.00-0518fje
Subject(s) - microbiology and biotechnology , mesangial cell , nitric oxide , nitric oxide synthase , messenger rna , chemistry , western blot , northern blot , transfection , glomerulonephritis , reporter gene , gene expression , cytokine , biology , gene , immunology , biochemistry , kidney , endocrinology , in vitro , organic chemistry
Nitric oxide is a crucial mediator of several forms of glomerulonephritis. We examined the effects of NO on the mRNA expression pattern in glomerular mesangial cells by using a low‐stringency reverse transcriptase‐polymerase chain reaction method and detected a cDNA fragment that was induced by interleukin 1β (IL‐1β) and further up‐regulated by the NO donor diethylenetriamine‐nitric oxide (DETA‐NO). Each respective cDNA fragment was found to match with the cDNAs of rat macrophage inflammatory protein 2 (MIP‐2) and GRO/cytokine‐induced neutrophil chemoattractant 2β (CINC‐2β). Further characterization of MIP‐2 regulation by Northern blot analysis confirmed an NO‐ and IL‐1β‐dependent increase in MIP‐2 mRNA levels. Moreover, inhibition of IL‐1β‐induced endogenous NO formation by the NO‐synthase (NOS) inhibitor L ‐NMMA markedly attenuated MIP‐2 protein expression. We cloned 770 bp of the 5′‐flanking region of rat MIP‐2 and fused this fragment to a luciferase reporter gene. Transfection of the construct into mesangial cells resulted in a 3.5‐fold increase in luciferase activity in cells treated with DETA‐NO when compared to controls, suggesting a transcriptional mechanism for NO‐induced MIP‐2 expression. Deletion and mutational analysis identified critical nuclear factor (NF)‐κB and NF‐IL‐6 binding sites required for NO regulation of MIP‐2. In vivo, inhibition of NO synthesis in the Thy‐1.1 model of mesangioproliferative glomerulonephritis by the specific inducible‐NOS inhibitor L ‐NIL resulted in a marked reduction of MIP‐2 mRNA expression. Furthermore, infiltration of neutrophils into the glomerulus was dramatically attenuated in L ‐NIL‐treated rats.