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ClC‐3 is required for normal NF‐kB activation by inflammatory mediators in vascular smooth muscle (VSM)
Author(s) -
Filali Mohammed,
Huss Gina J,
Barna Thomas J,
Miller Francis J,
Lamb Fred S
Publication year - 2006
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/fasebj.20.5.a1163-b
Subject(s) - nox1 , microbiology and biotechnology , nadph oxidase , intracellular , signal transduction , vascular smooth muscle , reactive oxygen species , chemistry , nf κb , apoptosis , biology , biochemistry , endocrinology , smooth muscle
Inflammatory mediators such as interleukin‐1beta (IL‐1β) and tumor necrosis factor alpha (TNFα) alter VSM cell proliferation and apoptosis in a reactive oxygen species (ROS)‐dependent manner involving the regulation of gene expression by nuclear factor kappa B (NF‐κB). VSM proliferation is inhibited by antisense oligo‐mediated reduction in the expression of the intracellular anion channel ClC‐3 ( Circ. Res. 91:E28–32, 2002). We observed that cultured Clcn3 −/− VSM cells did not proliferate as rapidly as Clcn3 +/+ cells, were more sensitive to H 2 O 2 ‐induced apoptosis, and displayed enhanced differentiation as reflected by increased expression of smooth muscle α‐actin and myosin heavy chain. We hypothesized that altered ROS‐dependent signaling explained these observations. Activation of NF‐κB in Clcn3 +/+ cells was blocked by the NADPH oxidase inhibitor DPI and the antioxidant N‐acetyl cysteine. Clcn3 −/− cells had lower basal NF‐κB activity and failed to properly activate NF‐κB in response to IL‐1β or TNFα. Treatment of Clcn3 +/+ VSM cells with DIDS (0.1–1mM) reduced basal NF‐κB activity, blocked activation by mitogens and decreased proliferation. Finally, an anti‐ClC‐3 Ab precipitates Nox1 from human aortic VSM lysates, as well as several proteins associated with intracellular vesicles. We conclude that ClC‐3 participates in NAPDH oxidase‐dependent signaling involving redox‐mediated activation of NF‐κB, and hypothesize that superoxide anion generated by Nox1 in intracellular vesicles moves through ClC‐3 into the cytoplasm where ROS signaling occurs. HL062483 and an AHA EI to FSL and HL081750 to FJM.