Evidence for a superoxide permeability pathway in endosomal membranes

Davis R Mumbengegwi; Qiang Li; Canhui Li; Christine E Bear; John F Engelhardt

doi:10.1128/MCB.02038-07

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Evidence for a superoxide permeability pathway in endosomal membranes

Journal article

Peer reviewed

Evidence for a superoxide permeability pathway in endosomal membranes

Davis R Mumbengegwi, Qiang Li, Canhui Li, Christine E Bear and John F Engelhardt

Molecular and cellular biology, Vol.28(11), pp.3700-3712

06/2008

DOI: 10.1128/MCB.02038-07

PMCID: PMC2423302

PMID: 18378695

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Abstract

The compartmentalized production of superoxide (*O(2)(-)) by endosomal NADPH oxidase is important in the redox-dependent activation of NF-kappaB following interleukin 1beta (IL-1beta) stimulation. It remains unclear how *O(2)(-) produced within endosomes facilitates redox-dependent signaling events in the cytoplasm. We evaluated *O(2)(-) movement out of IL-1beta-stimulated endosomes and whether SOD1 at the endosomal surface mediates redox-signaling events required for NF-kappaB activation. The relative outward permeability of NADPH-dependent *O(2)(-) from fractionated endosomes was assessed using membrane-permeable (luminol and lucigenin) and -impermeable (isoluminol) luminescent probes for *O(2)(-). In these studies, approximately 60% of *O(2)(-) efflux out of endosomes was inhibited by treatment with either of two anion channel blockers, 4'-diisothiocyano-2,2'-disulfonic acid stilbene (DIDS) or niflumic acid (NFA). Furthermore, radioisotopic electrodiffusion flux assays on endomembrane proteoliposomes suggested that *O(2)(-) and Cl(-) are transported through the same DIDS-sensitive channel(s). Rab5-based immunoaffinity isolation of IL-1beta-stimulated early endosomes demonstrated SOD1 recruitment to endosomes harboring the IL-1 receptor. Finally, SOD1-deficient cells were found to be defective in their ability to activate NF-kappaB following IL-1beta stimulation. Together, these results suggest that *O(2)(-) exits endosomes through a DIDS-sensitive chloride channel(s) and that SOD1-mediated dismutation of *O(2)(-) at the endosomal surface may produce the localized H(2)O(2) required for redox-activation of NF-kappaB.

Interleukin-1beta - pharmacology

Superoxide Dismutase - genetics

Humans

Proteolipids - metabolism

Chlorine - metabolism

NF-kappa B - metabolism

Endosomes - metabolism

Intracellular Membranes - ultrastructure

Xanthine Oxidase - chemistry

Receptors, Interleukin-1 Type I - metabolism

Endosomes - drug effects

Endosomes - ultrastructure

Superoxides - metabolism

Niflumic Acid - pharmacology

NADP - metabolism

Receptors, Interleukin-1 Type I - analysis

Superoxide Dismutase - metabolism

Chloride Channels - antagonists & inhibitors

Superoxide Dismutase - analysis

Oxidation-Reduction

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid - pharmacology

Permeability

Chloride Channels - metabolism

Cell Line, Tumor

Superoxide Dismutase-1

Intracellular Membranes - metabolism

Proteolipids - chemistry

Details

Title: Subtitle: Evidence for a superoxide permeability pathway in endosomal membranes
Creators: Davis R Mumbengegwi - Department of Anatomy and Cell Biology, College of Medicine, University of Iowa, 51 Newton Road, Iowa City, IA 52242, USA
Qiang Li
Canhui Li
Christine E Bear
John F Engelhardt
Resource Type: Journal article
Publication Details: Molecular and cellular biology, Vol.28(11), pp.3700-3712
DOI: 10.1128/MCB.02038-07
PMID: 18378695
PMCID: PMC2423302
NLM abbreviation: Mol Cell Biol
ISSN: 0270-7306
eISSN: 1098-5549
Publisher: United States
Grant note: DK067928 / NIDDK NIH HHS DK51315 / NIDDK NIH HHS R01 DK067928 / NIDDK NIH HHS P30 DK054759 / NIDDK NIH HHS P30 DK54759 / NIDDK NIH HHS R01 DK051315 / NIDDK NIH HHS
Language: English
Date published: 06/2008
Academic Unit: Roy J. Carver Department of Biomedical Engineering; Anatomy and Cell Biology; Radiation Oncology; Internal Medicine
Record Identifier: 9984025411202771

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