Nitrotyrosine proteome survey in asthma identifies oxidative mechanism of catalase inactivation.
Reactive oxygen species and reactive nitrogen species produced by epithelial and inflammatory cells are key mediators of the chronic airway inflammation of asthma. Detection of 3-nitrotyrosine in the asthmatic lung confirms the presence of increased reactive oxygen and nitrogen species, but the lack of identification of modified proteins has hindered an understanding of the potential mechanistic contributions of nitration/oxidation to airway inflammation. In this study, we applied a proteomic approach, using nitrotyrosine as a marker, to evaluate the oxidation of proteins in the allergen-induced murine model of asthma. Over 30 different proteins were targets of nitration following allergen challenge, including the antioxidant enzyme catalase. Oxidative modification and loss of catalase enzyme function were seen in this model. Subsequent investigation of human bronchoalveolar lavage fluid revealed that catalase activity was reduced in asthma by up to 50% relative to healthy controls. Analysis of catalase isolated from asthmatic airway epithelial cells revealed increased amounts of several protein oxidation markers, including chloro- and nitrotyrosine, linking oxidative modification to the reduced activity in vivo. Parallel in vitro studies using reactive chlorinating species revealed that catalase inactivation is accompanied by the oxidation of a specific cysteine (Cys(377)). Taken together, these studies provide evidence of multiple ongoing and profound oxidative reactions in asthmatic airways, with one early downstream consequence being catalase inactivation. Loss of catalase activity likely amplifies oxidative stress, contributing to the chronic inflammatory state of the asthmatic airway.
Ghosh
Sudakshina
S
Department of Pathobiology, Cleveland Clinic Foundation, 9500 Euclid Avenue/NC22, Cleveland, OH 44195, USA.
Janocha
Allison J
AJ
Aronica
Mark A
MA
Swaidani
Shadi
S
Comhair
Suzy A A
SA
Xu
Weiling
W
Zheng
Lemin
L
Kaveti
Suma
S
Kinter
Michael
M
Hazen
Stanley L
SL
Erzurum
Serpil C
SC
D000328:Adult; D000818:Animals; D001249:Asthma / Q000378:metabolism* / Q000473:pathology; D002374:Catalase / Q000737:chemistry / Q000378:metabolism*; D002460:Cell Line; D015180:Electrophoresis, Gel, Two-Dimensional; D004789:Enzyme Activation / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D010047:Ovalbumin / Q000494:pharmacology; D010084:Oxidation-Reduction / Q000187:drug effects; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics; D026361:Reactive Nitrogen Species / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
D020543:Proteome; D026361:Reactive Nitrogen Species; C002744:3-nitrotyrosine; D014443:Tyrosine; D010047:Ovalbumin; D002374:Catalase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III