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Translocation of heme oxygenase-1 to mitochondria is a novel cytoprotective mechanism against non-steroidal anti-inflammatory drug-induced mitochondrial oxidative stress, apoptosis and gastric mucosal injury.
MedLine Citation:
PMID:  21908612     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
The mechanism of action of heme oxygenase-1 (HO-1) in mitochondrial oxidative stress (MOS)-mediated apoptotic tissue injury has been investigated. MOS-mediated gastric mucosal apoptosis and injury was introduced in rat by indomethacin, a non-steroidal anti-inflammatory drug. Here, we report that HO-1 is not only induced but also translocated to mitochondria during gastric mucosal injury to favor repair mechanisms. Furthermore, mitochondrial translocation of HO-1 results in the prevention of MOS and mitochondrial pathology as evident from the restoration of complex-I driven mitochondrial respiratory control ratio (RCR) and transmembrane potential (Δψm). Mitochondrial translocation of HO-1 also results in time-dependent inhibition of apoptosis. We searched for the plausible mechanisms responsible for HO-1 induction and mitochondrial localization. Free heme, the substrate for HO-1 is increased inside mitochondria during gastric injury and mitochondrial entry of HO-1 decreases intra-mitochondrial free heme content suggesting a purpose of mitochondrial translocation of HO-1 is to detoxify accumulated heme. Heme may activate nuclear translocation of NF-E2-related factor 2 (Nrf2) to induce HO-1 through reactive oxygen species generation. Electrophoretic mobility shift assay and chromatin immunoprecipitation studies indicated nuclear translocation of Nrf-2 and its binding to HO-1 promoter to induce HO-1 expression during gastric injury. Inhibition of HO-1 by zinc protoporphyrin aggravated the mucosal injury and delayed healing. Zinc protoporphyrin further reduced RCR and Δψm and enhanced MOS and apoptosis. In contrast, induction of HO-1 by cobalt protoporphyrin reduced MOS, corrected mitochondrial dysfunctions, prevented apoptosis and gastric injury. Thus, induction and mitochondrial localization of HO-1 is a novel cytoprotective mechanism against MOS-mediated apoptotic tissue injury.
Authors:
Samik Bindu; Chinmay Pal; Sumanta Dey; Manish Goyal; Athar Alam; Mohd Shameel Iqbal; Shubham Dutta; Souvik Sarkar; Rahul Kumar; Pallab Maity; Uday Bandyopadhyay
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-9-9
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  -     ISSN:  1083-351X     ISO Abbreviation:  -     Publication Date:  2011 Sep 
Date Detail:
Created Date:  2011-9-12     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
Indian Institute of Chemical Biology, India.
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