Abstract |
Soluble epoxide hydrolase (sEH) is a phase-I xenobiotic metabolizing enzyme having both an N-terminal phosphatase activity and a C-terminal epoxide hydrolase activity. Endogenous hydrolase substrates include arachidonic acid epoxides, which have been involved in regulating blood pressure and inflammation. The subcellular localization of sEH has been controversial. Earlier studies using mouse and rat liver suggested that sEH may be cytosolic and/or peroxisomal. In this study we applied immunofluorescence and confocal microscopy using markers for different subcellular compartments to evaluate sEH colocalization in an array of human tissues. Results showed that sEH is both cytosolic and peroxisomal in human hepatocytes and renal proximal tubules and exclusively cytosolic in other sEH-containing tissues such as pancreatic islet cells, intestinal epithelium, anterior pituitary cells, adrenal gland, endometrium, lymphoid follicles, prostate ductal epithelium, alveolar wall, and blood vessels. sEH was not exclusively peroxisomal in any of the tissues evaluated. Our data suggest that human sEH subcellular localization is tissue dependent, and that sEH may have tissue- or cell-type-specific functionality. To our knowledge, this is the first report showing the subcellular localization of sEH in a wide array of human tissues.
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Authors | Ahmed E Enayetallah, Richard A French, Michele Barber, David F Grant |
Journal | The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society
(J Histochem Cytochem)
Vol. 54
Issue 3
Pg. 329-35
(Mar 2006)
ISSN: 0022-1554 [Print] United States |
PMID | 16314446
(Publication Type: Journal Article, Research Support, N.I.H., Extramural)
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Chemical References |
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Topics |
- Amino Acid Sequence
- Cell Compartmentation
- Cytosol
(enzymology)
- Epoxide Hydrolases
(metabolism)
- Fluorescent Antibody Technique
- Humans
- Microscopy, Confocal
- Molecular Sequence Data
- Organ Specificity
- Peroxisomes
(enzymology)
- Solubility
- Subcellular Fractions
(enzymology)
- Tissue Array Analysis
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