Abstract | OBJECTIVE: METHODS AND RESULTS: Western blotting and combined gas chromatography-mass spectrometry showed that human tendons contain significant amounts of CYP27A1 and its product, 27-hydroxycholesterol. Immunohistochemistry showed that CYP27A1 is present in macrophages and tenocytes. The tendons also contained cholestanol, with a cholestanol: cholesterol ratio slightly higher than that in the circulation. Recombinant human CYP27A1, and cultured human macrophages containing this enzyme, had similar activity toward cholesterol and cholestanol. After loading of macrophages with labeled cholesterol and cholestanol, there was an efflux of these steroids in both unmetabolized and 27-oxygenated form, resulting in a significant cellular accumulation of cholestanol compared with cholesterol. CONCLUSION: The results are consistent with the possibility that CYP27A1 is of importance for the efflux of both cholesterol and cholestanol from tendons.
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Authors | Sara von Bahr, Tomas Movin, Nikos Papadogiannakis, Irina Pikuleva, Per Rönnow, Ulf Diczfalusy, Ingemar Björkhem |
Journal | Arteriosclerosis, thrombosis, and vascular biology
(Arterioscler Thromb Vasc Biol)
Vol. 22
Issue 7
Pg. 1129-35
(Jul 01 2002)
ISSN: 1524-4636 [Electronic] United States |
PMID | 12117727
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Hydroxycholesterols
- 27-hydroxycholesterol
- Cholestanol
- Cytochrome P-450 Enzyme System
- Cholesterol
- Steroid Hydroxylases
- CYP27A1 protein, human
- Cholestanetriol 26-Monooxygenase
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Topics |
- Adult
- Alcoholism
(complications, enzymology)
- Arteriosclerosis
(enzymology, pathology)
- Blotting, Western
- Cells, Cultured
- Cholestanetriol 26-Monooxygenase
- Cholestanol
(metabolism)
- Cholesterol
(metabolism)
- Cytochrome P-450 Enzyme System
(metabolism, physiology)
- Diabetes Complications
- Diabetes Mellitus
(enzymology)
- Female
- Gas Chromatography-Mass Spectrometry
- Humans
- Hydroxycholesterols
(metabolism)
- Macrophages, Alveolar
(cytology, enzymology, metabolism)
- Male
- Middle Aged
- Steroid Hydroxylases
(metabolism, physiology)
- Substrate Specificity
- Xanthomatosis, Cerebrotendinous
(complications, enzymology, pathology)
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