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NKININ STEPHENSONW, STRINGER JAMESR, KEELY SCOTTP, SETCHELL KENNETHD, GINER JOSÉLUIS, KANESHIRO EDNAS. Pneumocystis carinii Sterol 14α-Demethylase Activity in Saccharomyces cerevisiae erg11 Knockout Mutant: Sterol Biochemistry. J Eukaryot Microbiol 2011; 58:383-92. [DOI: 10.1111/j.1550-7408.2011.00556.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Dubrac S, Lear SR, Ananthanarayanan M, Balasubramaniyan N, Bollineni J, Shefer S, Hyogo H, Cohen DE, Blanche PJ, Krauss RM, Batta AK, Salen G, Suchy FJ, Maeda N, Erickson SK. Role of CYP27A in cholesterol and bile acid metabolism. J Lipid Res 2004; 46:76-85. [PMID: 15520450 DOI: 10.1194/jlr.m400219-jlr200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The CYP27A gene encodes a mitochondrial cytochrome P450 enzyme, sterol 27-hydroxylase, that is expressed in many different tissues and plays an important role in cholesterol and bile acid metabolism. In humans, CYP27A deficiency leads to cerebrotendinous xanthomatosis. To gain insight into the roles of CYP27A in the regulation of cholesterol and bile acid metabolism, cyp27A gene knockout heterozygous, homozygous, and wild-type littermate mice were studied. In contrast to homozygotes, heterozygotes had increased body weight and were mildly hypercholesterolemic, with increased numbers of lipoprotein particles in the low density lipoprotein size range. Cyp7A expression was not increased in heterozygotes but was in homozygotes, suggesting that parts of the homozygous phenotype are secondary to increased cyp7A expression and activity. Homozygotes exhibited pronounced hepatomegaly and dysregulation in hepatic cholesterol, bile acid, and fatty acid metabolism. Hepatic cholesterol synthesis and synthesis of bile acid intermediates were increased; however, side chain cleavage was impaired, leading to decreased bile salt concentrations in gallbladder bile. Expression of Na-taurocholate cotransporting polypeptide, the major sinusoidal bile salt transporter, was increased, and that of bile salt export pump, the major canalicular bile salt transporter, was decreased. Gender played a modifying role in the homozygous response to cyp27A deficiency, with females being generally more severely affected. Thus, both cyp27A genotype and gender affected the regulation of hepatic bile acid, cholesterol, and fatty acid metabolism.
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Affiliation(s)
- Sandrine Dubrac
- Department of Medicine, University of California, San Francisco, CA 94143, USA
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Batta AK, Salen G, Tint GS. Hydrophilic 7 beta-hydroxy bile acids, lovastatin, and cholestyramine are ineffective in the treatment of cerebrotendinous xanthomatosis. Metabolism 2004; 53:556-62. [PMID: 15131757 DOI: 10.1016/j.metabol.2003.12.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We compared the effect of treatments with hydrophilic bile acids (ursodeoxycholic and ursocholic acids), cholestyramine, and lovastatin versus chenodeoxycholic acid in 4 patients with cerebrotendinous xanthomatosis (CTX). Bile acids and bile alcohols in plasma, bile, and urine before and after treatment were quantitated by gas-liquid chromatography. Untreated, all patients showed abnormal biliary bile acid composition: cholic acid (72.7%) and chenodeoxycholic acid (6.2%), and polyhydroxylated C(27)-bile alcohols (10.0%), and elevated plasma cholestanol levels. Treatment with hydrophobic chenodeoxycholic acid inhibited abnormal bile acid synthesis (virtual disappearance of C(27)-bile alcohols from plasma, bile, and urine and marked reduction of plasma cholestanol levels). Hydrophilic ursodeoxycholic and ursocholic acids did not inhibit abnormal bile acid synthesis, while cholestyramine increased abnormal bile acid synthesis (continued increased formation of polyhydroxylated C(27)-bile alcohols and further elevation of plasma cholestanol levels). Lovastatin did not affect abnormal bile acid synthesis or reduce plasma cholestanol levels. The results demonstrate that impaired side-chain oxidation in bile acid synthesis due to mutations of Cyp27 results in increased formation of polyhydroxylated C(27)-bile alcohols and cholestanol in CTX. Hydrophobic chenodeoxycholic acid, but not cholestyramine, lovastatin, or hydrophilic 7beta-hydroxy acids, inhibited the abnormal synthetic pathway. The role of chenodeoxycholic acid in downregulating abnormal bile acid synthesis in CTX is emphasized.
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Affiliation(s)
- Ashok K Batta
- Department of Medicine, University of Medicine and Dentistry, New Jersey Medical School, Newark, NJ, USA
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Batta AK, Salen G. Gas chromatography of bile acids. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 723:1-16. [PMID: 10080627 DOI: 10.1016/s0378-4347(98)00528-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Bile acids, the end products of cholesterol metabolism in the liver, are of vital importance in the tissue distribution of cholesterol. Abnormalities in cholesterol biosynthesis or metabolism are often reflected in the proportions, concentrations and conjugation of bile acids in various tissues and determination of bile acids in these tissues is important in the diagnosis of hepatobiliary diseases. Several methods for quantitative determination of bile acids in biological fluids are known and have been reviewed. In this review, we have discussed the gas-chromatographic method for determination of bile acids with special reference to bile acid quantitation in plasma, bile, urine and stool.
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Affiliation(s)
- A K Batta
- Department of Medicine and Liver Center, University of Medicine and Dentistry, New Jersey Medical School, Newark 07103, USA
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Sehayek E, Ono JG, Shefer S, Nguyen LB, Wang N, Batta AK, Salen G, Smith JD, Tall AR, Breslow JL. Biliary cholesterol excretion: a novel mechanism that regulates dietary cholesterol absorption. Proc Natl Acad Sci U S A 1998; 95:10194-9. [PMID: 9707623 PMCID: PMC21484 DOI: 10.1073/pnas.95.17.10194] [Citation(s) in RCA: 140] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The regulation of dietary cholesterol absorption was examined in C57BL/6 and transgenic mice with liver overexpression of the scavenger receptor BI (SR-BI Tg). In C57BL/6 animals, feeding 0.02 to 1% (wt/wt) dietary cholesterol resulted in a dose-dependent decrease in the percentage of dietary cholesterol absorbed. A plot of total daily mass of dietary cholesterol absorbed versus the percentage by weight of cholesterol in the diet yielded a curve suggesting a saturable process with a Km of 0.4% (wt/wt) and a Vmax of 0.65 mg cholesterol/g body weight per day. Dietary cholesterol suppressed hepatic 3-hydroxy-3-methylglutaryl CoA reductase activity, stimulated cholesterol 7alpha-hydroxylase activity, and enhanced fecal excretion of bile acids, but none of these changes correlated with the percentage of dietary cholesterol absorption. Dietary cholesterol also caused an increase in biliary cholesterol concentration, and in this case the concentration of biliary cholesterol was strongly and inversely correlated with the percentage dietary cholesterol absorption (r = -0.63, P < 0.0001). Biliary cholesterol concentration was also directly correlated with daily cholesterol intake, dietary cholesterol mass absorption, and liver cholesterol ester content. Transgene-induced overexpression of SR-BI resulted in a stimulation of excretion of cholesterol into the bile and suppressed percentage dietary cholesterol absorption. Furthermore, biliary cholesterol levels in SR-BI Tg mice were strongly and inversely correlated with the percentage of dietary cholesterol absorbed (r = -0.99, P < 0.0008). In summary, these results suggest that the excretion of cholesterol into the bile plays an important role in regulating the percentage absorption of dietary cholesterol.
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Affiliation(s)
- E Sehayek
- Laboratory of Biochemical Genetics and Metabolism, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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Batta AK, Salen G, Tint GS, Honda A, Shefer S. Synthesis of [3 alpha-3H]7-dehydrocholesterol via stable tritiated 4-phenyl-1,2,4-triazoline-3,5-dione derivative. Steroids 1997; 62:700-2. [PMID: 9366008 DOI: 10.1016/s0039-128x(97)00070-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Synthesis of [3 alpha-3H]7-dehydrocholesterol is described via protection of the 5,7-diene system in 7-dehydrocholesterol as the Diels-Alder adduct with 4-phenyl-1,2,4-triazoline-3,5-dione followed by oxidation of the hydroxyl group to give the 3-oxo adduct. Reduction of the keto adduct with [3H]sodium borohydride produced the adduct of [3 alpha-3H]7-dehydrocholesterol from which the radiolabeled sterol was obtained via treatment with lithium aluminum hydride. The advantage of the method is that highly labeled [3 alpha-3H]7-dehydrocholesterol can be prepared. Further, unlike 7-dehydrocholesterol, its adduct with 4-phenyl-1,2,4-triazoline-3,5-dione is stable and can be stored. This allows the preparation of small batches of [3 alpha-3H]7-dehydrocholesterol for immediate use in biological experiments, and losses due to decomposition of excess radiolabeled 7-dehydrocholesterol are minimized.
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Affiliation(s)
- A K Batta
- Department of Medicine, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, USA
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Batta AK, Salen G, Batta M, Earnest D, Alberts D. Capillary gas-liquid chromatography of acetate-methyl esters of bile acids. J Chromatogr A 1997; 766:286-91. [PMID: 9134735 DOI: 10.1016/s0021-9673(96)01016-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Gas-liquid chromatographic separations of acetate-methyl esters of several common bile acids with and without a hydroxyl group at C-6 are compared with those of the corresponding trimethylsilyl ether-methyl esters on a CP-Sil-5 CB capillary column. Unlike the trimethylsilyl ether derivatives, the retention indices of the corresponding acetates were greatly influenced by the number of hydroxyl groups in the ring system. Epimeric hydroxyl groups at carbons 6, 7 as well as 12 increased retention index of the acetate-methyl esters of the bile acids, the effect of the 7 beta-hydroxyl group being most prominent. The 6 beta-acetoxyl group increased the retention index more than the 6 alpha-acetoxy group and contrary to the trimethylsilyl ether derivatives, a 6 beta, 7 beta-diacetoxy group showed larger increase in the retention index than the corresponding 6 alpha, 7 beta-diacetoxy group. The acetate derivatives of bile acid-methyl esters show larger retention times and reduced sensitivity than the corresponding trimethylsilyl ether derivatives. However, gas chromatography of bile acid acetate-methyl esters can be very useful for the characterization of bile acids and for bile acid analysis in the rat where muricholic acids and hyodeoxycholic acid are in abundance, since these bile acids are difficult to resolve from each other and from other common bile acids as the trimethylsilyl ether derivatives.
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Affiliation(s)
- A K Batta
- Department of Medicine, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark 07103, USA
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Batta AK, Salen G, Tint GS, Shefer S. Identification of 19-nor-5,7,9(10)-cholestatrien-3 beta-ol in patients with Smith-Lemli-Opitz syndrome. J Lipid Res 1995. [DOI: 10.1016/s0022-2275(20)39722-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Batta AK, Aggarwal SK, Tint GS, Batta M, Salen G. Capillary gas-liquid chromatography of 6-hydroxylated bile acids. J Chromatogr A 1995; 704:228-33. [PMID: 7599745 DOI: 10.1016/0021-9673(95)00183-n] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Gas-liquid chromatographic separation of several bile acids with a hydroxyl group at C-6 is described on two capillary columns, CP-Sil-19 CB and CP-Sil-5 CB. The gas-liquid chromatographic retention indices of bile acids with 6 alpha- and 6 beta-hydroxyl groups are compared with those of bile acids without the C-6 hydroxyl group and the effect of the C-6 hydroxyl group on the retention indices of bile acids is determined. Both 6 alpha- and 6 beta-hydroxyl groups increase the retention index of a bile acid. The retention indices of 6 alpha- or 6 beta-hydroxyl derivatives of chenodeoxycholic acid were found to be higher than those of the corresponding 6-hydroxy derivatives of cholic acid on the CP-Sil-19 CB column but lower on the CP-Sil-5 CB column. Although all 6-hydroxylated derivatives of lithocholic, chenodeoxycholic and cholic acids were not completely resolved on either column alone, combining the two columns resulted in the complete separation of all these compounds.
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Affiliation(s)
- A K Batta
- Department of Medicine, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark 07103, USA
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Batta AK, Tint GS, Shefer S, Abuelo D, Salen G. Identification of 8-dehydrocholesterol (cholesta-5,8-dien-3 beta-ol) in patients with Smith-Lemli-Opitz syndrome. J Lipid Res 1995. [DOI: 10.1016/s0022-2275(20)40056-2] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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