ATP-Binding cassette transporter A1 is involved in hepatic α-tocopherol secretion
Vitamin E (α-tocopherol) is an essential fat-soluble nutrient with antioxidant properties. α-Tocopherol transfer protein (α-TTP), the product of the gene responsible for familial isolated vitamin E deficiency, plays an important role in maintaining the plasma α-tocopherol level by mediating the secr...
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| Main Authors: | , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
May 2010
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| In: |
The journal of nutritional biochemistry
Year: 2010, Volume: 21, Issue: 5, Pages: 451-456 |
| ISSN: | 1873-4847 |
| DOI: | 10.1016/j.jnutbio.2009.02.002 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1016/j.jnutbio.2009.02.002 Verlag, lizenzpflichtig, Volltext: https://www.sciencedirect.com/science/article/pii/S0955286309000382 
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| Author Notes: | Mototada Shichiri, Yasukazu Takanezawa, Daisy E. Rotzoll, Yasukazu Yoshida, Tomokuni Kokubu, Kazumitsu Ueda, Hiroshi Tamai, Hiroyuki Arai |
| Summary: | Vitamin E (α-tocopherol) is an essential fat-soluble nutrient with antioxidant properties. α-Tocopherol transfer protein (α-TTP), the product of the gene responsible for familial isolated vitamin E deficiency, plays an important role in maintaining the plasma α-tocopherol level by mediating the secretion of α-tocopherol by the liver. However, the mechanisms underlying hepatic α-tocopherol secretion are not fully understood. This study was undertaken to elucidate the mechanism of α-tocopherol re-efflux from hepatocytes, the cells that have the most important role in regulating plasma-α-tocopherol concentrations. From in vitro experiments using [3H]α-tocopheryl acetate and McARH7777 cells that stably express α-tocopherol transfer protein (α-TTP), the following results were obtained. First, addition of apolipoprotein A-I (apoA-I), a direct acceptor of the ATP-binding cassette transporter A1 (ABCA1)-secreted lipids, increased α-tocopherol secretion in a dose-dependent manner. Second, probucol, an antiatherogenic compound reported to be an inactivator of ABCA1 reduced hepatic α-tocopherol secretion. Third, ABCA1-RNAi suppressed hepatic α-tocopherol secretion. In a mouse in vivo experiment, addition of 1% probucol to the diet decreased plasma α-tocopherol concentrations. These results strongly suggest that ABCA1 is substantially involved in hepatic α-tocopherol secretion. |
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| Item Description: | Gesehen am 17.07.2023 |
| Physical Description: | Online Resource |
| ISSN: | 1873-4847 |
| DOI: | 10.1016/j.jnutbio.2009.02.002 |