caa a22 4500 445314168 CHVBK 20180317142640.0 cr unu---uuuuu 170323e20110201xx s 000 0 eng 10.1007/s11095-010-0294-4 doi (NATIONALLICENCE)springer-10.1007/s11095-010-0294-4 Human NPC1L1 Expression is Positively Regulated by PPARα [Elektronische Daten] [Yuki Iwayanagi, Tappei Takada, Fumiya Tomura, Yoshihide Yamanashi, Tomohiro Terada, Ken-ichi Inui, Hiroshi Suzuki] ABSTRACT: Purpose: Niemann-Pick C1-like 1 (NPC1L1), a pharmacological target of ezetimibe, is responsible for cholesterol absorption in enterocytes and hepatocytes. In the present study, the involvement of peroxisome proliferator-activated receptor α (PPARα) and its cofactor, PPARγ coactivator 1α (PGC1α) in the transcriptional regulation of human NPC1L1 was analyzed. Methods: Reporter gene assays and electrophoretic mobility shift assays (EMSAs) were performed with the 5′-flanking region of the human NPC1L1 gene and the effect of siPPARα was examined. Results: PPARα-mediated transactivation was observed with human NPC1L1 promoter constructs. Detailed analyses using deletion- and mutated-promoter constructs revealed the presence of a functional PPARα-response element (PPRE) upstream of the human NPC1L1 gene (−846/−834), a direct binding of PPARα and RXRα to which was confirmed by EMSAs. Moreover, PPARα-specific knockdown resulted in a significant decrease in the endogenous expression of NPC1L1 mRNA and protein in human-derived HepG2 cells. Furthermore, cotransfection of PGC1α stimulated the SREBP2/HNF4α- and PPARα/RXRα-mediated activation of the human NPC1L1 promoter. Conclusions: We found that PPARα positively regulates human NPC1L1 transcription via direct binding to a PPRE. Additionally, PGC1α stimulates the SREBP2/HNF4α- and PPARα/RXRα-mediated transactivation of human NPC1L1. These findings may provide new insights into the close relationship of glucose, fatty acids and cholesterol homeostasis. Springer Science+Business Media, LLC, 2010 cholesterol nationallicence ezetimibe nationallicence fenofibrate nationallicence fibrates nationallicence transporter nationallicence BSA : bovine serum albumin nationallicence DMEM : Dulbecco's Modified Eagle Medium nationallicence DR-1 : direct repeat-1 nationallicence EMSA : electrophoretic mobility shift assay nationallicence HNF4α : hepatocyte nuclear factor 4α nationallicence I-FABP : intestinal-fatty acid binding protein nationallicence NPC1L1 : Niemann-Pick C1-like 1 nationallicence PGC1α : PPARγ coactivator 1α nationallicence PPAR : peroxisome proliferator-activated receptor nationallicence PPRE : PPARα-response element nationallicence RXR : retinoid X receptor nationallicence SDS : sodium dodecyl sulfate nationallicence SREBP2 : sterol responsive element binding protein 2 nationallicence TBS-T : Tris-buffered saline containing 0.05% Tween 20 nationallicence Iwayanagi Yuki Department of Pharmacy, The University of Tokyo Hospital Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8655, Tokyo, Japan aut Takada Tappei Department of Pharmacy, The University of Tokyo Hospital Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8655, Tokyo, Japan aut Tomura Fumiya Department of Pharmacy, The University of Tokyo Hospital Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8655, Tokyo, Japan aut Yamanashi Yoshihide Department of Pharmacy, The University of Tokyo Hospital Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8655, Tokyo, Japan aut Terada Tomohiro Department of Pharmacy, Kyoto University Hospital Faculty of Medicine, Kyoto University, Sakyo-ku, 606-8507, Kyoto, Japan aut Inui Ken-ichi Department of Pharmacy, Kyoto University Hospital Faculty of Medicine, Kyoto University, Sakyo-ku, 606-8507, Kyoto, Japan aut Suzuki Hiroshi Department of Pharmacy, The University of Tokyo Hospital Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8655, Tokyo, Japan aut Pharmaceutical Research Springer US; http://www.springer-ny.com 28/2(2011-02-01), 405-412 0724-8741 28:2<405 2011 28 11095 https://doi.org/10.1007/s11095-010-0294-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11095-010-0294-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Iwayanagi Yuki Department of Pharmacy, The University of Tokyo Hospital Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8655, Tokyo, Japan aut NATIONALLICENCE 700 1- Takada Tappei Department of Pharmacy, The University of Tokyo Hospital Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8655, Tokyo, Japan aut NATIONALLICENCE 700 1- Tomura Fumiya Department of Pharmacy, The University of Tokyo Hospital Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8655, Tokyo, Japan aut NATIONALLICENCE 700 1- Yamanashi Yoshihide Department of Pharmacy, The University of Tokyo Hospital Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8655, Tokyo, Japan aut NATIONALLICENCE 700 1- Terada Tomohiro Department of Pharmacy, Kyoto University Hospital Faculty of Medicine, Kyoto University, Sakyo-ku, 606-8507, Kyoto, Japan aut NATIONALLICENCE 700 1- Inui Ken-ichi Department of Pharmacy, Kyoto University Hospital Faculty of Medicine, Kyoto University, Sakyo-ku, 606-8507, Kyoto, Japan aut NATIONALLICENCE 700 1- Suzuki Hiroshi Department of Pharmacy, The University of Tokyo Hospital Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8655, Tokyo, Japan aut NATIONALLICENCE 773 0- Pharmaceutical Research Springer US; http://www.springer-ny.com 28/2(2011-02-01), 405-412 0724-8741 28:2<405 2011 28 11095 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer