Transcriptional Regulation of Liver-specific Organic Anion Transporters and Those Clinical Application

点击翻译按钮获取中文摘要

In 1999, we have cloned a novel human organic anion transporter named LST-1. LST-1 is strongly expressed in liver and its substrates are bile acid, conjugated steroids, eicosanoids, and some kinds of drugs. Immunohistochemical analysis indicated that LST-1 was located at sinusoidal membrane of the hepatocytes. The aim of this study is to investigate the transcriptions]-regulation mechanism of human LST-1 gene and its clinical application. The results are follows;1. Luciferase assay using HT-17 cell lines derived from hepatocyte revealed that AP-1 site (-1100bp upstream from transcriptional starting site) and HNF-1 site (-60bp) were considered to be important region for transcription.2. Luciferase activity was decreased in the reporter plasmid which inserted point mutation in the HNF-1 binding site.3. Electrophoresis mobility shift assay (EMSA) using nuclear extract of HT17 revealed that specific protein-DNA complex was detected using oligonucleotide (from-78 to -48).4. Supershift band was observed by adding a HNF-1 a antibody.These results indicated that transcriptional factor, HNF-1 a was combined with about -60bp of LST-1 gene upstream and was considered to be most important by transcription of the LST-1 gene in hepatocytes.