The sequence of the 5'-flanking region of the rat Mrp3 gene was determined up to 2723 bp upstream of the translation start site. Regulatory regions crucial for Mrp3 promoter activity were characterized between -157 and -106 bp in hepatoma cells. Within this sequence we identified putative binding sites for C/EBP and Sp1. EMSA and supershift assays demonstrated specific binding of Sp1, Sp3, C/EBPalpha, beta, and delta. In Drosophila SL2 cells, both Sp1 and Sp3 transactivated the Mrp3 minimal promoter (pWT-157). Structural and functional analysis demonstrated that binding sites for C/EBPs, Sp1 and Sp3 were essential for transcription of the rat Mrp3 gene in Mrp3-expressing cells (including: H4IIE, H4IIE C3, BRL 3A, Clone 9, and RAT 2). Cotransfection assays demonstrated that C/EBP transcription factors modulated the basal and tissue specific activity of the Mrp3 gene promoter by recognition of the C/EBP (-157/-140) element and through functional cooperation with factors interacting with the Sp1 (3) and Sp1 (4) (-140/-106) cis-acting elements. In this study, we found C/EBPs and Sp1/Sp3 cooperatively regulated the promoter activity of rat Mrp3 gene through proximal (-157/-106) region. It suggested another fine-tune regulation mechanism may involve in Mrp3 gene expression.
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http://dx.doi.org/10.1007/s11373-005-9002-5 | DOI Listing |
Biomed Pharmacother
November 2024
Experimental Hepatology and Drug Targeting (HEVEPHARM), University of Salamanca, Salamanca, Spain; Institute for Biomedical Research of Salamanca (IBSAL), Salamanca, Spain; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Carlos III National Institute of Health, Madrid, Spain.
Aims: Drug export through ABC proteins hinders cancer response to chemotherapy. Here, we have evaluated the relevance of MRP3 (ABCC3) in cholangiocarcinoma (CCA) as a potential target to overcome drug resistance.
Methods: Gene expression was analyzed in silico using the TCGA-CHOL database and experimentally (mRNA and protein) in resected CCA tumors.
Front Oncol
August 2024
Department of Pharmacology, School of Pharmaceutical Sciences, China Medical University, Shenyang, China.
BMC Biol
September 2024
Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang, China.
Background: Haem is essential but toxic for metazoan organisms. Auxotrophic nematodes can acquire sufficient haem from the environment or their hosts in the meanwhile eliminate or detoxify excessive haem through tightly controlled machinery. In previous work, we reported a role of the unique transporter protein HRG-1 in the haem acquisition and homeostasis of parasitic nematodes.
View Article and Find Full Text PDFFluids Barriers CNS
August 2024
Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada.
Background: Folates are a family of B vitamins essential for normal growth and development in the central nervous system (CNS). Transport of folates is mediated by three major transport proteins: folate receptor alpha (FRα), proton-coupled folate transporter (PCFT), and reduced folate carrier (RFC). Brain folate uptake occurs at the choroid plexus (CP) epithelium through coordinated actions of FRα and PCFT, or directly into brain parenchyma at the vascular blood-brain barrier (BBB), mediated by RFC.
View Article and Find Full Text PDFJ Ethnopharmacol
October 2024
Department of Chinese Medicinal Chemistry, School of Pharmacy, Liaoning University of Traditional Chinese Medicine, 77, 1st Life Road, D D Port, Dalian, 116600, People's Republic of China. Electronic address:
Ethnopharmacological Relevance: Gentiana radix (GR) and wine-processed Gentiana radix (WGR) have been commonly used in folk medicine for the treatment of bile or liver disorders, including jaundice, hepatitis, swelling and inflammation for thousands of years. However, the therapeutic effects of gentian root (GR) and wine-made gentian root (WGR) treatment on damp-heat jaundice syndrome (DHJS) have not been studied in animal experiments.
Aim Of The Study: This study aimed to investigate the protective effects and mechanisms of GR and WGR on DHJS in rats.
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