Document Detail

Heterogeneous accumulation of fluorescent bile acids in primary rat hepatocytes does not correlate with their homogenous expression of ntcp.
MedLine Citation:
PMID:  21474652     Owner:  NLM     Status:  MEDLINE    
Sodium taurocholate-cotransporting polypeptide (ntcp) is considered to be a major determinant of bile acid uptake into hepatocytes. However, the regulation of ntcp and the degree that it participates in the accumulation of specific substrates are not well understood. We utilized fluorescent bile acid derivatives and direct quantitation of fluorescent microscopy images to examine the regulation of ntcp and its role in the cell-to-cell variability of fluorescent bile acid accumulation. Primary-cultured rat hepatocytes rapidly accumulated the fluorescent bile acids, chenodeoxycholylglycylamidofluorescein (CDCGamF), 7-β- nitrobenzoxadiazole 3-α hydroxy 5-β cholan-24-oic acid (NBD-CA), and cholyl-glycylamido-fluorescein (CGamF). However, in stably transfected HeLa cells, ntcp preferred CDCGamF, whereas the organic anion transporter, organic anion transporting polypeptide 1 (oatp1a1), preferred NBD-CA, and neither ntcp nor oatp1a1 showed strong accumulation of CGamF by these methods. Ntcp-mediated transport of CDCGamF was inhibited by taurocholate, cyclosporin, actin depolymerization, and an inhibitor of atypical PKC-ζ. The latter two agents altered the cellular distribution of ntcp as visualized in ntcp-green fluorescent protein-transfected cells. Although fluorescent bile acid accumulation was reproducible by the imaging assays, individual cells showed variable accumulation that was not attributable to changes in membrane permeability or cell viability. In HeLa cells, this was accounted for by variable levels of ntcp, whereas, in hepatocytes, ntcp expression was uniform, and low accumulation was seen in a large portion of cells despite the presence of ntcp. These studies indicate that single-cell imaging can provide insight into previously unrecognized details of anion transport in the complex environment of polarized hepatocytes.
John W Murray; Amar J Thosani; Pijun Wang; Allan W Wolkoff
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2011-04-07
Journal Detail:
Title:  American journal of physiology. Gastrointestinal and liver physiology     Volume:  301     ISSN:  1522-1547     ISO Abbreviation:  Am. J. Physiol. Gastrointest. Liver Physiol.     Publication Date:  2011 Jul 
Date Detail:
Created Date:  2011-06-29     Completed Date:  2011-09-06     Revised Date:  2013-06-30    
Medline Journal Info:
Nlm Unique ID:  100901227     Medline TA:  Am J Physiol Gastrointest Liver Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  G60-8     Citation Subset:  IM    
Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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MeSH Terms
Bile Acids and Salts / metabolism*
Cells, Cultured
Cyclosporine / pharmacology
Enzyme Inhibitors / pharmacology
Fluorescent Dyes / metabolism*
HeLa Cells
Hepatocytes / cytology,  metabolism*
Molecular Chaperones / antagonists & inhibitors
Organic Anion Transporters, Sodium-Dependent / antagonists & inhibitors,  biosynthesis*
Single-Cell Analysis
Symporters / antagonists & inhibitors,  biosynthesis*
Taurocholic Acid / pharmacology
Grant Support
Reg. No./Substance:
0/Bile Acids and Salts; 0/Enzyme Inhibitors; 0/Fluorescent Dyes; 0/Molecular Chaperones; 0/Organic Anion Transporters, Sodium-Dependent; 0/Prkcz protein, rat; 0/Symporters; 145420-23-1/sodium-bile acid cotransporter; 59865-13-3/Cyclosporine; 81-24-3/Taurocholic Acid

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