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  1. Article ; Online: Interaction of Human OATP1B1 with PDZK1 Is Required for Its Trafficking to the Hepatocyte Plasma Membrane.

    Wang, Pijun / Murray, John W / Wolkoff, Allan W

    Drug metabolism and disposition: the biological fate of chemicals

    2023  Volume 51, Issue 10, Page(s) 1342–1349

    Abstract: Uptake of xenobiotics by hepatocytes is mediated by specific proteins, including organic anion transporting polypeptides (OATPs), residing on the basolateral (sinusoidal) plasma membrane. Many of the OATPs have PDZ consensus binding sites, determined by ... ...

    Abstract Uptake of xenobiotics by hepatocytes is mediated by specific proteins, including organic anion transporting polypeptides (OATPs), residing on the basolateral (sinusoidal) plasma membrane. Many of the OATPs have PDZ consensus binding sites, determined by their C-terminal 4 amino acids, while others do not. Mouse and rat OATP1A1 are associated with PDZK1, which is necessary for their trafficking to the plasma membrane. humanOATP1B1 (hOATP1B1) is a major drug transporter in human liver. Although localized to the plasma membrane, it was thought to lack a PDZ consensus motif, suggesting that the trafficking paradigm for murine OATPs is not applicable to human liver. The aim of the present study was to determine whether hOATP1B1 is a ligand for hPDZK1. hOATP1B1 immunoprecipitates with hPDZK1 following co-expression in 293T cells as well as in normal human liver. Co-expression with each of the 4 PDZ domains revealed interaction with domain 1 only. A truncated version of hOATP1B1 that lacks its terminal 4 amino acid PDZ binding motif as well as hOATP1B3, which does not contain a PDZ binding consensus motif, failed to interact with hPDZK1. Immunofluorescence microscopy of hOATP1B1 in stably transfected HeLa cells that endogenously express hPDZK1 showed that it distributes predominantly along the plasma membrane whereas hOATP1B1 lacking its terminal 4 amino acids distributes primarily intracellularly with little plasma membrane localization. Similar to findings in rats and mice, human OATP1B1 is a ligand for PDZK1 and requires interaction with PDZK1 for optimal trafficking to the hepatocyte plasma membrane. SIGNIFICANCE: Previous studies suggested that OATP1B1, a major xenobiotic transporter in human liver, does not have a PDZ binding consensus motif and does not follow the paradigm for subcellular trafficking and function that was established for OATP1A1 in murine liver. We now demonstrated that OATP1B1 but not OATP1B3 has a PDZ binding consensus motif that mediates binding to PDZK1 and is required for its trafficking to the plasma membrane. Such interaction could be an important previously unrecognized modulator of transport function.
    MeSH term(s) Animals ; Humans ; Mice ; Rats ; Amino Acids/metabolism ; Cell Membrane/metabolism ; HeLa Cells ; Hepatocytes/metabolism ; Ligands ; Membrane Proteins/metabolism ; Organic Anion Transporters/metabolism ; Solute Carrier Organic Anion Transporter Family Member 1B3/metabolism
    Chemical Substances Amino Acids ; Ligands ; Membrane Proteins ; Organic Anion Transporters ; PDZK1 protein, human ; Solute Carrier Organic Anion Transporter Family Member 1B3 ; SLCO1B1 protein, human
    Language English
    Publishing date 2023-07-13
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 186795-7
    ISSN 1521-009X ; 0090-9556
    ISSN (online) 1521-009X
    ISSN 0090-9556
    DOI 10.1124/dmd.123.001248
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Book ; Online ; E-Book: The liver

    Arias, Irwin M. / Alter, Harvey J. / Boyer, James L. / Cohen, David E. / Shafritz, David A. / Wolkoff, Allan W. / Thorgeirsson, Snorri S.

    biology and pathobiology

    2020  

    Author's details Irwin M. Arias, Harvey J. Alter, James L. Boyer, David E. Cohen, David A. Shafritz, Allan W. Wolkoff, Snorri S. Thorgeirrson editors
    Keywords Electronic books
    Language English
    Size 1 Online-Ressource (xix, 1122 Seiten)
    Edition Sixth edition
    Publisher Wiley
    Publishing place Hoboken, NJ
    Publishing country United States
    Document type Book ; Online ; E-Book
    Note Description based on publisher supplied metadata and other sources
    Remark Zugriff für angemeldete ZB MED-Nutzerinnen und -Nutzer
    HBZ-ID HT020440507
    ISBN 978-1-119-43683-6 ; 9781119436829 ; 1-119-43683-4 ; 1119436826
    Database ZB MED Catalogue: Medicine, Health, Nutrition, Environment, Agriculture

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  3. Article ; Online: Organic anion uptake by hepatocytes.

    Wolkoff, Allan W

    Comprehensive Physiology

    2014  Volume 4, Issue 4, Page(s) 1715–1735

    Abstract: Many of the compounds taken up by the liver are organic anions that circulate tightly bound to protein carriers such as albumin. The fenestrated sinusoidal endothelium of the liver permits these compounds to have access to hepatocytes. Studies to ... ...

    Abstract Many of the compounds taken up by the liver are organic anions that circulate tightly bound to protein carriers such as albumin. The fenestrated sinusoidal endothelium of the liver permits these compounds to have access to hepatocytes. Studies to characterize hepatic uptake of organic anions through kinetic analyses, suggested that it was carrier-mediated. Attempts to identify specific transporters by biochemical approaches were largely unsuccessful and were replaced by studies that utilized expression cloning. These studies led to identification of the organic anion transport proteins (oatps), a family of 12 transmembrane domain glycoproteins that have broad and often overlapping substrate specificities. The oatps mediate Na(+)-independent organic anion uptake. Other studies identified a seven transmembrane domain glycoprotein, Na(+)/taurocholate transporting protein (ntcp) as mediating Na(+)-dependent uptake of bile acids as well as other organic anions. Although mutations or deficiencies of specific members of the oatp family have been associated with transport abnormalities, there have been no such reports for ntcp, and its physiologic role remains to be determined, although expression of ntcp in vitro recapitulates the characteristics of Na(+)-dependent bile acid transport that is seen in vivo. Both ntcp and oatps traffic between the cell surface and intracellular vesicular pools. These vesicles move through the cell on microtubules, using the microtubule based motors dynein and kinesins. Factors that regulate this motility are under study and may provide a unique mechanism that can alter the plasma membrane content of these transporters and consequently their accessibility to circulating ligands.
    MeSH term(s) Amino Acid Sequence ; Animals ; Bile Acids and Salts/blood ; Bile Acids and Salts/metabolism ; Bilirubin/blood ; Bilirubin/metabolism ; Hepatocytes/metabolism ; Humans ; Molecular Sequence Data ; Organic Anion Transporters/chemistry ; Organic Anion Transporters/genetics ; Organic Anion Transporters/metabolism
    Chemical Substances Bile Acids and Salts ; Organic Anion Transporters ; Bilirubin (RFM9X3LJ49)
    Language English
    Publishing date 2014-10
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Review
    ISSN 2040-4603
    ISSN (online) 2040-4603
    DOI 10.1002/cphy.c140023
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Interindividual Diversity in Expression of Organic Anion Uptake Transporters in Normal and Cirrhotic Human Liver.

    Taniguchi, Tatsuya / Zanetti-Yabur, Alana / Wang, Pijun / Usyk, Mykhaylo / Burk, Robert D / Wolkoff, Allan W

    Hepatology communications

    2020  Volume 4, Issue 5, Page(s) 739–752

    Abstract: The liver plays an essential role in removing endogenous and exogenous compounds from the circulation. This function is mediated by specific transporters, including members of the family of organic anion transport proteins (OATPs) and the ... ...

    Abstract The liver plays an essential role in removing endogenous and exogenous compounds from the circulation. This function is mediated by specific transporters, including members of the family of organic anion transport proteins (OATPs) and the Na
    Language English
    Publishing date 2020-03-11
    Publishing country United States
    Document type Journal Article
    ISSN 2471-254X
    ISSN (online) 2471-254X
    DOI 10.1002/hep4.1489
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Hepatic Predictors of Mortality in Severe Acute Respiratory Syndrome Coronavirus 2: Role of Initial Aspartate Aminotransferase/Alanine Aminotransferase and Preexisting Cirrhosis.

    Frager, Shalom Z / Szymanski, James / Schwartz, Jonathan M / Massoumi, Hatef S / Kinkhabwala, Milan / Wolkoff, Allan W

    Hepatology communications

    2020  Volume 5, Issue 3, Page(s) 424–433

    Abstract: The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) is the causative agent of coronavirus disease 2019 (COVID-19). The presenting symptoms of this virus are variable, and there is an increasing body of literature on risk ... ...

    Abstract The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) is the causative agent of coronavirus disease 2019 (COVID-19). The presenting symptoms of this virus are variable, and there is an increasing body of literature on risk factors for mortality. The aim of this study was to evaluate the effect of initial aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and preexisting liver disease, including cirrhosis, in a cohort of patients admitted with COVID-19 infection at a tertiary care hospital network in the Bronx, New York. We reviewed 3,352 patients who had a positive SARS-CoV2 nasal swab, were over 18 years of age, and had an associated inpatient admission and discharge (or death) to the Montefiore Medical Center from February 28, 2020, to May 22, 2020. Of these, 39/86 (45%) patients died when the initial ALT was >5 times the upper limit of normal (ULN); 115/230 (50%) patients died when the initial AST was >3 times the ULN. The mortality of patients without preexisting liver disease was 26.6% compared to a mortality rate of 29.5% in patients with liver disease. Subgroup analysis showed a mortality of 36.1% in the patients with cirrhosis. Cirrhosis conferred a hazard ratio for mortality of 1.67 (95% confidence interval, 1.09, 2.55;
    MeSH term(s) Aged ; Aged, 80 and over ; Alanine Transaminase/analysis ; Aspartate Aminotransferases/analysis ; COVID-19/diagnosis ; COVID-19/mortality ; Cohort Studies ; Female ; Hospitalization ; Humans ; Liver/physiopathology ; Liver/virology ; Liver Cirrhosis/complications ; Male ; Middle Aged ; New York ; Prognosis ; Respiratory Insufficiency ; Risk Factors ; Severity of Illness Index ; Survival Analysis ; Tertiary Care Centers
    Chemical Substances Aspartate Aminotransferases (EC 2.6.1.1) ; Alanine Transaminase (EC 2.6.1.2)
    Language English
    Publishing date 2020-12-05
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ISSN 2471-254X
    ISSN (online) 2471-254X
    DOI 10.1002/hep4.1648
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Deletion of the Pseudorabies Virus gE/gI-US9p complex disrupts kinesin KIF1A and KIF5C recruitment during egress, and alters the properties of microtubule-dependent transport in vitro.

    Diwaker, Drishya / Murray, John W / Barnes, Jenna / Wolkoff, Allan W / Wilson, Duncan W

    PLoS pathogens

    2020  Volume 16, Issue 6, Page(s) e1008597

    Abstract: During infection of neurons by alphaherpesviruses including Pseudorabies virus (PRV) and Herpes simplex virus type 1 (HSV-1) viral nucleocapsids assemble in the cell nucleus, become enveloped in the cell body then traffic into and down axons to nerve ... ...

    Abstract During infection of neurons by alphaherpesviruses including Pseudorabies virus (PRV) and Herpes simplex virus type 1 (HSV-1) viral nucleocapsids assemble in the cell nucleus, become enveloped in the cell body then traffic into and down axons to nerve termini for spread to adjacent epithelia. The viral membrane protein US9p and the membrane glycoprotein heterodimer gE/gI play critical roles in anterograde spread of both HSV-1 and PRV, and several models exist to explain their function. Biochemical studies suggest that PRV US9p associates with the kinesin-3 motor KIF1A in a gE/gI-stimulated manner, and the gE/gI-US9p complex has been proposed to recruit KIF1A to PRV for microtubule-mediated anterograde trafficking into or along the axon. However, as loss of gE/gI-US9p essentially abolishes delivery of alphaherpesviruses to the axon it is difficult to determine the microtubule-dependent trafficking properties and motor-composition of Δ(gE/gI-US9p) particles. Alternatively, studies in HSV-1 have suggested that gE/gI and US9p are required for the appearance of virions in the axon because they act upstream, to help assemble enveloped virions in the cell body. We prepared Δ(gE/gI-US9p) mutant, and control parental PRV particles from differentiated cultured neuronal or porcine kidney epithelial cells and quantitated the efficiency of virion assembly, the properties of microtubule-dependent transport and the ability of viral particles to recruit kinesin motors. We find that loss of gE/gI-US9p has no significant effect upon PRV particle assembly but leads to greatly diminished plus end-directed traffic, and enhanced minus end-directed and bidirectional movement along microtubules. PRV particles prepared from infected differentiated mouse CAD neurons were found to be associated with either kinesin KIF1A or kinesin KIF5C, but not both. Loss of gE/gI-US9p resulted in failure to recruit KIF1A and KF5C, but did not affect dynein binding. Unexpectedly, while KIF5C was expressed in undifferentiated and differentiated CAD neurons it was only found associated with PRV particles prepared from differentiated cells.
    MeSH term(s) Animals ; Biological Transport, Active ; Cell Line ; Gene Deletion ; Herpesvirus 1, Suid/genetics ; Herpesvirus 1, Suid/metabolism ; Humans ; Intracellular Signaling Peptides and Proteins/genetics ; Intracellular Signaling Peptides and Proteins/metabolism ; Kinesins/genetics ; Kinesins/metabolism ; Lipoproteins/genetics ; Lipoproteins/metabolism ; Microtubules/genetics ; Microtubules/metabolism ; Microtubules/virology ; Pseudorabies/genetics ; Pseudorabies/metabolism ; Pseudorabies/pathology ; Viral Envelope Proteins/genetics ; Viral Envelope Proteins/metabolism ; Viral Proteins/genetics ; Viral Proteins/metabolism ; Virus Release
    Chemical Substances Intracellular Signaling Peptides and Proteins ; KIF1A protein, human ; Lipoproteins ; US9 protein, Suid herpesvirus 1 ; Viral Envelope Proteins ; Viral Proteins ; glycoprotein E, Suid herpesvirus 1 ; KIF5C protein, human (EC 3.6.1.-) ; Kinesins (EC 3.6.4.4)
    Language English
    Publishing date 2020-06-08
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Video-Audio Media
    ZDB-ID 2205412-1
    ISSN 1553-7374 ; 1553-7374
    ISSN (online) 1553-7374
    ISSN 1553-7374
    DOI 10.1371/journal.ppat.1008597
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Reduction of organelle motility by removal of potassium and other solutes.

    Murray, John W / Yin, David / Wolkoff, Allan W

    PloS one

    2017  Volume 12, Issue 9, Page(s) e0184898

    Abstract: There are surprisingly few studies that describe how the composition of cell culture medium may affect the trafficking of organelles. Here we utilize time lapse multi-channel fluorescent imaging to show that short term exposure of Huh-7 cells to medium ... ...

    Abstract There are surprisingly few studies that describe how the composition of cell culture medium may affect the trafficking of organelles. Here we utilize time lapse multi-channel fluorescent imaging to show that short term exposure of Huh-7 cells to medium lacking potassium, sodium, or chloride strongly reduces but does not eliminate the characteristic back and forth and cell-traversing movement of fluorescent EGF (FL-EGF) containing organelles. We focused on potassium because of its relatively low abundance in media and serum and its energy requiring accumulation into cells. Upon exposure to potassium free medium, organelle motility declined steadily through 90 min and then persisted at a low level. Reduced motility was confirmed in 5 independent cell lines and for organelles of the endocytic pathway (FL-EGF and Lysotracker), autophagosomes (LC3-GFP), and mitochondria (TMRE). As has been previously established, potassium free medium also inhibited endocytosis. We expected that diminished cellular metabolism would precede loss of organelle motility. However, extracellular flux analysis showed near normal mitochondrial oxygen consumption and only a small decrease in extracellular acidification, the latter suggesting decreased glycolysis or proton efflux. Other energy dependent activities such as the accumulation of Lysotracker, TMRE, DiBAC4(3), and the exclusion of propidium iodide remained intact, as did the microtubule cytoskeleton. We took advantage of cell free in vitro motility assays and found that removal of potassium or sodium from the reconstituted cytosolic medium decreased the movement of endosomes on purified microtubules. The results indicate that although changes in proton homeostasis and cell energetics under solute depletion are not fully understood, potassium as well as sodium appear to be directly required by the motile machinery of organelles for optimal trafficking.
    MeSH term(s) Animals ; Autophagosomes/metabolism ; Dogs ; Endocytosis ; Endosomes/metabolism ; Humans ; Madin Darby Canine Kidney Cells ; Microtubules/metabolism ; Mitochondria/metabolism ; Potassium/metabolism ; Sodium/metabolism
    Chemical Substances Sodium (9NEZ333N27) ; Potassium (RWP5GA015D)
    Language English
    Publishing date 2017-09-18
    Publishing country United States
    Document type Journal Article
    ISSN 1932-6203
    ISSN (online) 1932-6203
    DOI 10.1371/journal.pone.0184898
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article: Prolonged Serum Alanine Aminotransferase Elevation Associated with Isotretinoin Administration.

    Nazarian, Roya S / Zheng, Elizabeth / Halverstam, Caroline / Cohen, Steven R / Wolkoff, Allan W

    Case reports in hepatology

    2019  Volume 2019, Page(s) 9270827

    Abstract: Isotretinoin is a highly effective oral retinoid derivative for severe forms of acne. Despite its high margin of safety, isotretinoin carries a risk of teratogenicity and mild to massive elevations of serum cholesterol and triglyceride levels, as well as ...

    Abstract Isotretinoin is a highly effective oral retinoid derivative for severe forms of acne. Despite its high margin of safety, isotretinoin carries a risk of teratogenicity and mild to massive elevations of serum cholesterol and triglyceride levels, as well as infrequent transaminitis. Liver dysfunction induced by isotretinoin is rare but it poses a management dilemma. We describe a 16-year-old male in whom alanine aminotransferase (ALT) rose from a baseline of 13 to 288 U/L after 20 weeks of treatment with 1.0-1.4 mg/kg of oral isotretinoin daily. Though the patient remained asymptomatic, ALT levels did not return to normal limits for approximately 8 months after discontinuation of therapy, an observation that has not been documented in the literature. When oral isotretinoin was readministered for intractable facial acne 3 years later, liver enzymes remained normal throughout the course of therapy. Although the pathogenesis and prognosis of retinoid-induced hepatotoxicity are unknown, this case illustrates that isotretinoin may be safely readministered after normalization of liver function tests.
    Language English
    Publishing date 2019-07-17
    Publishing country United States
    Document type Case Reports
    ISSN 2090-6587
    ISSN 2090-6587
    DOI 10.1155/2019/9270827
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Utilizing Fibrosis-4 score to assess risk for hepatic fibrosis in patients with psoriasis on methotrexate.

    Yim, Elizabeth / Deutsch, Alana / Nazarian, Roya S / McLellan, Beth N / Espinoza, Danielle / Wolkoff, Allan W / Cohen, Steven R

    International journal of dermatology

    2020  Volume 60, Issue 3, Page(s) e100–e101

    MeSH term(s) Humans ; Liver/pathology ; Liver Cirrhosis/pathology ; Methotrexate/adverse effects ; Psoriasis/drug therapy ; Psoriasis/pathology
    Chemical Substances Methotrexate (YL5FZ2Y5U1)
    Language English
    Publishing date 2020-09-29
    Publishing country England
    Document type Letter
    ZDB-ID 412254-9
    ISSN 1365-4632 ; 0011-9059 ; 1461-1244
    ISSN (online) 1365-4632
    ISSN 0011-9059 ; 1461-1244
    DOI 10.1111/ijd.15201
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  10. Article ; Online: Rab1a regulates sorting of early endocytic vesicles.

    Mukhopadhyay, Aparna / Quiroz, Jose A / Wolkoff, Allan W

    American journal of physiology. Gastrointestinal and liver physiology

    2014  Volume 306, Issue 5, Page(s) G412–24

    Abstract: We previously reported that Rab1a is associated with asialoorosomucoid (ASOR)-containing early endocytic vesicles, where it is required for their microtubule-based motility. In Rab1a knockdown (KD) cell lines, ASOR failed to segregate from its receptor ... ...

    Abstract We previously reported that Rab1a is associated with asialoorosomucoid (ASOR)-containing early endocytic vesicles, where it is required for their microtubule-based motility. In Rab1a knockdown (KD) cell lines, ASOR failed to segregate from its receptor and, consequently, did not reach lysosomes for degradation, indicating a defect in early endosome sorting. Although Rab1 is required for Golgi/endoplasmic reticulum trafficking, this process was unaffected, likely due to retained expression of Rab1b in these cells. The present study shows that Rab1a has a more general role in endocytic vesicle processing that extends to EGF and transferrin (Tfn) trafficking. Compared with results in control Huh7 cells, EGF accumulated in aggregates within Rab1a KD cells, failing to reach lysosomal compartments. Tfn, a prototypical example of recycling cargo, accumulated in a Rab11-mediated slow-recycling compartment in Rab1a KD cells, in contrast to control cells, which sort Tfn into a fast-recycling Rab4 compartment. These data indicate that Rab1a is an important regulator of early endosome sorting for multiple cargo species. The effectors and accessory proteins recruited by Rab1a to early endocytic vesicles include the minus-end-directed kinesin motor KifC1, while others remain to be discovered.
    MeSH term(s) Asialoglycoproteins/metabolism ; Biological Transport ; Cell Line, Tumor ; Endocytosis ; Fluorescent Antibody Technique ; Gene Expression Regulation/physiology ; Gene Knockdown Techniques ; Humans ; Kinesin/genetics ; Kinesin/metabolism ; Ovomucin/metabolism ; Transport Vesicles/physiology ; rab1 GTP-Binding Proteins/genetics ; rab1 GTP-Binding Proteins/metabolism
    Chemical Substances Asialoglycoproteins ; KIFC1 protein, human ; asialoovomucoid ; Ovomucin (37281-36-0) ; Kinesin (EC 3.6.4.4) ; rab1 GTP-Binding Proteins (EC 3.6.5.2)
    Language English
    Publishing date 2014-01-09
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 603840-2
    ISSN 1522-1547 ; 0193-1857
    ISSN (online) 1522-1547
    ISSN 0193-1857
    DOI 10.1152/ajpgi.00118.2013
    Database MEDical Literature Analysis and Retrieval System OnLINE

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