Novel Mechanisms of Valproate Hepatotoxicity: Impaired Mrp2 Trafficking and Hepatocyte Depolarization

Abstract Drug-induced liver injury (DILI) remains a major challenge in drug development. Although numerous mechanisms for DILI have been identified, few studies have focused on loss of hepatocyte polarization as a DILI mechanism. The current study investigated the effects of valproate (VPA), an antiepileptic drug with DILI risk, on the cellular mechanisms responsible for loss of hepatocyte polarization. Fully polarized collagen sandwich-cultured rat hepatocytes were treated with VPA (1–20 mM) for specified times (3–24 h). Hepatocyte viability was significantly decreased by 10 and 20 mM VPA. Valproate depolarized hepatocytes, even at noncytotoxic concentrations (≤5 mM). Depolarization was associated with significantly decreased canalicular levels of multidrug resistance-associated protein 2 (Mrp2) resulting in reduced canalicular excretion of the Mrp2 substrate carboxydichlorofluorescein. The decreased canalicular Mrp2 was associated with intracellular accumulation of Mrp2 in Rab11-positive recycling endosomes and early endosomes. Mechanistic studies suggested that VPA inhibited canalicular trafficking of Mrp2. This effect of VPA on Mrp2 appeared to be selective in that VPA had less impact on canalicular levels of the bile salt export pump (Bsep) and no detectable effect on P-glycoprotein (P-gp) canalicular levels. Treatment with VPA for 24 h also significantly downregulated levels of tight junction (TJ)-associated protein, zonula occludens 2 (ZO2), but appeared to have no effect on the levels of TJ proteins claudin 1, claudin 2, occludin, ZO1, and ZO3. These findings reveal that two novel mechanisms may contribute to VPA hepatotoxicity: impaired canalicular trafficking of Mrp2 and disruption of ZO2-associated hepatocyte polarization.

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Involvement of Reactive Metabolites of Diclofenac in Cytotoxicity in Sandwich-Cultured Rat Hepatocytes

International Journal of Toxicology ◽

10.1177/1091581817700584 ◽

2017 ◽

Vol 36 (3) ◽

pp. 260-267 ◽

Cited By ~ 8

Author(s):

Atsushi Kawase ◽

Ryota Hashimoto ◽

Mai Shibata ◽

Hiroaki Shimada ◽

Masahiro Iwaki

Keyword(s):

Lactate Dehydrogenase ◽

Rat Hepatocytes ◽

Protein Adducts ◽

Reactive Metabolites ◽

Uridine Diphosphate ◽

Drug Induced ◽

Drug Induced Liver Injury ◽

Protein Adduct ◽

Acute Cytotoxicity ◽

Cultured Rat Hepatocytes

Background and Objectives: Diclofenac (DIC) is metabolized to reactive metabolites such as diclofenac acyl-β-d-glucuronide (DIC-AG). It is possible that such reactive metabolites could cause tissue damage by formation of covalent protein adducts and other modification of cellular proteins or by induction of immune responses against its covalent protein adducts. However, the detailed mechanisms of idiosyncratic drug-induced liver injury (DILI) have been unclear. The objective is to clarify the involvement of DIC-AG and 4′hydroxydiclofenac (4′OH-DIC) in acute DILI. Methods: We examined the effects of inhibiting DIC-AG and 4′OH-DIC production on covalent protein adduct formation and lactate dehydrogenase leakage using sandwich-cultured rat hepatocytes (SCRHs). Results: After pretreatment of SCRH with (−)-borneol (BOR, a uridine diphosphate (UDP)-glucuronosyltransferase inhibitor) or sulfaphenazole (SUL, a cytochrome P450 2C9 inhibitor) for 30 minutes, intracellular concentrations of DIC, DIC-AG, and 4′OH-DIC were determined after further treating cells with 300 μM DIC for 3 hours. The decreased levels of reactive metabolites caused by BOR or SUL pretreatment resulted in decreased lactate dehydrogenase leakage from SCRH, although the formation of covalent protein adducts was not affected. Conclusion: These results suggested that both DIC-AG and 4′OH-DIC may be involved in acute cytotoxicity by DIC.

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Advances in Engineered Liver Models for Investigating Drug-Induced Liver Injury

BioMed Research International ◽

10.1155/2016/1829148 ◽

2016 ◽

Vol 2016 ◽

pp. 1-20 ◽

Cited By ~ 27

Author(s):

Christine Lin ◽

Salman R. Khetani

Keyword(s):

Liver Injury ◽

Human Liver ◽

Animal Studies ◽

Drug Exposure ◽

Induced Pluripotent Stem Cell ◽

Cell Types ◽

Rapid Decline ◽

Cellular Mechanisms ◽

Drug Induced ◽

Drug Induced Liver Injury

Drug-induced liver injury (DILI) is a major cause of drug attrition. Testing drugs on human liver models is essential to mitigate the risk of clinical DILI since animal studies do not always suffice due to species-specific differences in liver pathways. While primary human hepatocytes (PHHs) can be cultured on extracellular matrix proteins, a rapid decline in functions leads to low sensitivity (<50%) in DILI prediction. Semiconductor-driven engineering tools now allow precise control over the hepatocyte microenvironment to enhance and stabilize phenotypic functions. The latest platforms coculture PHHs with stromal cells to achieve hepatic stability and enable crosstalk between the various liver cell types towards capturing complex cellular mechanisms in DILI. The recent introduction of induced pluripotent stem cell-derived human hepatocyte-like cells can potentially allow a better understanding of interindividual differences in idiosyncratic DILI. Liver models are also being coupled to other tissue models via microfluidic perfusion to study the intertissue crosstalk upon drug exposure as in a live organism. Here, we review the major advances being made in the engineering of liver models and readouts as they pertain to DILI investigations. We anticipate that engineered human liver models will reduce drug attrition, animal usage, and cases of DILI in humans.

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Characterization of release profile of ornithine carbamoyltransferase from primary rat hepatocytes treated with hepatotoxic drugs: Implications for its unique potential as a drug-induced liver injury biomarker

Drug Metabolism and Pharmacokinetics ◽

10.1016/j.dmpk.2015.11.005 ◽

2016 ◽

Vol 31 (1) ◽

pp. 102-105 ◽

Cited By ~ 4

Author(s):

Tomomi Furihata ◽

Takayuki Aizawa ◽

Akira Koibuchi ◽

Meiyan Zhu ◽

Yuki Yamasaki ◽

...

Keyword(s):

Liver Injury ◽

Rat Hepatocytes ◽

Release Profile ◽

Ornithine Carbamoyltransferase ◽

Drug Induced ◽

Drug Induced Liver Injury ◽

Primary Rat Hepatocytes ◽

Unique Potential

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Drug-induced Liver Injury in a Patient With Coronavirus Disease 2019: Potential Interaction of Remdesivir With P-Glycoprotein Inhibitors

Clinical Infectious Diseases ◽

10.1093/cid/ciaa883 ◽

2020 ◽

Cited By ~ 4

Author(s):

Emiel Leegwater ◽

Anne Strik ◽

Erik B Wilms ◽

Liesbeth B E Bosma ◽

David M Burger ◽

...

Keyword(s):

Liver Injury ◽

Potential Interaction ◽

Drug Induced ◽

Glycoprotein P ◽

Drug Induced Liver Injury ◽

P Glycoprotein ◽

Glycoprotein Inhibitors ◽

Probable Interaction

Abstract We report a case of a man with COVID-19 who developed acute hepatotoxicity related to remdesivir with probable interaction of P-glycoprotein (P-gp) inhibitors. Until further details on this interaction become available, we recommend physicians to be cautious with the prescription of P-gp inhibitors in patients receiving remdesivir therapy.

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The chemical, genetic and immunological basis of idiosyncratic drug–induced liver injury

Human & Experimental Toxicology ◽

10.1177/0960327115606529 ◽

2015 ◽

Vol 34 (12) ◽

pp. 1310-1317 ◽

Cited By ~ 20

Author(s):

A Tailor ◽

L Faulkner ◽

DJ Naisbitt ◽

BK Park

Keyword(s):

Liver Injury ◽

Adaptive Immune System ◽

Idiosyncratic Drug Reactions ◽

Cellular Mechanisms ◽

Drug Induced ◽

Drug Induced Liver Injury ◽

Chemical Genetic ◽

Adaptive Immune ◽

Drug Companies

Idiosyncratic drug reactions can be extremely severe and are not accounted for by the regular pharmacology of a drug. Thus, the mechanism of idiosyncratic drug–induced liver injury (iDILI), a phenomenon that occurs with many drugs including β-lactams, anti-tuberculosis drugs and non-steroidal anti-inflammatories, has been difficult to determine and remains a pressing issue for patients and drug companies. Evidence has shown that iDILI is multifactorial and multifaceted, which suggests that multiple cellular mechanisms may be involved. However, a common initiating event has been proposed to be the formation of reactive drug metabolites and covalently bound adducts. Although the fate of these metabolites are unclear, recent evidence has shown a possible link between iDILI and the adaptive immune system. This review highlights the role of reactive metabolites, the recent genetic innovations which have provided molecular targets for iDILI, and the current literature which suggests an immunological basis for iDILI.

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Leberschaden unter oraler Antikoagulation, Statin- und ACE-Hemmertherapie

Praxis ◽

10.1024/1661-8157/a000298 ◽

2010 ◽

Vol 99 (21) ◽

pp. 1259-1265 ◽

Cited By ~ 2

Author(s):

Bruggisser ◽

Terraciano ◽

Rätz Bravo ◽

Haschke

Keyword(s):

Liver Injury ◽

Wird Eine ◽

Drug Induced ◽

Drug Induced Liver Injury

Ein 71-jähriger Patient stellt sich mit Epistaxis und ikterischen Skleren auf der Notfallstation vor. Der Patient steht unter einer Therapie mit Phenprocoumon, Atorvastatin und Perindopril. Anamnestisch besteht ein langjähriger Alkoholabusus. Laborchemisch werden massiv erhöhte Leberwerte (ALAT, Bilirubin) gesehen. Der INR ist unter oraler Antikoagulation und bei akuter Leberinsuffizienz >12. Die weiterführenden Abklärungen schliessen eine Virushepatitis und eine Autoimmunhepatitis aus. Nachdem eine Leberbiopsie durchgeführt werden kann, wird eine medikamentös-toxische Hepatitis, ausgelöst durch die Komedikation von Atorvastatin, Phenprocoumon und Perindopril bei durch Alkohol bereits vorgeschädigter Leber diagnostiziert. Epidemiologie, Pathophysiologie und Klink der medikamentös induzierten Leberschäden (drug induced liver injury, DILI), speziell von Coumarinen, Statinen und ACE-Hemmern werden im Anschluss an den Fallbericht diskutiert.

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