studies

HEPATOLOGY, VOLUME 62, NUMBER 1 (SUPPL) AASLD ABSTRACTS 1147A
JNK2 have combined effects in protecting mice from CCl 4
- and
acetaminophen-induced liver injury. It is important to study the
functions of both proteins, rather than just JNK1, to define their
role during toxic liver injury. JNK inhibition with SP600125
has off-target effects.
Disclosures:
Christian Trautwein - Grant/Research Support: BMS, Novartis, BMS, Novartis;
Speaking and Teaching: Roche, BMS, Roche, BMS
The following authors have nothing to disclose: Francisco Javier Cubero, Wei
Hu, Gang Zhao, Miguel Eugenio Zoubek, Jin Peng, Yulia A. Nevzorova, Malika
Al Masaoudi, Lars Bechmann, Mark V. Boekschoten, Michael Muller, Christian
Preisinger, Nikolaus Gassler, Ali Canbay, Tom Luedde, Roger J. Davis, Christian
Liedtke
1925
Translocation of Iron from Lysosomes to Mitochondria
during Acetaminophen-Induced Toxicity in Mouse
Hepatocytes
Jiangting Hu 1 , Andaleb Kholmukhamedov 1 , Hartmut Jaeschke 2 ,
John J. Lemasters 1 ; 1 Medical University of South Carolina, Charleston,
SC; 2 University of Kansas Medical Center, Kansas city, KS
Background: Acetaminophen (APAP) overdose causes hepatotoxicity
involving mitochondrial dysfunction and the mitochondrial
permeability transition (MPT). Reactive oxygen species
(ROS) play an important role in APAP-induced hepatotoxicity.
Iron is a critical catalyst for ROS formation. Previous studies
show that disrupted lysosomes release ferrous iron (Fe 2+ )
into the cytosol during APAP hepatotoxicity, which triggers
the MPT and cell killing. Here, our Aim was to investigate
the role of lysosomal iron mobilization into mitochondria
during APAP-induced toxicity to mouse hepatocytes. Methods:
Hepatocytes were isolated from fasted male C57BL/6 mice.
Necrotic cell killing was assessed by propidium iodide fluorimetry.
Mitochondrial membrane potential was visualized by
confocal microscopy of rhodamine 123 (Rh123) or tetramethylrhodamine
methylester (TMRM). Chelatable Fe 2+ was monitored
by quenching of calcein (cytosol) and mitoferrofluor (MFF,
mitochondria). Results: Starch-desferal (1 mM, a lysosomally
targeted iron chelator) and Ru360 (100 nM, an inhibitor of the
mitochondrial calcium uniporter [MCU]) decreased cell killing
after APAP (10 mM) by 50% and 25% at 10 h, respectively.
Progressive quenching of calcein and MFF began after ~4 h,
signifying increased cytosolic and mitochondrial chelatable
Fe 2+ . Mitochondria then depolarized after ~10 h. Dipyridyl, a
membrane-permeable iron chelator, dequenched calcein and
MFF fluorescence. Starch-desferal, but not Ru360, suppressed
cytosolic calcein quenching, whereas both starch-desferal and
Ru360 suppressed mitochondrial MFF quenching and mitochondrial
depolarization. Conclusion: Release of chelatable
Fe 2+ from lysosomes followed by uptake into mitochondria via
MCU occurs during APAP hepatotoxicity, which triggers the
MPT and cell killing. Ru360 prevents the increase of mitochondrial
but not cytosolic Fe 2+ after APAP but is not as protective as
starch-desferal, which prevents Fe 2+ increases in both compartments.
Thus, increased Fe 2+ in the cytosol may also contribute
to APAP hepatotoxicity.
Disclosures:
John J. Lemasters - Consulting: Novo Nordisk
The following authors have nothing to disclose: Jiangting Hu, Andaleb
Kholmukhamedov, Hartmut Jaeschke
1926
Azathioprine And 6-Mercaptopurine Induced Liver
Injury
Bjornsson S. Einar 1,2 , Jiezhun Gu 3 , David E. Kleiner 2 , Naga P.
Chalasani 4 , Paul H. Hayashi 5 , Jay H. Hoofnagle 6 ; 1 The NAtional
University Hospital of Iceland, Reykjavik, Iceland; 2 NIH, Bethesda,
MD; 3 3Duke Clinical Research Institute, Durham, NC; 4 Indiana
University School of Medicine, Indinapolis, IN; 5 University of
North Carolina, Chapel Hill, NC; 6 NIDDK, NIH, Bethesda, MD
Background: Most information of regarding the drug induced
liver injury (DILI) from azathioprine (Aza) and 6-mercaptopurine
(6-MP) comes from isolated case reports and the clinical
features and frequency of outcomes is not well defined. The
aims of this study were to better define the clinical, biochemical
and histologic features of Aza and 6-MP induced liver
injury. Methods: Patients with thiopurine hepatotoxicity from
the DILIN Prospective Study were identified. Patients enrolled
between 2004 and 2014 underwent structured assessment of
potential competing etiologies and analysis of clinical features.
Results: 22 patients (12 attributed to Aza, 10 to 6-MP, none
to thioguanine) were identified who had probable (n=8), very
likely (n=12) or definite (n=2) causality scores. The median
age was 55 years, and 68% were female. Inflammatory bowel
disease was the indication in 55%, and median dose was 150
mg daily (range 25-300 mg). The duration of therapy before
onset varied widely (median 75, range 3 to 2584 days). However,
injury often arose after a dose escalation (59%) and the
median time of onset after a last dose increase was 44 days
(range 3 to 254 days). Overall 73% of cases were icteric. The
median initial ALT was 210 U/L, Alk P 151 U/L and bilirubin
7.4 mg/dL. Median peak bilirubin levels were 13.4 mg/
dL and INR 1.3. Icteric and anicteric cases differed in their
typical clinical features. Cases without jaundiced had minimal
symptoms and a hepatocellular pattern of enzyme elevations,
whereas jaundiced cases had a self-limited cholestatic
hepatitis with minimal or modest elevations in enzyme levels.
Available biopsies (7 cases) showed cholestatic hepatitis; 3
also showed evidence of nodular regeneration. There was little
fibrosis except in the patient with pre-existing cirrhosis. There
were no major differences between Aza and 6-MP cases. One
The patient with pre-existing cirrhosis underwent emergency
liver transplantation, all others resolved the injury clinically,
although one patient had moderate Alk P elevations 2 years
after onset. Conclusions: Nearly three-quarters of thiopurine-induced
liver injury presents with self-limited cholestatic hepatitis.
Injury often arises within a few months of dose increase,
highlighting the importance of monitoring liver tests after dose
escalaction. The prognosis of Aza and 6-MP related liver injury
is favorable except in patients with pre-existing cirrhosis.
Disclosures:
Naga P. Chalasani - Consulting: Abbvie, Lilly, Celgene, Tobira, NuSirt, Takeda,
Merck/Anthem, Salix; Grant/Research Support: Intercept, Gilead, Galectin
The following authors have nothing to disclose: Bjornsson S. Einar, Jiezhun Gu,
David E. Kleiner, Paul H. Hayashi, Jay H. Hoofnagle
1927
Gender-specific glucuronidation of acetaminophen in
htgUGT1A WT mice
Anja Winkler, Sandra Kalthoff, Christian P. Strassburg; Clinics and
Policlinic I, University Hospital Bonn, Bonn, Germany
Aims: Acetaminophen (APAP) is a commonly used over-thecounter
drug with analgesic as well as antipyretic properties
and at low doses is primarily metabolized through sulfation
and glucuronidation, while only a small fraction is oxidized to
the reactive metabolite N-acetyl-p-benzoquinone (NAPQI) by