studies

HEPATOLOGY, VOLUME 62, NUMBER 1 (SUPPL) AASLD ABSTRACTS 871A
1345
An alarmin cytokine IL-33 inhibits type I NKT cells and
neutrophil accumulation into liver and mediates attenuation
of alcoholic liver disease
Igor Maricic, Ekihiro Seki, Idania Marrero, Vipin Kumar; Medicine,
University of California, La Jolla, CA
Natural killer T (NKT) cells, comprised of at least two distinct
subsets, type I and type II, recognize different lipid antigens
presented by CD1d molecules and are involved in inflammatory
liver diseases. We have recently found that type I but not
type II NKT cells become activated and mediate liver injury following
chronic plus binge feeding of Lieber-DeCarli liquid diet
in male C57BL/6 mice. Here we have analyzed the hepatic
cytokine gene expression using quantitative PCR, and found
that IL-33 is significantly upregulated during alcoholic liver disease
(ALD). Interestingly elevated levels of IL-33 are dependent
upon the presence of type I NKT cells as no upregulation was
observed in Jα18-/- mice. Additionally, inhibition of type I NKT
cells by sulfatide or retinoids also blunts IL-33 levels. Next we
examined the effect of IL-33 treatment on ALD. Surprisingly i.p.
administration of IL-33 (2 μg/mouse) resulted in the amelioration
of liver injury whereas anti-IL-33 (5 μg/mouse) treatment
leads to exacerbation of liver enzymes and hepatosteatosis
following alcohol ingestion. Notably IL-33 inhibits the proliferation
and effector function of type I NKT cells in both in vitro
and in vivo assays. Immunohistological analysis of liver sections
showed that the IL-33 administration leads to a significant
inhibition of Ly6G+ neutrophils accumulation into liver.
In contrast anti-IL-33 treatment results in a significant decrease
in neutrophils and an increase in F4/80+ macrophage populations.
These studies indicate that in this model of ALD, innate
cytokines such as IL-33 secreted by liver cells have a protective
role from injury and is regulated by interactions with type I NKT
cells and myeloid cells. Collectively these results suggest that
complex interactions of different innate cells play a central role
in mediating inflammatory liver disease and may offer novel
therapeutic targets.
Disclosures:
Ekihiro Seki - Consulting: Merck, Tobira; Grant/Research Support: Nippon Zoki
Vipin Kumar - Management Position: GRI bio
The following authors have nothing to disclose: Igor Maricic, Idania Marrero
1346
Macrophage Migration Inhibitory Factor is Protective in
a Model of Chronic-Binge Ethanol Feeding in Mice
Kyle L. Poulsen 3 , Natalia Rosso 1 , Veronica Marin 1 , Megan
R. McMullen 3 , Adam R. Morris 3 , Claudio Tiribelli 1,2 , Laura E.
Nagy 3,4 ; 1 Fondazione Italiana Fegato-Centro Studi Fegato, Italian
Liver Foundation - Liver Research Center, Trieste, Italy; 2 Clinica
Patologie del Fegato, Universita degli Studi di Trieste, Trieste, Italy;
3 Pathobiology, Center for Liver Disease Research - Cleveland Clinic
Foundation, Cleveland, OH; 4 Gastroenterology, Center for Liver
Disease Research - Cleveland Clinic Foundation, Cleveland, OH
Chronic alcohol abuse is a leading cause of preventable morbidity
and mortality worldwide. Ongoing and continued alcohol
intake by alcohol abusers is the most significant risk factor
associated with the development and progression of Alcoholic
Liver Disease (ALD), which encompasses a spectrum of liver-associated
pathologies. Macrophage Migration Inhibitory Factor
(MIF), a regulator of innate immunity with chemokine- and
cytokine-like activities, was previously identified as a key contributor
to the early stage of ALD after chronic ethanol feeding
to mice. While chronic ethanol feeding in mice results in mild
liver injury and steatosis, the recently developed Chronic-Binge
(Gao-binge) ethanol feeding protocol may better model of the
more severe condition of acute alcoholic hepatitis in humans.
The goal of the current study was to investigate the role of MIF
in liver injury in response to Chronic-Binge ethanol exposure
utilizing female C57Bl/6J and MIF -/- mice. In contrast to the
protection of MIF-/- mice from chronic ethanol feeding, MIF -
/-
mice were not protected from ethanol-mediated liver injury
in response to chronic-binge exposure, exhibiting exacerbated
liver injury as indicated by plasma ALT and AST activities.
Expression of pro-inflammatory cytokines TNFα and IL-1β, as
well as chemokines MCP-1 and MIP2, were enhanced in livers
of MIF -/- mice, further implicating MIF-mediated protection
following Chronic-Binge ethanol feeding. Adhesion molecules
CD62E and ICAM-1 were also enhanced in MIF -/- mice suggesting
that MIF limits leukocyte infiltration into the liver parenchyma.
Flow-cytometric analysis of liver non-parenchymal cells
confirmed that Chronic-Binge ethanol feeding increased infiltration
of CD45 + CD11B + Ly6C + (monocyte/ macrophage) and
CD45 + CD11B + Ly6G + (neutrophil) cells into the liver. While
MIF did not affect recruitment of Ly6C + cells, Ly6G + cells were
increased in MIF -/- mice, consistent with a role for neutrophils
in mediating inflammation in response to chronic binge ethanol
exposure. Taken together, these results suggest that MIF
protects from ethanol-mediated liver damage by limiting pro-inflammatory
cytokine/chemokine synthesis, adhesion marker
expression and neutrophil infiltration following Chronic-Binge
ethanol feeding.
Disclosures:
The following authors have nothing to disclose: Kyle L. Poulsen, Natalia Rosso,
Veronica Marin, Megan R. McMullen, Adam R. Morris, Claudio Tiribelli, Laura
E. Nagy
1347
Creatine Supplementation Does Not Prevent Alcoholic
Steatosis
Dan Feng 1,2 , Ryan W. Barton 2 , Paul G. Thomes 3 , Dean J. Tuma 1,2 ,
Natalia A. Osna 1,2 , Kusum K. Kharbanda 1,2 ; 1 Research Service,
Veterans Affairs Nebraska-Western Iowa Health Care System,
Omaha, NE; 2 Department of Internal Medicine, university
Nebraska Medical Center, Omaha, NE; 3 Liver Pathobiology Laboratory,
Cannon Research Center, Carolinas Healthcare System,
Charlotte, NC
In our ongoing investigation in understanding the pathogenesis
of alcohol induced injury, we have reported that chronic
ethanol intake lowers the hepatocellular S-adenosylmethionine
(SAM) to S-adenosylhomocysteine (SAH) ratio. The reduced
ratio significantly impairs the activities of several SAM-dependent
methyltransferases, leading to the generation of many
hallmark features of alcoholic liver injury (Kharbanda, Sem
Liv Dis, 2009). One such methyltransferase, guanidinoacetate
methyltransferase (GAMT), is severely impaired after ethanol
exposure that results in reduced hepatic creatine production.
This causes detrimental consequences in the liver but also affect
distal organs such as the heart, muscle and brain that depend
on a steady supply of creatine from the liver. Since creatine
supplementation has been recently reported to prevent high-fat
diet-induced hepatic steatosis (Deminice, J Nutr, 2011), we
sought to examine whether creatine supplementation could prevent
alcoholic liver injury. Further, since GAMT is a major consumer
of SAM, we were also interested in examining whether
creatine supplementation could spare this metabolite to preserve
hepatocellular SAM:SAH ratio as well as restore the
depleted hepatic and extrahepatic creatine levels. Adult male
Wistar rats were pair-fed the Lieber DeCarli control or ethanol
diet in the presence or absence of 1% creatine in these respec-