studies

874A AASLD ABSTRACTS HEPATOLOGY, October, 2015
hsp90 impacts epigenetic chromatin modifying enzymes
important in innate immune activation and lipid metabolism in
a cell-specific manner in ALD.
Disclosures:
The following authors have nothing to disclose: Pranoti Mandrekar, Aditya
Ambade, Arlene Lim
1352
Cyr61 protection of hepatocytes from alcohol-induced
endoplasmic reticulum stress
Sang Geon Kim, Tae Hyun Kim, Hyun Joo Kim; College of Pharmacy,
Seoul National University, Seoul, Korea (the Republic of)
The endoplasmic reticulum (ER), the major organelle responsible
for the biosynthesis, folding, assembly and modification
of soluble proteins and membrane proteins, senses cellular or
extracellular stresses. Since the liver plays a key role in energy
metabolism and toxicant detoxification as the portal organ, a
variety of harmful stimuli, including imbalance of energy supply,
alcohol intake, oxidative stress, and inflammatory mediators
induces ER stress, which may facilitate hepatocyte dysfunction
and injury. Cysteine-rich angiogenic protein 61 (Cyr61), a
member of matricellular cysteine-rich protein (CCN) family,
regulates cell survival, differentiation and inflammation. This
study investigated whether Cyr61 inhibits alcoholic steatohepatitis
(ASH), and if so, what the underlying mechanism is using
the database of ASH patients, animal and hepatocyte models.
Of the CCN family members, the transcript levels of CCN1
encoding for Cyr61 were uniquely and markedly diminished
in patients with alcoholic hepatitis. In the liver tissue or hepatocytes
prepared from mice fed on Lieber-DeCarli alcohol diet for
4 weeks or exposed to binge alcohol, Cyr61 expression levels
were substantially decreased with reciprocal increases of fatty
acid synthase and acetyl-CoA carboxylase. Cyr61 knockdown
augmented ER stress in hepatocytes, as indicated by changes
in ER stress markers, CHOP, Grp78, XBP-1 and IRE-1a. Conversely,
overexpression of Cyr61 suppressed ER stress. Moreover,
Cyr61 knockdown promoted PARP cleavage with the
induction of CYP2E1. Cyr61 overexpression diminished ethanol-induced
PARP-1 cleavage. Overall, our results demonstrate
that Cyr61 repression by alcohol intake promotes hepatocyte
injury through increase of ER stress, providing a novel link
between Cyr61 and ER stress in the progression of ASH.
Disclosures:
Sang Geon Kim - Consulting: Nature’s Sunshine Products, Inc
The following authors have nothing to disclose: Tae Hyun Kim, Hyun Joo Kim
1353
IL-13Rα1 signaling and M2 macrophages but not Th2 T
cells drive progression of CCL 4
-induce fibrosis
Shih-Yen Weng 1 , Xiaoyu Wang 1 , Yong Ook Kim 1 , Leonard Kaps 1 ,
Yilang Tang 2 , Olena Molokanova 1 , Jeff R. Crosby 3 , Michael L.
McCaleb 3 , Brombacher Frank 4 , Tobias Bopp 5 , Hans-Joerg Schild 5 ,
Ari Waisman 2 , Detlef Schuppan 1,6 ; 1 Institute of Translational
Immunology, University Medicine, Johannes Gutenberg University,
Mainz, Germany, Mainz, Germany; 2 Institute for Molecular
Medicine, Mainz, Germany; 3 Isis Pharmaceuticals, Carlsbad,
CA; 4 Institute of Infectious Disease and Molecular Medicine, Cape
Town, South Africa; 5 Institute of Immunology and Research Center
for Immunotherapy at UMC Mainz, Mainz, Germany; 6 Beth Israel
Deaconess Medical Center, Boston, MA
Background and aims: Liver fibrosis progression and regression
are modulated by cells of the immune system. CD4 T cells
regulate functional macrophages polarization by secreting
cytokines such as IFNg, IL-12, IL-4 and IL-13. To investigate the
roles of IL-4 and IL-13 in liver fibrosis development, systemic
IL-4/IL-13 double KO mice (IL-4/IL13 -/- ) and T cell specific deletion
of IL-4/IL-13 (IL-4/IL13 ∆CD4 ) and IL-4Rα (IL-4Rα ∆CD4 ) were
generated and subjected to liver fibrosis analysis. Methods:
Liver fibrosis progression was modeled by administration of
oral CCL 4
in increasing doses for 6 weeks. Antisense oligonucleotides
(ASO) were injected intraperitoneally at 40mg/kg 3
times per week during the 6 weeks of CCL 4
treatment . Results:
Histology analysis of IL-4/IL-13 -/- mice at 6 week of CCL 4
treatment
revealed significant reduction of collagen deposition indicated
by less Sirius Red-stained area (50% decrease) in. This
was accompanied by 6-fold reduction of procollagen α1(I)
and α-SMA transcripts, and a decreased ALT indicating suppressed
liver injury. IL-4/IL-13 -/- mice also showed an increase
in CD4 and CD8 T cells, monocytes and macrophages/Kupffer
cells as assessed by FACS. However, IL-4/IL-13 ΔCD4 mice and
IL-4Rα ΔCD4 mice showed no significant difference in liver fibrosis
compared to control mice. Therefore Th2 cells appear to
play only a minor role in CCL 4
-induced fibrosis, suggesting
other fibrogenic cells responding to IL-4/13. IL-13Rα1 was
previously characterized as an M2 macrophage marker. We
therefore applied an ASO against IL-13Rα1 to CCL 4
-treated
mice. Compared to control ASO treated mice, liver fibrosis as
assessed by collagen quantification and Sirius red morphometry,
was significantlyy attenuated by this treatment. Conclusions:
We demonstrate an important role of IL-4/IL-13 signaling
in CCL 4
-induced fibrogenesis. However, IL-4/13 producing
Th2 T cells do not play a significant role in fibrosis progression,
while M2 macrophages, responsive to IL-13, apparently produced
by other sources, are central to fibrosis progression. This
qualifies IL-13 and IL-13Rα1 as important targets for antifibrotic
therapies.
Disclosures:
Jeff R. Crosby - Employment: ISIS Pharmaceuticals
Michael L. McCaleb - Employment: Isis Pharmaceuticals; Stock Shareholder: Isis
Pharmaceuticals
The following authors have nothing to disclose: Shih-Yen Weng, Xiaoyu Wang,
Yong Ook Kim, Leonard Kaps, Yilang Tang, Olena Molokanova, Brombacher
Frank, Tobias Bopp, Hans-Joerg Schild, Ari Waisman, Detlef Schuppan