studies

862A AASLD ABSTRACTS HEPATOLOGY, October, 2015
necroptosis is RIP1-independent. In contrast, RIP3 knockout
mice had decreased neutrophil infiltration, serum alanine
amino transferase (ALT) activity and steatosis compared to wild
type mice after Gao-binge alcohol treatment, suggesting that
RIP3 but not RIP1 contributes to alcohol-induced necroptosis
and liver injury. Gao-binge alcohol treatment did not change
hepatic mRNA levels of RIP3 but decreased mRNA levels of
RIP1, suggesting the increase in hepatic RIP3 protein level in
alcohol-treated mouse livers was likely due to post-translational
regulation. In primary cultured mouse and human hepatocytes,
we found that alcohol treatment decreased proteasome activity
and increased the protein level of RIP3. Similarly, Bortezomib,
a proteasome inhibitor, also increased the protein level of RIP3
in cultured hepatocytes. Consistent with these in vitro findings,
we also found that Gao-binge alcohol treatment decreased
the levels of proteasome subunit alpha type-5 (PSMA5) and
proteasome subunit beta type-5 (PSMB5), two key proteasome
subunits that are important for proteasome function. As a result,
Gao-binge treatment also decreased proteasome activity in
the mouse livers. More importantly, we also found decreased
expression of PSMA5 and PSMB5 and increased protein levels
of RIP3 in human alcoholic liver biopsy samples compared
to healthy human livers. In conclusion, results from this study
suggest that impaired hepatic proteasome function by alcohol
exposure may contribute to alcohol-induced steatosis and liver
injury by inducing necroptosis through blocking proteasomal
degradation of RIP3.
Disclosures:
The following authors have nothing to disclose: Wen-Xing Ding, Shaogui Wang,
Hong-Min Ni
1326
Characteristic features of microbiomes in alcoholic
liver disease analyzed by 16S ribosomal RNA gene
pyrosequencing and transcriptional fragment length
polymorphism methods using fecal samples: the impact
of abstinence
Makiko Taniai, Etsuko Hashimoto, Kuniko Yamamoto, Yuichi
Ikarashi, Kazuhisa Kodama, Tomomi Kogiso, Nobuyuki Torii, Katsutoshi
Tokushige; Internal Medicine, Institute of Gastroenterology,
Tokyo Women’s Medical University, Tokyo, Japan
Intestinal bacterial overgrowth and dysbiosis
induced by ethanol ingestion appears to play an important
role in the pathogenesis of alcoholic liver disease (ALD).
Recently, determination of microbiomes by 16S ribosomal RNA
(rRNA) gene pyrosequencing and terminal restriction fragment
length polymorphism (TRFLP) using stool samples has been
widely used in place of conventional culture methods for the
assessment of the diversity of complex bacterial communities
and rapid comparison of the community structure. In this study,
we evaluated the characteristics of intestinal microbiomes in
ALD patients and the impact of abstinence on it using TRFLP
analysis. We investigated samples from 20 patients
clinicopathologically diagnosed as ALD (75% males, 21 to
76 years, including 7 patients with cirrhosis) and 10 healthy
volunteers as controls matched with age and sex. Five mg of
feces were collected for analysis. Principle component analysis
(PCA) and phylogenetic cluster analysis were employed to
assess the comparison about the component of microbiomes
in two groups. In 6 cases who successfully stopped drinking,
we rechecked the stool samples at the point from 3 to 6 weeks
after abstinence. Large differences at microbial phylum,
family, and genus levels were noted between the patients
with ALD and control subjects. The most striking feature about
microbiomes in ALD patients was the variability of microbiomes
were significantly decreased and very simplified compared to
that of control subjects. In ALD patients, the increase of Bacteroides
fragilis group and Clostridium coccoides group and the
decrease of Lactobacillus group were prominent. Interestingly,
in all cases who stopped drinking, the variability of microbiomes
dramatically improved and the components approached
to those of controls. Intestinal microbiomes
in ALD patients showed distinct composition and significant
decrease in the variability of microbiomes compared to that of
control subjects. Those dysbiosis improved after relatively shortterm
abstinence. This findings could lead to the elucidation of
pathogenesis and new therapeutic approach for ALD.
Disclosures:
The following authors have nothing to disclose: Makiko Taniai, Etsuko Hashimoto,
Kuniko Yamamoto, Yuichi Ikarashi, Kazuhisa Kodama, Tomomi Kogiso,
Nobuyuki Torii, Katsutoshi Tokushige
1327
LPS-TLR4 pathway mediates ductular reaction expansion
in alcoholic hepatitis
Gemma Odena 1 , Raluca Dumitru 2 , Jiegen Chen 1 , Jose Altamirano
3,4 , Veronica L. Massey 1 , Hiroshi Matsushita 5 , Daniel Rodrigo-Torres
3 , Oriol Morales-Ibanez 3 , Juan Caballeria 6,3 , Pere
Gines 6,3 , Ekihiro Seki 5 , Pau Sancho-Bru 3 , Ramon Bataller 1,3 ;
1 Division of Gastroenterology and Hepatology, Departments of
Medicine and Nutrition and Bowles Center For Alcohol Studies,
University of North Carolina at Chapel Hill, Chapel Hill, NC;
2 UNC Human Pluripotent Stem Cell Core, Neuroscience Center
and Department of Genetics, University of North Carolina at
Chapel Hill, Chapel Hill, NC; 3 Institut d’Investigacions Biomediques
August Pi i Sunyer (IDIBAPS), CIBER de Enfermedades Hepaticas y
Digestivas (CIBERehd), Barcelona, Spain; 4 Liver Unit-Internal Medicine
Department, Vall d’Hebron University Hospital, Vall d’Hebron
Institut de Recerca, Barcelona, Spain; 5 Division of Gastroenterology,
Department of Medicine, Cedars-Sinai Medical Center, Los
Angeles, CA; 6 Liver Unit, Hospital Clínic, Barcelona, Spain
Alcoholic hepatitis (AH) is the most severe form of alcoholic
liver disease and targeted therapies are urgently needed. We
recently showed that severe AH is characterized by progenitor
cell expansion and inefficient hepatic regeneration. Because
LPS is a major molecular driver in AH and its serum levels
correlate with patient outcome, we investigated whether the
LPS-TLR4 pathway mediates progenitor cell expansion. We first
assessed the potential role of LPS in patients with biopsy-proven
AH (n=28). LPS serum levels correlated with disease severity
(ABIC score; r=0.48, p=0.02) and markers of progenitor cell
expansion (KRT23, r=0.58, p