studies

1032A AASLD ABSTRACTS HEPATOLOGY, October, 2015
of the receptor for IL-1 (IL1R-/-) were exposed to DSS-PN for
14d. DSS-PN/IL1R-/- mice had significantly reduced serum
AST, ALT, bile acids, and bilirubin compared to DSS-PN mice.
Hepatic gene mRNA for Abcb11, Abcc2, and Abcg5/8 was
not reduced in DSS-PN IL1R-/- mice. Chromatin-immuno-precipitation
assays (ChIP) on liver demonstrated that in WT DSS-PN
mice binding of NFkB (downstream of IL1 signaling) to the
Abcg5/8 promoter was increased concomitant with reduced
binding of LXR (the transcription factor that promotes Abcg5/8
expression). In contrast, in DSS-PN IL1R-/- mice, binding of
NFkB was reduced concomitant with increased binding of LXR
to the Abcg5/8 promoter. Supporting these in vivo studies,
incubation of HepG2 and HuH7 cells with IL1b significantly
suppressed Abcg5/8 mRNA while markedly increasing NFkB
reporter activity. Finally, incubation of HepG2 cells with IL1b
suppressed the ability of an LXR agonist to induce activity
ABCG5/8 promoter linked luciferase. Conclusion: Hepatic IL1b
is a critical mediator in the pathogenesis of PNAC by promoting
suppression of the phytosterol transporter Abcg5/8 through
increased binding of NFkB and decreased binding of LXR to
the Abcg5/8 promotor. Reduced Abcg5/8 causes accumulation
of phytosterols which then interfere with hepatocyte FXR
signaling, thus promoting cholestasis.
Disclosures:
Ronald J. Sokol - Advisory Committees or Review Panels: Yasoo Health, Inc.; Consulting:
Roche, Ikaria, Otsuka American Pharmaceuticals, Alnylam, Retrophin;
Grant/Research Support: Mead Johnson Nutritionals, Lumena, FFF Enterprises
The following authors have nothing to disclose: Karim C. El Kasmi, Aimee Anderson,
Padade M. Vue, Michael W. Devereaux, Natarajan Balasubramaniyan,
Frederick J. Suchy
1689
Enteral Obeticholic Acid Promotes Intestinal Growth in
Total Parenteral Nutrition Fed Neonatal Pigs
Yanjun Jiang 1 , Zhengfeng Fang 2 , Barbara Stoll 1 , Gregory J. Guthrie
1 , Jens Holst 3 , Bolette Hartmann 3 , Douglas Burrin 1,4 ; 1 USDA
Children’s Nutrition Research Center, Department Pediatrics, Baylor
College of Medicine, Houston, TX; 2 Animal Nutrition Institute,
Sichuan Agricultural University, Chengdu, China; 3 The NNF Center
for Basic Metabolic Research and the Department of Biomedical
Sciences, University of Copenhagen, Copenhagen, Denmark;
4 Pediatric Gastroenterology, Hepatology and Nutrition, Department
Pediatrics, Baylor College of Medicine, Houston, TX
Intestinal atrophy is an adverse outcome associated with prolonged
total parenteral nutrition (PN) partly due to disruption
of normal enterohepatic circulation of bile acids. Previously
we showed that enteral treatment with chenodeoxycholic acid
(CDCA), a dual agonist for the nuclear receptor, farnesoid X
receptor (FXR) and G protein-coupled receptor TGR-5, induced
intestinal mucosal growth in a parenteral nutrition associated
liver disease (PNALD) piglet model. We hypothesized that the
intestinal trophic CDCA effects were mainly mediated by TGR5
receptor-mediated glucagon-like peptide 2 (GLP-2) released
from enteroendocrine cells. However, CDCA may also exert
trophic effects via FXR signaling in intestine. The aim of the current
study was to compare the physiological effects of a selective
and potent FXR agonist, obeticholic acid (OCA) vs CDCA
on intestinal growth in TPN-fed pigs. Term, newborn pigs were
assigned to receive complete TPN (PN), PN + enteral CDCA
(30 mg/kg), or PN +enteral OCA (0.5, 5, 15 mg/kg) daily for
19 d. The daily parenteral lipid was Intralipid given at 10 g/
kg. Intestinal growth and crypt cell proliferation (in vivo BrdU
labeling) were measured. We found that both CDCA and OCA
treatments significantly increased small intestinal weight, compared
to PN pigs, but OCA15 was higher than CDCA (146%
vs. 118%). The OCA-induced increase in jejunal and Ileal
weight was dose-dependent, yet the trophic effects of OCA and
CDCA were greater in the ileum than jejunum. Ileal villus height
and crypt depth were increased by OCA and CDCA. The percentage
of BrdU positive crypt cells in PN, CDCA, OCA0.5,
OCA5 and OCA15 groups were 31%, 40%, 40%, 46% and
46% respectively, suggesting OCA and CDCA increased crypt
cell proliferation. Portal plasma GLP-1 and -2 concentrations
were significantly increased in pigs treated with CDCA, but not
OCA, compared to PN pigs suggesting differential intestinal
activation of TGR5 signaling. OCA, but not CDCA, treatment
dose-dependently increased ileal transcriptional expression of
FXR target genes, small heterodimer partner (SHP), ileal lipid
binding protein (ILBP), and fibroblast growth factor 19 (FGF19).
The expression of fibroblast growth factor receptor 4 (FGFR4)
and β-Klotho mRNA were relative abundant in ileal tissue in all
groups. We conclude that the intestinal trophic effects of OCA
are greater than CDCA in TPN-fed pigs. The trophic effects of
CDCA appear to occur via TGR5-mediated GLP-2 secretion
rather than FXR signaling. We show novel evidence that OCA
exerts trophic effects in the neonatal intestine and this appears
to act mainly via FXR-dependent mechanisms.
Disclosures:
The following authors have nothing to disclose: Yanjun Jiang, Zhengfeng Fang,
Barbara Stoll, Gregory J. Guthrie, Jens Holst, Bolette Hartmann, Douglas Burrin
1690
Human iPSC-derived hepatocyte-like cells generated
from patients with bile salt export pump deficiency
recapitulate the phenotype of progressive familial intrahepatic
cholestasis type 2
Kazuo Imagawa 1,2 , Kazuo Takayama 2,3 , Shigemi Isoyama 1 , Ken
Tanikawa 4 , Masato Shinkai 5 , Masayoshi Kage 4 , Kenji Kawabata
6,7 , Ryo Sumazaki 1 , Hiroyuki Mizuguchi 2,3 ; 1 Department of
Child Health, Faculty of Medicine, University of Tsukuba, Tsukuba,
Japan; 2 Laboratory of Hepatocyte Regulation, National Institute of
Biomedical Innovation, Osaka, Japan; 3 Laboratory of Biochemistry
and Molecular Biology, Graduate School of Pharmaceutical
Sciences, Osaka University, Osaka, Japan; 4 Department of
Diagnostic Pathology, Kurume University Hospital, Kurume, Japan;
5 Department of Surgery, Kanagawa Children’s Medical Center,
Yokohama, Japan; 6 Laboratory of Stem Cell Regulation, National
Institute of Biomedical Innovation, Osaka, Japan; 7 Laboratory of
Biomedical Innovation, Graduate School of Pharmaceutical Sciences,
Osaka, Japan
Background: The bile salt export pump (BSEP) is a key molecule
that transports bile acid into the biliary canaliculi in
humans. Progressive familial intrahepatic cholestasis type 2
(PFIC2) is mainly characterized by BSEP deficiency, which is
followed by intrahepatic cholestasis. In many cases, liver transplantation
is the most effective therapy available. Hence, it is
necessary to identify novel therapeutic alternatives. To clarify
the underlying disease mechanisms and discover the novel
therapeutic options, we generated iPSCs from BSEP deficient
(BD) patients and analyzed the differentiated hepatocyte-like
cells (HLCs). Methods: One healthy donor and two BD patients
participated in present study. Patient 1 was diagnosed with
normal-gamma glutamyl transferase PFIC and presented with
the PFIC2 phenotype in infancy. Although her clinical features,
liver histology results, and BSEP deficiency were indicative
of the PFIC2 phenotype, exonic mutations were not found in
the BSEP gene. Patient 2 was diagnosed with PFIC2 based
on the presence of compound heterozygous mutations in the
BSEP gene (c.-24C>A and c.2416G>A) and liver histology
results. The iPSCs were generated from blood cells obtained
from all three participants (Control-iPSC and BD-iPSC) by using