studies

1270A AASLD ABSTRACTS HEPATOLOGY, October, 2015
2179
Digoxin provides hepatoprotection through inhibition of
HIF-1a-NOX4-ROS active pathway
Xinshou Ouyang 1 , Ji-Yuan Zhang 2 , Dechun Feng 3 , Shi-Ying Cai 1 ,
Irma Garcia-Martinez 1 , Sheng-Na Han 1 , Rafaz Hoque 1 , Yonglin
Chen 1 , Fu-Sheng Wang 2 , Bin Gao 3 , Natalie J. Torok 4 , Wajahat Z.
Mehal 1 ; 1 Yale University, New Haven, CT; 2 Liver Failure Therapy
and Research Center, Beijing 302 Hospital (PLA 302 Hospital),
Beijing, China; 3 NIAAA, NIH, Bethesda, MD; 4 Gastroenterology
and Hepatology, UC Davis, Sacramento, CA
Introduction: Reactive oxygen species (ROS) driven tissue damage
is common to liver diseases. NADPH oxidase family members
have shown important contribution to the production of
hepatic ROS, and this dependent in part to HIF-1a. The cardiac
glycoside digoxin was identified as potent HIF-1a antagonist
but its role in liver disease is not well defined. Aim: To assess
whether digoxin has therapeutic effects in Non Alcoholic Fatty
Liver Disease (NASH) and alcoholic liver disease (ALD) in
mice, and investigate the molecular mechanisms in both mouse
and human cell cultures. Methods: C57BL/6J male mice were
placed on a 45% high fat diet (HFD) for 11weeks with and without
digoxin (ip 1, 0.2 and 0.05 mg/kg twice a week). Digoxin
1mg/kg ip daily in mice results in the therapeutic serum levels
achieved in humans (0.5-2 ng/ml). Plasma ALT, liver histology,
neutrophil staining, leukocytes profiling, mitochondrial reactive
oxygen species (ROS) generation, and gene transcriptome
microarrays were analyzed. The chronic plus binge model of
ALD was performed. The mechanism of digoxin on inhibition
of HIF-1a mediated NADPH oxidase 4 (NOX4) transcription
and ROS production was tested by RT-PCR, reporter luciferase
and ChIP-PCR assay. Results: Digoxin dose-dependently
reduced histological injury, neutrophilic infiltrate and serum
ALT values in both co-treatment (starting digoxin same time
with HFD, ALT, 417 +/- 398 U/L in HFD vs 91 +/- 73 U/L
in HFD+DIG, P< 0.001) and post-treatment (starting digoxin
after 4 weeks HFD, neutrophil 24.6% in HFD vs 14.3% in
HFD+DIG; monocytes 31.6% in HFD vs 19.1% in HFD+DIG;
ALT, 400 +/- 130 U/L in HFD vs 80 +/- 17 U/L in HFD+DIG,
P< 0.001) without a reduction in food intake. A low dose of
digoxin (0.05 mg/kg) also shows significant protective effects
again injury and inflammation in both NASH and ALD models.
Further microarray analysis in HFD liver tissues revealed
that digoxin down-regulated ROS metabolism and antioxidant
pathway including NOX4. In vitro data showed that digoxin
dose-dependently inhibited mitochondrial ROS production
under TLR and hydrogen peroxide stimulation in multiple mouse
and human cell cultures. Digoxin increases VHL protein levels,
resulting in a corresponding reduction HIF-1a protein levels. In
addition digoxin blocks HIF-1a mediated NOX4 gene expression,
promoter activity and NOX4 mediated ROS. Digoxin
also reduces HIF-1a binding to the NOX4 promoter region.
Conclusions: Digoxin has strong effects in reducing liver steatosis
and inflammation in experimental models of NASH and
ALD via a HIF-1a-NOX4-ROS pathway. Low dose digoxin may
provide significant therapeutic value in the treatment of NASH
and ALD patients.
Disclosures:
The following authors have nothing to disclose: Xinshou Ouyang, Ji-Yuan Zhang,
Dechun Feng, Shi-Ying Cai, Irma Garcia-Martinez, Sheng-Na Han, Rafaz Hoque,
Yonglin Chen, Fu-Sheng Wang, Bin Gao, Natalie J. Torok, Wajahat Z. Mehal
2180
Can FibroMeter VCTE be useful for detecting hepatic
fibrosis in patients with non-alcoholic fatty liver disease?
Elif Dincses 3 , Yusuf Yilmaz 1,2 ; 1 Department of Gastroenterology,
Marmara University, School of Medicine, Istanbul, Turkey; 2 Liver
Research Unit, Institute of Gastroenterology, Marmara University,
Istanbul, Turkey; 3 Department of Internal Medicine, Marmara University,
Istanbul, Turkey
Hepatic fibrosis plays a paramount role in determining the
prognosis of patients with non-alcoholic fatty liver disease
(NAFLD). Originally developed for the non-invasive detection
of fibrosis in patients with chronic viral hepatitis, the FibroMeter
VTCE is a diagnostic tool comprising both biochemical
markers and transient elastography (TE). We conducted this
pilot study to investigate the diagnostic performance of the
FibroMeter VTCE tool for diagnosing fibrosis in patients with
biopsy-proven NAFLD and compare its diagnostic accuracy
with those of the NAFLD fibrosis score (NFSA) and TE alone.
We determined FibroMeter VTCE, NFSA, and TE in 52
NAFLD patients. The results of liver biopsies were considered
as the gold standard. Areas under the ROC curve (AUROCs)
were used to express the diagnostic accuracy of each test.
We detected significant (F≥2) and severe (F≥3) fibrosis in 20
(38%) and 10 (19%) patients, respectively. The sensitivity of
FibroMeter VTCE, NFSA, and TE for detecting significant
fibrosis was 70%, 65%, and 75%, respectively, whereas specificity
was 88%, 81%, and 78%. The sensitivity of FibroMeter
VTCE, NFSA, and TE for diagnosing severe fibrosis was
90%, 90%, and 100%, respectively, whereas specificity was
93%, 78%, and 76%. ROC analysis showed that FibroMeter
VTCE had a significantly larger AUROC (0.968) compared
to both NFSA (0.833, P < 0.001) and TE (0.922, P < 0.05) for
the detection of severe fibrosis (Table). To the best of our knowledge,
this is the first study showing that FibroMeter VTCE – a
tool originally developed for patients with viral hepatitis – can
be superior to both NFSA and TE for the detection of severe
hepatic fibrosis in patients with NAFLD. Financial disclosures:
The authors declare no conficts of interest.
AUROCs and sensitivities/specificities of FibroMeter VTCE,
NFSA, and TE for the detection of severe fibrosis (F≥3) in patients
with biopsy-proven non-alcoholic fatty liver disease
Abbreviations: AUROC = area under the receiver operating
characteristic curve; NFSA = NAFLD fibrosis score; TE = transient
elastography.
Disclosures:
The following authors have nothing to disclose: Elif Dincses, Yusuf Yilmaz