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result(s) for
"Fiel, M. Isabel"
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Modeling dysbiosis of human NASH in mice: Loss of gut microbiome diversity and overgrowth of Erysipelotrichales
by
Bhattacharya, Dipankar
,
Faith, Jeremiah J.
,
Borgerding, Joshua N.
in
Animal models
,
Animals
,
Bacteria
2021
Non-alcoholic steatohepatitis (NASH) is a severe form of non-alcoholic fatty liver disease (NAFLD) that is responsible for a growing fraction of cirrhosis and liver cancer cases worldwide. Changes in the gut microbiome have been implicated in NASH pathogenesis, but the lack of suitable murine models has been a barrier to progress. We have therefore characterized the microbiome in a well-validated murine NASH model to establish its value in modeling human disease.
The composition of intestinal microbiota was monitored in mice on a 12- or 24-week NASH protocol consisting of high fat, high sugar Western Diet (WD) plus once weekly i.p injection of low-dose CCl4. Additional mice were subjected to WD-only or CCl4-only conditions to assess the independent effect of these variables on the microbiome.
There was substantial remodeling of the intestinal microbiome in NASH mice, characterized by declines in both species diversity and bacterial abundance. Based on changes to beta diversity, microbiota from NASH mice clustered separately from controls in principal coordinate analyses. A comparison between WD-only and CCl4-only controls with the NASH model identified WD as the primary driver of early changes to the microbiome, resulting in loss of diversity within the 1st week. A NASH signature emerged progressively at weeks 6 and 12, including, most notably, a reproducible bloom of the Firmicute order Erysipelotrichales.
We have established a valuable model to study the role of gut microbes in NASH, enabling us to identify a new NASH gut microbiome signature.
Journal Article
Update on the New Classification of Hepatic Adenomas: Clinical, Molecular, and Pathologic Characteristics
by
Dhingra, Sadhna
,
Fiel, M. Isabel
in
Adenoma - diagnosis
,
Adenoma - genetics
,
Adenoma - metabolism
2014
Context.—Hepatic adenoma is an uncommon, benign, hepatic neoplasm that typically occurs in women of child-bearing age, often with a history of long-term use of oral contraceptive drugs. This is usually detected as an incidental mass lesion in a noncirrhotic liver during imaging studies. Pathologic evaluation by needle core biopsy remains the gold standard for diagnosis. Molecular studies have revealed that hepatic adenomas involve unique molecular pathways that are distinct from hepatocellular carcinoma. Based on these studies, a French collaborative group has recently proposed a molecular-pathologic classification for hepatic adenomas. In addition, advances in molecular studies have led to reclassification of the “telangiectatic variant of focal nodular hyperplasia” as “hepatic adenoma, inflammatory subtype.” Objective.—To review the proposed, new classification of hepatic adenoma and the changes in diagnostic workup in light of the above-mentioned developments. Data sources.—Review of published literature and illustrations from clinical case material. Conclusions.—Definitive diagnosis of liver mass lesion on needle core biopsies has a decisive role in clinical management. With the advent of the new classification of hepatic adenomas and its prognostic implications, it is vital for pathologists to be aware of the morphologic features seen in different subtypes and the available diagnostic tools, such as immunohistochemistry, to help identify the correct subtype.
Journal Article
Hepatocellular carcinoma detection in liver cirrhosis: diagnostic performance of contrast-enhanced CT vs. MRI with extracellular contrast vs. gadoxetic acid
2020
ObjectivesTo evaluate the diagnostic performance of contrast-enhanced CT vs. MRI with extracellular contrast agents (EC-MRI) vs. MRI with gadoxetic acid (EOB-MRI) for HCC detection in patients with liver cirrhosis using liver explant as the reference. The additional value of hepatobiliary phase (HBP) post Gadoxetic acid was also assessed.MethodsTwo-hundred seventy-seven consecutive patients who underwent liver transplantation over a 9 year period and imaging within 90 days of were retrospectively included. Imaging consisted in CT (n = 100), EC-MRI (n = 77) and EOB-MRI (n = 100), the latter subdivided into dynamic EOB-MRI and full EOB-MRI (dynamic+HBP). Three radiologists retrospectively categorized lesions ≥ 1 cm using the LI-RADSv2017 algorithm. Dynamic EOB-MRI was re-evaluated with the addition of HBP. Results were correlated with explant pathology.ResultsPathology demonstrated 265 HCCs (mean size 2.1 ± 1.4 cm) in 177 patients. Per-patient sensitivities were 86.3% for CT, 89.5% for EC-MRI, 92.8% for dynamic EOB-MRI and 95.2% for full EOB-MRI (pooled reader data), with a significant difference between CT and dynamic/full EOB-MRI (p = 0.032/0.002), and between EC-MRI and full EOB-MRI (p = 0.047). Per-lesion sensitivities for CT, EC-MRI, dynamic EOB-MRI and full EOB-MRI were 59.5%,78.5%,69.7% and 76.8%, respectively, with a significant difference between MRI groups and CT (p-range:0.001–0.04), and no difference between EC-MRI and dynamic EOB-MRI (p = 0.949). For HCCs 1–1.9 cm, sensitivities were 34.4%, 64.6%, 57.3% and 67.3%, respectively, with all MRI groups significantly superior to CT (p ≤ 0.01) and full EOB-MRI superior to dynamic EOB-MRI (p = 0.002).ConclusionsEOB-MRI outperforms CT and EC-MRI for per-patient HCC detection sensitivity, and is equivalent to EC-MRI for per-lesion sensitivity. MRI methods outperform CT for detection of HCCs 1–1.9 cm.Key points• MRI is superior to CT for HCC detection in patients with liver cirrhosis.• EOB-MRI outperforms CT and MRI using extracellular contrast agents (EC-MRI) for per-patient HCC detection sensitivity, and is equivalent to EC-MRI for per-lesion sensitivity.• The addition of hepatobiliary phase images improves HCC detection when using gadoxetic acid.
Journal Article
Autophagy is a gatekeeper of hepatic differentiation and carcinogenesis by controlling the degradation of Yap
2018
Activation of the Hippo pathway effector Yap underlies many liver cancers, however no germline or somatic mutations have been identified. Autophagy maintains essential metabolic functions of the liver, and autophagy-deficient murine models develop benign adenomas and hepatomegaly, which have been attributed to activation of the p62/Sqstm1-Nrf2 axis. Here, we show that Yap is an autophagy substrate and mediator of tissue remodeling and hepatocarcinogenesis independent of the p62/Sqstm1-Nrf2 axis. Hepatocyte-specific deletion of Atg7 promotes liver size, fibrosis, progenitor cell expansion, and hepatocarcinogenesis, which is rescued by concurrent deletion of Yap. Our results shed new light on mechanisms of Yap degradation and the sequence of events that follow disruption of autophagy, which is impaired in chronic liver disease.
Increased levels of the Yap oncoprotein stimulate liver growth and promote hepatocarcinogenesis. Here the authors show that hepatocyte-specific loss of
Atg7
in mice leads to decreased autophagic degradation of Yap and liver overgrowth, and further establish this association in human liver cancer tissues.
Journal Article
A pilot systematic genomic comparison of recurrence risks of hepatitis B virus-associated hepatocellular carcinoma with low- and high-degree liver fibrosis
by
Lee, Eunjee
,
Hiotis, Spiros P.
,
Wang, Wenhui
in
Biomedicine
,
Cancer genetics
,
Comparative analysis
2017
Background
Chronic hepatitis B virus (HBV) infection leads to liver fibrosis, which is a major risk factor in hepatocellular carcinoma (HCC) and an independent risk factor of recurrence after HCC tumor resection. The HBV genome can be inserted into the human genome, and chronic inflammation may trigger somatic mutations. However, how HBV integration and other genomic changes contribute to the risk of tumor recurrence with regards to the different degree of liver fibrosis is not clearly understood.
Methods
We sequenced mRNAs of 21 pairs of tumor and distant non-neoplastic liver tissues of HBV-HCC patients and performed comprehensive genomic analyses of our RNAseq data and public available HBV-HCC sequencing data.
Results
We developed a robust pipeline for sensitively identifying HBV integration sites based on sequencing data. Simulations showed that our method outperformed existing methods. Applying it to our data, 374 and 106 HBV host genes were identified in non-neoplastic liver and tumor tissues, respectively. When applying it to other RNA sequencing datasets, consistently more HBV integrations were identified in non-neoplastic liver than in tumor tissues. HBV host genes identified in non-neoplastic liver samples significantly overlapped with known tumor suppressor genes. More significant enrichment of tumor suppressor genes was observed among HBV host genes identified from patients with tumor recurrence, indicating the potential risk of tumor recurrence driven by HBV integration in non-neoplastic liver tissues. We also compared SNPs of each sample with SNPs in a cancer census database and inferred samples’ pathogenic SNP loads. Pathogenic SNP loads in non-neoplastic liver tissues were consistently higher than those in normal liver tissues. Additionally, HBV host genes identified in non-neoplastic liver tissues significantly overlapped with pathogenic somatic mutations, suggesting that HBV integration and somatic mutations targeting the same set of genes are important to tumorigenesis. HBV integrations and pathogenic mutations showed distinct patterns between low and high liver fibrosis patients with regards to tumor recurrence.
Conclusions
The results suggest that HBV integrations and pathogenic SNPs in non-neoplastic tissues are important for tumorigenesis and different recurrence risk models are needed for patients with low and high degrees of liver fibrosis.
Journal Article
A pilot study of ultra-deep targeted sequencing of plasma DNA identifies driver mutations in hepatocellular carcinoma
2018
Cellular components of solid tumors including DNA are released into the bloodstream, but data on circulating-free DNA (cfDNA) in hepatocellular carcinoma (HCC) are still scarce. This study aimed at analyzing mutations in cfDNA and their correlation with tissue mutations in patients with HCC. We included 8 HCC patients treated with surgical resection for whom we collected paired tissue and plasma/serum samples. We analyzed 45 specimens, including multiregional tumor tissue sampling (
n
= 24), peripheral blood mononuclear cells (PMBC,
n
= 8), plasma (
n
= 8) and serum (
n
= 5). Ultra-deep sequencing (5500× coverage) of all exons was performed in a targeted panel of 58 genes, including frequent HCC driver genes and druggable mutations. Mutations detected in plasma included known HCC oncogenes and tumor suppressors (e.g.,
TERT
promoter,
TP53
, and
NTRK3
) as well as a candidate druggable mutation (
JAK1
). This approach increased the detection rates previously reported for mutations in plasma of HCC patients. A thorough characterization of
cis
mutations found in plasma confirmed their tumoral origin, which provides definitive evidence of the release of HCC-derived DNA fragments into the bloodstream. This study demonstrates that ultra-deep sequencing of cfDNA is feasible and can confidently detect somatic mutations found in tissue; these data reinforce the role of plasma DNA as a promising minimally invasive tool to interrogate HCC genetics.
Journal Article
Quantification of hepatocellular carcinoma heterogeneity with multiparametric magnetic resonance imaging
2017
Tumour heterogeneity poses a significant challenge for treatment stratification. The goals of this study were to quantify heterogeneity in hepatocellular carcinoma (HCC) using multiparametric magnetic resonance imaging (mpMRI), and to report preliminary data correlating quantitative MRI parameters with advanced histopathology and gene expression in a patient subset. Thirty-two HCC patients with 39 HCC lesions underwent mpMRI including diffusion-weighted imaging (DWI), blood-oxygenation-level-dependent (BOLD), tissue-oxygenation-level-dependent (TOLD) and dynamic contrast-enhanced (DCE)-MRI. Histogram characteristics [central tendency (mean, median) and heterogeneity (standard deviation, kurtosis, skewness) MRI parameters] in HCC and liver parenchyma were compared using Wilcoxon signed-rank tests. Histogram data was correlated between MRI methods in all patients and with histopathology and gene expression in 14 patients. HCCs exhibited significantly higher intra-tissue heterogeneity vs. liver with all MRI methods (
P
< 0.030). Although central tendency parameters showed significant correlations between MRI methods and with each of histopathology and gene expression, heterogeneity parameters exhibited additional complementary correlations between BOLD and DCE-MRI and with histopathologic hypoxia marker HIF1α and gene expression of Wnt target
GLUL
, pharmacological target
FGFR4
, stemness markers
EPCAM
and
KRT19
and immune checkpoint
PDCD1
. Histogram analysis combining central tendency and heterogeneity mpMRI features is promising for non-invasive HCC characterization on the imaging, histologic and genomics levels.
Journal Article
Consensus report from the 9th International Forum for Liver Magnetic Resonance Imaging: applications of gadoxetic acid-enhanced imaging
2021
Objectives
The 9th International Forum for Liver Magnetic Resonance Imaging (MRI) was held in Singapore in September 2019, bringing together radiologists and allied specialists to discuss the latest developments in and formulate consensus statements for liver MRI, including the applications of gadoxetic acid–enhanced imaging.
Methods
As at previous Liver Forums, the meeting was held over 2 days. Presentations by the faculty on days 1 and 2 and breakout group discussions on day 1 were followed by delegate voting on consensus statements presented on day 2. Presentations and discussions centered on two main meeting themes relating to the use of gadoxetic acid–enhanced MRI in primary liver cancer and metastatic liver disease.
Results and conclusions
Gadoxetic acid–enhanced MRI offers the ability to monitor response to systemic therapy and to assist in pre-surgical/pre-interventional planning in liver metastases. In hepatocellular carcinoma, gadoxetic acid–enhanced MRI provides precise staging information for accurate treatment decision-making and follow-up post therapy. Gadoxetic acid–enhanced MRI also has potential, currently investigational, indications for the functional assessment of the liver and the biliary system. Additional voting sessions at the Liver Forum debated the role of multidisciplinary care in the management of patients with liver disease, evidence to support the use of abbreviated imaging protocols, and the importance of standardizing nomenclature in international guidelines in order to increase the sharing of scientific data and improve the communication between centers.
Key Points
•
Gadoxetic acid
–
enhanced MRI is the preferred imaging method for pre-surgical or pre-interventional planning for liver metastases after systemic therapy.
•
Gadoxetic acid
–
enhanced MRI provides accurate staging of HCC before and after treatment with locoregional/biologic therapies.
•
Abbreviated protocols for gadoxetic acid–enhanced MRI offer potential time and cost savings, but more evidence is necessary. The use of gadoxetic acid–enhanced MRI for the assessment of liver and biliary function is under active investigation.
Journal Article
NRBF2 regulates autophagy and prevents liver injury by modulating Atg14L-linked phosphatidylinositol-3 kinase III activity
2014
The Beclin 1-Vps34 complex, the core component of the class III phosphatidylinositol-3 kinase (PI3K-III), binds Atg14L or UVRAG to control different steps of autophagy. However, the mechanism underlying the control of PI3K-III activity remains elusive. Here we report the identification of NRBF2 as a component in the specific PI3K-III complex and a modulator of PI3K-III activity. Through its microtubule interaction and trafficking (MIT) domain, NRBF2 binds Atg14L directly and enhances Atg14L-linked Vps34 kinase activity and autophagy induction. NRBF2-deficient cells exhibit enhanced vulnerability to endoplasmic reticulum (ER) stress that is reversed by re-introducing exogenous NRBF2. NRBF2-deficient mice develop focal liver necrosis and ductular reaction, accompanied by impaired Atg14L-linked Vps34 activity and autophagy, although the mice show no increased mortality. Our data reveal a key role for NRBF2 in the assembly of the specific Atg14L-Beclin 1-Vps34-Vps15 complex for autophagy induction. Thus, NRBF2 modulates autophagy via regulation of PI3K-III and prevents ER stress-mediated cytotoxicity and liver injury.
Autophagosome biogenesis depends on the lipid kinase Vps34 and its binding proteins Beclin 1 and Atg14L. Lu
et al.
identify nuclear receptor binding factor 2 (NRBF2) as a regulator of this complex, and show that loss of NRBF2 impairs autophagy, enhances cell vulnerability to endoplasmic reticulum stress and promotes necrosis in the liver.
Journal Article
A subset of liver resident natural killer cells is expanded in hepatitis C-infected patients with better liver function
by
Eng, Francis
,
Klepper, Arielle L.
,
Branch, Andrea D.
in
692/4020/4021
,
692/4020/4021/234
,
692/4020/4021/234/2513
2021
Viral hepatitis leads to immune-mediated liver injury. The rate of disease progression varies between individuals. We aimed to phenotype immune cells associated with preservation of normal liver function during hepatitis C virus (HCV) infection. Clinical data and specimens were obtained from 19 HCV-infected patients undergoing liver transplantation. Liver and peripheral blood mononuclear cells were isolated and eight subsets of innate immune cells were delineated by multiparameter flow cytometry. Cytokine assays and microarrays were performed. Intrahepatic CD56
Bright
/CD16
-
natural killer (NK) cells comprised the only subset correlating with better liver function, i.e., lower bilirubin (
p
= 0.0002) and lower model for end stage of liver disease scores (
p
= 0.03). The signature of liver NK cells from HCV-infected patients included genes expressed by NK cells in normal liver and by decidual NK cells. Portal vein blood had a higher concentration of interleukin (IL)-10 than peripheral blood (
p
= 0.03). LMCs were less responsive to toll-like receptor (TLR) stimulation than PBMCs, with fewer pro-inflammatory gene-expression pathways up-regulated after in vitro exposure to lipopolysaccharide and a TLR-7/8 agonist. Hepatic CD56
Bright
/CD16
-
NK cells may be critical for maintaining liver homeostasis. Portal vein IL-10 may prime inhibitory pathways, attenuating TLR signaling and reducing responsiveness to pro-inflammatory stimuli.
Journal Article