Publications by authors named "Bryan C Fuchs"

83 Publications

Quantitative, noninvasive MRI characterization of disease progression in a mouse model of non-alcoholic steatohepatitis.

Sci Rep 2021 Mar 17;11(1):6105. Epub 2021 Mar 17.

Department of Radiology, Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Institute for Innovation in Imaging, Harvard Medical School, 149 13th St., Boston, MA, 02129, USA.

Non-alcoholic steatohepatitis (NASH) is an increasing cause of chronic liver disease characterized by steatosis, inflammation, and fibrosis which can lead to cirrhosis, hepatocellular carcinoma, and mortality. Quantitative, noninvasive methods for characterizing the pathophysiology of NASH at both the preclinical and clinical level are sorely needed. We report here a multiparametric magnetic resonance imaging (MRI) protocol with the fibrogenesis probe Gd-Hyd to characterize fibrotic disease activity and steatosis in a common mouse model of NASH. Mice were fed a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) to induce NASH with advanced fibrosis. Mice fed normal chow and CDAHFD underwent MRI after 2, 6, 10 and 14 weeks to measure liver T1, T2*, fat fraction, and dynamic T1-weighted Gd-Hyd enhanced imaging of the liver. Steatosis, inflammation, and fibrosis were then quantified by histology. NASH and fibrosis developed quickly in CDAHFD fed mice with strong correlation between morphometric steatosis quantification and liver fat estimated by MRI (r = 0.90). Sirius red histology and collagen quantification confirmed increasing fibrosis over time (r = 0.82). Though baseline T1 and T2* measurements did not correlate with fibrosis, Gd-Hyd signal enhancement provided a measure of the extent of active fibrotic disease progression and correlated strongly with lysyl oxidase expression. Gd-Hyd MRI accurately detects fibrogenesis in a mouse model of NASH with advanced fibrosis and can be combined with other MR measures, like fat imaging, to more accurately assess disease burden.
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http://dx.doi.org/10.1038/s41598-021-85679-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7971064PMC
March 2021

Risk Factors, Pathogenesis, and Strategies for Hepatocellular Carcinoma Prevention: Emphasis on Secondary Prevention and Its Translational Challenges.

J Clin Med 2020 Nov 25;9(12). Epub 2020 Nov 25.

Division of Surgical Oncology, Massachusetts General Hospital Cancer Center and Harvard Medical School, Boston, MA 02114, USA.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-associated mortality globally. Given the limited therapeutic efficacy in advanced HCC, prevention of HCC carcinogenesis could serve as an effective strategy. Patients with chronic fibrosis due to viral or metabolic etiologies are at a high risk of developing HCC. Primary prevention seeks to eliminate cancer predisposing risk factors while tertiary prevention aims to prevent HCC recurrence. Secondary prevention targets patients with baseline chronic liver disease. Various epidemiological and experimental studies have identified candidates for secondary prevention-both etiology-specific and generic prevention strategies-including statins, aspirin, and anti-diabetic drugs. The introduction of multi-cell based omics analysis along with better characterization of the hepatic microenvironment will further facilitate the identification of targets for prevention. In this review, we will summarize HCC risk factors, pathogenesis, and discuss strategies of HCC prevention. We will focus on secondary prevention and also discuss current challenges in translating experimental work into clinical practice.
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http://dx.doi.org/10.3390/jcm9123817DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7760293PMC
November 2020

Molecular Magnetic Resonance Imaging of Liver Fibrosis and Fibrogenesis Is Not Altered by Inflammation.

Invest Radiol 2021 Apr;56(4):244-251

Division of Surgical Oncology, Massachusetts General Hospital Cancer Center and Harvard Medical School, Boston, MA.

Methods: Three groups of mice that develop either mild type 2 inflammation and fibrosis (wild type), severe fibrosis with exacerbated type 2 inflammation (Il10-/-Il12b-/-Il13ra2-/-), or minimal fibrosis with marked type 1 inflammation (Il4ra∂/∂) after infection with S. mansoni were imaged using both probes for determination of signal enhancement. Schistosoma mansoni-infected wild-type mice developed chronic liver fibrosis.

Results: The liver MR signal enhancement after either probe administration was significantly higher in S. mansoni-infected wild-type mice compared with naive animals. The S. mansoni-infected Il4ra∂/∂ mice presented with little liver signal enhancement after probe injection despite the presence of substantial inflammation. Schistosoma mansoni-infected Il10-/-Il12b-/-Il13ra2-/- mice presented with marked fibrosis, which correlated to increased signal enhancement after injection of either probe.

Conclusions: Both MR probes, EP-3533 and Gd-Hyd, were specific for fibrosis in this model of chronic liver disease regardless of the presence or severity of the underlying inflammation. These results, in addition to previous findings, show the potential application of both molecular MR probes for detection and quantification of fibrosis from various etiologies.
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http://dx.doi.org/10.1097/RLI.0000000000000737DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7956154PMC
April 2021

Targeting acid ceramidase inhibits YAP/TAZ signaling to reduce fibrosis in mice.

Sci Transl Med 2020 08;12(557)

Department of Medicine, University of California, San Francisco, San Francisco, CA 94115, USA.

Hepatic stellate cells (HSCs) drive hepatic fibrosis. Therapies that inactivate HSCs have clinical potential as antifibrotic agents. We previously identified acid ceramidase (aCDase) as an antifibrotic target. We showed that tricyclic antidepressants (TCAs) reduce hepatic fibrosis by inhibiting aCDase and increasing the bioactive sphingolipid ceramide. We now demonstrate that targeting aCDase inhibits YAP/TAZ activity by potentiating its phosphorylation-mediated proteasomal degradation via the ubiquitin ligase adaptor protein β-TrCP. In mouse models of fibrosis, pharmacologic inhibition of aCDase or genetic knockout of aCDase in HSCs reduces fibrosis, stromal stiffness, and YAP/TAZ activity. In patients with advanced fibrosis, aCDase expression in HSCs is increased. Consistently, a signature of the genes most down-regulated by ceramide identifies patients with advanced fibrosis who could benefit from aCDase targeting. The findings implicate ceramide as a critical regulator of YAP/TAZ signaling and HSC activation and highlight aCDase as a therapeutic target for the treatment of fibrosis.
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http://dx.doi.org/10.1126/scitranslmed.aay8798DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7976849PMC
August 2020

Collagen-targeted molecular imaging in diffuse liver diseases.

Abdom Radiol (NY) 2020 11 31;45(11):3545-3556. Epub 2020 Jul 31.

Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA.

Liver fibrosis is a common pathway shared by all progressive chronic liver diseases (CLD) regardless of the underlying etiologies. With liver biopsy being the gold standard in assessing fibrosis degree, there is a large unmet clinical need to develop non-invasive imaging tools that can directly and repeatedly quantify fibrosis throughout the liver for a more accurate assessment of disease burden, progression, and treatment response. Type I collagen is a particularly attractive target for molecular imaging as its excessive deposition is specific to fibrosis, and it is present in concentrations suitable for many imaging modalities. Novel molecular MRI contrast agents designed to bind with collagen provide direct quantification of collagen deposition, which have been validated across animal species and liver injury models. Collagen-targeted molecular imaging probes hold great promise not only as a tool for initial staging and surveillance of fibrosis progression, but also as a marker of fibrosis regression in drug trials.
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http://dx.doi.org/10.1007/s00261-020-02677-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7606709PMC
November 2020

Fibrotic Response to Neoadjuvant Therapy Predicts Survival in Pancreatic Cancer and Is Measurable with Collagen-Targeted Molecular MRI.

Clin Cancer Res 2020 Sep 1;26(18):5007-5018. Epub 2020 Jul 1.

Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.

Purpose: To evaluate the prognostic value of posttreatment fibrosis in human PDAC patients, and to compare a type I collagen targeted MRI probe, CM-101, to the standard contrast agent, Gd-DOTA, for their abilities to identify FOLFIRINOX-induced fibrosis in a murine model of PDAC.

Experimental Design: Ninety-three chemoradiation-treated human PDAC samples were stained for fibrosis and outcomes evaluated. For imaging, C57BL/6 and FVB mice were orthotopically implanted with PDAC cells and FOLFIRINOX was administered. Mice were imaged with Gd-DOTA and CM-101.

Results: In humans, post-chemoradiation PDAC tumor fibrosis was associated with longer overall survival (OS) and disease-free survival (DFS) on multivariable analysis (OS = 0.028, DFS = 0.047). CPA increased the prognostic accuracy of a multivariable logistic regression model comprised of previously established PDAC risk factors [AUC CPA (-) = 0.76, AUC CPA (+) = 0.82]. In multiple murine orthotopic PDAC models, FOLFIRINOX therapy reduced tumor weight ( < 0.05) and increased tumor fibrosis by collagen staining ( < 0.05). CM-101 MR signal was significantly increased in fibrotic tumor regions. CM-101 signal retention was also increased in the more fibrotic FOLFIRINOX-treated tumors compared with untreated controls ( = 0.027), consistent with selective probe binding to collagen. No treatment-related differences were observed with Gd-DOTA imaging.

Conclusions: In humans, post-chemoradiation tumor fibrosis is associated with OS and DFS. In mice, our MR findings indicate that translation of collagen molecular MRI with CM-101 to humans might provide a novel imaging technique to monitor fibrotic response to therapy to assist with prognostication and disease management.
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http://dx.doi.org/10.1158/1078-0432.CCR-18-1359DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7980315PMC
September 2020

Platelet and neutrophil to lymphocyte ratios predict survival in patients with resectable colorectal liver metastases.

Am J Surg 2020 12 14;220(6):1579-1585. Epub 2020 May 14.

Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States. Electronic address:

Background: The prognostic significance of the platelet (PLR) and neutrophil (NLR) to lymphocyte ratios for patients with resectable colorectal cancer liver metastases (CLM) was evaluated.

Methods: Clinicopathologic data from patients who underwent hepatectomy for CLM at two tertiary care hospitals between 1995 and 2017 were collected. Blood counts were evaluated for prognostic significance.

Results: 151 patients met inclusion criteria. The median age was 58 years, 44% were female, and 58% had synchronous metastases. Median number of liver metastases was 2, and 59% of patients underwent lobectomy or extended lobectomy. On multivariable analysis, NLR ≥5 (HR 2.46 [1.08-5.60 CI], p = 0.032), PLR ≥ 220 (HR 2.10 [1.04-4.23 CI], p = 0.037), and greater than 2 liver metastases (HR 2.41 [1.06-5.45 CI], p = 0.035) were associated with reduced overall survival.

Conclusions: PLR ≥ 220 and NLR ≥ 5 may have utility as preoperative prognostic markers for overall survival in patients with resectable CLM.
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http://dx.doi.org/10.1016/j.amjsurg.2020.05.003DOI Listing
December 2020

Author Correction: Hepatic stellate cells secrete Ccl5 to induce hepatocyte steatosis.

Sci Rep 2020 Jun 19;10(1):10284. Epub 2020 Jun 19.

Department of Medicine, Gastrointestinal Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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http://dx.doi.org/10.1038/s41598-020-67553-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7303110PMC
June 2020

Acetyl-CoA carboxylase inhibition disrupts metabolic reprogramming during hepatic stellate cell activation.

J Hepatol 2020 10 4;73(4):896-905. Epub 2020 May 4.

Gilead Sciences, Foster City, CA, USA.

Background & Aims: Non-alcoholic steatohepatitis (NASH) is a chronic liver disease characterized by hepatic lipid accumulation, inflammation, and progressive fibrosis. Acetyl-CoA carboxylase (ACC) catalyzes the rate-limiting step of de novo lipogenesis and regulates fatty acid β-oxidation in hepatocytes. ACC inhibition reduces hepatic fat content and markers of liver injury in patients with NASH; however, the effect of ACC inhibition on liver fibrosis has not been reported.

Methods: A direct role for ACC in fibrosis was evaluated by measuring de novo lipogenesis, procollagen production, gene expression, glycolysis, and mitochondrial respiration in hepatic stellate cells (HSCs) in the absence or presence of small molecule inhibitors of ACC. ACC inhibitors were evaluated in rodent models of liver fibrosis induced by diet or the hepatotoxin, diethylnitrosamine. Fibrosis and hepatic steatosis were evaluated by histological and biochemical assessments.

Results: Inhibition of ACC reduced the activation of TGF-β-stimulated HSCs, as measured by both α-SMA expression and collagen production. ACC inhibition prevented a metabolic switch necessary for induction of glycolysis and oxidative phosphorylation during HSC activation. While the molecular mechanism by which inhibition of de novo lipogenesis blocks glycolysis and oxidative phosphorylation is unknown, we definitively show that HSCs require de novo lipogenesis for activation. Consistent with this direct antifibrotic mechanism in HSCs, ACC inhibition reduced liver fibrosis in a rat choline-deficient, high-fat diet model and in response to chronic diethylnitrosamine-induced liver injury (in the absence of hepatic lipid accumulation).

Conclusions: In addition to reducing lipid accumulation in hepatocytes, ACC inhibition also directly impairs the profibrogenic activity of HSCs. Thus, small molecule inhibitors of ACC may lessen fibrosis by reducing lipotoxicity in hepatocytes and by preventing HSC activation, providing a mechanistic rationale for the treatment of patients with advanced liver fibrosis due to NASH.

Lay Summary: Hepatic fibrosis is the most important predictor of liver-related outcomes in patients with non-alcoholic steatohepatitis (NASH). Small molecule inhibitors of acetyl-CoA carboxylase (ACC) reduce hepatic fat content and markers of liver injury in patients with NASH. Herein, we report that inhibition of ACC and de novo lipogenesis also directly suppress the activation of hepatic stellate cells - the primary cell responsible for generating fibrotic scar in the liver - and thus fibrosis. These data provide further evidence for the use of ACC inhibitors to treat patients with NASH and advanced fibrosis.
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http://dx.doi.org/10.1016/j.jhep.2020.04.037DOI Listing
October 2020

Advanced MRI of Liver Fibrosis and Treatment Response in a Rat Model of Nonalcoholic Steatohepatitis.

Radiology 2020 07 28;296(1):67-75. Epub 2020 Apr 28.

From the Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Institute for Innovation in Imaging (I.Y.Z., V.C.J., N.J.R., E.A., H.K., H.S., N.W., C.T.F., P.C.), Division of Surgical Oncology (S.K., G.A., K.K.T., B.C.F.), and Institute for Technology Assessment, Department of Radiology (N.M.), Massachusetts General Hospital and Harvard Medical School, Charlestown, 149 13th St, Boston, MA 02129; and Pfizer, Cambridge, Mass (J.W., R.M., F.S.).

Background Liver biopsy is the reference standard to diagnose nonalcoholic steatohepatitis (NASH) but is invasive with potential complications. Purpose To evaluate molecular MRI with type 1 collagen-specific probe EP-3533 and allysine-targeted fibrogenesis probe Gd-Hyd, MR elastography, and native T1 to characterize fibrosis and to assess treatment response in a rat model of NASH. Materials and Methods MRI was performed prospectively (June-November 2018) in six groups of male Wistar rats age- and weight-matched animals received standard chow ( = 12 per group); received choline-deficient, l-amino acid-defined, high-fat diet (CDAHFD) for 6 weeks or 9 weeks ( = 8 per group); were fed 6 weeks of CDAHFD and switched to standard chow for 3 weeks ( = 12); were fed CDAHFD for 9 weeks with daily treatment of elafibranor beginning at week 6 ( = 14). Differences in imaging measurements and tissue analyses among groups were tested with one-way analysis of variance. The ability of each imaging measurement to stage fibrosis was quantified by using area under the receiver operating characteristic curve (AUC) with quantitative digital pathology (collagen proportionate area [CPA]) as reference standard. Optimal cutoff values for distinguishing advanced fibrosis were used to assess treatment response. Results AUC for distinguishing fibrotic (CPA >4.8%) from nonfibrotic (CPA ≤4.8%) livers was 0.95 (95% confidence interval [CI]: 0.91, 1.00) for EP-3533, followed by native T1, Gd-Hyd, and MR elastography with AUCs of 0.90 (95% CI: 0.83, 0.98), 0.84 (95% CI: 0.74, 0.95), and 0.65 (95% CI: 0.51, 0.79), respectively. AUCs for discriminating advanced fibrosis (CPA >10.3%) were 0.86 (95% CI: 0.76, 0.97), 0.96 (95% CI: 0.90, 1.01), 0.84 (95% CI: 0.70, 0.98), and 0.74 (95% CI: 0.63, 0.86) for EP-3533, Gd-Hyd, MR elastography, and native T1, respectively. Gd-Hyd MRI had the highest accuracy (24 of 26, 92%; 95% CI: 75%, 99%) in identifying responders and nonresponders in the treated groups compared with MR elastography (23 of 26, 88%; 95% CI: 70%, 98%), EP-3533 (20 of 26, 77%; 95% CI: 56%, 91%), and native T1 (14 of 26, 54%; 95% CI: 33%, 73%). Conclusion Collagen-targeted molecular MRI most accurately detected early onset of fibrosis, whereas the fibrogenesis probe Gd-Hyd proved most accurate for detecting treatment response. © RSNA, 2020
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http://dx.doi.org/10.1148/radiol.2020192118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7325703PMC
July 2020

Epigallocatechin Gallate Induces Hepatic Stellate Cell Senescence and Attenuates Development of Hepatocellular Carcinoma.

Cancer Prev Res (Phila) 2020 06 6;13(6):497-508. Epub 2020 Apr 6.

Division of Surgical Oncology, Massachusetts General Hospital Cancer Center and Harvard Medical School, Boston, Massachusetts.

Hepatocellular carcinoma (HCC) is a highly morbid condition with lack of effective treatment options. HCC arises from chronically inflamed and damaged liver tissue; therefore, chemoprevention may be a useful strategy to reduce HCC incidence. Several reports suggest that epigallocatechin gallate (EGCG), extracted from green tea, can suppress liver inflammation and fibrosis in animal models, but its role in HCC chemoprevention is not well established. In this study, male Wistar rats were injected with diethylnitrosamine at 50 mg/kg for 18 weeks to induce cirrhosis and HCC, and EGCG was given in drinking water at a concentration of 0.02%. Clinically achievable dosing of EGCG was well-tolerated in diethylnitrosamine-injured rats and was associated with improved serum liver markers including alanine transaminase, aspartate transaminase, and total bilirubin, and reduced HCC tumor formation. Transcriptomic analysis of diethylnitrosamine-injured hepatic tissue was notable for increased expression of genes associated with the Hoshida high risk HCC gene signature, which was prevented with EGCG treatment. EGCG treatment also inhibited fibrosis progression, which was associated with inactivation of hepatic stellate cells and induction of the senescence-associated secretory phenotype. In conclusion, EGCG administered at clinically safe doses exhibited both chemopreventive and antifibrotic effects in a rat diethylnitrosamine liver injury model.
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http://dx.doi.org/10.1158/1940-6207.CAPR-19-0383DOI Listing
June 2020

Targeting clinical epigenetic reprogramming for chemoprevention of metabolic and viral hepatocellular carcinoma.

Gut 2021 Jan 26;70(1):157-169. Epub 2020 Mar 26.

Université de Strasbourg, Strasbourg, France

Objective: Hepatocellular carcinoma (HCC) is the fastest-growing cause of cancer-related mortality with chronic viral hepatitis and non-alcoholic steatohepatitis (NASH) as major aetiologies. Treatment options for HCC are unsatisfactory and chemopreventive approaches are absent. Chronic hepatitis C (CHC) results in epigenetic alterations driving HCC risk and persisting following cure. Here, we aimed to investigate epigenetic modifications as targets for liver cancer chemoprevention.

Design: Liver tissues from patients with NASH and CHC were analysed by ChIP-Seq (H3K27ac) and RNA-Seq. The liver disease-specific epigenetic and transcriptional reprogramming in patients was modelled in a liver cell culture system. Perturbation studies combined with a targeted small molecule screen followed by i and validation were used to identify chromatin modifiers and readers for HCC chemoprevention.

Results: In patients, CHC and NASH share similar epigenetic and transcriptomic modifications driving cancer risk. Using a cell-based system modelling epigenetic modifications in patients, we identified chromatin readers as targets to revert liver gene transcription driving clinical HCC risk. Proof-of-concept studies in a NASH-HCC mouse model showed that the pharmacological inhibition of chromatin reader bromodomain 4 inhibited liver disease progression and hepatocarcinogenesis by restoring transcriptional reprogramming of the genes that were epigenetically altered in patients.

Conclusion: Our results unravel the functional relevance of metabolic and virus-induced epigenetic alterations for pathogenesis of HCC development and identify chromatin readers as targets for chemoprevention in patients with chronic liver diseases.
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http://dx.doi.org/10.1136/gutjnl-2019-318918DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7116473PMC
January 2021

Molecular Magnetic Resonance Imaging of Fibrin Deposition in the Liver as an Indicator of Tissue Injury and Inflammation.

Invest Radiol 2020 04;55(4):209-216

Division of Surgical Oncology, Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA.

Rationale And Objectives: Liver inflammation is associated with nonalcoholic steatohepatitis and other pathologies, but noninvasive methods to assess liver inflammation are limited. Inflammation causes endothelial disruption and leakage of plasma proteins into the interstitial space and can result in extravascular coagulation with fibrin deposition. Here we assess the feasibility of using the established fibrin-specific magnetic resonance probe EP-2104R for the noninvasive imaging of fibrin as a marker of liver inflammation.

Methods: Weekly 100 mg/kg diethylnitrosamine (DEN) dosing was used to generate liver fibrosis in male rats; control animals received vehicle. Magnetic resonance imaging at 1.5 T with EP-2104R, a matched non-fibrin-binding control linear peptide, or the collagen-specific probe EP-3533 was performed at 1 day or 7 days after the last DEN administration. Imaging data were compared with quantitative histological measures of fibrosis and inflammation.

Results: After 4 or 5 DEN administrations, the liver becomes moderately fibrotic, and fibrosis is the same if the animal is killed 1 day (Ishak score, 3.62 ± 0.31) or 7 days (Ishak score, 3.82 ± 0.25) after the last DEN dose, but inflammation is significantly higher at 1 day compared with 7 days after the last DEN dose (histological activity index from 0-4, 3.54 ± 0.14 vs 1.61 ± 0.16, respectively; P < 0.0001). Peak EP-2104R signal enhancement was significantly higher in animals imaged at 1 day post-DEN compared with 7 days post-DEN or control rats (29.0% ± 3.2% vs 22.4% ± 2.0% vs 17.0% ± 0.2%, respectively; P = 0.017). Signal enhancement with EP-2104R was significantly higher than control linear peptide at 1 day post-DEN but not at 7 days post-DEN indicating specific fibrin binding during the inflammatory phase. Collagen molecular magnetic resonance with EP-3533 showed equivalent T1 change when imaging rats 1 day or 7 days post-DEN, consistent with equivalent fibrosis.

Conclusions: EP-2104R can specifically detect fibrin associated with inflammation in a rat model of liver inflammation and fibrosis.
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http://dx.doi.org/10.1097/RLI.0000000000000631DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7935409PMC
April 2020

Exploring donor demographics effects on hepatocyte yield and viability: Results of whole human liver isolation from one center.

Technology (Singap World Sci) 2019 Mar-Jun;7(1-2):1-11. Epub 2019 Apr 26.

Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.

Due to the growth of cell-based therapeutic alternatives addressing the shortage of livers for transplant, there is necessity for a reliable source of human hepatocytes. In addition, pharmaceutical research often requires human hepatocytes to assess new drug therapies during development or to achieve FDA approval. Whole human livers producing large quantities of cells from the same donor are ideal, enhancing reproducibility for all purposes, while also allowing for capturing variances in drug-metabolism across different demographics for pharmaceutical testing and development but are limited in availability and quality for research purposes. The present study investigates the effect of donor and liver procurement factors of 16 human livers on cell viability and yield, showing that typical exclusion criteria for transplant still produce viable hepatocytes with significant yields. Although limited in number of data points, which should be taken into consideration, the conclusions of this study could be utilized as indications, allowing for expansion of liver selection criteria for hepatocyte isolation and provide the necessary quality hepatocytes in large quantities for the growing pharmaceutical, biomedical, and therapeutic research fields.
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http://dx.doi.org/10.1142/S2339547819500018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6693938PMC
April 2019

Tumor Contrast Enhancement and Whole-Body Elimination of the Manganese-Based Magnetic Resonance Imaging Contrast Agent Mn-PyC3A.

Invest Radiol 2019 11;54(11):697-703

Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown.

Objectives: The goals of this study were to compare the efficacy of the new manganese-based magnetic resonance imaging (MRI) contrast agent Mn-PyC3A to the commercial gadolinium-based agents Gd-DOTA and to Gd-EOB-DTPA to detect tumors in murine models of breast cancer and metastatic liver disease, respectively, and to quantify the fractional excretion and elimination of Mn-PyC3A in rats.

Methods: T1-weighted contrast-enhanced MRI with 0.1 mmol/kg Mn-PyC3A was compared with 0.1 mmol/kg Gd-DOTA in a breast cancer mouse model (n = 8) and to 0.025 mmol/kg Gd-EOB-DTPA in a liver metastasis mouse model (n = 6). The fractional excretion, 1-day biodistribution, and 7-day biodistribution in rats after injection of 2.0 mmol/kg [Mn]Mn-PyC3A or Gd-DOTA were quantified by Mn gamma counting or Gd elemental analysis. Imaging data were compared with a paired t test; biodistribution data were compared with an unpaired t test.

Results: The postinjection-preinjection increases in tumor-to-muscle contrast-to-noise ratio (ΔCNR) 3 minutes after injection of Mn-PyC3A and Gd-DOTA (mean ± standard deviation) were 17 ± 3.8 and 20 ± 4.4, respectively (P = 0.34). Liver-to-tumor ΔCNR values at 8 minutes postinjection of Mn-PyC3A and Gd-EOB-DTPA were 28 ± 9.0 and 48 ± 23, respectively (P = 0.11). Mn-PyC3A is eliminated with 85% into the urine and 15% into the feces after administration to rats. The percentage of the injected doses (%ID) of Mn and Gd recovered in tissues after 1 day were 0.32 ± 0.12 and 0.57 ± 0.12, respectively (P = 0.0030), and after 7 days were 0.058 ± 0.051 and 0.19 ± 0.052, respectively (P < 0.0001).

Conclusions: Mn-PyC3A provides comparable tumor contrast enhancement to Gd-DOTA in a mouse breast cancer model and is more completely eliminated than Gd-DOTA; partial hepatobiliary elimination of Mn-PyC3A enables conspicuous delayed phase visualization of liver metastases.
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http://dx.doi.org/10.1097/RLI.0000000000000593DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6785385PMC
November 2019

Ga-NODAGA-Indole: An Allysine-Reactive Positron Emission Tomography Probe for Molecular Imaging of Pulmonary Fibrogenesis.

J Am Chem Soc 2019 04 27;141(14):5593-5596. Epub 2019 Mar 27.

The Athinoula A. Martinos Center for Biomedical Imaging, The Institute for Innovation in Imaging, Department of Radiology , Massachusetts General Hospital (MGH) & Harvard Medical School (HMS) , Charlestown , Massachusetts 02129 , United States.

Oxidized collagen, wherein lysine residues are converted to the aldehyde allysine, is a universal feature of fibrogenesis, i.e. actively progressive fibrosis. Here we report the small molecule, allysine-binding positron emission tomography probe, Ga-NODAGA-indole, that can noninvasively detect and quantify pulmonary fibrogenesis. We demonstrate that the uptake of Ga-NODAGA-indole in actively fibrotic lungs is 7-fold higher than in control groups and that uptake is linearly correlated ( R = 0.98) with the concentration of lung allysine.
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http://dx.doi.org/10.1021/jacs.8b12342DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6494104PMC
April 2019

The farnesoid X receptor agonist EDP-305 reduces interstitial renal fibrosis in a mouse model of unilateral ureteral obstruction.

FASEB J 2019 06 18;33(6):7103-7112. Epub 2019 Mar 18.

Division of Surgical Oncology, Massachusetts General Hospital Cancer Center-Harvard Medical School, Boston, Massachusetts, USA.

Farnesoid X receptor (FXR) is a nuclear receptor that has emerged as a key regulator in the maintenance of hepatic steatosis, inflammation, and fibrosis. However, the role of FXR in renal fibrosis remains to be established. Here, we investigate the effects of the FXR agonist EDP-305 in a mouse model of tubulointerstitial fibrosis unilateral ureteral obstruction (UUO). Male C57Bl/6 mice received a UUO on their left kidney. On postoperative d 4, mice received daily treatment by oral gavage with either vehicle control (0.5% methylcellulose) or 10 or 30 mg/kg EDP-305. All animals were euthanized on postoperative d 12. EDP-305 dose-dependently decreased macrophage infiltration as measured by the F4/80 staining area and proinflammatory cytokine gene expression. EDP-305 also dose-dependently reduced interstitial fibrosis as assessed by morphometric quantification of the collagen proportional area and kidney hydroxyproline levels. Finally, yes-associated protein (YAP) activation, a major driver of fibrosis, increased after UUO injury and was diminished by EDP-305 treatment. Consistently, EDP-305 decreased TGF-β1-induced YAP nuclear localization in human kidney 2 cells by increasing inhibitory YAP phosphorylation. YAP inhibition may be a novel antifibrotic mechanism of FXR agonism, and EDP-305 could be used to treat renal fibrosis.-Li, S., Ghoshal, S., Sojoodi, M., Arora, G., Masia, R., Erstad, D. J., Ferriera, D. S., Li, Y., Wang, G., Lanuti, M., Caravan, P., Or, Y. S., Jiang, L.-J., Tanabe, K. K., Fuchs, B. C. The farnesoid X receptor agonist EDP-305 reduces interstitial renal fibrosis in a mouse model of unilateral ureteral obstruction.
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http://dx.doi.org/10.1096/fj.201801699RDOI Listing
June 2019

Molecular Magnetic Resonance Imaging Using a Redox-Active Iron Complex.

J Am Chem Soc 2019 04 28;141(14):5916-5925. Epub 2019 Mar 28.

Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology , Massachusetts General Hospital/Harvard Medical School , 149 Thirteenth Street , Charlestown , Massachusetts 02129 , United States.

We introduce a redox-active iron complex, Fe-PyC3A, as a biochemically responsive MRI contrast agent. Switching between Fe-PyC3A and Fe-PyC3A yields a full order of magnitude relaxivity change that is field-independent between 1.4 and 11.7 T. The oxidation of Fe-PyC3A to Fe-PyC3A by hydrogen peroxide is very rapid, and we capitalized on this behavior for the molecular imaging of acute inflammation, which is characterized by elevated levels of reactive oxygen species.  Injection of Fe-PyC3A generates strong, selective contrast enhancement of inflamed pancreatic tissue in a mouse model (caerulein/LPS model). No significant signal enhancement is observed in normal pancreatic tissue (saline-treated mice). Importantly, signal enhancement of the inflamed pancreas correlates strongly and significantly with ex vivo quantitation of the pro-inflammatory biomarker myeloperoxidase. This is the first example of using metal ion redox for the MR imaging of pathologic change in vivo. Redox-active Fe complexes represent a new design paradigm for biochemically responsive MRI contrast agents.
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http://dx.doi.org/10.1021/jacs.9b00603DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6726119PMC
April 2019

HCV-Induced Epigenetic Changes Associated With Liver Cancer Risk Persist After Sustained Virologic Response.

Gastroenterology 2019 06 2;156(8):2313-2329.e7. Epub 2019 Mar 2.

INSERM U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France; Université de Strasbourg, Strasbourg, France; Institut Hospitalo-Universitaire, Pôle Hépato-digestif, Nouvel Hôpital Civil, Strasbourg, France; Institut Universitaire de France (IUF), Paris, France. Electronic address:

Background & Aims: Chronic hepatitis C virus (HCV) infection is an important risk factor for hepatocellular carcinoma (HCC). Despite effective antiviral therapies, the risk for HCC is decreased but not eliminated after a sustained virologic response (SVR) to direct-acting antiviral (DAA) agents, and the risk is higher in patients with advanced fibrosis. We investigated HCV-induced epigenetic alterations that might affect risk for HCC after DAA treatment in patients and mice with humanized livers.

Methods: We performed genome-wide ChIPmentation-based ChIP-Seq and RNA-seq analyses of liver tissues from 6 patients without HCV infection (controls), 18 patients with chronic HCV infection, 8 patients with chronic HCV infection cured by DAA treatment, 13 patients with chronic HCV infection cured by interferon therapy, 4 patients with chronic hepatitis B virus infection, and 7 patients with nonalcoholic steatohepatitis in Europe and Japan. HCV-induced epigenetic modifications were mapped by comparative analyses with modifications associated with other liver disease etiologies. uPA/SCID mice were engrafted with human hepatocytes to create mice with humanized livers and given injections of HCV-infected serum samples from patients; mice were given DAAs to eradicate the virus. Pathways associated with HCC risk were identified by integrative pathway analyses and validated in analyses of paired HCC tissues from 8 patients with an SVR to DAA treatment of HCV infection.

Results: We found chronic HCV infection to induce specific genome-wide changes in H3K27ac, which correlated with changes in expression of mRNAs and proteins. These changes persisted after an SVR to DAAs or interferon-based therapies. Integrative pathway analyses of liver tissues from patients and mice with humanized livers demonstrated that HCV-induced epigenetic alterations were associated with liver cancer risk. Computational analyses associated increased expression of SPHK1 with HCC risk. We validated these findings in an independent cohort of patients with HCV-related cirrhosis (n = 216), a subset of which (n = 21) achieved viral clearance.

Conclusions: In an analysis of liver tissues from patients with and without an SVR to DAA therapy, we identified epigenetic and gene expression alterations associated with risk for HCC. These alterations might be targeted to prevent liver cancer in patients treated for HCV infection.
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http://dx.doi.org/10.1053/j.gastro.2019.02.038DOI Listing
June 2019

Molecular imaging of fibrosis: recent advances and future directions.

J Clin Invest 2019 01 2;129(1):24-33. Epub 2019 Jan 2.

Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.

Fibrosis, the progressive accumulation of connective tissue that occurs in response to injury, causes irreparable organ damage and may result in organ failure. The few available antifibrotic treatments modify the rate of fibrosis progression, but there are no available treatments to reverse established fibrosis. Thus, more effective therapies are urgently needed. Molecular imaging is a promising biomedical methodology that enables noninvasive visualization of cellular and subcellular processes. It provides a unique means to monitor and quantify dysregulated molecular fibrotic pathways in a noninvasive manner. Molecular imaging could be used for early detection, disease staging, and prognostication, as well as for assessing disease activity and treatment response. As fibrotic diseases are often molecularly heterogeneous, molecular imaging of a specific pathway could be used for patient stratification and cohort enrichment with the goal of improving clinical trial design and feasibility and increasing the ability to detect a definitive outcome for new therapies. Here we review currently available molecular imaging probes for detecting fibrosis and fibrogenesis, the active formation of new fibrous tissue, and their application to models of fibrosis across organ systems and fibrotic processes. We provide our opinion as to the potential roles of molecular imaging in human fibrotic diseases.
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http://dx.doi.org/10.1172/JCI122132DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6307954PMC
January 2019

Pioglitazone Reduces Hepatocellular Carcinoma Development in Two Rodent Models of Cirrhosis.

J Gastrointest Surg 2019 01 26;23(1):101-111. Epub 2018 Oct 26.

Division of Surgical Oncology, Massachusetts General Hospital Cancer Center and Harvard Medical School, 55 Fruit Street, WRN 401, Boston, MA, 02114, USA.

Background: Hepatocellular carcinoma (HCC) is one of the deadliest malignancies worldwide due to the lack of effective treatments. Chemoprevention in high-risk patients is a promising, alternative strategy. In this study, pioglitazone was investigated for its ability to prevent hepatocarcinogenesis in two rodent models of cirrhosis.

Methods: In the first model, male Wistar rats were given repeated, low-dose injections of diethylnitrosamine (DEN) to accurately recapitulate the progression of fibrosis to cirrhosis and HCC. In the second model, a single dose of DEN was administered to male C57Bl/6 pups at day fifteen followed by administration of a choline-deficient, L-amino acid defined, high-fat diet (CDAHFD) at week six for 24 weeks. Pioglitazone treatment started at the first signs of fibrosis in both models.

Results: Pioglitazone effectively reduced fibrosis progression and HCC development in both models. Gross tumor nodules were significantly reduced after pioglitazone treatment (7.4 ± 1.6 vs. 16.6 ± 2.6 in the rat DEN model and 5.86 ± 1.82 vs. 13.2 ± 1.25 in the mouse DEN+CDAHFD model). In both models, pioglitazone reduced the activation of mitogen-activated protein kinase (MAPK) and upregulated the hepato-protective AMP-activated protein kinase (AMPK) pathway via increasing circulating adiponectin production.

Conclusion: Pioglitazone is an effective agent for chemoprevention in rodents and could be repurposed as a multi-targeted drug for delaying liver fibrosis and hepatocarcinogenesis.
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http://dx.doi.org/10.1007/s11605-018-4004-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6328630PMC
January 2019

Inhibition of Acetyl-CoA Carboxylase by Phosphorylation or the Inhibitor ND-654 Suppresses Lipogenesis and Hepatocellular Carcinoma.

Cell Metab 2019 01 20;29(1):174-182.e5. Epub 2018 Sep 20.

Divison of Surgical Oncology, Massachusetts General Hospital Cancer Center and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA. Electronic address:

The incidence of hepatocellular carcinoma (HCC) is rapidly increasing due to the prevalence of obesity and non-alcoholic fatty liver disease, but the molecular triggers that initiate disease development are not fully understood. We demonstrate that mice with targeted loss-of-function point mutations within the AMP-activated protein kinase (AMPK) phosphorylation sites on acetyl-CoA carboxylase 1 (ACC1 Ser79Ala) and ACC2 (ACC2 Ser212Ala) have increased liver de novo lipogenesis (DNL) and liver lesions. The same mutation in ACC1 also increases DNL and proliferation in human liver cancer cells. Consistent with these findings, a novel, liver-specific ACC inhibitor (ND-654) that mimics the effects of ACC phosphorylation inhibits hepatic DNL and the development of HCC, improving survival of tumor-bearing rats when used alone and in combination with the multi-kinase inhibitor sorafenib. These studies highlight the importance of DNL and dysregulation of AMPK-mediated ACC phosphorylation in accelerating HCC and the potential of ACC inhibitors for treatment.
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http://dx.doi.org/10.1016/j.cmet.2018.08.020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6643297PMC
January 2019

Manganese-Based Contrast Agents for Magnetic Resonance Imaging of Liver Tumors: Structure-Activity Relationships and Lead Candidate Evaluation.

J Med Chem 2018 10 25;61(19):8811-8824. Epub 2018 Sep 25.

Department of Surgical Oncology , Massachusetts General Hospital/Harvard Medical School , WRN401, 55 Fruit Street , Boston , Massachusetts 02114 , United States.

Gd-based MRI contrast agents (GBCAs) have come under intense regulatory scrutiny due to concerns of Gd retention and delayed toxicity. Three GBCAs comprising acyclic Gd chelates, the class of GBCA most prone to Gd release, are no longer marketed in Europe. Of particular concern are the acyclic chelates that remain available for liver scans, where there is an unmet diagnostic need and no replacement technology. To address this concern, we evaluated our previously reported Mn-based MRI contrast agent, Mn-PyC3A, and nine newly synthesized derivatives as liver specific MRI contrast agents. Within this focused library the transient liver uptake and rate of blood clearance are directly correlated with log P. The complex Mn-PyC3A-3-OBn emerged as the lead candidate due to a combination of high relaxivity, rapid blood clearance, and avid hepatocellular uptake. Mn-PyC3A-3-OBn rendered liver tumors conspicuously hypo-intense in a murine model and is wholly eliminated within 24 h of injection.
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http://dx.doi.org/10.1021/acs.jmedchem.8b00964DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6442678PMC
October 2018

Serum Angiopoietin-2 Predicts Mortality and Kidney Outcomes in Decompensated Cirrhosis.

Hepatology 2019 02 4;69(2):729-741. Epub 2019 Jan 4.

Liver Center and Gastrointestinal Division, Department of Medicine, Massachusetts General Hospital, Boston, MA.

Acute kidney injury in decompensated cirrhosis has limited therapeutic options, and novel mechanistic targets are urgently needed. Angiopoietin-2 is a context-specific antagonist of Tie2, a receptor that signals vascular quiescence. Considering the prominence of vascular destabilization in decompensated cirrhosis, we evaluated Angiopoietin-2 to predict clinical outcomes. Serum Angiopoietin-2 was measured serially in a prospective cohort of hospitalized patients with decompensated cirrhosis and acute kidney injury. Clinical characteristics and outcomes were examined over a 90-day period and analyzed according to Angiopoietin-2 levels. Primary outcome was 90-day mortality. Our study included 191 inpatients (median Angiopoietin-2 level 18.2 [interquartile range 11.8, 26.5] ng/mL). Median Model for End-Stage Liver Disease (MELD) score was 23 [17, 30] and 90-day mortality was 41%. Increased Angiopoietin-2 levels were associated with increased mortality (died 21.9 [13.9, 30.3] ng/mL vs. alive 15.2 [9.8, 23.0] ng/mL; P < 0.001), higher Acute Kidney Injury Network stage (stage I 13.4 [9.8, 20.1] ng/mL vs. stage II 20.0 [14.1, 26.2] ng/mL vs. stage III 21.9 [13.0, 29.5] ng/mL; P = 0.002), and need for renal replacement therapy (16.5 [11.3, 23.6] ng/mL vs. 25.1 [13.3, 30.3] ng/mL; P = 0.005). The association between Angiopoietin-2 and mortality was significant in unadjusted and adjusted Cox regression models (P ≤ 0.001 for all models), and improved discrimination for mortality when added to MELD score (integrated discrimination increment 0.067; P = 0.001). Conclusion: Angiopoietin-2 was associated with mortality and other clinically relevant outcomes in a cohort of patients with decompensated cirrhosis with acute kidney injury. Further experimental study of Angiopoietin/Tie2 signaling is warranted to explore its potential mechanistic and therapeutic role in this population.
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http://dx.doi.org/10.1002/hep.30230DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6351209PMC
February 2019

New Directions in the Study and Treatment of Metastatic Cancer.

Front Oncol 2018 10;8:258. Epub 2018 Jul 10.

MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.

Traditional cancer therapy has relied on a strictly cytotoxic approach that views non-metastatic and metastatic tumor cells as identical in terms of molecular biology and sensitivity to therapeutic intervention. Mounting evidence suggests that, in fact, non-metastatic and metastatic tumor cells differ in key characteristics that could explain the capacity of the metastatic cells to not only escape the primary organ but also to survive while in the circulation and to colonize a distant organ. Here, we lay out a framework for a new multi-pronged therapeutic approach. This approach involves modifying the local microenvironment of the primary tumor to inhibit the formation and release of metastatic cells; normalizing the microenvironment of the metastatic organ to limit the capacity of metastatic tumor cells to invade and colonize the organ; remediating the immune response to tumor neoantigens; and targeting metastatic tumor cells on a systemic level by restoring critical and unique aspects of the cell's phenotype, such as anchorage dependence. Given the limited progress against metastatic cancer using traditional therapeutic strategies, the outlined paradigm could provide a more rational alternative to patients with metastatic cancer.
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http://dx.doi.org/10.3389/fonc.2018.00258DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6048200PMC
July 2018

Molecular magnetic resonance imaging accurately measures the antifibrotic effect of EDP-305, a novel farnesoid X receptor agonist.

Hepatol Commun 2018 Jul 21;2(7):821-835. Epub 2018 May 21.

Division of Surgical Oncology, Massachusetts General Hospital Harvard Medical School Boston MA.

We examined a novel farnesoid X receptor agonist, EDP-305, for its antifibrotic effect in bile duct ligation (BDL) and choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) models of hepatic injury. We used molecular magnetic resonance imaging with the type 1 collagen-binding probe EP-3533 and the oxidized collagen-specific probe gadolinium hydrazide to noninvasively measure treatment response. BDL rats (n = 8 for each group) were treated with either low or high doses of EDP-305 starting on day 4 after BDL and were imaged on day 18. CDAHFD mice (n = 8 for each group) were treated starting at 6 weeks after the diet and were imaged at 12 weeks. Liver tissue was subjected to pathologic and morphometric scoring of fibrosis, hydroxyproline quantitation, and determination of fibrogenic messenger RNA expression. High-dose EDP-305 (30 mg/kg) reduced liver fibrosis in both the BDL and CDAHFD models as measured by collagen proportional area, hydroxyproline analysis, and fibrogenic gene expression (all < 0.05). Magnetic resonance signal intensity with both EP-3533 in the BDL model and gadolinium hydrazide in the CDAHFD model was reduced with EDP-305 30 mg/kg treatment ( < 0.01). Histologically, EDP-305 30 mg/kg halted fibrosis progression in the CDAHFD model. : EDP-305 reduced fibrosis progression in rat BDL and mouse CDAHFD models. Molecular imaging of collagen and oxidized collagen is sensitive to changes in fibrosis and could be used to noninvasively measure treatment response in clinical trials. ( 2018;2:821-835).
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http://dx.doi.org/10.1002/hep4.1193DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6049071PMC
July 2018

Orthotopic and heterotopic murine models of pancreatic cancer and their different responses to FOLFIRINOX chemotherapy.

Dis Model Mech 2018 07 30;11(7). Epub 2018 Jul 30.

Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, United States

Syngeneic, immunocompetent allograft tumor models recapitulate important aspects of the tumor microenvironment and have short tumor latency with predictable growth kinetics, making them useful for trialing novel therapeutics. Here, we describe surgical techniques for orthotopic and heterotopic pancreatic ductal adenocarcinoma (PDAC) tumor implantation and characterize phenotypes based on implantation site.Mice (=8 per group) were implanted with 10 cells in the pancreas or flank. Hy15549 and Han4.13 cell lines were derived from primary murine PDAC (Ptf1-Cre; LSL-KRAS-G12D; Trp53 Lox/+) on C57BL/6 and FVB strains, respectively. Single-cell suspension and solid tumor implants were compared. Tumors were treated with two intravenous doses of FOLFIRINOX and responses evaluated.All mice developed pancreatic tumors within 7 days. Orthotopic tumors grew faster and larger than heterotopic tumors. By 3 weeks, orthotopic mice began losing weight, and showed declines in body condition requiring euthanasia starting at 4 weeks. Single-cell injection into the pancreas had near 100% engraftment, but solid tumor implant engraftment was ∼50% and was associated with growth restriction. Orthotopic tumors were significantly more responsive to intravenous FOLFIRINOX compared with heterotopic tumors, with greater reductions in size and increased apoptosis. Heterotopic tumors were more desmoplastic and hypovascular. However, drug uptake into tumor tissue was equivalent regardless of tumor location or degree of fibrosis, indicating that microenvironment differences between heterotopic and orthotopic tumors influenced response to therapy.Our results show that orthotopic and heterotopic allograft locations confer unique microenvironments that influence growth kinetics, desmoplastic response and angiogenesis. Tumor location influences chemosensitivity to FOLFIRINOX and should inform future preclinical trials.This article has an associated First Person interview with the first author of the paper.
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http://dx.doi.org/10.1242/dmm.034793DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6078400PMC
July 2018

Prolonged cenicriviroc therapy reduces hepatic fibrosis despite steatohepatitis in a diet-induced mouse model of nonalcoholic steatohepatitis.

Hepatol Commun 2018 May 7;2(5):529-545. Epub 2018 Mar 7.

Gastrointestinal Unit Massachusetts General Hospital and Harvard Medical School Boston MA.

Nonalcoholic steatohepatitis (NASH) is a progressive liver disease projected to become the leading cause of cirrhosis and liver transplantation in the next decade. Cenicriviroc (CVC), a dual chemokine receptor 2 and 5 antagonist, prevents macrophage trafficking and is under clinical investigation for the treatment of human NASH fibrosis. We assessed the efficacy and durability of short and prolonged CVC therapy in a diet-induced mouse model of NASH, the choline deficient, L-amino acid-defined, high-fat diet (CDAHFD) model. C57BL/6 mice received 4 or 14 weeks of standard chow or the CDAHFD. CVC (10 mg/kg/day and 30 mg/kg/day for 4 weeks and 20 mg/kg/day and 30 mg/kg/day for 14 weeks) was initiated simultaneously with the CDAHFD. At 4 and 14 weeks, livers were harvested for histology and flow cytometric analyses of intrahepatic immune cells. High-dose CVC (30 mg/kg/day) therapy in CDAHFD mice for 4 or 14 weeks inhibited intrahepatic accumulation of Ly6C bone marrow-derived macrophages. Prolonged CVC therapy (14 weeks) yielded no significant differences in the total intrahepatic macrophage populations among treatment groups but increased the frequency of intrahepatic anti-inflammatory macrophages in the high-dose CVC group. Despite ongoing steatohepatitis, there was significantly less fibrosis in CDAHFD mice receiving high-dose CVC for 14 weeks based on histologic and molecular markers, mirroring observations in human NASH CVC trials. CVC also directly inhibited the profibrotic gene signature of transforming growth factor-β-stimulated primary mouse hepatic stellate cells . CVC is a novel therapeutic agent that is associated with reduced fibrosis despite ongoing steatohepatitis. Its ability to alter intrahepatic macrophage populations and inhibit profibrogenic genes in hepatic stellate cells in NASH livers may contribute to its observed antifibrotic effect. ( 2018;2:529-545).
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http://dx.doi.org/10.1002/hep4.1160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5944590PMC
May 2018

Hepatic stellate cells secrete Ccl5 to induce hepatocyte steatosis.

Sci Rep 2018 05 14;8(1):7499. Epub 2018 May 14.

Department of Medicine, Gastrointestinal Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA.

Non-alcoholic fatty liver disease (NAFLD) encompasses a wide spectrum of disease severity, starting from pure steatosis, leading to fatty inflammation labeled as non-alcoholic steatohepatitis (NASH), and finally fibrosis leading to cirrhosis. Activated hepatic stellate cells (HSCs) are known to contribute to fibrosis, but less is known about their function during NAFLD's early stages prior to fibrosis. We developed an ex vivo assay that cocultures primary HSCs from mouse models of liver disease with healthy hepatocytes to study their interaction. Our data indicate that chemokine Ccl5 is one of the HSC-secreted mediators in early NASH in humans and in mice fed with choline-deficient, L-amino acid defined, high fat diet. Furthermore, Ccl5 directly induces steatosis and pro-inflammatory factors in healthy hepatocytes through the receptor Ccr5. Although Ccl5 is already known to be secreted by many liver cell types including HSCs and its pro-fibrotic role well characterized, its pro-steatotic action has not been recognized until now. Similarly, the function of HSCs in fibrogenesis is widely accepted, but their pro-steatotic role has been unclear. Our result suggests that in early NASH, HSCs secrete Ccl5 which contributes to a broad array of mechanisms by which hepatic steatosis and inflammation are achieved.
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http://dx.doi.org/10.1038/s41598-018-25699-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5951796PMC
May 2018