Shvetank Sharma

GLP-1 analogs reduce hepatocyte steatosis and improve survival by enhancing the unfolded protein response and promoting macroautophagy.

Background Nonalcoholic fatty liver disease (NAFLD) is a known outcome of hepatosteatosis. Free fatty acids (FFA) induce the unfolded protein response (UPR) or endoplasmic reticulum (ER) stress that may induce apoptosis. Recent data indicate ER stress to be a major player in the progression of fatty liver to more aggressive lesions. Autophagy on the other hand has been demonstrated to be protective against ER stress- induced cell death. We hypothesized that exendin-4 (GLP-1 analog) treatment of fat loaded hepatocytes can reduce steatosis by autophagy which leads to reduced ER stress-related hepatocyte apoptosis. Methodology/Principal Findings Primary human hepatocytes were loaded with saturated, cis- and trans-unsaturated fatty acids (palmitic, oleic and elaidic acid respectively). Steatosis, induced with all three fatty acids, was significantly resolved after exendin-4 treatment. Exendin-4 sustained levels of GRP78 expression in fat-loaded cells when compared to untreated fat-loaded cells alone. In contrast, CHOP (C/EBP homologous protein); the penultimate protein that leads to ER stress-related cell death was significantly decreased by exendin-4 in hepatocytes loaded with fatty acids. Finally, exendin-4 in fat loaded hepatocytes clearly promoted gene products associated with macroautophagy as measured by enhanced production of both Beclin-1 and LC3B-II, markers for autophagy; and visualized by transmission electron microscopy (TEM). Similar observations were made in mouse liver lysates after mice were fed with high fat high fructose diet and treated with a long acting GLP-1 receptor agonist, liraglutide. Conclusions/Significance GLP-1 proteins appear to protect hepatocytes from fatty acid-related death by prohibition of a dysfunctional ER stress response; and reduce fatty acid accumulation, by activation of both macro-and chaperone-mediated autophagy. These findings provide a novel role for GLP-1 proteins in halting the progression of more aggressive lesions from underlying steatosis in humans afflicted with NAFLD.

Adiponectin antagonizes the oncogenic actions of leptin in hepatocellular carcinogenesis.

Obesity is rapidly becoming a pandemic and is associated with increased carcinogenesis. Obese populations have higher circulating levels of leptin in contrast to low concentrations of adiponectin. Hence, it is important to evaluate the dynamic role between adiponectin and leptin in obesity‐related carcinogenesis. Recently, we reported the oncogenic role of leptin including its potential to increase tumor invasiveness and migration of hepatocellular carcinoma (HCC) cells. In the present study we investigated whether adiponectin could antagonize the oncogenic actions of leptin in HCC. We employed HCC cell lines HepG2 and Huh7, the nude mice‐xenograft model of HCC, and immunohistochemistry data from tissue‐microarray to demonstrate the antagonistic role of adiponectin on the oncogenic actions of leptin. Adiponectin treatment inhibited leptin‐induced cell proliferation of HCC cells. Using scratch‐migration and electric cell‐substrate impedance‐sensing‐based migration assays, we found that adiponectin inhibited leptin‐induced migration of HCC cells. Adiponectin treatment effectively blocked leptin‐induced invasion of HCC cells in Matrigel invasion assays. Although leptin inhibited apoptosis in HCC cells, we found that adiponectin treatment induced apoptosis even in the presence of leptin. Analysis of the underlying molecular mechanisms revealed that adiponectin treatment reduced leptin‐induced Stat3 and Akt phosphorylation. Adiponectin also increased suppressor of cytokine signaling (SOCS3), a physiologic negative regulator of leptin signal transduction. Importantly, adiponectin significantly reduced leptin‐induced tumor burden in nude mice. In HCC samples, leptin expression significantly correlated with HCC proliferation as evaluated by Ki‐67, whereas adiponectin expression correlated significantly with increased disease‐free survival and inversely with tumor size and local recurrence. Conclusion: Collectively, these data demonstrate that adiponectin has the molecular potential to inhibit the oncogenic actions of leptin by blocking downstream effector molecules. (HEPATOLOGY 2010

Glp-1 analog, liraglutide, ameliorates hepatic steatosis and cardiac hypertrophy in C57BL/6J mice fed a Western diet

The aims of this study were designed to determine whether liraglutide, a long-acting glucagon-like peptide, could reverse the adverse effects of a diet high in fat that also contained trans-fat and high-fructose corn syrup (ALIOS diet). Specifically, we examined whether treatment with liraglutide could reduce hepatic insulin resistance and steatosis as well as improve cardiac function. Male C57BL/6J mice were pair fed or fed ad libitum either standard chow or the ALIOS diet. After 8 wk the mice were further subdivided and received daily injections of either liraglutide or saline for 4 wk. Hyperinsulinemic-euglycemic clamp studies were performed after 6 wk, revealing hepatic insulin resistance. Glucose tolerance and insulin resistance tests were performed at 8 and 12 wk prior to and following liraglutide treatment. Liver pathology, cardiac measurements, blood chemistry, and RNA and protein analyses were performed. Clamp studies revealed hepatic insulin resistance after 6 wk of ALIOS diet. Liraglutide reduced visceral adiposity and liver weight (P < 0.001). As expected, liraglutide improved glucose and insulin tolerance. Liraglutide improved hypertension (P < 0.05) and reduced cardiac hypertrophy. Surprisingly, liver from liraglutide-treated mice had significantly higher levels of fatty acid binding protein, acyl-CoA oxidase II, very long-chain acyl-CoA dehydrogenase, and microsomal triglyceride transfer protein. We conclude that liraglutide reduces the harmful effects of an ALIOS diet by improving insulin sensitivity and by reducing lipid accumulation in liver through multiple mechanisms including, transport, and increase β-oxidation.

Transjugular intrahepatic portosystemic shunt for the management of severe venoocclusive disease following bone marrow transplantation.

Hepatic venoocclusive disease (VOD) is a common, life‐threatening complication of bone marrow transplantation (BMT). Portal hypertension is usually present and accounts for many of the clinical manifestations of this syndrome. We describe the results of transjugular intrahepatic portosystemic shunt (TIPS) for the management of VOD after BMT TIPS was performed in six patients with histologically confirmed VOD who had progressive jaundice and ascites. Portal hypertension was improved by TIPS in all patients (mean portal pressure gradient before TIPS, 20.2 +/‐ 4.6 vs. 6.7 +/‐ 1.9 mm Hg post‐TIPS, P < .004). Three patients who underwent TIPS late in the course of VOD did not demonstrate any clinical improvement after TIPS and expired within 2 weeks of the procedure. The remaining three patients had less advanced disease and demonstrated decreases in serum bilirubin, improvement in coagulopathy, and decreased ascites after TIPS. Two patients subsequently expired, one with persistent histological changes of VOD. The lone survivor continues to do well with resolution of ascites, jaundice, and coagulopathy as of her last outpatient visit. TIPS was an effective method for portal decompression in patients with VOD after BMT, and was associated with clinical improvement in some patients. However, these effects may be transient and may not improve overall survival.

Adiponectin inhibits leptin signaling via multiple mechanisms to exert protective effects against hepatic fibrosis

Adiponectin is protective against hepatic fibrosis, whereas leptin promotes fibrosis. In HSCs (hepatic stellate cells), leptin signals via a JAK2 (Janus kinase 2)/STAT3 (signal transducer and activator of transcription 3) pathway, producing effects that enhance ECM (extracellular matrix) deposition. SOCS-3 (suppressor of cytokine signalling-3) and PTP1B (protein tyrosine phosphatase 1B) are both negative regulators of JAK/STAT signalling, and recent studies have demonstrated a role for adiponectin in regulating SOCS-3 expression. In the present study we investigate mechanisms whereby adiponectin dampens leptin signalling and prevents excess ECM production. We treated culture-activated rat HSCs with recombinant adiponectin, leptin, both or neither, and also treated adiponectin knockout (Ad-/-) and wild-type mice with leptin and/or carbon tetrachloride (CCl4) or saline. We analyse JAK2 and Ob-Rb (long form of the leptin receptor) phosphorylation, and PTP1B expression and activity. We also explore potential mechanisms through which adiponectin regulates SOCS-3-Ob-Rb association. Adiponectin inhibits leptin-stimulated JAK2 activation and Ob-Rb phosphorylation in HSCs, whereas both were increased in Ad-/- mice. Adiponectin stimulates PTP1B expression and activity in vitro, whereas PTP1B expression was lower in Ad-/-mice than in wild-type mice. Adiponectin also promotes SOCS-3-Ob-R association and blocks leptin-stimulated formation of extracellular TIMP-1 (tissue inhibitor of metalloproteinases-1)-MMP-1 (matrix metalloproteinase-1) complexes in vitro. These results suggest two novel mechanisms whereby adiponectin inhibits hepatic fibrosis: (i) by promoting binding of SOCS-3 to Ob-Rb, and (ii) by stimulating PTP1B expression and activity, thus inhibiting JAK2/STAT3 signalling at multiple points.

Healthy Donor Fecal Microbiota Transplantation in Steroid-Ineligible Severe Alcoholic Hepatitis: A Pilot Study

© 2017 by the AGA Institute 1542-3565/

Dysregulated iron homeostasis is strongly associated with multiorgan failure and early mortality in acute‐on‐chronic liver failure

36.00 http://dx.doi.org/10.1016/j.cgh.2016.10.029 Patients with untreated severe alcoholic hepatitis (SAH) have 50% 28-day survival; much worse in the steroid-ineligible group. Gut dysbiosis is common and plays a role in the development and progression of alcoholic liver disease. We undertook to modulate gut microbiota in patients with SAH through healthy donor fecal microbiota transplantation (FMT) therapy.

Hyperoxidized albumin modulates neutrophils to induce oxidative stress and inflammation in severe alcoholic hepatitis

Acute‐on‐chronic liver failure (ACLF) is an ailment with high incidence of multiorgan failure (MOF) and consequent mortality. Dysregulated iron homeostasis and macrophage dysfunction are linked to increased incidence of MOF. We investigated whether a panel of circulating iron‐regulating proteins are associated with development of MOF and can predict 15‐ or 30‐day mortality in ACLF patients. One hundred twenty patients with ACLF, 20 patients with compensated cirrhosis, and 20 healthy controls were studied. Relative protein expression profiling was performed in the derivative cohort and confirmed in the validation cohort. A panel of iron regulators and indices were determined. Multiparametric flow cytometry for quantitation of labile iron pool (LIP) was performed. Validation studies confirmed lower serum transferrin (Tf) and ceruloplasmin levels in ACLF and ACLF‐MOF, compared to patients with cirrhosis and controls (P < 0.01). Serum iron and ferritin levels were markedly elevated (P < 0.001; P < 0.05) and hepcidin levels were lower (P < 0.001) in ACLF patients with MOF than those without and other groups (P < 0.001). Percentage Tf saturation (%SAT) was higher in ACLF‐MOF (39.2%; P < 0.001) and correlated with poor outcome (hazard ratio: 6.970; P < 0.01). Intracellular LIP indices were significantly elevated in the subsets of circulating macrophages in ACLF‐MOF, compared to other groups (P < 0.01). Whereas expression of iron‐regulatory genes was markedly down‐regulated, genes related to endoplasmic reticulum stress, apoptosis, and inflammation were up‐regulated in ACLF patients, compared to patients with cirrhosis. Severe dysregulation of autophagy mechanisms was also observed in the former. Conclusions: Iron metabolism and transport are severely deranged in ACLF patients and more so in those with MOF. %SAT, circulating hepcidin, and LIP in macrophages correlate with disease severity and %SAT could be used for early prognostication in ACLF patients. (Hepatology 2015;61:1306–1320)

Bone marrow stem cells and their niche components are adversely affected in advanced cirrhosis of the liver.

Albumin is a potent scavenger of reactive oxygen species (ROS). However, modifications in albumin structure may reduce its antioxidant properties and modulate its immune‐regulatory functions. We examined alterations in circulating albumin in severe alcoholic hepatitis (SAH) patients and their contribution to neutrophil activation, intracellular stress, and alteration in associated molecular pathways. Albumin modifications and plasma oxidative stress were assessed in SAH patients (n = 90), alcoholic cirrhosis patients (n = 60), and healthy controls (n = 30) using liquid chromatography/mass spectrometry and spectrophotometry. Activation and intracellular ROS were measured in healthy neutrophils after treatment with purified albumin from the study groups. Gene expression of SAH neutrophils was analyzed and compared to gene expression from healthy neutrophils after stimulation with purified albumin from SAH patient plasma. SAH‐albumin showed the highest albumin oxidative state (P < 0.05) and prominent alteration as human nonmercaptalbumin 2 (P < 0.05). Plasma oxidative stress (advanced oxidative protein product) was higher in SAH versus alcoholic cirrhosis patients and healthy controls (P < 0.05). Neutrophil gelatinase‐associated lipocalin, myeloperoxidase, and intracellular ROS levels were highest in SAH‐albumin‐treated neutrophils (P < 0.05). Genes associated with neutrophil activation, ROS production, intracellular antioxidation, and leukocyte migration plus genes for proinflammatory cytokines and various toll‐like receptors were overexpressed in SAH neutrophils compared to healthy neutrophils (P < 0.05). Expression of the above‐mentioned genes in SAH‐albumin‐stimulated healthy neutrophils was comparable with SAH patient neutrophils, except for genes associated with apoptosis, endoplasmic reticulum stress, and autophagy (P < 0.05). Conclusions: In patients with SAH, there is a significant increase in albumin oxidation, and albumin acts as a pro‐oxidant; this promotes oxidative stress and inflammation in SAH patients through activation of neutrophils. (Hepatology 2017;65:631‐646).

Impact of family history of metabolic traits on severity of NASH related cirrhosis: a cross‐sectional study

Bone marrow (BM) is a reservoir for immune and hematopoietic cells and critical for tissue repair and regeneration. All of these functions are severely altered in cirrhosis. We investigated the cellular and functional state of BM in cirrhosis patients. We studied the histological, cellular, and molecular changes in BM of cirrhosis patients (n = 168) and controls (n = 44). Hematopoietic stem cells (HSCs) and associated niche cells, mesenchymal stem cells, Schwann cells, neural fibers, and endothelial cells were evaluated by immunohistochemistry. Cytokines and growth factors were analyzed in peripheral blood and BM plasma. Cirrhotic BM showed an inverse correlation between cluster of differentiation 34+HSCs and Model of End‐Stage Liver Disease (ρ = ‐0.582, P < 0.001) and Childs scores (P < 0.038). BMs of cirrhosis patients with higher Model of End‐Stage Liver Disease (>15) showed significantly decreased HSCs, mesenchymal stem cells, Schwann cells, and neural fibers; increased interleukin‐1β (P = 0.004), tumor necrosis factor‐α (P = 0.040), and interferon‐γ (P = 0.03); and decreased oncostatin M (P = 0.04), stem cell factor (P = 0.05), and stromal cell‐derived factor 1 (P = 0.03) compared to those with lower Model of End‐Stage Liver Disease scores (≤15). The cluster of differentiation 34+ cell population was a predictor for the development of sepsis (P < 0.001), and per unit loss increased the probability of sepsis by 16%. Cirrhosis patients with fewer HSCs had lower hemoglobin (P = 0.05) and platelet counts (P = 0.05) and showed early graft dysfunction. Conclusions: Increasing severity of cirrhosis causes derangement of the hematopoietic niche and loss of HSCs, contributing to the hematological and immunological dysfunctions and reduced potential for regeneration; restoring BM functions could provide new therapeutic options in cirrhosis. (Hepatology 2016;64:1273‐1288)