Hepatic steatosis is now understood to play an important role in the development of advanced liver disease. Alcoholic and nonalcoholic fatty liver each begin with the accumulation of lipids in the ...liver. Lipid accumulation in the liver can occur through maladaptations of fatty acid uptake (either through dietary sources or from fat tissue), fatty acid synthesis, fatty acid oxidation, or export of lipids from the liver. Alterations in mechanisms of fatty acid uptake through both dietary uptake and lipolysis in adipose tissue can contribute to the pathogenesis of both disorders, as can effects on fatty acid transporters. Effects on lipid synthesis in alcoholic and nonalcoholic fatty liver involve the endoplasmic reticulum (ER) stress response, homocysteine metabolism pathway, and different transcription factors regulating genes in the lipid synthesis pathway. Fatty acid oxidation, through effects on AMP-activated protein kinase (AMPK), adiponectin, peroxisome proliferator-activated receptors (PPARs), and mitochondrial function is predominantly altered in alcoholic liver disease, although studies suggest that activation of this pathway may improve nonalcoholic fatty liver disease. Finally, changes in fatty acid export, through effects on apolipoprotein B and microsomal transport protein are seen in both diseases. Thus, the similarities and differences in the mechanism of fat accumulation in the liver in nonalcoholic and alcoholic liver disease are explored in detail.
Intestinal dysbiosis is implicated in alcoholic hepatitis (AH). However, changes in the circulating microbiome, its association with the presence and severity of AH, and its functional relevance in ...AH is unknown. Qualitative and quantitative assessment of changes in the circulating microbiome were performed by sequencing bacterial DNA in subjects with moderate AH (MAH) (n = 18) or severe AH (SAH) (n = 19). These data were compared with heavy drinking controls (HDCs) without obvious liver disease (n = 19) and non–alcohol‐consuming controls (NACs, n = 20). The data were related to endotoxin levels and markers of monocyte activation. Linear discriminant analysis effect size (LEfSe) analysis, inferred metagenomics, and predictive functional analysis using PICRUSt were performed. There was a significant increase in 16S copies/ng DNA both in MAH (P < 0.01) and SAH (P < 0.001) subjects. Compared with NACs, the relative abundance of phylum Bacteroidetes was significantly decreased in HDCs, MAH, and SAH (P < 0.001). In contrast, all alcohol‐consuming groups had enrichment with Fusobacteria; this was greatest for HDCs and decreased progressively in MAH and SAH. Subjects with SAH had significantly higher endotoxemia (P = 0.01). Compared with alcohol‐consuming groups, predictive functional metagenomics indicated an enrichment of bacteria with genes related to methanogenesis and denitrification. Furthermore, both HDCs and SAH showed activation of a type III secretion system that has been linked to gram‐negative bacterial virulence. Metagenomics in SAH versus NACs predicted increased isoprenoid synthesis via mevalonate and anthranilate degradation, known modulators of gram‐positive bacterial growth and biofilm production, respectively. Conclusion: Heavy alcohol consumption appears to be the primary driver of changes in the circulating microbiome associated with a shift in its inferred metabolic functions. (Hepatology 2018;67:1284‐1302).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Patients with liver cirrhosis were traditionally believed to be protected against development of blood clots.Lately,studies have shown that these patients may probably be at an increased risk of ...venous thrombotic complications.Although the hemostatic changes in the chronic liver disease patients and the factors that may predict bleeding vs thrombotic complications remains an area of active research,it is believed that the coagulation cascade is delicately balanced in these patients because of parallel reduced hepatic synthesis of pro and anticoagulant factors.Thrombotic state in cirrhotic patients is responsible for not only portal or non-portal thrombosisdeep vein thrombosis(DVT)and pulmonary embolism(PE);it has also been associated with progression of liver fibrosis.The use of anticoagulants in cirrhosis patients is a challenging,and often a scary situation.This review summarizes the current literature on the prevalence of venous thrombosis(DVT and PE),risk factors and safety of prophylactic and therapeutic anticoagulation in patients with chronic liver disease.
Mitochondria-associated endoplasmic reticulum membrane (MAM) is a structural link between mitochondria and endoplasmic reticulum (ER). MAM regulates Ca
transport from the ER to mitochondria via an ...IP3R1-GRP75-VDAC1 complex-dependent mechanism. Excessive MAM formation may cause mitochondrial Ca
overload and mitochondrial dysfunction. However, the exact implication of MAM formation in metabolic syndromes remains debatable. Here, we demonstrate that PDK4 interacts with and stabilizes the IP3R1-GRP75-VDAC1 complex at the MAM interface. Obesity-induced increase in PDK4 activity augments MAM formation and suppresses insulin signaling. Conversely, PDK4 inhibition dampens MAM formation and improves insulin signaling by preventing MAM-induced mitochondrial Ca
accumulation, mitochondrial dysfunction, and ER stress. Furthermore,
mice exhibit reduced MAM formation and are protected against diet-induced skeletal muscle insulin resistance. Finally, forced formation and stabilization of MAMs with synthetic ER-mitochondria linker prevented the beneficial effects of PDK4 deficiency on insulin signaling. Overall, our findings demonstrate a critical mediatory role of PDK4 in the development of skeletal muscle insulin resistance via enhancement of MAM formation.
Liver diseases are perpetuated by the orchestration of hepatocytes and other hepatic non-parenchymal cells. These cells communicate and regulate with each other by secreting mediators such as ...peptides, hormones, and cytokines. Extracellular vesicles (EVs), small particles secreted from cells, contain proteins, DNAs, and RNAs as cargos. EVs have attracted recent research interests since they can communicate information from donor cells to recipient cells thereby regulating physiological events via delivering of specific cargo mediators. Previous studies have demonstrated that liver cells secrete elevated numbers of EVs during diseased conditions, and those EVs are internalized into other liver cells inducing disease-related reactions such as inflammation, angiogenesis, and fibrogenesis. Reactions in recipient cells are caused by proteins and RNAs carried in disease-derived EVs. This review summarizes cell-to-cell communication especially via EVs in the pathogenesis of liver diseases and their potential as a novel therapeutic target.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Excessive cholangiocyte expansion (ductular reaction) promotes liver disease progression, but the underlying mechanism is poorly understood. Here we identify biliary NF-κB-inducing kinase (NIK) as a ...pivotal regulator of ductular reaction. NIK is known to activate the noncanonical IKKα/NF-κB2 pathway and regulate lymphoid tissue development. We find that cholangiocyte NIK is upregulated in mice with cholestasis induced by bile duct ligation (BDL), 5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), or α-naphtyl-isothiocyanate (ANIT). DDC, ANIT, or BDL induces ductular reaction, liver injury, inflammation, and fibrosis in mice. Cholangiocyte-specific deletion of NIK, but not IKKα, blunts these pathological alterations. NIK inhibitor treatment similarly ameliorates DDC-induced ductular reaction, liver injury, and fibrosis. Biliary NIK directly increases cholangiocyte proliferation while suppressing cholangiocyte death, and it also promotes secretion of cholangiokines from cholangiocytes. Cholangiokines stimulate liver macrophages and hepatic stellate cells, augmenting liver inflammation and fibrosis. These results unveil a NIK/ductular reaction axis and a NIK/cholangiokine axis that promote liver disease progression.
Despite a rise in the prevalence of hepatocellular carcinoma (HCC), data on HCC-related hospitalizations and financial burden are limited. The aim of this study was to evaluate temporal trends of ...HCC-related hospitalizations and evaluate its financial influence.
Patients with the diagnosis of HCC, as reported by International Classification of Diseases-Ninth Revision code, were identified from the National Inpatient Sample databases from 2002-2011. The national estimates of hospitalizations were derived using appropriate sample weights. The change in total average charges per each hospitalization over the study period was calculated after adjusting for inflation.
Hospitalizations related to HCC have increased from 24,024 in 2002 to 50,609 in 2011. Of these admissions, HCC was the principal diagnosis in 10,762 and 16,350 subjects in 2002 and 2011, respectively. Most were white males (male: 70%; white: 55%). The overall inpatient mortality was significantly decreased from 13.5% in 2002 to 9.9% in 2011 (P < 0.01). The same trend was also observed for the length of hospital stay (6.5 versus 5.6 days in 2002 and 2011, respectively). The inflation-adjusted cost per hospitalization increased by approximately 47% during the study period.
Despite the decrease in mortality rate and length-of-stay, hospitalizations and financial burden associated with HCC continued to increase between 2002 and 2011 in the United States.
Intrahepatic neutrophil infiltration has been implicated in severe alcoholic hepatitis (SAH) pathogenesis; however, the mechanism underlying neutrophil-induced injury in SAH remains obscure. This ...translational study aims to describe the patterns of intrahepatic neutrophil infiltration and its involvement in SAH pathogenesis. Immunohistochemistry analyses of explanted livers identified two SAH phenotypes despite a similar clinical presentation, one with high intrahepatic neutrophils (Neu.sup.hi), but low levels of CD8* T cells, and vice versa. RNA-Seq analyses demonstrated that neutrophil cytosolic factor 1 (NCF1), a key factor in controlling neutrophilic ROS production, was upregulated and correlated with hepatic inflammation and disease progression. To study specifically the mechanisms related to Neu.sup.hi in AH patients and liver injury, we used the mouse model of chronic-plus-binge ethanol feeding and found that myeloid-specific deletion of the Ncf1 gene abolished ethanol-induced hepatic inflammation and steatosis. RNA-Seq analysis and the data from experimental models revealed that neutrophilic NCFI-dependent ROS promoted alcoholic hepatitis (AH) by inhibiting AMP-activated protein kinase (a key regulator of lipid metabolism) and microRNA-223 (a key antiinflammatory and antifibrotic microRNA). In conclusion, two distinct histopathological phenotypes based on liver immune phenotyping are observed in SAH patients, suggesting a separate mechanism driving liver injury and/or failure in these patients.
Forkhead O transcription factors (FOXOs) have been implicated in glucose and lipid homeostasis; however, the role of FOXOs in the development of nonalcoholic fatty liver disease (NAFLD) is not well ...understood. In this study, we designed experiments to examine the effects of two different diets-very high fat diet (HFD) and moderately high fat plus cholesterol diet (HFC)-on wildtype (WT) and liver-specific Foxo1/3/4 triple knockout mice (LTKO). Both diets induced severe hepatic steatosis in the LTKO mice as compared to WT controls. However, the HFC diet led to more severe liver injury and fibrosis compared to the HFD diet. At the molecular levels, hepatic Foxo1/3/4 deficiency triggered a significant increase in the expression of inflammatory and fibrotic genes including Emr1, Ccl2, Col1a1, Tgfb, Pdgfrb, and Timp1. Thus, our data suggest that FOXO transcription factors play a salutary role in the protection against the diet-induced fatty liver disease.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Hospital readmissions are common in patients with cirrhosis, but there are few studies describing readmission preventability. We aimed to describe the incidence, causes, and risk factors for ...preventable readmission in this population.
We performed a prospective cohort study of patients with cirrhosis hospitalized at a single center between June 2014 and March 2020 and followed up for 30 days postdischarge. Demographic, clinical, and socioeconomic data, functional status, and quality of life were collected. Readmission preventability was independently and systematically adjudicated by 3 reviewers. Multinomial logistic regression was used to compare those with (i) preventable readmission, (ii) nonpreventable readmission/death, and (iii) no readmission.
Of 654 patients, 246 (38%) were readmitted, and 29 (12%) were preventable readmissions. Reviewers agreed on preventability for 70% of readmissions. Twenty-two (including 2 with preventable readmission) died. The most common reasons for readmission were hepatic encephalopathy (22%), gastrointestinal bleeding (13%), acute kidney injury (13%), and ascites (6%), and these reasons were similar between preventable and nonpreventable readmissions. Preventable readmission was often related to paracentesis timeliness, diuretic adjustment monitoring, and hepatic encephalopathy treatment. Compared with nonreadmitted patients, preventable readmission was independently associated with racial and ethnic minoritized individuals (odds ratio OR 5.80; 95% CI, 1.96-17.13), nonmarried marital status (OR 2.88; 95% CI, 1.18-7.05), and admission in the prior 30 days (OR 3.45; 95% CI, 1.48-8.04).
For patients with cirrhosis, readmission is common, but most are not preventable. Preventable readmissions are often related to ascites and hepatic encephalopathy and are associated with racial and ethnic minorities, nonmarried status, and prior admissions.