Inflammation-associated interleukin-6/signal transducer and activator of transcription 3 activation ameliorates alcoholic and nonalcoholic fatty liver diseases in interleukin-10-deficient mice

Renalase Attenuates Mouse Fatty Liver Ischemia/Reperfusion Injury through Mitigating Oxidative Stress and Mitochondrial Damage via Activating SIRT1

Liver ischemia/reperfusion (IR) injury is a severe complication of liver surgery. Moreover, nonalcoholic fatty liver disease (NAFLD) patients are particularly vulnerable to IR injury, with higher rates of postoperative morbidity and mortality after liver surgeries. Our previous study found that renalase (RNLS) was highly sensitive and responsive to oxidative stress, which may be a promising biomarker for the evaluation of the severity of liver IR injury. However, the role of RNLS in liver IR injury remains unclear. In the present study, we intensively explored the role and mechanism of RNLS in fatty liver IR injury in vivo and in vitro. C57BL/6 mice were divided into 2 groups feeding with high-fat diet (HFD) and control diet (CD), respectively. After 20 weeks' feeding, they were suffered from portal triad blockage and reflow to induce liver IR injury. Additionally, oleic acid (OA) and tert-butyl hydroperoxide (t-BHP) were used in vitro to induce steatotic hepatocytes and to simulate ROS burst and mimic cellular oxidative stress following portal triad blockage and reflow, respectively. Our data showed that RNLS was downregulated in fatty livers, and RNLS administration effectively attenuated IR injury by reducing ROS production and improving mitochondrial function through activating SIRT1. Additionally, the downregulation of RNLS in the fatty liver was mediated by a decrease of signal transduction and activator of transcription 3 (STAT3) expression under HFD conditions. These findings make RNLS a promising therapeutic strategy for the attenuation of liver IR injury.

Anti-Inflammatory and Anticancer Properties of Bioactive Compounds from Sesamum indicum L.-A Review

The use of foodstuff as natural medicines has already been established through studies demonstrating the pharmacological activities that they exhibit. Knowing the nutritional and pharmacological significance of foods enables the understanding of their role against several diseases. Among the foods that can potentially be considered as medicine, is sesame or Sesamum indicum L., which is part of the Pedaliaceae family and is composed of its lignans such as sesamin, sesamol, sesaminol and sesamolin. Its lignans have been widely studied and are known to possess antiaging, anticancer, antidiabetes, anti-inflammatory and antioxidant properties. Modern chronic diseases, which can transform into clinical diseases, are potential targets of these lignans. The prime example of chronic diseases is rheumatic inflammatory diseases, which affect the support structures and the organs of the body and can also develop into malignancies. In line with this, studies emphasizing the anti-inflammatory and anticancer activities of sesame have been discussed in this review.

Crosstalk network among multiple inflammatory mediators in liver fibrosis

Liver fibrosis is the common pathological basis of all chronic liver diseases, and is the necessary stage for the progression of chronic liver disease to cirrhosis. As one of pathogenic factors, inflammation plays a predominant role in liver fibrosis via communication and interaction between inflammatory cells, cytokines, and the related signaling pathways. Damaged hepatocytes induce an increase in pro-inflammatory factors, thereby inducing the development of inflammation. In addition, it has been reported that inflammatory response related signaling pathway is the main signal transduction pathway for the development of liver fibrosis. The crosstalk regulatory network leads to hepatic stellate cell activation and proinflammatory cytokine production, which in turn initiate the fibrotic response. Compared with the past, the research on the pathogenesis of liver fibrosis has been greatly developed. However, the liver fibrosis mechanism is complex and many pathways involved need to be further studied. This review mainly focuses on the crosstalk regulatory network among inflammatory cells, cytokines, and the related signaling pathways in the pathogenesis of chronic inflammatory liver diseases. Moreover, we also summarize the recent studies on the mechanisms underlying liver fibrosis and clinical efforts on the targeted therapies against the fibrotic response.

The PNPLA3 rs738409 C>G variant influences the association between low skeletal muscle mass and NAFLD: the Shanghai Changfeng Study

BACKGROUND

Age-related skeletal muscle loss and patatin-like phospholipase domain-containing 3 (PNPLA3) polymorphisms are both associated with increased liver steatosis and fibrosis in the absence of obesity.

AIM

To investigate the influence of PNPLA3 polymorphism on the relationship between skeletal muscle loss and non-alcoholic fatty liver disease (NAFLD).

METHODS

Liver fat content was measured using a quantitative ultrasound method, and liver fibrosis was assessed by NAFLD fibrosis, BARD and FIB-4 scores in 3969 Chinese adults. The degree of sarcopenia was measured by weight-adjusted appendicular skeletal muscle mass (ASM% = appendicular skeletal muscle mass(kg)/body weight(kg)  100%).

RESULTS

The NAFLD proportion increased from 19.9% to 41.2% in men and 26.3% to 42.3% in women with decreasing ASM% quartiles (P < 0.001). Low ASM% was inversely associated with NAFLD in PNPLA3 CC (odds ratio [OR]: men, 0.735 [0.610-0.885] and women, 0.812 [0.718-0.918], both P = 0.001) and CG (OR: men, 0.673 [0.573-0.790] and women, 0.798 [0.713-0.893], both P < 0.001) but not GG genotype carriers. The association remained significant after adjustment for age, cigarette smoking, fat mass, interaction between fat mass and ASM%, obesity, diabetes and all components of metabolic syndrome. Subgroup analyses found that PNPLA3 GG gene variant did not increase the risk for NAFLD in individuals with low ASM% regardless of obesity status. Low ASM% also increased risk for liver fibrosis (all P < 0.05), which became insignificant after multiple adjustments.

CONCLUSIONS

Low ASM% is associated with NAFLD and liver fibrosis. Dissociation of sarcopenia and NAFLD was found in PNPLA3 GG genotype carriers. A stratification based on PNPLA3 genotypes might facilitate personalised treatment for NAFLD.

Immune Cells Gate White Adipose Tissue Expansion

The immune system plays a critical role in white adipose tissue (WAT) energy homeostasis and, by extension, whole-body metabolism. Substantial evidence from mouse and human studies firmly establishes that insulin sensitivity deteriorates as a result of subclinical inflammation in the adipose tissue of individuals with diabetes. However, the relationship between adipose tissue expandability and immune cell infiltration remains a complex problem important for understanding the pathogenesis of obesity. Notably, a large body of work challenges the idea that all immune responses are deleterious to WAT function. This review highlights recent advances that describe how immune cells and adipocytes coordinately enable WAT expansion and regulation of energy homeostasis.

Alcohol‑induced attenuation of post‑traumatic inflammation is not necessarily liver‑protective following trauma/hemorrhage

Due to their high prevalence, blunt chest trauma (TxT) and hemorrhagic shock have a significant influence on the outcomes of trauma patients, causing severe modulations of the immune system and high mortality rates. Alcohol consumption in trauma patients has a high clinical impact. Studies investigating the timing of alcohol intoxication prior to trauma are limited, although there are two typical scenarios regarding alcohol consumption: Acute ('drink and drive scenario') and sub‑acute ('evening binge drinking'). Therefore, the present study investigated the influence of either an acute or sub‑acute alcohol‑drinking scenario in an in vivo model of TxT and hemorrhagic shock, focusing on liver inflammation and outcomes. At 12 h (sub‑acute) or 2 h (acute) before the experiment, female Lewis rats received a single oral dose of alcohol (ethanol, EtOH) or saline (NaCl, ctrl), followed by TxT, hemorrhagic shock (35±3 mm Hg) and resuscitation (H/R). The animals were either sacrificed 2 h later or their survival was determined for 72 h. The results revealed that EtOH induced significant fatty changes in the liver. TxT + H/R‑induced increases in the gene expression of interleukin (IL)‑6 and intercellular adhesion molecule‑1 and the protein expression of tumor necrosis factor (TNF)‑α and IL‑1β were significantly reduced in both EtOH groups compared with those in the corresponding TxT + H/R ctrl groups. The local presence of IL‑10‑expressing cells in the liver was significantly increased following TxT + H/R in all groups, although the sub‑acute EtOH TxT + H/R group had a significantly higher proportion of IL‑10‑positive cells compared with all other groups. Stimulating peripheral whole blood with lipopolysaccharide led to significantly lower levels of TNF‑α release in the sub‑acute EtOH group compared with the levels in all other groups. Significant TxT + H/R‑induced increases in liver transaminases and liver damage were most prominent in the sub‑acute EtOH group. The TxT + H/R EtOH group exhibited the lowest levels of glucose. There were no significant differences in mortality rate among the TxT + H/R groups. The data obtained indicates that the severity of liver damage following TxT + H/R may depend on the timing of alcohol consumption and severity of trauma, but also on the balance between pro‑ and anti‑inflammatory responses.

Administration of the Hyper-immune Bovine Colostrum Extract IMM-124E Ameliorates Experimental Murine Colitis

BACKGROUND AND AIMS

Inflammatory bowel disease [IBD] is accompanied by lesions in the epithelial barrier, which allow translocation of bacterial products from the gut lumen to the host's circulation. IMM-124E is a colostrum-based product containing high levels of anti-E.coli-LPS IgG, and might limit exposure to bacterial endotoxins. Here, we investigated whether IMM-124E can ameliorate intestinal inflammation.

METHODS

Acute colitis was induced in WT C57Bl/6J mice by administration of 2.5% dextran sodium sulphate [DSS] for 7 days. T cell transfer colitis was induced via transfer of 0.5 x 106 naïve T cells into RAG2-/- C57Bl/6J mice. IMM-124E was administered daily by oral gavage, either preventively or therapeutically.

RESULTS

Treatment with IMM-124E significantly ameliorated colitis in acute DSS colitis and in T cell transfer colitis. Maximum anti-inflammatory effects were detected at an IMM-124E concentration of 100 mg/kg body weight, whereas 25 mg/kg and 500 mg/kg were less effective. Histology revealed reduced levels of infiltrating immune cells and less pronounced mucosal damage. Flow cytometry revealed reduced numbers of effector T helper cells in the intestine, whereas levels of regulatory T cells were enhanced. IMM-124E treatment reduced the DSS-induced increase of serum levels of lipopolysaccharide [LPS]-binding protein, indicating reduced systemic LPS exposure.

CONCLUSIONS

Our results demonstrate that oral treatment with IMM-124E significantly reduces intestinal inflammation, via decreasing the accumulation of pathogenic T cells and concomitantly increasing the induction of regulatory T cells. Our study confirms the therapeutic efficacy of IMM-124E in acute colitis and suggests that administration of IMM-124E might represent a novel therapeutic strategy to induce or maintain remission in chronic colitis.

Therapeutic Effect of HGF on NASH Mice Through HGF/c-Met and JAK2-STAT3 Signalling Pathway

INTRODUCTION AND AIM

Hepatocyte growth factor (HGF) has been shown to ameliorate liver inflammation and fibrosis; however, the mechanism underlying its effects in non-alcoholic steatohepatitis (NASH) is unclear. This study aimed to analyse the relationship between the JAK2-STAT3 signalling pathway and the ameliorating effect of HGF on NASH.

MATERIAL AND METHODS

Mice were fed a high-fat diet (HFD) for 16 weeks, and then plasma and hepatic tissues were collected. Histological and clinical chemistry assays were performed to assess liver disease. The mRNA and protein levels of JAK2, STAT3, and c-Met were assessed by real-time PCR and western blotting, respectively.

RESULTS

Serum ALT, AST, and TG levels were increased in NASH mice. Histological analysis showed different degrees of steatosis, inflammatory infiltrates, and fibrosis in HFD animals. Exogenous administration of recombinant human (rh) HGF via the tail vein for 14 days markedly decreased ALT and AST to levels lower than those in the control group. Compared with the levels in HFD mice, c-Met, p-c-Met, JAK2, p-JAK2, and p-STAT3 levels were increased in mice that were administered HGF (P &lt; 0.05). Furthermore, silencing of HGF or blocking of its receptor c-Met affected JAK2 and STAT3 protein phosphorylation.

CONCLUSIONS

Excess HGF highly probable improved NASH liver function. Combined with its ligand, c-Met, HGF may promote the phosphorylation of JAK2-STAT3 and inhibit inflammation in NASH. Therefore, it may be potentially useful treatment for NASH.

Age-Related Decrease in Skeletal Muscle Mass Is an Independent Risk Factor for Incident Nonalcoholic Fatty Liver Disease: A 10-Year Retrospective Cohort Study

Background/Aims

Sarcopenia has emerged as an important risk factor for nonalcoholic fatty liver disease (NAFLD). Although aging is the main cause of sarcopenia, the longitudinal association between age-related body composition changes and NAFLD development has not been fully investigated. Thus, we evaluated whether age-related increased fat mass or decreased muscle mass is an independent risk factor for incident NAFLD.

Methods

We conducted a retrospective cohort study involving 4,398 initially NAFLD-free subjects who underwent routine health examinations during 2004 to 2005 and returned for a follow-up during 2014 to 2015. Their body composition was measured by bioelectrical impedance analysis, and fatty liver was diagnosed by abdominal ultrasonography.

Results

At the 10-year follow-up, 591 out of 4,398 participants (13.4%) had developed NAFLD. In men and women, both increased fat mass and decreased appendicular skeletal muscle mass (ASM) with aging were significantly associated with incident NAFLD after adjustment. A subgroup analysis according to the baseline obesity status showed that increased fat mass was significantly associated with incident NAFLD in obese and nonobese subjects. However, decreased ASM was significantly associated with incident NAFLD in nonobese but not in obese subjects. According to ΔASM tertiles (decrease of ASM), the odds ratios for incident NAFLD in nonobese subjects were 1.38 (95% confidence interval [CI], 1.04 to 1.84) for the second tertile and 1.81 (95% CI, 1.34 to 2.45) for the third tertile after adjustment (p=0.001).

Conclusions

A progressive increase in fat mass and a loss of ASM with aging were significantly associated with incident NAFLD. This association was more prominent in nonobese subjects.

Deficient IL-6/Stat3 Signaling, High TLR7, and Type I Interferons in Early Human Alcoholic Liver Disease: A Triad for Liver Damage and Fibrosis

Mechanisms underlying alcohol-induced liver injury and its progression still remain incompletely understood. Animal models can only address some aspects of the pathophysiology that requires studies directly in humans, which are scarce. We assessed liver inflammatory and immune responses at early stages of alcoholic liver disease in a unique cohort of alcohol-dependent patients undergoing a highly standardized alcohol withdrawal program. In active drinkers, quantitative real-time polymerase chain reaction revealed alcohol-induced activation of tumor necrosis factor alpha, interleukin (IL)-1β, and nuclear factor kappa B in liver tissue already at early disease stages. Double immunofluorescence staining indicated that this proinflammatory response was restricted to activated, CD68-positive macrophages. In parallel, down-regulation of IL-6, inhibition of the signal transducer and activator of transcription 3 (Stat3) pathway, as well as blunted cyclin D expression in hepatocytes, reduced proliferation and favored hepatocyte apoptosis. In addition, immunofluorescence and quantitative real-time polymerase chain reaction of liver tissue showed that alcohol also activated the toll-like receptor (TLR) 7-interferon (IFN) axis in hepatocytes, which was confirmed in alcohol-stimulated primary human hepatocytes and precision-cut liver slices in vitro. Activation of the TLR7-IFN axis strongly correlated with liver fibrosis markers and disease progression. Two weeks of abstinence attenuated the inflammatory response but did not allow recovery of the defective Stat3 pathway or effect on fibrosis-associated factors. Conclusion: In humans, inflammation, activation of the TLR7-IFN axis, and inhibition of Stat3-dependent repair mechanisms in early alcoholic liver disease pave the way for fibrosis development and ultimately disease progression.

MicroRNA-140 inhibits skeletal muscle glycolysis and atrophy in endotoxin-induced sepsis in mice via the WNT signaling pathway

Sepsis is a systemic inflammatory response syndrome resulting from infection. This study aimed at exploring the role of microRNA-140 (miR-140) in septic mice. Wnt family member 11 (WNT11) was verified to be a target gene of miR-140 after bioinformatic prediction and dual luciferase reporter gene assay. Importantly, miR-140 negatively regulated WNT11. We initially induced the model of sepsis by endotoxin, and then ectopic expression and knockdown experiments were performed to explore the functional role of miR-140 in sepsis. Additionally, cross-sectional areas of muscle fiber, lactic acid production, 3-methylhistidine (3-MH) and tyrosine (Tyr) production in extensor digitorium longus (EDL) muscles, and serum levels of inflammatory factors were examined. The effect of miR-140 on the expression of WNT signaling pathway-related and apoptosis-related factors in skeletal muscle tissue was determined. The experimental results indicated that upregulated miR-140 or silenced WNT11 increased cross-sectional areas of muscle fiber while decreasing lactic acid production, skeletal muscle cell apoptosis [corresponding to downregulated B cell lymphoma 2 (Bcl-2)-associated X protein (Bax) and caspase-3 and upregulated Bcl-2], and the proteolytic rate of Tyr and 3-MH. Also, overexpressed miR-140 or silenced WNT11 reduced inflammation as reflected by decreased serum levels of IL-6, IL-10, and TNF-α. Furthermore, overexpression of miR-140 was shown to suppress the activation of the WNT signaling pathway, accompanied by decreased expression of WNT11, β-catenin, and GSK-3β. Taken together, upregulation of miR-140 could potentially inhibit skeletal muscle lactate release, an indirect measure of glycolysis, and atrophy in septic mice through suppressing the WNT signaling pathway via inhibiting WNT11 expression.

Regulatory T cells suppress excessive lipid accumulation in alcoholic liver disease

Sensitization of hepatic immune cells from chronic alcohol consumption gives rise to inflammatory accumulation, which is considered a leading cause of liver damage. Regulatory T cells (Tregs) are an immunosuppressive cell subset that plays an important role in a variety of liver diseases; however, data about pathological involvement of Tregs in liver steatosis of alcoholic liver disease (ALD) is insufficient. In mouse models of ALD, we found that increased lipid accumulation by chronic alcohol intake was accompanied by oxidative stress, inflammatory accumulation, and Treg decline in the liver. Adoptive transfer of Tregs relieved lipid metabolic disorder, oxidative stress, inflammation, and, consequently, ameliorated the alcoholic fatty liver. Macrophages are a dominant source of inflammation in ALD. Aberrant macrophage activation and cytokine production were activated during chronic alcohol consumption, but were significantly inhibited after Treg transfer. In vitro, macrophages were co-activated by alcohol and lipopolysaccharide to mimic a condition for alcoholic liver microenvironment. Tregs suppressed monocyte chemoattractant protein-1 and TNF-α production from these macrophages. However, such effects of Tregs were remarkably neutralized when interleukin (IL)-10 was blocked. Altogether, our data uncover a novel role of Tregs in restoring liver lipid metabolism in ALD, which partially relies on IL-10-mediated suppression of hepatic pro-inflammatory macrophages.

Trivalent Chromium Supplementation Ameliorates Oleic Acid-Induced Hepatic Steatosis in Mice

Trivalent chromium [Cr(III)] is recognized as an essential trace element for human health, whereas its effect on hepatic lipid metabolism has not yet been fully understood. This study aimed to investigate the beneficial effects and potential mechanisms of Cr(III) on hepatic steatosis in an oleic acid (OA) induced mice model. Mice were fed with high OA for 12 weeks to induce lipid accumulation, and co-administrated with Cr(III) supplementation. Indexes of liver lipid accumulation, associated lipid genes expression, fatty acids (FAs) profile and inflammatory cytokines were analyzed. The data showed that Cr(III) supplementation could attenuate disease progress of hepatic steatosis and protect liver from high OA. After Cr(III) supplementation, elevated body weight and liver injury in steatosis mice were reversed, excessive lipid accumulation and FAs were also reduced. The up-regulation of cluster of differentiation 36 (CD36) and diacylglycerol acyltransferase 2 (DGAT2) following steatosis induction were inhibited by Cr(III). Cr(III) reduced the content of pro-inflammatory cytokines (IL-1β and TNF-α, IL-12) and restored the level of anti-inflammatory cytokine (IL-10) to the control values. Our results suggest that Cr(III) supplementation is a novel strategy for alleviating OA-induced hepatic steatosis.

Role of MicroRNAs in the Development of Hepatocellular Carcinoma in Nonalcoholic Fatty Liver Disease

Hepatocellular carcinoma (HCC) is a prevalent liver malignancy that can be developed from nonalcoholic fatty liver disease (NAFLD). Numerous pathophysiological alterations, including insulin resistance, specific cytokine release, oxidative stress, and mitochondrial damage, are involved in the transition of NAFLD to cirrhosis and HCC. MicroRNAs, as post-transcriptional modulators, play a critical role in the pathogenesis of NAFLD-related HCC by regulating lipid metabolism, glucose homeostasis, cell proliferation, apoptosis, migration, and differentiation. This review summarizes the current progress of microRNAs in the risk and prognosis of NAFLD-related HCC. Anat Rec, 302:193-200, 2019. © 2018 Wiley Periodicals, Inc.

Regulation of Energy Expenditure and Brown/Beige Thermogenic Activity by Interleukins: New Roles for Old Actors

Obesity rates and the burden of metabolic associated diseases are escalating worldwide Energy burning brown and inducible beige adipocytes in human adipose tissues (ATs) have attracted considerable attention due to their therapeutic potential to counteract the deleterious metabolic effects of nutritional overload and overweight. Recent research has highlighted the relevance of resident and recruited ATs immune cell populations and their signalling mediators, cytokines, as modulators of the thermogenic activity of brown and beige ATs. In this review, we first provide an overview of the developmental, cellular and functional heterogeneity of the AT organ, as well as reported molecular switches of its heat-producing machinery. We also discuss the key contribution of various interleukins signalling pathways to energy and metabolic homeostasis and their roles in the biogenesis and function of brown and beige adipocytes. Besides local actions, attention is also drawn to their influence in the central nervous system (CNS) networks governing energy expenditure.

IL-6/STAT3 pathway intermediates M1/M2 macrophage polarization during the development of hepatocellular carcinoma

Human cancers, including hepatocellular carcinoma (HCC), are characterized by a high degree of drug resistance in chemotherapy. However, the underlying molecular mechanism remains unknown. To the role of interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in the regulation of macrophage polarization, M1-type and M2-type macrophages were separately induced using lipopolysaccharide and interleukin-4 (IL-4), and we found that the IL-6/STAT3 signaling pathway was inhibited in M1-type macrophages but activated in M2-type macrophages. After anti-IL-6-treated macrophages were separately induced by lipopolysaccharide and IL-4, we found that the inhibition of IL-6/STAT3 signaling pathway turned macrophages into M1-type. Co-culture with M1-type macrophages reduced HCC cell viability, proliferation, invasion, migration, drug resistance, but increased apoptosis. Co-culture with M2-type macrophages yielded reciprocal results. The inhibition of IL-6/STAT3 signaling pathway mediated by anti-IL6 was shown to significantly enhance the effects of M1-type macrophages on HCC cells and rescue HCC cells from co-culture with M2-type macrophages. Tumor xenografts of co-cultured HCC cells were established in nude mice and the results showed that the inhibition of IL-6/STAT3 signaling pathway mediated by anti-IL6 was found to reduce tumor formation of HCC cells co-cultured with M1- or M2-type macrophages and lung metastases. The current study reveals a novel mechanism of IL-6/STAT3 signaling pathway in the regulation of macrophage polarization, thus contributing to HCC metastasis and drug resistance in chemotherapy.

Stanniocalcin 2 Ameliorates Hepatosteatosis Through Activation of STAT3 Signaling

Stanniocalcin 2 (STC2), a secreted glycoprotein hormone, regulates many biological processes, including cell proliferation, apoptosis, tumorigenesis, and atherosclerosis. However, its role in hepatic triglyceride metabolism remains unknown. In the present study, we found that expression levels of STC2 were significantly reduced in the livers of leptin-deficient and high fat diet-induced obese mice. Systemic administration of STC2 recombinant protein or adenovirus-mediated overexpression of STC2 markedly attenuated hepatosteatosis and hypertriglyceridemia in obese mice. At the molecular level, we found that STC2 activated the STAT3 signaling pathway to inhibit lipogenic gene expression. Consistently, in vitro studies further showed that inhibition of STAT3 signaling abolished the anti-steatotic effects of STC2. Together, our results revealed an important role of STC2 in the regulation of hepatic triglyceride metabolism, which might provide a potential therapeutic target for the treatment of fatty liver and related metabolic disorders.

Tumor necrosis factor-α promotes hepatocellular carcinogenesis through the activation of hepatic progenitor cells

Hepatocellular carcinoma (HCC) is an inflammation-related disease. Tumor necrosis factor alpha (TNF-α) is an important inflammatory factor and it has been confirmed to promote tumor growth and poor prognosis of HCC. Hepatic progenitor cells (HPCs) are thought to play an important role in liver injury and repair, as well as tumorigenesis. Chronic inflammation influences HPCs activation as well as differentiation. However, the mechanism is still unclear. In our study, the rat liver cancer model was constructed by DEN treatment, TNFR2-Fc fusion protein variant (TNFR2-FcV) and TNF-α^-/- rats were used to detect the role of TNF-α in liver injury and tumorigenesis. And the effect of TNF-α on HPCs activation and proliferation was investigated, and the specific molecular mechanism was explored. We found that TNF-α inhibition and deletion could reduce tumor incidence but shorten survival time by increasing apoptosis and decreasing proliferation of hepatocytes. Further analysis indicated that TNF-α knochdown cloud inhibit HPCs activation and proliferation through TNFR2/STAT3 signaling pathway. And clinically TNF-α expression was correlated to HPCs activation and HCC recurrences. Our work suggested that TNF-α played a key role in liver injury and tumorigenesis.

Molecular mechanism for the influence of gender dimorphism on alcoholic liver injury in mice

It is known that women develop alcoholic liver injury more rapidly and have a lower alcohol toxic threshold than men. However, the detailed molecular mechanisms remain unclear. The precise mechanism responsible for the sex difference needs to be determined. Female and male mice were given ethanol by intragastric infusion every day for 4 weeks. The pathological changes were detected by hematoxylin-eosin, Sirius red, oil red O, periodic acid-Schiff, and Hochest33258 staining in the liver of female and male mice. The related gene and protein expression of hepatocytes stress, proliferation and apoptosis, glycogen synthesis, lipid metabolism, and hepatic fibrosis were also systematically analyzed in the female and male mice. Livers from ethanol-treated female mice had more serious hepatocyte necrosis, liver fibrosis ( P < 0.01), substantial micro/macrovesicular steatosis ( p < 0.01), glycogen consumption ( p < 0.05), and hepatocytes apoptosis ( p < 0.05) than ethanol-treated male mice. The expression of heat shock protein 27 (HSP27), HSP70, proliferating cell nuclear antigen, B-cell lymphoma/leukemia-2 (Bcl-2), and phosphorylated signal transducer and activators of transcription 3 (p-STAT3) was higher in ethanol-treated male mice than ethanol-treated female mice ( P < 0.05 or P < 0.01). But, the expression of Bax (Bcl-2-associated X protein), Caspase 3, CYP2E1 (cytochrome P4502E1), and transforming growth factor βl had the contrary results. Our study suggested that ethanol treatment induced more expression of HSP27 and HSP70, faster hepatocyte proliferation, higher level of glycogen, and interleukin-6 signaling pathway activation, but less hepatocyte apoptosis and CYP2E1 expression in male mice than female mice, which could be helpful to understand the molecular mechanism for the influence of sex difference on alcoholic liver injury.

Expression patterns of STAT3, ERK and estrogen-receptor α are associated with development and histologic severity of hepatic steatosis: a retrospective study

BACKGROUND

Hepatic steatosis renders hepatocytes vulnerable to injury, resulting in the progression of preexisting liver disease. Previous animal and cell culture studies implicated mammalian target of rapamycin (mTOR), signal transducer and activator of transcription-3 (STAT3), extracellular signal-regulated kinase (ERK) and estrogen-receptor α in the pathogenesis of hepatic steatosis and disease progression. However, to date there have been few studies performed using human liver tissue to study hepatic steatosis. We examined the expression patterns of mTOR, STAT3, ERK and estrogen-receptor α in liver tissues from patients diagnosed with hepatic steatosis.

METHODS

We reviewed the clinical and histomorphological features of 29 patients diagnosed with hepatic steatosis: 18 with non-alcoholic fatty liver disease (NAFLD), 11 with alcoholic fatty acid disease (AFLD), and a control group (16 biliary cysts and 22 hepatolithiasis). Immunohistochemistry was performed on liver tissue using an automated immunostainer. The histologic severity of hepatic steatosis was evaluated by assessing four key histomorphologic parameters common to NAFLD and AFLD: steatosis, lobular inflammation, ballooning degeneration and fibrosis.

RESULTS

mTOR, phosphorylated STAT3, phosphorylated pERK, estrogen-receptor α were found to be more frequently expressed in the hepatic steatosis group than in the control group. Specifically, mTOR was expressed in 78% of hepatocytes, and ERK in 100% of hepatic stellate cells, respectively, in patients with NAFLD. Interestingly, estrogen-receptor α was diffusely expressed in hepatocytes in all NALFD cases. Phosphorylated (active) STAT3 was expressed in 73% of hepatocytes and 45% of hepatic stellate cells in patients with AFLD, and phosphorylated (active) ERK was expressed in hepatic stellate cells in all AFLD cases. Estrogen-receptor α was expressed in all AFLD cases (focally in 64% of AFLD cases, and diffusely in 36%). Phosphorylated STAT3 expression in hepatocytes and hepatic stellate cells correlated with severe lobular inflammation, severe ballooning degeneration and advanced fibrosis, whereas diffusely expressed estrogen-receptor α correlated with a mild stage of fibrosis.

CONCLUSIONS

Our data indicate ERK activation and estrogen-receptor α may be relevant in the development of hepatic steatosis. However, diffuse expression of estrogen-receptor α would appear to impede disease progression, including hepatic fibrosis. Finally, phosphorylated STAT3 may also contribute to disease progression.

Type 2 immunity is protective in metabolic disease but exacerbates NAFLD collaboratively with TGF-β

Nonalcoholic fatty liver disease (NAFLD) is now the most common progressive liver disease in developed countries and is the second leading indication for liver transplantation due to the extensive fibrosis it causes. NAFLD progression is thought to be tied to chronic low-level type 1 inflammation originating in the adipose tissue during obesity; however, the specific immunological mechanisms regulating the progression of NAFLD-associated fibrosis in the liver are unclear. To investigate the immunopathogenesis of NAFLD more completely, we investigated adipose dysfunction, nonalcoholic steatohepatitis (NASH), and fibrosis in mice that develop polarized type 1 or type 2 immune responses. Unexpectedly, obese interleukin-10 (IL-10)/IL-4-deficient mice (type 1-polarized) were highly resistant to NASH. This protection was associated with an increased hepatic interferon-γ (IFN-γ) signature. Conversely, IFN-γ-deficient mice progressed rapidly to NASH with evidence of fibrosis dependent on transforming growth factor-β (TGF-β) and IL-13 signaling. Unlike increasing type 1 inflammation and the marked loss of eosinophils seen in expanding adipose tissue, progression of NASH was associated with increasing eosinophilic type 2 liver inflammation in mice and human patient biopsies. Finally, simultaneous inhibition of TGF-β and IL-13 signaling attenuated the fibrotic machinery more completely than TGF-β alone in NAFLD-associated fibrosis. Thus, although type 2 immunity maintains healthy metabolic signaling in adipose tissues, it exacerbates the progression of NAFLD collaboratively with TGF-β in the liver.

RORα Induces KLF4-Mediated M2 Polarization in the Liver Macrophages that Protect against Nonalcoholic Steatohepatitis

The regulation of M1/M2 polarization in liver macrophages is closely associated with the progression of nonalcoholic steatohepatitis (NASH); however, the mechanism involved in this process remains unclear. Here, we describe the orphan nuclear receptor retinoic-acid-related orphan receptor α (RORα) as a key regulator of M1/M2 polarization in hepatic residential Kupffer cells (KCs) and infiltrated monocyte-derived macrophages. RORα enhanced M2 polarization in KCs by inducing the kruppel-like factor 4. M2 polarization was defective in KCs and bone-marrow-derived macrophages of the myeloid-specific RORα null mice, and these mice were susceptible to HFD-induced NASH. We found that IL-10 played an important role in connecting the function of M2 KCs to lipid accumulation and apoptosis in hepatocytes. Importantly, M2 polarization was controlled by a RORα activator, JC1-40, which improved symptoms of NASH. Our results suggest that the M2-promoting effects of RORα in liver macrophages may provide better therapeutic strategies against NASH.

Investigation of the pronounced erythropoietin-induced reduction in hyperglycemia in type 1-like diabetic rats

Erythropoietin (EPO) is known to stimulate erythropoiesis after binding with its specific receptor. In clinics, EPO is widely used in hemodialyzed patients with diabetes. However, changes in the expression of the erythropoietin receptor (EPOR) under diabetic conditions are still unclear. Therefore, we investigated EPOR expression both in vivo and in vitro. Streptozotocin-induced type 1-like diabetic rats (STZ rats) were used to evaluate the blood glucose-lowering effects of EPO. The expression and activity of the transducer and activator of transcription 3 (STAT3), the potential signaling molecule, was investigated in cultured rat skeletal myoblast (L6) cells incubated in high-glucose (HG) medium to mimic the in vivo changes. The EPO-induced reduction in hyperglycemia was more pronounced in diabetic rats. The increased EPOR expression in the soleus muscle of diabetic rats was reversed by the reduction in hyperglycemia. Glucose uptake was also increased in high-glucose (HG)-treated L6 cells. Western blotting results indicated that the EPO-induced hyperglycemic activity was enhanced mainly through an increase in EPOR expression. Increased EPOR expression was associated with the enhanced nuclear expression of STAT3 in HG-exposed L6 cells. In addition, treatment with siRNA specific to STAT3 reversed the increased expression of EPOR observed in these cells. Treatment with Stattic at a dose sufficient to inhibit STAT3 reduced the expression level of EPOR in STZ rats. In conclusion, the increased expression of EPOR by hyperglycemia is mainly associated with an augmented expression of nuclear STAT3, which was identified both in vivo and in vitro in the present study.

IL-10 Signaling Remodels Adipose Chromatin Architecture to Limit Thermogenesis and Energy Expenditure

Signaling pathways that promote adipose tissue thermogenesis are well characterized, but the limiters of energy expenditure are largely unknown. Here, we show that ablation of the anti-inflammatory cytokine IL-10 improves insulin sensitivity, protects against diet-induced obesity, and elicits the browning of white adipose tissue. Mechanistic studies define bone marrow cells as the source of the IL-10 signal and adipocytes as the target cell type mediating these effects. IL-10 receptor alpha is highly enriched in mature adipocytes and is induced in response to differentiation, obesity, and aging. Assay for transposase-accessible chromatin sequencing (ATAC-seq), ChIP-seq, and RNA-seq reveal that IL-10 represses the transcription of thermogenic genes in adipocytes by altering chromatin accessibility and inhibiting ATF and C/EBPβ recruitment to key enhancer regions. These findings expand our understanding of the relationship between inflammatory signaling pathways and adipose tissue function and provide insight into the physiological control of thermogenesis that could inform future therapy.

Sarcopenia and risk of nonalcoholic fatty liver disease: A meta-analysis

Background/Aim

The association between sarcopenia and nonalcoholic fatty liver disease (NAFLD) has been suggested by recent epidemiological studies, although the results have been inconsistent. This meta-analysis was conducted to summarize all available data and estimate the risk of NAFLD among patients with sarcopenia.

Materials and Methods

A comprehensive literature review was conducted using MEDLINE and EMBASE databases through November 2016 to identify all studies that compared the risk of NAFLD among patients with sarcopenia versus those without sarcopenia. Effect estimates from each study were extracted and combined using the random-effect, generic inverse variance method of DerSimonian and Laird.

Results

Five cross-sectional studies with 27,804 participants met the eligibility criteria and were included in the meta-analysis. The risk of NAFLD in patients with sarcopenia was significantly higher than those without sarcopenia with the pooled odds ratio of 1.54 (95% confidence interval, 1.05-2.26). The statistical heterogeneity was high with an I2of 83%.

Conclusions

A significantly increased risk of NAFLD among patients with sarcopenia was observed in this study.

Sarcopenia in Liver Disease: Current Evidence and Issues to Be sResolved

Sarcopenia is a common clinical symptom in aging and patients with wasting diseases, characterized by a decreased skeletal muscle mass. As a consequence of lifestyle change, the nonalcoholic fatty liver disease (NAFLD) presents a rising trend. In the past three decades, increasing evidence has proved that sarcopenia is related to NAFLD. In this chapter, we will summarize the emerging evidence of the predictive role of sarcopenia in NAFLD and review the diagnosis value, feasible mechanism, and therapy strategies of sarcopenia in NAFLD. Sarcopenia is a potential risk factor for NAFLD, and targeting sarcopenia can benefit NAFLD to some extent.

Snail1-expressing cancer-associated fibroblasts induce lung cancer cell epithelial-mesenchymal transition through miR-33b

Lung cancer has a high propensity for metastasis. Cancer-associated fibroblasts (CAFs) are the main type of stromal cells in cancer tissue, are activated by tumor cells, and play a significant role in tumor development. However, whether CAFs induce lung cancer cell metastasis, as well as pathway involved in CAF-induced lung cancer cell metastasis, is uncertain. Snail1 is a transcriptional factor whose expression in the stroma is associated with lower survival rates in patients with cancer. However, how Snail1 regulates the crosstalk between stromal cells and tumor cells when it is expressed in the stroma has not been determined. Altered microRNA (miRNA) expression is correlated with lung cancer metastasis. Our previous study of microRNAs showed that miR-33b levels were clearly reduced in lung cancer cell lines and lung cancer tissues, and miR-33b suppressed tumor cell epithelial-mesenchymal transition (EMT) when its expression was elevated. In this study, we found that co-culturing CAFs with lung cancer cells induced miR-33b downregulation and promoted epithelial cells EMT. Moreover, we found that miR-33b overexpression in lung cancer cells counteracted CAF-induced EMT. Interestingly, Snail1 expression in fibroblasts activate the inductive effects of CAFs on lung cancer cell EMT. Hence, understanding the molecular mechanism underlying the communication between stromal cells and tumor cells mediated by miR-33b may lead to the identification of novel targets for the treatment of lung cancer. Additionally, understanding the role of Snail1 driving CAFs to induce lung cancer cell EMT may provide with a new perspective on the treatment of lung cancer.

Sarcopenia in hiding: The risk and consequence of underestimating muscle dysfunction in nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Up to one third of individuals with NAFLD will develop nonalcoholic steatohepatitis (NASH), which is associated with progression to cirrhosis and is rapidly becoming the leading indication for liver transplantation. Sarcopenia is defined as a progressive and generalized loss of skeletal muscle mass, strength, and function. It is observed in up to 60% of patients with end-stage liver disease and portends a poor prognosis. Recent studies have shown that sarcopenia is a novel risk factor for developing NAFLD. Pathophysiological mechanisms relating sarcopenia and NASH may include insulin resistance (IR) and increased inflammation. IR leads to accumulation of triglycerides in both muscle tissue and the liver. It also exacerbates proteolysis and leads to muscle depletion. Chronic inflammation leads to liver injury and progression of fibrosis. The inflammatory milieu also stimulates protein catabolism. Viewing skeletal muscle as an endocrine organ that secretes various salutary myokines may help us understand its role in the development of steatosis. A better understanding of the pathophysiology will aid in developing physical and pharmacological therapeutic interventions. In this review, we will explore the complex inter-relationships between sarcopenia and NASH. We will discuss the impact of sarcopenia in patients with NASH and therapeutic options for the management of sarcopenia. (Hepatology 2017;66:2055-2065).

Phosphorylation of signal transducer and activator of transcription 3 induced by hyperglycemia is different with that induced by lipopolysaccharide or erythropoietin via receptor‑coupled signaling in cardiac cells

The signal transducer and activator of transcription 3 (STAT3) is known to be involved in hypertrophy and fibrosis in cardiac dysfunction. The activation of STAT3 via the phosphorylation of STAT3 is required for the production of functional activity. It has been established that lipopolysaccharide (LPS)‑induced phosphorylation of STAT3 in cardiomyocytes primarily occurs through a direct receptor‑mediated action. This effect is demonstrated to be produced rapidly. STAT3 in cardiac fibrosis of diabetes is induced by high glucose through promotion of the STAT3‑associated signaling pathway. However, the time schedule for STAT3 activation between LPS and high glucose appears to be different. Therefore, the difference in STAT3 activation between LPS and hyperglycemia in cardiomyocytes requires elucidation. The present study investigated the phosphorylation of STAT3 induced by LPS and hyperglycemia in the rat cardiac cell line H9c2. Additionally, phosphorylation of STAT3 induced by erythropoietin (EPO) via receptor activation was compared. Then, the downstream signals for fibrosis, including the connective tissue growth factor (CTGF) and matrix metalloproteinase (MMP)‑9, were determined using western blotting, while the mRNA levels were quantified. LPS induced a rapid elevation of STAT3 phosphorylation in H9c2 cells within 30 min, similar to that produced by EPO. However, LPS or EPO failed to modify the mRNA level of STAT3, and/or the downstream signals for fibrosis. High glucose increased STAT3 phosphorylation to be stable after a long period of incubation. Glucose incubation for 24 h may augment the STAT3 expression in a dose‑dependent manner. Consequently, fibrosis‑associated signals, including CTGF and MMP‑9 protein, were raised in parallel. In the presence of tiron, an antioxidant, these changes by hyperglycemia were markedly reduced, demonstrating the mediation of oxidative stress. Therefore, LPS‑ or EPO‑induced STAT3 phosphorylation is different compared with that caused by high glucose in H9c2 cells. Sustained activation of STAT3 by hyperglycemia may promote the expression of fibrosis‑associated signals, including CTGF and MMP‑9, in H9c2 cells. Therefore, regarding the cardiac dysfunctions associated with diabetes and/or hyperglycemia, the identification of nuclear STAT3 may be more reliable compared with the assay of phosphorylated STAT3 in cardiac cells.

Oral Supplementation of Glutamine Attenuates the Progression of Nonalcoholic Steatohepatitis in C57BL/6J Mice

Background: Universally accepted therapeutic strategies for the treatment of nonalcoholic steatohepatitis (NASH) are still lacking. Studies suggest a preventive effect of oral Gln supplementation on the development of NASH; however, whether Gln also has therapeutic potential for pre-existing NASH has not yet been clarified.Objective: The aim of the present study was to determine whether Gln prevents the progression of diet-induced NASH in mice.Methods: For 8 wk, female C57BL/6J mice (6-8 wk old) were pair-fed a liquid Western-style diet [WSD, 25% of energy from fat, 50% wt:wt fructose, 0.16% wt:wt cholesterol] or control diet (C diet) to induce liver damage. From week 8 to 13, they were pair-fed the C diet or WSD alone or supplemented with l-Gln to provide 2.1 g/kg body weight (C diet + Gln or WSD + Gln). Energy intake was adjusted to the group with the lowest energy intake. Indexes of liver damage and inflammation, intestinal barrier function, and toll-like receptor 4 (Tlr4) signaling in the liver were determined.Results: The liver histology scores significantly increased from 8 to 13 wk (+31%) in WSD-fed mice and were significantly higher than in controls (P ≤ 0.05 for both time comparisons), whereas scores did not differ between C diet-fed and WSD + Gln-fed mice after 13 wk of feeding. The occludin protein concentrations in the small intestinal tissue were similarly reduced in both WSD-fed groups when compared with controls [WSD compared with C diet (-53%) and C diet + Gln (-42%), P ≤ 0.05; WSD + Gln compared with C diet + Gln (-34%), P ≤ 0.05] after 13 wk, whereas the expression of myeloid differentiation primary response gene 88 mRNA and concentration of inducible nitric oxide synthase and 4-hydroxynonenal protein adducts were significantly higher only in livers of WSD-fed mice (P ≤ 0.05 for the WSD group compared with all other groups; WSD + Gln group compared with the C diet groups: NS).Conclusion: Taken together, our data suggest that oral Gln supplementation protects mice from the progression of pre-existing, WSD-induced NASH.

CD40 signaling and hepatic steatosis: Unanticipated links

Obesity predisposes to an increased risk of nonalcoholic fatty liver disease (NAFLD). Hepatic steatosis is the key pathological feature of NAFLD and has emerged as a metabolic disorder in which innate and adaptive arms of the immune response play a central role in disease pathogenesis. Recent studies have revealed unexpected relationships between CD40 signaling and hepatic steatosis in high fat diet rodent models. CD154, the ligand of CD40, is a mediator of inflammation and controls several critical events of innate and adaptive immune responses. In the light of these reports, we discuss potential links between CD40 signaling and hepatic steatosis in NAFLD.

Polychlorinated biphenyls disrupt hepatic epidermal growth factor receptor signaling

1. Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that disrupt hepatic xenobiotic and intermediary metabolism, leading to metabolic syndrome and nonalcoholic steatohepatitis (NASH). 2. Since phenobarbital indirectly activates Constitutive Androstane Receptor (CAR) by antagonizing growth factor binding to the epidermal growth factor receptor (EGFR), we hypothesized that PCBs may also diminish EGFR signaling. 3. The effects of the PCB mixture Aroclor 1260 on the protein phosphorylation cascade triggered by EGFR activation were determined in murine (in vitro and in vivo) and human models (in vitro). EGFR tyrosine residue phosphorylation was decreased by PCBs in all models tested. 4. The IC₅₀ values for Aroclor 1260 concentrations that decreased Y1173 phosphorylation of EGFR were similar in murine AML-12 and human HepG2 cells (∼2-4 μg/mL). Both dioxin and non-dioxin-like PCB congeners decreased EGFR phosphorylation in cell culture. 5. PCB treatment reduced phosphorylation of downstream EGFR effectors including Akt and mTOR, as well as other phosphoprotein targets including STAT3 and c-RAF in vivo. 6. PCBs diminish EGFR signaling in human and murine hepatocyte models and may dysregulate critical phosphoprotein regulators of energy metabolism and nutrition, providing a new mechanism of action in environmental diseases.

Targeting inflammation for the treatment of alcoholic liver disease

Alcoholic liver disease (ALD) is a leading cause of chronic liver disease with a wide spectrum of manifestations including simple steatosis to steatohepatitis, cirrhosis, and hepatocellular carcinoma. Liver injury in ALD is caused by chronic inflammation, which has been actively investigated as a therapeutic target for the treatment of ALD for over the last four decades. In this review, we summarize a wide variety of inflammatory mediators that have been shown to contribute to the pathogenesis of ALD, and discuss the therapeutic potential of these mediators for the treatment of ALD.

Therapeutic strategies for alcoholic liver disease: Focusing on inflammation and fibrosis (Review)

Excessive alcohol consumption is the most common cause of liver disease in the world. Chronic alcohol abuse leads to liver damage, liver inflammation, fibrosis and hepatocellular carcinoma. Inflammatory cytokines, such as tumor necrosis factor-α and interferon-γ, induce liver injury, which leads to the develo-pment of alcoholic liver disease (ALD). Hepatoprotective cytokines, such as interleukin (IL)-6 and IL-10, are also associated with ALD. IL-6 improves ALD via the activation of STAT3 and the subsequent induction of a variety of hepatoprotective genes in hepatocytes. Alcohol consumption promotes liver inflammation by incre-asing the translocation of gut-derived endotoxins to the portal circulation and by activating Kupffer cells through the lipopolysaccharide/Toll-like receptor 4 pathways. Oxidative stress and microflora products are also associated with ALD. Hepatic stellate cells play an important role in angiogenesis and liver fibrosis. Anti-angiogenic therapy has been found to be effective in the prevention of fibrosis. This suggests that blocking angiogenesis could be a promising therapeutic option for patients with advanced fibrosis. This review discusses the main pathways associated with liver inflammation and liver fibrosis as well as new therapeutic strategies.

Sarcopenia is associated with severe liver fibrosis in patients with non-alcoholic fatty liver disease

BACKGROUND

Sarcopenia recognises insulin resistance and obesity as risk factors, and is frequently associated with cardiometabolic disorders, including non-alcoholic fatty liver disease (NAFLD).

AIM

To test the prevalence of sarcopenia and its relation with the severity of fibrosis (main outcome) and the entire spectrum of liver histology in patients with NAFLD.

METHODS

We considered 225 consecutive patients with histological diagnosis of NAFLD (Kleiner score). The skeletal muscle index (%) (total appendicular skeletal muscle mass (kg)/weight (kg) × 100), a validated measure of sarcopenia, was assessed by bioelectrical impedance analysis. Sarcopenia was defined as a skeletal muscle mass index ≤37 in males and ≤28 in females.

RESULTS

The prevalence of sarcopenia showed a linear increase with the severity of fibrosis, and severe fibrosis (F3-F4) was more than doubled in sarcopenia (48.3% vs. 20.4% in fibrosis ≤F2, P < 0.001). After adjusting for confounders, the association of sarcopenia with severe fibrosis was maintained (OR 2.36, CI 1.16-4.77, P = 0.01), together with age > 50 (OR 6.53, CI 2.95-14.4, P < 0.001), IFG/Diabetes (OR 2.14, CI 1.05-4.35, P = 0.03) and NASH (OR 13.3, CI 1.64-108.1, P = 0.01). Similarly, a significant association was found between sarcopenia and NASH (P = 0.01), steatosis severity (P = 0.006), and ballooning (P = 0.01), but only the association with severe steatosis was maintained (OR 2.02, CI 1.06-3.83, P = 0.03) after adjusting for confounders.

CONCLUSIONS

In Western patients with NAFLD, with high prevalence of metabolic disorders and advanced liver disease, sarcopenia was associated with the severity of fibrosis and steatosis, independently of hepatic and metabolic risk factors. Studies are needed to assess the impact of interventions to reduce sarcopenia on NAFLD progression.

TRIF Differentially Regulates Hepatic Steatosis and Inflammation/Fibrosis in Mice

BACKGROUND & AIMS

Toll-like receptor 4 (TLR4) signaling is activated through 2 adaptor proteins: MyD88 and TIR-domain containing adaptor-inducing interferon-β (TRIF). TLR4 and MyD88 are crucial in nonalcoholic steatohepatitis (NASH) and fibrosis. However, the role of TRIF in TLR4-mediated NASH and fibrosis has been elusive. This study investigated the differential roles of TRIF in hepatic steatosis and inflammation/fibrosis.

METHODS

A choline-deficient amino acid defined (CDAA) diet was used for the mouse NASH model. On this diet, the mice develop hepatic steatosis, inflammation, and fibrosis. TLR4 wild-type and TLR4^-/- bone marrow chimeric mice and TRIF^-/- mice were fed CDAA or a control diet for 22 weeks. Hepatic steatosis, inflammation, and fibrosis were examined.

RESULTS

In the CDAA diet-induced NASH, the mice with wild-type bone marrow had higher alanine aminotransferase and hepatic tumor necrosis factor levels than the mice with TLR4^-/- bone marrow. The nonalcoholic fatty liver disease activity score showed that both wild-type and TLR4^-/- bone marrow chimeras had reduced hepatic steatosis, and that both types of chimeras had similar levels of inflammation and hepatocyte ballooning to whole-body wild-type mice. Notably, wild-type recipients showed more liver fibrosis than TLR4^-/- recipients. Although TRIF^-/- mice showed reduced hepatic steatosis, these mice showed more liver injury, inflammation, and fibrosis than wild-type mice. TRIF^-/- stellate cells and hepatocytes produced more C-X-C motif chemokine ligand 1 (CXCL1) and C-C motif chemokine ligand than wild-type cells in response to lipopolysaccharide. Consistently, TRIF^-/- mice showed increased CXCL1 and CCL3 expression along with neutrophil and macrophage infiltration, which promotes liver inflammation and injury.

CONCLUSIONS

In TLR4-mediated NASH, different liver cells have distinct roles in hepatic steatosis, inflammation, and fibrosis. TRIF promotes hepatic steatosis but it inhibits injury, inflammation, and fibrosis.

Effect of ginseng extract on the TGF-β1 signaling pathway in CCl4-induced liver fibrosis in rats

Background

Liver diseases are major global health problems. Ginseng extract has antioxidant, immune-modulatory and anti-inflammatory activities. This study investigated the effect of ginseng extract on carbon tetrachloride (CCl4)-induced liver fibrosis in rats.

Methods

Male Wistar rats were divided into four groups: control group, ginseng group, CCl₄ group and CCl₄ + ginseng group. Liver injury was induced by the intraperitoneal (I.P) injection of 3 ml/kg CCl₄ (30% in olive oil) weekly for 8 weeks. The control group was I.P injected with olive oil. The expression of genes encoding transforming growth factor beta (TGF-β), type I TGF-β receptor (TβR-1), type II TGF-β receptor (TβR-II), mothers against decapentaplegic homolog 2 (Smad2), Smad3, Smad4, matrix metalloproteinase 2 (MMP2), MMP9, tissue inhibitor matrix metalloproteinase-1 (TIMP-1), Collagen 1a2 (Col1a2), Collagen 3a1 (Col3a1), interleukin-8 (IL-8) and interleukin -10 (IL-10) were measured by real-time PCR.

Results

Treatment with ginseng extract decreased hepatic fat deposition and lowered hepatic reticular fiber accumulation compared with the CCl₄ group. The CCl₄ group showed a significant increase in hepatotoxicity biomarkers and up-regulation of the expression of genes encoding TGF-β, TβR-I, TβR-II, MMP2, MMP9, Smad-2,-3, -4, and IL-8 compared with the control group. However, CCl₄ administration resulted in the significant down-regulation of IL-10 mRNA expression compared with the control group. Interestingly, ginseng extract supplementation completely reversed the biochemical markers of hepatotoxicity and the gene expression alterations induced by CCl₄.

Conclusion

ginseng extract had an anti‐fibrosis effect via the regulation of the TGF‐β1/Smad signaling pathway in the CCl₄‐induced liver fibrosis model. The major target was the inhibition of the expression of TGF‐β1, Smad2, and Smad3.

Lung Adenocarcinoma Distally Rewires Hepatic Circadian Homeostasis

The circadian clock controls metabolic and physiological processes through finely tuned molecular mechanisms. The clock is remarkably plastic and adapts to exogenous "zeitgebers," such as light and nutrition. How a pathological condition in a given tissue influences systemic circadian homeostasis in other tissues remains an unanswered question of conceptual and biomedical importance. Here, we show that lung adenocarcinoma operates as an endogenous reorganizer of circadian metabolism. High-throughput transcriptomics and metabolomics revealed unique signatures of transcripts and metabolites cycling exclusively in livers of tumor-bearing mice. Remarkably, lung cancer has no effect on the core clock but rather reprograms hepatic metabolism through altered pro-inflammatory response via the STAT3-Socs3 pathway. This results in disruption of AKT, AMPK, and SREBP signaling, leading to altered insulin, glucose, and lipid metabolism. Thus, lung adenocarcinoma functions as a potent endogenous circadian organizer (ECO), which rewires the pathophysiological dimension of a distal tissue such as the liver. PAPERCLIP.

Lung damage induced by hyperglycemia in diabetic rats: The role of signal transducer and activator of transcription 3 (STAT3)

Increased evidence has shown that diabetes can be a risk factor for pulmonary fibrosis. The objective of this study was to use streptozotocin-induced diabetic rats (STZ rats) to assess the possible signals associated with lung damage in diabetic disorders. The expression levels of signal transducer and activator of transcription 3 (STAT3) and connective tissue growth factor (CTGF) in lung tissues were measured through Western blot analysis and real-time PCR. Additionally, the potential mechanisms were confirmed in cultured rat lung cell line (L2) incubated in high-glucose (HG) medium to mimic the in vivo changes. The pathological changes in the lung tissues of STZ rats were characterized using the bleomycin-treated tissues as reference. Moreover, the higher expression levels of STAT3 and CTGF in the lung tissues of STZ rats were reversed by treating the hyperglycemia. CTGF expression increased following the higher expression of STAT3 in the cultured L2 cells exposed to HG, and this change was reversed by siRNA treatment specific for STAT3. Stattic, at a dose sufficient to inhibit STAT3, reduced the CTGF levels in the lungs of STZ rats. In conclusion, STAT3 enhanced CTGF expression in a type-1 diabetes model associated with lung damage. Thus, STAT3 inhibitors may be developed to improve diabetes-induced lung damage in the future.

Alcoholic Hepatitis: Risk Factors, Pathogenesis, and Approach to Treatment

BACKGROUND

Alcoholic hepatitis (AH) is an inflammatory disorder of the liver characterized clinically by jaundice, hepatomegaly, and abdominal pain, and histologically by macrovesicular steatosis and necroinflammation.

METHODS

This clinical review will cover what is known about the pathogenesis, clinical presentation, current treatments, and novel therapies for AH.

RESULTS

The pathogenesis and treatment of AH remain areas of active research. Although abstinence is the cornerstone of therapy for all stages of alcoholic liver disease, corticosteroids have shown modest short-term benefits in treatment of severe AH.

CONCLUSIONS

Improved understanding of the pathogenesis of AH has expanded the range of potential treatments for this devastating disease. Several novel therapies are also currently in various stages of testing through clinical trials.

The complement component C5 promotes liver steatosis and inflammation in murine non-alcoholic liver disease model

Non-Alcoholic Fatty Liver Disease (NALD) is considering a hepatic manifestation of metabolic syndrome. Although the pathogenesis of NALD is not completely understood, insulin resistance and inflammatory cytokines are implicated. Considering that component C5 is a central mediator of inflammation, we investigated the role of C5 in the establishment of NALD. Eight to ten-week old B6 C5(+) and A/J C5(-) male mice were fed a high fat diet containing glucose (HFDG) for 6 and 10 weeks. We observed that B6 C5(+) mice HFDG-fed for 10 weeks developed hepatomegaly, triglycerides (TG) accumulation, steatosis and enhanced liver TNF-α, IL-6, IL-12p70 and IL-17 levels when compared to A/J C5(-) mice. Next, B6 C5(+) mice were compared with congenic B6 C5(-) mice. Again, B6 C5(+) HFDG-fed mice developed more steatosis, liver centro-lobular inflammation and presented higher levels of liver IL-1β, IL-12p70, IL-17 and TFG-β than B6 C5(-) mice under the same conditions. B6 C5(+) mice HFDG-fed also presented lower concentrations of serum albumin, serum cholesterol, blood leukocytes and liver NO production when compared with B6 C5(-) mice. We concluded that murine C5 contributes effectively to liver steatosis and inflammation in NALD pathogenesis. In addition, C5 is also important to control serum cholesterol and albumin levels in the C57BL/6 genetic background.

Interleukin-10 attenuates tumour growth by inhibiting interleukin-6/signal transducer and activator of transcription 3 signalling in myeloid-derived suppressor cells

Interleukin-10 (IL-10) is a well-characterized anti-inflammatory cytokine, but its role in anti-cancer immunity is controversial. After injection with TC-1 cancer cells, we observed more rapid tumour growth and significantly higher interleukin-6 (IL-6) production in IL-10 knockout (IL-10(-/-)) mice than wild-type (WT) mice. Blocking IL-6 with an anti-IL-6 receptor (IL-6R) monoclonal antibody (mAb) inhibited tumour growth and myeloid-derived suppressor cell (MDSC) generation, which were significantly increased in IL-10-deficient mice. MDSCs and tumour cells from IL-10(-/-) mice had increased phosphorylated signal transducer and activator of transcription 3 (p-STAT3) levels. Treatment with a STAT3 inhibitor, S3I, reduced tumour growth, inhibited MDSC expansion, reduced IL-6 in tumours, and relieved T cell suppression. The combination of anti-IL-6R mAb and S3I further inhibited tumour growth compared to S3I treatment alone. These results suggested that the inhibition of the IL-6/STAT3 signalling axis is a candidate anti-cancer strategy, especially under systemic inflammatory conditions with high IL-6.