Resistin serum levels are associated with insulin resistance, disease severity, clinical complications, and prognosis in patients with chronic liver diseases

Serum resistin and the risk for hepatocellular carcinoma in diabetic patients

Hepatocellular carcinoma (HCC), the predominant type of liver cancer, is a major contributor to cancer-related fatalities across the globe. Diabetes has been identified as a significant risk factor for HCC, with recent research indicating that the hormone resistin could be involved in the onset and advancement of HCC in diabetic individuals. Resistin is a hormone that is known to be involved in inflammation and insulin resistance. Patients with HCC have been observed to exhibit increased resistin levels, which could be correlated with more severe disease stages and unfavourable prognoses. Nevertheless, the exact processes through which resistin influences the development and progression of HCC in diabetic patients remain unclear. This article aims to examine the existing literature on the possible use of resistin levels as a biomarker for HCC development and monitoring. Furthermore, it reviews the possible pathways of HCC initiation due to elevated resistin and offers new perspectives on comprehending the fundamental mechanisms of HCC in diabetic patients. Gaining a better understanding of these processes may yield valuable insights into HCC’s development and progression, as well as identify possible avenues for prevention and therapy.

Angiotensin II type 1 receptor (AT1) blockade by Telmisartan attenuates hepatic steatosis in high-fat fed mice reducing Resistin, TRL4, and Myd88 expression

Background

Telmisartan is a non-peptide angiotensin II receptor antagonist which acts by ACE/AngII/AT1 axis blockade (ARB). In the last years increasing evidence of its metabolic benefits pointed out this drug as the most promising ARB for nonalcoholic fatty liver disease (NAFLD) treatment. The aim of the present study was to investigate the Telmisartan effect on treating NAFLD in mice fed with a high-fat diet evaluating liver gene modulation. Twenty-four male mice were divided into four groups and fed for 60 days with a standard diet (ST), standard diet plus TEL (ST+TEL 5 mg/kg/day by gavage for 4 weeks), high-fat diet (HFD), or high-fat diet plus TEL (HFD+TEL 5 mg/kg/day by gavage for 4 weeks). Body weight, lipid profile, insulin, alanine transaminase, and aspartate aminotransferase were evaluated. Liver histology was analyzed. US imaging was performed to access liver dimension and echogenicity and also epididymal fat pad thickness. The expression of proinflammatory resistin/TRL4/MYD88 pathway was analyzed.

Results

The main findings showed that TEL reduced the resistin, TRL4, and Myd88 liver expression in the HFD + TEL group when compared to the obese control group (HFD). Decreased hepatic steatosis in the HFD + TEL group demonstrated by US measurements of the liver longitudinal axis and echogenicity were observed. In addition, TEL reduced epididymal adipose pad thickness, body weight, transaminases, and improved glucose tolerance test and HDL cholesterol.

Conclusions

We observed that Telmisartan treatment improved metabolism, decreasing NAFLD.

Graphical Abstract

Telmisartan improves metabolic and lipid profile and liver steatosis of obese mice

Early Diagnosis and Prevention of Infections in Cirrhosis

Strategies to prevent infection and improve outcomes in patients with cirrhosis. HAV, hepatitis A virus; HBV, hepatitis B virus; COVID-19, novel coronavirus disease 2019; NSBB, nonselective β-blocker; PPI, proton pump inhibitors.Cirrhosis is a risk factor for infections. Majority of hospital admissions in patients with cirrhosis are due to infections. Sepsis is an immunological response to an infectious process that leads to end-organ dysfunction and death. Preventing infections may avoid the downstream complications, and early diagnosis of infections may improve the outcomes. In this review, we discuss the pathogenesis, diagnosis, and biomarkers of infection; the incremental preventive strategies for infections and sepsi; and the consequent organ failures in cirrhosis. Strategies for primary prevention include reducing gut translocation by selective intestinal decontamination, avoiding unnecessary proton pump inhibitors' use, appropriate use of β-blockers, and vaccinations for viral diseases including novel coronavirus disease 2019. Secondary prevention includes early diagnosis and a timely and judicious use of antibiotics to prevent organ dysfunction. Organ failure support constitutes tertiary intervention in cirrhosis. In conclusion, infections in cirrhosis are potentially preventable with appropriate care strategies to then enable improved outcomes.

Hepatogenous diabetes: Knowledge, evidence, and skepticism

The diabetogenic potential of liver cirrhosis (LC) has been known for a long time, and the name "hepatogenous diabetes" (HD) was coined in 1906 to define the condition. Diabetes mellitus (DM) that develops as a consequence of LC is referred to as HD. In patients with LC, the prevalence rates of HD have been reported to vary from 21% to 57%. The pathophysiological basis of HD seems to involve insulin resistance (IR) and pancreatic β-cell dysfunction. The neurohormonal changes, endotoxemia, and chronic inflammation of LC initially create IR; however, the toxic effects eventually lead to β-cell dysfunction, which marks the transition from impaired glucose tolerance to HD. In addition, a number of factors, including sarcopenia, sarcopenic obesity, gut dysbiosis, and hyperammonemia, have recently been linked to impaired glucose metabolism in LC. DM is associated with complications and poor outcomes in patients with LC, although the individual impact of each type 2 DM and HD is unknown due to a lack of categorization of diabetes in most published research. In fact, there is much skepticism within scientific organizations over the recognition of HD as a separate disease and a consequence of LC. Currently, T2DM and HD are being treated in a similar manner although no standardized guidelines are available. The different pathophysiological basis of HD may have an impact on treatment options. This review article discusses the existence of HD as a distinct entity with high prevalence rates, a strong pathophysiological basis, clinical and therapeutic implications, as well as widespread skepticism and knowledge gaps.

Assessment of serum Resistin in detecting Insulin Resistance and their impact on response to direct acting antiviral in chronic viral hepatitis C patients

Background

Chronic hepatitis C (CHC) virus is associated with insulin resistance and diabetes which have been linked to progressive liver fibrosis and sustained virologic response (SVR) to antiviral treatment. Resistin is a polypeptide hormone belonging to adipokines that may contribute to the development of obesity, insulin resistance, and metabolic syndrome. Also, the link between resistin and insulin resistance in patients with chronic hepatitis C and the effect of new direct acting antivirals on them seems unclear at present. The aim of this study is to evaluate the role of Resistin in detecting Insulin Resistance and their impact on response to direct acting antiviral in chronic hepatitis C patients.

Results

The Study was prospective Cohort clinical study, in Hepatology outpatient clinic at Ain Shams University Hospitals .This study was performed on 40 Egyptian patients who have Chronic viral hepatitis C, divided into 3 groups: GROUP I includes: 20 patients with Chronic viral hepatitis C on Sofosbovir- Daclatasvir before start of treatment and Sustained viral response after 12 weeks [SVR 12]. GROUP II includes: 20 patients with Chronic viral hepatitis C and non-responders before start of 2nd line of treatment and SVR 12. GROUP III includes: 10 subjects not infected with HCV as control group. The following investigations were done: body mass index calculation, Laboratory investigations including CBC, complete hepatic function tests, FIB-4 calculation, fasting serum insulin, HOMA-IR and serum Resistin level at baseline and re-assessed 12 weeks post end of treatment. Fasting serum Insulin, HOMA-IR and Resistin level were statistically significant higher in both naïve & relapser chronic HCV infected patients than in control group (p value <0.001). SVR 12 weeks post treatment was achieved in all 40 patients received new direct acting antivirals with a Significant reduction in Fasting serum Insulin, HOMA-IR and Resistin level at SVR 12 week (p value 0,001, <0.001, <0.001) respectively. Significant positive correlation was found between Resistin level and HOMA-IR in both naïve and relapse chronic HCV patients. Calculation of FIB-4 among patients showed significant higher FIB-4 in naïve patients than relapser (p value 0,002). Serum Resistin at a cut off value >1800 ng/ml had 38.89 % sensitivity, 86.36 % specificity, 70 % PPV, 63.3 % NPV (with an overall accuracy of 57.1 %) in predicting absence of liver cirrhosis based on FIB-4. And at a cutoff value ≥2400 ng/ml had 93.55% sensitivity, 33.3% specificity, 82.9% positive predictive value, and 60% negative predictive value with an overall accuracy of 62.4% in prediction of significant insulin resistance among chronic HCV patients.

Conclusion

Serum Resistin level was significantly up regulated in patients with chronic HCV, with significant reduction in its level after achievement of SVR. Resistin has the potential to be a biomarker for screening of insulin resistance among chronic HCV patients.

A review of the role of ethanol-induced adipose tissue dysfunction in alcohol-associated liver disease

Alcohol-associated liver disease (AALD) encompasses a spectrum of liver diseases that includes simple steatosis, steatohepatitis, fibrosis, and cirrhosis. The adverse effects of alcohol in liver and the mechanisms by which ethanol (EtOH) promotes liver injury are well studied. Although liver is known to be the primary organ affected by EtOH exposure, alcohol's effects on other organs are also known to contribute significantly to the development of liver injury. It is becoming increasingly evident that adipose tissue (AT) is an important site of EtOH action. Both AT storage and secretory functions are altered by EtOH. For example, AT lipolysis, stimulated by EtOH, contributes to chronic alcohol-induced hepatic steatosis. Adipocytes secrete a wide variety of biologically active molecules known as adipokines. EtOH alters the secretion of these adipokines from AT, which include cytokines and chemokines that exert paracrine effects in liver. In addition, the level of EtOH-metabolizing enzymes, in particular, CYP2E1, rises in the AT of EtOH-fed mice, which promotes oxidative stress and/or inflammation in AT. Thus, AT dysfunction characterized by increased AT lipolysis and free fatty acid mobilization and altered secretion of adipokines can contribute to the severity of AALD. Of note, moderate EtOH exposure results in AT browning and activation of brown adipose tissue which, in turn, can promote thermogenesis. In this review article, we discuss the direct effects of EtOH consumption in AT and the mechanisms by which EtOH impacts the functions of AT, which, in turn, increases the severity of AALD in animal models and humans.

Acute Elevated Resistin Exacerbates Mitochondrial Damage and Aggravates Liver Steatosis Through AMPK/PGC-1α Signaling Pathway in Male NAFLD Mice

Resistin was identified as a link between obesity and insulin resistance and is associated with many diseases in mice. Deciphering the related development and molecular mechanism is necessary for the treatment of these diseases. Previous studies have revealed that increased resistin levels are correlated with lipid accumulation and play a role in non-alcoholic fatty liver disease (NAFLD) development. However, the exact mechanisms underlying these processes remain unclear. To further clarify whether acute elevated resistin level exacerbated liver steatosis, a high-fat diet-induced NAFLD animal model was used and treated with or without resistin for 6 days. We discovered that resistin altered mitochondrial morphology, decreased mitochondrial content, and increased lipid accumulation in HFD mice. qRT-PCR and western blot analysis showed that acute elevated resistin significantly altered the gene expression of mitochondrial biogenesis and liver lipid metabolism molecules in HFD mice. Consequently, in vitro experiments verified that resistin reduced the mitochondrial content, impaired the mitochondrial function and increased the lipid accumulation of palmitate-treated HepG2 cells. Additionally, we demonstrated that resistin upregulated proinflammatory factors, which confirmed that resistin promoted the development of inflammation in NAFLD mice and palmitate-treated HepG2 cells. Signaling-transduction analysis demonstrated that acute elevated resistin aggravated liver steatosis through AMPK/PGC-1α pathway in male mice. This reveals a novel pathway through which lipogenesis is induced by resistin and suggests that maintaining mitochondrial homeostasis may be key to treatments for preventing resistin-induced NAFLD aggravation.

Investigation of Genetic Modifiers of Copper Toxicosis in Labrador Retrievers

Copper toxicosis is a complex genetic disorder in Labrador retrievers characterized by hepatic copper accumulation eventually leading to liver cirrhosis. The variation of hepatic copper levels in Labrador retrievers has been partly explained by mutations in ATP7A c.980C>T and ATP7B c.4358G>A. To further elucidate the genetic background of this disease, we used targeted Next Generation Sequencing (NGS) in a cohort of 95 Labrador retrievers to analyze 72 potential modifier genes for variations associated with hepatic copper levels. Variants associated with copper levels were subsequently evaluated in a replication cohort of 144 Labrador retrievers. A total of 44 variants in 25 different genes were identified, of which four showed significant association with copper levels. Of the four variants found associated with hepatic copper levels in the NGS cohort, one was validated in the replication cohort. The non-reference allele of the variant NC_006602.3.g.52434480C>T in RETN resulting in amino-acid change p.Leu7Phe was associated with decreased hepatic copper levels. In humans, resistin is associated with severity of non-alcoholic fatty liver disease, fibrosis, cirrhosis and mitochondrial dysfunction in hepatocytes. Further studies are needed to investigate the biological function of RETN p.Leu7Phe in the development of copper toxicosis in Labrador retrievers.

Fluid Biomarkers for Predicting the Prognosis of Liver Cirrhosis

Liver cirrhosis is the terminal stage of most chronic liver conditions, with a high risk of mortality. Careful evaluation of the prognosis of cirrhotic patients and providing precise management are crucial to reduce the risk of mortality. Although the liver biopsy and hepatic venous pressure gradient (HVPG) can efficiently evaluate the prognosis of cirrhotic patients, their application is limited due to the invasion procedures. Child-Pugh score and the model for end-stage liver disease (MELD) score had been widely used in the assessment of cirrhotic prognosis, but the defects of subjective variable application in Child-Pugh score and unsuitability to all phases of liver cirrhosis in MELD score limit their prognostic values. In recent years, continuous efforts have been made to investigate the prognostic value of body fluid biomarkers for cirrhotic patients, and promising results have been reported. Since the collection of fluid specimens is easy, noninvasive, and repeatable, fluid biomarkers can be ideal indicators to predict the prognosis of cirrhosis. Here, we reviewed noninvasive fluid biomarkers in different prognostic functions, including the prediction of survival and complication development.

Circulating Resistin Is Associated with Plasma Glucagon-Like Peptide-1 in Cirrhotic Patients with Hepatitis C Virus Genotype-4 Infection

Purpose: Limited and contradictory data on the circulating levels of glucagon-like peptide (GLP-1) and resistin in hepatitis C virus genotype-4 (HCV-4) cirrhotic patients are present. Thus, this study aimed to evaluate their concentrations and to investigate the association between total GLP-1, resistin, and insulin resistance in those patients.Materials and Methods: Non-diabetic HCV-4 cirrhotic patients (n = 80; 40 with Child-Pugh A, 20 with Child-Pugh B, and 20 with Child-Pugh C), and 25 healthy subjects were enrolled in this study. The basal circulating levels of total GLP-1 and resistin along with serum insulin, glucose, total cholesterol, and triglycerides were measured.Results: Plasma GLP-1 and serum resistin levels were significantly higher in cirrhotic patients than controls (P < . 001). Moreover, circulating GLP-1 and resistin levels increased in a stepwise fashion in line with increasing grade of liver damage. According to Spearman's rank correlation, both GLP-1 and resisitin correlated positively with each other, insulin, homeostatic model assessment of insulin resistance, alanine aminotransferase (ALT), total bilirubin, and international normalized ratio while they correlated negatively with albumin (P < .001). Multiple stepwise regression analysis showed that ALT, serum resistin and Child-Pugh score independently influenced the GLP-1 levels in cirrhotic patients.Conclusions: Circulating levels of GLP-1 and resistin were elevated in cirrhotic patients with HCV-4. Further, the severity of liver cirrhosis and serum resistin were the determinant factors explaining the variability of GLP-1 levels by about 84%. In addition, a positive relation was found between insulin resistance and both GLP-1 and resistin levels.

Are presepsin and resistin better markers for bacterial infection in patients with decompensated liver cirrhosis?

BACKGROUND

Bacterial infections impair prognosis in patients with cirrhosis. Presepsin and, more recently, resistin are promising markers of infection and sepsis in patients without cirrhosis.

AIMS

The aim of our study was to assess the performance of presepsin and resistin as early markers of infection compared with C reactive protein (CRP) and procalcitonin (PCT), and their prognostic relevance in patients with decompensated cirrhosis.

METHODS

One hundred and fourteen consecutive patients with decompensated cirrhosis were enrolled and followed-up for 28 days. Diagnostic performances of CRP, PCT, presepsin and resistin were assessed.

RESULTS

Fifty-three (46.5%) patients had bacterial infections of which 30 (56%) had sepsis. Presepsin and resistin had similar performance as CRP and PCT for the diagnosis of infection (best cut-off of 1444 pg/ml and 20 ng/ml, respectively) and sepsis. Presepsin (HR = 5.5; 95%CI: 2.36-13.21, p < 0.0001) and the ≥500 pg/ml increase of presepsin at 48 h (HR = 9.24; 95%CI: 3.66-23.27, p < 0.008) were independently associated with 28-day mortality.

CONCLUSIONS

Presepsin and resistin have similar diagnostic performances to CRP and PCT for bacterial infection in decompensated cirrhosis. Presepsin and Δ presepsin ≥500 pg/ml have also a prognostic relevance for 28-day mortality.

Ascitic fluid regulates the local innate immune response of patients with cirrhosis

Ascitic neutrophils from cirrhotic patients with spontaneous bacterial peritonitis (SBP) exhibit an impaired oxidative burst that could facilitate bacterial infection. However, the influence of the cell-free ascitic fluid of these patients on neutrophil function has not been investigated. To analyze this influence, we determined the ascitic levels of cytokines, resistin, and lactoferrin and their association with neutrophil function, disease severity score, and SBP resolution. We analyzed NETosis induction by microscopy and oxidative burst by the flow cytometry of healthy neutrophils cultured in ascitic fluid from cirrhotic patients with sterile ascites (SA) and with SBP before and after antibiotic treatment. Resistin, IL-6, IL-1 receptor antagonist, IL-1β, and lactoferrin levels were measured in ascitic fluids and supernatants of cultured neutrophils and PBMCs by ELISA. Upon stimulation, healthy neutrophils cultured in SBP ascitic fluid produced lower NETosis and oxidative burst than those cultured in SA. Ascitic resistin levels were negatively correlated with NETosis, oxidative burst, and ascitic glucose levels; and positively correlated with the model for end-stage liver disease score. After an E. coli or TNF-α stimulus, neutrophils were the major resistin producers. Resistin indirectly reduced the oxidative burst of neutrophils and directly reduced the inflammatory phenotype of monocytes and TNF-α production. Bacterial-induced resistin production can down-regulate the inflammatory response of macrophages and neutrophil function in ascitic fluid. Consequently, this down-regulation may jeopardize the elimination of bacteria that translocate to ascitic fluid in patients with cirrhosis.

Activation of the porcine alveolar macrophages via toll-like receptor 4/NF-κB mediated pathway provides a mechanism of resistin leading to inflammation

Resistin, a previously discovered cysteine-rich adipokine known to regulate glucose metabolism, has been emerged as a mediator in inflammation and immunity. Its level was supposed to be related to the expression of indicators, such as interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) in inflammation. Toll-like receptor 4 (TLR4) was reported to be a receptor for resistin in cells, like leukocytes and peripheral blood mononuclear cells (PBMC). However, the pro-inflammatory role of resistin and its intracellular mechanisms in alveolar macrophages have not been thoroughly validated. Here we found that the pro-inflammatory cytokine expression in porcine alveolar macrophages (PAMs) was positively correlated with resistin. Our results also showed that resistin induced the expression of TLR4, intracellular molecules myeloid differentiation primary response protein 88 (MyD88), TRIF-related adaptor molecule (TRAM) and nuclear factor κB (NF-κB) in PAMs. In contrast, inhibition of TLR4, MyD88, TRAM and NF-κB abrogated the pro-inflammatory effect of resistin on PAMs. Additionally, the associations among TLR4, MyD88/TRAM and NF-κB were investigated by introducing TLR4-siRNA, MyD88-siRNA and TRAM-siRNA respectively into PAMs prior to the treatment with resistin. Taken together, our findings demonstrated that resistin promoted the production of pro-inflammatory cytokine in PAMs via TLR4/NF-κB-mediated pathway (TLR4/MyD88/TRAM/NF-κB).

Treatment of Type-1 Hepatorenal Syndrome with Pentoxifylline: A Randomized Placebo Controlled Clinical Trial

INTRODUCTION

Type-1 hepatorenal syndrome (HRS-1) portends a poor prognosis in patients with cirrhosis. Currently available medical therapies are largely ineffective, save for liver transplantation. We aimed to determine if pentoxifylline (PTX) therapy in addition to the standard of care of volume expansion with albumin and vasoconstriction with midodrine and octreotide (AMO) is safe and efficacious compared to AMO in HRS-1 treatment.

MATERIAL AND METHODS

Hospitalized subjects with decompensated cirrhosis and HRS-1 were enrolled. PTX or placebo was administered with AMO therapy for up to 14 days. The primary endpoint was HRS-1 resolution (serum creatinine ≤ 1.5 g/dL for &gt; 24 h). Secondary endpoints were change in creatinine and MELD score, partial treatment response, 30-and 180-day overall and transplant free survival.

RESULTS

Twelve subjects with mean age 58.9 ± 6.2 years were enrolled and randomized. Mean MELD score was 26.5 ± 7.4 and 58.3% were male. Overall cohort 30- and 180-day survival was 58.3% and 33.3% respectively. Two subjects underwent liver transplantation. HRS-1 resolution (16.7% vs. 16.7%, p = 1.000), partial treatment response (33.3% vs. 16.7%, p = 0.505), change in creatinine (+0.48 g/dL, 95% CI -0.49-1.46 vs. +0.03 g/dL, 95% CI -0.64- 0.70, p = 0.427), 30-day survival (66.6% vs. 50.0%, p = 0.558) and 180-day survival (50.0% vs. 16.7%, p = 0.221) were similar between the two groups. Serious adverse events necessitating treatment discontinuation were rare (n = 1, PTX).

DISCUSSION

The addition of PTX to AMO in the treatment of HRS-1 is safe when compared to the current standard of care. Future large-scale prospective study to validate the efficacy of this treatment seems warranted.

Adipokines in Liver Cirrhosis

Liver fibrosis can progress to cirrhosis, which is considered a serious disease. The Child-Pugh score and the model of end-stage liver disease score have been established to assess residual liver function in patients with liver cirrhosis. The development of portal hypertension contributes to ascites, variceal bleeding and further complications in these patients. A transjugular intrahepatic portosystemic shunt (TIPS) is used to lower portal pressure, which represents a major improvement in the treatment of patients. Adipokines are proteins released from adipose tissue and modulate hepatic fibrogenesis. These proteins affect various biological processes that are involved in liver function, including angiogenesis, vasodilation, inflammation and deposition of extracellular matrix proteins. The best studied adipokines are adiponectin and leptin. Adiponectin protects against hepatic inflammation and fibrogenesis, and leptin functions as a profibrogenic factor. These and other adipokines are supposed to modulate disease severity in patients with liver cirrhosis. Consequently, circulating levels of these proteins have been analyzed to identify associations with parameters of hepatic function, portal hypertension and its associated complications in patients with liver cirrhosis. This review article briefly addresses the role of adipokines in hepatitis and liver fibrosis. Here, studies having analyzed these proteins in systemic blood in cirrhotic patients are listed to identify adipokines that are comparably changed in the different cohorts of patients with liver cirrhosis. Some studies measured these proteins in systemic, hepatic and portal vein blood or after TIPS to specify the tissues contributing to circulating levels of these proteins and the effect of portal hypertension, respectively.

Proteomic Signature of Acute Liver Failure: From Discovery and Verification in a Pig Model to Confirmation in Humans

Acute liver failure (ALF) is a fatal condition hallmarked by rapid development. The present study aimed to describe the dynamic alterations of serum proteins associated with ALF development, and to seek for novel biomarkers of ALF. Miniature pigs (n = 38) were employed to establish ALF models by infusing d-galactosamine (GALN, 1.3 g/kg). A total of 1310 serum proteins were compared in pooled serum samples (n = 10) before and 36 h after GALN administration through label-free quantitation (LFQ) based shotgun proteomics. Functional analysis suggested a significant enrichment of ALF-related proteins involved in energy metabolism. Temporal changes of 20 energy metabolism related proteins were investigated in individual pigs (n = 8) via parallel reaction monitoring (PRM) based targeted proteomics. In addition, mitochondrion degeneration and gene expression alteration of aerobic metabolism genes were confirmed in GALN-insulted pig liver. In clinical validation study enrolled 34 ALF patients and 40 healthy controls, fructose-1,6-bisphosphatase 1 (FBP1) showed a prognostic value for short-term survival (30 days) equal to that of the Model of End-stage Liver Disease score (ROC-AUC = 0.778). Survival analysis suggested significantly higher death-related hazard in ALF patients with higher FBP1 levels (>16.89 μg/dL) than in those with lower FBP1 levels (p = 0.002). Additionally, serum retinol binding protein 4 (RBP4) level was found decreased prior to ALT elevation in GALN-insulted pig model. We also confirmed that serum level of RBP4 is significantly lower in ALF patients (p < 0.001) as compared with healthy controls. In summary, this translational study, displayed by multistaged proteomics techniques, unveiled underlying functional changes related to the development of ALF and facilitated the discovery of novel ALF markers.

Resistin and Insulin Resistance: A Link Between Inflammation and Hepatocarcinogenesis

BACKGROUND

Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third leading cause of cancer related death overall. The role of insulin resistance in the development of HCC associated with chronic HCV infection has not been established. Resistin is a polypeptide hormone belonging to the adipokine family which could contribute to tumorigenesis and angiogenesis. Our aim was to study serum resistin and insulin resistance as risk factors for HCC in HCV cirrhotic patients.

MATERIALS AND METHODS

This prospective case controlled study included 100 patients with HCV related liver cirrhosis and HCC, 100 patients with HCV related liver cirrhosis without HCC and 50 apparently healthy participants as controls. For all subjects, liver profile, serologic markers for viral hepatitis, lipid profile, alpha-fetoprotein level (AFP), homeostasis model assessment (HOMA) were examined along with resistin.

RESULTS

HCC patients had higher mean values of HOMA-IR and resistin than cirrhotic patients and the control subjects (p<0.01). HOMA and resistin were considered independent risk factors in development of HCC, those patients with resistin > 12 ng/ml and HOMA >4 being 1.6 times more likely to have HCC.

CONCLUSIONS

HOMA and serum resistin allow for early identification of patients with cirrhosis who are at substantially increased risk of HCC.

RECOMMENDATION

HOMA and serum resistin could represent novel markers to identify HCV cirrhotic patients at greater risk of development of HCC.

Resistin reinforces interferon λ-3 to eliminate hepatitis C virus with fine-tuning from RETN single-nucleotide polymorphisms

The effect of resistin (RETN) on the response to anti-HCV therapy remains unclear. A prospective cohort study was performed using 655 consecutive HCV patients, of whom 513 had completed a course of interferon-based therapy. Multivariate and GEE analyses revealed four RETN single-nucleotide polymorphisms (SNPs), rs34861192, rs3219175, rs3745367 and rs1423096, to be synergistically associated with resistin levels. After adjusting for co-factors such as interferon λ-3 (IFNL3)-rs12979860, the resistin level and the hyper-resistinemic genotype at the 4 RETN SNPs were positively and negatively associated with a sustained virological response (SVR), respectively. RETN-rs3745367 was in linkage disequilibrium with IFNL3-rs12979860. Compared to non-SVR patients, SVR patients had higher levels of pre-therapy resistin, primarily originating from intrahepatic lymphocytes, stellate cells, Kupffer cells, hepatic progenitor cells and hepatocytes. This difference diminished over the course of therapy, as only SVR patients exhibited a 24-week post-therapy decrease in resistin. Both resistin and IFNL3 mRNAs were upregulated, but only resistin mRNA was upregulated by recombinant resistin in peripheral blood mononuclear cells with and without hyper-resistinemic genotypes of the 4 RETN SNPs, respectively. Fine-tuned by RETN SNPs, intrahepatic, multi-cellular resistin reinforced IFNL3 in eliminating HCV via immunomodulation to counteract pro-inflammation. These results encourage the development of novel resistin-targeted anti-viral agents.

Adiponectin as an anti-fibrotic and anti-inflammatory adipokine in the liver

Hepatic fibrosis is a dynamic process resulting from excessive deposition of extracellular matrix in the liver; uncontrolled progression of fibrosis can eventually lead to liver cirrhosis and/or hepatocellular carcinoma. The fibrogenic process is complex and modulated by a number of both hepatic and extra-hepatic biological factors. Growing evidence indicates that adipokines, a group of cytokines produced by adipose tissue, impart dynamic functions in liver and are involved in modulation of hepatic fibrosis. In particular, two key adipokines, adiponectin and leptin, directly regulate many biological responses closely associated with development and progression of hepatic fibrosis. Leptin acts as a pro-fibrogenic cytokine, while adiponectin possesses anti-fibrogenic and anti-inflammatory properties. Adiponectin, acting via its cognate receptors, adiponectin receptors 1 and 2, potently suppresses fibrosis and inflammation in liver via multiple mechanisms. This review summarizes recent findings concerning the role of adiponectin in fibrogenic process in liver and addresses the underlying molecular mechanisms in modulation of fibrosis.

Adipokines levels are associated with the severity of liver disease in patients with alcoholic cirrhosis

AIM: To investigate the adipokine levels of leptin, adiponectin, resistin, visfatin, retinol-binding protein 4 (RBP4), apelin in alcoholic liver cirrhosis (ALC).

METHODS: Forty non-diabetic ALC patients [median age: 59 years, males: 35 (87.5%), Child-Pugh (CP) score: median 7 (5-12), CP A/B/C: 18/10/12, Model for End-stage Liver Disease (MELD): median 10 (6-25), follow-up: median 32.5 mo (10-43)] were prospectively included. The serum adipokine levels were estimated in duplicate by ELISA. Somatometric characteristics were assessed with tetrapolar bioelectrical impedance analysis. Pearson’s rank correlation coefficient was used to assess possible associations with adipokine levels. Univariate and multivariate Cox regression analysis was used to determine independent predictors for overall survival.

RESULTS: Body mass index: median 25.9 (range: 20.1-39.3), fat: 23.4% (7.6-42.1), fat mass: 17.8 (5.49-45.4), free fat mass: 56.1 (39.6-74.4), total body water (TBW): 40.6 (29.8-58.8). Leptin and visfatin levels were positively associated with fat mass (P < 0.001/P = 0.027, respectively) and RBP4 with TBW (P = 0.025). Median adiponectin levels were significantly higher in CPC compared to CPA (CPA: 7.99 ± 14.07, CPB: 7.66 ± 3.48, CPC: 25.73 ± 26.8, P = 0.04), whereas median RBP4 and apelin levels decreased across the spectrum of disease severity (P = 0.006/P = 0.034, respectively). Following adjustment for fat mass, visfatin and adiponectin levels were significantly increased from CPA to CPC (both P < 0.001), whereas an inverse correlation was observed for both RBP4 and apelin (both P < 0.001). In the multivariate Cox regression analysis, only MELD had an independent association with overall survival (HR = 1.53, 95%CI: 1.05-2.32; P = 0.029).

CONCLUSION: Adipokines are associated with deteriorating liver function in a complex manner in patients with alcoholic liver cirrhosis.

Adiponectin/resistin levels and insulin resistance in children: a four country comparison study

Background

There are few reports on the effects of ethnicity or gender in the association between adipocytokines and insulin resistance in children of different ages. This study assessed associations between serum concentrations of adiponectin/resistin and parameters of insulin resistance in children from 4 different countries.

Methods

A total of 2,290 children were analyzed in this study; each was from one of 4 different countries (Japan, Thailand, Italy and USA), and grouped according to age (8–11 years old in Group 1 and 12–15 years old in Group 2).

Results

Adioponectin was higher in female than in male children, and in Group 1 than in Group 2. Generally, adiponectin was lower in Asian as compared to Italian and American children. These tendencies remained even after adjustment for body mass index (BMI) or waist circumstance (WC). Among older children (Group 2), resistin was higher in female than in male children. Significant correlations by non-parametric univariate correlation coefficients and Spearman’s rank correlation coefficients were found between adiponectin and homeostasis model assessment of insulin resistance (HOMA-IR), and fasting serum insulin levels in young Japanese, Italian, and American female children(p < 0.01, p < 0.05, p < 0.05, respectively). Correlations between serum adiponectin and HOMA-IR were also found among older male Italian, American, and Thai children (p < 0.05, p < 0.001, p < 0.001, respectively). In multiple regression analysis by forced entry method, adiponectin correlated with HOMA-IR in Italian and American male children, and in all older female children regardless of country of origin. There was no correlation between resistin and markers of insulin resistance in children from any of the countries.

Conclusions

We conclude that serum adiponectin concentrations are lower in Asian as compared to Italian and American children, and that adiponectin but not resistin contributes to differences in markers for insulin resistance in children from different populations.

Role of resistin in the inflammatory response induced by nicotine plus lipopolysaccharide in human periodontal ligament cells in vitro

BACKGROUND AND OBJECTIVE

Resistin was recently reported to play a role in inflammation-related diseases such as arthritis. However, the precise role of resistin in chronic inflammatory diseases, such as periodontal disease, remains unclear. The aim of this study was to investigate the combined effects of nicotine and lipopolysaccharide (LPS) on the expression of resistin and to assess whether resistin expression influences the levels of inflammatory cytokines, extracellular matrix (ECM) molecules and MMPs in human periodontal ligament cells (PDLCs) stimulated with both nicotine and LPS.

MATERIAL AND METHODS

PDLCs were pretreated with isoproterenol or resistin-specific small interfering RNA (siRNA), stimulated with LPS plus nicotine for 24 h, and then monitored for the production of inflammatory mediators. The concentrations of prostaglandin E2 (PGE2) and nitric oxide (NO) were measured by radioimmunoassay and the Griess method, respectively. RT-PCR and western blot analysis were used to measure the levels of mRNA and protein, respectively. Western blot analysis was also used to assess the activation of various signal-transduction pathways.

RESULTS

Treatment with nicotine plus LPS up-regulated the expression of resistin mRNA and the production of resistin protein in PDLCs in a time- and concentration-dependent manner. Isoproterenol-mediated interference with the function of resistin, or siRNA-mediated knockdown of resistin expression, markedly attenuated the LPS plus nicotine-mediated stimulation of PGE2 and NO production, the production of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase proteins and the expression of proinflammatory cytokines [tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and IL-12] and MMPs (MMP-1, MMP-2 and MMP-9); however, these treatments restored the expression of ECM molecules. Furthermore, pretreatment with isoproterenol or resistin-specific siRNA blocked nicotine plus LPS-induced activation of phosphoinositide-3-kinase, glycogen synthase kinase-3 beta, β-catenin, p38, ERK, JNK and nuclear factor-κB.

CONCLUSION

This is the first study to show that the inhibition of resistin, by either a pharmacological or a genetic silencing approach, has anti-inflammatory effects. These effects include decreased levels of inflammatory cytokines and the prevention of ECM breakdown in a nicotine plus LPS-stimulated PDLC model.

Cross-talk between SIRT1 and endocrine factors: effects on energy homeostasis

The mammalian sirtuins (SIRT1-7) are a family of highly conserved nicotine adenine dinucleotide (NAD(+))-dependent deacetylases that act as cellular sensors to detect energy availability. SIRT1 is a multifaceted protein that is involved in a wide variety of cellular processes. SIRT1 is activated in response to caloric restriction, acting on multiple targets in a wide range of tissues. SIRT1 regulates the role of multiple hormones implicated in energy balance, including glucose and lipid metabolism. Here, we review the relevant role of SIRT1 as a mediator of endocrine function of several hormones to modulate energy balance. In addition, we analyze the potential of targeting SIRT1 for the treatment of obesity and type 2 diabetes mellitus.

Antidiabetic, renal/hepatic/pancreas/cardiac protective and antioxidant potential of methanol/dichloromethane extract of Albizzia Lebbeck Benth. stem bark (ALEx) on streptozotocin induced diabetic rats

BACKGROUND

Hypoglycemic and/or anti-hyperglycemic activities have been recorded with numerous plants, many of which are used as traditional herbal treatments of diabetes. Albizzia Lebbeck Benth. stem bark have been used in traditional medicine along with some preliminary reports on its hypoglycemic action. The aim of present investigation was to evaluate the antidiabetic and antioxidant activities of methanolic extract of stem bark of Albizzia Lebbeck Benth. in streptozotocin induced diabetic rats.

METHODS

The powdered stem bark of Albizzia Lebbeck Benth.. was extracted with methanol (MeOH) using soxhlation method and subjected to phytochemical analysis. The methanol/dichloromethane extract of Albizzia Lebbeck Benth. (ALEx) was concentrated to dryness using Rotary Evaporator. Diabetes was experimentally induced in the rats by single intraperitoneal administration of Streptozotocin (60 mg/kg). They glycemic control was measured by the blood glucose, glycated heamoglobin and plasma insulin. The oxidative stress was evaluated in the liver and kidney by level of antioxidant markers and various biochemical parameters were assessed in diabetic control and extract treated rats.

RESULTS

Streptozotocin induced diabetic rats depicted the increased blood glucose levels, total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-c), diminished level of high density lipoprotein cholesterol (HDL-c) level and perturb level of antioxidant markers. Oral administration of MeAL at a concentration of 100, 200, 300 and 400 mg/kg b.w daily for 30 days results a momentous decrease in fasting blood glucose, glycated heamoglobin and enhancement of plasma insulin level as compared with STZ induced diabetic rats. Furthermore, it significantly (p < 0.05) decreased the level of TC, TG, and LDL-c, VLDL-c. While it increases the level of HDL-c to a significant (p < 0.05) level. The treatment also resulted in a marked increase in reduced glutathione, glutathione Peroxidase, catalase and superoxide dismutase and diminished level of lipid peroxidation in liver and kidney of STZ induced diabetic rats. Histopathological studies suggest the diminution in the pancreatic, liver and cardiac muscle damage.

CONCLUSION

Our research exertion clearly indicates the considerable antihyperglycemic, antihyperlipidemic, antioxidant & pancreas/renal/hepatic/cardiac protective action of ALEx.

Serum adipokine and inflammatory markers before and after liver transplantation in recipients with major cardiovascular events

In the nontransplant setting, aberrant serum adipokine levels are associated with cardiovascular (CV) disease. The effects of liver transplantation (LT) on serum adipokine levels and their association with post-LT CV disease have not been studied. A nested case-control study of 77 patients with major CV events more than 4 months after LT analyzed serum adiponectin, resistin, leptin, C-reactive protein, and apolipoprotein levels measured before transplantation and 4, 12, and 24 months after LT. Adiponectin and resistin levels decreased dramatically after LT in all patients. Recipients with CV disease had lower levels of adiponectin and higher levels of resistin, leptin, C-reactive protein, and apolipoprotein B100 than controls. The pre-LT adiponectin level was associated with a 16% increased risk for CV events for every 1 μg/mL decrease in adiponectin [hazard ratio (HR) = 0.84, P = 0.046]. Pre-LT C-reactive protein levels (HR = 1.03, P = 0.047) and 12-month C-reactive protein levels (HR = 1.03, P = 0.03) were associated with CV events after LT. Pre-LT Diabetes (HR = 2.14, P = 0.09), and post-LT resistin (HR = 1.07, P = 0.07), and apolipoprotein B (HR = 1.08, P = 0.08) were associated with a nonsignificantly increased risk of CV events in this small sample size. In conclusion, pre- and post-LT changes in serum adipokine and inflammatory markers may be signals of an increased risk of CV events after LT, but further study is needed.

High prevalence of Y-box protein-1/p18 fragment in plasma of patients with malignancies of different origin

BACKGROUND

Expression of the cold shock protein Y-box protein 1 (YB-1) is associated with deleterious outcome in various malignant diseases. Our group recently showed that the detection of an 18 kDa YB-1 fragment (YB-1/p18) in human plasma identifies patients with malignant diseases. We now tested the prevalence, clinical, and diagnostic value of YB-1/p18 detection in common tumors.

METHODS

A newly established monoclonal YB-1 antibody was used to detect YB-1/p18 by immunoblotting in plasma samples from 151 unselected tumor patients, alongside established tumor markers and various diagnostic measures, during evaluation for a cancerous disease and in follow-up studies after therapeutic interventions.

RESULTS

Circulating YB-1/p18 was detected in 78% of patients having a tumor disease. YB-1/p18 positivity was highly prevalent in all examined malignancies, including lung cancer (32/37; 87%), breast cancer (7/10; 70%), cancer of unknown primary (CUP; 5/5, 100%) or hematological malignancies (42/62; 68%). Positivity for YB-1/p18 was independent of other routine laboratory parameters, tumor stage, or histology. In comparison to 13 established tumor markers (cancer antigens 15-3, 19-9, 72-4, and 125; carcinoembryonic antigen; cytokeratin fragments 21-1; neuron-specific enolase; alpha-fetoprotein; beta-2-microglobulin; squamous cell carcinoma antigen; thymidine kinase; tissue polypeptide antigen; pro-gastrin-releasing peptide), YB-1/p18 detection within serum samples was the most sensitive general parameter identifying malignant disorders. YB-1/p18 concentrations altered during therapeutic interventions, but did not predict prognosis.

CONCLUSIONS

Plasma YB-1/p18 detection has a high specific prevalence in malignancies, thereby providing a novel tool for cancer screening independent of the tumor origin.

Increased resistin in brain dead organ donors is associated with delayed graft function after kidney transplantation

INTRODUCTION

Resistin increases during several inflammatory diseases and after intracerebral bleeding or head trauma. Resistin activates the endothelium and may initiate an inflammatory response. No data are available on resistin in brain dead donors (DBD) that regularly manifest a pronounced inflammatory state.

METHODS

We analyzed plasma resistin in 63 DBDs and correlated results with donor variables and the postoperative course following kidney transplantation using organs from these donors. Endocan and monocyte chemotactic protein (MCP)-1 were also studied. Twenty-six live kidney donors (LD) and the corresponding kidney transplantations were used as controls.

RESULTS

DBDs had higher resistin (median/range 30.75 ng/ml, 5.41-173.6) than LD (7.71 ng/ml, 2.41-15.74, p < 0.0001). Resistin in DBD correlated with delayed graft function (DGF) in the kidney recipients (r = 0.321, p < 0.01); receiver operating characteristic curve revealed an area under the curve of 0.765 (95% confidence interval [CI] 0.648-0.881, p < 0.01) and a cut-off value for resistin of 25 ng/ml; MCP-1 and endocan were higher in DBDs (p < 0.0001) but did not correlate with DGF or acute rejection. No relationship was found between the studied molecules and the postoperative course of LD kidney transplants.

CONCLUSIONS

High resistin levels in the DBD before organ retrieval are associated with DGF after kidney transplantation. The resistin increase seems related to the inflammatory state after brain death but not to the cause of death.

Resistin impairs SIRT1 function and induces senescence-associated phenotype in hepatocytes

Resistin is a cysteine-rich secreted protein which significantly inhibits phosphorylation of AMP-activated protein kinase in both human and mouse hepatocytes. It has been demonstrated that resistin plays an important role in inducing hepatic insulin resistance. However, whether resistin has other unknown influences on hepatocytes still remains poorly studied. Here, we show that recombinant resistin protein significantly reduces expression of SIRT1, attenuates the interaction between SIRT1 and PPARα as well as PGC-1α, and increases PGC-1α acetyl-lysine levels in HepG2 cells. In line with this, resistin treatment weakens the association between SIRT1 and major satellite repeats and alters the transcription level of SIRT1 target genes in mouse primary hepatocytes. Resistin treatment also significantly increases senescence-associated β-galactosidase activity in mouse primary hepatocytes and this effect can be eliminated by co-treatment with the SIRT1 agonists resveratrol and nicotinamide mononucleotide. Our findings suggest that resistin is a negative regulator of SIRT1 in both human hepatoma cell line HepG2 and mouse hepatocytes and that it might also play an important role in the development of senescence-associated liver diseases.

Variations of serum levels of adiponectin and resistin in chronic viral hepatitis

BACKGROUND AND AIMS

Several studies investigated the possible role of adipokines during chronic viral hepatitis, not producing defined results neither clearly establishing their behavior in course of anti-viral treatment. Our study evaluated blood concentrations of adiponectin and resistin in patients with chronic hepatitis C (CHC), B (CHB), and D (CHD) receiving anti-viral treatment, at baseline and after therapy.

METHODS

We examined 122 subjects, divided into two groups: 64 patients with chronic hepatitis C virus (HCV) infection (38 males and 26 females, mean age 47.25 yr) and 58 patients including 39 ones with chronic hepatitis B virus (HBV) infection (26 males and 13 females, mean age 48.46 yr) and 19 ones with chronic HBV-hepatitis D virus (HDV) infection (15 males and 4 females, mean age 45.79 yr). Serum levels of adiponectin and resistin were assayed by enzyme-linked immunosorbent assay.

RESULTS

In the group of CHC patients we observed a significant decrease in resistin after therapy (p=0.006), while not a significant increase in adiponectin after treatment (p=0.32). Evaluation of changes in adiponectin and resistin levels after anti-viral treatment, both in responders and non-responders, revealed no significant variations. In the group of HBV+ and HBV-HDV+ patients, we found a decrease in resistin after therapy (p=0.0016) and a not significant reduction in adiponectin after treatment (p=0.13). Furthermore, we noticed a significant reduction of resistin (p=0.006) in the sub-group of responders.

CONCLUSIONS

Our data suggested the possible marker role of adiponectin and resistin in the inflammatory process in course of chronic viral hepatitis.

Resistin mediates the hepatic stellate cell phenotype

AIM: To describe the role of resistin in liver fibrosis.

METHODS: For the in vivo animal study, Sprague Dawley rats were subjected to bile duct ligation (BDL) for 4 wk. Rat liver, adipose tissue (epididymal fat) and serum were analyzed for resistin expression. For the in vitro experiment, rat primary hepatic stellate cells (HSCs) and Kupffer cells (KCs) were used. HSCs were exposed to recombinant resistin, and collagen I, transforming growth factor β1, α smooth muscle actin, tissue inhibitor of metalloproteinase 1 and connective tissue growth factor expression were analyzed. Resistin gene and protein expression was quantified as was the expression of pro-inflammatory cytokines including tumor necrosis factor α (TNFα), interleukin (IL)-1, IL-6, IL-8 and monocyte chemotactic protein-1 (MCP-1). The effects of resistin on HSC proliferation, migration and apoptosis were determined. The effects of resistin on KCs were also investigated.

RESULTS: Following BDL, rat epididymal fat and serum rather than liver showed higher resistin expression compared to control rats. In liver, resistin was expressed in quiescent HSCs and KCs. Resistin treatment resulted in enhancement of TNFα, IL-6, IL-8 and MCP-1 gene expression and increased IL-6 and MCP-1 protein in HSCs. Resistin activated HSC phospho-MAPK/p38, and p38 inhibition diminished IL-6 and MCP-1 expression. Furthermore, resistin facilitated HSC proliferation and migration, but decreased apoptosis which was via an IL-6 and MCP-1 mechanism. Finally, resistin-induced transforming growth factor β1 from KCs enhanced HSC collagen Iexpression.

CONCLUSION: Resistin directly and indirectly modulates HSC behavior towards a more pro-fibrogenic phenotype.

High prevalence of autoantibodies to C-reactive protein in patients with chronic hepatitis C infection: association with liver fibrosis and portal inflammation

The presence of autoantibodies against C-reactive protein (anti-CRP) has been reported in association with autoimmunity and histopathology in chronic hepatitis C virus (HCV) infection. Resistin could play a role in the pathogenesis of hepatitis, although results on HCV infection are ambiguous. Here we retrospectively analyzed anti-CRP and resistin levels in the sera of 38 untreated and well-characterized HCV patients at the time of their first liver biopsy. HCV activity and general health were assessed by a physician at least yearly until follow-up ended. Anti-CRP and resistin were also measured in patients with autoimmune hepatitis (AIH) and nonalcoholic fatty liver disease (NAFLD). Anti-CRP antibodies were registered in all HCV patients, whereas only a few AIH (11%) and NAFLD (12%) sera were positive. Anti-CRP levels were related to histopathological severity and were highest in patients with cirrhosis at baseline. Resistin levels were similar in HCV, AIH, and NAFLD patients, but high levels of resistin were associated with early mortality in HCV patients. Neither anti-CRP nor resistin predicted a response to interferon-based therapy or cirrhosis development or was associated with liver-related mortality. We conclude that anti-CRP antibodies are frequently observed in chronic HCV infection and could be a useful marker of advanced fibrosis and portal inflammation.

Resistin is associated with breach of tolerance and anti-nuclear antibodies in patients with hepatobiliary inflammation

Resistin is a cysteine-rich protein, which is abundantly expressed at the site of inflammation, and acts as a regulator of the NF-kB-dependent cytokine cascade. The aim of this study was to evaluate resistin levels in relation to inflammatory mediators, disease phenotype and autoantibody status in a spectrum of pathological conditions of the gastrointestinal tract. Resistin levels were measured with an ELISA in sera originated from 227 patients and 40 healthy controls (HC). Fifty patients diagnosed with non-alcoholic fatty liver disease (NAFLD), 53 ulcerative colitis (UC), 51 Crohn's disease (CD), 46 autoimmune hepatitis (AIH) and 27 primary sclerosing cholangitis (PSC) were included. The sera were analysed with respect to biochemical parameters of systemic inflammation and liver function and to the presence of antibodies to nuclear antigens (ANA), mitochondria (AMA) and smooth muscle (SMA). Compared with HC, resistin levels were raised in AIH (P = 0.017) and PSC (P = 0.03); compared with NAFLD, levels were elevated in CD (P = 0.041), AIH (P < 0.001) and PSC (P < 0.001). Patients with elevated levels of resistin were more often treated with corticosteroids, but no difference was found between active disease and clinical remission. Resistin levels were significantly higher in ANA-positive individuals compared with ANA-negative (P = 0.025). Resistin levels were directly correlated with IL-6 (r = 0.30, P = 0.02) and IL-8 (r = 0.51, P < 0.001). Elevated levels of resistin were prominent in patients with hepatobiliary inflammation and were associated with breach of self-tolerance, i.e. ANA positivity. Thus, we propose that resistin may be an important marker of disease severity in autoantibody-mediated gastrointestinal inflammatory diseases.

Y-box protein-1/p18 fragment identifies malignancies in patients with chronic liver disease

Background

Immunohistochemical detection of cold shock proteins is predictive for deleterious outcome in various malignant diseases. We recently described active secretion of a family member, denoted Y-box (YB) protein-1. We tested the clinical and diagnostic value of YB-1 protein fragment p18 (YB-1/p18) detection in blood for malignant diseases.

Methods

We used a novel monoclonal anti-YB-1 antibody to detect YB-1/p18 by immunoblotting in plasma samples of healthy volunteers (n = 33), patients with non-cancerous, mostly inflammatory diseases (n = 60), hepatocellular carcinoma (HCC; n = 25) and advanced solid tumors (n = 20). YB-1/p18 was then tested in 111 patients with chronic liver diseases, alongside established tumor markers and various diagnostic measures, during evaluation for potential liver transplantation.

Results

We developed a novel immunoblot to detect the 18 kD fragment of secreted YB-1 in human plasma (YB-1/p18) that contains the cold-shock domains (CSD) 1-3 of the full-length protein. YB-1/p18 was detected in 11/25 HCC and 16/20 advanced carcinomas compared to 0/33 healthy volunteers and 10/60 patients with non-cancerous diseases. In 111 patients with chronic liver disease, YB-1/p18 was detected in 20 samples. Its occurrence was not associated with advanced Child stages of liver cirrhosis or liver function. In this cohort, YB-1/p18 was not a good marker for HCC, but proved most powerful in detecting malignancies other than HCC (60% positive) with a lower rate of false-positive results compared to established tumor markers. Alpha-fetoprotein (AFP) was most sensitive in detecting HCC, but simultaneous assessment of AFP, CA19-9 and YB-1/p18 improved overall identification of HCC patients.

Conclusions

Plasma YB-1/p18 can identify patients with malignancies, independent of acute inflammation, renal impairment or liver dysfunction. The detection of YB-1/p18 in human plasma may have potential as a tumor marker for screening of high-risk populations, e.g. before organ transplantation, and should therefore be evaluated in larger prospective studies.

Circulating retinol binding protein 4 in critically ill patients before specific treatment: prognostic impact and correlation with organ function, metabolism and inflammation

INTRODUCTION

Hyperglycemia and insulin resistance are well-known features of critical illness and impact the mortality rate, especially in sepsis. Retinol binding protein 4 (RBP4) promotes insulin resistance in mice and is systemically elevated in patients with obesity and type 2 diabetes. We investigated the potential role of RBP4 in critically ill patients.

METHODS

We conducted a prospective single-center study of serum RBP4 concentrations in critically ill patients. One hundred twenty-three patients (85 with sepsis, 38 without sepsis) were studied at admission to a medical intensive care unit (ICU) before initiation of specific intensive care treatment measures and compared to 42 healthy nondiabetic controls. Clinical data, various laboratory parameters and metabolic and endocrine functions were assessed. Patients were followed for approximately 3 years.

RESULTS

Serum RBP4 was significantly reduced in ICU patients, independently of sepsis, as compared to healthy controls (P < 0.001). Patients with liver cirrhosis as the primary underlying diagnosis for ICU admission had significantly lower RBP4 levels as compared with other ICU patients. Accordingly, in all ICU patients, serum RBP4 closely correlated with liver function and increased with renal failure. No significant differences of serum RBP4 concentrations in septic patients with pulmonary or other origins of sepsis or nonseptic patients could be revealed. Acute phase proteins were inversely correlated with RBP4 in sepsis patients. RBP4 did not differ between patients with or without obesity or preexisting diabetes. However, serum RBP4 levels correlated with endogenous insulin secretion (C-peptide) and insulin resistance (HOMA index). Low serum RBP4 upon admission was an adverse predictor of short-term survival in the ICU, but was not associated with overall survival during long-term follow-up.

CONCLUSIONS

Serum RBP4 concentrations are significantly reduced in critically ill patients. The strong associations with hepatic and renal function, insulin resistance and acute mortality collectively suggest a role of RBP4 in the pathogenesis of critical illness, possibly as a negative acute phase reactant, and allow a proposition as a potential novel biomarker for ICU patients.

Genome-wide expression profiling deciphers host responses altered during dengue shock syndrome and reveals the role of innate immunity in severe dengue

Background

Deciphering host responses contributing to dengue shock syndrome (DSS), the life-threatening form of acute viral dengue infections, is required to improve both the differential prognosis and the treatments provided to DSS patients, a challenge for clinicians.

Methodology/Principal Findings

Based on a prospective study, we analyzed the genome-wide expression profiles of whole blood cells from 48 matched Cambodian children: 19 progressed to DSS while 16 and 13 presented respectively classical dengue fever (DF) or dengue hemorrhagic fever grades I/II (DHF). Using multi-way analysis of variance (ANOVA) and adjustment of p-values to control the False Discovery Rate (FDR<10%), we identified a signature of 2959 genes differentiating DSS patients from both DF and DHF, and showed a strong association of this DSS-gene signature with the dengue disease phenotype. Using a combined approach to analyse the molecular patterns associated with the DSS-gene signature, we provide an integrative overview of the transcriptional responses altered in DSS children. In particular, we show that the transcriptome of DSS children blood cells is characterized by a decreased abundance of transcripts related to T and NK lymphocyte responses and by an increased abundance of anti-inflammatory and repair/remodeling transcripts. We also show that unexpected pro-inflammatory gene patterns at the interface between innate immunity, inflammation and host lipid metabolism, known to play pathogenic roles in acute and chronic inflammatory diseases associated with systemic vascular dysfunction, are transcriptionnally active in the blood cells of DSS children.

Conclusions/Significance

We provide a global while non exhaustive overview of the molecular mechanisms altered in of DSS children and suggest how they may interact to lead to final vascular homeostasis breakdown. We suggest that some mechanisms identified should be considered putative therapeutic targets or biomarkers of progression to DSS.

Metabolic regulation of APOBEC-1 complementation factor trafficking in mouse models of obesity and its positive correlation with the expression of ApoB protein in hepatocytes

APOBEC-1 Complementation Factor (ACF) is an RNA-binding protein that interacts with apoB mRNA to support RNA editing. ACF traffics between the cytoplasm and nucleus. It is retained in the nucleus in response to elevated serum insulin levels where it supports enhanced apoB mRNA editing. In this report we tested whether ACF may have the ability to regulate nuclear export of apoB mRNA to the sites of translation in the cytoplasm. Using mouse models of obesity-induced insulin resistance and primary hepatocyte cultures we demonstrated that both nuclear retention of ACF and apoB mRNA editing were reduced in the livers of hyperinsulinemic obese mice relative to lean controls. Coincident with an increase in the recovery of ACF in the cytoplasm was an increase in the proportion of total cellular apoB mRNA recovered in cytoplasmic extracts. Cytoplasmic ACF from both lean controls and obese mouse livers was enriched in endosomal fractions associated with apoB mRNA translation and ApoB lipoprotein assembly. Inhibition of ACF export to the cytoplasm resulted in nuclear retention of apoB mRNA and reduced both intracellular and secreted ApoB protein in primary hepatocytes. The importance of ACF for modulating ApoB was supported by the finding that RNAi knockdown of ACF reduced ApoB secretion. An additional discovery from this study was the finding that leptin is a suppressor ACF expression. Dyslipidemia is a common pathology associated with insulin resistance that is in part due to the loss of insulin controlled secretion of lipid in ApoB-containing very low density lipoproteins. The data from animal models suggested that loss of insulin regulated ACF trafficking and leptin regulated ACF expression may make an early contribution to the overall pathology associated with very low density lipoprotein secretion from the liver in obese individuals.

Advances in the prevention and treatment of fatty liver disease

In recent years, lifestyle changes have resulted in a rising prevalence rate of fatty liver disease (FLD). Even worse, there are some misunderstandings concerning the prevention and treatment of FLD. Therefore, it is necessary to improve our understanding of FLD and explore and summarize effective countermeasures for prevention and treatment of FLD. In this article, we will review the recent advances in research of FLD from five aspects: epidemiology, pathogenesis, relationship with metabolic syndrome, misunderstandings concerning prevention and treatment and countermeasures, and highlight the necessity and urgency for prevention and treatment of FLD.

Resistin competes with lipopolysaccharide for binding to toll-like receptor 4

Toll-like receptors (TLRs) are a family of cellular structures activated by recognition of pathogen associated molecular sequences. The activation of TLRs triggers a variety of intracellular mechanisms aiming to protect the host from the invading microorganisms. Lipopolysaccharide (LPS) is the main ligand for TLR4. Here we show that resistin, a cystein-rich protein believed to regulate carbohydrate metabolism, competes with LPS for binding to TLR4. Binding of recombinant resistin to human myeloid and epithelial cells was assessed by flow cytometry and its co-precipitation with TLR4 was demonstrated. Antibodies against TLR4 abolished resistin binding to human leucocytes and cytokine production by peripheral blood mononuclear cells in response to resistin stimulation. In contrast, isotype-matched murine IgG or TLR2 antibodies were unable to prevent binding of resistin to the cells. Similarly, TLR4-dependent pattern of resistin binding was observed in epithelial cell line HEK293 (human epithelial kidney cell), where TLR4 transfected, but not myeloid differentiation factor 2/CD14-transfected, TLR2 transfected or HEKnull cells, responded functionally to resistin stimulation. Intracellular signalling of resistin was assessed using inhibitors of transcription factors mitogen activated protein kinases, nuclear factor-kappaB, phosphoinositide 3-kinase and siRNA targeting TLR4 and human myeloid differentiation factor 88. Results demonstrate that TLR4 serves as a receptor for the pro-inflammatory effects of resistin in human cells. This may partly explain the multifunctional role of resistin in chronic inflammation, atherosclerosis and insulin resistance.

Adipokines in liver diseases

Adipokines are polypeptides secreted in the adipose tissue in a regulated manner. While some of these molecules are expressed only by adipocytes, resident and infiltrating macrophages and components of the vascular stroma markedly contribute to expression of other adipokines. As a result, adipose tissue inflammation is associated with a modification in the pattern of adipokine secretion. Leptin, adiponectin, and resistin are the best-studied molecules in this class, but cytokines such as tumor necrosis factor or interleukin-6 are also secreted at high levels by the adipose tissue. Several other molecules have been recently identified and are actively investigated. Adipokines interfere with hepatic injury associated with fatty infiltration, differentially modulating steatosis, inflammation, and fibrosis. Several studies have investigated plasma levels of adiponectin in patients with nonalcoholic fatty liver disease, to establish correlations with the underlying state of insulin resistance and with the type and severity of hepatic damage. Hepatitis C is another disease where adipokines may represent a link between viral infection, steatosis, and metabolic disturbances. Identification of the mediators secreted by expanded adipose tissue and their pathogenic role is pivotal in consideration of the alarming increase in the prevalence of obesity and of the detrimental role that this condition exerts on the course of liver diseases.

Validation of connective tissue growth factor (CTGF/CCN2) and its gene polymorphisms as noninvasive biomarkers for the assessment of liver fibrosis

Clinical and experimental studies have demonstrated that connective-tissue growth factor (CTGF) expression is increased in fibrotic human liver and experimental animal models of liver fibrogenesis. CTGF has been linked to transforming growth factor-beta (TGF-beta) pathways in fibroproliferative diseases and specific polymorphisms within the CTGF gene may predispose for fibrosis in systemic sclerosis. As CTGF is detectable in various human fluids (serum, plasma and urine), it may provide information about fibrotic remodelling processes and reflect hepatic TGF-beta bioactivity. We established a novel ELISA for the measurement of serum CTGF and tested its clinical value in patients with chronic hepatitis C virus (HCV) infection and chronic liver disease (CLD). HCV infected patients (n = 138) had significantly higher serum CTGF levels than healthy controls. CTGF was linked to the histological degree of liver fibrosis. To expand the results to other aetiologies, a separate cohort of CLD patients (n = 129) was evaluated, showing higher serum CTGF than healthy controls and again an association with advanced stages of liver cirrhosis (Child B and C). Although independent of the underlying aetiology, serum CTGF was most powerful in indicating fibrosis/advanced disease states in HCV-related disorders. The genotyping of six polymorphisms (rs6917644, rs9399005, rs6918698, rs9493150, rs2151532 and rs11966728) covering the CTGF locus in 365 patients suffering from chronic hepatitis C revealed that none of these polymorphisms showed a genotypic or allelic association with the severity of hepatic fibrosis. Taken together, serum CTGF is suitable for determination of hepatic fibrosis and most powerful in patients with chronic HCV infection.

Serum resistin levels in critically ill patients are associated with inflammation, organ dysfunction and metabolism and may predict survival of non-septic patients

Introduction

Blood glucose levels and insulin resistance in critically ill patients on admission to intensive care units (ICUs) have been identified as factors influencing mortality. The pathogenesis of insulin resistance (IR) in critically ill patients is complex and not fully understood. Resistin is a hormone mainly derived from macrophages in humans and from adipose tissue in rodents, which regulates glucose metabolism and insulin sensitivity. In non-critically ill patients, resistin was found to be related to impaired glucose tolerance, insulin resistance, metabolic syndrome, obesity and type 2 diabetes. Therefore, resistin might represent a link between inflammation, acute phase response and insulin resistance in critically ill patients. We aimed to examine the correlation of serum resistin concentrations to parameters of inflammation, organ function, metabolism, disease severity and survival in critically ill patients.

Methods

On admission to the Medical ICU, 170 patients (122 with sepsis, 48 without sepsis) were studied prospectively and compared with 60 healthy non-diabetic controls. Clinical data, various laboratory parameters, metabolic and endocrine functions as well as investigational inflammatory cytokine profiles were assessed. Patients were followed for approximately three years.

Results

Resistin serum concentrations were significantly elevated in all critical care patients compared with healthy controls, and significantly higher in sepsis than in non-sepsis patients. Serum resistin concentrations were not associated with pre-existing type 2 diabetes or obesity. For all critically ill patients, a correlation to the homeostasis model assessment index of insulin resistance (HOMA-IR) was shown. Serum resistin concentrations were closely correlated to inflammatory parameters such as C-reactive protein, leukocytes, procalcitonin, and cytokines such as IL6 and TNF-α, as well as associated with renal failure and liver synthesis capacity. High resistin levels (> 10 ng/ml) were associated with an unfavourable outcome in non-sepsis patients on ICU and the overall survival.

Conclusions

Serum resistin concentrations are elevated in acute inflammation due to sepsis or systemic inflammatory response syndrome (SIRS). The close correlation with other acute phase proteins suggests a predominant, clinically relevant resistin release from macrophages in ICU patients. Moreover, resistin could potentially serve as a prognostic biomarker in non-sepsis critically ill patients.

Peritoneal fluid adipokines: ready for prime time?

BACKGROUND

Visceral adipose tissues secret a variety of adipokines; however, it is not known whether they are present in the peritoneal fluid. It was the aim of this study to investigate peritoneal fluid concentrations of novel (cartonectin, omentin) and classical adipokines (leptin, adiponectin, resistin, visfatin) in patients with ascites.

MATERIAL AND METHODS

Ninety-six patients (71 men and 25 women) undergoing paracentesis were included. Of these, 76 suffered from liver cirrhosis. Adipokines were measured by enzyme-linked immunosorbent assay or Western blot.

RESULTS

Each adipokine was detected in ascites with a broad range. Serum-ascites ratios (SAR) correlated with clinical and laboratory parameters. The main variables influencing peritoneal fluid adipokine concentrations were body mass index (BMI), local inflammation, systemic inflammation and serum adipokine concentrations. Resistin was significantly higher in patients with peritonitis and showed a positive correlation with peripheral leucocytes (white blood cell count). Leptin was correlated with the underlying disease. Visfatin correlated with peripheral white blood cell and C-reactive protein levels. Omentin expression was correlated with ascitic leucocyte count, ascitic albumin concentration and low albumin SAR. BMI was correlated positively with ascitic leptin levels and cartonectin protein levels.

CONCLUSIONS

Peritoneal fluid adipokine concentrations are characterized by individual SARs, depend on the presence of peritonitis, and correlate with underlying disease, BMI and systemic inflammation. The data open a new field of research on the role of the peritoneum and visceral adipokines in gastrointestinal diseases.

Inverse association between serum resistin and insulin resistance in humans

AIM

To determine how serum concentrations of resistin are distributed in humans in relation to insulin resistance, type 2 diabetes, and obesity.

METHODS

Cross-sectional, descriptive study carried out in a random sample (n=713, 43% men, 18-75 years) of general population of inhabitants of the Canary Islands (Spain). Serum resistin concentration, HOMA2-IR, anthropometric parameters, drug consumption and physical activity were recorded.

RESULTS

There were no differences in resistin concentration between participants with and without diabetes (3.1+/-0.2 vs. 3.2+/-0.1ng/mL; p=0.566), or between obese and non-obese participants (3.1+/-0.1 vs. 3.2+/-0.1ng/mL; p=0.803). Individuals with abdominal obesity (waist-hip ratio [WHR] >or=1 in men or >or=0.9 in women) had lower concentrations of resistin (3.0+/-0.13 vs. 3.4+/-0.1ng/mL; p<0.001). The correlations between resistin and HOMA2-IR (r=-0.231; p<0.001) and between resistin and WHR (r=-0.202; p<0.001) were inverse. Multivariate analysis corroborated the inverse association of this cytokine with HOMA2-IR, WHR and, in women, also retained in the model the direct association between resistin and physical activity and the inverse association between resistin and antihypertensive agents.

CONCLUSIONS

In this population resistin is inversely associated with insulin resistance and abdominal obesity.

Serum adipokine levels in chronic liver diseases: association of resistin levels with fibrosis severity

OBJECTIVE

Leptin and adiponectin have been implicated in the pathogenesis and progression of non-alcoholic steatohepatitis (NASH) and chronic hepatitis C (CHC), but little is known about the role of resistin in chronic liver diseases. The objective of this study was to investigate serum levels of the above three adipokines in relation to the etiology of liver disease and to determine their associations with histological severity.

MATERIAL AND METHODS

We prospectively evaluated 146 patients (HBeAg-negative chronic hepatitis B (CHB): 52, CHC: 70, NASH: 24) who consecutively underwent liver biopsy. Detailed epidemiological, anthropometric and laboratory data were recorded. Histological lesions were evaluated blindly according to the Ishak and the Brunt classifications for CHB/CHC and NASH, respectively.

RESULTS

Serum adipokine levels were similar between CHB and CHC patients, while CHB/CHC patients had significantly lower leptin levels compared with NASH patients (8.3+/-7.3 versus 17.6+/-16.6 ng/ml, p=0.012) and higher adiponectin (10.2+/-5.1 versus 7.5+/-4 microg/ml, p=0.018) and resistin levels (7.1+/-2.5 versus 5.7+/-2.8 ng/ml, p=0.016). In CHB/CHC, there was no significant association between steatosis or necroinflammation and levels of adipokines, while the presence of moderate/severe fibrosis (stages 4-6) was associated with higher leptin and adiponectin levels in male but not in female patients and with lower resistin levels irrespective of gender or other factors (adjusted odds ratio=0.788, p=0.035).

CONCLUSIONS

Serum adipokine levels depend on the etiology of liver disease differing between chronic viral hepatitis and NASH, but not between CHB and CHC. In CHB/CHC, resistin levels are independently associated with fibrosis severity, whereas in the association of leptin and adiponectin levels with fibrosis, it seems to be a gender effect.

Metabolic syndrome and estimates of cardiovascular disease in cirrhotic patients

OBJECTIVE

The expected survival rate in patients with liver cirrhosis has increased in recent years, putting them into a clinical scenario in which cardiovascular disease and metabolic syndrome could be common causes of morbidity and mortality. This study aimed to analyze the prevalence of metabolic syndrome and other risk factors and estimate the risk of cardiovascular disease in patients with liver cirrhosis.

METHODS

We conducted a cross-sectional study assessing the patients' lifestyle, and their anthropometric and biochemical data. Their metabolic syndrome and estimates of their risk of cardiovascular disease were calculated, comparing patients with and without liver cirrhosis.

RESULTS

The study included 355 patients (99 cirrhotic and 256 non-cirrhotic patients). There were no differences between them in the prevalence of metabolic syndrome (39.4% vs. 45.7%, P = 0.340). In patients with liver cirrhosis, the mean values of criteria for metabolic syndrome increased as the model end-stage liver disease (MELD) score increased (P = 0.01). The mean value of a 10-year risk for cardiovascular disease was lower in the cirrhotic patients (3.4 +/- 3.5% vs. 5.8 +/- 6.8%, P = 0.001).

CONCLUSION

Metabolic syndrome is prevalent in patients with liver cirrhosis, but their estimated risk for cardiovascular disease is lower than in non-cirrhotics. The MELD score is a good marker for assessing the severity of the metabolic syndrome in this group.