Mechanism of the development of nonalcoholic steatohepatitis after pancreaticoduodenectomy

Exploring the potential of drug repurposing for liver diseases: A comprehensive study

Drug repurposing involves the investigation of existing drugs for new indications. It offers a great opportunity to quickly identify a new drug candidate at a lower cost than novel discovery and development. Despite the importance and potential role of drug repurposing, there is no specific definition that healthcare providers and the World Health Organization credit. Unfortunately, many similar and interchangeable concepts are being used in the literature, making it difficult to collect and analyze uniform data on repurposed drugs. This research was conducted based on understanding general criteria for drug repurposing, concentrating on liver diseases. Many drugs have been investigated for their effect on liver diseases even though they were originally approved (or on their way to being approved) for other diseases. Some of the hypotheses for drug repurposing were first captured from the literature and then processed further to test the hypothesis. Recently, with the revolution in bioinformatics techniques, scientists have started to use drug libraries and computer systems that can analyze hundreds of drugs to give a short list of candidates to be analyzed pharmacologically. However, this study revealed that drug repurposing is a potential aid that may help deal with liver diseases. It provides available or under-investigated drugs that could help treat hepatitis, liver cirrhosis, Wilson disease, liver cancer, and fatty liver. However, many further studies are needed to ensure the efficacy of these drugs on a large scale.

Novel Insights into Postoperative Surveillance in Resected Pancreatic Cystic Neoplasms-A Review

Pancreatic cystic lesions (PCL) are frequently encountered in clinical practice and some are referred to surgery due to their neoplastic risk or malignant transformation. The management of PCL involves complex decision-making, with postoperative surveillance being a key component for long-term outcomes, due to the potential for recurrence and postoperative morbidity. Unfortunately, the follow-up of resected patients is far from being optimal and there is a lack of consensus on recommendations with regard to timing and methods of surveillance. Here, we summarize the current knowledge on the postoperative surveillance of neoplastic pancreatic cysts, focusing on the mechanisms and risk factors for recurrence, the recurrence rates according to the initial indication for surgery, the final result of the surgical specimen and neoplastic risk in the remaining pancreas, as well as the postsurgical morbidity comprising pancreatic exocrine insufficiency, metabolic dysfunction and diabetes after resection, according to the type of surgery performed. We analyze postsurgical recurrence rates and morbidity profiles, as influenced by different surgical techniques, to better delineate at-risk patients, and highlight the need for tailored surveillance strategies adapted to preoperative and operative factors with an impact on outcomes.

Lipid Metabolism in Metabolic-Associated Steatotic Liver Disease (MASLD)

Metabolic-associated steatotic liver disease (MASLD) is a cluster of pathological conditions primarily developed due to the accumulation of ectopic fat in the hepatocytes. During the severe form of the disease, i.e., metabolic-associated steatohepatitis (MASH), accumulated lipids promote lipotoxicity, resulting in cellular inflammation, oxidative stress, and hepatocellular ballooning. If left untreated, the advanced form of the disease progresses to fibrosis of the tissue, resulting in irreversible hepatic cirrhosis or the development of hepatocellular carcinoma. Although numerous mechanisms have been identified as significant contributors to the development and advancement of MASLD, altered lipid metabolism continues to stand out as a major factor contributing to the disease. This paper briefly discusses the dysregulation in lipid metabolism during various stages of MASLD.

Involvement of glyphosate in disruption of biotransformation P450 enzymes and hepatic lipid metabolism in chicken

The current study investigated the potentially harmful consequences of pure glyphosate or Roundup® on CYP family members and lipid metabolism in newly hatched chicks. On the sixth day, 225 fertilized eggs were randomly divided into three treatments: (1) the control group injected with deionized water, (2) the glyphosate group injected with 10 mg pure glyphosate/Kg egg mass and (3) the Roundup group injected 10 mg the active ingredient glyphosate in Roundup®/Kg egg. The results of the study revealed a reduction in hatchability in chicks treated with Roundup®. Moreover, change of Lipid concentration in serum and the liver-treated groups. Additionally, increased liver function enzymes and increased oxidative stress in the glyphosate and Roundup® groups. Furthermore, liver tissues showed histological changes and several lipid deposits in glyphosate-treated groups. Hepatic CYP1A2 and CYP1A4 expressions were significantly increased (p < .05) after glyphosate exposure, and suppression of CYP1C1 mRNA expression was significant (p < .05) after Roundup® exposure. The pro-inflammatory cytokines genes IFN-γ and IL-1β expression were significantly increased (p < .05) after Roundup® exposure. In addition, there were significant differences in the levels of expression genes which are related to lipid synthesis or catabolism in the liver. In conclusion, in ovo glyphosate exposure caused disruption of biotransformation, pro-inflammatory and lipid metabolism in chicks.

Hepatic Steatosis After Partial Pancreatectomy in a Cohort of Patients with Intraductal Papillary Mucinous Neoplasm

Background/Aims

Nonalcoholic fatty liver disease (NAFLD) has been observed in patients after partial pancreatectomy. Previous studies have been performed on oncologic patients who underwent partial pancreatectomy and received adjuvant chemotherapy. By studying a cohort of patients with intraductal papillary mucinous neoplasms (IPMNs) who did not receive chemotherapy, the authors investigate the isolated effect of partial pancreatectomy on the development of fatty liver.

Methods

A retrospective search for patients with pancreatic IPMNs who underwent partial pancreatectomy at an academic center from 2006 to 2014 identified 63 patients, including 42 who had pancreaticoduodenectomy (PD) and 21 who had distal pancreatectomy (DP). Fourteen patients with preoperative hepatic steatosis, diabetes, obesity, on steroid therapy, history of malignancy, or incomplete data were excluded. No patient received chemotherapy. Liver fat signal fraction (LFSF) was computed by the Dixon method using pre- and postoperative in- and out-of-phase MRI.

Results

Of the 49 patients included in the study, 29 (59%) underwent PD and 20 (41%) underwent DP. A total of 17 patients (34%) developed fatty liver after surgery. The entire cohort developed significant weight loss, 72.1 versus 69.4 kg (P < 0.01). Postoperatively, there was significant increase in LFSF, 1.3% versus 9.6% following PD (P < 0.01), and 2.1% versus 9.4% following DP (P = 0.01).

Conclusion

Partial pancreatectomy increases the risk of NAFLD independent of chemotherapy-induced hepatotoxicity. The underlying mechanism remains unclear and possibly related to pancreatic exocrine insufficiency and malnutrition.

A case of steatohepatitis that developed after pancreaticoduodenectomy and progressed rapidly to liver cirrhosis and hepatocellular carcinoma

Steatohepatitis has been reported to occur after pancreaticoduodenectomy (PD). We report a case of steatohepatitis that arose after PD and led to decompensated liver cirrhosis and hepatocellular carcinoma (HCC). A 65-year-old man underwent PD for suspected intraductal papillary mucinous neoplasm. Eight years after PD, he was diagnosed with liver cirrhosis by laboratory tests and computed tomography. Histological examination of liver biopsy revealed hepatic steatosis, inflammation with ballooning of hepatocytes, and fibrosis, indicating nonalcoholic steatohepatitis as the cause of liver cirrhosis. Ten years after PD, he developed HCC and radiotherapy was performed because of impaired liver function. Intrahepatic metastasis appeared subsequently, but no further treatment could be performed due to decompensated liver cirrhosis. Survival time after PD is being prolonged by improvements in imaging studies and therapeutic strategies. Accordingly, we consider that progression to liver cirrhosis and HCC will occur increasingly in cases such as the present patient, which will become a severe problem in long-term post-PD survival. Therefore, it is necessary to clarify the precise mechanism of steatohepatitis after PD and establish appropriate therapeutic strategies.

Nicotinamide N-methyltransferase upregulation contributes to palmitate-elicited peroxisome proliferator-activated receptor transactivation in hepatocytes

Peroxisome proliferator-activated receptor γ (PPARγ) plays a pivotal role in regulating lipid metabolism and hepatic PPARγ transactivation contributes to fatty liver development. Fatty acids (FAs) are well-known endogenous ligands for PPARγ. Palmitate, a 16-C saturated FA (SFA) and the most abundant SFA in human circulation, is a strong inducer of hepatic lipotoxicity, a central pathogenic factor for various fatty liver diseases. In this study, using both alpha mouse liver 12 (AML12) and primary mouse hepatocytes, we investigated the effects of palmitate on hepatic PPARγ transactivation and underlying mechanisms, as well as the role of PPARγ transactivation in palmitate-induced hepatic lipotoxicity, all of which remain ambiguous currently. Our data revealed that palmitate exposure was concomitant with both PPARγ transactivation and upregulation of nicotinamide N-methyltransferase (NNMT), a methyltransferase catalyzing the degradation of nicotinamide, the predominant precursor for cellular NAD+ biosynthesis. Importantly, we discovered that PPARγ transactivation by palmitate was blunted by NNMT inhibition, suggesting that NNMT upregulation plays a mechanistic role in PPARγ transactivation. Further investigations uncovered that palmitate exposure is associated with intracellular NAD+ decline and NAD+ replenishment with NAD+-enhancing agents, nicotinamide and nicotinamide riboside, obstructed palmitate-induced PPARγ transactivation, implying that cellular NAD+ decline resulted from NNMT upregulation represents a potential mechanism behind palmitate-elicited PPARγ transactivation. At last, our data showed that the PPARγ transactivation marginally ameliorated palmitate-induced intracellular triacylglycerol accumulation and cell death. Collectively, our data provided the first-line evidence supporting that NNMT upregulation plays a mechanistic role in palmitate-elicited PPARγ transactivation, potentially through reducing cellular NAD+ contents.NEW & NOTEWORTHY Hepatic PPARγ transactivation contributes to fatty liver development. Saturated fatty acids (SFAs) induce hepatic lipotoxicity. Here, we investigated whether and how palmitate, the most abundant SFA in the human blood, affects PPARγ transactivation in hepatocytes. We reported for the first time that upregulation of nicotinamide N-methyltransferase (NNMT), a methyltransferase catalyzing the degradation of nicotinamide, the predominant precursor for cellular NAD+ biosynthesis, plays a mechanistic role in regulating palmitate-elicited PPARγ transactivation through reducing intracellular NAD+ contents.

Development of the Rabbit NASH Model Resembling Human NASH and Atherosclerosis

Non-alcoholic steatohepatitis (NASH) is a chronic liver disease which may progress into liver fibrosis and cancer. Since NASH patients have a high prevalence of atherosclerosis and ensuing cardiovascular diseases, simultaneous management of NASH and atherosclerosis is required. Currently, rodents are the most common animal models for NASH and accompanying liver fibrosis, but there are great differences in lipoprotein profiles between rodents and humans, which makes it difficult to reproduce the pathology of NASH patients with atherosclerosis. Rabbits can be a promising candidate for assessing NASH and atherosclerosis because lipoprotein metabolism is more similar to humans compared with rodents. To develop the NASH model using rabbits, we treated the Japanese White rabbit with a newly developed high-fat high-cholesterol diet (HFHCD) containing palm oil 7.5%, cholesterol 0.5%, and ferrous citrate 0.5% for 16 weeks. HFHCD-fed rabbits exhibited NASH at 8 weeks after commencing the treatment and developed advanced fibrosis by the 14th week of treatment. In addition to hypercholesterolemia, atherosclerotic lesion developed in the aorta after 8 weeks. Therefore, this rabbit NASH model might contribute to exploring the concurrent treatment options for human NASH and atherosclerosis.

Development of de novo nonalcoholic fatty liver disease following pancreatectomy

De novo non-alcoholic fatty liver disease (NAFLD) after pancreatectomy is a recognized phenomenon; however, its pathophysiology is poorly understood. This study aimed to determine the incidence and identify peri-operative risk factors for the development of de novo NAFLD within various pancreatectomy groups. This single-center retrospective cohort study included patients who underwent pancreatectomy between 2000 and 2020. The incidence rate of de novo NAFLD and time to diagnosis were recorded across patients with malignant versus benign indications for pancreatectomy. The overall incidence of de novo NAFLD after pancreatectomy was 17.5% (24/136). Twenty-one percent (20/94) of patients with malignant indications for surgery developed NAFLD compared to 9.5% (4/42) with benign indications (P = .09). Time to development of hepatic steatosis in the malignant group was 26.4 months and was significantly shorter by an average of 6 months when compared to the benign group (32.8 months, P = .03). Higher pre-operative body mass index was associated with new-onset NAFLD (P = .03). Pre-operative body mass index is a significant predictor for de novo NAFLD and highlights a group that should be closely monitored post-operatively, especially after resections for pancreatic malignancy.

Association between patient's age and the utility of prognostic markers after pancreaticoduodenectomy for pancreatic cancer

BACKGROUND ＆ AIMS: Optimizing treatments balancing prognosis and therapeutic invasiveness is important in the management of pancreatic cancer (PC) owing to global ageing. This study aimed to verify the different utility of biomarkers by patients' age. MATERIALS ＆ METHODS: This is a single-center, retrospective cohort analysis involving 160 patients who undertook pancreaticoduodenectomy (PD) for PC. After comparing clinicopathological factors and survival after PD between aged (≥70 y/o) and young (＜70 y/o) patients, we compared neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), controlling nutrition (CONUT) score, carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 as well as clinicopathological factors between long and short survivors in each group. We also performed Kaplan-Meyer analysis between patients stratified by biomarkers. RESULTS: Overall survival (OS) was significantly worse in aged patients (p = 0.002). In aged patients, CEA was significantly higher in short survivors. In young patients, CONUT score and CA19-9 were higher in short survivors. Kaplan-Meyer analysis showed that NLR and CEA stratified OS in aged patients, whereas CONUT score and CA19-9 could stratify OS in young patients. CONCLUSION: Our current results suggest that these biomarkers had different impact on survivals according to the patients' age.

Use of Network Pharmacology to Investigate the Mechanism by Which Allicin Ameliorates Lipid Metabolism Disorder in HepG2 Cells

Allicin has been well documented to exhibit a wide spectrum of biological activities, especially lipid-lowering activity, as a promising candidate for the management of nonalcoholic fatty liver disease (NALFD). However, the mechanisms underlying the therapeutic effects of allicin require further investigation. It is tempting to think of combining network pharmacology and experimental validation to investigate the mechanism by which allicin ameliorates lipid metabolism disorder in HepG2 cells. We established a cell model of hepatic steatosis induced by PA to investigate the antisteatotic effects of allicin. The studies showed that allicin reduced PA-induced lipid accumulation using Nile red staining and TC and TG assays. Then, 219 potential targets of allicin were successfully predicted by PharmMapper. According to Reactome Pathway Analysis, 44 potential targets related to lipid metabolism were screened out. Molecular signaling cascades mediated by allicin included PPARA, PPARG, FABP4, and FABP6 by cytoHubba and qPCR analysis. Results revealed that allicin activated the gene expression of PPARA and FABP6 and suppressed the gene expression of FABP4 and PPARG. Thus, the present study united the methods of network pharmacology and experimental validation to investigate the protein targets of allicin on PA-induced lipid metabolism disorders to supply a reference for related application for the first time.

Preventive Effect of High-Dose Digestive Enzyme Management on Development of Nonalcoholic Fatty Liver Disease after Pancreaticoduodenectomy: A Randomized Controlled Clinical Trial

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a complication of pancreaticoduodenectomy (PD). We conducted a randomized clinical trial to determine if high-dose digestive enzymes prevented the development of NAFLD after PD.

STUDY DESIGN

This parallel-group, nonblinded, multicenter study enrolled patients undergoing elective PD at Shinshu University School of Medicine, from June 2011 to April 2017. Patients were randomly assigned to receive normal-dose (Excelase: 3.0 g/day [Meiji Seika Pharma Holdings Co, Ltd]) or high-dose digestive enzyme treatment (Excelase: 3.0 g/day; Pancreatin [Tokyo Chemical Industry Co Ltd]: 3.0 g/day; Berizym [Kyowa Pharmaceutical Industry Co Ltd]: 3.0 g/day; and Toughmac-E [Ono Pharmaceutical Co, Ltd]: 3.0 g/day) within 1 week after surgery. Because patients in the control group switched interventions upon receiving a diagnosis of NAFLD, intention-to-treat analysis was used. The primary endpoint was incidence of NAFLD within 1 year, and the secondary endpoints were the incidences of NAFLD at 1, 3, 6, and 12 months and the rate of improvement in NAFLD with high-dose transfer in the control group. The secondary analysis comprised assessment of risk factors for the development of NAFLD.

RESULTS

Eighty-four patients were randomly assigned (42 per group), 80 of whom were finally analyzed (39 normal-dose, 41 high-dose). The incidence of NAFLD was significantly lower in the high-dose (8 of 41) compared with the normal-dose (25 of 39) patients (p < 0.001). Multivariate analysis identified normal-dose (odds ratio [OR] 14.65, p < 0.001), total protein ≤ 6.5g/dL (OR 9.01, p = 0.018), pre-albumin ≤ 22.0 mg/dL (OR 7.71, p = 0.018), and pancreatic function diagnostic test ≤ 70% (OR 6.66, p = 0.009) as independent risk factors. There were no adverse effects. The model was accurate (c-index = 0.92) and reliable (Hosmer-Lemeshow test p = 0.32).

CONCLUSIONS

High-dose administration of digestive enzymes significantly reduced the onset of NAFLD after PD compared with normal-dose administration. Registration number: UMIN000005595 (http://www.umin.ac.jp/ctr/).

Mechanisms of nonalcoholic fatty liver disease and implications for surgery

Background

Nonalcoholic fatty liver disease (NAFLD) has become the most common form of chronic liver disease in both adults and children worldwide. Understanding the pathogenic mechanisms behind NAFLD provides the basis for identifying risk factors, such as metabolic syndrome, pancreatoduodenectomy, and host genetics, that lead to the onset and progression of the disease. The progression from steatosis to more severe forms, such as steatohepatitis, fibrosis, and cirrhosis, leads to an increased number of liver and non-liver complications.

Purpose

NAFLD-associated end-stage liver disease (ESLD) and hepatocellular carcinoma (HCC) often require surgery as the only curative treatment. In particular, the presence of NAFLD together with the coexisting metabolic comorbidities that usually occur in these patients requires careful preoperative diagnosis and peri-/postoperative management. Bariatric surgery, liver resection, and liver transplantation (LT) have shown favorable results for weight loss, HCC, and ESLD in patients with NAFLD. The LT demand and the increasing spread of NAFLD in the donor pool reinforce the already existing lack of donor organs.

Conclusion

In this review, we will discuss the diverse mechanisms underlying NAFLD, its implications for surgery, and the challenges for patient management.

PPARs as Metabolic Regulators in the Liver: Lessons from Liver-Specific PPAR-Null Mice

Peroxisome proliferator-activated receptor (PPAR) α, β/δ, and γ modulate lipid homeostasis. PPARα regulates lipid metabolism in the liver, the organ that largely controls whole-body nutrient/energy homeostasis, and its abnormalities may lead to hepatic steatosis, steatohepatitis, steatofibrosis, and liver cancer. PPARβ/δ promotes fatty acid β-oxidation largely in extrahepatic organs, and PPARγ stores triacylglycerol in adipocytes. Investigations using liver-specific PPAR-disrupted mice have revealed major but distinct contributions of the three PPARs in the liver. This review summarizes the findings of liver-specific PPAR-null mice and discusses the role of PPARs in the liver.

Targeting Oxidative Stress for the Treatment of Liver Fibrosis

Oxidative stress is a reflection of the imbalance between the production of reactive oxygen species (ROS) and the scavenging capacity of the antioxidant system. Excessive ROS, generated from various endogenous oxidative biochemical enzymes, interferes with the normal function of liver-specific cells and presumably plays a role in the pathogenesis of liver fibrosis. Once exposed to harmful stimuli, Kupffer cells (KC) are the main effectors responsible for the generation of ROS, which consequently affect hepatic stellate cells (HSC) and hepatocytes. ROS-activated HSC undergo a phenotypic switch and deposit an excessive amount of extracellular matrix that alters the normal liver architecture and negatively affects liver function. Additionally, ROS stimulate necrosis and apoptosis of hepatocytes, which causes liver injury and leads to the progression of end-stage liver disease. In this review, we overview the role of ROS in liver fibrosis and discuss the promising therapeutic interventions related to oxidative stress. Most importantly, novel drugs that directly target the molecular pathways responsible for ROS generation, namely, mitochondrial dysfunction inhibitors, endoplasmic reticulum stress inhibitors, NADPH oxidase (NOX) inhibitors, and Toll-like receptor (TLR)-affecting agents, are reviewed in detail. In addition, challenges for targeting oxidative stress in the management of liver fibrosis are discussed.

Current status, problems, and perspectives of non-alcoholic fatty liver disease research

Non-alcoholic fatty liver disease (NAFLD) is a major chronic liver disease that can lead to liver cirrhosis, liver cancer, and ultimately death. NAFLD is pathologically classified as non-alcoholic fatty liver (NAFL) or non-alcoholic steatohepatitis (NASH) based on the existence of ballooned hepatocytes, although the states have been known to transform into each other. Moreover, since the detection of ballooned hepatocytes may be difficult with limited biopsied specimens, its clinical significance needs reconsideration. Repeated liver biopsy to assess histological NAFLD activity for therapeutic response is also impractical, creating the need for body fluid biomarkers and less invasive imaging modalities. Recent longitudinal observational studies have emphasized the importance of advanced fibrosis as a determinant of NAFLD outcome. Thus, identifying predictors of fibrosis progression and developing better screening methods will enable clinicians to isolate high-risk NAFLD patients requiring early intensive intervention. Despite the considerable heterogeneity of NAFLD with regard to underlying disease, patient age, and fibrosis stage, several clinical trials are underway to develop a first-in-class drug. In this review, we summarize the present status and future direction of NAFLD/NASH research towards solving unmet medical needs.

Miglitol attenuates non-alcoholic steatohepatitis in diabetic patients

AIM

Postprandial hyperglycemia is frequently accompanied by non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH). Although α-glucosidase inhibitors (αGIs) can slow glucose absorption from the intestine and suppress the surge of circulating glucose concentration after meals, it remains unclear whether αGIs are also beneficial for NASH. The aim of this prospective study was to examine the efficacy and safety of miglitol, a typical αGI, for NASH.

METHODS

Seventeen patients with histologically confirmed NASH and hemoglobin A1c (HbA1c) >6.5% were treated with miglitol (150 mg/day) for 12 months. The changes in clinical parameters and liver histology were analyzed.

RESULTS

All patients completed the 12-month miglitol treatment course with no severe adverse events. The treatment significantly decreased body mass index, serum alanine aminotransferase levels, and HbA1c (all P < 0.001). Post-treatment liver biopsy of 11 patients revealed significant improvements in steatosis (from 2.2 ± 0.6 to 1.5 ± 0.7, P = 0.001), lobular inflammation (from 1.8 ± 0.8 to 1.3 ± 0.5, P = 0.014), portal inflammation scores (from 0.6 ± 0.5 to 0.1 ± 0.3, P = 0.025), and NAFLD activity score (from 5.5 ± 1.5 to 3.9 ± 1.4, P = 0.012). Fibrosis and hepatocyte ballooning scores were unchanged.

CONCLUSIONS

Miglitol appears to safely ameliorate NASH activity by attenuation of steatosis and lobular/portal inflammation. Appropriately powered controlled trials are warranted to validate our results.

A higher flavonoid intake is associated with less likelihood of nonalcoholic fatty liver disease: results from a multiethnic study

Limited information exists on the impact of flavonoid intake on nonalcoholic fatty liver disease (NAFLD). We evaluated the link between flavonoid intake, liver tests and risk of NAFLD in a randomly selected sample of US adults (from the National Health and Nutrition Examination Survey, NHANES, 2005-2010). Of the 17,685 participants, 46.9% were men and 45.4% had NAFLD. NAFLD patients had a significantly lower mean flavonoid intake than healthy individuals (111.3±3.6 vs. 201.3±2.3 mg/d, respectively; P<.001). Fatty liver index (FLI) and serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were significantly higher in the first tertile (T1) of flavonoid intake compared with the highest tertile (T3: with the highest flavonoid intake) (FLI: 67.1 vs. 36.2, AST: 31.2 VS 26.8 U/L and, ALT: 34.2 vs. 24.2 U/L, respectively; P<.001 for all comparisons). Adjusted linear regression displayed significant and negative associations between FLI, AST, ALT and flavonoid intake (P<.001 for all comparisons). Multivariable logistic regression showed that the risk for NAFLD significantly decreased as flavonoid intake tertiles increased in a stepwise manner (odds ratio: 0.81, 95% confidence interval: 0.78-0.86). Moderation analysis revealed that C-reactive protein (CRP) strongly modulated the impact of flavonoid intake on FLI; participants with higher CRP levels benefited less from flavonoid intake compared with those with lower CRP concentrations. In conclusions, our results suggest a reverse significant association between flavonoid consumption, liver tests and the risk for NAFLD. Furthermore, CRP was shown to essentially moderate this relationship. These findings support recommendations for consumption of flavonoid-rich foods to prevent cardiometabolic diseases.

Link between plasma trans-fatty acid and fatty liver is moderated by adiposity

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) is rising. This increase may be associated with obesity. It has been suggested that trans-fatty acids (TFAs) play an important role in non-communicable diseases.

AIM

We examined the link between liver tests, fatty liver index (FLI) and plasma TFAs. Furthermore, we evaluated the impact of adiposity on this link.

METHODS

The National Health and Nutrition Examination Survey (NHANES) was used to obtain the data on TFAs and liver function biomarkers. We took account of complex NHANES data, masked variance and weighting methodology.

RESULTS

Of the 4252 participants, 46.4% were men. The mean age was 50.6 years overall; 51.3 years for men and 49.8 years for women (p = 0.206). In a fully adjusted model (demographic and clinical factors), FLI increased as trans-9-hexadecenoic acid and trans-11-octadecenoic acid levels increased; FLI was 38.1 and 42.3 for the first quarter (Q1) of trans-9-hexadecenoic acid and trans-11-octadecenoic acid, respectively, reaching 65.1 and 69.3 for the highest quarters (Q4) (p < 0.001 for all comparisons). Multivariable logistic regression showed for all four studied TFAs, the likelihood of NAFLD (determined by FLI) increased with increasing TFAs levels (quartiles) in a stepwise manner (p < 0.001 for all comparisons). Based on moderation analysis, a strong impact of body mass index (BMI) on the link between FLI and TFAs was observed.

CONCLUSIONS

Our results suggest a direct significant association between plasma TFAs, liver tests and NAFLD (assessed by FLI). Furthermore, BMI was shown to mediate this relationship. These findings highlight the importance of avoiding TFAs consumption in order to minimize cardiometabolic risk.

Targeting nuclear receptors for the treatment of fatty liver disease

Ligand-activated nuclear receptors, including peroxisome proliferator-activated receptor alpha (PPARα), pregnane X receptor, and constitutive androstane receptor, were first identified as key regulators of the responses against chemical toxicants. However, numerous studies using mouse disease models and human samples have revealed critical roles for these receptors and others, such as PPARβ/δ, PPARγ, farnesoid X receptor (FXR), and liver X receptor (LXR), in maintaining nutrient/energy homeostasis in part through modulation of the gut-liver-adipose axis. Recently, disorders associated with disrupted nutrient/energy homeostasis, e.g., obesity, metabolic syndrome, and non-alcoholic fatty liver disease (NAFLD), are increasing worldwide. Notably, in NAFLD, a progressive subtype exists, designated as non-alcoholic steatohepatitis (NASH) that is characterized by typical histological features resembling alcoholic steatohepatitis (ASH), and NASH/ASH are recognized as major causes of hepatitis virus-unrelated liver cirrhosis and hepatocellular carcinoma. Since hepatic steatosis is basically caused by an imbalance between fat/energy influx and utilization, abnormal signaling of these nuclear receptors contribute to the pathogenesis of fatty liver disease. Standard therapeutic interventions have not been fully established for fatty liver disease, but some new agents that activate or inhibit nuclear receptor signaling have shown promise as possible therapeutic targets. In this review, we summarize recent findings on the roles of nuclear receptors in fatty liver disease and discuss future perspectives to develop promising pharmacological strategies targeting nuclear receptors for NAFLD/NASH.

Association between endotoxemia and histological features of nonalcoholic fatty liver disease

AIM

To assess whether surrogate biomarkers of endotoxemia were correlated with the histological features of nonalcoholic fatty liver disease (NAFLD).

METHODS

One hundred twenty-six NAFLD patients who had undergone percutaneous liver biopsy were enrolled. Serum lipopolysaccharide (LPS)-binding protein (LBP) and anti-endotoxin core immunoglobulin G (EndoCab IgG) antibody concentrations at the time of liver biopsy were measured using the enzyme-linked immunosorbent assays to examine for relationships between biomarker levels and histological scores.

RESULTS

Serum LBP concentration was significantly increased in nonalcoholic steatohepatitis (NASH) patients as compared with nonalcoholic fatty liver (NAFL) subjects and was correlated with steatosis (r = 0.38, P < 0.0001) and ballooning scores (r = 0.23, P = 0.01), but not with the severity of lobular inflammation or fibrosis. Multivariate linear regression analysis revealed that LBP was associated with steatosis score and circulating C-reactive protein, aspartate aminotransferase, and fibrinogen levels. Serum EndoCab IgG concentration was comparable between NASH and NAFL patients. No meaningful correlations were detected between EndoCab IgG and histological findings.

CONCLUSION

LBP/EndoCab IgG were not correlated with lobular inflammation or fibrosis. More accurate LPS biomarkers are required to stringently assess the contribution of endotoxemia to conventional NASH.

Intracellular and extracellular miRNome deregulation in cellular models of NAFLD or NASH: Clinical implications

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) represents the most common chronic liver disease in industrialized countries. NAFLD has the potential to progress through the inflammatory phase of nonalcoholic steatohepatitis (NASH) to fibrosis, cirrhosis, and hepatocellular carcinoma. Identifying patients at risk for this transition is a relevant clinical challenge. The complexity of these phenotypes in vivo made necessary the development of in vitro models in order to dissect the molecular signalling affected in NAFLD and NASH, but also to identify potential circulating biomarkers.

METHODS AND RESULTS

We profiled the expression of 754 cellular and medium-secreted human miRNAs in HepG2 cells after lipotoxic (Palmitate, model of NASH) or not-lipotoxic stimuli (Oleate-Palmitate, model of NAFLD). Results were validated through Single TaqMan assays. We performed computational analysis of miRNA targets and pathways. Oleate-palmitate treatment induced a variation of 2.8% and 10% of total miRNAs in cells and medium, respectively; palmitate treatment caused 10% and 19% intracellular and extracellular miRNA deregulation, respectively. We validated miR-126, miR-150, miR-223, miR-483-3p, miR-1226*, and miR-1290 deregulation. Through computational analysis, we observed that targets of both intracellular and extracellular DE miRNAs were involved in processes associated with the onset and progression of NAFLD and NASH, such as fatty acid metabolism, apoptosis and inflammation.

CONCLUSIONS

These data would be useful to elucidate the role of miRNAs in the pathogenesis and progression of the NAFLD spectrum, but they also allow the identification of novel potential biomarkers for differential diagnosis to be tested in vivo.

PPARα protects against trans-fatty-acid-containing diet-induced steatohepatitis

Consumption of trans-fatty acids (TFA), unsaturated fatty acids (FA) containing trans double bonds, is a risk factor for metabolic syndrome and steatohepatitis. Peroxisome proliferator-activated receptor α (PPARα) is a master regulator of hepatic lipid homeostasis. To examine the contribution of PPARα to changes in liver phenotypes induced by TFA, two diets were used: a purified control diet and an isocaloric diet in which most of the soybean oil, a major source of FA in the diet, was replaced with TFA-rich shortening. The diets were fed to wild-type and Ppara-null mice for 2 months. Ppara-null mice fed a TFA-containing diet showed more severe hepatic steatosis and liver damage compared with similarly treated wild-type mice, as revealed by increased hepatic triglyceride (TG) contents and serum alanine aminotransferase activities. While the TFA-rich diet increased the hepatic expression of enzymes involved in de novo FA synthesis and decreased TG-hydrolyzing enzymes in both genotypes, the expression of FA-catabolizing enzymes was decreased in Ppara-null mice, resulting in more severe hepatosteatosis. Additionally, the expression levels of key contributors to inflammation, such as osteopontin, were increased, and nuclear factor-kappa B was activated in TFA-containing diet-fed Ppara-null mice. Enhanced inflammatory signaling in these mice was presumably mediated by toll-like receptor 2, with no accompanying inflammasome activation. Collectively, these results suggest a protective role for PPARα in the pathological changes in the liver following TFA consumption. PPARα might prevent TFA-containing diet-induced steatohepatitis.

Brazilian propolis mitigates impaired glucose and lipid metabolism in experimental periodontitis in mice

Background

Periodontitis has been implicated as a risk factor for metabolic disorders associated with insulin resistance. Recently, we have demonstrated that orally administered Porphyromonas gingivalis, a representative periodontopathic bacterium, induces endotoxemia via reduced gut barrier function coupled with changes in gut microbiota composition, resulting in systemic inflammation and insulin resistance. Propolis, a resinous substance collected by honeybees from leaf buds and cracks in the bark of various plants, can positively affect metabolic disorders in various experimental models. In this study, we thus aimed to clarify the effect of propolis on impaired glucose and lipid metabolism induced by P. gingivalis administration.

Methods

Eight-week-old male C57BL/6 mice were orally administered P. gingivalis strain W83, propolis ethanol extract powder with P. gingivalis, or vehicle. We then analyzed the expression profile of glucose and lipid metabolism-related genes in the liver and adipose tissues. Serum endotoxin levels were also evaluated by a limulus amebocyte lysate test. In addition, we performed histological analysis of the liver and quantified alveolar bone loss by measuring the root surface area on the lower first molar.

Results

Oral administration of P. gingivalis induced downregulation of genes that improve insulin sensitivity in adipose tissue (C1qtnf9, Irs1, and Sirt1), but upregulation of genes associated with lipid droplet formation and gluconeogenesis (Plin2, Acox, and G6pc). However, concomitant administration of propolis abrogated these adverse effects of P. gingivalis. Consistent with gene expression, histological analysis showed that administered propolis suppressed hepatic steatosis induced by P. gingivalis. Furthermore, propolis inhibited the elevation of serum endotoxin levels induced by P. gingivalis administration. Contrary to the systemic effects, propolis had no beneficial effect on alveolar bone loss.

Conclusion

These results suggest that administration of propolis may be effective in suppressing periodontopathic bacteria-induced metabolic changes that increase the risk of various systemic diseases.