Pathophysiology of non-alcoholic steatohepatitis and basis for treatment

Hepatoprotective Activity of Lignin-Derived Polyphenols Dereplicated Using High-Resolution Mass Spectrometry, In Vivo Experiments, and Deep Learning

Chronic liver diseases affect more than 1 billion people worldwide and represent one of the main public health issues. Nonalcoholic fatty liver disease (NAFLD) accounts for the majority of mortal cases, while there is no currently approved therapeutics for its treatment. One of the prospective approaches to NAFLD therapy is to use a mixture of natural compounds. They showed effectiveness in alleviating NAFLD-related conditions including steatosis, fibrosis, etc. However, understanding the mechanism of action of such mixtures is important for their rational application. In this work, we propose a new dereplication workflow for deciphering the mechanism of action of the lignin-derived natural compound mixture. The workflow combines the analysis of molecular components with high-resolution mass spectrometry, selective chemical tagging and deuterium labeling, liver tissue penetration examination, assessment of biological activity in vitro, and computational chemistry tools used to generate putative structural candidates. Molecular docking was used to propose the potential mechanism of action of these structures, which was assessed by a proteomic experiment.

The Space of Disse: The Liver Hub in Health and Disease

Since it was first described by the German anatomist and histologist, Joseph Hugo Vincenz Disse, the structure and functions of the space of Disse, a thin perisinusoidal area between the endothelial cells and hepatocytes filled with blood plasma, have acquired great importance in liver disease. The space of Disse is home for the hepatic stellate cells (HSCs), the major fibrogenic players in the liver. Quiescent HSCs (qHSCs) store vitamin A, and upon activation they lose their retinol reservoir and become activated. Activated HSCs (aHSCs) are responsible for secretion of extracellular matrix (ECM) into the space of Disse. This early event in hepatic injury is accompanied by loss of the pores—known as fenestrations—of the endothelial cells, triggering loss of balance between the blood flow and the hepatocyte, and underlies the link between fibrosis and organ dysfunction. If the imbalance persists, the expansion of the fibrotic scar followed by the vascularized septae leads to cirrhosis and/or end-stage hepatocellular carcinoma (HCC). Thus, researchers have been focused on finding therapeutic targets that reduce fibrosis. The space of Disse provides the perfect microenvironment for the stem cells niche in the liver and the interchange of nutrients between cells. In the present review article, we focused on the space of Disse, its components and its leading role in liver disease development.

The effect of cannabinoid receptor 1 blockade on hepatic free fatty acid profile in mice with nonalcoholic fatty liver disease

We used rimonabant to investigate the role of CB1 receptor on hepatic FFAs profile during NAFLD. Male mice C57BL/6 were divided into: control group fed with control diet 20 weeks (C; n=6); group fed with HFD 20 weeks (HF; n=6); group fed with control diet and treated with rimonabant after 18 weeks (R; n=9); group fed with HFD and treated with rimonabant after 18 weeks (HFR; n=10). Rimonabant (10mg/kg) was administered daily to HFR and R group by oral gavage. Rimonabant decreased liver palmitic acid proportion in HFR group compared to HF group (p<0.05). Liver stearic and oleic acid proportions were decreased in R group compared to control (p<0.01 respectively). Rimonabant increased liver linoleic and arachidonic acid proportions in HFR group compared to HF group (p<0.01 respectively). CB1 blockade may be useful in the treatment of HFD-induced NAFLD due to modulation of plasma lipid and hepatic FFA profile.

Thiazolidinediones for nonalcoholic steatohepatitis: A meta-analysis of randomized clinical trials

The findings regarding the effects of thiazolidinediones (TZDs) in nonalcoholic steatohepatitis (NASH) patients have been inconsistent, and the assessment of different clinical variables for evaluating the effects of TZDs confound a direct comparison of the results of different randomized clinical trials (RCTs), especially with regard to lifestyle changes. In this paper, we performed a meta-analysis of randomized controlled trials to clarify the effects of TZD treatment with and without lifestyle changes on histological markers of NASH and clinical variables related to insulin resistance (IR), hyperlipidemia, and obesity. We searched the literature using the following MeSH terms: "nonalcoholic steatohepatitis," "non-alcoholic steatohepatitis," "thiazolidinedione," "pioglitazone," "rosiglitazone," "randomized," and "clinical trial." Five eligible RCTs were selected, in which patients were treated with either pioglitazone or rosiglitazone, with or without lifestyle changes. We compared the effects of TZD treatment on hepatic fibrosis, lobular inflammation, IR improvement, fasting serum insulin, adiposity, and dyslipidemia between the various studies using fixed and random effects models, and heterogeneity in clinical outcomes was assessed. Significant improvement in hepatic fibrosis did not occur among the patients treated with TZDs alone or in those who underwent both lifestyle changes and TZD therapy. Lobular inflammation decreased in NASH patients who received TZD treatment and in those who underwent both TZD therapy and lifestyle changes. Although TZD treatment resulted in no significant improvement in IR, NASH patients who underwent both lifestyle changes and TZD therapy experienced a significantly greater reduction in their fasting insulin level than that observed in the control patients, whereas patients treated with TZDs alone did not. Although TZD-treated patients experienced significantly greater weight gain than the control patients, TZD treatment had no significant impact on body-mass index, percentage of body fat, or serum levels of cholesterol and triglyceride. Our findings indicate that additional variables should be assessed to obtain a more comprehensive evaluation of the effects of TZD treatment on IR and comorbidity risk factors in NASH patients, and suggest that including lifestyle changes and additional insulin-sensitizing agents in TZD regimens might improve the benefits of TZD therapy for NASH.

Perilipin 5 restores the formation of lipid droplets in activated hepatic stellate cells and inhibits their activation

Hepatic stellate cells (HSC) are major effectors during hepatic fibrogenesis. The activation of HSC is coupled to the loss of lipid droplets (LDs), which are specialized organelles composed of neutral lipids surrounded by perilipins. LDs have emerged as a focal point of interest in understanding the metabolic regulation of intrahepatic lipids during lipid-mediated liver fibrogenesis. Perilipin 5 (Plin5) is a newly identified LD protein in the perilipin family, which plays a key role in regulating aspects of intracellular trafficking, signaling, and cytoskeletal organization in hepatocytes. Recent work in Plin5 knockout mice suggests a role in high fat diet-induced hepatic lipotoxicity. The current report is to evaluate the impact of Plin5 on HSC activation and to elucidate the underlying mechanisms. We now show that high fat diet-induced liver fibrosis is accompanied by an approximate 75% reduction in Plin5 in HSC, and that spontaneous activation of primary HSC produces temporally coincident loss of Plin5 expression and LD depletion. As modulating lipid content in HSC is a suggested strategy for inhibition of HSC activation and treatment of hepatic fibrosis, we asked whether exogenous Plin5 expression in primary HSC would reverse the activation phenotype and promote LD formation. Recombinant lentiviral Plin5 expression in primary mouse HSC restored the formation of LDs, increased lipid content by inducing expression of pro-lipogenic genes and suppressing expression of pro-lipolytic genes, and suppressed HSC activation (~two fold reduction in expression of procollagen and α-smooth muscle actin, two unique biomarkers for activated HSC). In addition, the expression of exogenous Plin5 in HSC attenuated cellular oxidative stress by reducing cellular reactive oxygen species, elevating cellular glutathione, and inducing gene expression of glutamate-cysteine ligase. Taken together, our results indicate that expression of Plin5 plays a critical role in the formation of LDs, the elevation of lipid content in HSC, and the inhibition of the activation of HSC.

Preventive effects of citrulline on Western diet-induced non-alcoholic fatty liver disease in rats

A Western diet induces insulin resistance, liver steatosis (non-alcoholic fatty liver disease (NAFLD)) and intestinal dysbiosis, leading to increased gut permeability and bacterial translocation, thus contributing to the progression of NAFLD to non-alcoholic steatohepatitis. In the present study, we sought, in a model of Western diet-induced NAFLD, to determine whether citrulline (Cit), an amino acid that regulates protein and energy metabolism, could decrease Western diet-induced liver injuries, as well as the mechanisms involved. Sprague-Dawley rats were fed a high-fat diet (45 %) and fructose (30 %) in drinking water or a control diet associated with water (group C) for 8 weeks. The high-fat, high-fructose diet (Western diet) was fed either alone (group WD) or with Cit (1 g/kg per d) (group WDC) or an isonitrogenous amount of non-essential amino acids (group WDA). We evaluated nutritional and metabolic status, liver function, intestinal barrier function, gut microbiota and splanchnic inflammatory status. Cit led to a lower level of hepatic TAG restricted to microvesicular lipid droplets and to a lower mRNA expression of CCAAT-enhancer-binding protein homologous protein, a marker of endoplasmic reticulum stress, of pro-inflammatory cytokines Il6 (P<0·05) and Tnfα, and of toll-like receptor 4 (Tlr4) (P<0·05). Cit also improved plasma TAG and insulin levels. In the colon, it decreased inflammation (Tnfα and Tlr4 expressions) and increased claudin-1 protein expression. This was associated with higher levels of Bacteroides/Prevotella compared with rats fed the Western diet alone. Cit improves Western diet-induced liver injuries via decreased lipid deposition, increased insulin sensitivity, lower inflammatory process and preserved antioxidant status. This may be related in part to its protective effects at the gut level.

Autophagy: a new target for nonalcoholic fatty liver disease therapy

Nonalcoholic fatty liver disease (NAFLD) has gained importance in recent decades due to drastic changes in diet, especially in Western countries. NAFLD occurs as a spectrum from simple hepatic steatosis, steatohepatitis to cirrhosis, and even hepatocellular carcinoma. Although the molecular mechanisms underlying the development of NAFLD have been intensively investigated, many issues remain to be resolved. Autophagy is a cell survival mechanism for disposing of excess or defective organelles, and has become a hot spot for research. Recent studies have revealed that autophagy is linked to the development of NAFLD and regulation of autophagy has therapeutic potential. Autophagy reduces intracellular lipid droplets by enclosing them and fusing with lysosomes for degradation. Furthermore, autophagy is involved in attenuating inflammation and liver injury. However, autophagy is regarded as a double-edged sword, as it may also affect adipogenesis and adipocyte differentiation. Moreover, it is unclear as to whether autophagy protects the body from injury or causes diseases and even death, and the association between autophagy and NAFLD remains controversial. This review is intended to discuss, comment, and outline the progress made in this field and establish the possible molecular mechanism involved.

Amphiregulin activates human hepatic stellate cells and is upregulated in non alcoholic steatohepatitis

Amphiregulin (AR) involvement in liver fibrogenesis and hepatic stellate cells (HSC) regulation is under study. Non-alcoholic fatty liver disease (NAFLD) and its more severe form non-alcoholic steatohepatitis (NASH) may progress to cirrhosis and hepatocellular cancer (HCC). Our aim was to investigate ex vivo the effect of AR on human primary HSC (hHSC) and verify in vivo the relevance of AR in NAFLD fibrogenesis. hHSC isolated from healthy liver segments were analyzed for expression of AR and its activator, TNF-α converting enzyme (TACE). AR induction of hHSC proliferation and matrix production was estimated in the presence of antagonists. AR involvement in fibrogenesis was also assessed in a mouse model of NASH and in humans with NASH. hHSC time dependently expressed AR and TACE. AR increased hHSC proliferation through several mitogenic signaling pathways such as EGFR, PI3K and p38. AR also induced marked upregulation of hHSC fibrogenic markers and reduced hHSC death. AR expression was enhanced in the HSC of a murine model of NASH and of severe human NASH. In conclusion, AR induces hHSC fibrogenic activity via multiple mitogenic signaling pathways, and is upregulated in murine and human NASH, suggesting that AR antagonists may be clinically useful anti-fibrotics in NAFLD.

Reduced serum chemerin in patients with more severe liver cirrhosis

Chemerin is a well-established modulator of immune cell function and its serum levels are induced in inflammatory diseases. Liver cirrhosis is associated with inflammation which is aggravated by portal hypertension. The objective of this study was to evaluate whether chemerin is induced in patients with more severe liver cirrhosis and portal hypertension. Chemerin has been measured by ELISA in the portal venous serum (PVS), systemic venous serum (SVS) and hepatic venous serum (HVS) of 45 patients with liver cirrhosis. Chemerin is higher in HVS compared to PVS in accordance with our recently published finding. SVS, HVS and PVS chemerin decline in patients with more advanced liver injury defined by the CHILD-PUGH score. Hepatic chemerin has been determined in a small cohort and is similarly expressed in normal and cirrhotic liver. MELD score and serum markers of liver and kidney function do not correlate with chemerin. There is a positive correlation of chemerin in all compartments with Quick prothrombin time and of SVS chemerin with systolic blood pressure. PVS chemerin is induced in patients with modest/massive ascites but this does not translate into higher HVS and SVS levels. Chemerin is not associated with variceal size. Reduction of portal pressure by transjugular intrahepatic portosystemic shunt does not affect chemerin levels. These data show that low chemerin in patients with more severe liver cirrhosis is associated with reduced Quick prothrombin time.

Inhibiting CB1 receptors improves lipogenesis in an in vitro non-alcoholic fatty liver disease model

BACKGROUND

The endocannabinoids system (ECs) mediated mainly by CB1 and CB2 receptors plays an important role in non-alcoholic fatty liver disease by regulating lipid metabolism. This study is to further investigate the expression of CB1 and CB2 in the fat accumulation liver cells and to identify possible underlying mechanism by detecting the key lipogenesis factors.

METHODS

Sodium oleate and sodium palmitate were added into the HepG2 cell line for forming fat accumulation liver cell. MTT assay was used to test the cell's cytotoxicity. The accumulation rate of fat in HepG2 cell was analyzed by the fluorescent staining. The mRNA and protein expression levels of CB1, CB2, SREBP-1c, ChREBP, L-PK, ACC1, FAS, LXRs and RXR were detected by RT-PCR and Western blot before and after the use of the antagonist.

RESULTS

The receptors of CB1 were expressed in HepG2 cells with low levels while in HepG2 fatty liver cells with higher levels (p < 0.05). However, after the application of antagonist, the expressions were significantly decreased (p < 0.05). The expressions of SREBP-1c, ChREBP and LXRs were detectable in HepG2 cells and the expressions were increased in HepG2 fatty liver cells (p < 0.05). After using the antagonists, the expressions of SREBP-1c, ChREBP, LXRs, ACC1 and FAS were significantly decreased (p < 0.05). But L-PK and RXR changed little in two groups (p > 0.05).

CONCLUSION

Results of the present study demonstrated that CB1 receptors had important pathophysiological effects on the formation of fatty liver. CB1 receptors could be regulated by SREBP-1c, ChREBP and LXRs. Therefore, targeting CB1 receptors for the treatment of NAFLD might have a potential application value.

Liver injury attenuation by curcumin in a rat NASH model: an Nrf2 activation-mediated effect?

AIM

Nuclear factor-erythroid 2-related factor-2 (Nrf2) acts as a defense system in the development of nonalcoholic steatohepatitis (NASH). Curcumin is a phenolic compound with lipid regulatory, anti-oxidative, anti-inflammatory and anti-tumorigenic properties that is beneficial in defending against NASH and was recently proved to be an Nrf2 activator. The aim of this study was to evaluate whether Nrf2 activation could be involved in NASH mitigation by curcumin.

METHODS

Hepatic, metabolic, and inflammatory parameters, along with hepatic Nrf2 protein expression were explored in adult Sprague-Dawley rats developing high-fat-diet-induced NASH and submitted to curcumin gavage for 6 weeks.

RESULTS

Curcumin administration led to lower degrees of hepatic steatosis and inflammation; lower levels of serum aminotransferases, lipids, and homeostasis model assessment of insulin resistance; and lower serum and hepatic contents of tumor necrosis factor-α (TNF-α), interleukin-6, and malondialdehyde. In contrast, higher hepatic contents of glutathione, heme oxygenase-1 and superoxide dismutase were observed in rats with curcumin. Moreover, Nrf2 expression in liver cell nuclei was significantly higher in rats with curcumin.

CONCLUSIONS

Curcumin can prevent and ameliorate NASH via lipid reduction, improve insulin resistance, improve anti-inflammatory, and have antioxidant effects, possibly related to its activation of Nrf2.

Fibrogenesis and Carcinogenesis in Nonalcoholic Steatohepatitis (NASH): Involvement of Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinase (TIMPs)

Nonalcoholic steatohepatitis (NASH) is emerging worldwide because life-styles have changed to include much over-eating and less physical activity. The clinical and pathophysiological features of NASH are very different from those of HBV- and HCV-chronic liver diseases. The prognosis of NASH is worse among those with nonalcoholic fatty liver diseases (NAFLD), and some NASH patients show HCC with or without cirrhosis. In the present review we discuss fibrogenesis and the relationship between fibrosis and HCC occurrence in NASH to clarify the role of MMPs and TIMPs in both mechanisms. Previously we proposed MMP and TIMP expression in the multi-step occurrence of HCC from the literature based on viral-derived HCC. We introduce again these expressions during hepatocarcinogenesis and compare them to those in NASH-derived HCC, although the relationship with hepatic stem/progenitor cells (HPCs) invasion remains unknown. Signal transduction of MMPs and TIMPs is also discussed because it is valuable for the prevention and treatment of NASH and NASH-derived HCC.

Curcumin eliminates the effect of advanced glycation end-products (AGEs) on the divergent regulation of gene expression of receptors of AGEs by interrupting leptin signaling

Non-alcoholic steatohepatitis (NASH) is a major risk factor for hepatic fibrogenesis. NASH is often found in diabetic patients with hyperglycemia. Hyperglycemia induces non-enzymatic glycation of proteins, yielding advanced glycation end-products (AGEs). Effects of AGEs are mainly mediated by two categories of cytoplasmic membrane receptors. Receptor for AGEs (RAGE) is associated with increased oxidative stress and inflammation, whereas AGE receptor-1 (AGE-R1) is involved in detoxification and clearance of AGEs. Activation of hepatic stellate cells (HSC) is crucial to the development of hepatic fibrosis. We recently reported that AGEs stimulated HSC activation likely by inhibiting gene expression of AGE-R1 and inducing gene expression of RAGE in HSC, which were eliminated by the antioxidant curcumin. This study is to test our hypothesis that curcumin eliminates the effects of AGEs on the divergent regulation of the two receptors of AGEs in HSC by interrupting the AGE-caused activation of leptin signaling, leading to the inhibition of HSC activation. We observed herein that AGEs activated leptin signaling by inducing gene expression of leptin and its receptor in HSC. Like AGEs, leptin differentially regulated gene expression of RAGE and AGE-R1. Curcumin eliminated the effects of AGEs in HSC by interrupting leptin signaling and activating transcription factor NF-E2 p45-related factor 2 (Nrf2), leading to the elevation of cellular glutathione and the attenuation of oxidative stress. In conclusions, curcumin eliminated the effects of AGEs on the divergent regulation of gene expression of RAGE and AGE-R1 in HSC by interrupting the AGE-caused activation of leptin signaling, leading to the inhibition of HSC activation.

Nonalcoholic fatty liver disease (NAFLD): a new risk factor for adverse cardiovascular events in dialysis patients

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in Western countries. Today it is believed that NAFLD is a hepatic manifestation of metabolic syndrome, and thus it is closely related to the cardiovascular morbidity and mortality. Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in patients with end-stage-renal disease (ESRD). NAFLD and ESRD share some important cardiometabolic risk factors and possible common pathophyisiological mechanisms, and are linked to an increased risk of incident CVD events. We hypothesize that the coexistence of these two conditions could lead to much faster progress of the aterogenic process. Furthermore, patients with ESRD who suffer from NAFLD have a much higher risk for the development of adverse CVD events. Given the high prevalence of NAFLD, and its tight association with other manifestations of the metabolic syndrome and thus cardiovascular complications, it is important to recognize and aggressively treat this condition in ESRD patients. To evaluate this hypothesis, we propose the use of non-invasive methods such as transient elastography (TE) (Fibroscan-CAP) for the detection and quantification of liver steatosis and fibrosis, as well as an abdominal ultrasound for detecting liver steatosis. We focus on their correlation with carotid intima-media thickness (IMT) and plaque as surrogate measures of increased cardiovascular risk in HD patients in order to investigate the association of NAFLD and increase risk of adverse CVD events. This evaluation will prove useful in assessing the risk in HD patients with NAFLD for increase CVD mortality.

Food-derived peroxidized fatty acids may trigger hepatic inflammation: a novel hypothesis to explain steatohepatitis

BACKGROUND & AIMS

Obesity and hepatic steatosis are frequently associated with the development of a non-alcoholic steatohepatitis (NASH). The mechanisms driving progression of a non-inflamed steatosis to NASH are largely unknown. Here, we investigated whether ingestion of peroxidized lipids, as being present in Western style diet, triggers the development of hepatic inflammation.

METHODS

Corn oil containing peroxidized fatty acids was administered to rats by gavage for 6 days. In a separate approach, hepatocytes (HC), endothelial (EC) and Kupffer cells (KC) were isolated from untreated livers, cultured, and incubated with peroxidized linoleic acid (LOOH; linoleic acid (LH) being the main fatty acid in corn oil). Samples obtained from in vivo and in vitro studies were mainly investigated by qRT-PCR and biochemical determinations of lipid peroxidation products.

RESULTS

Rat treatment with peroxidized corn oil resulted in increased hepatic lipid peroxidation, upregulation of nitric oxide synthetase-2 (NOS-2), cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNFα), elevation of total nitric oxides, and increase in cd68-, cd163-, TNFα-, and/or COX-2 positive immune cells in the liver. When investigating liver cell types, LOOH elevated the secretion of TNFα, p38MAPK phosphorylation, and mRNA levels of NOS-2, COX-2, and TNFα, mainly in KC. The elevation of gene expression could be abrogated by inhibiting p38MAPK, which indicates that p38MAPK activation is involved in the pro-inflammatory effects of LOOH.

CONCLUSIONS

These data show for the first time that ingestion of peroxidized fatty acids carries a considerable pro-inflammatory stimulus into the body which reaches the liver and may trigger the development of hepatic inflammation.

Liver fibrogenesis in non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is emerging as one of the most common chronic liver diseases in developed western countries. Non-alcoholic steatohepatitis (NASH) is the most severe form of NAFLD, and can progress to more severe forms of liver disease, including fibrosis, cirrhosis, and even hepatocellular carcinoma. The activation of hepatic stellate cells plays a critical role in NASH-related fibrogenesis. Multiple factors, such as insulin resistance, oxidative stress, pro-inflammatory cytokines and adipokines, and innate immune responses, are known to contribute to the development of NASH-related fibrogenesis. Furthermore, these factors may share synergistic interactions, which could contribute to the process of liver fibrosis. Given the complex etiology of NASH, combined treatment regimes that target these different factors provide potential treatment strategies for NASH-related liver fibrosis.

Nonalcoholic fatty liver disease/steatohepatitis: epidemiology, pathogenesis, clinical presentation and treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic hepatic disorder in Western countries, with a prevalence of 20-30%. NAFLD comprises 'silent liver disease', in which simple steatosis is the only histological finding and which is benign in course, and nonalcoholic steatohepatitis, which is characterized by hepatocellular injury and inflammation with or without fibrosis. NAFLD is clinically important, because even benign fatty liver can progress to steatohepatitis in many patients, which can lead to liver cirrhosis and its complications and hepatocellular carcinoma. NAFLD is a hepatic manifestation of metabolic syndrome; it is closely related to other clinical features of metabolic syndrome, and thus to cardiovascular morbidity. There are several different noninvasive techniques for formal diagnosis and follow-up, but liver biopsy remains the gold standard. The most important therapeutic strategies include lifestyle changes, including changes in dietary habits aimed at weight loss and blood pressure regulation, with a consequent decrease in insulin resistance. For some patients with NAFLD/nonalcoholic steatohepatitis, pharmacological treatment is the best option, although further studies are needed to confirm its efficacy and tolerability.

Unconjugated hyperbilirubinemia is inversely associated with non-alcoholic steatohepatitis (NASH)

BACKGROUND

It has been recognised that unconjugated bilirubin contains hepatic anti-fibrogenic and anti-inflammatory properties and is a potent physiological antioxidant cytoprotectant. We believe that unconjugated hyperbilirubinemia may protect against development of non-alcoholic steatohepatitis (NASH).

AIM

This study was conducted to assess the association of serum unconjugated bilirubin levels and histological liver damage in non-alcoholic fatty liver disease (NAFLD).

METHODS

This was a retrospective analysis involving adult patients from a tertiary medical centre undergoing liver biopsy to evaluate suspected NAFLD or NASH and a control group without NAFLD based on normal liver ultrasound, labs and history. Identification of unconjugated hyperbilirubinemia was based on the presence of predominantly unconjugated bilirubin ≥1.0 mg/dL (17.1 μmol/L) while fasting, in the absence of haemolytic disease or other hepatic function alteration.

RESULTS

Six-hundred and forty-one patients were included. Unconjugated hyperbilirubinemia was inversely associated with NASH (OR 16.1, 95% CI 3.7-70.8 P < 0.001). Of the patients without NAFLD (133 patients), 13 (9.8%) had unconjugated hyperbilirubinemia (range 1.0-1.8, mean 1.4). Of the patients with NAFLD without NASH (285 patients), 32 (11.2%) had unconjugated hyperbilirubinemia (range 1.0-3.0, mean 1.4). Of the patients with NASH (223 patients), three (1.3%) had unconjugated hyperbilirubinemia (1.0, 1.1, 1.4).

CONCLUSIONS

Unconjugated hyperbilirubinemia is inversely associated with the histopathological severity of liver damage in non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease in children now: lifestyle changes and pharmacologic treatments

Over the past decade, non-alcoholic fatty liver disease (NAFLD) has become one of most common chronic liver diseases in children. A greater understanding about the risk factors and molecular pathogenesis of NAFLD suggests that lifestyle interventions aiming to decrease obesity/body mass index and metabolic derangement are the first line of treatments adopted in children affected by this disease. However, because these therapeutic options are often at the beginning misjudged by the patients and their parents, the use of pharmacologic agents may help to protect the liver and other organs from further irreversible tissue damage. Pharmacologic therapies against one or more specific factors and/or molecules involved in the development of NAFLD (i.e., insulin resistance, free fatty acid lipid toxicity, and oxidative stress) also might slow the progression of this increasingly prevalent pediatric disorder. On this basis, insulin sensitizers, antioxidants, cytoprotective agents, and dietary supplementations have been evaluated in pediatric clinical trials. In this review, we discuss the efficacy of the dietary approaches, possibly coupled with regular exercise, on decreasing the metabolic and histologic damage in pediatric NAFLD. We also emphasize several advantages of the pharmacologic treatments adopted or adoptable in combination with lifestyle interventions in children with NAFLD.