A Meta-analysis on Associated Risk of Mortality in Nonalcoholic Fatty Liver Disease.

OBJECTIVE: Nonalcoholic fatty liver disease (NAFLD) affects much of the worldwide population and poses a significant burden to the global healthcare. The rising numbers of individuals with NAFLD and instances of mortality point toward the importance of understanding the association causes of mortality in NAFLD. This meta-analysis aimed to seek the associations of NAFLD with all-cause, cardiovascular disease (CVD)-related, liver-related, and cancer-related mortality. METHODS: MEDLINE and Embase were searched for articles relating to causes of mortality between NAFLD and non-NAFLD. The DerSimonian and Laird random-effects model was used to analyze adjusted hazard ratios (HR), and a sensitivity analysis was conducted to reduce heterogeneity through a graphical display of study heterogeneity. RESULTS: Fifteen studies involving 10 286 490 patients were included. Individuals with NAFLD exhibited an increased risk of all-cause mortality (HR, 1.32; 95% CI, 1.09-1.59; P < .01; I2 = 96.00%), CVD-related mortality (HR, 1.22; 95% CI, 1.06-1.41; P < .01; I2 = 81.00%), and cancer-related mortality (HR, 1.67; 95% CI, 1.15-2.41; P < .01; I2 = 95.00%). However, no significant association was found between liver-related mortality and NAFLD (HR, 3.58; 95% CI, 0.69-18.46; P =.13; I2 = 96.00%). The sensitivity analysis conducted with graphic display of heterogeneity and only population-based studies found similar results. CONCLUSION: NAFLD was associated with an increased risk of all-cause, CVD-related, and cancer-related mortality but not liver-related mortality. The finding is likely because of low fibrosis prevalence in the community. However, the significant burden in other causes of mortality beyond the liver points to a need for multidisciplinary efforts to reduce the mortality risks.

Mild exacerbation of obesity- and age-dependent liver disease progression by senolytic cocktail dasatinib + quercetin.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent and represents a growing challenge in terms of prevention and treatment. A minority of affected patients develops inflammation, subsequently fibrosis, cirrhosis and hepatocellular carcinoma (HCC). HCC is a leading cause of cancer-related death. An increased number of senescent cells correlate with age-related tissue degeneration during NAFLD-induced HCC. Senolytics are promising agents that target selectively senescent cells. Previous studies showed that whereas a combination of the senolytic drugs dasatinib and quercetin (D + Q) reduced NAFLD in mice, D + Q lacked efficacy in removing doxorubicin-induced ß-gal-positive senescent cells in human HCC xenografted mice. Whether D + Q has an effect on the age-associated spectrum of NAFLD-inflammation-HCC remains unknown. METHODS: Here, we utilized an established model of age- and obesity-associated HCC, the low dose diethylnitrosamine (DEN)/high fat diet (HFD), a regimen promoting liver inflammation and tumorigenesis over a long period of 9 months. Four groups of mice each were created: group 1 included control untreated mice; group 2 included mice treated with D + Q; group 3 included mice undergoing the DEN/HFD protocol; group 4 included mice undergoing the DEN/HFD protocol with the administration of D + Q. At the end of the chemical/dietary regimen, we analyzed liver damage and cell senescence by histopathology, qPCR and immunoblotting approaches. RESULTS: Unexpectedly, D + Q worsened liver disease progression in the DEN/HFD mouse model, slightly increasing histological damage and tumorigenesis, while having no effect on senescent cells removal. CONCLUSIONS: In summary, using an animal model that fully recapitulates NAFLD, we demonstrate that these compounds are ineffective against age-associated NAFLD-induced HCC. Video Abstract.

A Lipidomic Signature Complements Stemness Features Acquisition in Liver Cancer Cells.

Lipid catabolism and anabolism changes play a role in stemness acquisition by cancer cells, and cancer stem cells (CSCs) are particularly dependent on the activity of the enzymes involved in these processes. Lipidomic changes could play a role in CSCs' ability to cause disease relapse and chemoresistance. The exploration of lipid composition and metabolism changes in CSCs in the context of hepatocellular cancer (HCC) is still incomplete and their lipidomic scenario continues to be elusive. We aimed to evaluate through high-throughput mass spectrometry (MS)-based lipidomics the levels of the members of the six major classes of sphingolipids and phospholipids in two HCC cell lines (HepG2 and Huh-7) silenced for the expression of histone variant macroH2A1 (favoring stemness acquisition), or silenced for the expression of focal adhesion tyrosine kinase (FAK) (hindering aggressiveness and stemness). Transcriptomic changes were evaluated by RNA sequencing as well. We found definite lipidomic and transcriptomic changes in the HCC lines upon knockdown (KD) of macroH2A1 or FAK, in line with the acquisition or loss of stemness features. In particular, macroH2A1 KD increased total sphingomyelin (SM) levels and decreased total lysophosphatidylcholine (LPC) levels, while FAK KD decreased total phosphatidylcholine (PC) levels. In conclusion, in HCC cell lines knocked down for specific signaling/epigenetic processes driving opposite stemness potential, we defined a lipidomic signature that hallmarks hepatic CSCs to be exploited for therapeutic strategies.

Hepatic rhythmicity of endoplasmic reticulum stress is disrupted in perinatal and adult mice models of high-fat diet-induced obesity.

We investigated the regulation of hepatic ER stress in healthy liver and adult or perinatally programmed diet-induced non-alcoholic fatty liver disease (NAFLD). Female mice were fed either obesogenic or control diet before mating, during pregnancy and lactation. Post-weaning, offspring from each maternal group were divided into either obesogenic or control diet. At six months, offspring were sacrificed at 4-h intervals over 24 h. Offspring fed obesogenic diets developed NAFLD phenotype, and the combination of maternal and offspring obesogenic diets exacerbated this phenotype. UPR signalling pathways (IREα, PERK, ATF6) and their downstream regulators showed different basal rhythmicity, which was modified in offspring exposed to obesogenic diet and maternal programming. The double obesogenic hit increased liver apoptosis measured by TUNEL staining, active caspase-3 and phospho-JNK and GRP78 promoter methylation levels. This study demonstrates that hepatic UPR is rhythmically activated. The combination of maternal obesity (MO) and obesogenic diets in offspring triggered altered UPR rhythmicity, DNA methylation and cellular apoptosis.

Does Intragastric Balloon Treatment for Obesity in Chronic Kidney Disease Heighten Acute Kidney Injury Risk?

BACKGROUND: The outcomes of intragastric balloon (IGB) placement to achieve weight loss in obese patients with chronic kidney disease (CKD) have not been reported to date. This study aimed to assess the safety and efficacy of the IGB as a weight-loss treatment among this patient population. METHODS: A prospective, single-arm, 'first in CKD' interventional study was conducted in patients with a body mass index >35 kg/m2 and CKD stages 3-4, referred for weight loss. After clinical assessment, the IGB was endoscopically inserted into the stomach and kept in place for 6 months. Complications, adverse events, acceptability, weight loss and metabolic responses were monitored over 6 months. RESULTS: Eleven participants were recruited over 18 months. Two patients withdrew (1 prior to IGB insertion and 1 early removal after 3 days due to persistent vomiting) from the study; 9 patients completed the study. There were 5 episodes of acute kidney injury (AKI), occurring in 3 patients. After 6 months, the mean body mass decreased by 9.6% (SD ±6.8). Median waist circumference and total cholesterol decreased significantly (-7.7 cm; interquartile range (IQR) -15.3 to -3.9; and -0.2 mmol/l; IQR -0.6 to -0.05, respectively), with no changes in estimated glomerular filtration rate, blood pressure, triglycerides, adipokines, inflammation, or arterial stiffness measured by carotid-femoral pulse wave velocity. At IGB removal, there was 1 new case each of gastritis and esophagitis. CONCLUSIONS: Treatment with IGB has only moderate efficacy on weight loss; yet it results in a high rate of complications in obese patients with established CKD. The risk of AKI may be raised due to increased risk of dehydration secondary to gastrointestinal symptoms associated with IGB placement and reduced baseline kidney function.

Patatin-like phospholipase domain-containing protein 3 is involved in hepatic fatty acid and triglyceride metabolism through X-box binding protein 1 and modulation of endoplasmic reticulum stress in mice.

AIM: Non-alcoholic steatohepatitis (NASH) is the major cause of chronic liver disease worldwide. Endoplasmic reticulum (ER) stress is considered to be an important pathological characteristic in NASH. A sequence variation (I148M) in the patatin-like phospholipase domain-containing protein 3/adiponutrin (PNPLA3) gene is known to be associated with the development of NASH. However, PNPLA3 deficiency has been considered to not be associated with fatty liver disease. To clarify, therefore, the role of PNPLA3 in liver, we established PNPLA3 knockout (KO) mice and investigated the phenotypes and involved factors under ER stress. METHODS: ER stress was induced by i.p. injection with tunicamycin or with saline at 0 and 24 h in KO and C57BL/6 (wild-type [WT]) mice. At 48 h after the starting of treatment, blood and liver samples were studied. RESULTS: Hepatic steatosis and triglyceride content were remarkably increased in WT mice than in KO mice under ER stress. The hepatic palmitate/oleate ratio was significantly higher originally in KO mice than in WT mice. Moreover, the expression of stearoyl-coenzyme A desaturase-1 (SCD1) in KO mice under ER stress was decreased further than that in WT mice. Expression of ER stress markers X-box binding protein 1 (XBP1) and ERdj4 was increased in WT mice but not in KO mice under ER stress. CONCLUSION: We first demonstrated the hepatic phenotype of PNPLA3 deficiency under ER stress. Our observations would indicate that PNPLA3 has an important role in hepatic fatty acid metabolism and triglyceride accumulation through XBP1 under ER stress.

Acetylcholine induces fibrogenic effects via M2/M3 acetylcholine receptors in non-alcoholic steatohepatitis and in primary human hepatic stellate cells.

BACKGROUND: The parasympathetic nervous system (PNS), via neurotransmitter acetylcholine (ACh), modulates fibrogenesis in animal models. However, the role of ACh in human hepatic fibrogenesis is unclear. AIMS: We aimed to determine the fibrogenic responses of human hepatic stellate cells (hHSC) to ACh and the relevance of the PNS in hepatic fibrosis in patients with non-alcoholic steatohepatitis (NASH). METHODS: Primary hHSC were analyzed for synthesis of endogenous ACh and acetylcholinesterase and gene expression of choline acetyltransferase and muscarinic ACh receptors (mAChR). Cell proliferation and fibrogenic markers were analyzed in hHSC exposed to ACh, atropine, mecamylamine, methoctramine, and 4-diphenylacetoxy-N-methylpiperidine methiodide. mAChR expression was analyzed in human NASH scored for fibrosis. RESULTS: We observed that hHSC synthesize ACh and acetylcholinesterase and express choline acetyltransferase and M1-M5 mAChR. We also show that M2 was increased during NASH progression, while both M2 and M3 were found upregulated in activated hHSC. Furthermore, endogenous ACh is required for hHSC basal growth. Exogenous ACh resulted in hHSC hyperproliferation via mAChR and phosphoinositide 3-kinase and Mitogen-activated protein kinase kinase (MEK) signaling pathways, as well as increased fibrogenic markers. CONCLUSION: We show that ACh regulates hHSC activation via M2 and M3 mAChR involving the phosphoinositide 3-kinase and MEK pathways in vitro. Finally, we provide evidence that the PNS may be involved in human NASH fibrosis.

A Guide to Non-Alcoholic Fatty Liver Disease in Childhood and Adolescence.

Non-Alcoholic Fatty Liver Disease (NAFLD) is now the most prevalent form of chronic liver disease, affecting 10%-20% of the general paediatric population. Within the next 10 years it is expected to become the leading cause of liver pathology, liver failure and indication for liver transplantation in childhood and adolescence in the Western world. While our understanding of the pathophysiological mechanisms underlying this disease remains limited, it is thought to be the hepatic manifestation of more widespread metabolic dysfunction and is strongly associated with a number of metabolic risk factors, including insulin resistance, dyslipidaemia, cardiovascular disease and, most significantly, obesity. Despite this, "paediatric" NAFLD remains under-studied, under-recognised and, potentially, undermanaged. This article will explore and evaluate our current understanding of NAFLD in childhood and adolescence and how it differs from adult NAFLD, in terms of its epidemiology, pathophysiology, natural history, diagnosis and clinical management. Given the current absence of definitive radiological and histopathological diagnostic tests, maintenance of a high clinical suspicion by all members of the multidisciplinary team in primary and specialist care settings remains the most potent of diagnostic tools, enabling early diagnosis and appropriate therapeutic intervention.

The ß-adrenoceptor agonist isoproterenol rescues acetaminophen-injured livers through increasing progenitor numbers by Wnt in mice.

UNLABELLED: Acetaminophen (APAP)-induced acute liver injury (AILI) is a major health problem. Accumulating evidence suggests that the sympathetic nervous system (SNS) regulates neuronal and hematopoietic progenitors. SNS signaling affects hepatic progenitor/oval cells (HPCs) and ß-adrenoceptor agonism will expand HPCs to reduce AILI. Dopamine ß-hydroxylase-deficient mice (Dbh-/-), lacking catecholamine SNS neurotransmitters, isolated HPCs, and immature ductular 603B cells were initially used to investigate SNS involvement in HPC physiology. Subsequently, control mice were treated with APAP (350 mg/kg) followed by the ß-adrenoceptor agonist, isoproterenol (ISO), or the ß-adrenoceptor antagonist, propranolol. Mechanistic studies examined effects of non-SNS HPC expansion on AILI, involvement of the canonical Wnt/ß-catenin pathway (CWP) in the action of ISO on HPC expansion and comparison of ISO with the current standard of care, N-acetylcysteine (NAC). Dbh-/- mice lacking catecholamines had low HPC numbers, reconstituted by ISO. In vitro, ISO-induced proliferation of 603B cells was CWP dependent. In control mice, AILI raised HPC numbers, further increased by ISO, with attenuation of liver injury. Delayed administration of NAC did not, but delayed ISO did, reverse AILI. Propranolol worsened AILI. AILI activated the CWP, and ISO enhanced Wnt-ligand production. HPCs were the major source of Wnt ligands. Recombinant Wnt3a and ISO-603B-conditioned media, but not ISO alone, protected isolated hepatocytes from death, reversed by DKK1-a Wnt antagonist. Additionally, tumor-associated weak inducer of apoptosis expanded HPCs and protected against AILI. Furthermore, allotransplantation of HPCs from APAP+ISO-treated mice to other APAP-injured mice improved AILI, an effect antagonized by DKK1. CONCLUSION: SNS catecholamines expand HPCs, which are both targets and sources of Wnt ligands. Hepatoprotection by ISO is mediated by para- and autocrine effects of Wnt signaling. ISO represents novel pharmacotherapy for AILI.

Epigenetics of obesity: beyond the genome sequence.

PURPOSE OF REVIEW: After the study of the gene code as a trigger for obesity, epigenetic code has appeared as a novel tool in the diagnosis, prognosis and treatment of obesity, and its related comorbidities. This review summarizes the status of the epigenetic field associated with obesity, and the current epigenetic-based approaches for obesity treatment. RECENT FINDINGS: Thanks to technical advances, novel and key obesity-associated polymorphisms have been described by genome-wide association studies, but there are limitations with their predictive power. Epigenetics is also studied for disease association, which involves decoding of the genome information, transcriptional status and later phenotypes. Obesity could be induced during adult life by feeding and other environmental factors, and there is a strong association between obesity features and specific epigenetic patterns. These patterns could be established during early life stages, and programme the risk of obesity and its comorbidities during adult life. Furthermore, recent studies have shown that DNA methylation profile could be applied as biomarkers of diet-induced weight loss treatment. SUMMARY: High-throughput technologies, recently implemented for commercial genetic test panels, could soon lead to the creation of epigenetic test panels for obesity. Nonetheless, epigenetics is a modifiable risk factor, and different dietary patterns or environmental insights during distinct stages of life could lead to rewriting of the epigenetic profile.

Maternal obesity programs offspring nonalcoholic fatty liver disease by innate immune dysfunction in mice.

UNLABELLED: The global prevalence of obesity-induced liver disease (nonalcoholic fatty liver disease; NAFLD) is rising. Suggested causes include a role for in utero influences of maternal obesity compounded by the availability of energy-dense foods throughout postnatal life. Using a physiologically relevant model, we investigated the role of the innate immune system in liver injury induced by maternal obesity followed by a postnatal obesogenic diet. Female C57BL/6J mice were fed a standard or obesogenic diet before and throughout pregnancy and during lactation. Female offspring were weaned onto a standard or obesogenic diet at 3 weeks postpartum. Biochemical and histological indicators of dysmetabolism, NAFLD and fibrosis, analysis of profibrotic pathways, liver innate immune cells, and reactive oxygen species (ROS) were investigated at 3, 6, and 12 months. Female offspring exposed to a postweaning obesogenic diet (OffCon-OD) demonstrated evidence of liver injury, which was exacerbated by previous exposure to maternal obesity (OffOb-OD), as demonstrated by raised alanine aminotransferase, hepatic triglycerides, and hepatic expression of interleukin (IL)-6, tumor necrosis factor alpha, transforming growth factor beta, alpha smooth muscle actin, and collagen (P < 0.01). Histological evidence of hepatosteatosis and a more-robust NAFLD phenotype with hepatic fibrosis was observed at 12 months in OffOb-OD. A role for the innate immune system was indicated by increased Kupffer cell numbers with impaired phagocytic function and raised ROS synthesis (P < 0.01), together with reduced natural killer T cells and raised interleukin (IL)-12 and IL-18. CONCLUSION: Maternal obesity in the context of a postnatal hypercalorific obesogenic diet aggressively programs offspring NAFLD associated with innate immune dysfunction, resulting in a comprehensive phenotype that accurately reflects the human disease.

Propranolol, a ß-adrenoceptor antagonist, worsens liver injury in a model of non-alcoholic steatohepatitis.

Prazosin an α1-adrenoceptor (AR) antagonist has been shown to reduce liver injury in a mouse model of non-alcoholic steatohepatitis (NASH) and is suggested as a potential treatment of NASH especially given its concomitant anti-fibrotic properties. The effect however, of ß-AR blockade in non-cirrhotic NASH is unknown and is as such investigated here. In the presence of the ß-blocker propranolol (PRL), mice fed normal chow or a half methionine and choline deficient diet, supplemented with ethionine (HMCDE), to induce NASH, showed significantly enhanced liver injury, as evidenced by higher hepatic necrosis scores and elevated serum aminotransferases (ALT). Mechanistically, we showed that murine hepatocytes express α and ß adrenoceptors; that PRL directly induces hepatocyte injury and death as evidenced by increased release of lactate dehydrogenase, FASL and TNF-α from hepatocytes in the presence of PRL; and that PRL activated the apoptotic pathway in primary hepatocyte cultures, as indicated by upregulation of Fas receptor and caspase-8 proteins. The ß-AR antagonist PRL therefore appears to enhance liver injury through induction of hepatocyte death via the death pathway. Further studies are now required to extrapolate these findings to humans but meanwhile, ß-AR antagonists should be avoided or used with caution in patients with non-cirrhotic NASH as they may worsen liver injury.

Nicotine induces fibrogenic changes in human liver via nicotinic acetylcholine receptors expressed on hepatic stellate cells.

BACKGROUND AND AIMS: Cigarette smoke (CS) may cause liver fibrosis but possible involved mechanisms are unclear. Among the many chemicals in CS is nicotine - which affects cells through nicotinic acetylcholine receptors (nAChR). We studied the effects of nicotine, and involved pathways, on human primary hepatic stellate cells (hHSCs), the principal fibrogenic cells in the liver. We then determined possible disease relevance by assaying nAChR in liver samples from human non-alcoholic steatohepatitis (NASH). METHODS: hHSC were isolated from healthy human livers and nAChR expression analyzed - RT-PCR and Western blotting. Nicotine induction of hHSC proliferation, upregulation of collagen1-α2 and the pro-fibrogenic cytokine transforming growth factor beta 1 (TGF-ß1) was determined along with involved intracellular signaling pathways. nAChR mRNA expression was finally analyzed in whole liver biopsies obtained from patients diagnosed with non-alcoholic steatohepatitis (NASH). RESULTS: hHSCs express muscle type (α1, ß1, delta and epsilon) and neuronal type (α3, α6, α7, ß2 and ß4) nAChR subunits at the mRNA level. Among these subunits, α3, α7, ß1 and ε were predominantly expressed as confirmed by Western blotting. Nicotine induced hHSC proliferation was attenuated by mecamylamine (p<0.05). Additionally, collagen1-α2 and TGF-ß1 mRNA expression were significantly upregulated by nicotine and inhibited by mecamylamine. α1 and α3-nAChR mRNA expression was significantly upregulated in NASH fibrosis compared to normal livers. CONCLUSION: Nicotine at levels in smokers' blood is pro-fibrogenic, through actions on hHSCs expressed nAChRs. Therefore, CS, via its nicotine content, may worsen liver fibrosis. Moreover, nicotinic receptor antagonists may have utility as novel anti-fibrotic agents.

Non-alcoholic fatty liver disease: Is surgery the best current option and can novel endoscopy play a role in the future?

Over the last decade, non-alcoholic fatty liver disease (NAFLD) has overtaken alcohol as the leading cause of cirrhosis in the Western world. There remains to be a licensed pharmacological treatment for NAFLD. Weight loss is advised for all patients with NAFLD. Many patients however, struggle to lose the recommended weight with lifestyle modification alone. Many drugs have either failed to show significant improvement of steatosis or are poorly tolerated. Bariatric surgery has been shown to reduce liver steatosis and regress liver fibrosis. The pathophysiology is not fully understood, however recent evidence has pointed towards changes in the gut microbiome following surgery. Novel endoscopic treatment options provide a minimally invasive alternative for weight loss. Randomised controlled trials are now required for further clarification.

Fostering in mice induces cardiovascular and metabolic dysfunction in adulthood.

Cross-fostering is widely used in developmental programming studies to determine the relative contribution of the in utero and suckling periods in establishing the adult offspring phenotype in response to an environmental challenge. We have investigated whether the process of fostering per se influences cardiovascular and metabolic function in adult offspring of C57BL/6J mice in comparison with animals suckled by their biological dams. Cross-fostered (CF) mice demonstrated juvenile onset hyperphagia and significantly higher body weight (from weaning to 12 weeks: male control (CON) vs. CF: P < 0.01, female CON vs. CF: P < 0.001; RM ANOVA) accompanied by increased abdominal adiposity in males only (white adipose tissue mass (mg): CON 280.5 ± 13.4 [mean ± SEM] (n = 7) vs. CF, 549.8 ± 99.3 (n = 8), P < 0.01). Both male and female CF mice demonstrated significantly enhanced glucose tolerance. A marked increase in systolic blood pressure (SBP) was observed in male CF mice (SBP (mmHg), day: CON 100.5 ± 1.4 (n = 6) vs. CF 114.3 ± 0.7 (n = 6), P < 0.001; night: CON 108.0 ± 2.0 (n = 6) vs. CF 123.2 ± 1.1 (n = 6), P < 0.001). Endothelium-dependent relaxation was enhanced in male CF mice, and renal noradrenaline was increased in female CF mice. Concentration of serum triglycerides, cholesterol, insulin and leptin were increased in CF vs. CON. The process of cross-fostering profoundly affects cardiovascular and metabolic phenotype in mice. The findings have implications for the inclusion of appropriate controls in the design of future studies and in the interpretation of previous cross-fostering studies in mice.

A novel and comprehensive mouse model of human non-alcoholic steatohepatitis with the full range of dysmetabolic and histological abnormalities induced by gold thioglucose and a high-fat diet.

BACKGROUND: The search for effective treatments of non-alcoholic steatohepatitis (NASH), now the most common chronic liver disease in affluent countries, is hindered by a lack of animal models having the range of anthropometric and pathophysiological features as human NASH. AIMS: To examine if mice treated with gold thioglucose (GTG) - known to induce lesions in the ventromedial hypothalamus, leading to hyperphagia and obesity - and then fed a high-fat diet (HF) had a comprehensive histological and dysmetabolic phenotype resembling human NASH. METHODS: C57BL/6 mice were injected intraperitoneally with GTG and then fed HF for 12 weeks (GTG+HF). The extent of abdominal adiposity was assayed by CT scanning. A glucose tolerance test and an insulin tolerance test were performed to evaluate insulin resistance (IR). Histological, molecular and biochemical analyses were also performed. RESULTS: Gold thioglucose+HF induced dysmetabolism, with hyperphagia, obesity with increased abdominal adiposity, IR and consequent steatohepatitis, with hepatocyte ballooning, Mallory-Denk bodies, perivenular and pericellular fibrosis as seen in adult NASH, paralleled by an increased expression of the profibrogenic factors, transforming growth factor-ß1 and TIMP-1. Plasma adiponectin and the expression of adiponectin receptor 1 and receptor 2 were decreased, while PPAR-γ and FAS were increased in the livers of GTG+HF mice. In addition, GTG+HF mice showed glucose intolerance and severe IR. CONCLUSIONS: Treatment with GTG and HF diet induce, in mice, a comprehensive model of human NASH, with the full range of dysmetabolic and histological abnormalities.

Super paramagnetic iron oxide MRI shows defective Kupffer cell uptake function in non-alcoholic fatty liver disease.

BACKGROUND: The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is incompletely understood. Kupffer cells (KCs), phagocytic liver-resident macrophages, provide a protective barrier against egress of endotoxin from the portal to the systemic circulation. It is not known if KC phagocytic function is impaired in NAFLD. Super-paramagnetic iron oxide (SPIO) magnetic resonance imaging is a comparative technology dependent on KC phagocytic function. OBJECTIVE: To evaluate KC uptake function, in patients and experimental animals with NAFLD, using SPIO. METHODS: Abdominal CT and histological examination of liver biopsy specimens were used to estimate the degree of steatosis in patients with NAFLD and controls with chronic hepatitis C. SPIO-MRI was then performed in all patients. Normal rats fed a methionine-choline-deficient diet to induce non-alcoholic steatohepatitis (NASH), the more severe stage of NAFLD, and obese, insulin resistant, Zucker fa/fa rats with steatohepatitis, were also studied with SPIO-MRI and analysed for hepatic uptake of fluorescent microbeads. Immunohistochemical analysis evaluated the numbers of KCs in patients and rat livers. RESULTS: Relative signal enhancement (RSE), inversely proportional to KC function, was higher in patients with NAFLD than in controls and with the degree of steatosis on CT. RSE also positively correlated with the degree of steatosis on histology and was similarly higher in rats with induced severe NAFLD (NASH). On immunohistochemistry, defective phagocytic function was the result of reduced phagocytic uptake and not due to reduced KC numbers in rats or patients with NAFLD. CONCLUSIONS: KC uptake function is significantly impaired in patients with NAFLD and experimental animals with NASH, worsens with the degree of steatosis and is not due to a reduction of KC numbers.

Maternal obesity during pregnancy and lactation programs the development of offspring non-alcoholic fatty liver disease in mice.

BACKGROUND & AIMS: Obesity induced, non-alcoholic fatty liver disease (NAFLD), is now the major cause in affluent countries, of the spectrum of steatosis-to-cirrhosis. Obesity and NAFLD rates in reproductive age women, and adolescents, are rising worldwide. Our hypothesis was that maternal obesity and lactation transmit to the offspring a pre-disposition to dysmetabolism, obesity and NAFLD. METHODS: Female mice were fed standard or obesogenic chow, before, throughout pregnancy, and during lactation. The critical developmental period was studied by cross-fostering offspring of lean and obese dams. Offspring were then weaned onto standard chow and studied at 3months. Read-outs included markers of metabolic dysfunction, biochemical and histological indicators of NAFLD, induction of liver fibrogenesis, and activation of pro-fibrotic pathways. Mechanisms involved in programming a dysmetabolic and NAFLD phenotype were investigated by assaying breast milk components. RESULTS: Offspring of obese dams had a dysmetabolic, insulin resistant and NAFLD phenotype compared to offspring of lean dams. Offspring of lean dams that were suckled by obese dams showed an exaggerated dysmetabolic and NAFLD phenotype, with increased body weight, as well as increased levels of insulin, leptin, aspartate transaminase, interleukin-6, tumour necrosis factor-alpha, liver triglycerides, steatosis, hepatic fibrogenesis, renal norepinephrine, and liver alpha1-D plus beta1-adrenoceptors, indicative of sympathetic nervous system activation. Obese dams also had raised breast milk leptin levels compared to lean dams. CONCLUSIONS: Maternal obesity programs development of a dysmetabolic and NAFLD phenotype, which is critically dependent on the early postnatal period and possibly involving alteration of hypothalamic appetite nuclei signalling by maternal breast milk and neonatal adipose tissue derived, leptin.

Maternal obesity programmes offspring development of non-alcoholic fatty pancreas disease.

BACKGROUND AND AIMS: The prevalence of pancreatic adenocarcinoma (PAC) parallels rising rates of obesity and dysmetabolism, a possible link being non-alcoholic fatty pancreas disease (NAFPD). We have recently shown that maternal obesity programmes the development of a dysmetabolic and fatty liver (non-alcoholic fatty liver disease, NAFLD) phenotype in adult offspring. Since the pancreas and liver originate from the same embryonic bud, it is plausible that maternal obesity may similarly programme the development of NAFPD. Our objective was to determine the effect of maternal obesity on development of NAFPD in offspring and ascertain contributions of the intra/extra-uterine periods. METHODS: Female C57BL/6J mice were fed either a standard chow (3% fat, 7% sugar) or a hypercalorific diet (16% fat, 33% sugar) for six weeks prior to mating and throughout pregnancy and lactation. Female offspring were cross-fostered for suckling to dams on the same or opposite diet to yield four groups: offspring of lean suckled by lean dams (n=6), offspring of obese suckled by obese dams (n=6), offspring of lean suckled by obese dams (n=5) and offspring of obese suckled by lean dams (n=6). All offspring were weaned onto a standard chow diet at 21 days and sacrificed at 3 months post-partum for tissue collection. RESULTS: Offspring subjected to an adverse suckling environment showed significant increases in body weight, pancreatic triglyceride content, TGF-beta, collagen gene expression and SBP at rest along with an enhanced restraint stress response, indicating a dysmetabolic and NAFPD phenotype. CONCLUSIONS: Developmental programming is involved in the pathogenesis of NAFPD and appears to be largely dependent on an adverse extra-uterine environment.