Impact of PPAR-α induction on glucose homoeostasis in alcohol-fed mice

2013 ◽  
Vol 125 (11) ◽  
pp. 501-511 ◽  
Author(s):  
Valérie Lebrun ◽  
Olivier Molendi-Coste ◽  
Nicolas Lanthier ◽  
Christine Sempoux ◽  
Patrice D. Cani ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Liver Disease ◽  
Insulin Sensitivity ◽  
Alcohol Consumption ◽  
Insulin Signalling ◽  
Liver Steatosis ◽  
Hepatic Insulin Resistance ◽  
Alcoholic Fatty Liver ◽  
Glucose Homoeostasis

Alcohol consumption is a major cause of liver disease. It also associates with increased cardiovascular risk and Type 2 diabetes. ALD (alcoholic liver disease) and NAFLD (non-alcoholic fatty liver disease) share pathological features, pathogenic mechanisms and pattern of disease progression. In NAFLD, steatosis, lipotoxicity and liver inflammation participate to hepatic insulin resistance. The aim of the present study was to verify the effect of alcohol on hepatic insulin sensitivity and to evaluate the role of alcohol-induced steatosis and inflammation on glucose homoeostasis. C57BL/6J mice were fed for 20 days a modified Lieber–DeCarli diet in which the alcohol concentration was gradually increased up to 35% of daily caloric intake. OH (alcohol liquid diet)-fed mice had liver steatosis and inflammatory infiltration. In addition, these mice developed insulin resistance in the liver, but not in muscles, as demonstrated by euglycaemic–hyperinsulinaemic clamp and analysis of the insulin signalling cascade. Treatment with the PPAR-α (peroxisome-proliferator-activated receptor-α) agonist Wy14,643 protected against OH-induced steatosis and KC (Kupffer cell) activation and almost abolished OH-induced insulin resistance. As KC activation may modulate insulin sensitivity, we repeated the clamp studies in mice depleted in KC to decipher the role of macrophages. Depletion of KC using liposomes-encapsuled clodronate in OH-fed mice failed both to improve hepatic steatosis and to restore insulin sensitivity as assessed by clamp. Our study shows that chronic alcohol consumption induces steatosis, KC activation and hepatic insulin resistance in mice. PPAR-α agonist treatment that prevents steatosis and dampens hepatic inflammation also prevents alcohol-induced hepatic insulin resistance. However, KC depletion has little impact on OH-induced metabolic disturbances.

scholarly journals Role of Insulin Resistance in MAFLD

2021 ◽  
Vol 22 (8) ◽  
pp. 4156
Author(s):  
Yoshitaka Sakurai ◽  
Naoto Kubota ◽  
Toshimasa Yamauchi ◽  
Takashi Kadowaki
Keyword(s):  
Insulin Resistance ◽  
Liver Disease ◽  
Fatty Liver ◽  
Fatty Liver Disease ◽  
De Novo Lipogenesis ◽  
Hepatic Insulin Resistance ◽  
Metabolic Dysfunction ◽  
Alcoholic Fatty Liver ◽  
Fat Accumulation

Many studies have reported that metabolic dysfunction is closely involved in the complex mechanism underlying the development of non-alcoholic fatty liver disease (NAFLD), which has prompted a movement to consider renaming NAFLD as metabolic dysfunction-associated fatty liver disease (MAFLD). Metabolic dysfunction in this context encompasses obesity, type 2 diabetes mellitus, hypertension, dyslipidemia, and metabolic syndrome, with insulin resistance as the common underlying pathophysiology. Imbalance between energy intake and expenditure results in insulin resistance in various tissues and alteration of the gut microbiota, resulting in fat accumulation in the liver. The role of genetics has also been revealed in hepatic fat accumulation and fibrosis. In the process of fat accumulation in the liver, intracellular damage as well as hepatic insulin resistance further potentiates inflammation, fibrosis, and carcinogenesis. Increased lipogenic substrate supply from other tissues, hepatic zonation of Irs1, and other factors, including ER stress, play crucial roles in increased hepatic de novo lipogenesis in MAFLD with hepatic insulin resistance. Herein, we provide an overview of the factors contributing to and the role of systemic and local insulin resistance in the development and progression of MAFLD.

scholarly journals Beneficial effect of omarigliptin on diabetic patients with non-alcoholic fatty liver disease/non-alcoholic steatohepatitis

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Sachiko Hattori ◽  
Kazuomi Nomoto ◽  
Tomohiko Suzuki ◽  
Seishu Hayashi
Keyword(s):  
Insulin Resistance ◽  
Liver Disease ◽  
Liver Function ◽  
Fatty Liver ◽  
Fatty Liver Disease ◽  
Hepatic Insulin Resistance ◽  
Diabetic Patients ◽  
Alcoholic Fatty Liver ◽  
Dpp4 Inhibitor ◽  
Alcoholic Fatty Liver Disease

Abstract Background Dipeptidyl peptidase 4 (DPP4) is a serine exopeptidase able to inactivate various oligopeptides, and also a hepatokine. Hepatocyte-specific overexpression of DPP4 is associated with hepatic insulin resistance and liver steatosis. Method We examined whether weekly DPP4 inhibitor omarigliptin (OMG) can improve liver function as well as levels of inflammation and insulin resistance in type 2 diabetic patients with non-alcoholic fatty liver disease (NAFLD). Further, we investigated the effects of OMG in a diabetic patient with biopsy-confirmed nonalcoholic steatohepatitis (NASH). Results In NAFLD patients, OMG significantly decreased levels of aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, homeostatic model assessment of insulin resistance (HOMA-IR), and high-sensitivity C-reactive protein (hsCRP), while no significant change was seen in hemoglobin A1c or body mass index. In the NASH patient, liver function improved markedly, and levels of the hepatic fibrosis marker FIB-4 decreased in parallel with HOMA-IR and hsCRP. Slight but clear improvements in intrahepatic fat deposition and fibrosis appeared to be seen on diagnostic ultrasonography. Conclusion Weekly administration of the DPP4 inhibitor OMG in ameliorating hepatic insulin resistance may cause beneficial effects in liver with NAFLD/NASH.

scholarly journals Hepatic Insulin Resistance Is Not Pathway Selective in Humans With Nonalcoholic Fatty Liver Disease

2020 ◽  
Author(s):  
Kasper W. ter Horst ◽  
Daniel F. Vatner ◽  
Dongyan Zhang ◽  
Gary W. Cline ◽  
Mariette T. Ackermans ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Bariatric Surgery ◽  
Liver Disease ◽  
Fatty Liver ◽  
Insulin Signaling ◽  
Fatty Liver Disease ◽  
De Novo ◽  
Glucose Production ◽  
Hepatic Insulin Resistance ◽  
Alcoholic Fatty Liver

<b>Objective</b>: Both glucose and triglyceride production are increased in Type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). For decades, the leading hypothesis to explain these paradoxical observations has been selective hepatic insulin resistance, wherein insulin drives <i>de novo</i> lipogenesis (DNL), while failing to suppress glucose production. Here, we aimed to test this hypothesis in humans. <p><b>Research Design and Methods</b>: We recruited obese subjects who met criteria for bariatric surgery with (n=16) or without (n=15) NAFLD and assessed: i) insulin-mediated regulation of hepatic and peripheral glucose metabolism using hyperinsulinemic-euglycemic clamps with [6,6-<sup>2</sup>H<sub>2</sub>]glucose, ii) fasting and carbohydrate-driven hepatic DNL using deuterated water (<sup>2</sup>H<sub>2</sub>O), and iii) hepatocellular insulin signaling in liver biopsies collected during bariatric surgery.</p> <p><b>Results</b>: As compared with subjects without NAFLD, subjects with NAFLD demonstrated impaired insulin-mediated suppression of glucose production and attenuated -not increased- glucose-stimulated/high-insulin lipogenesis. Fructose-stimulated/low-insulin lipogenesis was intact. Hepatocellular insulin signaling, assessed for the first time in humans, exhibited a proximal block in insulin-resistant subjects: signaling was attenuated from the level of the insulin receptor through both glucose <i>and</i> lipogenesis pathways. The carbohydrate-regulated lipogenic transcription factor <i>ChREBP</i> was increased in subjects with NAFLD. </p> <b>Conclusions</b>: Acute increases in lipogenesis in humans with NAFLD are not explained by altered molecular regulation of lipogenesis through a paradoxical increase in lipogenic insulin action; rather, increases in lipogenic substrate availability may be the key. <a></a>

scholarly journals Duration of rise in free fatty acids determines salicylate's effect on hepatic insulin sensitivity

2013 ◽  
Vol 217 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Sandra Pereira ◽  
Wen Qin Yu ◽  
María E Frigolet ◽  
Jacqueline L Beaudry ◽  
Yaniv Shpilberg ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Muscle Protein ◽  
Hepatic Insulin Resistance ◽  
Skeletal Muscle Protein ◽  
Protein Levels ◽  
Peripheral Insulin Resistance ◽  
Plasma Ffa ◽  
A Site

We have shown in rats that sodium salicylate (SS), which inhibits IkBa kinase B (IKKB), prevents hepatic and peripheral insulin resistance caused by short-term (7 h) i.v. administration of Intralipid and heparin (IH). We wished to further determine whether this beneficial effect of SS persisted after prolonged (48 h) IH infusion, which better mimics the chronic free fatty acid (FFA) elevation of obesity. Hence, we performed hyperinsulinemic euglycemic clamps with tritiated glucose methodology to determine hepatic and peripheral insulin sensitivity in rats infused with saline, IH, IH and SS, or SS alone. SS prevented peripheral insulin resistance (P<0.05) caused by prolonged plasma FFA elevation; however, it did not prevent hepatic insulin resistance. In skeletal muscle, protein levels of phospho-IkBa were augmented by prolonged IH administration and this was prevented by SS, suggesting that IH activates while SS prevents the activation of IKKB. Markers of IKKB activation, namely protein levels of phospho-IkBa and IkBa, indicated that IKKB is not activated in the liver after prolonged FFA elevation. Phosphorylation of serine 307 at insulin receptor substrate (IRS)-1, which is a marker of proximal insulin resistance, was not altered by IH administration in the liver, suggesting that this is not a site of hepatic insulin resistance in the prolonged lipid infusion model. Our results suggest that the role of IKKB in fat-induced insulin resistance is time and tissue dependent and that hepatic insulin resistance induced by prolonged lipid elevation is not due to an IRS-1 serine 307 kinase.

scholarly journals Hexanoic, Octanoic and Decanoic Acids Promote Basal and Insulin-Induced Phosphorylation of the Akt-mTOR Axis and a Balanced Lipid Metabolism in the HepG2 Hepatoma Cell Line

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2315 ◽  
Author(s):  
Sabri Rial ◽  
Gaetan Ravaut ◽  
Tommy Malaret ◽  
Karl-F. Bergeron ◽  
Catherine Mounier
Keyword(s):  
Insulin Resistance ◽  
Fatty Acids ◽  
Prolonged Exposure ◽  
Hepatoma Cell ◽  
Liver Steatosis ◽  
Hepatic Insulin Resistance ◽  
Hepatoma Cell Line ◽  
Alcoholic Fatty Liver ◽  
Insulin Dependent ◽  
Chain Fatty Acids

Metabolic illnesses such as non-alcoholic fatty liver disease (NAFLD) are in constant increase worldwide. Highly consumed long chain fatty acids (LCFA) are among the most obesogenic and steatogenic nutrients. Hepatic steatosis is associated with several complications such as insulin resistance. Growing evidence points to medium chain fatty acids (MCFA), more efficiently oxidized than LCFA, as a promising dietary alternative against NAFLD. However, reports on the hepatic effects of MCFA are sometimes conflicting. In this study we exposed HepG2 cells, a human hepatocellular model, to 0.25 mM of hexanoic (C6), or octanoic (C8), and decanoic (C10) acids separately or in a C8 + C10 equimolar mix reflecting commercially available MCFA-rich oils. We found that C6, a poorly studied MCFA, as well as C8 and C10 did not provoke the deleterious lipid anabolism runaway typically induced by LCFA palmitate. MCFA tended, instead, to promote a balanced metabolic profile and were generally non-cytotoxic. Accordingly, mitochondrial integrity was mostly preserved following MCFA treatment. However, treatments with C8 induced a mitochondrial membrane potential decrease, suggesting prolonged exposure to this lipid could be problematic. Finally, MCFA treatments maintained optimal insulin sensitivity and even fostered basal and insulin-dependent phosphorylation of the Akt-mTOR pathway. Overall, MCFA could constitute an effective nutritional tool to manage liver steatosis and hepatic insulin resistance.

scholarly journals Role of Cannabinoid Receptor Type 1 in Insulin Resistance and Its Biological Implications

2019 ◽  
Vol 20 (9) ◽  
pp. 2109 ◽  
Author(s):  
Arulkumar Nagappan ◽  
Jooyeon Shin ◽  
Myeong Ho Jung
Keyword(s):  
Insulin Resistance ◽  
Body Weight ◽  
Insulin Sensitivity ◽  
Hepatic Steatosis ◽  
Cannabinoid Receptor ◽  
Inflammatory Responses ◽  
Hepatic Insulin Resistance ◽  
Leptin Resistance ◽  
Peripheral Tissues

Endogenous cannabinoids (ECs) are lipid-signaling molecules that specifically bind to cannabinoid receptor types 1 and 2 (CB1R and CB2R) and are highly expressed in central and many peripheral tissues under pathological conditions. Activation of hepatic CB1R is associated with obesity, insulin resistance, and impaired metabolic function, owing to increased energy intake and storage, impaired glucose and lipid metabolism, and enhanced oxidative stress and inflammatory responses. Additionally, blocking peripheral CB1R improves insulin sensitivity and glucose metabolism and also reduces hepatic steatosis and body weight in obese mice. Thus, targeting EC receptors, especially CB1R, may provide a potential therapeutic strategy against obesity and insulin resistance. There are many CB1R antagonists, including inverse agonists and natural compounds that target CB1R and can reduce body weight, adiposity, and hepatic steatosis, and those that improve insulin sensitivity and reverse leptin resistance. Recently, the use of CB1R antagonists was suspended due to adverse central effects, and this caused a major setback in the development of CB1R antagonists. Recent studies, however, have focused on development of antagonists lacking adverse effects. In this review, we detail the important role of CB1R in hepatic insulin resistance and the possible underlying mechanisms, and the therapeutic potential of CB1R targeting is also discussed.

Mo1016 Role of Oxidative Stress and Insulin Resistance in the Disease Severity of Non-Alcoholic Fatty Liver Disease

2013 ◽  
Vol 144 (5) ◽  
pp. S-1013
Author(s):  
Billur Canbakan ◽  
Hakan Senturk ◽  
Murat Tuncer ◽  
Ibrahim Hatemi ◽  
Emine Koroglu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Liver Disease ◽  
Fatty Liver ◽  
Disease Severity ◽  
Fatty Liver Disease ◽  
Alcoholic Fatty Liver ◽  
Alcoholic Fatty Liver Disease

scholarly journals Insulin resistance is positively associated with plasma cathepsin D activity in NAFLD patients

2021 ◽  
Vol 12 (1) ◽  
pp. 110-115
Author(s):  
Lingling Ding ◽  
Toon. J. I. De Munck ◽  
Yvonne Oligschlaeger ◽  
Jef Verbeek ◽  
Ger. H. Koek ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Liver Disease ◽  
Cathepsin D ◽  
Fatty Liver Disease ◽  
Plasma Insulin ◽  
Hepatic Insulin Resistance ◽  
Alcoholic Fatty Liver ◽  
Plasma Insulin Levels ◽  
Cathepsin D Activity ◽  
Alcoholic Fatty Liver Disease

Abstract Previous studies associated plasma cathepsin D (CTSD) activity with hepatic insulin resistance in overweight and obese humans. Insulin resistance is a major feature of non-alcoholic fatty liver disease (NAFLD) and is one of the multiple hits determining the progression towards non-alcoholic steatohepatitis (NASH). In line, we have previously demonstrated that plasma CTSD levels are increased in NASH patients. However, it is not known whether insulin resistance associates with plasma CTSD activity in NAFLD. To increase our understanding regarding the mechanisms by which insulin resistance mediates NAFLD, fifty-five liver biopsy or MRI-proven NAFLD patients (BMI>25kg/m2) were included to investigate the link between plasma CTSD activity to insulin resistance in NAFLD. We concluded that HOMA-IR and plasma insulin levels are independently associated with plasma CTSD activity in NAFLD patients (standardized coefficient β: 0.412, 95% Cl: 0.142~0.679, p=0.004 and standardized coefficient β: 0.495, 95% Cl: 0.236~0.758, p=0.000, respectively). Together with previous studies, these data suggest that insulin resistance may link to NAFLD via elevation of CTSD activity in plasma. As such, these data pave the way for testing CTSD inhibitors as a pharmacological treatment of NAFLD.

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