scholarly journals Pharmacological Macrophage Attenuation by Imatinib Reverts Hepatic Steatosis and Inflammation in Obese Mice

2017 ◽  
Author(s):  
Shefaa AlAsfoor ◽  
Theresa V. Rohm ◽  
Angela J. T. Bosch ◽  
Thomas Dervos ◽  
Diego Calabrese ◽  
...  
Keyword(s):  
Hepatic Steatosis ◽  
Immune Modulation ◽  
Diabetic Patients ◽  
Human Monocytes ◽  
Obese Mice ◽  
Alcoholic Fatty Liver ◽  
Murine Macrophages ◽  
Beneficial Effects

AbstractAimsNon-alcoholic fatty liver disease (NAFLD) has become one of the most common liver diseases worldwide. As macrophages play a key role in NAFLD, therapies targeting macrophages have been postulated. Indeed, strategies depleting macrophages or blocking monocyte recruitment into the liver improve NAFLD, however, are not feasible in clinical practice. Our goal was to assess whether attenuation of macrophages can be achieved by imatinib, an anti-leukemia drug with known anti-inflammatory and anti-diabetic properties, and how this impacts NAFLD.Materials and MethodsMurine macrophages were polarized in vitro to different activation states in the presence or absence of imatinib; mice on high fat diet orally treated with imatinib or vehicle; and human monocytes of diabetic patients and healthy controls treated with or without imatinib for translational application.ResultsImatinib specifically attenuated pro-inflammatory murine macrophages in vitro and in vivo. In livers of obese mice, imatinib caused Kupffer cells to adopt an attenuated phenotype via modulation of the TNFα-pathway. This immune-modulation resulted in markedly improved hepatic steatosis along with beneficial effects on liver function, lipids and systemic inflammation. The immune-dampening effect of imatinib also prevailed in human monocytes, indicating translational applicability.ConclusionsImmune-modulation of myeloid cells as exemplified by imatinib may be a novel therapeutic strategy in patients with NAFLD.

scholarly journals The Role of AMPK/mTOR Signaling Pathway in Anticancer Activity of Metformin

2021 ◽  
pp. 501-508
Author(s):  
Nikola Chomanicova ◽  
Andrea Gazova ◽  
Adriana Adamickova ◽  
Simona Valaskova ◽  
Jan Kyselovic
Keyword(s):  
Anticancer Activity ◽  
Mammalian Target Of Rapamycin ◽  
Adenosine Monophosphate ◽  
Mtor Pathway ◽  
Diabetic Patients ◽  
Beneficial Effects ◽  
Treatment Of Diabetes

Metformin (MTF) is a widely used drug for the treatment of diabetes mellitus type 2 (DM2) and frequently used as an adjuvant therapy for polycystic ovarian syndrome, metabolic syndrome, and in some cases also tuberculosis. Its protective effect on the cardiovascular system has also been described. Recently, MTF was subjected to various analyzes and studies that showed its beneficial effects in cancer treatment such as reducing cancer cell proliferation, reducing tumor growth, inducing apoptosis, reducing cancer risk in diabetic patients, or reducing likelihood of relapse. One of the MTF’s mechanisms of action is the activation of adenosine-monophosphate-activated protein kinase (AMPK). Several studies have shown that AMPK/mammalian target of rapamycin (mTOR) pathway has anticancer effect in vivo and in vitro. The aim of this review is to present the anticancer activity of MTF highlighting the importance of the AMPK/mTOR pathway in the cancer process.

scholarly journals Naringin protects against non-alcoholic fatty liver disease by promoting autophagic flux and lipophagy

2021 ◽  
Author(s):  
Lingling Guan ◽  
Lan Guo ◽  
Heng Zhang ◽  
Hao Liu ◽  
Yuan Qiao ◽  
...  
Keyword(s):  
Liver Disease ◽  
Fatty Liver ◽  
Hepatic Steatosis ◽  
Fatty Liver Disease ◽  
Autophagic Flux ◽  
Mechanism Study ◽  
Alcoholic Fatty Liver ◽  
Alcoholic Fatty Liver Disease

Abstract Background and Purpose: The autophagic degradation of lipid droplets (LDs), termed lipophagy, is the main mechanism contributing to lipid consumption in hepatocytes. The identification of effective and safe natural compounds that target lipophagy to eliminate excess lipids may be a potential therapeutic strategy for non-alcoholic fatty liver disease (NAFLD). Here, we investigated the effects of naringin on NAFLD and the underlying mechanism. Experimental Approach: The role of naringin was investigated in mice fed a high-fat diet (HFD) to induce NAFLD, as well as in AML12 cells and primary hepatocytes stimulated by palmitate (PA). Transcription factor EB (TFEB)-knockdown AML12 cells and hepatocyte-specific TFEB-knockout mice were also used for the mechanism study. In vivo and in vitro studies were conducted using transmission electron microscopy, immunofluorescence techniques and western blot analysis. Key Results: We found that naringin treatment effectively relieved HFD-induced hepatic steatosis in mice and inhibited palmitate (PA)-induced lipid accumulation in hepatocytes. The increased p62 and LC3-II levels observed with excess lipid-support autophagosome accumulation and impaired autophagic flux. Treatment with naringin restored TFEB-mediated lysosomal biogenesis, thereby promoting the fusion of autophagosomes and lysosomes, restoring impaired autophagic flux and further inducing lipophagy. However, the knockdown of TFEB in hepatocytes or the hepatocyte-specific knockout of TFEB in mice abrogated naringin-induced lipophagy, which eliminated the therapeutic effect of naringin on hepatic steatosis. Conclusion and Implications: These results demonstrate that TFEB-mediated lysosomal biogenesis and subsequent lipophagy play essential roles in the ability of naringin to mitigate hepatic steatosis and suggest that naringin is a promising drug for treating or relieving NAFLD.

scholarly journals Resveratrol and Diabetic Cardiomyopathy: Focusing on the Protective Signaling Mechanisms

2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Yan-Jun Song ◽  
Chong-Bin Zhong ◽  
Wei Wu
Keyword(s):  
Diabetic Cardiomyopathy ◽  
Early Stage ◽  
Heart Diseases ◽  
Diabetic Patients ◽  
Beneficial Effects ◽  
Forkhead Box ◽  
Protective Signaling ◽  
Extracellular Regulated Protein Kinases

Diabetic cardiomyopathy (DCM) is a common cardiovascular complication of diabetic mellitus that is characterized by diastolic disorder in the early stage and clinical heart failure in the later stage. Presently, DCM is considered one of the major causes of death in diabetic patients. Resveratrol (RSV), a naturally occurring stilbene, is widely reported as a cardioprotective substance in many heart diseases. Thus far, the specific roles of RSV in DCM prevention and treatment have attracted great attention. Here, we discuss the roles of RSV in DCM by focusing its downstream targets from both in vivo and in vitro studies. Among such targets, Sirtuins 1/3 and AMP-activated kinase have been identified as key mediators that induce cardioprotection during hyperglycemia. In addition, many other signaling molecules (e.g., forkhead box-O3a and extracellular regulated protein kinases) are also regulated in the presence of RSV and exert beneficial effects such as opposing oxidative stress, inflammation, and apoptosis in cardiomyocytes exposed to high-glucose conditions. The beneficial potential of an RSV/stem cell cotherapy is also reviewed as a promising therapeutic strategy for preventing the development of DCM.

scholarly journals L-theanine Prevents Progression of Nonalcoholichepatic Steatosis by Regulating Hepatocyte Lipid Metabolic Pathways via the CaMKKβ-AMPK Signaling Pathway

2021 ◽  
Author(s):  
Juanjuan Liang ◽  
Lili Gu ◽  
Xianli Liu ◽  
Xintong Yan ◽  
Xiaowen Bi ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Protein Kinase ◽  
Signaling Pathway ◽  
Hepatic Steatosis ◽  
Metabolic Pathways ◽  
Alcoholic Fatty Liver ◽  
Ampk Signaling ◽  
Nonalcoholic Hepatic Steatosis

Abstract Background: L-theanine, a non-protein amino acid found principally in the green tea, has been previously shown to possess potent anti-obesity property and hepatoprotective effect. Herein, we investigated the effects of L-theanine on alleviating nonalcoholic hepatic steatosis in vitro and in vivo, and explored the underlying molecular mechanism. Methods: In vitro, HepG2 and AML12 cells were treated with 500 μM oleic acid (OA) or treated with OA accompanied by L-theanine. In vivo, C57BL/6J mice were fed with normal control diet (NCD), high‐fat diet (HFD), or HFD along with L-theanine for 16 weeks. The levels of TG, accumulation of lipid droplets and the expression of genes related to hepatocyte lipid metabolic pathways were detected in vitro and in vivo.Results: Our data indicated that, in vivo, L-theanine significantly reduced body weight, hepatic steatosis, serum levels of alanine transaminase (ALT), aspartate transaminase (AST), TG and LDL cholesterol (LDL-C) in HFD-induced Non-alcoholic fatty liver disease (NAFLD) mice. In vitro, L-theanine also significantly alleviated OA induced hepatocytes steatosis. Mechanic studies showed that L-theanine significantly inhibited the nucleus translocation of sterol regulatory element binding protein 1c (SREBP-1c) through AMPK-mTOR signaling pathway, thereby contributing to the reduction of fatty acid synthesis. We also identified that L-theanine enhanced fatty acid β-oxidation by increasing the expression of peroxisome proliferator–activated receptor α (PPARα) and carnitine palmitoyltransferase-1 A (CPT1A) through AMP-activated protein kinase (AMPK). Furthermore, our study indicated that L-theanine can active AMPK via its upstream kinase Calmodulin-dependent protein kinase kinase-β (CaMKKβ). Conclusions: Taken together, our findings suggest that L-theanine alleviates nonalcoholic hepatic steatosis by regulating hepatocyte lipid metabolic pathways via the CaMKKβ-AMPK signaling pathway.

scholarly journals Liraglutide Alleviates Hepatic Steatosis by Activating the TFEB-Regulated Autophagy-Lysosomal Pathway

2020 ◽  
Vol 8 ◽  
Author(s):  
Yunyun Fang ◽  
Linlin Ji ◽  
Chaoyu Zhu ◽  
Yuanyuan Xiao ◽  
Jingjing Zhang ◽  
...  
Keyword(s):  
Hepatic Steatosis ◽  
Lipid Accumulation ◽  
Underlying Mechanism ◽  
Autophagic Flux ◽  
Alcoholic Fatty Liver ◽  
Lipid Degradation ◽  
Hepatic Lipid Accumulation ◽  
Lysosome Biogenesis

Liraglutide, a glucagon-like peptide-1 receptor agonist (GLP-1RA), has been demonstrated to alleviate non-alcoholic fatty liver disease (NAFLD). However, the underlying mechanism has not been fully elucidated. Increasing evidence suggests that autophagy is involved in the pathogenesis of hepatic steatosis. In this study, we examined whether liraglutide could alleviate hepatic steatosis through autophagy-dependent lipid degradation and investigated the underlying mechanisms. Herein, the effects of liraglutide on NAFLD were evaluated in a high-fat diet (HFD)-induced mouse model of NAFLD as well as in mouse primary and HepG2 hepatocytes exposed to palmitic acid (PA). The expression of the GLP-1 receptor (GLP-1R) was measured in vivo and in vitro. Oil red O staining was performed to detect lipid accumulation in hepatocytes. Electron microscopy was used to observe the morphology of autophagic vesicles and autolysosomes. Autophagic flux activity was measured by infecting HepG2 cells with mRFP-GFP-LC3 adenovirus. The roles of GLP-1R and transcription factor EB (TFEB) in autophagy-lysosomal activation were explored using small interfering RNA. Liraglutide treatment alleviated hepatic steatosis in vivo and in vitro. In models of hepatic steatosis, microtubule-associated protein 1B light chain-3-II (LC3-II) and SQSTM1/P62 levels were elevated in parallel to blockade of autophagic flux. Liraglutide treatment restored autophagic activity by improving lysosomal function. Furthermore, treatment with autophagy inhibitor chloroquine weakened liraglutide-induced autophagy activation and lipid degradation. TFEB has been identified as a key regulator of lysosome biogenesis and autophagy. The protein levels of nuclear TFEB and its downstream targets CTSB and LAMP1 were decreased in hepatocytes treated with PA, and these decreases were reversed by liraglutide treatment. Knockdown of TFEB expression compromised the effects of liraglutide on lysosome biogenesis and hepatic lipid accumulation. Mechanistically, GLP-1R expression was decreased in HFD mouse livers as well as PA-stimulated hepatocytes, and liraglutide treatment reversed the downregulation of GLP-1R expression in vivo and in vitro. Moreover, GLP-1R inhibition could mimic the effect of the TFEB downregulation-mediated decrease in lysosome biogenesis. Thus, our findings suggest that liraglutide attenuated hepatic steatosis via restoring autophagic flux, specifically the GLP-1R-TFEB-mediated autophagy-lysosomal pathway.

scholarly journals miRNA-132 induces hepatic steatosis and hyperlipidaemia by synergistic multitarget suppression

Gut ◽  
2017 ◽  
Vol 67 (6) ◽  
pp. 1124-1134 ◽  
Author(s):  
Geula Hanin ◽  
Nadav Yayon ◽  
Yonat Tzur ◽  
Rotem Haviv ◽  
Estelle R Bennett ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Fatty Liver ◽  
Hepatic Steatosis ◽  
Mouse Models ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Obese Mice ◽  
Alcoholic Fatty Liver

ObjectiveBoth non-alcoholic fatty liver disease (NAFLD) and the multitarget complexity of microRNA (miR) suppression have recently raised much interest, but the in vivo impact and context-dependence of hepatic miR-target interactions are incompletely understood. Assessing the relative in vivo contributions of specific targets to miR-mediated phenotypes is pivotal for investigating metabolic processes.DesignWe quantified fatty liver parameters and the levels of miR-132 and its targets in novel transgenic mice overexpressing miR-132, in liver tissues from patients with NAFLD, and in diverse mouse models of hepatic steatosis. We tested the causal nature of miR-132 excess in these phenotypes by injecting diet-induced obese mice with antisense oligonucleotide suppressors of miR-132 or its target genes, and measured changes in metabolic parameters and transcripts.ResultsTransgenic mice overexpressing miR-132 showed a severe fatty liver phenotype and increased body weight, serum low-density lipoprotein/very low-density lipoprotein (LDL/VLDL) and liver triglycerides, accompanied by decreases in validated miR-132 targets and increases in lipogenesis and lipid accumulation-related transcripts. Likewise, liver samples from both patients with NAFLD and mouse models of hepatic steatosis or non-alcoholic steatohepatitis (NASH) displayed dramatic increases in miR-132 and varying decreases in miR-132 targets compared with controls. Furthermore, injecting diet-induced obese mice with anti-miR-132 oligonucleotides, but not suppressing its individual targets, reversed the hepatic miR-132 excess and hyperlipidemic phenotype.ConclusionsOur findings identify miR-132 as a key regulator of hepatic lipid homeostasis, functioning in a context-dependent fashion via suppression of multiple targets and with cumulative synergistic effects. This indicates reduction of miR-132 levels as a possible treatment of hepatic steatosis.

scholarly journals ERK-dependent mTOR pathway is involved in berberine-induced autophagy in hepatic steatosis

2016 ◽  
Vol 57 (4) ◽  
pp. 251-260 ◽  
Author(s):  
Qin He ◽  
Dan Mei ◽  
Sha Sha ◽  
Shanshan Fan ◽  
Lin Wang ◽  
...  
Keyword(s):  
Hepatic Steatosis ◽  
Lipid Accumulation ◽  
Mtor Pathway ◽  
Mice Model ◽  
Alcoholic Fatty Liver ◽  
Hepatic Lipid ◽  
Hepatic Lipid Accumulation ◽  
Positive Effects

Non-alcoholic fatty liver disease (NAFLD) is a burgeoning health problem and is considered as a hepatic manifestation of metabolic syndrome. Increasing evidence demonstrates that berberine (BBR), a natural plant alkaloid, is beneficial for obesity-associated NAFLD. However, the mechanisms about how BBR improves hepatic steatosis remain uncertain. Recently, some reports revealed that enhanced autophagy could decrease hepatic lipid accumulation. In this study, we first established a high-fed diet (HFD) mice model and oleate–palmitate-induced lipotoxicity hepatocytes to explore the association among BBR, autophagy and hepatic steatosis. Our data demonstrated that BBR had profound effects on improving hepatic lipid accumulation bothin vivoandin vitro, and led to high autophagy flux. The molecular alterations proceeding these changes were characterized by inhibition of the ERK/mTOR pathway. These findings suggest an important mechanism for the positive effects of BBR on hepatic steatosis, and may provide new evidence for the clinical use of BBR in NAFLD.

Reliability of a Single β-Thromboglobulin Measurement in a Diabetic Population : Importance of PGE1 in Anticoagulant Mixture

1987 ◽  
Vol 57 (02) ◽  
pp. 201-204 ◽  
Author(s):  
P Y Scarabin ◽  
L Strain ◽  
C A Ludlam ◽  
J Jones ◽  
E M Kohner
Keyword(s):  
In Vitro Release ◽  
Mean Value ◽  
Reliable Estimate ◽  
Diabetic Patients ◽  
Single Measurement ◽  
Diabetic Population ◽  
The Difference ◽  
Vitro Release

SummaryDuring the collection of samples for plasma β-thromboglobulin (β-TG) determination, it is well established that artificially high values can be observed due to in-vitro release. To estimate the reliability of a single β-TG measurement, blood samples were collected simultaneously from both arms on two separate occasions in 56 diabetic patients selected for a clinical trial. From each arm, blood was taken into two tubes containing an anticoagulant mixture with (tube A) and without (tube B) PGE!. The overall mean value of B-TG in tube B was 1.14 times higher than in tube A (p <0.01). The markedly large between-arms variation accounted for the most part of within-subject variation in both tubes and was significantly greater in tube B than in tube A. Based on the difference between B-TG values from both arms, the number of subjects with artifically high B-TG values was significantly higher in tube B than in tube A on each occasion (overall rate: 28% and 14% respectively). Estimate of between-occasions variation showed that B-TG levels were relatively stable for each subject between two occasions in each tube. It is concluded that the use of PGEi decreases falsely high B-TG levels, but a single measurement of B-TG does not provide a reliable estimate of the true B-TG value in vivo.

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