Role of ceramide in hepatic lipid accumulation in rats with non-alcoholic fatty liver disease

2015 ◽  
Vol 23 (32) ◽  
pp. 5196
Author(s):  
Yang Hu
Author(s):  
Ahmed Ayyash ◽  
Alison C Holloway

Fluoxetine, a commonly prescribed selective serotonin reuptake inhibitor antidepressant, has been shown to increase hepatic lipid accumulation, a key factor in the development of non-alcoholic fatty liver disease. Interestingly, fluoxetine has also been reported to increase peripheral serotonin synthesis. As emerging evidence suggests that serotonin may be involved in the development of non-alcoholic fatty liver disease we sought to determine if fluoxetine-induced hepatic lipid accumulation is mediated via altered serotonin production. Fluoxetine treatment increased lipid accumulation in association with increased mRNA expression of tryptophan hydroxylase 1 (<i>Tph1, serotonin biosynthetic enzyme) and intracellular serotonin content. Serotonin alone had a similar effect to increase lipid accumulation. Moreover, blocking serotonin synthesis reversed the fluoxetine-induced increases in lipid accumulation. Collectively, these data suggest that fluoxetine induced lipid accumulation can be mediated, in part, by elevated serotonin production. These results suggest a potential therapeutic target to ameliorate the adverse metabolic effects of fluoxetine exposure.


Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1458
Author(s):  
Po-An Hu ◽  
Chia-Hui Chen ◽  
Bei-Chia Guo ◽  
Yu Ru Kou ◽  
Tzong-Shyuan Lee

We aimed to investigate the effect of bromelain, the extract from stems of pineapples on the high-fat diet (HFD)-induced deregulation of hepatic lipid metabolism and non-alcoholic fatty liver disease (NAFLD), and its underlying mechanism in mice. Mice were daily administrated with HFD with or without bromelain (20 mg/kg) for 12 weeks, and we found that bromelain decreased the HFD-induced increase in body weight by ~30%, organ weight by ~20% in liver weight and ~40% in white adipose tissue weight. Additionally, bromelain attenuated HFD-induced hyperlipidemia by decreasing the serum level of total cholesterol by ~15% and triglycerides level by ~25% in mice. Moreover, hepatic lipid accumulation, particularly that of total cholesterol, free cholesterol, triglycerides, fatty acids, and glycerol, was decreased by 15–30% with bromelain treatment. Mechanistically, these beneficial effects of bromelain on HFD-induced hyperlipidemia and hepatic lipid accumulation may be attributed to the decreased fatty acid uptake and cholesteryl ester synthesis and the increased lipoprotein internalization, bile acid metabolism, cholesterol clearance, the assembly and secretion of very low-density lipoprotein, and the β-oxidation of fatty acids by regulating the protein expression involved in the above mentioned hepatic metabolic pathways. Collectively, these findings suggest that bromelain has therapeutic value for treating NAFLD and metabolic diseases.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yong Zou ◽  
Zhengtang Qi

Nonalcoholic fatty liver disease (NAFLD) is globally prevalent and characterized by abnormal lipid accumulation in the liver, frequently accompanied by insulin resistance (IR), enhanced hepatic inflammation, and apoptosis. Recent studies showed that endoplasmic reticulum stress (ERS) at the subcellular level underlies these featured pathologies in the development of NAFLD. As an effective treatment, exercise significantly reduces hepatic lipid accumulation and thus alleviates NAFLD. Confusingly, these benefits of exercise are associated with increased or decreased ERS in the liver. Further, the interaction between diet, medication, exercise types, and intensity in ERS regulation is more confusing, though most studies have confirmed the benefits of exercise. In this review, we focus on understanding the role of exercise-modulated ERS in NAFLD and ERS-linked molecular pathways. Moderate ERS is an essential signaling for hepatic lipid homeostasis. Higher ERS may lead to increased inflammation and apoptosis in the liver, while lower ERS may lead to the accumulation of misfolded proteins. Therefore, exercise acts like an igniter or extinguisher to keep ERS at an appropriate level by turning it up or down, which depends on diet, medications, exercise intensity, etc. Exercise not only enhances hepatic tolerance to ERS but also prevents the malignant development of steatosis due to excessive ERS.


2021 ◽  
Author(s):  
Zheng Lu ◽  
Lu Liu ◽  
Shunxin Zhao ◽  
Jiangtao Zhao ◽  
Sujun Li

Abstract Background: Apigenin, a flavone found in several plant foods with various biological properties including anti-inflammatory and other abilities, alleviated non-alcohol fatty liver disease (NAFLD) induced by a high fat diet (HFD) in mice. However, the mechanisms underlying this protection of inflammation and NAFLD has not been known clearly. Methods: Low density lipoprotein receptor-deficient (Ldlr-/-) mice were fed with HFD diet to induce NAFLD model and were treated with apigenin (50 mg/kg/day) for eight weeks. Hepatic lipid accumulation and inflammation in the livers were analyzed and quantified. In vitro experiments, HepG2 cells were stimulated by LPS plus oleic acid (OA) in the absence of presence of apigenin (50μM). Lipid accumulation and the effect of apigenin on NLRP3/NF-κB signaling pathway was investigated.Results: Apigenin administration reduce the weight, plasma lipid levels in Ldlr-/- mice when fed an HFD. Apigenin (50 mg/kg/day) treated mice displayed reduced hepatic lipid accumulation and inflammation in the livers of mice given the HFD diet. Treating the HepG2 cells with apigenin reduced lipid accumulation. And, apigenin also inhibited activation of NLRP3/NF-κB signaling pathway stimulated by OA together with LPS. Conclusions: Our results indicated that apigenin supplementation prevented NAFLD via down-regulating the NLRP3/NF-κB signaling pathway in mice, and suggested apigenin might be a potential therapeutic agent for the prevention of NAFLD.


2021 ◽  
Author(s):  
Zuyin Li ◽  
Gang Wu ◽  
Chen Qiu ◽  
Zhijie Zhou ◽  
Yupeng Wang ◽  
...  

Abstract Background and aims : Lack of effective pharmacotherapies for nonalcoholic fatty liver disease (NAFLD) is mainly attributed to an insufficient research on its pathogenesis. In this paper, we investigated the role of TM6SF2 on fatty acid metabolism in the background of fatty liver, and proposed the possible therapeutic strategies of NAFLD caused by TM6SF2 deficiency. Methods Liver samples collected from both NAFLD mouse models and human subjects, and RNA-seq data retrieved from GEO database were used to evaluate the expression of TM6SF2 in NAFLD. Knockdown of TM6SF2 was performed for clarifying the mechanistic basis of hepatic lipid accumulation in NAFLD. After confirming that TM6SF2 deficiency would cause an abnormality in fatty acid metabolism, MK-4074 administration served as the therapeutic intervention to evaluate its effect on NAFLD caused by TM6SF2 deficiency. Results Hepatic TM6SF2 levels are elevated in both NAFLD patients and mouse NAFLD models. In vivo and in vitro experiments confirmed that TM6SF2 knockdown increases intracellular lipid deposition due to dysregulated fatty acid metabolism in the context of TM6SF2 deficiency, being characterized by enhanced fatty acid uptake and synthesis, accompanied by impaired fatty acid oxidation. Moreover, MK-4074 treatment could reverse the NAFLD phenotypes caused by TM6SF2 deficiency. Conclusions TM6SF2 deficiency enhanced hepatic lipid accumulation through dysregulated fatty acid metabolism and MK-4074 treatment could alleviate the NAFLD phenotypes caused by TM6SF2 deficiency.


Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 565
Author(s):  
Susara Madduma Hewage ◽  
Suvira Prashar ◽  
Karmin O ◽  
Yaw L. Siow

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease globally and there is a pressing need for effective treatment. Lipotoxicity and oxidative stress are the important mediators in NAFLD pathogenesis. Lingonberry (Vaccinium vitis-idaea L.) is rich in anthocyanins that have antioxidant and anti-inflammatory properties. The present study investigated the effect of lingonberry supplementation on liver injury in C57BL/6J male mice fed a high-fat diet (HFD) for 12 weeks. Mice fed HFD displayed liver injury with steatosis, increased lipid peroxidation and inflammatory cytokine expression in the liver as compared to mice fed a control diet. Lingonberry supplementation for 12 weeks alleviated HFD-induced liver injury, attenuated hepatic lipid accumulation, and inflammatory cytokine expression. Lingonberry supplementation inhibited the expression of sterol regulatory element-binding protein-1c (SREBP-1c) and acetyl-CoA carboxylase-1 (AAC-1) as well as activated AMP-activated protein kinase (AMPK) in the liver. It also decreased HFD-induced hepatic oxidative stress and aggregation of inflammatory foci. This was associated with a restoration of nuclear factor erythroid 2–related factor 2 (Nrf2) and glutathione level in the liver. These results suggest that lingonberry supplementation can protect against HFD-induced liver injury partly through attenuation of hepatic lipid accumulation, oxidative stress, and inflammatory response.


2021 ◽  
Vol 11 ◽  
Author(s):  
Aldo Grefhorst ◽  
Ivo P. van de Peppel ◽  
Lars E. Larsen ◽  
Johan W. Jonker ◽  
Adriaan G. Holleboom

Non-alcoholic fatty liver disease (NAFLD) or metabolic (dysfunction) associated liver disease (MAFLD), is, with a global prevalence of 25%, the most common liver disorder worldwide. NAFLD comprises a spectrum of liver disorders ranging from simple steatosis to steatohepatitis, fibrosis, cirrhosis and eventually end-stage liver disease. The cause of NAFLD is multifactorial with genetic susceptibility and an unhealthy lifestyle playing a crucial role in its development. Disrupted hepatic lipid homeostasis resulting in hepatic triglyceride accumulation is an hallmark of NAFLD. This disruption is commonly described based on four pathways concerning 1) increased fatty acid influx, 2) increased de novo lipogenesis, 3) reduced triglyceride secretion, and 4) reduced fatty acid oxidation. More recently, lipophagy has also emerged as pathway affecting NAFLD development and progression. Lipophagy is a form of autophagy (i.e. controlled autolysosomal degradation and recycling of cellular components), that controls the breakdown of lipid droplets in the liver. Here we address the role of hepatic lipid homeostasis in NAFLD and specifically review the current literature on lipophagy, describing its underlying mechanism, its role in pathophysiology and its potential as a therapeutic target.


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