scholarly journals Chronic Transient Hypoxia Alleviates High Fat Diet-Induced Obesity and Fatty Liver in C57 Mice by Upregulating Epinephrine Levels and Activation of AMPK

Author(s):  
Yunfei Luo ◽  
Zhijun Luo

Abstract Background According to epidemiologic studies, it was found that people living in high altitude areas have a lower prevalence of obesity and diabetes, and the main environmental differences between high altitude areas and plain areas are temperature and oxygen concentration. In this study, we investigated the effect of chronic transient hypoxia on obesity and fatty liver caused by high-fat diet in mice. Methods Put the mice under 10% oxygen concentration for 1 hour every day, this method is different from high altitude hypoxia and will not cause a series of acute altitude sicknesses. Intraperitoneal injection of epinephrine or propranolol was employed to examine the effect of chronic transient hypoxia on HFD-induced obesity, hyperglycemia and hepatic lipid accumulation. Results It showed that chronic transient hypoxia environment reduces the weight of mice and improve glucose tolerance, reduce the fat content of mice and alleviate fatty liver, reduces liver fat synthesis, promotes the expression M2 phenotype of macrophage genes in liver and thermogenic genes in brown fat. Furthermore, we showed that blocking the rise of epinephrine will compromise the chronic transient hypoxia environment beneficial ability to obesity and fatty liver, diminished expression of the liver AMPK phosphorylation and CD206. Conclusions These results suggest that chronic transient hypoxia activation of AMPK, induction of M2 type macrophage marker CD206 expression in the liver leads to significant weight loss and remission the severity of fatty liver through the adrenergic system.

2013 ◽  
Vol 305 (8) ◽  
pp. E987-E998 ◽  
Author(s):  
K. Tajima ◽  
A. Nakamura ◽  
J. Shirakawa ◽  
Y. Togashi ◽  
K. Orime ◽  
...  

The prevalence of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) is increasing with the growing epidemics of obesity and diabetes. NAFLD encompasses a clinicopathologic spectrum of disease ranging from isolated hepatic steatosis to NASH, which is a more aggressive form of fatty liver disease, to cirrhosis and, finally, hepatocellular carcinoma (HCC). The exact mechanism behind the development of HCC in NASH remains unclear; however, it has been established that hepatic steatosis is the important risk factor in the development of HCC. Metformin has recently drawn attention because of its potential antitumor effect. Here, we investigated the effects of metformin on high-fat diet (HFD)-induced liver tumorigenesis, using a mouse model of NASH and liver tumor. Metformin prevented long-term HFD-induced liver tumorigenesis in C57Bl/6 mice. Of note, metformin failed to protect against liver tumorigenesis in mice that had already begun to develop NAFLD. Metformin improved short-term HFD-induced fat accumulation in the liver, associated with the suppression of adipose tissue inflammation. Collectively, these results suggest that metformin may prevent liver tumorigenesis via suppression of liver fat accumulation in the early stage, before the onset of NAFLD, which seems to be associated with a delay in the development of inflammation of the adipose tissue.


2019 ◽  
Vol 8 ◽  
Author(s):  
Paola Vitaglione ◽  
Giovanna Mazzone ◽  
Vincenzo Lembo ◽  
Giuseppe D'Argenio ◽  
Antonella Rossi ◽  
...  

AbstractCoffee consumption is inversely associated with the risk of non-alcoholic fatty liver disease (NAFLD). A gap in the literature still exists concerning the intestinal mechanisms that are involved in the protective effect of coffee consumption towards NAFLD. In this study, twenty-four C57BL/6J mice were divided into three groups each receiving a standard diet, a high-fat diet (HFD) or an HFD plus decaffeinated coffee (HFD+COFFEE) for 12 weeks. Coffee supplementation reduced HFD-induced liver macrovesicular steatosis (P < 0·01) and serum cholesterol (P < 0·001), alanine aminotransferase and glucose (P < 0·05). Accordingly, liver PPAR- α (P < 0·05) and acyl-CoA oxidase-1 (P < 0·05) as well as duodenal ATP-binding cassette (ABC) subfamily A1 (ABCA1) and subfamily G1 (ABCG1) (P < 0·05) mRNA expressions increased with coffee consumption. Compared with HFD animals, HFD+COFFEE mice had more undigested lipids in the caecal content and higher free fatty acid receptor-1 mRNA expression in the duodenum and colon. Furthermore, they showed an up-regulation of duodenal and colonic zonulin-1 (P < 0·05), duodenal claudin (P < 0·05) and duodenal peptide YY (P < 0·05) mRNA as well as a higher abundance of Alcaligenaceae in the faeces (P < 0·05). HFD+COFFEE mice had an energy intake comparable with HFD-fed mice but starting from the eighth intervention week they gained significantly less weight over time. Data altogether showed that coffee supplementation prevented HFD-induced NAFLD in mice by reducing hepatic fat deposition and metabolic derangement through modification of pathways underpinning liver fat oxidation, intestinal cholesterol efflux, energy metabolism and gut permeability. The hepatic and metabolic benefits induced by coffee were accompanied by changes in the gut microbiota.


2021 ◽  
Vol 8 ◽  
Author(s):  
Feng-Li Zhang ◽  
Ya-Lin Yang ◽  
Zhen Zhang ◽  
Yuan-Yuan Yao ◽  
Rui Xia ◽  
...  

Fatty liver and intestinal barrier damage were widespread in most farmed fish, which severely restrict the development of aquaculture. Therefore, there was an urgent need to develop green feed additives to maintain host liver and intestinal health. In this study, a probiotic pili-like protein, Amuc_1100 (AM protein), was anchored to the surface of Lactococcus lactis ZHY1, and the effects of the recombinant bacteria AM-ZHY1 on liver fat accumulation and intestinal health were evaluated. Zebrafish were fed a basal diet, high-fat diet, and high-fat diet with AM-ZHY1 (108 cfu/g) or control bacteria ZHY1 for 4 weeks. Treatment with AM-ZHY1 significantly reduced hepatic steatosis in zebrafish. Quantitative PCR (qPCR) detection showed that the expression of the lipogenesis [peroxisome-proliferator-activated receptors (PPARγ), sterol regulatory element-binding proteins-1c (SREBP-1c), fatty acid synthase (FAS), and acetyl-CoA carboxylase 1 (ACC1)] and lipid transport genes (CD36 and FABP6) in the liver were significantly downregulated (p &lt; 0.05), indicating that AM-ZHY1 could reduce liver fat accumulation by inhibiting lipid synthesis and absorption. Moreover, supplementing AM-ZHY1 to a high-fat diet could significantly reduce serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, indicating that liver injury caused by high-fat diets was improved. The expression of tumor necrosis factor (TNF)-a and interleukin (IL)-6 in the liver decreased significantly (p &lt; 0.05), while IL-1β and IL-10 did not change significantly in the AM-ZHY1 group. Compared to the high-fat diet-fed group, the AM-ZHY1 group, but not the ZHY1 group, significantly increased the expression of intestinal tight junction (TJ) proteins (TJP1a, claudina, claudin7, claudin7b, claudin11a, claudin12, and claudin15a; p &lt; 0.05). Compared to the high-fat diet group, the Proteobacteria and Fusobacteria were significantly reduced and increased in the AM-ZHY1 group, respectively. In conclusion, the recombinant bacteria AM-ZHY1 has the capacity to maintain intestinal health by protecting intestinal integrity and improving intestinal flora structure and improving fatty liver disease by inhibiting lipid synthesis and absorption. This study will lay a foundation for the application of AM protein in improving abnormal fat deposition and restoring the intestinal barrier in fish.


2021 ◽  
Vol 22 (18) ◽  
pp. 9931
Author(s):  
Koichi Fujisawa ◽  
Taro Takami ◽  
Shoki Okubo ◽  
Yuto Nishimura ◽  
Yusaku Yamada ◽  
...  

Among lifestyle-related diseases, fatty liver is the most common liver disease. To date, mammalian models have been used to develop methods for inhibiting fatty liver progression; however, new, more efficient models are expected. This study investigated the creation of a new model to produce fatty liver more efficiently than the high-fat diet medaka model that has been used to date. We compared the GAN (Gubra-Amylin nonalcoholic steatohepatitis) diet, which has been used in recent years to induce fatty liver in mice, and the high-fat diet (HFD). Following administration of the diets for three months, enlarged livers and pronounced fat accumulation was noted. The GAN group had large fat vacuoles and lesions, including ballooning, compared to the HFD group. The GAN group had a higher incidence of lesions. When fenofibrate was administered to the fatty liver model created via GAN administration and liver steatosis was assessed, a reduction in liver fat deposition was observed, and this model was shown to be useful in drug evaluations involving fatty liver. The medaka fatty liver model administered with GAN will be useful in future fatty liver research.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Ding Zheng ◽  
Mengyun Peng ◽  
Xiaoning Zhu ◽  
Jing Wang

The purpose of this study was to investigate the effect of Qutanhuoxue decoction on AQP7 and AQP9 expression in nonalcoholic fatty liver model rats. Nighty male SD rats (six weeks old, 250 ± 10 g) were randomly divided into 5 groups: normal diet group (ND group), high-fat diet (HFD group), HFD + low dose Qd group, HFD + middle dose Qd group, and HFD + high dose Qd group. Rats in ND group were fed with a regular diet, while rats in other groups were fed with high-fat diet. After the success of the molding, HFD + low dose Qd group, HFD + middle dose Qd group, and HFD + high dose Qd group were, respectively, gavaged by Qutanhuoxue decoction with concentration of 4.5g.kg−1.d−1, 9.0g.kg−1.d−1, and 18g.kg−1.d−1. The ND group and HFD group were gavaged by the same volume of physiological saline lavage, once a day. During the period of gavaging, the other four groups continue to be fed with high-fat fodder except ND group. All rats were killed at 14d, 21d, and 28d, respectively. HE staining was used to observe the pathological changes of liver tissues and serum level of ALT AST GGT and TC TG was detected by automatic analyzer. The expression levels of liver AQP9 mRNA and adipose tissue AQP7 mRNA were detected by real-time PCR. Quhuoxue decoction can significantly reduce the liver function (ALT, AST, and GGT) and blood fat (TG, TC) levels of NAFLD rats and reduce the degree of liver fat degeneration. The effect was the best in the HFD + high dose Qd group of 28d. Qutanhuoxue decoction can decrease the expression of liver AQP9 mRNA and increase the expression of adipose tissue AQP7 mRNA. In conclusion, Qutanhuoxue decoction can reduce the degree of hepatic steatosis, which may be closely related to the increase of AQP7 expression in adipose tissue and the decrease of AQP9 expression in liver.


2013 ◽  
Author(s):  
Marcos Hiromu Okuda ◽  
de Santana Aline Alves ◽  
Mayara Franzoi Moreno ◽  
Ana Claudia Hachul ◽  
Nelson Inacio Neto ◽  
...  

2021 ◽  
Author(s):  
Yilin Liu ◽  
Chunyan Xie ◽  
Zhenya Zhai ◽  
Ze-yuan Deng ◽  
Hugo R. De Jonge ◽  
...  

This study aimed to investigate the effect of uridine on obesity, fat accumulation in liver, and gut microbiota composition in high-fat diet-fed mice.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takuya Kawamura ◽  
Hiroaki Tanaka ◽  
Ryota Tachibana ◽  
Kento Yoshikawa ◽  
Shintaro Maki ◽  
...  

AbstractWe aimed to investigate the effects of maternal tadalafil therapy on fetal programming of metabolic function in a mouse model of fetal growth restriction (FGR). Pregnant C57BL6 mice were divided into the control, L-NG-nitroarginine methyl ester (L-NAME), and tadalafil + L-NAME groups. Six weeks after birth, the male pups in each group were given a high-fat diet. A glucose tolerance test (GTT) was performed at 15 weeks and the pups were euthanized at 20 weeks. We then assessed the histological changes in the liver and adipose tissue, and the adipocytokine production. We found that the non-alcoholic fatty liver disease activity score was higher in the L-NAME group than in the control group (p < 0.05). Although the M1 macrophage numbers were significantly higher in the L-NAME/high-fat diet group (p < 0.001), maternal tadalafil administration prevented this change. Moreover, the epididymal adipocyte size was significantly larger in the L-NAME group than in the control group. This was also improved by maternal tadalafil administration (p < 0.05). Further, we found that resistin levels were significantly lower in the L-NAME group compared to the control group (p < 0.05). The combination of exposure to maternal L-NAME and a high-fat diet induced glucose impairment and non-alcoholic fatty liver disease. However, maternal tadalafil administration prevented these complications. Thus, deleterious fetal programming caused by FGR might be modified by in utero intervention with tadalafil.


Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1740
Author(s):  
Yuning Pang ◽  
Xiang Xu ◽  
Xiaojun Xiang ◽  
Yongnan Li ◽  
Zengqi Zhao ◽  
...  

A high-fat diet often leads to excessive fat deposition and adversely affects the organism. However, the mechanism of liver fat deposition induced by high fat is still unclear. Therefore, this study aimed at acetyl-CoA carboxylase (ACC) to explore the mechanism of excessive liver deposition induced by high fat. In the present study, the ORF of ACC1 and ACC2 were cloned and characterized. Meanwhile, the mRNA and protein of ACC1 and ACC2 were increased in liver fed with a high-fat diet (HFD) or in hepatocytes incubated with oleic acid (OA). The phosphorylation of ACC was also decreased in hepatocytes incubated with OA. Moreover, AICAR dramatically improved the phosphorylation of ACC, and OA significantly inhibited the phosphorylation of the AMPK/ACC pathway. Further experiments showed that OA increased global O-GlcNAcylation and agonist of O-GlcNAcylation significantly inhibited the phosphorylation of AMPK and ACC. Importantly, the disorder of lipid metabolism caused by HFD or OA could be rescued by treating CP-640186, the dual inhibitor of ACC1 and ACC2. These observations suggested that high fat may activate O-GlcNAcylation and affect the AMPK/ACC pathway to regulate lipid synthesis, and also emphasized the importance of the role of ACC in lipid homeostasis.


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