scholarly journals Prolyl Endopeptidase Gene Disruption Improves Gut Dysbiosis and Non-alcoholic Fatty Liver Disease in Mice Induced by a High-Fat Diet

Author(s):  
Daixi Jiang ◽  
Jianbin Zhang ◽  
Shuangzhe Lin ◽  
Yuqin Wang ◽  
Yuanwen Chen ◽  
...  

The gut-liver axis is increasingly recognized as being involved in the pathogenesis and progression of non-alcoholic fatty liver disease (NAFLD). Prolyl endopeptidase (PREP) plays a role in gut metabolic homeostasis and neurodegenerative diseases. We investigated the role of PREP disruption in the crosstalk between gut flora and hepatic steatosis or inflammation in mice with NAFLD. Wild-type mice (WT) and PREP gene knocked mice (PREPgt) were fed a low-fat diet (LFD) or high-fat diet (HFD) for 16 or 24 weeks. Murine gut microbiota profiles were generated at 16 or 24 weeks. Liver lipogenesis-associated molecules and their upstream mediators, AMP-activated protein kinase (AMPK) and sirtuin1 (SIRT1), were detected using RT-PCR or western blot in all mice. Inflammatory triggers and mediators from the gut or infiltrated inflammatory cells and signal mediators, such as p-ERK and p-p65, were determined. We found that PREP disruption modulated microbiota composition and altered the abundance of several beneficial bacteria such as the butyrate-producing bacteria in mice fed a HFD for 16 or 24 weeks. The level of butyrate in HFD-PREPgt mice significantly increased compared with that of the HFD-WT mice at 16 weeks. Interestingly, PREP disruption inhibited p-ERK and p-p65 and reduced the levels of proinflammatory cytokines in response to endotoxin and proline-glycine-proline, which guided macrophage/neutrophil infiltration in mice fed a HFD for 24 weeks. However, at 16 weeks, PREP disruption, other than regulating hepatic inflammation, displayed improved liver lipogenesis and AMPK/SIRT1 signaling. PREP disruption may target multiple hepatic mechanisms related to the liver, gut, and microbiota, displaying a dynamic role in hepatic steatosis and inflammation during NAFLD. PREP might serve as a therapeutic target for NAFLD.

2021 ◽  
Vol 22 (6) ◽  
pp. 3091
Author(s):  
Saeromi Kang ◽  
Ae-Yeon Lee ◽  
So-Young Park ◽  
Kwang-Hyeon Liu ◽  
Dong-Soon Im

Non-alcoholic fatty liver disease is recognized as the leading cause of chronic liver disease. Overnutrition and obesity are associated with hepatic steatosis. G protein-coupled receptor 55 (GPR55) has not been extensively studied in hepatic steatosis, although its endogenous ligands have been implicated in liver disease progression. Therefore, the functions of GPR55 were investigated in Hep3B human hepatoma cells and mice fed high-fat diets. O-1602, the most potent agonist of GPR55, induced lipid accumulation in hepatocytes, which was reversed by treatment with CID16020046, an antagonist of GPR55. O-1602 also induced intracellular calcium rise in Hep3B cells in a GPR55-independent manner. O-1602-induced lipid accumulation was dependent on the PI3 kinase/Akt/SREBP-1c signaling cascade. Furthermore, we found increased levels of lysophosphatidylinositol species of 16:0, 18:0, 18:1, 18:2, 20:1, and 20:2 in the livers of mice fed a high-fat diet for 4 weeks. One-week treatment with CID16020046 suppressed high-fat diet-induced lipid accumulation and O-1602-induced increase of serum triglyceride levels in vivo. Therefore, the present data suggest the pro-steatotic function of GPR55 signaling in hepatocytes and provide a potential therapeutic target for non-alcoholic fatty liver disease.


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.


2014 ◽  
Vol 10 (6) ◽  
pp. 2917-2923 ◽  
Author(s):  
XIANG WANG ◽  
QIAOHUA REN ◽  
TAO WU ◽  
YONG GUO ◽  
YONG LIANG ◽  
...  

Author(s):  
Ana Lemus-Conejo ◽  
Elena Grao-Cruces ◽  
Rocio Toscano ◽  
Lourdes M Varela ◽  
Carmen Claro ◽  
...  

Bioactive peptides are related to the prevention and treatment of many diseases. GPETAFLR is an octapeptide which was isolated from lupine (Lupinus angustifolius L.) and showed anti-inflammatory properties. The aim of this study was to evaluate the potential activity of GPETAFLR to prevent non-alcoholic fatty liver disease (NAFLD) in high-fat diet (HFD)-induced obese mice. C57BL/6J mice were fed a standard diet or an HFD. Two of the groups fed the HFD diet were treated with GPETAFLR in their drinking water at 0,5 mg/kg/d or 1 mg/kg/d. To determine the ability of GPETAFLR to improve the onset and progression of NAFLD, histological studies, hepatic enzyme profile, inflammatory cytokine and lipid metabolism-related genes and proteins were analyzed. Our results suggest that HFD-induced inflammatory metabolic disorders were alleviated by treatment with GPETAFLR. In conclusion, dietary lupine consumption could repair HFD-induced hepatic damage, possibly via modifications in the liver&rsquo;s lipid signalling pathways.


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