scholarly journals GP73 is a TBC-domain Rab GTPase-activating protein contributing to the pathogenesis of non-alcoholic fatty liver disease without obesity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yumeng Peng ◽  
Qiang Zeng ◽  
Luming Wan ◽  
Enhao Ma ◽  
Huilong Li ◽  
...  

AbstractThe prevalence of non-obese nonalcoholic fatty liver disease (NAFLD) is increasing worldwide with unclear etiology and pathogenesis. Here, we show GP73, a Golgi protein upregulated in livers from patients with a variety of liver diseases, exhibits Rab GTPase-activating protein (GAP) activity regulating ApoB export. Upon regular-diet feeding, liver-GP73-high mice display non-obese NAFLD phenotype, characterized by reduced body weight, intrahepatic lipid accumulation, and gradual insulin resistance development, none of which can be recapitulated in liver-GAP inactive GP73-high mice. Common and specific gene expression signatures associated with GP73-induced non-obese NAFLD and high-fat diet (HFD)-induced obese NAFLD are revealed. Notably, metformin inactivates the GAP activity of GP73 and alleviates GP73-induced non-obese NAFLD. GP73 is pathologically elevated in NAFLD individuals without obesity, and GP73 blockade improves whole-body metabolism in non-obese NAFLD mouse model. These findings reveal a pathophysiological role of GP73 in triggering non-obese NAFLD and may offer an opportunity for clinical intervention.

JCI Insight ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Maria E. Moreno-Fernandez ◽  
Daniel A. Giles ◽  
Traci E. Stankiewicz ◽  
Rachel Sheridan ◽  
Rebekah Karns ◽  
...  

2018 ◽  
Vol 1 (2) ◽  
pp. 24-28
Author(s):  
Tanita Suttichaimongkol

Non-alcoholic fatty liver disease (NAFLD) is a leading cause of death from liver cirrhosis, endstage liver disease, and hepatocellular carcinoma. It is also associated with increased cardiovasculardisease and cancer related mortality. While lifestyle modifications are the mainstay of treatment,only a proportion of patients are able to make due to difficult to achieve and maintain, and so moretreatment options are required such as pharmacotherapy. This review presents the drugs used inmanaging NAFLD and their pharmacologic targets. Therapies are currently directed towards improvingthe metabolic status of the liver, insulin resistance, cell oxidative stress, apoptosis, inflammation orfibrosis. Several agents are now in large clinical trials and within the next few years, the availability oftherapeutic options for NAFLD will be approved.     Keywords: nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, fibrosis, cirrhosis  


2020 ◽  
Vol 21 (6) ◽  
pp. 599-609 ◽  
Author(s):  
Longxin Qiu ◽  
Chang Guo

Aldose reductase (AR) has been reported to be involved in the development of nonalcoholic fatty liver disease (NAFLD). Hepatic AR is induced under hyperglycemia condition and converts excess glucose to lipogenic fructose, which contributes in part to the accumulation of fat in the liver cells of diabetes rodents. In addition, the hyperglycemia-induced AR or nutrition-induced AR causes suppression of the transcriptional activity of peroxisome proliferator-activated receptor (PPAR) α and reduced lipolysis in the liver, which also contribute to the development of NAFLD. Moreover, AR induction in non-alcoholic steatohepatitis (NASH) may aggravate oxidative stress and the expression of inflammatory cytokines in the liver. Here, we summarize the knowledge on AR inhibitors of plant origin and review the effect of some plant-derived AR inhibitors on NAFLD/NASH in rodents. Natural AR inhibitors may improve NAFLD at least in part through attenuating oxidative stress and inflammatory cytokine expression. Some of the natural AR inhibitors have been reported to attenuate hepatic steatosis through the regulation of PPARα-mediated fatty acid oxidation. In this review, we propose that the natural AR inhibitors are potential therapeutic agents for NAFLD.


2015 ◽  
Vol 32 (2) ◽  
pp. 71-77 ◽  
Author(s):  
Shahinul Alam ◽  
Mahabubul Alam ◽  
Sheikh Mohammad Noor E Alam ◽  
Ziaur Rahman Chowdhury ◽  
Jahangir Kabir

Fatty liver is a common cause of chronic liver disease in developed as well as developing countries.We have designed this study to estimate the prevalence and predictors for non alcoholic steatohepatitis (NASH) in non alcoholic fatty liver disease (NAFLD). We have included 493 patients with sonographic evidence of fatty change in liver and 177 of them had done liver biopsy for histopathological study. Other causes of liver disease and alcohol consumption were excluded. Metabolic syndrome and biochemical and anthropometric evaluation was done. Females were predominating 250 (57.0 %). Centrally obese 422 (96.2 %) was more than over all obesity330 (75.1%). NASH was absent in 10 (5.6%) cases and diagnostic of NASH was 75 Journal of Bangladesh College of Physicians and Surgeons Vol. 32, No. 2, April 2014 (42.4 %).Presence of diabetes could significantly (p = 0.001) predicted NASH. Age, sex, BMI, waist circumference, Serum HDL,triglyceride, insulin resistance index, hypertension, metabolic syndrome could not predict NASH. Serum GGT level was significantly (p = 0.05) higher in NASHwith a sensitivity of 45 % and specificity of 68 % only. Serum ALT and AST level could not detect NASH. Females were predominant sufferer of NAFLD in Bangladesh. Prevalence of NASH was much higher42.4%. Diabetes was the main predictor of NASH. GGT was the only biochemical indicator of NASH. We recommend liver biopsy in NAFLD with diabetes and raised GGT.J Bangladesh Coll Phys Surg 2014; 32: 71-77


2021 ◽  
Vol 22 (18) ◽  
pp. 9969
Author(s):  
Mariano Schiffrin ◽  
Carine Winkler ◽  
Laure Quignodon ◽  
Aurélien Naldi ◽  
Martin Trötzmüller ◽  
...  

Men with nonalcoholic fatty liver disease (NAFLD) are more exposed to nonalcoholic steatohepatitis (NASH) and liver fibrosis than women. However, the underlying molecular mechanisms of NALFD sex dimorphism are unclear. We combined gene expression, histological and lipidomic analyses to systematically compare male and female liver steatosis. We characterized hepatosteatosis in three independent mouse models of NAFLD, ob/ob and lipodystrophic fat-specific (PpargFΔ/Δ) and whole-body PPARγ-null (PpargΔ/Δ) mice. We identified a clear sex dimorphism occurring only in PpargΔ/Δ mice, with females showing macro- and microvesicular hepatosteatosis throughout their entire life, while males had fewer lipid droplets starting from 20 weeks. This sex dimorphism in hepatosteatosis was lost in gonadectomized PpargΔ/Δ mice. Lipidomics revealed hepatic accumulation of short and highly saturated TGs in females, while TGs were enriched in long and unsaturated hydrocarbon chains in males. Strikingly, sex-biased genes were particularly perturbed in both sexes, affecting lipid metabolism, drug metabolism, inflammatory and cellular stress response pathways. Most importantly, we found that the expression of key sex-biased genes was severely affected in all the NAFLD models we tested. Thus, hepatosteatosis strongly affects hepatic sex-biased gene expression. With NAFLD increasing in prevalence, this emphasizes the urgent need to specifically address the consequences of this deregulation in humans.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hongguo Guan ◽  
Yiyan Wang ◽  
Huitao Li ◽  
Qiqi Zhu ◽  
Xiaoheng Li ◽  
...  

Background: 11β-Hydroxysteroid dehydrogenase one is responsible for activating inert glucocorticoid cortisone into biologically active cortisol in humans and may be a novel target for the treatment of nonalcoholic fatty liver disease.Methods: A series of benzylidene cyclopentanone derivatives were synthesized, and the selective inhibitory effects on rat, mouse and human 11β-hydroxysteroid dehydrogenase one and two were screened. The most potent compound [5-bis-(2,6-difluoro-benzylidene)-cyclopentanone] (WZS08), was used to treat nonalcoholic fatty liver disease in mice fed a high-fat-diet for 100 days.Results: WZS08 was the most potent inhibitor of rat, mouse, and human 11β-hydroxysteroid dehydrogenase 1, with half maximum inhibitory concentrations of 378.0, 244.1, and 621.1 nM, respectively, and it did not affect 11β-hydroxysteroid dehydrogenase two at 100 μM. When mice were fed WZS08 (1, 2, and 4 mg/kg) for 100 days, WZS08 significantly lowered the serum insulin levels and insulin index at 4 mg/kg. WZS08 significantly reduced the levels of serum triglycerides, cholesterol, low-density lipoprotein, and hepatic fat ratio at low concentration of 1 mg/kg. It down-regulated Plin2 expression and up-regulated Fabp4 expression at low concentration of 1 mg/kg. It significantly improved the morphology of the non-alcoholic fatty liver.Conclusion: WZS08 selectively inhibits rat, mouse, and human 11β-hydroxysteroid dehydrogenase 1, and can treat non-alcoholic fatty liver disease in a mouse model.


2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Takhar Kasumov

Objectives: Nonalcoholic fatty liver disease (NAFLD) is associated with an increased rate of cardiovascular disease (CVD) related mortality. HDL protects against CVD through reverse cholesterol transport, anti-oxidant and anti-inflammatory functions. HDL functions and the proteome composition are altered in CVD. We used 2 H 2 O metabolic labeling approach to test hypothesis that altered HDL proteome dynamics is involved in HDL dysfunction in NAFLD. Methods: The kinetics of HDL proteins were measured in patients NAFLD (n=12) and healthy controls (n=8). Each subject consumed 2 H 2 O in their drinking water and blood samples were collected at different time points during one week. 2 H-enrichment of tryptic peptides from HDL proteins were analyzed by mass spectrometry. Oxidase activity of HDL-associated ceruloplasmin (Cp) and HDL’s inflammatory index were quantified using spectrophotometric assays. Results: Compared to control, NAFLD had higher BMI, Hba1c, HOMA-IR, plasma AST, ALT and triglycerides, but similar LDL and HDL cholesterol. NAFLD also had higher inflammatory index (1.8±0.5 vs 1.2±0.2 RUF/mgHDLc/min, p<0.05) and oxidase activity of Cp (93.7±61.2 vs 61.2 U/L, p<0.005). This was associated with increased serum actvity of MPO (6.2±1.2 vs 8.4±1.6, p<0.05), a nutrophile-derived protein involved in HDL dysfunction. HDL NAFLD was significantly enriched with proteins involved in the acute phase response (complement 3, Cp) but depleted in apoAII and PON1. These changes were associated with increased fractional catabolic rates (FCRs) of apoAI (1.6±0.2 vs 1.1±0.3 %/h), apoAII (1.6±0.2 vs 1.1±0.3 %/h), apoAIV (2.6±0.8 vs 3.9±0.7%/h) and increased relative production rate (RPR) of complement 3 (>4 fold). Oxidase activity of Cp was positively associated with FCR of apoAI (r=0.53, p=0.002) and RPR of C3 (r=0.32, p=0.03). Conclusions: HDL dysfunction in NASH could be related to the altered turnover of HDL proteins, including increased degradation of apoAI, apoAII, apoAIV and increased production of C3.


1970 ◽  
Vol 1 (2) ◽  
pp. 60-63
Author(s):  
Ankush Mittal ◽  
Brijesh Sathian ◽  
Nishida Chandrasekharan ◽  
Akshay Lekhi ◽  
Shamim Mohammad Farooqui ◽  
...  

Background: Liver diseases is apparently increasing and emerging as a major public health problem. Worldwide,  chronic hepatitis B has  become  the tenth leading cause of death  and  persons infected with chronic hepatitis B virus (HBV) and hepatitis C virus (HCV), are about 350 million and  125 million respectively. The aim of current retrospective comparative study was concerned primarily to evaluate the significance of non invasive serological markers for diagnosing liver diseases and their predictive implications in Pokhara valley. Materials and Methods: It was a hospital based retrospective study carried out using the data maintained in the Department of Biochemistry of the Manipal Teaching Hospital, Pokhara, Nepal between 1st June 2009 and 31st   October 2010.  The variables collected were total protein, albumin, AST, ALT, total bilirubin, direct bilirubin.  Descriptive statistics and testing of hypothesis were used for the analysis. Data was analyzed using EPI INFO and SPSS 16 software. Results: Of 515 subjects, 120 were suffering from viral hepatitis and 88 had non alcoholic fatty liver disease. In cases of viral hepatitis, mean values of AST (CI 730.65 to 902.68) and ALT (CI 648.14 to 847.59) were markedly increased as compared to controls. Mild to moderate elevations in serum levels of aspartate aminotransferase (CI 43.42 to 49.49), alanine aminotransferase (CI 43.90 to 53.92) were the most common laboratory abnormalities found in patients with nonalcoholic fatty liver disease. Conclusion: Non invasive tests have demonstrated a reasonable ability to identify significant fibrosis, cirrhosis in particular, nor is it surprising that liver disease specialists and patients favour a non invasive approach.Key words: Viral hepatitis; Nonalcoholic fatty liver disease; Nepal.DOI: http://dx.doi.org/10.3126/nje.v1i2.5137 Nepal Journal of Epidemiology 2011;1 (2):60-63


2012 ◽  
Vol 113 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Ciaran E. Fealy ◽  
Jacob M. Haus ◽  
Thomas P. J. Solomon ◽  
Mangesh Pagadala ◽  
Chris A. Flask ◽  
...  

Increased hepatocyte apoptosis is a hallmark of nonalcoholic fatty liver disease (NAFLD) and contributes to the profibrogenic state responsible for the progression to nonalcoholic steatohepatitis (NASH). Strategies aimed at reducing apoptosis may result in better outcomes for individuals with NAFLD. We therefore examined the effect of a short-term exercise program on markers of apoptosis—plasma cytokeratin 18 (CK18) fragments, alanine aminotransferase (ALT), aspartate aminotransferase (AST), soluble Fas (sFas), and sFas ligand (sFasL)—in 13 obese individuals with NAFLD [body mass index 35.2 ± 1.2 kg/m2, >5% intrahepatic lipid (IHL) assessed by 1H-MR spectroscopy]. Exercise consisted of treadmill walking for 60 min/day on 7 consecutive days at ∼85% of maximal heart rate. Additionally, subjects underwent an oral glucose tolerance test and a maximal oxygen consumption (V̇o2max) test before and after the exercise intervention. The Matsuda index was used to assess insulin sensitivity. We observed significant decreases in CK18 fragments (558.4 ± 106.8 vs. 323.4 ± 72.5 U/l, P < 0.01) and ALT (30.2 ± 5.1 vs. 24.3 ± 4.8 U/l, P < 0.05), and an increase in whole body fat oxidation (49.3 ± 6.1 vs. 69.4 ± 7.1 mg/min, P < 0.05), while decreases in circulating sFasL approached statistical significance (66.5 ± 6.0 vs. 63.0 ± 5.7 pg/ml, P = 0.06), as did the relationship between percent change in circulating CK18 fragments and ALT (r = 0.55, P = 0.05). We also observed a significant correlation between changes in fat oxidation and circulating sFasL (rho = −0.65, P < 0.05). There was no change in IHL following the intervention (18.2 ± 2.5 vs. 17.5 ± 2.1%, NS). We conclude that short-term exercise reduces a circulatory marker of hepatocyte apoptosis in obese individuals with NAFLD and propose that changes in the proapoptotic environment may be mediated through improved insulin sensitivity and increased oxidative capacity.


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