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Molecular Link between Steatosis and Obesity

A special issue of International Journal of Molecular Sciences (ISSN 1422-0067). This special issue belongs to the section "Molecular Biology".

Deadline for manuscript submissions: closed (28 February 2022) | Viewed by 54229

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Guest Editor
Department of Food and Nutrition, Sunchon National University, Suncheon 57922, Republic of Korea
Interests: osteoporosis; bone; osteoclast; barley; extracts; nfatc1

Special Issue Information

Dear Colleagues,

The obesity epidemic is highly connected to the rising prevalence of non-alcoholic fatty liver (steatosis). It is less than a few decades, we have witnessed a severe increase in the incidence of fatty liver derived from obesity in childhood, which has manifested as a serious social problem. A “multiple-hit” pathogenic model has been suggested to explain progressive obesity-related steatosis. A vast range of anti-obesity drugs and natural resources are being investigated at the moment, including targeting insulin resistance, proinflammatory pathway, dyslipidemia, gut microbiota, gut–liver axis dysfunction, and metabolites. In addition, obesity suppression studies on “circadian rhythms control” have recently been conducted. However, no convincing consensus has emerged linking obesity with the pathogenesis of steatosis. Steatosis often develops into steatohepatitis, cirrhosis, and hepatocellular carcinoma, and therefore, it should be very carefully managed to prevent serious non-alcoholic liver diseases. This Special Issue aims to shared new insights into the prevention and treatment of obesity-induced steatosis; studies on molecular-linked genes, proteins, metabolites, and microbiota are invited.

Dr. Mi-Kyung Lee
Guest Editor

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Keywords

  • Adipose tissue-liver axis
  • anti-obesity medication (including alternative)
  • distribution of fat tissue
  • epidemiological surveillance
  • mitochondrial dysfunction and lipogenesis
  • non-alcoholic liver disease
  • obesity
  • signaling crosstalk between obesity and steatosis

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Published Papers (12 papers)

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Research

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20 pages, 3252 KiB  
Article
Phosphatidylethanolamines Are Associated with Nonalcoholic Fatty Liver Disease (NAFLD) in Obese Adults and Induce Liver Cell Metabolic Perturbations and Hepatic Stellate Cell Activation
by Samaa Shama, Hyejeong Jang, Xiaokun Wang, Yang Zhang, Nancy Nabil Shahin, Tarek Kamal Motawi, Seongho Kim, Samer Gawrieh and Wanqing Liu
Int. J. Mol. Sci. 2023, 24(2), 1034; https://doi.org/10.3390/ijms24021034 - 5 Jan 2023
Cited by 15 | Viewed by 3795
Abstract
Pathogenesis roles of phospholipids (PLs) in nonalcoholic fatty liver disease (NAFLD) remain incompletely understood. This study investigated the role of PLs in the progression of NAFLD among obese individuals via studying the alterations in serum PL composition throughout the spectrum of disease progression [...] Read more.
Pathogenesis roles of phospholipids (PLs) in nonalcoholic fatty liver disease (NAFLD) remain incompletely understood. This study investigated the role of PLs in the progression of NAFLD among obese individuals via studying the alterations in serum PL composition throughout the spectrum of disease progression and evaluating the effects of specific phosphatidylethanolamines (PEs) on FLD development in vitro. A total of 203 obese subjects, who were undergoing bariatric surgery, were included in this study. They were histologically classified into 80 controls (C) with normal liver histology, 93 patients with simple hepatic steatosis (SS), 16 with borderline nonalcoholic steatohepatitis (B-NASH) and 14 with progressive NASH (NASH). Serum PLs were profiled by automated electrospray ionization tandem mass spectrometry (ESI-MS/MS). HepG2 (hepatoma cells) and LX2 (immortalized hepatic stellate cells or HSCs) were used to explore the roles of PL in NAFLD/NASH development. Several PLs and their relative ratios were significantly associated with NAFLD progression, especially those involving PE. Incubation of HepG2 cells with two phosphatidylethanolamines (PEs), PE (34:1) and PE (36:2), resulted in significant inhibition of cell proliferation, reduction of mitochondrial mass and membrane potential, induction of lipid accumulation and mitochondrial ROS production. Meanwhile, treatment of LX2 cells with both PEs markedly increased cell activation and migration. These effects were associated with a significant change in the expression levels of genes involved in lipogenesis, lipid oxidation, autophagy, apoptosis, inflammation, and fibrosis. Thus, our study demonstrated that elevated level of PEs increases susceptibility to the disease progression of obesity associated NAFLD, likely through a causal cascade of impacts on the function of different liver cells. Full article
(This article belongs to the Special Issue Molecular Link between Steatosis and Obesity)
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17 pages, 6367 KiB  
Article
Sesamolin Alleviates Nonalcoholic Fatty Liver Disease through Modulating Gut Microbiota and Metabolites in High-Fat and High-Fructose Diet-Fed Mice
by Jing Yu, Hao Sun, Yang Yang and Yaping Yan
Int. J. Mol. Sci. 2022, 23(22), 13853; https://doi.org/10.3390/ijms232213853 - 10 Nov 2022
Cited by 8 | Viewed by 5481
Abstract
Nonalcoholic fatty liver disease (NAFLD) has become a major public health problem. The effects of sesamolin on obesity-associated NAFLD and its possible mechanism are still poorly understood. The present study investigated the effects of sesamolin on NAFLD and changes in gut microbiota and [...] Read more.
Nonalcoholic fatty liver disease (NAFLD) has become a major public health problem. The effects of sesamolin on obesity-associated NAFLD and its possible mechanism are still poorly understood. The present study investigated the effects of sesamolin on NAFLD and changes in gut microbiota and serum metabolites in high-fat and high-fructose (HF-HF) diet-fed mice. Mice with NAFLD were treated with or without sesamolin. Sesamolin effectively suppressed obesity-associated metabolic disorder, attenuated hepatic steatosis and the infiltration of inflammatory cells, and decreased levels of hepatic proinflammatory cytokines. Sesamolin also altered the composition of gut microbiota at the genus level. Additionally, differential serum metabolite biomarkers identified in an untargeted metabolomics analysis showed that sesamolin changed the levels of metabolites and influenced metabolomics pathways including caffeine metabolism, steroid hormone biosynthesis, and cysteine and methionine metabolism. Changes in metabolite biomarkers and the abundances of Faecalibaculum, Lachnoclostridium, Mucispirillum, Allobaculum, and Bacteroides are highly correlated with those factors involved in the progression of NAFLD. These results are important in deciphering new mechanisms by which changes in bacteria and metabolites in sesamolin treatment might be associated with the alleviation of obesity-associated NAFLD in HF-HF diet-fed mice. Thus, sesamolin may be a potential compound for obesity-associated NAFLD treatment. Full article
(This article belongs to the Special Issue Molecular Link between Steatosis and Obesity)
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20 pages, 3729 KiB  
Article
E4orf1 Prevents Progression of Fatty Liver Disease in Mice on High Fat Diet
by Rownock Afruza, Nikhil V. Dhurandhar and Vijay Hegde
Int. J. Mol. Sci. 2022, 23(16), 9286; https://doi.org/10.3390/ijms23169286 - 18 Aug 2022
Viewed by 2071
Abstract
Non-alcoholic fatty liver disease (NAFLD) covers a broad spectrum of liver diseases ranging from steatosis to cirrhosis. There are limited data on prevention of hepatic steatosis or its progression to liver disease. Here, we tested if either transgenic (Tg) doxycycline-induced expression in adipose [...] Read more.
Non-alcoholic fatty liver disease (NAFLD) covers a broad spectrum of liver diseases ranging from steatosis to cirrhosis. There are limited data on prevention of hepatic steatosis or its progression to liver disease. Here, we tested if either transgenic (Tg) doxycycline-induced expression in adipose tissue of E4orf1 (E4), an adenoviral protein, or dietary fat restriction attenuated hepatic steatosis or its progression in mice. Twelve to fourteen-week-old TgE4 mice (E4 group) and control mice were exposed to a 60% (Kcal) high fat diet (HFD) for 20 weeks, while another group of mice on HFD for 10 weeks were switched to a chow diet (chow group) for another 10 weeks. Glycemic control was determined at weeks 10 and 20. Tissues were collected for gene and protein analysis at sacrifice. Compared to control, diet reversal significantly reduced body weight in the chow group, whereas E4 expression attenuated weight gain, despite HFD. E4 mice evinced significantly improved glucose clearance, lower endogenous insulin secretion, reduced serum triglycerides, attenuated hepatic steatosis and inflammation. Interestingly, in spite of weight loss and lower liver fat, chow mice showed significant upregulation of hepatic genes involved in lipid metabolism. Despite HFD, E4 prevents hepatic lipid accumulation and progression of hepatic steatosis, while diet reversal maintains hepatic health, but is unable to improve molecular changes. Full article
(This article belongs to the Special Issue Molecular Link between Steatosis and Obesity)
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18 pages, 8795 KiB  
Article
Meta-Inflammation and De Novo Lipogenesis Markers Are Involved in Metabolic Associated Fatty Liver Disease Progression in BTBR ob/ob Mice
by Lucas Opazo-Ríos, Manuel Soto-Catalán, Iolanda Lázaro, Aleix Sala-Vila, Luna Jiménez-Castilla, Macarena Orejudo, Juan Antonio Moreno, Jesús Egido and Sebastián Mas-Fontao
Int. J. Mol. Sci. 2022, 23(7), 3965; https://doi.org/10.3390/ijms23073965 - 2 Apr 2022
Cited by 8 | Viewed by 3795
Abstract
Metabolic associated fatty liver disease (MAFLD) is a hepatic manifestation of metabolic syndrome and usually associated with obesity and diabetes. Our aim is to characterize the pathophysiological mechanism involved in MAFLD development in Black Tan and brachyuric (BTBR) insulin-resistant mice in combination with [...] Read more.
Metabolic associated fatty liver disease (MAFLD) is a hepatic manifestation of metabolic syndrome and usually associated with obesity and diabetes. Our aim is to characterize the pathophysiological mechanism involved in MAFLD development in Black Tan and brachyuric (BTBR) insulin-resistant mice in combination with leptin deficiency (ob/ob). We studied liver morphology and biochemistry on our diabetic and obese mice model (BTBR ob/ob) as well as a diabetic non-obese control (BTBR + streptozotocin) and non-diabetic control mice (BTBR wild type) from 4–22 weeks. Lipid composition was assessed, and lipid related pathways were studied at transcriptional and protein level. Microvesicular steatosis was evident in BTBR ob/ob from week 6, progressing to macrovesicular in the following weeks. At 12th week, inflammatory clusters, activation of STAT3 and Nrf2 signaling pathways, and hepatocellular ballooning. At 22 weeks, the histopathological features previously observed were maintained and no signs of fibrosis were detected. Lipidomic analysis showed profiles associated with de novo lipogenesis (DNL). BTBR ob/ob mice develop MAFLD profile that resemble pathological features observed in humans, with overactivation of inflammatory response, oxidative stress and DNL signaling pathways. Therefore, BTBR ob/ob mouse is an excellent model for the study of the steatosis to steatohepatitis transition. Full article
(This article belongs to the Special Issue Molecular Link between Steatosis and Obesity)
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15 pages, 7602 KiB  
Article
Heat Shock Protein 60 Restricts Release of Mitochondrial dsRNA to Suppress Hepatic Inflammation and Ameliorate Non-Alcoholic Fatty Liver Disease in Mice
by Ying-Hsien Huang, Feng-Sheng Wang, Pei-Wen Wang, Hung-Yu Lin, Sheng-Dean Luo and Ya-Ling Yang
Int. J. Mol. Sci. 2022, 23(1), 577; https://doi.org/10.3390/ijms23010577 - 5 Jan 2022
Cited by 17 | Viewed by 6326
Abstract
Non-alcoholic fatty liver disease (NAFLD), the most common cause of chronic liver disease, consists of fat deposited (steatosis) in the liver due to causes besides excessive alcohol use. The folding activity of heat shock protein 60 (HSP60) has been shown to protect mitochondria [...] Read more.
Non-alcoholic fatty liver disease (NAFLD), the most common cause of chronic liver disease, consists of fat deposited (steatosis) in the liver due to causes besides excessive alcohol use. The folding activity of heat shock protein 60 (HSP60) has been shown to protect mitochondria from proteotoxicity under various types of stress. In this study, we investigated whether HSP60 could ameliorate experimental high-fat diet (HFD)-induced obesity and hepatitis and explored the potential mechanism in mice. The results uncovered that HSP60 gain not only alleviated HFD-induced body weight gain, fat accumulation, and hepatocellular steatosis, but also glucose tolerance and insulin resistance according to intraperitoneal glucose tolerance testing and insulin tolerance testing in HSP60 transgenic (HSP60Tg) compared to wild-type (WT) mice by HFD. Furthermore, overexpression of HSP60 in the HFD group resulted in inhibited release of mitochondrial dsRNA (mt-dsRNA) compared to WT mice. In addition, overexpression of HSP60 also inhibited the activation of toll-like receptor 3 (TLR3), melanoma differentiation-associated gene 5 (MDA5), and phosphorylated-interferon regulatory factor 3 (p-IRF3), as well as inflammatory biomarkers such as mRNA of il-1β and il-6 expression in the liver in response to HFD. The in vitro study also confirmed that the addition of HSP-60 mimics in HepG2 cells led to upregulated expression level of HSP60 and restricted release of mt-dsRNA, as well as downregulated expression levels of TLR3, MDA5, and pIRF3. This study provides novel insight into a hepatoprotective effect, whereby HSP60 inhibits the release of dsRNA to repress the TLR3/MDA5/pIRF3 pathway in the context of NAFLD or hepatic inflammation. Therefore, HSP60 may serve as a possible therapeutic target for improving NAFLD. Full article
(This article belongs to the Special Issue Molecular Link between Steatosis and Obesity)
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18 pages, 5992 KiB  
Article
Leptin Reduces Plin5 m6A Methylation through FTO to Regulate Lipolysis in Piglets
by Dongqin Wei, Qian Sun, Yizhou Li, Chaowei Li, Xinjian Li and Chao Sun
Int. J. Mol. Sci. 2021, 22(19), 10610; https://doi.org/10.3390/ijms221910610 - 30 Sep 2021
Cited by 10 | Viewed by 2509
Abstract
Perilipin5 (Plin5) is a scaffold protein that plays an important role in lipid droplets (LD) formation, but the regulatory effect of leptin on it is unclear. Our study aimed to explore the underlying mechanisms by which leptin reduces the N6-methyladenosine (m [...] Read more.
Perilipin5 (Plin5) is a scaffold protein that plays an important role in lipid droplets (LD) formation, but the regulatory effect of leptin on it is unclear. Our study aimed to explore the underlying mechanisms by which leptin reduces the N6-methyladenosine (m6A) methylation of Plin5 through fat mass and obesity associated genes (FTO) and regulates the lipolysis. To this end, 24 Landrace male piglets (7.73 ± 0.38 kg) were randomly sorted into two groups, either a control group (Control, n = 12) or a 1 mg/kg leptin recombinant protein treatment group (Leptin, n = 12). After 4 weeks of treatment, the results showed that leptin treatment group had lower body weight, body fat percentage and blood lipid levels, but the levels of Plin5 mRNA and protein increased significantly in adipose tissue (p < 0.05). Leptin promotes the up-regulation of FTO expression level in vitro, which in turn leads to the decrease of Plin5 M6A methylation (p < 0.05). In in vitro porcine adipocytes, overexpression of FTO aggravated the decrease of M6A methylation and increased the expression of Plin5 protein, while the interference fragment of FTO reversed the decrease of m6A methylation (p < 0.05). Finally, the overexpression in vitro of Plin5 significantly reduces the size of LD, promotes the metabolism of triglycerides and the operation of the mitochondrial respiratory chain, and increases thermogenesis. This study clarified that leptin can regulate Plin5 M6A methylation by promoting FTO to affect the lipid metabolism and energy consumption, providing a theoretical basis for treating diseases related to obesity. Full article
(This article belongs to the Special Issue Molecular Link between Steatosis and Obesity)
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14 pages, 1293 KiB  
Article
A Distinctive NAFLD Signature in Adipose Tissue from Women with Severe Obesity
by Óscar Osorio-Conles, Arturo Vega-Beyhart, Ainitze Ibarzabal, José María Balibrea, Isabel Graupera, Jordi Rimola, Josep Vidal and Ana de Hollanda
Int. J. Mol. Sci. 2021, 22(19), 10541; https://doi.org/10.3390/ijms221910541 - 29 Sep 2021
Cited by 16 | Viewed by 3292
Abstract
Development and severity of nonalcoholic fatty liver disease (NAFLD) have been linked to obesity and white adipose tissue (WAT) dysfunction plays a key role in this relation. We compared the main features of subcutaneous (SAT) and visceral WAT (VAT) tissue dysfunction in 48 [...] Read more.
Development and severity of nonalcoholic fatty liver disease (NAFLD) have been linked to obesity and white adipose tissue (WAT) dysfunction plays a key role in this relation. We compared the main features of subcutaneous (SAT) and visceral WAT (VAT) tissue dysfunction in 48 obese women without (Ob) and with NAFLD (Ob-NAFLD) undergoing bariatric surgery and matched for age, BMI and T2D status. Fat cell area, adipocyte size distribution, the degree of histological fibrosis and the mRNA expression of adipokines and genes implicated in inflammation, adipogenesis, angiogenesis, metabolism and extracellular matrix remodeling were measured by RT-qPCR in both fat depots. Ob-NAFLD group showed higher TG and lower HDL circulating levels, increased VAT fat cell area and similar WAT fibrosis in comparison with Ob group. A sPLS-DA was performed in order to identify the set of genes that better characterize the presence of NAFLD. Finally, we build a multinomial logistic model including seven genes that explained 100% of the variance in NAFLD and correctly predicted 100% of cases. Our data support the existence of distinctive NAFLD signatures in WAT from women with severe obesity. A better understanding of these pathways may help in future strategies for the prevention and treatment of NAFLD. Full article
(This article belongs to the Special Issue Molecular Link between Steatosis and Obesity)
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13 pages, 1744 KiB  
Article
Deregulation of Secreted Frizzled-Related Protein 5 in Nonalcoholic Fatty Liver Disease Associated with Obesity
by Laia Bertran, Marta Portillo-Carrasquer, Carmen Aguilar, José Antonio Porras, David Riesco, Salomé Martínez, Margarita Vives, Fàtima Sabench, Eva Gonzalez, Daniel Del Castillo, Cristóbal Richart and Teresa Auguet
Int. J. Mol. Sci. 2021, 22(13), 6895; https://doi.org/10.3390/ijms22136895 - 27 Jun 2021
Cited by 6 | Viewed by 2562
Abstract
Secreted frizzled-related protein 5 (SFRP5), an antagonist of the noncanonical WNT pathway, has a controversial role in liver disease. The aim of this study was to analyze the role of SFRP5 and the noncanonical WNT pathway in nonalcoholic fatty liver disease (NAFLD). Plasma [...] Read more.
Secreted frizzled-related protein 5 (SFRP5), an antagonist of the noncanonical WNT pathway, has a controversial role in liver disease. The aim of this study was to analyze the role of SFRP5 and the noncanonical WNT pathway in nonalcoholic fatty liver disease (NAFLD). Plasma SFRP5 levels were determined by ELISA in women with normal weight (NW; n = 20) and morbid obesity (MO; n = 69). Women with MO were subclassified according to hepatic histology into normal liver (NL; n = 28), NAFLD (n = 41) (simple steatosis (SS; n = 24), and nonalcoholic steatohepatitis (NASH; n = 17)). We used RT-qPCR to evaluate the hepatic mRNA expression of SFRP5, WNT5A, and JNK in women with MO. SFRP5 levels were lower in NW than in MO patients who underwent a very low-calorie diet before surgery. Hepatic SFRP5 mRNA expression was higher in SS than in NL or NASH; additionally, patients with hepatic inflammation or ballooning presented lower SFRP5 abundance. WNT5A and JNK expression was enhanced in NAFLD compared with NL. In conclusion, circulating SFRP5 levels depend on the diet, and hepatic SFRP5 seems to have a protective role in the first steps of NAFLD; however, SFRP5 could be deregulated in an advanced stage while WNT5A and JNK are activated, promoting liver damage. Full article
(This article belongs to the Special Issue Molecular Link between Steatosis and Obesity)
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15 pages, 3074 KiB  
Article
Effects of Edible Insect Tenebrio molitor Larva Fermentation Extract as a Substitute Protein on Hepatosteatogenesis and Proteomic Changes in Obese Mice Induced by High-Fat Diet
by Ju Ri Ham, Ra-Yeong Choi, Yongjin Lee and Mi-Kyung Lee
Int. J. Mol. Sci. 2021, 22(7), 3615; https://doi.org/10.3390/ijms22073615 - 31 Mar 2021
Cited by 16 | Viewed by 3745
Abstract
Mealworms (Tenebrio molitor larva) are an edible insect and a protein-rich food; however, research on mealworms as a substitute protein is insufficient. In this study, mealworm fermentation extract (TMP) was assessed as a replacement for soy protein (SP) in a control diet [...] Read more.
Mealworms (Tenebrio molitor larva) are an edible insect and a protein-rich food; however, research on mealworms as a substitute protein is insufficient. In this study, mealworm fermentation extract (TMP) was assessed as a replacement for soy protein (SP) in a control diet (CON) or a high-fat diet (HFD) of mice for 12 weeks. TMP substitution reduced body weight, body weight gain, body fat mass (perirenal and mesenteric), fat size, glucose intolerance, and insulin resistance compared to the HFD-SP group. TMP alleviated hepatic steatosis (lipid contents and lipid droplets) in high-fat-fed mice and down-regulated the PPARγ, CD36, and DGAT2 gene levels. Proteomic analysis showed that a HFD for 12 weeks up-regulated 20 proteins and down-regulated 17 proteins in mice fed SP. On the other hand, TMP reversed the protein profiles. TMP significantly down-regulated KHK, GLO1, ATP5H, SOD, and DDAH1 and up-regulated DLD, Mup1, CPS1, Ces3b, PDI, and HYOU1 compared to the HFD-SP group. These proteins are involved in the glucose, lipid, and amino acid metabolism, as well as in oxidative stress and endoplasmic reticulum stress. Thus, substituting SP for TMP helped improve HFD-induced obesity, steatosis, and insulin resistance in mice. These results suggest that TMP is a potential substitute for commonly used protein sources. Full article
(This article belongs to the Special Issue Molecular Link between Steatosis and Obesity)
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13 pages, 3574 KiB  
Article
Absence of Adiponutrin (PNPLA3) and Monoacylglycerol Lipase Synergistically Increases Weight Gain and Aggravates Steatohepatitis in Mice
by Matteo Tardelli, Francesca V. Bruschi, Claudia D. Fuchs, Thierry Claudel, Nicole Auer, Victoria Kunczer, Onne A. H. O. Ronda, Henkjan J. Verkade, Tatjana Stojakovic, Hubert Scharnagl and Michael Trauner
Int. J. Mol. Sci. 2021, 22(4), 2126; https://doi.org/10.3390/ijms22042126 - 20 Feb 2021
Cited by 3 | Viewed by 3413
Abstract
Altered lipid metabolic pathways including hydrolysis of triglycerides are key players in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Whether adiponutrin (patatin-like phospholipase domain containing protein-3—PNPLA3) and monoacylglycerol lipase (MGL) synergistically contribute to disease progression remains unclear. We generated double knockout ( [...] Read more.
Altered lipid metabolic pathways including hydrolysis of triglycerides are key players in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Whether adiponutrin (patatin-like phospholipase domain containing protein-3—PNPLA3) and monoacylglycerol lipase (MGL) synergistically contribute to disease progression remains unclear. We generated double knockout (DKO) mice lacking both Mgl and Pnpla3; DKO mice were compared to Mgl−/− after a challenge by high-fat diet (HFD) for 12 weeks to induce steatosis. Serum biochemistry, liver transaminases as well as histology were analyzed. Fatty acid (FA) profiling was assessed in liver and adipose tissue by gas chromatography. Markers of inflammation and lipid metabolism were analyzed. Bone marrow derived macrophages (BMDMs) were isolated and treated with oleic acid. Combined deficiency of Mgl and Pnpla3 resulted in weight gain on a chow diet; when challenged by HFD, DKO mice showed increased hepatic FA synthesis and diminished beta-oxidation compared to Mgl−/−.DKO mice exhibited more pronounced hepatic steatosis with inflammation and recruitment of immune cells to the liver associated with accumulation of saturated FAs. Primary BMDMs isolated from the DKO mice showed increased inflammatory activities, which could be reversed by oleic acid supplementation. Pnpla3 deficiency aggravates the effects of Mgl deletion on steatosis and inflammation in the liver under HFD challenge. Full article
(This article belongs to the Special Issue Molecular Link between Steatosis and Obesity)
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Review

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33 pages, 572 KiB  
Review
Molecular and Pathophysiological Links between Metabolic Disorders and Inflammatory Bowel Diseases
by Chang-Kee Hyun
Int. J. Mol. Sci. 2021, 22(17), 9139; https://doi.org/10.3390/ijms22179139 - 24 Aug 2021
Cited by 34 | Viewed by 4694
Abstract
Despite considerable epidemiological evidence indicating comorbidity between metabolic disorders, such as obesity, type 2 diabetes, and non-alcoholic fatty liver disease, and inflammatory bowel diseases (IBD), such as Crohn’s disease and ulcerative colitis, as well as common pathophysiological features shared by these two categories [...] Read more.
Despite considerable epidemiological evidence indicating comorbidity between metabolic disorders, such as obesity, type 2 diabetes, and non-alcoholic fatty liver disease, and inflammatory bowel diseases (IBD), such as Crohn’s disease and ulcerative colitis, as well as common pathophysiological features shared by these two categories of diseases, the relationship between their pathogenesis at molecular levels are not well described. Intestinal barrier dysfunction is a characteristic pathological feature of IBD, which also plays causal roles in the pathogenesis of chronic inflammatory metabolic disorders. Increased intestinal permeability is associated with a pro-inflammatory response of the intestinal immune system, possibly leading to the development of both diseases. In addition, dysregulated interactions between the gut microbiota and the host immunity have been found to contribute to immune-mediated disorders including the two diseases. In connection with disrupted gut microbial composition, alterations in gut microbiota-derived metabolites have also been shown to be closely related to the pathogeneses of both diseases. Focusing on these prominent pathophysiological features observed in both metabolic disorders and IBD, this review highlights and summarizes the molecular risk factors that may link between the pathogeneses of the two diseases, which is aimed at providing a comprehensive understanding of molecular mechanisms underlying their comorbidity. Full article
(This article belongs to the Special Issue Molecular Link between Steatosis and Obesity)
22 pages, 2181 KiB  
Review
Fructose and the Liver
by Pablo Muriel, Pedro López-Sánchez and Erika Ramos-Tovar
Int. J. Mol. Sci. 2021, 22(13), 6969; https://doi.org/10.3390/ijms22136969 - 28 Jun 2021
Cited by 77 | Viewed by 11338
Abstract
Chronic diseases represent a major challenge in world health. Metabolic syndrome is a constellation of disturbances affecting several organs, and it has been proposed to be a liver-centered condition. Fructose overconsumption may result in insulin resistance, oxidative stress, inflammation, elevated uric acid levels, [...] Read more.
Chronic diseases represent a major challenge in world health. Metabolic syndrome is a constellation of disturbances affecting several organs, and it has been proposed to be a liver-centered condition. Fructose overconsumption may result in insulin resistance, oxidative stress, inflammation, elevated uric acid levels, increased blood pressure, and increased triglyceride concentrations in both the blood and liver. Non-alcoholic fatty liver disease (NAFLD) is a term widely used to describe excessive fatty infiltration in the liver in the absence of alcohol, autoimmune disorders, or viral hepatitis; it is attributed to obesity, high sugar and fat consumption, and sedentarism. If untreated, NAFLD can progress to nonalcoholic steatohepatitis (NASH), characterized by inflammation and mild fibrosis in addition to fat infiltration and, eventually, advanced scar tissue deposition, cirrhosis, and finally liver cancer, which constitutes the culmination of the disease. Notably, fructose is recognized as a major mediator of NAFLD, as a significant correlation between fructose intake and the degree of inflammation and fibrosis has been found in preclinical and clinical studies. Moreover, fructose is a risk factor for liver cancer development. Interestingly, fructose induces a number of proinflammatory, fibrogenic, and oncogenic signaling pathways that explain its deleterious effects in the body, especially in the liver. Full article
(This article belongs to the Special Issue Molecular Link between Steatosis and Obesity)
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