Ursodeoxycholic acid ameliorates hepatic lipid metabolism in LO2 cells by regulating the AKT/mTOR/SREBP-1 signaling pathway

Unlocking the lipid code: SREBPs as key drivers in gastrointestinal tumour metabolism

In recent years, metabolic reprogramming has emerged as a significant breakthrough in elucidating the onset and progression of gastrointestinal (GI) malignancies. As central regulatory hubs for lipid metabolism, sterol regulatory element binding proteins (SREBPs) integrate dietary metabolic signals and carcinogenic stimuli through subtype-specific mechanisms, thereby promoting malignant tumour phenotypes. In this review, we first present the molecular background, structural characteristics, and posttranscriptional regulatory networks associated with SREBPs. We subsequently describe a systematic analysis of the distinct activation patterns of SREBPs in liver, gastric, colorectal, and other gastrointestinal cancers. Furthermore, we explore targeted intervention strategies for different SREBP subtypes, including small molecule inhibitors (such as fatostatin, which inhibits SREBP cleavage), natural compounds (such as berberine, which modulates the AMPK/mTOR pathway), and statin-mediated inhibition of the mevalonic acid pathway. These strategies may enhance tumour cell sensitivity to chemotherapeutic agents (such as 5-FU, gezil, and tabine) and improve the response to synergistic chemoradiotherapy by reversing adaptive metabolic resistance driven by the tumour microenvironment. Through this review, we hope to provide new insights into precise interventions targeting various subtypes of the SREBP molecule.

Effect of midlife exercise on lipid metabolism in aging mice: comparable to lifelong exercise, better than ceasing midlife exercise

This study examines the effects of continuous versus interrupted lifelong exercise on lipid metabolism in naturally aging male BALB/c mice. Five-week-old male BALB/c mice were randomly assigned to five groups: young control group (YC), natural ageing control group (AC), exercise cessation group (DE), middle-aged commencing exercise group (ME), and lifelong exercise group (LE). Moderate Intensity Continuous Training exercise sessions were conducted three times per week, with each session lasting 50 min; after exercise interventions until 72 weeks of age, the following parameters were measured: body morphology, exercise capacity, blood lipid, liver fat content, liver function, expression of liver lipid metabolism-related genes and endoplasmic reticulum stress-related genes, and activities of liver metabolism enzymes. The results suggest that advancing age leads to disrupted lipid processing, reduced hepatic performance, and increased endoplasmic reticular tension. Compared with the AC group, the ME and LE cohorts showed reduced serum lipids, whereas the LE group exhibited elevated high-density lipoprotein cholesterol (HDL-C) levels (P < 0.05). Post-exercise reductions were observed in hepatic total cholesterol and free fatty acid (FFA). Moreover, the exercises mitigated age-related hepatic impairments and diminished susceptibility towards cirrhosis despite higher aspartate aminotransferase (AST) and lower albumin (ALB) levels being evident within the DE cohort (P < 0.05). Exercise demonstrates the potential to mitigate age-related abnormalities in lipid metabolism. Middle-aged commencing and lifelong exercise interventions are more effective in alleviating lipid abnormalities than exercise cessation in middle age. This disparity in efficacy can be attributed to differences in regulating endoplasmic reticulum stress, enhancing liver lipid oxidation capacity, and reducing lipid synthesis ability. Notably, middle-aged individuals commencing exercise yield similar outcomes in regulating aging-associated abnormal lipid metabolism compared to the lifelong exercise group. This highlights the importance of initiating exercise in middle age, as it remains beneficial even if lifelong commitment is unfeasible, so exercise initiation in midlife is still beneficial. However, to prevent liver lipid metabolism disorders later in life, the earlier exercise initiation, the better.

Cardiac Molecular Analysis Reveals Aging-Associated Metabolic Alterations Promoting Glycosaminoglycans Accumulation via Hexosamine Biosynthetic Pathway

Age is a prominent risk factor for cardiometabolic disease, often leading to heart structural and functional changes. However, precise molecular mechanisms underlying cardiac remodeling and dysfunction exclusively resulting from physiological aging remain elusive. Previous research demonstrated age-related functional alterations in baboons, analogous to humans. The goal of this study is to identify early cardiac molecular alterations preceding functional adaptations, shedding light on the regulation of age-associated changes. Unbiased transcriptomics of left ventricle samples are performed from female baboons aged 7.5-22.1 years (human equivalent ≈30-88 years). Weighted-gene correlation network and pathway enrichment analyses are performed, with histological validation. Modules of transcripts negatively correlated with age implicated declined metabolism-oxidative phosphorylation, tricarboxylic acid cycle, glycolysis, and fatty-acid β-oxidation. Transcripts positively correlated with age suggested a metabolic shift toward glucose-dependent anabolic pathways, including hexosamine biosynthetic pathway (HBP). This shift is associated with increased glycosaminoglycan synthesis, modification, precursor synthesis via HBP, and extracellular matrix accumulation, verified histologically. Upregulated extracellular matrix-induced signaling coincided with glycosaminoglycan accumulation, followed by cardiac hypertrophy-related pathways. Overall, these findings revealed a transcriptional shift in metabolism favoring glycosaminoglycan accumulation through HBP before cardiac hypertrophy. Unveiling this metabolic shift provides potential targets for age-related cardiac diseases, offering novel insights into early age-related mechanisms.

3,5-Dimethyl-2,4,6-trimethoxychalcone Lessens Obesity and MAFLD in Leptin-Deficient ob/ob Mice

Chalcones constitute an important group of natural compounds abundant in fruits and comestible plants. They are a subject of increasing interest because of their biological activities, including anti-diabetic and anti-obesity effects. The simple chalcone structural scaffold can be modified at multiple sites with different chemical moieties. Here, we generated an artificial chalcone, i.e., 3,5-dimethyl-2,4,6-trimethoxychalcone (TriMetChalc), derived from 2',4'-Dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC). DMC is a major compound of Cleistocalyx operculatus, a plant widely used in Asia for its anti-hyperglycemic activity. Using ob/ob mice as an obesity model, we report that, after 3 weeks of per os administration, TriMetChalc modified food intake through the specific activation of brain structures dedicated to the regulation of energy balance. TriMetChalc also decreased weight gain, glucose intolerance, and hepatic steatosis. Moreover, through extensive liver lipidomic analysis, we identified TriMetChalc-induced modifications that could contribute to improving the liver status of the animals. Hence, TriMetChalc is a chalcone derivative capable of reducing food intake and the addition of glucose intolerance and hepatic steatosis in a mouse model of obesity. In light of these results, we believe that TriMetChalc action deserves to be more deeply evaluated over longer treatment periods and/or in combination with other chalcones with protective effects on the liver.

Subchronic toxic effects of bisphenol A on the gut-liver-hormone axis in rats via intestinal flora and metabolism

Background

Bisphenol A (BPA), a characteristic endocrine disruptor, is a substance that seriously interferes with the human endocrine system and causes reproductive disorders and developmental abnormalities. However, its toxic effects on the gut-liver-hormone axis are still unclear.

Method

Male and female rats were exposed to BPA (300 mg/kg) by oral gavage for 60 consecutive days. H&E staining was used for histopathological evaluation, and the serum biochemical indexes were determined using an automatic analyzer. The 16S rRNA gene sequencing was used to detect the intestinal microbial diversity, and the GC-MS was used to analyze the contents of short-chain fatty acids (SCFAs) in colon contents. UPLC-QTOF MS was used to analyze the related metabolites. The ELISA method was used to assess the levels of serum inflammatory factors.

Results

Histopathological analysis indicated that the liver, heart, and testis were affected by BPA. There was a significant effect on alanine aminotransferase (ALT), triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL) in the male-BPA group (P < 0.05), and globulin (GLB), indirect bilirubin (IBIL), alkaline phosphatase (ALP), ALT, TG, TC, high-density lipoprotein (HDL), and creatinine (Cr) in the female-BPA group (P < 0.05). Metagenomics (16S rRNA gene sequencing) analysis indicated that BPA reduced the diversity and changed the composition of gut microbiota in rats significantly. Compared with the control and blank groups, the contents of caproic acid, isobutyric acid, isovaleric acid, and propanoic acid in the colon contents decreased in the male-BPA group (P < 0.05), and caproic acid, isobutyric acid, isovaleric acid, and valeric acid in the colon contents decreased in the female-BPA group (P < 0.05). Metabolomic analysis of the serum indicated that BPA could regulate bile acid levels, especially ursodeoxycholic acid (UDCA) and its conjugated forms. The contents of amino acids, hormones, and lipids were also significantly affected after exposure to BPA. The increase in interleukin-6 (IL-6), interleukin-23 (IL-23), and transforming growth factor-β (TGF-β) in the serum of the male-BPA group suggests that BPA exposure affects the immune system.

Conclusion

BPA exposure will cause toxicity to rats via disrupting the gut-liver-hormone axis.

BI-7273, a BRD9 inhibitor, reduces lipid accumulation by downregulating the AKT/mTOR/SREBP1 signaling pathway

Increases in de novo lipogenesis that disturbed lipid homeostasis and caused lipid accumulation are a major cause of NAFLD and obesity. SREBP1 is a crucial regulatory factor controlling the expression of rate-limiting enzymes of lipid synthesis. A reduction in SREBP1expression can reduce lipid accumulation. Thus, we utilized an SREBP1-luciferase-KI HEK293 cell line constructed by our lab to screen 200 kinds of epigenetic drugs for their ability to downregulate SREBP1expression. BI-7273, an inhibitor of bromodomain-containing protein 9 (BRD9), was screened and found to decrease SREBP1 expression. What is more, BI-7273 has been confirmed that it could reduce lipid accumulation in HepG2 cells by BODIPY staining, and significantly decrease the protein expression of SREBP1 and FASN. To explore the potential mechanism BI-7273 reducing lipid accumulation, RNA sequencing (RNA-seq) was performed and demonstrated that BI-7273 reduced lipid accumulation by downregulating the AKT/mTOR/SREBP1 pathway in vitro. Finally, these results were verified in NAFLD and obesity mouse model induced by high fat diet (HFD). The results indicated that BI-7273 could decrease mouse body weight and improve insulin sensitivity, but also exhibited a strong negative correlation with serum lipid levels, and also demonstrated that BI-7273 reduced lipid accumulation via AKT/mTOR/SREBP1 pathway in vivo. In conclusion, our results revealed that BI-7273 decreases lipid accumulation by downregulating the AKT/mTOR/SREBP1 pathway in vivo and in vitro. This is the first report demonstrating the protective effect of this BRD9 inhibitor against NAFLD and obesity. BRD9 may be a novel target for the discovery of effective drugs to treat lipid metabolism disorders.

Understanding the role of ursodeoxycholic acid and gut microbiome in non-alcoholic fatty liver disease: current evidence and perspectives

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, resulting in a huge medical burden worldwide. Accumulating evidence suggests that the gut microbiome and bile acids play pivotal roles during the development of NAFLD. Patients with NAFLD exhibit unique signatures of the intestinal microbiome marked by the priority of Gram-negative bacteria, decreased ratio of Firmicutes/Bacteroidetes (F/B), and increased Prevotella and Lachnospiraceae. The intestinal microbiota is involved in the metabolism of bile acids. Ursodeoxycholic acid (UDCA) is a key determinant in maintaining the dynamic communication between the host and gut microbiota. It generally shows surprising therapeutic potential in NAFLD with several mechanisms, such as improving cellular autophagy, apoptosis, and mitochondrial functions. This action is based on its direct or indirect effect, targeting the farnesoid X receptor (FXR) and various other nuclear receptors. This review aims to discuss the current studies on the involvement of the microbiome-UDCA interface in NAFLD therapy and provide prospective insights into future preventative and therapeutic approaches for NAFLD.

Leucine regulates lipid metabolism in adipose tissue through adipokine-mTOR-SIRT1 signaling pathway and bile acid-microbe axis in a finishing pig model

This study was conducted to explore the regulatory mechanism of leucine (Leu) on lipid metabolism of finishing pigs. Twenty-four Duroc × Landrace × Large cross pigs with an average body weight of 68.33 ± 0.97 kg were randomly allocated into 3 treatment groups with 8 replicates per group (1 pig per replicate). The dietary treatments were as follows: control group (CON), 0.25% Leu group and 0.50% Leu group. The experimental period was 42 d. The results showed as follows. (1) Compared with the CON, 0.25% and 0.50% Leu increased (P < 0.01) the average daily gain (ADG), while the average backfat thickness (ABT) and the ratio of feed intake to body weight gain (F:G ratio) were decreased (P < 0.05). (2) In the 0.25% Leu group, the relative mRNA expression levels of sterol regulatory element binding protein-1c (SREBP1c), recombinant fatty acid transport protein 1 (FATP1), chemerin and peroxisome proliferator-activated receptor γ (PPARγ) were decreased but the level of fatty acid binding protein 4 (FABP4) and fatty acid translocase (FAT/CD36) were increased in backfat tissue. In the 0.25% Leu group, the protein levels of p-Rictor, p-Raptor, p-eIF4E-binding protein 1 (p-4EBP1), p-silent mating type information regulator 2 homolog 1 (p-SIRT1) and acetylation ribosome s6 protein kinase 1 (Ac-S6K1) were increased (P < 0.05). (3) Compared to the CON, the diversity of gut microbiota in the 0.25% Leu group was increased. Principal component analysis showed that the relative abundance of Bacteroidetes, Lactobacillus and Desulfovibrio was higher in the 0.25% Leu group than the CON, but the relative abundance of Firmicutes, Treponema and Shigella was lower than in the CON (P < 0.05). (4) Four different metabolites were screened out from the serum of finishing pigs including allolithocholic acid (alloLCA), isolithocholic acid (isoLCA), ursodeoxycholic acid (UDCA) and hyodeoxycholic acid (HDCA), which correlate to various degrees with the above microorganisms. In conclusion, Leu could promote adipose tissue lipolysis of finishing pigs through the mTOR-SIRT1 signaling pathway, and S6K1 is acetylated at the same time, and the interaction between gut microbiota and bile acid metabolism is also involved.

Flavonoids from mulberry leaves inhibit fat production and improve fatty acid distribution in adipose tissue in finishing pigs

This study evaluated the effects of flavonoids from mulberry leaves (FML) on plasma biochemical indices, serum activities of lipid metabolism-related enzymes, fat morphology, fatty acid composition, and lipid metabolism in different adipose tissues of finishing pigs. We used 120 Chinese hybrid barrows of Berkshire and Bama mini-pigs with an average initial body weight of 45.11 ± 4.23 kg. The pigs were randomly assigned to five treatment groups and fed a control diet based on corn, soybean meal, and wheat bran or a control diet supplemented with 0.02%, 0.04%, 0.08%, or 0.16% FML. Each experimental group had six replicates (pens), with four pigs per pen. After a 7-d adaptation period, the feeding trial was conducted for 58 d. Blood and adipose tissue samples were collected from 30 pigs (one pig per pen) at the end of the test. The results showed that FML supplementation significantly decreased the feed intake to body gain ratio, the plasma concentrations of total cholesterol and free fatty acids, and the serum activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase (linear or quadratic effects, P < 0.05), and decreased the plasma triglyceride concentration (quadratic, P = 0.07). Increasing FML supplementation increased the average daily gain and serum activities of lipoprotein lipase (linear and quadratic effects, P < 0.05) and adipose triglyceride lipase (linear, P < 0.05). Dietary FML supplementation decreased the adipocyte area in the dorsal subcutaneous adipose (DSA) tissue of finishing pigs (linear, P = 0.05) and increased the adipocyte area in the visceral adipose tissue (quadratic, P < 0.01). Increasing FML supplementation decreased the C20:1 content in DSA, abdominal subcutaneous adipose, and visceral adipose tissues of finishing pigs (P < 0.05) and increased the C18:3n3 and n-3 PUFA contents (P < 0.05). The lipid metabolism genes were regulated by the PPARγ-LXRα-ABCA1 signaling pathway, and their expressions differed in different adipose tissues. These findings suggest that FML improved growth performance, regulated lipid metabolism, inhibited fat production, and improved fatty acid distribution in the adipose tissue of finishing pigs, thereby improving pig fat's nutritional quality and health value.

Muscular lipidomics and transcriptomics reveal the effects of bile acids on lipid metabolism in high-fat diet-fed grouper

Little information is available on how exogenous bile acids alter lipid metabolism in muscle of fish. In the present study, an 8-week feeding trial were used to investigate the impacts of bile acids on lipid deposition, lipid metabolism, lipidomics, and transcriptomics in muscle of pearl gentian grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂) fed a high-fat diet (HD). The HD treatment significantly increased the crude lipid content, while bile acids diet (BD) treatment decreased it (p = 0.057). BD treatment significantly decreased triglycerides level and significantly increased phosphatidylcholines, phosphatidylethanolamines, and phosphatidylglycerol levels. The contents of TG (17:0/18:2/18:2), TG (17:1/18:2/22:6), PC (6:0/22:1), PC (9:0/26:1), PC (26:1/6:0), PC (17:2/18:2), PE (16:0/18:1), PE (18:0/17:1), PG (18:0/20:5), PG (18:3/20:5), PG (19:0/16:1), and PG (18:0/18:1) in muscle were well response to dietary lipid level and bile acids supplementation. HD and BD groups induced a variety of adaptive metabolic responses in transcriptomics. HD treatment increased the lipogenesis and decreased lipolysis, whereas BD treatment decreased the lipogenesis and increased lipolysis. Present study revealed the improvement of muscular lipid metabolism and lipid composition in response to bile acids administration in pearl gentian grouper.

Roles of immune dysregulation in MASLD

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease worldwide. Its occurrence and progression involve the process from simple hepatic steatosis to metabolic dysfunction associated steatohepatitis (MASH), which could develop into advanced liver fibrosis, cirrhosis, or hepatocellular carcinoma (HCC). Growing evidences support that the pathogenesis and progression of MASLD are closely related to immune system dysfunction. This review aims to summarize the association of MASLD with immune disorders and the prospect of using immunotherapy for MASLD.

Electroacupuncture Suppresses Oxidative Stress and Ferroptosis by Activating the mTOR/SREBP1 Pathway in Ischemic Stroke

Ischemic stroke (IS) is one of the leading causes of death and disability worldwide. Electroacupuncture (EA) has been shown to exert a neuroprotective effect in IS. However, its specific anti-IS mechanisms remain to be fully elucidated. By constructing a rat IS (middle cerebral artery occlusion, or MCAO) model and performing EA treatment, neurological deficit score, brain water content, and cerebral infarction were evaluated. ELISA was used to measure the levels of oxidative stress-related molecules (MDA, SOD, GSH, and CAT). Ferroptosis-related proteins (GPX4, SLC7A11, TfR1, L-ferritin, and hepcidin), neurological damage-related proteins (GFAP, Iba-1, and Nestin), α7nAChR, and mTOR pathway-related proteins (mTOR, p-mTOR, and SREBP1) in the rat brain penumbra were assessed by western blotting. Following EA treatment, neurological deficit scores, brain water content, cerebral infarction area, and GFAP, Iba-1, and Nestin expression were reduced. Additionally, EA treatment decreased MDA and increased SOD, GSH, and CAT. Moreover, the rats showed elevated GPX4 and SLC7A11 and lowered TfR1, L-ferritin, and hepcidin. In contrast, a7nAChR, mTOR, p-mTOR, and SREBP1 expression were upregulated. EA treatment inhibited OS and ferroptosis to exert a neuroprotective effect in IS, which might be realized via the activation of mTOR/SREBP1 signaling.

Strategic design of an NIR probe for viscosity imaging in inflammatory and non-alcoholic steatohepatitis mice

Two novel near-infrared (NIR) fluorescent probes Cy-Vis1 and Cy-Vis2 with large Stokes shifts (>100 nm) were constructed using a "symmetry collapse" strategy. Notably, Cy-Vis2 was significantly more sensitive to viscosity than Cy-Vis1 through an enhanced intramolecular interaction strategy. The fluorescence intensities of Cy-Vis1 and Cy-Vis2 exhibited increases, by 7.6- and 19.9-fold, respectively, across the viscosity range from 0.8 cp to 359.9 cp. Cy-Vis2 was successfully used to visualize viscosity abnormalities in lipopolysaccharide (LPS)-induced inflammatory and NASH model mice.

Cardiac Molecular Analysis Reveals Aging-Associated Metabolic Alterations Promoting Glycosaminoglycans Accumulation Via Hexosamine Biosynthetic Pathway

Age is a prominent risk factor for cardiometabolic disease, and often leads to heart structural and functional changes. However, precise molecular mechanisms underlying cardiac remodeling and dysfunction resulting from physiological aging per se remain elusive. Understanding these mechanisms requires biological models with optimal translation to humans. Previous research demonstrated that baboons undergo age-related reduction in ejection fraction and increased heart sphericity, mirroring changes observed in humans. The goal of this study was to identify early cardiac molecular alterations that precede functional adaptations, shedding light on the regulation of age-associated changes. We performed unbiased transcriptomics of left ventricle (LV) samples from female baboons aged 7.5-22.1 years (human equivalent ~30-88 years). Weighted-gene correlation network and pathway enrichment analyses were performed to identify potential age-associated mechanisms in LV, with histological validation. Myocardial modules of transcripts negatively associated with age were primarily enriched for cardiac metabolism, including oxidative phosphorylation, tricarboxylic acid cycle, glycolysis, and fatty-acid β-oxidation. Transcripts positively correlated with age suggest upregulation of glucose uptake, pentose phosphate pathway, and hexosamine biosynthetic pathway (HBP), indicating a metabolic shift towards glucose-dependent anabolic pathways. Upregulation of HBP commonly results in increased glycosaminoglycan precursor synthesis. Transcripts involved in glycosaminoglycan synthesis, modification, and intermediate metabolism were also upregulated in older animals, while glycosaminoglycan degradation transcripts were downregulated with age. These alterations would promote glycosaminoglycan accumulation, which was verified histologically. Upregulation of extracellular matrix (ECM)-induced signaling pathways temporally coincided with glycosaminoglycan accumulation. We found a subsequent upregulation of cardiac hypertrophy-related pathways and an increase in cardiomyocyte width. Overall, our findings revealed a transcriptional shift in metabolism from catabolic to anabolic pathways that leads to ECM glycosaminoglycan accumulation through HBP prior to upregulation of transcripts of cardiac hypertrophy-related pathways. This study illuminates cellular mechanisms that precede development of cardiac hypertrophy, providing novel potential targets to remediate age-related cardiac diseases.

Amorphous solid dispersion augments the bioavailability of phloretin and its therapeutic efficacy via targeting mTOR/SREBP-1c axis in NAFLD mice

The escalating incidences of non-alcoholic fatty liver disease (NAFLD) and associated metabolic disorders are global health concerns. Phloretin (Ph) is a natural phenolic compound, that exhibits a wide array of pharmacological actions including its efficacy towards NAFLD. However, poor solubility and bioavailability of phloretin limits its clinical translation. Here, to address this concern we developed an amorphous solid dispersion of phloretin (Ph-SD) using Soluplus® as a polymer matrix. We further performed solid-state characterization through SEM, P-XRD, FT-IR, and TGA/DSC analysis. Phloretin content, encapsulation efficiency, and dissolution profile of the developed formulation were evaluated through reverse phase HPLC. Finally, the oral bioavailability of Ph-SD and its potential application in the treatment of experimental NAFLD mice was investigated. Results demonstrated that the developed formulation (Ph-PD) augments the dissolution profile and oral bioavailability of the native phloretin (Ph). In NAFLD mice, histopathological studies revealed the preventive effect of Ph-SD on degenerative changes, lipid accumulation, and inflammation in the liver. Ph-SD also improved the serum lipid profile, ALT, and AST levels and lowered the interleukin-6 and tumor necrosis factor-α levels in the liver. Further, Ph-SD reduced fibrotic changes in the liver tissues and attenuates NAFLD progression by blocking the mTOR/SREBP-1c pathway. In a nutshell, the results of our study strongly suggest that Ph-SD has the potential to be a therapeutic candidate in the treatment of NAFLD and can be carried forward for further clinical studies.

miR-363-3p/PTEN is involved in the regulation of lipid metabolism by genistein in HepG2 cells via ERβ

BACKGROUND

Genistein (GEN) is one of the most well-known phytoestrogens identified in various legumes. Although increasing evidence shows GEN has a potential use in phytotherapy to regulate lipid metabolism, its therapeutic mechanisms have not yet been completely elucidated, especially epigenetic alterations of miRNAs to alleviate lipid accumulation in the liver remains unknown.

PURPOSE

To clarify how GEN modulates the miRNA profile in HepG2 cells and investigate molecular mechanisms of the modulated miRNA on regulating hepatic lipid metabolism.

METHODS

The miRNA microarray was performed to compare the miRNAs expression patterns, followed by determining principal miRNA and its target gene associated with hepatic lipid metabolism modulated by GEN. miR-363-3p mimics (mi) and phosphatase and tensin homolog (PTEN)-siRNA were transfected into HepG2 cells and GEN was further treated with the cells for 24 h RESULTS: GEN induced downregulation of miR-363-3p and upregulation of PTEN, which was a target mRNA of miR-363-3p. The miR-363-3p mi led to an upregulation of sterol-regulatory element-binding protein-1c (SREBP-1c) and its downstream lipid synthesis-related factors in HepG2 cells. In addition, the inhibition of PTEN led to an increase of lipogenesis, which was associated with the AKT/mTOR signal regulation. However, GEN treatment could abrogate the lipogenic effects of miR-363-3p mi or PTEN siRNA. The modulation was associated with estrogen receptor β (ERβ).

CONCLUSION

We discerned a new mechanism that GEN regulated hepatic lipid metabolism by inhibiting miR-363-3p, which could be mediated via ERβ and by targeting PTEN in HepG2 cells. Additionally, GEN reduced hepatic lipid accumulation by regulating PTEN-AKT/mTOR signal. It implicated a protective role of GEN by elucidating its epigenetic modification of the miRNA modulated by ERβ on improving hepatic lipid metabolism and provided novel evidence of the mechanism on targeting miR-363-3p/PTEN in treating hepatic lipid disorders.

Bile acids supplementation modulates lipid metabolism, intestinal function, and cecal microbiota in geese

Bile acids(BAs) are important components of bile and play a significant role in fat metabolism. However, there is currently no systematic evaluation of the use of BAs as feed additives for geese.This study aimed to investigate the effects of adding BAs to goose feed on growth performance, lipid metabolism, intestinal morphology, mucosal barrier function, and cecal microbiota. A total of 168 28-day-old geese were randomly assigned to four treatment groups and fed diets supplemented with 0, 75, 150, or 300 mg/kg of BAs for 28 days. The addition of 75 and 150 mg/kg of BAs significantly improved the feed/gain (F/G) (p  < 0.05).The addition of BAs decreased abdominal fat percentage and serum total cholesterol (TC) levels, with 150 mg/kg of BAs significantly reducing serum triglyceride levels and increased expression of Farnesoid X Receptor (FXR) mRNA in the liver(p  < 0.05), 300 mg/kg of BAs significantly increasing the expression level of liver peroxisome proliferator-activated receptor α (PPARα) (p < 0.05). In terms of intestinal morphology and mucosal barrier function, 150 mg/kg of BAs significantly increased villus height (VH) and VH/crypt depth (CD) in the jejunum (p < 0.05). The addition of 150 and 300 mg/kg of BAs significantly reduced the CD in the ileum, while increasing VH and VH/CD (p<0.05). Additionally, the addition of 150 and 300 mg/kg of BAs significantly increased the expression levels of zonula occludens-1 (ZO-1) and occludin in the jejunum. Simultaneously 150mg/kg and 300mg/kg BAs increased the total short-chain fatty acids (SCFA) concentrations in the jejunum and cecum(p < 0.05).Supplementation with BAs resulted in a significant increase in the ɑ-diversity of cecal microbiota and a decrease in the abundance of Proteobacteria in the cecum. The addition of 150 mg/kg of BAs significantly reduced the abundance of Bacteroidetes and increased the abundance of Firmicutes. Moreover,Linear discriminant analysis Effect Size analysis (LEfSe) showed that the abundances of bacteria producing SCFA and bile salt hydrolases (BSH) were increased in the BAs-treated group. Furthermore, Spearman's analysis showed that the genus Balutia, which is negatively correlated with visceral fat area, was positively correlated with serum high-density lipoprotein cholesterol (HDL-C), while Clostridium was positively correlated with intestinal VH and VH/CD. In conclusion, BAs can be considered an effective feed additive for geese, as they increased SCFA concentration, improve lipid metabolism and intestinal health by enhancing the intestinal mucosal barrier, improving intestinal morphology, and altering the cecal microbiota structure.

Farnesoid X Receptor (FXR) Regulates mTORC1 Signaling and Autophagy by Inhibiting SESN2 Expression

SCOPE

The mechanistic target of rapamycin complex 1 (mTORC1), as a link between nutrients and autophagy, senses many nutrients in the microenvironment. A growing body of recent literature describes the function of bile acids (BAs) as versatile signaling molecules, while it remains largely unclear whether mTORC1 can sense BAs and the mechanism has not been studied.

METHODS AND RESULTS

After treating LO2 cells with indicated concentration of chenodeoxycholic acid (CDCA) and farnesoid X receptor (FXR) inhibitor/activator for 6 h, it finds that CDCA and FXR significantly accelerate mTORC1 activation. The results of immunofluorescence indicate that CDCA and FXR inhibit cellular autophagy through activating mTORC1 pathway. In particular, these findings show that CDCA and FXR promote the lysosomal translocation and activation of mTORC1 in an amino acid-sensitive manner. Mechanistically, the transcriptomics data indicate that SESN2 is a checkpoint for mTORC1 lysosome translocation and activation induced by FXR, and knockdown SESN2 with siRNA suppresses the regulation of FXR on autophagy.

CONCLUSION

These results indicate that FXR-induced decrease in SESN2 expression and activation of the mTORC1 pathway can control autophagy and be explored as potential therapeutic targets for enterohepatic and metabolic disorders.

The Role of PI3K/AKT/mTOR Signaling in Hepatocellular Carcinoma Metabolism

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths in the world. Metabolic reprogramming is considered a new hallmark of cancer, but it remains unclearly described in HCC. The dysregulation of the PI3K/AKT/mTOR signaling pathway is common in HCC and is, therefore, a topic of further research and the concern of developing a novel target for liver cancer therapy. In this review, we illustrate mechanisms by which this signaling network is accountable for regulating HCC cellular metabolism, including glucose metabolism, lipid metabolism, amino acid metabolism, pyrimidine metabolism, and oxidative metabolism, and summarize the ongoing clinical trials based on the inhibition of the PI3K/AKT/mTOR pathway in HCC.

Oleic acid-induced steatosis model establishment in LMH cells and its effect on lipid metabolism

Hepatic steatosis is a highly prevalent liver disease, yet research on it is hampered by the lack of tractable cellular models in poultry. To examine the possibility of using organoids to model steatosis and detect it efficiently in leghorn male hepatocellular (LMH) cells, we first established steatosis using different concentrations of oleic acid (OA) (0.05-0.75 mmol/L) for 12 or 24 h. The subsequent detections found that the treatment of LMH cells with OA resulted in a dramatic increase in intracellular triglyceride (TG) concentrations, which was positively associated with the concentration of the inducing OA (R2 > 0.9). Then, the modeled steatosis was detected by flow cytometry after NileRed staining and it was found that the intensity of NileRed-A was positively correlated with the TG concentration (R2 > 0.93), which demonstrates that the flow cytometry is suitable for the detection of steatosis in LMH cells. According to the detection results of the different steatosis models, we confirmed that the optimal induction condition for the establishment of the steatosis model in LMH cells is OA (0.375 mmol/L) incubation for 12 h. Finally, the transcription and protein content of fat metabolism-related genes in steatosis model cells were detected. It was found that OA-induced steatosis could significantly decrease the expression of nuclear receptor PPAR-γ and the synthesis of fatty acids (SREBP-1C, ACC1, FASN), increasing the oxidative decomposition of triglycerides (CPT1A) and the assembly of low-density lipoproteins (MTTP, ApoB). Sterol metabolism in model cells was also significantly enhanced (HMGR, ABCA1, L-BABP). This study established, detected, and analyzed an OA-induced steatosis model in LMH cells, which provides a stable model and detection method for the study of poultry steatosis-related diseases.

Lead induced disorders of lipid metabolism and glycometabolism in the liver of developmental Japanese quails (Coturnix japonica) via inhibiting PI3K/Akt signaling pathway

The lead (Pb) contamination is considered a lethal threat to birds. However, Pb-induced hepatotoxicology especially its impacts on metabolic processes in the liver of birds is not yet fully understood. Therefore, we tried to determine the toxicological effects of Pb exposure on hepatic carbohydrate and lipid metabolism via Phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway by using an animal model- Japanese quail (Coturnix japonica). One-week old female Japanese quails were randomly allocated into four groups and fed with 0, 50 ppm, 500 ppm and 1000 ppm Pb drinking water respectively for 49 days. The results showed that Pb accumulated in the liver as a dose-dependent manner. Exposure to high dose of Pb (500 and 1000 ppm Pb) led to severe histopathological damages characterized by irregularity and dilation of liver sinusoids, hepatic lipid vacuolization and hepatocellular cytoplasm hyalinization. Meanwhile, Pb exposure caused glycogen increase and lipid droplets decrease in the liver. Pb exposure was also attributable to a decreased triglyceride level in the plasma. In addition, the transcriptional levels of PI3K and Akt in the liver were downregulated by Pb exposure. Subsequently, the mRNA expressions of genes related with glycometabolism in the liver were remarkably altered and the mRNA levels of genes involved in fat synthesis and oxidation in the liver were also markedly changed. it seems that Pb could lead to liver metabolic disorder through structural damages and PI3K/Akt signaling pathway disruption.

The essential effect of mTORC1-dependent lipophagy in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a chronic progressive liver disease with increasing prevalence. Lipophagy is a type of programmed cell death that plays an essential role in maintaining the body's balance of fatty acid metabolism. However, the livers of NAFLD patients are abnormally dysregulated in lipophagy. mTORC1 is a critical negative regulator of lipophagy, which has been confirmed to participate in the process of lipophagy through various complex mechanisms. Therefore, targeting mTORC1 to restore failed autophagy may be an effective therapeutic strategy for NAFLD. This article reviews the main pathways through which mTORC1 participates in the formation of lipophagy and the intervention effect of mTORC1-regulated lipophagy in NAFLD, providing new therapeutic strategies for the prevention and treatment of NAFLD in the future.

Network Pharmacology and Molecular Docking Study on the Multi-Target Mechanisms of Aloe vera for Non-Alcoholic Steatohepatitis Treatment

Non-alcoholic steatohepatitis (NASH) is a leading cause of chronic liver disease with limited treatment options. The widely distributed plant Aloe vera has shown protective effects against NASH in animals, yet the precise mechanism remains unknown. In this study, we investigated the potential mechanisms underlying the anti-NASH effects of Aloe vera using a network pharmacology and molecular docking approach. By searching online databases and analyzing the Gene Expression Omnibus dataset, we obtained 260 Aloe vera-NASH common targets. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses showed that the common targets were strongly associated with the key pathological processes implicated in NASH, including lipid and glucose metabolism, inflammation, apoptosis, oxidative stress, and liver fibrosis. Four core proteins, AKT serine/threonine kinase 1 (AKT1), tumor necrosis factor alpha (TNFα), transcription factor c-Jun, and tumor suppressor protein p53, were identified from compound-target-pathway and protein-protein interaction networks. Molecular docking analysis verified that the active ingredients of Aloe vera were able to interact with the core proteins, especially AKT1 and TNFα. The results demonstrate the multi-compound, multi-target, and multi-pathway mechanisms of Aloe vera against NASH. Our study has shown the scientific basis for further experiments in terms of the mechanism to develop Aloe vera-based natural products as complementary treatments for NASH. Furthermore, it identifies novel drug candidates based on the structures of Aloe vera's active compounds.

Integration of clinical and transcriptomics reveals programming of the lipid metabolism in gastric cancer

Lipid metabolism has a profound impact on gastric cancer (GC) progression and is a newly targetable vulnerability for cancer therapy. Given the importance of lipids in cancer cellular processes, in this study we employed lipidomic clinical and transcriptomic data to connect the variations of lipid metabolism changes of GC. We constructed a clinical nomogram based on the lipid factors and other clinical items. Then by using multi-omics techniques, we established a lipid-related gene signature for individualized prognosis prediction in patients with GC. Moreover, a total of 1357 GC cases were then applied to evaluate the robustness of this model. WGCNA was used to identify co-expression modules and enriched genes associated with GC lipid metabolism. The role of key genes ACLY in GC was further investigated. The prognostic value of the lipgenesis signature was analyzed using Cox regression model, and clinical nomogram was established. Among them, we observed overexpression of ACLY significantly increased the levels of intracellular free fatty acid and triglyceride, and activated AKT/mTOR pathway to promote cancer development. In conclusion, our findings revealed that GC exhibited a reprogramming of lipid metabolism in association with an altered expression of associated genes. Among them, ACLY significantly promoted GC lipid metabolism and increased cancer cell proliferation, suggesting that this pathway can be targetable as a metabolic vulnerability in future GC therapy.

Crosstalk between Hypoxia and Extracellular Matrix in the Tumor Microenvironment in Breast Cancer

Even though breast cancer is the most diagnosed cancer among women, treatments are not always successful in preventing its progression. Recent studies suggest that hypoxia and the extracellular matrix (ECM) are important in altering cell metabolism and tumor metastasis. Therefore, the aim of this review is to study the crosstalk between hypoxia and the ECM and to assess their impact on breast cancer progression. The findings indicate that hypoxic signaling engages multiple mechanisms that directly contribute to ECM remodeling, ultimately increasing breast cancer aggressiveness. Second, hypoxia and the ECM cooperate to alter different aspects of cell metabolism. They mutually enhance aerobic glycolysis through upregulation of glucose transport, glycolytic enzymes, and by regulating intracellular pH. Both alter lipid and amino acid metabolism by stimulating lipid and amino acid uptake and synthesis, thereby providing the tumor with additional energy for growth and metastasis. Third, YAP/TAZ signaling is not merely regulated by the tumor microenvironment and cell metabolism, but it also regulates it primarily through its target c-Myc. Taken together, this review provides a better understanding of the crosstalk between hypoxia and the ECM in breast cancer. Additionally, it points to a role for the YAP/TAZ mechanotransduction pathway as an important link between hypoxia and the ECM in the tumor microenvironment, driving breast cancer progression.

Activated autophagy-lysosomal pathway in dairy cows with hyperketonemia is associated with lipolysis of adipose tissues

Activated autophagy-lysosomal pathway (ALP) can degrade virtually all kinds of cellular components, including intracellular lipid droplets, especially during catabolic conditions. Sustained lipolysis and increased plasma fatty acids concentrations are characteristic of dairy cows with hyperketonemia. However, the status of ALP in adipose tissue during this physiological condition is not well known. The present study aimed to ascertain whether lipolysis is associated with activation of ALP in adipose tissues of dairy cows with hyperketonemia and in calf adipocytes. In vivo, blood and subcutaneous adipose tissue (SAT) biopsies were collected from nonhyperketonemic (nonHYK) cows [blood β-hydroxybutyrate (BHB) concentration <1.2 mM, n = 10] and hyperketonemic (HYK) cows (blood BHB concentration 1.2-3.0 mM, n = 10) with similar days in milk (range: 3-9) and parity (range: 2-4). In vitro, calf adipocytes isolated from 5 healthy Holstein calves (1 d old, female, 30-40 kg) were differentiated and used for (1) treatment with lipolysis inducer isoproterenol (ISO, 10 µM, 3 h) or mammalian target of rapamycin inhibitor Torin1 (250 nM, 3 h), and (2) pretreatment with or without the ALP inhibitor leupeptin (10 μg/mL, 4 h) followed by ISO (10 µM, 3 h) treatment. Compared with nonHYK cows, serum concentration of free fatty acids was greater and serum glucose concentration, DMI, and milk yield were lower in HYK cows. In SAT of HYK cows, ratio of phosphorylated hormone-sensitive lipase to hormone-sensitive lipase, and protein abundance of adipose triacylglycerol lipase were greater, but protein abundance of perilipin 1 (PLIN1) and cell death-inducing DNA fragmentation factor-α-like effector c (CIDEC) was lower. In addition, mRNA abundance of autophagy-related 5 (ATG5), autophagy-related 7 (ATG7), and microtubule-associated protein 1 light chain 3 beta (MAP1LC3B), protein abundance of lysosome-associated membrane protein 1, and cathepsin D, and activity of β-N-acetylglucosaminidase were greater, whereas protein abundance of sequestosome-1 (p62) was lower in SAT of HYK cows. In calf adipocytes, treatment with ISO or Torin1 decreased protein abundance of PLIN1, and CIDEC, and triacylglycerol content in calf adipocytes, but increased glycerol content in the supernatant of calf adipocytes. Moreover, the mRNA abundance of ATG5, ATG7, and MAP1LC3B was upregulated, the protein abundance of lysosome-associated membrane protein 1, cathepsin D, and activity of β-N-acetylglucosaminidase were increased, whereas the protein abundance of p62 was decreased in calf adipocytes treated with ISO or Torin1 compared with control group. Compared with treatment with ISO alone, the protein abundance of p62, PLIN1, and CIDEC, and triacylglycerol content in calf adipocytes were higher, but the glycerol content in the supernatant of calf adipocytes was lower in ISO and leupeptin co-treated group. Overall, these data indicated that activated ALP is associated with increased lipolysis in adipose tissues of dairy cows with hyperketonemia and in calf adipocytes.

The effect of bile salt diet supplementation on genes related to fat metabolism in yellow-feathered broilers

Background and Aim:

As a new feed additive, bile acid (BA) can promote the absorption and transport of lipids and fat-soluble vitamins. In recent years, BAs have been widely used in animal feed to promote fat absorption. Therefore, this study aimed to investigate the effect of bile salt supplementation in the diet of yellow-feathered broilers on messenger RNA (mRNA) expression of sterol regulatory element-binding protein 1 (SREBF1), fatty acid synthase (FAS), acetyl-coenzyme A carboxylase (ACC), and fatty acid transport protein 4 (FATP4).

Materials and Methods:

Four hundred and twenty commercial male chicks were randomly divided into seven groups (with four replicates per group and 15 chickens per replicate). They were fed diets supplemented with bile salts at 0, 1.5, 2.5, 3.5, 4.5, 5.5 mg/kg, and 2 mg/kg tylosin for 30 days. Changes in SREBF1, fatty acid transporter 4, FAS, and acetyl-CoA carboxylase genes in intestinal mucosa and liver of yellow-feathered broilers were determined using a quantitative fluorescence polymerase chain reaction.

Results:

mRNA expression of SREBF1, FAS, ACC, and FATP4 in the small intestine decreased in chicks fed diets supplemented with 3.5 and 4.5 mg/kg bile salts (p<0.05) compared with the control group on 7 days and 14 d. The mRNA expressions of SREBF1, FAS, ACC, and FATP4 in liver tissue decreased in chicks fed diets supplemented with 4.5 and 5.5 mg/kg bile salts (p<0.05) compared to the control group on 7 days. The mRNA expression of SREBF1, FAS, ACC, and FATP4 in the liver at 14 days and the small intestine on 21 days also decreased in chicks fed diets supplemented with 4.5 mg/kg bile salts (p<0.05) compared to the control group. When contrasted with the control group on day 21, the mRNA expression of SRWBF1, FAS, ACC, and FATP4 detected in the liver was lower in chicks fed diets supplemented with bile salts (p<0.05).

Conclusion:

The dietary supplementation of bile salts at 4.5 mg/kg effectively regulates the expression of fat metabolism genes, such as SREBF1, FAS, ACC, and FATP4 mRNA. At this concentration, bile salts promote fat catabolism, inhibit fat synthesis, and play an essential role in improving the fat deposition of broilers.

Diterpenoid Alkaloids Isolated from Delphinium brunonianum and Their Inhibitory Effects on Hepatocytes Lipid Accumulation

This research aimed to excavate compounds with activity reducing hepatocytes lipid accumulation from Delphinium brunonianum. Four novel diterpenoid alkaloids, brunodelphinine B–E, were isolated from D. brunonianum together with eleven known diterpenoid alkaloids through a phytochemical investigation. Their structures were elucidated by comprehensive spectroscopy methods including HR-ESI-MS, NMR, IR, UV, CD, and single-crystal X-ray diffraction analysis. The inhibitory effects of a total of 15 diterpenoid alkaloids on hepatocytes lipid accumulation were evaluated using 0.5 mM FFA (oleate/palmitate 2:1 ratio) to induce buffalo rat liver (BRL) cells by measuring the levels of triglyceride (TG), total cholesterol (TC), alanine transaminase (ALT), aspartate transaminase (AST), and the staining of oil red O. The results show that five diterpenoid alkaloids—brunodelphinine E (4), delbruline (5), lycoctonine (7), delbrunine (8), and sharwuphinine A (12)—exhibited significant inhibitory effects on lipid accumulation in a dose-dependent manner and without cytotoxicity. Among them, sharwuphinine A (12) displayed the strongest inhibition of hepatocytes lipid accumulation in vitro. Our research increased the understanding on the chemical composition of D. brunonianum and provided experimental and theoretical evidence for the active ingredients screened from this herbal medicine in the treatment of the diseases related to lipid accumulation, such as non-alcoholic fatty liver disease and hyperlipidemia.

Ursodesoxycholic acid is an FFA4 agonist and reduces hepatic steatosis via FFA4 signaling

Ursodeoxycholic acid (UDCA) is a safe bile acid effective in reducing hepatic steatosis in non-alcoholic fatty liver disease (NAFLD). However, the mechanism of action linked to this effect is poorly defined. In the present study, we identified that UDCA acted as a free fatty acid receptor 4 (FFA4) agonist with EC50 of 10.4 ± 0.7 μM, and its activity was determined by dynamic mass redistribution, fluorometric imaging plate reader, inositol monophosphate and bioluminescence resonance energy transfer assays. Moreover, UDCA showed FFA4 selectivity over eleven other G protein-coupled receptors. Real-Time PCR and immunocytochemistry analyses showed that FFA4 was abundantly expressed in human hepatocytes HuH-7 cells. In an in vitro model of NAFLD induced by oleic acid (OA), UDCA downregulated lipid accumulation in HuH-7 cells and suppressed sterol-regulatory element binding protein-1c (SREBP-1c) mRNA expression. This suppression of SREBP-1c was restored when FFA4 expression was knocked down in siRNA assay. In a mouse model of hepatic steatosis, db/db mice were exposed to a high-fat diet (HFD), and treatment of UDCA or docosahexaenoic acid (DHA, an endogenous FFA4 agonist) effectively prevented body weight gain and hepatic fat deposition and reduced triglyceride (TG) levels in serum and liver. This study not only identified a new skeleton of FFA4 agonists, but also demonstrated that FFA4 signal was accounting for the protective effects of UDCA in the NAFLD treatment.

Alcoholic liver disease-from steatosis to cirrhosis - a biochemistry approach

Nowadays, chronic alcoholism and its health implications represent a global concern. Over three million deaths are linked to chronic alcohol intake every year. This article aims to spread awareness about the negative impact ethanol can have on almost every organ in the body, especially the liver. Understanding ethanol metabolism and the cellular pathways through which alcohol increases liver oxidative stress may prevent a broad spectrum of hepatic lesions such as steatosis, steatohepatitis, and, ultimately, cirrhosis. After a short review of ethanol metabolism and liver oxidative stress, each hepatic lesion will be individually discussed regarding the mechanism of apparition, treatment, and future targeted therapies.

Gestational bisphenol A exposure impairs hepatic lipid metabolism by altering mTOR/CRTC2/SREBP1 in male rat offspring

Lipid metabolism is an important biochemical process in the body. Recent studies have found that environmental endocrine disruptors play an important role in the regulation of lipid metabolism. Bisphenol A (BPA), a common environmental endocrine disruptor, has adverse effects on lipid metabolism, but the mechanism is still unclear. This study aimed to investigate the effects of gestational BPA exposure on hepatic lipid metabolism and its possible mechanism in male offspring. The pregnant Sprague-Dawley rats were exposed to BPA (0, 0.05, 0.5, 5 mg/kg/day) from day 5 to day 19 of gestation to investigate the levels of triglyceride (TG) and total cholesterol (TC), and the expression of liver lipid metabolism-related genes in male offspring rats. The results showed that compared with the control group, the TG and TC levels in serum and liver in BPA-exposed groups was increased. And the expressions of liver fatty acid oxidation related genes, such as peroxisome proliferators-activated receptor α (PPARα) and carnitine palmitoyl transferase 1α (CPT1α), were down-regulated. However, the expressions of fatty acid synthesis related genes, such as sterol regulatory element binding proteins 1 (SREBP-1), acetyl-CoA carboxylase 1 (ACC1), fatty acid synthase (FAS) and stearoyl-CoA desaturase 1 (SCD-1), were up-regulated. The increased protein levels of mTOR and p-CRTC2 suggested that CREB-regulated transcription coactivator 2 (CRTC2) might be an important mediator in the mTOR/SREBP-1 pathway. In conclusion, these results demonstrated that mTOR/CRTC2/SREBP-1 could be affected by gestational BPA exposure, which may involve in the lipid metabolic disorders in later life.

Application of herbs and active ingredients ameliorate non-alcoholic fatty liver disease under the guidance of traditional Chinese medicine

Non-alcoholic fatty liver disease (NAFLD) is a global health problem, and its prevalence has been on the rise in recent years. Traditional Chinese Medicine (TCM) contains a wealth of therapeutic resources and has been in use for thousands of years regarding the prevention of liver disease and has been shown to be effective in the treatment of NAFLD in China. but the molecular mechanisms behind it have not been elucidated. In this article, we have updated and summarized the research and evidence concerning herbs and their active ingredients for the treatment in vivo and vitro models of NAFLD or NASH, by searching PubMed, Web of Science and SciFinder databases. In particular, we have found that most of the herbs and active ingredients reported so far have the effect of clearing heat and dispelling dampness, which is consistent with the concept of dampness-heat syndrome, in TCM theory. we have attempted to establish the TCM theory and modern pharmacological mechanisms links between herbs and monomers according to their TCM efficacy, experiment models, targets of modulation and amelioration of NAFLD pathology. Thus, we provide ideas and perspectives for further exploration of the pathogenesis of NAFLD and herbal therapy, helping to further the scientific connotation of TCM theories and promote the modernization of TCM.

Target Deconvolution of Fenofibrate in Nonalcoholic Fatty Liver Disease Using Bioinformatics Analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a prevalent form of liver damage, affecting ~25% of the global population. NAFLD comprises a spectrum of liver pathologies, from hepatic steatosis to nonalcoholic steatohepatitis (NASH), and may progress to liver fibrosis and cirrhosis. The presence of NAFLD correlates with metabolic disorders such as hyperlipidemia, obesity, blood hypertension, cardiovascular, and insulin resistance. Fenofibrate is an agonist drug for peroxisome proliferator-activated receptor alpha (PPARα), used principally for treatment of hyperlipidemia. However, fenofibrate has recently been investigated in clinical trials for treatment of other metabolic disorders such as diabetes, cardiovascular disease, and NAFLD. The evidence to date indicates that fenofibrate could improve NAFLD. While PPARα is considered to be the main target of fenofibrate, fenofibrate may exert its effect through impact on other genes and pathways thereby alleviating, and possibly reversing, NAFLD. In this study, using bioinformatics tools and gene-drug, gene-diseases databases, we sought to explore possible targets, interactions, and pathways involved in fenofibrate and NAFLD.

METHODS

We first determined significant protein interactions with fenofibrate in the STITCH database with high confidence (0.7). Next, we investigated the identified proteins on curated targets in two databases, including the DisGeNET and DISEASES databases, to determine their association with NAFLD. We finally constructed a Venn diagram for these two collections (curated genes-NAFLD and fenofibrate-STITCH) to uncover possible primary targets of fenofibrate. Then, Gene Ontology (GO) and KEGG were analyzed to detect the significantly involved targets in molecular function, biological process, cellular component, and biological pathways. A P value < 0.01 was considered the cut-off criterion. We also estimated the specificity of targets with NAFLD by investigating them in disease-gene associations (STRING) and EnrichR (DisGeNET). Finally, we verified our findings in the scientific literature.

RESULTS

We constructed two collections, one with 80 protein-drug interactions and the other with 95 genes associated with NAFLD. Using the Venn diagram, we identified 11 significant targets including LEP, SIRT1, ADIPOQ, PPARA, SREBF1, LDLR, GSTP1, VLDLR, SCARB1, MMP1, and APOC3 and then evaluated their biological pathways. Based on Gene Ontology, most of the targets are involved in lipid metabolism, and KEGG enrichment pathways showed the PPAR signaling pathway, AMPK signaling pathway, and NAFLD as the most significant pathways. The interrogation of those targets on authentic disease databases showed they were more specific to both steatosis and steatohepatitis liver injury than to any other diseases in these databases. Finally, we identified three significant genes, APOC3, PPARA, and SREBF1, that showed robust drug interaction with fenofibrate.

CONCLUSION

Fenofibrate may exert its effect directly or indirectly, via modulation of several key targets and pathways, in the treatment of NAFLD.

Target Therapies for NASH/NAFLD: From the Molecular Aspect to the Pharmacological and Surgical Alternatives

Non-alcoholic fatty liver disease represents an increasing cause of chronic hepatic disease in recent years. This condition usually arises in patients with multiple comorbidities, the so-called metabolic syndrome. The therapeutic options are multiple, ranging from lifestyle modifications, pharmacological options, to liver transplantation in selected cases. The choice of the most beneficial one and their interactions can be challenging. It is mandatory to stratify the patients according to the severity of their disease to tailor the available treatments. In our contribution, we review the most recent pharmacological target therapies, the role of bariatric surgery, and the impact of liver transplantation on the NAFLD outcome.

Feprazone Displays Antiadipogenesis and Antiobesity Capacities in in Vitro 3 T3-L1 Cells and in Vivo Mice

BACKGROUND AND PURPOSE

Excessive lipid accumulation in adipose tissues and deregulation of adipogenesis-induced obesity affect millions of people worldwide. Feprazone, a nonsteroidal anti-inflammatory drug, has a wide clinical use. However, it is unknown whether Feprazone possesses an antiadipogenic ability. The aim of this study is to investigate whether Feprazone possesses an antiadipogenic ability in 3 T3-L1 cells and an antiobesity capacity in mouse models.

METHODS

An MTT assay was used to determine the optimized incubation concentrations of Feprazone in 3 T3-L1 cells. The lipid accumulation was evaluated using Oil Red O staining. The concentrations of triglyceride and glycerol release were detected to check the lipolysis during 3 T3-L1 adipogenesis. A quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the expressions of sterol regulatory element-binding protein-1C (SREBP-1C) and fatty acid binding protein 4 (FABP4) in treated cells. The expressions of peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding protein α (C/EBP-α), adipose triglyceride lipase (ATGL), and aquaporin-7 (AQP-7) were detected using qRT-PCR and Western blot analysis. After the high-fat diet (HFD) mice were treated with Feprazone, the pathological state of adipocyte tissues was evaluated using HE staining. The adipocyte size, visceral adipocyte tissue weight, and bodyweights were recorded.

RESULTS

According to the proliferation result, 30 and 60 μM Feprazone were used as the optimized concentrations of Feprazone. In the in vitro study, lipid accumulation, elevated production of triglycerides, the release of glycerol, upregulated SREBP-1C, FABP4, PPAR-γ, and C/EBP-α and downregulated ATGL and AQP-7 in the 3 T3-L1 adipocytes induced by the adipocyte differentiation cocktail medium were significantly reversed by treatment with Feprazone. In the in vivo experiment, we found that the increased adipocyte size, visceral adipocyte tissue weight, and body weights induced by HFD feeding in mice were significantly suppressed by the administration of Feprazone.

CONCLUSION

Feprazone might display anti-adipogenic and antiobesity capacities in in vitro 3 T3-L1 cells and in vivo mice.

Extracellular Matrix Stiffness: New Areas Affecting Cell Metabolism

In recent years, in-depth studies have shown that extracellular matrix stiffness plays an important role in cell growth, proliferation, migration, immunity, malignant transformation, and apoptosis. Most of these processes entail metabolic reprogramming of cells. However, the exact mechanism through which extracellular matrix stiffness leads to metabolic reprogramming remains unclear. Insights regarding the relationship between extracellular matrix stiffness and metabolism could help unravel novel therapeutic targets and guide development of clinical approaches against a myriad of diseases. This review provides an overview of different pathways of extracellular matrix stiffness involved in regulating glucose, lipid and amino acid metabolism.

Systemic Overexpression of GDF5 in Adipocytes but Not Hepatocytes Alleviates High-Fat Diet-Induced Nonalcoholic Fatty Liver in Mice

OBJECTIVE

Our recent study demonstrated that growth differentiation factor 5 (GDF5) could promote white adipose tissue thermogenesis and alleviate high-fat diet- (HFD-) induced obesity in fatty acid-binding protein 4- (Fabp4-) GDF5 transgenic mice (TG). Here, we further investigated the effects of systemic overexpression of the GDF5 gene in adipocytes HFD-induced nonalcoholic fatty liver disease (NAFLD).

METHODS

Fabp4-GDF5 TG mice were administered an HFD feeding. NAFLD-related indicators associated with lipid metabolism and inflammation were measured. A GDF5 lentiviral vector was constructed, and the LO2 NAFLD cell model was induced by FFA solution (oleic acid and palmitic acid). The alterations in liver function, liver lipid metabolism, and related inflammatory indicators were analyzed.

RESULTS

The liver weight was significantly reduced in the TG group, which was in accordance with the significantly downregulated expression of TNFα, MCP1, Aim2, and SREBP-1c and significantly upregulated expression of CPT-1α and ACOX2 in TG mouse livers. Compared to that of cells in the FAA-free control group, LO2 cells with in situ overexpression of GDF5 developed lipid droplets after FFA treatment; the levels of triglycerides, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were significantly increased in both the GDF5 lentivirus and control lentivirus groups compared with those of the FAA-free group. Additionally, the levels of FAS, SREBP-1, CPT-1α, and inflammation-associated genes, such as ASC and NLRC4, were unaltered despite GDF5 treatment.

CONCLUSION

Systemic overexpression of GDF5 in adipose tissue in vivo significantly reduced HFD-induced NAFLD liver damage in mice. The overexpression of GDF5 in hepatocytes failed to improve lipid accumulation and inflammation-related reactions induced by mixed fatty acids, suggesting that the protective effect of GDF5 in NAFLD was mainly due to the reduction in adipose tissue and improvements in metabolism. Hence, our study suggests that the management of NAFLD should be targeted to reduce the overall amount of body fat and improve metabolic status before the progression to nonalcoholic steatohepatitis occurs.

MIEF2 reprograms lipid metabolism to drive progression of ovarian cancer through ROS/AKT/mTOR signaling pathway

MIEF2 (mitochondrial elongation factor 2) is one of the key regulators of mitochondrial fission. Bioinformatics analysis indicated that high expression of MIEF2 predicted a poor prognosis in ovarian cancer patients. However, the relationship between MIEF2 and aberrant lipid metabolism in OC remains elusive. In this study, we demonstrated that MIEF2 significantly promoted lipid synthesis, while has no significant effect on fatty acid uptake and oxidation in OC cells. MIEF2 enhanced de novo fatty acid synthesis through up-regulating the expression of sterol regulatory element binding protein 1 (SREBP1) and its transcriptional target lipogenic genes ACC1, FASN and SCD1. Meanwhile, MIEF2-promoted cholesterol biosynthesis through up-regulating the expression of sterol regulatory element binding protein 2 (SREBP2) and its transcriptional target cholesterol biosynthesis genes HMGCS1 and HMGCR. Mechanistically, increased mitochondrial reactive oxygen species (ROS) production and subsequently activation of AKT/mTOR signaling pathway was found to be involved in the up-regulation of SREBP1 and SREBP2 in OC cells. Moreover, cell growth and metastasis assays indicated that MIEF2-regulated fatty acid synthesis and cholesterol biosynthesis played a critical role in the progression of OC. Taken together, our findings indicate that MIEF2 is a critical regulator of lipid synthesis in OC, which provides a strong line of evidence for this molecule to serve as a drug target in the treatment of this malignancy.

Regulation of autophagy by bile acids and in cholestasis - CholestoPHAGY or CholeSTOPagy

Autophagy is a lysosomal degradation pathway in which the cell self-digests its own components to provide nutrients in harsh environmental conditions. It also represents an opportunity to rid the cell of superfluous and damaged organelles, misfolded proteins or invaded microorganisms. Liver autophagy contributes to basic hepatic functions such as lipid, glycogen and protein turnover. Deregulated hepatic autophagy has been linked to many liver diseases including alpha-1-antitrypsin deficiency, alcoholic and non-alcoholic fatty liver diseases, hepatitis B and C infections, liver fibrosis as well as liver cancer. Recently, bile acids and the bile acid receptor FXR have been implicated in the regulation of hepatic autophagy, which implies a role of autophagy also for cholestatic liver diseases. This review summarizes the current evidence of bile acid mediated effects on autophagy and how this affects cholestatic liver diseases. Although detailed studies are lacking, we suggest a concept that the activity of autophagy in cholestasis depends on the disease stage, where autophagy may be induced at early stages ("cholestophagy") but may be impaired in prolonged cholestatic states ("cholestopagy").

Liraglutide ameliorates lipotoxicity-induced inflammation through the mTORC1 signalling pathway

Lipotoxicity has been implicated in many disease processes, and prolonged exposure to high lipid levels often leads to the activation of a variety of abnormal signals, which in turn leads to the induction of inflammation. The aim of our study was to explore the correlation between mammalian target of rapamycin (mTOR) and inflammation by studying high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) in rats and palmitate (PA)-induced inflammation (lipotoxicity) in HepG2 cells. In addition, we investigated whether the glucagon-like peptide-1 (GLP-1) analogue liraglutide can protect rats and HepG2 cells from lipotoxicity. Our results showed that an HFD and PA significantly increased inflammation by activating the mTORC1 pathway in vitro and in vivo. Treatment with rapamycin (an mTOR inhibitor) inhibited some effects of PA on inflammation. Furthermore, we observed that liraglutide inhibited PA-induced inflammation by inactivating mTORC1 signalling molecules. Overall, our findings demonstrated that mTORC1 signalling pathways were involved primarily in high lipid level-induced inflammation. Importantly, liraglutide may protect against lipotoxicity-induced inflammation by regulating mTORC1-dependent pathways.

Veratrilla baillonii Franch Could Alleviate Lipid Accumulation in LO2 Cells by Regulating Oxidative, Inflammatory, and Lipid Metabolic Signaling Pathways

Based on the pathological theory of lipid metabolism and using network pharmacology, this study was designed to investigate the protective effect of water extract of Veratrilla baillonii (WVBF) on non-alcoholic fatty liver disease (NAFLD) model using LO2 cells and to identify the potential mechanism underlying the effect. The components of V. baillonii were identified from the public database of traditional Chinese medicine systems pharmacology database (TCMSP). Cytoscape software was used to construct the related composite target network. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were carried out for critical nodes. The BioGPS database was used to determine the distribution of the target in tissues and organs. Moreover, the inhibitory effect of V. baillonii was further investigated using an in vitro hepatocyte NAFLD model. Fourteen active components were then selected from the 27 known compounds of V. baillonii. The targets of gene enrichment analysis were mainly distributed in the lipid catabolism-related signaling pathway. Network analysis revealed that five target genes of TNF, MAPK8, mTOR, NF-ĸB, and SREBP-1c were key nodes and played important roles in this process. Organ localization analysis indicated that one of the core target site of V. baillonii was liver tissue. The results of the in vitro study revealed that WVBF can alleviate the inflammatory response and lipid accumulation in LO2 hepatocytes by inhibiting oxidative stress and the adipocytokine signaling pathway. Genes and proteins related to the lipid synthesis, such as SREBP-1C, acetyl-CoA carboxylase (ACC), and fatty acid synthase (FASN), were significantly decreased, and PPARα expression is significantly increased with WVBF administration. In conclusion, V. baillonii may regulate local lipid metabolism and attenuate oxidative stress and inflammatory factors through the PPARα/SREBP-1c signaling pathway. The present study also indicates that multiple components of V. baillonii regulate multiple targets and pathways in NAFLD. The findings highlight the potential of V. baillonii as a promising treatment strategy for nonalcoholic fatty liver injury.

Role of the Sterol Regulatory Element Binding Protein Pathway in Tumorigenesis

Metabolic changes are a major feature of tumors, including various metabolic forms, such as energy, lipid, and amino acid metabolism. Sterol regulatory element binding proteins (SREBPs) are important modules in regulating lipid metabolism and play an essential role in metabolic diseases. In the previous decades, the regulatory range of SREBPs has been markedly expanded. It was found that SREBPs also played a critical role in tumor development. SREBPs are involved in energy supply, lipid supply, immune environment and inflammatory environment shaping in tumor cells, and as a protective umbrella to support the malignant proliferation of tumor cells. Natural medicine and traditional Chinese medicine, as an important part of drug therapy, demonstrates the multifaceted effects of SREBPs regulation. This review summarizes the core processes in the involvement of SREBPs in tumors and provides a comprehensive understanding of the pathways through which natural drugs target the SREBP pathway and regulate tumor progression.

Ursodeoxycholic acid alleviates nonalcoholic fatty liver disease by inhibiting apoptosis and improving autophagy via activating AMPK

Ursodeoxycholic acid (UDCA), first identified in bear bile, was widely used in cholestatic liver diseases. Our previous studies have suggested UDCA may exert favorable influence on hepatic steatosis. However, the molecular mechanism remains elusive. Given the role of autophagy and apoptosis dysregulation in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and pharmacological effects of UDCA on modulating autophagy, apoptosis. we sought to investigate whether UDCA had therapeutic effect on NAFLD and its mechanism of modulating autophagy, apoptosis. Our finding revealed that UDCA exerted obviously favorable influence on hepatic steatosis in NAFLD rats by activating AMP-activated protein kinase (AMPK). Mechanistic studies indicated UDCA inhibited apoptosis and improved autophagy by influencing Bcl-2/Beclin-1 and Bcl-2/Bax complex interaction. Importantly, above-mentioned influence of UDCA on autophagy, apoptosis and Bcl-2/Beclin-1, Bcl-2/Bax complex interaction in NAFLD were partly counteracted by AMPK inhibitor compound C(CC). In conclusion, UDCA exerts favorable influence on hepatic steatosis in NAFLD rats, which is attributable to apoptosis inhibition and autophagy induction by influencing Bcl-2/Beclin-1 complex and Bcl-2/Bax complex interaction via activating AMPK, indicating that UDCA may be a promising therapeutic target for NAFLD.

Gypenoside Inhibits Endothelial Cell Apoptosis in Atherosclerosis by Modulating Mitochondria through PI3K/Akt/Bad Pathway

Atherosclerosis remains the most common cause of deaths worldwide. Endothelial cell apoptosis is an important process in the progress of atherosclerosis, as it can cause the endothelium to lose their capability in regulating the lipid homeostasis, inflammation, and immunity. Endothelial cell injury can disrupt the integrity and barrier function of an endothelium and facilitate lipid deposition, leading to atherogenesis. Chinese medicine techniques for preventing and treating atherosclerosis are gaining attention, especially natural products. In this study, we demonstrated that gypenoside could decrease the levels of serum lipid, alleviate the formation of atherosclerotic plaque, and lessen aortic intima thickening. Gypenoside potentially activates the PI3K/Akt/Bad signal pathway to modulate the apoptosis-related protein expression in the aorta. Moreover, gypenoside downregulated mitochondrial fission and fusion proteins, mitochondrial energy-related proteins in the mouse aorta. In conclusion, this study demonstrated a new function of gypenoside in endothelial apoptosis and suggested a therapeutic potential of gypenoside in atherosclerosis associated with apoptosis by modulating mitochondrial function through the PI3K/Akt/Bad pathway.

Activation of mTOR Signaling Pathway in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer and occurs mainly in patients with liver cirrhosis. The mammalian target of rapamycin (mTOR) signaling pathway is involved in many hallmarks of cancer including cell growth, metabolism re-programming, proliferation and inhibition of apoptosis. The mTOR pathway is upregulated in HCC tissue samples as compared with the surrounding liver cirrhotic tissue. In addition, the activation of mTOR is more intense in the tumor edge, thus reinforcing its role in HCC proliferation and spreading. The inhibition of the mTOR pathway by currently available pharmacological compounds (i.e., sirolimus or everolimus) is able to hamper tumor progression both in vitro and in animal models. The use of mTOR inhibitors alone or in combination with other therapies is a very attractive approach, which has been extensively investigated in humans. However, results are contradictory and there is no solid evidence suggesting a true benefit in clinical practice. As a result, neither sirolimus nor everolimus are currently approved to treat HCC or to prevent tumor recurrence after curative surgery. In the present comprehensive review, we analyzed the most recent scientific evidence while providing some insights to understand the gap between experimental and clinical studies.