Gene Expression Patterns Are Altered in Athymic Mice and Metabolic Syndrome Factors Are Reduced in C57BL/6J Mice Fed High-Fat Diets Supplemented with Soy Isoflavones

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.

Multi-omics analysis explores the effect of chronic exercise on liver metabolic reprogramming in mice

Background: The effect of exercise on human metabolism is obvious. However, the effect of chronic exercise on liver metabolism in mice is less well described. Methods: The healthy adult mice running for 6 weeks as exercise model and sedentary mice as control were used to perform transcriptomic, proteomic, acetyl-proteomics, and metabolomics analysis. In addition, correlation analysis between transcriptome and proteome, and proteome and metabolome was conducted as well. Results: In total, 88 mRNAs and 25 proteins were differentially regulated by chronic exercise. In particular, two proteins (Cyp4a10 and Cyp4a14) showed consistent trends (upregulated) at transcription and protein levels. KEGG enrichment analysis indicated that Cyp4a10 and Cyp4a14 are mainly involved in fatty acid degradation, retinol metabolism, arachidonic acid metabolism and PPAR signaling pathway. For acetyl-proteomics analysis, 185 differentially acetylated proteins and 207 differentially acetylated sites were identified. Then, 693 metabolites in positive mode and 537 metabolites in negative mode were identified, which were involved in metabolic pathways such as fatty acid metabolism, citrate cycle and glycolysis/gluconeogenesis. Conclusion: Based on the results of transcriptomic, proteomics, acetyl-proteomics and metabolomics analysis, chronic moderate intensity exercise has certain effects on liver metabolism and protein synthesis in mice. Chronic moderate intensity exercise may participate in liver energy metabolism by influencing the expression of Cyp4a14, Cyp4a10, arachidonic acid and acetyl coenzyme A and regulating fatty acid degradation, arachidonic acid metabolism, fatty acyl metabolism and subsequent acetylation.

Dietary Soy Isoflavones Prevent Metabolic Disturbs Associated with a Deleterious Combination of Obesity and Menopause

This study aimed to evaluate the effects of soy isoflavone supplementation (25 mg/kg) on insulin resistance and inflammation in adipose tissue in an experimental model of menopause-obesity. Twenty-four female Wistar rats were ovariectomized (O) and distributed among the groups: OSD-ovariectomized rats submitted to normocaloric standard diet (n = 6); OHF-ovariectomized rats submitted to high-fat diet (n = 9); and OHFI-ovariectomized rats submitted to high-fat diet with isoflavones (n = 9). Weight gain, body adiposity, food and caloric intake, blood pressure, and glucose tolerance were assessed. After 24 weeks, the rats were euthanized; the thoracic blood collected for serum insulin determination and the homeostatic model assessment-insulin resistance) (HOMA-IR) and homeostatic model assessment-β cell (HOMA-β) indices were calculated. Abdominal adipose tissues were removed, weighed, and fixed for immunohistochemical and morphometric studies. Isoflavones decreased weight gain and blood pressure without changing the food and caloric intake (P < .05). Isoflavones did not affect the weight of the abdominal adipose tissue depots (P < .05). Although they did not alter glucose tolerance, the isoflavones reduced HOMA-IR and HOMA-β, serum insulin levels, in addition to reducing adipocytes' size (P < .05). The number of macrophages, lymphocytes, and crown-like structures in adipose tissue was lower in the group treated with isoflavones (P < .05). In conclusion, our data show that dietary soy isoflavones' supplementation prevents many of well-known deleterious combination of obesity and menopause on metabolism, such as body overweight, adipocyte hypertrophy, and hypertension, as well as insulin resistance and adipose tissue inflammation.

Lipid-Lowering Effects of Inonotus obliquus Polysaccharide In Vivo and In Vitro

Excessive lipid intake will cause hyperlipidemia, fatty liver metabolism disease, and endanger people’s health. Edible fungus polysaccharide is a natural active substance for lipid lowering. In this study, the HepG2 cell model induced by oleic acid and mice model induced by a high-fat diet was established. The lipid-lowering effects of Inonotus obliquus polysaccharide (IOP) was investigated in vivo and in vitro. Glucose (251.33 mg/g), rhamnose (11.53 mg/g), ribose (5.10 mg/g), glucuronic acid (6.30 mg/g), and galacturonic acid (2.95 mg/g) are present in IOP, at a ratio of 85.2:3.91:1.73:2.14:1. The molecular weight of IOP is 42.28 kDa. Treatment with 60 mg/L of IOP showed a significant lipid-lowering effect in HepG2 cells compared with the oleic acid-treated group. In the oil red O-stained images, the red fat droplets in the IOP-treated groups were significantly reduced. TC and TG levels of IOP-treated groups decreased. IOP can alleviate the lipid deposition in the mice liver due to high-fat diet, and significantly reduce their serum TC, TG, and LDL-C contents. IOP could activate AMPK but decrease the SREBP-1C, FAS, and ACC protein expression related to adipose synthesis in mice. IOP has a certain potential for lipid-lowering effects both in vivo and in vitro.

Genistein Regulates Lipid Metabolism via Estrogen Receptor β and Its Downstream Signal Akt/mTOR in HepG2 Cells

Genistein (GEN) has been shown to significantly inhibit hepatic triglyceride accretion triggered by estrogen deficiency. The main purpose of this in vitro study was to investigate the function and molecular mechanism of estrogen receptor β (ERβ) in regulating hepatic lipid metabolism induced by GEN. Different doses of GEN or GEN with an ERβ antagonist were treated with HepG2 cells. Results showed that 25 μM GEN significantly diminished triglyceride levels. Meanwhile, GEN downregulated the levels of genes and proteins involved in lipogenesis, such as sterol-regulatory element-binding protein-1c (SREBP-1c), fatty acid synthase (FASN), and stearoyl-coenzyme A desaturase 1 (SCD1), and upregulated the gene and protein levels of the regulation factors responsible for fatty acid β-oxidation, such as carnitine palmitoyltransferase 1α (CPT-1α) and peroxisome proliferator-activated receptor α (PPARα). Furthermore, 25 μM GEN reduced the levels of phosphorylation of protein kinase B (Akt) and mechanistic target of rapamycin (mTOR). Moreover, most of these effects from GEN were reverted by pretreatment with the antagonist of ERβ. In conclusion, GEN improved hepatic lipid metabolism by activating ERβ and further modulation of Akt/mTOR signals. The results provide novel aspects of the regulatory mechanism of ERβ on hepatic lipid metabolism and might help to profoundly understand the functions of food-derived phytoestrogens in preventing and treating hepatic steatosis in postmenopausal women.

High fat diet significantly changed the global gene expression profile involved in hepatic drug metabolism and pharmacokinetic system in mice

Background

High fat diet impact transcription of hepatic genes responsible for drug metabolism and pharmacokinetics. Until now, researches just focused on a couple specific genes without a global profile showing. Age-dependent manner was also not noted well. This study aims to investigate the high fat diet effect on transcriptome of drug metabolism and pharmacokinetic system in mouse livers and show the age-dependent evidence.

Methods

C57BL/6 male mice were used in this experiment. High fat diet was used to treat mice for 16 and 38 weeks. Serum total cholesterol, low density lipoprotein cholesterol, aspartate transaminase, and alanine transaminaselevels were measured. Meanwhile, Histology, RNA-Seq, RT-PCR analysis and fourteen major hepatic bile acids quantification were performed for the liver tissues. Data was mined at levels of genes, drug metabolism and pharmacokinetic sysem, and genome wide.

Results

Treatment with high fat diet for 38 weeks significantly increased levels of serum lipids as well as aspartate transaminase, and alanine transaminase. Meanwhile, lipid accumulation in livers was observed. At week 38 of the experiment, the profile of 612 genes involved in drug metabolism and pharmacokinetics was significantly changed, indicated by a heatmap visulization and a principal component analysis. In total 210 genes were significantly regulated. Cyp3a11, Cyp4a10, and Cyp4a14 were down-regulated by 10–35 folds, while these three genes also were highly expressed in the liver. High fat diet regulated 11% of genome-wide gene while 30% of genes involved in the hepatic drug metabolism and pharmacokinetic system. Genes, including Adh4, Aldh1b1, Cyp3a11, Cyp4a10, Cyp8b1, Fmo2, Gsta3, Nat8f1, Slc22a7, Slco1a4, Sult5a1, and Ugt1a9, were regulated by high fat diet as an aging-dependent manner. Bile acids homeostasis, in which many genes related to metabolism and transportation were enriched, was also changed by high fat diet with an aging-dependet manner. Expression of genes in drug metabolism and disposition system significantly correlated to serum lipid profiles, and frequently correlated with each other.

Conclusions

High fat diet changed the global transcription profile of hepatic drug metabolism and pharmacokinetic system with a age-dependent manner.

Metabolic Syndrome Is Reduced in C57BL/6J Mice Fed High-Fat Diets Supplemented with Oak Tannins

BACKGROUND

Wine aged in oak barrels will incorporate polyphenols inherent in the staves, suggesting that wine stored in these wooden containers will introduce oak compounds into the human body after consumption.

OBJECTIVE

The purpose of the present study is to test whether consumption of these oak compounds could favorably influence metabolism in mice fed an obesogenic diet.

METHODS

C57BL/6  male mice (n = 8) were fed diets for 10 wk as follows: low-fat (LF), high-fat (HF), and HF containing 0.17% of oak tannin (HF+OT). A second 10-wk study was completed; mice were provided LF, HF, and HF diets supplemented with 7.0% of concentrates made from oaked wine (HF+OWC) or unoaked wine (HF+UWC). Physiological parameters were measured during the feeding trial and serum markers and hepatic gene expression measured from samples obtained at necropsy.

RESULTS

Intake of HF+OT significantly reduced body-weight gain (18.4 ± 1.2 g in HF vs. 13.2 ± 1.4 g in HF+OT, P < 0.05). Serum resistin concentrations were lower in HF+OT mice compared with HF mice (301 ± 10.1 pg/mL in HF+OT vs. 374 ± 10.9 pg/mL in HF; P < 0.05). Hepatic lipid accumulation and expression of glutathione-S-transferase-m2 (Gstm2) and NAD(P)H:quinone oxidoreductase (Nqo1) mRNAs were significantly decreased in HF+OT compared with HF mice (P < 0.05). When compared with HF-fed mice, intake of both OWC and UWC decreased body-weight gain (P < 0.05), with no significant impact on food consumption. Fasting glucose concentrations, serum insulin, and hepatic lipid accumulation were reduced in HF+OWC-fed mice compared with HF+UWC-fed mice (P < 0.05). Furthermore, hepatic glutathione-S-transferase-a1 (Gsta1) mRNA levels were significantly reduced in OWC-supplemented (0.25 ± 0.08) compared with UWC-supplemented (1.71 ± 0.24) mice (P < 0.05).

CONCLUSIONS

In this mouse model of metabolic disease, intake of OTs and a concentrate made from an oaked wine had a potent impact on alleviating HF-induced metabolic syndrome. Thus, intake of OTs, provided passively in oaked wine or as a dietary supplement, may act as an agent to attenuate the markers of metabolic syndrome.

Consuming Diet Supplemented with Either Red Wheat Bran or Soy Extract Changes Glucose and Insulin Levels in Female Obese Zucker Rats

Type 2 diabetes mellitus is characterized by the inability to regulate blood glucose levels due to insulin resistance, resulting in hyperglycemia and hyperinsulinemia. Research has shown that consuming soy and fiber may protect against type 2 diabetes mellitus. We performed a study to determine whether supplementing diet with soy extract (0.5% weight of diet) or fiber (as red wheat bran; 11.4% weight of diet) would decrease serum insulin and blood glucose levels in a pre-diabetic/metabolic syndrome animal model. In our study, female obese Zucker rats were fed either a control diet (n = 8) or control diet supplemented with either soy extract (n = 7) or red wheat bran (n = 8) for seven weeks. Compared to rats consuming control diet, rats fed treatment diets had significantly lower (p-value < 0.05) fasting serum insulin (control = 19.34±1.6; soy extract = 11.1±1.54; red wheat bran = 12.4±1.11) and homeostatic model assessment of insulin resistance values (control = 2.16±0.22; soy extract = 1.22±0.21; red wheat bran = 1.54±0.16). Non-fasted blood glucose was also significantly lower (p-value < 0.05) in rats fed treatment diets compared to rats consuming control diet at weeks four (control = 102.63±5.67; soy extract = 80.14±2.13; red wheat bran = 82.63±3.16), six (control = 129.5±10.83; soy extract = 89.14±2.48; red wheat bran = 98.13±3.54), and seven (control = 122.25±8.95; soy extract = 89.14±4.52; red wheat bran = 84.75±4.15). Daily intake of soy extract and red wheat bran may protect against type 2 diabetes mellitus by maintaining normal glucose homeostasis.

Soy Isoflavones and their Effects on Xenobiotic Metabolism

BACKGROUND

Soy isoflavones, such as genistein and daidzein, are bioflavonoids found in soy products that are able to interact with various hormones such as estrogen. Epidemiological studies reveal a proper level of isoflavones in diet can prevent many diseases like cancers or diabetes. Therefore, it is important to study the biotransformation and xenobiotic metabolism of soy isoflavones.

METHODS

A systematic review of published studies was carried out to investigate the characterization of isoflavones and their metabolites, sample pretreatment and quantitative analysis of isoflavones, and the influence of soy isoflavones on drug and xenobiotic metabolism.

RESULTS

Aglycones with weak estrogen-like activities are the biologically active forms of the soy isoflavones in mammals. The most recent advances including extraction, purification and detection of isoflavones in soybean and soy products are discussed. The effects of soy isoflavones on drug and xenobiotic metabolism involve in regulation of phase I cytochrome P450 (CYPs) enzyme and phase I detoxifying enzymes expression and activity. At the molecular level, soy isoflavones have proved capable of estrogenic/antiestrogenic with tissue-selective, anti-cancer, antiobesity, anti-oxidation, and tyrosine kinase inhibition activities.

CONCLUSION

This review summarized different aspects of soy isoflavones and their molecular mechanisms of pharmacological action on xenobiotic, which demonstrated that soy isoflavones can decrease the incidence of many diseases and benefit for human health. However, since the lack of clinical research for evaluation of the proper dosage of intake of soy isoflavones in diet or adjunctive therapy, there is a need for further studies on the selection of doses, biomedical applications and adverse effects of isoflavones for human health.

Genistein and daidzein decrease food intake and body weight gain in mice, and alter LXR signaling in vivo and in vitro

The study is designed to determine whether consumption of the soy isoflavones, genistein and daidzein, differentially influence metabolic syndrome, and to further investigate the involvement of Liver X Receptor (LXR) regulation. C57BL/6J mice were fed diets as follows: low fat diet (LF), western-style diet (WD), and WD containing 0.16% (w/w) of genistein (WD + G) or daidzein (WD + D) for 10 weeks. Intake of WD + G and WD + D produced a robust decrease in body weight gain by 40% and 19%, respectively (p < 0.05). Genistein reduced energy intake by 26%, and daidzein decreased energy intake by 8% (p < 0.05). A glucose tolerance test indicated that genistein consumption significantly decreased the incremental areas under the curve (AUC) from 60-120 min, compared to WD-fed mice. Gene array profiling of hepatic mRNA, and cell studies utilizing transiently-transfected HepG2 cells and mouse embryonic fibroblast cells devoid of or expressing LXRα, indicate that genistein and daidzein induce LXR-mediated pathways. In summary, addition of genistein, compared to daidzein, to a western-style diet, more profoundly decreased food intake, body weight gain, while both appear to regulate LXR-mediated pathways.

Cichoric Acid Prevents Free-Fatty-Acid-Induced Lipid Metabolism Disorders via Regulating Bmal1 in HepG2 Cells

Cichoric acid (CA), a polyphenol component from Echinacea purpurea, exhibits preventive effects on liver lipid-metabolism disorders in obesity. This research aimed to determine the role of circadian rhythm signaling during the process of CA-attenuated lipid accumulation in hepatocytes. In the current study, CA treatments improved cell morphology changes and hepatic lipid levels, which were triggered by free fatty acids (2:1, oleate: palmitate) in a dose-dependent way. Besides, CA (200 μM) regulated the circadian rhythm expressions of clock genes and the relatively shallow daily oscillations. Moreover, silencing Bmal1 significantly blocked the p-Akt/Akt pathway to 80.1% ± 1.5% and the p-GSK3β/GSK3β pathway to 64.7% ± 2.8% ( p < 0.05). Furthermore, silencing Bmal1 elevated the expressions of FAS and ACC to 122.4% ± 5.6% and 114.9% ± 1.7% in protein levels ( p < 0.05) and to 166.5% ± 18.5% and 131.4% ± 5.5% in mRNA levels ( p < 0.05). Therefore, our results demonstrated that CA has a Bmal1 resistance to lipid accumulation by enhancing the Akt/GSK3β signaling pathways and modulating the downstream expressions related to lipid metabolism, which indicated that CA might be useful as a natural and promising nonalcoholic fatty liver diseases (NAFLD) modulator.

The relationship between urinary genistein levels and serum alanine aminotransferase levels in adults in the USA: National Health and Nutrition Examination Survey 1999-2010

BACKGROUND

Genistein, a phytoestrogen with similarities to female sex hormones, has been shown to protect against oxidative stress and fibrosis in nonalcoholic fatty liver injury in animal studies. However, few studies have examined genistein's effects on liver function in humans.

PARTICIPANTS AND METHODS

We analyzed data from the National Health and Nutrition Examination Survey from 1999 to 2010. Individuals younger than 21 years, with viral hepatitis, or with serum alanine aminotransferase (ALT) at the extremes of distribution (5% on each extreme) were excluded. Urinary genistein was normalized by urinary creatinine levels. The relationship between normalized urinary genistein (nUG) and serum ALT was examined using linear regression models with and without adjustment for potential confounders, and the differential effect of sex was examined using an interaction term.

RESULTS

Of the 9864 participants, 52% were female, 50% were White, 24% were elderly, 36% had hypertension, 12% had diabetes, and 8.1% were heavy alcohol drinkers. Serum ALT was significantly lower in the highest quartile compared with the lowest quartile of nUG (22.3 vs. 23.5 U/l; P<0.001). In adjusted models, individuals in the highest quartile had 0.75 U/l lower ALT levels than those in the lowest quartile (P=0.02). We found a significant difference in ALT levels between the lowest and highest quartiles of nUG in males, but not in females (difference in differences=1.77 U/l, interaction P=0.04).

CONCLUSION

We found a statistically significant association between higher nUG and lower serum ALT in males, but not in females. The sex-specific role of genistein in mitigating liver disease merits further study.