Polyunsaturated fatty acid suppression of fatty acid synthase (FASN): evidence for dietary modulation of NF-Y binding to the Fasn promoter by SREBP-1c

Using comparative transcriptome analysis to identify molecular response mechanisms to salinity stress in channel catfish (Ictalurus punctatus)

Channel catfish (Ictalurus punctatus) are an important global aquaculture species. To explore gene expression patterns and identify adaptive molecular mechanisms in catfish during salinity stress, we performed growth comparison and comparative transcriptome sequencing on liver tissue. Our study revealed that salinity stress has a significant impact on the growth, survival, and antioxidant system of channel catfish. 927 and 1356 significant DEGs were identified in L vs. C group and H vs. C group. Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses suggested that both high and low salinity stress affected gene expression related to oxygen carrier activity, hemoglobin complex, and oxygen transport pathways, and also amino acid metabolism, immune responses, and energy and fatty acid metabolism in catfish. Among mechanisms, amino acid metabolism genes were significantly up-regulated in the low salt stress group, immune response genes were significantly up-regulated in the high salt stress group, and fatty acid metabolism genes were significantly up-regulated in both groups. These results provided a platform for unraveling steady-state regulatory mechanisms in channel catfish under salinity stress, and may limit the impact of extreme salinity changes on catfish during aquaculture practices.

Docosahexaenoic Acid Alters Lipid Metabolism Processes via H3K9ac Epigenetic Modification in Dairy Goat

Goat milk is increasingly recognized by consumers due to its high nutritional value, richness in short- and medium-chain fatty acids, and richness in polyunsaturated fatty acids (PUFA). Exogenous supplementation of docosahexaenoic acid (DHA) is an important approach to increasing the content of PUFA in goat milk. Several studies have reported benefits of dietary DHA in terms of human health, including potential against chronic diseases and tumors. However, the mechanisms whereby an increased supply of DHA regulates mammary cell function is unknown. In this study, we investigated the effect of DHA on lipid metabolism processes in goat mammary epithelial cells (GMEC) and the function of H3K9ac epigenetic modifications in this process. Supplementation of DHA promoted lipid droplet accumulation increased the DHA content and altered fatty acid composition in GMEC. Lipid metabolism processes were altered by DHA supplementation through transcriptional programs in GMEC. ChIP-seq analysis revealed that DHA induced genome-wide H3K9ac epigenetic changes in GMEC. Multiomics analyses (H3K9ac genome-wide screening and RNA-seq) revealed that DHA-induced expression of lipid metabolism genes (FASN, SCD1, FADS1, FADS2, LPIN1, DGAT1, MBOAT2), which were closely related with changes in lipid metabolism processes and fatty acid profiles, were regulated by modification of H3K9ac. In particular, DHA increased the enrichment of H3K9ac in the promoter region of PDK4 and promoted its transcription, while PDK4 inhibited lipid synthesis and activated AMPK signaling in GMEC. The activation of the expression of fatty acid metabolism-related genes FASN, FADS2, and SCD1 and their upstream transcription factor SREBP1 by the AMPK inhibitor was attenuated in PDK4-overexpressing GMEC. In conclusion, DHA alters lipid metabolism processes via H3K9ac modifications and the PDK4-AMPK-SREBP1 signaling axis in goat mammary epithelial cells, providing new insights into the mechanism through which DHA affects mammary cell function and regulates milk fat metabolism.

Fatty Acid Synthase (FASN): A Patent Review Since 2016-Present

INTRODUCTION

Fatty acid synthase (FASN), is a key metabolic enzyme involved in fatty acid biosynthesis and is an essential target for multiple disease progressions like cancer, obesity, NAFLD, etc. Aberrant expression of FASN is associated with deregulated energy metabolism of cells in these diseases.

AREA COVERED

This article provides a summary of the most recent developments in the discovery of novel FASN inhibitors with potential therapeutic uses in cancer, obesity, and other metabolic disorders such as nonalcoholic fatty liver disease from 2016 to the present. The recently published patent applications and forthcoming clinical data of FASN inhibitors from both academia and the pharma industries are also highlighted in this study.

EXPERT OPINION

The implication of FASN in multiple diseases has provided an impetus for developing novel inhibitors by both pharma companies and academia. Critical analysis of the patent literature reveals the exploration of diverse molecular scaffolds to identify potential FASN inhibitors that target the different catalytic domains of the enzyme. In spite of these multifaceted efforts, only one molecule, TVB-2640, has reached phase II trials for nonalcoholic steatohepatitis (NASH) and many malignancies. However, thecombined efforts of pharma companies to produce several FASN inhibitors might facilitate the clinical translation of this unique class of inhibitors. Nevertheless, concerted efforts towards developing multiple FASN inhibitors by pharma companies might facilitate the clinical translation of this novel class of inhibitors.

Plant and marine N3-PUFA regulation of fatty acid trafficking along the adipose tissue-liver axis varies according to nutritional state

BACKGROUND

Marine sourced N3-PUFA regulate lipid metabolism in adipose tissue and liver; however, less is known about plant sourced N3-PUFA. The goal of this study was to investigate plant and marine N3-PUFA regulation of fatty acid trafficking along the adipose tissue-liver axis according to nutritional state.

METHODS

Mice were fed low-fat diets (7% w/w) containing either lard, flaxseed, or menhaden oils for 8 weeks, and were euthanized in either fed or fasted states. Substrate utilization and physical activity were assessed during the transition from a fed to fasted state. Plasma biomarkers (triglycerides (TAG), non-esterified fatty acids (NEFA)), as well as liver and epididymal adipose tissue (eWAT) lipogenic and lipolytic markers, were measured.

RESULTS

Neither plant nor marine N3-PUFA influenced substrate utilization or activity during the transition from a fed to fasted state. In the fed state, marine N3-PUFA reduced plasma TAG levels compared to the other diets, with no further reduction seen in fasted mice. Hepatic lipogenic markers (Fasn, Acc, Scd1, and Elovl6) were reduced in the fed state with marine N3-PUFA, but not plant N3-PUFA. In the fasted state, mice fed either N3-PUFA accumulated less liver TAG, had lower plasma NEFA, and suppressed eWAT HSL activity compared to lard.

CONCLUSION

Marine N3-PUFA are more potent regulators of lipogenesis than plant N3-PUFA in the fed state, whereas both N3-PUFA influence eWAT lipolysis and plasma NEFA in the fasted state. This work provides novel insights regarding N3-PUFA regulation of fatty acid trafficking along the adipose tissue-liver axis according to nutritional state.

Relationship between dietary macronutrient composition and non-alcoholic fatty liver disease in lean and non-lean populations: a cross-sectional study

OBJECTIVE

The current study aimed to customize dietary changes for lean patients with non-alcoholic fatty liver disease (NAFLD).

DESIGN

The current study was done with a population-based cross-sectional design. The FFQ was used to analyse dietary macronutrient intake and ultrasonography results for NAFLD diagnosis. The study subjects were divided into the lean and non-lean groups based on their BMI (< 25 and ≥ 25). Multivariable logistic regression was used to evaluate the relationship between dietary macronutrients and NAFLD. Substitution analyses were also performed.

SETTING

Amol and its suburban areas in Iran.

PARTICIPANTS

Adults in the age range of 18 to < 65 with full relevant data.

RESULTS

Among the total study subjects (2308), 46·7 % had fatty liver. The substitution of polysaccharides for animal protein and SFA in the lean group resulted in a significant NAFLD reduction, whereas the substitution of SFA for all types of macronutrients, except for n-6 and mono-disaccharides, led to a significant increase in NAFLD (P < 0·05). In non-lean participants, the substitution of MUFA for mono-disaccharides resulted in a significant reduction of NAFLD (P < 0·05). In this group, the substitution of SFA and mono-disaccharides for MUFA, and n-6 for all macronutrients, except vegetable protein and SFA, were significantly related to an increase in NAFLD (P < 0·05).

CONCLUSIONS

Lower lean NAFLD is correlated with increasing polysaccharides in exchange for SFA and animal protein intake, whereas lower non-lean NAFLD is correlated with increasing MUFA in exchange for mono-disaccharides and reducing n-6 and SFA.

The Mutual Inhibition of FoxO1 and SREBP-1c Regulated the Progression of Hepatoblastoma by Regulating Fatty Acid Metabolism

Background

Hepatoblastoma (HB) is the most common liver malignancy in pediatrics, but the treatment for this disease is minimal. This study is aimed at exploring the effect of FoxO1 and SREBP-1c on HB and their mechanism.

Methods

FoxO1, SREBP-1c, FASN, ACLY, ACC, and MAGL expressions in tissue samples were detected by RT-qPCR and WB. IHC was utilized to measure FASN content. Overexpression and knockdown of FoxO1 and sSREBP-1c were performed on Huh-6 cells. Cell proliferation, migration, and invasion were examined by CCK8, scratch, and transwell assay. ELISA was performed to test the ATP, FAO, NEFA, and Acetyl-CoA contents. ChIP was used to detect the interaction between SREBP-1c protein and the FoxO1 gene. In vivo tumorigenesis was conducted on mice. The morphology of tumor tissue sections was observed by HE staining.

Results

FoxO1 expression was downregulated in HB tissue, while the expressions of SREBP-1c, FASN, ACLY, ACC, and MAGL were upregulated. In Huh-6 cells and mouse tumor tissues, FoxO1 knockdown resulted in increased cell proliferation, migration, and invasion and active fatty acid metabolism. On the contrary, after the knockdown of SREBP-1c, cell proliferation, migration, and invasion were weakened, and fatty acid metabolism was significantly reduced. SREBP-1c interacted with the promoter of the FoxO1 gene. When FoxO1 was knocked down, the tumor tissue was more closely packed. After the knockdown of the SREBP-1c gene, the structure of tumor cells was deformed.

Conclusion

FoxO1 and SREBP-1c inhibited each other in HB, leading to the increase of intracellular fatty acid metabolism, and ultimately facilitated the development of HB.

Immunonutritional Bioactives from Chenopodium quinoa and Salvia hispanica L. Flour Positively Modulate Insulin Resistance and Preserve Alterations in Peripheral Myeloid Population

Innate immunity plays a determinant role in high fat diet (HFD)-induced insulin resistance. This study compares the effects of immunonutritional bioactives from Chenopodium quinoa (WQ) or Salvia hispanica L. (Ch) when used to partially replace wheat flour (WB) into bread formulations. These flours were chosen to condition starch and lipid content in the products as well as because their immunonutritional activity. To be administered with different bread formulations, HFD-fed C57BL/6J mice were distributed in different groups: (i) wild type, (ii) displaying inherited disturbances in glucose homeostasis, and (iii) displaying dietary iron-mediated impairment of the innate immune TLR4/TRAM/TRIF pathway. We analyze the effects of the products on glycaemia and insulin resistance (HOMA-IR), plasmatic triglycerides, intestinal and hepatic gene expression and variations of myeloid (MY), and lymphoid (LY) cells population in peripheral blood. Our results show that feeding animals with WQ and Ch formulations influenced the expression of lipogenic and coronary risk markers, thus attaining a better control of hepatic lipid accumulation. WQ and Ch products also improved glucose homeostasis compared to WB, normalizing the HOMA-IR in animals with an altered glucose and lipid metabolism. These positive effects were associated with positive variations in the peripheral myeloid cells population.

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.

Fish Oil Diet during Pre-mating, Gestation, and Lactation in Adult Offspring Rats on Cancer Cachexia Prevention

SCOPE

Nutritional supplementation of the maternal diet can modify the cancer susceptibility in adult offspring. Therefore, the authors evaluate the effects of a fish-oil diet administered to a long-term, during pre-mating, gestation, and lactation, in reducing cancer-cachexia damages in adult Walker-256 tumor-bearing offspring.

METHODS AND RESULTS

Female rats receive control or fish oil diet during pre-mating, gestation, and lactation. After weaning, male offspring are fed the control diet until adulthood and distributed in (C) control adult-offspring; (W) adult tumor-bearing offspring; (OC) adult-offspring of maternal fish oil diet; (WOC) adult tumor-bearing offspring of maternal fish oil diet groups. Fat body mass is preserved, muscle expression of mechanistic target of rapamicin (mTOR) and eukariotic binding protein of eukariotic factor 4E (4E-BP1) is modified, being associated with lower 20S proteasome protein expression, and the liver alanine aminotransferase (ALT) enzyme content maintained in the WOC group. Also, the OC group shows reduced triglyceridemia.

CONCLUSION

In this experimental model of cachexia, the long-term maternal supplementation is a positive strategy to improve liver function and lipid metabolism, as well as to modify muscle proteins expression in the mTOR pathway and also reduce the 20S muscle proteasome protein, without altering the tumor development and muscle wasting in adult tumor-bearing offspring.

Gender dependent differences in lipid metabolism in individuals with type 2 diabetes mellitus

Aim

The present study investigates gender dependent effects of insulin resistance on lipid profile and adipocytokines in individuals with diabetes receiving oral antidiabetic drugs (OADs). The aim was also to reveal the changes in the expression of genes involved in lipid metabolism and inflammation.

Methods

Lipid profile, adipocytokine levels and homeostatic model assessment of insulin resistance (HOMA-IR) was assessed in 100 patients with diabetes (M = 43, F = 57) matched for age and gender with healthy individuals (M = 45, F = 55). The expression pattern of genes was analyzed by quantitative real time PCR.

Results

Males consuming metformin with other drugs exhibited a positive association between HOMA-IR and cholesterol, triglyceride and very low density lipoprotein (VLDL). Females consuming only metformin and metformin with other drugs, showed a positive association of HOMA-IR with cholesterol and a negative association with adiponectin. In males and females with diabetes, a comparable expression of peroxisome proliferator activated receptor γ (PPARγ) while higher expression of sterol regulatory element binding protein 1 (SREBP1) was observed. Expression of fatty acid synthase (FAS), long chain acyl CoA Synthetases (ACSL), malonyl-CoA-acyl carrier protein transacylase (MCAT) and nuclear factor kappa β (NFkβ) was higher in men with diabetes than healthy males. Expression of tumor necrosis factor α (TNF-α) was higher in males and females with diabetes than respective healthy genders.

Conclusion

Insulin resistance adversely affects lipid profile, adipocytokines in males with type 2 diabetes. Expression of genes involved in lipid metabolism and inflammation is found to be undesirably and differentially altered in both the genders.

Additive Effects of Omega-3 Fatty Acids and Thiazolidinediones in Mice Fed a High-Fat Diet: Triacylglycerol/Fatty Acid Cycling in Adipose Tissue

Long-chain n-3 polyunsaturated fatty acids (Omega-3) and anti-diabetic drugs thiazolidinediones (TZDs) exhibit additive effects in counteraction of dietary obesity and associated metabolic dysfunctions in mice. The underlying mechanisms need to be clarified. Here, we aimed to learn whether the futile cycle based on the hydrolysis of triacylglycerol and re-esterification of fatty acids (TAG/FA cycling) in white adipose tissue (WAT) could be involved. We compared Omega-3 (30 mg/g diet) and two different TZDs—pioglitazone (50 mg/g diet) and a second-generation TZD, MSDC-0602K (330 mg/g diet)—regarding their effects in C57BL/6N mice fed an obesogenic high-fat (HF) diet for 8 weeks. The diet was supplemented or not by the tested compound alone or with the two TZDs combined individually with Omega-3. Activity of TAG/FA cycle in WAT was suppressed by the obesogenic HF diet. Additive effects in partial rescue of TAG/FA cycling in WAT were observed with both combined interventions, with a stronger effect of Omega-3 and MSDC-0602K. Our results (i) supported the role of TAG/FA cycling in WAT in the beneficial additive effects of Omega-3 and TZDs on metabolism of diet-induced obese mice, and (ii) showed differential modulation of WAT gene expression and metabolism by the two TZDs, depending also on Omega-3.

The Protective Effect of Myristica fragrans Houtt. Extracts Against Obesity and Inflammation by Regulating Free Fatty Acids Metabolism in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a disorder characterized by the excess accumulation of fat in the hepatocytes. It is commonly associated with severe obesity and inflammation. Free fatty acids (FFAs) are the key to regulate lipid metabolism and immune response in hepatocyte cells. This study examined the effects of AEN (alcohol extract of nutmeg, the seed of Myristica fragrans Houtt.) on the inhibition of lipid synthesis and inflammation in vitro and in vivo and on high-fat diet-induced obesity in NAFLD mice. Our results showed that AEN treatment could downregulate the expression of lipid synthesis-related genes fatty acid synthase (FASN) and sterol regulatory element-binding protein 1c (SREBP-1c) and lower the lipid content of cells. AEN also inhibited FFAs-mediated inflammation-related cytokines interleukin-6 (IL-6) and tumor necrosis factor α (TNFα) expression in cells. In a mouse model, AEN reduced the bodyweight of obese mice and improved NAFLD without affecting food intake. Further analysis revealed that AEN significantly reduced inflammation level, cholesterol and lipid accumulation, blood glucose, and other liver function indexes in mice fed with a high-fat diet. In conclusion, AEN inhibited the aggravation of obesity and inflammation by downregulating lipid-gene expression in the liver to ameliorate NAFLD.

Comparative Effects of Dietary Hemp and Poppy Seed Oil on Lipid Metabolism and the Antioxidant Status in Lean and Obese Zucker Rats

The objective of this study was to compare the effects of the dietary inclusion of hemp seed oil (HO) and poppy seed oil (PO) on the lipid metabolism and antioxidant status of lean and genetically obese Zucker rats. The rats were fed a control diet for laboratory rodents or a modification with HO or PO. Both oils reduced body and epididymal fat and liver cholesterol levels and promoted oxidative stress in the liver of obese rats. The HO reduced plasma triglycerides and had a stronger liver cholesterol-lowering effect in obese rats than PO. In the lean rats, HO and PO had no effects on the body fat content, plasma lipid profile, or lipid metabolism in the liver. HO considerably elevated the content of α-linolenic acid in the liver and increased the liver ratio of reduced glutathione (GSH)/oxidized glutathione (GSSG) in the lean rats. In conclusion, the regular consumption of both oils increases the accumulation of essential fatty acids in the liver of healthy animals, whilst not having any adverse effects on the body, whereas in genetically obese rats, the effects of both dietary oils on the lipid metabolism and antioxidant status are unequivocal and only partially beneficial.

Hypolipidemic constituents from the aerial portion of Sibiraea angustata

Two new monoterpene acylglucosides (1-2) and one new aromatic glycoside (3), together with five known compounds (4-8), were isolated from 95% ethanol extract of Sibiraea angustata. The structures of these compounds were characterized by 2D-NMR and mass spectrometry. Compounds were evaluated for their hypolipidemic activity using oleic acid-induced lipid accumulation in HepG2 cells. RT-PCR analysis revealed that compound 5 could decrease the expression level of fatty acid synthase (FASN). Lipidomics analysis indicated that compound 5 significantly decreased the levels of 11 lipids in oleic acid-induced lipid accumulation, including triglycerides (TG), diglycerides (DG), phosphatidylcholines (PC) and 1-acyl-sn-glycero-3-phosphocholines (lysoPC). These data demonstrated that terpene acylglucosides are the major active constituents in Sibiraea angustata.

The Impact of Glucose-Based or Lipid-Based Total Parenteral Nutrition on the Free Fatty Acids Profile in Critically Ill Patients

Introduction: Our study aim was to assess how the macronutrient intake during total parenteral nutrition (TPN) modulates plasma total free fatty acids (FFAs) levels and individual fatty acids in critically ill patients. Method: Adult patients aged 18–80, admitted to the intensive care unit (ICU), who were indicated for TPN, with an expected duration of more than three days, were included in the study. Isoenergetic and isonitrogenous TPN solutions were given with a major non-protein energy source, which was glucose (group G) or glucose and lipid emulsions (Smof lipid; group L). Blood samples were collected on days 0, 1, 3, 6, 9, 14, and 28. Results: A significant decrease (p < 0.001) in total FFAs occurred in both groups with a bigger decrease in group G (p < 0.001) from day 0 (0.41 ± 0.19 mmol∙L⁻¹) to day 28 (0.10 ± 0.07 mmol∙L⁻¹). Increased palmitooleic acid and decreased linoleic and docosahexaenoic acids, with a trend of increased mead acid to arachidonic acid ratio, on day 28 were observed in group G in comparison with group L. Group G had an insignificant increase in leptin with no differences in the concentrations of vitamin E, triacylglycerides, and plasminogen activator inhibitor-1. Conclusion: Decreased plasma FFA in critically ill patients who receive TPN may result from increased insulin sensitivity with a better effect in group G, owing to higher insulin and glucose dosing and no lipid emulsions. It is advisable to include a lipid emulsion at the latest from three weeks of TPN to prevent essential fatty acid deficiency.

Impact of dietary oil replacement on muscle and liver enzymes activity, histomorphology and growth-related genes on Nile tilapia

This study evaluated the efficacy of replacing dietary fish oil (FO) with vegetable oils (virgin coconut and corn oil) on enzyme activities (glycolytic, oxidative and lipid metabolites), mRNA expression of lipid metabolic genes and histomorphology of liver and intestine in O. niloticus. O. niloticus (6.07 ± 0.07 g) was fed six experimental diets where fish oil (FO) served as the control diet, and then was supplemented by dietary oils; virgin coconut oil (VCO) {3%FO + 3%VCO; 3FVCO}, and corn oil (CO) {3%FO + 3%CO; 3FCO}, 6%VCO (VCO), 6%CO (CO) and 6%VO {3%VCO + 3%CO; VO}. Growth performances measured indicated fish fed diet 3FCO had higher weight gain (WG) and specific growth rate (SGR). Fish fed diet 3FCO recorded the highest activities in lactate dehydrogenase (LDH), pyruvate kinase (PK), citrate synthase (CS), cytochrome coxidase (COX), malic enzymes (ME) and lipoprotein lipase (LPL) respectively. Stearoyl-CoA desaturase (SCD1) was upregulated in groups fed diets 3FVCO and 3FCO. Also, groups fed diet VCO and CO expressed highly in LPL, whereas, elongase of very long-chain fatty acids (ELOVL-5) was not influenced by the lipid sources. Histological representations in the liver were highly impacted in vegetable diets where lipid accumulation was higher except those fed VCO. However, in the digestive tract from distal to middle and posterior, the same group (VCO) exhibited altered morphological structure as those fed diet 3FCO were similar to FO. The study shows that, corn oil in diets relates positively to growth and enzymatic activities which becomes evident in their depositions in liver and functional intestinal tracts. This study indicates dietary alternatives may cause alterations in lipid metabolic pathways (LPL and SCD1) involved in fatty acid transport. As such, polyunsaturated fatty acid (PUFA) rich diets (CO) based on this study results increases metabolic activities involving especially the production, distribution and consumption of adenosine triphosphate (ATP) in O. niloticus.

Efficacy of ω-3 supplementation on nutritional status, skeletal muscle, and chemoradiotherapy toxicity in cervical cancer patients: A randomized, triple-blind, clinical trial conducted in a middle-income country

OBJECTIVES

Supplementation with ω-3 has been shown to favor the preservation of body weight and skeletal muscle. The aim of this study was to evaluate the efficacy of ω-3 supplementation on nutritional status, skeletal muscle quantity and quality, and toxicity for treatment of women with cervical cancer.

METHODS

This was a randomized, triple-blinded, placebo-controlled clinical trial in women diagnosed with cervical cancer who underwent chemoradiotherapy between March 2016 and August 2017. The intervention group received four capsules with ω-3 (2.5 g/d) and the control group (CG) received the same number of identical-looking capsules with olive oil, for 45 d. Nutritional status was measured by anthropometry and Patient-Generated Subjective Global Assessment. Body composition was assessed by computed tomography. The skeletal muscle index was calculated using the range -29 to +150 HU. For skeletal muscle quality, the area comprised between -29 and +29 HU was denominated low-radiodensity skeletal muscle index and the range between +30 and +150 HU high-radiodensity skeletal muscle index, representing the skeletal muscle area with high or low intramuscular fat infiltration, respectively.

RESULTS

The study population comprised 40 patients, with an average age 44.53 ± 8.73. The intervention group maintained body weight and showed an improvement in Patient-Generated Subjective Global Assessment score. A significant reduction in skeletal muscle index was observed in both groups. However, in regard to skeletal muscle quality, patients in the intervention group preserved low- and high-radiodensity skeletal muscle index, whereas those in the control group had increased low-radiodensity skeletal muscle index and significantly reduced high-radiodensity skeletal muscle index, reflecting high intramuscular fat infiltration only in the control group. The incidence of chemotherapy toxicity was significantly lower in the intervention group.

CONCLUSIONS

The results suggest that ω-3 supplementation is effective in maintaining nutritional status, skeletal muscle quality, and reduced symptoms of chemoradiotherapy among women with cervical cancer.

Benefits of blended oil consumption over other sources of lipids on the cardiovascular system in obese rats

High consumption of cooking oils in modern society is believed to be the major cause of cardiovascular disease.

Impact of pre-diagnostic triglycerides and HDL-cholesterol on breast cancer recurrence and survival by breast cancer subtypes

BACKGROUND

High triglycerides and low levels of high density lipoprotein (HDL)-cholesterol are observed to promote tumor growth. However, whether breast cancer heterogeneity may explain the contradictory influence of triglycerides and cholesterol observed on breast cancer prognosis remains unclear.

METHODS

A population-based survival study among 464 breast cancer cases identified within the Tromsø study was conducted. Pre-diagnostic triglycerides, total-cholesterol and HDL-cholesterol were measured, and detailed clinical and histopathological data were obtained. Using tissue microarray, all breast cancer cases were reclassified into the following subtypes: Luminal A, Luminal B, HER2-enriched, and triple negative breast cancer (TNBC). Multivariable Cox proportional hazards regression models were used to study the associations between pre-diagnostic lipids and breast cancer recurrence, mortality, and survival.

RESULTS

A total of 464 breast cancer patients, with mean age at diagnosis of 57.9 years, were followed for a mean 8.4 years. TNBC patients in the highest tertile of triglycerides (≥ 1.23 mmol/l) had 3 times higher overall mortality compared to TNBC patients in the lowest tertile (≤ 0.82 mmol/l) (HR 2.99, 95% CI 1.17-7.63), and the 5-year overall survival was 19% lower for TNBC patients in the highest vs. lowest tertile of triglycerides (65% vs. 84%). TNBC patients in the highest tertile of the HDL-cholesterol/total-cholesterol ratio (≥0.35), compared to those in the lowest tertile (≤0.27), had a 67% reduced overall mortality risk (HR 0.33, 95% CI 0.12-0.89). No associations were observed between lipids and prognostic outcome among breast cancer patients overall, or among patients with luminal A and luminal B subtypes. Among HER2-enriched patients, pre-diagnostic triglyceride level was inversely associated with overall mortality.

CONCLUSION

Our study suggests that pre-diagnostic triglycerides and the HDL-cholesterol/total-cholesterol ratio may independently provide unique information regarding prognostic outcome among triple negative breast cancer patients. However, a small sample size underlines the need for additional studies.

Selective insulin resistance with differential expressions of IRS-1 and IRS-2 in human NAFLD livers

Background/objective:

Insulin signals, via the regulation of key enzyme expression, both suppress gluconeogenesis and enhance lipid synthesis in the liver. Animal studies have revealed insulin signaling favoring gluconeogenesis suppression to be selectively impaired in steatotic livers. However, whether, and if so how, such selective insulin resistance occurs in human steatotic livers remains unknown. Our aim was to investigate selective insulin resistance in human livers with non-alcoholic fatty liver disease (NAFLD).

Subjects/methods:

We examined mRNA expressions of key molecules for insulin signaling, gluconeogenesis and lipogenesis in human liver biopsy samples obtained from 51 non-diabetic subjects: 9 healthy controls and 42 NAFLD patients, and analyzed associations of these molecules with each other and with detailed pathological and clinical biochemistry data.

Results:

In NAFLD patients, insulin receptor substrate (IRS)-2 expression was decreased, while those of key enzymes for gluconeogenesis were increased. These alterations of IRS-2 and gluconeogenesis enzymes were induced both in simple steatosis (SS) and non-alcoholic steatohepatitis (NASH), while these expression levels did not differ between SS and NASH. Furthermore, alterations in the expressions of IRS-2 and gluconeogenesis enzymes showed strong negative correlations and were concurrently induced in the early histological stage of NAFLD. In contrast, fatty acid synthase (FAS) expression was not decreased in NAFLD, despite IRS-2 downregulation, but correlated strongly with IRS-1 expression. Furthermore, no histological scores were associated with these molecules. Thus, IRS-1 signaling, which is not impaired in NAFLD, appears to modulate FAS expression.

Conclusion:

These analyses revealed that selective insulin resistance is present in human NAFLD livers and occurs in its early phases. The effect of insulin, during the IRS step, on gene expressions for lipogenesis and gluconeogenesis are apparently distinct and preferential downregulation of IRS-2 may contribute to selective resistance to the suppressive effects of insulin on gluconeogenesis.

Characteristics of the fads2 gene promoter in marine teleost Epinephelus coioides and role of Sp1-binding site in determining promoter activity

Δ6 fatty acyl desaturase (Fads2) is a rate-limiting enzyme in long-chain polyunsaturated fatty acids (LC-PUFA) biosynthesis. Comparative analysis of gene promoters of Fads2 between salmonids and carnivorous marine fish suggested that the lack of binding site for stimulatory protein 1 (Sp1) was responsible for the low expression of fads2 gene of carnivorous marine species. To confirm this speculation, the fads2 candidate promoter (2646 bp) was cloned from carnivorous marine teleost Epinephelus coioides, and 330 bp core regulatory region was identified. Several binding sites for transcriptional factors such as nuclear factor 1, nuclear factor Y, sterol regulatory element and hepatocyte nuclear factor 4γ were identified, while that for Sp1 was shown to be absent in the promoter by both bioinformatic analysis and site-directed mutation. Moreover, after the Sp1-binding site from the fads2 promoter of herbivorous Siganus canaliculatus, the first marine teleost demonstrated to have LC-PUFA biosynthetic ability, was inserted into the corresponding region of E. coioides fads2 promoter, activity was significantly increased. The results provided direct data for the importance of the Sp1-binding site in determining fads2 promoter activity, and indicated that its lack may be a reason for low expression of fads2 and poor LC-PUFA biosynthetic ability in E. coioides.

Transcriptional activation of zebrafish fads2 promoter and its transient transgene expression in yolk syncytial layer of zebrafish embryos

The front-end desaturases (Fads) are rate-limiting enzymes responsible for production of long-chain polyunsaturated fatty acids (LC-PUFA). The full spectrum of the transcriptional regulation of fads is still incomplete, as cloning of fads promoter is limited to a few species. Here, we described the cloning and characterisation of the zebrafish fads2 promoter. Using 5'-deletion and mutation analysis on this promoter, we identified a specific region containing the sterol regulatory element (SRE) which is responsible for the activation of the fads2 promoter. In tandem, two conserved CCAAT boxes were also present adjacent to the SRE and mutation of either of these binding sites attenuates the transcriptional activation of the fads2 promoter. An in vivo analysis employing GFP reporter gene in transiently transfected zebrafish embryos showed that this 1754 bp upstream region of the fads2 gene specifically directs GFP expression in the yolk syncytial layer (YSL) region. This indicates a role for LC-PUFA in the transport of yolk lipids through this tissue layer. In conclusion, besides identifying novel core elements for transcriptional activation in zebrafish fads2 promoter, we also reveal a potential role for fads2 or LC-PUFA in YSL during development.

An inverse association between serum resistin levels and n-3 polyunsaturated fatty acids intake was strongest in the SNP-420 G/G genotype in the Japanese cohort: The Toon Genome Study

OBJECTIVE

Resistin is secreted by monocytes/macrophages and is associated with insulin resistance, inflammation and cardiovascular diseases. In the Japanese cohort, serum resistin is tightly associated with a single-nucleotide polymorphism (SNP) at -420 (rs1862513) in the promoter region of the human resistin gene. However, interactions between SNP-420 and environmental factors remain to be elucidated. The aim of this study was to investigate the association between serum resistin levels and nutrient intake, and the effect of SNP-420 on this association.

DESIGN, PARTICIPANTS AND MEASUREMENTS

The Toon Genome Study is a cohort study of Japanese community-dwelling subjects. A total of 1981 participants were cross-sectionally analysed. Each nutrient intake was assessed using the semiquantitative food frequency questionnaire and categorized into the quartiles (Q1-Q4). Serum resistin was measured by ELISA.

RESULTS

Serum resistin tended to be inversely associated with fish intake and positively associated with meat intake after adjustment for age, sex, BMI and energy intake. Serum resistin was inversely associated with n-3 polyunsaturated fatty acids (PUFA) intake after adjustment for age, sex, BMI and energy intake (Q1 12.5, Q2 12.5, Q3 12.2, Q4 11.5 ng/mL; P for trend = .007). This inverse association was strongest in the G/G genotype of SNP-420, followed by C/G and C/C (G/G, Q1 18.9, Q2 19.5, Q3 18.4, Q4 14.5 ng/mL, P = .001; C/G, 14.4, 13.3, 13.1, 12.9, P = .015; C/C, 9.5, 9.5, 9.2, 8.8, P = .020; P for interaction = .004).

CONCLUSIONS

The inverse association between serum resistin and n-3 PUFA intake was strongest in SNP-420 G/G genotype in the Japanese cohort.

Could omega-3 fatty acids a therapeutic treatment of the immune-metabolic consequence of intermittent hypoxia in obstructive sleep apnea?

Obesity and Obstructive sleep Apnea (OSA) seems to bi-directional; obesity itself increases the risk of OSA, but on the other hand, OSA may also predispose the individuals to weight gain, both obesity and OSA share a common immune-metabolic link state which have a synergistic effect on the activation of inflammation, insulin resistance and dyslipidemia, and cardiovascular disease. The Immune-metabolic role of omega-3 fatty acids Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA), which capable of modulating both metabolic and immune process, which may decrease pro-inflammatory cytokines, insulin resistance, and dyslipidemia. To date, no study in humans suffering from OSA and omega-3 fatty acids has been performed. Hence, the objective of this review aimed to discussing the link between immune-metabolic consequences related to intermittent hypoxia and does Omega-3 fatty acids a therapeutic treatment for co-morbidity associated with obstructive sleep apnea.

Oryzanol Modifies High Fat Diet-Induced Obesity, Liver Gene Expression Profile, and Inflammation Response in Mice

In Western countries and China, the dietary habit of high calories usually results in hyperlipidemia, which is closely associated with cardiovascular diseases. In the study, we investigated the antihyperlipidemic effect of oryzanol and its molecular mechanism in the high fat diet (HFD) mouse model. In total, 60 ICR mice were randomly divided into control group, HFD group, and HFD+Ory group. The mice from the HFD+Ory group were additionally fed with 100 mg/kg of oryzanol by intragastric administration. Our data indicated that oryzanol treatment for 10 weeks significantly reduced bodyweight, liver weight, and adipose tissues weight of the mice; lowered the contents of total cholesterol (TC), triglycerides (TG), and low density lipoprotein-cholesterol (LDL-C); and elevated high density lipoprotein-cholesterol (HDL-C) in the plasma of HFD mice. Compared with the HFD group, H&E staining showed that oryzanol treatment decreased the size of fat droplets of liver tissues and the size of adipocytes. Gene chip data found that oryzanol administration caused 32 genes to increase expressions while 60 genes had reduced expressions in the liver tissues of HFD mice. IPA software was used to analyze the protein interaction network and found that transcript factor NF-κB located in the central role of network, meaning NF-κB may have important function in the lipid-lowering effect of oryzanol. Western blotting and RT-qPCR confirmed that lipid metabolism-related gene expressions were obviously regulated by oryzanol administration. Oryzanol also inhibited expressions of inflammatory factor in the liver tissues of HDF mice. Taken together, our data indicate that oryzanol treatment can regulate lipid metabolism-related gene expressions and inhibit HDF-caused obesity in mice.

Transcription factor NF‑YA promotes a malignant phenotype by upregulating fatty acid synthase expression

Recent studies have revealed that increased expression of the alpha subunit of nuclear transcription factor Y (NF‑YA) is associated with the malignant phenotype of various tumors. However, whether elevated expression of NF‑YA promotes a malignant phenotype in osteosarcoma (OS), and the molecular mechanisms underlying this predicted effect is currently unknown. In the present study, small hairpin RNA (shRNA)‑mediated knockdown of endogenous NF‑YA significantly inhibited the migration and invasion capabilities of OS cells in vitro, whereas ectopic expression of NF‑YA increased the migration and invasion capabilities of these cells. In addition, the induction of upregulated NF‑YA expression on the malignant phenotype of OS cells was attenuated by silencing fatty acid synthase (FASN) expression. Furthermore, the expression level of FASN was increased by upregulating NF‑YA, while decreased FASN expression was observed following NF‑YA silencing in OS cells. The results of the present study suggest that NF‑YA may promote a malignant phenotype in OS cells, in part, by activating the FASN signaling pathway, which may represent a promising target for the management of OS.

Promising therapies for treatment of nonalcoholic steatohepatitis

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) has become the most common etiology for abnormal aminotransferase levels and chronic liver disease. Its growing prevalence is largely linked to the presence of metabolic syndrome, particularly diabetes and insulin resistance. It is estimated that 60-80% of the type 2 diabetic population has NAFLD. NAFLD encompasses a range of conditions ranging from simple steatosis to non-alcoholic steatohepatitis (NASH). A subset of patients with hepatic steatosis progress to NASH, while 15-20% of patients with NASH develop cirrhosis. This progression is thought to be multifactorial, and there are currently no FDA-approved medications for the treatment of NASH.

AREAS COVERED

We review drugs currently in Phase II and III clinical trials for treatment of NAFLD and NASH, including their mechanisms of action, relationship to the pathophysiology of NASH, and rationale for their development.

EXPERT OPINION

The treatment of NASH is complex and necessitates targeting a number of different pathways. Combination therapy, preferably tailored toward the disease stage and severity, will be needed to achieve maximum therapeutic effect. With multiple agents currently being developed, there may soon be an ability to effectively slow or even reverse the disease process in many NAFLD/NASH patients.

Triiodothyronine enhances accumulation of intracellular lipids in adipocytes through thyroid hormone receptor α via direct and indirect mechanisms

Triiodothyronine (T3) enhanced the expression of adipogenic and lipogenic genes with elevation of the intracellular lipids through thyroid hormone receptor (TR) α in mouse 3T3-L1 cells. However, the transcription of the SREBP-1c and HSL genes was decreased by T3. Such T3-mediated alterations were negated by TRα siRNA. Chromatin immunoprecipitation assay showed that the binding of TRα to the TR-responsive element (TRE) of the FAS promoter was elevated by T3. In contrast, the ability of TRα to bind to the TRE of the SREBP-1c promoter was decreased by T3. In addition, the binding of SREBP-1c to the SRE of the HSL promoter was lowered by T3. These results indicate that T3 increased the accumulation of intracellular lipids by enhancing the expression of the FAS gene through direct binding of TRα to the FAS promoter and simultaneously lowered the amount of lipolysis via reduced binding of T3-decreased SREBP-1c to the HSL promoter.

Perinatal maternal high-fat diet promotes alterations in hepatic lipid metabolism and resistance to the hypolipidemic effect of fish oil in adolescent rat offspring

SCOPE

Maternal high-fat diet (HFD) promotes obesity and metabolic disturbances in offspring at weaning and adult life. We investigated metabolic consequences of maternal HFD in adolescent rat offspring and the potential benefic effects of fish oil (FO) (n-3 polyunsaturated fatty acid source).

METHODS AND RESULTS

Female rats received isocaloric, standard diet (STD: 9% fat) or HFD (28.6%) before mating, and throughout pregnancy and lactation. After weaning, male offspring received standard diet and, from 25th to 45th day, received oral administration of soybean oil (SO) or FO. HFD offspring showed higher body weight and adiposity, which was not attenuated by FO. In STD offspring, FO reduced serum triglyceride and cholesterol, as expected, but not in HFD offspring. Liver of HFD offspring groups showed increased free cholesterol and FO-treated HFD group showed lower expression of Abcg8, suggesting decreased cholesterol biliary excretion. HFD offspring presented higher hepatic expression of lipogenic markers, Srebf1 mRNA and acetyl CoA carboxylase (ACC). Serum n-3 PUFA were decreased in FO-treated HFD compared to FO-treated STD offspring, which may explain the reduced hypolipidemic FO effect.

CONCLUSION

Maternal HFD impaired the ability of FO to reduce adiposity and serum lipids in adolescent offspring, suggesting a potential predisposition to future development of metabolic disorders.

Comparative anti-inflammatory and lipid-normalizing effects of metformin and omega-3 fatty acids through modulation of transcription factors in diabetic rats

BACKGROUND

Emerging evidence suggests beneficial effects of omega-3 fatty acids on diabetic complications. The present study compared the progressive effects of metformin and flax/fish oil on lipid metabolism, inflammatory markers, and liver and renal function test markers in streptozotocin-nicotinamide-induced diabetic rats.

METHODS

Streptozotocin-induced diabetic rats were randomized into control and four diabetic groups: streptozotocin (STZ), metformin (200 mg/kg body weight (b.w)/day (D)), flax and fish oil (500 mg/kg b.w/D).

RESULTS

Metformin and flax and fish oil exhibited increased expression of transcription factor peroxisome proliferator-activated receptor γ while the treatment downregulated sterol regulatory element-binding protein 1 and nuclear factor kβ as compared to those of the STZ group. Apart from modulation of transcription factor expression, the expression of fatty acid synthase, long chain acyl CoA synthase, and malonyl-CoA-acyl carrier protein transacylase was lowered by flax/fish oil treatment. Serum cholesterol, triglycerides, and VLDL were also significantly reduced in the treatment groups as compared to those in the STZ group. Although pathological abnormalities were seen in the liver and kidneys of rats on metformin, no significant changes in liver/renal function markers were observed at day 15 and day 30 of the treatment groups. Flax/fish oil had protective effects toward pathological abnormalities in the liver and kidney. Flax/fish oil improved lipid profile and alkaline phosphatase at day 30 as compared to that at day 15.

CONCLUSIONS

The present study demonstrates potential beneficial effects of metformin and flax/fish oil intervention in improving serum lipid profile by regulating the expression of transcription factors and genes involved in lipid metabolism in diabetic rats. In addition, these interventions also lowered the expression of atherogenic cytokines. The protective effects of flax/fish oil are worth investigating in human subjects on metformin monotherapy.

Targeting metabolism in breast cancer: How far we can go?

Adjuvant therapies for breast cancer have achieved great success in recent years and early breast cancer is now a curable or chronic disease. Targeted therapies, including endocrine therapy and human epidermal growth factor receptor-2 targeted therapy, marked a new era of breast cancer treatment. However, except for chemotherapy, an efficient drug treatment to improve the overall survival of breast cancer patients is still lacking for triple negative breast cancer. Furthermore, a certain proportion of breast cancer patients present with resistance to drug therapy, making it much more difficult to control the deterioration of the disease. Recently, altered energy metabolism has become one of the hallmarks of cancer, including breast cancer, and it may be linked to drug resistance. Targeting cellular metabolism is becoming a promising strategy to overcome drug resistance in cancer therapy. This review discusses metabolic reprogramming in breast cancer and the possible complex mechanism of modulation. We also summarize the recent advances in metabolic therapy targeted glycolysis, glutaminolysis and fatty acids synthesis in breast cancer.

Noncoding RNAs in Regulation of Cancer Metabolic Reprogramming

Since the description of the Warburg effect 90 years ago, metabolic reprogramming has been gradually recognized as a major hallmark of cancer cells. Mounting evidence now indicates that cancer is a kind of metabolic disease, quite distinct from conventional perception. While metabolic alterations in cancer cells have been extensively observed in glucose, lipid, and amino acid metabolisms, its underlying regulatory mechanisms are still poorly understood. Noncoding RNA, also known as the "dark matter in life," functions through various mechanisms at RNA level regulating different biological pathways. The last two decades have witnessed the booming of noncoding RNA study on microRNA (miRNA), long noncoding RNA (lncRNA), circular RNA (circRNA), PIWI-interacting RNA (piRNA), etc. In this chapter, we will discuss the regulatory roles of noncoding RNAs on cancer metabolism.

Hypoxia is associated with a lower expression of genes involved in lipogenesis in visceral adipose tissue

Background

A key role for HIF-1α in the promotion and maintenance of dietary obesity has been proposed. We analyzed the association between hypoxia and de novo lipogenesis in human adipose tissue.

Methods

We studied HIF-1α mRNA and protein expression in fasting status in visceral adipose tissue (VAT) from non-obese and morbidly obese subjects, and in VAT from wild-type and ob/ob C57BL6J mice in both fasting and feeding status. We also analyzed the effect of hypoxia on the VAT mRNA expression of genes involved in lipogenesis.

Results

HIF-1α was increased in VAT from morbidly obese subjects. In fasting status, C57BL6J ob/ob mice had a higher VAT HIF-1α mRNA expression than C57BL6J wild-type mice. In feeding status, VAT HIF-1α mRNA expression significantly increased in C57BL6J wild-type, but not in C57BL6J ob/ob mice. In humans, HIF-1α mRNA expression correlated positively with body mass index and insulin resistance. VAT HIF-1α mRNA expression correlated negatively with ACC1, PDHB and SIRT3 mRNA expression, and positively with PPAR-γ. VAT explants incubated in hypoxia showed reduced SIRT3 and increased PPAR-γ, SREBP-1c, ACLY, ACC1 and FASN mRNA expression.

Conclusions

Morbidly obese subjects have a higher level of VAT HIF-1α. Postprandial status is associated with an increase in HIF-1α mRNA expression in C57BL6J wild-type mice. Hypoxia alters the mRNA expression of genes involved in de novo lipogenesis in human VAT.

Chokeberry attenuates the expression of genes related to de novo lipogenesis in the hepatocytes of mice with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), which is characterized by steatosis, is a major public health concern. Previous studies have shown that chokeberry has anti-inflammatory, antimutagenic, hepatoprotective, cardioprotective, and antidiabetic effects. In this study, we hypothesized that chokeberry powder can attenuate the expression of genes related to de novo lipogenesis and the triglyceride levels in the hepatocytes of mice with high-fat diet-induced NAFLD. After coadministering chokeberry powder for 8weeks (0.5% and 1% powder) with a high-fat diet, mice that consumed chokeberry powder diets, regardless of the dose, had significantly lower liver triglyceride levels than control mice that were fed a high-fat diet (P=.0145 and P<.0012, respectively). Compared with mice that were fed a high-fat diet, mice that were given 1% chokeberry powder exhibited significantly decreased mRNA expression of sterol regulatory element-binding protein (P=.009) and acetyl-CoA carboxylase (P=.0032) in the liver. Compared with mice in the control group, fatty acid synthase (FAS) expression significantly increased in the mice that were fed a high-fat diet, but both chokeberry powder-treated groups had significantly decreased FAS expression (P=.0157 and P<.0001, respectively). The size of the fat droplets was decreased in the livers of the chokeberry-supplemented groups. In summary, the administration of chokeberry powder may help attenuate high-fat diet-induced NAFLD by regulating the expression levels of sterol regulatory element-binding protein, acetyl-CoA carboxylase, and FAS and by decreasing the size of the fat droplets in the liver.

Maternal omega-3 fatty acids and micronutrients modulate fetal lipid metabolism: A review

It is well established that alterations in the mother's diet or metabolism during pregnancy has long-term adverse effects on the lipid metabolism in the offspring. There is growing interest in the role of specific nutrients especially omega-3 fatty acids in the pathophysiology of lipid disorders. A series of studies carried out in humans and rodents in our department have consistently suggested a link between omega-3 fatty acids especially docosahexaenoic acid and micronutrients (vitamin B12 and folic acid) in the one carbon metabolic cycle and its effect on the fatty acid metabolism, hepatic transcription factors and DNA methylation patterns. However the association of maternal intake or metabolism of these nutrients with fetal lipid metabolism is relatively less explored. In this review, we provide insights into the role of maternal omega-3 fatty acids and vitamin B12 and their influence on fetal lipid metabolism through various mechanisms which influence phosphatidylethanolamine-N-methyltransferase activity, peroxisome proliferator activated receptor, adiponectin signaling pathway and epigenetic process like chromatin methylation. This will help understand the possible mechanisms involved in fetal lipid metabolism and may provide important clues for the prevention of lipid disorders in the offspring.

Genome-based nutrition: An intervention strategy for the prevention and treatment of obesity and nonalcoholic steatohepatitis

Obesity and nonalcoholic steatohepatitis are increasing in westernized countries, regardless of their geographic location. In Latin America, most countries, including Mexico, have a heterogeneous admixture genome with Amerindian, European and African ancestries. However, certain high allelic frequencies of several nutrient-related polymorphisms may have been achieved by past gene-nutrient interactions. Such interactions may have promoted the positive selection of variants adapted to regional food sources. At present, the unbalanced diet composition of the Mexicans has led the country to a 70% prevalence rate of overweightness and obesity due to substantial changes in food habits, among other factors. International guidelines and intervention strategies may not be adequate for all populations worldwide because they do not consider disparities in genetic and environmental factors, and thus there is a need for differential prevention and management strategies. Here, we provide the rationale for an intervention strategy for the prevention and management of obesity-related diseases such as non-alcoholic steatohepatitis based on a regionalized genome-based diet. The components required to design such a diet should focus on the specific ancestry of each population around the world and the convenience of consuming traditional ethnic food.

Recent advances in dietary supplementation, in treating non-alcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is currently known as the most common liver problem, characterized by excessive lipid accumulation in hepatocytes, which may progress to other liver diseases such as nonalcoholic steatohepatitis, hepatic tissue fibrosis, liver cirrhosis, and failure or hepatocellular carcinoma. Since NAFLD is positively associated with the development of obesity, insulin resistance, and ultimately type 2 diabetes mellitus, it is often regarded as the hepatic manifestation of the metabolic syndrome. No pharmacologic treatment has yet been proven for this disease. For most patients with presumed or confirmed NAFLD, the only proven strategy is to offer lifestyle advice that can lead to sustained weight loss. Since insulin resistance, oxidative stress, inflammation, and necro-apoptosis are involved in NAFLD pathogenesis, it seems that every potential therapeutic agent should target one or some of these pathologic events. There are many well known anti-oxidants, anti-inflammatory, and insulin sensitizer dietary supplements which have shown beneficial effects on NAFLD improvement in animal and human studies. The purpose of this review is to explore the existing evidences on dietary supplements considered to have hepatoprotective properties, and to present some proposed mechanisms by which they may protect against NAFLD.

Linoleic and α-linolenic fatty acid consumption over three generations exert cumulative regulation of hepatic expression of genes related to lipid metabolism

The essential fatty acids, omega-3 and omega-6, consumed during pregnancy can benefit maternal and offspring health. For instance, they could activate a network of genes related to the nuclear receptor peroxisome proliferator-activated receptor α (Ppara) and sterol regulatory element binding transcription factor 1 (Srebf1), which play a role in fatty acid oxidation and lipogenesis. The present study aimed to investigate the effects of diets with different omega-3/omega-6 ratio consumed over three generations on blood biochemical parameters and hepatic expression of Ppara- and Srebf1-related genes. During three consecutive generations adult Wistar rats were evaluated in the postpartum period (21 days after parturition). Regardless of prenatal dietary omega-3/omega-6 ratio, an upregulation in liver tissue was observed for Rxra, Lxra and Srebf1 and a downregulation for Fasn in all the evaluated generations. The diet with higher omega-3/omega-6 ratio decreased triacylglycerol serum levels and resulted in a constant non-esterified fatty acid level. Our results indicated that the PUFAs effect on the modulation of genes related to fatty acid oxidation and lipogenesis is cumulative through generations.

Suppression of adipogenesis by valproic acid through repression of USF1-activated fatty acid synthesis in adipocytes

Valproic acid suppresses the accumulation of the intracellular lipids through suppression of fatty acid synthesis via repression of USF1-mediated expression of the fatty acid synthase gene in adipocytes.

Differential regulation of hepatic transcription factors in the Wistar rat offspring born to dams fed folic acid, vitamin B12 deficient diets and supplemented with omega-3 fatty acids

Nutritional status of the mother is known to influence various metabolic adaptations required for optimal fetal development. These may be mediated by transcription factors like peroxisome proliferator activated receptors (PPARs), which are activated by long chain polyunsaturated fatty acids. The objective of the current study was to examine the expression of different hepatic transcription factors and the levels of global methylation in the liver of the offspring born to dams fed micronutrient deficient (folic acid and vitamin B₁₂) diets and supplemented with omega-3 fatty acids. Female rats were divided into five groups (n = 8/group) as follows; control, folic acid deficient (FD), vitamin B₁₂ deficient (BD) and omega-3 fatty acid supplemented groups (FDO and BDO). Diets were given starting from pre-conception and continued throughout pregnancy and lactation. Pups were dissected at the end of lactation. Liver tissues were removed; snap frozen and stored at −80°C. Maternal micronutrients deficiency resulted in lower (p<0.05) levels of pup liver docosahexaenoic acid (DHA) and arachidonic acid (ARA) as compared to the control group. Pup liver PPARα and PPARγ expression was lower (p<0.05) in the BD group although there were no differences in the expression of SREBP-1c, LXRα and RXRα expression. Omega-3 fatty acids supplementation to this group normalized (p<0.05) levels of both PPARα and PPARγ but reduced (p<0.05) SREBP-1c, LXRα and RXRα expression. There was no change in any of the transcription factors in the pup liver in the FD group. Omega-3 fatty acids supplementation to this group reduced (p<0.05) PPARα, SREBP-1c and RXRα expression. Pup liver global methylation levels were higher (p<0.01) in both the micronutrients deficient groups and could be normalized (p<0.05) by omega-3 fatty acid supplementation. Our novel findings suggest a role for omega-3 fatty acids in the one carbon cycle in influencing the hepatic expression of transcription factors in the offspring.

A corn oil-based diet protects against combined ethanol and iron-induced liver injury in a mouse model of hemochromatosis

BACKGROUND

Combined iron overload and alcohol may promote synergistic chronic liver injury and toxicity. The role of specific dietary fats in influencing the development of co-toxic alcoholic liver disease needs further evaluation and is investigated in this study.

METHODS

Wild-type (WT) and the iron-loaded Hfe-null (Hfe(-/-) ) mice were fed chow (CC), a AIN-93G standard control (SC), or a corn oil-modified, AIN-93G-based (CO) diet with or without the addition of 20% ethanol (EtOH) in the drinking water for 8 weeks and assessed for liver injury.

RESULTS

WT mice on CC, SC, and CO diets had no liver injury, although mild steatosis developed in the SC and CO groups. The addition of EtOH resulted in mild steatohepatitis in WT mice fed SC but not those on a CO diet. EtOH administration in Hfe(-/-) animals on the CC and SC diets caused marked oxidative stress, inflammatory activity, and subsinusoidal and portal-portal tract linkage fibrosis with significant up-regulation of genes involved in cellular stress signaling and fibrogenic pathways. These effects were abrogated in the CO-fed mice, despite elevated serum EtOH levels and hepatic iron concentrations, reduced hepatic glutathione and mitochondrial superoxide dismutase activities. Feeding with the CO diet led to increased hepatic glutathione peroxidase and catalase activities and attenuated alcohol-induced hepatic steatosis in the Hfe(-/-) animals. Iron and EtOH feeding markedly reduced p-STAT3 and p-AMPK protein levels, but this effect was significantly attenuated when a CO diet was consumed.

CONCLUSIONS

A CO-based diet is protective against combined EtOH- and iron-induced liver toxicity, likely via attenuation of hepatic steatosis and oxidative stress and may have a role in the prevention of fibrosis development in chronic liver disease.

Secretory leukocyte protease inhibitor reverses inhibition by CNS myelin, promotes regeneration in the optic nerve, and suppresses expression of the transforming growth factor-β signaling protein Smad2

After CNS injury, axonal regeneration is limited by myelin-associated inhibitors; however, this can be overcome through elevation of intracellular cyclic AMP (cAMP), as occurs with conditioning lesions of the sciatic nerve. This study reports that expression of secretory leukocyte protease inhibitor (SLPI) is strongly upregulated in response to elevation of cAMP. We also show that SLPI can overcome inhibition by CNS myelin and significantly enhance regeneration of transected retinal ganglion cell axons in rats. Furthermore, regeneration of dorsal column axons does not occur after a conditioning lesion in SLPI null mutant mice, indicating that expression of SLPI is required for the conditioning lesion effect. Mechanistically, we demonstrate that SLPI localizes to the nuclei of neurons, binds to the Smad2 promoter, and reduces levels of Smad2 protein. Adenoviral overexpression of Smad2 also blocked SLPI-induced axonal regeneration. SLPI and Smad2 may therefore represent new targets for therapeutic intervention in CNS injury.

Effects of short- and long-chain fatty acids on the expression of stearoyl-CoA desaturase and other lipogenic genes in bovine mammary epithelial cells

Stearoyl-CoA desaturase (SCD) in the bovine mammary gland introduces a cis-double bond at the Δ9 position in a wide range of fatty acids (FA). Several long-chain polyunsaturated fatty acids (PUFA) inhibit expression of SCD, but information on the effect of short-chain fatty acids on mammary SCD expression is scarce. We used a bovine mammary cell line (MAC-T) to assess the effect of acetic acid (Ac) and β-hydroxybutyric acid (BHBA) in comparison with the effect of various long-chain fatty acids on the mRNA expression of the lipogenic enzymes SCD, acetyl-CoA carboxylase (ACACA), fatty acid synthase (FASN) and their associated gene regulatory proteins sterol regulatory element binding transcription factor 1 (SREBF1), insulin-induced gene 1 protein (INSIG1) and peroxisome proliferator-activated receptor alpha (PPARA)and peroxisome proliferator-activated receptor delta (PPARD) by quantitative real-time PCR. MAC-T cells were treated for 12 h without FA additions (CON) or with either 5 mM Ac, 5 mM BHBA, a combination of 5 mM Ac + 5 mM BHBA, 100 μM C16:0, 100 μM C18:0, 100 μM C18:1 cis-9, 100 μM C18:1 trans-11, 100 μM C18:2 cis-9,12 or 100 μM C18:3 cis-9,12,15. Compared with control, mRNA expression of SCD1 was increased by Ac (+61%) and reduced by C18:1 cis-9 (-61%), C18:2 cis-9,12 (-84%) and C18:3 cis-9,12,15 (-88%). In contrast to native bovine mammary gland tissue, MAC-T cells did not express SCD5. Expression of ACACA was increased by Ac (+44%) and reduced by C18:2 cis-9,12 (-48%) and C18:3 cis-9,12,15 (-49%). Compared with control, FASN expression was not significantly affected by the treatments. The mRNA level of SREBF1 was not affected by Ac or BHBA, but was reduced by C18:1 cis-9 (-44%), C18:1 trans-11 (-42%), C18:2 cis-9,12 (-62%) and C18:3 cis-9,12,15 (-68%) compared with control. Expression of INSIG1 was downregulated by C18:0 (-37%), C18:1 cis-9 (-63%), C18:1 trans-11 (-53%), C18:2 cis-9,12 (-81%) and C18:3 cis-9,12,15 (-91%). Both PPARA and PPARD expression were not significantly affected by the treatments. Our results show that Ac upregulated mRNA expression of SCD1 and ACACA in MAC-T cells. The opposite effect of the PUFA C18:2 cis-9,12 and C18:3 cis-9,12,15 on the these genes and the failure of Ac to mimic the PUFA-inhibited SREBF1 and INSIG1 mRNA expression, suggest that Ac can stimulate mammary lipogenesis via a transcriptional regulatory mechanism different from PUFA.

Nutrition therapy for liver diseases based on the status of nutritional intake

The dietary intake of patients with nonalcoholic fatty liver disease (NAFLD) is generally characterized by high levels of carbohydrate, fat, and/or cholesterol, and these dietary patterns influence hepatic lipid metabolism in the patients. Therefore, careful investigation of dietary habits could lead to better nutrition therapy in NAFLD patients. The main treatment for chronic hepatitis C (CHC) is interferon-based antiviral therapy, which often causes a decrease in appetite and energy intake; hence, nutritional support is also required during therapy to prevent undernourishment, treatment interruption, and a reduction in quality of life. Moreover, addition of some nutrients that act to suppress viral proliferation is recommended. As a substitutive treatment, low-iron diet therapy, which is relatively safe and effective for preventing hepatocellular carcinoma, is also recommended for CHC patients. Some patients with liver cirrhosis (LC) have decreased dietary energy and protein intake, while the number of LC patients with overeating and obesity is increasing, indicating that the nutritional state of LC patients has a broad spectrum. Therefore, nutrition therapy for LC patients should be planned on an assessment of their complications, nutritional state, and dietary intake. Late evening snacks, branched-chain amino acids, zinc, and probiotics are considered for effective nutritional utilization.

Protein utilisation and intermediary metabolism of Senegalese sole (Solea senegalensis) as a function of protein:lipid ratio

Previous experiments with Senegalese sole (Solea senegalensis) have demonstrated that dietary lipid levels above 8 % impaired growth and did not promote protein retention. We hypothesised that this low ability to use high-lipid diets may depend on the dietary protein level. In the present study, a 2 × 2 factorial design was applied where two dietary lipid (4–17 % DM) and two dietary protein (below and above the requirement levels, 48 and 54 % DM) levels were tested in juveniles for 114 d. Growth performance was not improved by the increase in dietary fat, irrespectively of the dietary protein levels. Protein retention was similar among the diets, although fish fed the diets with high lipid content resulted in significantly lower protein gain. Among the enzymes involved in amino acid catabolism, only aspartate aminotransferase activity in the liver was affected by the dietary lipid levels, being stimulated in fish fed high-lipid diets. Moreover, phosphofructokinase 1 activity was significantly elevated in the muscle of Senegalese sole fed 4 % lipid diets, suggesting enhanced glycolysis in the muscle when the dietary lipid supply was limited and dietary starch increased. The results confirmed that high-lipid diets do not enhance growth, and data from the selected enzymes support the assumption that lipids are not efficiently used for energy production and protein sparing, even when dietary protein is below the protein requirement of the species. Furthermore, data suggest a significant role of glucose as the energy source in Senegalese sole.

Health implications of high dietary omega-6 polyunsaturated Fatty acids

Omega-6 (n-6) polyunsaturated fatty acids (PUFA) (e.g., arachidonic acid (AA)) and omega-3 (n-3) PUFA (e.g., eicosapentaenoic acid (EPA)) are precursors to potent lipid mediator signalling molecules, termed "eicosanoids," which have important roles in the regulation of inflammation. In general, eicosanoids derived from n-6 PUFA are proinflammatory while eicosanoids derived from n-3 PUFA are anti-inflammatory. Dietary changes over the past few decades in the intake of n-6 and n-3 PUFA show striking increases in the (n-6) to (n-3) ratio (~15 : 1), which are associated with greater metabolism of the n-6 PUFA compared with n-3 PUFA. Coinciding with this increase in the ratio of (n-6) : (n-3) PUFA are increases in chronic inflammatory diseases such as nonalcoholic fatty liver disease (NAFLD), cardiovascular disease, obesity, inflammatory bowel disease (IBD), rheumatoid arthritis, and Alzheimer's disease (AD). By increasing the ratio of (n-3) : (n-6) PUFA in the Western diet, reductions may be achieved in the incidence of these chronic inflammatory diseases.