Fatty Acid Synthase mRNA Research Articles

FASN contributes to ADM resistance of diffuse large B-cell lymphoma by inhibiting ferroptosis via nf-κB/STAT3/GPX4 axis

ABSTRACT Drug resistance is a critical impediment to efficient therapy of diffuse large B-cell lymphoma (DLBCL) patients. Recent studies have highlighted the association between ferroptosis and drug resistance that has been reported. Fatty acid synthase (FASN) is always related to a poor prognosis. In this study, we investigate the impact of FASN on drug resistance in DLBCL and explore its potential modulation of ferroptosis mechanisms. The clinical correlation of FASN mRNA expression was first analyzed to confirm the role of FASN on drug resistance in DLBCL based on the TCGA database. Next, the impact of FASN on ferroptosis was investigated in vitro and in vivo. Furthermore, a combination of RNA-seq, western blot, luciferase reporter, and ChIP experiments was employed to elucidate the underlying mechanism. The prognosis for patients with DLBCL was worse when FASN was highly expressed, particularly in those undergoing chemotherapy for Adriamycin (ADM). FASN promoted tumor growth and resistance of DLBCL to ADM, both in vitro and in vivo. It is noteworthy that this effect was achieved by inhibiting ferroptosis, since Fer-1 (a ferroptosis inhibitor) treatment significantly recovered the effects of silencing FASN on inhibiting ferroptosis, while Erastin (a ferroptosis inducer) treatment attenuated the impact of overexpressing FASN. Mechanistically, FASN activated NF-κB/STAT3 signaling pathway through phosphorylating the upstream IKKα and IκBα, and the activated STAT3 promoted GPX4 expression by directly binding to GPX4 promoter. FASN inhibits ferroptosis in DLBCL via NF-κB/STAT3/GPX4 signaling pathway, indicating its critical role in mediating ADM resistance of DLBCL.

2-Deoxy-D-Glucose Downregulates Fatty Acid Synthase Gene Expression Via an Endoplasmic Reticulum Stress-Dependent Pathway in HeLa Cells.

Fatty acid synthase (FASN) catalyzes the rate-limiting step of cellular lipogenesis. FASN expression is upregulated in various types of cancer cells, implying that FASN is a potential target for cancer therapy. 2-Deoxy-D-glucose (2-DG) specifically targets cancer cells by inhibiting glycolysis and glucose metabolism, resulting in multiple anticancer effects. However, whether the effects of 2-DG involve lipogenic metabolism remains to be elucidated. We investigated the effect of 2-DG administration on FASN expression in HeLa human cervical cancer cells. 2-DG treatment for 24 h decreased FASN mRNA and protein levels and suppressed the activity of an exogenous rat Fasn promoter. The use of a chemical activator or inhibitors or of a mammalian expression plasmid showed that neither AMPK nor the Sp1 transcription factor is responsible for the inhibitory effect of 2-DG on FASN expression. Administration of thapsigargin, an endoplasmic reticulum (ER) stress inducer, or 4-(2-aminoethyl) benzenesulfonyl fluoride (AEBSF), a site 1 protease inhibitor, mimicked the inhibitory effect of 2-DG on FASN expression. 2-DG did not further decrease FASN expression in the presence of thapsigargin or AEBSF. Site 1 protease mediates activation of ATF6, an ER stress mediator, as well as sterol regulatory element-binding protein 1 (SREBP1), a robust transcription factor for FASN. Administration of 2-DG or thapsigargin for 24 h suppressed activation of ATF6 and SREBP1, as did AEBSF. We speculated that these effects of 2-DG or thapsigargin are due to feedback inhibition via increased GRP78 expression following ER stress. Supporting this, exogenous overexpression of GRP78 in HeLa cells suppressed SREBP1 activation and Fasn promoter activity. These results suggest that 2-DG suppresses FASN expression via an ER stress-dependent pathway, providing new insight into the molecular basis of FASN regulation in cancer.

MSI2 Modulates Unsaturated Fatty Acid Metabolism by Binding FASN in Bovine Mammary Epithelial Cells.

The regulation of fatty acid metabolism is crucial for milk flavor and quality. Therefore, it is important to explore the genes that play a role in fatty acid metabolism and their mechanisms of action. The RNA-binding protein Musashi2 (MSI2) is involved in the regulation of numerous biological processes and plays a regulatory role in post-transcriptional translation. However, its role in the mammary glands of dairy cows has not been reported. The present study examined MSI2 expression in mammary glands from lactating and dry milk cows. Experimental results in bovine mammary epithelial cells (BMECs) showed that MSI2 was negatively correlated with the ability to synthesize milk fat and that MSI2 decreased the content of unsaturated fatty acids (UFAs) in BMECs. Silencing of Msi2 increased triglyceride accumulation in BMECs and increased the proportion of UFAs. MSI2 affects TAG synthesis and milk fat synthesis by regulating fatty acid synthase (FASN). In addition, RNA immunoprecipitation experiments in BMECs demonstrated for the first time that MSI2 can bind to the 3'-UTR of FASN mRNA to exert a regulatory effect. In conclusion, MSI2 affects milk fat synthesis and fatty acid metabolism by regulating the triglyceride synthesis and UFA content through binding FASN.

Probiotics Increase Intramuscular Fat and Improve the Composition of Fatty Acids in Sunit Sheep through the Adenosine 5'-Monophosphate-Activated Protein Kinase (AMPK) Signaling Pathway.

This experiment aims to investigate the impact of probiotic feed on growth performance, carcass traits, plasma lipid biochemical parameters, intramuscular fat and triglyceride content, fatty acid composition, mRNA expression levels of genes related to lipid metabolism, and the activity of the enzyme in Sunit sheep. In this experiment, 12 of 96 randomly selected Sunit sheep were assigned to receive the basic diet or the basic diet supplemented with probiotics. The results showed that supplementation with probiotics significantly increased the loin eye area, and decreased plasma triglycerides and free fatty acids, increasing the content of intramuscular fat and triglycerides in the muscle and improving the composition of the fatty acids. The inclusion of probiotics in the diet reduced the expression of adenosine 5'-monophosphate-activated protein kinase alpha 2 (AMPKα2) mRNA and carnitine palmitoyltransferase 1B (CPT1B) mRNA, while increasing the expression of acetyl-CoA carboxylase alpha (ACCα) mRNA, sterol regulatory element-binding protein-1c (SREBP-1c) mRNA, fatty acid synthase mRNA, and stearoyl-CoA desaturase 1 mRNA. The results of this study indicate that supplementation with probiotics can regulate fat deposition and improves the composition of fatty acids in Sunit sheep through the signaling pathways AMPK-ACC-CPT1B and AMPK-SREBP-1c. This regulatory mechanism leads to an increase in intramuscular fat content, a restructuring of muscle composition of the fatty acids, and an enhancement of the nutritional value of meat. These findings contribute to a better understanding of the food science of animal resources and provide valuable references for the production of meat of higher nutritional value.

Kaempferia parviflora rhizome extract exerts anti-obesity effect in high-fat diet-induced obese C57BL/6N mice.

Kaempferia parviflora (KP) rhizome, also called black ginger, has been used as a herbal medicine for many centuries. This current study was aimed at exploring whether KP rhizome extract (KPE) had anti-obesity effects and the mechanism involved. Five-week-old C57BL/6N male mice were allocated into five groups for 8-week feeding with control diet (CD), high-fat diet (HFD), HFD + 150 mg/kg body weight (BW)/day KPE (HFD+K150), HFD + 300 mg/kg BW/day KPE (HFD+K300), and HFD + 600 mg/kg BW/day KPE (HFD+K600). KPE decreased BW, body fat mass, adipose tissue weight, adipocyte size, and serum levels of glucose, triglycerides, cholesterol, insulin, and leptin in HFD-induced obese C57BL/6N mice. KPE inhibited adipogenesis by decreasing CCAAT/enhancer binding protein α, peroxisome proliferator-activated receptor γ, sterol regulatory element-binding protein-1c, acetyl-CoA carboxylase 1, ATP-citrate lyase, and fatty acid synthase mRNA expression. KPE improved lipolysis by increasing carnitine palmitoyl transferase 1 and hormone-sensitive lipase mRNA expression. These results suggest that KPE may have inhibited HFD-induced obesity by regulating several pathways involved in decreasing adipogenesis and enhancing lipolysis. Thus, the results suggest that KPE (or KP) may be applicable as an anti-obesity agent.

CircFOXN2 alleviates glucocorticoid- and tacrolimus-induced dyslipidemia by reducing FASN mRNA stability by binding to PTBP1 during liver transplantation.

We aimed to examine impacts and functional mechanism of circular RNA forkhead box N2 (FOXN2) in tacrolimus (TAC)- and dexamethasone (Dex)-induced lipid metabolism disorders. RNA level and protein contents in TAC, Dex, or combined TAC- plus Dex-treated patients and Huh-7 cells were measured utilizing quantitative real-time (qRT)-PCR and western blotting assays measured the formation of lipid droplet. Total cholesterol (TC) and triglyceride (TG) levels were determined using corresponding commercial kits and Oil red O staining. RNA immunoprecipitation and RNA pull-down verified the binding relationship among circFOXN2, polypyrimidine tract binding protein 1 (PTBP1) and fatty acid synthase (FASN). Male C57BL/6 mice were used to establish a dyslipidemia mouse model to validate the discoveries at the cellular level. Dex treatment significantly promoted TAC-mediated increase of TC and TG in serum samples and Huh-7 cells. Moreover, circFOXN2 was reduced but FASN was elevated in TAC-treated Huh-7 cells, and these expression trends were markedly enhanced by Dex cotreatment. Overexpression of circFOXN2 could reverse the accumulation of TC and TG and the upregulation of FASN and sterol regulatory element binding transcription factor 2 (SREBP2) mediated by Dex and TAC cotreatment. Mechanistically, circFOXN2 reduced FASN mRNA stability by recruiting PTBP1. The protective roles of circFOXN2 overexpression on lipid metabolism disorders were weakened by FASN overexpression. In vivo finding also disclosed that circFOXN2 greatly alleviated the dysregulation of lipid metabolism triggered by TAC plus Dex. CircFOXN2 alleviated the dysregulation of lipid metabolism induced by the combination of TAC and Dex by modulating the PTBP1/FASN axis.NEW & NOTEWORTHY Collectively, our experiments revealed for the first time that circFOXN2 alleviated the Dex- and TAC-induced dysregulation of lipid metabolism by regulating the PTBP1/FASN axis. These findings suggested that circFOXN2 and FASN might be candidate targets for the treatment of Dex- and TAC-induced metabolic disorders.

Allium macrostemon whole extract ameliorates obesity-induced inflammation and endoplasmic reticulum stress in adipose tissue of high-fat diet-fed C57BL/6N mice.

Obesity is a major risk factor for metabolic syndrome and a serious health concern worldwide. Various strategies exist to treat and prevent obesity, including dietary approaches using bioactive ingredients from natural sources. This study aimed to investigate the anti-obesity effect of whole-plant Allium macrostemon (also called as long-stamen chive) extract (AME) as a potential new functional food. C57BL/6N mice were divided into three groups and fed either a control diet (CD), high-fat diet (HFD), or HFD with AME treatment (200 mg/kg BW daily) for 9 weeks. The mice in the CD and HFD groups were treated with vehicle control. AME supplementation reduced HFD-induced body weight gain, fat mass, and adipocyte size. AME suppressed peroxisome proliferator-activated receptor γ and fatty acid synthase mRNA expression, indicating reduced adipogenesis and lipogenesis in adipose tissue. In addition, AME lowered inflammation in adipose tissue, as demonstrated by the lower number of crown-like structures, mRNA, and/or protein expression of macrophage filtration markers, as well as pro-inflammatory cytokines, including F4/80 and IL-6. Endoplasmic reticulum stress was also alleviated by AME administration in adipose tissue. Several phenolic acids known to have anti-obesity effects, including ellagic acid, protocatechuic acid, and catechin, have been identified in AME. By suppressing adipose tissue expansion and inflammation, AME is a potential functional food for the prevention and/or treatment of obesity and its complications.

Effect of diosgenin on mTOR/FASN/HIF-1α/VEGFA expression in rats with non-alcoholic fatty liver disease

The present study aimed to investigate the effect of diosgenin on mammalian target of rapamycin(mTOR), fatty acid synthase(FASN), hypoxia inducible factor-1α(HIF-1α), and vascular endothelial growth factor A(VEGFA) expression in liver tissues of rats with non-alcoholic fatty liver disease(NAFLD) and explore the mechanism of diosgenin on lipogenesis and inflammation in NAFLD. Forty male SD rats were divided into a normal group(n=8) fed on the normal diet and an experimental group(n=32) fed on the high-fat diet(HFD) for the induction of the NAFLD model. After modeling, the rats in the experimental group were randomly divided into an HFD group, a low-dose diosgenin group(150 mg·kg~(-1)·d~(-1)), a high-dose diosgenin group(300 mg·kg~(-1)·d~(-1)), and a simvastatin group(4 mg·kg~(-1)·d~(-1)), with eight rats in each group. The drugs were continuously given by gavage for eight weeks. The levels of triglyceride(TG), total cholesterol(TC), low-density lipoprotein cholesterol(LDL-C), alanine transaminase(ALT), and aspartate transaminase(AST) in the serum were detected by the biochemical method. The content of TG and TC in the liver was detected by the enzyme method. Enzyme-linked immunosorbent assay(ELISA) was used to measure interleukin 1β(IL-1β) and tumor necrosis factor α(TNF-α) in the serum. Lipid accumulation in the liver was detected by oil red O staining. Pathological changes of liver tissues were detected by hematoxylin-eosin(HE) staining. The mRNA and protein expression levels of mTOR, FASN, HIF-1α, and VEGFA in the liver of rats were detected by real-time fluorescence-based quantitative polymerase chain reaction(PCR) and Western blot, respectively. Compared with the normal group, the HFD group showed elevated body weight and levels of TG, TC, LDL-C, ALT, AST, IL-1β, and TNF-α(P<0.01), increased lipid accumulation in the liver(P<0.01), obvious liver steatosis, up-regulated mRNA expression levels of mTOR, FASN, HIF-1α, and VEGFA(P<0.01), and increased protein expression levels of p-mTOR, FASN, HIF-1α, and VEGFA(P<0.01). Compared with the HFD group, the groups with drug treatment showed lowered body weight and levels of TG, TC, LDL-C, ALT, AST, IL-1β, and TNF-α(P<0.05, P<0.01), reduced lipid accumulation in the liver(P<0.01), improved liver steatosis, decreased mRNA expression levels of mTOR, FASN, HIF-1α, and VEGFA(P<0.05, P<0.01), and declining protein expression levels of p-mTOR, FASN, HIF-1α, and VEGFA(P<0.01). The therapeutic effect of the high-dose diosgenin group was superior to that of the low-dose diosgenin group and the simvastatin group. Diosgenin may reduce liver lipid synthesis and inflammation and potentiate by down-regulating the mTOR, FASN, HIF-1α, and VEGFA expression, playing an active role in preventing and treating NAFLD.

Exercise Down-Regulates Hepatic Lipogenic Enzymes in Food-Deprived and Refed Rats

The effects of an acute bout of prolonged exercise on the activities of several hepatic lipogenic enzymes and the abundance of fatty acid synthase (FAS) mRNA were evaluated using a food deprivation-refeeding protocol in which diets contained 50% of the energy from either fructose or cornstarch. Food was withheld from male rats for 48 h and refed for 0, 4, 8, 12, 24 or 48 h. At each time point, half of each dietary group was subjected to a single bout of treadmill running until exhaustion and killed immediately. The other half of each group rested without food for the same amount of time before being killed. Exercise significantly decreased FAS activity by 57, 46, 10, 26 and 70% at 4, 8, 12, 24 and 48 h of refeeding, respectively, in the fructose-fed rats; and by 70 and 63% at 24 and 48 h of refeeding, respectively, in the cornstarch-fed rats. Activities of L-type pyruvate kinase and glucose 6-phosphate dehydrogenase were significantly decreased after exercise in the fructose-fed, but not cornstarch-fed rats. In rested rats, FAS mRNA abundance increased ∼fourfold above the unfed levels after 8 and 12 h of refeeding. Exercise attenuated the diet-induced increases in FAS mRNA abundance. At 8 h of refeeding, both cornstarch- and fructose-fed exercised rats had 71% (P < 0.05) of the FAS mRNA levels of their rested counterparts; at 12 h, these exercised rats showed only 46 and 27% (P < 0.05) of FAS mRNA levels compared with rested rats fed the same diet. We conclude that dietary induction of FAS activity and mRNA abundance can be inhibited by prolonged exercise, suggesting that exercise may influence FAS transcription and/or mRNA stability.

Effect of Dangfei Liganning capsule on liver X receptor α/steroid regulatory element binding protein-1/fatty acid synthase signal pathway in rats with metabolic- associated fatty liver disease.

To study the mechanism of Dangfei Liganning capsule in the treatment of rats with metabolic associated fatty liver disease (MAFLD). Totally 48 specific pathogen free Sprague-Dawley male rats were randomly divided into normal Group, model group, Dangfei Liganning high, moderate, and low-dose groups and Essentiale group which were fed with high fat diet for 8 weeks, and gavage and molding were carried out simultaneously. Dangfei Liganning high, middle and low-dose group were given 0.27, 0.135 and 0.0675 g·kg·d respectively by gavage, Essentiale group was given 0.123 g·kg·d by gavage, the same amount of distilled water was given by gavage in the normal group and the model group. The rats were weighed at the 0th week, 2nd week, 4th week, 6th week and 8th weekend respectively. The rats were sacrificed at the end of the 8th week. Serum levels of alanine aminotransferase (ALT), alanine aminotransferase (AST), triglyceride (TG), total cholesterol (CHO), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein (LDL-C), total protein (TP), albumin (Alb), globulin (GLB), total bilirubin (TBIL), direct bilirubin (DBIL), tumor necrosis factor-α(TNF-α) and interleukin-6 (IL-6) were measured. The levels of liver tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and liver pathology [hematoxylin and eosin (HE) staining, oil red O staining] were detected. The expression levels of liver X receptor α (LXRα), steroid regulatory element binding protein-1 (SREBP-1) and fatty acid synthase (FAS) were detected by immunohistochemistry, Western blot and reverse transcription-polymerase chain reaction reverse transcription-polymerase chain reaction. From the beginning to the 8th week, the growth rate of body weight in the Dangfei Liganning high-dose group was slower than all other groups. There was no significant difference in ALB level in all groups ( 0.05). Compared with the model group, the levels of ALT, AST, LDL-C, TG, CHO, TP, GLB, TBIL, DBIL, IL-6, TNF-α were significantly decreased and HDL-C were significantly increased in Dangfei Liganning high-dose group (0.01, < 0.05). HE and oil red O staining showed that the fatty lesions in rat liver were alleviated, while the expressions of LXRα, SREBP-1, FAS mRNA and protein were significantly decreased (0.01). Dangfei Liganning capsule can slow down the increase of body weight of MAFLD rats, reduce the levels of transaminase, Lipid and inflammatory factors in MAFLD rats, promote the synthesis of liver protein and bile metabolism, and improve the liver fatty lesion of MAFLD rats, among which the Dangfei Liganning high-dose group is more effective. The mechanism of action may be through blocking LXR-SREBP-1-FAS signal pathway.

RF13 | PMON48 A novel missense variant in the gene encoding Fatty Acid Synthase (FASN) associated with a unique multi-system disorder including hypopituitarism and hypoparathyroidism

Abstract A male patient presented with a unique complex phenotype including panhypopituitarism, short stature with failure to respond to GH [IGF-1 generation test: no response to 2.8 mg/m2/day GH], sensorineural deafness, hypoparathyroidism, retinal dystrophy, and intellectual disability. He was 127cm tall at the age of 21 and was completely prepubertal (LH 0.8 U/L, FSH 2.6 U/L, Testosterone &amp;lt;0.69 nmol/L) with a bone age of 12 years. A trial of recombinant IGF-1 failed to improve growth. He died at the age of 26 years following a collapse of unknown etiology. Exome sequencing and subsequent variant calling on this patient revealed a novel heterozygous de novo missense variant (c.6395C&amp;gt;T, p.A2132V) at a highly conserved residue in FASN encoding Fatty Acid Synthase. The variant was not present in any control database, including the GnomAD browser. Human embryonic brain expression analysis using in situ hybridisation, revealed FASN mRNA transcript staining in the diencephalon and hypothalamus at Carnegie stages (CS) 16, 19, 20 and 23, and in Rathke's pouch (primordium of the anterior pituitary) at CS16 only. Fatty acid synthase (FASN), a crucial multienzyme with seven different catalytic activities, converts acetyl-CoA and malonyl-CoA into long-chain saturated fatty acids such as palmitate, in the presence of NADPH. Murine null mutant Fasn-/- embryos die before implantation and Fasn+/- embryos at various stages in the early postnatal period. Fasn is expressed in multiple tissues including the brain, parathyroids, liver and adrenal. Biochemical investigation of the patient revealed high triglyceride concentrations (3.81-6.49 mmol/L; NR 0.38-2) at all time points during an 18 hour fast. He mobilised free fatty acids but did not generate an increase in 3-hydroxybutyrate, suggesting a defect in fatty acid oxidation or ketone body synthesis. He maintained normoglycaemia with normal hormone responses to fasting, except for an undetectable IGF-1 (&amp;lt;25 ng/ml) and IGFBP-3 (1.17 mg/L). We measured de novo fatty acid synthesis in cultured patient and control fibroblast cells with 13C-Glucose, with and without the C75 fatty acid synthase inhibitor. Cell pellets were collected at three time-points, and 13C-fatty acids derived from 13C-glucose were analysed by mass spectrometry. Preliminary data showed that more C13-glucose was incorporated into de novo synthesised palmitic acid in control cells, suggesting reduced fatty acid synthesis in the patient. Our data suggest that FASN p.A2132V is pathogenic and contributed significantly to the complex patient phenotype, consistent with recent studies suggesting that neural stem/progenitor cells (NSPCs) in the rodent brain are governed by Fasn-dependent de novo lipogenesis for proliferation. Presentation: Sunday, June 12, 2022 12:36 p.m. - 12:41 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Effect of n-6/n-3 PUFA ratio on body fat deposition, tissues fatty acid composition and key genes expression of liver lipid metabolism in silver foxes (Vulpes vulpes fulva) during the winter fur-growth period.

The proportion of n-6/n-3 polyunsaturated fatty acid (PUFA) plays an important role in regulating lipid metabolism. This study aimed to investigate the effects of dietary n-6/n-3 PUFA ratios on body fat deposition, tissues fatty acid composition, and gene expression of liver lipid metabolism of silver foxes during the winter fur growth period. Forty-eight age-matched male silver foxes with similar body weights were randomly divided into four dietary groups for 47 days, which were fed n-6/n-3 PUFA ratio with 3, 18, 41, and 136 experimental diets, respectively. Dietary n-6/n-3 PUFA ratio did not significantly influence fat deposition parameters except for hepatic fat content. The variation trend of the fatty acid composition of liver, intramuscular fat, and subcutaneous fat in silver fox was directly related to dietary fatty acid content (p < 0.05). With the dietary n-6/n-3 PUFA ratio increasing, the expression of liver fatty acid synthase (FAS) mRNA and peroxisome proliferator-activated receptor (PPAR) mRNA exhibited the trend of first decreasing and then increasing (p < 0.05), whereas L-fatty acid binding protein (L-FABP) mRNA expression showed a gradual increasing trend (p < 0.05). In summary, silver foxes fed an n-6/n-3 PUFA ratio 18:1 diet (supplementing with 9.38% corn oil and 4.62% soybean oil) was more conducive to lipid decomposition, PUFA transport, and utilization of tissues, thereby meeting it for supplying energy and withstanding the cold.

Expression patterns of AMPK and genes associated with lipid metabolism in newly hatched chicks during the metabolic perturbation of fasting and refeeding

Fasting-refeeding perturbation has been extensively used to reveal specific genes and metabolic pathways that control energy metabolism in chickens. In this study, 200 chickens were randomly assigned to 2 groups after hatching: the control group (C, fed ad libitum) and the fasting-refeeding group (T, water ad libitum). The chicks in Group T were fasted for 72 h, and then fed for another 48 h. Liver, hypothalamus, and adipose samples were collected at 0 (F0), 24 (F24), 48 (F48), and 72 h (F72) after fasting and 4 (FR4), 12 (FR12), 24 (FR24), and 48 h (FR48) after refeeding, respectively. Results showed that Group T had a significantly higher number of liver vacuoles (P < 0.05 or P < 0.01) and a significantly lower gray value of Sudan IIIstained sections (P < 0.05 or P < 0.01) than Group C at F48-FR48. In addition, compared with the Group C, fasting and refeeding reduced the expression of stearoyl CoA desaturase (SCD) mRNA (P < 0.05 or P < 0.01) in the liver and adipose tissues, the expression of glucocorticoid receptor (GR) mRNA (P < 0.05 or P < 0.01) in the liver, adipose, and hypothalamus tissues, and the expression of fatty acid synthase (FAS) mRNA (P < 0.05 or P < 0.01) in the liver at F24-FR24. Moreover, relative to those in Group C, fasting and refeeding increased the mRNA expression levels of adenosine monophosphate-activated protein kinase (AMPK) α, AMPKβ, and AMPKγ in the hypothalamus (P < 0.05 or P < 0.01) at F24-FR24. In conclusion, fasting and refeeding increased the fat content of the liver, and the expression of lipolytic genes in the hypothalamus (e.g., AMPKα, AMPKβ, and AMPKγ) but decreased the expression of fat synthesis genes in the liver (e.g., SCD, GR, and FAS), adipose (SCD and GR), and hypothalamus (GR).

Changes in the triglyceride metabolism in the thigh muscle and liver of broilers injected intravenously with angiopoietin-like protein 4

Angiopoietin-like protein 4 (ANGPTL4) is a potential circulating mediator connecting nutritional factors and fat metabolism, however, information is lacking on the exact role of ANGPTL4 on triglyceride metabolism in the thigh muscles and livers of broilers. The objective of this study was to determine the changes in the triglyceride metabolism in the thigh muscles and livers of broilers injected intravenously with ANGPTL4. In experiment 1, 36 male Arbor Acres broilers at 35 days of age were randomly allocated into six treatments with six replicates. The broilers were subjected to intravenous injection of polyhistidine-small ubiquitin-related modifier-ANGPTL4 (His-SUMO-ANGPTL4) once at a dose of 0, 20, 100, 500, 2 500, or 12 500 ng/kg body weight (BW), respectively. The results showed that the injection of His-SUMO-ANGPTL4 at a dose of 500, 2 500 and 12 500 ng/kg BW decreased (P &amp;lt; 0.05) the broilers’ heart-fatty acid-binding protein (H-FABP) mRNA expression in the thigh muscle. All of the His-SUMO-ANGPTL4 broiler injected groups had a lower (P &amp;lt; 0.05) adipocyte-fatty acid-binding protein mRNA expression in the thigh muscle. In experiment 2, 18 male Arbor Acres broilers at 35 days of age were randomly allocated into three treatments with six replicates. The broilers were given an injection of normal saline (NS), His-SUMO, or His-SUMO-ANGPTL4 (500 ng/kg BW) once. The results showed that the broilers receiving an injection of ANGPTL4 at a dose of 500 ng/kg BW decreased (P &amp;lt; 0.05) the H-FABP mRNA expression in the thigh muscle. Besides, the broilers given an injection of ANGPTL4 at a dose of 500 ng/kg BW increased (P &amp;lt; 0.05) the fatty acid synthase mRNA expression and activity and decreased (P &amp;lt; 0.05) the microsomal triglyceride transfer protein mRNA expression in the liver. However, the concentrations of the high-density lipoprotein, low-density lipoprotein, very low-density lipoprotein, insulin, growth hormone and leptin in the serum were not affected by the ANGPTL4 injection. In conclusion, ANGPTL4 has the ability to change the triglyceride metabolism in the thigh muscles and livers of broilers.

P10.08.A Lipogenesis inhibition by fatostatin shows effectiveness in glioblastoma models highly expressing fatty acid synthase (FASN)

Abstract Background Glioblastoma (GBM) is the most common and most aggressive primary brain tumour in adults. Despite intensive treatment, the medium overall survival of GBM patients remains below 20 months after diagnosis. Therefore, new tumour specific targets allowing successful therapeutic treatment are needed to distinctly enhance GBM patient overall survival. Reprogramming of lipid metabolism leading to highly upregulated anabolic pathways, like phosphatidylinositol-3-kinase (PI3K)/AKT pathway and subsequently lipogenesis, is a hallmark of cancer cells including glioblastomas to meet increased energy demands for proliferation and cell growth. Accordingly, lipogenesis inhibition might be a promising strategy to impede GBM cell growth. Therefore, it was aim of our study to analyse the effect of the lipogenesis inhibitor fatostatin on downstream targets e.g. fatty acid synthase (FASN) and its impact on cell growth in GBM cells in vitro. Material and Methods In a cohort of 52 GBM-derived cell lines, FASN mRNA was investigated by qRT-PCR. The impact of fatostatin on cell viability (IC50) was analysed in selected cell lines using cell viability assays (Cell Titer Glo®). To elucidate whether fatostatin exposure affects cell migration, wound healing assays were performed. The effect of fatostatin on cell cycle and apoptosis was analysed by flow cytometry. Additionally, expression of FASN and level of phosphorylated AKT, the active form of AKT serine/threonine kinase, were examined before and after fatostatin treatment with qRT-PCR (mRNA) and Western blot (protein), respectively. Results FASN mRNA was found to be expressed at varying levels in our GBM-derived cell line cohort (n=52). Compared to normal astrocytes, FASN mRNA expression was significantly upregulated in GBM cells (p=0.0127). Furthermore, high FASN mRNA expression was significantly associated with higher sensitivity against fatostatin (p=0.0352). Regarding corresponding recurrences, the response to the inhibitor was shown to be persistent. Accordingly, the effectiveness of fatostatin treatment resulted in substantial downregulation of AKT phosphorylation and consequently in the induction of apoptosis and G2/M arrest of the cell cycle. In addition, a significant inhibition of the migration potential by fatostatin treatment was observed. Conclusion In summary, FASN expression represents a promising biomarker and therapy target within the lipid metabolism indicated by a significant sensitivity to fatostatin in FASN overexpressing GBM cell lines. Consequently, lipogenesis inhibition by fatostatin might be a promising novel therapeutic option in glioblastoma.

Salinity levels affect the lysine nutrient requirements and nutrient metabolism of juvenile genetically improved farmed tilapia (Oreochromis niloticus).

This 62-d research aimed to evaluate the effects of dietary lysine levels (DLL) and salinity on growth performance and nutrition metabolism of genetically improved farmed tilapia (GIFT) juveniles (Oreochromis niloticus). Six diets with lysine supplementation (1·34, 1·70, 2·03, 2·41, 2·72 and 3·04 % of DM) were formulated under different cultured salinities in a two-factorial design. The results indicated that supplemental lysine improved the specific growth rate (SGR) and weight gain (WG) and decreased the feed conversion ratio (FCR). Meanwhile, the fish had higher SGR and WG and lower FCR at 8 ‰ salinity. Except for moisture, the whole-body protein, lipid and ash content of GIFT were increased by 8 ‰ salinity, which showed that DLL (1·34 %) increased the whole-body fat content and DLL (2·41 %) increased whole-body protein content. Appropriate DLL up-regulated mRNA levels of protein metabolism-related genes such as target of rapamycin, 4EBP-1 and S6 kinase 1. However, 0 ‰ salinity reduced these protein metabolism-related genes mRNA levels, while proper DLL could improve glycolysis and gluconeogenesis mRNA levels but decrease lipogenesis-related genes mRNA levels in liver. 0 ‰ salinity improved GLUT2, glucokinase and G6 Pase mRNA levels; however, sterol regulatory element-binding protein 1 and fatty acid synthase mRNA levels were higher at 8 ‰ salinity. Moreover, 8 ‰ salinity also increased plasma total protein and cholesterol levels and decreased glucose levels. These results indicated that the recommended range of lysine requirement under different salinity was 2·03-2·20 % (0 ‰) and 2·20-2·41 % (8 ‰) and 8 ‰ salinity resulted in higher lysine requirements due to changes in the related nutrient metabolism, which might provide useful information for designing more effective feed formulations for GIFT cultured in different salinity environment.

Intrauterine Growth-Restricted Piglets Are Predisposed to Develop Metabolic Disorders in Adulthood When Fed With Parenteral Nutrition in the Neonatal Period

ObjectivesTotal parenteral nutrition (TPN) is lifesaving yet non-normal nutrition regimen during the neonatal period. However, studies have shown that TPN feeding early in life can permanently alter metabolism at later ages. Moreover, intrauterine growth restricted (IUGR) neonates also have a higher risk of developing metabolic diseases (such as obesity and dyslipidemia) in later life. Because a substantial proportion of IUGR neonates receive TPN in early life, we wondered if the metabolic effects of feeding TPN early in life would exacerbate these effects of IUGR? We hypothesized that feeding TPN to IUGR neonates would aggravate the risk of developing obesity and dyslipidemia in adulthood.MethodsSixteen normal weight female piglets (7 d old) were randomized to sow-fed (SF) or early TPN (TPN-CON); 8 (IUGR or runt) piglets were fed TPN as a third group (TPN-IUGR). After 2 weeks of TPN or suckling, all pigs were fed a normal grower diet for 8 mo. At 8 mo, catheters were implanted and in vivo metabolic tests were conducted.ResultsTPN-IUGR pigs demonstrated catch-up growth by 4 mo, and body weights were not different among groups at 8 mo. The metabolic effects of feeding TPN persisted into adulthood, as indicated by higher postprandial plasma triglycerides (TG) and fasting plasma non-esterified fatty acids (NEFA), compared to SF (P < 0.05). IUGR exacerbated TPN-induced risk for diseases by worsening obesity outcomes with greater subcutaneous fat deposition (P < 0.05) and greater ectopic TG deposition in the liver (P < 0.05) and muscle (P < 0.05). Furthermore, IUGR led to dyslipidemia as indicated by higher cholesterol in fasted plasma LDL (P < 0.05), slower postprandial TG clearance (P < 0.05), higher fasting plasma NEFA (P < 0.001) and higher plasma dimethylglycine (P < 0.05), compared to the TPN-CON. IUGR pigs had greater VLDL secretion, as suggested by higher microsomal transfer protein mRNA (P < 0.05). Early TPN programmed reduced lipogenesis, as indicated by lower fatty acid synthase mRNA (P < 0.05), compared to SF.ConclusionsCollectively, these findings conclude that although TPN is a lifesaving measure, feeding TPN to IUGR neonates has long-term metabolic consequences predisposing them to develop metabolic disorders in adulthood.Funding SourcesCanadian Institutes of Health Research.

Efficacy of aqueous extract of flower of Edgeworthia gardneri (Wall.) Meisn on glucose and lipid metabolism in KK/Upj-Ay/J mice.

To observe the effects of the flower of Edgeworthia gardneri (Wall.) Meisn (EWM) on glucose and lipid metabolism in KK/upj-Ay/J (KKAy) mice and investigate the possible mechanism of EWM in the liver of KKAy mice by transcriptome analysis. Forty KKAy mice were fed a high-sugar and high-fat diet for 3 weeks to establish the animal model of metabolic syndrome. After 5 weeks of continuous administration of EWM, serum high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TG), total cholesterol (TC), and free fatty acids (FFA) were detected by radioimmunoassay. Serum fasting insulin (Fins) and adiponectin levels were measured by enzyme-linked immunosorbent assay. Liver tissue fixed with paraformaldehyde was stained with hematoxylin-eosin and oil red O. Transcriptome analysis was used to evaluate the liver tissue. The expressions of lipoprotein lipase (LPL), peroxisome proliferator-activated receptor-γ (PPARγ), adenosine 5'-monophosphate-activated protein kinase (AMPK), sterol regulatory element binding protein-1c (SREBP-1c), and fatty acid synthase (Fas) mRNA and protein in liver tissue were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. EWM slightly reduced FBG and Fins in KKAy mice. Furthermore, EWM was able to downregulate serum LDL, TG, TC, and FFA and upregulate the expression of serum HDL and adiponectin. Transcriptome analysis revealed the following differential pathways: the peroxisome proliferator-activated receptor (PPAR) signaling pathway and the AMPK signaling pathway. RT-PCR and western blot analysis detected the associated genes and proteins. In addition, EWM was able to upregulate the expression of AMPK and downregulate the expression of PPARγ, SREBP1c, and Fas mRNA and protein and upregulate the expression of LPL mRNA. EWM can alleviate lipid metabolism disorders and to some extent improve glucose metabolism disorders in KKAy mice. These effects may be related to regulating PPARγ/LPL and activating the AMPK/SREBP1c/Fas pathway.

Vitamin D promotes growth, feed utilization and gene expression related to lipid metabolism for juvenile Orange-spotted grouper Epinephelus coioides

This study aimed to evaluate vitamin D (VD) levels on growth, feed utilization, enzymatic activity in lipid metabolism and mRNA expression for juvenile Orange-spotted grouper Epinephelus coioides (initial weight:7.40 ± 0.03 g) for 8 weeks. Six group fishes were fed diets containing different VD levels (0, 500, 1000, 2000, 4000, and 10,000 IU/kg, respectively). Compared to the control group, the weight gain rate and feed utilization rate showed a significant increase and then decreased (P < 0.05). The highest activities of alkaline phosphatase and superoxide dismutase were observed in the groups supplemented with 4000 and 1000 IU/kg VD, respectively (P < 0.05). With VD increased, triglyceride content gradually decreased (P < 0.05), whereas high-density lipoprotein content initially increased and then decreased. By comparison, cholesterol and low-density lipoprotein contents were not affected by VD supplementation levels (P > 0.05). VD supplementation levels significantly reduced liver fatty acid synthase activity (P < 0.05), but significantly promoted lipoprotein lipase and hepatic lipase activities (P < 0.05). As VD increased, liver VD deposition increased significantly in the 2000 IU/kg group. Fatty acid synthase (fas) mRNA expression was significantly down-regulated and then up-regulated (P < 0.05), whereas hepatic lipase (hl) mRNA expression levels exhibited the opposite trend. In summary, based on the broken-line regression analysis of WGR and dietary VD levels, the optimal dietary VD requirement was 930 IU/kg VD for juvenile Orange-spotted grouper Epinephelus coioides. A diet with a VD supplement from 1000 to 2000 IU/kg significantly improved the lipid metabolism in the liver for juvenile Orange-spotted grouper Epinephelus coioides, reducing fat deposition in the liver.

Helicoverpa armigera miR-2055 regulates lipid metabolism via fatty acid synthase expression.

Insect hormones and microRNAs regulate lipid metabolism, but the mechanisms are not fully elucidated. Here, we found that cotton bollworm larvae feeding on Arabidopsis thaliana (AT) leaves had a lower triacylglycerol (TAG) level and more delayed development than individuals feeding on artificial diet (AD). Association analysis of small RNA and mRNA revealed that the level of miR-2055, a microRNA related to lipid metabolism, was significantly higher in larvae feeding on AT. Dual-luciferase reporter assays demonstrated miR-2055 binding to 3' UTR of fatty acid synthase (FAS) mRNA to suppress its expression. Elevating the level of miR-2055 in larvae by agomir injection decreased FAS mRNA and protein levels, which resulted in reduction of free fatty acid (FFA) and TAG in fat body. Interestingly, in vitro assays illustrated that juvenile hormone (JH) increased miR-2055 accumulation in a dosage-dependent manner, whereas knockdown of Methoprene tolerant (Met) or Kruppel homologue 1 (Kr-h1) decreased the miR-2055 level. This implied that JH induces the expression of miR-2055 via a Met-Kr-h1 signal. These findings demonstrate that JH and miRNA cooperate to modulate lipid synthesis, which provides new insights into the regulatory mechanisms of metabolism in insects.