Fatty Acid Synthase mRNA Research Articles

Overexpressed Fatty Acid Synthase in Gastrointestinal Stromal Tumors: Targeting a Progression-Associated Metabolic Driver Enhances the Antitumor Effect of Imatinib.

Purpose: In gastrointestinal stromal tumors (GIST), lipid-metabolizing enzymes remain underexplored, including fatty acid synthase (FASN).Experimental Design: Forty GISTs were quantitated for FASN mRNA abundance. FASN immunoexpression was informative in 350 GISTs, including 213 with known KIT/PDGFRA/BRAF genotypes. In imatinib-resistant FASN-overexpressing GIST cells, the roles of overexpressed FASN and FASN-targeting C75 in tumor phenotypes, apoptosis and autophagy, KIT transcription, PI3K/AKT/mTOR activation, and imatinib resistance were analyzed by RNAi or myristoylated-AKT transfection. The therapeutic relevance of dual blockade of FASN and KIT was evaluated in vivoResults:FASN mRNA abundance significantly increased from very low/low-risk to high-risk levels of NCCN guidelines (P < 0.0001). FASN overexpression was associated with a nongastric location (P = 0.05), unfavorable genotype (P = 0.005), and increased risk level (P < 0.001) and independently predicted shorter disease-free survival (P < 0.001). In vitro, FASN knockdown inhibited cell growth and migration, inactivated the PI3K/AKT/mTOR pathway, and resensitized resistant GIST cells to imatinib. C75 transcriptionally repressed the KIT promoter, downregulated KIT expression and phosphorylation, induced LC3-II and myristoylated AKT-suppressible activity of caspases 3 and 7, attenuated the PI3K/AKT/mTOR/RPS6/4E-BP1 pathway activation, and exhibited dose-dependent therapeutic additivism with imatinib. Compared with both monotherapies, the C75/imatinib combination more effectively suppressed the growth of xenografts, exhibiting decreased KIT phosphorylation, Ki-67, and phosphorylated PI3K/AKT/mTOR levels and increased TUNEL labeling.Conclusions: We have characterized the prognostic, biological, and therapeutic implications of overexpressed FASN in GISTs. C75 represses KIT transactivation, abrogates PI3K/AKT/mTOR activation, and provides a rationale for dual blockade of KIT and FASN in treating imatinib-resistant GISTs. Clin Cancer Res; 23(16); 4908-18. ©2017 AACR.

Environmental exposure to a major urban wastewater effluent: Effects on the energy metabolism of northern pike

Municipal wastewater effluents (MWWEs) consist of dynamic and complex mixtures of chemical and biological compounds that can alter the health of exposed aquatic organisms. Disturbance of energy metabolism has been reported in fish exposed to MWWEs. However, there is a scarcity of knowledge on the physiological events leading to perturbation of energy balance and thyroid regulation, and associated lipid metabolism. The objective of the present study was to use a set of biomarkers, from gene transcription to body condition, to investigate the effects of a chronic environmental exposure to a major primary MWWE on fatty acid metabolism and thyroid hormone levels in northern pike (Esox lucius) collected from the St. Lawrence River near Montreal (QC, Canada). The exposure of pike to MWWE was examined through determination of a suite of persistent and bioaccumulative halogenated flame retardants in liver as this effluent is a known regional source for these chemicals. Greater hepatic concentrations of polybrominated diphenyl ethers (PBDEs, range: 29.6–465ng/g w.w. and 88.8–823ng/g w.w. in females and males, respectively) and other halogenated flame retardants (e.g., dechlorane-related compounds) were determined in fish collected downstream of the MWWE’s point of discharge relative to the upstream site. This exposure in male pike was associated with decreased acyl-coA oxidase (acox1) and fatty acid synthase (fasn) mRNA levels as well as a decreased acyl-coA oxidase (ACOX) activity in liver. In female pike, MWWE exposure was associated with lower circulating free and total triiodothyronine (T3) levels and a tendency for greater total lipid percentages in liver. Present findings provide evidence that chronic exposure of a top predator fish to MWWE can be related to gender-specific effects on fatty acid metabolism and thyroid hormone homeostasis, and highlight the need for further investigation.

Effects of dietary vitamin A on growth, feed utilization, lipid metabolism enzyme activities, and fatty acid synthase and hepatic lipase mRNA expression levels in the liver of juvenile orange spotted grouper, Epinephelus coioides

A 10-week feeding trial was conducted to investigate the effects of dietary vitamin A (VA) on growth, feed utilization, lipid metabolism enzyme activities, and fatty acid synthase (FAS), and hepatic lipase (HL) mRNA expression levels in the liver of juvenile Epinephelus coioides. Six semi-purified diets were formulated to contain VA as retinyl acetate at concentrations of 0, 1000, 2000, 4000, 8000, and 20,000IU·kg−1, providing actual dietary values of 387 (control group), 1256, 2242, 4102, 7635, and 18,231IUVA·kg−1 diet, respectively. A total of 540 juvenile E. coioides were randomly stocked into 18,500L fiberglass tanks with 30 fish per tank and 3 tanks per diet. The results showed weight gain rate (WGR), specific growth rate (SGR), and survival rate (SR), significantly increased in fish supplemented with over 1000IU dietary VA compared with the control group (P<0.05). The feed conversion ratio (FCR) significantly decreased in fish supplemented with dietary VA from 2000IU·kg−1 to 8000IU·kg−1 compared with fish in the other groups (P<0.05). However, supplementing the diet with VA at >8000IU·kg−1 inhibited the growth of juvenile E. coioides (P<0.05). The FAS and HL activities were significantly higher in the livers of the group supplemented with 2000IUVA·kg−1 compared to those of the control group and the group supplemented with 1000IUVA·kg−1 (P<0.05), but dietary VA did not significantly affect whole body lipid deposition in fish (P>0.05). The FAS and HL mRNA expression levels were significantly higher in the groups with dietary VA levels from 4000IU·kg−1 to 8000IU·kg−1 compared to those in the control group (P<0.05). Based on the broken-line regression analysis of WGR and dietary VA levels, the optimal dietary VA requirement is 1775IUVA·kg−1for juvenile grouper. At the same time, under the condition of this experiment, a dietary VA level of 4000IU·kg−1 promoted lipolytic enzyme activity and the expression of lipid decomposition genes in the liver of groupers.

Nuclear receptor subfamily 1 group H member 2 (LXRB) is the predominant liver X receptor subtype regulating transcription of 2 major lipogenic genes in goat primary mammary epithelial cells.

In ruminants, recent research has identified a crucial role for liver X receptors (LXR) in regulating lipid metabolism in mammary cells. However, the differences between LXR subtypes in regulating ruminant lipid metabolism are unknown. We used overexpression and knockdown of LXRA and LXRB in goat primary mammary epithelial cells to distinguish subtype-specific regulation of sterol regulatory element binding protein 1c (SREBP1c) and fatty acid synthase (FASN) mRNA expression and their promoter activity. Incubation with siRNA targeting LXR decreased expression of LXRA and LXRB. Knockdown of LXRA and LXRB in cells incubated with dimethyl sulfoxide (DMSO, control) had no effect on the expression of SREBP1c or FASN. Knockdown of LXRB in cells incubated with LXR ligand T0901317 (T09) led to decreased expression of FASN, but not SREBP1c. Overexpression of LXRB plus T09 dramatically upregulated SREBP1c and FASN to levels higher than overexpression of LXRA with T09. Luciferase reporter assays in cells with site-directed mutagenesis of LXR response elements (LXRE; LXRE1 from -286 to -251 bp or LXRE2 from -235 to -219 bp) revealed that the SREBP1c promoter with the wild type or either LXRE mutation in cells supplemented with T09 decreased markedly only when LXRB was knocked down. Knockdown of LXRA and LXRB had no effect on the SREBP1c promoter when cells had a double LXRE mutation. Overexpression of LXRA only in cells incubated with T09 increased the activity of the SREBP1c promoter with the wild type and the LXRE2 mutation. In contrast, compared with each control group, overexpression of LXRB dramatically increased SREBP1c promoter activity, regardless of LXRE mutation. Furthermore, in cells stimulated with T09, knockdown of either LXRA or LXRB did not alter wild-type FASN promoter activity. Knockdown of LXRA increased wild-type and LXRE-site-mutated (LXRE from -677 to -662 bp) FASN promoter activity. Overexpression of LXRB increased wild-type and LXRE-site-mutated FASN promoter activity regardless of treatment with DMSO or T09, but overexpression of LXRA altered LXRE-site-mutated FASN promoter activity only in cells treated with DMSO. Increased activation of SREBP1c or FASN promoters containing LXRE mutations after overexpression of LXRB suggested that LXRB activates endogenous SREBP1c, which can then bind to the promoter of SREBP1c via an auto-loop circuit regulatory mechanism. Collectively, these results highlight an important role for LXRB in the transcriptional regulation of SREBP1c and FASN in goat mammary epithelial cells. Activation of this nuclear receptor controls lipogenesis via different mechanisms.

The additive effects of the TM6SF2 E167K and PNPLA3 I148M polymorphisms on lipid metabolism.

There is a genetic susceptibility for nonalcoholic fatty liver disease (NAFLD). To examine the role of genetic factors in the disease, a Bayesian analysis was performed to model gene relationships in NAFLD pathogenesis. The Bayesian analysis indicated a potential gene interaction between the TM6SF2 and PNPLA3 genes. Next, to explore the underlying mechanism at the cellular level, we evaluated the additive effects between the TM6SF2 E167K and PNPLA3 I148M polymorphisms on lipid metabolism. Hepa 1-6 cells were transfected with a control vector or with overexpression vectors for TM6SF2/PNPLA3-wild type, TM6SF2-mutant type, PNPLA3-mutant type, or TM6SF2/PNPLA3-mutant type. Commercial kits were used to measure triglyceride and total cholesterol levels in each of the five groups. The mRNA and protein expression levels of sterol regulatory element-binding transcription factor 1c and fatty acid synthase were analyzed using real-time PCR and western blotting. The triglyceride and total cholesterol contents were significantly different among the groups. The triglyceride and total cholesterol contents and the sterol regulatory element-binding transcription factor 1c and fatty acid synthase mRNA and protein expression levels were significantly higher in the TM6SF2/PNPLA3-mutant type group than in the TM6SF2-mutant type group or the PNPLA3-mutant type group. The TM6SF2 E167K and PNPLA3 I148M polymorphisms may have additive effects on lipid metabolism by increasing the expression of sterol regulatory element-binding transcription factor 1c and fatty acid synthase.

Supplementation of glycerol or fructose via drinking water to grazing lambs on tissue glycogen level and lipogenesis.

Lambs ( = 18; 40.1 ± 7.4 kg BW) were used to assess supplementation of glycerol or fructose via drinking water on growth, tissue glycogen levels, postmortem glycolysis, and lipogenesis. Lambs were blocked by BW and allocated to alfalfa paddocks (2 lambs/paddock and 3 paddocks/treatment). Each paddock within a block was assigned randomly to drinking water treatments for 30 d: 1) control (CON), 2) 120 g fructose/L of drinking water (FRU), or 3) 120 g glycerol/L of drinking water (GLY). Lambs grazed alfalfa with free access to water treatments for 28 d and then were fasted in indoor pens for a final 2 d with access to only water treatments. Data were analyzed using the MIXED procedure of SAS with water treatment and time (when appropriate) in the model. During the 28-d grazing period, ADG was greater ( < 0.05) for GLY than for CON or FRU. During the 2-d fasting period, BW shrink was lower ( < 0.05) for GLY compared with CON or FRU. Hot carcass weight was greater ( < 0.05) for GLY than for FRU. The interaction for glycogen content × postmortem time was significant ( = 0.003) in LM and semitendinosus (ST) muscles. Glycogen content in the LM was greater ( < 0.05) for GLY at 2 and 3 h and for FRU at 1 h postmortem compared with CON. Glycogen content in ST did not differ between treatments ( > 0.05). Liver glycogen content was over 14-fold greater ( < 0.05) for GLY compared with FRU or CON. Liver free glucose was greater ( < 0.05) for GLY than for CON, whereas liver lipid content was higher ( < 0.05) for CON than for GLY. Supplementation with GLY increased ( < 0.05) odd-chain fatty acids in LM, subcutaneous fat (SQ), and the liver. Stearic acid (C18:0) concentrations were reduced in LM ( = 0.064) and subcutaneous adipose tissue (SQ; = 0.018), whereas oleic acid (C18:1 -9) concentration tended to be increased ( = 0.066) in SQ with FRU and GLY. Linolenic acid (C18:3 -3) was reduced ( = 0.031) and all long-chain -3 fatty acid (eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid) concentrations were increased ( < 0.05) with FRU and GLY compared with CON. Glycerol supplementation upregulated ( < 0.05) stearoyl-CoA desaturate () and fatty acid synthase () mRNA by over 40-fold in the SQ and 5-fold in the liver. Glycerol supplementation also upregulated ( < 0.05) glucose transporters and glycogen branching enzyme in the liver. Overall, glycerol supplementation improved growth, reduced BW shrink during fasting, increased glycogen content in muscle and the liver, and stimulated de novo lipogenesis.

Tributyltin and triphenyltin exposure promotes in vitro adipogenic differentiation but alters the adipocyte phenotype in rainbow trout

Numerous environmental pollutants have been identified as potential obesogenic compounds affecting endocrine signaling and lipid homeostasis. Among them, well-known organotins such as tributyltin (TBT) and triphenyltin (TPT), can be found in significant concentrations in aquatic environments. The aim of the present study was to investigate in vitro the effects of TBT and TPT on the development and lipid metabolism of rainbow trout (Onchorynchus mykiss) primary cultured adipocytes. Results showed that TBT and TPT induced lipid accumulation and slightly enhanced peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT enhancer binding protein alpha (C/EBPα) protein expression when compared to a control, both in the presence or absence of lipid mixture. However, the effects were higher when combined with lipid, and in the absence of it, the organotins did not cause complete mature adipocyte morphology. Regarding gene expression analyses, exposure to TBT and TPT caused an increase in fatty acid synthase (fasn) mRNA levels confirming the pro-adipogenic properties of these compounds. In addition, when added together with lipid, TBT and TPT significantly increased cebpa, tumor necrosis factor alpha (tnfa) and ATP-binding cassette transporter 1 (abca1) mRNA levels suggesting a synergistic effect. Overall, our data highlighted that TBT and TPT activate adipocyte differentiation in rainbow trout supporting an obesogenic role for these compounds, although by themselves they are not able to induce complete adipocyte development and maturation suggesting that these adipocytes might not be properly functional.

MAPK/P53-mediated FASN expression in bone tumors.

The correlation between mitogen-activated protein kinase (MAPK)/P53 signaling-dependent fatty acid synthase (FASN) expression and bone tumors was examined in the present study. We established the SH081 bone tumor cell line, which was used to determine the expression of FASN and MAPK/P53 at the mRNA and protein levels in bone tumor cells and normal cells. Compared with the normal cells, the expression of MAPK/P53 and FASN mRNA was significantly elevated, whereas inhibition of MAPK/P53 decreased FASN expression. Similarly, the expression of FASN and MAPK/P53 proteins were significantly elevated in the bone tumor cells and treatment with the MAPK/P53 inhibitor decreased the expression of FASN. To determine the role of MAPK/P53 in cell proliferation, bone cancer cells were treated with MAPK/P53 inhibitor and the results showed a reduced proliferation rate. Thus, FASN promotes the development of bone tumors and MAPK/P53 signaling contributes to bone tumors by upregulating the expression of FASN.

ERK1 and ERK2 activation modulates diet-induced obesity in mice

Obesity is a worldwide problem, and dietary lipids play an important role in its pathogenesis. Recently, Erk1 knock-out (ERK1−/−) mice have been shown to exhibit low preference for dietary fatty acids. Hence, we maintained Erk1−/− mice on a high-fat diet (HFD) to assess the implication of this mitogen-activated protein (MAP) kinase in obesity. The Erk1−/− mice, fed the HFD, were more obese than wild-type (WT) animals, fed the same diet. Erk1−/− obese mice gained more fat and liver mass than WT obese animals. No difference was observed in daily food and energy intake in HFD-fed both group of animals. However, feed efficiency was higher in Erk1−/− than WT animals. Blood cholesterol, triglyceride and insulin concentrations were higher in Erk1−/− obese mice compared to WT obese animals. Accordingly, homeostatic model assessment of insulin resistance (HOMA-IR) value was higher in Erk1−/− obese mice compared to WT obese animals. Interestingly, only Erk1−/− obese mice, but not WT-obese animals, exhibited high degree of phosphorylation of liver MEK, the upstream regulator of ERK1/2. This phenomenon was associated with high liver ERK2 phosphorylation in Erk1−/− obese mice which also had high liver acetyl-CoA carboxylase 1 (ACC1) and fatty acid synthase (FAS) mRNA expression, suggesting high lipogenesis in these animals. The Erk1−/− obese mice also had low PPAR-α and CPT1β mRNA, indicating low fatty acid oxidation. Our observations suggest that ERK1 and ERK2 might play key roles in the regulation of obesity.

Dietary intervention, but not losartan, completely reverses non-alcoholic steatohepatitis in obese and insulin resistant mice

BackgroundDietary intervention is the cornerstone of non-alcoholic steatohepatitis (NASH) treatment. However, histological evidence of its efficacy is limited and its impact on hepatic pathways involved in NASH is underreported. The efficacy of the angiotensin receptor type 1 blocker losartan is controversial because of varying results in a few animal and human studies. We evaluated the effect of dietary intervention versus losartan on NASH and associated systemic metabolic features in a representative mouse model.MethodsMale C57BL/6 J mice with high fat-high sucrose diet (HF-HSD) induced NASH, obesity, insulin resistance and hypercholesterolemia were subjected to dietary intervention (switch from HF-HSD to normal chow diet (NCD)) (n = 9), continuation HF-HSD together with losartan (30 mg/kg/day) (n = 9) or continuation HF-HSD only (n = 9) for 8 weeks. 9 mice received NCD during the entire experiment (20 weeks). We assessed the systemic metabolic effects and performed a detailed hepatic histological and molecular profiling. A P-value of < 0.05, using the group with continuation of HF-HSD only as control, was considered as statistically significant.ResultsDietary intervention normalized obesity, insulin resistance, and hypercholesterolemia (for all P < 0.001), and remarkably, completely reversed all histological features of pre-existent NASH (for all P < 0.001), including fibrosis measured by quantification of collagen proportional area (P < 0.01). At the hepatic molecular level, dietary intervention targeted fibrogenesis with a normalization of collagen type I alpha 1, transforming growth factor β1, tissue inhibitor of metalloproteinase 1 mRNA levels (for all P < 0.01), lipid metabolism with a normalization of fatty acid translocase/CD36, fatty acid transport protein 5, fatty acid synthase mRNA levels (P < 0.05) and markers related to mitochondrial function with a normalization of hepatic ATP content (P < 0.05) together with sirtuin1 and uncoupling protein 2 mRNA levels (for both P < 0.001). Dietary intervention abolished p62 accumulation (P < 0.01), suggesting a restoration of autophagic flux. Losartan did not significantly affect obesity, insulin resistance, hypercholesterolemia or any histological NASH feature.ConclusionsDietary intervention, and not losartan, completely restores the metabolic phenotype in a representative mouse model with pre-existent NASH, obesity, insulin resistance and hypercholesterolemia.

Distinct prostate cancer-related mRNA cargo in extracellular vesicle subsets from prostate cell lines

BackgroundMultiple types of extracellular vesicles (EVs), including microvesicles (MVs) and exosomes (EXOs), are released by all cells constituting part of the cellular EV secretome. The bioactive cargo of EVs can be shuffled between cells and consists of lipids, metabolites, proteins, and nucleic acids, including multiple RNA species from non-coding RNAs to messenger RNAs (mRNAs). In this study, we hypothesized that the mRNA cargo of EVs could differ based on the EV cellular origin and subpopulation analyzed.MethodsWe isolated MVs and EXOs from PC-3 and LNCaP prostate cancer cells by differential centrifugation and compared them to EVs derived from the benign PNT2 prostate cells. The relative mRNA levels of 84 prostate cancer-related genes were investigated and validated using quantitative reverse transcription PCR arrays.ResultsBased on the mRNA abundance, MVs rather than EXOs were enriched in the analyzed transcripts, providing a snapshot of the tumor transcriptome. LNCaP MVs specifically contained significantly increased mRNA levels of NK3 Homeobox 1 (NKX3-1), transmembrane protease serine 2 (TMPRSS2), and tumor protein 53 (TP53) genes, whereas PC-3 MVs carried increased mRNA levels of several genes including, caveolin-2 (CAV2), glutathione S-transferase pi 1 (GSTP1), pescadillo ribosomal biogenesis factor 1 (PES1), calmodulin regulated spectrin associated protein 1 (CAMSAP1), zinc-finger protein 185 (ZNF185), and others compared to PNT2 MVs. Additionally, ETS variant 1 (ETV1) and fatty acid synthase (FASN) mRNAs identified in LNCaP- and PC-3- derived MVs highly correlated with prostate cancer progression.ConclusionsOur study provides new understandings of the variability of the mRNA cargo of MVs and EXOs from different cell lines despite same cancer origin, which is essential to better understand the the proportion of the cell transcriptome that can be detected within EVs and to evaluate their role in disease diagnosis.

Ionic Detoxification Reduces Obesity and Fatty Liver in Rats Fed a High- Fat Diet

Background: Ionic detoxification (ID) or ionic water bath treatment is a simple alternative method to improve health but lacks scientific evidence. It is hypothesized that regular ID treatment can increase the excretion of toxic molecules from the body and improve metabolic disorders including obesity. Methods: To investigate the effect of ID treatment on high-fat diet-induced obesity and fatty liver, male Wistar rats were fed a low-fat control diet, a high-fat (HF) diet, or a HF diet with ID treatment (3 times/week) for 11 weeks. Triglyceride contents and fatty acid metabolic genes in perirenal adipose tissue and liver were determined. Results: Rats fed the HF diet had significantly higher body weight, liver weight, and adipose tissue (perirenal and epididymal) weight than did animals fed the low-fat diet. ID treatment significantly reduced body weight and perirenal adipose tissue weight induced by the HF diet. In addition, ID treatment reduced hepatic cholesterol and triglyceride contents. In liver, ID treatment reduced fatty acid synthesis (acetyl-CoA carboxylase and fatty acid synthase mRNA) more significantly than fatty acid oxidation (carnitine palmitoyl-transferase 1 and acyl CoA oxidase mRNA). In perirenal adipose tissue, ID treatment increased the lipolysis rate and reduced the triglyceride level. However, ID treatment had no significant effects on lipogenesis gene expression or adipose size in perirenal adipose tissue. Conclusions: The results of this study suggest that regular ID treatment may have beneficial effects on reducing obesity and fatty liver.

(-)-Hydroxycitric Acid Reduced Lipid Droplets Accumulation Via Decreasing Acetyl-Coa Supply and Accelerating Energy Metabolism in Cultured Primary Chicken Hepatocytes

Background/Aims: (-)-Hydroxycitric acid (HCA) had been shown to suppress fat accumulation in animals and humans, while the underlying biochemical mechanism is not fully understood, especially little information is available on whether (-)-HCA regulates energy metabolism and consequently affects fat deposition. Methods: Hepatocytes were cultured for 24 h and then exposed to (-)-HCA (0, 1, 10, 50 µM), enzyme protein content was determined by ELISA; lipid metabolism gene mRNA levels were detected by RT-PCR. Results: (-)-HCA significantly decreased the number and total area of lipid droplets. ATP-citrate lyase, fatty acid synthase and sterol regulatory element binding protein-1c mRNA level were significantly decreased after (-)-HCA treatment, whereas peroxisome proliferator-activated receptor α mRNA level was significantly increased. (-)-HCA significantly decreased ATP-citrate lyase activity and acetyl-CoA content in cytosol, but significantly increased glucose consumption and mitochondrial oxygen consumption rate. (-)-HCA promoted the activity/content of glucokinase, phosphofructokinase-1, pyruvate kinase, pyruvate dehydrogenase, citrate synthase, aconitase, succinate dehydrogenase, malate dehydrogenase, NADH dehydrogenase and ATP synthase remarkably. Conclusions: (-)-HCA decreased lipid droplets accumulation by reducing acetyl-CoA supply, which mainly achieved via inhibition of ATP-citrate lyase, and accelerating energy metabolism in chicken hepatocytes. These results proposed a biochemical mechanism of fat reduction by (-)-HCA in broiler chickens in term of energy metabolism.

Changes in milk performance and hepatic metabolism in mid-lactating dairy goats after being fed a high concentrate diet for 10 weeks

Feeding a high concentrate (HC) diet is a widely used strategy for supporting high milk yields, yet it may cause certain metabolic disorders. This study aimed to investigate the changes in milk production and hepatic metabolism in goats fed different proportions of concentrate in the diet for 10 weeks. In total, 12 mid-lactating goats were randomly assigned to an HC diet (65% concentrate of dry matter, n=6) or a low concentrate (LC) diet (35% concentrate of dry matter, n=6). Compared with LC, HC goats produced greater amounts of volatile fatty acids and produced more milk and milk lactose, fat and protein (P<0.01). HC goats showed a greater concentration of ATP, NAD, plasma non-esterified fatty acids and hepatic triglycerides than LC goats (P<0.05). Real-time PCR results showed that messenger RNA (mRNA) expression of gluconeogenic genes, namely, glucose-6-phosphatase, pyruvate carboxylase and phosphoenolpyruvate carboxykinase were significantly up-regulated and accompanied greater gluconeogenic enzyme activities in the liver of HC goats. Moreover, the expression of hepatic lipogenic genes including sterol regulatory element-binding protein 1c, fatty acid synthase and diacylglycerol acyltransferase mRNA was also up-regulated by the HC diet (P<0.05). HC goats had greater hepatic phosphorylation of AMP-activated protein kinase than LC (P<0.05). Furthermore, histone-3-lysine-27-acetylation contributed to this elevation of gluconeogenic gene expression. These results indicate that lactating goats fed an HC diet for 10 weeks produced more milk, which was associated with up-regulated gene expression and enzyme activities involved in hepatic gluconeogenesis and lipogenesis.

Impacts of Camellia kucha and its main chemical components on the lipid accumulation in 3T3‐L1 adipocytes

SummaryCamellia kucha, a wild tea plant with potent antioxidant potential, has been consumed as local beverage for a long history. It is featured for the presence of theacrine and low content of caffeine. Interestingly, compared with caffeine showed strong stimulant effect, theacrine showed sedation, hypnoses and promoting memory function. In this study, the anti‐adipogenic ability of Kucha tea (KT) and its main components were evaluated in mouse 3T3‐L1 cells. The results indicated that KT acted significantly to decrease lipid droplet accumulation. Moreover, KT decreased the expression of major transcription factors of adipogenesis pathway, such as PPAR γ and C/EBP α. KT also decreased the mRNA and protein levels of fatty acid synthase, fatty acid translocase, steroylcoenzyme A desaturase‐1, lipoprotein lipase and acetyl‐CoA carboxylase‐1. Furthermore, KT suppressed the activation of ERK, p38 and JNK.

Fatty acid synthase is a primary target of MiR-15a and MiR-16-1 in breast cancer.

Fatty acid synthase (FASN) is upregulated in breast cancer and correlates with poor prognosis. FASN contributes to mammary oncogenesis and serves as a bona fide target in cancer therapies. MicroRNAs inhibit gene expression through blocking mRNA translation or promoting mRNA degradation by targeting their 3′-UTRs. We identified four microRNAs in two microRNA clusters miR-15a-16-1 and miR-497-195 that share a common seed sequence to target the 3′-UTR of the FASN mRNA. In reporter assays, both of these microRNA clusters inhibited the expression of a reporter construct containing the FASN 3′-UTR. However, only ectopic miR-15a-16-1, but not miR-497-195, markedly reduced the levels of endogenous FASN in breast cancer cells. Both miR-15a and miR-16-1 contributes to inhibiting FASN expression and breast cancer cell proliferation. Consistently, a sponge construct consisting of eight repeats of the FASN 3′-UTR region targeted by these microRNAs could markedly increase endogenous FASN levels in mammary cells. When FASN expression was restored by ectopic expression in breast cancer cells, retarded cell proliferation caused by miR-15a-16-1 was partially rescued. In conclusion, we demonstrated that FASN expression is primarily downregulated by miR-15a and miR-16-1 in mammary cells and FASN is one of the major targets of these two tumor suppressive microRNAs.

Testosterone inhibits expression of lipogenic genes in visceral fat by an estrogen-dependent mechanism.

The influence of the aromatase enzyme on the chronic fat-sparing effects of testosterone requires further elucidation. Our purpose was to determine whether chronic anastrozole (AN, an aromatase inhibitor) treatment alters testosterone-mediated lipolytic/lipogenic gene expression in visceral fat. Ten-month-old Fischer 344 rats (n = 6/group) were subjected to sham surgery (SHAM), orchiectomy (ORX), ORX + treatment with testosterone enanthate (TEST, 7.0 mg/wk), or ORX + TEST + AN (0.5 mg/day), with drug treatment beginning 14 days postsurgery. At day 42, ORX animals exhibited nearly undetectable serum testosterone and 29% higher retroperitoneal fat mass than SHAM animals (P < 0.001). TEST produced a ∼380-415% higher serum testosterone than SHAM (P < 0.001) and completely prevented ORX-induced visceral fat gain (P < 0.001). Retroperitoneal fat was 21% and 16% lower in ORX + TEST than SHAM (P < 0.001) and ORX + TEST + AN (P = 0.007) animals, while serum estradiol (E2) was 62% (P = 0.024) and 87% (P = 0.010) higher, respectively. ORX stimulated lipogenic-related gene expression in visceral fat, demonstrated by ∼84-154% higher sterol regulatory element-binding protein-1 (SREBP-1, P = 0.023), fatty acid synthase (P = 0.01), and LPL (P < 0.001) mRNA than SHAM animals, effects that were completely prevented in ORX + TEST animals (P < 0.01 vs. ORX for all). Fatty acid synthase (P = 0.061, trend) and LPL (P = 0.043) mRNA levels were lower in ORX + TEST + AN than ORX animals and not different from SHAM animals but remained higher than in ORX + TEST animals (P < 0.05). In contrast, the ORX-induced elevation in SREBP-1 mRNA was not prevented by TEST + AN, with SREBP-1 expression remaining ∼117-171% higher than in SHAM and ORX + TEST animals (P < 0.01). Across groups, visceral fat mass and lipogenic-related gene expression were negatively associated with serum testosterone, but not E2 Aromatase inhibition constrains testosterone-induced visceral fat loss and the downregulation of key lipogenic genes at the mRNA level, indicating that E2 influences the visceral fat-sparing effects of testosterone.

Differential expression of six genes in fat-type Hungarian Mangalica and other pigs

Abstract. In order to identify potential variances in gene expression of phenotypically different pig breeds, six fat-metabolism-related genes were analyzed in backfat and muscle tissues of fat-type Mangalica (MAN), Mangalica × Duroc (MD), and lean-type Hungarian Large White (HLW) and Pietrain × Duroc (PD) pigs by means of quantitative reverse transcription PCR (qRT-PCR). Higher (P &lt; 0.05) adipocyte fatty-acid-binding protein (A-FABP) expression was observed in backfat and muscle tissues of purebred and crossbred MAN than in those of HLW and PD. In all breeds and crosses, adiponectin (ADIPOQ) was predominantly expressed in backfat at a similar level (P &gt; 0.05), whereas muscle ADIPOQ expression was highest (P &lt; 0.05) in MAN and MD. Levels of fatty acid synthase (FASN) mRNA were greatest in MAN, moderate in MD, and lowest in HLW and PD backfat and muscle. The fat mass and obesity-associated gene (FTO) was more abundant in MAN and MD backfat, whereas muscle expressions did not differ (P &gt; 0.05) between breeds. Regarding leptin (LEP) expression, MAN produced the greatest levels in backfat, while HLW produced the lowest. In muscle, highest LEP was detected in MAN and MD. Between groups, perilipin 2 (PLIN2) was expressed similarly in backfat; however, PLIN2 was more abundant in muscle of MAN and MD than in that of HLW and PD. Differences in gene expression can contribute to the development of the characteristic fatty phenotype in MAN pigs. The identification of differentially expressed genes facilitates targeted sequencing and genotyping efforts for further studies.

Dietary n-3 LC-PUFAs affect lipoprotein lipase (LPL) and fatty acid synthase (FAS) activities and mRNA expression during vitellogenesis and ovarian fatty acid composition of female silver pomfret (Pampus argenteus) broodstock

We studied the effects of dietary n-3 LC-PUFAs on the activities and mRNA expression levels of tissue lipoprotein lipase (LPL) and fatty acid synthase (FAS) during vitellogenesis and ovarian fatty acid composition in female silver pomfret broodstock. Broodstock were fed one of four experimental diets for 185 days: FO (100% fish oil), FSO (70% fish oil + 30% soybean oil), SFO (30% fish oil + 70% soybean oil) or SO (100% soybean oil). The results revealed that hepatic LPL and FAS and ovarian FAS activities and mRNA expression levels significantly increased at vitellogenesis and postvitellogenesis relative to previtellogenesis, with no significant differences between these two stages, except for hepatic LPL mRNA expression. Dietary n-3 LC-PUFAs decreased tissue FAS and increased LPL activities and mRNA expression levels. The ovarian concentrations of 20:4n-6 (ARA), 20:5n-3 (EPA), 22:6n-3 (DHA) and n-3 LC-PUFAs were directly influenced by n-3 LC-PUFA levels. Total n-3 LC-PUFA concentrations in SO were 57% lower than those in FO, while 18:2n-6 concentrations in SO were 4.7 × higher than those in FO. These results revealed that high dietary n-3 LC-PUFAs levels significantly affected tissue lipid metabolism in female silver pomfret broodstock during vitellogenesis by upregulating LPL and downregulating FAS.

Solanum nigrum Protects against Hepatic Fibrosis via Suppression of Hyperglycemia in High-Fat/Ethanol Diet-Induced Rats.

Background: Advanced glycation end products (AGEs) signal through the receptor for AGE (RAGE), which can lead to hepatic fibrosis in hyperglycemia and hyperlipidemia. We investigated the inhibitory effect of aqueous extracts from Solanum nigrum (AESN) on AGEs-induced RAGE signaling and activation of hepatic stellate cells (HSCs) and hyperglycemia induced by high-fat diet with ethanol. Methods: An animal model was used to evaluate the anti-hepatic fibrosis activity of AESN in rats fed a high-fat diet (HFD; 30%) with ethanol (10%). Male Wistar rats (4 weeks of age) were randomly divided into four groups (n = 6): (1) control (basal diet); (2) HFD (30%) + ethanol (10%) (HFD/ethanol); (3) HFD/ethanol + AESN (100 mg/kg, oral administration); and (4) HFD/ethanol + pioglitazone (10 mg/kg, oral administration) and treated with HFD for 6 months in the presence or absence of 10% ethanol in dietary water. Results: We found that AESN improved insulin resistance and hyperinsulinemia, and downregulated lipogenesis via regulation of the peroxisome proliferator-activated receptor α (PPARα), PPARγ co-activator (PGC-1α), carbohydrate response element-binding protein (ChREBP), acetyl-CoA carboxylase (ACC), and fatty acid synthase (FAS) mRNA levels in the liver of HFD/ethanol-treated rats. In turn, AESN may delay and inhibit the progression of hepatic fibrosis, including α-smooth muscle actin (α-SMA) inhibition and MMP-2 production. Conclusions: These results suggest that AESN may be further explored as a novel anti-fibrotic strategy for the prevention of liver disease.