Effect of dietary egg yolk lecithin levels on survival, growth, lipid metabolism, and antioxidant capacity of early juvenile green mud crab Scylla paramamosain

The influence of dietary arachidonic acid on growth performance, fatty acid composition and antioxidant capacity on postlarva of mud crab Scylla paramamosain

Insulin acutely decreases hepatic fatty acid synthase activity

An eight-week feeding trail was carried out to investigate the impacts of different dietary arachidonic acid (ARA) supplementations on growth performance, antioxidant capacity, tissue fatty acid profiles, and lipid metabolism of mud crab (Scylla paramamosain) juvenile. Six isonitrogenous (480 g kg-1 crude protein) and isolipidic (80 g kg-1 crude lipid) diets were formulated to contain 0.40, 2.50, 4.60, 8.90, 12.50, and 15.70 g ARA kg-1 (dry matter), respectively. Each experimental treatment included 24 mud crab juveniles (initial weight 11.29 ± 0.09 g) and was assigned to triplicate groups (n = 3). Crabs fed diets with 2.50, 4.60, and 8.90 g kg-1 ARA presented significantly higher percent weight gain (PWG) and specific growth rate (SGR) than those fed the other diets. Based on two-slope broken-line and quadratic curve regression analysis of PWG against dietary ARA levels, optimal dietary ARA levels were determined to be 5.20 g kg-1 and 6.20 g kg-1, respectively. Crabs fed with 4.60 g kg-1 ARA diet showed the lowest activities of alanine aminotransferase (ALT) as well as aspartate aminotransferase (AST) in hemolymph among all treatments. In hemolymph and hepatopancreas, total antioxidant capacity (T-AOC), the activities of total superoxide dismutase (T-SOD), and glutathione peroxidase (GSH-Px) as well as the contents of reduced glutathione (GSH) rose first and then dropped with the increase of dietary ARA levels, while the concentration of malondialdehyde (MDA) showed an opposite trend. Tissue fatty acid profiles reflected diets fatty acid compositions. The ARA contents in hepatopancreas and muscle significantly increased with the increase of dietary ARA levels. Furthermore, the areas of blasenzellen (B) cells and restzellen (R) cells were significantly downregulated with the increase of dietary ARA levels. Crabs fed with 0.40 g kg-1 ARA diet showed significantly higher gene expression levels of fatty acid synthase (fas) as well as acetyl-CoA carboxylase (acc) among all treatments. Relative gene expression levels of 6-phosphogluconate dehydrogenase (6pgd) as well as glucose-6-phosphate dehydrogenase (g6pd) have been significantly upregulated in 0.40 and 2.50 g kg-1 ARA groups. Relative gene expression level of fatty acid binding protein 1 (fabp1) significantly increased in 4.60, 8.90, 12.50, and 15.70 g kg-1 ARA groups. However, the gene expression levels of fatty acid binding protein 4 (fabp4) as well as scavenger receptor class 2 (srb2) have not been influenced by dietary ARA levels. What is more, crabs fed diets with 4.60, 8.90, 12.50, and 15.70 g kg-1 ARA had a significantly higher expression level of carnitine palmitoyltransferase 1 (cpt1) than those fed diets with 0.40 and 2.50 g kg-1 ARA. In summary, optimum dietary ARA can promote growth, enhance antioxidant capacity, and improve health of mud crab juveniles. It also demonstrated that lipogenesis has been restrained with the increasing dietary ARA levels. These findings could provide theoretical guidance and reference for the lipid nutrition research as well as the development of the commercial diet in mud crab.

Expression of estrogen receptor (ER) is detected in more than sixty percent of breast tumors. High levels of Fatty acid synthase (FAS) have been detected in aggressive breast cancers. Due to its high level of expression, FAS has been considered as a tumor marker and a therapeutic target. In normal rat liver, increase in expression of FAS requires glucose and a combination of hormones. Activity of FAS is indirectly regulated by the upstream signaling factor AMPK. AMPK is considered to be the main regulator of cellular metabolism. Upon activation, AMPK down regulates FAS activity and other ATP consuming pathways. In this study, we investigated the possible regulatory role of estrogen receptor (ER) signaling on FAS level and activity. In a panel of ER+ cell lines, very high levels of FAS expression was observed in the majority of the cell lines. The highest levels of FAS were in the ER+/HER2+ cell lines, HCC1419, BT474 and MDA-MB-361, respectively. However, in two other ER+/HER2+ cell lines, UACC732 and UACC812, the expression was similar to or even lower than the HER2 negative cell lines. Three HER2 negative cell lines in the panel also showed very high levels of FAS expression. Upon incubation of the cells in the absence of serum and phenol red condition, a general decrease in the FAS levels was observed that was more evident in HER2 negative cell lines. In the same condition, the effects of ER inhibitory drugs, fulvestrant and tamoxifen, on FAS and p-AMPKα levels were investigated. In ER+ cell lines that contain high levels of p-AKT, ER inhibitors did not affect levels of FAS and p-AMPKα. However, in some cell lines with lower levels of active AKT, tamoxifen and fulvestrant induced changes in FAS and p-AMPKα levels that were variable from cell line to cell line. In MCF-7 cell line, which is highly sensitive to ER inhibitors, both tamoxifen and fulvestrant induced lower FAS and higher p-AMPKα levels. Contrary to this observation, tamoxifen induced higher FAS and lower p-AMPKα levels in T-47D and KPL-1 cell lines. Fulvestrant induced a similar effect in ZR-75-1 cell line. This inducing effect of ER antagonists on FAS perhaps reflects one of the mechanisms that cause the elevation of blood lipids in post menopausal and tamoxifen treated women. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4602.

Dietary copper supplementation enhances lipolysis in Rex rabbits

Background: Cancer cells require nutrients to survive in the unfavorable microenvironment of primary solid tumors or metastases before angiogenesis development. Fatty acid synthase (FASN) is a multi-enzyme protein that catalyzes fatty acid synthesis. Expression levels of FASN are low or undetectable in normal human tissues except for the liver and the adipose tissue. In contrast, high levels of FASN expression have been detected in breast cancer tumors and other human carcinomas. Several reports highlight that FASN overexpression in tumor samples correlates with progression, aggressiveness and metastatic potential of the disease. In adition, some studies have suggested the same correlation with serum levels of FASN. Our aim was to analyze the association between the expression of tumor and serum levels of FASN with clinical and pathological prognostic factors in early-stage breast cancer patients. Methods: Fifty-five patients with early-stage breast cancer treated with surgery and post-operative chemotherapy were included in the study. We prospectively measured the levels of FASN in tumor and serum samples. Clinical data included demographic characteristics, menarche, pregnancy, breast feeding, menopausal status and body mass index (BMI). Pathological and molecular data included: pathological state, histological grade, estrogen and progesterone receptors, HER2 status, p53 mutation and Ki 67 levels. FASN tissue expression levels were determined by IHC and circulating FASN levels were determined by ELISA. FASN expression was graded from 0 to 3+, meaning 0–1+ normal amounts of FASN protein compared to non-tumor breast tissue, 2+ moderate amounts and 3+ the highest levels of FASN expression. Baseline characteristics were summarized descriptively. Categorical variables were compared by c2 or Fisher's exact. For continuous variables, if the data are approximately normal, the two groups were compared using ANOVA. If the normality assumption is not warranted, then the Kruskall-Wallis test has been used. Results: Median age was 49 (rage 33–77). 51% of the patients were menopausal and median BMI was 24,75. Thirty-four percent of the patients had stage I, 51% stage II and 15% stage III. We observed a statistically significant association between FASN over expression and the lack of progesterone receptors (p = 0.027) in tumor samples. In contrast, we found no relation between FASN and estrogen receptor nor between FASN and HER2 tumor expression in this setting. Menopause and age were strongly related to higher levels of FASN tumor expression (p < 0.001). Patients with higher BMI had higher levels of FASN in tumor tissue although this association was not statistically significant (p = 0.07). Finally, we observed a positive relation between breast cancer stage and the levels of FASN tumor (p = 0.05). In contrast, circulating FASN levels were not associated with any pathological or clinical prognostic factor. Conclusions: Our study suggests that FASN overexpression is significantly related to age, menopausal status, more advanced stages and lack of progesterone receptor expression in early-stage breast cancer patients. However, no relation between serum levels of FASN and the clinical or molecular prognostic factors have been observed. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-09-10.

Effect of photoperiod on growth, survival, and lipid metabolism of mud crab Scylla paramamosain juveniles

Four iso-nitrogenous and iso-lipidic diets were designed to investigate the effects of dietary phospholipids (PL) levels (with 0%, 1%, 2%, and 4% PL supplementation) on growth performance, lipid metabolism, and antioxidant capacity in early juvenile green mud crab (Scylla paramamosain). There were three replicates of 28 crabs (initial body weight from 42.02 to 42.44 mg) for each diet treatment, and growth trial lasted for 8 weeks. At the end of the growth trial, there was no significant difference in survival among all treatments. Crabs fed diet with 2% PL obtained highest weight gain (WG) and specific growth rate than other crabs. The molting frequency was not affected by different dietary PL addition. Besides, the contents of whole body lipid and long chain highly unsaturated fatty acids significantly increased with elevating dietary PL levels. In the hepatopancreas, crabs fed diet with 0% PL had significantly higher malondialdehyde concentration than other crabs. And crabs fed diet with 2% PL obtained significantly higher superoxide dismutase activity than crabs fed diets with 0% and 4% PL. Moreover, the mRNA expression of Na+/K+-ATPase was significantly down-regulated with dietary PL supplementation over 2%. Based on the second order polynomial regression analysis of WG, 2.37% dietary PL level was the optimal demand for early juvenile S. paramamosain. Moreover, we found crabs fed diet with 2% PL obtained better antioxidant capacity than other crabs.

An 8-week feeding trial was conducted to evaluate the effects of dietary n-3 LC-PUFA levels on growth performance, tissue fatty acid profiles and relative expression of genes involved in the lipid metabolism of mud crab (Scylla paramamosain). Ten isonitrogenous diets were formulated to contain five n-3 LC-PUFA levels at 7 and 12 % dietary lipid levels. The highest weight gain and specific growth rate were observed in crabs fed the diets with 19·8 and 13·2 mg/g n-3 LC-PUFA at 7 and 12 % lipid, respectively. Moisture and lipid contents in hepatopancreas and muscle were significantly influenced by dietary n-3 LC-PUFA at the two lipid levels. The DHA, EPA, n-3 LC-PUFA contents and n-3:n-6 PUFA ratio in hepatopancreas and muscle significantly increased as dietary n-3 LC-PUFA levels increased at both lipid levels. The expression levels of -6 fatty acyl desaturase and acyl-CoA oxidase in hepatopancreas increased significantly, and expression levels of fatty acid synthase, carnitine palmitoyltransferase I and hormone-sensitive TAG lipase were down-regulated, with increased dietary n-3 LC-PUFA regardless of lipid level. Based on weight gain, n-3 LC-PUFA requirements of S. paramamosain were estimated to be 20·1 and 12·7 mg/g of diet at 7 and 12 % dietary lipid, respectively. Overall, dietary lipid level influenced lipid metabolism, and purified, high-lipid diets rich in palmitic acid reduced the n-3 LC-PUFA requirement of juvenile mud crab.

This study investigated the effect of lipid levels on growth, body composition, lipid metabolism enzymes activity and related genes expression in hybrid grouper (♀Epinephelus fuscointestinestatus× ♂E. lanceolatu). Three diets with different lipid levels of 6% (low-lipid feed, LF), 11% (medium-lipid feed, MF) and 16% (high-lipid feed, HF) were designed and each diet was fed to triplicate groups of 30 fish each (6.73 ± 0.00g) for eight weeks. The results revealed the following. 1) The maximum weight gain rate (WGR), specific growth rate (SGR), protein efficiency ratio (PER) and the lowest feed conversion ratio (FCR) values were found in the HF group. There was no significant difference in the survival rate (SR) among the groups (P> 0.05). 2) Condition factor (CF), hepatosomatic index (HSI) and visceralsomatic index (VSI) increased with increasing dietary lipid. 3) Crude lipid content in the whole-body and muscle increased significantly as the dietary lipid level increased (P< 0.05). 4) Principal component analysis of fatty acids showed that sum n-3 polyunsaturated fatty acids (∑n-3PUFA)/sum n-6 polyunsaturated fatty acids (∑n-6PUFA) was significantly higher in the HF group than in the other two groups (P< 0.05). 5) Biochemical serum indexes showed higher triglycerides (TG), total cholesterol (TC), alkaline phosphatase (AKP) and low-density lipoprotein-cholesterol (LDL-C) levels but lower high-density lipoprotein-cholesterol (HDL-C) level in the HF group. 6) Liver lipid metabolism enzymes activity and biochemical indicators showed that fish fed the MF diet had higher lipoprotein lipase (LPL), hepatic lipase (HL) and triglyceride lipase (ATGL) activity but lower fatty acid synthase (FAS) activity and very-low density lipoprotein-cholesterol (VLDL-C) level. 7) The relative expression levels of lipoprotein lipase (lpl), adipocyte-type fatty acid-binding protein (a-fabp), liver-type fatty acid-binding protein (l-fabp), heart-type fatty acid-binding protein (h-fabp) and hormone-sensitive lipase (hsl) genes in the fish liver were higher in the MF group with increasing dietary lipid (P< 0.05), while the fatty acid synthase (fas) gene was expressed at lower relative level (P< 0.05). 8) Histological oil-red sections of the liver showed that fish in the HF group had larger and more hepatic lipid droplets than those fed the other diets. It was concluded that fish fed the HF diet had better growth performance but this diet was not conducive to the progress of lipid metabolism, resulting in lipid accumulation and affecting the quality of the fish. This study provides useful information for the formulation of environmentally friendly and cost-effective diets for hybrid grouper.

Simple SummaryAlpha-ketoglutarate (AKG) is a critical intermediate in the tricarboxylic acid cycle. AKG has been reported to participate in energy production, promote protein synthesis, and improve amino acid metabolism. However, whether AKG functionally participates in the regulation of fat metabolism remains unknown. The objective of this experiment was to evaluate the impact of dietary supplementation with AKG on lipid metabolism in a pig model. The present results suggest that AKG supplementation in a reduced-protein diet could increase the intramuscular fat (IMF) and monounsaturated fatty acid (MUFA) contents in the biceps femoris muscles of pigs. These effects could be linked to the altered lipid metabolism related gene mRNA expression, which promotes the absorption and deposition of fatty acids in the muscle tissues. The results of this study can provide better understanding of the mechanisms by which dietary AKG modulates muscle lipid metabolism in pigs, and this could help to improve pig feeding strategies and supply high-quality pork for humans.The aim of the current study was to investigate whether dietary supplementation with alpha-ketoglutarate (AKG) in a reduced crude protein (CP) diet would affect fatty acid composition and lipid metabolism related gene expression in the muscles of growing pigs. A total of 27 Large White × Landrace growing pigs at 44 ± 1 d of age (11.96 ± 0.18 kg) were randomly allocated to three treatments (n = 9). Dietary treatments included: (1) normal protein diet with 20% crude protein (CP) (NP); (2) a low crude protein diet formulated to contain approximately 17% CP (LP); and (3) a low crude protein diet with 17% CP supplemented with 1% AKG at the expense of regular corn components (ALP). The experimental trial lasted 35 d. The results showed that compared with the NP and LP diets, supplementation with AKG in a low-protein diet increased the intramuscular fat (IMF), oleic acid (C18:1n-9), and monounsaturated fatty acid (MUFA) contents (p < 0.05), and tended to increase the percentage of palmitoleic acid (C16:1) and stearic acid (C18:0) (p < 0.10) in the biceps femoris and longissimus dorsi muscles of growing pigs. These effects may be associated with increased relative mRNA expression levels of fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), adipocyte determination and differentiation factor 1 (ADD1), fatty acid binding protein 4 (FABP4), and stearoyl-CoA desaturase (SCD) in skeletal muscle, indicating that AKG might be involved in the differential regulation of some key lipogenic genes in skeletal muscles of pigs.

Balancing act: How cholesterol and phospholipids influence juvenile mud crab Scylla paramamosain growth and lipid metabolism

The energy available from the diet, which affects fat deposition in vivo, is a major factor in the expression of genes regulating fat deposition in the longissimus dorsi muscle. Providing high-energy diets to yaks might increase intramuscular fat deposition and fatty acid concentrations under a traditional grazing system in cold seasons. A total of fifteen adult castrated male yaks with an initial body weight 274.3 ± 3.14 kg were analyzed for intramuscular adipose deposition and fatty acid composition. The animals were divided into three groups and fed low-energy (LE: 5.5 MJ/kg), medium-energy (ME: 6.2 MJ/kg) and high-energy (HE: 6.9 MJ/kg) diets, respectively. All animals were fed ad libitum twice daily at 08:00–09:00 am and 17:00–18:00 pm and with free access to water for 74 days, including a 14-d period to adapt to the diets and the environment. Intramuscular fat (IMF) content, fatty acid profile and mRNA levels of genes involved in fatty acid synthesis were determined. The energy levels of the diets significantly (P<0.05) affected the content of IMF, total SFA, total MUFA and total PUFA. C16:0, C18:0 and C18:1n9c account for a large proportion of total fatty acids. Relative expression of acetyl-CoA carboxylase (ACACA), fatty acid synthase (FASN), stearoyl-CoA desaturase (SCD), sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor γ (PPARγ) and fatty acid-binding protein 4 (FABP4) was greater in HE than in LE yaks (P<0.05). Moreover, ME yaks had higher (P<0.05) mRNA expression levels of PPARγ, ACACA, FASN, SCD and FABP4 than did the LE yaks. The results demonstrate that the higher energy level of the diets increased IMF deposition and fatty acid content as well as increased intramuscular lipogenic gene expression during the experimental period.

Although the pathophysiology of diabetes is characterized by elevated levels of glucose and long-chain fatty acids (LCFA), nuclear mechanisms linking glucose and LCFA metabolism are poorly understood. As the liver fatty acid binding protein (L-FABP) shuttles LCFA to the nucleus, where L-FABP directly interacts with peroxisome proliferator-activated receptor-α (PPARα), the effect of glucose on these processes was examined. In vitro studies showed that L-FABP strongly bound glucose and glucose-1-phosphate (K(d) = 103 ± 19 nM and K(d) = 20 ± 3 nM, respectively), resulting in altered L-FABP conformation, increased affinity for lipid ligands, and enhanced interaction with PPARα. In living cells, glucose stimulated cellular uptake and nuclear localization of a nonmetabolizable fluorescent fatty acid analog (BODIPY C-16), particularly in the presence of L-FABP. These data suggest for the first time a direct role of glucose in facilitating L-FABP-mediated uptake and distribution of lipidic ligands to the nucleus for regulation of PPARα transcriptional activity.

Broiler chicken has high fat content, especially abdominal and subcutan fat which reduced carcass quality and efficiency of feed energy. Genetic approach could be potentially applied to reduce high abdominal and intramuscular fat in broiler chicken through the selection program at gene level related to fat metabolism. This paper describes the metabolism and biosynthesis of body fat and the role of its controlled genes. Fat synthesis is controlled by feed quality and metabolism and biosynthesis process occurred in liver. These processes are controlled by many family genes, but certain genes have dominant role in the process; those are triglyceride lipase genes, fatty acid synthase genes and fatty acid binding protein genes. Expression of fatty acid synthase genes has positive correlation with fat content in liver and intramuscular. Expression of fatty acid binding protein genes was related to the increased abdominal fat deposit. These genes are polymorphic, so that they can be used as a genetic marker in selection to optimize feed efficiency, to minimize abdominal fat and to increase economic value of broiler chicken.