Liver Transcriptome Profiling Reveals That Dietary DHA and EPA Levels Influence Suites of Genes Involved in Metabolism, Redox Homeostasis, and Immune Function in Atlantic Salmon (Salmo salar).
肝脏转录组分析揭示了膳食 DHA 和 EPA 水平影响大西洋鲑鱼 (Salmo salar) 参与代谢、氧化还原稳态和免疫功能的一系列基因。
- 作者列表："Xue X","Hall JR","Caballero-Solares A","Eslamloo K","Taylor RG","Parrish CC","Rise ML
:The optimal dietary requirement of omega-3 long-chain polyunsaturated fatty acids (ω3 LC-PUFA), namely docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), for Atlantic salmon that promotes growth and health warrants careful investigation. We used 44K microarrays to study the influence of increasing levels of dietary DHA + EPA (0, 1.0, and 1.4% of the diet, as formulated) in the presence of high linoleic acid (LA) on Atlantic salmon growth and liver transcriptome. After a 14-week feeding trial, Atlantic salmon fed diet ω3LC0 (i.e. 0% of DHA + EPA) showed significantly lower final weight and weight gain, and higher feed conversion ratio compared with ω3LC1.0 and ω3LC1.4 diet groups. The microarray experiment identified 55 and 77 differentially expressed probes (Rank Products analyses; PFP < 10%) in salmon fed diets ω3LC1.4 and ω3LC1.0 compared with those fed diet ω3LC0, respectively. The comparison between ω3LC1.4 and ω3LC1.0 revealed 134 differentially expressed probes. The microarray results were confirmed by qPCR analyses of 22 microarray-identified transcripts. Several key genes involved in fatty acid metabolism including LC-PUFA synthesis were upregulated in fish fed ω3LC0 compared with both other groups. Hierarchical clustering and linear regression analyses of liver qPCR and fatty acid composition data demonstrated significant correlations. In the current study, 1.0% ω3 LC-PUFA seemed to be the minimum requirement for Atlantic salmon based on growth performance; however, multivariate statistical analyses (PERMANOVA and SIMPER) showed that fish fed ω3LC1.0 and ω3LC1.4 diets had similar hepatic fatty acid profiles but marked differences in the transcript expression of biomarker genes involved in redox homeostasis (mgst1), immune responses (mxb, igmb, irf3, lect2a, srk2, and lyz2), and LC-PUFA synthesis (srebp1, fadsd5, and elovl2). This research has provided new insights into dietary requirement of DHA and EPA and their impact on physiologically important pathways in addition to lipid metabolism in Atlantic salmon.
: Ω-3 长链多不饱和脂肪酸 (ω 3 LC-PUFA) 即二十二碳六烯酸 (DHA) 和二十碳五烯酸 (EPA) 的最佳膳食需要量, 对于促进生长和健康的大西洋鲑鱼，值得仔细研究。我们使用 44 K 微阵列来研究增加膳食 DHA + EPA 水平的影响 (0，1.0 和 1.4% 的膳食，按照配方) 存在高亚油酸 (LA) 对大西洋鲑鱼生长和肝脏转录组的影响。经过 14 周的喂养试验，大西洋鲑鱼喂养了 ω 3lc0 (0% 的 DHA + EPA) 与 ω 3lc1.0 和 ω 3lc1.4 日粮组相比，表现出显著较低的最终体重和增重，以及较高的饲料转化率。微阵列实验确定了 55 和 77 个差异表达探针 (Rank 产品分析; pfp
METHODS:BACKGROUND:Given the importance of habitual dietary protein intake, distribution patterns and dietary sources in the aetiology of age-related declines of muscle mass and function, the present study examined these factors as a function of sex and age in Irish adults aged 18-90 years comprising The National Adult Nutrition Survey (NANS). METHODS:In total, 1051 (males, n = 523; females, n = 528) undertook a 4-day semi-weighed food diary. Total, body mass relative intake and percentage contribution to total energy intake of dietary protein were determined in addition to protein distribution scores (PDS), as well as the contribution of food groups, animal- and plant-based foods to total protein intake. RESULTS:Total and relative protein intake [mean (SD)] were highest in those aged 18-35 years [96 (3) g day , 1.32 (0.40) g kg day ], with lower protein intakes with increasing age (i.e. in adults aged ≥65 years [82 (22) g, 1.15 (0.34) g kg day , P < 0.001 for both]. Differences in protein intake between age groups were more pronounced in males compared to females. Protein distribution followed a skewed pattern for all age groups [breakfast, 15 (10) g; lunch, 30 (15) g; dinner, 44 (17) g]. Animal-based foods were the dominant protein source within the diet [63% (11%) versus 37% (11%) plant protein, P < 0.001]. CONCLUSIONS:Protein intake and the number of meals reaching the purported threshold for maximising post-prandial anabolism were highest in young adults, and lower with increasing age. For main meals, breakfast provided the lowest quantity of protein across all age categories and may represent an opportunity for improving protein distribution, whereas, in older adults, increasing the number of meals reaching the anabolic threshold regardless of distribution pattern may be more appropriate.
METHODS:BACKGROUND:Low cardiorespiratory fitness (CRF) increases risk of all-cause mortality and cardiovascular events. Periodic CRF assessment can have an important preventive function. OBJECTIVE:To develop a protocol-free method to estimate CRF in daily life based on heart rate (HR) and body acceleration measurements. METHODS:Acceleration and HR data were collected from 37 subjects (M=49%) while performing a standardized laboratory activity protocol (sitting, walking, running, cycling) and during a 5-days free-living monitoring period. CRF was determined by oxygen uptake (VO2max) during maximal exercise testing. A doubly-labeled water validated equation was used to predict total energy expenditure (TEE) from acceleration data. A fitness index was defined as the ratio between TEE and HR (TEE-pulse). Activity recognition techniques were used to process acceleration features and classify sedentary, ambulatory and other activity types. Regression equations based on TEE-pulse data from each activity type were developed to predict VO2max. RESULTS:TEE-pulse measured within each activity type of the laboratory protocol was highly correlated to VO2max (r from 0.74 to 0.91). Averaging the outcome of each activity-type specific equation based on TEE-pulse from the laboratory data led to accurate estimates of VO2max (RMSE: 300.0 mlO2/min or 10%). The difference between laboratory and free-living determined TEE-pulse was 3.7 ± 11% (r =0.85). The prediction method preserved the prediction accuracy when applied to free-living data (RMSE: 367 mlO2/min or 12%). CONCLUSIONS:Measurements of body acceleration and HR can be used to predict VO2max in daily life. Activity-specific prediction equations are needed to achieve highly accurate estimates of CRF.
METHODS:OBJECTIVE:Postprandial dyslipidemia is a common feature of insulin resistant states and contributes to increased cardiovascular disease risk. Recently, bile acids have been recognized beyond their emulsification properties as important signaling molecules that promote energy expenditure, improve insulin sensitivity, and lower fasting lipemia. While bile acid receptors have become novel pharmaceutical targets, their effects on postprandial lipid metabolism remain unclear. Here we investigated the potential role of bile acids in regulation of postprandial chylomicron production and triglyceride excursion. Approach and Results: Healthy C57BL/6 mice were given an intraduodenal infusion of taurocholic acid (TA) under fat-loaded conditions and circulating lipids were measured. Targeting of bile acid receptors was achieved with GW4064, a synthetic agonist to the farnesoid X receptor (FXR), and with deoxycholic acid (DCA), an activator of the Takeda G-protein-coupled receptor 5. TA, GW4064, and DCA treatments all lowered postprandial lipemia. FXR agonism also reduced intestinal triglyceride content and activity of microsomal triglyceride transfer protein, involved in chylomicron assembly. Importantly, TA effects (but not DCA) were largely lost in FXR knockout mice. These bile acid effects are reminiscent of the anti-diabetic hormone glucagon-like peptide-1 (GLP-1). While the GLP-1 receptor agonist exendin-4 retained its ability to acutely lower postprandial lipemia during bile acid sequestration and FXR deficiency, it did raise hepatic expression of the rate limiting enzyme for bile acid synthesis. CONCLUSIONS:Bile acid signaling may be an important mechanism of controlling dietary lipid absorption and bile acid receptors may constitute novel targets for the treatment of postprandial dyslipidemia.