Expression data from murine liver tissue. Mus musculus

Our previous studies have linked Trans-fat and monosodium glutamate (MSG) to the development of Nonalcoholic Fatty Liver Disease (NAFLD). We have also shown that MSG can interact with another commonly consumed food additive, aspartame, to impair glucose homeostasis, which is also disrupted in NAFLD. This most recent nutrigenomic study shows how aspartame, MSG and Trans-fat can unfavorably alter hepatic and adipose tissue gene expression. We used microarray analysis to examine changes in liver gene transcription in response to TFA MSG and/or ASP feeding in male C57Bl/6J mice. Overall design: Our study animals were bred from female C57Bl/6J mice fed a standard chow diet until 6 weeks of age whereupon they were placed on one of 4 different dietary regimens for a period of 3 weeks prior to mating. The four dietary regimens used in this study were: [1] TFA diet: consisting of 20% (w/w) Partially Hydrogenated Vegetable Shortening (Test Diet #5C4M containing 8.68% w/w Trans fatty acids; Test Diet Purina, USA), with ad lib drinking water. [2] MSG+TFA diet: TFA diet with ad lib drinking water containing 0.75 g/L of L -Glutamic acid monosodium salt hydrate (MSG catalog G1626 Sigma Aldrich). [3] ASP+TFA diet: (TFA diet with ad lib drinking water containing 0.25 g/L Asp-Phe methyl ester (aspartame, ASP, catalog A5139 Sigma Aldrich). [4] ASP+MSG+TFA diet: TFA diet with ad lib drinking water containing 0.25 g/L aspartame and 0.75 g/L monosodium glutamate. After the 3-week period of adjustment to the respective diets, 15 male offspring were bred, weaned and maintained on these diets for the duration of the study. Offspring were weaned at 4 weeks of age . Liver tissue (15 per diet group) were used at 20 weeks for RNA extraction and hybridization on Affymetrix microarrays.

我们既往的研究已将反式脂肪酸（Trans-fat）与谷氨酸钠（MSG，又称味精）关联至非酒精性脂肪性肝病（NAFLD）的发生发展。本团队同时证实，MSG可与另一常用食品添加剂阿斯巴甜（aspartame）相互作用，损害葡萄糖稳态——而葡萄糖稳态的紊乱同样见于NAFLD患者中。这项最新的营养基因组学（nutrigenomic）研究阐明了反式脂肪酸、MSG与阿斯巴甜如何对肝脏及脂肪组织的基因表达产生不利调控改变。本研究采用基因芯片分析（microarray analysis），检测雄性C57BL/6J小鼠在摄入反式脂肪酸、MSG及/或阿斯巴甜后，肝脏基因转录水平的变化。
整体实验设计：本研究的实验动物均由饲喂标准维持饲料至6周龄的雌性C57BL/6J小鼠繁育而来，随后将其分为4种不同膳食方案组，适应膳食3周后进行交配。本研究采用的4种膳食方案分别为：
[1] 反式脂肪酸膳食组：饲喂含20%（质量分数）部分氢化植物起酥油的试验饲料#5C4M（该饲料含8.68%质量分数的反式脂肪酸，购自美国普瑞纳（Purina）公司），并提供自由饮水。
[2] MSG+反式脂肪酸膳食组：在反式脂肪酸膳食基础上，自由饮水添加0.75 g/L的L-谷氨酸单钠盐水合物（MSG，货号G1626，西格玛奥德里奇（Sigma Aldrich）公司）。
[3] 阿斯巴甜+反式脂肪酸膳食组：在反式脂肪酸膳食基础上，自由饮水添加0.25 g/L的天冬氨酰苯丙氨酸甲酯（阿斯巴甜，ASP，货号A5139，西格玛奥德里奇公司）。
[4] 阿斯巴甜+MSG+反式脂肪酸膳食组：在反式脂肪酸膳食基础上，自由饮水添加0.25 g/L阿斯巴甜与0.75 g/L谷氨酸钠。
在适应各自膳食方案3周后，繁育得到的雄性子代小鼠于4周龄断奶，并在整个研究期间维持饲喂对应膳食。本研究共设4个膳食组，每组包含15只雄性子代小鼠，在小鼠20周龄时采集各组肝脏组织（每组15份）用于RNA提取，并在Affymetrix基因芯片上完成杂交实验。