Mangravite Lara M, Dawson Kevin, Davis Ryan R, Gregg Jeffrey P, Krauss Ronald M
Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA.
Am J Clin Nutr. 2007 Sep;86(3):759-67. doi: 10.1093/ajcn/86.3.759.
Atherogenic dyslipidemia associated with elevated plasma triacylglycerol concentrations and reduced HDL is improved by both caloric restriction and reduced carbohydrate consumption.
We aimed to identify the molecular pathways responsive to both caloric restriction and dietary composition within adipose tissue by monitoring transcriptional expression.
Subcutaneous adipose tissue biopsy specimens were obtained from 131 moderately overweight men [body mass index (in kg/m2): 29.2 +/- 2.0] after 1 wk of a basal diet [54%, 16%, and 30% carbohydrate, protein, and fat, respectively; 7% saturated fat), after 3 wk with 1 of 4 randomized diets [basal diet; moderate-carbohydrate (39%) diet; low-carbohydrate (26%) and low-saturated-fat (9%) diet; low-carbohydrate (26%) and high-saturated-fat (15%) diet], after 5 wk of acute weight loss with a randomized diet (-1103.0 +/- 216.5 kcal/d, which resulted in a loss of 10.0 +/- 3.3 lb, or 4.5 +/- 1.5 kg), and after 4 wk of being stabilized at a reduced weight. Transcriptional response was identified by using expression array analysis and was confirmed by using real-time polymerase chain reaction analysis.
Of the 1473 transcripts significantly decreased in expression in response to acute weight loss, 30 were responsive to isocaloric alterations in dietary composition, including stearoyl-coenzyme A desaturase (SCD), fatty acid desaturases 1 and 2 (FADS1 and FADS2), and diacylglycerol transferase 2 (DGAT2). Response was confirmed by real-time polymerase chain reaction analysis for these genes (P < 0.003). SCD expression in response to isocaloric dietary change was most strongly correlated with carbohydrate intake (P = 0.019) and, with the low-carbohydrate diet, SCD expression was inversely correlated with saturated fat intake (P = 0.05). Triacylglycerol responses to changes in dietary composition were independently correlated with SCD (P = 0.003) and DGAT2 (P = 0.05) responses.
SCD expression in adipose tissue is independently regulated by weight loss and by carbohydrate and saturated fat intakes. Moreover, SCD and DGAT2 expression may be involved in dietary regulation of systemic triacylglycerol metabolism.
与血浆甘油三酯浓度升高和高密度脂蛋白降低相关的致动脉粥样硬化性血脂异常可通过热量限制和减少碳水化合物摄入得到改善。
我们旨在通过监测转录表达来确定脂肪组织中对热量限制和饮食组成均有反应的分子途径。
从131名中度超重男性[体重指数（kg/m²）：29.2±2.0]身上获取皮下脂肪组织活检标本，这些男性在接受1周基础饮食[碳水化合物、蛋白质和脂肪分别占54%、16%和30%；饱和脂肪占7%]后，随机接受4种饮食中的1种，持续3周[基础饮食；中等碳水化合物（39%）饮食；低碳水化合物（26%）和低饱和脂肪（9%）饮食；低碳水化合物（26%）和高饱和脂肪（15%）饮食]，然后随机饮食进行5周急性体重减轻（-1103.0±216.5千卡/天，导致体重减轻10.0±3.3磅，即4.5±1.5千克），最后在体重减轻后稳定4周。通过使用表达阵列分析确定转录反应，并通过实时聚合酶链反应分析进行确认。
在因急性体重减轻而表达显著降低的1473个转录本中，有30个对饮食组成的等热量变化有反应，包括硬脂酰辅酶A去饱和酶（SCD）、脂肪酸去饱和酶1和2（FADS1和FADS2）以及二酰甘油转移酶2（DGAT2）。通过对这些基因进行实时聚合酶链反应分析确认了反应（P<0.003）。SCD对等热量饮食变化的表达与碳水化合物摄入量最密切相关（P = 0.019），并且在低碳水化合物饮食中，SCD表达与饱和脂肪摄入量呈负相关（P = 0.05）。甘油三酯对饮食组成变化的反应与SCD（P = 0.003）和DGAT2（P = 0.05）的反应独立相关。
脂肪组织中SCD的表达受体重减轻以及碳水化合物和饱和脂肪摄入量的独立调节。此外，SCD和DGAT2的表达可能参与全身甘油三酯代谢的饮食调节。
