Differences in the regulation of adipose tissue and liver lipogenesis by carbohydrates in humans

Abstract

We assessed the contributions of human liver and adipose tissue de novo lipogenesis (DNL) to triacylglycerol (TAG) synthesis. Volunteers were fed a high-energy, highcarbohydrate diet (HC, n ‫؍‬ 5) or a normocaloric diet (NC, n ‫؍‬ 10). NC subjects remained in the fasting state (Study 1, n ‫؍‬ 5) or received oral glucose (Study 2, n ‫؍‬ 5) throughout the test (12 h). HC subjects remained in the fasting state

Markers of de novo lipogenesis in adipose tissue: associations with small adipocytes and insulin sensitivity in humans

“…In our study, IS was not independently related to DNL gene expression after controlling for BMI. BMI and cell size, however, remained strongly [10,35]. Also, the increased hepatic DNL in obese individuals compared with lean is not accompanied by increases in adipose tissue lipogenic capacity [13].…”

“…Caution should be exercised in extrapolating results from rat studies, as the lipogenic capacity of adipose tissue in humans is lower than in rats [9]. Nevertheless, it is clear that DNL does operate in human adipose tissue [10,11], although it is not the major pathway for fat deposition. Expression of several lipogenic genes, principally FASN, has been shown to be higher in smaller human adipocytes [12,13].…”

Genome-wide transcriptome expression in the liver of a mouse model of high carbohydrate diet-induced liver steatosis and its significance for the disease

“…Human clinical investigations have demonstrated that a diet low in fat and rich in carbohydrates (closely resembling the HCD used in our mouse study), even when administered for short periods of time, for example, 5 or 25 days, can lead to occurrence of uncomplicated fatty liver [12][13][14][15]. Thus, this mouse model is a highly relevant means of investigating mechanisms of hepatic steatosis.…”

The role of the endocannabinoid system in the control of energy homeostasis

“…27 However, the role of adipose tissue in lipogenesis is minor compared to that of the liver. 46 In a recent study, the tissue mRNA level of the lipogenic transcription factor sterol response element-binding protein-1c (SREBP-1c) was consistently lower in both liver and adipose tissue from CB1 À/À compared to wild-type mice, suggesting that SREBP1c expression may be tonically increased by endocannabinoids acting at CB1 receptors. 44 SREBP1c regulates the expression of genes involved in fatty acid synthesis, both acetyl coenzyme carboxylase-1 (ACC1) and fatty acid synthase (FAS), 47 and treatment of normal mice with the potent CB1 agonist HU-210 (20 ng/g) was found to increase the hepatic mRNA levels for SREBP1c, ACC1, and FAS, which could be prevented by pretreatment with 3 mg/g rimonabant.…”