The impact of protein quantity during energy restriction on genome-wide gene expression analysis in adipose tissue of obese humans

BACKGROUND: Overweight and obesity is a growing health problem worldwide. The most effective strategy to reduce weight is energy restriction (ER). ER has been shown to be beneficial in disease prevention and it reduces chronic inflammation. Recent studies suggest that reducing the protein quantity of a diet contributes to the beneficial effects by ER. The organ most extensively affected during ER is white adipose tissue (WAT). OBJECTIVE: The first objective was to assess changes in gene expression between a high protein diet and a normal protein diet during ER. Secondly, the total effect of ER on changes in gene expression in WAT was assessed. METHODS: In a parallel double-blinded controlled study, overweight older participants adhered to a 25% ER diet, either combined with high protein intake (HP-ER, 1.7 g/kg per day), or with normal protein intake (NP-ER, 0.9 g/kg per 40 day) for 12 weeks. From 10 HP-ER participants and 12 NP-ER participants subcutaneous WAT biopsies were collected before and after the diet intervention. Adipose tissue was used to isolate total RNA and to evaluate whole genome gene expression changes upon a HP-ER and NP-ER diet. RESULTS: A different gene expression response between HP-ER and NP-ER was observed for 530 genes. After NP-ER a downregulation in expression of genes linked to immune cell infiltration, adaptive immune response, and inflammasome was found whereas no such effect was found after HP-ER. HP-ER resulted in upregulation in expression of genes linked to cell cycle, GPCR signalling, olfactory signalling and nitrogen metabolism. Upon 25% ER, gene sets related to energy metabolism and immune response were decreased. CONCLUSIONS: Based on gen e expression changes, we concluded that consumption of normal protein quantity compared to high protein quantity during ER has a more beneficial effect on inflammation-related gene expression in WAT

Cognitive and behavioral evaluation of nutritional interventions in rodent models of brain aging and dementia

Devin Wahl,1,2 Sean CP Coogan,1,3 Samantha M Solon-Biet,1,2 Rafael de Cabo,4 James B Haran,5 David Raubenheimer,1,6,7 Victoria C Cogger,1,2 Mark P Mattson,8 Stephen J Simpson,1,2,7 David G Le Couteur1,2 1Charles Perkins Centre, University of Sydney, Sydney, 2Aging and Alzheimers Institute, ANZAC Research Institute, Concord Clinical School/Sydney Medical School, Concord, NSW, Australia; 3Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada; 4Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA; 5Philadelphia College of Osteopathic Medicine, Philadelphia, PA, USA; 6Faculty of Veterinary Science, 7School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia; 8Laboratory of Neurosciences, National Institute on Aging’s Intramural Research Program, National Institutes of Health, Baltimore, MD, USA Abstract: Evaluation of behavior and cognition in rodent models underpins mechanistic and interventional studies of brain aging and neurodegenerative diseases, especially ­dementia. Commonly used tests include Morris water maze, Barnes maze, object recognition, fear ­conditioning, radial arm water maze, and Y maze. Each of these tests reflects some aspects of human memory including episodic memory, recognition memory, semantic memory, spatial memory, and emotional memory. Although most interventional studies in rodent models of dementia have focused on pharmacological agents, there are an increasing number of studies that have evaluated nutritional interventions including caloric restriction, intermittent fasting, and manipulation of macronutrients. Dietary interventions have been shown to influence ­various cognitive and behavioral tests in rodents indicating that nutrition can influence brain aging and possibly neurodegeneration. Keywords: calorie restriction, intermittent fasting, aging, memory, macronutrient

The effects of dietary macronutrient balance on skin structure in aging male and female mice

© 2016 Hew et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Nutrition influences skin structure; however, a systematic investigation into how energy and macronutrients (protein, carbohydrate and fat) affects the skin has yet to be conducted. We evaluated the associations between macronutrients, energy intake and skin structure in mice fed 25 experimental diets and a control diet for 15 months using the Geometric Framework, a novel method of nutritional analysis. Skin structure was associated with the ratio of dietary macronutrients eaten, not energy intake, and the nature of the effect differed between the sexes. In males, skin structure was primarily associated with protein intake, whereas in females carbohydrate intake was the primary correlate. In both sexes, the dermis and subcutaneous fat thicknesses were inversely proportional. Subcutaneous fat thickness varied positively with fat intake, due to enlarged adipocytes rather than increased adipocyte number. We therefore demonstrated clear interactions between skin structure and macronutrient intakes, with the associations being sex-specific and dependent on dietary macronutrient balance