Cellular mechanisms regulating fuel metabolism in mammals: Role of adipose tissue and lipids during prolonged food deprivation

Viscarra, José A.; Ortiz, Rudy M.

doi:10.1016/j.metabol.2012.12.014

Cited by 69 publications

(51 citation statements)

References 100 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…During a fast, triglycerides are cleaved by lipoprotein lipase (LPL), adipose triglyceride lipase, hormone-sensitive lipase (HSL), and monoglyceride lipase into nonesterified fatty acids (NEFAs) and glycerol, which can either be metabolized within cells or released into circulation to travel through the body attached to protein carriers (e.g., albumin) (569). Liver activity and mRNA expression of LPL and HSL increase by 2-to 3-fold within 2 to 3 weeks of fasting for the Nile tilapia (O. niloticus) (549).…”

Section: Lipidsmentioning

confidence: 99%

Integrative Physiology of Fasting

Secor

Carey

2016

Comprehensive Physiology

136

144

View full text Add to dashboard Cite

Extended bouts of fasting are ingrained in the ecology of many organisms, characterizing aspects of reproduction, development, hibernation, estivation, migration, and infrequent feeding habits. The challenge of long fasting episodes is the need to maintain physiological homeostasis while relying solely on endogenous resources. To meet that challenge, animals utilize an integrated repertoire of behavioral, physiological, and biochemical responses that reduce metabolic rates, maintain tissue structure and function, and thus enhance survival. We have synthesized in this review the integrative physiological, morphological, and biochemical responses, and their stages, that characterize natural fasting bouts. Underlying the capacity to survive extended fasts are behaviors and mechanisms that reduce metabolic expenditure and shift the dependency to lipid utilization. Hormonal regulation and immune capacity are altered by fasting; hormones that trigger digestion, elevate metabolism, and support immune performance become depressed, whereas hormones that enhance the utilization of endogenous substrates are elevated. The negative energy budget that accompanies fasting leads to the loss of body mass as fat stores are depleted and tissues undergo atrophy (i.e., loss of mass). Absolute rates of body mass loss scale allometrically among vertebrates. Tissues and organs vary in the degree of atrophy and downregulation of function, depending on the degree to which they are used during the fast. Fasting affects the population dynamics and activities of the gut microbiota, an interplay that impacts the host's fasting biology. Fasting-induced gene expression programs underlie the broad spectrum of integrated physiological mechanisms responsible for an animal's ability to survive long episodes of natural fasting.

show abstract

Section: Lipidsmentioning

confidence: 99%

Integrative Physiology of Fasting

Secor

Carey

2016

Comprehensive Physiology

136

144

View full text Add to dashboard Cite

show abstract

“…Moreover, adenosine triphosphate can be produced through the oxidation of FFAs, and glycerol can be used as a substrate in gluconeogenesis or lipogenesis Fasting, Cognitive Performance and Exercise [50]. Therefore, adipose tissue can directly and indirectly modulate the availability of other metabolic substrates [52].…”

Section: Intermittent Fastingmentioning

confidence: 99%

Effects of Intermittent Fasting, Caloric Restriction, and Ramadan Intermittent Fasting on Cognitive Performance at Rest and During Exercise in Adults

et al. 2015

View full text Add to dashboard Cite

The aim of this review was to highlight the potent effects of intermittent fasting on the cognitive performance of athletes at rest and during exercise. Exercise interacts with dietary factors and has a positive effect on brain functioning. Furthermore, physical activity and exercise can favorably influence brain plasticity. Mounting evidence indicates that exercise, in combination with diet, affects the management of energy metabolism and synaptic plasticity by affecting molecular mechanisms through brain-derived neurotrophic factor, an essential neurotrophin that acts at the interface of metabolism and plasticity. The literature has also shown that certain aspects of physical performance and mental health, such as coping and decision-making strategies, can be negatively affected by daylight fasting. However, there are several types of intermittent fasting. These include caloric restriction, which is distinct from fasting and allows subjects to drink water ad libitum while consuming a very low-calorie food intake. Another type is Ramadan intermittent fasting, which is a religious practice of Islam, where healthy adult Muslims do not eat or drink during daylight hours for 1 month. Other religious practices in Islam (Sunna) also encourage Muslims to practice intermittent fasting outside the month of Ramadan. Several cross-sectional and longitudinal studies have shown that intermittent fasting has crucial effects on physical and intellectual performance by affecting various aspects of bodily physiology and biochemistry that could be important for athletic success. Moreover, recent findings revealed that immunological variables are also involved in cognitive functioning and that intermittent fasting might impact the relationship between cytokine expression in the brain and cognitive deficits, including memory deficits.

show abstract

“…Lipogenesis is well known to be stimulated by high carbohydrate (CH) diet (Kersten, 2001), mainly postprandially, as plasma glucose levels stimulate lipogenesis by different mechanisms. On the opposite, lipogenesis is inhibited by polyunsaturated fatty acids (PUFA), high fat diets and food deprivation (O'Hea and Leveille, 1969;Kersten, 2001;Sampath and Ntambi, 2006), and the latter one conversely enhances lipolysis in adipose tissue (Viscarra and Ortiz, 2013). These effects are in part mediated by hormones as leptin (Wang et al, 1999), which stimulates FA oxidation and inhibits lipogenesis by down-regulating the expression of genes involved in FA and triglycerides synthesis.…”

Section: Introductionmentioning

confidence: 99%

Adipose tissue transcriptional response of lipid metabolism genes in growing Iberian pigs fed oleic acid v. carbohydrate enriched diets

Benítez¹,

Núñez²,

Fernández³

et al. 2016

Animal

View full text Add to dashboard Cite

Diet influences animal body and tissue composition due to direct deposition and to the nutrients effects on metabolism. The influence of specific nutrients on the molecular regulation of lipogenesis is not well characterized and is known to be influenced by many factors including timing and physiological status. A trial was performed to study the effects of different dietary energy sources on lipogenic genes transcription in ham adipose tissue of Iberian pigs, at different growth periods and on feeding/fasting situations. A total of 27 Iberian male pigs of 28 kg BW were allocated to two separate groups and fed with different isocaloric feeding regimens: standard diet with carbohydrates as energy source (CH) or diet enriched with high oleic sunflower oil (HO). Ham subcutaneous adipose tissue was sampled by biopsy at growing (44 kg mean BW) and finishing (100 kg mean BW) periods. The first sampling was performed on fasted animals, while the last sampling was performed twice, with animals fasted overnight and 3 h after refeeding. Effects of diet, growth period and feeding/fasting status on gene expression were explored quantifying the expression of a panel of key genes implicated in lipogenesis and lipid metabolism processes. Quantitative PCR revealed several differentially expressed genes according to diet, with similar results at both timings: RXRG, LEP and FABP5 genes were upregulated in HO group while ME1, FASN, ACACA and ELOVL6 were upregulated in CH. The diet effect on ME1 gene expression was conditional on feeding/fasting status, with the higher ME1 gene expression in CH than HO groups, observed only in fasting samples. Results are compatible with a higher de novo endogenous synthesis of fatty acids (FA) in the carbohydrate-supplemented group and a higher FA transport in the oleic acid-supplemented group. Growth period significantly affected the expression of most of the studied genes, with all but PPARG showing higher expression in finishing pigs according to a pattern dissimilar from the usual in cosmopolitan pig breeds. Feeding/fasting status only influenced PPARG gene transcription. The lack of effects of feeding/ fasting status on lipogenic gene expression and the higher ME1 response to diet in fasting samples than in postprandial sampling, suggest the persistence of de novo lipogenesis during fasting. Overall results improve the understanding of the influence of different factors on lipid metabolism regulation in Iberian pigs.

show abstract

Cellular mechanisms regulating fuel metabolism in mammals: Role of adipose tissue and lipids during prolonged food deprivation

Cited by 69 publications

References 100 publications

Integrative Physiology of Fasting

Integrative Physiology of Fasting

Effects of Intermittent Fasting, Caloric Restriction, and Ramadan Intermittent Fasting on Cognitive Performance at Rest and During Exercise in Adults

Adipose tissue transcriptional response of lipid metabolism genes in growing Iberian pigs fed oleic acid v. carbohydrate enriched diets

Contact Info

Product

Resources

About