Epigenetic modulation of metabolic decisions

The Impact of Maternal Obesity on Adipose Progenitor Cells

The concept of Developmental Origin of Health and Disease (DOHaD) postulates that adult-onset metabolic disorders may originate from suboptimal conditions during critical embryonic and fetal programming windows. In particular, nutritional disturbance during key developmental stages may program the set point of adiposity and its associated metabolic diseases later in life. Numerous studies in mammals have reported that maternal obesity and the resulting accelerated growth in neonates may affect adipocyte development, resulting in persistent alterations in adipose tissue plasticity (i.e., adipocyte proliferation and storage) and adipocyte function (i.e., insulin resistance, impaired adipokine secretion, reduced thermogenesis, and higher inflammation) in a sex- and depot-specific manner. Over recent years, adipose progenitor cells (APCs) have been shown to play a crucial role in adipose tissue plasticity, essential for its development, maintenance, and expansion. In this review, we aim to provide insights into the developmental timeline of lineage commitment and differentiation of APCs and their role in predisposing individuals to obesity and metabolic diseases. We present data supporting the possible implication of dysregulated APCs and aberrant perinatal adipogenesis through epigenetic mechanisms as a primary mechanism responsible for long-lasting adipose tissue dysfunction in offspring born to obese mothers.

Long-Lasting Effects of Incubation Temperature During Fetal Development on Subcutaneous Adipose Tissue of Broilers

Increasing evidence indicates that fetal programming may cause permanent effects on offspring adipose tissue and body composition. Previous study showed reduction in newly-hatched broiler chick adiposity by manipulating incubation temperature during fetal development. The present study examined whether incubation temperature during fetal development has long-term effects on post-hatching fat deposition in broilers. Broiler breeder eggs (Cobb-500^®) were incubated under constant low (36°C, LT), control (37.5°C, CT) or high (39°C, HT) temperature from day 13 onward, giving to eggshell temperature of 37.3 ± 0.08°C, 37.8 ± 0.2°C, and 38.8 ± 0.3°C, respectively. Male chicks were reared under recommended temperatures until 42 days old. LT 21 days old broilers exhibited higher blood cholesterol than CT broilers, and higher triglycerids, VLDL, and LDL, and lower HDL than CT and HT broilers. LT broilers presented higher liver cholesterol than CT broilers and lower ether extract percentage than CT broilers. Adipocyte count was lower in the abdomen than in the thigh. Until day 21 of age, feed intake was higher in LT than in HT broilers. At day 42 of age, blood cholesterol and LDL were higher in HT broilers than in CT and LT broilers. Liver cholesterol was higher in LT than in HT broilers. LT treatment reduced neck and increased thigh adipocyte size compared to CT treatment, while the HT treatment reduced abdomen and neck adipocyte size compared to other two treatments and in the thigh compared to LT treatment. In CT broilers, thigh adipocytes were smaller than abdomen and neck adipocytes. HT treatment increased adipocyte number per area in the neck compared to LT and CT treatment, and LT and HT treatments reduced adipocyte count in the thigh compared to CT treatment. CT broilers presented higher adipocyte count in the thigh than the abdomen and neck, while HT broilers presented higher adipocyte count in the neck than the abdomen and thigh. Cell proliferation was lower in the abdomen than in the thigh. The results show incubation temperature manipulation during fetal development has long-term and distinct effects on regional adiposity, and can be used to modulate broiler fat deposition.

Sexual fate of murine external genitalia development: Conserved transcriptional competency for male-biased genes in both sexes

Testicular androgen is a master endocrine factor in the establishment of external genital sex differences. The degree of androgenic exposure during development is well known to determine the fate of external genitalia on a spectrum of female- to male-specific phenotypes. However, the mechanisms of androgenic regulation underlying sex differentiation are poorly defined. Here, we show that the genomic environment for the expression of male-biased genes is conserved to acquire androgen responsiveness in both sexes. Histone H3 at lysine 27 acetylation (H3K27ac) and H3K4 monomethylation (H3K4me1) are enriched at the enhancer of male-biased genes in an androgen-independent manner. Specificity protein 1 (Sp1), acting as a collaborative transcription factor of androgen receptor, regulates H3K27ac enrichment to establish conserved transcriptional competency for male-biased genes in both sexes. Genetic manipulation of MafB, a key regulator of male-specific differentiation, and Sp1 regulatory MafB enhancer elements disrupts male-type urethral differentiation. Altogether, these findings demonstrate conservation of androgen responsiveness in both sexes, providing insights into the regulatory mechanisms underlying sexual fate during external genitalia development.

CD40L/CD40 regulates adipokines and cytokines by H3K4me3 modification in epicardial adipocytes

ABSTRACT

Epicardial adipose tissue (EAT) dysfunction mediates chronic inflammation by regulating inflammation-related adipokines and cytokines, and further promotes coronary artery disease (CAD) development. CD40L/CD40 is involved in multiple inflammatory pathways that contribute to various pathophysiological processes. However, the function of CD40L/CD40 in adipokine and cytokine expression and production in epicardial adipocytes remains unclear. The purpose of the present study was to explore the role and underlying mechanisms of CD40L/CD40 in adipokine and cytokine expression and production. We isolated adipocytes from EAT tissues of CAD and non-CAD patients. We noticed that CD40 was dramatically increased in EAT tissues of CAD patients. Loss-of-function and gain-of-function studies were performed. The results showed that CD40 silencing reduced recombinant CD40 ligand (rCD40L)-induced up-regulation of plasminogen activator inhibitor-1 (PAI-1), leptin, interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1) mRNA levels and secretion. Overexpression of CD40 displayed the opposite results. In addition, rCD40L triggered mixed lineage leukemia protein-1 (MLL1) expression both in mRNA and protein levels. CD40 depletion apparently blocked MLL1 expression, whereas gain of function of CD40 resulted in augmentation of MLL1 levels. Interestingly, ChIP-qCPR analysis revealed that CD40 elimination dampened histone H3 lysine 4 trimethylation (H3K4me3) enrichment at PAI-1, leptin, IL-6 and MCP-1 promoter regions in the presence of rCD40L. The reverse pattern was observed upon ectopic expression of CD40. Most important, MLL1 silencing effectively reversed the promotive effects of CD40 on adipokine and cytokine secretion. Taken together, our findings suggest that CD40L/CD40 regulates adipokine and cytokine expression by H3K4me3 modification in adipocytes.

Maternal obesity as a risk factor for developing diabetes in offspring: An epigenetic point of view

According to the developmental origin of health and disease concept, the risk of many age-related diseases is not only determined by genetic and adult lifestyle factors but also by factors acting during early development. In particular, maternal obesity and neonatal accelerated growth predispose offspring to overweight and type 2 diabetes (T2D) in adulthood. This concept mainly relies on the developmental plasticity of adipose tissue and pancreatic β-cell programming in response to suboptimal milieu during the perinatal period. These changes result in unhealthy hypertrophic adipocytes with decreased capacity to store fat, low-grade inflammation and loss of insulin-producing pancreatic β-cells. Over the past years, many efforts have been made to understand how maternal obesity induces long-lasting adipose tissue and pancreatic β-cell dysfunction in offspring and what are the molecular basis of the transgenerational inheritance of T2D. In particular, rodent studies have shed light on the role of epigenetic mechanisms in linking maternal nutritional manipulations to the risk for T2D in adulthood. In this review, we discuss epigenetic adipocyte and β-cell remodeling during development in the progeny of obese mothers and the persistence of these marks as a basis of obesity and T2D predisposition.

Epigenetic Programming of Adipose Tissue in the Progeny of Obese Dams

According to the Developmental Origin of Health and Disease (DOHaD) concept, maternal obesity and the resulting accelerated growth in neonates predispose offspring to obesity and associated metabolic diseases that may persist across generations. In this context, the adipose tissue has emerged as an important player due to its involvement in metabolic health, and its high potential for plasticity and adaptation to environmental cues. Recent years have seen a growing interest in how maternal obesity induces long-lasting adipose tissue remodeling in offspring and how these modifications could be transmitted to subsequent generations in an inter- or transgenerational manner. In particular, epigenetic mechanisms are thought to be key players in the developmental programming of adipose tissue, which may partially mediate parts of the transgenerational inheritance of obesity. This review presents data supporting the role of maternal obesity in the developmental programming of adipose tissue through epigenetic mechanisms. Inter- and transgenerational effects on adipose tissue expansion are also discussed in this review.

Starvation promotes histone lysine butyrylation in the liver of male but not female mice

AIMS

Post-translational modifications (PTMs) of histones are regulated by the availability of their respective acyl-CoAs. Among these histone PTMs, the metabolic origin of histone butyrylation (Kbu) is still poorly understood.

MATERIAL AND METHODS

The impact of starvation on the levels of Kbu was determined by western blotting on histones extracted from the liver of fed and fasted C57BL/6 mice and immunohistochemistry on liver paraffin sections.

KEY FINDINGS

Using animal model we provide evidence that the stimulation of ketogenesis following starvation, in addition to histone beta-hydroxybutyrylation (Kbhb), also leads to an increase in histone butyrylation (Kbu). Using an immunohistochemistry (IHC) approach we report first that hepatocytes contained butyrylated histones with important cell-to-cell heterogeneity. More importantly, our investigations based on western blotting and IHC also proposed that the basal levels of Kbu differ between male and female mice, with female mouse hepatocytes containing higher levels of butyrylated histones. Starvation enhanced solely histone Kbu levels in the liver of males but not females.

SIGNIFICANCE

This is the first demonstration of a sex-dependent large-scale stimulation of histone acylation. Our data also point to different basal metabolic conditions of the male and female liver cells with a sex-dependent impact on the hepatocytes' epigenome.

Peroxisomal β-oxidation regulates histone acetylation and DNA methylation in Arabidopsis

Epigenetic markers, such as histone acetylation and DNA methylation, determine chromatin organization. In eukaryotic cells, metabolites from organelles or the cytosol affect epigenetic modifications. However, the relationships between metabolites and epigenetic modifications are not well understood in plants. We found that peroxisomal acyl-CoA oxidase 4 (ACX4), an enzyme in the fatty acid β-oxidation pathway, is required for suppressing the silencing of some endogenous loci, as well as Pro35S:NPTII in the ProRD29A:LUC/C24 transgenic line. The acx4 mutation reduces nuclear histone acetylation and increases DNA methylation at the NOS terminator of Pro35S:NPTII and at some endogenous genomic loci, which are also targeted by the demethylation enzyme REPRESSOR OF SILENCING 1 (ROS1). Furthermore, mutations in multifunctional protein 2 (MFP2) and 3-ketoacyl-CoA thiolase-2 (KAT2/PED1/PKT3), two enzymes in the last two steps of the β-oxidation pathway, lead to similar patterns of DNA hypermethylation as in acx4 Thus, metabolites from fatty acid β-oxidation in peroxisomes are closely linked to nuclear epigenetic modifications, which may affect diverse cellular processes in plants.

Dynamics and functional interplay of histone lysine butyrylation, crotonylation, and acetylation in rice under starvation and submergence

BACKGROUND

Histone lysine acylations by short-chain fatty acids are distinct from the widely studied histone lysine acetylation in chromatin, although both modifications are regulated by primary metabolism in mammalian cells. It remains unknown whether and how histone acylation and acetylation interact to regulate gene expression in plants that have distinct regulatory pathways of primary metabolism.

RESULTS

We identify 4 lysine butyrylation (Kbu) sites (H3K14, H4K12, H2BK42, and H2BK134) and 45 crotonylation (Kcr) sites on rice histones by mass spectrometry. Comparative analysis of genome-wide Kbu and Kcr and H3K9ac in combination with RNA sequencing reveals 25,306 genes marked by Kbu and Kcr in rice and more than 95% of H3K9ac-marked genes are marked by both. Kbu and Kcr are enriched at the 5' region of expressed genes. In rice under starvation and submergence, Kbu and Kcr appear to be less dynamic and display changes in different sets of genes compared to H3K9ac. Furthermore, Kbu seems to preferentially poise gene activation by external stresses, rather than internal circadian rhythm which has been shown to be tightly associated with H3K9ac. In addition, we show that rice sirtuin histone deacetylase (SRT2) is involved in the removal of Kcr.

CONCLUSION

Kbu, Kcr, and H3K9ac redundantly mark a large number of active genes but display different responses to external and internal signals. Thus, the proportion of rice histone lysine acetylation and acylation is dynamically regulated by environmental and metabolic cues, which may represent an epigenetic mechanism to fine-tune gene expression for plant adaptation.

Histone modifications in fatty acid synthase modulated by carbohydrate responsive element binding protein are associated with non‑alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a manifestation of metabolic syndrome in the liver and is closely associated with diabetes; however, its pathogenesis remains to be elucidated. Carbohydrate responsive element binding protein (ChREBP), the hub of glucolipid metabolism, regulates the induction of fatty acid synthase (FASN), the key enzyme of de novo lipogenesis, by directly binding to carbohydrate response element (ChoRE) in its promoter. Investigations of histone modifications on NAFLD remain in their infancy. In the present study, by using ChIP, the association between histone modifications and FASN transcription was investigated and histone modifications in FASN modulated by ChREBP were measured. It was demonstrated that ChREBP induced FASN ChREBP-ChoRE binding to accelerate the expression of FASN, leading to hepatocellular steatosis by facilitating H3 and H4 acetylation, H3K4 trimethylation and the phosphorylation of H3S10, but inhibiting the trimethylation of H3K9 and H4K20 in FASN promoter regions of HepG2 and L02 cells. It was also found that ChREBP-ChoRE binding of FASN relied on histone acetylation and that the transcriptional activity of ChREBP on FASN is required, based on the premise that histone acetylation causes conformational changes in FASN chromatin. This indicated histone acetylation as a crucial mechanism involved in the transcription of FASN modulated by ChREBP. Consequently, the present study provides further insight into the pathophysiology and a novel therapeutic potential of NAFLD based on epigenetic mechanisms.

Reduced PPARγ2 expression in adipose tissue of male rat offspring from obese dams is associated with epigenetic modifications

According to the Developmental Origin of Health and Disease (DOHaD) concept, maternal obesity and accelerated growth in neonates program obesity later in life. White adipose tissue (WAT) has been the focus of developmental programming events, although underlying mechanisms remain elusive. In rodents, WAT development primarily occurs during lactation. We previously reported that adult rat offspring from dams fed a high-fat (HF) diet exhibited fat accumulation and decreased peroxisome proliferator-activated receptor γ (PPARγ) mRNA levels in WAT. We hypothesized that PPARγ down-regulation occurs via epigenetic malprogramming which takes place during adipogenesis. We therefore examined epigenetic modifications in the PPARγ1 and PPARγ2 promoters in perirenal (pWAT) and inguinal fat pads of HF offspring at weaning (postnatal d 21) and in adulthood. Postnatal d 21 is a period characterized by active epigenomic remodeling in the PPARγ2 promoter (DNA hypermethylation and depletion in active histone modification H3ac and H3K4me3) in pWAT, consistent with increased DNA methyltransferase and DNA methylation activities. Adult HF offspring exhibited sustained hypermethylation and histone modification H3ac of the PPARγ2 promoter in both deposits, correlated with persistent decreased PPARγ2 mRNA levels. Consistent with the DOHaD hypothesis, retained epigenetic marks provide a mechanistic basis for the cellular memory linking maternal obesity to a predisposition for later adiposity.-Lecoutre, S., Pourpe, C., Butruille, L., Marousez, L., Laborie, C., Guinez, C., Lesage, J., Vieau, D., Eeckhoute, J., Gabory, A., Oger, F., Eberlé, D., Breton, C. Reduced PPARγ2 expression in adipose tissue of male rat offspring from obese dams is associated with epigenetic modifications.

Rice NAD+-dependent histone deacetylase OsSRT1 represses glycolysis and regulates the moonlighting function of GAPDH as a transcriptional activator of glycolytic genes

Sirtuins, a family of proteins with homology to the yeast silent information regulator 2 (Sir2), are NAD⁺-dependent histone deacetylases and play crucial roles in energy sensing and regulation in yeast and animal cells. Plants are autotrophic organisms and display distinct features of carbon and energy metabolism. It remains largely unexplored whether and how plant cells sense energy/redox status to control carbon metabolic flux under various growth conditions. In this work, we show that the rice nuclear sirtuin OsSRT1 not only functions as an epigenetic regulator to repress glycolytic genes expression and glycolysis in seedlings, but also inhibits transcriptional activity of glyceraldehyde-3-phosphatedehydrogenase (GAPDH) that is enriched on glycolytic genes promoters and stimulates their expression. We show that OsSRT1 reduces GAPDH lysine acetylation and nuclear accumulation that are enhanced by oxidative stress. Mass spectrometry identified six acetylated lysines regulated by OsSRT1. OsSRT1-dependent lysine deacetylation of OsGAPDH1 represses transcriptional activity of the protein. The results indicate that OsSRT1 represses glycolysis by both regulating epigenetic modification of histone and inhibiting the moonlighting function of GAPDH as a transcriptional activator of glycolytic genes in rice.

Histone Deacetylase AtSRT1 Links Metabolic Flux and Stress Response in Arabidopsis

How plant metabolic flux alters gene expression to optimize plant growth and response to stress remains largely unclear. Here, we report that Arabidopsis thaliana NAD⁺-dependent histone deacetylase AtSRT1 negatively regulates plant tolerance to stress and glycolysis but stimulates mitochondrial respiration. We found that AtSRT1 interacts with Arabidopsis cMyc-Binding Protein 1 (AtMBP-1), a transcriptional repressor produced by alternative translation of the cytosolic glycolytic enolase gene LOS2/ENO2. We demonstrated that AtSRT1 could associate with the chromatin of AtMBP-1 targets LOS2/ENO2 and STZ/ZAT10, both of which encode key stress regulators, and reduce the H3K9ac levels at these genes to repress their transcription. Overexpression of both AtSRT1 and AtMBP-1 had synergistic effects on the expression of glycolytic genes, glycolytic enzymatic activities, and mitochondrial respiration. Furthermore, we found that AtMBP-1 is lysine-acetylated and vulnerable to proteasomal protein degradation, while AtSRT1 could remove its lysine acetylation and significantly enhance its stability in vivo. Taken together, these results indicate that AtSRT1 regulates primary metabolism and stress response by both epigenetic regulation and modulation of AtMBP-1 transcriptional activity in Arabidopsis.

Maternal obesity programs increased leptin gene expression in rat male offspring via epigenetic modifications in a depot-specific manner

Objective

According to the Developmental Origin of Health and Disease (DOHaD) concept, maternal obesity and accelerated growth in neonates predispose offspring to white adipose tissue (WAT) accumulation. In rodents, adipogenesis mainly develops during lactation. The mechanisms underlying the phenomenon known as developmental programming remain elusive. We previously reported that adult rat offspring from high-fat diet-fed dams (called HF) exhibited hypertrophic adipocyte, hyperleptinemia and increased leptin mRNA levels in a depot-specific manner. We hypothesized that leptin upregulation occurs via epigenetic malprogramming, which takes place early during development of WAT.

Methods

As a first step, we identified in silico two potential enhancers located upstream and downstream of the leptin transcription start site that exhibit strong dynamic epigenomic remodeling during adipocyte differentiation. We then focused on epigenetic modifications (methylation, hydroxymethylation, and histone modifications) of the promoter and the two potential enhancers regulating leptin gene expression in perirenal (pWAT) and inguinal (iWAT) fat pads of HF offspring during lactation (postnatal days 12 (PND12) and 21 (PND21)) and in adulthood.

Results

PND12 is an active period for epigenomic remodeling in both deposits especially in the upstream enhancer, consistent with leptin gene induction during adipogenesis. Unlike iWAT, some of these epigenetic marks were still observable in pWAT of weaned HF offspring. Retained marks were only visible in pWAT of 9-month-old HF rats that showed a persistent “expandable” phenotype.

Conclusions

Consistent with the DOHaD hypothesis, persistent epigenetic remodeling occurs at regulatory regions especially within intergenic sequences, linked to higher leptin gene expression in adult HF offspring in a depot-specific manner.

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The white adipose tissue is an important target of developmental programming.

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Higher leptin gene expression occurs in offspring from obese dams in a depot-specific manner.

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Leptin upregulation occurs via epigenetic malprogramming during development of adipose tissue.

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Persistent genomic epigenetic remodeling occurs in adipose tissue of offspring from obese dams.

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Intergenic regions were more affected than the leptin promoter region in offspring of obese dams.

Metabolism disrupting chemicals and metabolic disorders

The recent epidemics of metabolic diseases, obesity, type 2 diabetes(T2D), liver lipid disorders and metabolic syndrome have largely been attributed to genetic background and changes in diet, exercise and aging. However, there is now considerable evidence that other environmental factors may contribute to the rapid increase in the incidence of these metabolic diseases. This review will examine changes to the incidence of obesity, T2D and non-alcoholic fatty liver disease (NAFLD), the contribution of genetics to these disorders and describe the role of the endocrine system in these metabolic disorders. It will then specifically focus on the role of endocrine disrupting chemicals (EDCs) in the etiology of obesity, T2D and NAFLD while finally integrating the information on EDCs on multiple metabolic disorders that could lead to metabolic syndrome. We will specifically examine evidence linking EDC exposures during critical periods of development with metabolic diseases that manifest later in life and across generations.

Parental nutritional programming and a reminder during juvenile stage affect growth, lipid metabolism and utilisation in later developmental stages of a marine teleost, the gilthead sea bream (Sparus aurata)

Nutrition during periconception and early development can modulate metabolic routes to prepare the offspring for adverse conditions through a process known as nutritional programming. In gilthead sea bream, replacement of fish oil (FO) with linseed oil (LO) in broodstock diets improves growth in the 4-month-old offspring challenged with low-FO and low-fishmeal (FM) diets for 1 month. The present study further investigated the effects of broodstock feeding on the same offspring when they were 16 months old and were challenged for a second time with the low-FM and low-FO diet for 2 months. The results showed that replacement of parental moderate-FO feeding with LO, combined with juvenile feeding at 4 months old with low-FM and low-FO diets, significantly (P<0·05) improved offspring growth and feed utilisation of low-FM/FO diets even when they were 16 months old: that is, when they were on the verge of their first reproductive season. Liver fatty acid composition was significantly affected by broodstock or reminder diets as well as by their interaction. Moreover, the reduction of long-chain PUFA and increase in α-linolenic acid and linoleic acid in broodstock diets lead to a significant down-regulation of hepatic lipoprotein lipase (P<0·001) and elongation of very long-chain fatty acids protein 6 (P<0·01). Besides, fatty acid desaturase 2 values were positively correlated to hepatic levels of 18 : 4n-3, 18 : 3n-6, 20 : 5n-3, 22 : 6n-3 and 22 : 5n-6. Thus, this study demonstrated the long-term nutritional programming of gilthead sea bream through broodstock feeding, the effect of feeding a ‘reminder’ diet during juvenile stages to improve utilisation of low-FM/FO diets and fish growth as well as the regulation of gene expression along the fish’s life-cycle.

Epigenetic Regulation of the Thermogenic Adipose Program

In contrast to white adipose tissue (WAT), which stores energy in the form of triglycerides, brown adipose tissue (BAT) dissipates energy by producing heat to maintain body temperature by burning glucose and fatty acids in a process called adaptive thermogenesis. The presence of an inducible thermogenic adipose tissue, and its beneficial effects for maintaining body weight and glucose and lipid homeostasis, has raised intense interest in understanding the regulation of thermogenesis. Elucidating the regulatory mechanisms underlying the thermogenic adipose program may provide excellent targets for therapeutics against obesity and diabetes. Here we review recent research on the role of epigenetics in the thermogenic gene program, focusing on DNA methylation and histone modifications.

Cofactors As Metabolic Sensors Driving Cell Adaptation in Physiology and Disease

Chromatin architectures and epigenetic fingerprint regulation are fundamental for genetically determined biological processes. Chemical modifications of the chromatin template sensitize the genome to intracellular metabolism changes to set up diverse functional adaptive states. Accumulated evidence suggests that the action of epigenetic modifiers is sensitive to changes in dietary components and cellular metabolism intermediates, linking nutrition and energy metabolism to gene expression plasticity. Histone posttranslational modifications create a code that acts as a metabolic sensor, translating changes in metabolism into stable gene expression patterns. These observations support the notion that epigenetic reprograming-linked energy input is connected to the etiology of metabolic diseases and cancer. In the present review, we introduce the role of epigenetic cofactors and their relation with nutrient intake and we question the links between epigenetic regulation and the development of metabolic diseases.

Depot- and sex-specific effects of maternal obesity in offspring's adipose tissue

According to the Developmental Origin of Health and Disease (DOHaD) concept, alterations of nutrient supply in the fetus or neonate result in long-term programming of individual body weight (BW) setpoint. In particular, maternal obesity, excessive nutrition, and accelerated growth in neonates have been shown to sensitize offspring to obesity. The white adipose tissue may represent a prime target of metabolic programming induced by maternal obesity. In order to unravel the underlying mechanisms, we have developed a rat model of maternal obesity using a high-fat (HF) diet (containing 60% lipids) before and during gestation and lactation. At birth, newborns from obese dams (called HF) were normotrophs. However, HF neonates exhibited a rapid weight gain during lactation, a key period of adipose tissue development in rodents. In males, increased BW at weaning (+30%) persists until 3months of age. Nine-month-old HF male offspring was normoglycemic but showed mild glucose intolerance, hyperinsulinemia, and hypercorticosteronemia. Despite no difference in BW and energy intake, HF adult male offspring was predisposed to fat accumulation showing increased visceral (gonadal and perirenal) depots weights and hyperleptinemia. However, only perirenal adipose tissue depot exhibited marked adipocyte hypertrophy and hyperplasia with elevated lipogenic (i.e. sterol-regulated element binding protein 1 (Srebp1), fatty acid synthase (Fas), and leptin) and diminished adipogenic (i.e. peroxisome proliferator-activated receptor gamma (Pparγ), 11β-hydroxysteroid dehydrogenase type 1 (11β-Hds1)) mRNA levels. By contrast, very few metabolic variations were observed in HF female offspring. Thus, maternal obesity and accelerated growth during lactation program offspring for higher adiposity via transcriptional alterations of visceral adipose tissue in a depot- and sex-specific manner.

T cell metabolism drives immunity

Buck et al. discuss the role of lymphocyte metabolism on immune cell development and function.

Lymphocytes must adapt to a wide array of environmental stressors as part of their normal development, during which they undergo a dramatic metabolic remodeling process. Research in this area has yielded surprising findings on the roles of diverse metabolic pathways and metabolites, which have been found to regulate lymphocyte signaling and influence differentiation, function and fate. In this review, we integrate the latest findings in the field to provide an up-to-date resource on lymphocyte metabolism.