RESUMEN
Microproteins (MPs) are a potentially rich source of uncharacterized metabolic regulators. Here, we use ribosome profiling (Ribo-seq) to curate 3,877 unannotated MP-encoding small ORFs (smORFs) in primary brown, white, and beige mouse adipocytes. Of these, we validated 85 MPs by proteomics, including 33 circulating MPs in mouse plasma. Analyses of MP-encoding mRNAs under different physiological conditions (high-fat diet) revealed that numerous MPs are regulated in adipose tissue in vivo and are co-expressed with established metabolic genes. Furthermore, Ribo-seq provided evidence for the translation of Gm8773, which encodes a secreted MP that is homologous to human and chicken FAM237B. Gm8773 is highly expressed in the arcuate nucleus of the hypothalamus, and intracerebroventricular administration of recombinant mFAM237B showed orexigenic activity in obese mice. Together, these data highlight the value of this adipocyte MP database in identifying MPs with roles in fundamental metabolic and physiological processes such as feeding.
Asunto(s)
Adipocitos Blancos , Tejido Adiposo Pardo , Humanos , Animales , Ratones , Adipocitos Blancos/metabolismo , Tejido Adiposo Pardo/metabolismo , Sistemas de Lectura Abierta/genética , Tejido Adiposo Blanco/metabolismo , Adipocitos Marrones/metabolismo , MicropéptidosRESUMEN
Fibroblast growth factor 21 (FGF21) induces weight loss in mouse, monkey, and human studies. In mice, FGF21 is thought to cause weight loss by stimulating thermogenesis, but whether FGF21 increases energy expenditure (EE) in primates is unclear. Here, we explore the transcriptional response and gene networks active in adipose tissue of rhesus macaques following FGF21-induced weight loss. Genes related to thermogenesis responded inconsistently to FGF21 treatment and weight loss. However, expression of gene modules involved in triglyceride (TG) synthesis and adipogenesis decreased, and this was associated with greater weight loss. Conversely, expression of innate immune cell markers was increased post-treatment and was associated with greater weight loss. A lipogenesis gene module associated with weight loss was evaluated by testing the function of member genes in mice. Overexpression of NRG4 reduced weight gain in diet-induced obese mice, while overexpression of ANGPTL8 resulted in elevated TG levels in lean mice. These observations provide evidence for a shifting balance of lipid storage and metabolism due to FGF21-induced weight loss in the non-human primate model, and do not fully recapitulate increased EE seen in rodent and in vitro studies. These discrepancies may reflect inter-species differences or complex interplay of FGF21 activity and counter-regulatory mechanisms.
Asunto(s)
Factores de Crecimiento de Fibroblastos/farmacología , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Lipogénesis/efectos de los fármacos , Grasa Subcutánea/metabolismo , Pérdida de Peso/efectos de los fármacos , Animales , Femenino , Humanos , Macaca mulatta , Masculino , RatonesRESUMEN
BACKGROUND: We and others have previously shown that alterations in the mammalian gut microbiome are associated with diet, notably early life exposure to a maternal high fat diet (HFD). Here, we aimed to further these studies by examining alterations in the gut microbiome of juvenile Japanese macaques (Macaca fuscata) that were exposed to a maternal HFD, weaned onto a control diet, and later supplemented with a synbiotic comprised of psyllium seed and Enterococcus and Lactobacillus species. RESULTS: Eighteen month old offspring (n = 7) of 36% HFD fed dams were fed a control (14% fat) diet post weaning, then were synbiotic supplemented for 75 days and longitudinal stool and serum samples were obtained. All stool samples were subjected to 16S rRNA metagenomic sequencing, and microbiome profiles and serum lipids and triglycerides were compared to untreated, healthy age matched and diet matched controls (n = 7). Overall, 16S-based metagenomic analysis revealed that supplementation exerted minimal alterations to the gut microbiome including transient increased abundance of Lactobacillus species and decreased abundance of few bacterial genera, including Faecalibacterium and Anaerovibrio. However, serum lipid analysis revealed significant decreases in triglycerides, cholesterol, and LDL (p < 0.05). Nevertheless, supplemented juveniles challenged 4 months later were not protected from HFD-induced gut dysbiosis. CONCLUSIONS: Synbiotic supplementation is temporally associated with alterations in the gut microbiome and host lipid profiles of juvenile Japanese macaques that were previously exposed to a maternal HFD. Despite these presumptive temporal benefits, a protective effect against later HFD-challenge gut dysbiosis was not observed.
Asunto(s)
Bacterias/clasificación , Bacterias/metabolismo , Dieta Alta en Grasa , Microbioma Gastrointestinal/fisiología , Primates/microbiología , Simbióticos , Animales , Bacterias/genética , Disbiosis/microbiología , Enterococcus/fisiología , Faecalibacterium , Heces/microbiología , Femenino , Firmicutes , Microbioma Gastrointestinal/genética , Lactobacillus/fisiología , Lípidos/sangre , Macaca/microbiología , Masculino , Redes y Vías Metabólicas , Metagenómica , Probióticos , Psyllium , ARN Ribosómico 16S/genética , Especificidad de la Especie , Triglicéridos/sangreRESUMEN
Maternal high-fat-diet (HFD) consumption during pregnancy decreased fetal body weight and impacted development of hypothalamic melanocortin neural circuitry in nonhuman primate offspring. We investigated whether these impairments during gestation persisted in juvenile offspring and examined the interaction between maternal and early postnatal HFD consumption. Adult dams consumed either a control diet (CTR; 15% calories from fat) or a high-saturated-fat diet (HFD; 37% calories from fat) during pregnancy. Offspring were weaned onto a CTR or HFD at ~8 mo of age. Offspring from HFD-fed dams displayed early catch-up growth and elevated body weight at 6 and 13 mo of age. Maternal and postnatal HFD exposure reduced the amount of agouti-related peptide fibers in the paraventricular nucleus of the hypothalamus. Postnatal HFD consumption also decreased the amount of agouti-related peptide fibers in the arcuate nucleus of the hypothalamus. Postnatal HFD was associated with decreased food intake and increased activity. These results support and extend our previous findings of maternal diet effects on fetal development and reveal, for the first time in a nonhuman primate model, that maternal HFD-induced disturbances in offspring body weight regulation extended past gestation into the juvenile period. Maternal HFD consumption increases the risk for offspring developing obesity, with the developmental timing of HFD exposure differentially impacting the melanocortin system and energy balance regulation. The present findings provide translational insight into human clinical populations, suggesting that profound health consequences may await individuals later in life following intrauterine and postnatal HFD exposure.
Asunto(s)
Dieta Alta en Grasa/efectos adversos , Ingestión de Alimentos , Hipotálamo/fisiopatología , Melanocortinas/metabolismo , Obesidad/fisiopatología , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Animales , Metabolismo Energético , Conducta Alimentaria , Femenino , Desarrollo Fetal , Humanos , Macaca , Masculino , Obesidad/etiología , Embarazo , Preñez , Transducción de SeñalRESUMEN
Maternal obesity contributes to an increased risk of lifelong morbidity and mortality for both the mother and her offspring. In order to better understand the molecular mechanisms underlying these risks, we previously established and extensively characterized a primate model in Macaca fuscata (Japanese macaque). In prior studies we have demonstrated that a high fat, caloric dense maternal diet structures the offspring's epigenome, metabolome, and intestinal microbiome. During the course of this work we have consistently observed that a 36% fat diet leads to obesity in the majority, but not all, of exposed dams. In the current study, we sought to identify the genomic loci rendering resistance to obesity despite chronic consumption of a high fat diet in macaque dams. Through extensive phenotyping together with exon capture array and targeted resequencing, we identified three novel single nucleotide polymorphisms (SNPs), two in apolipoprotein B (APOB) and one in phospholipase A2 (PLA2G4A) that significantly associated with persistent weight stability and insulin sensitivity in lean macaques. By application of explicit orthogonal modeling (NOIA), we estimated the polygenic and interactive nature of these loci against multiple metabolic traits and their measures (i.e., serum LDL levels) which collectively render an obesity resistant phenotype in our adult female dams.
Asunto(s)
Dieta Alta en Grasa/efectos adversos , Obesidad/genética , Obesidad/prevención & control , Animales , Apolipoproteínas B/genética , Modelos Animales de Enfermedad , Exones , Femenino , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Variación Genética , Genoma , Genotipo , Resistencia a la Insulina/genética , Macaca , Obesidad/etiología , Polimorfismo de Nucleótido Simple , EmbarazoRESUMEN
BACKGROUND AND OBJECTIVE: Atherosclerosis is both a chronic inflammatory disease and a lipid metabolism disorder. C/EBPß is well documented for its role in the development of hematopoietic cells and integration of lipid metabolism. However, C/EBPß's role in atherosclerotic progression has not been examined. We assessed the impact of hematopoietic CEBPß deletion in ApoE(-/-) mice on hyperlipidemia, inflammatory responses and lesion formation in the aorta. METHODS AND RESULTS: ApoE(-/-) mice were reconstituted with bone marrow cells derived from either WT or C/EBPß(-/-) mice and placed on low fat or high fat/high cholesterol diet for 11 weeks. Hematopoietic C/EBPß deletion in ApoE(-/-) mice reduced blood and hepatic lipids and gene expression of hepatic stearoyl CoA desaturase 1 and fatty acid synthase while expression of ATP binding cassette transporter G1, cholesterol 7-alpha-hydroxylase, and liver X receptor alpha genes were significantly increased. ApoE(-/-) mice reconstituted with C/EBPß(-/-) bone marrow cells also significantly reduced blood cytokine levels and reduced lesion area in aortic sinuses compared with ApoE(-/-) mice reconstituted with WT bone marrow cells. Silencing of C/EBPß in RAW264.7 macrophage cells prevented oxLDL-mediated foam cell formation and inflammatory cytokine secretion in conditioned medium. CONCLUSION: C/EBPß in hematopoietic cells is crucial to regulate diet-induced inflammation, hyperlipidemia and atherosclerosis development.
Asunto(s)
Aterosclerosis/metabolismo , Médula Ósea/metabolismo , Proteína beta Potenciadora de Unión a CCAAT/metabolismo , Colesterol/sangre , Dieta/efectos adversos , Inflamación/metabolismo , Animales , Células de la Médula Ósea/metabolismo , Medios de Cultivo Condicionados/química , Citocinas/metabolismo , Femenino , Células Espumosas/metabolismo , Regulación de la Expresión Génica , Silenciador del Gen , Hematopoyesis , Hiperlipidemias , Metabolismo de los Lípidos , Lípidos/química , Hígado/enzimología , Macrófagos/metabolismo , Ratones , Ratones Noqueados para ApoE , Células RAW 264.7RESUMEN
OBJECTIVE: To utilize a nonhuman primate model to examine the impact of maternal high-fat diet (HFD) consumption and pre-pregnancy obesity on offspring intake of palatable food and to examine whether maternal HFD consumption impaired development of the dopamine system, critical for the regulation of hedonic feeding. METHODS: The impact of exposure to maternal HFD and obesity on offspring consumption of diets of varying composition was assessed after weaning. The influence of maternal HFD consumption on the development of the prefrontal cortex-dopaminergic system at 13 months of age was also examined. RESULTS: During a preference test, offspring exposed to maternal HFD consumption and obesity displayed increased intake of food high in fat and sugar content relative to offspring from lean control mothers. Maternal HFD consumption suppressed offspring dopamine signaling (as assessed by immunohistochemistry) relative to control offspring. Specifically, there was decreased abundance of dopamine fibers and of dopamine receptor 1 and 2 proteins. CONCLUSIONS: This study reveals that offspring exposed to both maternal HFD consumption and maternal obesity during early development are at increased risk for obesity due to overconsumption of palatable energy-dense food, a behavior that may be related to reduced central dopamine signaling.
Asunto(s)
Dieta Alta en Grasa/efectos adversos , Dopamina/metabolismo , Ingestión de Alimentos/fisiología , Fenómenos Fisiologicos Nutricionales Maternos , Obesidad/metabolismo , Complicaciones del Embarazo/metabolismo , Efectos Tardíos de la Exposición Prenatal , Animales , Conducta Alimentaria/fisiología , Femenino , Masculino , Modelos Animales , Obesidad/etiología , Embarazo , Complicaciones del Embarazo/fisiopatología , Efectos Tardíos de la Exposición Prenatal/metabolismo , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Primates , Transducción de Señal , Gusto/fisiologíaRESUMEN
Neurons coexpressing neuropeptide Y, agouti-related peptide, and GABA (NAG) play an important role in ingestive behavior and are located in the arcuate nucleus of the hypothalamus. NAG neurons receive both GABAergic and glutamatergic synaptic inputs, however, the developmental time course of synaptic input organization of NAG neurons in mice is unknown. In this study, we show that these neurons have low numbers of GABAergic synapses and that GABA is inhibitory to NAG neurons during early postnatal period. In contrast, glutamatergic inputs onto NAG neurons are relatively abundant by P13 and are comparatively similar to the levels observed in the adult. As mice reach adulthood (9-10 weeks), GABAergic tone onto NAG neurons increases. At this age, NAG neurons received similar numbers of inhibitory and EPSCs. To further differentiate age-associated changes in synaptic distribution, 17- to 18-week-old lean and diet-induced obesity (DIO) mice were studied. Surprisingly, NAG neurons from lean adult mice exhibit a reduction in the GABAergic synapses compared with younger adults. Conversely, DIO mice display reductions in the number of GABAergic and glutamatergic inputs onto NAG neurons. Based on these experiments, we propose that synaptic distribution in NAG neurons is continuously restructuring throughout development to accommodate the animals' energy requirements.
Asunto(s)
Núcleo Arqueado del Hipotálamo/citología , Núcleo Arqueado del Hipotálamo/crecimiento & desarrollo , Neuronas/fisiología , Sinapsis/fisiología , 2-Amino-5-fosfonovalerato/farmacología , 6-Ciano 7-nitroquinoxalina 2,3-diona/farmacología , Factores de Edad , Animales , Animales Recién Nacidos , Antagonistas de Aminoácidos Excitadores/farmacología , Potenciales Postsinápticos Excitadores/efectos de los fármacos , Potenciales Postsinápticos Excitadores/genética , Femenino , Potenciales Postsinápticos Inhibidores/efectos de los fármacos , Potenciales Postsinápticos Inhibidores/genética , Lisina/análogos & derivados , Lisina/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Neuropéptido Y/genética , Neuropéptido Y/metabolismo , Bloqueadores de los Canales de Sodio/farmacología , Sinapsis/efectos de los fármacos , Sinapsis/genética , Tetrodotoxina/farmacología , Proteínas del Transporte Vesicular de Aminoácidos Inhibidores/metabolismo , Ácido gamma-Aminobutírico/farmacologíaRESUMEN
The intestinal microbiome is a unique ecosystem and an essential mediator of metabolism and obesity in mammals. However, studies investigating the impact of the diet on the establishment of the gut microbiome early in life are generally lacking, and most notably so in primate models. Here we report that a high-fat maternal or postnatal diet, but not obesity per se, structures the offspring's intestinal microbiome in Macaca fuscata (Japanese macaque). The resultant microbial dysbiosis is only partially corrected by a low-fat, control diet after weaning. Unexpectedly, early exposure to a high-fat diet diminished the abundance of non-pathogenic Campylobacter in the juvenile gut, suggesting a potential role for dietary fat in shaping commensal microbial communities in primates. Our data challenge the concept of an obesity-causing gut microbiome and rather provide evidence for a contribution of the maternal diet in establishing the microbiota, which in turn affects intestinal maintenance of metabolic health.
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Dieta Alta en Grasa/efectos adversos , Disbiosis/etiología , Intestinos/microbiología , Microbiota , Efectos Tardíos de la Exposición Prenatal/etiología , Animales , Dieta con Restricción de Grasas , Disbiosis/microbiología , Femenino , Macaca , Embarazo , Efectos Tardíos de la Exposición Prenatal/microbiología , DesteteRESUMEN
The origins of nonalcoholic fatty liver disease (NAFLD) may lie in early intrauterine exposures. Here we examined the maternal response to chronic maternal high-fat (HF) diet and the impact of postweaning healthy diet on mechanisms for NAFLD development in juvenile nonhuman primate (NHP) offspring at 1 year of age. Pregnant females on HF diet were segregated as insulin resistant (IR; HF+IR) or insulin sensitive (IS; HF+IS) compared with control (CON)-fed mothers. HF+IR mothers have increased body mass, higher triglycerides, and increased placental cytokines. At weaning, offspring were placed on a CON or HF diet. Only offspring from HF+IR mothers had increased liver triglycerides and upregulated pathways for hepatic de novo lipid synthesis and inflammation that was irreversible upon switching to a healthy diet. These juvenile livers also showed a combination of classical and alternatively activated hepatic macrophages and natural killer T cells, in the absence of obesity or insulin resistance. Our findings suggest that maternal insulin resistance, including elevated triglycerides, insulin, and weight gain, initiates dysregulation of the juvenile hepatic immune system and development of de novo lipogenic pathways that persist in vitro and may be an irreversible "first hit" in the pathogenesis of NAFLD in NHP.
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Grasas de la Dieta/efectos adversos , Hígado Graso/etiología , Resistencia a la Insulina , Hígado/metabolismo , Tejido Adiposo , Alimentación Animal , Animales , Citocinas/genética , Citocinas/metabolismo , Femenino , Regulación de la Expresión Génica , Prueba de Tolerancia a la Glucosa , Inflamación/metabolismo , Metabolismo de los Lípidos , Macaca , Activación de Macrófagos/fisiología , Macrófagos/metabolismo , Enfermedad del Hígado Graso no Alcohólico , Embarazo , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
Drugs designed specifically to activate liver X receptors (LXRs) have beneficial effects on lowering cholesterol metabolism and inflammation but unfortunately lead to severe hepatic steatosis. The transcription factor CCAAT/enhancer binding protein beta (C/EBPß) is an important regulator of liver gene expression but little is known about its involvement in LXR-based steatosis and cholesterol metabolism. The present study investigated the role of C/EBPß expression in LXR agonist (T0901317)-mediated alteration of hepatic triglyceride (TG) and lipogenesis in mice. C/EBPß deletion in mice prevented LXR agonist-mediated induction of lipogenic gene expression in liver in conjunction with significant reduction of liver TG accumulation. Surprisingly, C/EBPß(-/-) mice showed a major increase in liver mitochondrial electron chain function compared to WT mice. Furthermore, LXR activation in C/EBPß(-/-) mice increased the expression of liver ATP-binding cassette transporter ABCG1, a gene implicated in cholesterol efflux and reducing blood levels of total and LDL-cholesterol. Together, these findings establish a central role for C/EBPß in the LXR-mediated steatosis and mitochondrial function, without impairing the influence of LXR activation on lowering LDL and increasing HDL-cholesterol. Inactivation of C/EBPß might therefore be an important therapeutic strategy to prevent LXR activation-mediated adverse effects on liver TG metabolism without disrupting its beneficial effects on cholesterol metabolism.
Asunto(s)
Anticolesterolemiantes/efectos adversos , Proteína beta Potenciadora de Unión a CCAAT/genética , Hígado Graso/inducido químicamente , Hígado Graso/genética , Hidrocarburos Fluorados/efectos adversos , Mitocondrias Hepáticas/metabolismo , Receptores Nucleares Huérfanos/agonistas , Sulfonamidas/efectos adversos , Animales , Anticolesterolemiantes/administración & dosificación , HDL-Colesterol/metabolismo , Eliminación de Gen , Hidrocarburos Fluorados/administración & dosificación , Lipogénesis/efectos de los fármacos , Receptores X del Hígado , Masculino , Ratones , Ratones Mutantes , Sulfonamidas/administración & dosificación , Triglicéridos/metabolismoRESUMEN
Strong evidence exists for a link between chronic low level inflammation and dietary-induced insulin resistance; however, little is known about the transcriptional networks involved. Here we show that high fat diet (HFD) or saturated fatty acid exposure directly activates CCAAT/enhancer-binding protein ß (C/EBPß) protein expression in liver, adipocytes, and macrophages. Global C/EBPß deletion prevented HFD-induced inflammation and surprisingly increased mitochondrial gene expression in white adipose tissue along with brown adipose tissue markers PRDM16, CIDEa, and UCP1, consistent with a resistance to HFD-induced obesity. In isolated peritoneal macrophages from C/EBPß(-/-) mice, the anti-inflammatory gene LXRα and its targets SCD1 and DGAT2 were strikingly up-regulated along with IL-10, while NLRP3, a gene important for activating the inflammasome, was suppressed in response to palmitate. Using RAW 264.7 macrophage cells or 3T3-L1 adipocytes, C/EBPß knockdown prevented palmitate-induced inflammation and p65-NFκB DNA binding activity, while C/EBPß overexpression induced NFκB binding, JNK activation, and pro-inflammatory cytokine gene expression directly. Finally, chimeric bone marrow mice transplanted with bone marrow lacking C/EBPß(-/-) demonstrated reduced systemic and adipose tissue inflammatory markers, macrophage content, and maintained insulin sensitivity on HFD. Taken together, these results demonstrate that HFD or palmitate exposure triggers C/EBPß expression that controls expression of distinct aspects of alternative macrophage activation. Reducing C/EBPß in macrophages confers protection from HFD-induced systemic inflammation and insulin resistance, suggesting it may be an attractive therapeutic target for ameliorating obesity-induced inflammatory responses.