Neonatal overfeeding during lactation rapidly and permanently misaligns the hepatic circadian rhythm and programmes adult NAFLD

Childhood obesity is a strong risk factor for adult obesity, type 2 diabetes, and cardiovascular disease. The mechanisms that link early adiposity with late-onset chronic diseases are poorly characterised. We developed a mouse model of early adiposity through litter size reduction. Mice reared in small litters (SLs) developed obesity, insulin resistance, and hepatic steatosis during adulthood. The liver played a major role in the development of the disease. Objective: To gain insight into the molecular mechanisms that link early development and childhood obesity with adult hepatic steatosis and insulin resistance. Methods: We analysed the hepatic transcriptome (Affymetrix) of control and SL mice to uncover potential pathways involved in the long-term programming of disease in our model. Results: The circadian rhythm was the most significantly deregulated Gene Ontology term in the liver of adult SL mice. Several core clock genes, such as period 1e3 and cryptochrome 1e2, were altered in two-week-old SL mice and remained altered throughout their life course until they reached 4e6 months of age. Defective circadian rhythm was restricted to the periphery since the expression of clock genes in the hypothalamus, the central pacemaker, was normal. The period-cryptochrome genes were primarily entrained by dietary signals. Hence, restricting food availability during the light cycle only uncoupled the central rhythm from the peripheral and completely normalised hepatic triglyceride content in adult SL mice. This effect was accompanied by better re-alignment of the hepatic period genes, suggesting that they might have played a causal role in mediating hepatic steatosis in the adult SL mice. Functional downregulation of Per2 in hepatocytes in vitro confirmed that the period genes regulated lipid-related genes in part through peroxisome proliferator-activated receptor alpha (Ppara). Conclusions: The hepatic circadian rhythm matures during early development, from birth to postnatal day 30. Hence, nutritional challenges during early life may misalign the hepatic circadian rhythm and secondarily lead to metabolic derangements. Specific time-restricted feeding interventions improve metabolic health in the context of childhood obesity by partially re-aligning the peripheral circadian rhythm

Dietary betaine supplementation increases Fgf21 levels to improve glucose homeostasis and reduce hepatic lipid accumulation in mice

Identifying markers of human insulin resistance may permit development of new approaches for treatment and prevention of type 2 diabetes. To this end, we analyzed the fasting plasma metabolome in metabolically characterized human volunteers across a spectrum of insulin resistance. We demonstrate that plasma betaine levels are reduced in insulin-resistant humans and correlate closely with insulin sensitivity. Moreover, betaine administration to mice with diet-induced obesity prevents the development of impaired glucose homeostasis, reduces hepatic lipid accumulation, increases white adipose oxidative capacity, and enhances whole-body energy expenditure. In parallel with these beneficial metabolic effects, betaine supplementation robustly increased hepatic and circulating fibroblast growth factor (Fgf)21 levels. Betaine administration failed to improve glucose homeostasis and liver fat content in Fgf21(-/-) mice, demonstrating that Fgf21 is necessary for betaine's beneficial effects. Together, these data indicate that dietary betaine increases Fgf21 levels to improve metabolic health in mice and suggest that betaine supplementation merits further investigation as a supplement for treatment or prevention of type 2 diabetes in humans

Role of early postnatal nutrition during lactation in offspring metabolic health programming

[eng] Childhood obesity and overweight can often cause severe complications, including hypertension, dyslipidemia, insulin resistance, type 2 diabetes, and non-alcoholic fatty liver disease, amongst other disorders. Several studies have shown that early postnatal nutrition is of great importance in modulating newborn health outcomes. In this work, we have studied the role of nutrition during early stages of life in long-term metabolic health applying two different approaches: a) transgenerational transmission of impaired metabolic health induced by accelerated early weight gain caused by postnatal overnutrition and b) short and long-term metabolic effects on offspring of maternal diet supplementation with betaine. Rapid weight gain during early life has been associated with several components of the Metabolic Syndrome. Previously we developed a mouse model of neonatal overfeeding and rapid weight gain by litter size reduction. Neonatal overnutrition (ON) altered the metabolism of the exposed individuals (F0). Furthermore, offspring (F1) and grand-offspring (F2) of postnatal overfed male mice also developed metabolic complications during adulthood. In agreement, it has been shown that environmental exposure on males can affect health in subsequent generations. Here, we hypothesized that epigenetic modifications, including DNA methylation, histone modifications, and noncoding-RNA, might be involved in the inheritance of diabetes risk in our model. We analyzed sperm methylome of F0 and F1 generations, and in the liver of 8-day-old mice of F1 and F2 generations, observing significant changes in methylation of specific DNA regions. We found 912 probes differentially methylated when comparing control and ON mice throughout the three generations, between the two tissues. Our results suggest that methylation of the male germ line caused by nutritional challenges during early life may carry information that influence metabolism across multiple generations. We then analyzed gene expression by qPCR of these genes in the liver of 8-days-old mice finding differences in some genes. Breast milk composition is important in modulating growth and health of the infant. Amongst the many nutrients that breast milk contains one worth highlighting is glycine betaine (or betaine). In addition to decreasing levels of fat in the liver, previous data demonstrated that maternal supplementation with betaine during breastfeeding also improves glucose homeostasis and modulates offspring early-life gut microbiota composition. Gut microbiota in the newborn is defined at birth and during early nutrition. Breast milk also contains essential bacteria that can influence gut microbiota composition of the breastfed infant. Changes in the microbiome caused by antibiotic administration during early life were significantly correlated to higher adiposity and development of obesity during adulthood. We observed beneficial short and long-term metabolic effects of betaine on offspring and protection against adult diet-induced obesity. We have analyzed ilea and gut microbiota of mice supplemented with betaine, and with or without antibiotics at different stages of life. Analyzing the microbiome we found that microbial community composition was modulated by betaine supplementation in 2-week-old offspring. Antibiotic treatment annulled completely long-term betaine-induced effects on body weight. Moreover, glucose tolerance was no longer improved when combining antibiotics with betaine treatment.[cat] L'obesitat i el sobrepès infantil poden causar sovint complicacions greus en la salut, incloent hipertensió, dislipèmia, resistència a la insulina, diabetis tipus 2 i esteatosis hepàtica no alcohòlica, entre d’altres. Diversos estudis han demostrat que la nutrició post-natal precoç és de gran importància en la modulació de la salut del nounat. En aquesta tesis, hem estudiat el paper de la nutrició durant les primeres etapes de la vida en la salut metabòlica a llarg termini aplicant dos enfocaments diferents: a) efectes metabòlics de suplementar de la dieta materna durant la lactància amb betaïna sobre la descendència a curt i llarg termini i b) transmissió transgeneracional del fenotip d’intolerància a la glucosa induïda per un augment accelerat de pes en etapes primerenques de la vida, causat per l'excés de nutrició post-natal. La composició de la llet materna és important per modular el creixement i la salut metabòlica de l'infant. Entre els nutrients que conté la llet materna, cal destacar la glicina betaïna (o betaïna). A més de disminuir els nivells de greix en fetge, diverses publicacions demostren que suplementar la dieta materna amb betaïna durant la lactància també millora l'homeòstasi de la glucosa i modula la composició de la microbiota intestinal del nounat. Al suplementar amb betaïna l’aigua de femelles durant la lactància vam observar efectes beneficiosos en la descendència a nivell metabòlic a curt i llarg termini. També vam poder observar que la betaïna protegia contra l'obesitat induïda per una dieta rica en greixos en l’etapa adulta. Se sap que la llet materna també conté bacteris essencials que poden influir en la composició de microbiota intestinal del lactant. S'ha analitzat la microbiota de l’ili i cec de ratolins suplementats amb betaïna, i amb o sense antibiòtics en diferents etapes de la vida. Analitzant el microbioma trobem que la composició de la comunitat microbiana dels ratolins de dues setmanes de vida estava modulada per la suplementació de betaina. Els canvis en el microbioma causats per l'administració d'antibiòtics durant la lactància estan significativament correlacionats amb una major adipositat i risc de desenvolupar obesitat durant l'edat adulta. El tractament amb antibiòtics en els nostres ratolins va anul·lar els efectes induïts per betaïna a llarg termini sobre el pes corporal. A més, la tolerància a la glucosa no estava millorarada quan es combinaven els antibiòtics amb el tractament amb betaïna. L'augment ràpid de pes durant les primeres etapes de la vida s'ha associat a diversos components de la Síndrome Metabòlica en l’adult. Prèviament en aquest laboratori hem desenvolupat un model murí de sobrealimentació neonatal i augment de pes ràpid a partir d’una reducció de la mida de la ventrada. L'excés d'alimentació neonatal (ON) va alterar el metabolisme dels mascles exposats (F0). A més, els fills (F1) i els néts (F2) dels ratolins exposats a la sobrenutrició també van desenvolupar un metabolisme alterat durant l'edat adulta. En acord, s'ha demostrat que l'exposició ambiental sobre els mascles pot afectar la salut de generacions posteriors. Així, ens vam plantejar que les modificacions epigenètiques, incloses la metilació de l'ADN, les modificacions de l'histona i l'ARN no codificant, podrien estar implicades en l'herència del risc de diabetis en el nostre model. Es va analitzar el metilma d’esperma de les generacions F0 i F1, i el metiloma de fetges de ratolins de 8 dies d'edat de les generacions F1 i F2, observant canvis significatius en la metilació de regions específiques d'ADN. Al comparar els ratolins control amb ON de cada generació i teixit, vam trobar 912 sondes diferentment metiladas. Els nostres resultats suggereixen que la metilació de la línia germinal masculina provocada per reptes nutricionals durant etapes primerenques de la vida pot portar informació que influeixi en el metabolisme en les següents generacions

Dietary betaine supplementation increases Fgf21 levels to improve glucose homeostasis and reduce hepatic lipid accumulation in mice

Identifying markers of human insulin resistance may permit development of new approaches for treatment and prevention of type 2 diabetes. To this end, we analyzed the fasting plasma metabolome in metabolically characterized human volunteers across a spectrum of insulin resistance. We demonstrate that plasma betaine levels are reduced in insulin-resistant humans and correlate closely with insulin sensitivity. Moreover, betaine administration to mice with diet-induced obesity prevents the development of impaired glucose homeostasis, reduces hepatic lipid accumulation, increases white adipose oxidative capacity, and enhances whole-body energy expenditure. In parallel with these beneficial metabolic effects, betaine supplementation robustly increased hepatic and circulating fibroblast growth factor (Fgf)21 levels. Betaine administration failed to improve glucose homeostasis and liver fat content in Fgf21(-/-) mice, demonstrating that Fgf21 is necessary for betaine's beneficial effects. Together, these data indicate that dietary betaine increases Fgf21 levels to improve metabolic health in mice and suggest that betaine supplementation merits further investigation as a supplement for treatment or prevention of type 2 diabetes in humans

Dietary betaine supplementation increases Fgf21 levels to improve glucose homeostasis and reduce hepatic lipid accumulation in mice

Identifying markers of human insulin resistance may permit development of new approaches for treatment and prevention of type 2 diabetes. To this end, we analyzed the fasting plasma metabolome in metabolically characterized human volunteers across a spectrum of insulin resistance. We demonstrate that plasma betaine levels are reduced in insulin-resistant humans and correlate closely with insulin sensitivity. Moreover, betaine administration to mice with diet-induced obesity prevents the development of impaired glucose homeostasis, reduces hepatic lipid accumulation, increases white adipose oxidative capacity, and enhances whole-body energy expenditure. In parallel with these beneficial metabolic effects, betaine supplementation robustly increased hepatic and circulating fibroblast growth factor (Fgf)21 levels. Betaine administration failed to improve glucose homeostasis and liver fat content in Fgf21(-/-) mice, demonstrating that Fgf21 is necessary for betaine's beneficial effects. Together, these data indicate that dietary betaine increases Fgf21 levels to improve metabolic health in mice and suggest that betaine supplementation merits further investigation as a supplement for treatment or prevention of type 2 diabetes in humans