In utero undernutrition in male mice programs liver lipid metabolism in the second-generation offspring involving altered lxra DNA methylation

SummaryObesity and type 2 diabetes have a heritable component that is not attributable to genetic factors. Instead, epigenetic mechanisms may play a role. We have developed a mouse model of intrauterine growth restriction (IUGR) by in utero malnutrition. IUGR mice developed obesity and glucose intolerance with aging. Strikingly, offspring of IUGR male mice also developed glucose intolerance. Here, we show that in utero malnutrition of F1 males influenced the expression of lipogenic genes in livers of F2 mice, partly due to altered expression of Lxra. In turn, Lxra expression is attributed to altered DNA methylation of its 5′ UTR region. We found the same epigenetic signature in the sperm of their progenitors, F1 males. Our data indicate that in utero malnutrition results in epigenetic modifications in germ cells (F1) that are subsequently transmitted and maintained in somatic cells of the F2, thereby influencing health and disease risk of the offspring

Origen neonatal de la síndrome metabòlica en l'adult

[cat] Es coneix que la nutrició en les primeres etapes de la vida és un factor clau que contribueix a la prevalença de l'obesitat, així com la resta de característiques de la Síndrome Metabòlica en l'edat adulta (Langley-Evans SC, 2006; Neu J, 2007; Patel MS, 2011; Jimenez-Chillaron JC, 2012; Wang X, 2013; Waterland RA, 2013). Nombrosos estudis fets en models experimentals i corroborats en humans demostren una interelació entre la nutrició postnatal, el patró de creixement durant la infància i les alteracions metabòliques que s'observen en l'edat adulta (Neu J, 2007). Aquest fenomen es clau en determinar la salut de l'individu al llarg de la vida. De fet, aquestes observacions es recullen en la hipòtesi, ja descrita, de l'Origen Primerenc de la Salut i la Malaltia en l'Adult (Developmental Origins of Health and Disease, DOHaD), que proposa el programming o efecte permanent de les condicions primerenques com a influència en el creixement i metabolisme en l'edat adulta (Lucas A, 1991; Gluckman P, 2004; Wang X, 2013). Hem desenvolupat al laboratori un model murí de sobrenutrició neonatal amb creixement postnatal accelerat que desenvolupa moltes de les característiques de la Síndrome metabòlica en l'adult, on els animals desenvolupen hipertriglicèridèmia, hiperinsulinèmia, intolerància a la glucosa i resistència a la insulina (Pentinat T, 2010). L'alteració de la tolerància a la glucosa sembla que es deu a una resistència perifèrica a la insulina, donat que la funció de la cèl·lula beta és normal. Per contra, via de senyalització de la insulina es troba alterada des de les primeres setmanes de vida. Sorprenentment, els canvis induïts durant les primeres setmanes de vida no solament afecten la salut de l'individu adult, sinó també la seva descendència. La progressió transgeneracional del fenotip metabòlic a través del llinatge patern suggereix l'epigenètica com a mecanismes responsables.[eng] Epidemiological and clinical data show that rapid weight gain in early life is strongly associated with several components of the metabolic syndrome and influence risk in subsequent generations. In order to determine which events occurring at early life determined the adverse metabolic consequences in adulthood we have developed a mouse model of postnatal accelerated growth rate by neonatal overnutrition, ON. We forced neonatal overfeeding by culling the offspring to 4 male pups per mouse during lactation. As expected, ON mice exhibited accelerated growth and by age 4 months, developed many features of the metabolic syndrome, including obesity , impaired glucose tolerance and insulin resistance. Impaired glucose tolerance in ON mice appeared to be accounted for primarily by peripheral insulin resistance, because beta-cell function remained normal. In contrast, insulin signaling was impaired since early life. Likewise, ON mice show altered lipid metabolism in early life with impaired lipogenic gene expression and impaired lipogenesis de novo that together leads to TAG accumulation. Interestingly, the observed features occurring in early life not only affects the lifespan of affected individuals, but also subsequent generations. Transgenerational progression of metabolic phenotypes through the paternal lineage suggests the role for epigenetic mechanisms in mediating these effects

The role of nutrition on epigenetic modifications and their implications on health

Nutrition plays a key role in many aspects of health and dietary imbalances are major determinants of chronic diseases including cardiovascular disease, obesity, diabetes and cancer. Adequate nutrition is particularly essential during critical periods in early life (both pre- and postnatal). In this regard, there is extensive epidemiologic and experimental data showing that early sub-optimal nutrition can have health consequences several decades later. The hypothesis that epigenetic mechanisms may link such nutritional imbalances with altered disease risk has been gaining acceptance over recent years. Epigenetics can be defined as the study of heritable changes in gene expression that do not involve alterations in the DNA sequence. Epigenetic marks include DNA methylation, histone modifications and a variety of non-coding RNAs. Strikingly, they are plastic and respond to environmental signals, including diet. Here we will review how dietary factors modulate the establishment and maintenance of epigenetic marks, thereby influencing gene expression and, hence, disease risk and health. (C) 2012 Elsevier Masson SAS. All rights reserved

Fatty acid transport protein 1 (FATP1) delivered into skeletal muscle localizes in mitochondria and regulates lipid and ketone body disposal

FATP1 mediates skeletal muscle cell fatty acid import, yet its intracellular localization and metabolic control role are not completely defined. Here, we examine FATP1 localization and metabolic effects of its overexpression in mouse skeletal muscle. The FATP1 protein was detected in mitochondrial and plasma membrane fractions, obtained by differential centrifugation, of mouse gastrocnemius muscle. FATP1 was most abundant in purified mitochondria, and in the outer membrane and soluble intermembrane, but not in the inner membrane plus matrix, enriched subfractions of purified mitochondria. Immunogold electron microscopy localized FATP1-GFP in mitochondria of transfected C2C12 myotubes. FATP1 was overexpressed in gastrocnemius mouse muscle, by adenovirus-mediated delivery of the gene into hindlimb muscles of newborn mice, fed after weaning a chow or high-fat diet. Compared to GFP delivery, FATP1 did not alter body weight, serum fed glucose, insulin and triglyceride levels, and whole-body glucose tolerance, in either diet. However, fatty acid levels were lower and beta-hydroxybutyrate levels were higher in FATP1-than GFP-mice, irrespective of diet. Moreover, intramuscular triglyceride content was lower in FATP1-versus GFP-mice regardless of diet, and beta-hydroxybutyrate content was unchanged in high-fat-fed mice. Electroporation-mediated FATP1 overexpression enhanced palmitate oxidation to CO2, but not to acid-soluble intermediate metabolites, while CO2 production from beta-hydroxybutyrate was inhibited and that from glucose unchanged, in isolated mouse gastrocnemius strips. In summary, FATP1 was localized in mitochondria, in the outer membrane and intermembrane parts, of mouse skeletal muscle, what may be crucial for its metabolic effects. Overexpressed FATP1 enhanced disposal of both systemic fatty acids and intramuscular triglycerides. Consistently, it did not contribute to the high-fat diet-induced metabolic dysregulation. However, FATP1 lead to hyperketonemia, likely secondary to the sparing of ketone body oxidation by the enhanced oxidation of fatty acids

Fatty acid transport protein 1 (FATP1) delivered into skeletal muscle localizes in mitochondria and regulates lipid and ketone body disposal

FATP1 mediates skeletal muscle cell fatty acid import, yet its intracellular localization and metabolic control role are not completely defined. Here, we examine FATP1 localization and metabolic effects of its overexpression in mouse skeletal muscle. The FATP1 protein was detected in mitochondrial and plasma membrane fractions, obtained by differential centrifugation, of mouse gastrocnemius muscle. FATP1 was most abundant in purified mitochondria, and in the outer membrane and soluble intermembrane, but not in the inner membrane plus matrix, enriched subfractions of purified mitochondria. Immunogold electron microscopy localized FATP1-GFP in mitochondria of transfected C2C12 myotubes. FATP1 was overexpressed in gastrocnemius mouse muscle, by adenovirus-mediated delivery of the gene into hindlimb muscles of newborn mice, fed after weaning a chow or high-fat diet. Compared to GFP delivery, FATP1 did not alter body weight, serum fed glucose, insulin and triglyceride levels, and whole-body glucose tolerance, in either diet. However, fatty acid levels were lower and beta-hydroxybutyrate levels were higher in FATP1-than GFP-mice, irrespective of diet. Moreover, intramuscular triglyceride content was lower in FATP1-versus GFP-mice regardless of diet, and beta-hydroxybutyrate content was unchanged in high-fat-fed mice. Electroporation-mediated FATP1 overexpression enhanced palmitate oxidation to CO2, but not to acid-soluble intermediate metabolites, while CO2 production from beta-hydroxybutyrate was inhibited and that from glucose unchanged, in isolated mouse gastrocnemius strips. In summary, FATP1 was localized in mitochondria, in the outer membrane and intermembrane parts, of mouse skeletal muscle, what may be crucial for its metabolic effects. Overexpressed FATP1 enhanced disposal of both systemic fatty acids and intramuscular triglycerides. Consistently, it did not contribute to the high-fat diet-induced metabolic dysregulation. However, FATP1 lead to hyperketonemia, likely secondary to the sparing of ketone body oxidation by the enhanced oxidation of fatty acids

Body weight, blood metabolites and insulin levels in GFP- and FATP1-mice.

<p>Body weight, blood glucose, serum insulin, triglyceride, fatty acid and β-hydroxybutyrate levels were measured in <i>ad libitum</i> fed either diet GFP- or FATP1-mice at 15- to 16-weeks of age. Data are means ± SEM of at least five samples. The significance of the Student's t test is: ^†p<0.05 females fed a high-fat versus chow diet with the same viral treatment; ^*p<0.01 GFP-females fed a high-fat versus chow diet; ^#p<0.05 GFP-females versus GFP-males fed a chow diet; ^‡p<0.005 FATP1-females versus FATP1-males fed chow; and ^¥p<0.05 FATP1-mice versus GFP-mice irrespective of diet and gender. ND means not determined.</p

Electron microscopic localization of FATP1-GFP in C2C12 myotubes.

<p>C2C12 myoblasts were transfected with (a,b) pFATP1-GFP or (c) pGFP (control), and induced to differentiate into myotubes. Four days post-transfection, myotubes were fixed, gelatin blocks mounted and sections were prepared in an ultracryomicrotome, incubated with anti-GFP antibody and analyzed by electronic microscopy. (a,b) Image of FATP1-GFP localized inside the mitochondria (see arrows); (c) image of GFP localized in the Golgi complex (see continuous arrows) and nuclei (dotted arrow). The observations were made in an electron microscope with a CCD camera and an electron accelerating voltage of 80 Kv was employed for the measurements. Bar represents 200 nm.</p

Fatty acid transport protein 1 (FATP1) delivered into skeletal muscle localizes in mitochondria and regulates lipid and ketone body disposal

FATP1 mediates skeletal muscle cell fatty acid import, yet its intracellular localization and metabolic control role are not completely defined. Here, we examine FATP1 localization and metabolic effects of its overexpression in mouse skeletal muscle. The FATP1 protein was detected in mitochondrial and plasma membrane fractions, obtained by differential centrifugation, of mouse gastrocnemius muscle. FATP1 was most abundant in purified mitochondria, and in the outer membrane and soluble intermembrane, but not in the inner membrane plus matrix, enriched subfractions of purified mitochondria. Immunogold electron microscopy localized FATP1-GFP in mitochondria of transfected C2C12 myotubes. FATP1 was overexpressed in gastrocnemius mouse muscle, by adenovirus-mediated delivery of the gene into hindlimb muscles of newborn mice, fed after weaning a chow or high-fat diet. Compared to GFP delivery, FATP1 did not alter body weight, serum fed glucose, insulin and triglyceride levels, and whole-body glucose tolerance, in either diet. However, fatty acid levels were lower and beta-hydroxybutyrate levels were higher in FATP1-than GFP-mice, irrespective of diet. Moreover, intramuscular triglyceride content was lower in FATP1-versus GFP-mice regardless of diet, and beta-hydroxybutyrate content was unchanged in high-fat-fed mice. Electroporation-mediated FATP1 overexpression enhanced palmitate oxidation to CO2, but not to acid-soluble intermediate metabolites, while CO2 production from beta-hydroxybutyrate was inhibited and that from glucose unchanged, in isolated mouse gastrocnemius strips. In summary, FATP1 was localized in mitochondria, in the outer membrane and intermembrane parts, of mouse skeletal muscle, what may be crucial for its metabolic effects. Overexpressed FATP1 enhanced disposal of both systemic fatty acids and intramuscular triglycerides. Consistently, it did not contribute to the high-fat diet-induced metabolic dysregulation. However, FATP1 lead to hyperketonemia, likely secondary to the sparing of ketone body oxidation by the enhanced oxidation of fatty acids

Triglyceride levels in skm, liver and adipose tissue of GFP- and FATP1-mice.

<p>Triglyceride levels were measured in extracts from the gastrocnemius muscle, liver and white adipose tissue of <i>ad libitum</i> fed GFP- or FATP1-mice. Data are means ± SEM of at least four samples. The significance of the Student's t test is: ^*p<0.05 and ^**p<0.001 female versus male GFP-mice fed chow; ^#p<0.01 female versus male FATP1-mice fed chow; ^†p<0.05 and ^††p<0.001 female GFP-mice fed high-fat versus chow; ^‡p<0.05 and ^‡‡p<0.001 female FATP1-mice fed high-fat versus chow; and ^¥p<0.05 FATP1- versus GFP-mice irrespective of diet and gender.</p