Effect of hypercaloric and isocaloric diets different in fatty acid content on the endo cannabinoid system in pregnant dams and their offspring.

Lipid molecules are the building blocks of all cell membranes and provide essential secondary metabolites. The central nervous system is enriched in polyunsaturated fatty acids (PUFAs): arachidonic acid (AA) and docosahexaenoic acid (DHA). During brain development, PUFAs play a critical role in determining neuronal structure, particularly axonal outgrowth. In mammals, AA and DHA cannot be synthesized de novo and must be obtained largely from dietary sources. Moreover, during pregnancy and lactation, fetuses and infants rely on PUFAs from their mothers through the placenta and breast milk, respectively. Thus, the maternal diet needs to contain an appropriate omega-3/omega-6 PUFAs ratio to help child development. Based on these premises, we investigated the consequences of maternal malnutrition, defined as a shifted dietary ratio of omega-3 or omega-6 PUFAs on the brain of the offspring. In particular, we modeled human relevance by manipulating both the content and time of daily diets, with a keen focus on endocannabinoid (eCB) system given the critical roles of this AA-derived neuromodulator system during pre- and postnatal brain development. In the first approach of this project we fed female mice with hypercaloric diets, rich in omega-3 or in omega-6 PUFA, for two (short-term diet) or nine weeks (long-term diet) before mating and during gestation. We found that, levels of endocannabinoids (AEA, 2-AG) and AEA-like mediators (PEA, OEA) did not change with short-term diet in pregnant dams. Moreover, only omega-3 diet induced a significant increase of 2-AG levels, after long-term protocol. In embryos, we found that the short-term exposure of two weeks of omega-3 and omega-6 diet feeding is already sufficient to allow alteration of endocannabinoid system, especially FAAH and CB1R. In fact, in female embryos, we found down-regulation of CB1R and increase of FAAH after treatment with both diets. Interestingly, both enzyme and receptor levels are normalized after high-fat diet administration for a long period, where AEA levels were found decreased. By contrast, in males the alterations found in CB1R after the shorter protocol persist also after the prolongation of the treatment. In line with this, these data suggest a relationship among AEA, CB1R and FAAH, and an important link between PUFAs and endocannabinoid system. The second approach of this project was based on the administration of isocaloric diets, different in omega-3 levels but not in omega-6 PUFAs throughout gestation and until adulthood. We discovered that during gestation, not only the increase but also the decrease of omega-3 levels markedly affected the eCB system in the hippocampus of embryos. Furthermore, our in vivo results strongly suggest that omega-3 diets enriched and deficient affect the principal presynaptic marker in embryonic hippocampus but not in adult, where maternal malnutrition leads to long-term behavioral alterations in adult rats characterized by the presence of recognition memory deficits. As a whole, the second approach of this study supports our hypothesis about a relationship between PUFAs and the endocannabinoid system and provides further evidence on the importance of omega-3 PUFA on hippocampal development and functioning. All together, our results suggest that changes in dietary omega-3/omega-6 PUFAs ratio during gestation affect the endocannabinoid system in the brain of the offspring and the major effects of diets are present at the beginning of the treatment (i.e during gestation). Moreover, these data suggest that not only lipids but also fat can have a role in these changes

Effect of hypercaloric and isocaloric diets different in fatty acid content on the endo cannabinoid system in pregnant dams and their offspring.

Lipid molecules are the building blocks of all cell membranes and provide essential secondary metabolites. The central nervous system is enriched in polyunsaturated fatty acids (PUFAs): arachidonic acid (AA) and docosahexaenoic acid (DHA). During brain development, PUFAs play a critical role in determining neuronal structure, particularly axonal outgrowth. In mammals, AA and DHA cannot be synthesized de novo and must be obtained largely from dietary sources. Moreover, during pregnancy and lactation, fetuses and infants rely on PUFAs from their mothers through the placenta and breast milk, respectively. Thus, the maternal diet needs to contain an appropriate omega-3/omega-6 PUFAs ratio to help child development. Based on these premises, we investigated the consequences of maternal malnutrition, defined as a shifted dietary ratio of omega-3 or omega-6 PUFAs on the brain of the offspring. In particular, we modeled human relevance by manipulating both the content and time of daily diets, with a keen focus on endocannabinoid (eCB) system given the critical roles of this AA-derived neuromodulator system during pre- and postnatal brain development. In the first approach of this project we fed female mice with hypercaloric diets, rich in omega-3 or in omega-6 PUFA, for two (short-term diet) or nine weeks (long-term diet) before mating and during gestation. We found that, levels of endocannabinoids (AEA, 2-AG) and AEA-like mediators (PEA, OEA) did not change with short-term diet in pregnant dams. Moreover, only omega-3 diet induced a significant increase of 2-AG levels, after long-term protocol. In embryos, we found that the short-term exposure of two weeks of omega-3 and omega-6 diet feeding is already sufficient to allow alteration of endocannabinoid system, especially FAAH and CB1R. In fact, in female embryos, we found down-regulation of CB1R and increase of FAAH after treatment with both diets. Interestingly, both enzyme and receptor levels are normalized after high-fat diet administration for a long period, where AEA levels were found decreased. By contrast, in males the alterations found in CB1R after the shorter protocol persist also after the prolongation of the treatment. In line with this, these data suggest a relationship among AEA, CB1R and FAAH, and an important link between PUFAs and endocannabinoid system. The second approach of this project was based on the administration of isocaloric diets, different in omega-3 levels but not in omega-6 PUFAs throughout gestation and until adulthood. We discovered that during gestation, not only the increase but also the decrease of omega-3 levels markedly affected the eCB system in the hippocampus of embryos. Furthermore, our in vivo results strongly suggest that omega-3 diets enriched and deficient affect the principal presynaptic marker in embryonic hippocampus but not in adult, where maternal malnutrition leads to long-term behavioral alterations in adult rats characterized by the presence of recognition memory deficits. As a whole, the second approach of this study supports our hypothesis about a relationship between PUFAs and the endocannabinoid system and provides further evidence on the importance of omega-3 PUFA on hippocampal development and functioning. All together, our results suggest that changes in dietary omega-3/omega-6 PUFAs ratio during gestation affect the endocannabinoid system in the brain of the offspring and the major effects of diets are present at the beginning of the treatment (i.e during gestation). Moreover, these data suggest that not only lipids but also fat can have a role in these changes

Effect of hypercaloric and isocaloric diets different in fatty acid content on the endo cannabinoid system in pregnant dams and their offspring.

Lipid molecules are the building blocks of all cell membranes and provide essential secondary metabolites. The central nervous system is enriched in polyunsaturated fatty acids (PUFAs): arachidonic acid (AA) and docosahexaenoic acid (DHA). During brain development, PUFAs play a critical role in determining neuronal structure, particularly axonal outgrowth. In mammals, AA and DHA cannot be synthesized de novo and must be obtained largely from dietary sources. Moreover, during pregnancy and lactation, fetuses and infants rely on PUFAs from their mothers through the placenta and breast milk, respectively. Thus, the maternal diet needs to contain an appropriate omega-3/omega-6 PUFAs ratio to help child development. Based on these premises, we investigated the consequences of maternal malnutrition, defined as a shifted dietary ratio of omega-3 or omega-6 PUFAs on the brain of the offspring. In particular, we modeled human relevance by manipulating both the content and time of daily diets, with a keen focus on endocannabinoid (eCB) system given the critical roles of this AA-derived neuromodulator system during pre- and postnatal brain development. In the first approach of this project we fed female mice with hypercaloric diets, rich in omega-3 or in omega-6 PUFA, for two (short-term diet) or nine weeks (long-term diet) before mating and during gestation. We found that, levels of endocannabinoids (AEA, 2-AG) and AEA-like mediators (PEA, OEA) did not change with short-term diet in pregnant dams. Moreover, only omega-3 diet induced a significant increase of 2-AG levels, after long-term protocol. In embryos, we found that the short-term exposure of two weeks of omega-3 and omega-6 diet feeding is already sufficient to allow alteration of endocannabinoid system, especially FAAH and CB1R. In fact, in female embryos, we found down-regulation of CB1R and increase of FAAH after treatment with both diets. Interestingly, both enzyme and receptor levels are normalized after high-fat diet administration for a long period, where AEA levels were found decreased. By contrast, in males the alterations found in CB1R after the shorter protocol persist also after the prolongation of the treatment. In line with this, these data suggest a relationship among AEA, CB1R and FAAH, and an important link between PUFAs and endocannabinoid system. The second approach of this project was based on the administration of isocaloric diets, different in omega-3 levels but not in omega-6 PUFAs throughout gestation and until adulthood. We discovered that during gestation, not only the increase but also the decrease of omega-3 levels markedly affected the eCB system in the hippocampus of embryos. Furthermore, our in vivo results strongly suggest that omega-3 diets enriched and deficient affect the principal presynaptic marker in embryonic hippocampus but not in adult, where maternal malnutrition leads to long-term behavioral alterations in adult rats characterized by the presence of recognition memory deficits. As a whole, the second approach of this study supports our hypothesis about a relationship between PUFAs and the endocannabinoid system and provides further evidence on the importance of omega-3 PUFA on hippocampal development and functioning. All together, our results suggest that changes in dietary omega-3/omega-6 PUFAs ratio during gestation affect the endocannabinoid system in the brain of the offspring and the major effects of diets are present at the beginning of the treatment (i.e during gestation). Moreover, these data suggest that not only lipids but also fat can have a role in these changes

Life-long epigenetic programming of cortical architecture by maternal ‘Western’ diet during pregnancy

Funding: European Research Council (SECRET-CELLS, ERC-2015-AdG-695136; T.H.); Wellcome Trust grant number 094476/Z/10/Z, which funded the purchase of the TripleTOF 5600 mass spectrometer at the BSRC Mass Spectrometry and Proteomics Facility, University of St. Andrews.The evolution of human diets led to preferences toward polyunsaturated fatty acid (PUFA) content with ‘Western’ diets enriched in ω-6 PUFAs. Mounting evidence points to ω-6 PUFA excess limiting metabolic and cognitive processes that define longevity in humans. When chosen during pregnancy, ω-6 PUFA-enriched ‘Western’ diets can reprogram maternal bodily metabolism with maternal nutrient supply precipitating the body-wide imprinting of molecular and cellular adaptations at the level of long-range intercellular signaling networks in the unborn fetus. Even though unfavorable neurological outcomes are amongst the most common complications of intrauterine ω-6 PUFA excess, cellular underpinnings of life-long modifications to brain architecture remain unknown. Here, we show that nutritional ω-6 PUFA-derived endocannabinoids desensitize CB1 cannabinoid receptors, thus inducing epigenetic repression of transcriptional regulatory networks controlling neuronal differentiation. We found that cortical neurons lose their positional identity and axonal selectivity when mouse fetuses are exposed to excess ω-6 PUFAs in utero. Conversion of ω-6 PUFAs into endocannabinoids disrupted the temporal precision of signaling at neuronal CB1 cannabinoid receptors, chiefly deregulating Stat3-dependent transcriptional cascades otherwise required to execute neuronal differentiation programs. Global proteomics identified the immunoglobulin family of cell adhesion molecules (IgCAMs) as direct substrates, with DNA methylation and chromatin accessibility profiling uncovering epigenetic reprogramming at >1400 sites in neurons after prolonged cannabinoid exposure. We found anxiety and depression-like behavioral traits to manifest in adult offspring, which is consistent with genetic models of reduced IgCAM expression, to suggest causality for cortical wiring defects. Overall, our data uncover a regulatory mechanism whose disruption by maternal food choices could limit an offspring’s brain function for life.PostprintPeer reviewe

Life-long impairment of glucose homeostasis upon prenatal exposure to psychostimulants

Maternal drug abuse during pregnancy is a rapidly escalating societal problem. Psychostimulants, including amphetamine, cocaine, and methamphetamine, are amongst the illicit drugs most commonly consumed by pregnant women. Neuropharmacology concepts posit that psychostimulants affect monoamine signaling in the nervous system by their affinities to neurotransmitter reuptake and vesicular transporters to heighten neurotransmitter availability extracellularly. Exacerbated dopamine signaling is particularly considered as a key determinant of psychostimulant action. Much less is known about possible adverse effects of these drugs on peripheral organs, and if in utero exposure induces lifelong pathologies. Here, we addressed this question by combining human RNA-seq data with cellular and mouse models of neuroendocrine development. We show that episodic maternal exposure to psychostimulants during pregnancy coincident with the intrauterine specification of pancreatic beta cells permanently impairs their ability of insulin production, leading to glucose intolerance in adult female but not male offspring. We link psychostimulant action specifically to serotonin signaling and implicate the sex-specific epigenetic reprogramming of serotonin-related gene regulatory networks upstream from the transcription factor Pet1/Fev as determinants of reduced insulin production.Peer reviewe

Life-long epigenetic programming of cortical architecture by maternal 'Western' diet during pregnancy

The evolution of human diets led to preferences toward polyunsaturated fatty acid (PUFA) content with 'Western' diets enriched in ω-6 PUFAs. Mounting evidence points to ω-6 PUFA excess limiting metabolic and cognitive processes that define longevity in humans. When chosen during pregnancy, ω-6 PUFA-enriched 'Western' diets can reprogram maternal bodily metabolism with maternal nutrient supply precipitating the body-wide imprinting of molecular and cellular adaptations at the level of long-range intercellular signaling networks in the unborn fetus. Even though unfavorable neurological outcomes are amongst the most common complications of intrauterine ω-6 PUFA excess, cellular underpinnings of life-long modifications to brain architecture remain unknown. Here, we show that nutritional ω-6 PUFA-derived endocannabinoids desensitize CB1 cannabinoid receptors, thus inducing epigenetic repression of transcriptional regulatory networks controlling neuronal differentiation. We found that cortical neurons lose their positional identity and axonal selectivity when mouse fetuses are exposed to excess ω-6 PUFAs in utero. Conversion of ω-6 PUFAs into endocannabinoids disrupted the temporal precision of signaling at neuronal CB1 cannabinoid receptors, chiefly deregulating Stat3-dependent transcriptional cascades otherwise required to execute neuronal differentiation programs. Global proteomics identified the immunoglobulin family of cell adhesion molecules (IgCAMs) as direct substrates, with DNA methylation and chromatin accessibility profiling uncovering epigenetic reprogramming at >1400 sites in neurons after prolonged cannabinoid exposure. We found anxiety and depression-like behavioral traits to manifest in adult offspring, which is consistent with genetic models of reduced IgCAM expression, to suggest causality for cortical wiring defects. Overall, our data uncover a regulatory mechanism whose disruption by maternal food choices could limit an offspring's brain function for life