High-fat diet consumption during pregnancy and lactation modulates the hypothalamic Notch signaling and the population of POMC cells in mice offspring

Orientador: Marcio Alberto TorsoniTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Estudos mostram que o consumo materno de dieta hiperlipídica (HFD) é capaz de prejudicar a formação de circuitos neuronais hipotalâmicos em proles de camundongos, contribuindo para um fenótipo hiperfágico que pode estar relacionado com obesidade na vida adulta. Este distúrbio parece ser mediado pela ativação da via de sinalização Notch1 levando à repressão de fatores proneurais como Mash1 e Ngn2/3 que são importantes na neurogênese hipotalâmica e diferenciação neuronal. O objetivo do estudo foi avaliar os efeitos do consumo materno de dieta hiperlipídica durante a gestação e lactação sobre a via Notch1 no hipotálamo e no núcleo arqueado hipotalâmico (ARC) da prole de camundongos. Para isso utilizou-se proles de camundongos Swiss (machos) de mães alimentadas com HFD e com ração comercial durante a gestação e lactação. Foram avaliados neonatos (P0), proles com 28 dias de vida (P28) e proles adultas (P82). Determinou-se peso corporal e adiposidade das proles. Investigou-se os níveis de mRNA dos genes que codificam proteínas Notch1, Hes5 e Mash1, citocinas pró-inflamatórias Il-1b e TNF-a e neuropeptídios AgRP e POMC. Fez-se análise do conteúdo das proteínas da via Notch1 e das proteínas inflamatórias JNK e NF-kB. Avaliou-se a proliferação celular por marcação com BrDU e a presença de Mash1 e neurônios recém-formados, por imunohistoquímica. Além de avaliar a população de neurônios POMC e NPY no ARC da prole de camundongos, por imunofluorescência. Observou-se maior peso corporal e adiposidade nas proles de mães alimentadas com HFD. Notou-se também aumento nos níveis hipotalâmicos de mRNA de Il-1?. Acompanhado de aumento nos níveis de mRNA de Hes5 e redução nos níveis de mRNA de Ascl1 (Mash1) no hipotálamo e ARC das proles de mães HFD. Além disso, os dados demonstraram maior número de células marcadas com BrDU seguido de aumento na população de neurônios NPY ao passo que a população de neurônios POMC apresentou-se diminuída no ARC das proles de mães HFD. Os resultados apontam alterações na neurogênese hipotalâmica e diferenciação neuronal, levando a uma redução de neurônios POMC que parece ser mediada pela supressão de Mash1, acompanhada de aumento compensatório de neurônios NPY. Estas alterações contribuem para hiperfagia e aumento do peso corporal, podendo compor um dos mecanismos responsáveis pela obesidade na vida adultaAbstract: Studies show that maternal high-fat diet (HFD) consumption can be able to impair the formation of hypothalamic neuronal networks in mice offspring contributing to a phenotype of hyperphagia that can be related to obesity in adulthood. This disturbance seems to be mediated by Notch1 signaling pathway activation leading to the repression of proneural factors as Mash1 and Ngn2/3 which are important in hypothalamic neurogenesis and neuronal differentiation. The aim of the study was to evaluate the maternal HFD consumption effects during gestation and lactation on the Notch1 signaling in the hypothalamus and hypothalamic arcuate nucleus (ARC) of mice offspring. To do this, we used mice offspring Swiss (males) from dams fed with HFD and standard chow (SC) during pregnancy and lactation. It was evaluated neonates (P0), young and adult offspring (P28 and P82, respectively). We determined body weight and adiposity of mice offspring, the mRNA levels of genes that code Notch1, Hes5 and Mash1 proteins; pro-inflammatory cytokines as Il-1b and TNF-a, and neuropeptides as AgRP and POMC. We evaluated the content of Notch1 pathway proteins and inflammatory proteins as JNK and NF-kB. To measure the cell proliferation, we used BrDU labeling. We analyzed presence of Mash1 and newborn neurons by immunohistochemistry. Besides, we measured the population of POMC and NPY neurons in the ARC of mice offspring by immunofluorescence. We observed an increased body weight and adiposity in mice offspring from dams fed with HFD. We noticed an increase in the mRNA levels of Il-1? accompanied by higher mRNA levels of Hes5 and lower mRNA levels of Ascl1 (Mash1) in the hypothalamus and ARC of mice offspring from HFD dams. In addition, data showed higher number of BrDU-labeled cells followed by increase in the NPY neurons population and reduction in the POMC neurons population in the ARC of these mice offspring. The results indicate alterations in the hypothalamic neurogenesis and neuronal differentiation leading to a reduction of POMC neurons that seems to be mediated by Mash1 suppression accompanied by compensatory increase of NPY neurons. These alterations contribute to hyperphagia and increase of body weight that could be one of the responsible mechanisms for obesity in adulthoodDoutoradoFisiologiaDoutora em Biologia Funcional e Molecular94328641115CAPE

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2013/05691-1Maternal high-fat diet (HFD) impairs hippocampal development of offspring promoting decreased proliferation of neural progenitors, in neuronal differentiation, in dendritic spine density and synaptic plasticity reducing neurogenic capacity. Notch signaling pathway participates in molecular mechanisms of the neurogenesis. The activation of Notch signaling leads to the upregulation of Hes5, which inhibits the proliferation and differentiation of neural progenitors. This study aimed to investigate the Notch/Hes pathway activation in the hippocampus of the offspring of dams fed an HFD. Female Swiss mice were fed a control diet (CD) and an HFD from pre-mating until suckling. The bodyweight and mass of adipose tissue in the mothers and pups were also measured. The mRNA and protein expression of Notch1, Hes5, Mash1, and Delta1 in the hippocampus was assessed by RT-PCR and western blotting, respectively. Dams fed the HFD and their pups had an increased bodyweight and amount of adipose tissue. Furthermore, the offspring of mothers fed the HFD exhibited an increased Hes5 expression in the hippocampus compared with CD offspring. In addition, HFD offspring also expressed increased amounts of Notch1 and Hes5 mRNA, whereas Mash1 expression was decreased. However, the expression of Delta1 did not change significantly. We propose that the overexpression of Hes5, a Notch effector, downregulates the expression of the proneural gene Mash1 in the offspring of obese mothers, delaying cellular differentiation. These results provide further evidence that an offspring's hippocampus is molecularly susceptible to maternal HFD and suggest that Notch1 signaling in this brain region is important for neuronal differentiation.Maternal high-fat diet (HFD) impairs hippocampal development of offspring promoting decreased prolif-neuralprogenitors,inneuronaldifferentiation,indendriticspinedensityandsynapticplasticityreducing neurogenic capacity. Notch signaling pathway participates403542FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2013/05691-12013/05691-

Short-Term High-Fat Diet Consumption Reduces Hypothalamic Expression of the Nicotinic Acetylcholine Receptor α7 Subunit (α7nAChR) and Affects the Anti-inflammatory Response in a Mouse Model of Sepsis

Sepsis is one of the leading causes of death in hospitalized patients and the chronic and low-grade inflammation observed in obesity seems to worsen susceptibility and morbidity of infections. However, little is known with respect to a short-term high-fat diet (HFD) and its role in the development of sepsis. Here, we show for the first time, that short-term HFD consumption impairs early nicotinic acetylcholine receptor α7 subunit (α7nAChR)- mediated signaling, one of the major components of the cholinergic anti-inflammatory pathway, with a focus on hypothalamic inflammation and innate immune response. Mice were randomized to a HFD or standard chow (SC) for 3 days, and sepsis was subsequently induced by a lethal intraperitoneal (i.p.) injection of lipopolysaccharide (LPS) or by cecal ligation and puncture (CLP) surgery. In a separate experiment, both groups received LPS (i.p.) or LPS (i.p.) in conjunction with the selective α7nAChR agonist, PNU-282987 (i.p. or intracerebroventricular; i.c.v.), and were sacrificed 2 h after the challenge. Short-term HFD consumption significantly reduced the α7nAChR mRNA and protein levels in the hypothalamus and liver (p < 0.05). Immunofluorescence microscopy demonstrated lower cholinergic receptor nicotinic α7 subunit (α7nAChR)+ cells in the arcuate nucleus (ARC) (α7nAChR+ cells in SC = 216 and HFD = 84) and increased F4/80+ cells in the ARC (2.6-fold) and median eminence (ME) (1.6-fold), which can contribute to neuronal damage. Glial fibrillary acidic protein (GFAP)+ cells and neuronal nuclear antigen (NeuN)+ cells were also increased following consumption of HFD. The HFD-fed mice died quickly after a lethal dose of LPS or following CLP surgery (2-fold compared with SC). The LPS challenge raised most cytokine levels in both groups; however, higher levels of TNF-α (Spleen and liver), IL-1β and IL-6 (in all tissues evaluated) were observed in HFD-fed mice. Moreover, PNU-282987 administration (i.p. or i.c.v.) reduced the levels of inflammatory markers in the hypothalamus following LPS injection. Nevertheless, when the i.c.v. injection of PNU-282987 was performed the anti-inflammatory effect was much smaller in HFD-fed mice than SC-fed mice. Here, we provide evidence that a short-term HFD impairs early α7nAChR expression in central and peripheral tissues, contributing to a higher probability of death in sepsis

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Short-term high-fat diet consumption reduces hypothalamic expression of the nicotinic acetylcholine receptor alpha 7 subunit (alpha 7nAChR) and affects the anti-inflammatory response in a mouse model of sepsis

Sepsis is one of the leading causes of death in hospitalized patients and the chronic and low-grade inflammation observed in obesity seems to worsen susceptibility and morbidity of infections. However, little is known with respect to a short-term high-fat diet (HFD) and its role in the development of sepsis. Here, we show for the first time, that short-term HFD consumption impairs early nicotinic acetylcholine receptor alpha 7 subunit (alpha 7nAChR)-mediated signaling, one of the major components of the cholinergic anti-inflammatory pathway, with a focus on hypothalamic inflammation and innate immune response. Mice were randomized to a HFD or standard chow (SC) for 3 days, and sepsis was subsequently induced by a lethal intraperitoneal (i.p.) injection of lipopolysaccharide (LPS) or by cecal ligation and puncture (CLP) surgery. In a separate experiment, both groups received LPS (i.p.) or LPS (i.p.) in conjunction with the selective a alpha nAChR agonist, PNU-282987 (i.p. or intracerebroventricular; i.c.v.), and were sacrificed 2 h after the challenge. Short-term HFD consumption significantly reduced the alpha 7nAChR mRNA and protein levels in the hypothalamus and liver (p < 0.05). Immunofluorescence microscopy demonstrated lower cholinergic receptor nicotinic alpha 7 subunit (alpha 7nAChR)+ cells in the arcuate nucleus (ARC) (alpha 7nAChR+ cells in SC = 216 and HFD = 84) and increased F4/80+ cells in the ARC (2.6-fold) and median eminence (ME) (1.6-fold), which can contribute to neuronal damage. Glial fibrillary acidic protein (GFAP)+ cells and neuronal nuclear antigen (NeuN)+ cells were also increased following consumption of HFD. The HFD-fed mice died quickly after a lethal dose of LPS or following CLP surgery (2-fold compared with SC). The LPS challenge raised most cytokine levels in both groups; however, higher levels of TNF-alpha (Spleen and liver), IL-1 beta and IL-6 (in all tissues evaluated) were observed in HFD-fed mice. Moreover, PNU-282987 administration (i.p. or i.c.v.) reduced the levels of inflammatory markers in the hypothalamus following LPS injection. Nevertheless, when the i.c.v. injection of PNU-282987 was performed the anti-inflammatory effect was much smaller in HFD-fed mice than SC-fed mice. Here, we provide evidence that a short-term HFD impairs early alpha 7nAChR expression in central and peripheral tissues, contributing to a higher probability of death in sepsis10CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informação16/23484-1; 13/07607-

High-fat diet during pregnancy and lactation impairs the cholinergic anti-inflammatory pathway in the liver and white adipose tissue of mouse offspring

14/18165-9; 13/10706-8476643/2012-0Cholinergic anti-inflammatory pathway (CAP) prevents inflammatory cytokines production. The main was to evaluate the effect of maternal obesity on cholinergic pathway in the offspring. Female mice were subjected to either standard chow (SC) or high-fat diet (HFD) during pregnancy and the lactation period. After weaning, only male offspring from HFD dams (HFD-O) and from SC dams (SC-O) were fed the SC diet. Key proteins of the CAP were downregulated and serum TNF-α was elevated in the HFD-O mice. STAT3 and NF-κB activation in HFD-O mice ICV injected with nicotine (agonist) were lower than SC-O mice. Basal cholinesterase activity was upregulated in HFD-O mice in both investigated tissues. Lipopolysaccharide increased TNF-α and IL-1β expression in the liver and WAT of SC-O mice, but this effect was greater in HFD-O mice. In conclusion these changes exacerbated cytokine production in response to LPS and contributed to the reduced sensitivity of the CAP.Cholinergic anti-inflammatory pathway (CAP) prevents inflammatory cytokines production. The main was to evaluate the effect of maternal obesity on cholinergic pathway in the offspring. Female mice were subjected to either standard chow (SC) or high-fat di422192202FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTIFICO E TECNOLOGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTIFICO E TECNOLOGICO14/18165-9; 13/10706-8476643/2012-014/18165-9; 13/10706-8476643/2012-0Les cages généralement utilisées en expérimentation animale peuvent empêcher les rats d'adopter la plupart des formes naturelles de comportement locomoteur. Ces animaux ont tendance a` adopter des habitudes sédentaires. Dans cette étude, nous démontrons