A vegetable fat-based diet delays psychomotor and cognitive development compared with maternal dairy fat intake in infant gray mouse lemurs.

Dairy fat has a unique lipid profile; it is rich in short- and medium-chain saturated fatty acids that induce ketone production and has a balanced ω6/ω3 ratio that promotes cognitive development in early life. Moreover, the high consumption of vegetable oils in pregnant and lactating women raises concerns regarding the quality of lipids provided to offspring. Here, we investigate maternal dairy fat intake during gestation and lactation in a highly valuable primate model for infant nutritional studies, the gray mouse lemur (Microcebus murinus).

Evidence for the Neuronal Expression and Secretion of Adiponectin.

Peripheral adiponectin acts on the hypothalamus to inhibit energy expenditure and increase food intake through its receptors AdipoR1 and adipoR2. The hypothalamic expression of adiponectin is poorly documented. We hypothesize that whether hypothalamic adiponectin is confirmed, its expression and secretion could be regulated as peripheral adiponectin.

Prolonged Consumption of Sweetened Beverages Lastingly Deteriorates Cognitive Functions and Reward Processing in Mice.

We investigated the detrimental effects of chronic consumption of sweet or sweetened beverages in mice. We report that consumption of beverages containing small amounts of sucrose during several weeks impaired reward systems. This is evidenced by robust changes in the activation pattern of prefrontal brain regions associated with abnormal risk-taking and delayed establishment of decision-making strategy.

Ovarian insufficiency impairs glucose-stimulated insulin secretion through activation of hypothalamic de novo ceramide synthesis.

Oestrogens regulate body weight through their action on hypothalamus to modulate food intake and energy expenditure. Hypothalamic de novo ceramide synthesis plays a central role on obesity induced by oestrogen deficiency. Depletion in oestrogens is also known to be associated with glucose intolerance, which favours type 2 diabetes (T2D).

Is resistin the master link between inflammation and inflammation-related chronic diseases?

Resistin has been firstly discovered in mice and was identified as an adipose tissue-secreted hormone or adipokine linking obesity and insulin resistance. In humans, resistin has been characterized as a hormone expressed and secreted by Immune cells especially by macrophages, and was linked to many inflammatory responses including inflammation of adipose tissue due to macrophages' infiltration. Human and mouse resistin display sequence and structural similarities and also dissimilarities that could explain their different expression pattern.

Palmitic acid promotes resistin-induced insulin resistance and inflammation in SH-SY5Y human neuroblastoma.

Saturated fatty acids such as palmitic acid promote inflammation and insulin resistance in peripheral tissues, contrasting with the protective action of polyunsaturated fatty acids such docosahexaenoic acid. Palmitic acid effects have been in part attributed to its potential action through Toll-like receptor 4. Beside, resistin, an adipokine, also promotes inflammation and insulin resistance via TLR4.

Sonic Hedgehog receptor Patched deficiency in astrocytes enhances glucose metabolism in mice.

Objective: Astrocytes are glial cells proposed as the main Sonic hedgehog (Shh)-responsive cells in the adult brain. Their roles in mediating Shh functions are still poorly understood. In the hypothalamus, astrocytes support neuronal circuits implicated in the regulation of energy metabolism.

Molecular Mechanisms Underlying Obesity-Induced Hypothalamic Inflammation and Insulin Resistance: Pivotal Role of Resistin/TLR4 Pathways.

Low-grade inflammation and insulin resistance are among the clinical features of obesity that are thought to promote the progressive onset of type 2 diabetes. However, the underlying mechanisms linking these disorders remain not fully understood. Recent reports pointed out hypothalamic inflammation as a major step in the onset of obesity-induced insulin resistance.

Maternal resistin predisposes offspring to hypothalamic inflammation and body weight gain.

Resistin promotes hypothalamic neuroinflammation and insulin resistance through Toll like receptor 4 (TLR4), this hormone is thought to be a link between obesity and insulin-resistance. Indeed, resistin plasma levels are higher in obese and insulin resistant subjects. However, the impact of maternal resistin on the predisposition of offspring to hypothalamic neuroinflammation is unknown.

Resistin inhibits neuronal autophagy through Toll-like receptor 4.

Autophagy is a non-selective degradation pathway induced in energy-deprived cells and in non-starved cells by participating in cellular inflammatory responses mainly through the elimination of injured and aged mitochondria that constitute an important source of reactive oxygen species. We have previously reported that resistin/TLR4 signaling pathway induces inflammation and insulin resistance in neuronal cell. However, the impact of resistin-induced inflammation on neuronal autophagy is unknown.

miRNA Long-Term Response to Early Metabolic Environmental Challenge in Hypothalamic Arcuate Nucleus.

Epidemiological reports and studies using rodent models indicate that early exposure to nutrient and/or hormonal challenges can reprogram metabolism at adulthood. Hypothalamic arcuate nucleus (ARC) integrates peripheral and central signals to adequately regulate energy homeostasis. microRNAs (miRNAs) participate in the control of gene expression of large regulatory networks including many signaling pathways involved in epigenetics regulations.

Formula derived Maillard reaction products in post-weaning intrauterine growth-restricted piglets induce developmental programming of hepatic oxidative stress independently of microRNA-21 and microRNA-155.

We recently reported augmentation of lipid peroxidation products in the liver of intrauterine growth-restricted (IUGR) piglets fed a high load of Maillard reaction products (MRPs) during suckling period. The underlying mechanisms of MRPs effects remain unknown. Here, we studied the long-term impact of MRPs exposure on liver oxidative status of IUGR juvenile pigs.

MicroRNAs in the hypothalamus.

The brain is considered a major site for microRNA (miRNA) expression; as evidenced by several studies reporting microarray data of different brain substructures. The hypothalamus is among the brain regions that plays a crucial role in integrating signals from other brain nuclei as well as environmental, hormonal, metabolic and neuronal signals from the periphery in order to deliver an adequate response. The hypothalamus controls vital functions such as reproduction, energy homeostasis, water balance, circadian rhythm and stress.

Central Resistin/TLR4 Impairs Adiponectin Signaling, Contributing to Insulin and FGF21 Resistance.

Adiponectin, an insulin-sensitizing hormone, and resistin, known to promote insulin resistance, constitute a potential link between obesity and type 2 diabetes. In addition, fibroblast growth factor (FGF)21 has effects similar to those of adiponectin in regulating glucose and lipid metabolism and insulin sensitivity. However, the interplay between adiponectin, FGF21, and resistin signaling pathways during the onset of insulin resistance is unknown.

Odontella aurita-enriched diet prevents high fat diet-induced liver insulin resistance.

The beneficial effect of polyunsaturated omega-3 fatty acid (w-3 FA) consumption regarding cardiovascular diseases, insulin resistance and inflammation has been widely reported. Fish oil is considered as the main source of commercialized w-3 FAs, and other alternative sources have been reported such as linseed or microalgae. However, despite numerous reports, the underlying mechanisms of action of w-3 FAs on insulin resistance are still not clearly established, especially those from microalgae.

Milk-soluble formula increases food intake and reduces Il6 expression in elderly rat hypothalami.

Malnutrition in the elderly is accompanied by several metabolic dysfunctions, especially alterations in energy homeostasis regulation and a loss of insulin responsiveness. Nutritional recommendations aim to enrich food with high protein and energy supplements, and protein composition and lipid quality have been widely studied. Despite the numerous studies that have examined attempts to overcome malnutrition in the elderly through such nutritional supplementation, it is still necessary to study the effects of a combination of protein, lipids, and vitamin D (VitD).

Hippocampal GSK3β as a Molecular Link Between Obesity and Depression.

Obesity is considered as a risk factor for mood disorders including depression. Nevertheless, the mechanisms underlying this association are not clearly understood. To address this issue, we investigated the impact of high-fat (HF)-diet-induced obesity on depressive-like behavior and on serotonin (5-HT)-dependent Akt/glycogen synthase kinase 3β (GSK3β) signaling in the dentate gyrus (DG) of the hippocampus, which has been associated with mood regulation.

Negative regulation of MAP kinase signaling in Drosophila by Ptp61F/PTP1B.

PTP1B is an important negative regulator of insulin and other signaling pathways in mammals. However, the role of PTP1B in the regulation of RAS-MAPK signaling remains open to deliberation, due to conflicting evidence from different experimental systems. The Drosophila orthologue of mammalian PTP1B, PTP61F, has until recently remained largely uncharacterized.

The over-expression of miR-200a in the hypothalamus of ob/ob mice is linked to leptin and insulin signaling impairment.

Early in life, leptin plays a crucial role in hypothalamic neural organization. Leptin, most likely, controls neural gene expression conferring then specific phenotype regarding energy homeostasis. MicroRNAs are new regulators for several physiological functions, including the regulation of metabolism.

Keys for microRNA expression profiling of single rat hypothalamic nuclei and multiplex sequencing strategies.

Integrative research has taken on the challenge of addressing questions in physiology by using novel knowledge and novel techniques. Recently, small and long non-coding RNAs have emerged as key regulators of gene expression, while next-generation sequencing technologies have revolutionized the characterization of genomes and gene expression. For a decade, it has been known that microRNAs (miRNAs) are RNAs of 18-24 bases that regulate gene expression in mammals.

Cerebral cortex and hippocampus respond differently after post-natal exposure to uranium.

The central nervous system (CNS) is known to be sensitive to pollutants during its development. Uranium (U) is a heavy metal that occurs naturally in the environment as a component of the earth's crust, and populations may therefore be chronically exposed to U through drinking water and food. Previous studies have shown that the CNS is a target of U in rats exposed in adulthood.