Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020505 (hyperphagia)
 6,116 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A restricted schedule of food access promotes numerous metabolic and physiological adaptations to optimize the biochemical handling of nutrients. The restricted feeding activates responses in hypothalamic and midbrain areas, as well as in peripheral organs involved in energy metabolism. A restricted feeding schedule (RFS) is associated with marked behavioral arousal coincident with the food anticipatory activity (FAA) and extreme hyperphagia during food access. Food restriction is also accompanied by changes in an array of stress-related parameters, such as increase in corticosterone, slower rate in body weight gain, and reduction in retroperitoneal and epididymal adipose tissue. During RFS, the liver shows a diversity of biochemical and physiologically adaptations that are advantageous for food ingestion and processing, as well as for adequate nutrient distribution to other tissues. Taking into account the probable relationship between stressful conditions and the metabolic adaptations in the liver, we addressed whether an acute-phase response (APR), or a pro-inflammatory state, occurred after three weeks of 2 h food restriction. First, we compared the circulating levels of inflammation markers (interleukin-1alpha, interleukin-6, tumor necrosis factor-alpha), and APR proteins (C-reactive protein and fibrinogen) in rats under food restriction to those in rats treated with lipopolysacharide, a strong inducer of the APR. Second, the influence of RFS on the daily rhythms of systemic cytokines and APR proteins was characterized. Third, we tested if the feeding condition (22 h fasting and 2 h refeeding) influences these parameters. Finally, we assessed if a local stressed state was established in the liver associated with the restricted feeding by measuring the activation of the transcriptional factor NF-kappaB (nuclear factor kappa-light-chain-enhancer of activated B cells). The results showed that the following occurred during RFS: no APR was implemented; food restriction modified the rhythmic 24 h fluctuations of IL-1alpha, IL-6, TNF-alpha, and fibrinogen; simple fasting-refeeding modulated the level of IL-1alpha, IL-6, and fibrinogen, but this effect was not observed before and after food access in rats with restricted food; and food restriction produced a significant peak in NF-kappaB signal in the liver (including its translocation into the nuclei of hepatocytes) that was dependent on feeding condition, as it was coincident with the time after food access. In conclusion, the stress condition associated with RFS is not sufficient to induce an APR, but it could be related to a local stress-response within the liver.
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PMID:Restricted feeding entrains rhythms of inflammation-related factors without promoting an acute-phase response. 1991 39

Prolactin and placental lactogens control mammary development and lactation as well as play an important role in maternal behaviors. However, the molecular mechanisms in the brain responsible for this regulation remain largely unknown. Therefore, the present study investigated whether Signal Transducer and Activator of Transcription 5 (STAT5) signaling in the brain, the key transcriptional factor recruited by prolactin receptor and other hormones, is required for postpartum maternal behavior, maintenance of lactation and offspring growth. Neuronal ablation of STAT5 impaired the control of prolactin secretion and reduced the hypothalamic expression of suppressors of cytokine signaling (i.e., SOCS3 and CISH). In addition, neuronal STAT5 deletion attenuated the hyperphagia commonly observed during lactation by decreasing the hypothalamic expression of orexigenic neurotransmitters such as the neuropeptide Y and agouti-related protein. The lower food intake of lactating neuron-specific STAT5 knockout females resulted in reduced milk production and offspring growth. Unexpectedly, postpartum maternal behavior expression was not impaired in neuron-specific STAT5 knockout females. On the contrary, the latency to retrieve and group the pups into the nest was reduced in mutant dams. Finally, we demonstrated that approximately 30% of recorded neurons in the medial preoptic area were acutely depolarized by prolactin suggesting that fast STAT5-independent signaling pathways may be involved in the regulation of maternal behaviors. Overall, our results revealed important information about the molecular mechanisms recruited by hormones to orchestrate the activation of neural circuitries engaged in the induction of maternal care.
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PMID:Neuronal STAT5 signaling is required for maintaining lactation but not for postpartum maternal behaviors in mice. 2589 18

Smith-Magenis syndrome (SMS; OMIM #182290) is a complex genetic disorder characterized by distinctive physical features, developmental delay, cognitive impairment, and a typical behavioral phenotype. SMS is caused by interstitial 17p11.2 deletions, encompassing multiple genes and including the retinoic acid-induced 1 gene (RAI1), or by mutations in RAI1 itself. About 10% of all the SMS patients, in fact, carry an RAI1 mutation responsible for the phenotype. RAI1 (OMIM *607642) is a dosage-sensitive gene expressed in many tissues and highly conserved among species. Over the years, several studies have demonstrated that RAI1 (or its homologs in animal models) acts as a transcriptional factor implicated in embryonic neurodevelopment, neuronal differentiation, cell growth and cell cycle regulation, bone and skeletal development, lipid and glucose metabolisms, behavioral functions, and circadian activity. Patients with RAI1 pathogenic variants show some phenotypic differences when compared to those carrying the typical deletion. They usually have lower incidence of hypotonia and less cognitive impairment than those with 17p11.2 deletions but more frequently show the behavioral characteristics of the syndrome and overeating issues. These differences reflect the primary pathogenetic role of RAI1 without the pathogenetic contribution of the other genes included in the typical 17p11.2 deletion. The better comprehension of physiological roles of RAI1, its molecular co-workers and interactors, and its contribution in determining the typical SMS phenotype will certainly open a new path for therapeutic interventions.
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PMID:RAI1 gene mutations: mechanisms of Smith-Magenis syndrome. 2913 88

Maternal nutritional imbalances trigger developmental adaptations involving early epigenetic mechanisms associated with adult chronic disease. Maternal high-fat (HF) diet promotes obesity and hypothalamic leptin resistance in male rat offspring at weaning and adulthood. Leptin resistance is associated with over activation of the endocannabinoid system (ECS). The ECS mainly consists of endocannabinoids derived from n-6 fatty acids and cannabinoid receptors (CB1 coded by Cnr1 and CB2 coded by Cnr2). The CB1 activation in hypothalamus stimulates feeding and appetite for fat while CB2 activation seems to play an immunomodulatory role. We demonstrated that maternal HF diet increases hypothalamic CB1 in male offspring while increases CB2 in female offspring at birth, prior to obesity development. However, the molecular mechanisms behind these changes remain unexplored. We hypothesized that maternal HF diet would down-regulate leptin signaling and up-regulate Cnr1 mRNA levels in the hypothalamus of the offspring at birth, associated with sex-specific changes in epigenetic markers and sex steroid signaling. To test our hypothesis, we used progenitor female rats that received control diet (C, 9% fat) or isocaloric high-fat diet (HF, 28% fat) from 8 weeks before mating until delivery. Blood, hypothalamus and carcass from C and HF male and female offspring were collected for biochemical and molecular analyses at birth. Maternal HF diet down-regulated the transcriptional factor STAT3 in the hypothalamus of male and female offspring, but induced hypoleptinemia only in males and decreased phosphorylated STAT3 only in female offspring. Because leptin acts through STAT3 pathway to inhibit central ECS, our results suggest that leptin pathway impairment might contribute to increased levels of Crn1 mRNA in hypothalamus of both sex offspring. Besides, maternal HF diet increased the histone acetylation percentage of Cnr1 promoter in male offspring and increased the androgen receptor binding to the Cnr1 promoter, which can contribute to higher expression of Cnr1 in newborn HF offspring. Maternal HF diet increased plasma n6 to n3 fatty acid ratio in male offspring, which is an important risk factor to metabolic diseases and might indicate an over activation of endocannabinoid signaling. Thus, although maternal HF diet programs a similar phenotype in adult offspring of both sexes (obesity, hyperphagia and higher preference for fat), here we showed that molecular mechanisms involving leptin signaling, ECS, epigenetic markers and sex hormone signaling were modified prior to obesity development and can differ between newborn male and female offspring. These observations may provide molecular insights into sex-specific targets for anti-obesity therapies.
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PMID:Maternal high-fat diet impairs leptin signaling and up-regulates type-1 cannabinoid receptor with sex-specific epigenetic changes in the hypothalamus of newborn rats. 3077 74