Neuropeptide Y and agouti-related peptide mediate complementary functions of hyperphagia and reduced energy expenditure in leptin receptor deficiency.

PubMed

Luo, Na; Marcelin, Genevieve; Liu, Shun Mei; Schwartz, Gary; Chua, Streamson

2011-03-01

Neuropeptide Y (NPY) and agouti-related peptide (AGRP) can produce hyperphagia, reduce energy expenditure, and promote triglyceride deposition in adipose depots. As these two neuropeptides are coexpressed within the hypothalamic arcuate nucleus and mediate a major portion of the obesity caused by leptin signaling deficiency, we sought to determine whether the two neuropeptides mediated identical or complementary actions. Because of separate neuropeptide receptors and signal transduction mechanisms, there is a possibility of distinct encoding systems for the feeding and energy expenditure aspects of leptin-regulated metabolism. We have genetically added NPY deficiency and/or AGRP deficiency to LEPR deficiency isolated to AGRP cells. Our results indicate that the obesity of LEPR deficiency in AGRP/NPY neurons can produce obesity with either AGRP or NPY alone with AGRP producing hyperphagia while NPY promotes reduced energy expenditure. The absence of both NPY and AGRP prevents the development of obesity attributable to isolated LEPR deficiency in AGRP/NPY neurons. Operant behavioral testing indicated that there were no alterations in the reward for a food pellet from the AGRP-specific LEPR deficiency.

Neuropeptide Y and Agouti-Related Peptide Mediate Complementary Functions of Hyperphagia and Reduced Energy Expenditure in Leptin Receptor Deficiency

PubMed Central

Luo, Na; Marcelin, Genevieve; Liu, Shun Mei; Schwartz, Gary

2011-01-01

Neuropeptide Y (NPY) and agouti-related peptide (AGRP) can produce hyperphagia, reduce energy expenditure, and promote triglyceride deposition in adipose depots. As these two neuropeptides are coexpressed within the hypothalamic arcuate nucleus and mediate a major portion of the obesity caused by leptin signaling deficiency, we sought to determine whether the two neuropeptides mediated identical or complementary actions. Because of separate neuropeptide receptors and signal transduction mechanisms, there is a possibility of distinct encoding systems for the feeding and energy expenditure aspects of leptin-regulated metabolism. We have genetically added NPY deficiency and/or AGRP deficiency to LEPR deficiency isolated to AGRP cells. Our results indicate that the obesity of LEPR deficiency in AGRP/NPY neurons can produce obesity with either AGRP or NPY alone with AGRP producing hyperphagia while NPY promotes reduced energy expenditure. The absence of both NPY and AGRP prevents the development of obesity attributable to isolated LEPR deficiency in AGRP/NPY neurons. Operant behavioral testing indicated that there were no alterations in the reward for a food pellet from the AGRP-specific LEPR deficiency. PMID:21285324

Protective role of AgRP neuron's PDK1 against salt-induced hypertension.

PubMed

Zhang, Boyang; Nakata, Masanori; Lu, Ming; Nakae, Jun; Okada, Takashi; Ogawa, Wataru; Yada, Toshihiko

2018-06-12

In the hypothalamic arcuate nucleus (ARC), orexigenic agouti-related peptide (AgRP) neurons regulate feeding behavior and energy homeostasis. The 3-phosphoinositide-dependent protein kinase-1 (PDK1) in AgRP neurons serves as a major signaling molecule for leptin and insulin, the hormones regulating feeding behavior, energy homeostasis and circulation. However, it is unclear whether PDK1 in AGRP neurons is also involved in regulation of blood pressure. This study explored it by generating and analyzing AgRP neuron-specific PDK1 knockout (Agrp-Pdk1 flox/flox ) mice and effect of high salt diet on blood pressure in KO and WT mice was analyzed. Under high salt diet feeding, systolic blood pressure (SBP) of Agrp-Pdk1 flox/flox mice was significantly elevated compared to Agrp-Cre mice. When the high salt diet was switched to control low salt diet, SBP of Agrp-Pdk1 flox/flox mice returned to the basal level observed in Agrp-Cre mice within 1 week. In Agrp-Pdk1 flox/flox mice, urinary noradrenalin excretion and NUCB2 mRNA expression in hypothalamic paraventricular nucleus (PVN) were markedly upregulated. Moreover, silencing of NUCB2 in the PVN counteracted the rises in urinary noradrenalin excretions and SBP. These results demonstrate a novel role of PDK1 in AgRP neurons to counteract the high salt diet-induced hypertension by preventing hyperactivation of PVN nesfatin-1 neurons. Copyright © 2018 Elsevier Inc. All rights reserved.

Hypothalamic interactions between neuropeptide Y, agouti-related protein, cocaine- and amphetamine-regulated transcript and alpha-melanocyte-stimulating hormone in vitro in male rats.

PubMed

Dhillo, W S; Small, C J; Stanley, S A; Jethwa, P H; Seal, L J; Murphy, K G; Ghatei, M A; Bloom, S R

2002-09-01

A number of neuropeptides implicated in the hypothalamic regulation of appetite are synthesized in the arcuate nucleus (Arc). Neuropeptide Y (NPY) and agouti-related protein (Agrp) are orexigenic. The pro-opiomelanocortin (POMC) product alpha-melanocyte-stimulating hormone (alpha-MSH) is anorectic. Intracerebroventricular administration of cocaine- and amphetamine-regulated transcript (CART) decreases food intake. However, recent results show that CART is orexigenic when injected into discrete hypothalamic nuclei. There is almost complete coexpression of NPY and Agrp mRNA in Arc neurones, and the majority of CART-containing neurones in the Arc also contain POMC mRNA. We investigated possible interactions between these neuropeptides in vitro using a rat hypothalamic explant system. Administration of 1, 10 and 100 nm of NPY to hypothalamic explants significantly increased release of Agrp(83-132)-immunoreactivity (IR). NPY (10 and 100 nm) significantly increased the release of CART(55-102)-IR and alpha-MSH-IR from hypothalamic explants. Agrp(83-132) (10 nm) administered to hypothalamic explants significantly increased the release of NPY-IR. Agrp(83-132) (10 and 100 nm) significantly decreased the release of CART(55-102)-IR from hypothalamic explants. Administration of 1, 10 and 100 nm CART(55-102) to hypothalamic explants resulted in a significant increase in NPY-IR release. Administration of 10 nm CART(55-102) to hypothalamic explants significantly increased the release of Agrp(83-132)-IR. NDP-MSH (10 nm) administered to hypothalamic explants significantly increased the release of NPY-IR. NDP-MSH (10 and 100 nm) significantly increased the release of Agrp(83-132)-IR from hypothalamic explants. These data suggest that orexigenic neuropeptides in the arcuate nucleus stimulate the release of each other, perhaps reinforcing orexigenic behaviour via a positive-feedback loop. Our results are also in keeping with the possibility that the melanocortin-3 receptor in the

Action of Neurotransmitter: A Key to Unlock the AgRP Neuron Feeding Circuit

PubMed Central

Liu, Tiemin; Wang, Qian; Berglund, Eric D.; Tong, Qingchun

2013-01-01

The current obesity epidemic and lack of efficient therapeutics demand a clear understanding of the mechanism underlying body weight regulation. Despite intensive research focus on obesity pathogenesis, an effective therapeutic strategy to treat and cure obesity is still lacking. Exciting studies in last decades have established the importance of hypothalamic agouti-related protein-expressing neurons (AgRP neurons) in the regulation of body weight homeostasis. AgRP neurons are both required and sufficient for feeding regulation. The activity of AgRP neurons is intricately regulated by nutritional hormones as well as synaptic inputs from upstream neurons. Changes in AgRP neuron activity lead to alterations in the release of mediators, including neuropeptides Neuropeptide Y (NPY) and AgRP, and fast-acting neurotransmitter GABA. Recent studies based on mouse genetics, novel optogenetics, and designer receptor exclusively activated by designer drugs have identified a critical role for GABA release from AgRP neurons in the parabrachial nucleus and paraventricular hypothalamus in feeding control. This review will summarize recent findings about AgRP neuron-mediated control of feeding circuits with a focus on the role of neurotransmitters. Given the limited knowledge on feeding regulation, understanding the action of neurotransmitters may be a key to unlock neurocircuitry that governs feeding. PMID:23346045

Inhibition of agouti-related peptide expression by glucose in a clonal hypothalamic neuronal cell line is mediated by glycolysis, not oxidative phosphorylation.

PubMed

Cheng, Hui; Isoda, Fumiko; Belsham, Denise D; Mobbs, Charles V

2008-02-01

The regulation of neuroendocrine electrical activity and gene expression by glucose is mediated through several distinct metabolic pathways. Many studies have implicated AMP and ATP as key metabolites mediating neuroendocrine responses to glucose, especially through their effects on AMP-activated protein kinase (AMPK), but other studies have suggested that glycolysis, and in particular the cytoplasmic conversion of nicotinamide adenine dinucleotide (NAD+) to reduced NAD (NADH), may play a more important role than oxidative phosphorylation for some effects of glucose. To address these molecular mechanisms further, we have examined the regulation of agouti-related peptide (AgRP) in a clonal hypothalamic cell line, N-38. AgRP expression was induced monotonically as glucose concentrations decreased from 10 to 0.5 mm glucose and with increasing concentrations of glycolytic inhibitors. However, neither pyruvate nor 3-beta-hydroxybutyrate mimicked the effect of glucose to reduce AgRP mRNA, but on the contrary, produced the opposite effect of glucose and actually increased AgRP mRNA. Nevertheless, 3beta-hydroxybutyrate mimicked the effect of glucose to increase ATP and to decrease AMPK phosphorylation. Similarly, inhibition of AMPK by RNA interference increased, and activation of AMPK decreased, AgRP mRNA. Additional studies demonstrated that neither the hexosamine nor the pentose/carbohydrate response element-binding protein pathways mediate the effects of glucose on AgRP expression. These studies do not support that either ATP or AMPK mediate effects of glucose on AgRP in this hypothalamic cell line but support a role for glycolysis and, in particular, NADH. These studies support that cytoplasmic or nuclear NADH, uniquely produced by glucose metabolism, mediates effects of glucose on AgRP expression.

Liver ERα regulates AgRP neuronal activity in the arcuate nucleus of female mice.

PubMed

Benedusi, Valeria; Della Torre, Sara; Mitro, Nico; Caruso, Donatella; Oberto, Alessandra; Tronel, Claire; Meda, Clara; Maggi, Adriana

2017-04-26

Recent work revealed the major role played by liver Estrogen Receptor α (ERα) in the regulation of metabolic and reproductive functions. By using mutant mice with liver-specific ablation of Erα, we here demonstrate that the hepatic ERα is essential for the modulation of the activity of Agouti Related Protein (AgRP) neurons in relation to the reproductive cycle and diet. Our results suggest that the alterations of hepatic lipid metabolism due to the lack of liver ERα activity are responsible for a neuroinflammatory status that induces refractoriness of AgRP neurons to reproductive and dietary stimuli. The study therefore points to the liver ERα as a necessary sensor for the coordination of systemic energy metabolism and reproductive functions.

The Relevance of AgRP Neuron-Derived GABA Inputs to POMC Neurons Differs for Spontaneous and Evoked Release

PubMed Central

2017-01-01

Hypothalamic agouti-related peptide (AgRP) neurons potently stimulate food intake, whereas proopiomelanocortin (POMC) neurons inhibit feeding. Whether AgRP neurons exert their orexigenic actions, at least in part, by inhibiting anorexigenic POMC neurons remains unclear. Here, the connectivity between GABA-releasing AgRP neurons and POMC neurons was examined in brain slices from male and female mice. GABA-mediated spontaneous IPSCs (sIPSCs) in POMC neurons were unaffected by disturbing GABA release from AgRP neurons either by cell type-specific deletion of the vesicular GABA transporter or by expression of botulinum toxin in AgRP neurons to prevent vesicle-associated membrane protein 2-dependent vesicle fusion. Additionally, there was no difference in the ability of μ-opioid receptor (MOR) agonists to inhibit sIPSCs in POMC neurons when MORs were deleted from AgRP neurons, and activation of the inhibitory designer receptor hM4Di on AgRP neurons did not affect sIPSCs recorded from POMC neurons. These approaches collectively indicate that AgRP neurons do not significantly contribute to the strong spontaneous GABA input to POMC neurons. Despite these observations, optogenetic stimulation of AgRP neurons reliably produced evoked IPSCs in POMC neurons, leading to the inhibition of POMC neuron firing. Thus, AgRP neurons can potently affect POMC neuron function without contributing a significant source of spontaneous GABA input to POMC neurons. Together, these results indicate that the relevance of GABAergic inputs from AgRP to POMC neurons is state dependent and highlight the need to consider different types of transmitter release in circuit mapping and physiologic regulation. SIGNIFICANCE STATEMENT Agouti-related peptide (AgRP) neurons play an important role in driving food intake, while proopiomelanocortin (POMC) neurons inhibit feeding. Despite the importance of these two well characterized neuron types in maintaining metabolic homeostasis, communication between these

The Relevance of AgRP Neuron-Derived GABA Inputs to POMC Neurons Differs for Spontaneous and Evoked Release.

PubMed

Rau, Andrew R; Hentges, Shane T

2017-08-02

Hypothalamic agouti-related peptide (AgRP) neurons potently stimulate food intake, whereas proopiomelanocortin (POMC) neurons inhibit feeding. Whether AgRP neurons exert their orexigenic actions, at least in part, by inhibiting anorexigenic POMC neurons remains unclear. Here, the connectivity between GABA-releasing AgRP neurons and POMC neurons was examined in brain slices from male and female mice. GABA-mediated spontaneous IPSCs (sIPSCs) in POMC neurons were unaffected by disturbing GABA release from AgRP neurons either by cell type-specific deletion of the vesicular GABA transporter or by expression of botulinum toxin in AgRP neurons to prevent vesicle-associated membrane protein 2-dependent vesicle fusion. Additionally, there was no difference in the ability of μ-opioid receptor (MOR) agonists to inhibit sIPSCs in POMC neurons when MORs were deleted from AgRP neurons, and activation of the inhibitory designer receptor hM4Di on AgRP neurons did not affect sIPSCs recorded from POMC neurons. These approaches collectively indicate that AgRP neurons do not significantly contribute to the strong spontaneous GABA input to POMC neurons. Despite these observations, optogenetic stimulation of AgRP neurons reliably produced evoked IPSCs in POMC neurons, leading to the inhibition of POMC neuron firing. Thus, AgRP neurons can potently affect POMC neuron function without contributing a significant source of spontaneous GABA input to POMC neurons. Together, these results indicate that the relevance of GABAergic inputs from AgRP to POMC neurons is state dependent and highlight the need to consider different types of transmitter release in circuit mapping and physiologic regulation. SIGNIFICANCE STATEMENT Agouti-related peptide (AgRP) neurons play an important role in driving food intake, while proopiomelanocortin (POMC) neurons inhibit feeding. Despite the importance of these two well characterized neuron types in maintaining metabolic homeostasis, communication between these

Ablation of neurons expressing agouti-related protein, but not melanin concentrating hormone, in leptin-deficient mice restores metabolic functions and fertility

PubMed Central

Wu, Qi; Whiddon, Benjamin B.; Palmiter, Richard D.

2012-01-01

Leptin-deficient (Lepob/ob) mice are obese, diabetic, and infertile. Ablation of neurons that make agouti-related protein (AgRP) in moderately obese adult Lepob/ob mice caused severe anorexia. The mice stopped eating for 2 wk and then gradually recovered. Their body weight fell to within a normal range for WT mice, at which point food intake and glucose tolerance were restored to that of WT mice. Remarkably, both male and female Lepob/ob mice became fertile. Ablation of neurons that express melanin-concentrating hormone (MCH) in adult Lepob/ob mice had no effect on food intake, body weight, or fertility, but resulted in improved glucose tolerance. We conclude that AgRP-expressing neurons play a critical role in mediating the metabolic syndrome and infertility of Lepob/ob mice, whereas MCH-expressing neurons have only a minor role. PMID:22232663

Corticotropin-releasing hormone (CRH) transgenic mice display hyperphagia with increased Agouti-related protein mRNA in the hypothalamic arcuate nucleus.

PubMed

Nakayama, Shuichi; Nishiyama, Mitsuru; Iwasaki, Yasumasa; Shinahara, Masayuki; Okada, Yasushi; Tsuda, Masayuki; Okazaki, Mizuho; Tsugita, Makoto; Taguchi, Takafumi; Makino, Shinya; Stenzel-Poore, Mary P; Hashimoto, Kozo; Terada, Yoshio

2011-01-01

Although glucocorticoid-induced hyperphagia is observed in the patients with glucocorticoid treatment or Cushing's syndrome, its molecular mechanism is not clear. We thus explored the expression of neuropeptide mRNAs in the hypothalamus related to appetite regulation in CRH over-expressing transgenic mice (CRH-Tg), a model of Cushing's syndrome. We measured food intake, body weight (including body fat weight) and plasma corticosterone levels in CRH-Tg and their wild-type littermates (WT) at 6 and 14 weeks old. We also examined neuropeptide Y (NPY), proopiomelanocortin (POMC) and Agouti-related protein (AgRP) mRNAs in the arcuate nucleus (ARC) using in situ hybridization. Circulating corticosterone levels in CRH-Tg were markedly elevated at both 6 and 14 weeks old. Body fat weight in CRH-Tg was significantly increased at 14 weeks old, which is considered as an effect of chronic glucocorticoid excess. At both 6 and 14 weeks old, CRH-Tg mice showed significant hyperphagia compared with WT (14w old: WT 3.9±0.1, CRH-Tg 5.1±0.7 g/day, p<0.05). Unexpectedly, NPY mRNA levels in CRH-Tg were significantly decreased at 14 weeks old (WT: 1571.5±111.2, CRH-Tg: 949.1±139.3 dpm/mg, p<0.05), and there were no differences in POMC mRNA levels between CRH-Tg and WT. On the other hand, AgRP mRNA levels in CRH-Tg were significantly increased compared with WT at both ages (14w old: WT 365.6±88.6, CRH-Tg 660.1±87.2 dpm/ mg, p<0.05). These results suggest that glucocorticoid-induced hyperphagia is associated with increased hypothalamic AgRP. Our results also indicate that hypothalamic NPY does not have an essential role in the increased food intake during glucocorticoid excess.

A Postsynaptic AMPK→p21-Activated Kinase Pathway Drives Fasting-Induced Synaptic Plasticity in AgRP Neurons.

PubMed

Kong, Dong; Dagon, Yossi; Campbell, John N; Guo, Yikun; Yang, Zongfang; Yi, Xinchi; Aryal, Pratik; Wellenstein, Kerry; Kahn, Barbara B; Sabatini, Bernardo L; Lowell, Bradford B

2016-07-06

AMP-activated protein kinase (AMPK) plays an important role in regulating food intake. The downstream AMPK substrates and neurobiological mechanisms responsible for this, however, are ill defined. Agouti-related peptide (AgRP)-expressing neurons in the arcuate nucleus regulate hunger. Their firing increases with fasting, and once engaged they cause feeding. AgRP neuron activity is regulated by state-dependent synaptic plasticity: fasting increases dendritic spines and excitatory synaptic activity; feeding does the opposite. The signaling mechanisms underlying this, however, are also unknown. Using neuron-specific approaches to measure and manipulate kinase activity specifically within AgRP neurons, we establish that fasting increases AMPK activity in AgRP neurons, that increased AMPK activity in AgRP neurons is both necessary and sufficient for fasting-induced spinogenesis and excitatory synaptic activity, and that the AMPK phosphorylation target mediating this plasticity is p21-activated kinase. This provides a signaling and neurobiological basis for both AMPK regulation of energy balance and AgRP neuron state-dependent plasticity. Copyright © 2016 Elsevier Inc. All rights reserved.

Stereochemical studies of the monocyclic agouti-related protein (103-122) Arg-Phe-Phe residues: conversion of a melanocortin-4 receptor antagonist into an agonist and results in the discovery of a potent and selective melanocortin-1 agonist.

PubMed

Joseph, Christine G; Wang, Xiang S; Scott, Joseph W; Bauzo, Rayna M; Xiang, Zhimin; Richards, Nigel G; Haskell-Luevano, Carrie

2004-12-30

The agouti-related protein (AGRP) is an endogenous antagonist of the centrally expressed melanocortin receptors. The melanocortin-4 receptor (MC4R) is involved in energy homeostasis, food intake, sexual function, and obesity. The endogenous hAGRP protein is 132 amino acids in length, possesses five disulfide bridges at the C-terminus of the molecule, and is expressed in the hypothalamus of the brain. We have previously reported that a monocyclic hAGRP(103-122) peptide is an antagonist at the melanocortin receptors expressed in the brain. Stereochemical inversion from the endogenous l- to d-isomers of single or multiple amino acid modifications in this monocyclic truncated hAGRP sequence resulted in molecules that are converted from melanocortin receptor antagonists into melanocortin receptor agonists. The Asp-Pro-Ala-Ala-Thr-Ala-Tyr-cyclo[Cys-Arg-DPhe-DPhe-Asn-Ala-Phe-Cys]-Tyr-Ala-Arg-Lys-Leu peptide resulted in a 60 nM melanocortin-1 receptor agonist that is 100-fold selective versus the mMC4R, 1000-fold selective versus the mMC3R, and ca. 180-fold selective versus the mMC5R. In attempts to identify putative ligand-receptor interactions that may be participating in the agonist induced stimulation of the MC4R, selected ligands were docked into a homology molecular model of the mMC4R. These modeling studies have putatively identified hAGRP ligand DArg111-mMC4RAsn115 (TM3) and the hAGRP DPhe113-mMC4RPhe176 (TM4) interactions as important for agonist activity.

Differential expression of cocaine- and amphetamine-regulated transcript and agouti related-protein in chronically food-restricted sheep.

PubMed

Henry, B A; Rao, A; Ikenasio, B A; Mountjoy, K G; Tilbrook, A J; Clarke, I J

2001-11-09

Recently, much attention has focused on the role of the melanocortin system in the regulation of energy homeostasis, especially the satiety effects of the pro-opiomelanocortin (POMC)-derived peptide alpha-melanocyte stimulating hormone (alpha-MSH). We have found that POMC mRNA levels are similar in fat and thin sheep and the current study sought to further characterize the effects of nutritional status on the melanocortin system. To this end, we studied the expression of agouti-related peptide (AGRP) (an endogenous antagonist of alpha-MSH) and cocaine- and amphetamine-regulated transcript (CART), which is co-localized within POMC cells of the arcuate nucleus (ARC) in rodents. Twelve ovariectomized ewes were randomly divided into two groups and fed a maintenance (n=6) or restricted diet (n=6). At the time of experimentation, the animals had significantly (P<0.0001) different bodyweights (53.4+/-2.2 kg, ad libitum vs. 30.4+/-1.2 kg, food-restricted), which was largely due to altered body fat deposits. In situ hybridization was used to study the expression of POMC, AGRP and CART. The expression of POMC in the ARC was similar in ad libitum and food-restricted animals but the expression of AGRP was profoundly increased in the food-restricted group. The expression of CART was abundant throughout the hypothalamus but was not found in the ARC. In food-restricted animals, the expression of CART was lower in the retrochiasmatic nucleus (P<0.01), paraventricular nucleus (P<0.001), the dorsomedial nucleus and the lateral hypothalamic area (P<0.05), but was higher (P<0.01) in the posterior hypothalamic area. Thus, long-term changes in nutritional status have profound effects on the expression of AGRP and CART in the hypothalamus.

AgRP Neurons Control Systemic Insulin Sensitivity via Myostatin Expression in Brown Adipose Tissue.

PubMed

Steculorum, Sophie M; Ruud, Johan; Karakasilioti, Ismene; Backes, Heiko; Engström Ruud, Linda; Timper, Katharina; Hess, Martin E; Tsaousidou, Eva; Mauer, Jan; Vogt, Merly C; Paeger, Lars; Bremser, Stephan; Klein, Andreas C; Morgan, Donald A; Frommolt, Peter; Brinkkötter, Paul T; Hammerschmidt, Philipp; Benzing, Thomas; Rahmouni, Kamal; Wunderlich, F Thomas; Kloppenburg, Peter; Brüning, Jens C

2016-03-24

Activation of Agouti-related peptide (AgRP) neurons potently promotes feeding, and chronically altering their activity also affects peripheral glucose homeostasis. We demonstrate that acute activation of AgRP neurons causes insulin resistance through impairment of insulin-stimulated glucose uptake into brown adipose tissue (BAT). AgRP neuron activation acutely reprograms gene expression in BAT toward a myogenic signature, including increased expression of myostatin. Interference with myostatin activity improves insulin sensitivity that was impaired by AgRP neurons activation. Optogenetic circuitry mapping reveals that feeding and insulin sensitivity are controlled by both distinct and overlapping projections. Stimulation of AgRP → LHA projections impairs insulin sensitivity and promotes feeding while activation of AgRP → anterior bed nucleus of the stria terminalis (aBNST)vl projections, distinct from AgRP → aBNSTdm projections controlling feeding, mediate the effect of AgRP neuron activation on BAT-myostatin expression and insulin sensitivity. Collectively, our results suggest that AgRP neurons in mice induce not only eating, but also insulin resistance by stimulating expression of muscle-related genes in BAT, revealing a mechanism by which these neurons rapidly coordinate hunger states with glucose homeostasis. Copyright © 2016 Elsevier Inc. All rights reserved.

Pharmacological Characterization of 30 Human Melanocortin-4 Receptor Polymorphisms with the Endogenous Proopiomelanocortin Derived Agonists, Synthetic Agonists, and the Endogenous Agouti-Related Protein (AGRP) Antagonist

PubMed Central

Xiang, Zhimin; Proneth, Bettina; Dirain, Marvin L.; Litherland, Sally A.; Haskell-Luevano, Carrie

2010-01-01

The melanocortin-4 receptor (MC4R) is a G-protein coupled receptor (GPCR) that is expressed in the central nervous system and has a role in regulating feeding behavior, obesity, energy homeostasis, male erectile response, and blood pressure. Since the report of the MC4R knockout mouse in 1997, the field has been searching for links between this genetic bio marker and human obesity and type 2 diabetes. More then 80 single nucleotide polymorphisms (SNPs) have been identified from human patients, both obese and non-obese controls. Many significant studies have been performed examining the pharmacological characteristics of these hMC4R SNPs in attempts to identify a molecular defects/insights that might link a genetic factor to the obese phenotype observed in patients possessing these mutations. Our laboratory has previously reported the pharmacological characterization of 40 of these polymorphic hMC4 receptors with multiple endogenous and synthetic ligands. The goal of the current study is to perform a similar comprehensive side-by-side characterization of 30 additional human hMC4R with single nucleotide polymorphisms using multiple endogenous agonists [α-, β, γ2-melanocyte stimulating hormones (MSH) and adrenocorticotropin (ACTH)], the antagonist agouti-related protein hAGRP(87-132), and synthetic agonists [NDP-MSH, MTII, and the tetrapeptide Ac-His-DPhe-Arg-Trp-NH2 (JRH887-9)]. These in vitro data, in some cases, provide a putative molecular link between dysfunctional hMC4R's and human obesity. These 30 hMC4R SNPs include R7H, R18H, R18L, S36Y, P48S, V50M, F51L, E61K, I69T, D90N, S94R, G98R, I121T, A154D, Y157S, W174C, G181D, F202L, A219V, I226T, G231S, G238D, N240S, C271R, S295P, P299L, E308K, I317V, L325F and 750DelGA. All but the N240S hMC4R were identified in obese patients. Additionally, we have characterized a double I102T/V103I hMC4R. In addition to the pharmacological characterization, the hMC4R variants were evaluated for cell surface expression by flow

Reduced AgRP activation in the hypothalamus of cows with high extent of fat mobilization after parturition.

PubMed

Börner, Sabina; Albrecht, Elke; Schäff, Christine; Hacke, Sandra; Kautzsch, Ulrike; Derno, Michael; Hammon, Harald M; Röntgen, Monika; Sauerwein, Helga; Kuhla, Björn

2013-11-01

Agouti-related protein (AgRP), produced by neurons located in the arcuate nucleus of the hypothalamus stimulates feed intake. During early lactation dairy cows increase their feed intake and additionally mobilize their fat reserves leading to increased plasma non-esterified fatty acid (NEFA) concentrations. Since cows with a higher extent of fat mobilization exhibit the lower feed intake, it seems that high NEFA concentrations confine hyperphagia. To test the involvement of AgRP neurons, we investigated 18 cows from parturition until day 40 postpartum (pp) and assigned the cows according to their NEFA concentration on day 40pp to either group H (high NEFA) or L (low NEFA). Both groups had comparable feed intake, body weight, milk yield, energy balance, plasma amino acids and leptin concentrations. Studies in respiratory chambers revealed the higher oxygen consumption and the lower respiratory quotient (RQ) in H compared to L cows. mRNA abundance of neuropeptide Y, peroxisome proliferator-activated receptor-gamma, AMP-activated protein kinase, and leptin receptor in the arcuate nucleus were comparable between groups. Immunohistochemical studies revealed the same number of AgRP neurons in H and L cows. AgRP neurons were co-localized with phosphorylated adenosine monophosphate-activated kinase without any differences between groups. The percentage of cFOS-activated AgRP neurons per total AgRP cells was lower in H cows and correlated negatively with oxygen consumption and NEFA, positively with RQ, but not with feed intake. We conclude that AgRP activation plays a pivotal role in the regulation of substrate utilization and metabolic rate in high NEFA dairy cows during early lactation. Copyright © 2013 Elsevier Inc. All rights reserved.

AMPK is essential for energy homeostasis regulation and glucose sensing by POMC and AgRP neurons.

PubMed

Claret, Marc; Smith, Mark A; Batterham, Rachel L; Selman, Colin; Choudhury, Agharul I; Fryer, Lee G D; Clements, Melanie; Al-Qassab, Hind; Heffron, Helen; Xu, Allison W; Speakman, John R; Barsh, Gregory S; Viollet, Benoit; Vaulont, Sophie; Ashford, Michael L J; Carling, David; Withers, Dominic J

2007-08-01

Hypothalamic AMP-activated protein kinase (AMPK) has been suggested to act as a key sensing mechanism, responding to hormones and nutrients in the regulation of energy homeostasis. However, the precise neuronal populations and cellular mechanisms involved are unclear. The effects of long-term manipulation of hypothalamic AMPK on energy balance are also unknown. To directly address such issues, we generated POMC alpha 2KO and AgRP alpha 2KO mice lacking AMPK alpha2 in proopiomelanocortin- (POMC-) and agouti-related protein-expressing (AgRP-expressing) neurons, key regulators of energy homeostasis. POMC alpha 2KO mice developed obesity due to reduced energy expenditure and dysregulated food intake but remained sensitive to leptin. In contrast, AgRP alpha 2KO mice developed an age-dependent lean phenotype with increased sensitivity to a melanocortin agonist. Electrophysiological studies in AMPK alpha2-deficient POMC or AgRP neurons revealed normal leptin or insulin action but absent responses to alterations in extracellular glucose levels, showing that glucose-sensing signaling mechanisms in these neurons are distinct from those pathways utilized by leptin or insulin. Taken together with the divergent phenotypes of POMC alpha 2KO and AgRP alpha 2KO mice, our findings suggest that while AMPK plays a key role in hypothalamic function, it does not act as a general sensor and integrator of energy homeostasis in the mediobasal hypothalamus.

Effects of AgRP Inhibition on Energy Balance and Metabolism in Rodent Models

PubMed Central

Dutia, Roxanne; Kim, Andrea J.; Modes, Matthew; Rothlein, Robert; Shen, Jane M.; Tian, Ye Edward; Ihbais, Jumana; Victory, Sam F.; Valcarce, Carmen; Wardlaw, Sharon L.

2013-01-01

Activation of brain melanocortin-4 receptors (MC4-R) by α-melanocyte-stimulating hormone (MSH) or inhibition by agouti-related protein (AgRP) regulates food intake and energy expenditure and can modulate neuroendocrine responses to changes in energy balance. To examine the effects of AgRP inhibition on energy balance, a small molecule, non-peptide compound, TTP2515, developed by TransTech Pharma, Inc., was studied in vitro and in rodent models in vivo. TTP2515 prevented AgRP from antagonizing α-MSH-induced increases in cAMP in HEK 293 cells overexpressing the human MC4-R. When administered to rats by oral gavage TTP2515 blocked icv AgRP-induced increases in food intake, weight gain and adiposity and suppression of T4 levels. In both diet-induced obese (DIO) and leptin-deficient mice, TTP2515 decreased food intake, weight gain, adiposity and respiratory quotient. TTP2515 potently suppressed food intake and weight gain in lean mice immediately after initiation of a high fat diet (HFD) but had no effect on these parameters in lean chow-fed mice. However, when tested in AgRP KO mice, TTP2515 also suppressed food intake and weight gain during HFD feeding. In several studies TTP2515 increased T4 but not T3 levels, however this was also observed in AgRP KO mice. TTP2515 also attenuated refeeding and weight gain after fasting, an effect not evident in AgRP KO mice when administered at moderate doses. This study shows that TTP2515 exerts many effects consistent with AgRP inhibition however experiments in AgRP KO mice indicate some off-target effects of this drug. TTP2515 was particularly effective during fasting and in mice with leptin deficiency, conditions in which AgRP is elevated, as well as during acute and chronic HFD feeding. Thus the usefulness of this drug in treating obesity deserves further exploration, to define the AgRP dependent and independent mechanisms by which TTP2515 exerts its effects on energy balance. PMID:23762342

Opioid receptor involvement in the effect of AgRP- (83-132) on food intake and food selection.

PubMed

Hagan, M M; Rushing, P A; Benoit, S C; Woods, S C; Seeley, R J

2001-03-01

Agouti-related peptide (AgRP) is a receptor antagonist of central nervous system (CNS) melanocortin receptors and appears to have an important role in the control of food intake since exogenous CNS administration in rats and overexpression in mice result in profound hyperphagia and weight gain. Given that AgRP is heavily colocalized with neuropeptide Y (NPY) and that orexigenic effects of NPY depend on activity at opioid receptors, we hypothesized that AgRP's food-intake effects are also mediated by opioid receptors. Subthreshold doses of the opioid receptor antagonist naloxone blocked AgRP-induced intake when given simultaneously but not 24 h after AgRP injection. Opioids not only influence food intake but food selection as well. Hence, we tested AgRP's effect to alter food choice between matched diets with differing dietary fat content. AgRP selectively enhanced intake of the high-fat but not the low-fat diet. Additionally, AgRP selectively increased chow intake in rats given ad libitum access to a 20% sucrose solution and standard rat chow. The current results indicate that AgRP influences not only caloric intake but food selection as well and that the early effects of AgRP depend critically on an interaction with opioid receptors.

Arcuate hypothalamic AgRP and putative POMC neurons show opposite changes in spiking across multiple timescales

PubMed Central

Mandelblat-Cerf, Yael; Ramesh, Rohan N; Burgess, Christian R; Patella, Paola; Yang, Zongfang; Lowell, Bradford B; Andermann, Mark L

2015-01-01

Agouti-related-peptide (AgRP) neurons—interoceptive neurons in the arcuate nucleus of the hypothalamus (ARC)—are both necessary and sufficient for driving feeding behavior. To better understand the functional roles of AgRP neurons, we performed optetrode electrophysiological recordings from AgRP neurons in awake, behaving AgRP-IRES-Cre mice. In free-feeding mice, we observed a fivefold increase in AgRP neuron firing with mounting caloric deficit in afternoon vs morning recordings. In food-restricted mice, as food became available, AgRP neuron firing dropped, yet remained elevated as compared to firing in sated mice. The rapid drop in spiking activity of AgRP neurons at meal onset may reflect a termination of the drive to find food, while residual, persistent spiking may reflect a sustained drive to consume food. Moreover, nearby neurons inhibited by AgRP neuron photostimulation, likely including satiety-promoting pro-opiomelanocortin (POMC) neurons, demonstrated opposite changes in spiking. Finally, firing of ARC neurons was also rapidly modulated within seconds of individual licks for liquid food. These findings suggest novel roles for antagonistic AgRP and POMC neurons in the regulation of feeding behaviors across multiple timescales. DOI: http://dx.doi.org/10.7554/eLife.07122.001 PMID:26159614

Ribosomal S6K1 in POMC and AgRP Neurons Regulates Glucose Homeostasis but Not Feeding Behavior in Mice

PubMed Central

Smith, Mark A.; Katsouri, Loukia; Irvine, Elaine E.; Hankir, Mohammed K.; Pedroni, Silvia M.A.; Voshol, Peter J.; Gordon, Matthew W.; Choudhury, Agharul I.; Woods, Angela; Vidal-Puig, Antonio; Carling, David; Withers, Dominic J.

2015-01-01

Summary Hypothalamic ribosomal S6K1 has been suggested as a point of convergence for hormonal and nutrient signals in the regulation of feeding behavior, bodyweight, and glucose metabolism. However, the long-term effects of manipulating hypothalamic S6K1 signaling on energy homeostasis and the cellular mechanisms underlying these roles are unclear. We therefore inactivated S6K1 in pro-opiomelanocortin (POMC) and agouti-related protein (AgRP) neurons, key regulators of energy homeostasis, but in contrast to the current view, we found no evidence that S6K1 regulates food intake and bodyweight. In contrast, S6K1 signaling in POMC neurons regulated hepatic glucose production and peripheral lipid metabolism and modulated neuronal excitability. S6K1 signaling in AgRP neurons regulated skeletal muscle insulin sensitivity and was required for glucose sensing by these neurons. Our findings suggest that S6K1 signaling is not a general integrator of energy homeostasis in the mediobasal hypothalamus but has distinct roles in the regulation of glucose homeostasis by POMC and AgRP neurons. PMID:25865886

Long-term orexigenic effects of AgRP-(83---132) involve mechanisms other than melanocortin receptor blockade.

PubMed

Hagan, M M; Rushing, P A; Pritchard, L M; Schwartz, M W; Strack, A M; Van Der Ploeg, L H; Woods, S C; Seeley, R J

2000-07-01

Overexpression of agouti-related peptide (AgRP), an endogenous melanocortin (MC) 3 and 4 receptor antagonist (MC3/4-R), causes obesity. Exogenous AgRP-(83---132) increases food intake, but its duration and mode of action are unknown. We report herein that doses as low as 10 pmol can have a potent effect on food intake of rats over a 24-h period after intracerebroventricular injection. Additionally, a single third ventricular dose as low as 100 pmol in rats produces a robust increase in food intake that persists for an entire week. AgRP-(83---132) completely blocks the anorectic effect of MTII (MC3/4-R agonist), given simultaneously, consistent with a competitive antagonist action. However, when given 24 h prior to MTII, AgRP-(83---132) is ineffective at reversing the anorectic effects of the agonist. These results support a critical role of MC tone in limiting food intake and indicate that the orexigenic effects of AgRP-(83---132) are initially mediated by competitive antagonism at MC receptors but are sustained by alternate mechanisms.

Ribosomal S6K1 in POMC and AgRP Neurons Regulates Glucose Homeostasis but Not Feeding Behavior in Mice.

PubMed

Smith, Mark A; Katsouri, Loukia; Irvine, Elaine E; Hankir, Mohammed K; Pedroni, Silvia M A; Voshol, Peter J; Gordon, Matthew W; Choudhury, Agharul I; Woods, Angela; Vidal-Puig, Antonio; Carling, David; Withers, Dominic J

2015-04-21

Hypothalamic ribosomal S6K1 has been suggested as a point of convergence for hormonal and nutrient signals in the regulation of feeding behavior, bodyweight, and glucose metabolism. However, the long-term effects of manipulating hypothalamic S6K1 signaling on energy homeostasis and the cellular mechanisms underlying these roles are unclear. We therefore inactivated S6K1 in pro-opiomelanocortin (POMC) and agouti-related protein (AgRP) neurons, key regulators of energy homeostasis, but in contrast to the current view, we found no evidence that S6K1 regulates food intake and bodyweight. In contrast, S6K1 signaling in POMC neurons regulated hepatic glucose production and peripheral lipid metabolism and modulated neuronal excitability. S6K1 signaling in AgRP neurons regulated skeletal muscle insulin sensitivity and was required for glucose sensing by these neurons. Our findings suggest that S6K1 signaling is not a general integrator of energy homeostasis in the mediobasal hypothalamus but has distinct roles in the regulation of glucose homeostasis by POMC and AgRP neurons. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

GABAergic signaling by AgRP neurons prevents anorexia via a melanocortin-independent mechanism.

PubMed

Wu, Qi; Palmiter, Richard D

2011-06-11

The hypothalamic arcuate nucleus contains two anatomically and functionally distinct populations of neurons-the agouti-related peptide (AgRP)- and pro-opiomelanocortin (POMC)-expressing neurons that integrate various nutritional, hormonal, and neuronal signals to regulate food intake and energy expenditure, and thereby help achieve energy homeostasis. AgRP neurons, also co-release neuropeptide Y (NPY) and γ-aminobutyric acid (GABA) to promote feeding and inhibit metabolism through at least three possible mechanisms: (1) suppression of the melanocortin signaling system through competitive binding of AgRP with the melanocortin 4 receptors; (2) NPY-mediated inhibition of post-synaptic neurons that reside in hypothalamic nuclei; (3) GABAergic inhibition of POMC neurons in their post-synaptic targets including the parabrachial nucleus (PBN), a brainstem structure that relays gustatory and visceral sensory information. Acute ablation of AgRP neurons in adult mice by the action of diphtheria toxin (DT) results in precipitous reduction of food intake, and eventually leads to starvation within 6days of DT treatment. Chronic delivery of bretazenil, a GABA(A) receptor partial agonist, into the PBN is sufficient to restore feeding and body weight when AgRP neurons are ablated, whereas chronic blockade of melanocortin 4 receptor signaling is inadequate. This review summarizes the physiological roles of a neural circuitry regulated by AgRP neurons in control of feeding behavior with particular emphasis of the GABA output to the parabrachial nucleus. We also describe a compensatory mechanism that is gradually engaged after ablation of AgRP neurons that allows mice to continue eating without them. Copyright © 2010 Elsevier B.V. All rights reserved.

Ghrelin receptors mediate ghrelin-induced excitation of agouti-related protein/neuropeptide Y but not pro-opiomelanocortin neurons.

PubMed

Chen, Shao-Rui; Chen, Hong; Zhou, Jing-Jing; Pradhan, Geetali; Sun, Yuxiang; Pan, Hui-Lin; Li, De-Pei

2017-08-01

Ghrelin increases food intake and body weight by stimulating orexigenic agouti-related protein (AgRP)/neuropeptide Y (NPY) neurons and inhibiting anorexic pro-opiomelanocortin (POMC) neurons in the hypothalamus. Growth hormone secretagogue receptor (Ghsr) mediates the effect of ghrelin on feeding behavior and energy homeostasis. However, the role of Ghsr in the ghrelin effect on these two populations of neurons is unclear. We hypothesized that Ghsr mediates the effect of ghrelin on AgRP and POMC neurons. In this study, we determined whether Ghsr similarly mediates the effects of ghrelin on AgRP/NPY and POMC neurons using cell type-specific Ghsr-knockout mice. Perforated whole-cell recordings were performed on green fluorescent protein-tagged AgRP/NPY and POMC neurons in the arcuate nucleus in hypothalamic slices. In Ghsr +/+ mice, ghrelin (100 nM) significantly increased the firing activity of AgRP/NPY neurons but inhibited the firing activity of POMC neurons. In Ghsr -/- mice, the excitatory effect of ghrelin on AgRP/NPY neurons was abolished. Ablation of Ghsr also eliminated ghrelin-induced increases in the frequency of GABAergic inhibitory postsynaptic currents of POMC neurons. Strikingly, ablation of Ghsr converted the ghrelin effect on POMC neurons from inhibition to excitation. Des-acylated ghrelin had no such effect on POMC neurons in Ghsr -/- mice. In both Ghsr +/+ and Ghsr -/- mice, blocking GABA A receptors with gabazine increased the basal firing activity of POMC neurons, and ghrelin further increased the firing activity of POMC neurons in the presence of gabazine. Our findings provide unequivocal evidence that Ghsr is essential for ghrelin-induced excitation of AgRP/NPY neurons. However, ghrelin excites POMC neurons through an unidentified mechanism that is distinct from conventional Ghsr. © 2017 International Society for Neurochemistry.

AgRP Neurons Can Increase Food Intake during Conditions of Appetite Suppression and Inhibit Anorexigenic Parabrachial Neurons.

PubMed

Essner, Rachel A; Smith, Alison G; Jamnik, Adam A; Ryba, Anna R; Trutner, Zoe D; Carter, Matthew E

2017-09-06

To maintain energy homeostasis, orexigenic (appetite-inducing) and anorexigenic (appetite suppressing) brain systems functionally interact to regulate food intake. Within the hypothalamus, neurons that express agouti-related protein (AgRP) sense orexigenic factors and orchestrate an increase in food-seeking behavior. In contrast, calcitonin gene-related peptide (CGRP)-expressing neurons in the parabrachial nucleus (PBN) suppress feeding. PBN CGRP neurons become active in response to anorexigenic hormones released following a meal, including amylin, secreted by the pancreas, and cholecystokinin (CCK), secreted by the small intestine. Additionally, exogenous compounds, such as lithium chloride (LiCl), a salt that creates gastric discomfort, and lipopolysaccharide (LPS), a bacterial cell wall component that induces inflammation, exert appetite-suppressing effects and activate PBN CGRP neurons. The effects of increasing the homeostatic drive to eat on feeding behavior during appetite suppressing conditions are unknown. Here, we show in mice that food deprivation or optogenetic activation of AgRP neurons induces feeding to overcome the appetite suppressing effects of amylin, CCK, and LiCl, but not LPS. AgRP neuron photostimulation can also increase feeding during chemogenetic-mediated stimulation of PBN CGRP neurons. AgRP neuron stimulation reduces Fos expression in PBN CGRP neurons across all conditions. Finally, stimulation of projections from AgRP neurons to the PBN increases feeding following administration of amylin, CCK, and LiCl, but not LPS. These results demonstrate that AgRP neurons are sufficient to increase feeding during noninflammatory-based appetite suppression and to decrease activity in anorexigenic PBN CGRP neurons, thereby increasing food intake during homeostatic need. SIGNIFICANCE STATEMENT The motivation to eat depends on the relative balance of activity in distinct brain regions that induce or suppress appetite. An abnormal amount of activity in

PTP1B deficiency improves hypothalamic insulin sensitivity resulting in the attenuation of AgRP mRNA expression under high-fat diet conditions.

PubMed

Sugiyama, Mariko; Banno, Ryoichi; Mizoguchi, Akira; Tominaga, Takashi; Tsunekawa, Taku; Onoue, Takeshi; Hagiwara, Daisuke; Ito, Yoshihiro; Morishita, Yoshiaki; Iwama, Shintaro; Goto, Motomitsu; Suga, Hidetaka; Arima, Hiroshi

2017-06-17

Hypothalamic insulin receptor signaling regulates energy balance and glucose homeostasis via agouti-related protein (AgRP). While protein tyrosine phosphatase 1B (PTP1B) is classically known to be a negative regulator of peripheral insulin signaling by dephosphorylating both insulin receptor β (IRβ) and insulin receptor substrate, the role of PTP1B in hypothalamic insulin signaling remains to be fully elucidated. In the present study, we investigated the role of PTP1B in hypothalamic insulin signaling using PTP1B deficient (KO) mice in vivo and ex vivo. For the in vivo study, hypothalamic insulin resistance induced by a high-fat diet (HFD) improved in KO mice compared to wild-type (WT) mice. Hypothalamic AgRP mRNA expression levels were also significantly decreased in KO mice independent of body weight changes. In an ex vivo study using hypothalamic organotypic cultures, insulin treatment significantly increased the phosphorylation of both IRβ and Akt in the hypothalamus of KO mice compared to WT mice, and also significantly decreased AgRP mRNA expression levels in KO mice. While incubation with inhibitors of phosphatidylinositol-3 kinase (PI3K) had no effect on basal levels of Akt phosphorylation, these suppressed insulin induction of Akt phosphorylation to almost basal levels in WT and KO mice. The inhibition of the PI3K-Akt pathway blocked the downregulation of AgRP mRNA expression in KO mice treated with insulin. These data suggest that PTP1B acts on the hypothalamic insulin signaling via the PI3K-Akt pathway. Together, our results suggest a deficiency of PTP1B improves hypothalamic insulin sensitivity resulting in the attenuation of AgRP mRNA expression under HFD conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

An excitatory paraventricular nucleus to AgRP neuron circuit that drives hunger.

PubMed

Krashes, Michael J; Shah, Bhavik P; Madara, Joseph C; Olson, David P; Strochlic, David E; Garfield, Alastair S; Vong, Linh; Pei, Hongjuan; Watabe-Uchida, Mitsuko; Uchida, Naoshige; Liberles, Stephen D; Lowell, Bradford B

2014-03-13

Hunger is a hard-wired motivational state essential for survival. Agouti-related peptide (AgRP)-expressing neurons in the arcuate nucleus (ARC) at the base of the hypothalamus are crucial to the control of hunger. They are activated by caloric deficiency and, when naturally or artificially stimulated, they potently induce intense hunger and subsequent food intake. Consistent with their obligatory role in regulating appetite, genetic ablation or chemogenetic inhibition of AgRP neurons decreases feeding. Excitatory input to AgRP neurons is important in caloric-deficiency-induced activation, and is notable for its remarkable degree of caloric-state-dependent synaptic plasticity. Despite the important role of excitatory input, its source(s) has been unknown. Here, through the use of Cre-recombinase-enabled, cell-specific neuron mapping techniques in mice, we have discovered strong excitatory drive that, unexpectedly, emanates from the hypothalamic paraventricular nucleus, specifically from subsets of neurons expressing thyrotropin-releasing hormone (TRH) and pituitary adenylate cyclase-activating polypeptide (PACAP, also known as ADCYAP1). Chemogenetic stimulation of these afferent neurons in sated mice markedly activates AgRP neurons and induces intense feeding. Conversely, acute inhibition in mice with caloric-deficiency-induced hunger decreases feeding. Discovery of these afferent neurons capable of triggering hunger advances understanding of how this intense motivational state is regulated.

Lipopolysacharide Rapidly and Completely Suppresses AgRP Neuron-Mediated Food Intake in Male Mice

PubMed Central

Liu, Yang; Huang, Ying; Liu, Tiemin; Wu, Hua; Cui, Huxing

2016-01-01

Although Agouti-related peptide (AgRP) neurons play a key role in the regulation of food intake, their contribution to the anorexia caused by proinflammatory insults has yet to be identified. Using a combination of neuroanatomical and pharmacogenetics experiments, this study sought to investigate the importance of AgRP neurons and downstream targets in the anorexia caused by the peripheral administration of a moderate dose of lipopolysaccharide (LPS) (100 μg/kg, ip). First, in the C57/Bl6 mouse, we demonstrated that LPS induced c-fos in select AgRP-innervated brain sites involved in feeding but not in any arcuate proopiomelanocortin neurons. Double immunohistochemistry further showed that LPS selectively induced c-Fos in a large subset of melanocortin 4 receptor-expressing neurons in the lateral parabrachial nucleus. Secondly, we used pharmacogenetics to stimulate the activity of AgRP neurons during the course of LPS-induced anorexia. In AgRP-Cre mice expressing the designer receptor hM3Dq-Gq only in AgRP neurons, the administration of the designer drug clozapine-N-oxide (CNO) induced robust food intake. Strikingly, CNO-mediated food intake was rapidly and completely blunted by the coadministration of LPS. Neuroanatomical experiments further indicated that LPS did not interfere with the ability of CNO to stimulate c-Fos in AgRP neurons. In summary, our findings combined together support the view that the stimulation of select AgRP-innervated brain sites and target neurons, rather than the inhibition of AgRP neurons themselves, is likely to contribute to the rapid suppression of food intake observed during acute bacterial endotoxemia. PMID:27111742

Lipopolysacharide Rapidly and Completely Suppresses AgRP Neuron-Mediated Food Intake in Male Mice.

PubMed

Liu, Yang; Huang, Ying; Liu, Tiemin; Wu, Hua; Cui, Huxing; Gautron, Laurent

2016-06-01

Although Agouti-related peptide (AgRP) neurons play a key role in the regulation of food intake, their contribution to the anorexia caused by proinflammatory insults has yet to be identified. Using a combination of neuroanatomical and pharmacogenetics experiments, this study sought to investigate the importance of AgRP neurons and downstream targets in the anorexia caused by the peripheral administration of a moderate dose of lipopolysaccharide (LPS) (100 μg/kg, ip). First, in the C57/Bl6 mouse, we demonstrated that LPS induced c-fos in select AgRP-innervated brain sites involved in feeding but not in any arcuate proopiomelanocortin neurons. Double immunohistochemistry further showed that LPS selectively induced c-Fos in a large subset of melanocortin 4 receptor-expressing neurons in the lateral parabrachial nucleus. Secondly, we used pharmacogenetics to stimulate the activity of AgRP neurons during the course of LPS-induced anorexia. In AgRP-Cre mice expressing the designer receptor hM3Dq-Gq only in AgRP neurons, the administration of the designer drug clozapine-N-oxide (CNO) induced robust food intake. Strikingly, CNO-mediated food intake was rapidly and completely blunted by the coadministration of LPS. Neuroanatomical experiments further indicated that LPS did not interfere with the ability of CNO to stimulate c-Fos in AgRP neurons. In summary, our findings combined together support the view that the stimulation of select AgRP-innervated brain sites and target neurons, rather than the inhibition of AgRP neurons themselves, is likely to contribute to the rapid suppression of food intake observed during acute bacterial endotoxemia.

ROCK1 in AgRP neurons regulates energy expenditure and locomotor activity in male mice.

PubMed

Huang, Hu; Lee, Seung Hwan; Ye, Chianping; Lima, Ines S; Oh, Byung-Chul; Lowell, Bradford B; Zabolotny, Janice M; Kim, Young-Bum

2013-10-01

Normal leptin signaling is essential for the maintenance of body weight homeostasis. Proopiomelanocortin- and agouti-related peptide (AgRP)-producing neurons play critical roles in regulating energy metabolism. Our recent work demonstrates that deletion of Rho-kinase 1 (ROCK1) in the AgRP neurons of mice increased body weight and adiposity. Here, we report that selective loss of ROCK1 in AgRP neurons caused a significant decrease in energy expenditure and locomotor activity of mice. These effects were independent of any change in food intake. Furthermore, AgRP neuron-specific ROCK1-deficient mice displayed central leptin resistance, as evidenced by impaired Signal Transducer and Activator of Transcription 3 activation in response to leptin administration. Leptin's ability to hyperpolarize and decrease firing rate of AgRP neurons was also abolished in the absence of ROCK1. Moreover, diet-induced and genetic forms of obesity resulted in reduced ROCK1 activity in murine arcuate nucleus. Of note, high-fat diet also impaired leptin-stimulated ROCK1 activity in arcuate nucleus, suggesting that a defect in hypothalamic ROCK1 activity may contribute to the pathogenesis of central leptin resistance in obesity. Together, these data demonstrate that ROCK1 activation in hypothalamic AgRP neurons is required for the homeostatic regulation of energy expenditure and adiposity. These results further support previous work identifying ROCK1 as a key regulator of energy balance and suggest that targeting ROCK1 in the hypothalamus may lead to development of antiobesity therapeutics.

A rare mutation in AgRP, +79G>A, affects promoter activity.

PubMed

Sözen, M A; de Jonge, L H M; Greenway, F; Ravussin, E; Smith, S R; Argyropoulos, G

2007-06-01

The agouti-related protein is a powerful orexigenic peptide. A rare mutation, +79G>A, was identified in its minimal promoter in two white carriers. Comparison of the 45-year-old male proband, who was also a carrier of the common Ala67Thr polymorphism, with an age- and weight-matching wild-type population showed marginal differences for resting metabolic rate (RMR) and body mass index. The second carrier however was an obese 57-year-old female with reduced RMR. Functional analysis in hypothalamus- and periphery-derived cell lines showed reduced promoter activity for the +79A allele in the adrenocortical cells only, suggesting that it could affect the peripheral expression levels of AgRP. The +79G>A mutation could predispose to body weight gain (as suggested by the phenotype of the second carrier), but it could only affect the proband at an older age as he may be protected by the Ala67Thr polymorphism that is associated with resistance to late-onset fatness.

Optogenetic Stimulation of Arcuate Nucleus Kiss1 Neurons Reveals a Steroid-Dependent Glutamatergic Input to POMC and AgRP Neurons in Male Mice

PubMed Central

Nestor, Casey C; Qiu, Jian; Padilla, Stephanie L.; Zhang, Chunguang; Bosch, Martha A.; Fan, Wei; Aicher, Sue A.; Palmiter, Richard D.

2016-01-01

Kisspeptin (Kiss1) neurons are essential for reproduction, but their role in the control of energy balance and other homeostatic functions remains unclear. Proopiomelanocortin (POMC) and agouti-related peptide (AgRP) neurons, located in the arcuate nucleus (ARC) of the hypothalamus, integrate numerous excitatory and inhibitory inputs to ultimately regulate energy homeostasis. Given that POMC and AgRP neurons are contacted by Kiss1 neurons in the ARC (Kiss1ARC) and they express androgen receptors, Kiss1ARC neurons may mediate the orexigenic action of testosterone via POMC and/or AgRP neurons. Quantitative PCR analysis of pooled Kiss1ARC neurons revealed that mRNA levels for Kiss1 and vesicular glutamate transporter 2 were higher in castrated male mice compared with gonad-intact males. Single-cell RT-PCR analysis of yellow fluorescent protein (YFP) ARC neurons harvested from males injected with AAV1-EF1α-DIO-ChR2:YFP revealed that 100% and 88% expressed mRNAs for Kiss1 and vesicular glutamate transporter 2, respectively. Whole-cell, voltage-clamp recordings from nonfluorescent postsynaptic ARC neurons showed that low frequency photo-stimulation (0.5 Hz) of Kiss1-ChR2:YFP neurons elicited a fast glutamatergic inward current in POMC and AgRP neurons. Paired-pulse, photo-stimulation revealed paired-pulse depression, which is indicative of greater glutamate release, in the castrated male mice compared with gonad-intact male mice. Group I and group II metabotropic glutamate receptor agonists depolarized and hyperpolarized POMC and AgRP neurons, respectively, which was mimicked by high frequency photo-stimulation (20 Hz) of Kiss1ARC neurons. Therefore, POMC and AgRP neurons receive direct steroid- and frequency-dependent glutamatergic synaptic input from Kiss1ARC neurons in male mice, which may be a critical pathway for Kiss1 neurons to help coordinate energy homeostasis and reproduction. PMID:27093227

Circulating Levels of Orexin-A, Nesfatin-1, Agouti-Related Peptide, and Neuropeptide Y in Patients with Hyperthyroidism.

PubMed

Tohma, Yusuf; Akturk, Mujde; Altinova, Alev; Yassibas, Emine; Cerit, Ethem Turgay; Gulbahar, Ozlem; Arslan, Metin; Sanlier, Nevin; Toruner, Fusun

2015-07-01

There is insufficient information about the appetite-related hormones orexin-A, nesfatin-1, agouti-related peptide (AgRP), and neuropeptide Y (NPY) in hyperthyroidism. The aim of the present study was to investigate the effects of hyperthyroidism on the basal metabolic rate (BMR) and energy intake, orexin-A, nesfatin-1, AgRP, NPY, and leptin levels in the circulation, and their relationship with each other and on appetite. In this prospective study, patients were evaluated in hyperthyroid and euthyroid states in comparison with healthy subjects. Twenty-one patients with overt hyperthyroidism and 33 healthy controls were included in the study. Daily energy intake in the hyperthyroid state was found to be higher than that in the euthyroid state patient group (p=0.039). BMR was higher in hyperthyroid patients than the control group (p=0.018). Orexin-A was lower and nesfatin-1 was higher in hyperthyroid patients compared to the controls (p<0.001), whereas orexin-A increased and nesfatin-1 decreased after euthyroidism (p=0.003, p<0.001). No differences were found in the AgRP, NPY, and leptin levels between the hyperthyroid and euthyroid states and controls (p>0.05). Orexin-A correlated negatively with nesfatin-1 (p=0.042), BMR (p=0.013), free triiodothyronine (fT3; p<0.001), and free thyroxine (fT4; p<0.001) and positively with thyrotropin (TSH; p<0.001). Nesfatin-1 correlated negatively with orexin-A (p=0.042) and TSH (p<0.001) and positively with fT3 (p=0.005) and fT4 (p=0.001). In the regression analysis, "diagnosis of hyperthyroidism" was the main factor affecting orexin-A (p<0.001). Although it seems that no relationship exists among orexin-A, nesfatin-1, and increased appetite in hyperthyroidism, the orexin-A and nesfatin-1 levels are markedly affected by hyperthyroidism.

Isolation and characterization of Agouti: a diabetes/obesity related gene

DOEpatents

Woychik, Richard P.

1998-01-01

The present invention relates to the cloning and expression of the Agouti gene and analogous genes in transformed, transfected and transgenic mice. The present invention provides an animal model for the study of diabetes, obesity and tumors for the testing of potential therapeutic agents. The present invention provides oligonucleotide probes for the detection of the Agouti gene and mutations in the gene. The present invention also relates to the isolation and recombinant production of the Agouti gene product, production of antibodies to the Agouti gene product and their use as diagnostic and therapeutic agents.

Isolation and characterization of Agouti: a diabetes/obesity related gene

DOEpatents

Woychik, Richard P.

2000-06-27

The present invention relates to the cloning and expression of the Agouti gene and analogous genes in transformed, transfected and transgenic mice. The present invention provides an animal model for the study of diabetes, obesity and tumors for the testing of potential therapeutic agents. The present invention provides oligonucleotide probes for the detection of the Agouti gene and mutations in the gene. The present invention also relates to the isolation and recombinant production of the Agouti gene product, production of antibodies to the Agouti gene product and their use as diagnostic and therapeutic agents.

AgRP to Kiss1 neuron signaling links nutritional state and fertility

PubMed Central

Padilla, Stephanie L.; Qiu, Jian; Nestor, Casey C; Zhang, Chunguang; Smith, Arik W.; Whiddon, Benjamin B.; Rønnekleiv, Oline K.; Kelly, Martin J.; Palmiter, Richard D.

2017-01-01

Mammalian reproductive function depends upon a neuroendocrine circuit that evokes the pulsatile release of gonadotropin hormones (luteinizing hormone and follicle-stimulating hormone) from the pituitary. This reproductive circuit is sensitive to metabolic perturbations. When challenged with starvation, insufficient energy reserves attenuate gonadotropin release, leading to infertility. The reproductive neuroendocrine circuit is well established, composed of two populations of kisspeptin-expressing neurons (located in the anteroventral periventricular hypothalamus, Kiss1AVPV, and arcuate hypothalamus, Kiss1ARH), which drive the pulsatile activity of gonadotropin-releasing hormone (GnRH) neurons. The reproductive axis is primarily regulated by gonadal steroid and circadian cues, but the starvation-sensitive input that inhibits this circuit during negative energy balance remains controversial. Agouti-related peptide (AgRP)-expressing neurons are activated during starvation and have been implicated in leptin-associated infertility. To test whether these neurons relay information to the reproductive circuit, we used AgRP-neuron ablation and optogenetics to explore connectivity in acute slice preparations. Stimulation of AgRP fibers revealed direct, inhibitory synaptic connections with Kiss1ARH and Kiss1AVPV neurons. In agreement with this finding, Kiss1ARH neurons received less presynaptic inhibition in the absence of AgRP neurons (neonatal toxin-induced ablation). To determine whether enhancing the activity of AgRP neurons is sufficient to attenuate fertility in vivo, we artificially activated them over a sustained period and monitored fertility. Chemogenetic activation with clozapine N-oxide resulted in delayed estrous cycles and decreased fertility. These findings are consistent with the idea that, during metabolic deficiency, AgRP signaling contributes to infertility by inhibiting Kiss1 neurons. PMID:28196880

Hypothalamic Agouti-Related Peptide mRNA is Elevated During Natural and Stress-Induced Anorexia.

PubMed

Dunn, I C; Wilson, P W; D'Eath, R B; Boswell, T

2015-09-01

As part of their natural lives, animals can undergo periods of voluntarily reduced food intake and body weight (i.e. animal anorexias) that are beneficial for survival or breeding, such as during territorial behaviour, hibernation, migration and incubation of eggs. For incubation, a change in the defended level of body weight or 'sliding set point' appears to be involved, although the neural mechanisms reponsible for this are unknown. We investigated how neuropeptide gene expression in the arcuate nucleus of the domestic chicken responded to a 60-70% voluntary reduction in food intake measured both after incubation and after an environmental stressor involving transfer to unfamiliar housing. We hypothesised that gene expression would not change in these circumstances because the reduced food intake and body weight represented a defended level in birds with free access to food. Unexpectedly, we observed increased gene expression of the orexigenic peptide agouti-related peptide (AgRP) in both incubating and transferred animals compared to controls. Also pro-opiomelanocortin (POMC) mRNA was higher in incubating hens and significantly increased 6 days after exposure to the stressor. Conversely expression of neuropeptide Y and cocaine- and amphetamine-regulated transcript gene was unchanged in both experimental situations. We conclude that AgRP expression remains sensitive to the level of energy stores during natural anorexias, which is of adaptive advantage, although its normal orexigenic effects are over-ridden by inhibitory signals. In the case of stress-induced anorexia, increased POMC may contribute to this inhibitory role, whereas, for incubation, reduced feeding may also be associated with increased expression in the hypothalamus of the anorexigenic peptide vasoactive intestinal peptide. © 2015 British Society for Neuroendocrinology.

Leptin Signaling in AgRP Neurons Modulates Puberty Onset and Adult Fertility in Mice.

PubMed

Egan, Olivia K; Inglis, Megan A; Anderson, Greg M

2017-04-05

The hormone leptin indirectly communicates metabolic information to brain neurons that control reproduction, using GABAergic circuitry. Agouti-related peptide (AgRP) neurons in the arcuate nucleus are GABAergic, express leptin receptors (LepR), and are known to influence reproduction. This study tested whether leptin actions on AgRP neurons are required and sufficient for puberty onset and subsequent fertility. First, Agrp- Cre and Lepr- flox mice were used to target deletion of LepR to AgRP neurons. AgRP-LepR knock-out female mice exhibited mild obesity and adiposity as described previously, as well as a significant delay in the pubertal onset of estrous cycles compared with control animals. No significant differences in male puberty onset or adult fecundity in either sex were observed. Next, mice with a floxed polyadenylation signal causing premature transcriptional termination of the Lepr gene were crossed with AgRP-Cre mice to generate mice with AgRP neuron-specific rescue of LepR. Lepr-null control males and females were morbidly obese and exhibited delayed puberty onset, no evidence of estrous cycles, and minimal fecundity. Remarkably, AgRP-LepR rescue partially or fully restored all of these reproductive attributes to levels similar to those of LepR-intact controls despite minimal rescue of metabolic function. These results indicate that leptin signaling in AgRP neurons is sufficient for puberty onset and normal adult fecundity in both sexes when leptin signaling is absent in all other cells and that in females, the absence of AgRP neuron leptin signaling delays puberty. These actions appear to be independent of leptin's metabolic effects. SIGNIFICANCE STATEMENT Sexual maturation and fertility are dispensable at the individual level but critical for species survival. Conditions such as nutritional imbalance may therefore suppress puberty onset and fertility in an individual. In societies characterized by widespread obesity, the sensitivity of reproduction to

Agouti signaling protein stimulates cell division in "viable yellow" (A vy/a) mouse liver

USDA-ARS?s Scientific Manuscript database

Enhanced linear growth, hyperplasia, and tumorigenesis are well-known characteristics of "viable yellow" agouti Avy/- mice (1); however, the functional basis for this aspect of the phenotype is unknown. In the present study, we ascertained whether agouti signaling protein (ASIP) levels in Avy/a or a...

The role of GluN2A and GluN2B NMDA receptor subunits in AgRP and POMC neurons on body weight and glucose homeostasis.

PubMed

Üner, Aykut; Gonçalves, Gabriel H M; Li, Wenjing; Porceban, Matheus; Caron, Nicole; Schönke, Milena; Delpire, Eric; Sakimura, Kenji; Bjørbæk, Christian

2015-10-01

Hypothalamic agouti-related peptide (AgRP) and pro-opiomelanocortin (POMC) expressing neurons play critical roles in control of energy balance. Glutamatergic input via n-methyl-d-aspartate receptors (NMDARs) is pivotal for regulation of neuronal activity and is required in AgRP neurons for normal body weight homeostasis. NMDARs typically consist of the obligatory GluN1 subunit and different GluN2 subunits, the latter exerting crucial differential effects on channel activity and neuronal function. Currently, the role of specific GluN2 subunits in AgRP and POMC neurons on whole body energy and glucose balance is unknown. We used the cre-lox system to genetically delete GluN2A or GluN2B only from AgRP or POMC neurons in mice. Mice were then subjected to metabolic analyses and assessment of AgRP and POMC neuronal function through morphological studies. We show that loss of GluN2B from AgRP neurons reduces body weight, fat mass, and food intake, whereas GluN2B in POMC neurons is not required for normal energy balance control. GluN2A subunits in either AgRP or POMC neurons are not required for regulation of body weight. Deletion of GluN2B reduces the number of AgRP neurons and decreases their dendritic length. In addition, loss of GluN2B in AgRP neurons of the morbidly obese and severely diabetic leptin-deficient Lep (ob/ob) mice does not affect body weight and food intake but, remarkably, leads to full correction of hyperglycemia. Lep (ob/ob) mice lacking GluN2B in AgRP neurons are also more sensitive to leptin's anti-obesity actions. GluN2B-containing NMDA receptors in AgRP neurons play a critical role in central control of body weight homeostasis and blood glucose balance via mechanisms that likely involve regulation of AgRP neuronal survival and structure, and modulation of hypothalamic leptin action.

Agouti polypeptide compositions

DOEpatents

Woychik, Richard P.; Bultman, Scott J.; Michaud, Edward J.

2001-10-30

Disclosed are methods and compositions comprising novel agouti polypeptides and the polynucleotides which encode them. Also disclosed are DNA segments encoding these proteins derived from human and murine cell lines, and the use of these polynucleotides and polypeptides in a variety of diagnostic and therapeutic applications. Methods, compositions, kits, and devices are also provided for identifying compounds which are inhibitors of agouti activity, and for altering fatty acid synthetase activity and intracellular calcium levels in transformed cells.

Comparative in Vivo Investigation of Intrathecal and Intracerebroventricular Administration with Melanocortin Ligands MTII and AGRP into Mice.

PubMed

Adank, Danielle N; Lunzer, Mary M; Lensing, Cody J; Wilber, Stacey L; Gancarz, Amy M; Haskell-Luevano, Carrie

2018-02-21

Central administration of melanocortin ligands has been used as a critical technique to study energy homeostasis. While intracerebroventricular (ICV) injection is the most commonly used method during these investigations, intrathecal (IT) injection can be equally efficacious for the central delivery of ligands. Importantly, intrathecal administration can optimize exploration of melanocortin receptors in the spinal cord. Herein, we investigate comparative IT and ICV administration of two melanocortin ligands, the synthetic MTII (Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH 2 ) MC4R agonist and agouti-related peptide [AGRP(87-132)] MC4R inverse agonist/antagonist, on the same batch of age-matched mice in TSE metabolic cages undergoing a nocturnal satiated paradigm. To our knowledge, this is the first study to test how central administration of these ligands directly to the spinal cord affects energy homeostasis. Results showed, as expected, that MTII IT administration caused a decrease in food and water intake and an overall negative energy balance without affecting activity. As anticipated, IT administration of AGRP caused weight gain, increase of food/water intake, and increase respiratory exchange ratio (RER). Unexpectantly, the prolonged activity of AGRP was notably shorter (2 days) compared to mice given ICV injections of the same concentrations in previous studies (7 days or more).1-4 It appears that IT administration results in a more sensitive response that may be a good approach for testing synthetic compound potency values ranging in nanomolar to high micromolar in vitro EC 50 values. Indeed, our investigation reveals that the spine influences a different melanocortin response compared to the brain for the AGRP ligand. This study indicates that IT administration can be a useful technique for future metabolic studies using melanocortin ligands and highlights the importance of exploring the role of melanocortin receptors in the spinal cord.

Analysis of the function of the agouti gene in obesity and diabetes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mynatt, R.L.; Miltenberger, R.J.; Klebig, M.L.

1996-09-01

This chapter discusses the agouti gene and dominant mutations in that gene that lead to agouti-induced obesity, and recent work with transgenic mice to elucidate the role of agouti in obesity. Agouti was cloned in 1992 by the lab of Rick Woychik at Oak Ridge National Laboratory, making it the first of many recently cloned mouse obesity genes. Sequence analysis predicted that mouse agouti is a secreted protein of 131 amino acids. The mature protein has a basic central region (lys57-arg85), a proline-rich domain (pro86-pro91) and a C-terminal region (cys 92-cys 13 1) containing 10 cysteine residues which form 5more » disulfide bonds. The human homologue of agouti has also been cloned by the Woychik lab and maps to human chromosome 20q 11.2. Human agouti is 132 amino acids long and is 85% similar to the mouse agouti protein and is normally expressed in adipose tissue. The researchers have been able to recapitulate obesity, hyperinsulinemia, and hyperglycemia with the ubiquitous expression of agouti. Agouti expression in either liver and adipose tissue alone does not cause obesity, and there`s a dose-dependent effect of agouti on body weight, food efficiency, body temperature, and insulin and glucose levels.« less

Pharmacological characterization of 30 human melanocortin-4 receptor polymorphisms with the endogenous proopiomelanocortin-derived agonists, synthetic agonists, and the endogenous agouti-related protein antagonist.

PubMed

Xiang, Zhimin; Proneth, Bettina; Dirain, Marvin L; Litherland, Sally A; Haskell-Luevano, Carrie

2010-06-08

The melanocortin-4 receptor (MC4R) is a G-protein-coupled receptor (GPCR) that is expressed in the central nervous system and has a role in regulating feeding behavior, obesity, energy homeostasis, male erectile response, and blood pressure. Since the report of the MC4R knockout mouse in 1997, the field has been searching for links between this genetic biomarker and human obesity and type 2 diabetes. More then 80 single nucleotide polymorphisms (SNPs) have been identified from human patients, both obese and nonobese controls. Many significant studies have been performed examining the pharmacological characteristics of these hMC4R SNPs in attempts to identify a molecular defects/insights that might link a genetic factor to the obese phenotype observed in patients possessing these mutations. Our laboratory has previously reported the pharmacological characterization of 40 of these polymorphic hMC4 receptors with multiple endogenous and synthetic ligands. The goal of the current study is to perform a similar comprehensive side-by-side characterization of 30 additional human hMC4R with single nucleotide polymorphisms using multiple endogenous agonists [alpha-, beta-, and gamma(2)-melanocyte stimulating hormones (MSH) and adrenocorticotropin (ACTH)], the antagonist agouti-related protein hAGRP(87-132), and synthetic agonists [NDP-MSH, MTII, and the tetrapeptide Ac-His-dPhe-Arg-Trp-NH(2) (JRH887-9)]. These in vitro data, in some cases, provide a putative molecular link between dysfunctional hMC4R's and human obesity. These 30 hMC4R SNPs include R7H, R18H, R18L, S36Y, P48S, V50M, F51L, E61K, I69T, D90N, S94R, G98R, I121T, A154D, Y157S, W174C, G181D, F202L, A219 V, I226T, G231S, G238D, N240S, C271R, S295P, P299L, E308K, I317V, L325F, and 750DelGA. All but the N240S hMC4R were identified in obese patients. Additionally, we have characterized a double I102T/V103I hMC4R. In addition to the pharmacological characterization, the hMC4R variants were evaluated for cell surface

Molecular analysis of the mouse agouti gene and the role of dominant agouti-locus mutations in obesity and insulin resistance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klebig, M.L.; Woychik, R.P.; Wilkinson, J.E.

1994-09-01

The lethal yellow (A{sup y/-}) and viable yellow (A{sup vy/-}) mouse agouti mutants have a predominantly yellow pelage and display a complex syndrome that includes obesity, hyperinsulinemia, and insulin resistance, hallmark features of obesity-associated noninsulin-dependent diabetes mellitus (NIDDM) in humans. A new dominant agouti allele, A{sup iapy}, has recently been identified; like the A{sup vy} allele, it is homozygous viable and confers obesity and yellow fur in heterozygotes. The agouti gene was cloned and characterized at the molecular level. The gene is expressed in the skin during hair growth and is predicted to encode a 131 amino acid protein, thatmore » is likely to be a secreted factor. In both Ay/- and A{sup iapy}/- mice, the obesity and other dominant pleiotropic effects are associated with an ectopic expression of agouti in many tissues where the gene product is normally not produced. In Ay, a 170-kb deletion has occurred that causes an upstream promoter to drive the ectopic expression of the wild-type agouti coding exons. In A{sup iapy}, the coding region of the gene is expressed from a cryptic promoter within the LTR of an intracisternal A-particle (IAP), which has integrated within the region just upstream of the first agouti coding exon. Transgenic mice ubiquitously expressing the cloned agouti gene under the influence of the beta-actin and phosphoglycerate kinase promoters display obesity, hyperinsulinemia, and yellow coat color. This demonstrates unequivocally that ectopic expression of agouti is responsible for the yellow obese syndrome.« less

Agouti polynucleotide compositions and methods of use

DOEpatents

Woychik, Richard P.; Bultman, Scott J.; Michaud, Edward J.

2003-02-04

Disclosed are methods and compositions comprising novel agouti polypeptides and the polynucleotides which encode them. Also disclosed are DNA segments encoding these proteins derived from human and murine cell lines, and the use of these polynucleotides and polypeptides in a variety of diagnostic and therapeutic applications. Methods, compositions, kits, and devices are also provided for identifying compounds which are inhibitors of agouti activity, and for altering fatty acid synthetase activity and intracellular calcium levels in transformed cells.

Lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNFα) blunt the response of Neuropeptide Y/Agouti-related peptide (NPY/AgRP) glucose inhibited (GI) neurons to decreased glucose

PubMed Central

Hao, Lihong; Sheng, Zhenyu; Potian, Joseph; Deak, Adam; Rohowsky-Kochan, Christine; Routh, Vanessa H.

2016-01-01

A population of Neuropeptide Y (NPY) neurons which co-express Agouti-related peptide (AgRP) in the arcuate nucleus of the hypothalamus (ARC) are inhibited at physiological levels of brain glucose and activated when glucose levels decline (e.g. glucose-inhibited or GI neurons). Fasting enhances the activation of NPY/AgRP-GI neurons by low glucose. In the present study we tested the hypothesis that lipopolysaccharide (LPS) inhibits the enhanced activation of NPY/AgRP-GI neurons by low glucose following a fast. Mice which express green fluorescent protein (GFP) on their NPY promoter were used to identify NPY/AgRP neurons. Fasting for 24 hours and LPS injection decreased blood glucose levels. As we have found previously, fasting increased c-fos expression in NPY/AgRP neurons and increased the activation of NPY/AgRP-GI neurons by decreased glucose. As we predicted, LPS blunted these effects of fasting at the 24 hour time point. Moreover, the inflammatory cytokine tumor necrosis factor alpha (TNFα) blocked the activation of NPY/AgRP-GI neurons by decreased glucose. These data suggest that LPS and TNFα may alter glucose and energy homeostasis, in part, due to changes in the glucose sensitivity of NPY/AgRP neurons. Interestingly, our findings also suggest that NPY/AgRP-GI neurons use a distinct mechanism to sense changes in extracellular glucose as compared to our previous studies of GI neurons in the adjacent ventromedial hypothalamic nucleus. PMID:27473896

Structure-activity relationships of the unique and potent agouti-related protein (AGRP)-melanocortin chimeric Tyr-c[beta-Asp-His-DPhe-Arg-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH2 peptide template.

PubMed

Wilczynski, Andrzej; Wilson, Krista R; Scott, Joseph W; Edison, Arthur S; Haskell-Luevano, Carrie

2005-04-21

The melanocortin receptor system consists of endogenous agonists, antagonists, G-protein coupled receptors, and auxiliary proteins that are involved in the regulation of complex physiological functions such as energy and weight homeostasis, feeding behavior, inflammation, sexual function, pigmentation, and exocrine gland function. Herein, we report the structure-activity relationship (SAR) of a new chimeric hAGRP-melanocortin agonist peptide template Tyr-c[beta-Asp-His-DPhe-Arg-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH(2) that was characterized using amino acids previously reported in other melanocortin agonist templates. Twenty peptides were examined in this study, and six peptides were selected for (1)H NMR and computer-assisted molecular modeling structural analysis. The most notable results include the identification that modification of the chimeric template at the His position with Pro and Phe resulted in ligands that were nM mouse melanocortin-3 receptor (mMC3R) antagonists and nM mouse melanocortin-4 receptor (mMC4R) agonists. The peptides Tyr-c[beta-Asp-His-DPhe-Ala-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH(2) and Tyr-c[beta-Asp-His-DNal(1')-Arg-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH(2) resulted in 730- and 560-fold, respectively, mMC4R versus mMC3R selective agonists that also possessed nM agonist potency at the mMC1R and mMC5R. Structural studies identified a reverse turn occurring in the His-DPhe-Arg-Trp domain, with subtle differences observed that may account for the differences in melanocortin receptor pharmacology. Specifically, a gamma-turn secondary structure involving the DPhe(4) in the central position of the Tyr-c[beta-Asp-Phe-DPhe-Arg-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH(2) peptide may differentiate the mixed mMC3R antagonist and mMC4R agonist pharmacology.

Role of Hypothalamic Melanocortin System in Adaptation of Food Intake to Food Protein Increase in Mice

PubMed Central

Pillot, Bruno; Duraffourd, Céline; Bégeot, Martine; Joly, Aurélie; Luquet, Serge; Houberdon, Isabelle; Naville, Danielle; Vigier, Michèle; Gautier-Stein, Amandine; Magnan, Christophe; Mithieux, Gilles

2011-01-01

The hypothalamic melanocortin system—the melanocortin receptor of type 4 (MC4R) and its ligands: α-melanin-stimulating hormone (α-MSH, agonist, inducing hypophagia), and agouti-related protein (AgRP, antagonist, inducing hyperphagia)—is considered to play a central role in the control of food intake. We tested its implication in the mediation of the hunger-curbing effects of protein-enriched diets (PED) in mice. Whereas there was a 20% decrease in food intake in mice fed on the PED, compared to mice fed on an isocaloric starch-enriched diet, there was a paradoxical decrease in expression of the hypothalamic proopiomelanocortin gene, precursor of α-MSH, and increase in expression of the gene encoding AgRP. The hypophagia effect of PED took place in mice with invalidation of either MC4R or POMC, and was even strengthened in mice with ablation of the AgRP-expressing neurons. These data strongly suggest that the hypothalamic melanocortin system does not mediate the hunger-curbing effects induced by changes in the macronutrient composition of food. Rather, the role of this system might be to defend the body against the variations in food intake generated by the nutritional environment. PMID:21544212

AgRP and MC3/4 receptor agonists both inhibit excitatory hypothalamic ventromedial nucleus neurons

PubMed Central

Fu, Li-Ying; van den Pol, Anthony N.

2009-01-01

Anorexigenic melanocortins decrease food intake by activating MC3/MC4 receptors (MC3/4R); the prevailing view is that the orexigenic neuropeptide AgRP exerts the opposite action by acting as an antagonist at MC3/MC4 receptors. 370 VMH glutamatergic neurons were studied using whole-cell recording in hypothalamic slices from a novel mouse expressing GFP under control of the vGluT2 promoter. Massive numbers of GFP-expressing VMH dendrites extended out of the core of the nucleus into the surrounding cell-poor shell. VMH dendrites received frequent appositions from AgRP immunoreactive axons in the shell of the nucleus, but not the core, suggesting that AgRP may influence target VMH neurons. Alpha-MSH, MTII, and selective MC3R or MC4R agonists were all inhibitory, reducing the spontaneous firing rate and hyperpolarizing vGluT2 neurons. The MC3/4R antagonist SHU9119 was excitatory. Unexpectedly, AgRP did not attenuate MTII actions on these neurons; instead these two compounds showed an additive inhibitory effect. In the absence of synaptic activity, no hyperpolarization or change in input resistance was evoked by either MTII or AgRP, suggesting indirect actions. Consistent with this view, MTII increased the frequency of spontaneous and miniature IPSCs. In contrast, the mechanism of AgRP inhibition was dependent on presynaptic inhibition of EPSCs mediated by Gi/Go proteins, and was attenuated by pertussis toxin and NF023, inconsistent with mediation by Gs proteins associated with MC receptors. Together, our data suggest that the mechanism of AgRP actions on these excitatory VMH cells appears to be independent of the actions of melanocortins on MC receptors. PMID:18495877

O-GlcNAc transferase enables AgRP neurons to suppress browning of white fat

PubMed Central

Ruan, Hai-Bin; Dietrich, Marcelo O.; Liu, Zhong-Wu; Zimmer, Marcelo R.; Li, Min-Dian; Singh, Jay Prakash; Zhang, Kaisi; Yin, Ruonan; Wu, Jing; Horvath, Tamas L.; Yang, Xiaoyong

2014-01-01

SUMMARY Induction of beige cells causes the browning of white fat and improves energy metabolism. However, the central mechanism that controls adipose tissue browning and its physiological relevance are largely unknown. Here we demonstrate that fasting and chemical-genetic activation of orexigenic AgRP neurons in the hypothalamus suppress the browning of white fat. O-linked β-N-acetylglucosamine (O-GlcNAc) modification of cytoplasmic and nuclear proteins regulates fundamental cellular processes. The levels of O-GlcNAc transferase (OGT) and O-GlcNAc modification are enriched in AgRP neurons and are elevated by fasting. Genetic ablation of OGT in AgRP neurons inhibits neuronal excitability through the voltage-dependent potassium channel, promotes white adipose tissue browning, and protects mice against diet-induced obesity and insulin resistance. These data reveal adipose tissue browning as a highly dynamic physiological process under central control, in which O-GlcNAc signaling in AgRP neurons is essential for suppressing thermogenesis to conserve energy in response to fasting. PMID:25303527

Control of energy balance by hypothalamic gene circuitry involving two nuclear receptors, neuron-derived orphan receptor 1 and glucocorticoid receptor.

PubMed

Kim, Sun-Gyun; Lee, Bora; Kim, Dae-Hwan; Kim, Juhee; Lee, Seunghee; Lee, Soo-Kyung; Lee, Jae W

2013-10-01

Nuclear receptors (NRs) regulate diverse physiological processes, including the central nervous system control of energy balance. However, the molecular mechanisms for the central actions of NRs in energy balance remain relatively poorly defined. Here we report a hypothalamic gene network involving two NRs, neuron-derived orphan receptor 1 (NOR1) and glucocorticoid receptor (GR), which directs the regulated expression of orexigenic neuropeptides agouti-related peptide (AgRP) and neuropeptide Y (NPY) in response to peripheral signals. Our results suggest that the anorexigenic signal leptin induces NOR1 expression likely via the transcription factor cyclic AMP response element-binding protein (CREB), while the orexigenic signal glucocorticoid mobilizes GR to inhibit NOR1 expression by antagonizing the action of CREB. Also, NOR1 suppresses glucocorticoid-dependent expression of AgRP and NPY. Consistently, relative to wild-type mice, NOR1-null mice showed significantly higher levels of AgRP and NPY and were less responsive to leptin in decreasing the expression of AgRP and NPY. These results identify mutual antagonism between NOR1 and GR to be a key rheostat for peripheral metabolic signals to centrally control energy balance.

Lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNFα) blunt the response of Neuropeptide Y/Agouti-related peptide (NPY/AgRP) glucose inhibited (GI) neurons to decreased glucose.

PubMed

Hao, Lihong; Sheng, Zhenyu; Potian, Joseph; Deak, Adam; Rohowsky-Kochan, Christine; Routh, Vanessa H

2016-10-01

A population of Neuropeptide Y (NPY) neurons which co-express Agouti-related peptide (AgRP) in the arcuate nucleus of the hypothalamus (ARC) are inhibited at physiological levels of brain glucose and activated when glucose levels decline (e.g. glucose-inhibited or GI neurons). Fasting enhances the activation of NPY/AgRP-GI neurons by low glucose. In the present study we tested the hypothesis that lipopolysaccharide (LPS) inhibits the enhanced activation of NPY/AgRP-GI neurons by low glucose following a fast. Mice which express green fluorescent protein (GFP) on their NPY promoter were used to identify NPY/AgRP neurons. Fasting for 24h and LPS injection decreased blood glucose levels. As we have found previously, fasting increased c-fos expression in NPY/AgRP neurons and increased the activation of NPY/AgRP-GI neurons by decreased glucose. As we predicted, LPS blunted these effects of fasting at the 24h time point. Moreover, the inflammatory cytokine tumor necrosis factor alpha (TNFα) blocked the activation of NPY/AgRP-GI neurons by decreased glucose. These data suggest that LPS and TNFα may alter glucose and energy homeostasis, in part, due to changes in the glucose sensitivity of NPY/AgRP neurons. Interestingly, our findings also suggest that NPY/AgRP-GI neurons use a distinct mechanism to sense changes in extracellular glucose as compared to our previous studies of GI neurons in the adjacent ventromedial hypothalamic nucleus. Copyright © 2016 Elsevier B.V. All rights reserved.

Arcuate AgRP neurons mediate orexigenic and glucoregulatory actions of ghrelin★

PubMed Central

Wang, Qian; Liu, Chen; Uchida, Aki; Chuang, Jen-Chieh; Walker, Angela; Liu, Tiemin; Osborne-Lawrence, Sherri; Mason, Brittany L.; Mosher, Christina; Berglund, Eric D.; Elmquist, Joel K.; Zigman, Jeffrey M.

2013-01-01

The hormone ghrelin stimulates eating and helps maintain blood glucose upon caloric restriction. While previous studies have demonstrated that hypothalamic arcuate AgRP neurons are targets of ghrelin, the overall relevance of ghrelin signaling within intact AgRP neurons is unclear. Here, we tested the functional significance of ghrelin action on AgRP neurons using a new, tamoxifen-inducible AgRP-CreERT2 transgenic mouse model that allows spatiotemporally-controlled re-expression of physiological levels of ghrelin receptors (GHSRs) specifically in AgRP neurons of adult GHSR-null mice that otherwise lack GHSR expression. AgRP neuron-selective GHSR re-expression partially restored the orexigenic response to administered ghrelin and fully restored the lowered blood glucose levels observed upon caloric restriction. The normalizing glucoregulatory effect of AgRP neuron-selective GHSR expression was linked to glucagon rises and hepatic gluconeogenesis induction. Thus, our data indicate that GHSR-containing AgRP neurons are not solely responsible for ghrelin's orexigenic effects but are sufficient to mediate ghrelin's effects on glycemia. PMID:24567905

Arcuate AgRP neurons mediate orexigenic and glucoregulatory actions of ghrelin.

PubMed

Wang, Qian; Liu, Chen; Uchida, Aki; Chuang, Jen-Chieh; Walker, Angela; Liu, Tiemin; Osborne-Lawrence, Sherri; Mason, Brittany L; Mosher, Christina; Berglund, Eric D; Elmquist, Joel K; Zigman, Jeffrey M

2014-02-01

The hormone ghrelin stimulates eating and helps maintain blood glucose upon caloric restriction. While previous studies have demonstrated that hypothalamic arcuate AgRP neurons are targets of ghrelin, the overall relevance of ghrelin signaling within intact AgRP neurons is unclear. Here, we tested the functional significance of ghrelin action on AgRP neurons using a new, tamoxifen-inducible AgRP-CreER(T2) transgenic mouse model that allows spatiotemporally-controlled re-expression of physiological levels of ghrelin receptors (GHSRs) specifically in AgRP neurons of adult GHSR-null mice that otherwise lack GHSR expression. AgRP neuron-selective GHSR re-expression partially restored the orexigenic response to administered ghrelin and fully restored the lowered blood glucose levels observed upon caloric restriction. The normalizing glucoregulatory effect of AgRP neuron-selective GHSR expression was linked to glucagon rises and hepatic gluconeogenesis induction. Thus, our data indicate that GHSR-containing AgRP neurons are not solely responsible for ghrelin's orexigenic effects but are sufficient to mediate ghrelin's effects on glycemia.

Enhanced anorexigenic signaling in lean obesity resistant syndecan-3 null mice

PubMed Central

Zheng, Qiao; Zhu, Jinling; Shanabrough, Marya; Borok, Erzsebet; Benoit, Stephen C.; Horvath, Tamas L.; Clegg, Deborah J.; Reizes, Ofer

2010-01-01

Obesity is associated with increased risk of diabetes, cardiovascular disease and several types of cancers. The hypothalamus is a region of the brain critical in the regulation of body weight. One of the critical and best studied hypothalamic circuits is comprised of the melanocortinergic orexigenic agouti -related protein (AgRP) and anorexigenic α-melanocyte stimulating hormone (α-MSH) neurons. These neurons project axons to the same hypothalamic target neurons and balance each other’s activity leading to body weight regulation. We previously showed that the brain proteoglycan syndecan-3 regulates feeding behavior and body weight, and syndecan-3 null (SDC-3−/−) mice are lean and obesity resistant. Here we show that the melanocortin agonist MTII potently suppresses food intake and activates the hypothalamic paraventricular nuclei (PVN) in SDC-3−/− mice based on c-fos immunoreactivity. Interestingly, we determined that the AgRP neuropeptide is reduced in the PVN of SDC-3−/− mice compared to wild type mice. In contrast, neuropeptide Y, coexpressed in the AgRP neuron, is not differentially expressed nor is the counteracting neuropeptide αMSH. These findings are unprecedented and indicate that AgRP protein localization can be selectively regulated within the hypothalamus resulting in altered neuropeptide response and tone. PMID:20923696

Failure to upregulate Agrp and Orexin in response to activity based anorexia in weight loss vulnerable rats characterized by passive stress coping and prenatal stress experience

PubMed Central

Boersma, Gretha J.; Liang, Nu-Chu; Lee, Richard S.; Albertz, Jennifer D.; Kastelein, Anneke; Moody, Laura A.; Aryal, Shivani; Moran, Timothy H.; Tamashiro, Kellie L.

2016-01-01

We hypothesize that Anorexia Nervosa (AN) poses a physiological stress. Therefore, the way an individual copes with stress may affect AN vulnerability. Since prenatal stress (PNS) exposure alters stress responsivity in offspring this may increase their risk of developing AN. We tested this hypothesis using the activity based anorexia (ABA) rat model in control and PNS rats that were characterized by either proactive or passive stress-coping behavior. We found that PNS passively coping rats ate less and lost more weight during the ABA paradigm. Exposure to ABA resulted in higher baseline corticosterone and lower insulin levels in all groups. However, leptin levels were only decreased in rats with a proactive stress-coping style. Similarly, ghrelin levels were increased only in proactively coping ABA rats. Neuropeptide Y (Npy) expression was increased and proopiomelanocortin (Pomc) expression was decreased in all rats exposed to ABA. In contrast, agouti-related peptide (Agrp) and orexin (Hctr) expression were increased in all but the PNS passively coping ABA rats. Furthermore, DNA methylation of the orexin gene was increased after ABA in proactive coping rats and not in passive coping rats. Overall our study suggests that passive PNS rats have innate impairments in leptin and ghrelin in responses to starvation combined with prenatal stress associated impairments in Agrp and orexin expression in response to starvation. These impairments may underlie decreased food intake and associated heightened body weight loss during ABA in the passively coping PNS rats. PMID:26907996

Failure to upregulate Agrp and Orexin in response to activity based anorexia in weight loss vulnerable rats characterized by passive stress coping and prenatal stress experience.

PubMed

Boersma, Gretha J; Liang, Nu-Chu; Lee, Richard S; Albertz, Jennifer D; Kastelein, Anneke; Moody, Laura A; Aryal, Shivani; Moran, Timothy H; Tamashiro, Kellie L

2016-05-01

We hypothesize that anorexia nervosa (AN) poses a physiological stress. Therefore, the way an individual copes with stress may affect AN vulnerability. Since prenatal stress (PNS) exposure alters stress responsivity in offspring this may increase their risk of developing AN. We tested this hypothesis using the activity based anorexia (ABA) rat model in control and PNS rats that were characterized by either proactive or passive stress-coping behavior. We found that PNS passively coping rats ate less and lost more weight during the ABA paradigm. Exposure to ABA resulted in higher baseline corticosterone and lower insulin levels in all groups. However, leptin levels were only decreased in rats with a proactive stress-coping style. Similarly, ghrelin levels were increased only in proactively coping ABA rats. Neuropeptide Y (Npy) expression was increased and proopiomelanocortin (Pomc) expression was decreased in all rats exposed to ABA. In contrast, agouti-related peptide (Agrp) and orexin (Hctr) expression were increased in all but the PNS passively coping ABA rats. Furthermore, DNA methylation of the orexin gene was increased after ABA in proactive coping rats and not in passive coping rats. Overall our study suggests that passive PNS rats have innate impairments in leptin and ghrelin in responses to starvation combined with prenatal stress associated impairments in Agrp and orexin expression in response to starvation. These impairments may underlie decreased food intake and associated heightened body weight loss during ABA in the passively coping PNS rats. Published by Elsevier Ltd.

Glucose Alters Per2 Rhythmicity Independent of AMPK, Whereas AMPK Inhibitor Compound C Causes Profound Repression of Clock Genes and AgRP in mHypoE-37 Hypothalamic Neurons.

PubMed

Oosterman, Johanneke E; Belsham, Denise D

2016-01-01

Specific neurons in the hypothalamus are regulated by peripheral hormones and nutrients to maintain proper metabolic control. It is unclear if nutrients can directly control clock gene expression. We have therefore utilized the immortalized, hypothalamic cell line mHypoE-37, which exhibits robust circadian rhythms of core clock genes. mHypoE-37 neurons were exposed to 0.5 or 5.5 mM glucose, comparable to physiological levels in the brain. Per2 and Bmal1 mRNAs were assessed every 3 hours over 36 hours. Incubation with 5.5 mM glucose significantly shortened the period and delayed the phase of Per2 mRNA levels, but had no effect on Bmal1. Glucose had no significant effect on phospho-GSK3β, whereas AMPK phosphorylation was altered. Thus, the AMPK inhibitor Compound C was utilized, and mRNA levels of Per2, Bmal1, Cryptochrome1 (Cry1), agouti-related peptide (AgRP), carnitine palmitoyltransferase 1C (Cpt1c), and O-linked N-acetylglucosamine transferase (Ogt) were measured. Remarkably, Compound C dramatically reduced transcript levels of Per2, Bmal1, Cry1, and AgRP, but not Cpt1c or Ogt. Because AMPK was not inhibited at the same time or concentrations as the clock genes, we suggest that the effect of Compound C on gene expression occurs through an AMPK-independent mechanism. The consequences of inhibition of the rhythmic expression of clock genes, and in turn downstream metabolic mediators, such as AgRP, could have detrimental effects on overall metabolic processes. Importantly, the effects of the most commonly used AMPK inhibitor Compound C should be interpreted with caution, considering its role in AMPK-independent repression of specific genes, and especially clock gene rhythm dysregulation.

Glucose Alters Per2 Rhythmicity Independent of AMPK, Whereas AMPK Inhibitor Compound C Causes Profound Repression of Clock Genes and AgRP in mHypoE-37 Hypothalamic Neurons

PubMed Central

Oosterman, Johanneke E.; Belsham, Denise D.

2016-01-01

Specific neurons in the hypothalamus are regulated by peripheral hormones and nutrients to maintain proper metabolic control. It is unclear if nutrients can directly control clock gene expression. We have therefore utilized the immortalized, hypothalamic cell line mHypoE-37, which exhibits robust circadian rhythms of core clock genes. mHypoE-37 neurons were exposed to 0.5 or 5.5 mM glucose, comparable to physiological levels in the brain. Per2 and Bmal1 mRNAs were assessed every 3 hours over 36 hours. Incubation with 5.5 mM glucose significantly shortened the period and delayed the phase of Per2 mRNA levels, but had no effect on Bmal1. Glucose had no significant effect on phospho-GSK3β, whereas AMPK phosphorylation was altered. Thus, the AMPK inhibitor Compound C was utilized, and mRNA levels of Per2, Bmal1, Cryptochrome1 (Cry1), agouti-related peptide (AgRP), carnitine palmitoyltransferase 1C (Cpt1c), and O-linked N-acetylglucosamine transferase (Ogt) were measured. Remarkably, Compound C dramatically reduced transcript levels of Per2, Bmal1, Cry1, and AgRP, but not Cpt1c or Ogt. Because AMPK was not inhibited at the same time or concentrations as the clock genes, we suggest that the effect of Compound C on gene expression occurs through an AMPK-independent mechanism. The consequences of inhibition of the rhythmic expression of clock genes, and in turn downstream metabolic mediators, such as AgRP, could have detrimental effects on overall metabolic processes. Importantly, the effects of the most commonly used AMPK inhibitor Compound C should be interpreted with caution, considering its role in AMPK-independent repression of specific genes, and especially clock gene rhythm dysregulation. PMID:26784927

A small potassium current in AgRP/NPY neurons regulates feeding behavior and enery metabolism

USDA-ARS?s Scientific Manuscript database

Neurons that co-express agouti-related peptide (AgRP) and neuropeptide Y (NPY) are indispensable for normal feeding behavior. Firing activities of AgRP/NPY neurons are dynamically regulated by energy status and coordinate appropriate feeding behavior to meet nutritional demands. However, intrinsic m...

AgRP Neural Circuits Mediate Adaptive Behaviors in the Starved State

PubMed Central

Padilla, Stephanie L.; Qiu, Jian; Soden, Marta E.; Sanz, Elisenda; Nestor, Casey C; Barker, Forrest D.; Quintana, Albert; Zweifel, Larry S.; Rønnekleiv, Oline K.; Kelly, Martin J.; Palmiter, Richard D.

2016-01-01

In the face of starvation animals will engage in high-risk behaviors that would normally be considered maladaptive. Starving rodents for example will forage in areas that are more susceptible to predators and will also modulate aggressive behavior within a territory of limited or depleted nutrients. The neural basis of these adaptive behaviors likely involves circuits that link innate feeding, aggression, and fear. Hypothalamic AgRP neurons are critically important for driving feeding and project axons to brain regions implicated in aggression and fear. Using circuit-mapping techniques, we define a disynaptic network originating from a subset of AgRP neurons that project to the medial nucleus of the amygdala and then to the principle bed nucleus of the stria terminalis, which plays a role in suppressing territorial aggression and reducing contextual fear. We propose that AgRP neurons serve as a master switch capable of coordinating behavioral decisions relative to internal state and environmental cues. PMID:27019015

TCPTP Regulates Insulin Signalling in AgRP Neurons to Coordinate Glucose Metabolism with Feeding.

PubMed

Dodd, Garron T; Lee-Young, Robert S; Brüning, Jens C; Tiganis, Tony

2018-04-30

Insulin regulates glucose metabolism by eliciting effects on peripheral tissues as well as the brain. Insulin receptor (IR) signalling inhibits AgRP-expressing neurons in the hypothalamus to contribute to the suppression of hepatic glucose production (HGP) by insulin, whereas AgRP neuronal activation attenuates brown adipose tissue (BAT) glucose uptake. The tyrosine phosphatase TCPTP suppresses IR signalling in AgRP neurons. Hypothalamic TCPTP is induced by fasting and degraded after feeding. Here we assessed the influence of TCPTP in AgRP neurons in the control of glucose metabolism. TCPTP deletion in AgRP neurons ( Agrp -Cre; Ptpn2 fl/fl ) enhanced insulin sensitivity as assessed by the increased glucose infusion rates and reduced HGP during hyperinsulinemic-euglycemic clamps, accompanied by increased [ 14 C]-2-deoxy-D-glucose uptake in BAT and browned white adipose tissue. TCPTP deficiency in AgRP neurons promoted the intracerebroventricular insulin-induced repression of hepatic gluconeogenesis in otherwise unresponsive food-restricted mice yet had no effect in fed/satiated mice where hypothalamic TCPTP levels are reduced. The improvement in glucose homeostasis in Agrp -Cre; Ptpn2 fl/fl mice was corrected by IR heterozygosity ( Agrp -Cre; Ptpn2 fl/fl ; Insr fl/+ ), causally linking the effects on glucose metabolism with the IR signalling in AgRP neurons. Our findings demonstrate that TCPTP controls IR signalling in AgRP neurons to coordinate HGP and brown/beige adipocyte glucose uptake in response to feeding/fasting. © 2018 by the American Diabetes Association.

Hunger-Driven Motivational State Competition.

PubMed

Burnett, C Joseph; Li, Chia; Webber, Emily; Tsaousidou, Eva; Xue, Stephen Y; Brüning, Jens C; Krashes, Michael J

2016-10-05

Behavioral choice is ubiquitous in the animal kingdom and is central to goal-oriented behavior. Hypothalamic Agouti-related peptide (AgRP) neurons are critical regulators of appetite. Hungry animals, bombarded by multiple sensory stimuli, are known to modify their behavior during times of caloric need, rapidly adapting to a consistently changing environment. Utilizing ARC AgRP neurons as an entry point, we analyzed the hierarchical position of hunger related to rival drive states. Employing a battery of behavioral assays, we found that hunger significantly increases its capacity to suppress competing motivational systems, such as thirst, anxiety-related behavior, innate fear, and social interactions, often only when food is accessible. Furthermore, real-time monitoring of ARC AgRP activity revealed time-locked responses to conspecific investigation in addition to food presentation, further establishing that, even at the level of ARC AgRP neurons, choices are remarkably flexible computations, integrating internal state, external factors, and anticipated yield. VIDEO ABSTRACT. Published by Elsevier Inc.

Apolipoprotein A-IV inhibits AgRP/NPY neurons and activates POMC neurons in the arcuate nucleus

USDA-ARS?s Scientific Manuscript database

Apolipoprotein A-IV (apoA-IV) in the brain potently suppresses food intake. However the mechanisms underlying its anorexigenic effects remain to be identified. We first examined the effects of apoA-IV on cellular activities in hypothalamic neurons that co-express agouti-related peptide (AgRP) and ne...

Fasting Activation of AgRP Neurons Requires NMDA Receptors and Involves Spinogenesis and Increased Excitatory Tone

PubMed Central

Liu, Tiemin; Kong, Dong; Shah, Bhavik P.; Ye, Chianping; Koda, Shuichi; Saunders, Arpiar; Ding, Jun B.; Yang, Zongfang; Sabatini, Bernardo L.; Lowell, Bradford B.

2012-01-01

SUMMARY AgRP neuron activity drives feeding and weight gain while that of nearby POMC neurons does the opposite. However, the role of excitatory glutamatergic input in controlling these neurons is unknown. To address this question, we generated mice lacking NMDA receptors (NMDARs) on either AgRP or POMC neurons. Deletion of NMDARs from AgRP neurons markedly reduced weight, body fat and food intake whereas deletion from POMC neurons had no effect. Activation of AgRP neurons by fasting, as assessed by c-Fos, Agrp and Npy mRNA expression, AMPA receptor-mediated EPSCs, depolarization and firing rates, required NMDARs. Furthermore, AgRP but not POMC neurons have dendritic spines and increased glutamatergic input onto AgRP neurons caused by fasting was paralleled by an increase in spines, suggesting fasting induced synaptogenesis and spinogenesis. Thus glutamatergic synaptic transmission and its modulation by NMDARs play key roles in controlling AgRP neurons and determining the cellular and behavioral response to fasting. PMID:22325203

A missense mutation in the agouti signaling protein gene (ASIP) is associated with the no light points coat phenotype in donkeys.

PubMed

Abitbol, Marie; Legrand, Romain; Tiret, Laurent

2015-04-08

Seven donkey breeds are recognized by the French studbook and are characterized by a black, bay or grey coat colour including light cream-to-white points (LP). Occasionally, Normand bay donkeys give birth to dark foals that lack LP and display the no light points (NLP) pattern. This pattern is more frequent and officially recognized in American miniature donkeys. The LP (or pangare) phenotype resembles that of the light bellied agouti pattern in mouse, while the NLP pattern resembles that of the mammalian recessive black phenotype; both phenotypes are associated with the agouti signaling protein gene (ASIP). We used a panel of 127 donkeys to identify a recessive missense c.349 T > C variant in ASIP that was shown to be in complete association with the NLP phenotype. This variant results in a cysteine to arginine substitution at position 117 in the ASIP protein. This cysteine is highly-conserved among vertebrate ASIP proteins and was previously shown by mutagenesis experiments to lie within a functional site. Altogether, our results strongly support that the identified mutation is causative of the NLP phenotype. Thus, we propose to name the c.[349 T > C] allele in donkeys, the a(nlp) allele, which enlarges the panel of coat colour alleles in donkeys and ASIP recessive loss-of-function alleles in animals.

mTORC1 in AGRP neurons integrates exteroceptive and interoceptive food-related cues in the modulation of adaptive energy expenditure in mice

PubMed Central

Burke, Luke K; Darwish, Tamana; Cavanaugh, Althea R; Virtue, Sam; Roth, Emma; Morro, Joanna; Liu, Shun-Mei; Xia, Jing; Dalley, Jeffrey W; Burling, Keith; Chua, Streamson; Vidal-Puig, Toni; Schwartz, Gary J; Blouet, Clémence

2017-01-01

Energy dissipation through interscapular brown adipose tissue (iBAT) thermogenesis is an important contributor to adaptive energy expenditure. However, it remains unresolved how acute and chronic changes in energy availability are detected by the brain to adjust iBAT activity and maintain energy homeostasis. Here, we provide evidence that AGRP inhibitory tone to iBAT represents an energy-sparing circuit that integrates environmental food cues and internal signals of energy availability. We establish a role for the nutrient-sensing mTORC1 signaling pathway within AGRP neurons in the detection of environmental food cues and internal signals of energy availability, and in the bi-directional control of iBAT thermogenesis during nutrient deficiency and excess. Collectively, our findings provide insights into how mTORC1 signaling within AGRP neurons surveys energy availability to engage iBAT thermogenesis, and identify AGRP neurons as a neuronal substrate for the coordination of energy intake and adaptive expenditure under varying physiological and environmental contexts. DOI: http://dx.doi.org/10.7554/eLife.22848.001 PMID:28532548

Distribution and female reproductive state differences in orexigenic and anorexigenic neurons in the brain of the mouth brooding African cichlid fish, Astatotilapia burtoni.

PubMed

Porter, Danielle T; Roberts, David A; Maruska, Karen P

2017-10-01

Integration of reproduction and metabolism is necessary for species survival. While the neural circuits controlling energy homeostasis are well-characterized, the signals controlling the relay of nutritional information to the reproductive axis are less understood. The cichlid fish Astatotilapia burtoni is ideal for studying the neural regulation of feeding and reproduction because females cycle between a feeding gravid state and a period of forced starvation while they brood developing young inside their mouths. To test the hypothesis that candidate neuropeptide-containing neurons known to be involved in feeding and energy homeostasis in mammals show conserved distribution patterns, we performed immunohistochemistry and in situ hybridization to localize appetite-stimulating (neuropeptide Y, NPY; agouti-related protein, AGRP) and appetite-inhibiting (cocaine and amphetamine-regulated transcript, CART; pro-opiomelanocortin, pomc1a) neurons in the brain. NPY, AGRP, CART, and pomc1a somata showed distribution patterns similar to other teleosts, which included localization to the lateral tuberal nucleus (NLT), the putative homolog of the mammalian arcuate nucleus. Gravid females also had larger NPY and AGRP neurons in the NLT compared to brooding females, but brooding females had larger pomc1a neurons compared to gravid females. Hypothalamic agrp mRNA levels were also higher in gravid compared to brooding females. Thus, larger appetite-stimulating neurons (NPY, AGRP) likely promote feeding while females are gravid, while larger pomc1a neurons may act as a signal to inhibit food intake during mouth brooding. Collectively, our data suggest a potential role for NPY, AGRP, POMC, and CART in regulating energetic status in A. burtoni females during varying metabolic and reproductive demands. © 2017 Wiley Periodicals, Inc.

Anabolic androgenic steroid nandrolone decanoate reduces hypothalamic proopiomelanocortin mRNA levels.

PubMed

Lindblom, Jonas; Kindlundh, Anna M S; Nyberg, Fred; Bergström, Lena; Wikberg, Jarl E S

2003-10-03

Supratherapeutical doses of anabolic androgenic steroids (AASs) have dramatic effects on metabolism in humans, and also inhibit feeding and reduce the rate of body weight gain in rats. In order to test the hypothesis that the AAS metabolic syndrome is accompanied by alterations in the central melanocortin system, we evaluated body weight, food intake and hypothalamic agouti-related protein (AgRP) and proopiomelanocortin (POMC) mRNA levels following administration of different doses of the anabolic androgenic steroid nandrolone decanoate. In order to distinguish changes induced by the steroid treatment per se from those resulting from the reduced food intake and growth rate, we also compared the effect of nandrolone decanoate on AgRP and POMC mRNA expression with both normally fed, and food restricted control groups. We here report that administration of nandrolone specifically reduces arcuate nucleus POMC mRNA levels while not affecting the expression level of AgRP. The effect on POMC expression was not observed in the food restricted controls, excluding the possibility that the observed effect was a mere response to the reduced food intake and body weight. These results raise the possibility that some of the metabolic and behavioural consequences of AAS abuse may be the result of alterations in the melanocortin system.

Effect of gonadectomy on AgRP-induced weight gain in rats.

PubMed

Goodin, Sean Z; Kiechler, Alicia R; Keichler, Alicia R; Smith, Marissa; Wendt, Donna; Strader, April D

2008-12-01

Agouti-related peptide (AgRP), the endogenous antagonist to the melanocortin 3 and 4 receptors, elicits robust hyperphagia and weight gain in rodents when administered directly into the central nervous system. The relative influence of AgRP to cause weight gain in rodents partially depends on the activity level of the melanocortin agonist-producing proopiomelanocortin neurons. Both proopiomelanocortin and AgRP neurons within the arcuate nucleus receive energy storage information from circulating peripheral signals such as leptin and insulin. Another modulator of AgRP activity includes the cell surface molecule syndecan-3. Because leptin and insulin affect food intake in a sexually dimorphic way in rodents and syndecan-3-deficient mice regulate adiposity levels through distinct physiological mechanisms, we hypothesized that AgRP-induced weight gain would also be sexually dimorphic in rats. In the present study, the behavioral and physiological effects of centrally-administered AgRP in male and female were investigated. In male rats, AgRP (1 nmol) induced 5 days (P < 0.0001) of significantly elevated feeding compared with vehicle-treated controls, while females displayed 3 days of hyperphagia (P < 0.05). However, 1 wk after the injection, both male and female rats gained the same percent body weight (6%). Interestingly, female rats exhibited a greater reduction in energy expenditure (Vo2) following AgRP compared with male rats (P < 0.05). Removal of the gonads did not alter cumulative food intake in male or female rats but did attenuate the dramatic reduction in Vo2 exhibited by females. Both intact and gonadectomized rats demonstrated significantly increased respiratory quotient supporting the anabolic action of AgRP (P < 0.01). These findings are novel in that they reveal sex-specific underlying physiology used to achieve weight gain following central AgRP in rats.

Glucocorticoids decrease body weight and food intake and inhibit appetite regulatory peptide expression in the hypothalamus of rats

PubMed Central

LIU, XIAO-YAN; SHI, JIAN-HUA; DU, WEN-HUA; FAN, YAN-PING; HU, XIAO-LEI; ZHANG, CHEN-CHEN; XU, HUAN-BAI; MIAO, YAN-JUN; ZHOU, HAI-YAN; XIANG, PING; CHEN, FENG-LING

2011-01-01

The aim of the present study was to investigate the effects of glucocorticoids (GCs) on appetite and gene expression of the hypothalamic appetite regulatory peptides, neuropeptide Y (NPY), agouti-related protein (AGRP) and cocaine and amphetamine-regulated transcript (CART), in non-obese and obese rats. Both non-obese and obese rats were randomly assigned to three groups: normal saline, low- and high-dose GC groups (NSG, LDG and HDG, respectively), which received an intraperitoneal injection with normal saline (0.2 ml/100 g) or hydrocortisone sodium succinate at 5 and 15 mg/kg, respectively, for 20 days. The expression levels of NPY, AGRP and CART mRNA in the hypothalamus were measured by real-time quantitative PCR. Non-obese and obese rats were found to undergo weight loss after GC injection, and a higher degree of weight loss was observed in the HDG rats. The average and cumulative food intakes in the obese and non-obese rats injected with high-dose GC were lower compared to that in the NSG (p<0.05). mRNA expression levels of the orexigenic neuropeptides, NPY and AGRP, and the anorexigenic neuropeptide, CART, were significantly lower in the HDG than levels in the NSG for both the obese and non-obese rats (p<0.05). GC treatment decreased appetite and body weight, induced apparent glucolipid metabolic disturbances and hyperinsulinemia, while down-regulated mRNA expression levels of the orexigenic neuropeptides, NPY and AGRP, and anorexigenic neuropeptide, CART, in the hypothalamus in the rats. The mechanism which induces this neuropeptide expression requires further study. PMID:22977608

Maternal epigenetics and methyl supplements affect agouti gene expression in Avy/a mice.

PubMed

Wolff, G L; Kodell, R L; Moore, S R; Cooney, C A

1998-08-01

'Viable yellow' (Avy/a) mice are larger, obese, hyperinsulinemic, more susceptible to cancer, and, on average, shorter lived than their non-yellow siblings. They are epigenetic mosaics ranging from a yellow phenotype with maximum ectopic agouti overexpression, through a continuum of mottled agouti/yellow phenotypes with partial agouti overexpression, to a pseudoagouti phenotype with minimal ectopic expression. Pseudoagouti Avy/a mice are lean, healthy, and longer lived than their yellow siblings. Here we report that feeding pregnant black a/a dams methyl-supplemented diets alters epigenetic regulation of agouti expression in their offspring, as indicated by increased agouti/black mottling in the direction of the pseudoagouti phenotype. We also present confirmatory evidence that epigenetic phenotypes are maternally heritable. Thus Avy expression, already known to be modulated by imprinting, strain-specific modification, and maternal epigenetic inheritance, is also modulated by maternal diet. These observations suggest, at least in this special case, that maternal dietary supplementation may positively affect health and longevity of the offspring. Therefore, this experimental system should be useful for identifying maternal factors that modulate epigenetic mechanisms, especially DNA methylation, in developing embryos.

Molecular analyses of the agouti allele in the Japanese house mouse identify a novel variant of the agouti gene.

PubMed

Iwasa, Masahiro A; Kawamura, Sayaka; Myoshu, Hikari; Suzuki, Taichi A

2018-03-01

It has been thought that the Japanese house mouse carries the A w allele at the agouti locus causing light-colored bellies, but they do not always show this coloration. Thus, the presence of the A w allele seems to be doubtful in them. To ascertain whether the A w allele is present, a two-pronged approach was used. First, we compared lengths of DNA fragments obtained from three PCRs conducted on them to the known fragment sizes generated from mouse strains exhibiting homozygosities of either a/a, A/A, or A w /A w . PCR I, PCR II, and PCR III amplify only in the A and A w alleles, the a and A w alleles, and the a allele, respectively, and we detected amplifications in strains with A/A and A w /A w by PCR I, in those with a/a and the Japanese house mouse by PCR II, and in those with a/a by PCR III. Second, we sequenced the exon 1A region of the agouti gene and obtained sequences corresponding to the above strains and the Japanese house mouse, but their sequences were similar to those of the a allele. We concluded that their agouti allele is not identical to the A w allele and seems to be a novel type similar to the a allele.

Melanocortin antagonism ameliorates muscle wasting and inflammation in chronic kidney disease.

PubMed

Cheung, Wai W; Mak, Robert H

2012-11-01

Aberrant melanocortin signaling has been implicated in the pathogenesis of wasting in chronic kidney disease (CKD). Previously, we demonstrated that agouti-related peptide (AgRP), a melenocortin-4 receptor antagonist, reduced CKD-associated cachexia in CKD mice. Our previous studies with AgRP utilized dual energy X-ray (DXA) densitometry to assess the body composition in mice (Cheung W, Kuo HJ, Markison S, Chen C, Foster AC, Marks DL, Mak RH. J Am Soc Nephrol 18: 2517-2524, 2007; Cheung W, Yu PX, Little BM, Cone RD, Marks DL, Mak RH. J Clin Invest 115: 1659-1665, 2005). DXA is unable to differentiate water content in mice, and fluid retention in CKD may lead to an overestimate of lean mass. In this study, we employed quantitative magnetic resonance technique to evaluate body composition change following central administration of AgRP in a CKD mouse model. AgRP treatment improved energy expenditure, total body mass, fat mass, and lean body mass in CKD mouse. We also investigated the effect of CKD-associated cachexia on the signaling pathways leading to wasting in skeletal muscle, as well as whether these changes can be ameliorated by central administration of AgRP. AgRP treatment caused an overall decrease in proinflammatory cytokines, which may be one important mechanism of its effects. Muscle wasting in CKD may be due to the activation of proteolytic pathways as well as inhibition of myogenesis and muscle regeneration processes. Our results suggest that these aberrant pathological pathways leading to muscle wasting in CKD mice were ameliorated by central administration of AgRP.

Hyperphagia induced by sucrose: relation to circulating and CSF glucose and corticosterone and orexigenic peptides in the arcuate nucleus.

PubMed

Gaysinskaya, V A; Karatayev, O; Shuluk, J; Leibowitz, S F

2011-01-01

Sucrose-rich diets compared to starch-rich diets are known to stimulate overeating under chronic conditions. The present study in normal-weight rats established an acute "preload-to-test meal" paradigm for demonstrating sucrose-induced hyperphagia and investigating possible mechanisms that mediate this behavioral phenomenon. In this acute paradigm, the rats were first given a small (15 kcal) sucrose preload (30% sucrose) for 30 min compared to an equicaloric, starch preload (25% starch with 5% sucrose) and then allowed to freely consume a subsequent test meal of lab chow. The sucrose preload, when compared to a starch preload equal in energy density and palatability, consistently increased food intake in the subsequent test meal occurring between 60 and 120 min after the end of the preload. Measurements of hormones, metabolites and hypothalamic peptides immediately preceding this hyperphagia revealed marked differences between the sucrose vs starch groups that could contribute to the increase in food intake. Whereas the sucrose group compared to the starch group immediately after the preload (at 10 min) had elevated levels of glucose in serum and cerebrospinal fluid (CSF) along with reduced expressions of neuropeptide Y (NPY) and agouti-related protein (AgRP) in the arcuate nucleus (ARC), the subsequent effects (at 30-60 min) just preceding the test meal hyperphagia were the reverse. Along with lower levels of glucose, they included markedly elevated serum and CSF levels of corticosterone and mRNA levels of NPY and AgRP in the ARC. In addition to establishing an animal model for sucrose-induced hyperphagia, these results demonstrate peripheral and central mechanisms that may mediate this behavioral phenomenon. Copyright © 2010 Elsevier Inc. All rights reserved.

HYPERPHAGIA INDUCED BY SUCROSE: RELATION TO CIRCULATING AND CSF GLUCOSE AND CORTICOSTERONE AND OREXIGENIC PEPTIDES IN THE ARCUATE NUCLEUS

PubMed Central

Gaysinskaya, V. A.; Karatayev, O.; Shuluk, J.; Leibowitz, S. F.

2010-01-01

Sucrose-rich diets compared to starch-rich diets are known to stimulate overeating under chronic conditions. The present study in normal-weight rats established an acute “preload-to-test meal” paradigm for demonstrating sucrose-induced hyperphagia and investigating possible mechanisms that mediate this behavioral phenomenon. In this acute paradigm, the rats were first given a small (15 kcals) sucrose preload (30% sucrose) for 30 min compared to an equicaloric, starch preload (25% starch with 5% sucrose) and then allowed to freely consume a subsequent test meal of lab chow. The sucrose preload, when compared to a starch preload equal in energy density and palatability, consistently increased food intake in the subsequent test meal occurring between 60–120 min after the end of the preload. Measurements of hormones, metabolites and hypothalamic peptides immediately preceding this hyperphagia revealed marked differences between the sucrose vs starch groups that could contribute to the increase in food intake. Whereas the sucrose group compared to starch group immediately after the preload (at 10 min) had elevated levels of glucose in serum and cerebrospinal fluid (CSF) along with reduced expression of neuropeptide Y (NPY) and agouti-related protein (AgRP) in the arcuate nucleus (ARC), the subsequent effects (at 30–60 min) just preceding the test meal hyperphagia were the reverse. Along with lower levels of glucose, they included markedly elevated serum and CSF levels of corticosterone and mRNA levels of NPY and AgRP in the ARC. In addition to establishing an animal model for sucrose-induced hyperphagia, these results demonstrate peripheral and central mechanisms that may mediate this behavioral phenomenon. PMID:21036188

Characterization of the dog agouti gene and a nonagouti mutation in german shepherd dogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerns, Julie A.; Newton, J.; Berryere, Tom G.

The interaction between two genes, Agouti and Melanocortin-1 receptor (Mc1r), produces diverse pigment patterns in mammals by regulating the type, amount, and distribution pattern of the two pigment types found in mammalian hair: eumelanin (brown/black) and pheomelanin (yellow/red). In domestic dogs (Canis familiaris), there is a tremendous variation in coat color patterns between and within breeds; however, previous studies suggest that the molecular genetics of pigment-type switching in dogs may differ from that of other mammals. Here we report the identification and characterization of the Agouti gene from domestic dogs, predicted to encode a 131-amino-acid secreted protein 98 percent identicalmore » to the fox homolog, and which maps to chromosome CFA24 in a region of conserved linkage. Comparative analysis of the Doberman Pinscher Agouti cDNA, the fox cDNA, and 180 kb of Doberman Pinscher genomic DNA suggests that, as with laboratory mice, different pigment-type-switching patterns in the canine family are controlled by alternative usage of different promoters and untranslated first exons. A small survey of Labrador Retrievers, Greyhounds, Australian Shepherds, and German Shepherd Dogs did not uncover any polymorphisms, but we identified a single nucleotide variant in black German Shepherd Dogs predicted to cause an Arg-to-Cys substitution at codon 96, which is likely to account for recessive inheritance of a uniform black coat.« less

Hypothalamic neuropeptides, not leptin sensitivity, contributes to the hyperphagia in lactating Brandt's voles, Lasiopodomys brandtii.

PubMed

Cui, Jian-Guo; Tang, Gang-Bing; Wang, De-Hua

2011-07-01

Both pregnancy and lactation are associated with hyperphagia, and circulating leptin levels are elevated during pregnancy but decreased during lactation in Brandt's voles, Lasiopodomys brandtii. Previous findings suggest that impaired leptin sensitivity contributes to hyperphagia during pregnancy. The present study aimed to examine whether the decreased circulating leptin level and/or hypothalamic leptin sensitivity contributed to the hyperphagia during lactation in Brandt's voles. The serum leptin level and mRNA expression of the long form of the leptin receptor (Ob-Rb), suppressor-of-cytokine-signalling-3 (SOCS-3), neuropeptide Y (NPY), agouti-related protein (AgRP), pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) in the hypothalamus were examined on dioestrous, day 5, day 17 of lactation and day 27 (1 week after weaning) in Brandt's voles. Compared with controls, hypothalamic Ob-Rb and SOCS-3 mRNA expression was not significantly changed during lactation. The serum leptin level was significantly lower in lactating females than in the non-reproductive group. Hypothalamic NPY and AgRP mRNA expression significantly increased whereas POMC mRNA expression was significantly decreased during lactation compared with controls. However, there were no significant changes in hypothalamic CART mRNA expression. Food intake was positively correlated with NPY and AgRP mRNA expression but negatively correlated with POMC mRNA expression during lactation. These data suggest that hyperphagia during lactation was associated with low leptin levels, but not impaired leptin sensitivity, and that the hypothalamic neuropeptides NPY, AgRP and POMC are involved in mediating the role of leptin in food intake regulation in lactating Brandt's voles.

[Methyl-containing diet of mothers affects the AGOUTI gene expression in the offspring of rats with various behavioral types].

PubMed

Prasolova, L A; Os'kina, I N; Pliusnina, I Z; Trut, L N

2009-05-01

The effects of selection of agouti rats (with genotype AAHH) on the tame and aggressive behavior and dietary methyl given to females from the eighth day of pregnancy to the fifth day after the birth of the offspring on the intensity of the agouti coat color in the offspring have been studied. The morphometric parameters of hair determining the darkness of the agouti color (the total length of guard hairs, the lengths of their eumelanin end and pheomelanin band, the ratio between the lengths of the eumelanin and pheomelanin portions of the hair, the total length of the awn hairs, and the relative length of their widened "lanceolate" upper end) have been compared. It has been found that selection of agouti rats for aggressive behavior is accompanied by darkening of the coat color compared to tame rats due to an increase in the ratio of the length of the black eumelanin end of the guard hairs to the length of the yellow pheomelanin band. Methyl-containing additives to the diet of females affect the intensity of the agouti coat color in the offsprings with both types of behavior, but to different extents. Aggressive offspring is more sensitive to the mother's methyl-containing diet: the percentage of animals that are darker than control rats is higher among aggressive animals than among tame ones due to a greater increase in the ratio between dark and light portions of hairs. The possible mechanisms of differences in the phenotypic modifications of coat color in control and experimental agouti rats with different types of behavior are discussed.

SUSPECTED HYPERVITAMINOSIS D IN RED-RUMPED AGOUTI ( DASYPROCTA LEPORINA) RECEIVING A COMMERCIAL RODENT DIET.

PubMed

Anderson, Kadie M; Lewandowski, Albert; Dennis, Patricia M

2018-03-01

An 8 yr, intact male red-rumped agouti ( Dasyprocta leporina) was evaluated for weight loss. Examination revealed poor body condition, hypercalcemia, elevated serum 25-hydroxyvitamin D, metastatic calcification of soft tissues, and hyperechoic kidneys. The diet, formulated for laboratory rodents, contained elevated levels of vitamin D 3 . Histopathology from a female conspecific that died 5 mo prior identified dystrophic mineralization and nephrosclerosis, suggestive of a vitamin D 3 toxicity. The male agouti responded well to a dietary reduction in vitamin D 3 and calcium. Six months into therapy, progressive renal failure was identified and was further managed with enalapril, phosphorus binders, and dietary manipulation. Suspected vitamin D 3 toxicity has been reported in pacas ( Cuniculus paca) and agouti and has been linked to exposure to New World primate diets. In this brief communication, an agouti developed suspected hypervitaminosis D after receiving a commercial rodent diet commonly fed to this species in captivity.

Hypothalamic Non-AgRP, Non-POMC GABAergic Neurons Are Required for Postweaning Feeding and NPY Hyperphagia

PubMed Central

Kim, Eun Ran; Wu, Zhaofei; Sun, Hao; Xu, Yuanzhong; Mangieri, Leandra R.; Xu, Yong

2015-01-01

The hypothalamus is critical for feeding and body weight regulation. Prevailing studies focus on hypothalamic neurons that are defined by selectively expressing transcription factors or neuropeptides including those expressing proopiomelanocortin (POMC) and agouti-related peptides (AgRP). The Cre expression driven by the pancreas-duodenum homeobox 1 promoter is abundant in several hypothalamic nuclei but not in AgRP or POMC neurons. Using this line, we generated mice with disruption of GABA release from a major subset of non-POMC, non-AgRP GABAergic neurons in the hypothalamus. These mice exhibited a reduction in postweaning feeding and growth, and disrupted hyperphagic responses to NPY. Disruption of GABA release severely diminished GABAergic input to the paraventricular hypothalamic nucleus (PVH). Furthermore, disruption of GABA-A receptor function in the PVH also reduced postweaning feeding and blunted NPY-induced hyperphagia. Given the limited knowledge on postweaning feeding, our results are significant in identifying GABA release from a major subset of less appreciated hypothalamic neurons as a key mediator for postweaning feeding and NPY hyperphagia, and the PVH as one major downstream site that contributes significantly to the GABA action. SIGNIFICANCE STATEMENT Prevalent studies on feeding in the hypothalamus focus on well characterized, selective groups neurons [e.g., proopiomelanocortin (POMC) and agouti-related peptide (AgRP) neurons], and as a result, the role of the majority of other hypothalamic neurons is largely neglected. Here, we demonstrated an important role for GABAergic projections from non-POMC non-AgRP neurons to the paraventricular hypothalamic nucleus in promoting postweaning (mainly nocturnal) feeding and mediating NPY-induced hyperphagia. Thus, these results signify an importance to study those yet to be defined hypothalamic neurons in the regulation of energy balance and reveal a neural basis for postweaning (nocturnal) feeding and NPY

Hypothalamic Non-AgRP, Non-POMC GABAergic Neurons Are Required for Postweaning Feeding and NPY Hyperphagia.

PubMed

Kim, Eun Ran; Wu, Zhaofei; Sun, Hao; Xu, Yuanzhong; Mangieri, Leandra R; Xu, Yong; Tong, Qingchun

2015-07-22

The hypothalamus is critical for feeding and body weight regulation. Prevailing studies focus on hypothalamic neurons that are defined by selectively expressing transcription factors or neuropeptides including those expressing proopiomelanocortin (POMC) and agouti-related peptides (AgRP). The Cre expression driven by the pancreas-duodenum homeobox 1 promoter is abundant in several hypothalamic nuclei but not in AgRP or POMC neurons. Using this line, we generated mice with disruption of GABA release from a major subset of non-POMC, non-AgRP GABAergic neurons in the hypothalamus. These mice exhibited a reduction in postweaning feeding and growth, and disrupted hyperphagic responses to NPY. Disruption of GABA release severely diminished GABAergic input to the paraventricular hypothalamic nucleus (PVH). Furthermore, disruption of GABA-A receptor function in the PVH also reduced postweaning feeding and blunted NPY-induced hyperphagia. Given the limited knowledge on postweaning feeding, our results are significant in identifying GABA release from a major subset of less appreciated hypothalamic neurons as a key mediator for postweaning feeding and NPY hyperphagia, and the PVH as one major downstream site that contributes significantly to the GABA action. Significance statement: Prevalent studies on feeding in the hypothalamus focus on well characterized, selective groups neurons [e.g., proopiomelanocortin (POMC) and agouti-related peptide (AgRP) neurons], and as a result, the role of the majority of other hypothalamic neurons is largely neglected. Here, we demonstrated an important role for GABAergic projections from non-POMC non-AgRP neurons to the paraventricular hypothalamic nucleus in promoting postweaning (mainly nocturnal) feeding and mediating NPY-induced hyperphagia. Thus, these results signify an importance to study those yet to be defined hypothalamic neurons in the regulation of energy balance and reveal a neural basis for postweaning (nocturnal) feeding and

Maternal epigenetics and methyl supplements affect agouti gene expression in A{sup vy}/a mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolff, G.L.; Kodell, R.L.; Cooney, C.A.

Viable yellow (A{sup vy}/a) mice are larger, obese, hyperinsulinemic, more susceptible to cancer, and, on average, shorter lived than their non-yellow siblings. They are epigenetic mosaics ranging from a yellow phenotype with maximum ectopic agouti overexpression, through a continuum of mottled agouti/yellow phenotypes with partial agouti overexpression, to a pseudoagouti phenotype with minimal ectopic expression. Pseudoagouti A{sup vy}/a mice are lean, healthy, and longer lived than their yellow siblings. Here the authors report that feeding pregnant black a/a dams methyl-supplemented diets alters epigenetic regulation of agouti expression in their offspring, as indicated by increased agouti/black mottling in the direction ofmore » the pseudoagouti phenotype. They also present confirmatory evidence that epigenetic phenotypes are maternally heritable. Thus A{sup vy} expression, already known to be modulated by imprinting, strain-specific modification, and maternal epigenetic inheritance, is also modulated by maternal diet. These observations suggest, at least in this special case, that maternal dietary supplementation may positively affect health and longevity of the offspring. Therefore, this experimental system should be useful for identifying maternal factors that modulate epigenetic mechanisms, especially DNA methylation, in developing embryos.« less

Administration of IL-1beta to the 4th ventricle causes anorexia that is blocked by agouti-related peptide and that coincides with activation of tyrosine-hydroxylase neurons in the nucleus of the solitary tract.

PubMed

DeBoer, Mark D; Scarlett, Jarrad M; Levasseur, Peter R; Grant, Wilmon F; Marks, Daniel L

2009-02-01

Inflammation-associated cachexia is associated with multiple chronic diseases and involves activation of appetite regulating centers in the arcuate nucleus of the hypothalamus (ARH). The nucleus of the solitary tract (NTS) in the brainstem has also been implicated as an important nucleus involved in appetite regulation. We set out to determine whether the NTS may be involved in inflammation-associated anorexia by injecting IL-1 beta into the 4th ventricle and assessing food intake and NTS neuronal activation. Injection of IL-1 beta produced a decrease in food intake at 3 and 12h after injection which was ameliorated at the 12h time point by a sub-threshold dose of agouti-related peptide (AgRP). Investigation into neuron types in the NTS revealed that IL-1 beta injection was associated with an increase in c-Fos activity in NTS neurons expressing tyrosine hydroxylase (TH). Additionally, injection of IL-1 beta into the 4th ventricle did not produce c-Fos activation of neurons expressing pro-opiomelanocortin (POMC) in the ARH, cells known to be involved in producing anorexia in response to systemic inflammation. Double-label in situ hybridization revealed that TH neurons did not express IL-1 receptor I (IL1-RI) transcript, demonstrating that c-Fos activation of TH neurons in this setting was not via direct stimulation of IL-1 beta on TH neurons themselves. We conclude that IL-1 beta injection into the 4th ventricle produces anorexia and is accompanied by an increase in activation in TH neurons in the NTS. This provides evidence that the brainstem may be an important mediator of anorexia in the setting of inflammation.

Administration of IL-1β to the 4th ventricle causes anorexia that is blocked by agouti-related peptide and that coincides with activation of tyrosine-hydroxylase neurons in the nucleus of the solitary tract

PubMed Central

DeBoer, Mark D.; Scarlett, Jarrad M.; Levasseur, Peter R.; Grant, Wilmon F.; Marks, Daniel L.

2010-01-01

Inflammation-associated cachexia is associated with multiple chronic diseases and involves activation of appetite regulating centers in the arcuate nucleus of the hypothalamus (ARH). The nucleus of the solitary tract (NTS) in the brainstem has also been implicated as an important nucleus involved in appetite regulation. We set out to determine whether the NTS may be involved in inflammation-associated anorexia by injecting IL-1β into the 4th ventricle and assessing food intake and NTS neuronal activation. Injection of IL-1β produced a decrease in food intake at 3 and 12 h after injection which was ameliorated at the 12 h time point by a sub-threshold dose of agouti-related peptide (AgRP). Investigation into neuron types in the NTS revealed that IL-1β injection was associated with an increase in c-Fos activity in NTS neurons expressing tyrosine hydroxylase (TH). Additionally, injection of IL-1β into the 4th ventricle did not produce c-Fos activation of neurons expressing pro-opiomelanocortin (POMC) in the ARH, cells known to be involved in producing anorexia in response to systemic inflammation. Double-label in situ hybridization revealed that TH neurons did not express IL-1 receptor I (IL1-RI) transcript, demonstrating that c-Fos activation of TH neurons in this setting was not via direct stimulation of IL-1β on TH neurons themselves. We conclude that IL-1β injection into the 4th ventricle produces anorexia and is accompanied by an increase in activation in TH neurons in the NTS. This provides evidence that the brainstem may be an important mediator of anorexia in the setting of inflammation. PMID:19028534

Hypothalamic AgRP-neurons control peripheral substrate utilization and nutrient partitioning

PubMed Central

Joly-Amado, Aurélie; Denis, Raphaël G P; Castel, Julien; Lacombe, Amélie; Cansell, Céline; Rouch, Claude; Kassis, Nadim; Dairou, Julien; Cani, Patrice D; Ventura-Clapier, Renée; Prola, Alexandre; Flamment, Melissa; Foufelle, Fabienne; Magnan, Christophe; Luquet, Serge

2012-01-01

Obesity-related diseases such as diabetes and dyslipidemia result from metabolic alterations including the defective conversion, storage and utilization of nutrients, but the central mechanisms that regulate this process of nutrient partitioning remain elusive. As positive regulators of feeding behaviour, agouti-related protein (AgRP) producing neurons are indispensible for the hypothalamic integration of energy balance. Here, we demonstrate a role for AgRP-neurons in the control of nutrient partitioning. We report that ablation of AgRP-neurons leads to a change in autonomic output onto liver, muscle and pancreas affecting the relative balance between lipids and carbohydrates metabolism. As a consequence, mice lacking AgRP-neurons become obese and hyperinsulinemic on regular chow but display reduced body weight gain and paradoxical improvement in glucose tolerance on high-fat diet. These results provide a direct demonstration of a role for AgRP-neurons in the coordination of efferent organ activity and nutrient partitioning, providing a mechanistic link between obesity and obesity-related disorders. PMID:22990237

Central melanocortins regulate the motivation for sucrose reward.

PubMed

Pandit, Rahul; van der Zwaal, Esther M; Luijendijk, Mieneke C M; Brans, Maike A D; van Rozen, Andrea J; Oude Ophuis, Ralph J A; Vanderschuren, Louk J M J; Adan, Roger A H; la Fleur, Susanne E

2015-01-01

The role of the melanocortin (MC) system in feeding behavior is well established. Food intake is potently suppressed by central infusion of the MC 3/4 receptor agonist α-melanocyte stimulating hormone (α-MSH), whereas the MC 3/4 receptor inverse-agonist Agouti Related Peptide (AGRP) has the opposite effect. MC receptors are widely expressed in both hypothalamic and extra-hypothalamic brain regions, including nuclei involved in food reward and motivation, such as the nucleus accumbens (NAc) and the ventral tegmental area. This suggests that MCs modulate motivational aspects of food intake. To test this hypothesis, rats were injected intracerebroventricularly with α-MSH or AGRP and their motivation for sucrose was tested under a progressive ratio schedule of reinforcement. Food motivated behavior was dose-dependently decreased by α-MSH. Conversely, AGRP increased responding for sucrose, an effect that was blocked by pretreatment with the dopamine receptor antagonist α-flupenthixol. In contrast to progressive ratio responding, free intake of sucrose remained unaltered upon α-MSH or AGRP infusion. In addition, we investigated whether the effects of α-MSH and AGRP on food motivation were mediated by the NAc shell. In situ hybridization of MC3 and MC4 receptor expression confirmed that the MC4 receptor was expressed throughout the NAc, and injection of α-MSH and AGRP into the NAc shell caused a decrease and an increase in motivation for sucrose, respectively. These data show that the motivation for palatable food is modulated by MC4 receptors in the NAc shell, and demonstrate cross-talk between the MC and dopamine system in the modulation of food motivation.

New inducible genetic method reveals critical roles of GABA in the control of feeding and metabolism.

PubMed

Meng, Fantao; Han, Yong; Srisai, Dollada; Belakhov, Valery; Farias, Monica; Xu, Yong; Palmiter, Richard D; Baasov, Timor; Wu, Qi

2016-03-29

Currently available inducible Cre/loxP systems, despite their considerable utility in gene manipulation, have pitfalls in certain scenarios, such as unsatisfactory recombination rates and deleterious effects on physiology and behavior. To overcome these limitations, we designed a new, inducible gene-targeting system by introducing an in-frame nonsense mutation into the coding sequence of Cre recombinase (nsCre). Mutant mRNAs transcribed from nsCre transgene can be efficiently translated into full-length, functional Cre recombinase in the presence of nonsense suppressors such as aminoglycosides. In a proof-of-concept model, GABA signaling from hypothalamic neurons expressing agouti-related peptide (AgRP) was genetically inactivated within 4 d after treatment with a synthetic aminoglycoside. Disruption of GABA synthesis in AgRP neurons in young adult mice led to a dramatic loss of body weight due to reduced food intake and elevated energy expenditure; they also manifested glucose intolerance. In contrast, older mice with genetic inactivation of GABA signaling by AgRP neurons had only transient reduction of feeding and body weight; their energy expenditure and glucose tolerance were unaffected. These results indicate that GABAergic signaling from AgRP neurons plays a key role in the control of feeding and metabolism through an age-dependent mechanism. This new genetic technique will augment current tools used to elucidate mechanisms underlying many physiological and neurological processes.

New inducible genetic method reveals critical roles of GABA in the control of feeding and metabolism

PubMed Central

Meng, Fantao; Han, Yong; Srisai, Dollada; Belakhov, Valery; Farias, Monica; Xu, Yong; Palmiter, Richard D.; Baasov, Timor; Wu, Qi

2016-01-01

Currently available inducible Cre/loxP systems, despite their considerable utility in gene manipulation, have pitfalls in certain scenarios, such as unsatisfactory recombination rates and deleterious effects on physiology and behavior. To overcome these limitations, we designed a new, inducible gene-targeting system by introducing an in-frame nonsense mutation into the coding sequence of Cre recombinase (nsCre). Mutant mRNAs transcribed from nsCre transgene can be efficiently translated into full-length, functional Cre recombinase in the presence of nonsense suppressors such as aminoglycosides. In a proof-of-concept model, GABA signaling from hypothalamic neurons expressing agouti-related peptide (AgRP) was genetically inactivated within 4 d after treatment with a synthetic aminoglycoside. Disruption of GABA synthesis in AgRP neurons in young adult mice led to a dramatic loss of body weight due to reduced food intake and elevated energy expenditure; they also manifested glucose intolerance. In contrast, older mice with genetic inactivation of GABA signaling by AgRP neurons had only transient reduction of feeding and body weight; their energy expenditure and glucose tolerance were unaffected. These results indicate that GABAergic signaling from AgRP neurons plays a key role in the control of feeding and metabolism through an age-dependent mechanism. This new genetic technique will augment current tools used to elucidate mechanisms underlying many physiological and neurological processes. PMID:26976589

Microarray analysis sheds light on the dedifferentiating role of agouti signal protein in murine melanocytes via the Mc1r

PubMed Central

Le Pape, Elodie; Passeron, Thierry; Giubellino, Alessio; Valencia, Julio C.; Wolber, Rainer; Hearing, Vincent J.

2009-01-01

The melanocortin-1 receptor (MC1R) is a key regulator of pigmentation in mammals and is tightly linked to an increased risk of skin cancers, including melanoma, in humans. Physiologically activated by α-melanocyte stimulating hormone (αMSH), MC1R function can be antagonized by a secreted factor, agouti signal protein (ASP), which is responsible for the lighter phenotypes in mammals (including humans), and is also associated with increased risk of skin cancer. It is therefore of great interest to characterize the molecular effects elicited by those MC1R ligands. In this study, we determined the gene expression profiles of murine melan-a melanocytes treated with ASP or αMSH over a 4-day time course using genome-wide oligonucleotide microarrays. As expected, there were significant reductions in expression of numerous melanogenic proteins elicited by ASP, which correlates with its inhibition of pigmentation. ASP also unexpectedly modulated the expression of genes involved in various other cellular pathways, including glutathione synthesis and redox metabolism. Many genes up-regulated by ASP are involved in morphogenesis (especially in nervous system development), cell adhesion, and extracellular matrix-receptor interactions. Concomitantly, ASP enhanced the migratory potential and the invasiveness of melanocytic cells in vitro. These results demonstrate the role of ASP in the dedifferentiation of melanocytes, identify pigment-related genes targeted by ASP and by αMSH, and provide insights into the pleiotropic molecular effects of MC1R signaling that may function during development and may affect skin cancer risk. PMID:19174519

Structural and ultrastructural features of the agouti tongue (Dasyprocta aguti Linnaeus, 1766)

PubMed Central

Ciena, Adriano Polican; Bolina, Cristina de Sousa; de Almeida, Sonia Regina Yokomizo; Rici, Rose Eli Grassi; de Oliveira, Moacir Franco; da da Silva, Marcelo Cavenaghi Pereira; Miglino, Maria Angélica; Watanabe, Ii-sei

2013-01-01

The agouti (Dasyprocta aguti Linnaeus, 1766) is a wild rodent belonging to the family Dasyproctidae that is found throughout Brazil and feeds on fruits and seeds. The aim of the present study was to describe the following features of the tongue of agouti: its morphological structures, the three-dimensional characteristics of the lingual papillae surface, the connective tissue cores (CTCs) and the epithelial cell ultrastructure. Four types of papillae were observed on the dorsal surface of the tongue with a triangular shape: filiform, fungiform, foliate and vallate. Filiform papillae were distributed throughout the tongue surface, and removal of the epithelial surface revealed conical CTCs and multifilaments. Fungiform papillae were observed in the rostral and middle regions, whereas foliate papillae developed in pairs on the lateral margin of the caudal region. Removal of the epithelium in these regions revealed CTCs with parallel laminar conformation. Vallate papillae were arranged in a V-shape in the caudal region, and their CTCs ranged in shape from elongate to ovoid. The ultrastructural components of the dorsal epithelium were the basal, spinous, granular and keratinised layers. A broad area with cytoplasmic projections was identified in the interface region between the lamina propria and the basal layer. Flattened cells with intermediate filaments were observed in the transitional region between spinous and granular layers. The keratinised layer was composed of superimposed epithelial cells where desmosomes and cell-surface microridges were observed. These structural features, including the three-dimensional aspects of the lingual papillae, the CTCs and the epithelial ultrastructure, indicate that when compared with other animals, particularly other rodent species, the morphological features of the tongue of agouti are relatively well developed, especially regarding foliate and vallate papillae. PMID:23701183

Prenatal programming by testosterone of hypothalamic metabolic control neurones in the ewe.

PubMed

Sheppard, K M; Padmanabhan, V; Coolen, L M; Lehman, M N

2011-05-01

Ewes treated prenatally with testosterone develop metabolic deficits, including insulin resistance, in addition to reproductive dysfunctions that collectively mimic polycystic ovarian syndrome (PCOS), a common endocrine disease in women. We hypothesised that metabolic deficits associated with prenatal testosterone excess involve alterations in arcuate nucleus (ARC) neurones that contain either agouti-related peptide (AgRP) or pro-opiomelanocortin (POMC). Characterisation of these neurones in the ewe showed that immunoreactive AgRP and POMC neurones were present in separate populations in the ARC, that AgRP and POMC neurones co-expressed either neuropeptide Y or cocaine- and amphetamine-regulated transcript, respectively, and that each population had a high degree of co-localisation with androgen receptors. Examination of the effect of prenatal testosterone exposure on the number of AgRP and POMC neurones in adult ewes showed that prenatal testosterone excess significantly increased the number of AgRP but not POMC neurones compared to controls; this increase was restricted to the middle division of the ARC, was mimicked by prenatal treatment with dihydrotestosterone, a non-aromatisable androgen, and was blocked by co-treatment of prenatal testosterone with the anti-androgen, flutamide. The density of AgRP fibre immunoreactivity in the preoptic area, paraventricular nucleus, lateral hypothalamus and dorsomedial hypothalamic nucleus was also increased by prenatal testosterone exposure. Thus, ewes that were exposed to androgens during foetal life showed alterations in the number of AgRP-immunoreactive neurones and the density of fibre immunoreactivity in their projection areas, suggestive of permanent prenatal programming of metabolic circuitry that may, in turn, contribute to insulin resistance and an increased risk of obesity in this model of PCOS. © 2011 The Authors. Journal of Neuroendocrinology © 2011 Blackwell Publishing Ltd.

Homeostatic circuits selectively gate food cue responses in insular cortex

PubMed Central

Livneh, Yoav; Ramesh, Rohan n.; Burgess, christian R.; Levandowski, Kirsten M.; Madara, Joseph c.; Fenselau, henning; Goldey, Glenn J.; Diaz, Veronica E.; Jikomes, nick; Resch, Jon M.; Lowell, Bradford B.; Andermann, Mark L.

2017-01-01

Physiological needs bias perception and attention to relevant sensory cues. This process is ‘hijacked’ by drug addiction, causing cue-induced cravings and relapse. Similarly, its dysregulation contributes to failed diets, obesity, and eating disorders. Neuroimaging studies in humans have implicated insular cortex in these phenomena. However, it remains unclear how ‘cognitive’ cortical representations of motivationally relevant cues are biased by subcortical circuits that drive specific motivational states. Here we develop a microprism-based cellular imaging approach to monitor visual cue responses in the insular cortex of behaving mice across hunger states. Insular cortex neurons demonstrate food- cue-biased responses that are abolished during satiety. Unexpectedly, while multiple satiety-related visceral signals converge in insular cortex, chemogenetic activation of hypothalamic ‘hunger neurons’ (expressing agouti-related peptide (AgRP)) bypasses these signals to restore hunger-like response patterns in insular cortex. Circuit mapping and pathway-specific manipulations uncover a pathway from AgRP neurons to insular cortex via the paraventricular thalamus and basolateral amygdala. These results reveal a neural basis for state-specific biased processing of motivationally relevant cues. PMID:28614299

Who's behind that mask and cape? The Asian leopard cat's Agouti (ASIP) allele likely affects coat colour phenotype in the Bengal cat breed.

PubMed

Gershony, L C; Penedo, M C T; Davis, B W; Murphy, W J; Helps, C R; Lyons, L A

2014-12-01

Coat colours and patterns are highly variable in cats and are determined mainly by several genes with Mendelian inheritance. A 2-bp deletion in agouti signalling protein (ASIP) is associated with melanism in domestic cats. Bengal cats are hybrids between domestic cats and Asian leopard cats (Prionailurus bengalensis), and the charcoal coat colouration/pattern in Bengals presents as a possible incomplete melanism. The complete coding region of ASIP was directly sequenced in Asian leopard, domestic and Bengal cats. Twenty-seven variants were identified between domestic and leopard cats and were investigated in Bengals and Savannahs, a hybrid with servals (Leptailurus serval). The leopard cat ASIP haplotype was distinguished from domestic cat by four synonymous and four non-synonymous exonic SNPs, as well as 19 intronic variants, including a 42-bp deletion in intron 4. Fifty-six of 64 reported charcoal cats were compound heterozygotes at ASIP, with leopard cat agouti (A(P) (be) ) and domestic cat non-agouti (a) haplotypes. Twenty-four Bengals had an additional unique haplotype (A2) for exon 2 that was not identified in leopard cats, servals or jungle cats (Felis chaus). The compound heterozygote state suggests the leopard cat allele, in combination with the recessive non-agouti allele, influences Bengal markings, producing a darker, yet not completely melanistic coat. This is the first validation of a leopard cat allele segregating in the Bengal breed and likely affecting their overall pelage phenotype. Genetic testing services need to be aware of the possible segregation of wild felid alleles in all assays performed on hybrid cats. © 2014 The Authors. Animal Genetics published by John Wiley & Sons Ltd on behalf of Stichting International Foundation for Animal Genetics.

Rapamycin ameliorates age-dependent obesity associated with increased mTOR signaling in hypothalamic POMC neurons

PubMed Central

Yang, Shi-Bing; Tien, An-Chi; Boddupalli, Gayatri; Xu, Allison W.; Jan, Yuh Nung; Jan, Lily Yeh

2012-01-01

Summary The prevalence of obesity in older people is the leading cause of metabolic syndromes. Central neurons serving as homeostatic sensors for bodyweight control include hypothalamic neurons that express pro-opiomelanocortin (POMC) or neuropeptide-Y (NPY) and agouti-related protein (AgRP). Here we report an age-dependent increase of mammalian target of rapamycin (mTOR) signaling in POMC neurons that elevates the ATP-sensitive potassium (KATP) channel activity cell-autonomously to silence POMC neurons. Systemic or intracerebral administration of the mTOR inhibitor rapamycin causes weight loss in old mice. Intracerebral rapamycin infusion into old mice enhances the excitability and neurite projection of POMC neurons, thereby causing a reduction of food intake and bodyweight. Conversely, young mice lacking the mTOR negative regulator TSC1 in POMC neurons, but not those lacking TSC1 in NPY/AgRP neurons, were obese. Our study reveals that an increase in mTOR signaling in hypothalamic POMC neurons contributes to age-dependent obesity. PMID:22884327

Agrp neurons mediate Sirt1’s action on the melanocortin system and energy balance: roles for Sirt1 in neuronal firing and synaptic plasticity

PubMed Central

Dietrich, Marcelo O.; Antunes, Catiele; Geliang, Gan; Liu, Zhong-Wu; Borok, Erzsebet; Nie, Yongzhan; Xu, Allison W.; Souza, Diogo O.; Gao, Qian; Diano, Sabrina; Gao, Xiao-Bing; Horvath, Tamas L.

2010-01-01

Sirt1 has been associated with various effects of calorie restriction, including an increase in lifespan. Here we show in mice that a central regulatory component in energy metabolism, the hypothalamic melanocortin system, is affected by Sirt1, which promotes the activity and connectivity of this system resulting in negative energy balance. In adult mice, the pharmacological inhibition of brain Sirt1 activity decreased the inhibitory tone on the anorexigenic POMC neurons, as measured by the number of synaptic inputs to these neurons. When a Sirt1 inhibitor (EX-527) was injected either peripherally (i.p., 10mg/kg) or directly into the brain (i.c.v., 1.5 nmol/mouse), it decreased both food intake during the dark cycle and ghrelin-induced food intake. This effect on feeding is mediated by upstream melanocortin receptors, because the MC4R antagonist, SHU9119, reversed Sirt1’s effect on food intake. This action of Sirt1 required an appropriate shift in the mitochondrial redox state: in the absence of such an adaptation enabled by the mitochondrial protein, UCP2, Sirt1-induced cellular and behavioral responses were impaired. The selective knockout of Sirt1 in hypothalamic Agrp neurons through the use of Cre-Lox technology decreased electric responses of Agrp neurons to ghrelin and decreased food intake, leading to decreased lean mass, fat mass and body weight. The present data indicate that Sirt1 has a central mode of action by acting on the NPY/Agrp neurons to affect body metabolism. PMID:20810901

Multicentric squamous cell carcinona in a paca (Agouti paca) resembling Bowen's disease.

PubMed

Luppi, Marcela M; Malta, Marcelo C C; Costa, Maria E L T; Motta, Rafael O C; Santos, Renato L

2008-06-01

An 8-yr-old female paca (Agouti paca) was admitted at the Veterinary Hospital of the Belo Horizonte Zoo (Brazil) with an ulcerated cutaneous nodule of approximately 1.5 cm in diameter in the left ear. One week later, other cutaneous nodules were detected in various body locations. The animal died during a surgical procedure to remove the tumors. All cutaneous nodules were histologically similar with features of squamous cell carcinoma. Considering the predominant in situ nature of the lesion as well as its multicentric localization, the disease reported here closely resembles Bowen's disease, which has been described in humans and which has been identified as a rare neoplastic disease of cats, with one single report in a dog. This is the first report of a neoplastic disease in Agouti

Leptin and insulin pathways in POMC and AgRP neurons that modulate energy balance and glucose homeostasis.

PubMed

Varela, Luis; Horvath, Tamas L

2012-12-01

With the steady rise in the prevalence of obesity and its associated diseases, research aimed at understanding the mechanisms that regulate and control whole body energy homeostasis has gained new interest. Leptin and insulin, two anorectic hormones, have key roles in the regulation of body weight and energy homeostasis, as highlighted by the fact that several obese patients develop resistance to these hormones. Within the brain, the hypothalamic proopiomelanocortin and agouti-related protein neurons have been identified as major targets of leptin and insulin action. Many studies have attempted to discern the individual contributions of various components of the principal pathways that mediate the central effects of leptin and insulin. The aim of this review is to discuss the latest findings that might shed light on, and lead to a better understanding of, energy balance and glucose homeostasis. In addition, recently discovered targets and mechanisms that mediate hormonal action in the brain are highlighted.

Leptin and insulin pathways in POMC and AgRP neurons that modulate energy balance and glucose homeostasis

PubMed Central

Varela, Luis; Horvath, Tamas L

2012-01-01

With the steady rise in the prevalence of obesity and its associated diseases, research aimed at understanding the mechanisms that regulate and control whole body energy homeostasis has gained new interest. Leptin and insulin, two anorectic hormones, have key roles in the regulation of body weight and energy homeostasis, as highlighted by the fact that several obese patients develop resistance to these hormones. Within the brain, the hypothalamic proopiomelanocortin and agouti-related protein neurons have been identified as major targets of leptin and insulin action. Many studies have attempted to discern the individual contributions of various components of the principal pathways that mediate the central effects of leptin and insulin. The aim of this review is to discuss the latest findings that might shed light on, and lead to a better understanding of, energy balance and glucose homeostasis. In addition, recently discovered targets and mechanisms that mediate hormonal action in the brain are highlighted. PMID:23146889

α-melanocyte stimulating hormone modulates the central acyl ghrelin-induced stimulation of feeding, gastrointestinal motility, and colonic secretion.

PubMed

Huang, Hsien-Hao; Chen, Liang-Yu; Doong, Ming-Luen; Chang, Shi-Chuan; Chen, Chih-Yen

2017-01-01

Acyl ghrelin-induced intake depends on hypothalamic neuropeptide Y and agouti-related protein (AgRP) neurotransmitters. Intracerebroventricular (ICV) injection of AgRP increases feeding through competitive antagonism at melanocortin receptors. ICV administration of α-melanocyte stimulating hormone (α-MSH), a natural antagonist of AgRP, may modulate the acyl ghrelin-induced orexigenic effect. This study aimed to investigate the modulating effect of α-MSH on the central acyl ghrelin-induced food intake, gastrointestinal motility, and colonic secretion in rats. We examined the effects of α-MSH and acyl ghrelin on food intake, gastric emptying, small intestinal transit, colonic motility, and secretion in conscious rats with a chronic implant of ICV catheters. ICV injection of O - n -octanoylated ghrelin (0.1 nmol/rat) significantly increased the cumulative food intake up to 8 h ( P <0.01), enhanced non-nutrient semi-liquid gastric emptying ( P <0.001), increased the geometric center and running percentage of small intestinal transit ( P <0.001), accelerated colonic transit time ( P <0.05), and increased fecal pellet output ( P <0.01) and total fecal weight ( P <0.01). Pretreatment with ICV injection of α-MSH (1.0 and 2.0 nmol/rat) attenuated the acyl ghrelin-induced hyperphagic effect, fecal pellet output, and total fecal weight, while higher dose of α-MSH (2.0 nmol/rat) attenuated the increase in the geometric center of small intestinal transit ( P <0.01). However, neither dose of α-MSH altered acyl ghrelin-stimulated gastroprokinetic effect, increase in the running percentage of small intestinal transit, nor accelerated colonic transit time. α-MSH is involved in central acyl ghrelin-elicited feeding, small intestinal transit, fecal pellet output, and fecal weight. α-MSH does not affect central acyl ghrelin-induced acceleration of gastric emptying and colonic transit time in rats.

Genetic Instability at the Agouti Locus of the Mouse (Mus Musculus). I. Increased Reverse Mutation Frequency to the A(w) Allele in a/a Heterozygotes

PubMed Central

Sandulache, R.; Neuhauser-Klaus, A.; Favor, J.

1994-01-01

We have compiled the reverse mutation rate data to the white bellied agouti (A(w)) allele in heterozygous A/a mice and shown it to be increased by a factor of at least 350 in comparison to the reverse mutation rate in homozygous a/a mice. Employing tightly linked flanking restriction fragment length polymorphism DNA markers, we have shown that reversion to A(w) is associated with crossing over in the vicinity of the agouti locus. The non-agouti (a) allele has been recently shown to contain an 11-kb insert within the first intron of the agouti gene. Together with our present results, these observations suggest possible mechanisms to explain the reversion events. PMID:7982562

Genetic association analysis of 30 genes related to obesity in a European American population.

PubMed

Li, P; Tiwari, H K; Lin, W-Y; Allison, D B; Chung, W K; Leibel, R L; Yi, N; Liu, N

2014-05-01

Obesity, which is frequently associated with diabetes, hypertension and cardiovascular diseases, is primarily the result of a net excess of caloric intake over energy expenditure. Human obesity is highly heritable, but the specific genes mediating susceptibility in non-syndromic obesity remain unclear. We tested candidate genes in pathways related to food intake and energy expenditure for association with body mass index (BMI). We reanalyzed 355 common genetic variants of 30 candidate genes in seven molecular pathways related to obesity in 1982 unrelated European Americans from the New York Cancer Project. Data were analyzed by using a Bayesian hierarchical generalized linear model. The BMIs were log-transformed and then adjusted for covariates, including age, age(2), gender and diabetes status. The single-nucleotide polymorphisms (SNPs) were modeled as additive effects. With the stipulated adjustments, nine SNPs in eight genes were significantly associated with BMI: ghrelin (GHRL; rs35683), agouti-related peptide (AGRP; rs5030980), carboxypeptidase E (CPE; rs1946816 and rs4481204), glucagon-like peptide-1 receptor (GLP1R; rs2268641), serotonin receptors (HTR2A; rs912127), neuropeptide Y receptor (NPY5R;Y5R1c52), suppressor of cytokine signaling 3 (SOCS3; rs4969170) and signal transducer and activator of transcription 3 (STAT3; rs4796793). We also found a gender-by-SNP interaction (rs1745837 in HTR2A), which indicated that variants in the gene HTR2A had a stronger association with BMI in males. In addition, NPY1R was detected as having a significant gene effect even though none of the SNPs in this gene was significant. Variations in genes AGRP, CPE, GHRL, GLP1R, HTR2A, NPY1R, NPY5R, SOCS3 and STAT3 showed modest associations with BMI in European Americans. The pathways in which these genes participate regulate energy intake, and thus these associations are mechanistically plausible in this context.

Knockout of the Gnrh genes in zebrafish: effects on reproduction and potential compensation by reproductive and feeding-related neuropeptides.

PubMed

Marvel, Miranda; Spicer, Olivia Smith; Wong, Ten-Tsao; Zmora, Nilli; Zohar, Yonathan

2018-04-04

Gonadotropin-releasing hormone (GnRH) is known as a pivotal upstream regulator of reproduction in vertebrates. However, reproduction is not compromised in the hypophysiotropic Gnrh3 knockout line in zebrafish (gnrh3-/-). In order to determine if Gnrh2, the only other Gnrh isoform in zebrafish brains, is compensating for the loss of Gnrh3, we generated a double Gnrh knockout zebrafish line. Surprisingly, the loss of both Gnrh isoforms resulted in no major impact on reproduction, indicating that a compensatory response, outside of the Gnrh system, was evoked. A plethora of factors acting along the reproductive hypothalamus-pituitary axis were evaluated as possible compensators based on neuroanatomical and differential gene expression studies. In addition, we also examined the involvement of feeding factors in the brain as potential compensators for Gnrh2, which has known anorexigenic effects. We found that the double knockout fish exhibited upregulation of several genes in the brain, specifically gonadotropin-inhibitory hormone (gnih), secretogranin 2 (scg2), tachykinin 3a (tac3a), and pituitary adenylate cyclase-activating peptide 1 (pacap1), and downregulation of agouti-related peptide 1 (agrp1), indicating the compensation occurs outside of Gnrh cells and therefore is a non-cell autonomous response to the loss of Gnrh. While the differential expression of gnih and agrp1 in the double knockout line was confined to the periventricular nucleus and hypothalamus, respectively, the upregulation of scg2 corresponded with a broader neuronal redistribution in the lateral hypothalamus and hindbrain. In conclusion, our results demonstrate the existence of a redundant reproductive regulatory system that comes into play when Gnrh2 and Gnrh3 are lost.

NPY/AgRP neurons are not essential for feeding responses to glucoprivation.

PubMed

Luquet, Serge; Phillips, Colin T; Palmiter, Richard D

2007-02-01

Animals respond to hypoglycemia by eating and by stimulating gluconeogenesis. These responses to glucose deprivation are initiated by glucose-sensing neurons in the brain, but the neural circuits that control feeding behavior are not well established. Neurons in the arcuate region of the hypothalamus that express neuropeptide Y (NPY) and agouti-related protein (AgRP) have been implicated in mediating the feeding response to glucoprivation. We devised a method to selectively ablate these neurons in neonatal mice and then tested adult mice for their feeding responses to fasting, mild hypoglycemia, 2-deoxy-d-glucose and a ghrelin receptor agonist. Whereas the feeding response to the ghrelin receptor agonist was completely abrogated, the feeding response to glucoprivation was normal. The feeding response after a fast was attenuated when standard chow was available but normal with more palatable solid or liquid diet. We conclude that NPY/AgRP neurons are not necessary for generating or mediating the orexigenic response to glucose deficiency, but they are essential for the feeding response to ghrelin and refeeding on standard chow after a fast.

Alterations of arcuate nucleus neuropeptidergic development in contactin-deficient mice: comparison with anorexia and food-deprived mice.

PubMed

Fetissov, Sergueï O; Bergström, Ulrika; Johansen, Jeanette E; Hökfelt, Tomas; Schalling, Martin; Ranscht, Barbara

2005-12-01

A mutation in the Contactin-1 gene results in an ataxic and anorectic phenotype that is apparent by postnatal day 10 and lethal by postnatal day 19 [Berglund et al. (1999) Neuron 24, 739-750]. The resemblance of this phenotype with the anorexia (anx/anx) mouse mutation prompted us to investigate the hypothalamic neurochemistry of Contactin knock-out (KO) mice. Contactin was expressed in the hypothalamic neuropil of wild-type (WT) but not Contactin KO mice. In the KO condition, neuropeptide Y (NPY) and agouti-related protein (AgRP) immunoreactivity (IR) accumulated in the somata of arcuate nucleus neurons, whereas IR for these neuropeptides as well as for alpha-melanocyte-stimulating hormone (alpha-MSH) decreased in the corresponding axon projections. These changes in the pattern of neuropeptide expression in the Contactin-deficient hypothalamus were similar but more pronounced than those found in anx/anx mice. Increased levels of NPY and AgRP and decreased concentrations of pro-opiomelanocortin mRNA in arcuate neurons accompanied these changes. In relating these alterations a 24-h food deprivation period, we observed in 3-week-old WT mice an elevation of NPY- and AgRP-IR in the perikarya of arcuate neurons without notable reduction of NPY- or AgRP-IR in nerve fibers, suggesting that the decrease of arcuate projections can be associated with postnatal anorectic phenotype. Our data implicate Contactin in the postnatal development of the NPY/AgRP and alpha-MSH arcuate neurons and suggest that similar to anx/anx mutant mice, compromised orexigenic signaling via NPY/AgRP neurons may contribute to reduced food intake by the Contactin-mutant animals.

The gut microbiota reduces leptin sensitivity and the expression of the obesity-suppressing neuropeptides proglucagon (Gcg) and brain-derived neurotrophic factor (Bdnf) in the central nervous system.

PubMed

Schéle, Erik; Grahnemo, Louise; Anesten, Fredrik; Hallén, Anna; Bäckhed, Fredrik; Jansson, John-Olov

2013-10-01

The gut microbiota contributes to fat mass and the susceptibility to obesity. However, the underlying mechanisms are not completely understood. To investigate whether the gut microbiota affects hypothalamic and brainstem body fat-regulating circuits, we compared gene expression of food intake-regulating neuropeptides between germ-free and conventionally raised (CONV-R) mice. We found that CONV-R mice had decreased expression of the antiobesity neuropeptide glucagon-like peptide-1 (GLP-1) precursor proglucagon (Gcg) in the brainstem. Moreover, in both the hypothalamus and the brainstem, CONV-R mice had decreased expression of the antiobesity neuropeptide brain-derived neurotrophic factor (Bdnf). CONV-R mice had reduced expression of the pro-obesity peptides neuropeptide-Y (Npy) and agouti-related protein (Agrp), and increased expression of the antiobesity peptides proopiomelanocortin (Pomc) and cocaine- and amphetamine-regulated transcript (Cart) in the hypothalamus. The latter changes in neuropeptide expression could be secondary to elevated fat mass in CONV-R mice. Leptin treatment caused less weight reduction and less suppression of orexigenic Npy and Agrp expression in CONV-R mice compared with germ-free mice. The hypothalamic expression of leptin resistance-associated suppressor of cytokine signaling 3 (Socs-3) was increased in CONV-R mice. In conclusion, the gut microbiota reduces the expression of 2 genes coding for body fat-suppressing neuropeptides, Gcg and Bdnf, an alteration that may contribute to fat mass induction by the gut microbiota. Moreover, the presence of body fat-inducing gut microbiota is associated with hypothalamic signs of Socs-3-mediated leptin resistance, which may be linked to failed compensatory body fat reduction.

Prenatal development of the agouti (Dasyprocta prymnolopha Wagler, 1831): External features and growth curves.

PubMed

Fortes, Eunice Anita de Moura; Ferraz, Maíra Soares; Bezerra, Dayseanny Oliveira; Júnior, Aírton Mendes Conde; Cabral, Rosa Maria; Sousa, Francisco das Chagas Araújo; Almeida, Hatawa Melo; Pessoa, Gerson Tavares; Menezes, Danilo José Ayres de; Guerra, Sérgio Paulo Lima; Sampaio, Ivan Barbosa Machado; Assis Neto, Antônio Chaves; Carvalho, Maria Acelina Martins de

2013-08-01

The gestation period in agoutis can range from 104 to 120 days. Knowledge regarding the morphological characteristics of embryos and fetuses is important as a base for studies in reproduction biotechnology, such as in vitro fertilization, embryo transfer and helps in determining congenital anomalies during the development phase. Thus, given the importance and lack of information about agouti embryology, the objective of this study was to characterize the external morphology and define the biometry of embryos and fetuses, at different days of development. Nine females were submitted to daily colpocytology to identify the estrus, confirm mating and identify day zero of the gestation. When the mating was confirmed they were weighed, underwent abdominal ultrasonography and surgery was conducted on the females at the gestational ages of 25, 30, 35, 40, 45, 50, 75 and 100 days. Sixteen embryos/fetuses were weighed and measured. Agouti embryos at 25 days after mating are "C" shaped, with primitive structures, 0.4±0.01cm crown-rump and weighed 0.06±0.01g; at 30 days after mating the crown-rump was 0.95±0.07cm and weighed 0.28±0.00g; at 35 days after mating the crown-rump was 155±0.07cm and weighed 0.38±0.01g; at 40 days after mating the crown-rump was 2.25±0.21cm and weighed 1.25±0.07g; at 45 days after mating the crown-rump was 3.45±0.35cm and weighed 2.75±0.64g; at 50 days after mating the crown-rump was 5.0±0.3cm and weighed 7.01±2.6g; at 75 days after mating, the skin was dark, the crown-rump was 10.0±0.14cm and weighed 55.2±0.07g. At 100 days after mating, the crown-rump was 13.8±0.49cm and fetuses weighed 136.7±9.40g. Based on the morphological data assessed the embryo and fetus age could be assessed and the size and average weight of agouti embryos was established. Copyright © 2013 Elsevier B.V. All rights reserved.

Involvement of CD36 in Modulating the Decrease of NPY and AgRP Induced by Acute Palmitic Acid Stimulation in N1E-115 Cells.

PubMed

Ma, Yan; Wang, Xiaoyi; Yang, Hongying; Zhang, Xu; Yang, Nianhong

2017-06-17

Central nervous system (CNS) fatty acid sensing plays an important role in the regulation of food intake, and palmitic acid (PA) is the most important long chain fatty acid (LCFA) in the mammalian diet. To explore the effect of PA on central neuropeptide expression and the role of the cluster of the differentiation of 36 (CD36) in the process, N1E-115 cells were cultured with PA in the presence or absence of sulfosuccinimidyl-oleate (SSO), a CD36 inhibitor. Results showed that 10 μmol/L PA significantly reduced NPY and AgRP mRNA expression after 20 min of exposure, while the expression of CD36 was upregulated. The presence of SSO significantly attenuated the decrease of NPY and AgRP expression that was induced by PA alone, although no notable effect on PA- induced CD36 gene expression was observed. In conclusion, our study suggests the involvement of CD36 in the PA-induced decrease of NPY and AgRP in N1E-115 cells.

Involvement of CD36 in Modulating the Decrease of NPY and AgRP Induced by Acute Palmitic Acid Stimulation in N1E-115 Cells

PubMed Central

Ma, Yan; Wang, Xiaoyi; Yang, Hongying; Zhang, Xu; Yang, Nianhong

2017-01-01

Central nervous system (CNS) fatty acid sensing plays an important role in the regulation of food intake, and palmitic acid (PA) is the most important long chain fatty acid (LCFA) in the mammalian diet. To explore the effect of PA on central neuropeptide expression and the role of the cluster of the differentiation of 36 (CD36) in the process, N1E-115 cells were cultured with PA in the presence or absence of sulfosuccinimidyl-oleate (SSO), a CD36 inhibitor. Results showed that 10 μmol/L PA significantly reduced NPY and AgRP mRNA expression after 20 min of exposure, while the expression of CD36 was upregulated. The presence of SSO significantly attenuated the decrease of NPY and AgRP expression that was induced by PA alone, although no notable effect on PA- induced CD36 gene expression was observed. In conclusion, our study suggests the involvement of CD36 in the PA-induced decrease of NPY and AgRP in N1E-115 cells. PMID:28629148

Interleukin 6 deficiency modulates the hypothalamic expression of energy balance regulating peptides during pregnancy in mice.

PubMed

Pazos, Patricia; Lima, Luis; Casanueva, Felipe F; Diéguez, Carlos; García, María C

2013-01-01

Pregnancy is associated with hyperphagia, increased adiposity and multiple neuroendocrine adaptations. Maternal adipose tissue secretes rising amounts of interleukin 6 (IL6), which acts peripherally modulating metabolic function and centrally increasing energy expenditure and reducing body fat. To explore the role of IL6 in the central mechanisms governing dam's energy homeostasis, early, mid and late pregnant (gestational days 7, 13 and 18) wild-type (WT) and Il6 knockout mice (Il6-KO) were compared with virgin controls at diestrus. Food intake, body weight and composition as well as indirect calorimetry measurements were performed in vivo. Anabolic and orexigenic peptides: neuropeptide Y (Npy) and agouti-related peptide (Agrp); and catabolic and anorectic neuropeptides: proopiomelanocortin (Pomc), corticotrophin and thyrotropin-releasing hormone (Crh and Trh) mRNA levels were determined by in situ hybridization. Real time-PCR and western-blot were used for additional tissue gene expression and protein studies. Non-pregnant Il6-KO mice were leaner than WT mice due to a decrease in fat but not in lean body mass. Pregnant Il6-KO mice had higher fat accretion despite similar body weight gain than WT controls. A decreased fat utilization in absence of Il6 might explain this effect, as shown by increased respiratory exchange ratio (RER) in virgin Il6-KO mice. Il6 mRNA levels were markedly enhanced in adipose tissue but reduced in hypothalamus of mid and late pregnant WT mice. Trh expression was also stimulated at gestational day 13 and lack of Il6 blunted this effect. Conversely, in late pregnant mice lessened hypothalamic Il6 receptor alpha (Il6ra), Pomc and Crh mRNA were observed. Il6 deficiency during this stage up-regulated Npy and Agrp expression, while restoring Pomc mRNA levels to virgin values. Together these results demonstrate that IL6/IL6Ra system modulates Npy/Agrp, Pomc and Trh expression during mouse pregnancy, supporting a role of IL6 in the central

CARDIOTHORACIC RATIO AND VERTEBRAL HEART SCALE IN CLINICALLY NORMAL BLACK-RUMPED AGOUTIS (DASYPROCTA PRYMNOLOPHA, WAGLER 1831).

PubMed

de Moura, Charlys Rhands Coelho; das Neves Diniz, Anaemilia; da Silva Moura, Laecio; das Chagas Araújo Sousa, Francisco; Baltazar, Pollyana Irene; Freire, Larisse Danielle; Guerra, Porfírio Candanedo; de Sousa, João Macedo; Giglio, Robson Fortes; Pessoa, Gerson Tavares; de Sá, Renan Paraguassu; Alves, Flávio Ribeiro

2015-06-01

Wild rodents, such as the lowland paca (Cuniculus paca), capybara (Hydrochoerus hydrochaeris), rock cavy (Kerodon rupestris), guinea pig (Cavia aperea), and black-rumped agouti (Dasyprocta prymnolopha) are intensely hunted throughout Amazonia and at the semiarid regions of northeastern Brazil. To contribute to the preservation of these species, more information about their anatomy, physiology and pathophysiology is needed. The aim of this study was to standardize the vertebral heart scale (VHS) and cardiothoracic ratio (CTR) in clinically normal black-rumped agouti, as well as to compare the results of these two methods, which are commonly used to evaluate the cardiac silhouette in domestic animals. Twelve healthy black-rumped agoutis, divided into two groups (six males and six females), obtained from the Nucleus for Wild Animal Studies and Conservation at the Federal University of Piauí, were radiographed in right and left lateral and dorsoventral projections. The values of the VHS were 8.00±0.31v (the number of thoracic vertebral length spanned by each dimension, starting at T4) for males and 8.11±0.41v for females, and there was no statistical difference between the decubitus (right and left) or between males and females (P>0.05). The CTR mean values obtained were 0.51±0.03 for males, and 0.52±0.02 for females, and there was no statistical difference between the genders (P>0.05). However, there was positive correlation between VHS and CTR (r=0.77 right decubitus and r=0.82 left decubitus). The thoracic and heart diameter had mean values of 6.72±0.61 and 3.48±0.30 cm (males), and for the females, it was 6.61±0.51 and 3.5±0.30 cm, respectively, and there was statistical difference between the genders. The results demonstrated high correlation between the VHS and CTR producing similar results, indicating similar clinical precision for assessing the size of the cardiac silhouette in the black-rumped agoutis.

1,2,3-Triazole Rings as a Disulfide Bond Mimetic in Chimeric AGRP-Melanocortin Peptides: Design, Synthesis, and Functional Characterization.

PubMed

Tala, Srinivasa R; Singh, Anamika; Lensing, Cody J; Schnell, Sathya M; Freeman, Katie T; Rocca, James R; Haskell-Luevano, Carrie

2018-05-16

The melanocortin system is involved in the regulation of complex physiological functions, including energy and weight homeostasis, feeding behavior, inflammation, sexual function, pigmentation, and exocrine gland function. The five melanocortin receptors that belong to the superfamily of G protein-coupled receptors (GPCRs) are regulated by endogenously expressed agonists and antagonists. The aim of this study was to explore the potential of replacing the disulfide bridge in chimeric AGRP-melanocortin peptide Tyr-c[Cys-His-d-Phe-Arg-Trp-Asn-Ala-Phe-Cys]-Tyr-NH 2 (1) with 1,2,3-triazole moieties. A series of 1,2,3-triazole-bridged peptidomimetics were designed, synthesized, and pharmacologically evaluated at the mouse melanocortin receptors. The ligands possessed nanomolar to micromolar agonist cAMP signaling potency. A key finding was that the disulfide bond in peptide 1 can be replaced with the monotriazole ring with minimal effect on the functional activity at the melanocortin receptors. The 1,5-disubstituted triazole-bridged peptide 6 showed equipotent functional activity at the mMC3R and modest 5-fold decreased agonist potency at the mMC4R compared to those of 1. Interestingly, the 1,4- and 1,5-disubstituted isomers of the triazole ring resulted in different selectivities at the receptor subtypes, indicating subtle structural features that may be exploited in the generation of selective melanocortin ligands. Introducing cyclic and acyclic bis-triazole moieties into chimeric AGRP template 1 generally decreased agonist activity. These results will be useful for the further design of neuronal chemical probes for the melanocortin receptors as well as in other receptor systems.

Structure-activity relationships of the melanocortin tetrapeptide Ac-His-DPhe-Arg-Trp-NH2 at the mouse melanocortin receptors. Part 3: modifications at the Arg position.

PubMed

Holder, Jerry Ryan; Xiang, Zhimin; Bauzo, Rayna M; Haskell-Luevano, Carrie

2003-01-01

The melanocortin pathway is involved in the regulation of several physiological functions including skin pigmentation, steroidogenesis, obesity, energy homeostasis, and exocrine gland function. This melanocortin pathway consists of five known G-protein coupled receptors, endogenous agonists derived from the proopiomelanocortin (POMC) gene transcript, the endogenous antagonists Agouti and the Agouti-related protein (AGRP) and signals through the intracellular cAMP signal transduction pathway. The melanocortin-3 receptor (MC3R) and melanocortin-4 receptor (MC4R) located in the brain are implicated as participating in the metabolic and food intake aspects of energy homeostasis and are stimulated by melanocortin agonists such as alpha-melanocyte stimulation hormone (alpha-MSH). All the endogenous (POMC-derived) melanocortin agonists contain the putative message sequence "His-Phe-Arg-Trp." Herein, we report 12 tetrapeptides, based upon the template Ac-His(6)-DPhe(7)-Arg(8)-Trp(9)-NH(2) (alpha-MSH numbering) that have been modified at the Arg(8) position by neutral, basic, or acidic amino acid side chains. These peptides have been pharmacologically characterized for agonist activity at the mouse melanocortin receptors MC1R, MC3R, MC4R, and MC5R. The most notable results of this study include the observation that removal of the guanidinyl side chain moiety results in decreased melanocortin receptor potency, but that this Arg(8) side chain is not critical for melanocortin receptor agonist activity. Additionally, incorporation of the homoArg(8) residue results in 56-fold MC4R versus MC3R selectivity, and the Orn(8) residue results in 123-fold MC4R versus MC5R and 63-fold MC5R versus MC3R selectivity. Copyright 2002 Elsevier Science Inc.

Induction of NPY/AgRP orexigenic peptide expression in rat hypothalamus is an early event in fasting: relationship with circulating leptin, insulin and glucose.

PubMed

Palou, Mariona; Sánchez, Juana; Rodríguez, Ana M; Priego, Teresa; Picó, Catalina; Palou, Andreu

2009-01-01

Hypothalamus is crucial in the control of energy intake and expenditure in mammals, presenting two interconnected populations of neurons producing orexigenic NPY/AgRP (neuropeptide Y; agouti related peptide) and anorexigenic POMC/CART (pro-opiomelanocortin; cocaine and amphetamine regulated transcript) neuropeptides. We aimed to shed more light on the response and sensitivity in the production of these neuropeptides to face nutritional changes, particularly food deprivation, and on the signals that regulate them. Male Wistar rats were fasted for 0, 4, 8 and 24h and refed for 3h after 8h fasting. mRNA levels of gastric and adipose tissue (retroperitoneal, mesenteric and inguinal) leptin, and of hypothalamic NPY, AgRP, POMC, CART, leptin receptor, SOCS3 (suppressor of cytokine signaling 3) and insulin receptor were analyzed. Gastric and circulating leptin, and circulating insulin, glucose and ghrelin were also determined. The only neuropeptide mRNAs that responded (increasing) to the short-term periods of fasting used were those of NPY (transiently) and AgRP, and these changes were accompanied by an increase in leptin receptor mRNA levels and by a decrease in adipose and gastric leptin expression and in the circulating levels of leptin, insulin and glucose, but without changes in circulating ghrelin. The elevation in AgRP and leptin receptor mRNA levels and the drop in circulating leptin were not reverted with refeeding. It is suggested that the induction of expression of the orexigenic molecules in NPY/AgRP neurons is an early event upon fasting, related with changes in leptin, insulin and glucose levels, but with the role of leptin signaling in particular. 2009 S. Karger AG, Basel.

Olanzapine-induced hyperphagia and weight gain associate with orexigenic hypothalamic neuropeptide signaling without concomitant AMPK phosphorylation.

PubMed

Fernø, Johan; Varela, Luis; Skrede, Silje; Vázquez, María Jesús; Nogueiras, Rubén; Diéguez, Carlos; Vidal-Puig, Antonio; Steen, Vidar M; López, Miguel

2011-01-01

The success of antipsychotic drug treatment in patients with schizophrenia is limited by the propensity of these drugs to induce hyperphagia, weight gain and other metabolic disturbances, particularly evident for olanzapine and clozapine. However, the molecular mechanisms involved in antipsychotic-induced hyperphagia remain unclear. Here, we investigate the effect of olanzapine administration on the regulation of hypothalamic mechanisms controlling food intake, namely neuropeptide expression and AMP-activated protein kinase (AMPK) phosphorylation in rats. Our results show that subchronic exposure to olanzapine upregulates neuropeptide Y (NPY) and agouti related protein (AgRP) and downregulates proopiomelanocortin (POMC) in the arcuate nucleus of the hypothalamus (ARC). This effect was evident both in rats fed ad libitum and in pair-fed rats. Of note, despite weight gain and increased expression of orexigenic neuropeptides, subchronic administration of olanzapine decreased AMPK phosphorylation levels. This reduction in AMPK was not observed after acute administration of either olanzapine or clozapine. Overall, our data suggest that olanzapine-induced hyperphagia is mediated through appropriate changes in hypothalamic neuropeptides, and that this effect does not require concomitant AMPK activation. Our data shed new light on the hypothalamic mechanism underlying antipsychotic-induced hyperphagia and weight gain, and provide the basis for alternative targets to control energy balance.

Olanzapine-Induced Hyperphagia and Weight Gain Associate with Orexigenic Hypothalamic Neuropeptide Signaling without Concomitant AMPK Phosphorylation

PubMed Central

Fernø, Johan; Vázquez, María Jesús; Nogueiras, Rubén; Diéguez, Carlos; Vidal-Puig, Antonio; Steen, Vidar M.; López, Miguel

2011-01-01

The success of antipsychotic drug treatment in patients with schizophrenia is limited by the propensity of these drugs to induce hyperphagia, weight gain and other metabolic disturbances, particularly evident for olanzapine and clozapine. However, the molecular mechanisms involved in antipsychotic-induced hyperphagia remain unclear. Here, we investigate the effect of olanzapine administration on the regulation of hypothalamic mechanisms controlling food intake, namely neuropeptide expression and AMP-activated protein kinase (AMPK) phosphorylation in rats. Our results show that subchronic exposure to olanzapine upregulates neuropeptide Y (NPY) and agouti related protein (AgRP) and downregulates proopiomelanocortin (POMC) in the arcuate nucleus of the hypothalamus (ARC). This effect was evident both in rats fed ad libitum and in pair-fed rats. Of note, despite weight gain and increased expression of orexigenic neuropeptides, subchronic administration of olanzapine decreased AMPK phosphorylation levels. This reduction in AMPK was not observed after acute administration of either olanzapine or clozapine. Overall, our data suggest that olanzapine-induced hyperphagia is mediated through appropriate changes in hypothalamic neuropeptides, and that this effect does not require concomitant AMPK activation. Our data shed new light on the hypothalamic mechanism underlying antipsychotic-induced hyperphagia and weight gain, and provide the basis for alternative targets to control energy balance. PMID:21695181

Rapid development of semistarvation-induced hyperactivity in Dark Agouti rats. Excessive wheel running and effect of 3,4-methylenedioxymethamphetamine (MDMA).

PubMed

Vidal, Pedro; Pérez-Padilla, Ángeles; Pellón, Ricardo

2013-02-01

Clinical studies have found that patients with anorexia develop high activity levels. These data suggest a possible implication of activity in the aetiology of anorexia and are in line with findings obtained in animals during experimental procedures to model interactions between activity and weight loss. Activity-based anorexia (ABA) and semistarvation-induced hyperactivity (SIH) develop when laboratory rats have food access restricted to a single period in the day and are given free access to an activity wheel. This experiment sought to show the effect on weight loss of the excessive activity normally seen in Dark Agouti rats and of hyperactivity induced by 3,4-methylenedioxymethamphetamine (MDMA). To this end, 32 female rats of the Dark Agouti strain were selected and divided into four groups in accordance with a 2 × 2 factorial design, in which one factor was treatment (saline or MDMA) and the other was access or lack of access to an activity wheel. Animals with wheel running access displayed a marked increase in running combined with accelerated weight loss. Although pharmacological treatment resulted in no observable effect on weight loss, rats treated with 12.5mg/kg MDMA generally registered more wheel running than did those treated with saline. Analysis of data on the temporal distribution of wheel running revealed an alteration in circadian activity patterns as a consequence of MDMA. These results, by showing a general high level of wheel running in Dark Agouti rats, once again emphasise the close relationship between activity and weight loss in the development of SIH and related phenomena such as ABA. Copyright © 2012 Elsevier Ltd. All rights reserved.

Collection and evaluation of epididymal sperm in captive agoutis (Dasyprocta aguti).

PubMed

Ferraz, M S; de Menezes, D J A; Pessoa, G T; Cabral, R M; Illera, M J; Silva, A R; Carvalho, M A M

2011-02-01

The objective was to establish a protocol for the collection and evaluation of epididymal sperm in agoutis. Eight males (1-2 y old) underwent left orchidectomy and epididymal sperma were collected by retrograde flush. Average values were flush volume 32 μL, pH 6.9, sperm concentration 748 x 10(6) sperm/mL, with motility 86.5% and vigor 4.6. Viable sperm were present in all flush samples; 66% of sperm were alive, and 41.9% of sperm responded positively to the hypoosmotic test (using distilled water). There were 21.1% morphologically abnormal sperm, of which 2.0 and 19.1% were primary and secondary defects, respectively. The acrosome was intact in 99.5% of sperm. The sperm head was 4.89 ± 0.41 μm long and 3.13 ± 0.35 μm wide, with an area of 13.01 ± 2.01 μm(2). Midpieces were 5.33 ± 0.44 μm long and 0.98 ± 0.13 wide, sperm tails were 29.91 ± 2.29 μm, and overall sperm length was 40.12 ± 2.44 μm. In conclusion, epididymal sperm collection from agoutis was satisfactory; the collected sperm has the potential to be stored, facilitating development of other reproductive biotechnologies for this species. Copyright © 2011 Elsevier Inc. All rights reserved.

Functional anatomy of the female genital organs of the wild black agouti (Dasyprocta fuliginosa) female in the Peruvian Amazon.

PubMed

Mayor, P; Bodmer, R E; Lopez-Bejar, M

2011-02-01

This study examined anatomical and histological characteristics of genital organs of 38 black agouti females in the wild in different reproductive stages, collected by rural hunters in the North-eastern Peruvian Amazon. Females in the follicular phase of the estrous cycle had greater antral follicle sizes than other females, the largest antral follicle measuring 2.34mm. Antral follicles in pregnant females and females in luteal phase of the estrous cycle had an average maximum diameter smaller than 1mm. In black agouti females in follicular phase, some antral follicles are selected to continue to growth, reaching a pre-ovulatory diameter of 2mm. Mean ovulation rate was 2.5 follicles and litter size was 2.1 embryos or fetuses per pregnant female, resulting in a rate of ovum mortality of 20.8%. Many follicles from which ovulation did not occur of 1-mm maximum diameter luteinize forming accessory CL. The constituent active luteal tissues of the ovary are functional and accessory CL. Although all females had accessory CL, transformation of follicles into accessory CL occurred especially in pregnant females, resulting in a contribution from 9% to 23% of the total luteal volume as pregnancy advances. The persistence of functional CL throughout pregnancy might reflect the importance for the maintenance of gestation and may be essential for the continuous hormonal production. The duplex uterus of the agouti female is composed by two completely independent uterine horns with correspondent separate cervices opening into the vagina. In pregnant females, most remarkable observed uterine adaptations were induced by the progressive enlargement caused by the normal pregnancy evolution. The wild black agouti showed different vaginal epithelium features in accordance with the reproductive state of the female. Copyright © 2011 Elsevier B.V. All rights reserved.

Effects of random food deprivation and refeeding on energy metabolism, behavior and hypothalamic neuropeptide expression in Apodemus chevrieri.

PubMed

Wan-Long, Zhu; Zheng-Kun, Wang

2016-11-01

Maintaining adaptive control of behavior and physiology is the main strategy used by animals in responding to changes of food resources. To investigate the effects of random food deprivation (FD) and refeeding on energy metabolism and behavior in Apodemus chevrieri, we acclimated adult males to FD for 4weeks, then refed them ad libitum for 4weeks (FD-Re group). During the period of FD, animals were fed ad libitum for 4 randomly assigned days each week, and deprived of food the other 3days. A control group was fed ad libitum for 8weeks. At 4 and 8weeks we measured body mass, thermogenesis, serum leptin levels, body composition, gastrointestinal tract morphology, behavior and hypothalamic neuropeptide expression. At 4weeks, food intake, gastrointestinal mass, neuropeptide Y (NPY) and agouti-related protein (AgRP) mRNA expressions increased and thermogenesis, leptin levels, pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) expressions decreased in FD compared with controls. FD also showed more resting behavior and less activity than the controls on ad libitum day. There were no differences between FD-Re and controls at 8weeks, indicating significant plasticity. These results suggested that animals can compensate for unpredictable reduction in food availability by increasing food intake and reducing energy expended through thermogenesis and activity. Leptin levels, NPY, AgRP, POMC, and CART mRNA levels may also regulate energy metabolism. Significant plasticity in energy metabolism and behavior was shown by A. chevrieri over a short timescale, allowing them to adapt to food shortages in nutritionally unpredictable environments. Copyright © 2016 Elsevier Inc. All rights reserved.

ECHOCARDIOGRAPHIC FINDINGS OF BIDIMENSIONAL MODE, M-MODE, AND DOPPLER OF CLINICALLY NORMAL BLACK-RUMPED AGOUTI (DASYPROCTA PRYMNOLOPHA, WAGLER 1831).

PubMed

Diniz, Anaemilia das Neves; Pessoa, Gerson Tavares; da Silva Moura, Laecio; de Sousa, André Braga; Sousa, Francisco das Chagas Araújo; de Sá Rodrigues, Renan Paraguassu; da Silva Barbosa, Maria Angélica Parente; de Almeida, Hatawa Melo; Freire, Larisse Danielle Silva; Sanches, Marina Pinto; Júnior, Antônio Augusto Nascimento Machado; Guerra, Porfírio Candanedo; Neves, Willams Costa; de Sousa, João Macedo; Bolfer, Luiz; Giglio, Robson Fortes; Alves, Flávio Ribeiro

2017-06-01

The black-rumped agouti ( Dasyprocta prymnolopha , Wagler 1831) is currently under intense ecologic pressure, which has resulted in its disappearance from some regions of Brazil. Echocardiography is widely used in veterinary medicine but it is not yet part of the clinical routine for wild animals. The objective of the present study was to assess the applicability of the echocardiographic exam in nonanesthetized agouti and to establish normal reference values for echocardiographic measurements in bidimensional mode (2D), M-mode, and Doppler for this species, and a lead II electrocardiogram was simultaneously recorded. Twenty agouti were used in this study. All the echocardiographic measurements were positively correlated with weight (P < 0.05), and there were no significant differences between sexes (P > 0.05). Blood flow velocities in the pulmonary and aortic artery ranged from 67.32-71.28 cm/sec and 79.22-101.84 cm/sec, respectively. The isovolumic relaxation time was assessed in all the animals and ranged from 38.5 to 56.6 ms. The maximum value for the nonfused E and A waves and the Et and At waves was 158 beats/min for both. The results obtained for the morphologic and heart hemodynamic measurements can guide future studies and help in the clinical management of these animals in captivity.

Energy Balance Regulating Neuropeptides Are Expressed through Pregnancy and Regulated by Interleukin-6 Deficiency in Mouse Placenta.

PubMed

Pazos, Patricia; Lima, Luis; Diéguez, Carlos; García, María C

2014-01-01

The placenta produces a number of signaling molecules including metabolic and reproductive hormones as well as several inflammatory mediators. Among them, Interleukin-6 (IL-6), a well-known immune and metabolic regulator, acts peripherally modulating metabolic function and centrally increasing energy expenditure and reducing body fat. IL-6 interacts with key hypothalamic neuropeptidergic systems controlling energy homeostasis such as those producing the orexigenic/anabolic: neuropeptide Y (NPY) and agouti-related peptide (AgRP) and anorectic/catabolic neuropeptides: proopiomelanocortin (POMC) and cocaine and amphetamine regulated transcript (CART). Human and rat placenta have been identified as source of these neuropeptides, but their expression and regulation in murine placental tissues remain unknown. Therefore, placental mRNA levels of IL-6, NPY, AgRP, POMC, and CART at different pregnancy stages (gestational days 13, 15, and 18) were analyzed by real time PCR, as were the effect of IL-6 deficiency (IL-6 knockout mice) on their placental expression. Our results showed that placenta-derived neuropeptides were regulated by gestational age and IL-6 throughout the second half of mouse pregnancy. These data suggest that IL-6 may participate in the fine tune control of energy balance during pregnancy by extending its action as a metabolic signal to the main organ at the fetomaternal interface: the placenta.

Angiotensin AT1A receptors on leptin receptor-expressing cells control resting metabolism.

PubMed

Claflin, Kristin E; Sandgren, Jeremy A; Lambertz, Allyn M; Weidemann, Benjamin J; Littlejohn, Nicole K; Burnett, Colin M L; Pearson, Nicole A; Morgan, Donald A; Gibson-Corley, Katherine N; Rahmouni, Kamal; Grobe, Justin L

2017-04-03

Leptin contributes to the control of resting metabolic rate (RMR) and blood pressure (BP) through its actions in the arcuate nucleus (ARC). The renin-angiotensin system (RAS) and angiotensin AT1 receptors within the brain are also involved in the control of RMR and BP, but whether this regulation overlaps with leptin's actions is unclear. Here, we have demonstrated the selective requirement of the AT1A receptor in leptin-mediated control of RMR. We observed that AT1A receptors colocalized with leptin receptors (LEPRs) in the ARC. Cellular coexpression of AT1A and LEPR was almost exclusive to the ARC and occurred primarily within neurons expressing agouti-related peptide (AgRP). Mice lacking the AT1A receptor specifically in LEPR-expressing cells failed to show an increase in RMR in response to a high-fat diet and deoxycorticosterone acetate-salt (DOCA-salt) treatments, but BP control remained intact. Accordingly, loss of RMR control was recapitulated in mice lacking AT1A in AgRP-expressing cells. We conclude that angiotensin activates divergent mechanisms to control BP and RMR and that the brain RAS functions as a major integrator for RMR control through its actions at leptin-sensitive AgRP cells of the ARC.

Energy Balance Regulating Neuropeptides Are Expressed through Pregnancy and Regulated by Interleukin-6 Deficiency in Mouse Placenta

PubMed Central

Pazos, Patricia; Lima, Luis; Diéguez, Carlos; García, María C.

2014-01-01

The placenta produces a number of signaling molecules including metabolic and reproductive hormones as well as several inflammatory mediators. Among them, Interleukin-6 (IL-6), a well-known immune and metabolic regulator, acts peripherally modulating metabolic function and centrally increasing energy expenditure and reducing body fat. IL-6 interacts with key hypothalamic neuropeptidergic systems controlling energy homeostasis such as those producing the orexigenic/anabolic: neuropeptide Y (NPY) and agouti-related peptide (AgRP) and anorectic/catabolic neuropeptides: proopiomelanocortin (POMC) and cocaine and amphetamine regulated transcript (CART). Human and rat placenta have been identified as source of these neuropeptides, but their expression and regulation in murine placental tissues remain unknown. Therefore, placental mRNA levels of IL-6, NPY, AgRP, POMC, and CART at different pregnancy stages (gestational days 13, 15, and 18) were analyzed by real time PCR, as were the effect of IL-6 deficiency (IL-6 knockout mice) on their placental expression. Our results showed that placenta-derived neuropeptides were regulated by gestational age and IL-6 throughout the second half of mouse pregnancy. These data suggest that IL-6 may participate in the fine tune control of energy balance during pregnancy by extending its action as a metabolic signal to the main organ at the fetomaternal interface: the placenta. PMID:24744782

Effects of acute handling stress on short-term central expression of orexigenic/anorexigenic genes in zebrafish.

PubMed

Cortés, Raul; Teles, Mariana; Oliveira, Miguel; Fierro-Castro, Camino; Tort, Lluis; Cerdá-Reverter, José Miguel

2018-02-01

Physiological mechanisms driving stress response in vertebrates are evolutionarily conserved. These mechanisms involve the activation of both the hypothalamic-sympathetic-chromaffin cell (HSC) and the hypothalamic-pituitary-adrenal (HPA) axes. In fish, the reduction of food intake levels is a common feature of the behavioral response to stress but the central mechanisms coordinating the energetic response are not well understood yet. In this work, we explore the effects of acute stress on key central systems regulating food intake in fish as well as on total body cortisol and glucose levels. We show that acute stress induced a rapid increase in total body cortisol with no changes in body glucose, at the same time promoting a prompt central response by activating neuronal pathways. All three orexigenic peptides examined, i.e., neuropeptide y (npy), agouti-related protein (agrp), and ghrelin, increased their central expression level suggesting that these neuronal systems are not involved in the short-term feeding inhibitory effects of acute stress. By contrast, the anorexigenic precursors tested, i.e., cart peptides and pomc, exhibited increased expression after acute stress, suggesting their involvement in the anorexigenic effects.

An obesity-dependent lactation defect in the viable yellow agouti mouse is associated with mammary inflammation

USDA-ARS?s Scientific Manuscript database

Maternal obesity is known to delay lactogenesis in breast-feeding women, as well as negatively impact lactation in other species. Obesity is also understood to be associated with inflammation. Work with the viable yellow agouti (Avy) mouse in our laboratory has documented a lactation defect in obese...

Influence of abnormally high leptin levels during pregnancy on metabolic phenotypes in progeny mice.

PubMed

Makarova, Elena N; Chepeleva, Elena V; Panchenko, Polina E; Bazhan, Nadezhda M

2013-12-01

Maternal obesity increases the risk of obesity in offspring, and obesity is accompanied by an increase in blood leptin levels. The "yellow" mutation at the mouse agouti locus (A(y)) increases blood leptin levels in C57BL preobese pregnant mice without affecting other metabolic characteristics. We investigated the influence of the A(y) mutation or leptin injection at the end of pregnancy in C57BL mice on metabolic phenotypes and the susceptibility to diet-induced obesity (DIO) in offspring. In both C57BL-A(y) and leptin-treated mice, the maternal effect was more pronounced in male offspring. Compared with males born to control mothers, males born to A(y) mothers displayed equal food intake (FI) but decreased body weight (BW) gain after weaning, equal glucose tolerance, and enhanced FI-to-BW ratios on the standard diet but the same FI and BW on the high-fat diet. Males born to A(y) mothers were less responsive to the anorectic effect of exogenous leptin and less resistant to fasting (were not hyperphagic and gained less weight during refeeding after food deprivation) compared with males born to control mothers. However, all progeny displayed equal hypothalamic expression of Agouti gene-related protein (AgRP), neuropeptide Y (NPY), and proopiomelanocortin (POMC) and equal plasma leptin and glucose levels after food deprivation. Leptin injections in C57BL mice on day 17 of pregnancy decreased BW in both male and female offspring but inhibited FI and DIO only in male offspring. Our results show that hyperleptinemia during pregnancy has sex-specific long-term effects on energy balance regulation in progeny and does not predispose offspring to developing obesity.

Fto colocalizes with a satiety mediator oxytocin in the brain and upregulates oxytocin gene expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, Pawel K., E-mail: olsze005@umn.edu; Minnesota Obesity Center, Saint Paul, MN 55108; Fredriksson, Robert

2011-05-13

Highlights: {yields} The majority of neurons synthesizing a satiety mediator, oxytocin, coexpress Fto. {yields} The level of colocalization is similar in the male and female brain. {yields} Fto overexpression in hypothalamic neurons increases oxytocin mRNA levels by 50%. {yields} Oxytocin does not affect Fto expression through negative feedback mechanisms. -- Abstract: Single nucleotide polymorphisms in the fat mass and obesity-associated (FTO) gene have been associated with obesity in humans. Alterations in Fto expression in transgenic animals affect body weight, energy expenditure and food intake. Fto, a nuclear protein and proposed transcription co-factor, has been speculated to affect energy balance throughmore » a functional relationship with specific genes encoding feeding-related peptides. Herein, we employed double immunohistochemistry and showed that the majority of neurons synthesizing a satiety mediator, oxytocin, coexpress Fto in the brain of male and female mice. We then overexpressed Fto in a murine hypothalamic cell line and, using qPCR, detected a 50% increase in the level of oxytocin mRNA. Expression levels of several other feeding-related genes, including neuropeptide Y (NPY) and Agouti-related protein (AgRP), were unaffected by the FTO transfection. Addition of 10 and 100 nmol oxytocin to the cell culture medium did not affect Fto expression in hypothalamic cells. We conclude that Fto, a proposed transcription co-factor, influences expression of the gene encoding a satiety mediator, oxytocin.« less

Hypothalamic Integration of Metabolic, Endocrine, and Circadian Signals in Fish: Involvement in the Control of Food Intake

PubMed Central

Delgado, María J.; Cerdá-Reverter, José M.; Soengas, José L.

2017-01-01

The regulation of food intake in fish is a complex process carried out through several different mechanisms in the central nervous system (CNS) with hypothalamus being the main regulatory center. As in mammals, a complex hypothalamic circuit including two populations of neurons: one co-expressing neuropeptide Y (NPY) and Agouti-related peptide (AgRP) and the second one population co-expressing pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) is involved in the integration of information relating to food intake control. The production and release of these peptides control food intake, and the production results from the integration of information of different nature such as levels of nutrients and hormones as well as circadian signals. The present review summarizes the knowledge and recent findings about the presence and functioning of these mechanisms in fish and their differences vs. the known mammalian model. PMID:28694769

Prevention of duodenal ileus reveals functional differences in the duodenal response to luminal hypertonicity in Sprague-Dawley and Dark Agouti rats.

PubMed

Sedin, J; Sjöblom, M; Nylander, O

2014-03-01

The mechanism by which the duodenum adjusts the luminal osmolality remains unclear. The aim was to compare the duodenal osmoregulation in response to different hyperosmolar solutions in Sprague-Dawley and Dark Agouti rats and to elucidate whether cyclooxygenase-2 inhibition affects these responses. The duodenum was perfused in situ with a 700-milliosmolar solution (NaCl alone, D-glucose ± NaCl, D-mannitol ± NaCl or orange juice), and the effects on the duodenal motility, mucosal permeability, luminal alkalinization, fluid flux and osmoregulation were assessed in anaesthetized rats. The change in net fluid flux and luminal osmolality, in response to a given hyperosmolar solution, was almost identical in control rats of both strains. In control rats, hypertonic D-glucose-NaCl induced fluid secretion only in the presence of phlorizin, an inhibitor of SGLT1. Cyclooxygenase-2 inhibition potentiated the hypertonicity-induced fluid secretion and increased the osmolality-adjusting capability in both strains, but the responses were greater in Dark Agouti rats. While cyclooxygenase-2-inhibited Dark Agouti rats responded to the hyperosmolar solutions with depression of motility and increased mucosal permeability, these effects were absent or smaller in the Sprague-Dawley strain. In contrast, orange juice induced the same duodenal responses in cyclooxygenase-2-inhibited Dark Agouti and Sprague-Dawley rats. The duodenum possesses the ability to absorb fluid despite a very high luminal osmolality. Inhibition of cyclooxygenase-2 markedly enhanced the capability of the duodenum to secrete fluid and to decrease luminal osmolality, irrespective of the hyperosmolar solution or the rat strain used, and revealed notable differences between the two strains with regard to their osmolality-adjusting capability. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Anorexia is Associated with Stress-Dependent Orexigenic Responses to Exogenous Neuropeptide Y.

PubMed

Yi, J; Delp, M S; Gilbert, E R; Siegel, P B; Cline, M A

2016-05-01

Chicken lines that have been divergently selected for either low (LWS) or high (HWS) body weight at 56 days of age for more than 57 generations have different feeding behaviours in response to a range of i.c.v. injected neurotransmitters. The LWS have different severities of anorexia, whereas the HWS become obese. Previously, we demonstrated that LWS chicks did not respond, whereas HWS chicks increased food intake, after central injection of neuropeptide Y (NPY). The present study aimed to determine the molecular mechanisms underlying the loss of orexigenic function of NPY in LWS. Chicks were divided into four groups: stressed LWS and HWS on day of hatch, and control LWS and HWS. The stressor was a combination of food deprivation and cold exposure. On day 5 post-hatch, each chick received an i.c.v. injection of vehicle or 0.2 nmol of NPY. Only the LWS stressed group did not increase food intake in response to i.c.v. NPY. Hypothalamic mRNA abundance of appetite-associated factors was measured at 1 h post-injection. Interactions of genetic line, stress and NPY treatment were observed for the mRNA abundance of agouti-related peptide (AgRP) and synaptotagmin 1 (SYT1). Intracerebroventricular injection of NPY decreased and increased AgRP and SYT1 mRNA, respectively, in the stressed LWS and increased AgRP mRNA in stressed HWS chicks. Stress was associated with increased NPY, orexin receptor 2, corticotrophin-releasing factor receptor 1, melanocortin receptor 3 (MC3R) and growth hormone secretagogue receptor expression. In conclusion, the loss of responsiveness to exogenous NPY in stressed LWS chicks may be a result of the decreased and increased hypothalamic expression of AgRP and MC3R, respectively. This may induce an intensification of anorexigenic melanocortin signalling pathways in LWS chicks that block the orexigenic effect of exogenous NPY. These results provide insights onto the anorexic condition across species, and especially for forms of inducible anorexia

Hunger-driven motivational state competition

PubMed Central

Burnett, C. Joseph; Li, Chia; Webber, Emily; Tsaousidou, Eva; Xue, Stephen Y.; Brüning, Jens C.; Krashes, Michael J.

2016-01-01

Summary Behavioral choice is ubiquitous in the animal kingdom and is central to goal-oriented behavior. Hypothalamic Agouti-related peptide (AgRP) neurons are critical regulators of appetite. Hungry animals, bombarded by multiple sensory stimuli, are known to modify their behavior during times of caloric need, rapidly adapting to a consistently changing environment. Utilizing ARCAgRP neurons as an entry point, we analyzed the hierarchical position of hunger related to rival drive states. Employing a battery of behavioral assays we found that hunger significantly increases its capacity to suppress competing motivational systems such as thirst, anxiety-related behavior, innate fear and social interactions often only when food is accessible. Furthermore, real-time monitoring of ARCAgRP activity revealed time-locked responses to conspecific investigation in addition to food presentation, further establishing that even at the level of ARCAgRP neurons choices are remarkably flexible computations integrating internal state, external factors and anticipated yield. PMID:27693254

Doppler ultrasound of the placenta and maternal and fetal vessels during normal gestation in captive agoutis (Dasyprocta prymnolopha, Wagler, 1831).

PubMed

Sousa, Francisco C A; Pessoa, Gerson T; Moura, Laecio S; Rodrigues, Renan P S; Diniz, Anaemilia N; Souza, André B; Silva, Elzivânia G; Sanches, Marina P; Silva-Filho, Osmar F; Guerra, Porfirio C; Sousa, João M; Neves, Willams C; Alves, Flávio R

2016-11-01

The use of ultrasound for pregnancy monitoring is critical for the evaluation of hemodynamic parameters essential to fetal viability. In the present study, using B-mode and Doppler ultrasound, we characterized the placenta, subplacenta, maternal, and fetal vessels during normal gestation of healthy agoutis raised in captivity. In total, 30 agoutis were obtained from the Center for the Study and Preservation of Wild Animals, Center of Agricultural Sciences, Federal University of Piauí (Núcleo de Estudos e Preservação de Animais Silvestres-NEPAS, Centro de Ciências Agrárias-CCA, Universidade Federal do Piauí-UFPI). These animals were subjected to B-mode and Doppler ultrasound examinations to evaluate their maternal and fetal hemodynamic profiles. The placenta was located in the mesometrial region and had a discoid, ellipsoid, or globular aspect. With spectral Doppler, characteristic systolic and diastolic flow was observed in the umbilical artery. This flow increased during pregnancy. A cross-sectional view revealed a goblet-shaped placenta. The uteroplacental blood flow was characterized by a marked increase in systolic peak velocity during pregnancy, the presence of a rapid deceleration ramp, and a relatively high diastolic speed. The fetal aortic vascular flow was predominantly systolic and diastolic. The caudal vena cava blood flow was characterized by a systolic peak followed by a decreased diastolic wave throughout pregnancy. In the present study, we characterized the morphologic and hemodynamic interactions of the placenta/subplacenta with maternal and fetal vessels in agoutis at 30, 45, 60, 75, and 90 days gestation using B-mode and Doppler ultrasound. We determined the approximation and separation of the blood flow values of the umbilical artery, subplacental flow, uteroplacental artery, fetal aorta, and fetal vena cava. We believe these values may contribute to an understanding of the gestational biology and aid delivery prediction in this species

Arcuate Na+,K+-ATPase senses systemic energy states and regulates feeding behavior through glucose-inhibited neurons.

PubMed

Kurita, Hideharu; Xu, Kai Y; Maejima, Yuko; Nakata, Masanori; Dezaki, Katsuya; Santoso, Putra; Yang, Yifei; Arai, Takeshi; Gantulga, Darambazar; Muroya, Shinji; Lefor, Alan K; Kakei, Masafumi; Watanabe, Eiju; Yada, Toshihiko

2015-08-15

Feeding is regulated by perception in the hypothalamus, particularly the first-order arcuate nucleus (ARC) neurons, of the body's energy state. However, the cellular device for converting energy states to the activity of critical neurons in ARC is less defined. We here show that Na(+),K(+)-ATPase (NKA) in ARC senses energy states to regulate feeding. Fasting-induced systemic ghrelin rise and glucose lowering reduced ATP-hydrolyzing activity of NKA and its substrate ATP level, respectively, preferentially in ARC. Lowering glucose concentration (LG), which mimics fasting, decreased intracellular NAD(P)H and increased Na(+) concentration in single ARC neurons that subsequently exhibited [Ca(2+)]i responses to LG, showing that they were glucose-inhibited (GI) neurons. Third ventricular injection of the NKA inhibitor ouabain induced c-Fos expression in agouti-related protein (AgRP) neurons in ARC and evoked neuropeptide Y (NPY)-dependent feeding. When injected focally into ARC, ouabain stimulated feeding and mRNA expressions for NPY and AgRP. Ouabain increased [Ca(2+)]i in single NPY/AgRP neurons with greater amplitude than in proopiomelanocortin neurons in ARC. Conversely, the specific NKA activator SSA412 suppressed fasting-induced feeding and LG-induced [Ca(2+)]i increases in ARC GI neurons. NPY/AgRP neurons highly expressed NKAα3, whose knockdown impaired feeding behavior. These results demonstrate that fasting, via ghrelin rise and LG, suppresses NKA enzyme/pump activity in ARC and thereby promotes the activation of GI neurons and NPY/AgRP-dependent feeding. This study identifies ARC NKA as a hypothalamic sensor and converter of metabolic states to key neuronal activity and feeding behaviour, providing a new target to treat hyperphagic obesity and diabetes. Copyright © 2015 the American Physiological Society.

Voluntary exercise prevents the obese and diabetic metabolic syndrome of the melanocortin-4 receptor knockout mouse.

PubMed

Haskell-Luevano, Carrie; Schaub, Jay W; Andreasen, Amy; Haskell, Kim R; Moore, Marcus C; Koerper, Lorraine M; Rouzaud, Francois; Baker, Henry V; Millard, William J; Walter, Glenn; Litherland, S A; Xiang, Zhimin

2009-02-01

Exercise is a mechanism for maintenance of body weight in humans. Morbidly obese human patients have been shown to possess single nucleotide polymorphisms in the melanocortin-4 receptor (MC4R). MC4R knockout mice have been well characterized as a genetic model that possesses phenotypic metabolic disorders, including obesity, hyperphagia, hyperinsulinemia, and hyperleptinemia, similar to those observed in humans possessing dysfunctional hMC4Rs. Using this model, we examined the effect of voluntary exercise of MC4R knockout mice that were allowed access to a running wheel for a duration of 8 wk. Physiological parameters that were measured included body weight, body composition of fat and lean mass, food consumption, body length, and blood levels of cholesterol and nonfasted glucose, insulin, and leptin. At the termination of the experiment, hypothalamic mRNA expression levels of neuropeptide Y (NPY), agouti-related protein (AGRP), proopiomelanocortin (POMC), cocaine- and amphetamine-regulated transcript (CART), orexin, brain-derived neurotropic factor (BDNF), phosphatase with tensin homology (Pten), melanocortin-3 receptor (MC3R), and NPY-Y1R were determined. In addition, islet cell distribution and function in the pancreas were examined. In the exercising MC4R knockout mice, the pancreatic islet cell morphology and other physiological parameters resembled those observed in the wild-type littermate controls. Gene expression profiles identified exercise as having a significant effect on hypothalamic POMC, orexin, and MC3R levels. Genotype had a significant effect on AGRP, POMC, CART, and NPY-Y1R, with an exercise and genotype interaction effect on NPY gene expression. These data support the hypothesis that voluntary exercise can prevent the genetic predisposition of melanocortin-4 receptor-associated obesity and diabetes.

Hypoxemia-induced leptin secretion: a mechanism for the control of food intake in diseased fish.

PubMed

MacDonald, Lauren E; Alderman, Sarah L; Kramer, Sarah; Woo, Patrick T K; Bernier, Nicholas J

2014-06-01

Leptin is a potent anorexigen, but little is known about the physiological conditions under which this cytokine regulates food intake in fish. In this study, we characterized the relationships between food intake, O2-carrying capacity, liver leptin-A1 (lep-a1) gene expression, and plasma leptin-A1 in rainbow trout infected with a pathogenic hemoflagellate, Cryptobia salmositica. As lep gene expression is hypoxia-sensitive and Cryptobia-infected fish are anemic, we hypothesized that Cryptobia-induced anorexia is mediated by leptin. A 14-week time course experiment revealed that Cryptobia-infected fish experience a transient 75% reduction in food intake, a sharp initial drop in hematocrit and hemoglobin levels followed by a partial recovery, a transient 17-fold increase in lep-a1 gene expression, and a sustained increase in plasma leptin-A1 levels. In the hypothalamus, peak anorexia was associated with decreases in mRNA levels of neuropeptide Y (npy) and cocaine- and amphetamine-regulated transcript (cart), and increases in agouti-related protein (agrp) and pro-opiomelanocortin A2 (pomc). In contrast, in non-infected fish pair-fed to infected animals, lep-a1 gene expression and plasma levels did not differ from those of non-infected satiated fish. Pair-fed fish were also characterized by increases in hypothalamic npy and agrp, no changes in pomc-a2, and a reduction in cart mRNA expression. Finally, peak infection was characterized by a significant positive correlation between O2-carrying capacity and food intake. These findings show that hypoxemia, and not feed restriction, stimulates leptin-A1 secretion in Cryptobia-infected rainbow trout and suggest that leptin contributes to anorexia by inhibiting hypothalamic npy and stimulating pomc-a2. © 2014 Society for Endocrinology.

The morphology of the pineal gland of the yellow-toothed cavy (Galea Spixii Wagler, 1831) and red-rumped agouti (Dasyprocta leporina linnaeus, 1758).

PubMed

Câmara, Felipe Venceslau; Lopes, Igor Renno Guimarães; de Oliveira, Gleidson Benevides; Bezerra, Ferdinando Vinicius Fernandes; de Oliveira, Radan Elvis Matias; Oliveira Júnior, Carlos Magno; Silva, Alexandre Rodrigues; de Oliveira, Moacir Franco

2015-08-01

The pineal gland is an endocrine gland found in all mammals. This article describes the morphology of this important gland in two species of Caviideae, namely the yellow-toothed cavy and the red-rumped agouti. Ten adult animals of the two species used in current analysis were retrieved from the Center for the Multiplication of Wild Animals (CEMAS/UFERSA) and euthanized. The glands were removed and photographed in situ and ex situ. They were fixed in a paraformaldehyde solution 4% or glutaraldehyde 2.5% solution and submitted to routine histological techniques respectively for light and scanning electron microscopy. Macroscopically, the pineal gland with its elongated structure may be found between the cerebral hemispheres facing the rostral colliculi. Microscopically, pinealocytes and some glia cells were predominant. Contrastingly, to the cavy's pineal gland, a capsule covered the organ in the agouti, with the emission of incomplete septa to the interior, which divided it into two lobules. Light and scanning electron microscopes failed to show calcareous concretions in the pineal gland. Based on the topography of the cavy's and agouti's pineal gland, it may be classified as supra-callosum and ABC type. © 2015 Wiley Periodicals, Inc.

Copy number variation and missense mutations of the agouti signaling protein (ASIP) gene in goat breeds with different coat colors.

PubMed

Fontanesi, L; Beretti, F; Riggio, V; Gómez González, E; Dall'Olio, S; Davoli, R; Russo, V; Portolano, B

2009-01-01

In goats, classical genetic studies reported a large number of alleles at the Agouti locus with effects on coat color and pattern distribution. From these early studies, the dominant A(Wt) (white/tan) allele was suggested to cause the white color of the Saanen breed. Here, we sequenced the coding region of the goat ASIP gene in 6 goat breeds (Girgentana, Maltese, Derivata di Siria, Murciano-Granadina, Camosciata delle Alpi, and Saanen), with different coat colors and patterns. Five single nucleotide polymorphisms (SNPs) were identified, 3 of which caused missense mutations in conserved positions of the cysteine-rich carboxy-terminal domain of the protein (p.Ala96Gly, p.Cys126Gly, and p.Val128Gly). Allele and genotype frequencies suggested that these mutations are not associated or not completely associated with coat color in the investigated goat breeds. Moreover, genotyping and sequencing results, deviation from Hardy-Weinberg equilibrium, as well as allele copy number evaluation from semiquantitative fluorescent multiplex PCR, indicated the presence of copy number variation (CNV) in all investigated breeds. To confirm the presence of CNV and evaluate its extension, we applied a bovine-goat cross-species array comparative genome hybridization (aCGH) experiment using a custom tiling array based on bovine chromosome 13. aCGH results obtained for 8 goat DNA samples confirmed the presence of CNV affecting a region of less that 100 kb including the ASIP and AHCY genes. In Girgentana and Saanen breeds, this CNV might cause the A(Wt) allele, as already suggested for a similar structural mutation in sheep affecting the ASIP and AHCY genes, providing evidence for a recurrent interspecies CNV. However, other mechanisms may also be involved in determining coat color in these 2 breeds. Copyright 2009 S. Karger AG, Basel.

Regulatory Alterations of Energy Homeostasis in Spontaneously Hypertensive Rats (SHR).

PubMed

Furedi, Nora; Miko, Alexandra; Aubrecht, Bianka; Gaszner, Balazs; Feller, Diana; Rostas, Ildiko; Tenk, Judit; Soos, Szilvia; Balasko, Marta; Balogh, Andras; Pap, Marianna; Petervari, Erika

2016-08-01

Spontaneously hypertensive rats (SHR) have high sympathetic tone and progressive hypertension. Chronic calorie-restriction prevents hypertension. Their food intake (FI) and body weight are lower than in normotensive (NT) controls, even on a high-fat diet, suggesting a dysregulation of energy homeostasis. We assumed enhanced activity of hypothalamic anorexigenic melanocortins and diminished tone of orexigenic neuropeptide Y (NPY) in the background. FI of male SHR and NT Wistar rats was recorded in a FeedScale system upon intracerebroventricular injection of NPY, melanocortin ligands alpha-melanocyte-stimulating hormone (alpha-MSH), and agouti-related peptide (AgRP) or during a 7-day intracerebroventricular infusion of melanocortin antagonist HS024. Alpha-MSH, NPY, and AgRP immunoreactivities were semi-quantified in the arcuate (ARC) and paraventricular (PVN) nuclei of the hypothalamus in NT vs. SHR. Proopiomelanocortin gene expression was also assessed by quantitative RT-PCR in the ARC. Melanocortin-induced anorexia was stronger, FI induced by NPY or HS024 was smaller and delayed in SHR. Cellular alpha-MSH-specific signal density was higher in the ARC of SHR as evaluated by immunofluerescence, which was supported by PCR data. In the PVN, no differences in alpha-MSH-, NPY-, or AgRP-immunosignal were observed. Our results suggest that a higher melanocortin production/responsiveness and lower NPY responsiveness may contribute to the body weight dysregulation of SHR.

Recovery and cryopreservation of epididymal sperm from agouti (Dasiprocta aguti) using powdered coconut water (ACP-109c) and Tris extenders.

PubMed

Silva, M A; Peixoto, G C X; Santos, E A A; Castelo, T S; Oliveira, M F; Silva, A R

2011-10-01

The objective was to compare the use of powdered coconut water (ACP-109c; ACP Biotecnologia, Fortaleza, CE, Brazil) and Tris extenders for recovery and cryopreservation of epididymal sperm from agouti. The caudae epididymus and proximal ductus deferens from 10 sexually mature agoutis were subjected to retrograde washing using ACP-109c (ACP Biotecnologia) or Tris. Epididymal sperm were evaluated for motility, vigor, sperm viability, membrane integrity, and morphology. Samples were centrifuged, and extended in the same diluents plus egg yolk (20%) and glycerol (6%), frozen in liquid nitrogen, and subsequently thawed at 37°C for 1 min, followed by re-evaluation of sperm characteristics. The two extenders were similarly efficient for epididymal recovery, with regard to the number and quality of sperm recovered. However, for both extenders, sperm quality decreased (P < 0.05) after centrifugation and dilution. After sperm cryopreservation and thawing, there were (mean ± SEM) 26.5 ± 2.6% motile sperm with 2.6 ± 0.2 vigor in the ACP-109c (ACP Biotecnologia) group, which was significantly better than 9.7 ± 2.6% motile sperm with 1.2 ± 0.3 vigor in Tris. In conclusion, agouti epididymal sperm were successfully recovered using either ACP-109c (ACP Biotecnologia) or Tris extenders; however, ACP-109c (ACP Biotecnologia) was a significantly better extender for processing and cryopreserving these sperm. Copyright © 2011 Elsevier Inc. All rights reserved.

Serological evaluation of ovarian steroids of red-rumped agouti (Dasyprocta leporina) during the estrous cycle phases.

PubMed

Singh, Michele D; Morris, Michael J; Guimarães, Diva Anelie; Bourne, Gregory; Garcia, Gary W

2016-12-01

The objective of this study was to evaluate serum progesterone (P4) and 17β estradiol (E2) concentrations throughout the estrous cycle in the red-rumped agouti (Dasyprocta leporina). A total of eight multiparous, captive-bred females were bled throughout their estrous cycle via saphenous venipuncture, with E2 and P4 concentrations being measured via ELISA of the serum collected. Serum E 2 ranged from 1212 to 3500pg/ml with a peak value coinciding with observed estrus. However, two additional peak values for E 2 were also recorded, one each in metestrus and proestrus respectively. P4 concentrations reached a maximum of 4.23ng/ml, and increases in P4 immediately followed the second E2 peak in metestrus. The highest concentrations of P4 were recorded in mid diestrus; between days 23-25 of the 31-day cycle. This phase was the longest in the agouti, consisting of approximately 19days and accounted for 61% of the cycle. This study increased the basal scientific reproductive knowledge of this potentially valuable neo-tropical species. Copyright © 2016 Elsevier B.V. All rights reserved.

Hyperphagia and central mechanisms for leptin resistance during pregnancy.

PubMed

Trujillo, M L; Spuch, C; Carro, E; Señarís, R

2011-04-01

The purpose of this work was to study the central mechanisms involved in food intake regulation and leptin resistance during gestation in the rat. Sprague Dawley rats of 7, 13, and 18 d of pregnancy [days of gestation (G) 7, G13, and G18] were used and compared with nonpregnant animals in diestrus-1. Food intake was already increased in G7, before hyperleptinemia and central leptin resistance was established in midpregnancy. Leptin resistance was due to a reduction in leptin transport through the blood-brain barrier (BBB) and to alterations in leptin signaling within the hypothalamus based on an increase in suppressor of cytokine signaling 3 levels and a blockade of signal transducer and activator of transcription-3 phosphorylation (G13), followed by a decrease in LepRb and of Akt phosphorylation (G18). In early gestation (G7), no change in hypothalamic neuropeptide Y (NPY), agouti-related peptide (AgRP), or proopiomelanocortin (POMC) expression was shown. Nevertheless, an increase in NPY and AgRP and a decrease in POMC mRNA were observed in G13 and G18 rats, probably reflecting the leptin resistance. To investigate the effect of maternal vs. placental hormones on these mechanisms, we used a model of pseudogestation. Rats of 9 d of pseudogestation were hyperphagic, showing an increase in body and adipose tissue weight, normoleptinemia, and normal responses to iv/intracerebroventricular leptin on hypothalamic leptin signaling, food intake, and body weight. Leptin transport through the BBB, and hypothalamic NPY, AgRP and POMC expression were unchanged. Finally, the transport of leptin through the BBB was assessed using a double-chamber culture system of choroid plexus epithelial cells or brain microvascular endothelial cells. We found that sustained high levels of prolactin significantly reduced leptin translocation through the barrier, whereas progesterone and β-estradiol did not show any effect. Our data demonstrate a dual mechanism of leptin resistance during mid

Identification of single nucleotide polymorphisms in the agouti signaling protein (ASIP) gene in some goat breeds in tropical and temperate climates.

PubMed

Adefenwa, Mufliat A; Peters, Sunday O; Agaviezor, Brilliant O; Wheto, Matthew; Adekoya, Khalid O; Okpeku, Moses; Oboh, Bola; Williams, Gabriel O; Adebambo, Olufunmilayo A; Singh, Mahipal; Thomas, Bolaji; De Donato, Marcos; Imumorin, Ikhide G

2013-07-01

The agouti-signaling protein (ASIP) plays a major role in mammalian pigmentation as an antagonist to melanocortin-1 receptor gene to stimulate pheomelanin synthesis, a major pigment conferring mammalian coat color. We sequenced a 352 bp fragment of ASIP gene spanning part of exon 2 and part of intron 2 in 215 animals representing six goat breeds from Nigeria and the United States: West African Dwarf, predominantly black; Red Sokoto, mostly red; and Sahel, mostly white from Nigeria; black and white Alpine, brown and white Spanish and white Saanen from the US. Twenty haplotypes from nine mutations representing three intronic, one silent and five missense (p.S19R, p.N35K, p.L36V, p.M42L and p.L45W) mutations were identified in Nigerian goats. Approximately 89 % of Nigerian goats carry haplotype 1 (TGCCATCCG) which seems to be the wild type configuration of mutations in this region of the gene. Although we found no association between these polymorphisms in the ASIP gene and coat color in Nigerian goats, in-silico functional analysis predicts putative deleterious functional impact of the p.L45W mutation on the basic amino-terminal domain of ASIP. In the American goats, two intronic mutations, g.293G>A and g.327C>A, were identified in the Alpine breed, although the g.293G>A mutation is common to American and Nigerian goat populations. All Sannen and Sahel goats in this study belong to haplotypes 1 of both populations which seem to be the wild-type composite ASIP haplotype. Overall, there was no clear association of this portion of the ASIP gene interrogated in this study with coat color variation. Therefore, additional genomic analyses of promoter sequence, the entire coding and non-coding regions of the ASIP gene will be required to obtain a definite conclusion.

Hunger States Control the Directions of Synaptic Plasticity via Switching Cell Type-Specific Subunits of NMDA Receptors.

PubMed

Qi, Yong; Yang, Yunlei

2015-09-23

It remains largely unknown whether and how hunger states control activity-dependent synaptic plasticity, such as long-term potentiation (LTP) and long-term depression (LTD). We here report that both LTP and LTD of excitatory synaptic strength within the appetite control circuits residing in hypothalamic arcuate nucleus (ARC) behave in a manner of hunger states dependence and cell type specificity. For instance, we find that tetanic stimulation induces LTP at orexigenic agouti-related protein (AgRP) neurons in ad libitum fed mice, whereas it induces LTD in food-deprived mice. In an opposite direction, the same induction protocol induces LTD at anorexigenic pro-opiomelanocortin (POMC) neurons in fed mice but weak LTP in deprived mice. Mechanistically, we also find that food deprivation increases the expressions of NR2C/NR2D/NR3-containing NMDA receptors (NMDARs) at AgRP neurons that contribute to the inductions of LTD, whereas it decreases their expressions at POMC neurons. Collectively, our data reveal that hunger states control the directions of activity-dependent synaptic plasticity by switching NMDA receptor subpopulations in a cell type-specific manner, providing insights into NMDAR-mediated interactions between energy states and associative memory. Significance statement: Based on the experiments performed in this study, we demonstrate that activity-dependent synaptic plasticity is also under the control of energy states by regulating NMDAR subpopulations in a cell type-specific manner. We thus propose a reversible memory configuration constructed from energy states-dependent cell type-specific bidirectional conversions of LTP and LTD. Together with the distinct functional roles played by NMDAR signaling in the control of food intake and energy states, these findings reveal a new reciprocal interaction between energy states and associative memory, one that might serve as a target for therapeutic treatments of the energy-related memory disorders or vice versa

Cytochrome P450 dependent metabolism of the new designer drug 1-(3-trifluoromethylphenyl)piperazine (TFMPP). In vivo studies in Wistar and Dark Agouti rats as well as in vitro studies in human liver microsomes.

PubMed

Staack, Roland F; Paul, Liane D; Springer, Dietmar; Kraemer, Thomas; Maurer, Hans H

2004-01-15

1-(3-Trifluoromethylphenyl)piperazine (TFMPP) is a designer drug with serotonergic properties. Previous studies with male Wistar rats (WI) had shown, that TFMPP was metabolized mainly by aromatic hydroxylation. In the current study, it was examined whether this reaction may be catalyzed by cytochrome P450 (CYP)2D6 by comparing TFMPP vs. hydroxy TFMPP ratios in urine from female Dark Agouti rats, a model of the human CYP2D6 poor metabolizer phenotype (PM), male Dark Agouti rats, an intermediate model, and WI, a model of the human CYP2D6 extensive metabolizer phenotype. Furthermore, the human hepatic CYPs involved in TFMPP hydroxylation were identified using cDNA-expressed CYPs and human liver microsomes. Finally, TFMPP plasma levels in the above mentioned rats were compared. The urine studies suggested that TFMPP hydroxylation might be catalyzed by CYP2D6 in humans. Studies using human CYPs showed that CYP1A2, CYP2D6 and CYP3A4 catalyzed TFMPP hydroxylation, with CYP2D6 being the most important enzyme accounting for about 81% of the net intrinsic clearance, calculated using the relative activity factor approach. The hydroxylation was significantly inhibited by quinidine (77%) and metabolite formation in poor metabolizer genotype human liver microsomes was significantly lower (63%) compared to pooled human liver microsomes. Analysis of the plasma samples showed that female Dark Agouti rats exhibited significantly higher TFMPP plasma levels compared to those of male Dark Agouti rats and WI. Furthermore, pretreatment of WI with the CYP2D inhibitor quinine resulted in significantly higher TFMPP plasma levels. In conclusion, the presented data give hints for possible differences in pharmacokinetics in human PM and human CYP2D6 extensive metabolizer phenotype subjects relevant for risk assessment.

BAC Recombineering of the Agouti Loci from Spotted Gar and Zebrafish Reveals the Evolutionary Ancestry of Dorsal-Ventral Pigment Asymmetry in Fish.

PubMed

Cal, Laura; MegÍas, Manuel; Cerdá-Reverter, José Miguel; Postlethwait, John H; Braasch, Ingo; Rotllant, Josep

2017-11-01

Dorsoventral pigment patterning, characterized by a light ventrum and a dark dorsum, is one of the most widespread chromatic adaptations in vertebrate body coloration. In mammals, this countershading depends on differential expression of agouti-signaling protein (ASIP), which drives a switch of synthesis of one type of melanin to another within melanocytes. Teleost fish share countershading, but the pattern results from a differential distribution of multiple types of chromatophores, with black-brown melanophores most abundant in the dorsal body and reflective iridophores most abundant in the ventral body. We previously showed that Asip1 (a fish ortholog of mammalian ASIP) plays a role in patterning melanophores. This observation leads to the surprising hypothesis that agouti may control an evolutionarily conserved pigment pattern by regulating different mechanisms in mammals and fish. To test this hypothesis, we compared two ray-finned fishes: the teleost zebrafish and the nonteleost spotted gar (Lepisosteus oculatus). By examining the endogenous pattern of asip1 expression in gar, we demonstrate a dorsoventral-graded distribution of asip1 expression that is highest ventrally, similar to teleosts. Additionally, in the first reported experiments to generate zebrafish transgenic lines carrying a bacterial artificial chromosome (BAC) from spotted gar, we show that both transgenic zebrafish lines embryos replicate the endogenous asip1 expression pattern in adult zebrafish, showing that BAC transgenes from both species contain all of the regulatory elements required for regular asip1 expression within adult ray-finned fishes. These experiments provide evidence that the mechanism leading to an environmentally important pigment pattern was likely in place before the origin of teleosts. © 2017 Wiley Periodicals, Inc.

Family trios analysis of common polymorphisms in the obestatin/ghrelin, BDNF and AGRP genes in patients with Anorexia nervosa: association with subtype, body-mass index, severity and age of onset.

PubMed

Dardennes, Roland M; Zizzari, Philippe; Tolle, Virginie; Foulon, Christine; Kipman, Amélie; Romo, Lucia; Iancu-Gontard, Dana; Boni, Claudette; Sinet, Pierre-Marie; Thérèse Bluet, Marie; Estour, Bruno; Mouren, Marie-Christine; Guelfi, Julien-Daniel; Rouillon, Frédéric; Gorwood, Philip; Epelbaum, Jacques

2007-02-01

Anorexia nervosa (AN) affects 0.3% of young girls with a mortality of 6%/decade and is strongly familial with genetic factors. Ghrelin is an upstream regulator of the orexigenic peptides NPY and AgRP and acts as a natural antagonist to leptin's effects on NPY/AgRP-expressing neurons, resulting in an increase in feeding and body weight. Obestatin which counteracts ghrelin action on feeding is derived from the same propeptide than ghrelin. BDNF has been involved in body weight regulation and its Val66Met polymorphism associated with AN. We therefore re-investigated the association between AN and the Leu72Met and Gln90Leu polymorphisms of the prepro-ghrelin/obestatin gene, the Ala67Thr polymorphism of AgRP and the Val66Met polymorphism of BDNF taking into account clinical subtypes (restrictive--ANR--and bingeing/purging--ANB--subtypes). Family trios study of these 4 single nucleotide polymorphisms were performed in 114 probands with AN and both their parents recruited in two specialized French centres. A transmission disequilibrium was observed for the Leu72Met SNP of the preproghrelin gene and for the Ala67Thr SNP of the AgRP gene. When stratified by clinical subtype, these two polymorphisms were preferentially transmitted for the trios with a bingeing/purging proband. An excess of transmission of the Gln90Leu72 preproghrelin/obestatin haplotype in patients with AN was observed. These results do not provide evidence for a preferential transmission of the 66Met allele of BDNF but support the hypothesis that ghrelin and AGRP polymorphisms confers susceptibility to AN. Further simultaneous analysis of genetic variants of the biological determinants of energy metabolism and feeding behaviour in very large populations should contribute to the understanding of the high degree of heritability of eating disorders and to the description of pathophysiological patterns leading to life-threatening conditions in a highly redundant system.

AgRP(83-132) and SHU9119 differently affect activity-based anorexia.

PubMed

Hillebrand, Jacquelien J G; Kas, Martien J H; Scheurink, Anton J W; van Dijk, Gertjan; Adan, Roger A H

2006-08-01

Activity-based anorexia (ABA) mimics starvation and hyperactivity of anorexia nervosa patients in rats. Activation of the melanocortin (MC) system leads to hypophagia and increased energy expenditure in ad libitum fed rats. Therefore, activation of the MC system might underlie the development and propagation of ABA. Pro-opiomelanocortin (POMC) gene expression is normally decreased during negative energy balance. Strikingly, we found a transient up-regulation of POMC mRNA levels in the arcuate nucleus during the development of ABA, indicating a hyperactive MC system. However, wheel running and food intake were not influenced by treating ABA rats with the competitive antagonist SHU9119. This suggests that agonism of MC receptors by endogenous alpha-melanocyte-stimulating hormone (alpha-MSH) levels does not underlie ABA. Instead, treatment with the inverse agonist AgRP(83-132) did ameliorate signs of ABA. This implies that modulation of constitutive MC receptor activity rather than antagonizing putative alpha-MSH release contributes to the development and propagation of ABA.

Agouti sequence polymorphisms in coyotes, wolves and dogs suggest hybridization.

PubMed

Schmutz, Sheila M; Berryere, Thomas G; Barta, Jodi L; Reddick, Kimberley D; Schmutz, Josef K

2007-01-01

Domestic dogs have been shown to have multiple alleles of the Agouti Signal Peptide (ASIP) in exon 4 and we wished to determine the level of polymorphism in the common wild canids of Canada, wolves and coyotes, in comparison. All Canadian coyotes and most wolves have banded hairs. The ASIP coding sequence of the wolf did not vary from the domestic dog but one variant was detected in exon 4 of coyotes that did not alter the arginine at this position. Two other differences were found in the sequence flanking exon 4 of coyotes compared with the 45 dogs and 1 wolf. The coyotes also demonstrated a relatively common polymorphism in the 3' UTR sequence that could be used for population studies. One of the ASIP alleles (R96C) in domestic dogs causes a solid black coat color in homozygotes. Although some wolves are melanistic, this phenotype does not appear to be caused by this same mutation. However, one wolf, potentially a dog-wolf hybrid or descendant thereof, was heterozygous for this allele. Likewise 2 coyotes, potentially dog-coyote or wolf-coyote hybrid descendants, were heterozygous for the several polymorphisms in and flanking exon 4. We could conclude that these were coyote-dog hybrids because both were heterozygous for 2 mutations causing fawn coat color in dogs.

Peptides and Food Intake

PubMed Central

Sobrino Crespo, Carmen; Perianes Cachero, Aránzazu; Puebla Jiménez, Lilian; Barrios, Vicente; Arilla Ferreiro, Eduardo

2014-01-01

The mechanisms for controlling food intake involve mainly an interplay between gut, brain, and adipose tissue (AT), among the major organs. Parasympathetic, sympathetic, and other systems are required for communication between the brain satiety center, gut, and AT. These neuronal circuits include a variety of peptides and hormones, being ghrelin the only orexigenic molecule known, whereas the plethora of other factors are inhibitors of appetite, suggesting its physiological relevance in the regulation of food intake and energy homeostasis. Nutrients generated by food digestion have been proposed to activate G-protein-coupled receptors on the luminal side of enteroendocrine cells, e.g., the L-cells. This stimulates the release of gut hormones into the circulation such as glucagon-like peptide-1 (GLP-1), oxyntomodulin, pancreatic polypeptides, peptide tyrosine tyrosine, and cholecystokinin, which inhibit appetite. Ghrelin is a peptide secreted from the stomach and, in contrast to other gut hormones, plasma levels decrease after a meal and potently stimulate food intake. Other circulating factors such as insulin and leptin relay information regarding long-term energy stores. Both hormones circulate at proportional levels to body fat content, enter the CNS proportionally to their plasma levels, and reduce food intake. Circulating hormones can influence the activity of the arcuate nucleus (ARC) neurons of the hypothalamus, after passing across the median eminence. Circulating factors such as gut hormones may also influence the nucleus of the tractus solitarius (NTS) through the adjacent circumventricular organ. On the other hand, gastrointestinal vagal afferents converge in the NTS of the brainstem. Neural projections from the NTS, in turn, carry signals to the hypothalamus. The ARC acts as an integrative center, with two major subpopulations of neurons influencing appetite, one of them coexpressing neuropeptide Y and agouti-related protein (AgRP) that increases food

Diabetes Management by Probiotics: Current Knowledge and Future Pespective.

PubMed

Homayouni-Rad, Aziz; Soroush, Ahmad-Reza; Khalili, Leila; Norouzi-Panahi, Leila; Kasaie, Zahra; Ejtahed, Hanieh-Sadat

2017-04-24

Diabetes mellitus, a multifactorial disorder, is related to the intestinal microbiota via numerous molecular mechanisms. The vast increase in the prevalence of diabetes and its associated complications requires a natural and safe solution. There is a growing evidence of gut microbiota effi ciency in improving insulin resistance, impaired insulin secretion, and metabolic complications in diabetic patients. Probiotics are defi ned as live microorganisms that, when ingested in adequate amounts, exert health benefi ts to the host. Probiotics can increase insulin sensitivity and reduce autoimmune responses by modulating intestinal microbiota and decreasing the infl ammatory reactions and oxidative stress. Recent evidences show that the intestinal microbiota infl uences the host through modulating intestinal permeability and mucosal immune response, manipulating eating behaviors by appetite-regulating hormones, including agouti related protein (AgRP), glucagon like peptide-1 (GLP-1) and neuropeptide Y, and controlling gut endocannabinoid (eCB) system which is now believed to be associated with infl ammation and diabetes. Moreover, intestinal microbiota control the host metabolism by affecting energy extraction from food and by biochemically converting molecules derived from the host or from gut microbes themselves. Experimental studies and clinical trials support the hypothesis that the modulation of the intestinal microbiota by probiotics, especially Lactobacillus and Bifidobacterium strains may be effective in prevention and management of diabetes. This review will highlight the current evidences in probiotic effectiveness and future prospects for exploring probiotic therapy in prevention and control of diabetes.

Central and peripheral effects of chronic food restriction and weight restoration in the rat.

PubMed

Kinzig, Kimberly P; Hargrave, Sara L; Tao, Erin E

2009-02-01

Previous studies have demonstrated that some endocrine consequences of long-term caloric restriction persist after weight restoration in human subjects. Here we evaluate effects of chronic food restriction in rats that were restricted to 70% of control kcal for 4 wk and subsequently weight restored. Measures were taken from rats at 80% (chronically restricted; CR), 90% (partially weight restored; PR), 100% (fully weight restored; FR), and after 4 wk at 100% body weight of controls (extended weight restored; ER). Plasma insulin and leptin were decreased, and ghrelin was increased in CR compared with controls. Leptin and ghrelin normalized with weight restoration at PR, FR, and ER; however, baseline insulin was not normalized until the ER state. Hypothalamic mRNA expression levels for proopiomelanocortin (POMC), agouti-related protein (AgRP), and neuropeptide Y (NPY) revealed significantly less POMC mRNA expression in CR and PR rats, and significantly less arcuate NPY mRNA in PR and FR. In the dorsomedial hypothalamus, CR, PR, and FR rats had significantly increased NPY expression that was not normalized until the ER state. In response to a test meal, insulin and ghrelin release patterns were altered through the FR stage, and ghrelin remained affected at ER. Collectively, these data demonstrate that mere weight restoration is not sufficient to normalize hypothalamic gene expression levels and endocrine responses to a meal, and that meal-related ghrelin responses persist despite weight restoration for up to 4 wk.

Exposure to increased levels of estradiol during development can have long-term effects on the response to undernutrition in female rats.

PubMed

Carrillo, B; Collado, P; Díaz, F; Chowen, J A; Pinos, H

2016-11-01

Undernutrition during development alters the expression of peptides that control energy expenditure and feeding behavior. Estrogens can also modulate these peptides. Here, we analyze whether the early postnatal administration of estradiol modulates the effects of undernutrition on neuroendocrine parameters in adult female Wistar rats. Control rats were fed a control diet. Undernourished pups were submitted to a restricted diet with half of the undernourished rats receiving 0.4 mg/kg s.c. of estradiol benzoate (EB) from postnatal day (P) 6 until P13. Quantitative real-time polymerase chain reaction was performed to determine expression in the hypothalamus of agouti-related peptide (AgRP), proopiomelanocortin (POMC), neuropeptide Y (NPY), and cocaine- and amphetamine-regulated transcript. Plasma estradiol, testosterone, and adiponectin levels were measured by enzyme-linked immunosorbent assay. Total and acylated ghrelin levels were measured in plasma by radioimmunoassay. Insulin and leptin were measured by mulitplex immunoassays. Undernourishment decreased body weight, fat mass, plasma leptin and insulin levels, and hypothalamic POMC mRNA levels. An increase in orexigenic signals AgRP and NPY mRNA levels, and in plasma adiponectin levels were found in undernourished animals. Early postnatal treatment with EB to undernourished female rats reversed the effects of undernutrition on adult hypothalamic POMC mRNA levels. In addition, neonatal EB treatment to undernourished females significantly decreased adult plasma testosterone, estradiol, and acylated ghrelin levels. Our results suggest that increased estradiol during a critical period of development has the capacity to modulate the alterations that undernutrition produces on energy metabolism.

Creating leptin-like biofunctions by active immunization against chicken leptin receptor in growing chickens.

PubMed

Lei, M M; Wu, S Q; Shao, X B; Li, X W; Chen, Z; Ying, S J; Shi, Z D

2015-01-01

In this study, immunization against chicken leptin receptor (cLEPR) extracellular domain (ECD) was applied to investigate leptin regulation and LEPR biofunction in growing chicken pullets. A recombinant protein (cLEPR ECD) based on the cLEPR complemenary DNA sequence corresponding to the 582nd to 796th amino acid residues of cLEPR mature peptide was prepared and used as antigen. Immunization against cLEPR ECD in growing chickens increased anti-cLEPR ECD antibody titers in blood, enhanced proportions of phosphorylated janus kinase 2 (JAK2) and served as signal transducer and activator of transcription 3 (STAT3) protein in liver tissue. Chicken live weight gain and abdominal fat mass were significantly decreased (P < 0.05), but feed intake was stimulated by cLEPR ECD immunization (P < 0.05). The treatment also upregulated the gene expression levels of lepR, AMP-activated protein kinase (AMPK), acetyl CoA carboxylase-2 (ACC2), and uncoupling protein 3 (UCP3) in liver, abdominal fat, and breast muscle (P < 0.05) but decreased fasn expression levels (P < 0.01). Apart from that of lepR, the expression of appetite-regulating genes, such as orexigenic genes, agouti-related peptide (AgRP) and neuropeptide Y (NPY), were upregulated (P < 0.01), whereas the anorexigenic gene proopiomelanocortin (POMC) was downregulated in the hypothalamic tissue of cLEPR-immunized pullets (P < 0.01). Blood concentrations of metabolic molecules, such as glucose, triglycerides, and very-low-density lipoprotein, were significantly decreased in cLEPR-immunized pullets but those of cholesterol, high-density lipoprotein, and low-density lipoprotein increased. These results demonstrate that antibodies to membrane proximal cLEPR ECD enhance cLEPR signal transduction, which stimulates metabolism and reduces fat deposition in chickens. Copyright © 2015 Elsevier Inc. All rights reserved.

Hypothalamic mTOR pathway mediates thyroid hormone-induced hyperphagia in hyperthyroidism.

PubMed

Varela, Luis; Martínez-Sánchez, Noelia; Gallego, Rosalía; Vázquez, María J; Roa, Juan; Gándara, Marina; Schoenmakers, Erik; Nogueiras, Rubén; Chatterjee, Krishna; Tena-Sempere, Manuel; Diéguez, Carlos; López, Miguel

2012-06-01

Hyperthyroidism is characterized in rats by increased energy expenditure and marked hyperphagia. Alterations of thermogenesis linked to hyperthyroidism are associated with dysregulation of hypothalamic AMPK and fatty acid metabolism; however, the central mechanisms mediating hyperthyroidism-induced hyperphagia remain largely unclear. Here, we demonstrate that hyperthyroid rats exhibit marked up-regulation of the hypothalamic mammalian target of rapamycin (mTOR) signalling pathway associated with increased mRNA levels of agouti-related protein (AgRP) and neuropeptide Y (NPY), and decreased mRNA levels of pro-opiomelanocortin (POMC) in the arcuate nucleus of the hypothalamus (ARC), an area where mTOR co-localizes with thyroid hormone receptor-α (TRα). Central administration of thyroid hormone (T3) or genetic activation of thyroid hormone signalling in the ARC recapitulated hyperthyroidism effects on feeding and the mTOR pathway. In turn, central inhibition of mTOR signalling with rapamycin in hyperthyroid rats reversed hyperphagia and normalized the expression of ARC-derived neuropeptides, resulting in substantial body weight loss. The data indicate that in the hyperthyroid state, increased feeding is associated with thyroid hormone-induced up-regulation of mTOR signalling. Furthermore, our findings that different neuronal modulations influence food intake and energy expenditure in hyperthyroidism pave the way for a more rational design of specific and selective therapeutic compounds aimed at reversing the metabolic consequences of this disease. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

C1q/TNF-related Protein 4 (CTRP4) Is a Unique Secreted Protein with Two Tandem C1q Domains That Functions in the Hypothalamus to Modulate Food Intake and Body Weight*

PubMed Central

Byerly, Mardi S.; Petersen, Pia S.; Ramamurthy, Santosh; Seldin, Marcus M.; Lei, Xia; Provost, Elayne; Wei, Zhikui; Ronnett, Gabriele V.; Wong, G. William

2014-01-01

CTRP4 is a unique member of the C1q family, possessing two tandem globular C1q domains. Its physiological function is poorly defined. Here, we show that CTRP4 is an evolutionarily conserved, ∼34-kDa secretory protein expressed in the brain. In human, mouse, and zebrafish brain, CTRP4 expression begins early in development and is widespread in the central nervous system. Neurons, but not astrocytes, express and secrete CTRP4, and secreted proteins form higher-order oligomeric complexes. CTRP4 is also produced by peripheral tissues and circulates in blood. Its serum levels are increased in leptin-deficient obese (ob/ob) mice. Functional studies suggest that CTRP4 acts centrally to modulate energy metabolism. Refeeding following an overnight fast induced the expression of CTRP4 in the hypothalamus. Central administration of recombinant protein suppressed food intake and altered the whole-body energy balance in both chow-fed and high-fat diet-fed mice. Suppression of food intake by CTRP4 is correlated with a decreased expression of orexigenic neuropeptide (Npy and Agrp) genes in the hypothalamus. These results establish CTRP4 as a novel nutrient-responsive central regulator of food intake and energy balance. PMID:24366864

Hypothalamic Integration of the Endocrine Signaling Related to Food Intake.

PubMed

Klockars, Anica; Levine, Allen S; Olszewski, Pawel K

2018-06-10

Hypothalamic integration of gastrointestinal and adipose tissue-derived hormones serves as a key element of neuroendocrine control of food intake. Leptin, adiponectin, oleoylethanolamide, cholecystokinin, and ghrelin, to name a few, are in a constant "cross talk" with the feeding-related brain circuits that encompass hypothalamic populations synthesizing anorexigens (melanocortins, CART, oxytocin) and orexigens (Agouti-related protein, neuropeptide Y, orexins). While this integrated neuroendocrine circuit successfully ensures that enough energy is acquired, it does not seem to be equally efficient in preventing excessive energy intake, especially in the obesogenic environment in which highly caloric and palatable food is constantly available. The current review presents an overview of intricate mechanisms underlying hypothalamic integration of energy balance-related peripheral endocrine input. We discuss vulnerabilities and maladaptive neuroregulatory processes, including changes in hypothalamic neuronal plasticity that propel overeating despite negative consequences.

Essential role of UCP1 modulating the central effects of thyroid hormones on energy balance

PubMed Central

Alvarez-Crespo, Mayte; Csikasz, Robert I.; Martínez-Sánchez, Noelia; Diéguez, Carlos; Cannon, Barbara; Nedergaard, Jan; López, Miguel

2016-01-01

Objective Classically, metabolic effects of thyroid hormones (THs) have been considered to be peripherally mediated, i.e. different tissues in the body respond directly to thyroid hormones with an increased metabolism. An alternative view is that the metabolic effects are centrally regulated. We have examined here the degree to which prolonged, centrally infused triiodothyronine (T3) could in itself induce total body metabolic effects and the degree to which brown adipose tissue (BAT) thermogenesis was essential for such effects, by examining uncoupling protein 1 (UCP1) KO mice. Methods Wildtype and UPC1 KO mice were centrally-treated with T3 by using minipumps. Metabolic measurements were analyzed by indirect calorimetry and expression analysis by RT-PCR or western blot. BAT morphology and histology were studied by immunohistochemistry. Results We found that central T3-treatment led to reduced levels of hypothalamic AMP-activated protein kinase (AMPK) and elevated body temperature (0.7 °C). UCP1 was essential for the T3-induced increased rate of energy expenditure, which was only observable at thermoneutrality and notably only during the active phase, for the increased body weight loss, for the increased hypothalamic levels of neuropeptide Y (NPY) and agouti-related peptide (AgRP) and for the increased food intake induced by central T3-treatment. Prolonged central T3-treatment also led to recruitment of BAT and britening/beiging (“browning”) of inguinal white adipose tissue (iWAT). Conclusions We conclude that UCP1 is essential for mediation of the central effects of thyroid hormones on energy balance, and we suggest that similar UCP1-dependent effects may underlie central energy balance effects of other agents. PMID:27069867

Description of a new species of Ixodes Latreille, 1795 (Acari: Ixodidae) and redescription of I. lasallei Méndez & Ortiz, 1958, parasites of agoutis and pacas (Rodentia: Dasyproctidae, Cuniculidae) in Central and South America.

PubMed

Apanaskevich, Dmitry A; Bermúdez, Sergio E

2017-05-01

Ixodes bocatorensis n. sp. (Acari: Ixodidae), is described based on adults ex agoutis (Rodentia: Dasyproctidae), pacas (Rodentia: Cuniculidae) and "tapir and sloth" (Perissodactyla: Tapiridae and Pilosa) from Colombia, Panama and Venezuela. Adults of I. bocatorensis n. sp. are similar to those of I. lasallei Méndez & Ortiz, 1958 but can be distinguished by the scutum dimensions, punctation pattern, gnathosoma and palpi measurements and their ratios, basis capituli anterior angle and shape of the spur of palpal segment I ventrally. For comparative purposes the female of I. lasallei is redescribed and the true male of this species is described for the first time. Studied adults of I. lasallei were found on agoutis, pacas and ocelot (Carnivora: Felidae) in Colombia, Peru and Venezuela.

Proteomic analysis of serum biomarkers for prediabetes using the Long-Evans Agouti rat, a spontaneous animal model of type 2 diabetes mellitus.

PubMed

Takahashi, Eri; Unoki-Kubota, Hiroyuki; Shimizu, Yukiko; Okamura, Tadashi; Iwata, Wakiko; Kajio, Hiroshi; Yamamoto-Honda, Ritsuko; Shiga, Tomoko; Yamashita, Shigeo; Tobe, Kazuyuki; Okumura, Akinori; Matsumoto, Michihiro; Yasuda, Kazuki; Noda, Mitsuhiko; Kaburagi, Yasushi

2017-09-01

To identify candidate serum molecules associated with the progression of type 2 diabetes mellitus, differential serum proteomic analysis was carried out on a spontaneous animal model of type 2 diabetes mellitus without obesity, the Long-Evans Agouti (LEA) rat. We carried out quantitative proteomic analysis using serum samples from 8- and 16-week-old LEA and control Brown Norway (BN) rats (n = 4/group). Differentially expressed proteins were validated by multiple reaction monitoring analysis using the sera collected from 8-, 16-, and 24-week-old LEA (n = 4/each group) and BN rats (n = 5/each group). Among the validated proteins, we also examined the possible relevance of the human homolog of serine protease inhibitor A3 (SERPINA3) to type 2 diabetes mellitus. The use of 2-D fluorescence difference gel electrophoresis analysis and the following liquid chromatography-multiple reaction monitoring analysis showed that the serum levels of five proteins were differentially changed between LEA rats and BN rats at all three time-points examined. Among the five proteins, SERPINA3N was increased significantly in the sera of LEA rats compared with age-matched BN rats. The serum level of SERPINA3 was also found to be significantly higher in type 2 diabetes mellitus patients than in healthy control participants. Furthermore, glycated hemoglobin, fasting insulin and estimated glomerular filtration rate were independently associated with the SERPINA3 levels. These findings suggest a possible role for SERPINA3 in the development of the early stages of type 2 diabetes mellitus, although further replication studies and functional investigations regarding their role are required. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

[Ovarian activity of Agouti paca (Rodentia: Agoutidae) under captivity].

PubMed

Montes Pérez, Rubén C; Cabrera Baz, Elsy A

2006-09-01

The ovarian activity of Agouti paca was characterized by hormonal profiles and ovarian structures. Samples of blood were taken from eight females (seven adults and one juvenile) at the breeding grounds of the Facultad de Medicina Veterinaria y Zootecnia in Yucatśn, Mexico. Sampling lasted approximately two months and was done every three and six days. Blood was collected from anesthetized animals, and the levels of progesterone (P4) and 17 beta estradiol (E2) were analized by radioimmunoassay technique. Macroscopic and microscopic analyses were carried out in ovaries of dead animals. The estrous cycle lasted 29+/-8.4 days, levels of 1.61+/-0.65 ng/ml for P4 and 39+/-24 pg/ml for E2 were observed for a follicular phase, 6.18+/-3.70 ng/ml and 29+/-16 pg/ml for P4 and E2 respectively in the luteal phase. Statistically significant differences were found between phases for P4 but not for E2. The presence of extragonadal steroids with levels of P4 of 1.9+/-0.77 ng/ml and E2 of 22+/-17 pg/ml were observed, which are not produced by the effects of managing stress. The changes in the levels of P4 during the cycle are indicators of luteal activity, with the intersticial tissue acting probably as active steroids-producing gland. Follicular growth was observed during the entire cycle.

Diet-induced obesity attenuates fasting-induced hyperphagia.

PubMed

Briggs, D I; Lemus, M B; Kua, E; Andrews, Z B

2011-07-01

Obesity impairs arcuate (ARC) neuropeptide Y (NPY)/agouti-releated peptide (AgRP) neuronal function and renders these homeostatic neurones unresponsive to the orexigenic hormone ghrelin. In the present study, we investigated the effect of diet-induced obesity (DIO) on feeding behaviour, ARC neuronal activation and mRNA expression following another orexigenic stimulus, an overnight fast. We show that 9 weeks of high-fat feeding attenuates fasting-induced hyperphagia by suppressing ARC neuronal activation and hypothalamic NPY/AgRP mRNA expression. Thus, the lack of appropriate feeding responses in DIO mice to a fast is caused by failure ARC neurones to recognise and/or respond to orexigenic cues. We propose that fasting-induced hyperphagia is regulated not by homeostatic control of appetite in DIO mice, but rather by changes in the reward circuitry. © 2011 The Authors. Journal of Neuroendocrinology © 2011 Blackwell Publishing Ltd.

Transient early food restriction leads to hypothalamic changes in the long-lived crowded litter female mice.

PubMed

Sadagurski, Marianna; Landeryou, Taylor; Cady, Gillian; Bartke, Andrzej; Bernal-Mizrachi, Ernesto; Miller, Richard A

2015-04-01

Transient nutrient restriction in the 3 weeks between birth and weaning (producing "crowded litter" or CL mice) leads to a significant increase in lifespan and is associated with permanent changes in energy homeostasis, leptin, and insulin sensitivity. Here, we show this brief period of early food restriction leads to permanent modulation of the arcuate nucleus of the hypothalamus (ARH), markedly increasing formation of both orexigenic agouti-related peptide (AgRP) and anorexigenic proopiomelanocortin (POMC) projections to the paraventricular nucleus of the hypothalamus (PVH). An additional 4 weeks of caloric restriction, after weaning, does not further intensify the formation of AgRP and POMC projections. Acute leptin stimulation of 12-month-old mice leads to a stronger increase in the levels of hypothalamic pStat3 and cFos activity in CL mice than in controls, suggesting that preweaning food restriction leads to long-lasting enhancement of leptin signaling. In contrast, FoxO1 nuclear exclusion in response to insulin is equivalent in young adult CL and control mice, suggesting that hypothalamic insulin signaling is not modulated by the crowded litter intervention. Markers of hypothalamic reactive gliosis associated with aging, such as Iba1-positive microglia and GFAP-positive astrocytes, are significantly reduced in CL mice as compared to controls at 12 and 22 months of age. Lastly, age-associated overproduction of TNF-α in microglial cells is reduced in CL mice than in age-matched controls. Together, these results suggest that transient early life nutrient deprivation leads to long-term hypothalamic changes which may contribute to the longevity of CL mice. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

A Small Potassium Current in AgRP/NPY Neurons Regulates Feeding Behavior and Energy Metabolism.

PubMed

He, Yanlin; Shu, Gang; Yang, Yongjie; Xu, Pingwen; Xia, Yan; Wang, Chunmei; Saito, Kenji; Hinton, Antentor; Yan, Xiaofeng; Liu, Chen; Wu, Qi; Tong, Qingchun; Xu, Yong

2016-11-08

Neurons that co-express agouti-related peptide (AgRP) and neuropeptide Y (NPY) are indispensable for normal feeding behavior. Firing activities of AgRP/NPY neurons are dynamically regulated by energy status and coordinate appropriate feeding behavior to meet nutritional demands. However, intrinsic mechanisms that regulate AgRP/NPY neural activities during the fed-to-fasted transition are not fully understood. We found that AgRP/NPY neurons in satiated mice express high levels of the small-conductance calcium-activated potassium channel 3 (SK3) and are inhibited by SK3-mediated potassium currents; on the other hand, food deprivation suppresses SK3 expression in AgRP/NPY neurons, and the decreased SK3-mediated currents contribute to fasting-induced activation of these neurons. Genetic mutation of SK3 specifically in AgRP/NPY neurons leads to increased sensitivity to diet-induced obesity, associated with chronic hyperphagia and decreased energy expenditure. Our results identify SK3 as a key intrinsic mediator that coordinates nutritional status with AgRP/NPY neural activities and animals' feeding behavior and energy metabolism. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Dark Agouti rat model of chemotherapy-induced mucositis: establishment and current state of the art.

PubMed

Vanhoecke, Barbara; Bateman, Emma; Mayo, Bronwen; Vanlancker, Eline; Stringer, Andrea; Thorpe, Daniel; Keefe, Dorothy

2015-06-01

Mucositis is a major oncological problem. The entire gastrointestinal and genitourinary tract and also other mucosal surfaces can be affected in recipients of radiotherapy, and/or chemotherapy. Major progress has been made in recent years in understanding the mechanisms of oral and small intestinal mucositis, which appears to be more prominent than colonic damage. This progress is largely due to the development of representative laboratory animal models of mucositis. This review focuses on the development and establishment of the Dark Agouti rat mammary adenocarcinoma model by the Mucositis Research Group of the University of Adelaide over the past 20 years to characterize the mechanisms underlying methotrexate-, 5-fluorouracil-, and irinotecan-induced mucositis. It also aims to summarize the results from studies using different animal model systems to identify new molecular and cellular markers of mucositis. © 2015 by the Society for Experimental Biology and Medicine.

Factor H-related proteins.

PubMed

Józsi, Mihály; Meri, Seppo

2014-01-01

Factor H-related proteins (CFHRs) are plasma glycoproteins related in structure and antigenicity to each other and to the complement inhibitory protein factor H. Such proteins are found in most mammals but their number and domain composition vary. This chapter summarizes our current knowledge on the human factor H-related proteins. In contrast to factor H, they have no strong complement inhibitory activity, although for some of them regulatory or complement modulatory activity has been reported. A common feature of CFHRs is that they bind to the C3b component of complement. Novel links between CFHRs and various diseases (C3 glomerulopathies, atypical hemolytic uremic syndrome and age-related macular degeneration) have been revealed in recent years, but we are still far from understanding their biological function.

Brain innate immunity regulates hypothalamic arcuate neuronal activity and feeding behavior.

PubMed

Reis, Wagner L; Yi, Chun-Xia; Gao, Yuanqing; Tschöp, Mathias H; Stern, Javier E

2015-04-01

Hypothalamic inflammation, involving microglia activation in the arcuate nucleus (ARC), is proposed as a novel underlying mechanism in obesity, insulin and leptin resistance. However, whether activated microglia affects ARC neuronal activity, and consequently basal and hormonal-induced food intake, is unknown. We show that lipopolysaccharide, an agonist of the toll-like receptor-4 (TLR4), which we found to be expressed in ARC microglia, inhibited the firing activity of the majority of orexigenic agouti gene-related protein/neuropeptide Y neurons, whereas it increased the activity of the majority of anorexigenic proopiomelanocortin neurons. Lipopolysaccharide effects in agouti gene-related protein/neuropeptide Y (but not in proopiomelanocortin) neurons were occluded by inhibiting microglia function or by blocking TLR4 receptors. Finally, we report that inhibition of hypothalamic microglia altered basal food intake, also preventing central orexigenic responses to ghrelin. Our studies support a major role for a TLR4-mediated microglia signaling pathway in the control of ARC neuronal activity and feeding behavior.

SARM1 deletion restrains NAFLD induced by high fat diet (HFD) through reducing inflammation, oxidative stress and lipid accumulation.

PubMed

Pan, Zhen-Guo; An, Xu-Sheng

2018-04-06

SARM1 (Sterile alpha and armadillo motif-containing protein 1) is the recently identified TIR domain-containing cytosolic protein, which is involved in toll-like receptors (TLRs) signaling transduction. In the present study, the role of SARM1 in high fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) progression was explored. We found that SARM1 was expressed highly in fatty liver. And SARM1-knockout (KO) reduced steatohepatitis and metabolic disorders induced by HFD. SARM1-deletion decreased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels in HFD-fed mice. Additionally, inflammatory response caused by HFD was alleviated by SARM1-deletion through inactivating TLR4/7/9 and nuclear factor kappa B (NF-κB) pathways. Of note, SARM1-deletion also reduced the expressions of inflammation-associated molecules in hypothalamus of HFD-fed mice. Furthermore, HFD administration led to oxidative stress in liver of mice, while being decreased in SARM1-KO mice. Moreover, SARM1-ablation improved lipid dyslipidemia by suppressing the mRNA levels of genes, linked to glycolysis, lipogenesis and transcriptional regulation. Insulin resistance was also attenuated by SARM1-deficiency through enhancing the activation of liver Akt/glycogen synthase kinase-3β (GSK3β) and insulin receptor substrate-1 (IRS1)/FOXO1 pathways in HFD-fed mice. Also, SARM1-knockout improved neuropeptide Y (NPY), Pro-Opiomelanocortins (POMC), Agouti-related Protein (AGRP) and Cocaine-and-Amphetamine Responsive Transcript 1 (CART1) expressions in hypothalamus of mice after HFD administration. In vitro, we found that the reduction of inflammatory response, oxidative stress and dyslipidemia induced by SARM1-knockout in primary hepatocytes after fructose stimulation was largely attributed to its suppression to TLR4/7/9. Together, the findings demonstrated that SARM1 might be an effective target for developing effective therapeutic strategies against NAFLD. Copyright © 2018

Amylin blunts hyperphagia and reduces weight and fat gain during recovery in socially stressed rats.

PubMed

Smeltzer, Michael; Scott, Karen; Melhorn, Susan; Krause, Eric; Sakai, Randall

2012-09-15

During recovery from social stress in a visible burrow system (VBS), during which a dominance hierarchy is formed among the males, rats display hyperphagia and gain weight preferentially as visceral adipose tissue. By proportionally increasing visceral adiposity, social stress may contribute to the establishment of metabolic disorder. Amylin was administered to rats fed ad libitum during recovery from VBS stress in an attempt to prevent hyperphagia and the resultant gain in body weight and fat mass. Amylin treatment reduced food intake, weight gain, and accumulation of fat mass in male burrow rats, but not in male controls that spent time housed with a single female rather than in the VBS. Amylin did not alter neuropeptide Y (NPY), agouti-related peptide (AgRP), or proopiomelanocortin (POMC) mRNA expression in the arcuate nucleus of the hypothalamus as measured at the end of the recovery period, nor did it affect plasma corticosterone or leptin. Amylin exerted most of its effect on food intake during the first few days of recovery, possibly through antagonism of NPY and/or increasing leptin sensitivity. The potential for chronic social stress to contribute to metabolic disorder is diminished by amylin treatment, though the neuroendocrine mechanisms behind this effect remain elusive.

The effect of physical exercise on orexigenic and anorexigenic peptides and its role on long-term feeding control.

PubMed

Benite-Ribeiro, Sandra Aparecida; Putt, David A; Santos, Júlia Matzenbacher

2016-08-01

Over the past decades, life-styles changing have led to exacerbated food and caloric intake and a reduction in energy expenditure. Obesity, main outcome of these changes, increases the risk for developing type 2 diabetes, cardiovascular disease and metabolic syndrome, the leading cause of death in adult and middle age population. Body weight and energy homeostasis are maintained via complex interactions between orexigenic and anorexigenic neuropeptides that take place predominantly in the hypothalamus. Overeating may disrupt the mechanisms of feeding control, by decreasing the expression of proopiomelanocortin (POMC) and α-melanocyte stimulating hormone (α-MSH) and increasing orexigenic neuropeptide Y (NPY) and agouti-related peptide (AgRP), which leads to a disturbance in appetite control and energy balance. Studies have shown that regular physical exercise might decrease body-weight, food intake and improve the metabolic profile, however until the currently there is no consensus about its effects on the expression of orexigenic/anorexigenic neuropeptides expression. Therefore, we propose that the type and length of physical exercise affect POMC/αMSH and NPY/AgRP systems differently and plays an important role in feeding behavior. Moreover, based on the present reports, we hypothesize that increased POMC/αMSH overcome NPY/AgRP expression decreasing food intake in long term physical exercise and that results in amelioration of several conditions related to overweight and obesity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transcription Factor IIB (TFIIB)-Related Protein (pBrp), a Plant-Specific Member of the TFIIB-Related Protein Family

PubMed Central

Lagrange, Thierry; Hakimi, Mohamed-Ali; Pontier, Dominique; Courtois, Florence; Alcaraz, Jean Pierre; Grunwald, Didier; Lam, Eric; Lerbs-Mache, Silva

2003-01-01

Although it is now well documented that metazoans have evolved general transcription factor (GTF) variants to regulate their complex patterns of gene expression, there is so far no information regarding the existence of specific GTFs in plants. Here we report the characterization of a ubiquitously expressed gene that encodes a bona fide novel transcription factor IIB (TFIIB)-related protein in Arabidopsis thaliana. We have shown that this protein is the founding member of a plant-specific TFIIB-related protein family named pBrp (for plant-specific TFIIB-related protein). Surprisingly, in contrast to common GTFs that are localized in the nucleus, the bulk of pBrp proteins are bound to the cytoplasmic face of the plastid envelope, suggesting an organelle-specific function for this novel class of TFIIB-related protein. We show that pBrp proteins harbor conditional proteolytic signals that can target these proteins for rapid turnover by the proteasome-mediated protein degradation pathway. Interestingly, under conditions of proteasome inhibition, pBrp proteins accumulate in the nucleus. Together, our results suggest a possible involvement of these proteins in an intracellular signaling pathway between plastids and the nucleus. Our data provide the first evidence for an organelle-related evolution of the eukaryotic general transcription machinery. PMID:12697827

The tyrosine kinase receptor Tyro3 enhances lifespan and neuropeptide Y (Npy) neuron survival in the mouse anorexia (anx) mutation.

PubMed

Kim, Dennis Y; Yu, Joanna; Mui, Ryan K; Niibori, Rieko; Taufique, Hamza Bin; Aslam, Rukhsana; Semple, John W; Cordes, Sabine P

2017-05-01

Severe appetite and weight loss define the eating disorder anorexia nervosa, and can also accompany the progression of some neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS). Although acute loss of hypothalamic neurons that produce appetite-stimulating neuropeptide Y (Npy) and agouti-related peptide (Agrp) in adult mice or in mice homozygous for the anorexia ( anx ) mutation causes aphagia, our understanding of the factors that help maintain appetite regulatory circuitry is limited. Here we identify a mutation (C19T) that converts an arginine to a tryptophan (R7W) in the TYRO3 protein tyrosine kinase 3 ( Tyro3 ) gene, which resides within the anx critical interval, as contributing to the severity of anx phenotypes. Our observation that, like Tyro3 -/- mice, anx/anx mice exhibit abnormal secondary platelet aggregation suggested that the C19T Tyro3 variant might have functional consequences. Tyro3 is expressed in the hypothalamus and other brain regions affected by the anx mutation, and its mRNA localization appeared abnormal in anx/anx brains by postnatal day 19 (P19). The presence of wild-type Tyro3 transgenes, but not an R7W-Tyro3 transgene, doubled the weight and lifespans of anx/anx mice and near-normal numbers of hypothalamic Npy-expressing neurons were present in Tyro3 -transgenic anx/anx mice at P19. Although no differences in R7W-Tyro3 signal sequence function or protein localization were discernible in vitro , distribution of R7W-Tyro3 protein differed from that of Tyro3 protein in the cerebellum of transgenic wild-type mice. Thus, R7W-Tyro3 protein localization deficits are only detectable in vivo Further analyses revealed that the C19T Tyro3 mutation is present in a few other mouse strains, and hence is not the causative anx mutation, but rather an anx modifier. Our work shows that Tyro3 has prosurvival roles in the appetite regulatory circuitry and could also provide useful insights towards the development of interventions targeting

Neurons for hunger and thirst transmit a negative-valence teaching signal

PubMed Central

Gong, Rong; Magnus, Christopher J.; Yu, Yang; Sternson, Scott M.

2015-01-01

Homeostasis is a biological principle for regulation of essential physiological parameters within a set range. Behavioural responses due to deviation from homeostasis are critical for survival, but motivational processes engaged by physiological need states are incompletely understood. We examined motivational characteristics and dynamics of two separate neuron populations that regulate energy and fluid homeostasis by using cell type-specific activity manipulations in mice. We found that starvation-sensitive AGRP neurons exhibit properties consistent with a negative-valence teaching signal. Mice avoided activation of AGRP neurons, indicating that AGRP neuron activity has negative valence. AGRP neuron inhibition conditioned preference for flavours and places. Correspondingly, deep-brain calcium imaging revealed that AGRP neuron activity rapidly reduced in response to food-related cues. Complementary experiments activating thirst-promoting neurons also conditioned avoidance. Therefore, these need-sensing neurons condition preference for environmental cues associated with nutrient or water ingestion, which is learned through reduction of negative-valence signals during restoration of homeostasis. PMID:25915020

Neurons for hunger and thirst transmit a negative-valence teaching signal.

PubMed

Betley, J Nicholas; Xu, Shengjin; Cao, Zhen Fang Huang; Gong, Rong; Magnus, Christopher J; Yu, Yang; Sternson, Scott M

2015-05-14

Homeostasis is a biological principle for regulation of essential physiological parameters within a set range. Behavioural responses due to deviation from homeostasis are critical for survival, but motivational processes engaged by physiological need states are incompletely understood. We examined motivational characteristics of two separate neuron populations that regulate energy and fluid homeostasis by using cell-type-specific activity manipulations in mice. We found that starvation-sensitive AGRP neurons exhibit properties consistent with a negative-valence teaching signal. Mice avoided activation of AGRP neurons, indicating that AGRP neuron activity has negative valence. AGRP neuron inhibition conditioned preference for flavours and places. Correspondingly, deep-brain calcium imaging revealed that AGRP neuron activity rapidly reduced in response to food-related cues. Complementary experiments activating thirst-promoting neurons also conditioned avoidance. Therefore, these need-sensing neurons condition preference for environmental cues associated with nutrient or water ingestion, which is learned through reduction of negative-valence signals during restoration of homeostasis.

VGF is required for obesity induced by diet, gold thioglucose treatment, and agouti and is differentially regulated in pro-opiomelanocortin- and neuropeptide Y-containing arcuate neurons in response to fasting.

PubMed

Hahm, Seung; Fekete, Csaba; Mizuno, Tooru M; Windsor, Joan; Yan, Hai; Boozer, Carol N; Lee, Charlotte; Elmquist, Joel K; Lechan, Ronald M; Mobbs, Charles V; Salton, Stephen R J

2002-08-15

Targeted deletion of the gene encoding the neuronal and neuroendocrine secreted polypeptide VGF (nonacronymic) produces a lean, hypermetabolic mouse. Consistent with this phenotype, VGF mRNA levels are regulated in the hypothalamic arcuate nucleus in response to fasting. To gain insight into the site(s) and mechanism(s) of action of VGF, we further characterized VGF expression in the hypothalamus. Double-label studies indicated that VGF and pro-opiomelanocortin were coexpressed in lateral arcuate neurons in the fed state, and that VGF expression was induced after fasting in medial arcuate neurons that synthesize neuropeptide Y (NPY). Like NPY, VGF mRNA induction in this region of the hypothalamus in fasted mice was inhibited by exogenous leptin. In leptin-deficient ob/ob and receptor-mutant db/db mice, VGF mRNA levels in the medial arcuate were elevated. To identify neural pathways that are functionally compromised by Vgf ablation, VGF mutant mice were crossed with obese A(y)/a (agouti) and ob/ob mice. VGF deficiency completely blocked the development of obesity in A(y)/a mice, whereas deletion of Vgf in ob/ob mice attenuated weight gain but had no impact on adiposity. Hypothalamic levels of NPY and agouti-related polypeptide mRNAs in both double-mutant lines were dramatically elevated 10- to 15-fold above those of wild-type mice. VGF-deficient mice were also found to resist diet- and gold thioglucose-induced obesity. These data and the susceptibility of VGF mutant mice to monosodium glutamate-induced obesity are consistent with a role for VGF in outflow pathways, downstream of hypothalamic and/or brainstem melanocortin 4 receptors, that project via the autonomic nervous system to peripheral metabolic tissues and regulate energy homeostasis.

Parathyroid hormone-related protein blood test

MedlinePlus

... gov/ency/article/003691.htm Parathyroid hormone-related protein blood test To use the sharing features on ... page, please enable JavaScript. The parathyroid hormone-related protein (PTH-RP) test measures the level of a ...

Role of hormonal and inflammatory alterations in obesity-related reproductive dysfunction at the level of the hypothalamic-pituitary-ovarian axis.

PubMed

Goldsammler, Michelle; Merhi, Zaher; Buyuk, Erkan

2018-05-09

Besides being a risk factor for multiple metabolic disorders, obesity could affect female reproduction. While increased adiposity is associated with hormonal changes that could disrupt the function of the hypothalamus and the pituitary, compelling data suggest that obesity-related hormonal and inflammatory changes could directly impact ovarian function. To review the available data related to the mechanisms by which obesity, and its associated hormonal and inflammatory changes, could affect the female reproductive function with a focus on the hypothalamic-pituitary-ovarian (HPO) axis. PubMed database search for publications in English language until October 2017 pertaining to obesity and female reproductive function was performed. The obesity-related changes in hormone levels, in particular leptin, adiponectin, ghrelin, neuropeptide Y and agouti-related protein, are associated with reproductive dysfunction at both the hypothalamic-pituitary and the ovarian levels. The pro-inflammatory molecules advanced glycation end products (AGEs) and monocyte chemotactic protein-1 (MCP-1) are emerging as relatively new players in the pathophysiology of obesity-related ovarian dysfunction. There is an intricate crosstalk between the adipose tissue and the inflammatory system with the HPO axis function. Understanding the mechanisms behind this crosstalk could lead to potential therapies for the common obesity-related reproductive dysfunction.

Development of injury in a rat model of chronic renal allograft rejection: effect of dietary protein restriction.

PubMed

Bombas, A; Stein-Oakley, A N; Baxter, K; Thomson, N M; Jablonski, P

1999-01-01

Non-allogeneic factors such as increased nephron "workload" may contribute to chronic renal allograft rejection. Reducing dietary protein from 20% to 8% was tested in a model of chronic rejection: Dark Agouti kidney to Albino Surgery recipient, "tolerised" by previous donor blood transfusions. Survival, weight gain, serum creatinine concentration and creatinine clearance were similar for both groups at all times. Urinary protein was significantly (P < 0.05) lower in the low-protein (LP) group 1 month after transplantation. After 3 and 6 months, both groups demonstrated mild chronic rejection. After 6 months, tubular atrophy was significantly (P < 0.05) less in the LP group and interstitial fibrosis was marginally reduced. Glomerular hypertrophy, glomerular sclerosis, tubular dilatation, leucocyte infiltration, adhesion molecule expression and TGF-beta1 mRNA expression were similarly increased in both groups. Thus, reducing dietary protein to 8% lowered urinary protein, but did not significantly affect the development of chronic rejection in renal allografts beyond affording a degree of protection from tubulointerstitial damage.

Dietary challenges differentially affect activity and sleep/wake behavior in mus musculus: Isolating independent associations with diet/energy balance and body weight.

PubMed

Perron, Isaac J; Keenan, Brendan T; Chellappa, Karthikeyani; Lahens, Nicholas F; Yohn, Nicole L; Shockley, Keith R; Pack, Allan I; Veasey, Sigrid C

2018-01-01

Associated with numerous metabolic and behavioral abnormalities, obesity is classified by metrics reliant on body weight (such as body mass index). However, overnutrition is the common cause of obesity, and may independently contribute to these obesity-related abnormalities. Here, we use dietary challenges to parse apart the relative influence of diet and/or energy balance from body weight on various metabolic and behavioral outcomes. Seventy male mice (mus musculus) were subjected to the diet switch feeding paradigm, generating groups with various body weights and energetic imbalances. Spontaneous activity patterns, blood metabolite levels, and unbiased gene expression of the nutrient-sensing ventral hypothalamus (using RNA-sequencing) were measured, and these metrics were compared using standardized multivariate linear regression models. Spontaneous activity patterns were negatively related to body weight (p<0.0001) but not diet/energy balance (p = 0.63). Both body weight and diet/energy balance predicted circulating glucose and insulin levels, while body weight alone predicted plasma leptin levels. Regarding gene expression within the ventral hypothalamus, only two genes responded to diet/energy balance (neuropeptide y [npy] and agouti-related peptide [agrp]), while others were related only to body weight. Collectively, these results demonstrate that individual components of obesity-specifically obesogenic diets/energy imbalance and elevated body mass-can have independent effects on metabolic and behavioral outcomes. This work highlights the shortcomings of using body mass-based indices to assess metabolic health, and identifies novel associations between blood biomarkers, neural gene expression, and animal behavior following dietary challenges.

Electronegativity and intrinsic disorder of preeclampsia-related proteins.

PubMed

Polanco, Carlos; Castañón-González, Jorge Alberto; Uversky, Vladimir N; Buhse, Thomas; Samaniego Mendoza, José Lino; Calva, Juan J

2017-01-01

Preeclampsia, hemorrhage, and infection are the leading causes of maternal death in underdeveloped countries. Since several proteins associated with preeclampsia are known, we conducted a computational study which evaluated the commonness and potential functionality of intrinsic disorder of these proteins and also made an attempt to characterize their origin. The origin of the preeclampsia-related proteins was assessed with a supervised technique, a Polarity Index Method (PIM), which evaluates the electronegativity of proteins based solely on their sequence. The commonness of intrinsic disorder was evaluated using several disorder predictors from the PONDR family, the charge-hydropathy plot (CH-plot) and cumulative distribution function (CDF) analyses, and using the MobiDB web-based tool, whereas potential functionality of intrinsic disorder was studied with the D2P2 resource and ANCHOR predictor of disorder-based binding sites, and the STRING tool was used to build the interactivity networks of the preeclampsia-related proteins. Peculiarities of the PIM-derived polar profile of the group of preeclampsia-related proteins were then compared with profiles of a group of lipoproteins, antimicrobial peptides, angiogenesis-related proteins, and the intrinsically disordered proteins. Our results showed a high graphical correlation between preeclampsia proteins, lipoproteins, and the angiogenesis proteins. We also showed that many preeclampsia-related proteins contain numerous functional disordered regions. Therefore, these bioinformatics results led us to assume that the preeclampsia proteins are highly associated with the lipoproteins group, and that some preeclampsia-related proteins contain significant amounts of functional disorders.

Ribosome-Inactivating and Related Proteins

PubMed Central

Schrot, Joachim; Weng, Alexander; Melzig, Matthias F.

2015-01-01

Ribosome-inactivating proteins (RIPs) are toxins that act as N-glycosidases (EC 3.2.2.22). They are mainly produced by plants and classified as type 1 RIPs and type 2 RIPs. There are also RIPs and RIP related proteins that cannot be grouped into the classical type 1 and type 2 RIPs because of their different sizes, structures or functions. In addition, there is still not a uniform nomenclature or classification existing for RIPs. In this review, we give the current status of all known plant RIPs and we make a suggestion about how to unify those RIPs and RIP related proteins that cannot be classified as type 1 or type 2 RIPs. PMID:26008228

Alterations in the hypothalamic melanocortin pathway in amyotrophic lateral sclerosis.

PubMed

Vercruysse, Pauline; Sinniger, Jérôme; El Oussini, Hajer; Scekic-Zahirovic, Jelena; Dieterlé, Stéphane; Dengler, Reinhard; Meyer, Thomas; Zierz, Stephan; Kassubek, Jan; Fischer, Wilhelm; Dreyhaupt, Jens; Grehl, Torsten; Hermann, Andreas; Grosskreutz, Julian; Witting, Anke; Van Den Bosch, Ludo; Spreux-Varoquaux, Odile; Ludolph, Albert C; Dupuis, Luc

2016-04-01

Amyotrophic lateral sclerosis, the most common adult-onset motor neuron disease, leads to death within 3 to 5 years after onset. Beyond progressive motor impairment, patients with amyotrophic lateral sclerosis suffer from major defects in energy metabolism, such as weight loss, which are well correlated with survival. Indeed, nutritional intervention targeting weight loss might improve survival of patients. However, the neural mechanisms underlying metabolic impairment in patients with amyotrophic lateral sclerosis remain elusive, in particular due to the lack of longitudinal studies. Here we took advantage of samples collected during the clinical trial of pioglitazone (GERP-ALS), and characterized longitudinally energy metabolism of patients with amyotrophic lateral sclerosis in response to pioglitazone, a drug with well-characterized metabolic effects. As expected, pioglitazone decreased glycaemia, decreased liver enzymes and increased circulating adiponectin in patients with amyotrophic lateral sclerosis, showing its efficacy in the periphery. However, pioglitazone did not increase body weight of patients with amyotrophic lateral sclerosis independently of bulbar involvement. As pioglitazone increases body weight through a direct inhibition of the hypothalamic melanocortin system, we studied hypothalamic neurons producing proopiomelanocortin (POMC) and the endogenous melanocortin inhibitor agouti-related peptide (AGRP), in mice expressing amyotrophic lateral sclerosis-linked mutant SOD1(G86R). We observed lower Pomc but higher Agrp mRNA levels in the hypothalamus of presymptomatic SOD1(G86R) mice. Consistently, numbers of POMC-positive neurons were decreased, whereas AGRP fibre density was elevated in the hypothalamic arcuate nucleus of SOD1(G86R) mice. Consistent with a defect in the hypothalamic melanocortin system, food intake after short term fasting was increased in SOD1(G86R) mice. Importantly, these findings were replicated in two other amyotrophic

Protein function prediction using neighbor relativity in protein-protein interaction network.

PubMed

Moosavi, Sobhan; Rahgozar, Masoud; Rahimi, Amir

2013-04-01

There is a large gap between the number of discovered proteins and the number of functionally annotated ones. Due to the high cost of determining protein function by wet-lab research, function prediction has become a major task for computational biology and bioinformatics. Some researches utilize the proteins interaction information to predict function for un-annotated proteins. In this paper, we propose a novel approach called "Neighbor Relativity Coefficient" (NRC) based on interaction network topology which estimates the functional similarity between two proteins. NRC is calculated for each pair of proteins based on their graph-based features including distance, common neighbors and the number of paths between them. In order to ascribe function to an un-annotated protein, NRC estimates a weight for each neighbor to transfer its annotation to the unknown protein. Finally, the unknown protein will be annotated by the top score transferred functions. We also investigate the effect of using different coefficients for various types of functions. The proposed method has been evaluated on Saccharomyces cerevisiae and Homo sapiens interaction networks. The performance analysis demonstrates that NRC yields better results in comparison with previous protein function prediction approaches that utilize interaction network. Copyright © 2012 Elsevier Ltd. All rights reserved.

Somato-Dendritic Localization and Signaling by Leptin Receptors in Hypothalamic POMC and AgRP Neurons

PubMed Central

Ha, Sangdeuk; Baver, Scott; Huo, Lihong; Gata, Adriana; Hairston, Joyce; Huntoon, Nicholas; Li, Wenjing; Zhang, Thompson; Benecchi, Elizabeth J.; Ericsson, Maria; Hentges, Shane T.; Bjørbæk, Christian

2013-01-01

Leptin acts via neuronal leptin receptors to control energy balance. Hypothalamic pro-opiomelanocortin (POMC) and agouti-related peptide (AgRP)/Neuropeptide Y (NPY)/GABA neurons produce anorexigenic and orexigenic neuropeptides and neurotransmitters, and express the long signaling form of the leptin receptor (LepRb). Despite progress in the understanding of LepRb signaling and function, the sub-cellular localization of LepRb in target neurons has not been determined, primarily due to lack of sensitive anti-LepRb antibodies. Here we applied light microscopy (LM), confocal-laser scanning microscopy (CLSM), and electron microscopy (EM) to investigate LepRb localization and signaling in mice expressing a HA-tagged LepRb selectively in POMC or AgRP/NPY/GABA neurons. We report that LepRb receptors exhibit a somato-dendritic expression pattern. We further show that LepRb activates STAT3 phosphorylation in neuronal fibers within several hypothalamic and hindbrain nuclei of wild-type mice and rats, and specifically in dendrites of arcuate POMC and AgRP/NPY/GABA neurons of Leprb +/+ mice and in Leprb db/db mice expressing HA-LepRb in a neuron specific manner. We did not find evidence of LepRb localization or STAT3-signaling in axon-fibers or nerve-terminals of POMC and AgRP/NPY/GABA neurons. Three-dimensional serial EM-reconstruction of dendritic segments from POMC and AgRP/NPY/GABA neurons indicates a high density of shaft synapses. In addition, we found that the leptin activates STAT3 signaling in proximity to synapses on POMC and AgRP/NPY/GABA dendritic shafts. Taken together, these data suggest that the signaling-form of the leptin receptor exhibits a somato-dendritic expression pattern in POMC and AgRP/NPY/GABA neurons. Dendritic LepRb signaling may therefore play an important role in leptin’s central effects on energy balance, possibly through modulation of synaptic activity via post-synaptic mechanisms. PMID:24204898

Essential Role for Hypothalamic Calcitonin Receptor‒Expressing Neurons in the Control of Food Intake by Leptin.

PubMed

Pan, Warren; Adams, Jessica M; Allison, Margaret B; Patterson, Christa; Flak, Jonathan N; Jones, Justin; Strohbehn, Garth; Trevaskis, James; Rhodes, Christopher J; Olson, David P; Myers, Martin G

2018-04-01

The adipocyte-derived hormone leptin acts via its receptor (LepRb) on central nervous system neurons to communicate the repletion of long-term energy stores, to decrease food intake, and to promote energy expenditure. We generated mice that express Cre recombinase from the calcitonin receptor (Calcr) locus (Calcrcre mice) to study Calcr-expressing LepRb (LepRbCalcr) neurons, which reside predominantly in the arcuate nucleus (ARC). Calcrcre-mediated ablation of LepRb in LepRbCalcrknockout (KO) mice caused hyperphagic obesity. Because LepRb-mediated transcriptional control plays a crucial role in leptin action, we used translating ribosome affinity purification followed by RNA sequencing to define the transcriptome of hypothalamic Calcr neurons, along with its alteration in LepRbCalcrKO mice. We found that ARC LepRbCalcr cells include neuropeptide Y (NPY)/agouti-related peptide (AgRP)/γ-aminobutyric acid (GABA) ("NAG") cells as well as non-NAG cells that are distinct from pro-opiomelanocortin cells. Furthermore, although LepRbCalcrKO mice exhibited dysregulated expression of several genes involved in energy balance, neither the expression of Agrp and Npy nor the activity of NAG cells was altered in vivo. Thus, although direct leptin action via LepRbCalcr cells plays an important role in leptin action, our data also suggest that leptin indirectly, as well as directly, regulates these cells.

Dietary Slowly Digestible Starch Triggers the Gut-Brain Axis in Obese Rats with Accompanied Reduced Food Intake.

PubMed

Hasek, Like Y; Phillips, Robert J; Zhang, Genyi; Kinzig, Kimberly P; Kim, Choon Young; Powley, Terry L; Hamaker, Bruce R

2018-03-01

Slowly digestible starch (SDS), as a functional carbohydrate providing a slow and sustained glucose release, may be able to modulate food intake through activation of the gut-brain axis. Diet-induced obese rats were used to test the effect on feeding behavior of high-fat (HF) diets containing an SDS, fabricated to digest into the ileum, as compared to rapidly digestible starch (RDS). Ingestion of the HF-SDS diet over an 11-week period reduced daily food intake, through smaller meal size, to the same level as a lean body control group, while the group consuming the HF-RDS diet remained at a high food intake. Expression levels (mRNA) of the hypothalamic orexigenic neuropeptide Y (NPY) and Agouti-related peptide (AgRP) were significantly reduced, and the anorexigenic corticotropin-releasing hormone (CRH) was increased, in the HF-SDS fed group compared to the HF-RDS group, and to the level of the lean control group. SDS with digestion into the ileum reduced daily food intake and paralleled suppressed expression of appetite-stimulating neuropeptide genes associated with the gut-brain axis. This novel finding suggests further exploration involving a clinical study and potential development of SDS-based functional foods as an approach to obesity control. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Predicting disease-related proteins based on clique backbone in protein-protein interaction network.

PubMed

Yang, Lei; Zhao, Xudong; Tang, Xianglong

2014-01-01

Network biology integrates different kinds of data, including physical or functional networks and disease gene sets, to interpret human disease. A clique (maximal complete subgraph) in a protein-protein interaction network is a topological module and possesses inherently biological significance. A disease-related clique possibly associates with complex diseases. Fully identifying disease components in a clique is conductive to uncovering disease mechanisms. This paper proposes an approach of predicting disease proteins based on cliques in a protein-protein interaction network. To tolerate false positive and negative interactions in protein networks, extending cliques and scoring predicted disease proteins with gene ontology terms are introduced to the clique-based method. Precisions of predicted disease proteins are verified by disease phenotypes and steadily keep to more than 95%. The predicted disease proteins associated with cliques can partly complement mapping between genotype and phenotype, and provide clues for understanding the pathogenesis of serious diseases.

Targeting protein-trafficking pathways alters melanoma treatment sensitivity

PubMed Central

Huang, Zhi-ming; Chinen, Milka; Chang, Philip J.; Xie, Tong; Zhong, Lily; Demetriou, Stephanie; Patel, Mira P.; Scherzer, Rebecca; Sviderskaya, Elena V.; Bennett, Dorothy C.; Millhauser, Glenn L.; Oh, Dennis H.; Cleaver, James E.; Wei, Maria L.

2012-01-01

Protein-trafficking pathways are targeted here in human melanoma cells using methods independent of oncogene mutational status, and the ability to up-regulate and down-regulate tumor treatment sensitivity is demonstrated. Sensitivity of melanoma cells to cis-diaminedichloroplatinum II (cDDP, cis-platin), carboplatin, dacarbazine, or temozolomide together with velaparib, an inhibitor of poly (ADP ribose) polymerase 1, is increased by up to 10-fold by targeting genes that regulate both protein trafficking and the formation of melanosomes, intracellular organelles unique to melanocytes and melanoma cells. Melanoma cells depleted of either of the protein-trafficking regulators vacuolar protein sorting 33A protein (VPS33A) or cappuccino protein (CNO) have increased nuclear localization of cDDP, increased nuclear DNA damage by platination, and increased apoptosis, resulting in increased treatment sensitivity. Depleted cells also exhibit a decreased proportion of intracellular, mature melanosomes compared with undepleted cells. Modulation of protein trafficking via cell-surface signaling by binding the melanocortin 1 receptor with the antagonist agouti-signaling protein decreased the proportion of mature melanosomes formed and increased cDDP sensitivity, whereas receptor binding with the agonist melanocyte-stimulating hormone resulted in an increased proportion of mature melanosomes formed and in decreased sensitivity (i.e., increased resistance) to cDDP. Mutation of the protein-trafficking gene Hps6, known to impair the formation of mature melanosomes, also increased cDDP sensitivity. Together, these results indicate that targeting protein-trafficking molecules markedly increases melanoma treatment sensitivity and influences the degree of melanosomes available for sequestration of therapeutic agents. PMID:22203954

The mouse p (pink-eyed dilution) and human P genes, oculocutaneous albinism type 2 (OCA2), and melanosomal pH.

PubMed

Brilliant, M H

2001-04-01

Recessive mutations of the mouse p (pink-eyed dilution) gene lead to hypopigmentation of the eyes, skin, and fur. Mice lacking a functional p protein have pink eyes and light gray fur (if non-agouti) or cream-colored fur (if agouti). The human orthologue is the P protein. Humans lacking a functional P protein have oculocutaneous albinism type 2 (OCA2). Melanocytes from p-deficient mice or OCA2 individuals contain small, minimally pigmented melanosomes. The mouse and human proteins are predicted to have 12 membrane spanning domains and possess significant sequence homology to a number of membrane transport proteins, some of which are involved in the transport of anions. The p protein has been localized to the melanosome membrane. Recently, it has been shown that melanosomes from p protein-deficient melanocytes have an abnormal pH. Melanosomes in cultured melanocytes derived from wild-type mice are typically acidic, whereas melanosomes from p protein-deficient mice are non-acidic. Melanosomes and related endosome-derived organelles (i.e., lysosomes) are thought to have an adenosine triphosphate (ATP)-driven proton pump that helps to generate an acidic lumen. To compensate for the charge of these protons, anions must also be transported to the lumen of the melanosome. In light of these observations, a model of p protein function is presented in which the p protein, together with the ATP-driven proton pump, regulates the pH of the melanosome.

DITOP: drug-induced toxicity related protein database.

PubMed

Zhang, Jing-Xian; Huang, Wei-Juan; Zeng, Jing-Hua; Huang, Wen-Hui; Wang, Yi; Zhao, Rui; Han, Bu-Cong; Liu, Qing-Feng; Chen, Yu-Zong; Ji, Zhi-Liang

2007-07-01

Drug-induced toxicity related proteins (DITRPs) are proteins that mediate adverse drug reactions (ADRs) or toxicities through their binding to drugs or reactive metabolites. Collection of these proteins facilitates better understanding of the molecular mechanisms of drug-induced toxicity and the rational drug discovery. Drug-induced toxicity related protein database (DITOP) is such a database that is intending to provide comprehensive information of DITRPs. Currently, DITOP contains 1501 records, covering 618 distinct literature-reported DITRPs, 529 drugs/ligands and 418 distinct toxicity terms. These proteins were confirmed experimentally to interact with drugs or their reactive metabolites, thus directly or indirectly cause adverse effects or toxicities. Five major types of drug-induced toxicities or ADRs are included in DITOP, which are the idiosyncratic adverse drug reactions, the dose-dependent toxicities, the drug-drug interactions, the immune-mediated adverse drug effects (IMADEs) and the toxicities caused by genetic susceptibility. Molecular mechanisms underlying the toxicity and cross-links to related resources are also provided while available. Moreover, a series of user-friendly interfaces were designed for flexible retrieval of DITRPs-related information. The DITOP can be accessed freely at http://bioinf.xmu.edu.cn/databases/ADR/index.html. Supplementary data are available at Bioinformatics online.

Epistasis between QTLs for bone density variation in Copenhagen × dark agouti F2 rats

PubMed Central

Liu, Lixiang; Alam, Imranul; Sun, Qiwei; Econs, Michael J.; Foroud, Tatiana; Turner, Charles H.

2010-01-01

The variation in several of the risk factors for osteoporotic fracture, including bone mineral density (BMD), has been shown to be strongly influenced by genetic differences. However, the genetic architecture of BMD is complex in both humans and in model organisms. We previously reported quantitative trait locus (QTL) results for BMD from a genome screen of 828 F2 progeny of Copenhagen and dark agouti rats. These progeny also provide an excellent opportunity to search for epistatic effects, or interaction between genetic loci, that contribute to fracture risk. Microsatellite marker data from a 20-cM genome screen was analyzed along with weight-adjusted bone density (DXA and pQCT) phenotypic data using the R/qtl software package. Genotype and phenotype data were permuted to determine genome-wide significance thresholds for the full model and epistasis (interaction) LOD scores corresponding to an alpha level of 0.01. A novel locus on chromosome 15 and a previously reported chromosome 14 QTL demonstrated a strong epistatic effect on BMD at the femur by DXA (LOD = 5.4). Two novel QTLs on chromosomes 2 and 12 were found to interact to affect total BMD at the femur midshaft by pQCT (LOD = 5.0). These results provide new information regarding the mode of action of previously identified QTL in the rat, as well as identifying novel loci that act in combination with known QTL or with other novel loci to contribute to BMD variation. PMID:19153792

Epistasis between QTLs for bone density variation in Copenhagen x dark agouti F2 rats.

PubMed

Koller, Daniel L; Liu, Lixiang; Alam, Imranul; Sun, Qiwei; Econs, Michael J; Foroud, Tatiana; Turner, Charles H

2009-03-01

The variation in several of the risk factors for osteoporotic fracture, including bone mineral density (BMD), has been shown to be strongly influenced by genetic differences. However, the genetic architecture of BMD is complex in both humans and in model organisms. We previously reported quantitative trait locus (QTL) results for BMD from a genome screen of 828 F2 progeny of Copenhagen and dark agouti rats. These progeny also provide an excellent opportunity to search for epistatic effects, or interaction between genetic loci, that contribute to fracture risk. Microsatellite marker data from a 20-cM genome screen was analyzed along with weight-adjusted bone density (DXA and pQCT) phenotypic data using the R/qtl software package. Genotype and phenotype data were permuted to determine genome-wide significance thresholds for the full model and epistasis (interaction) LOD scores corresponding to an alpha level of 0.01. A novel locus on chromosome 15 and a previously reported chromosome 14 QTL demonstrated a strong epistatic effect on BMD at the femur by DXA (LOD = 5.4). Two novel QTLs on chromosomes 2 and 12 were found to interact to affect total BMD at the femur midshaft by pQCT (LOD = 5.0). These results provide new information regarding the mode of action of previously identified QTL in the rat, as well as identifying novel loci that act in combination with known QTL or with other novel loci to contribute to BMD variation.

Actin, actin-binding proteins, and actin-related proteins in the nucleus.

PubMed

Kristó, Ildikó; Bajusz, Izabella; Bajusz, Csaba; Borkúti, Péter; Vilmos, Péter

2016-04-01

Extensive research in the past decade has significantly broadened our view about the role actin plays in the life of the cell and added novel aspects to actin research. One of these new aspects is the discovery of the existence of nuclear actin which became evident only recently. Nuclear activities including transcriptional activation in the case of all three RNA polymerases, editing and nuclear export of mRNAs, and chromatin remodeling all depend on actin. It also became clear that there is a fine-tuned equilibrium between cytoplasmic and nuclear actin pools and that this balance is ensured by an export-import system dedicated to actin. After over half a century of research on conventional actin and its organizing partners in the cytoplasm, it was also an unexpected finding that the nucleus contains more than 30 actin-binding proteins and new classes of actin-related proteins which are not able to form filaments but had evolved nuclear-specific functions. The actin-binding and actin-related proteins in the nucleus have been linked to RNA transcription and processing, nuclear transport, and chromatin remodeling. In this paper, we attempt to provide an overview of the wide range of information that is now available about actin, actin-binding, and actin-related proteins in the nucleus.

The melanocortinergic pathway is rapidly recruited by emotional stress and contributes to stress-induced anorexia and anxiety-like behavior.

PubMed

Liu, Jing; Garza, Jacob C; Truong, Ha V; Henschel, John; Zhang, Wei; Lu, Xin-Yun

2007-11-01

Neurons producing melanocortin receptor agonist, alpha-MSH derived from proopiomelanocortin, and antagonist, agouti-related protein, are known to be sensitive to metabolic stress such as food deprivation and glucoprivation. However, how these neurons respond to emotional/psychological stress remained to be elucidated. We report here that acute emotional stressors, i.e. restraint and forced swim, evoked mRNA expression of c-fos, a neuronal activation marker, in a high percentage of proopiomelanocortin neurons (up to 53% for restraint stress and 62% for forced swim), with marked variations along the rostro-caudal axis of the arcuate nucleus. In contrast, only a small population of agouti-related protein neurons in this brain region was activated. These neuronal activation patterns were correlated with behavioral reactions. Both stressors suppressed feeding and induced anxiety-like behavior in the elevated plus-maze test, as reflected by a reduction in the percentage of entries and time spent in the open arms. Central pretreatment with SHU9119, a melanocortin receptor antagonist, dose dependently attenuated the anorectic and anxiogenic effects elicited by acute restraint or forced swim. These results indicate that the melancortinergic pathway can be rapidly recruited by acute emotional stress, and that activation of melanocortin signaling is involved in mediating stress-induced anorexia and anxiety.

Glucokinase inhibitor glucosamine stimulates feeding and activates hypothalamic neuropeptide Y and orexin neurons.

PubMed

Zhou, Ligang; Yueh, Chen-Yu; Lam, Daniel D; Shaw, Jill; Osundiji, Mayowa; Garfield, Alastair S; Evans, Mark; Heisler, Lora K

2011-09-12

Maintaining glucose levels within the appropriate physiological range is necessary for survival. The identification of specific neuronal populations, within discreet brain regions, sensitive to changes in glucose concentration has led to the hypothesis of a central glucose-sensing system capable of directly modulating feeding behaviour. Glucokinase (GK) has been identified as a glucose-sensor responsible for detecting such changes both within the brain and the periphery. We previously reported that antagonism of centrally expressed GK by administration of glucosamine (GSN) was sufficient to induce protective glucoprivic feeding in rats. Here we examine a neurochemical mechanism underlying this effect and report that GSN stimulated food intake is highly correlated with the induction of the neuronal activation marker cFOS within two nuclei with a demonstrated role in central glucose sensing and appetite, the arcuate nucleus of the hypothalamus (ARC) and lateral hypothalamic area (LHA). Furthermore, GSN stimulated cFOS within the ARC was observed in orexigenic neurons expressing the endogenous melanocortin receptor antagonist agouti-related peptide (AgRP) and neuropeptide Y (NPY), but not those expressing the anorectic endogenous melanocortin receptor agonist alpha-melanocyte stimulating hormone (α-MSH). In the LHA, GSN stimulated cFOS was found within arousal and feeding associated orexin/hypocretin (ORX), but not orexigenic melanin-concentrating hormone (MCH) expressing neurons. Our data suggest that GK within these specific feeding and arousal related populations of AgRP/NPY and ORX neurons may play a modulatory role in the sensing of and appetitive response to hypoglycaemia. Copyright © 2011 Elsevier B.V. All rights reserved.

Neuronal hypothalamic regulation of body metabolism and bone density is galanin dependent.

PubMed

Idelevich, Anna; Sato, Kazusa; Nagano, Kenichi; Rowe, Glenn; Gori, Francesca; Baron, Roland

2018-06-01

In the brain, the ventral hypothalamus (VHT) regulates energy and bone metabolism. Whether this regulation uses the same or different neuronal circuits is unknown. Alteration of AP1 signaling in the VHT increases energy expenditure, glucose utilization, and bone density, yet the specific neurons responsible for each or all of these phenotypes are not identified. Using neuron-specific, genetically targeted AP1 alterations as a tool in adult mice, we found that agouti-related peptide-expressing (AgRP-expressing) or proopiomelanocortin-expressing (POMC-expressing) neurons, predominantly present in the arcuate nucleus (ARC) within the VHT, stimulate whole-body energy expenditure, glucose utilization, and bone formation and density, although their effects on bone resorption differed. In contrast, AP1 alterations in steroidogenic factor 1-expressing (SF1-expressing) neurons, present in the ventromedial hypothalamus (VMH), increase energy but decrease bone density, suggesting that these effects are independent. Altered AP1 signaling also increased the level of the neuromediator galanin in the hypothalamus. Global galanin deletion (VHT galanin silencing using shRNA) or pharmacological galanin receptor blockade counteracted the observed effects on energy and bone. Thus, AP1 antagonism reveals that AgRP- and POMC-expressing neurons can stimulate body metabolism and increase bone density, with galanin acting as a central downstream effector. The results obtained with SF1-expressing neurons, however, indicate that bone homeostasis is not always dictated by the global energy status, and vice versa.

Melanocortin-3 receptors expressed in Nkx2.1(+ve) neurons are sufficient for controlling appetitive responses to hypocaloric conditioning

PubMed Central

Girardet, Clémence; Mavrikaki, Maria M.; Stevens, Joseph R.; Miller, Courtney A.; Marks, Daniel L.; Butler, Andrew A.

2017-01-01

Melanocortin-3 receptors (MC3R) have a contextual role in appetite control that is amplified with hypocaloric conditioning. C57BL/6J (B6) mice subjected to hypocaloric feeding schedules (HFS) exhibit compulsive behavioral responses involving food anticipatory activity (FAA) and caloric loading following food access. These homeostatic responses to calorie-poor environs are attenuated in B6 mice in which Mc3r transcription is suppressed by a lox-stop-lox sequence in the 5’UTR (Mc3rTB/TB). Here, we report that optimization of caloric loading in B6 mice subject to HFS, characterized by increased meal size and duration, is not observed in Mc3rTB/TB mice. Analysis of hypothalamic and neuroendocrine responses to HFS throughout the light-dark cycle suggests uncoupling of hypothalamic responses involving appetite-stimulating fasting-responsive hypothalamic neurons expressing agouti-related peptide (AgRP) and neuropeptide Y (Npy). Rescuing Mc3rs expression in Nkx2.1(+ve) neurons is sufficient to restore normal hypothalamic responses to negative energy balance. In addition, Mc3rs expressed in Nkx2.1(+ve) neurons are also sufficient to restore FAA and caloric loading of B6 mice subjected to HFS. In summary, MC3Rs expressed in Nkx2.1(+ve) neurons are sufficient to coordinate hypothalamic response and expression of compulsive behavioral responses involving meal anticipation and consumption of large meals during situations of prolonged negative energy balance. PMID:28294152

Enhanced Ghrelin Levels and Hypothalamic Orexigenic AgRP and NPY Neuropeptide Expression in Models of Jejuno-Colonic Short Bowel Syndrome

PubMed Central

Gillard, Laura; Billiauws, Lore; Stan-Iuga, Bogdan; Ribeiro-Parenti, Lara; Jarry, Anne-Charlotte; Cavin, Jean-Baptiste; Cluzeaud, Françoise; Mayeur, Camille; Thomas, Muriel; Freund, Jean-Noël; Lacorte, Jean-Marc; Le Gall, Maude; Bado, André; Joly, Francisca; Le Beyec, Johanne

2016-01-01

Short bowel syndrome (SBS) patients developing hyperphagia have a better outcome. Gastrointestinal endocrine adaptations help to improve intestinal functions and food behaviour. We investigated neuroendocrine adaptations in SBS patients and rat models with jejuno-ileal (IR-JI) or jejuno-colonic (IR-JC) anastomosis with and without parenteral nutrition. Circulating levels of ghrelin, PYY, GLP-1, and GLP-2 were determined in SBS rat models and patients. Levels of mRNA for proglucagon, PYY and for hypothalamic neuropeptides were quantified by qRT-PCR in SBS rat models. Histology and immunostaining for Ki67, GLP-1 and PYY were performed in SBS rats. IR-JC rats, but not IR-JI, exhibited significantly higher crypt depths and number of Ki67-positive cells than sham. Fasting and/or postprandial plasma ghrelin and PYY concentrations were higher, or tend to be higher, in IR-JC rats and SBS-JC patients than in controls. Proglucagon and Pyy mRNA levels were significantly enhanced in IR-JC rats. Levels of mRNA coding hypothalamic orexigenic NPY and AgRP peptides were significantly higher in IR-JC than in sham rats. We demonstrate an increase of plasma ghrelin concentrations, major changes in hypothalamic neuropeptides levels and greater induction of PYY in SBS-JC rats and patients suggesting that jejuno-colonic continuity creates a peculiar environment promoting further gut-brain adaptations. PMID:27323884

Enhanced Ghrelin Levels and Hypothalamic Orexigenic AgRP and NPY Neuropeptide Expression in Models of Jejuno-Colonic Short Bowel Syndrome.

PubMed

Gillard, Laura; Billiauws, Lore; Stan-Iuga, Bogdan; Ribeiro-Parenti, Lara; Jarry, Anne-Charlotte; Cavin, Jean-Baptiste; Cluzeaud, Françoise; Mayeur, Camille; Thomas, Muriel; Freund, Jean-Noël; Lacorte, Jean-Marc; Le Gall, Maude; Bado, André; Joly, Francisca; Le Beyec, Johanne

2016-06-21

Short bowel syndrome (SBS) patients developing hyperphagia have a better outcome. Gastrointestinal endocrine adaptations help to improve intestinal functions and food behaviour. We investigated neuroendocrine adaptations in SBS patients and rat models with jejuno-ileal (IR-JI) or jejuno-colonic (IR-JC) anastomosis with and without parenteral nutrition. Circulating levels of ghrelin, PYY, GLP-1, and GLP-2 were determined in SBS rat models and patients. Levels of mRNA for proglucagon, PYY and for hypothalamic neuropeptides were quantified by qRT-PCR in SBS rat models. Histology and immunostaining for Ki67, GLP-1 and PYY were performed in SBS rats. IR-JC rats, but not IR-JI, exhibited significantly higher crypt depths and number of Ki67-positive cells than sham. Fasting and/or postprandial plasma ghrelin and PYY concentrations were higher, or tend to be higher, in IR-JC rats and SBS-JC patients than in controls. Proglucagon and Pyy mRNA levels were significantly enhanced in IR-JC rats. Levels of mRNA coding hypothalamic orexigenic NPY and AgRP peptides were significantly higher in IR-JC than in sham rats. We demonstrate an increase of plasma ghrelin concentrations, major changes in hypothalamic neuropeptides levels and greater induction of PYY in SBS-JC rats and patients suggesting that jejuno-colonic continuity creates a peculiar environment promoting further gut-brain adaptations.

A protein relational database and protein family knowledge bases to facilitate structure-based design analyses.

PubMed

Mobilio, Dominick; Walker, Gary; Brooijmans, Natasja; Nilakantan, Ramaswamy; Denny, R Aldrin; Dejoannis, Jason; Feyfant, Eric; Kowticwar, Rupesh K; Mankala, Jyoti; Palli, Satish; Punyamantula, Sairam; Tatipally, Maneesh; John, Reji K; Humblet, Christine

2010-08-01

The Protein Data Bank is the most comprehensive source of experimental macromolecular structures. It can, however, be difficult at times to locate relevant structures with the Protein Data Bank search interface. This is particularly true when searching for complexes containing specific interactions between protein and ligand atoms. Moreover, searching within a family of proteins can be tedious. For example, one cannot search for some conserved residue as residue numbers vary across structures. We describe herein three databases, Protein Relational Database, Kinase Knowledge Base, and Matrix Metalloproteinase Knowledge Base, containing protein structures from the Protein Data Bank. In Protein Relational Database, atom-atom distances between protein and ligand have been precalculated allowing for millisecond retrieval based on atom identity and distance constraints. Ring centroids, centroid-centroid and centroid-atom distances and angles have also been included permitting queries for pi-stacking interactions and other structural motifs involving rings. Other geometric features can be searched through the inclusion of residue pair and triplet distances. In Kinase Knowledge Base and Matrix Metalloproteinase Knowledge Base, the catalytic domains have been aligned into common residue numbering schemes. Thus, by searching across Protein Relational Database and Kinase Knowledge Base, one can easily retrieve structures wherein, for example, a ligand of interest is making contact with the gatekeeper residue.

Dysfunction of intraflagellar transport-A causes hyperphagia-induced obesity and metabolic syndrome

PubMed Central

Jacobs, Damon T.; Silva, Luciane M.; Allard, Bailey A.; Schonfeld, Michael P.; Chatterjee, Anindita; Talbott, George C.

2016-01-01

ABSTRACT Primary cilia extend from the plasma membrane of most vertebrate cells and mediate signaling pathways. Ciliary dysfunction underlies ciliopathies, which are genetic syndromes that manifest multiple clinical features, including renal cystic disease and obesity. THM1 (also termed TTC21B or IFT139) encodes a component of the intraflagellar transport-A complex and mutations in THM1 have been identified in 5% of individuals with ciliopathies. Consistent with this, deletion of murine Thm1 during late embryonic development results in cystic kidney disease. Here, we report that deletion of murine Thm1 during adulthood results in obesity, diabetes, hypertension and fatty liver disease, with gender differences in susceptibility to weight gain and metabolic dysfunction. Pair-feeding of Thm1 conditional knock-out mice relative to control littermates prevented the obesity and related disorders, indicating that hyperphagia caused the obese phenotype. Thm1 ablation resulted in increased localization of adenylyl cyclase III in primary cilia that were shortened, with bulbous distal tips on neurons of the hypothalamic arcuate nucleus, an integrative center for signals that regulate feeding and activity. In pre-obese Thm1 conditional knock-out mice, expression of anorexogenic pro-opiomelanocortin (Pomc) was decreased by 50% in the arcuate nucleus, which likely caused the hyperphagia. Fasting of Thm1 conditional knock-out mice did not alter Pomc nor orexogenic agouti-related neuropeptide (Agrp) expression, suggesting impaired sensing of changes in peripheral signals. Together, these data indicate that the Thm1-mutant ciliary defect diminishes sensitivity to feeding signals, which alters appetite regulation and leads to hyperphagia, obesity and metabolic disease. PMID:27482817

Dysfunction of intraflagellar transport-A causes hyperphagia-induced obesity and metabolic syndrome.

PubMed

Jacobs, Damon T; Silva, Luciane M; Allard, Bailey A; Schonfeld, Michael P; Chatterjee, Anindita; Talbott, George C; Beier, David R; Tran, Pamela V

2016-07-01

Primary cilia extend from the plasma membrane of most vertebrate cells and mediate signaling pathways. Ciliary dysfunction underlies ciliopathies, which are genetic syndromes that manifest multiple clinical features, including renal cystic disease and obesity. THM1 (also termed TTC21B or IFT139) encodes a component of the intraflagellar transport-A complex and mutations in THM1 have been identified in 5% of individuals with ciliopathies. Consistent with this, deletion of murine Thm1 during late embryonic development results in cystic kidney disease. Here, we report that deletion of murine Thm1 during adulthood results in obesity, diabetes, hypertension and fatty liver disease, with gender differences in susceptibility to weight gain and metabolic dysfunction. Pair-feeding of Thm1 conditional knock-out mice relative to control littermates prevented the obesity and related disorders, indicating that hyperphagia caused the obese phenotype. Thm1 ablation resulted in increased localization of adenylyl cyclase III in primary cilia that were shortened, with bulbous distal tips on neurons of the hypothalamic arcuate nucleus, an integrative center for signals that regulate feeding and activity. In pre-obese Thm1 conditional knock-out mice, expression of anorexogenic pro-opiomelanocortin (Pomc) was decreased by 50% in the arcuate nucleus, which likely caused the hyperphagia. Fasting of Thm1 conditional knock-out mice did not alter Pomc nor orexogenic agouti-related neuropeptide (Agrp) expression, suggesting impaired sensing of changes in peripheral signals. Together, these data indicate that the Thm1-mutant ciliary defect diminishes sensitivity to feeding signals, which alters appetite regulation and leads to hyperphagia, obesity and metabolic disease. © 2016. Published by The Company of Biologists Ltd.

The melanocortins and melanin-concentrating hormone in the central regulation of feeding behavior and energy homeostasis.

PubMed

Nahon, Jean-Louis

2006-08-01

A number of different neuropeptides exert powerful concerted controls on feeding behavior and energy balance, most of them being produced in hypothalamic neuronal networks under stimulation by anabolic and catabolic peripheral hormones such as ghrelin and leptin, respectively. These peptide-expressing neurons interconnect extensively to integrate the multiple opposing signals that mediate changes in energy expenditure. In the present review I have summarized our current knowledge about two key peptidic systems involved in regulating appetite and energy homeostasis, the melanocortin system (alpha-MSH, agouti and Agouti-related peptides, MC receptors and mahogany protein) and the melanin-concentrating hormone system (proMCH-derived peptides and MCH receptors) that contribute to satiety and feeding-initiation, respectively, with concurrent effects on energy expenditure. I have focused particularly on recent data concerning transgenic mice and the ongoing development of MC/MCH receptor antagonists/agonists that may represent promising drugs to treat human eating disorders on both sides of the energy balance (anorexia, obesity).

Phylogeny of lion tamarins (Leontopithecus spp) based on interphotoreceptor retinol binding protein intron sequences.

PubMed

Mundy, N I; Kelly, J

2001-05-01

The evolutionary relationships of the lion tamarins (Leontopithecus) were investigated using nuclear interphotoreceptor retinol binding protein (IRBP) intron sequences. Phylogenetic reconstructions strongly support the monophyly of the genus, and a sister relationship between the golden lion tamarin, Leontopithecus rosalia, and the black lion tamarin, L. chrysopygus, to the exclusion of the golden-headed lion tamarin, L. chrysomelas. The most parsimonious evolutionary reconstruction suggests that the ancestral lion tamarin and the common ancestor of L. rosalia and L. chrysopygus had predominantly black coats. This reconstruction is not consistent with a theory of orthogenetic evolution of coat color that was based on coat color evolution in marmosets and tamarins. An alternative reconstruction that is consistent with metachromism requires that ancestral lion tamarins had agouti hairs. Copyright 2001 Wiley-Liss, Inc.

ABA, porphyrins and plant TSPO-related protein.

PubMed

Guillaumot, Damien; Guillon, Stéphanie; Morsomme, Pierre; Batoko, Henri

2009-11-01

We have shown that, unexpectedly, AtTSPO (Arabidopsis thaliana TSPO-related protein) is an endoplasmic reticulum and Golgi-localized membrane protein in plant cells.(1) This localization contrasts with that of mammalian 18-kDa translocator protein (at least for the mostly studied isoform, 18-kDa TSPO), a mitochondrial outer membrane protein (reviewed in ref. 2). Whereas the potential functions of 18-kDa TSPO are well documented, involved mainly in mitochondrial physiology,(2) and its interest as drugs target is been explored,(3) the roles of TSPO-related proteins in plant growth and development are yet to be specified. AtTSPO is expressed in dry seeds and can be induced in vegetative tissues by osmotic and salt stress or abscisic acid (ABA) treatment. Moreover, it was shown that the ABA-dependent induction is transient, and that boosting tetrapyrroles biosynthesis through 5-aminolevulinic acid (ALA) feeding enhanced downregulation of AtTSPO, suggesting an inherent post-translational regulation mechanism also involving ABA and likely porphyrins. We present additional evidence that ABA can help stabilize constitutively expressed AtTSPO and that ALA feeding to knockout mutant seeds, induces substantial germination delay. Here we discuss the possible link between ABA and tetrapyrroles in AtTSPO expression and post-translational regulation.

Effect of dietary carbohydrate source on the development of obesity in agouti transgenic mice.

PubMed

Morris, Kristin L; Zemel, Michael B

2005-01-01

Our objective was to evaluate the effects of a qualitative change in dietary carbohydrate source on body weight and adiposity in a rodent model of diet-induced obesity. We evaluated the effects of high-fat diets (basal) varying in carbohydrate source in aP2-agouti transgenic mice. In the ad libitum study, animals were given free access to the basal diet or one of four test diets for 6 weeks. In two of the diets, dietary carbohydrate was derived from a single source: mung bean noodles (MUNG) or rolled oats (ROLL). The remaining diets were designed to mimic commercially available instant oatmeal with added sugar (IO-S) or flavored instant oatmeal (IO-F). In the energy-restricted study, animals were given ad libitum access to the basal diet for 6 weeks. Subsequently, animals were assigned to one of six treatment groups for 6 weeks. One group was continued on the basal diet ad libitum. The remaining groups were maintained with energy restriction (70% ad libitum) on either the basal, MUNG, ROLL, IO-S, or IO-F diet. Subcutaneous fat pad mass was significantly higher (p<0.05) in the energy-restricted basal and IO-S groups compared with the energy-restricted ROLL diet. Similarly, visceral fat pad mass was significantly lower with ROLL and MUNG diets (p<0.05 for both) compared with basal and IO-S diets, and the insulin:glucose ratio was reduced (by 23% to 34%, p<0.05) in these two diets compared with all others. In ad libitum-fed animals, liver fatty acid synthase expression was 43% to 62% lower (p<0.05) with ROLL and MUNG diets compared with all others. These data suggest that a qualitative change in dietary carbohydrate source modulates body weight and adiposity.

Gene expression analysis indicates CB1 receptor upregulation in the hippocampus and neurotoxic effects in the frontal cortex 3 weeks after single-dose MDMA administration in Dark Agouti rats

PubMed Central

2013-01-01

Background 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") is a widely used recreational drug known to impair cognitive functions on the long-run. Both hippocampal and frontal cortical regions have well established roles in behavior, memory formation and other cognitive tasks and damage of these regions is associated with altered behavior and cognitive functions, impairments frequently described in heavy MDMA users. The aim of this study was to examine the hippocampus, frontal cortex and dorsal raphe of Dark Agouti rats with gene expression arrays (Illumina RatRef bead arrays) looking for possible mechanisms and new candidates contributing to the effects of a single dose of MDMA (15 mg/kg) 3 weeks earlier. Results The number of differentially expressed genes in the hippocampus, frontal cortex and the dorsal raphe were 481, 155, and 15, respectively. Gene set enrichment analysis of the microarray data revealed reduced expression of 'memory’ and 'cognition’, 'dendrite development’ and 'regulation of synaptic plasticity’ gene sets in the hippocampus, parallel to the upregulation of the CB1 cannabinoid- and Epha4, Epha5, Epha6 ephrin receptors. Downregulated gene sets in the frontal cortex were related to protein synthesis, chromatin organization, transmembrane transport processes, while 'dendrite development’, 'regulation of synaptic plasticity’ and 'positive regulation of synapse assembly’ gene sets were upregulated. Changes in the dorsal raphe region were mild and in most cases not significant. Conclusion The present data raise the possibility of new synapse formation/synaptic reorganization in the frontal cortex three weeks after a single neurotoxic dose of MDMA. In contrast, a prolonged depression of new neurite formation in the hippocampus is suggested by the data, which underlines the particular vulnerability of this brain region after the drug treatment. Finally, our results also suggest the substantial contribution of CB1 receptor and

Current overview of allergens of plant pathogenesis related protein families.

PubMed

Sinha, Mau; Singh, Rashmi Prabha; Kushwaha, Gajraj Singh; Iqbal, Naseer; Singh, Avinash; Kaushik, Sanket; Kaur, Punit; Sharma, Sujata; Singh, Tej P

2014-01-01

Pathogenesis related (PR) proteins are one of the major sources of plant derived allergens. These proteins are induced by the plants as a defense response system in stress conditions like microbial and insect infections, wounding, exposure to harsh chemicals, and atmospheric conditions. However, some plant tissues that are more exposed to environmental conditions like UV irradiation and insect or fungal attacks express these proteins constitutively. These proteins are mostly resistant to proteases and most of them show considerable stability at low pH. Many of these plant pathogenesis related proteins are found to act as food allergens, latex allergens, and pollen allergens. Proteins having similar amino acid sequences among the members of PR proteins may be responsible for cross-reactivity among allergens from diverse plants. This review analyzes the different pathogenesis related protein families that have been reported as allergens. Proteins of these families have been characterized in regard to their biological functions, amino acid sequence, and cross-reactivity. The three-dimensional structures of some of these allergens have also been evaluated to elucidate the antigenic determinants of these molecules and to explain the cross-reactivity among the various allergens.

Resource for structure related information on transmembrane proteins

NASA Astrophysics Data System (ADS)

Tusnády, Gábor E.; Simon, István

Transmembrane proteins are involved in a wide variety of vital biological processes including transport of water-soluble molecules, flow of information and energy production. Despite significant efforts to determine the structures of these proteins, only a few thousand solved structures are known so far. Here, we review the various resources for structure-related information on these types of proteins ranging from the 3D structure to the topology and from the up-to-date databases to the various Internet sites and servers dealing with structure prediction and structure analysis. Abbreviations: 3D, three dimensional; PDB, Protein Data Bank; TMP, transmembrane protein.

Structural studies of human glioma pathogenesis-related protein 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asojo, Oluwatoyin A., E-mail: oasojo@unmc.edu; Koski, Raymond A.; Bonafé, Nathalie

2011-10-01

Structural analysis of a truncated soluble domain of human glioma pathogenesis-related protein 1, a membrane protein implicated in the proliferation of aggressive brain cancer, is presented. Human glioma pathogenesis-related protein 1 (GLIPR1) is a membrane protein that is highly upregulated in brain cancers but is barely detectable in normal brain tissue. GLIPR1 is composed of a signal peptide that directs its secretion, a conserved cysteine-rich CAP (cysteine-rich secretory proteins, antigen 5 and pathogenesis-related 1 proteins) domain and a transmembrane domain. GLIPR1 is currently being investigated as a candidate for prostate cancer gene therapy and for glioblastoma targeted therapy. Crystal structuresmore » of a truncated soluble domain of the human GLIPR1 protein (sGLIPR1) solved by molecular replacement using a truncated polyalanine search model of the CAP domain of stecrisp, a snake-venom cysteine-rich secretory protein (CRISP), are presented. The correct molecular-replacement solution could only be obtained by removing all loops from the search model. The native structure was refined to 1.85 Å resolution and that of a Zn{sup 2+} complex was refined to 2.2 Å resolution. The latter structure revealed that the putative binding cavity coordinates Zn{sup 2+} similarly to snake-venom CRISPs, which are involved in Zn{sup 2+}-dependent mechanisms of inflammatory modulation. Both sGLIPR1 structures have extensive flexible loop/turn regions and unique charge distributions that were not observed in any of the previously reported CAP protein structures. A model is also proposed for the structure of full-length membrane-bound GLIPR1.« less

Prediction of the Ebola Virus Infection Related Human Genes Using Protein-Protein Interaction Network.

PubMed

Cao, HuanHuan; Zhang, YuHang; Zhao, Jia; Zhu, Liucun; Wang, Yi; Li, JiaRui; Feng, Yuan-Ming; Zhang, Ning

2017-01-01

Ebola hemorrhagic fever (EHF) is caused by Ebola virus (EBOV). It is reported that human could be infected by EBOV with a high fatality rate. However, association factors between EBOV and host still tend to be ambiguous. According to the "guilt by association" (GBA) principle, proteins interacting with each other are very likely to function similarly or the same. Based on this assumption, we tried to obtain EBOV infection-related human genes in a protein-protein interaction network using Dijkstra algorithm. We hope it could contribute to the discovery of novel effective treatments. Finally, 15 genes were selected as potential EBOV infection-related human genes. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The selectivity of protein-imprinted gels and its relation to protein properties: A computer simulation study.

PubMed

Yankelov, Rami; Yungerman, Irena; Srebnik, Simcha

2017-07-01

Polymer-based protein recognition systems have enormous potential within clinical and diagnostic fields due to their reusability, biocompatibility, ease of manufacturing, and potential specificity. Imprinted polymer matrices have been extensively studied and applied as a simple technique for creating artificial polymer-based recognition gels for a target molecule. Although this technique has been proven effective when targeting small molecules (such as drugs), imprinting of proteins have so far resulted in materials with limited selectivity due to the large molecular size of the protein and aqueous environment. Using coarse-grained molecular simulation, we investigate the relation between protein makeup, polymer properties, and the selectivity of imprinted gels. Nonspecific binding that results in poor selectivity is shown to be strongly dependent on surface chemistry of the template and competitor proteins as well as on polymer chemistry. Residence time distributions of proteins diffusing within the gels provide a transparent picture of the relation between polymer constitution, protein properties, and the nonspecific interactions with the imprinted gel. The pronounced effect of protein surface chemistry on imprinted gel specificity is demonstrated. Copyright © 2017 John Wiley & Sons, Ltd.

Liquid and Frozen Storage of Agouti (Dasyprocta leporina) Semen Extended with UHT Milk, Unpasteurized Coconut Water, and Pasteurized Coconut Water

PubMed Central

Mollineau, W. M.; Adogwa, A. O.; Garcia, G. W.

2011-01-01

This study evaluated the effects of semen extension and storage on forward progressive motility % (FPM%) in agouti semen. Three extenders were used; sterilized whole cow's milk (UHT Milk), unpasteurized (CW) and pasteurized coconut water (PCW), and diluted to 50, 100, 150, and 200 × 106 spermatozoa/ml. Experiment 1: 200 ejaculates were extended for liquid storage at 5∘C and evaluated every day for 5 days to determine FPM% and its rate of deterioration. Experiment 2: 150 ejaculates were extended for storage as frozen pellets in liquid nitrogen at −195∘C, thawed at 30∘ to 70∘C for 20 to 50 seconds after 5 days and evaluated for FPM% and its rate of deterioration. Samples treated with UHT milk and storage at concentrations of 100 × 106 spermatozoa/ml produced the highest means for FPM% and the slowest rates of deterioration during Experiment 1. During Experiment 2 samples thawed at 30∘C for 20 seconds exhibited the highest means for FPM% (12.18 ± 1.33%), 85% rate of deterioration. However, samples were incompletely thawed. This was attributed to the diameter of the frozen pellets which was 1 cm. It was concluded that the liquid storage method was better for short term storage. PMID:20871831

Diet-induced obesity causes ghrelin resistance in reward processing tasks.

PubMed

Lockie, Sarah H; Dinan, Tara; Lawrence, Andrew J; Spencer, Sarah J; Andrews, Zane B

2015-12-01

Diet-induced obesity (DIO) causes ghrelin resistance in hypothalamic Agouti-related peptide (AgRP) neurons. However, ghrelin promotes feeding through actions at both the hypothalamus and mesolimbic dopamine reward pathways. Therefore, we hypothesized that DIO would also establish ghrelin resistance in the ventral tegmental area (VTA), a major site of dopaminergic cell bodies important in reward processing. We observed reduced sucrose and saccharin consumption in Ghrelin KO vs Ghrelin WT mice. Moreover, DIO reduced saccharin consumption relative to chow-fed controls. These data suggest that the deletion of ghrelin and high fat diet both cause anhedonia. To assess if these are causally related, we tested whether DIO caused ghrelin resistance in a classic model of drug reward, conditioned place preference (CPP). Chow or high fat diet (HFD) mice were conditioned with ghrelin (1mg/kg in 10ml/kg ip) in the presence or absence of food in the conditioning chamber. We observed a CPP to ghrelin in chow-fed mice but not in HFD-fed mice. HFD-fed mice still showed a CPP for cocaine (20mg/kg), indicating that they maintained the ability to develop conditioned behaviour. The absence of food availability during ghrelin conditioning sessions induced a conditioned place aversion, an effect that was still present in both chow and HFD mice. Bilateral intra-VTA ghrelin injection (0.33μg/μl in 0.5μl) robustly increased feeding in both chow-fed and high fat diet (HFD)-fed mice; however, this was correlated with body weight only in the chow-fed mice. Our results suggest that DIO causes ghrelin resistance albeit not directly in the VTA. We suggest there is impaired ghrelin sensitivity in upstream pathways regulating reward pathways, highlighting a functional role for ghrelin linking appropriate metabolic sensing with reward processing. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Nasal protein profiles in work-related asthma caused by different exposures.

PubMed

Suojalehto, H; Lindström, I; Wolff, H; Puustinen, A

2018-03-01

The mechanisms of work-related asthma (WRA) are incompletely delineated. Nasal cell samples may be informative about processes in the lower airways. Our aim was to determine the nasal protein expression profiles of WRA caused by different kind of exposures. We collected nasal brush samples from 82 nonsmoking participants, including healthy controls and WRA patients exposed to (i) protein allergens, (ii) isocyanates and (iii) welding fumes the day after relevant exposure. The proteome changes in samples were analysed by two-dimensional difference gel electrophoresis, and the differentially regulated proteins found were identified by mass spectrometry. Immunological comparison was carried out using Western blot. We detected an average of 2500 spots per protein gel. Altogether, 228 protein spots were chosen for identification, yielding 77 different proteins. Compared to the controls, exposure to protein allergens had the largest effects on the proteome. Hierarchical clustering revealed that protein allergen- and isocyanate-related asthma had similar profiles, whereas asthma related to welding fumes differed. The highly overrepresented functional categories in the asthma groups were defence response, protease inhibitor activity, inflammatory and calcium signalling, complement activation and cellular response to oxidative stress. Immunological analysis confirmed the found abundance differences in galectin 10 and protein S100-A9 between the groups. Work-related asthma patients exposed to protein allergens and isocyanates elicit similar nasal proteome responses and the profiles of welders and healthy controls were alike. Revealed biological activities of the protein expression changes are associated with allergic inflammation and asthma. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

Proteomic Analysis of Sauvignon Blanc Grape Skin, Pulp and Seed and Relative Quantification of Pathogenesis-Related Proteins.

PubMed

Tian, Bin; Harrison, Roland; Morton, James; Deb-Choudhury, Santanu

2015-01-01

Thaumatin-like proteins (TLPs) and chitinases are the main constituents of so-called protein hazes which can form in finished white wine and which is a great concern of winemakers. These soluble pathogenesis-related (PR) proteins are extracted from grape berries. However, their distribution in different grape tissues is not well documented. In this study, proteins were first separately extracted from the skin, pulp and seed of Sauvignon Blanc grapes, followed by trypsin digestion and analysis by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Proteins identified included 75 proteins from Sauvignon Blanc grape skin, 63 from grape pulp and 35 from grape seed, mostly functionally classified as associated with metabolism and energy. Some were present exclusively in specific grape tissues; for example, proteins involved in photosynthesis were only detected in grape skin and proteins found in alcoholic fermentation were only detected in grape pulp. Moreover, proteins identified in grape seed were less diverse than those identified in grape skin and pulp. TLPs and chitinases were identified in both Sauvignon Blanc grape skin and pulp, but not in the seed. To relatively quantify the PR proteins, the protein extracts of grape tissues were seperated by HPLC first and then analysed by SDS-PAGE. The results showed that the protein fractions eluted at 9.3 min and 19.2 min under the chromatographic conditions of this study confirmed that these corresponded to TLPs and chitinases seperately. Thus, the relative quantification of TLPs and chitinases in protein extracts was carried out by comparing the area of corresponding peaks against the area of a thamautin standard. The results presented in this study clearly demonstrated the distribution of haze-forming PR proteins in grape berries, and the relative quantification of TLPs and chitinases could be applied in fast tracking of changes in PR proteins during grape growth and determination of PR

Proteomic Analysis of Sauvignon Blanc Grape Skin, Pulp and Seed and Relative Quantification of Pathogenesis-Related Proteins

PubMed Central

Tian, Bin; Harrison, Roland; Morton, James; Deb-Choudhury, Santanu

2015-01-01

Thaumatin-like proteins (TLPs) and chitinases are the main constituents of so-called protein hazes which can form in finished white wine and which is a great concern of winemakers. These soluble pathogenesis-related (PR) proteins are extracted from grape berries. However, their distribution in different grape tissues is not well documented. In this study, proteins were first separately extracted from the skin, pulp and seed of Sauvignon Blanc grapes, followed by trypsin digestion and analysis by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Proteins identified included 75 proteins from Sauvignon Blanc grape skin, 63 from grape pulp and 35 from grape seed, mostly functionally classified as associated with metabolism and energy. Some were present exclusively in specific grape tissues; for example, proteins involved in photosynthesis were only detected in grape skin and proteins found in alcoholic fermentation were only detected in grape pulp. Moreover, proteins identified in grape seed were less diverse than those identified in grape skin and pulp. TLPs and chitinases were identified in both Sauvignon Blanc grape skin and pulp, but not in the seed. To relatively quantify the PR proteins, the protein extracts of grape tissues were seperated by HPLC first and then analysed by SDS-PAGE. The results showed that the protein fractions eluted at 9.3 min and 19.2 min under the chromatographic conditions of this study confirmed that these corresponded to TLPs and chitinases seperately. Thus, the relative quantification of TLPs and chitinases in protein extracts was carried out by comparing the area of corresponding peaks against the area of a thamautin standard. The results presented in this study clearly demonstrated the distribution of haze-forming PR proteins in grape berries, and the relative quantification of TLPs and chitinases could be applied in fast tracking of changes in PR proteins during grape growth and determination of PR

Quantitative Evaluation of Serum Proteins Uncovers a Protein Signature Related to Maturity-Onset Diabetes of the Young (MODY).

PubMed

Tuerxunyiming, Muhadasi; Xian, Feng; Zi, Jin; Yimamu, Yilihamujiang; Abuduwayite, Reshalaiti; Ren, Yan; Li, Qidan; Abudula, Abulizi; Liu, SiQi; Mohemaiti, Patamu

2018-01-05

Maturity-onset diabetes of the young (MODY) is an inherited monogenic type of diabetes. Genetic mutations in MODY often cause nonsynonymous changes that directly lead to the functional distortion of proteins and the pathological consequences. Herein, we proposed that the inherited mutations found in a MODY family could cause a disturbance of protein abundance, specifically in serum. The serum samples were collected from a Uyghur MODY family through three generations, and the serum proteins after depletion treatment were examined by quantitative proteomics to characterize the MODY-related serum proteins followed by verification using target quantification of proteomics. A total of 32 serum proteins were preliminarily identified as the MODY-related. Further verification test toward the individual samples demonstrated the 12 candidates with the significantly different abundance in the MODY patients. A comparison of the 12 proteins among the sera of type 1 diabetes, type 2 diabetes, MODY, and healthy subjects was conducted and revealed a protein signature related with MODY composed of the serum proteins such as SERPINA7, APOC4, LPA, C6, and F5.

Carboxyl methylation of Ras-related proteins during signal transduction in neutrophils.

PubMed

Philips, M R; Pillinger, M H; Staud, R; Volker, C; Rosenfeld, M G; Weissmann, G; Stock, J B

1993-02-12

In human neutrophils, as in other cell types, Ras-related guanosine triphosphate-binding proteins are directed toward their regulatory targets in membranes by a series of posttranslational modifications that include methyl esterification of a carboxyl-terminal prenylcysteine residue. In intact cells and in a reconstituted in vitro system, the amount of carboxyl methylation of Ras-related proteins increased in response to the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (FMLP). Activation of Ras-related proteins by guanosine-5'-O-(3-thiotriphosphate) had a similar effect and induced translocation of p22rac2 from cytosol to plasma membrane. Inhibitors of prenylcysteine carboxyl methylation effectively blocked neutrophil responses to FMLP. These findings suggest a direct link between receptor-mediated signal transduction and the carboxyl methylation of Ras-related proteins.

[Nucleotidic variations of two captive groups of tepezcuintle, Agouti paca (Rodentia: Agoutidae), from two sites in Yucatan, Mexico].

PubMed

Montes-Pérez, Rubén C; García, Adán W Echeverría; Castro, Jorge Zavala; Gamboa, Militza G Alfaro

2006-09-01

The objective of this work was to estimate the nucleotidic variation between two groups of tepezcuintles (Agouti paca) from the states of Campeche and Quintana Roo, Mexico and within members of each group. Blood samples were collected from eleven A. paca kept in captivity. DNA from leukocytic cells was used for Ramdom Amplification of DNA Polimorphism (RAPD). The primers three 5'-d(GTAGACCCGT)- 3' and six 5'-d(CCCGTCAGCA)- 3' were selected from de Amersham kit (Ready.To.Go. RAPD Analysis Beads, Amersham Pharmacia Biotech), because they produced an adequate number of bands. The electrophoretic pattern of bands obtained was analyzed using software for phylogenetic analysis based on the UPGMA method, to estimate the units of nucleotidic variation. The phylogenetic tree obtained with primer three reveals a dicotomic grouping between the animals from both states in the Yucatan Peninsula showing a divergent value of 1.983 nucleotides per hundred. Animals from Quintana Roo show a grouping with primer six; an additional grouping was observed with animals from Campeche. Nucleotidic variation between both groups was 2.118 nucleotides per hundred. The nucleotidic variation for the two primers within the groups from both states, showed fluctuating values from 0.46 to 1.68 nucleotides per hundred, which indicates that nucleotidic variation between the two groups of animals is around two nucleotides per hundred and, within the groups, less than 1.7 nucleotides per hundred.

Hunger neurons drive feeding through a sustained, positive reinforcement signal.

PubMed

Chen, Yiming; Lin, Yen-Chu; Zimmerman, Christopher A; Essner, Rachel A; Knight, Zachary A

2016-08-24

The neural mechanisms underlying hunger are poorly understood. AgRP neurons are activated by energy deficit and promote voracious food consumption, suggesting these cells may supply the fundamental hunger drive that motivates feeding. However recent in vivo recording experiments revealed that AgRP neurons are inhibited within seconds by the sensory detection of food, raising the question of how these cells can promote feeding at all. Here we resolve this paradox by showing that brief optogenetic stimulation of AgRP neurons before food availability promotes intense appetitive and consummatory behaviors that persist for tens of minutes in the absence of continued AgRP neuron activation. We show that these sustained behavioral responses are mediated by a long-lasting potentiation of the rewarding properties of food and that AgRP neuron activity is positively reinforcing. These findings reveal that hunger neurons drive feeding by transmitting a positive valence signal that triggers a stable transition between behavioral states.

Deconstruction of a neural circuit for hunger.

PubMed

Atasoy, Deniz; Betley, J Nicholas; Su, Helen H; Sternson, Scott M

2012-08-09

Hunger is a complex behavioural state that elicits intense food seeking and consumption. These behaviours are rapidly recapitulated by activation of starvation-sensitive AGRP neurons, which present an entry point for reverse-engineering neural circuits for hunger. Here we mapped synaptic interactions of AGRP neurons with multiple cell populations in mice and probed the contribution of these distinct circuits to feeding behaviour using optogenetic and pharmacogenetic techniques. An inhibitory circuit with paraventricular hypothalamus (PVH) neurons substantially accounted for acute AGRP neuron-evoked eating, whereas two other prominent circuits were insufficient. Within the PVH, we found that AGRP neurons target and inhibit oxytocin neurons, a small population that is selectively lost in Prader-Willi syndrome, a condition involving insatiable hunger. By developing strategies for evaluating molecularly defined circuits, we show that AGRP neuron suppression of oxytocin neurons is critical for evoked feeding. These experiments reveal a new neural circuit that regulates hunger state and pathways associated with overeating disorders.

Deconstruction of a neural circuit for hunger

PubMed Central

Atasoy, Deniz; Betley, J. Nicholas; Su, Helen H.; Sternson, Scott M.

2012-01-01

Hunger is a complex behavioural state that elicits intense food seeking and consumption. These behaviours are rapidly recapitulated by activation of starvation-sensitive AGRP neurons, which present an entry point for reverse-engineering neural circuits for hunger. We mapped synaptic interactions of AGRP neurons with multiple cell populations and probed the contribution of these distinct circuits to feeding behaviour using optogenetic and pharmacogenetic techniques. An inhibitory circuit with paraventricular hypothalamus (PVH) neurons substantially accounted for acute AGRP neuron-evoked eating, whereas two other prominent circuits were insufficient. Within the PVH, we found that AGRP neurons target and inhibit oxytocin neurons, a small population that is selectively lost in Prader-Willi syndrome, a condition involving insatiable hunger. By developing strategies for evaluating molecularly-defined circuits, we show that AGRP neuron suppression of oxytocin neurons is critical for evoked feeding. These experiments reveal a new neural circuit that regulates hunger state and pathways associated with overeating disorders. PMID:22801496

Mineral-related proteins of sea urchin teeth: Lytechinus variegatus.

PubMed

Veis, Arthur; Barss, Joseph; Dahl, Thomas; Rahima, Mohammed; Stock, Stuart

2002-12-01

Sea urchins have a set of five continuously growing teeth, each of which has a very complex structure. The mineral phase is calcite of varying Mg content, depending on the location within a tooth. The calcium carbonate is present in amorphous, plate-like and rod-like forms. It has been hypothesized that the mineral deposition is a matrix-mediated process, similar to that in vertebrate bone and tooth, wherein certain macromolecules within the organic matrix of the mineralized tissue play an important role in nucleating and controlling the growth habit of the mineral crystals. It has also been hypothesized that the mineral-related macromolecules involved in urchin teeth might bear a direct evolutionary relationship to those of the vertebrate tooth. These hypotheses are explored here by examining the pattern and nature of the mineral distribution, using microCT of intact teeth, and the nature of the mineral-related matrix proteins. The mineral-related proteins were extracted and fractionated by anion exchange chromatography. The relationship of certain fractions to vertebrate matrix proteins was established by immunoblots using antibodies to vertebrate tooth proteins. The antibodies were then used to localize the proteins within the teeth, by immunocytochemistry and histology with specific staining. The microCT data on mineral density has been correlated with the patterns of cellular migration and mineral deposition within the tooth as it grows. It appears that the mineralization within the different tooth compartments might take place under the influence of different matrix proteins. Further studies are in progress to more completely describe the vertebrate-invertebrate immunologically cross-reactive proteins of the urchin teeth. Copyright 2002 Wiley-Liss, Inc.

A transthyretin-related protein is functionally expressed in Herbaspirillum seropedicae.

PubMed

Matiollo, Camila; Vernal, Javier; Ecco, Gabriela; Bertoldo, Jean Borges; Razzera, Guilherme; de Souza, Emanuel M; Pedrosa, Fábio O; Terenzi, Hernán

2009-10-02

Transthyretin-related proteins (TRPs) constitute a family of proteins structurally related to transthyretin (TTR) and are found in a large range of bacterial, fungal, plant, invertebrate, and vertebrate species. However, it was recently recognized that both prokaryotic and eukaryotic members of this family are not functionally related to transthyretins. TRPs are in fact involved in the purine catabolic pathway and function as hydroxyisourate hydrolases. An open reading frame encoding a protein similar to the Escherichia coli TRP was identified in Herbaspirillum seropedicae genome (Hs_TRP). It was cloned, overexpressed in E. coli, and purified to homogeneity. Mass spectrometry data confirmed the identity of this protein, and circular dichroism spectrum indicated a predominance of beta-sheet structure, as expected for a TRP. We have demonstrated that Hs_TRP is a 5-hydroxyisourate hydrolase and by site-directed mutagenesis the importance of three conserved catalytic residues for Hs_TRP activity was further confirmed. The production of large quantities of this recombinant protein opens up the possibility of obtaining its 3D-structure and will help further investigations into purine catabolism.

Exploration of Spinal Cord Aging-Related Proteins Using a Proteomics Approach.

PubMed

Kamiya, Koshiro; Furuya, Takeo; Hashimoto, Masayuki; Mannoji, Chikato; Inada, Taigo; Ota, Mitsutoshi; Maki, Satoshi; Ijima, Yasushi; Saito, Junya; Kitamura, Mitsuhiro; Ohtori, Seiji; Orita, Sumihisa; Inage, Kazuhide; Yamazaki, Masashi; Koda, Masao

2017-01-01

How aging affects the spinal cord at a molecular level is unclear. The aim of this study was to explore spinal cord aging-related proteins that may be involved in pathological mechanisms of age-related changes in the spinal cord. Spinal cords of 2-year-old and 8-week-old female Sprague-Dawley rats were dissected from the animals. Protein samples were subjected to 2-dimentional polyacrylamide gel electrophoresis followed by mass spectrometry. Screened proteins were further investigated with immunohistochemistry and Western blotting. Among the screened proteins, we selected α-crystallin B-subunit (αB-crystallin) and peripherin for further investigation because these proteins were previously reported to be related to central nervous system pathologies. Immunohistochemistry and Western blotting revealed significant upregulation of αB-crystallin and peripherin expression in aged rat spinal cord. Further exploration is needed to elucidate the precise mechanism and potential role of these upregulated proteins in spinal cord aging processes.

Exploration of Spinal Cord Aging–Related Proteins Using a Proteomics Approach

PubMed Central

Kamiya, Koshiro; Furuya, Takeo; Hashimoto, Masayuki; Mannoji, Chikato; Inada, Taigo; Ota, Mitsutoshi; Maki, Satoshi; Ijima, Yasushi; Saito, Junya; Kitamura, Mitsuhiro; Ohtori, Seiji; Orita, Sumihisa; Inage, Kazuhide; Yamazaki, Masashi; Koda, Masao

2017-01-01

How aging affects the spinal cord at a molecular level is unclear. The aim of this study was to explore spinal cord aging–related proteins that may be involved in pathological mechanisms of age-related changes in the spinal cord. Spinal cords of 2-year-old and 8-week-old female Sprague-Dawley rats were dissected from the animals. Protein samples were subjected to 2-dimentional polyacrylamide gel electrophoresis followed by mass spectrometry. Screened proteins were further investigated with immunohistochemistry and Western blotting. Among the screened proteins, we selected α-crystallin B-subunit (αB-crystallin) and peripherin for further investigation because these proteins were previously reported to be related to central nervous system pathologies. Immunohistochemistry and Western blotting revealed significant upregulation of αB-crystallin and peripherin expression in aged rat spinal cord. Further exploration is needed to elucidate the precise mechanism and potential role of these upregulated proteins in spinal cord aging processes. PMID:28634429

Genetic Association Analysis of 30 Genes Related to Obesity in a European American Population

PubMed Central

Li, Peng; Tiwari, Hemant K.; Lin, Wan-Yu; Allison, David B.; Chung, Wendy K.; Leibel, Rudolph L.; Yi, Nengjun; Liu, Nianjun

2013-01-01

Objective Obesity, which is frequently associated with diabetes, hypertension, and cardiovascular diseases, is primarily the result of a net excess of caloric intake over energy expenditure. Human obesity is highly heritable, but the specific genes mediating susceptibility in non-syndromic obesity remain unclear. We tested candidate genes in pathways related to food intake and energy expenditure for association with body mass index (BMI). Methods We re-analyzed 355 common genetic variants of 30 candidate genes in 7 molecular pathways related to obesity in 1,982 unrelated European Americans from the New York Health Project. Data were analyzed by using a Bayesian hierarchical generalized linear model. The BMIs were log-transformed and then adjusted for covariates including age, age2, gender, and diabetes status. The single nucleotide polymorphisms (SNPs) were modeled as additive effects. Results With the stipulated adjustments, nine SNPs in eight genes were significantly associated with BMI: GHRL (rs35683), AGRP (rs5030980), CPE (rs1946816 and rs4481204), GLP1R (rs2268641), HTR2A (rs912127), NPY5R (Y5R1c52), SOCS3 (rs4969170), and STAT3 (rs4796793). We also found a gender-by-SNP interaction (rs1745837 in HTR2A), which indicated that variants in the gene HTR2A had a stronger association with BMI in males. In addition, NPY1R was detected as having a significant gene effect even though none of the SNPs in this gene was significant. Conclusion Variations in genes AGRP, CPE, GHRL, GLP1R, HTR2A, NPY1R, NPY5R, SOCS3, and STAT3 showed modest associations with BMI in European Americans. The pathways in which these genes participate regulate energy intake and thus these associations are mechanistically plausible in this context. PMID:23900445

The pathogen-related yeast protein Pry1, a member of the CAP protein superfamily, is a fatty acid-binding protein

PubMed Central

Darwiche, Rabih; Mène-Saffrané, Laurent; Gfeller, David; Asojo, Oluwatoyin A.; Schneiter, Roger

2017-01-01

Members of the CAP superfamily (cysteine-rich secretory proteins, antigen 5, and pathogenesis-related 1 proteins), also known as SCP superfamily (sperm-coating proteins), have been implicated in many physiological processes, including immune defenses, venom toxicity, and sperm maturation. Their mode of action, however, remains poorly understood. Three proteins of the CAP superfamily, Pry1, -2, and -3 (pathogen related in yeast), are encoded in the Saccharomyces cerevisiae genome. We have shown previously that Pry1 binds cholesterol in vitro and that Pry function is required for sterol secretion in yeast cells, indicating that members of this superfamily may generally bind sterols or related small hydrophobic compounds. On the other hand, tablysin-15, a CAP protein from the horsefly Tabanus yao, has been shown to bind leukotrienes and free fatty acids in vitro. Therefore, here we assessed whether the yeast Pry1 protein binds fatty acids. Computational modeling and site-directed mutagenesis indicated that the mode of fatty acid binding is conserved between tablysin-15 and Pry1. Pry1 bound fatty acids with micromolar affinity in vitro, and its function was essential for fatty acid export in cells lacking the acyl-CoA synthetases Faa1 and Faa4. Fatty acid binding of Pry1 is independent of its capacity to bind sterols, and the two sterol- and fatty acid-binding sites are nonoverlapping. These results indicate that some CAP family members, such as Pry1, can bind different lipids, particularly sterols and fatty acids, at distinct binding sites, suggesting that the CAP domain may serve as a stable, secreted protein domain that can accommodate multiple ligand-binding sites. PMID:28365570

Green tea polyphenols reduce body weight in rats by modulating obesity-related genes.

PubMed

Lu, Chuanwen; Zhu, Wenbin; Shen, Chwan-Li; Gao, Weimin

2012-01-01

Beneficial effects of green tea polyphenols (GTP) against obesity have been reported, however, the mechanism of this protection is not clear. Therefore, the objective of this study was to identify GTP-targeted genes in obesity using the high-fat-diet-induced obese rat model. A total of three groups (n = 12/group) of Sprague Dawley (SD) female rats were tested, including the control group (rats fed with low-fat diet), the HF group (rats fed with high-fat diet), and the HF+GTP group (rats fed with high-fat diet and GTP in drinking water). The HF group increased body weight as compared to the control group. Supplementation of GTP in the drinking water in the HF+GTP group reduced body weight as compared to the HF group. RNA from liver samples was extracted for gene expression analysis. A total of eighty-four genes related to obesity were analyzed using PCR array. Compared to the rats in the control group, the rats in the HF group had the expression levels of 12 genes with significant changes, including 3 orexigenic genes (Agrp, Ghrl, and Nr3c1); 7 anorectic genes (Apoa4, Cntf, Ghr, IL-1β, Ins1, Lepr, and Sort); and 2 genes that relate to energy expenditure (Adcyap1r1 and Adrb1). Intriguingly, the HF+GTP group restored the expression levels of these genes in the high-fat-induced obese rats. The protein expression levels of IL-1β and IL-6 in the serum samples from the control, HF, and HF+GTP groups confirmed the results of gene expression. Furthermore, the protein expression levels of superoxide dismutase-1 (SOD1) and catechol-O-methyltransferase (COMT) also showed GTP-regulated protective changes in this obese rat model. Collectively, this study revealed the beneficial effects of GTP on body weight via regulating obesity-related genes, anti-inflammation, anti-oxidant capacity, and estrogen-related actions in high-fat-induced obese rats.

Green Tea Polyphenols Reduce Body Weight in Rats by Modulating Obesity-Related Genes

PubMed Central

Lu, Chuanwen; Zhu, Wenbin; Shen, Chwan-Li; Gao, Weimin

2012-01-01

Beneficial effects of green tea polyphenols (GTP) against obesity have been reported, however, the mechanism of this protection is not clear. Therefore, the objective of this study was to identify GTP-targeted genes in obesity using the high-fat-diet-induced obese rat model. A total of three groups (n = 12/group) of Sprague Dawley (SD) female rats were tested, including the control group (rats fed with low-fat diet), the HF group (rats fed with high-fat diet), and the HF+GTP group (rats fed with high-fat diet and GTP in drinking water). The HF group increased body weight as compared to the control group. Supplementation of GTP in the drinking water in the HF+GTP group reduced body weight as compared to the HF group. RNA from liver samples was extracted for gene expression analysis. A total of eighty-four genes related to obesity were analyzed using PCR array. Compared to the rats in the control group, the rats in the HF group had the expression levels of 12 genes with significant changes, including 3 orexigenic genes (Agrp, Ghrl, and Nr3c1); 7 anorectic genes (Apoa4, Cntf, Ghr, IL-1β, Ins1, Lepr, and Sort); and 2 genes that relate to energy expenditure (Adcyap1r1 and Adrb1). Intriguingly, the HF+GTP group restored the expression levels of these genes in the high-fat-induced obese rats. The protein expression levels of IL-1β and IL-6 in the serum samples from the control, HF, and HF+GTP groups confirmed the results of gene expression. Furthermore, the protein expression levels of superoxide dismutase-1 (SOD1) and catechol-O-methyltransferase (COMT) also showed GTP-regulated protective changes in this obese rat model. Collectively, this study revealed the beneficial effects of GTP on body weight via regulating obesity-related genes, anti-inflammation, anti-oxidant capacity, and estrogen-related actions in high-fat-induced obese rats. PMID:22715380

Metabolic Benefit of Chronic Caloric Restriction and Activation of Hypothalamic AGRP/NPY Neurons in Male Mice Is Independent of Ghrelin

PubMed Central

Rogers, Nicole H.; Walsh, Heidi; Alvarez-Garcia, Oscar; Park, Seongjoon; Gaylinn, Bruce; Thorner, Michael O.

2016-01-01

Aging is associated with attenuated ghrelin signaling. During aging, chronic caloric restriction (CR) produces health benefits accompanied by enhanced ghrelin production. Ghrelin receptor (GH secretagogue receptor 1a) agonists administered to aging rodents and humans restore the young adult phenotype; therefore, we tested the hypothesis that the metabolic benefits of CR are mediated by endogenous ghrelin. Three month-old male mice lacking ghrelin (Ghrelin−/−) or ghrelin receptor (Ghsr−/−), and their wild-type (WT) littermates were randomly assigned to 2 groups: ad libitum (AL) fed and CR, where 40% food restriction was introduced gradually to allow Ghrelin−/− and Ghsr−/− mice to metabolically adapt and avoid severe hypoglycemia. Twelve months later, plasma ghrelin, metabolic parameters, ambulatory activity, hypothalamic and liver gene expression, as well as body composition were measured. CR increased plasma ghrelin and des-acyl ghrelin concentrations in WT and Ghsr−/− mice. CR of WT, Ghsr−/−, and Ghrelin−/− mice markedly improved metabolic flexibility, enhanced ambulatory activity, and reduced adiposity. Inactivation of Ghrelin or Ghsr had no effect on AL food intake or food anticipatory behavior. In contrast to the widely held belief that endogenous ghrelin regulates food intake, CR increased expression of hypothalamic Agrp and Npy, with reduced expression of Pomc across genotypes. In the AL context, ablation of ghrelin signaling markedly inhibited liver steatosis, which correlated with reduced Pparγ expression and enhanced Irs2 expression. Although CR and administration of GH secretagogue receptor 1a agonists both benefit the aging phenotype, we conclude the benefits of chronic CR are a consequence of enhanced metabolic flexibility independent of endogenous ghrelin or des-acyl ghrelin signaling. PMID:26812158

Soy protein isolate reduces hepatosteatosis in yellow Avy/a mice without altering coat color phenotype

USDA-ARS?s Scientific Manuscript database

Agouti (Avy/a) mice fed an AIN-93G diet containing the soy isoflavone genistein (GEN) prior to and during pregnancy were reported to shift coat color and body composition phenotypes from obese-yellow towards lean pseudoagouti, suggesting epigenetic programming. Human consumption of purified GEN is r...

Glycolysis-related proteins are broad spectrum vaccine candidates against aquacultural pathogens.

PubMed

Liu, Xiaohong; Sun, Jiamin; Wu, Haizhen

2017-07-05

Reverse vaccinology (RV) has become a popular method for developing vaccines. Although Edwardsiella tarda is deemed to be an important fish pathogen, so far, no reports have used a genome-based approach to screen vaccine candidates against E. tarda. In the current study, protective antigens of E. tarda were screened using RV. Large-scale cloning, expression and purification of potential candidates were carried out, and their immunoprotective potential was evaluated. A candidate fructose-bisphosphate aldolase (FBA) exhibited broad spectrum protection, as did another glycolysis-related protein glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which we reported previously, indicating the potential of other glycolysis-related proteins of E. tarda as broad spectrum protective antigens. In total, half (5 out 10) of these proteins showed prominent immunoprotective potential. Therefore, we suggest that glycolysis-related proteins are a class of potential broad spectrum protective antigens and that these proteins should be preferentially selected. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hunger neurons drive feeding through a sustained, positive reinforcement signal

PubMed Central

Chen, Yiming; Lin, Yen-Chu; Zimmerman, Christopher A; Essner, Rachel A; Knight, Zachary A

2016-01-01

The neural mechanisms underlying hunger are poorly understood. AgRP neurons are activated by energy deficit and promote voracious food consumption, suggesting these cells may supply the fundamental hunger drive that motivates feeding. However recent in vivo recording experiments revealed that AgRP neurons are inhibited within seconds by the sensory detection of food, raising the question of how these cells can promote feeding at all. Here we resolve this paradox by showing that brief optogenetic stimulation of AgRP neurons before food availability promotes intense appetitive and consummatory behaviors that persist for tens of minutes in the absence of continued AgRP neuron activation. We show that these sustained behavioral responses are mediated by a long-lasting potentiation of the rewarding properties of food and that AgRP neuron activity is positively reinforcing. These findings reveal that hunger neurons drive feeding by transmitting a positive valence signal that triggers a stable transition between behavioral states. DOI: http://dx.doi.org/10.7554/eLife.18640.001 PMID:27554486

Models for evaluation of relative immunogenic potential of protein particles in biopharmaceutical protein formulations.

PubMed

Johnson, Richard; Jiskoot, Wim

2012-10-01

An immune response to a therapeutic protein that compromises the biopharmaceutical activity or cross-reacts with an endogenous protein is a serious clinical event. The role of protein aggregates and particles in biopharmaceutical formulations in mediating this immune response has gained considerable attention over the recent past. Model systems that could consistently and reliably predict the relative immunogenicity of biopharmaceutical protein formulations would be extremely valuable. Several approaches have been developed in an attempt to provide this insight, including in silico algorithms, in vitro tests utilizing human leukocytes and in vivo animal models. This commentary provides an update of these various approaches as well as the author's perspectives on the pros and cons of these different methods. Copyright © 2012 Wiley Periodicals, Inc.

Cellular Insulin Resistance Disrupts Leptin-Mediated Control of Neuronal Signaling and Transcription

PubMed Central

Nazarians-Armavil, Anaies; Menchella, Jonathan A.

2013-01-01

Central resistance to the actions of insulin and leptin is associated with the onset of obesity and type 2 diabetes mellitus, whereas leptin and insulin signaling is essential for both glucose and energy homeostasis. Although it is known that leptin resistance can lead to attenuated insulin signaling, whether insulin resistance can lead to or exacerbate leptin resistance is unknown. To investigate the molecular events underlying crosstalk between these signaling pathways, immortalized hypothalamic neuronal models, rHypoE-19 and mHypoA-2/10, were used. Prolonged insulin exposure was used to induce cellular insulin resistance, and thereafter leptin-mediated regulation of signal transduction and gene expression was assessed. Leptin directly repressed agouti-related peptide mRNA levels but induced urocortin-2, insulin receptor substrate (IRS)-1, IRS2, and IR transcription, through leptin-mediated phosphatidylinositol 3-kinase/Akt activation. Neuronal insulin resistance, as assessed by attenuated Akt phosphorylation, blocked leptin-mediated signal transduction and agouti-related peptide, urocortin-2, IRS1, IRS2, and insulin receptor synthesis. Insulin resistance caused a substantial decrease in insulin receptor protein levels, forkhead box protein 1 phosphorylation, and an increase in suppressor of cytokine signaling 3 protein levels. Cellular insulin resistance may cause or exacerbate neuronal leptin resistance and, by extension, obesity. It is essential to unravel the effects of neuronal insulin resistance given that both peripheral, as well as the less widely studied central insulin resistance, may contribute to the development of metabolic, reproductive, and cardiovascular disorders. This study provides improved understanding of the complex cellular crosstalk between insulin-leptin signal transduction that is disrupted during neuronal insulin resistance. PMID:23579487

Tumour biology of obesity-related cancers: understanding the molecular concept for better diagnosis and treatment.

PubMed

Teoh, Seong Lin; Das, Srijit

2016-11-01

Obesity continues to be a major global problem. Various cancers are related to obesity and proper understanding of their aetiology, especially their molecular tumour biology is important for early diagnosis and better treatment. Genes play an important role in the development of obesity. Few genes such as leptin, leptin receptor encoded by the db (diabetes), pro-opiomelanocortin, AgRP and NPY and melanocortin-4 receptors and insulin-induced gene 2 were linked to obesity. MicroRNAs control gene expression via mRNA degradation and protein translation inhibition and influence cell differentiation, cell growth and cell death. Overexpression of miR-143 inhibits tumour growth by suppressing B cell lymphoma 2, extracellular signal-regulated kinase-5 activities and KRAS oncogene. Cancers of the breast, uterus, renal, thyroid and liver are also related to obesity. Any disturbance in the production of sex hormones and insulin, leads to distortion in the balance between cell proliferation, differentiation and apoptosis. The possible mechanism linking obesity to cancer involves alteration in the level of adipokines and sex hormones. These mediators act as biomarkers for cancer progression and act as targets for cancer therapy and prevention. Interestingly, many anti-cancerous drugs are also beneficial in treating obesity and vice versa. We also reviewed the possible link in the mechanism of few drugs which act both on cancer and obesity. The present review may be important for molecular biologists, oncologists and clinicians treating cancers and also pave the way for better therapeutic options.

Closely related dermatophyte species produce different patterns of secreted proteins.

PubMed

Giddey, Karin; Favre, Bertrand; Quadroni, Manfredo; Monod, Michel

2007-02-01

Dermatophytes are the most common infectious agents responsible for superficial mycosis in humans and animals. Various species in this group of fungi show overlapping characteristics. We investigated the possibility that closely related dermatophyte species with different behaviours secrete distinct proteins when grown in the same culture medium. Protein patterns from culture filtrates of several strains of the same species were very similar. In contrast, secreted protein profiles from various species were different, and so a specific signature could be associated with each of the six analysed species. In particular, protein patterns were useful to distinguish Trichophyton tonsurans from Trichophyton equinum, which cannot be differentiated by ribosomal DNA sequencing. The secreted proteases Sub2, Sub6 and Sub7 of the subtilisin family, as well as Mep3 and Mep4 of the fungalisin family were identified. SUB6, SUB7, MEP3 and MEP4 genes were cloned and sequenced. Although the protein sequence of each protease was highly conserved across species, their level of secretion by the various species was not equivalent. These results suggest that a switch of habitat could be related to a differential expression of genes encoding homologous secreted proteins.

Identification of the G13 (cAMP-response-element-binding protein-related protein) gene product related to activating transcription factor 6 as a transcriptional activator of the mammalian unfolded protein response.

PubMed

Haze, K; Okada, T; Yoshida, H; Yanagi, H; Yura, T; Negishi, M; Mori, K

2001-04-01

Eukaryotic cells control the levels of molecular chaperones and folding enzymes in the endoplasmic reticulum (ER) by a transcriptional induction process termed the unfolded protein response (UPR). The mammalian UPR is mediated by the cis-acting ER stress response element consisting of 19 nt (CCAATN(9)CCACG), the CCACG part of which is considered to provide specificity. We recently identified the basic leucine zipper (bZIP) protein ATF6 as a mammalian UPR-specific transcription factor; ATF6 is activated by ER stress-induced proteolysis and binds directly to CCACG. Here we report that eukaryotic cells express another bZIP protein closely related to ATF6 in both structure and function. This protein encoded by the G13 (cAMP response element binding protein-related protein) gene is constitutively synthesized as a type II transmembrane glycoprotein anchored in the ER membrane and processed into a soluble form upon ER stress as occurs with ATF6. The proteolytic processing of ATF6 and the G13 gene product is accompanied by their relocation from the ER to the nucleus; their basic regions seem to function as a nuclear localization signal. Overexpression of the soluble form of the G13 product constitutively activates the UPR, whereas overexpression of a mutant lacking the activation domain exhibits a strong dominant-negative effect. Furthermore, the soluble forms of ATF6 and the G13 gene product are unable to bind to several point mutants of the cis-acting ER stress response element in vitro that hardly respond to ER stress in vivo. We thus concluded that the two related bZIP proteins are crucial transcriptional regulators of the mammalian UPR, and propose calling the ATF6 gene product ATF6alpha and the G13 gene product ATF6beta.

Huntingtin-associated protein-1 (HAP1) regulates endocytosis and interacts with multiple trafficking-related proteins.

PubMed

Mackenzie, Kimberly D; Lim, Yoon; Duffield, Michael D; Chataway, Timothy; Zhou, Xin-Fu; Keating, Damien J

2017-07-01

Huntingtin-associated protein 1 (HAP1) was initially identified as a binding partner of huntingtin, mutations in which underlie Huntington's disease. Subcellular localization and protein interaction data indicate that HAP1 may be important in vesicle trafficking, cell signalling and receptor internalization. In this study, a proteomics approach was used for the identification of novel HAP1-interacting partners to attempt to shed light on the physiological function of HAP1. Using affinity chromatography with HAP1-GST protein fragments bound to Sepharose columns, this study identified a number of trafficking-related proteins that bind to HAP1. Interestingly, many of the proteins that were identified by mass spectrometry have trafficking-related functions and include the clathrin light chain B and Sec23A, an ER to Golgi trafficking vesicle coat component. Using co-immunoprecipitation and GST-binding assays the association between HAP1 and clathrin light chain B has been validated in vitro. This study also finds that HAP1 co-localizes with clathrin light chain B. In line with a physiological function of the HAP1-clathrin interaction this study detected a dramatic reduction in vesicle retrieval and endocytosis in adrenal chromaffin cells. Furthermore, through examination of transferrin endocytosis in HAP1 -/- cortical neurons, this study has determined that HAP1 regulates neuronal endocytosis. In this study, the interaction between HAP1 and Sec23A was also validated through endogenous co-immunoprecipitation in rat brain homogenate. Through the identification of novel HAP1 binding partners, many of which have putative trafficking roles, this study provides us with new insights into the mechanisms underlying the important physiological function of HAP1 as an intracellular trafficking protein through its protein-protein interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

Cilia/Ift protein and motor -related bone diseases and mouse models.

PubMed

Yuan, Xue; Yang, Shuying

2015-01-01

Primary cilia are essential cellular organelles projecting from the cell surface to sense and transduce developmental signaling. They are tiny but have complicated structures containing microtubule (MT)-based internal structures (the axoneme) and mother centriole formed basal body. Intraflagellar transport (Ift) operated by Ift proteins and motors are indispensable for cilia formation and function. Mutations in Ift proteins or Ift motors cause various human diseases, some of which have severe bone defects. Over the last few decades, major advances have occurred in understanding the roles of these proteins and cilia in bone development and remodeling by examining cilia/Ift protein-related human diseases and establishing mouse transgenic models. In this review, we describe current advances in the understanding of the cilia/Ift structure and function. We further summarize cilia/Ift-related human diseases and current mouse models with an emphasis on bone-related phenotypes, cilia morphology, and signaling pathways.

PPI-IRO: a two-stage method for protein-protein interaction extraction based on interaction relation ontology.

PubMed

Li, Chuan-Xi; Chen, Peng; Wang, Ru-Jing; Wang, Xiu-Jie; Su, Ya-Ru; Li, Jinyan

2014-01-01

Mining Protein-Protein Interactions (PPIs) from the fast-growing biomedical literature resources has been proven as an effective approach for the identification of biological regulatory networks. This paper presents a novel method based on the idea of Interaction Relation Ontology (IRO), which specifies and organises words of various proteins interaction relationships. Our method is a two-stage PPI extraction method. At first, IRO is applied in a binary classifier to determine whether sentences contain a relation or not. Then, IRO is taken to guide PPI extraction by building sentence dependency parse tree. Comprehensive and quantitative evaluations and detailed analyses are used to demonstrate the significant performance of IRO on relation sentences classification and PPI extraction. Our PPI extraction method yielded a recall of around 80% and 90% and an F1 of around 54% and 66% on corpora of AIMed and BioInfer, respectively, which are superior to most existing extraction methods.

Protein Simulation Data in the Relational Model.

PubMed

Simms, Andrew M; Daggett, Valerie

2012-10-01

High performance computing is leading to unprecedented volumes of data. Relational databases offer a robust and scalable model for storing and analyzing scientific data. However, these features do not come without a cost-significant design effort is required to build a functional and efficient repository. Modeling protein simulation data in a relational database presents several challenges: the data captured from individual simulations are large, multi-dimensional, and must integrate with both simulation software and external data sites. Here we present the dimensional design and relational implementation of a comprehensive data warehouse for storing and analyzing molecular dynamics simulations using SQL Server.

Protein Simulation Data in the Relational Model

PubMed Central

Simms, Andrew M.; Daggett, Valerie

2011-01-01

High performance computing is leading to unprecedented volumes of data. Relational databases offer a robust and scalable model for storing and analyzing scientific data. However, these features do not come without a cost—significant design effort is required to build a functional and efficient repository. Modeling protein simulation data in a relational database presents several challenges: the data captured from individual simulations are large, multi-dimensional, and must integrate with both simulation software and external data sites. Here we present the dimensional design and relational implementation of a comprehensive data warehouse for storing and analyzing molecular dynamics simulations using SQL Server. PMID:23204646

The sterol-binding activity of PATHOGENESIS-RELATED PROTEIN 1 reveals the mode of action of an antimicrobial protein.

PubMed

Gamir, Jordi; Darwiche, Rabih; Van't Hof, Pieter; Choudhary, Vineet; Stumpe, Michael; Schneiter, Roger; Mauch, Felix

2017-02-01

Pathogenesis-related proteins played a pioneering role 50 years ago in the discovery of plant innate immunity as a set of proteins that accumulated upon pathogen challenge. The most abundant of these proteins, PATHOGENESIS-RELATED 1 (PR-1) encodes a small antimicrobial protein that has become, as a marker of plant immune signaling, one of the most referred to plant proteins. The biochemical activity and mode of action of PR-1 proteins has remained elusive, however. Here, we provide genetic and biochemical evidence for the capacity of PR-1 proteins to bind sterols, and demonstrate that the inhibitory effect on pathogen growth is caused by the sequestration of sterol from pathogens. In support of our findings, sterol-auxotroph pathogens such as the oomycete Phytophthora are particularly sensitive to PR-1, whereas sterol-prototroph fungal pathogens become highly sensitive only when sterol biosynthesis is compromised. Our results are in line with previous findings showing that plants with enhanced PR-1 expression are particularly well protected against oomycete pathogens. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Low Proportion of Dietary Plant Protein among Athletes with Premenstrual Syndrome-Related Performance Impairment.

PubMed

Yamada, Keiko; Takeda, Takashi

2018-02-01

Premenstrual syndrome (PMS) is psychosomatic disorder that are limited to the late luteal phase in the menstrual cycle. PMS could impair athletic performance. To investigate associations between proportions of dietary plant and animal protein and PMS-related impairment of athletic performance, we surveyed 135 female athletes aged 18-23 years attending Kindai University. Participants belonged to authorized university clubs, all of which have high rankings in Japanese university sports. Participants completed self-administered questionnaires on diet history, demographics, and PMS-related impairment of athletic performance. Total protein, animal protein, and plant protein intake were examined, and the proportion of dietary plant protein was calculated for each participant. We divided athletes into two groups: those without PMS-related impairment of athletic performance (n = 117) and those with PMS-related performance impairment (n = 18). A t-test was used to compare mean values and multivariable adjusted mean values between groups; adjustment variables were energy intake, body mass index, and daily training duration. Total protein intake was not significantly different between the groups. However, athletes whose performance was affected by PMS reported higher intake of animal protein (mean 50.6 g) than athletes whose performance was unaffected by PMS (mean 34.9 g). Plant protein intake was lower among athletes with PMS-related impairment (mean 25.4 g) than among athletes without impairment (mean 26.9 g). The proportion of dietary plant protein was lower among athletes with PMS-related impairment (39.3%) than those without impairment (45.9%). A low proportion of dietary plant protein may cause PMS-related athletic impairment among athletes.

JAM related proteins in mucosal homeostasis and inflammation

PubMed Central

Luissint, Anny-Claude; Nusrat, Asma; Parkos, Charles A.

2014-01-01

Mucosal surfaces are lined by epithelial cells that form a physical barrier protecting the body against external noxious substances and pathogens. At a molecular level, the mucosal barrier is regulated by tight junctions (TJs) that seal the paracellular space between adjacent epithelial cells. Transmembrane proteins within TJs include Junctional Adhesion Molecules (JAMs) that belong to the CTX (Cortical Thymocyte marker for Xenopus) family of proteins. JAM family encompasses three classical members (JAM-A, -B and –C) and related molecules including JAM4, JAM-Like protein (JAM-L), Coxsackie and Adenovirus Receptor (CAR), CAR-Like Membrane Protein (CLMP) and Endothelial cell-Selective Adhesion Molecule (ESAM). JAMs have multiple functions that include regulation of endothelial and epithelial paracellular permeability, leukocyte recruitment during inflammation, angiogenesis, cell migration and proliferation. In this review, we summarize the current knowledge regarding the roles of the JAM family members in the regulation of mucosal homeostasis and leukocyte trafficking with a particular emphasis on barrier function and its perturbation during pathological inflammation. PMID:24667924

Sex differences in the physiology of eating

PubMed Central

Asarian, Lori

2013-01-01

Hypothalamic-pituitary-gonadal (HPG) axis function fundamentally affects the physiology of eating. We review sex differences in the physiological and pathophysiological controls of amounts eaten in rats, mice, monkeys, and humans. These controls result from interactions among genetic effects, organizational effects of reproductive hormones (i.e., permanent early developmental effects), and activational effects of these hormones (i.e., effects dependent on hormone levels). Male-female sex differences in the physiology of eating involve both organizational and activational effects of androgens and estrogens. An activational effect of estrogens decreases eating 1) during the periovulatory period of the ovarian cycle in rats, mice, monkeys, and women and 2) tonically between puberty and reproductive senescence or ovariectomy in rats and monkeys, sometimes in mice, and possibly in women. Estrogens acting on estrogen receptor-α (ERα) in the caudal medial nucleus of the solitary tract appear to mediate these effects in rats. Androgens, prolactin, and other reproductive hormones also affect eating in rats. Sex differences in eating are mediated by alterations in orosensory capacity and hedonics, gastric mechanoreception, ghrelin, CCK, glucagon-like peptide-1 (GLP-1), glucagon, insulin, amylin, apolipoprotein A-IV, fatty-acid oxidation, and leptin. The control of eating by central neurochemical signaling via serotonin, MSH, neuropeptide Y, Agouti-related peptide (AgRP), melanin-concentrating hormone, and dopamine is modulated by HPG function. Finally, sex differences in the physiology of eating may contribute to human obesity, anorexia nervosa, and binge eating. The variety and physiological importance of what has been learned so far warrant intensifying basic, translational, and clinical research on sex differences in eating. PMID:23904103

Ac-Trp-DPhe(p-I)-Arg-Trp-NH2, a 250-Fold Selective Melanocortin-4 Receptor (MC4R) Antagonist over the Melanocortin-3 Receptor (MC3R), Affects Energy Homeostasis in Male and Female Mice Differently.

PubMed

Lensing, Cody J; Adank, Danielle N; Doering, Skye R; Wilber, Stacey L; Andreasen, Amy; Schaub, Jay W; Xiang, Zhimin; Haskell-Luevano, Carrie

2016-09-21

The melanocortin-4 receptor (MC4R) has been indicated as a therapeutic target for metabolic disorders such as anorexia, cachexia, and obesity. The current study investigates the in vivo effects on energy homeostasis of a 15 nM MC4R antagonist SKY2-23-7, Ac-Trp-DPhe(p-I)-Arg-Trp-NH2, that is a 3700 nM melanocortin-3 receptor (MC3R) antagonist with minimal MC3R and MC4R agonist activity. When monitoring both male and female mice in TSE metabolic cages, sex-specific responses were observed in food intake, respiratory exchange ratio (RER), and energy expenditure. A 7.5 nmol dose of SKY2-23-7 increased food intake, increased RER, and trended toward decreasing energy expenditure in male mice. However, this compound had minimal effect on female mice's food intake and RER at the 7.5 nmol dose. A 2.5 nmol dose of SKY2-23-7 significantly increased female food intake, RER, and energy expenditure while having a minimal effect on male mice at this dose. The observed sex differences of SKY2-23-7 administration result in the discovery of a novel chemical probe for elucidating the molecular mechanisms of the sexual dimorphism present within the melanocortin pathway. To further explore the melanocortin sexual dimorphism, hypothalamic gene expression was examined. The mRNA expression of the MC3R and proopiomelanocortin (POMC) were not significantly different between sexes. However, the expression of agouti-related peptide (AGRP) was significantly higher in female mice which may be a possible mechanism for the sex-specific effects observed with SKY2-23-7.

Leptin action in the dorsomedial hypothalamus increases sympathetic tone to brown adipose tissue in spite of systemic leptin resistance.

PubMed

Enriori, Pablo J; Sinnayah, Puspha; Simonds, Stephanie E; Garcia Rudaz, Cecilia; Cowley, Michael A

2011-08-24

Leptin regulates body weight in mice by decreasing appetite and increasing sympathetic nerve activity (SNA), which increases energy expenditure in interscapular brown adipose tissue (iBAT). Diet-induced obese mice (DIO) are resistant to the anorectic actions of leptin. We evaluated whether leptin still stimulated sympathetic outflow in DIO mice. We measured iBAT temperature as a marker of SNA. We found that obese hyperleptinemic mice have higher iBAT temperature than mice on regular diet. Conversely, obese leptin-deficient ob/ob mice have lower iBAT temperature. Additionally, leptin increased SNA in obese (DIO and ob/ob) and control mice, despite DIO mice being resistant to anorectic action of leptin. We demonstrated that neurons in the dorsomedial hypothalamus (DMH) of DIO mice mediate the thermogenic responses to hyperleptinemia in obese mammals because blockade of leptin receptors in the DMH prevented the thermogenic effects of leptin. Peripheral Melotan II (MTII) injection increased iBAT temperature, but it was blunted by blockade of DMH melanocortin receptors (MC4Rs) by injecting agouti-related peptide (AgRP) directly into the DMH, suggesting a physiological role of the DMH on temperature regulation in animals with normal body weight. Nevertheless, obese mice without a functional melanocortin system (MC4R KO mice) have an increased sympathetic outflow to iBAT compared with their littermates, suggesting that higher leptin levels drive sympathoexcitation to iBAT by a melanocortin-independent pathway. Because the sympathetic nervous system contributes in regulating blood pressure, heart rate, and hepatic glucose production, selective leptin resistance may be a crucial mechanism linking adiposity and metabolic syndrome.

Growth hormone modulates hypothalamic inflammation in long-lived pituitary dwarf mice.

PubMed

Sadagurski, Marianna; Landeryou, Taylor; Cady, Gillian; Kopchick, John J; List, Edward O; Berryman, Darlene E; Bartke, Andrzej; Miller, Richard A

2015-12-01

Mice in which the genes for growth hormone (GH) or GH receptor (GHR(-/-) ) are disrupted from conception are dwarfs, possess low levels of IGF-1 and insulin, have low rates of cancer and diabetes, and are extremely long-lived. Median longevity is also increased in mice with deletion of hypothalamic GH-releasing hormone (GHRH), which leads to isolated GH deficiency. The remarkable extension of longevity in hypopituitary Ames dwarf mice can be reversed by a 6-week course of GH injections started at the age of 2 weeks. Here, we demonstrate that mutations that interfere with GH production or response, in the Snell dwarf, Ames dwarf, or GHR(-/-) mice lead to reduced formation of both orexigenic agouti-related peptide (AgRP) and anorexigenic proopiomelanocortin (POMC) projections to the main hypothalamic projection areas: the arcuate nucleus (ARH), paraventricular nucleus (PVH), and dorsomedial nucleus (DMH). These mutations also reduce hypothalamic inflammation in 18-month-old mice. GH injections, between 2 and 8 weeks of age, reversed both effects in Ames dwarf mice. Disruption of GHR specifically in liver (LiGHRKO), a mutation that reduces circulating IGF-1 but does not lead to lifespan extension, had no effect on hypothalamic projections or inflammation, suggesting an effect of GH, rather than peripheral IGF-1, on hypothalamic development. Hypothalamic leptin signaling, as monitored by induction of pStat3, is not impaired by GHR deficiency. Together, these results suggest that early-life disruption of GH signaling produces long-term hypothalamic changes that may contribute to the longevity of GH-deficient and GH-resistant mice. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Web-Based Information Management System for the Investigation, Reporting, and Analysis of Human Error in Naval Aviation Maintenance

DTIC Science & Technology

2001-09-01

groupwork # table (rd int identity primary key,agrp varchar(150),bgrp varchar(150),ard int,brd int) -- declare @trans# table (rd int identity,agg varchar(300...8217 */ -- Store field and associated fields within it. insert @ groupwork #(agrp,bgrp,ard,brd) select a.grp,b.grp,a.rd,b.rd --select a.rd as a_rd,cast(a.grp as...8217 end +’#rac.’+bgrp, @str1=agrp from @ groupwork # where ard<@k /* don’t want last field */ order by rd -- Fields set @mgrpsupdate5= ’ case when #rac.cgrps

Expression of Lipid Metabolism-Related Proteins in Metastatic Breast Cancer.

PubMed

Jung, Yoon Yang; Kim, Hye Min; Koo, Ja Seung

2015-01-01

The tumor biology of metastatic breast cancers differ according to the metastatic sites, and the features of cancer metabolism may also be different. The aim of this study is to investigate the expression of lipid metabolism-related proteins in metastatic breast cancer according to metastatic site and discuss the clinical significance thereof. Immunohistochemical staining for lipid metabolism-related proteins [fatty acid synthase (FASN), hormone-sensitive lipase (HSL), carnitine palmitoyltransferase IA (CPT-1A), acyl-CoA oxidase 1 (ACOX1), fatty acid binding protein 4 (FABP4,) and perilipin 1 (PLIN1)] was performed using a tissue microarray of 149 cases of metastatic breast cancer (bone metastasis = 39, brain metastasis = 37, liver metastasis = 21, and lung metastasis = 52). The expression levels of ACOX1 (p = 0.009) and FASN (p = 0.007) varied significantly according to metastatic site, with the highest expression in brain metastasis and the lowest expression in liver metastasis. ACOX1 positivity (p = 0.005) and FASN positivity (p = 0.003) correlated with HER-2 positivity. The expression of FASN was significantly higher in HER-2 type breast cancer, and lower in luminal A and TNBC type breast cancer (p<0.001). Among lipid metabolism-related proteins, PLIN1 positivity was found to be an independent poor prognostic factor on multivariate analysis (Hazard ratio: 4.979, 95% CI: 1.054-22.59, p = 0.043). Different expression levels of lipid metabolism-related proteins were observed according to metastatic site. The expression of ACOX1 and FASN was highest in brain metastasis. These results suggest that the metastatic site should be considered when using lipid metabolism inhibitors for targeted therapy.

Relating protein conformational changes to packing efficiency and disorder

PubMed Central

Bhardwaj, Nitin; Gerstein, Mark

2009-01-01

Changes in protein conformation play key roles in facilitating various biochemical processes, ranging from signaling and phosphorylation to transport and catalysis. While various factors that drive these motions such as environmental changes and binding of small molecules are well understood, specific causative effects on the structural features of the protein due to these conformational changes have not been studied on a large scale. Here, we study protein conformational changes in relation to two key structural metrics: packing efficiency and disorder. Packing has been shown to be crucial for protein stability and function by many protein design and engineering studies. We study changes in packing efficiency during conformational changes, thus extending the analysis from a static context to a dynamic perspective and report some interesting observations. First, we study various proteins that adopt alternate conformations and find that tendencies to show motion and change in packing efficiency are correlated: residues that change their packing efficiency show larger motions. Second, our results suggest that residues that show higher changes in packing during motion are located on the changing interfaces which are formed during these conformational changes. These changing interfaces are slightly different from shear or static interfaces that have been analyzed in previous studies. Third, analysis of packing efficiency changes in the context of secondary structure shows that, as expected, residues buried in helices show the least change in packing efficiency, whereas those embedded in bends are most likely to change packing. Finally, by relating protein disorder to motions, we show that marginally disordered residues which are ordered enough to be crystallized but have sequence patterns indicative of disorder show higher dislocation and a higher change in packing than ordered ones and are located mostly on the changing interfaces. Overall, our results demonstrate

SH2/SH3 adaptor proteins can link tyrosine kinases to a Ste20-related protein kinase, HPK1.

PubMed

Anafi, M; Kiefer, F; Gish, G D; Mbamalu, G; Iscove, N N; Pawson, T

1997-10-31

Ste20-related protein kinases have been implicated as regulating a range of cellular responses, including stress-activated protein kinase pathways and the control of cytoskeletal architecture. An important issue involves the identities of the upstream signals and regulators that might control the biological functions of mammalian Ste20-related protein kinases. HPK1 is a protein-serine/threonine kinase that possesses a Ste20-like kinase domain, and in transfected cells activates a protein kinase pathway leading to the stress-activated protein kinase SAPK/JNK. Here we have investigated candidate upstream regulators that might interact with HPK1. HPK1 possesses an N-terminal catalytic domain and an extended C-terminal tail with four proline-rich motifs. The SH3 domains of Grb2 bound in vitro to specific proline-rich motifs in the HPK1 tail and functioned synergistically to direct the stable binding of Grb2 to HPK1 in transfected Cos1 cells. Epidermal growth factor (EGF) stimulation did not affect the binding of Grb2 to HPK1 but induced recruitment of the Grb2.HPK1 complex to the autophosphorylated EGF receptor and to the Shc docking protein. Several activated receptor and cytoplasmic tyrosine kinases, including the EGF receptor, stimulated the tyrosine phosphorylation of the HPK1 serine/threonine kinase. These results suggest that HPK1, a mammalian Ste20-related protein-serine/threonine kinase, can potentially associate with protein-tyrosine kinases through interactions mediated by SH2/SH3 adaptors such as Grb2. Such interaction may provide a possible mechanism for cross-talk between distinct biochemical pathways following the activation of tyrosine kinases.

LC3/GABARAP family proteins: autophagy-(un)related functions.

PubMed

Schaaf, Marco B E; Keulers, Tom G; Vooijs, Marc A; Rouschop, Kasper M A

2016-12-01

From yeast to mammals, autophagy is an important mechanism for sustaining cellular homeostasis through facilitating the degradation and recycling of aged and cytotoxic components. During autophagy, cargo is captured in double-membraned vesicles, the autophagosomes, and degraded through lysosomal fusion. In yeast, autophagy initiation, cargo recognition, cargo engulfment, and vesicle closure is Atg8 dependent. In higher eukaryotes, Atg8 has evolved into the LC3/GABARAP protein family, consisting of 7 family proteins [LC3A (2 splice variants), LC3B, LC3C, GABARAP, GABARAPL1, and GABARAPL2]. LC3B, the most studied family protein, is associated with autophagosome development and maturation and is used to monitor autophagic activity. Given the high homology, the other LC3/GABARAP family proteins are often presumed to fulfill similar functions. Nevertheless, substantial evidence shows that the LC3/GABARAP family proteins are unique in function and important in autophagy-independent mechanisms. In this review, we discuss the current knowledge and functions of the LC3/GABARAP family proteins. We focus on processing of the individual family proteins and their role in autophagy initiation, cargo recognition, vesicle closure, and trafficking, a complex and tightly regulated process that requires selective presentation and recruitment of these family proteins. In addition, functions unrelated to autophagy of the LC3/GABARAP protein family members are discussed.-Schaaf, M. B. E., Keulers, T. G, Vooijs, M. A., Rouschop, K. M. A. LC3/GABARAP family proteins: autophagy-(un)related functions. © FASEB.

Yeast hnRNP-related proteins contribute to the maintenance of telomeres

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee-Soety, Julia Y., E-mail: jlee04@sju.edu; Jones, Jennifer; MacGibeny, Margaret A.

Highlights: Black-Right-Pointing-Pointer Yeast hnRNP-related proteins are able to prevent faster senescence in telomerase-null cells. Black-Right-Pointing-Pointer The conserved RRMs in Npl3 are important for telomere maintenance. Black-Right-Pointing-Pointer Human hnRNP A1 is unable to complement the lack of NPL3 in yeast. Black-Right-Pointing-Pointer Npl3 and Cbc2 may work as telomere capping proteins. -- Abstract: Telomeres protect the ends of linear chromosomes, which if eroded to a critical length can become uncapped and lead to replicative senescence. Telomerase maintains telomere length in some cells, but inappropriate expression facilitates the immortality of cancer cells. Recently, proteins involved in RNA processing and ribosome assembly, such asmore » hnRNP (heterogeneous nuclear ribonucleoprotein) A1, have been found to participate in telomere maintenance in mammals. The Saccharomyces cerevisiae protein Npl3 shares significant amino acid sequence similarities with hnRNP A1. We found that deleting NPL3 accelerated the senescence of telomerase null cells. The highly conserved RNA recognition motifs (RRM) in Npl3 appear to be important for preventing faster senescence. Npl3 preferentially binds telomere sequences in vitro, suggesting that Npl3 may affect telomeres directly. Despite similarities between the two proteins, human hnRNP A1 is unable to complement the lack of Npl3 to rescue accelerated senescence in tlc1 npl3 cells. Deletion of CBC2, which encodes another hnRNP-related protein that associates with Npl3, also accelerates senescence. Potential mechanisms by which hnRNP-related proteins maintain telomeres are discussed.« less

Comparison of CYP2D metabolism and hepatotoxicity of the myocardial metabolic agent perhexiline in Sprague-Dawley and Dark Agouti rats.

PubMed

Licari, Giovanni; Somogyi, Andrew A; Milne, Robert W; Sallustio, Benedetta C

2015-01-01

1. Perhexiline, a chiral anti-anginal agent, may be useful to develop new cardiovascular therapies, despite its potential hepatotoxicity. 2. This study compared Dark Agouti (DA) and Sprague-Dawley (SD) rats, as models of perhexiline's metabolism and hepatotoxicity in humans. Rats (n = 4/group) received vehicle or 200 mg/kg/d of racemic perhexiline maleate for 8 weeks. Plasma and liver samples were collected to determine concentrations of perhexiline and its metabolites, hepatic function and histology. 3. Median (range) plasma and liver perhexiline concentrations in SD rats were 0.09 (0.04-0.13) mg/L and 5.42 (0.92-8.22) ng/mg, respectively. In comparison, DA rats showed higher (p < 0.05) plasma 0.50 (0.16-1.13) mg/L and liver 24.5 (9.40-54.7) ng/mg perhexiline concentrations, respectively, 2.5- and 3.7-fold higher cis-OH-perhexiline concentrations, respectively (p < 0.05), and lower plasma metabolic ratio (0.89 versus 1.55, p < 0.05). In both strains, the (+):(-) enantiomer ratio was 2:1. Perhexiline increased plasma LDH concentrations in DA rats (p < 0.05), but had no effect on plasma biochemistry in SD rats. Liver histology revealed lower glycogen content in perhexiline-treated SD rats (p < 0.05), but no effects on lipid content in either strain. 4. DA rats appeared more similar to humans with respect to plasma perhexiline concentrations, metabolic ratio, enantioselective disposition and biochemical changes suggestive of perhexiline-induced toxicity.

Effect of solvation-related interaction on the low-temperature dynamics of proteins

NASA Astrophysics Data System (ADS)

Zuo, Guanghong; Wang, Jun; Qin, Meng; Xue, Bin; Wang, Wei

2010-03-01

The effect of solvation-related interaction on the low-temperature dynamics of proteins is studied by taking into account the desolvation barriers in the interactions of native contacts. It is found out that about the folding transition temperature, the protein folds in a cooperative manner, and the water molecules are expelled from the hydrophobic core at the final stage in the folding process. At low temperature, however, the protein would generally be trapped in many metastable conformations with some water molecules frozen inside the protein. The desolvation takes an important role in these processes. The number of frozen water molecules and that of frozen states of proteins are further analyzed with the methods based on principal component analysis (PCA) and the clustering of conformations. It is found out that both the numbers of frozen water molecules and the frozen states of the protein increase quickly below a certain temperature. Especially, the number of frozen states of the protein increases exponentially following the decrease in the temperature, which resembles the basic features of glassy dynamics. Interestingly, it is observed that the freezing of water molecules and that of protein conformations happen at almost the same temperature. This suggests that the solvation-related interaction performs an important role for the low-temperature dynamics of the model protein.

The Diversity of Yellow-Related Proteins in Sand Flies (Diptera: Psychodidae)

PubMed Central

Sima, Michal; Novotny, Marian; Pravda, Lukas; Sumova, Petra; Rohousova, Iva; Volf, Petr

2016-01-01

Yellow-related proteins (YRPs) present in sand fly saliva act as affinity binders of bioamines, and help the fly to complete a bloodmeal by scavenging the physiological signals of damaged cells. They are also the main antigens in sand fly saliva and their recombinant form is used as a marker of host exposure to sand flies. Moreover, several salivary proteins and plasmids coding these proteins induce strong immune response in hosts bitten by sand flies and are being used to design protecting vaccines against Leishmania parasites. In this study, thirty two 3D models of different yellow-related proteins from thirteen sand fly species of two genera were constructed based on the known protein structure from Lutzomyia longipalpis. We also studied evolutionary relationships among species based on protein sequences as well as sequence and structural variability of their ligand-binding site. All of these 33 sand fly YRPs shared a similar structure, including a unique tunnel that connects the ligand-binding site with the solvent by two independent paths. However, intraspecific modifications found among these proteins affects the charges of the entrances to the tunnel, the length of the tunnel and its hydrophobicity. We suggest that these structural and sequential differences influence the ligand-binding abilities of these proteins and provide sand flies with a greater number of YRP paralogs with more nuanced answers to bioamines. All these characteristics allow us to better evaluate these proteins with respect to their potential use as part of anti-Leishmania vaccines or as an antigen to measure host exposure to sand flies. PMID:27812196

Defense-related proteins involved in sugarcane responses to biotic stress

PubMed Central

Souza, Thais P.; Dias, Renata O.; Silva-Filho, Marcio C.

2017-01-01

Abstract Sugarcane is one of the most important agricultural crops in the world. However, pathogen infection and herbivore attack cause constant losses in yield. Plants respond to pathogen infection by inducing the expression of several protein types, such as glucanases, chitinases, thaumatins, peptidase inhibitors, defensins, catalases and glycoproteins. Proteins induced by pathogenesis are directly or indirectly involved in plant defense, leading to pathogen death or inducing other plant defense responses. Several of these proteins are induced in sugarcane by different pathogens or insects and have antifungal or insecticidal activity. In this review, defense-related proteins in sugarcane are described, with their putative mechanisms of action, pathogen targets and biotechnological perspectives. PMID:28222203

FYVE-dependent endosomal targeting of an arrestin-related protein in amoeba.

PubMed

Guetta, Dorian; Langou, Karine; Grunwald, Didier; Klein, Gérard; Aubry, Laurence

2010-12-13

Visual and β-arrestins are scaffolding proteins involved in the regulation of receptor-dependent intracellular signaling and their trafficking. The arrestin superfamilly includes several arrestin domain-containing proteins and the structurally related protein Vps26. In Dictyostelium discoideum, the arrestin-domain containing proteins form a family of six members, namely AdcA to -F. In contrast to canonical arrestins, Dictyostelium Adc proteins show a more complex architecture, as they possess, in addition to the arrestin core, other domains, such as C2, FYVE, LIM, MIT and SAM, which potentially mediate selective interactions with either lipids or proteins. A detailed analysis of AdcA has been performed. AdcA extends on both sides of the arrestin core, in particular by a FYVE domain which mediates selective interactions with PI(3)P, as disclosed by intrinsic fluorescence measurements and lipid overlay assays. Localization studies showed an enrichment of tagged- and endogenous AdcA on the rim of early macropinosomes and phagosomes. This vesicular distribution relies on a functional FYVE domain. Our data also show that the arrestin core binds the ADP-ribosylation factor ArfA, the unique amoebal Arf member, in its GDP-bound conformation. This work describes one of the 6 arrestin domain-containing proteins of Dictyostelium, a novel and atypical member of the arrestin clan. It provides the basis for a better understanding of arrestin-related protein involvement in trafficking processes and for further studies on the expanding roles of arrestins in eukaryotes.

Characterization of a novel binding partner of the melanocortin-4 receptor: attractin-like protein.

PubMed Central

Haqq, Andrea M; René, Patricia; Kishi, Toshiro; Khong, Kathy; Lee, Charlotte E; Liu, Hongyan; Friedman, Jeffrey M; Elmquist, Joel K; Cone, Roger D

2003-01-01

The gene dosage effect of the MC4-R (melanocortin 4 receptor) on obesity suggests that regulation of MC4-R expression and function is critically important to the central control of energy homoeostasis. In order to identify putative MC4-R regulatory proteins, we performed a yeast two-hybrid screen of a mouse brain cDNA library using the mouse MC4-R intracellular tail (residues 303-332) as bait. We report here on one positive clone that shares 63% amino acid identity with the C-terminal part of the mouse attractin gene product, a single-transmembrane-domain protein characterized as being required for agouti signalling through the melanocortin 1 receptor. We confirmed a direct interaction between this ALP (attractin-like protein) and the C-terminus of the mouse MC4-R by glutathione S-transferase pulldown experiments, and mapped the regions involved in this interaction using N- and C-terminal truncation constructs; residues 303-313 in MC4-R and residues 1280-1317 in ALP are required for binding. ALP is highly expressed in brain, but also in heart, lung, kidney and liver. Furthermore, co-localization analyses in mice showed co-expression of ALP in cells expressing MC4-R in a number of regions known to be important in the regulation of energy homoeostasis by melanocortins, such as the paraventricular nucleus of hypothalamus and the dorsal motor nucleus of the vagus. PMID:14531729

Long-Term Effects of (–)-Epigallocatechin Gallate (EGCG) on Pristane-Induced Arthritis (PIA) in Female Dark Agouti Rats

PubMed Central

Leichsenring, Anna; Bäcker, Ingo; Furtmüller, Paul G.; Obinger, Christian; Lange, Franziska; Flemmig, Jörg

2016-01-01

Rheumatoid arthritis (RA)—a widespread chronic inflammatory disease in industrialized countries—is characterized by a persistent and progressive joint destruction. The chronic pro-inflammatory state results from a mutual activation of the innate and the adaptive immune system, while the exact pathogenesis mechanism is still under discussion. New data suggest a role of the innate immune system and especially polymorphonuclear granulocytes (PMNs, neutrophils) not only during onset and the destructive phase of RA but also at the chronification of the disease. Thereby the enzymatic activity of myeloperoxidase (MPO), a peroxidase strongly abundant in neutrophils, may be important: While its peroxidase activity is known to contribute to cartilage destruction at later stages of RA the almost MPO-specific oxidant hypochlorous acid (HOCl) is also discussed for certain anti-inflammatory effects. In this study we used pristane-induced arthritis (PIA) in Dark Agouti rats as a model for the chronic course of RA in man. We were able to shown that a specific detection of the HOCl-producing MPO activity provides a sensitive new marker to evaluate the actual systemic inflammatory status which is only partially detectable by the evaluation of clinical symptoms (joint swelling and redness measurements). Moreover, we evaluated the long-term pharmacological effect of the well-known anti-inflammatory flavonoid epigallocatechin gallate (EGCG). Thereby only upon early and continuous oral application of this polyphenol the arthritic symptoms were considerably diminished both in the acute and in the chronic phase of the disease. The obtained results were comparable to the treatment control (application of methotrexate, MTX). As revealed by stopped-flow kinetic measurements, EGCG may regenerate the HOCl-production of MPO which is known to be impaired at chronic inflammatory diseases like RA. It can be speculated that this MPO activity-promoting effect of EGCG may contribute to the

Relating the effects of protein type and content in increased-protein cheese pies to consumers' perception of satiating capacity.

PubMed

Marcano, J; Varela, P; Fiszman, S

2015-02-01

Since proteins have been shown to have the highest satiation-inducing effects of all the macronutrients, increasing the protein level is one of the main strategies for designing foods with enhanced satiating capacity. However, few studies analyze the effect that protein addition has on the texture and flavor characteristics of the target food item to relate it to the expected satiating capacity it elicits. The present work studied cheese pies with three levels of soy and whey proteins. Since the protein level altered the rheological behavior of the batters before baking and the texture of the baked pies, the feasibility of adding several protein levels for obtaining a range of final products was investigated. A check-all-that-apply questionnaire containing 32 sensory and non-sensory characteristics of the samples was given to consumers (n = 131) who also scored the perceived samples' satiating capacity. The results showed that the type and content of protein contributed distinctive sensory characteristics to the samples that could be related to their satiating capacity perception. Harder and drier samples (high protein levels) were perceived as more satiating with less perceptible sweet and milky cheese pie characteristic flavors. Soy contributed an off-flavour. These results will contribute to a better understanding of the interrelation of all these factors, aiding the development of highly palatable solid foods with enhanced satiating capacities.

Composition-related structural transition of random peptides: insight into the boundary between intrinsically disordered proteins and folded proteins.

PubMed

Kang, Wen-Bin; He, Chuan; Liu, Zhen-Xing; Wang, Jun; Wang, Wei

2018-05-16

Previous studies based on bioinformatics showed that there is a sharp distinction of structural features and residue composition between the intrinsically disordered proteins and the folded proteins. What induces such a composition-related structural transition? How do various kinds of interactions work in such processes? In this work, we investigate these problems based on a survey on peptides randomly composed of charged residues (including glutamic acids and lysines) and the residues with different hydrophobicity, such as alanines, glycines, or phenylalanines. Based on simulations using all-atom model and replica-exchange Monte Carlo method, a coil-globule transition is observed for each peptide. The corresponding transition temperature is found to be dependent on the contents of the hydrophobic and charged residues. For several cases, when the mean hydrophobicity is larger than a certain threshold, the transition temperature is higher than the room temperature, and vise versa. These thresholds of hydrophobicity and net charge are quantitatively consistent with the border line observed from the study of bioinformatics. These results outline the basic physical reasons for the compositional distinction between the intrinsically disordered proteins and the folded proteins. Furthermore, the contributions of various interactions to the structural variation of peptides are analyzed based on the contact statistics and the charge-pattern dependence of the gyration radii of the peptides. Our observations imply that the hydrophobicity contributes essentially to such composition-related transitions. Thus, we achieve a better understanding on composition-structure relation of the natural proteins and the underlying physics.

The La and related RNA-binding proteins (LARPs): structures, functions, and evolving perspectives.

PubMed

Maraia, Richard J; Mattijssen, Sandy; Cruz-Gallardo, Isabel; Conte, Maria R

2017-11-01

La was first identified as a polypeptide component of ribonucleic protein complexes targeted by antibodies in autoimmune patients and is now known to be a eukaryote cell-ubiquitous protein. Structure and function studies have shown that La binds to a common terminal motif, UUU-3'-OH, of nascent RNA polymerase III (RNAP III) transcripts and protects them from exonucleolytic decay. For precursor-tRNAs, the most diverse and abundant of these transcripts, La also functions as an RNA chaperone that helps to prevent their misfolding. Related to this, we review evidence that suggests that La and its link to RNAP III were significant in the great expansions of the tRNAomes that occurred in eukaryotes. Four families of La-related proteins (LARPs) emerged during eukaryotic evolution with specialized functions. We provide an overview of the high-resolution structural biology of La and LARPs. LARP7 family members most closely resemble La but function with a single RNAP III nuclear transcript, 7SK, or telomerase RNA. A cytoplasmic isoform of La protein as well as LARPs 6, 4, and 1 function in mRNA metabolism and translation in distinct but similar ways, sometimes with the poly(A)-binding protein, and in some cases by direct binding to poly(A)-RNA. New structures of LARP domains, some complexed with RNA, provide novel insights into the functional versatility of these proteins. We also consider LARPs in relation to ancestral La protein and potential retention of links to specific RNA-related pathways. One such link may be tRNA surveillance and codon usage by LARP-associated mRNAs. WIREs RNA 2017, 8:e1430. doi: 10.1002/wrna.1430 For further resources related to this article, please visit the WIREs website. © 2017 Wiley Periodicals, Inc.

Oxysterol-binding protein-related protein (ORP) 9 is a PDK-2 substrate and regulates Akt phosphorylation.

PubMed

Lessmann, Eva; Ngo, Mike; Leitges, Michael; Minguet, Susana; Ridgway, Neale D; Huber, Michael

2007-02-01

The oxysterol-binding protein and oxysterol-binding protein-related protein family has been implicated in lipid transport and metabolism, vesicle trafficking and cell signaling. While investigating the phosphorylation of Akt/protein kinase B in stimulated bone marrow-derived mast cells, we observed that a monoclonal antibody directed against phospho-S473 Akt cross-reacted with oxysterol-binding protein-related protein 9 (ORP9). Further analysis revealed that mast cells exclusively express ORP9S, an N-terminal truncated version of full-length ORP9L. A PDK-2 consensus phosphorylation site in ORP9L and OPR9S at S287 (VPEFS(287)Y) was confirmed by site-directed mutagenesis. In contrast to Akt, increased phosphorylation of ORP9S S287 in stimulated mast cells was independent of phosphatidylinositol 3-kinase but sensitive to inhibition of conventional PKC isotypes. PKC-beta dependence was confirmed by lack of ORP9S phosphorylation at S287 in PKC-beta-deficient, but not PKC-alpha-deficient, mast cells. Moreover, co-immunoprecipitation of PKC-beta and ORP9S, and in vitro phosphorylation of ORP9S in this complex, argued for direct phosphorylation of ORP9S by PKC-beta, introducing ORP9S as a novel PKC-beta substrate. Akt was also detected in a PKC-beta/ORP9S immune complex and phosphorylation of Akt on S473 was delayed in PKC-deficient mast cells. In HEK293 cells, RNAi experiments showed that depletion of ORP9L increased Akt S473 phosphorylation 3-fold without affecting T308 phosphorylation in the activation loop. Furthermore, mammalian target of rapamycin was implicated in ORP9L phosphorylation in HEK293 cells. These studies identify ORP9 as a PDK-2 substrate and negative regulator of Akt phosphorylation at the PDK-2 site.

Identification of a crustacean β-1,3-glucanase related protein as a pattern recognition protein in antibacterial response.

PubMed

Chai, Lian-Qin; Meng, Jing-Hui; Gao, Jie; Xu, Yi-Hui; Wang, Xian-Wei

2018-06-02

Prophenoloxidase (proPO) activating system is an important immune response for arthropods. β-1, 3-glucanase related protein (previously named as lipopolysaccharide and β-1, 3-glucan binding protein (LGBP) in crustaceans) is a typical pattern recognition receptor family involved in the proPO activation by recognizing the invading microbes. In this study, we pay special attention to a bacteria-induced β-1,3-glucanase related protein from red swamp crayfish Procambarus clarkii, an important aquaculture specie in China. This protein, designated PcBGRP, was found a typical member of crustacean BGRP family with the glucanase-related domain and the characteristic motifs. PcBGRP was expressed in hemcoyes and hepatopancreas, and its expression could be induced by the carbohydrate and bacteria stimulants. The induction by lipopolysaccharide (LPS) and β-1,3-glucan (βG) was more significant than by peptidoglycan (PG). The response of PcBGRP to the native Gram-negative bacterial pathogen Aeromonas hydrophila was more obvious than to Gram-positive bacteria. Using RNA interference and recombinant protein, PcBGRP was found to protect crayfish from A. hydrophila infection revealed by the survival test and morphological analysis. A mechanism study found PcBGRP could bind LPS and βG in a dose-dependent manner, and the LPS recognizing ability determined the Gram-negative bacterium binding activity of PcBGRP. PcBGRP was found to enhance the PO activation both in vitro and in vivo, and the protective role was related to the PO activating ability of PcBGRP. This study emphasized the role of BGRP family in crustacean immune response, and provided new insight to the immunity of red swamp crayfish which suffered serious disease during the aquaculture in China. Copyright © 2018 Elsevier Ltd. All rights reserved.

The TRH neuron: a hypothalamic integrator of energy metabolism.

PubMed

Lechan, Ronald M; Fekete, Csaba

2006-01-01

Thyrotropin-releasing hormone (TRH) has an important role in the regulation of energy homeostasis not only through effects on thyroid function orchestrated through hypophysiotropic neurons in the hypothalamic paraventricular nucleus (PVN), but also through central effects on feeding behavior, thermogenesis, locomotor activation and autonomic regulation. Hypophysiotropic TRH neurons are located in the medial and periventricular parvocellular subdivisions of the PVN and receive direct monosynaptic projections from two, separate, populations of leptin-responsive neurons in the hypothalamic arcuate nucleus containing either alpha-melanocyte-stimulating hormone (alpha-MSH) and cocaine- and amphetamine-regulated transcript (CART), peptides that promote weight loss and increase energy expenditure, or neuropeptide Y (NPY) and agouti-related protein (AGRP), peptides that promote weight gain and reduce energy expenditure. During fasting, the reduction in TRH mRNA in hypophysiotropic neurons mediated by suppression of alpha-MSH/CART simultaneously with an increase in NPY/AGRP gene expression in arcuate nucleus neurons contributes to the fall in circulating thyroid hormone levels, presumably by increasing the sensitivity of the TRH gene to negative feedback inhibition by thyroid hormone. Endotoxin administration, however, has the paradoxical effect of increasing circulating levels of leptin and melanocortin signaling and CART gene expression in arcuate nucleus neurons, but inhibiting TRH gene expression in hypophysiotropic neurons. This may be explained by an overriding inhibitory effect of endotoxin to increase type 2 iodothyroine deiodinase (D2) in a population of specialized glial cells, tanycytes, located in the base and infralateral walls of the third ventricle. By increasing the conversion of T4 into T3, tanycytes may increase local tissue concenetrations of thyroid hormone, and thereby induce a state of local tissue hyperthyroidism in the region of hypophysisotrophic

A topologically related singularity suggests a maximum preferred size for protein domains.

PubMed

Zbilut, Joseph P; Chua, Gek Huey; Krishnan, Arun; Bossa, Cecilia; Rother, Kristian; Webber, Charles L; Giuliani, Alessandro

2007-02-15

A variety of protein physicochemical as well as topological properties, demonstrate a scaling behavior relative to chain length. Many of the scalings can be modeled as a power law which is qualitatively similar across the examples. In this article, we suggest a rational explanation to these observations on the basis of both protein connectivity and hydrophobic constraints of residues compactness relative to surface volume. Unexpectedly, in an examination of these relationships, a singularity was shown to exist near 255-270 residues length, and may be associated with an upper limit for domain size. Evaluation of related G-factor data points to a wide range of conformational plasticity near this point. In addition to its theoretical importance, we show by an application of CASP experimental and predicted structures, that the scaling is a practical filter for protein structure prediction. 2006 Wiley-Liss, Inc.

Kelch-like ECH-associated Protein 1-dependent Nuclear Factor-E2-related Factor 2 Activation in Relation to Antioxidation Induced by Sevoflurane Preconditioning.

PubMed

Cai, Min; Tong, Li; Dong, Beibei; Hou, Wugang; Shi, Likai; Dong, Hailong

2017-03-01

The authors have reported that antioxidative effects play a crucial role in the volatile anesthetic-induced neuroprotection. Accumulated evidence shows that endogenous antioxidation could be up-regulated by nuclear factor-E2-related factor 2 through multiple pathways. However, whether nuclear factor-E2-related factor 2 activation is modulated by sevoflurane preconditioning and, if so, what is the signaling cascade underlying upstream of this activation are still unknown. Sevoflurane preconditioning in mice was performed with sevoflurane (2.5%) 1 h per day for five consecutive days. Focal cerebral ischemia/reperfusion injury was induced by middle cerebral artery occlusion. Expression of nuclear factor-E2-related factor 2, kelch-like ECH-associated protein 1, manganese superoxide dismutase, thioredoxin-1, and nicotinamide adenine dinucleotide phosphate quinolone oxidoreductase-1 was detected (n = 6). The antioxidant activities and oxidative product expression were also examined. To determine the role of kelch-like ECH-associated protein 1 inhibition-dependent nuclear factor-E2-related factor 2 activation in sevoflurane preconditioning-induced neuroprotection, the kelch-like ECH-associated protein 1-nuclear factor-E2-related factor 2 signal was modulated by nuclear factor-E2-related factor 2 knockout, kelch-like ECH-associated protein 1 overexpression lentivirus, and kelch-like ECH-associated protein 1 deficiency small interfering RNA (n = 8). The infarct volume, neurologic scores, and cellular apoptosis were assessed. Sevoflurane preconditioning elicited neuroprotection and increased nuclear factor-E2-related factor 2 nuclear translocation, which in turn up-regulated endogenous antioxidation and reduced oxidative injury. Sevoflurane preconditioning reduced kelch-like ECH-associated protein 1 expression. Nuclear factor-E2-related factor 2 ablation abolished neuroprotection and reversed sevoflurane preconditioning by mediating the up-regulation of antioxidants. Kelch

Posttranslational modification of autophagy-related proteins in macroautophagy

PubMed Central

Xie, Yangchun; Kang, Rui; Sun, Xiaofang; Zhong, Meizuo; Huang, Jin; Klionsky, Daniel J.; Tang, Daolin

2014-01-01

Macroautophagy is an intracellular catabolic process involved in the formation of multiple membrane structures ranging from phagophores to autophagosomes and autolysosomes. Dysfunction of macroautophagy is implicated in both physiological and pathological conditions. To date, 38 autophagy-related (ATG) genes have been identified as controlling these complicated membrane dynamics during macroautophagy in yeast; approximately half of these genes are clearly conserved up to human, and there are additional genes whose products function in autophagy in higher eukaryotes that are not found in yeast. The function of the ATG proteins, in particular their ability to interact with a number of macroautophagic regulators, is modulated by posttranslational modifications (PTMs) such as phosphorylation, glycosylation, ubiquitination, acetylation, lipidation, and proteolysis. In this review, we summarize our current knowledge of the role of ATG protein PTMs and their functional relevance in macroautophagy. Unraveling how these PTMs regulate ATG protein function during macroautophagy will not only reveal fundamental mechanistic insights into the regulatory process, but also provide new therapeutic targets for the treatment of autophagy-associated diseases. PMID:25484070

Neural input is critical for arcuate hypothalamic neurons to mount intracellular signaling responses to systemic insulin and deoxyglucose challenges in male rats: implications for communication within feeding and metabolic control networks.

PubMed

Khan, Arshad M; Walker, Ellen M; Dominguez, Nicole; Watts, Alan G

2014-02-01

The hypothalamic arcuate nucleus (ARH) controls rat feeding behavior in part through peptidergic neurons projecting to the hypothalamic paraventricular nucleus (PVH). Hindbrain catecholaminergic (CA) neurons innervate both the PVH and ARH, and ablation of CA afferents to PVH neuroendocrine neurons prevents them from mounting cellular responses to systemic metabolic challenges such as insulin or 2-deoxy-d-glucose (2-DG). Here, we asked whether ablating CA afferents also limits their ARH responses to the same challenges or alters ARH connectivity with the PVH. We examined ARH neurons for three features: (1) CA afferents, visualized by dopamine-β-hydroxylase (DBH)- immunoreactivity; (2) activation by systemic metabolic challenge, as measured by increased numbers of neurons immunoreactive (ir) for phosphorylated ERK1/2 (pERK1/2); and (3) density of PVH-targeted axons immunoreactive for the feeding control peptides Agouti-related peptide and α-melanocyte-stimulating hormone (αMSH). Loss of PVH DBH immunoreactivity resulted in concomitant ARH reductions of DBH-ir and pERK1/2-ir neurons in the medial ARH, where AgRP neurons are enriched. In contrast, pERK1/2 immunoreactivity after systemic metabolic challenge was absent in αMSH-ir ARH neurons. Yet surprisingly, axonal αMSH immunoreactivity in the PVH was markedly increased in CA-ablated animals. These results indicate that (1) intrinsic ARH activity is insufficient to recruit pERK1/2-ir ARH neurons during systemic metabolic challenges (rather, hindbrain-originating CA neurons are required); and (2) rats may compensate for a loss of CA innervation to the ARH and PVH by increased expression of αMSH. These findings highlight the existence of a hierarchical dependence for ARH responses to neural and humoral signals that influence feeding behavior and metabolism.

Increase in hypothalamic AMPK phosphorylation induced by prolonged exposure to LPS involves ghrelin and CB1R signaling.

PubMed

Rivas, Priscila M S; Vechiato, Fernanda M V; Borges, Beatriz C; Rorato, Rodrigo; Antunes-Rodrigues, Jose; Elias, Lucila L K

2017-07-01

Acute administration of lipopolysaccharide (LPS) from Gram-negative bacteria induces hypophagia. However, the repeated administration of LPS leads to desensitization of hypophagia, which is associated with increased hypothalamic p-AMPK expression. Because ghrelin and endocannabinoids modulate AMPK activity in the hypothalamus, we hypothesized that these neuromodulators play a role in the reversal of tolerance to hypophagia in rats under long-term exposure to LPS. Male Wistar rats were treated with single (1 LPS, 100μg/kg body weight, ip) or repeated injections of LPS over 6days (6 LPS). Food intake was reduced in the 1 LPS, but not in the 6 LPS group. 6 LPS rats showed an increased serum concentration of acylated ghrelin and reduced ghrelin receptor mRNA expression in the hypothalamus. Ghrelin injection (40μg/kg body weight, ip) increased food intake, body weight gain, p-AMPK hypothalamic expression, neuropeptide Y (NPY) and Agouti related peptide (AgRP) mRNA expression in control animals (Saline). However, in 6 LPS rats, ghrelin did not alter these parameters. Central administration of a CB1R antagonist (AM251, 200ng/μl in 5μl/rat) induced hypophagia in 6 LPS animals, suggesting that the endocannabinoid system contributes to preserved food intake during LPS tolerance. In the presence of AM251, the ability of ghrelin to phosphorylate AMPK in the hypothalamus of 6 LPS group was restored, but not its orexigenic effect. Our data highlight that the orexigenic effects of ghrelin require CB1R signaling downstream of AMPK activation. Moreover, CB1R-mediated pathways contribute to the absence of hypophagia during repeated exposure to endotoxin. Copyright © 2017 Elsevier Inc. All rights reserved.

Arrestin-related proteins mediate pH signaling in fungi.

PubMed

Herranz, Silvia; Rodríguez, José M; Bussink, Henk-Jan; Sánchez-Ferrero, Juan C; Arst, Herbert N; Peñalva, Miguel A; Vincent, Olivier

2005-08-23

Metazoan arrestins bind to seven-transmembrane (7TM) receptors to regulate function. Aspergillus nidulans PalF, a protein involved in the fungal ambient pH signaling pathway, contains arrestin N-terminal and C-terminal domains and binds strongly to two different regions within the C-terminal cytoplasmic tail of the 7TM, putative pH sensor PalH. Upon exposure to alkaline ambient pH, PalF is phosphorylated and, like mammalian beta-arrestins, ubiquitinated in a signal-dependent and 7TM protein-dependent manner. Substitution in PalF of a highly conserved arrestin N-terminal domain Ser residue prevents PalF-PalH interaction and pH signaling in vivo. Thus, PalF is the first experimentally documented fungal arrestin-related protein, dispelling the notion that arrestins are restricted to animal proteomes. Epistasis analyses demonstrate that PalF posttranslational modification is partially dependent on the 4TM protein PalI but independent of the remaining pH signal transduction pathway proteins PalA, PalB, and PalC, yielding experimental evidence bearing on the order of participation of the six components of the pH signal transduction pathway. Our data strongly implicate PalH as an ambient pH sensor, possibly with the cooperation of PalI.

BLOC-2, AP-3, and AP-1 Proteins Function in Concert with Rab38 and Rab32 Proteins to Mediate Protein Trafficking to Lysosome-related Organelles*

PubMed Central

Bultema, Jarred J.; Ambrosio, Andrea L.; Burek, Carolyn L.; Di Pietro, Santiago M.

2012-01-01

Lysosome-related organelles (LROs) are synthesized in specialized cell types where they largely coexist with conventional lysosomes. Most of the known cellular transport machinery involved in biogenesis are ubiquitously expressed and shared between lysosomes and LROs. Examples of common components are the adaptor protein complex-3 (AP-3) and biogenesis of lysosome-related organelle complex (BLOC)-2. These protein complexes control sorting and transport of newly synthesized integral membrane proteins from early endosomes to both lysosomes and LROs such as the melanosome. However, it is unknown what factors cooperate with the ubiquitous transport machinery to mediate transport to LROs in specialized cells. Focusing on the melanosome, we show that the ubiquitous machinery interacts with cell type-specific Rab proteins, Rab38 and Rab32, to facilitate transport to the maturing organelle. BLOC-2, AP-3, and AP-1 coimmunoprecipitated with Rab38 and Rab32 from MNT-1 melanocytic cell extracts. BLOC-2, AP-3, AP-1, and clathrin partially colocalized with Rab38 and Rab32 by confocal immunofluorescence microscopy in MNT-1 cells. Rab38- and Rab32-deficient MNT-1 cells displayed abnormal trafficking and steady state levels of known cargoes of the BLOC-2, AP-3, and AP-1 pathways, the melanin-synthesizing enzymes tyrosinase and tyrosinase-related protein-1. These observations support the idea that Rab38 and Rab32 are the specific factors that direct the ubiquitous machinery to mediate transport from early endosomes to maturing LROs. Additionally, analysis of tyrosinase-related protein-2 and total melanin production indicates that Rab32 has unique functions that cannot be carried out by Rab38 in melanosome biogenesis. PMID:22511774

BLOC-2, AP-3, and AP-1 proteins function in concert with Rab38 and Rab32 proteins to mediate protein trafficking to lysosome-related organelles.

PubMed

Bultema, Jarred J; Ambrosio, Andrea L; Burek, Carolyn L; Di Pietro, Santiago M

2012-06-01

Lysosome-related organelles (LROs) are synthesized in specialized cell types where they largely coexist with conventional lysosomes. Most of the known cellular transport machinery involved in biogenesis are ubiquitously expressed and shared between lysosomes and LROs. Examples of common components are the adaptor protein complex-3 (AP-3) and biogenesis of lysosome-related organelle complex (BLOC)-2. These protein complexes control sorting and transport of newly synthesized integral membrane proteins from early endosomes to both lysosomes and LROs such as the melanosome. However, it is unknown what factors cooperate with the ubiquitous transport machinery to mediate transport to LROs in specialized cells. Focusing on the melanosome, we show that the ubiquitous machinery interacts with cell type-specific Rab proteins, Rab38 and Rab32, to facilitate transport to the maturing organelle. BLOC-2, AP-3, and AP-1 coimmunoprecipitated with Rab38 and Rab32 from MNT-1 melanocytic cell extracts. BLOC-2, AP-3, AP-1, and clathrin partially colocalized with Rab38 and Rab32 by confocal immunofluorescence microscopy in MNT-1 cells. Rab38- and Rab32-deficient MNT-1 cells displayed abnormal trafficking and steady state levels of known cargoes of the BLOC-2, AP-3, and AP-1 pathways, the melanin-synthesizing enzymes tyrosinase and tyrosinase-related protein-1. These observations support the idea that Rab38 and Rab32 are the specific factors that direct the ubiquitous machinery to mediate transport from early endosomes to maturing LROs. Additionally, analysis of tyrosinase-related protein-2 and total melanin production indicates that Rab32 has unique functions that cannot be carried out by Rab38 in melanosome biogenesis.

Sources of Dietary Protein in Relation to Blood Pressure in a General Dutch Population

PubMed Central

Altorf - van der Kuil, Wieke; Engberink, Mariëlle F.; Vedder, Moniek M.; Boer, Jolanda M. A.; Verschuren, W. M. Monique; Geleijnse, Johanna M.

2012-01-01

Background Little is known about the relation of different dietary protein types with blood pressure (BP). We examined whether intake of total, plant, animal, dairy, meat, and grain protein was related to BP in a cross sectional cohort of 20,820 Dutch adults, aged 20–65 y and not using antihypertensive medication. Design Mean BP levels were calculated in quintiles of energy-adjusted protein with adjustment for age, sex, BMI, education, smoking, and intake of energy, alcohol, and other nutrients including protein from other sources. In addition, mean BP difference after substitution of 3 en% carbohydrates or MUFA with protein was calculated. Results Total protein and animal protein were not associated with BP (ptrend = 0.62 and 0.71 respectively), both at the expense of carbohydrates and MUFA. Systolic BP was 1.8 mmHg lower (ptrend<0.01) in the highest (>36 g/d) than in the lowest (<27 g/d) quintile of plant protein. This inverse association was present both at the expense of carbohydrates and MUFA and more pronounced in individuals with untreated hypertension (−3.6 mmHg) than in those with normal (+0.1 mmHg) or prehypertensive BP (−0.3 mmHg; pinteraction<0.01). Meat and grain protein were not related to BP. Dairy protein was directly associated with systolic BP (+1.6 mmHg, ptrend<0.01), but not with diastolic BP (ptrend = 0.24). Conclusions Total protein and animal protein were not associated with BP in this general untreated Dutch population. Plant protein may be beneficial to BP, especially in people with elevated BP. However, because high intake of plant protein may be a marker of a healthy diet and lifestyle in general, confirmation from randomized controlled trials is warranted. PMID:22347387

Proteomic analysis identifies insulin-like growth factor-binding protein-related protein-1 as a podocyte product.

PubMed

Matsumoto, Takayuki; Hess, Sonja; Kajiyama, Hiroshi; Sakairi, Toru; Saleem, Moin A; Mathieson, Peter W; Nojima, Yoshihisa; Kopp, Jeffrey B

2010-10-01

The podocyte secretory proteome may influence the phenotype of adjacent podocytes, endothelial cells, parietal epithelial cells, and tubular epithelial cells but has not been systematically characterized. We have initiated studies to characterize this proteome, with the goal of further understanding the podocyte cell biology. We cultured differentiated conditionally immortalized human podocytes and subjected the proteins in conditioned medium to mass spectrometry. At a false discovery rate of <3%, we identified 111 candidates from conditioned medium, including 44 proteins that have signal peptides or are described as secreted proteins in the UniProt database. As validation, we confirmed that one of these proteins, insulin-like growth factor-binding protein-related protein-1 (IGFBP-rP1), was expressed in mRNA and protein of cultured podocytes. In addition, transforming growth factor-β1 stimulation increased IGFBP-rP1 in conditioned medium. We analyzed IGFBP-rP1 glomerular expression in a mouse model of human immunodeficiency virus-associated nephropathy. IGFBP-rP1 was absent from podocytes of normal mice and was expressed in podocytes and pseudocrescents of transgenic mice, where it was coexpressed with desmin, a podocyte injury marker. We conclude that IGFBP-rP1 may be a product of injured podocytes. Further analysis of the podocyte secretory proteome may identify biomarkers of podocyte injury.

Protein level affects the relative lysine requirement of growing rainbow trout (Oncorhynchus mykiss) fry.

PubMed

Bodin, Noelie; Govaerts, Bernadette; Abboudi, Tarik; Detavernier, Christel; De Saeger, Sarah; Larondelle, Yvan; Rollin, Xavier

2009-07-01

The effect of two digestible protein levels (310 and 469 g/kg DM) on the relative lysine (Lys; g Lys/kg DM or g Lys/100 g protein) and the absolute Lys (g Lys intake/kg 0.75 per d) requirements was studied in rainbow trout fry using a dose-response trial. At each protein level, sixteen isoenergetic (22-23 MJ digestible energy/kg DM) diets were tested, involving a full range (2-70 g/kg DM) of sixteen Lys levels. Each diet was given to one group of sixty rainbow trout fry (mean initial body weight 0.78 g) reared at 15 degrees C for 31 feeding d. The Lys requirements were estimated based on the relationships between weight, protein, and Lys gains (g/kg 0.75 per d) and Lys concentration (g/kg DM or g/100 g protein) or Lys intake (g/kg 0.75 per d), using the broken-line model (BLM) and the non-linear four-parameter saturation kinetics model (SKM-4). Both the model and the response criterion chosen markedly impacted the relative Lys requirement. The relative Lys requirement for Lys gain of rainbow trout estimated with the BLM (and SKM-4 at 90 % of the maximum response) increased from 16.8 (19.6) g/kg DM at a low protein level to 23.4 (24.5) g/kg DM at a high protein level. However, the dietary protein content affected neither the absolute Lys requirement nor the relative Lys requirement expressed as g Lys/100 g protein nor the Lys requirement for maintenance (21 mg Lys/kg 0.75 per d).

Autophagy in the control of food intake.

PubMed

Singh, Rajat

2012-04-01

The cellular nutrient sensing apparatus detects nutritional depletion and transmits this information to downstream effectors that generate energy from alternate sources. Autophagy is a crucial catabolic pathway that turns over redundant cytoplasmic components in lysosomes to provide energy to the starved cell. Recent studies have described a role for hypothalamic autophagy in the control of food intake and energy balance. Activated autophagy in hypothalamic neurons during starvation mobilized neuron-intrinsic lipids to generate free fatty acids that increased AgRP levels. AgRP neuron-specific inhibition of autophagy decreased fasting-induced increases in AgRP levels and food intake. Deletion of autophagy in AgRP neurons led to constitutive increases in levels of proopiomelanocortin and its active processed product, α-melanocyte stimulating hormone that contributed to reduced adiposity in these rodents. The current manuscript discusses these new findings and raises additional questions that may help understand how hypothalamic autophagy controls food intake and energy balance. These studies may have implications for designing new therapies against obesity and insulin resistance.

Expression of Iron-Related Proteins Differentiate Non-Cancerous and Cancerous Breast Tumors

PubMed Central

Pizzamiglio, Sara; De Bortoli, Maida; Taverna, Elena; Signore, Michele; Veneroni, Silvia; Chi-shing Cho, William; Orlandi, Rosaria; Verderio, Paolo; Bongarzone, Italia

2017-01-01

We have previously reported hepcidin and ferritin increases in the plasma of breast cancer patients, but not in patients with benign breast disease. We hypothesized that these differences in systemic iron homeostasis may reflect alterations in different iron-related proteins also play a key biochemical and regulatory role in breast cancer. Thus, here we explored the expression of a bundle of molecules involved in both iron homeostasis and tumorigenesis in tissue samples. Enzyme-linked immunosorbent assay (ELISA) or reverse-phase protein array (RPPA), were used to measure the expression of 20 proteins linked to iron processes in 24 non-cancerous, and 56 cancerous, breast tumors. We found that cancerous tissues had higher level of hepcidin than benign lesions (p = 0.012). The univariate analysis of RPPA data highlighted the following seven proteins differentially expressed between non-cancerous and cancerous breast tissue: signal transducer and transcriptional activator 5 (STAT5), signal transducer and activator of transcription 3 (STAT3), bone morphogenetic protein 6 (BMP6), cluster of differentiation 74 (CD74), transferrin receptor (TFRC), inhibin alpha (INHA), and STAT5_pY694. These findings were confirmed for STAT5, STAT3, BMP6, CD74 and INHA when adjusting for age. The multivariate statistical analysis indicated an iron-related 10-protein panel effective in separating non-cancerous from cancerous lesions including STAT5, STAT5_pY694, myeloid differentiation factor 88 (MYD88), CD74, iron exporter ferroportin (FPN), high mobility group box 1 (HMGB1), STAT3_pS727, TFRC, ferritin heavy chain (FTH), and ferritin light chain (FTL). Our results showed an association between some iron-related proteins and the type of tumor tissue, which may provide insight in strategies for using iron chelators to treat breast cancer. PMID:28216608

PPInterFinder--a mining tool for extracting causal relations on human proteins from literature.

PubMed

Raja, Kalpana; Subramani, Suresh; Natarajan, Jeyakumar

2013-01-01

One of the most common and challenging problem in biomedical text mining is to mine protein-protein interactions (PPIs) from MEDLINE abstracts and full-text research articles because PPIs play a major role in understanding the various biological processes and the impact of proteins in diseases. We implemented, PPInterFinder--a web-based text mining tool to extract human PPIs from biomedical literature. PPInterFinder uses relation keyword co-occurrences with protein names to extract information on PPIs from MEDLINE abstracts and consists of three phases. First, it identifies the relation keyword using a parser with Tregex and a relation keyword dictionary. Next, it automatically identifies the candidate PPI pairs with a set of rules related to PPI recognition. Finally, it extracts the relations by matching the sentence with a set of 11 specific patterns based on the syntactic nature of PPI pair. We find that PPInterFinder is capable of predicting PPIs with the accuracy of 66.05% on AIMED corpus and outperforms most of the existing systems. DATABASE URL: http://www.biomining-bu.in/ppinterfinder/

Cell protein cross-linking by erbstatin and related compounds | Center for Cancer Research

Cancer.gov

The scheme depicts a possible mechanism of cross-linking by erbstatin and related analogues. A mechanism of action is proposed which involves initial oxidation to reactive quinone intermediates that subsequently cross-link protein nucleophiles via multiple 1,4-Michael-type additions. Similar alkylation of protein by protein-tyrosine kinase inhibitors, such as herbimycin A, has

Dynamin-Related Protein 1 and Mitochondrial Fragmentation in Neurodegenerative Diseases

PubMed Central

Reddy, P. Hemachandra; Reddy, Tejaswini P.; Manczak, Maria; Calkins, Marcus J.; Shirendeb, Ulziibat; Mao, Peizhong

2010-01-01

The purpose of this article is to review the recent developments of abnormal mitochondrial dynamics, mitochondrial fragmentation, and neuronal damage in neurodegenerative diseases, including Alzheimer’s, Parkinson’s, Huntington’s, and amyotrophic lateral sclerosis. The GTPase family of proteins, including fission proteins, dynamin related protein 1 (Drp1), mitochondrial fission 1 (Fis1), and fusion proteins (Mfn1, Mfn2 and Opa1) are essential to maintain mitochondrial fission and fusion balance, and to provide necessary adenosine triphosphate to neurons. Among these, Drp1 is involved in several important aspects of mitochondria, including shape, size, distribution, remodeling, and maintenance of X in mammalian cells. In addition, recent advancements in molecular, cellular, electron microscopy, and confocal imaging studies revealed that Drp1 is associated with several cellular functions, including mitochondrial and peroxisomal fragmentation, phosphorylation, SUMOylation, ubiquitination, and cell death. In the last two decades, tremendous progress has been made in researching mitochondrial dynamics, in yeast, worms, and mammalian cells; and this research has provided evidence linking Drp1 to neurodegenerative diseases. Researchers in the neurodegenerative disease field are beginning to recognize the possible involvement of Drp1 in causing mitochondrial fragmentation and abnormal mitochondrial dynamics in neurodegenerative diseases. This article summarizes research findings relating Drp1 to mitochondrial fission and fusion, in yeast, worms, and mammals. Based on findings from the Reddy laboratory and others’, we propose that mutant proteins of neurodegenerative diseases, including AD, PD, HD, and ALS, interact with Drp1, activate mitochondrial fission machinery, fragment mitochondria excessively, and impair mitochondrial transport and mitochondrial dynamics, ultimately causing mitochondrial dysfunction and neuronal damage. PMID:21145355

Inflammation-initiating illnesses, inflammation-related proteins, and cognitive impairment in extremely preterm infants.

PubMed

O'Shea, T Michael; Shah, Bhavesh; Allred, Elizabeth N; Fichorova, Raina N; Kuban, Karl C K; Dammann, Olaf; Leviton, Alan

2013-03-01

Neonatal inflammation is associated with perinatal brain damage. We evaluated to what extent elevated blood levels of inflammation-related proteins supplement information about the risk of impaired early cognitive function provided by inflammation-related illnesses. From 800 infants born before the 28th week of gestation, we collected blood spots on days 1, 7 and 14, for analysis of 25 inflammation-related proteins, and data about culture-positive bacteremia, necrotizing enterocolitis (Bell stage IIIb), and isolated perforation of the intestine, during the first two weeks, and whether they were ventilated on postnatal day 14. We considered a protein to be persistently or recurrently elevated if its concentration was in the top quartile (for gestational age and day blood was collected) on two separate days one week apart. We assessed the children at 2 years of age with the Bayley Mental Development Index (MDI). The combinations of NEC and ventilation on day 14, and of bacteremia and ventilation on day 14 consistently provided information about elevated risk of MDI <55, regardless of whether or not a variable for an elevated protein concentration was included in the model. A variable for a persistently or recurrently elevated concentration of each of the following proteins provided additional information about an increased risk of MDI <55: CRP, SAA, IL-6, TNF-alpha, IL-8, MIP-1beta, ICAM-1, E-SEL, and IGFBP-1. We conclude that elevated blood concentrations of inflammation-related proteins provide information about the risk of impaired cognitive function at age 2 years that supplements information provided by inflammation-associated illnesses. Copyright © 2013 Elsevier Inc. All rights reserved.

The maize pathogenesis-related PRms protein localizes to plasmodesmata in maize radicles.

PubMed Central

Murillo, I; Cavallarin, L; San Segundo, B

1997-01-01

Pathogenesis-related (PR) proteins are plant proteins induced in response to infection by pathogens. In this study, an antibody raised against the maize PRms protein was used to localize the protein in fungal-infected maize radicles. The PRms protein was found to be localized at the contact areas between parenchyma cells of the differentiating protoxylem elements. By using immunoelectron microscopy, we found that these immunoreactive regions correspond to plasmodesmal regions. This was also true for the parenchyma cells filling the central pith of the vascular cylinder, although PRms mRNA accumulation was not detected in these cells. These findings suggest that for one cell type, the parenchyma cells of the central pith, the protein is imported rather than synthesized. The localization of the PRms protein indicates the possible existence of mechanisms for sorting of plant proteins to plasmodesmata and suggests that this protein may have a specialized function in the plant defense response. These findings are discussed with respect to the structure and function of plasmodesmata in cell-to-cell communication processes in higher plants. PMID:9061947

Clinical spectrum and diagnostic value of antibodies against the potassium channel-related protein complex☆

PubMed Central

Montojo, M.T.; Petit-Pedrol, M.; Graus, F.; Dalmau, J.

2016-01-01

Introduction Antibodies against a protein complex that includes voltage-gated potassium channels (VGKC) have been reported in patients with limbic encephalitis, peripheral nerve hyperexcitability, Morvan's syndrome, and a large variety of neurological syndromes. Review summary In this article, a review is presented of the syndromes associated with antibodies against VGKC-related proteins and the main antigens of this protein complex, the proteins LGI1 (leucine rich glioma inactivated protein 1) and Caspr2 (contactin-associated protein-like 2). The conceptual problems and clinical implications of the description of antibodies against VGKC-related proteins other than LGI1 and Caspr2 are also discussed. Although initial studies indicated the occurrence of antibodies against VGKC, recent investigations have shown that the main antigens are a neuronal secreted protein known as LGI1 which modulates synaptic excitability, and a protein called Caspr2 located on the cell surface and processes of neurons of different brain regions, and at the juxtaparanodal region of myelinated axons. While antibodies against LGI1 preferentially associate with classical limbic encephalitis, antibodies against Caspr2 associate with a wider spectrum of symptoms, including Morvan's syndrome, peripheral nerve hyperexcitability or neuromyotonia, and limbic or more extensive encephalitis. In addition there are reports of patients with antibodies against VGKC-related proteins that are different from LGI1 or Caspr2. In these cases, the identity and location of the antigens are unknown, the syndrome association is not specific, and the response to treatment uncertain. Conclusions The discovery of antigens such as LGI1 and Caspr2 has resulted in a clinical and molecular definition of the broad group of diseases previously attributed to antibodies against VGKC. Considering the literature that describes the presence of antibodies against VGKC other than LGI1 and Caspr2 proteins, we propose a practical

Protective Immunogenicity of Group A Streptococcal M-Related Proteins

PubMed Central

Niedermeyer, Shannon E.; Agbaosi, Tina; Hysmith, Nicholas D.; Penfound, Thomas A.; Hohn, Claudia M.; Pullen, Matthew; Bright, Michael I.; Murrell, Daniel S.; Shenep, Lori E.; Courtney, Harry S.

2015-01-01

Many previous studies have focused on the surface M proteins of group A streptococci (GAS) as virulence determinants and protective antigens. However, the majority of GAS isolates express M-related protein (Mrp) in addition to M protein, and both have been shown to be required for optimal virulence. In the current study, we evaluated the protective immunogenicity of Mrp to determine its potential as a vaccine component that may broaden the coverage of M protein-based vaccines. Sequence analyses of 33 mrp genes indicated that there are three families of structurally related Mrps (MrpI, MrpII, and MrpIII). N-terminal peptides of Mrps were cloned, expressed, and purified from M type 2 (M2) (MrpI), M4 (MrpII), and M49 (MrpIII) GAS. Rabbit antisera against the Mrps reacted at high titers with the homologous Mrp, as determined by enzyme-linked immunosorbent assay, and promoted bactericidal activity against GAS emm types expressing Mrps within the same family. Mice passively immunized with rabbit antisera against MrpII were protected against challenge infections with M28 GAS. Assays for Mrp antibodies in serum samples from 281 pediatric subjects aged 2 to 16 indicated that the Mrp immune response correlated with increasing age of the subjects. Affinity-purified human Mrp antibodies promoted bactericidal activity against a number of GAS representing different emm types that expressed an Mrp within the same family but showed no activity against emm types expressing an Mrp from a different family. Our results indicate that Mrps have semiconserved N-terminal sequences that contain bactericidal epitopes which are immunogenic in humans. These findings may have direct implications for the development of GAS vaccines. PMID:25630406

Co-infections of the cestode Echinococcus vogeli and the nematode Calodium hepaticum in the hystricomorphic rodent Agouti paca from a forest reserve in Acre, Brazil.

PubMed

Almeida, F; Caldas, R; Corrêa, C; Rodrigues-Silva, R; Siqueira, N; Machado-Silva, J R

2013-12-01

The helminth fauna of Agouti paca (Linnaeus, 1766) has seldom been studied. In this paper, we report an unusual mixed infection of Echinococcus vogeli Rausch & Bernstein, 1972 and Calodium hepaticum (syn. Capillaria hepatica Bancroft, 1863) in free-ranging paca from a forested region in Acre (Brazil). Gross morphological examination revealed that paca liver contained multiple spherical to subspherical white or translucent lesions, which were isolated or frequently contiguous and partially covered by Glisson's capsule. Microscopic examination revealed unilocular cystic structures that contained abundant brood capsules in which numerous protoscolices budded from the inner surface. The protoscolices possessed rostellar hooks (33-41 μm in length), a morphological characteristic of the blade and calcareous corpuscles that is consistent with the metacestode E. vogeli. The diagnosis of C. hepaticum infection was based on the morphology and morphometry of the egg-shaped ellipsoids with bipolar plugs (44.8 ± 1.9 μm (length) × 24.4 ± 2.0 μm (width)) and liver histopathology. This finding expands the known range of C. hepaticum hosts in South America and, to the best of our knowledge, it is the first case of a mixed infection of E. vogeli and C. hepaticum. Furthermore, our data provide evidence that wild animal meat may be a source of C. hepaticum infection.

Website on Protein Interaction and Protein Structure Related Work

NASA Technical Reports Server (NTRS)

Samanta, Manoj; Liang, Shoudan; Biegel, Bryan (Technical Monitor)

2003-01-01

In today's world, three seemingly diverse fields - computer information technology, nanotechnology and biotechnology are joining forces to enlarge our scientific knowledge and solve complex technological problems. Our group is dedicated to conduct theoretical research exploring the challenges in this area. The major areas of research include: 1) Yeast Protein Interactions; 2) Protein Structures; and 3) Current Transport through Small Molecules.

Protein v. carbohydrate intake differentially affects liking- and wanting-related brain signalling.

PubMed

Born, Jurriaan M; Martens, Mieke J I; Lemmens, Sofie G T; Goebel, Rainer; Westerterp-Plantenga, Margriet S

2013-01-28

Extreme macronutrient intakes possibly lead to different brain signalling. The aim of the present study was to determine the effects of ingesting high-protein v. high-carbohydrate food on liking and wanting task-related brain signalling (TRS) and subsequent macronutrient intake. A total of thirty female subjects (21.6 (SD 2.2) years, BMI 25.0 (SD 3.7) kg/m²) completed four functional MRI scans: two fasted and two satiated on two different days. During the scans, subjects rated all food items for liking and wanting, thereby choosing the subsequent meal. The results show that high-protein (PROT) v. high-carbohydrate (CARB) conditions were generated using protein or carbohydrate drinks at the first meal. Energy intake and hunger were recorded. PROT (protein: 53.7 (SD 2.1) percentage of energy (En%); carbohydrate: 6.4 (SD 1.3) En%) and CARB conditions (protein: 11.8 (SD 0.6) En%; carbohydrate: 70.0 (SD 2.4) En%) were achieved during the first meal, while the second meals were not different between the conditions. Hunger, energy intake, and behavioural liking and wanting ratings were decreased after the first meal (P< 0.001). Comparing the first with the second meal, the macronutrient content changed: carbohydrate -26.9 En% in the CARB condition, protein -37.8 En% in the PROT condition. After the first meal in the CARB condition, wanting TRS was increased in the hypothalamus. After the first meal in the PROT condition, liking TRS was decreased in the putamen (P< 0.05). The change in energy intake from the first to the second meal was inversely related to the change in liking TRS in the striatum and hypothalamus in the CARB condition and positively related in the PROT condition (P< 0.05). In conclusion, wanting and liking TRS were affected differentially with a change in carbohydrate or protein intake, underscoring subsequent energy intake and shift in macronutrient composition.

On the nature of a glassy state of matter in a hydrated protein: Relation to protein function.

PubMed

Teeter, M M; Yamano, A; Stec, B; Mohanty, U

2001-09-25

Diverse biochemical and biophysical experiments indicate that all proteins, regardless of size or origin, undergo a dynamic transition near 200 K. The cause of this shift in dynamic behavior, termed a "glass transition," and its relation to protein function are important open questions. One explanation postulated for the transition is solidification of correlated motions in proteins below the transition. We verified this conjecture by showing that crambin's radius of gyration (Rg) remains constant below approximately 180 K. We show that both atom position and dynamics of protein and solvent are physically coupled, leading to a novel cooperative state. This glassy state is identified by negative slopes of the Debye-Waller (B) factor vs. temperature. It is composed of multisubstate side chains and solvent. Based on generalization of Adam-Gibbs' notion of a cooperatively rearranging region and decrease of the total entropy with temperature, we calculate the slope of the Debye-Waller factor. The results are in accord with experiment.

Quantity of protein deposited on hydrogel contact lenses and its relation to visible protein deposits.

PubMed

Myers, R I; Larsen, D W; Tsao, M; Castellano, C; Becherer, L D; Fontana, F; Ghormley, N R; Meier, G

1991-10-01

The purposes of this study were to determine if the quantity of protein deposited (QPD) upon hydrogel lenses was affected by enzymatic cleaning and to test the potential relation between QPD and visible protein deposition (VPD) and change. Seventy-four contact lens patients classified as "heavy depositors" wore new lenses for an average of 80 (SD = 32) days. Cleaning and disinfection solutions varied. One lens was cleaned weekly by a papain enzymatic treatment. The distribution of QPD measurements was bimodal and was related to the FDA material for nonionic, low water content lenses (FDA Materials Group no. 1). The mean deposition was 45 micrograms/cm2 (N = 112) compared with that of ionic, high water content lenses (FDA Materials Group no. 4), which was 1010 micrograms/cm2 (N = 30). VPD distributions were the same for the FDA Group no. 1 and no. 4 lenses. Enzymatic treatment did not significantly reduce QPD; however, enzymatic treatment did reduce VPD. Thus QPD and VPD are independent phenomena and possible reasons for this are given.

Molecular Basis for Transmission Barrier and Interference between Closely Related Prion Proteins in Yeast*

PubMed Central

Afanasieva, Evgenia G.; Kushnirov, Vitaly V.; Tuite, Mick F.; Ter-Avanesyan, Michael D.

2011-01-01

Replicating amyloids, called prions, are responsible for transmissible neurodegenerative diseases in mammals and some heritable phenotypes in fungi. The transmission of prions between species is usually inhibited, being highly sensitive to small differences in amino acid sequence of the prion-forming proteins. To understand the molecular basis of this prion interspecies barrier, we studied the transmission of the [PSI+] prion state from Sup35 of Saccharomyces cerevisiae to hybrid Sup35 proteins with prion-forming domains from four other closely related Saccharomyces species. Whereas all the hybrid Sup35 proteins could adopt a prion form in S. cerevisiae, they could not readily acquire the prion form from the [PSI+] prion of S. cerevisiae. Expression of the hybrid Sup35 proteins in S. cerevisiae [PSI+] cells often resulted in frequent loss of the native [PSI+] prion. Furthermore, all hybrid Sup35 proteins showed different patterns of interaction with the native [PSI+] prion in terms of co-polymerization, acquisition of the prion state, and induced prion loss, all of which were also dependent on the [PSI+] variant. The observed loss of S. cerevisiae [PSI+] can be related to inhibition of prion polymerization of S. cerevisiae Sup35 and formation of a non-heritable form of amyloid. We have therefore identified two distinct molecular origins of prion transmission barriers between closely sequence-related prion proteins: first, the inability of heterologous proteins to co-aggregate with host prion polymers, and second, acquisition by these proteins of a non-heritable amyloid fold. PMID:21454674

Comparisons of MRI images, and auditory-related and vocal-related protein expressions in the brain of echolocation bats and rodents.

PubMed

Hsiao, Chun-Jen; Hsu, Chih-Hsiang; Lin, Ching-Lung; Wu, Chung-Hsin; Jen, Philip Hung-Sun

2016-08-17

Although echolocating bats and other mammals share the basic design of laryngeal apparatus for sound production and auditory system for sound reception, they have a specialized laryngeal mechanism for ultrasonic sound emissions as well as a highly developed auditory system for processing species-specific sounds. Because the sounds used by bats for echolocation and rodents for communication are quite different, there must be differences in the central nervous system devoted to producing and processing species-specific sounds between them. The present study examines the difference in the relative size of several brain structures and expression of auditory-related and vocal-related proteins in the central nervous system of echolocation bats and rodents. Here, we report that bats using constant frequency-frequency-modulated sounds (CF-FM bats) and FM bats for echolocation have a larger volume of midbrain nuclei (inferior and superior colliculi) and cerebellum relative to the size of the brain than rodents (mice and rats). However, the former have a smaller volume of the cerebrum and olfactory bulb, but greater expression of otoferlin and forkhead box protein P2 than the latter. Although the size of both midbrain colliculi is comparable in both CF-FM and FM bats, CF-FM bats have a larger cerebrum and greater expression of otoferlin and forkhead box protein P2 than FM bats. These differences in brain structure and protein expression are discussed in relation to their biologically relevant sounds and foraging behavior.

Heat-induced Protein Structure and Subfractions in Relation to Protein Degradation Kinetics and Intestinal Availability in Dairy Cattle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doiron, K.; Yu, P; McKinnon, J

2009-01-01

The objectives of this study were to reveal protein structures of feed tissues affected by heat processing at a cellular level, using the synchrotron-based Fourier transform infrared microspectroscopy as a novel approach, and quantify protein structure in relation to protein digestive kinetics and nutritive value in the rumen and intestine in dairy cattle. The parameters assessed included (1) protein structure a-helix to e-sheet ratio; (2) protein subfractions profiles; (3) protein degradation kinetics and effective degradability; (4) predicted nutrient supply using the intestinally absorbed protein supply (DVE)/degraded protein balance (OEB) system for dairy cattle. In this study, Vimy flaxseed protein wasmore » used as a model feed protein and was autoclave-heated at 120C for 20, 40, and 60 min in treatments T1, T2, and T3, respectively. The results showed that using the synchrotron-based Fourier transform infrared microspectroscopy revealed and identified the heat-induced protein structure changes. Heating at 120C for 40 and 60 min increased the protein structure a-helix to e-sheet ratio. There were linear effects of heating time on the ratio. The heating also changed chemical profiles, which showed soluble CP decreased upon heating with concomitant increases in nonprotein nitrogen, neutral, and acid detergent insoluble nitrogen. The protein subfractions with the greatest changes were PB1, which showed a dramatic reduction, and PB2, which showed a dramatic increase, demonstrating a decrease in overall protein degradability. In situ results showed a reduction in rumen-degradable protein and in rumen-degradable dry matter without differences between the treatments. Intestinal digestibility, determined using a 3-step in vitro procedure, showed no changes to rumen undegradable protein. Modeling results showed that heating increased total intestinally absorbable protein (feed DVE value) and decreased degraded protein balance (feed OEB value), but there were no

High Dietary Protein Intake and Protein-Related Acid Load on Bone Health.

PubMed

Cao, Jay J

2017-12-01

Consumption of high-protein diets is increasingly popular due to the benefits of protein on preserving lean mass and controlling appetite and satiety. The paper is to review recent clinical research assessing dietary protein on calcium metabolism and bone health. Epidemiological studies show that long-term, high-protein intake is positively associated with bone mineral density and reduced risk of bone fracture incidence. Short-term interventional studies demonstrate that a high-protein diet does not negatively affect calcium homeostasis. Existing evidence supports that the negative effects of the acid load of protein on urinary calcium excretion are offset by the beneficial skeletal effects of high-protein intake. Future research should focus on the role and the degree of contribution of other dietary and physiological factors, such as intake of fruits and vegetables, in reducing the acid load and further enhancing the anabolic effects of protein on the musculoskeletal system.

76 FR 63316 - Prospective Grant of Exclusive License: Secreted Frizzled Related Protein-1 (sFRP-1) and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-12

... Exclusive License: Secreted Frizzled Related Protein-1 (sFRP-1) and derivatives thereof and their Use In... belonging to the patent families having HHS Reference Numbers E-160-1997/0,/1,/2 and/3; E-014-2000/0; and E... Related Protein-1 (sFRP-1). sFRP-1, also known as SARP-2 (Secreted Apoptosis Related Protein-2). The IP...

β-Catenin activity in the dermal papilla of the hair follicle regulates pigment-type switching

PubMed Central

Enshell-Seijffers, David; Lindon, Catherine; Wu, Eleanor; Taketo, Makoto M.; Morgan, Bruce A.

2010-01-01

The switch between black and yellow pigment is mediated by the interaction between Melanocortin receptor 1 (Mc1r) and its antagonist Agouti, but the genetic and developmental mechanisms that modify this interaction to obtain different coat color in distinct environments are poorly understood. Here, the role of Wnt/β-catenin signaling in the regulation of pigment-type switching was studied. Loss and gain of function of β-catenin in the dermal papilla (DP) of the hair follicle results in yellow and black animals, respectively. β-Catenin activity in the DP suppresses Agouti expression and activates Corin, a negative regulator of Agouti activity. In addition, β-catenin activity in the DP regulates melanocyte activity by a mechanism that is independent of both Agouti and Corin. The coordinate and inverse regulation of Agouti and Corin renders pelage pigmentation sensitive to changes in β-catenin activity in the DP that do not alter pelage structure. As a result, the signals that specify two biologically distinct quantitative traits are partially uncoupled despite their common regulation by the β-catenin pathway in the same cells. PMID:21098273

Eukaryotic elongation factor 2 kinase regulates the synthesis of microtubule-related proteins in neurons.

PubMed

Kenney, Justin W; Genheden, Maja; Moon, Kyung-Mee; Wang, Xuemin; Foster, Leonard J; Proud, Christopher G

2016-01-01

Modulation of the elongation phase of protein synthesis is important for numerous physiological processes in both neurons and other cell types. Elongation is primarily regulated via eukaryotic elongation factor 2 kinase (eEF2K). However, the consequence of altering eEF2K activity on the synthesis of specific proteins is largely unknown. Using both pharmacological and genetic manipulations of eEF2K combined with two protein-labeling techniques, stable isotope labeling of amino acids in cell culture and bio-orthogonal non-canonical amino acid tagging, we identified a subset of proteins whose synthesis is sensitive to inhibition of eEF2K in murine primary cortical neurons. Gene ontology (GO) analyses indicated that processes related to microtubules are particularly sensitive to eEF2K inhibition. Our findings suggest that eEF2K likely contributes to neuronal function by regulating the synthesis of microtubule-related proteins. Modulation of the elongation phase of protein synthesis is important for numerous physiological processes in neurons. Here, using labeling of new proteins coupled with proteomic techniques in primary cortical neurons, we find that the synthesis of microtubule-related proteins is up-regulated by inhibition of elongation. This suggests that translation elongation is a key regulator of cytoskeletal dynamics in neurons. © 2015 The Authors. Journal of Neurochemistry published by John Wiley & Sons Ltd on behalf of International Society for Neurochemistry.

Clinical spectrum and diagnostic value of antibodies against the potassium channel related protein complex.

PubMed

Montojo, M T; Petit-Pedrol, M; Graus, F; Dalmau, J

2015-06-01

Antibodies against a protein complex that includes voltage-gated potassium channels (VGKC) have been reported in patients with limbic encephalitis, peripheral nerve hyperexcitability, Morvan's syndrome, and a large variety of neurological syndromes. In this article, a review is presented of the syndromes associated with antibodies against VGKC-related proteins and the main antigens of this protein complex, the proteins LGI1 (leucine rich glioma inactivated protein 1) and Caspr2 (contactin-associated protein-like 2). The conceptual problems and clinical implications of the description of antibodies against VGKC-related proteins other than LGI1 and Caspr2 are also discussed. Although initial studies indicated the occurrence of antibodies against VGKC, recent investigations have shown that the main antigens are a neuronal secreted protein known as LGI1 which modulates synaptic excitability, and a protein called Caspr2 located on the cell surface and processes of neurons of different brain regions, and at the juxtaparanodal region of myelinated axons. While antibodies against LGI1 preferentially associate with classical limbic encephalitis, antibodies against Caspr2 associate with a wider spectrum of symptoms, including Morvan's syndrome, peripheral nerve hyperexcitability or neuromyotonia, and limbic or more extensive encephalitis. In addition there are reports of patients with antibodies against VGKC-related proteins that are different from LGI1 or Caspr2. In these cases, the identity and location of the antigens are unknown, the syndrome association is not specific, and the response to treatment uncertain. The discovery of antigens such as LGI1 and Caspr2 has resulted in a clinical and molecular definition of the broad group of diseases previously attributed to antibodies against VGKC. Considering the literature that describes the presence of antibodies against VGKC other than LGI1 and Caspr2 proteins, we propose a practical algorithm for the diagnosis and treatment

A close relative of the nuclear, chromosomal high-mobility group protein HMG1 in yeast mitochondria.

PubMed Central

Diffley, J F; Stillman, B

1991-01-01

ABF2 (ARS-binding factor 2), a small, basic DNA-binding protein that binds specifically to the autonomously replicating sequence ARS1, is located primarily in the mitochondria of the yeast Saccharomyces cerevisiae. The abundance of ABF2 and the phenotype of abf2- null mutants argue that this protein plays a key role in the structure, maintenance, and expression of the yeast mitochondrial genome. The predicted amino acid sequence of ABF2 is closely related to the high-mobility group proteins HMG1 and HMG2 from vertebrate cell nuclei and to several other DNA-binding proteins. Additionally, ABF2 and the other HMG-related proteins are related to a globular domain from the heat shock protein hsp70 family. ABF2 interacts with DNA both nonspecifically and in a specific manner within regulatory regions, suggesting a mechanism whereby it may aid in compacting the mitochondrial genome without interfering with expression. Images PMID:1881919

High dietary protein intake and protein-related acid load on bone health

USDA-ARS?s Scientific Manuscript database

Protein is an essential nutrient for humans and is required for maintaining optimal bone structure and growth. Consumption of high protein diets in excess of the Recommended Dietary Allowance of (0.8 g protein/kg body weight/d) is increasingly popular due to the benefits of protein on preserving lea...

Age-related carbonylation of fibrocartilage structural proteins drives tissue degenerative modification.

PubMed

Scharf, Brian; Clement, Cristina C; Yodmuang, Supansa; Urbanska, Aleksandra M; Suadicani, Sylvia O; Aphkhazava, David; Thi, Mia M; Perino, Giorgio; Hardin, John A; Cobelli, Neil; Vunjak-Novakovic, Gordana; Santambrogio, Laura

2013-07-25

Aging-related oxidative stress has been linked to degenerative modifications in different organs and tissues. Using redox proteomic analysis and illustrative tandem mass spectrometry mapping, we demonstrate oxidative posttranslational modifications in structural proteins of intervertebral discs (IVDs) isolated from aging mice. Increased protein carbonylation was associated with protein fragmentation and aggregation. Complementing these findings, a significant loss of elasticity and increased stiffness was measured in fibrocartilage from aging mice. Studies using circular dichroism and intrinsic tryptophan fluorescence revealed a significant loss of secondary and tertiary structures of purified collagens following oxidation. Collagen unfolding and oxidation promoted both nonenzymatic and enzymatic degradation. Importantly, induction of oxidative modification in healthy fibrocartilage recapitulated the biochemical and biophysical modifications observed in the aging IVD. Together, these results suggest that protein carbonylation, glycation, and lipoxidation could be early events in promoting IVD degenerative changes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Prion Protein M129V Polymorphism Affects Retrieval-Related Brain Activity

ERIC Educational Resources Information Center

Buchmann, Andreas; Mondadori, Christian R. A.; Hanggi, Jurgen; Aerni, Amanda; Vrticka, Pascal; Luechinger, Roger; Boesiger, Peter; Hock, Christoph; Nitsch, Roger M.; de Quervain, Dominique J.-F.; Papassotiropoulos, Andreas; Henke, Katharina

2008-01-01

The prion protein Met129Val polymorphism has recently been related to human long-term memory with carriers of either the 129[superscript MM] or the 129[superscript MV] genotype recalling 17% more words than 129[superscript VV] carriers at 24 h following learning. Here, we sampled genotype differences in retrieval-related brain activity at 30 min…

The etiology of human age-related cataract. Proteins don't last forever.

PubMed

Truscott, Roger J W; Friedrich, Michael G

2016-01-01

It is probable that the great majority of human cataract results from the spontaneous decomposition of long-lived macromolecules in the human lens. Breakdown/reaction of long-lived proteins is of primary importance and recent proteomic analysis has enabled the identification of the particular crystallins, and their exact sites of amino acid modification. Analysis of proteins from cataractous lenses revealed that there are sites on some structural proteins that show a consistently greater degree of deterioration than age-matched normal lenses. The most abundant posttranslational modification of aged lens proteins is racemization. Deamidation, truncation and crosslinking, each arising from the spontaneous breakdown of susceptible amino acids within proteins, are also present. Fundamental to an understanding of nuclear cataract etiology, it is proposed that once a certain degree of modification at key sites occurs, that protein-protein interactions are disrupted and lens opacification ensues. Since long-lived proteins are now recognized to be present in many other sites of the body, such as the brain, the information gleaned from detailed analyses of degraded proteins from aged lenses will apply more widely to other age-related human diseases. This article is part of a Special Issue entitled Crystallin Biochemistry in Health and Disease. Copyright © 2015 Elsevier B.V. All rights reserved.

Cysteine-rich domains related to Frizzled receptors and Hedgehog-interacting proteins

PubMed Central

Pei, Jimin; Grishin, Nick V

2012-01-01

Frizzled and Smoothened are homologous seven-transmembrane proteins functioning in the Wnt and Hedgehog signaling pathways, respectively. They harbor an extracellular cysteine-rich domain (FZ-CRD), a mobile evolutionary unit that has been found in a number of other metazoan proteins and Frizzled-like proteins in Dictyostelium. Domains distantly related to FZ-CRDs, in Hedgehog-interacting proteins (HHIPs), folate receptors and riboflavin-binding proteins (FRBPs), and Niemann-Pick Type C1 proteins (NPC1s), referred to as HFN-CRDs, exhibit similar structures and disulfide connectivity patterns compared with FZ-CRDs. We used computational analyses to expand the homologous set of FZ-CRDs and HFN-CRDs, providing a better understanding of their evolution and classification. First, FZ-CRD-containing proteins with various domain compositions were identified in several major eukaryotic lineages including plants and Chromalveolata, revealing a wider phylogenetic distribution of FZ-CRDs than previously recognized. Second, two new and distinct groups of highly divergent FZ-CRDs were found by sensitive similarity searches. One of them is present in the calcium channel component Mid1 in fungi and the uncharacterized FAM155 proteins in metazoans. Members of the other new FZ-CRD group occur in the metazoan-specific RECK (reversion-inducing-cysteine-rich protein with Kazal motifs) proteins that are putative tumor suppressors acting as inhibitors of matrix metalloproteases. Finally, sequence and three-dimensional structural comparisons helped us uncover a divergent HFN-CRD in glypicans, which are important morphogen-binding heparan sulfate proteoglycans. Such a finding reinforces the evolutionary ties between the Wnt and Hedgehog signaling pathways and underscores the importance of gene duplications in creating essential signaling components in metazoan evolution. PMID:22693159

The 29-kDa proteins phosphorylated ion thrombin-activated human platelets are forms of the estrogen receptor-related 27-kDa heat shock protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mendelsohn, M.E.; Yan Zhu; O'Neill, S.

Thrombin plays a critical role in platelet activation, hemostasis, and thrombosis. Cellular activation by thrombin leads to the phosphorylation of multiple proteins, most of which are unidentified. The authors have characterized several 29-kDa proteins that are rapidly phosphorylated following exposure of intact human platelets to thrombin. A murine monoclonal antibody raised to an unidentified estrogen receptor-related 29-kDa protein selectively recognized these proteins as well as a more basic, unphosphorylated 27-kDa protein. Cellular activation by thrombin led to a marked shift in the proportion of protein from the 27-kDa unphosphorylated form to the 29-kDa phosphoprotein species. Using this antibody, they isolatedmore » and sequenced a human cDNA clone encoding a protein that was identical to the mammalian 27-kDa heat shock protein (HSP27), a protein of uncertain function that is known to be phosphorylated to several forms and to be transcriptionally induced by estrogen. The 29-kDa proteins were confirmed to be phosphorylated forms of HSP27 by immunoprecipitation studies. Thus, the estrogen receptor-related protein is HSP27, and the three major 20-kDa proteins phosphorylated in thrombin-activated platelets are forms of HSP27. These data suggest a role for HSP27 in the signal transduction events of platelet activation.« less

Incorporating significant amino acid pairs and protein domains to predict RNA splicing-related proteins with functional roles

NASA Astrophysics Data System (ADS)

Hsu, Justin Bo-Kai; Huang, Kai-Yao; Weng, Tzu-Ya; Huang, Chien-Hsun; Lee, Tzong-Yi

2014-01-01

Machinery of pre-mRNA splicing is carried out through the interaction of RNA sequence elements and a variety of RNA splicing-related proteins (SRPs) (e.g. spliceosome and splicing factors). Alternative splicing, which is an important post-transcriptional regulation in eukaryotes, gives rise to multiple mature mRNA isoforms, which encodes proteins with functional diversities. However, the regulation of RNA splicing is not yet fully elucidated, partly because SRPs have not yet been exhaustively identified and the experimental identification is labor-intensive. Therefore, we are motivated to design a new method for identifying SRPs with their functional roles in the regulation of RNA splicing. The experimentally verified SRPs were manually curated from research articles. According to the functional annotation of Splicing Related Gene Database, the collected SRPs were further categorized into four functional groups including small nuclear Ribonucleoprotein, Splicing Factor, Splicing Regulation Factor and Novel Spliceosome Protein. The composition of amino acid pairs indicates that there are remarkable differences among four functional groups of SRPs. Then, support vector machines (SVMs) were utilized to learn the predictive models for identifying SRPs as well as their functional roles. The cross-validation evaluation presents that the SVM models trained with significant amino acid pairs and functional domains could provide a better predictive performance. In addition, the independent testing demonstrates that the proposed method could accurately identify SRPs in mammals/plants as well as effectively distinguish between SRPs and RNA-binding proteins. This investigation provides a practical means to identifying potential SRPs and a perspective for exploring the regulation of RNA splicing.

Incorporating significant amino acid pairs and protein domains to predict RNA splicing-related proteins with functional roles.

PubMed

Hsu, Justin Bo-Kai; Huang, Kai-Yao; Weng, Tzu-Ya; Huang, Chien-Hsun; Lee, Tzong-Yi

2014-01-01

Machinery of pre-mRNA splicing is carried out through the interaction of RNA sequence elements and a variety of RNA splicing-related proteins (SRPs) (e.g. spliceosome and splicing factors). Alternative splicing, which is an important post-transcriptional regulation in eukaryotes, gives rise to multiple mature mRNA isoforms, which encodes proteins with functional diversities. However, the regulation of RNA splicing is not yet fully elucidated, partly because SRPs have not yet been exhaustively identified and the experimental identification is labor-intensive. Therefore, we are motivated to design a new method for identifying SRPs with their functional roles in the regulation of RNA splicing. The experimentally verified SRPs were manually curated from research articles. According to the functional annotation of Splicing Related Gene Database, the collected SRPs were further categorized into four functional groups including small nuclear Ribonucleoprotein, Splicing Factor, Splicing Regulation Factor and Novel Spliceosome Protein. The composition of amino acid pairs indicates that there are remarkable differences among four functional groups of SRPs. Then, support vector machines (SVMs) were utilized to learn the predictive models for identifying SRPs as well as their functional roles. The cross-validation evaluation presents that the SVM models trained with significant amino acid pairs and functional domains could provide a better predictive performance. In addition, the independent testing demonstrates that the proposed method could accurately identify SRPs in mammals/plants as well as effectively distinguish between SRPs and RNA-binding proteins. This investigation provides a practical means to identifying potential SRPs and a perspective for exploring the regulation of RNA splicing.

PPInterFinder—a mining tool for extracting causal relations on human proteins from literature

PubMed Central

Raja, Kalpana; Subramani, Suresh; Natarajan, Jeyakumar

2013-01-01

One of the most common and challenging problem in biomedical text mining is to mine protein–protein interactions (PPIs) from MEDLINE abstracts and full-text research articles because PPIs play a major role in understanding the various biological processes and the impact of proteins in diseases. We implemented, PPInterFinder—a web-based text mining tool to extract human PPIs from biomedical literature. PPInterFinder uses relation keyword co-occurrences with protein names to extract information on PPIs from MEDLINE abstracts and consists of three phases. First, it identifies the relation keyword using a parser with Tregex and a relation keyword dictionary. Next, it automatically identifies the candidate PPI pairs with a set of rules related to PPI recognition. Finally, it extracts the relations by matching the sentence with a set of 11 specific patterns based on the syntactic nature of PPI pair. We find that PPInterFinder is capable of predicting PPIs with the accuracy of 66.05% on AIMED corpus and outperforms most of the existing systems. Database URL: http://www.biomining-bu.in/ppinterfinder/ PMID:23325628

ECM Proteins Glycosylation and Relation to Diabetes

NASA Astrophysics Data System (ADS)

Pernodet, Nadine; Bloomberg, Ayla; Sood, Vandana; Slutsky, Lenny; Ge, Shouren; Clark, Richard; Rafailovich, Miriam

2004-03-01

The chemical modification and crosslinking of proteins by sugar glycosylation contribute to the aging of tissue proteins, and acceleration of this reaction during hyperglycemia is implicated in the pathogenesis of diabetic complications, such as disorder of the wound healing. Advanced glycation endproducts (AGEs) formation and protein crosslinking are irreversible processes that alter the structural and functional properties of proteins, lipid components and nucleic acids. And the mechanism, by which it happens, is not clear. Fibrinogen and fibronectin are plasma proteins, which play a major role in human wound healing. Fibrinogen converts to an insoluble fibrin "gel" following a cut, which eventually forms a clot to prevent blood loss, to direct cell adhesion and migration for forming scars. Fibronectin is a critical protein for cell adhesion and migration in wound healing. The effects of glucose on the binding of these plasma proteins from the extra cellular matrix (ECM) were followed at different concentrations by atomic force microscopy and lateral force modulation to measure the mechanical response of the samples. Glucose solutions (1, 2, and 3mg/mL) were incubated with the protein (100 mg/ml) and silicon (Si) substrates spun with sulfonated polystyrene (SPS) 28% for five days. Data showed that not only the organization of the protein on the surface was affected but also its mechanical properties. At 3 mg/mL glucose, Fn fibers were observed to be harder than those of the control, in good agreement with our hypothesis that glycosylation hardens tissues by crosslinking of proteins in the ECM and might cause fibers to break more easily.

Effect of ethephon on protein degradation and the accumulation of pathogensis-related (PR) proteins in tomato leaf discs. [Lycopersicon esculentum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vera, P.; Conejero, V.

The effect of ethephon (2-chloroetylphosphonic acid) on the degradation of proteins and on the induction of Lycopersicon esculentum pathogenesis-related (PR) proteins was studied in tomato leaf discs. The rate of ribulose, -1,5-bisphosphate carboxylase/oxygenase (Rubisco) degradation was maximal in discs after 48 hours of incubation with 1 millimolar ethephon, leading to complete disappearance of Rubisco after 96 hours. This effect was correlated with an increase in PR protein synthesis and the induction of the previously reported alkaline proteolytic enzyme PR-P69. In vivo pulse-chase experiments demonstrated that ethephon not only affected Rubisco content but that of many other {sup 35}S-labeled proteins asmore » well, indicating that ethylene activates a general and nonspecific mechanism of protein degradation. This effect was partially inhibited in vivo by the action of pCMB, a selective inhibitor of cysteine-proteinases such as P69. These data reinforce the hypothesis that P69 and perhaps other PR proteins are involved in the mechanism of accelerated protein degradation activated by ethylene.« less

CMP‑N‑acetylneuraminic acid synthetase interacts with fragile X related protein 1.

PubMed

Ma, Yun; Tian, Shuai; Wang, Zongbao; Wang, Changbo; Chen, Xiaowei; Li, Wei; Yang, Yang; He, Shuya

2016-08-01

Fragile X mental retardation protein (FMRP), fragile X related 1 protein (FXR1P) and FXR2P are the members of the FMR protein family. These proteins contain two KH domains and a RGG box, which are characteristic of RNA binding proteins. The absence of FMRP, causes fragile X syndrome (FXS), the leading cause of hereditary mental retardation. FXR1P is expressed throughout the body and important for normal muscle development, and its absence causes cardiac abnormality. To investigate the functions of FXR1P, a screen was performed to identify FXR1P‑interacting proteins and determine the biological effect of the interaction. The current study identified CMP‑N‑acetylneuraminic acid synthetase (CMAS) as an interacting protein using the yeast two‑hybrid system, and the interaction between FXR1P and CMAS was validated in yeast using a β‑galactosidase assay and growth studies with selective media. Furthermore, co‑immunoprecipitation was used to analyze the FXR1P/CMAS association and immunofluorescence microscopy was performed to detect expression and intracellular localization of the proteins. The results of the current study indicated that FXR1P and CMAS interact, and colocalize in the cytoplasm and the nucleus of HEK293T and HeLa cells. Accordingly, a fragile X related 1 (FXR1) gene overexpression vector was constructed to investigate the effect of FXR1 overexpression on the level of monosialotetrahexosylganglioside 1 (GM1). The results of the current study suggested that FXR1P is a tissue‑specific regulator of GM1 levels in SH‑SY5Y cells, but not in HEK293T cells. Taken together, the results initially indicate that FXR1P interacts with CMAS, and that FXR1P may enhance the activation of sialic acid via interaction with CMAS, and increase GM1 levels to affect the development of the nervous system, thus providing evidence for further research into the pathogenesis of FXS.

Differentiation of the Ribosomal Protein Compositions in the Genus Escherichia and Its Related Bacteria

PubMed Central

Osawa, Syozo; Itoh, Takuzi; Otaka, Eiko

1971-01-01

Compositions of the ribosomal proteins of 60 bacterial strains belonging to the genus Escherichia and its related genera were examined by use of a column of carboxymethyl cellulose. The ribosomes were classified into seven groups and were further differentiated into several types (subgroups) according to their protein compositions. It was shown that ribosomal protein composition is a useful characteristic for studies of bacterial taxonomy. PMID:5563866

Activation of multiple mitogen-activated protein kinases by recombinant calcitonin gene-related peptide receptor.

PubMed

Parameswaran, N; Disa, J; Spielman, W S; Brooks, D P; Nambi, P; Aiyar, N

2000-02-18

Calcitonin gene-related peptide is a 37-amino-acid neuropeptide and a potent vasodilator. Although calcitonin gene-related peptide has been shown to have a number of effects in a variety of systems, the mechanisms of action and the intracellular signaling pathways, especially the regulation of mitogen-activated protien kinase (MAPK) pathway, is not known. In the present study we investigated the role of calcitonin gene-related peptide in the regulation of MAPKs in human embryonic kidney (HEK) 293 cells stably transfected with a recombinant porcine calcitonin gene-related peptide-1 receptor. Calcitonin gene-related peptide caused a significant dose-dependent increase in cAMP response and the effect was inhibited by calcitonin gene-related peptide(8-37), the calcitonin gene-related peptide-receptor antagonist. Calcitonin gene-related peptide also caused a time- and concentration-dependent increase in extracellular signal-regulated kinase (ERK) and P38 mitogen-activated protein kinase (P38 MAPK) activities, with apparently no significant change in cjun-N-terminal kinase (JNK) activity. Forskolin, a direct activator of adenylyl cyclase also stimulated ERK and P38 activities in these cells suggesting the invovement of cAMP in this process. Calcitonin gene-related peptide-stimulated ERK and P38 MAPK activities were inhibited significantly by calcitonin gene-related peptide receptor antagonist, calcitonin gene-related peptide-(8-37) suggesting the involvement of calcitonin gene-related peptide-1 receptor. Preincubation of the cells with the cAMP-dependent protein kinase inhibitor, H89 [¿N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide, hydrochloride¿] inhibited calcitonin gene-related peptide-mediated activation of ERK and p38 kinases. On the other hand, preincubation of the cells with wortmannin ¿[1S-(1alpha,6balpha,9abeta,11alpha, 11bbeta)]-11-(acetyloxy)-1,6b,7,8,9a,10,11, 11b-octahydro-1-(methoxymethyl)-9a,11b-dimethyl-3H-furo[4,3, 2-de]indeno[4,5-h]-2

The Primary Role of Fibrinogen-Related Proteins in Invertebrates Is Defense, Not Coagulation

PubMed Central

Hanington, Patrick C.; Zhang, Si-Ming

2010-01-01

In vertebrates, the conversion of fibrinogen into fibrin is an essential process that underlies the establishment of the supporting protein framework required for coagulation. In invertebrates, fibrinogen-domain-containing proteins play a role in the defense response generated against pathogens; however, they do not function in coagulation, suggesting that this role has been recently acquired. Molecules containing fibrinogen motifs have been identified in numerous invertebrate organisms, and most of these molecules known to date have been linked to defense. Moreover, recent genome projects of invertebrate animals have revealed surprisingly high numbers of fibrinogen-like loci in their genomes, suggesting important and perhaps diverse functions of fibrinogen-like proteins in invertebrates. The ancestral role of molecules containing fibrinogen-related domains (FReDs) with immunity is the focus of this review, with emphasis on specific FReDs called fibrinogen-related proteins (FREPs) identified from the schistosome-transmitting mollusc Biomphalaria glabrata. Herein, we outline the range of invertebrate organisms FREPs can be found in, and detail the roles these molecules play in defense and protection against infection. PMID:21063081

Domain fusion analysis by applying relational algebra to protein sequence and domain databases.

PubMed

Truong, Kevin; Ikura, Mitsuhiko

2003-05-06

Domain fusion analysis is a useful method to predict functionally linked proteins that may be involved in direct protein-protein interactions or in the same metabolic or signaling pathway. As separate domain databases like BLOCKS, PROSITE, Pfam, SMART, PRINTS-S, ProDom, TIGRFAMs, and amalgamated domain databases like InterPro continue to grow in size and quality, a computational method to perform domain fusion analysis that leverages on these efforts will become increasingly powerful. This paper proposes a computational method employing relational algebra to find domain fusions in protein sequence databases. The feasibility of this method was illustrated on the SWISS-PROT+TrEMBL sequence database using domain predictions from the Pfam HMM (hidden Markov model) database. We identified 235 and 189 putative functionally linked protein partners in H. sapiens and S. cerevisiae, respectively. From scientific literature, we were able to confirm many of these functional linkages, while the remainder offer testable experimental hypothesis. Results can be viewed at http://calcium.uhnres.utoronto.ca/pi. As the analysis can be computed quickly on any relational database that supports standard SQL (structured query language), it can be dynamically updated along with the sequence and domain databases, thereby improving the quality of predictions over time.

Domain fusion analysis by applying relational algebra to protein sequence and domain databases

PubMed Central

Truong, Kevin; Ikura, Mitsuhiko

2003-01-01

Background Domain fusion analysis is a useful method to predict functionally linked proteins that may be involved in direct protein-protein interactions or in the same metabolic or signaling pathway. As separate domain databases like BLOCKS, PROSITE, Pfam, SMART, PRINTS-S, ProDom, TIGRFAMs, and amalgamated domain databases like InterPro continue to grow in size and quality, a computational method to perform domain fusion analysis that leverages on these efforts will become increasingly powerful. Results This paper proposes a computational method employing relational algebra to find domain fusions in protein sequence databases. The feasibility of this method was illustrated on the SWISS-PROT+TrEMBL sequence database using domain predictions from the Pfam HMM (hidden Markov model) database. We identified 235 and 189 putative functionally linked protein partners in H. sapiens and S. cerevisiae, respectively. From scientific literature, we were able to confirm many of these functional linkages, while the remainder offer testable experimental hypothesis. Results can be viewed at . Conclusion As the analysis can be computed quickly on any relational database that supports standard SQL (structured query language), it can be dynamically updated along with the sequence and domain databases, thereby improving the quality of predictions over time. PMID:12734020

PACSY, a relational database management system for protein structure and chemical shift analysis.

PubMed

Lee, Woonghee; Yu, Wookyung; Kim, Suhkmann; Chang, Iksoo; Lee, Weontae; Markley, John L

2012-10-01

PACSY (Protein structure And Chemical Shift NMR spectroscopY) is a relational database management system that integrates information from the Protein Data Bank, the Biological Magnetic Resonance Data Bank, and the Structural Classification of Proteins database. PACSY provides three-dimensional coordinates and chemical shifts of atoms along with derived information such as torsion angles, solvent accessible surface areas, and hydrophobicity scales. PACSY consists of six relational table types linked to one another for coherence by key identification numbers. Database queries are enabled by advanced search functions supported by an RDBMS server such as MySQL or PostgreSQL. PACSY enables users to search for combinations of information from different database sources in support of their research. Two software packages, PACSY Maker for database creation and PACSY Analyzer for database analysis, are available from http://pacsy.nmrfam.wisc.edu.

PACSY, a relational database management system for protein structure and chemical shift analysis

PubMed Central

Lee, Woonghee; Yu, Wookyung; Kim, Suhkmann; Chang, Iksoo

2012-01-01

PACSY (Protein structure And Chemical Shift NMR spectroscopY) is a relational database management system that integrates information from the Protein Data Bank, the Biological Magnetic Resonance Data Bank, and the Structural Classification of Proteins database. PACSY provides three-dimensional coordinates and chemical shifts of atoms along with derived information such as torsion angles, solvent accessible surface areas, and hydrophobicity scales. PACSY consists of six relational table types linked to one another for coherence by key identification numbers. Database queries are enabled by advanced search functions supported by an RDBMS server such as MySQL or PostgreSQL. PACSY enables users to search for combinations of information from different database sources in support of their research. Two software packages, PACSY Maker for database creation and PACSY Analyzer for database analysis, are available from http://pacsy.nmrfam.wisc.edu. PMID:22903636

Moderate high fat diet increases sucrose self-administration in young rats.

PubMed

Figlewicz, Dianne P; Jay, Jennifer L; Acheson, Molly A; Magrisso, Irwin J; West, Constance H; Zavosh, Aryana; Benoit, Stephen C; Davis, Jon F

2013-02-01

We have previously reported that a moderately high fat diet increases motivation for sucrose in adult rats. In this study, we tested the motivational, neurochemical, and metabolic effects of the high fat diet in male rats transitioning through puberty, during 5-8 weeks of age. We observed that the high fat diet increased motivated responding for sucrose, which was independent of either metabolic changes or changes in catecholamine neurotransmitter metabolites in the nucleus accumbens. However, AGRP mRNA levels in the hypothalamus were significantly elevated. We demonstrated that increased activation of AGRP neurons is associated with motivated behavior, and that exogenous (third cerebroventricular) AGRP administration resulted in significantly increased motivation for sucrose. These observations suggest that increased expression and activity of AGRP in the medial hypothalamus may underlie the increased responding for sucrose caused by the high fat diet intervention. Finally, we compared motivation for sucrose in pubertal vs. adult rats and observed increased motivation for sucrose in the pubertal rats, which is consistent with previous reports that young animals and humans have an increased preference for sweet taste, compared with adults. Together, our studies suggest that background diet plays a strong modulatory role in motivation for sweet taste in adolescent animals. Published by Elsevier Ltd.

Moderate High Fat Diet Increases Sucrose Self-Administration In Young Rats

PubMed Central

Figlewicz, Dianne P.; Jay, Jennifer L.; Acheson, Molly A.; Magrisso, Irwin J.; West, Constance H.; Zavosh, Aryana; Benoit, Stephen C.; Davis, Jon F.

2012-01-01

We have previously reported that a moderately high fat diet increases motivation for sucrose in adult rats. In this study, we tested the motivational, neurochemical, and metabolic effects of the high fat diet in male rats transitioning through puberty, during 5-8 weeks of age. We observed that the high fat diet increased motivated responding for sucrose, which was independent of either metabolic changes or changes in catecholamine neurotransmitter metabolites in the nucleus accumbens. However, AGRP mRNA levels in the hypothalamus were significantly elevated. We demonstrated that increased activation of AGRP neurons is associated with motivated behavior, and that exogenous (third cerebroventricular) AGRP administration resulted in significantly increased motivation for sucrose. These observations suggest that increased expression and activity of AGRP in the medial hypothalamus may underlie the increased responding for sucrose caused by the high fat diet intervention. Finally, we compared motivation for sucrose in pubertal vs. adult rats and observed increased motivation for sucrose in the pubertal rats, which is consistent with previous reports that young animals and humans have an increased preference for sweet taste, compared with adults. Together, our studies suggest that background diet plays a strong modulatory role in motivation for sweet taste in adolescent animals. PMID:23023044

The Saccharomyces cerevisiae enolase-related regions encode proteins that are active enolases.

PubMed

Kornblatt, M J; Richard Albert, J; Mattie, S; Zakaib, J; Dayanandan, S; Hanic-Joyce, P J; Joyce, P B M

2013-02-01

In addition to two genes (ENO1 and ENO2) known to code for enolase (EC4.2.1.11), the Saccharomyces cerevisiae genome contains three enolase-related regions (ERR1, ERR2 and ERR3) which could potentially encode proteins with enolase function. Here, we show that products of these genes (Err2p and Err3p) have secondary and quaternary structures similar to those of yeast enolase (Eno1p). In addition, Err2p and Err3p can convert 2-phosphoglycerate to phosphoenolpyruvate, with kinetic parameters similar to those of Eno1p, suggesting that these proteins could function as enolases in vivo. To address this possibility, we overexpressed the ERR2 and ERR3 genes individually in a double-null yeast strain lacking ENO1 and ENO2, and showed that either ERR2 or ERR3 could complement the growth defect in this strain when cells are grown in medium with glucose as the carbon source. Taken together, these data suggest that the ERR genes in Saccharomyces cerevisiae encode a protein that could function in glycolysis as enolase. The presence of these enolase-related regions in Saccharomyces cerevisiae and their absence in other related yeasts suggests that these genes may play some unique role in Saccharomyces cerevisiae. Further experiments will be required to determine whether these functions are related to glycolysis or other cellular processes. Copyright © 2012 John Wiley & Sons, Ltd.

A longitudinal analysis of circulating stress-related proteins and chronic ethanol self-administration in cynomolgus macaques

PubMed Central

Helms, Christa M.; Messaoudi, Ilhem; Jeng, Sophia; Freeman, Willard M.; Vrana, Kent E.; Grant, Kathleen A.

2011-01-01

Background Alcoholics have alterations in endocrine and immune function and increased susceptibility to stress-related disorders. A longitudinal analysis of chronic ethanol intake on homeostatic mechanisms is, however, incompletely characterized in primates. Methods Plasma proteins (n = 60; Luminex) and hormones (adrenocorticotropic hormone, ACTH; cortisol) were repeatedly measured in adult male cynomolgus monkeys (Macaca fascicularis, n = 10) during a 32-month experimental protocol at baseline, during induction of water and ethanol (4% w/v in water) self-administration, after 4 months and after 12 months of 22-h daily concurrent access to ethanol and water. Results Significant changes were observed in ACTH, cortisol and 45/60 plasma proteins: a majority (28/45) were suppressed as a function of ethanol self-administration, eight proteins were elevated and nine showed biphasic changes. Cortisol and ACTH were greatest during induction, and correlations between these hormones and plasma proteins varied across the experiment. Pathway analyses implicated nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) as possible mediators of ethanol-induced effects on immune-related proteins in primates. Conclusion Chronic ethanol consumption in primates leads to an allostatic state of physiological compromise with respect to circulating immune- and stress-related proteins in NF-κB- and STAT/JAK-related pathways in correlation with altered endocrine activity. PMID:22141444

Equilibrium fluctuation relations for voltage coupling in membrane proteins.

PubMed

Kim, Ilsoo; Warshel, Arieh

2015-11-01

A general theoretical framework is developed to account for the effects of an external potential on the energetics of membrane proteins. The framework is based on the free energy relation between two (forward/backward) probability densities, which was recently generalized to non-equilibrium processes, culminating in the work-fluctuation theorem. Starting from the probability densities of the conformational states along the "voltage coupling" reaction coordinate, we investigate several interconnected free energy relations between these two conformational states, considering voltage activation of ion channels. The free energy difference between the two conformational states at zero (depolarization) membrane potential (i.e., known as the chemical component of free energy change in ion channels) is shown to be equivalent to the free energy difference between the two "equilibrium" (resting and activated) conformational states along the one-dimensional voltage couplin reaction coordinate. Furthermore, the requirement that the application of linear response approximation to the free energy functionals of voltage coupling should satisfy the general free energy relations, yields a novel closed-form expression for the gating charge in terms of other basic properties of ion channels. This connection is familiar in statistical mechanics, known as the equilibrium fluctuation-response relation. The theory is illustrated by considering the coupling of a unit charge to the external voltage in the two sites near the surface of membrane, representing the activated and resting states. This is done using a coarse-graining (CG) model of membrane proteins, which includes the membrane, the electrolytes and the electrodes. The CG model yields Marcus-type voltage dependent free energy parabolas for the response of the electrostatic environment (electrolytes etc.) to the transition from the initial to the final configuratinal states, leading to equilibrium free energy difference and free

Predicting network modules of cell cycle regulators using relative protein abundance statistics.

PubMed

Oguz, Cihan; Watson, Layne T; Baumann, William T; Tyson, John J

2017-02-28

Parameter estimation in systems biology is typically done by enforcing experimental observations through an objective function as the parameter space of a model is explored by numerical simulations. Past studies have shown that one usually finds a set of "feasible" parameter vectors that fit the available experimental data equally well, and that these alternative vectors can make different predictions under novel experimental conditions. In this study, we characterize the feasible region of a complex model of the budding yeast cell cycle under a large set of discrete experimental constraints in order to test whether the statistical features of relative protein abundance predictions are influenced by the topology of the cell cycle regulatory network. Using differential evolution, we generate an ensemble of feasible parameter vectors that reproduce the phenotypes (viable or inviable) of wild-type yeast cells and 110 mutant strains. We use this ensemble to predict the phenotypes of 129 mutant strains for which experimental data is not available. We identify 86 novel mutants that are predicted to be viable and then rank the cell cycle proteins in terms of their contributions to cumulative variability of relative protein abundance predictions. Proteins involved in "regulation of cell size" and "regulation of G1/S transition" contribute most to predictive variability, whereas proteins involved in "positive regulation of transcription involved in exit from mitosis," "mitotic spindle assembly checkpoint" and "negative regulation of cyclin-dependent protein kinase by cyclin degradation" contribute the least. These results suggest that the statistics of these predictions may be generating patterns specific to individual network modules (START, S/G2/M, and EXIT). To test this hypothesis, we develop random forest models for predicting the network modules of cell cycle regulators using relative abundance statistics as model inputs. Predictive performance is assessed by the

Screening and identification of resistance related proteins from apple leaves inoculated with Marssonina coronaria (EII. & J. J. Davis)

PubMed Central

2014-01-01

Background Apple, an invaluable fruit crop worldwide, is often prone to infection by pathogenic fungi. Identification of potentially resistance-conferring apple proteins is one of the most important aims for studying apple resistance mechanisms and promoting the development of disease-resistant apple strains. In order to find proteins which promote resistance to Marssonina coronaria, a deadly pathogen which has been related to premature apple maturation, proteomes from apple leaves inoculated with M. coronaria were characterized at 3 and 6 days post-inoculation by two dimensional electrophoresis (2-DE). Results Overall, 59 differentially accumulated protein spots between inoculation and non-inoculation were successfully identified and aligned as 35 different proteins or protein families which involved in photosynthesis, amino acid metabolism, transport, energy metabolism, carbohydrate metabolism, binding, antioxidant, defense and stress. Quantitative real-time PCR (qRT-PCR) was also used to examine the change of some defense and stress related genes abundance under inoculated conditions. Conclusions In a conclusion, different proteins in response to Marssonina coronaria were identified by proteomic analysis. Among of these proteins, there are some PR proteins, for example class III endo-chitinase, beta-1,3-glucanase and thaumatine-like protein, and some antioxidant related proteins including aldo/keto reductase AKR, ascorbate peroxidase and phi class glutathione S-transferase protein that were associated with disease resistance. The transcription levels of class III endo-chitinase (L13) and beta-1, 3-glucanase (L17) have a good relation with the abundance of the encoded protein’s accumulation, however, the mRNA abundance of thaumatine-like protein (L22) and ascorbate peroxidase (L28) are not correlated with their protein abundance of encoded protein. To elucidate the resistant mechanism, the data in the present study will promote us to investigate further the

Equilibrium Fluctuation Relations for Voltage Coupling in Membrane Proteins

PubMed Central

Kim, Ilsoo; Warshel, Arieh

2015-01-01

A general theoretical framework is developed to account for the effects of an external potential on the energetics of membrane proteins. The framework is based on the free energy relation between two (forward/backward) probability densities, which was recently generalized to non-equilibrium processes, culminating in the work-fluctuation theorem. Starting from the probability densities of the conformational states along the reaction coordinate of “voltage coupling”, we investigate several interconnected free energy relations between these two conformational states, considering voltage activation of ion channels. The free energy difference at zero membrane potential (i.e., between the two “non-equilibrium” conformational states) is shown to be equivalent to the free energy difference between the two “equilibrium” conformational states along the one-dimensional reaction coordinate of voltage coupling. Furthermore, the requirement that the application of linear response approximation to the free energy functions (free energies) of voltage coupling should satisfy the general free energy relations, yields a novel expression for the gating charge in terms of other experimentally measurable quantities. This connection is familiar in statistical mechanics, known as the equilibrium fluctuation-response relation. The theory is illustrated by considering the movement of a unit charge within the membrane under the influence of an external potential, using a coarse-graining (CG) model of membrane proteins, which includes the membrane, the electrolytes and the electrodes. The CG model yields Marcus–type voltage dependent free energy parabolas for the two conformational states, which allow for quantitative estimations of an equilibrium free energy difference, a free energy of barrier, and the voltage dependency of channel activation (Q-V curve) for the unit charge movement. In addition, our analysis offers a quantitative rationale for the correlation between the free

Intrinsic fluorescence of protein in turbid media using empirical relation based on Monte Carlo lookup table

NASA Astrophysics Data System (ADS)

Einstein, Gnanatheepam; Udayakumar, Kanniyappan; Aruna, Prakasarao; Ganesan, Singaravelu

2017-03-01

Fluorescence of Protein has been widely used in diagnostic oncology for characterizing cellular metabolism. However, the intensity of fluorescence emission is affected due to the absorbers and scatterers in tissue, which may lead to error in estimating exact protein content in tissue. Extraction of intrinsic fluorescence from measured fluorescence has been achieved by different methods. Among them, Monte Carlo based method yields the highest accuracy for extracting intrinsic fluorescence. In this work, we have attempted to generate a lookup table for Monte Carlo simulation of fluorescence emission by protein. Furthermore, we fitted the generated lookup table using an empirical relation. The empirical relation between measured and intrinsic fluorescence is validated using tissue phantom experiments. The proposed relation can be used for estimating intrinsic fluorescence of protein for real-time diagnostic applications and thereby improving the clinical interpretation of fluorescence spectroscopic data.

[STUDY RELATIVE EXPRESSION OF GENES THAT CONTROL GLUCOSE METABOLISM IN THE LIVER IN MICE WITH DEVELOPMENT OF MELANOCORTIN OBESITY].

PubMed

Baklanov, A V; Bazhan, N M

2015-06-01

The relative gene expressions of glucose-6-phosphatase (G6P), phosphoenolpyruvate carbo- xykinase (PEPCK)--markers of gluconeogenesis, glucokinase (GK)--a marker of glycolysis, glucose transporter type 2 (GLUT2)--a marker of input and output of glucose in the liver were measured during the development of melanocortin (MC) obesity in male mice of C57BL/6J strain with mutation yellow in the Agouti locus (Ay/a mice). The mutation decreases MC receptor activity and induces hyperphagia and MC obesity. The males of the same line with mutation nonagouti were used as control. Tissue samples were taken at age 10 (before obesity), 15 (moderate obesity) and 30 (developed obesity) weeks. It has been shown that Ay/a mice had decreased glucose tolerance since 10-week age. There were age-related changes in mRNA levels in the liver of Ay/a mice, unlike a/a mice. In Ay/a mice the mRNA GLUT2 levels at the age of 10 weeks, mRNA GK levels at the age of 15 weeks, and mRNA G6P levels at the age of 3O weeks were higher than those in Ada mice of other ages. InAYfa mice the mRNA GK levels at the age of 15 weeks and mRNA G6F levels at the age of 30 weeks were increased relatively to those in a/a mice. Thus, Ay/a mice before the development of MK obesity had changes in the mRNA levels genes of proteins that regulate hepatic glucose metabolism, which may contribute to the compensation of glucose metabolism disorders caused by a hereditary decrease of MK system activity

Identification of related gene/protein names based on an HMM of name variations.

PubMed

Yeganova, L; Smith, L; Wilbur, W J

2004-04-01

Gene and protein names follow few, if any, true naming conventions and are subject to great variation in different occurrences of the same name. This gives rise to two important problems in natural language processing. First, can one locate the names of genes or proteins in free text, and second, can one determine when two names denote the same gene or protein? The first of these problems is a special case of the problem of named entity recognition, while the second is a special case of the problem of automatic term recognition (ATR). We study the second problem, that of gene or protein name variation. Here we describe a system which, given a query gene or protein name, identifies related gene or protein names in a large list. The system is based on a dynamic programming algorithm for sequence alignment in which the mutation matrix is allowed to vary under the control of a fully trainable hidden Markov model.

Pathogenesis-Related Proteins of Tomato 1

PubMed Central

Vera, Pablo; Conejero, Vicente

1988-01-01

An endoproteinase induced by citrus exocortis viroid has been purified from tomato (Lycopersicon esculentum Mill, cv “Rutgers”) leaves. The proteinase corresponds to one of the major pathogenesis-related proteins of tomato plants and was designated proteinase P-69 as it has a molecular weight of 69,000 to 70,000. The proteinase was purified in four steps: (NH4)2SO4 fractionation, chromatography on Bio-Gel P-60, DEAE-Sepharose chromatography, and casein-Sepharose affinity chromatography. The proteinase had a pH optimum of 8.5 to 9.0 when assayed with either fluorescein thiocarbamoyl derivative (FTC)-casein or FTC-ribulose 1,5-bisphosphate carboxylase/oxygenase as substrates. The proteinase activity was inhibited by pCMB and strongly activated by calcium and magnesium ions as well as by DTT. When analyzed by electrofocusing, the activity showed a pI around 9.0. Images Fig. 4 Fig. 8 PMID:16666127

Macroevolutionary trends of atomic composition and related functional group proportion in eukaryotic and prokaryotic proteins.

PubMed

Zhang, Yu-Juan; Yang, Chun-Lin; Hao, You-Jin; Li, Ying; Chen, Bin; Wen, Jian-Fan

2014-01-25

To fully explore the trends of atomic composition during the macroevolution from prokaryote to eukaryote, five atoms (oxygen, sulfur, nitrogen, carbon, hydrogen) and related functional groups in prokaryotic and eukaryotic proteins were surveyed and compared. Genome-wide analysis showed that eukaryotic proteins have more oxygen, sulfur and nitrogen atoms than prokaryotes do. Clusters of Orthologous Groups (COG) analysis revealed that oxygen, sulfur, carbon and hydrogen frequencies are higher in eukaryotic proteins than in their prokaryotic orthologs. Furthermore, functional group analysis demonstrated that eukaryotic proteins tend to have higher proportions of sulfhydryl, hydroxyl and acylamino, but lower of sulfide and carboxyl. Taken together, an apparent trend of increase was observed for oxygen and sulfur atoms in the macroevolution; the variation of oxygen and sulfur compositions and their related functional groups in macroevolution made eukaryotic proteins carry more useful functional groups. These results will be helpful for better understanding the functional significances of atomic composition evolution. Copyright © 2013 Elsevier B.V. All rights reserved.

Collagen-induced arthritis in Dark Agouti rats as a model for study of immunological sexual dimorphisms in the human disease.

PubMed

Dimitrijević, Mirjana; Arsenović-Ranin, Nevena; Bufan, Biljana; Nacka-Aleksić, Mirjana; Macanović, Mirjana Lazarević; Milovanović, Petar; Đurić, Marija; Sopta, Jelena; Leposavić, Gordana

2018-05-21

Collagen-induced arthritis (CIA) is a frequently used animal model of rheumatoid arthritis, human autoimmune disease that exhibits clear sex bias in incidence and clinical course. Female Dark Agouti rats immunized for CIA showed also greater incidence and higher arthritic score than their male counterparts. The study investigated sex differences in mechanisms controlling the primary immune responses in draining lymph nodes (dLNs), as a factor contributing to this dimorphism. The higher frequencies of CD4 + CD25 + Foxp3- cells, presumably activated effector T (Teff) cells, and IL-17+, IFN-γ + and IL-17 + IFN-γ + T cells were found in female compared with male rat dLNs. However, the frequency of CD4 + CD25 + Foxp3+ T regulatory cells (Treg) did not differ between sexes. Thus, CD4+ Teff cells/Treg ratio, and IL-17+ T cells/Treg and IFN-γ + T cells/Treg ratios were higher in female than in male rats, and among them was found lower frequency of PD-1+ cells. This suggested less efficient control of (auto)immune Th1/Th17 cell responses in female rat dLNs. On the contrary, the frequency of IL-4+ T cells was lower in female than in male rat dLNs. Consistently, the ratio of serum levels of collagen-specific IgG2a (IFN-γ-dependent, with an important pathogenic role in CIA) and IgG1 (IL-4-dependent) was shifted towards IgG2a in female compared with male rats. As a whole, the study suggests that sexual dimorphism in the control of T cell activation/polarization could contribute to sex bias in the susceptibility to CIA. Moreover, the study advises the use of animals of both sexes in the preclinical testing of new drugs for rheumatoid arthritis. Copyright © 2018 Elsevier Inc. All rights reserved.

Multivariate Modeling of Proteins Related to Trapezius Myalgia, a Comparative Study of Female Cleaners with or without Pain

PubMed Central

Hadrevi, Jenny; Ghafouri, Bijar; Larsson, Britt; Gerdle, Björn; Hellström, Fredrik

2013-01-01

The prevalence of chronic trapezius myalgia is high in women with high exposure to awkward working positions, repetitive movements and movements with high precision demands. The mechanisms behind chronic trapezius myalgia are not fully understood. The purpose of this study was to explore the differences in protein content between healthy and myalgic trapezius muscle using proteomics. Muscle biopsies from 12 female cleaners with work-related trapezius myalgia and 12 pain free female cleaners were obtained from the descending part of the trapezius. Proteins were separated with two-dimensional differential gel electrophoresis (2D-DIGE) and selected proteins were identified with mass spectrometry. In order to discriminate the two groups, quantified proteins were fitted to a multivariate analysis: partial least square discriminate analysis. The model separated 28 unique proteins which were related to glycolysis, the tricaboxylic acid cycle, to the contractile apparatus, the cytoskeleton and to acute response proteins. The results suggest altered metabolism, a higher abundance of proteins related to inflammation in myalgic cleaners compared to healthy, and a possible alteration of the contractile apparatus. This explorative proteomic screening of proteins related to chronic pain in the trapezius muscle provides new important aspects of the pathophysiology behind chronic trapezius myalgia. PMID:24023854

Multivariate modeling of proteins related to trapezius myalgia, a comparative study of female cleaners with or without pain.

PubMed

Hadrevi, Jenny; Ghafouri, Bijar; Larsson, Britt; Gerdle, Björn; Hellström, Fredrik

2013-01-01

The prevalence of chronic trapezius myalgia is high in women with high exposure to awkward working positions, repetitive movements and movements with high precision demands. The mechanisms behind chronic trapezius myalgia are not fully understood. The purpose of this study was to explore the differences in protein content between healthy and myalgic trapezius muscle using proteomics. Muscle biopsies from 12 female cleaners with work-related trapezius myalgia and 12 pain free female cleaners were obtained from the descending part of the trapezius. Proteins were separated with two-dimensional differential gel electrophoresis (2D-DIGE) and selected proteins were identified with mass spectrometry. In order to discriminate the two groups, quantified proteins were fitted to a multivariate analysis: partial least square discriminate analysis. The model separated 28 unique proteins which were related to glycolysis, the tricaboxylic acid cycle, to the contractile apparatus, the cytoskeleton and to acute response proteins. The results suggest altered metabolism, a higher abundance of proteins related to inflammation in myalgic cleaners compared to healthy, and a possible alteration of the contractile apparatus. This explorative proteomic screening of proteins related to chronic pain in the trapezius muscle provides new important aspects of the pathophysiology behind chronic trapezius myalgia.

RELATIVE ACTIN NUCLEATION PROMOTION EFFICIENCY BY WASP AND WAVE PROTEINS IN ENDOTHELIAL CELLS

PubMed Central

Kang, Hyeran; Wang, Jingjing; Longley, Sarah J.; Tang, Jay X.; Shaw, Sunil K.

2010-01-01

The mammalian genome encodes multiple WASP1 (Wiskott-Aldrich Syndrome Protein)/WAVE (WASP-family Verprolin homologous) proteins. Members of this family interact with the Arp (actin related protein) 2/3 complex to promote growth of a branched actin network near the plasma membrane or the surface of moving cargos. Arp2/3 mediated branching can further lead to formation of comet tails (actin rockets). Despite their similar domain structure, different WASP/WAVE family members fulfill unique functions that depend on their subcellular location and activity levels. We measured the relative efficiency of actin nucleation promotion of full length WASP/WAVE proteins in a cytoplasmic extract from primary human umbilical vein endothelial cells (HUVEC). In this assay WAVE2 and WAVE3 complexes showed higher nucleation efficiency than WAVE1 and N-WASP, indicating distinct cellular controls for different family members. Previously, WASP and N-WASP were the only members that were known to stimulate comet formation. We observed that in addition to N-WASP, WAVE3 also induced short actin tails, and the other WAVEs induced formation of asymmetric actin shells. Differences in shape and structure of actin-based growth may reflect varying ability of WASP/WAVE proteins to break symmetry of the actin shell, possibly by differential recruitment of actin bundling or severing (pruning or debranching) factors. PMID:20816932

Collagenase-3 binds to a specific receptor and requires the low density lipoprotein receptor-related protein for internalization

NASA Technical Reports Server (NTRS)

Barmina, O. Y.; Walling, H. W.; Fiacco, G. J.; Freije, J. M.; Lopez-Otin, C.; Jeffrey, J. J.; Partridge, N. C.

1999-01-01

We have previously identified a specific receptor for collagenase-3 that mediates the binding, internalization, and degradation of this ligand in UMR 106-01 rat osteoblastic osteosarcoma cells. In the present study, we show that collagenase-3 binding is calcium-dependent and occurs in a variety of cell types, including osteoblastic and fibroblastic cells. We also present evidence supporting a two-step mechanism of collagenase-3 binding and internalization involving both a specific collagenase-3 receptor and the low density lipoprotein receptor-related protein. Ligand blot analysis shows that (125)I-collagenase-3 binds specifically to two proteins ( approximately 170 kDa and approximately 600 kDa) present in UMR 106-01 cells. Western blotting identified the 600-kDa protein as the low density lipoprotein receptor-related protein. Our data suggest that the 170-kDa protein is a specific collagenase-3 receptor. Low density lipoprotein receptor-related protein-null mouse embryo fibroblasts bind but fail to internalize collagenase-3, whereas UMR 106-01 and wild-type mouse embryo fibroblasts bind and internalize collagenase-3. Internalization, but not binding, is inhibited by the 39-kDa receptor-associated protein. We conclude that the internalization of collagenase-3 requires the participation of the low density lipoprotein receptor-related protein and propose a model in which the cell surface interaction of this ligand requires a sequential contribution from two receptors, with the collagenase-3 receptor acting as a high affinity primary binding site and the low density lipoprotein receptor-related protein mediating internalization.

Tardigrade workbench: comparing stress-related proteins, sequence-similar and functional protein clusters as well as RNA elements in tardigrades.

PubMed

Förster, Frank; Liang, Chunguang; Shkumatov, Alexander; Beisser, Daniela; Engelmann, Julia C; Schnölzer, Martina; Frohme, Marcus; Müller, Tobias; Schill, Ralph O; Dandekar, Thomas

2009-10-12

Tardigrades represent an animal phylum with extraordinary resistance to environmental stress. To gain insights into their stress-specific adaptation potential, major clusters of related and similar proteins are identified, as well as specific functional clusters delineated comparing all tardigrades and individual species (Milnesium tardigradum, Hypsibius dujardini, Echiniscus testudo, Tulinus stephaniae, Richtersius coronifer) and functional elements in tardigrade mRNAs are analysed. We find that 39.3% of the total sequences clustered in 58 clusters of more than 20 proteins. Among these are ten tardigrade specific as well as a number of stress-specific protein clusters. Tardigrade-specific functional adaptations include strong protein, DNA- and redox protection, maintenance and protein recycling. Specific regulatory elements regulate tardigrade mRNA stability such as lox P DICE elements whereas 14 other RNA elements of higher eukaryotes are not found. Further features of tardigrade specific adaption are rapidly identified by sequence and/or pattern search on the web-tool tardigrade analyzer http://waterbear.bioapps.biozentrum.uni-wuerzburg.de. The work-bench offers nucleotide pattern analysis for promotor and regulatory element detection (tardigrade specific; nrdb) as well as rapid COG search for function assignments including species-specific repositories of all analysed data. Different protein clusters and regulatory elements implicated in tardigrade stress adaptations are analysed including unpublished tardigrade sequences.

Overexpression of the RD RNA binding protein in hepatitis C virus-related hepatocellular carcinoma.

PubMed

Iida, Michihisa; Iizuka, Norio; Tsunedomi, Ryouichi; Tsutsui, Masahiro; Yoshida, Shin; Maeda, Yoshinari; Tokuhisa, Yoshihiro; Sakamoto, Kazuhiko; Yoshimura, Kiyoshi; Tamesa, Takao; Oka, Masaaki

2012-08-01

Hepatocellular carcinoma (HCC) often exhibits a poor prognosis due to metastatic spread caused by portal vein invasion (PVI). In the present study, we attempted to identify a novel therapeutic target related to PVI of HCC. Based on pooled genomic data, we identified RD RNA binding protein (RDBP), a member of the negative elongation factor (NELF) transcription elongation regulatory complex, to be preferentially overexpressed in HCC with PVI. We used quantitative reverse transcription polymerase chain reaction (RT-PCR) and immuno-histochemical analyses to investigate the relationship between RDBP mRNA and protein with metastatic potential in sample sets of hepatitis C virus (HCV)-related HCC and corresponding non-HCC liver tissues. We also used the small interfering RNA technique to examine the role of RDBP in invasion and proliferation of HCC cells in vitro. Our data showed that both mRNA and protein levels of RDBP were significantly higher in HCC compared to non-HCC liver tissue, and that these levels were also significantly higher in HCC with PVI compared to HCC without PVI. Multivariate analysis revealed that RDBP protein levels were an independent risk factor for early intrahepatic recurrence of HCC within 2 years of surgery. Knockdown of RDBP protein significantly inhibited the proliferation and invasion of cells in vitro. These data demonstrate that RDBP is related to the metastatic potential of HCC, suggesting a possible candidate for prevention of HCC cell metastasis.

Distribution of language-related Cntnap2 protein in neural circuits critical for vocal learning.

PubMed

Condro, Michael C; White, Stephanie A

2014-01-01

Variants of the contactin associated protein-like 2 (Cntnap2) gene are risk factors for language-related disorders including autism spectrum disorder, specific language impairment, and stuttering. Songbirds are useful models for study of human speech disorders due to their shared capacity for vocal learning, which relies on similar cortico-basal ganglia circuitry and genetic factors. Here we investigate Cntnap2 protein expression in the brain of the zebra finch, a songbird species in which males, but not females, learn their courtship songs. We hypothesize that Cntnap2 has overlapping functions in vocal learning species, and expect to find protein expression in song-related areas of the zebra finch brain. We further expect that the distribution of this membrane-bound protein may not completely mirror its mRNA distribution due to the distinct subcellular localization of the two molecular species. We find that Cntnap2 protein is enriched in several song control regions relative to surrounding tissues, particularly within the adult male, but not female, robust nucleus of the arcopallium (RA), a cortical song control region analogous to human layer 5 primary motor cortex. The onset of this sexually dimorphic expression coincides with the onset of sensorimotor learning in developing males. Enrichment in male RA appears due to expression in projection neurons within the nucleus, as well as to additional expression in nerve terminals of cortical projections to RA from the lateral magnocellular nucleus of the nidopallium. Cntnap2 protein expression in zebra finch brain supports the hypothesis that this molecule affects neural connectivity critical for vocal learning across taxonomic classes. Copyright © 2013 Wiley Periodicals, Inc.

Structure–Function Relationships of Pre-Fibrillar Protein Assemblies in Alzheimer's Disease and Related Disorders

PubMed Central

Rahimi, F.; Shanmugam, A.; Bitan, G.

2010-01-01

Several neurodegenerative diseases, including Alzheimer's, Parkinson's, Huntington's and prion diseases, are characterized pathognomonically by the presence of intra- and/or extracellular lesions containing proteinaceous aggregates, and by extensive neuronal loss in selective brain regions. Related non-neuropathic systemic diseases, e.g., light-chain and senile systemic amyloidoses, and other organ-specific diseases, such as dialysis-related amyloidosis and type-2 diabetes mellitus, also are characterized by deposition of aberrantly folded, insoluble proteins. It is debated whether the hallmark pathologic lesions are causative. Substantial evidence suggests that these aggregates are the end state of aberrant protein folding whereas the actual culprits likely are transient, pre-fibrillar assemblies preceding the aggregates. In the context of neurodegenerative amyloidoses, the proteinaceous aggregates may eventuate as potentially neuroprotective sinks for the neurotoxic, oligomeric protein assemblies. The pre-fibrillar, oligomeric assemblies are believed to initiate the pathogenic mechanisms that lead to synaptic dysfunction, neuronal loss, and disease-specific regional brain atrophy. The amyloid β-protein (Aβ), which is believed to cause Alzheimer's disease (AD), is considered an archetypal amyloidogenic protein. Intense studies have led to nominal, functional, and structural descriptions of oligomeric Aβ assemblies. However, the dynamic and metastable nature of Aβ oligomers renders their study difficult. Different results generated using different methodologies under different experimental settings further complicate this complex area of research and identification of the exact pathogenic assemblies in vivo seems daunting. Here we review structural, functional, and biological experiments used to produce and study pre-fibrillar Aβ assemblies, and highlight similar studies of proteins involved in related diseases. We discuss challenges that contemporary

Myotubularin-related protein 7 inhibits insulin signaling in colorectal cancer

PubMed Central

Gutting, Tobias; Friedrich, Teresa; Gaiser, Timo; Magdeburg, Julia; Kienle, Peter; Ruh, Hermelindis; Hopf, Carsten; Behrens, Hans-Michael; Röcken, Christoph; Hanoch, Tamar; Seger, Rony; Ebert, Matthias P.A.; Burgermeister, Elke

2016-01-01

Phosphoinositide (PIP) phosphatases such as myotubularins (MTMs) inhibit growth factor receptor signaling. However, the function of myotubularin-related protein 7 (MTMR7) in cancer is unknown. We show that MTMR7 protein was down-regulated with increasing tumor grade (G), size (T) and stage (UICC) in patients with colorectal cancer (CRC) (n=1786). The presence of MTMR7 in the stroma correlated with poor prognosis, whereas MTMR7 expression in the tumor was not predictive for patients' survival. Insulin reduced MTMR7 protein levels in human CRC cell lines, and CRC patients with type 2 diabetes mellitus (T2DM) or loss of imprinting (LOI) of insulin-like growth factor 2 (IGF2) had an increased risk for MTMR7 loss. Mechanistically, MTMR7 lowered PIPs and inhibited insulin-mediated AKT-ERK1/2 signaling and proliferation in human CRC cell lines. MTMR7 provides a novel link between growth factor signaling and cancer, and may thus constitute a potential marker or drug target for human CRC. PMID:27409167

Molecular and Insecticidal Characterization of a Novel Cry-Related Protein from Bacillus Thuringiensis Toxic against Myzus persicae

PubMed Central

Palma, Leopoldo; Muñoz, Delia; Berry, Colin; Murillo, Jesús; Ruiz de Escudero, Iñigo; Caballero, Primitivo

2014-01-01

This study describes the insecticidal activity of a novel Bacillus thuringiensis Cry-related protein with a deduced 799 amino acid sequence (~89 kDa) and ~19% pairwise identity to the 95-kDa-aphidicidal protein (sequence number 204) from patent US 8318900 and ~40% pairwise identity to the cancer cell killing Cry proteins (parasporins Cry41Ab1 and Cry41Aa1), respectively. This novel Cry-related protein contained the five conserved amino acid blocks and the three conserved domains commonly found in 3-domain Cry proteins. The protein exhibited toxic activity against the green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae) with the lowest mean lethal concentration (LC50 = 32.7 μg/mL) reported to date for a given Cry protein and this insect species, whereas it had no lethal toxicity against the Lepidoptera of the family Noctuidae Helicoverpa armigera (Hübner), Mamestra brassicae (L.), Spodoptera exigua (Hübner), S. frugiperda (J.E. Smith) and S. littoralis (Boisduval), at concentrations as high as ~3.5 μg/cm2. This novel Cry-related protein may become a promising environmentally friendly tool for the biological control of M. persicae and possibly also for other sap sucking insect pests. PMID:25384108

Conserved and divergent features of the structure and function of La and La-related proteins (LARPs)

PubMed Central

Bayfield, Mark A.; Yang, Ruiqing; Maraia, Richard J.

2010-01-01

Genuine La proteins contain two RNA binding motifs, a La motif (LAM) followed by a RNA recognition motif (RRM), arranged in a unique way to bind RNA. These proteins interact with an extensive variety of cellular RNAs and exhibit activities in two broad categories: i) to promote the metabolism of nascent pol III transcripts, including precursor-tRNAs, by binding to their common, UUU-3’OH containing ends, and ii) to modulate the translation of certain mRNAs involving an unknown binding mechanism. Characterization of several La-RNA crystal structures as well as biochemical studies reveal insight into their unique two-motif domain architecture and how the LAM recognizes UUU-3’OH while the RRM binds other parts of a pre-tRNA. Recent studies of members of distinct families of conserved La-related proteins (LARPs) indicate that some of these harbor activity related to genuine La proteins, suggesting that their UUU-3’OH binding mode has been appropriated for the assembly and regulation of a specific snRNP (e.g., 7SK snRNA assembly by hLARP7/PIP7S). Analyses of other LARP family members (i.e., hLARP4, hLARP6) suggest more diverged RNA binding modes and specialization for cytoplasmic mRNA-related functions. Thus it appears that while genuine La proteins exhibit broad general involvement in both snRNA-related and mRNA-related functions, different LARP families may have evolved specialized activities in either snRNA or mRNA related functions. In this review, we summarize recent progress that has led to greater understanding of the structure and function of La proteins and their roles in tRNA processing and RNP assembly dynamics, as well as progress on the different LARPs. PMID:20138158

Conserved and divergent features of the structure and function of La and La-related proteins (LARPs).

PubMed

Bayfield, Mark A; Yang, Ruiqing; Maraia, Richard J

2010-01-01

Genuine La proteins contain two RNA binding motifs, a La motif (LAM) followed by a RNA recognition motif (RRM), arranged in a unique way to bind RNA. These proteins interact with an extensive variety of cellular RNAs and exhibit activities in two broad categories: i) to promote the metabolism of nascent pol III transcripts, including precursor-tRNAs, by binding to their common, UUU-3'OH containing ends, and ii) to modulate the translation of certain mRNAs involving an unknown binding mechanism. Characterization of several La-RNA crystal structures as well as biochemical studies reveal insight into their unique two-motif domain architecture and how the LAM recognizes UUU-3'OH while the RRM binds other parts of a pre-tRNA. Recent studies of members of distinct families of conserved La-related proteins (LARPs) indicate that some of these harbor activity related to genuine La proteins, suggesting that their UUU-3'OH binding mode has been appropriated for the assembly and regulation of a specific snRNP (e.g., 7SK snRNP assembly by hLARP7/PIP7S). Analyses of other LARP family members suggest more diverged RNA binding modes and specialization for cytoplasmic mRNA-related functions. Thus it appears that while genuine La proteins exhibit broad general involvement in both snRNA-related and mRNA-related functions, different LARP families may have evolved specialized activities in either snRNA or mRNA-related functions. In this review, we summarize recent progress that has led to greater understanding of the structure and function of La proteins and their roles in tRNA processing and RNP assembly dynamics, as well as progress on the different LARPs.

Identification and preliminary characterization of a protein motif related to the zinc finger.

PubMed Central

Lovering, R; Hanson, I M; Borden, K L; Martin, S; O'Reilly, N J; Evan, G I; Rahman, D; Pappin, D J; Trowsdale, J; Freemont, P S

1993-01-01

We have identified a protein motif, related to the zinc finger, which defines a newly discovered family of proteins. The motif was found in the sequence of the human RING1 gene, which is proximal to the major histocompatibility complex region on chromosome six. We propose naming this motif the "RING finger" and it is found in 27 proteins, all of which have putative DNA binding functions. We have synthesized a peptide corresponding to the RING1 motif and examined a number of properties, including metal and DNA binding. We provide evidence to support the suggestion that the RING finger motif is the DNA binding domain of this newly defined family of proteins. Images Fig. 1 Fig. 4 PMID:7681583

LDL receptor-related protein 1 regulates the abundance of diverse cell-signaling proteins in the plasma membrane proteome.

PubMed

Gaultier, Alban; Simon, Gabriel; Niessen, Sherry; Dix, Melissa; Takimoto, Shinako; Cravatt, Benjamin F; Gonias, Steven L

2010-12-03

LDL receptor-related protein 1 (LRP1) is an endocytic receptor, reported to regulate the abundance of other receptors in the plasma membrane, including uPAR and tissue factor. The goal of this study was to identify novel plasma membrane proteins, involved in cell-signaling, that are regulated by LRP1. Membrane protein ectodomains were prepared from RAW 264.7 cells in which LRP1 was silenced and control cells using protease K. Peptides were identified by LC-MS/MS. By analysis of spectral counts, 31 transmembrane and secreted proteins were regulated in abundance at least 2-fold when LRP1 was silenced. Validation studies confirmed that semaphorin4D (Sema4D), plexin domain-containing protein-1 (Plxdc1), and neuropilin-1 were more abundant in the membranes of LRP1 gene-silenced cells. Regulation of Plxdc1 by LRP1 was confirmed in CHO cells, as a second model system. Plxdc1 coimmunoprecipitated with LRP1 from extracts of RAW 264.7 cells and mouse liver. Although Sema4D did not coimmunoprecipitate with LRP1, the cell-surface level of Sema4D was increased by RAP, which binds to LRP1 and inhibits binding of other ligands. These studies identify Plxdc1, Sema4D, and neuropilin-1 as novel LRP1-regulated cell-signaling proteins. Overall, LRP1 emerges as a generalized regulator of the plasma membrane proteome.

Expression of the Grb2-related protein of the lymphoid system in B cell subsets enhances B cell antigen receptor signaling through mitogen-activated protein kinase pathways.

PubMed

Yankee, Thomas M; Solow, Sasha A; Draves, Kevin D; Clark, Edward A

2003-01-01

Adapter proteins play a critical role in regulating signals triggered by Ag receptor cross-linking. These small molecules link receptor proximal events with downstream signaling pathways. In this study, we explore the expression and function of the Grb2-related protein of the lymphoid system (GrpL)/Grb2-related adaptor downstream of Shc adapter protein in human B cells. GrpL is expressed in naive B cells and is down-regulated following B cell Ag receptor ligation. By contrast, germinal center and memory B cells express little or no GrpL. Using human B cell lines, we detected constitutive interactions between GrpL and B cell linker protein, Src homology (SH)2 domain-containing leukocyte protein of 76 kDa, hemopoietic progenitor kinase 1, and c-Cbl. The N-terminal SH3 domain of GrpL binds c-Cbl while the C-terminal SH3 domain binds B cell linker protein and SH2 domain-containing leukocyte protein of 76 kDa. Exogenous expression of GrpL in a GrpL-negative B cell line leads to enhanced Ag receptor-induced extracellular signal-related kinase and p38 mitogen-activated protein kinase phosphorylation. Thus, GrpL expression in human B cell subsets appears to regulate Ag receptor-mediated signaling events.

Biotechnological production of inducible defense-related proteins in edible radish (raphanus sativus) found in Nepal.

PubMed

Khanal, Praval; Karmacharya, Anil; Sharma, Shishir; Nepal, Ashwini K; Shrestha, Kanti

2014-01-01

Fungal infection in plant leads to use of many hazardous antifungal chemicals. Alternative to these chemicals, defense related antifungal proteins can be used in case of fungal diseases. An experiment was done in two varieties of edible radish (Raphanus sativus var. Pyuthane Raato and Raphanus sativus var. all season) with aims to produce defense protein within the plant, to identify and perform molecular characterization of those antifungal proteins. The next aim was to compare the antifungal property of those proteins with commercially available synthetic pesticides. Both varieties of radish were infected with fungi (Alternaria alternata and Fusarium oxysporum). Protein samples were isolated from leaves following the standard protocol as described for β-glucuronidase (GUS) assay and were run along with the standard protein marker of 10-250kDa in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to identify and molecularly characterize them. An additional band in the range of 37-50kDa was observed in the fungal infected samples, which was not seen on uninfected samples. The antifungal assay was carried out for every sample in 96 wells microtitre plate. The extracted protein samples from fungal inoculated plants showed the significant inhibition of fungal growth compared to other samples. On the basis of molecular weight and their antifungal properties, the protein samples from the fungal infected plant were found to be PR2 (Glucanase) and PR3 (Chitinase). Defense related proteins were successfully produced in two varieties of radish found in Nepal. The use of such biologically produced proteins may reduce the use of biologically harmful synthetic pesticides.

Arabidopsis dynamin-related protein 1A polymers bind, but do not tubulate, liposomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Backues, Steven K.; Bednarek, Sebastian Y., E-mail: sybednar@wisc.edu

2010-03-19

The Arabidopsis dynamin-related protein 1A (AtDRP1A) is involved in endocytosis and cell plate maturation in Arabidopsis. Unlike dynamin, AtDRP1A does not have any recognized membrane binding or protein-protein interaction domains. We report that GTPase active AtDRP1A purified from Escherichia coli as a fusion to maltose binding protein forms homopolymers visible by negative staining electron microscopy. These polymers interact with protein-free liposomes whose lipid composition mimics that of the inner leaflet of the Arabidopsis plasma membrane, suggesting that lipid-binding may play a role in AtDRP1A function. However, AtDRP1A polymers do not appear to assemble and disassemble in a dynamic fashion andmore » do not have the ability to tubulate liposomes in vitro, suggesting that additional factors or modifications are necessary for AtDRP1A's in vivo function.« less

Toward rules relating zinc finger protein sequences and DNA binding site preferences.

PubMed

Desjarlais, J R; Berg, J M

1992-08-15

Zinc finger proteins of the Cys2-His2 type consist of tandem arrays of domains, where each domain appears to contact three adjacent base pairs of DNA through three key residues. We have designed and prepared a series of variants of the central zinc finger within the DNA binding domain of Sp1 by using information from an analysis of a large data base of zinc finger protein sequences. Through systematic variations at two of the three contact positions (underlined), relatively specific recognition of sequences of the form 5'-GGGGN(G or T)GGG-3' has been achieved. These results provide the basis for rules that may develop into a code that will allow the design of zinc finger proteins with preselected DNA site specificity.

Proteomic analysis of stress-related proteins and metabolic pathways in Picea asperata somatic embryos during partial desiccation.

PubMed

Jing, Danlong; Zhang, Jianwei; Xia, Yan; Kong, Lisheng; OuYang, Fangqun; Zhang, Shougong; Zhang, Hanguo; Wang, Junhui

2017-01-01

Partial desiccation treatment (PDT) stimulates germination and enhances the conversion of conifer somatic embryos. To better understand the mechanisms underlying the responses of somatic embryos to PDT, we used proteomic and physiological analyses to investigate these responses during PDT in Picea asperata. Comparative proteomic analysis revealed that, during PDT, stress-related proteins were mainly involved in osmosis, endogenous hormones, antioxidative proteins, molecular chaperones and defence-related proteins. Compared with those in cotyledonary embryos before PDT, these stress-related proteins remained at high levels on days 7 (D7) and 14 (D14) of PDT. The proteins that differentially accumulated in the somatic embryos on D7 were mapped to stress and/or stimuli. They may also be involved in the glyoxylate cycle and the chitin metabolic process. The most significant difference in the differentially accumulated proteins occurred in the metabolic pathways of photosynthesis on D14. Furthermore, in accordance with the changes in stress-related proteins, analyses of changes in water content, abscisic acid, indoleacetic acid and H 2 O 2 levels in the embryos indicated that PDT is involved in water-deficit tolerance and affects endogenous hormones. Our results provide insight into the mechanisms responsible for the transition from morphologically mature to physiologically mature somatic embryos during the PDT process in P. asperata. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Tardigrade workbench: comparing stress-related proteins, sequence-similar and functional protein clusters as well as RNA elements in tardigrades

PubMed Central

2009-01-01

Background Tardigrades represent an animal phylum with extraordinary resistance to environmental stress. Results To gain insights into their stress-specific adaptation potential, major clusters of related and similar proteins are identified, as well as specific functional clusters delineated comparing all tardigrades and individual species (Milnesium tardigradum, Hypsibius dujardini, Echiniscus testudo, Tulinus stephaniae, Richtersius coronifer) and functional elements in tardigrade mRNAs are analysed. We find that 39.3% of the total sequences clustered in 58 clusters of more than 20 proteins. Among these are ten tardigrade specific as well as a number of stress-specific protein clusters. Tardigrade-specific functional adaptations include strong protein, DNA- and redox protection, maintenance and protein recycling. Specific regulatory elements regulate tardigrade mRNA stability such as lox P DICE elements whereas 14 other RNA elements of higher eukaryotes are not found. Further features of tardigrade specific adaption are rapidly identified by sequence and/or pattern search on the web-tool tardigrade analyzer http://waterbear.bioapps.biozentrum.uni-wuerzburg.de. The work-bench offers nucleotide pattern analysis for promotor and regulatory element detection (tardigrade specific; nrdb) as well as rapid COG search for function assignments including species-specific repositories of all analysed data. Conclusion Different protein clusters and regulatory elements implicated in tardigrade stress adaptations are analysed including unpublished tardigrade sequences. PMID:19821996

Predicting Protein Relationships to Human Pathways through a Relational Learning Approach Based on Simple Sequence Features.

PubMed

García-Jiménez, Beatriz; Pons, Tirso; Sanchis, Araceli; Valencia, Alfonso

2014-01-01

Biological pathways are important elements of systems biology and in the past decade, an increasing number of pathway databases have been set up to document the growing understanding of complex cellular processes. Although more genome-sequence data are becoming available, a large fraction of it remains functionally uncharacterized. Thus, it is important to be able to predict the mapping of poorly annotated proteins to original pathway models. We have developed a Relational Learning-based Extension (RLE) system to investigate pathway membership through a function prediction approach that mainly relies on combinations of simple properties attributed to each protein. RLE searches for proteins with molecular similarities to specific pathway components. Using RLE, we associated 383 uncharacterized proteins to 28 pre-defined human Reactome pathways, demonstrating relative confidence after proper evaluation. Indeed, in specific cases manual inspection of the database annotations and the related literature supported the proposed classifications. Examples of possible additional components of the Electron transport system, Telomere maintenance and Integrin cell surface interactions pathways are discussed in detail. All the human predicted proteins in the 2009 and 2012 releases 30 and 40 of Reactome are available at http://rle.bioinfo.cnio.es.

Visualisation of variable binding pockets on protein surfaces by probabilistic analysis of related structure sets.

PubMed

Ashford, Paul; Moss, David S; Alex, Alexander; Yeap, Siew K; Povia, Alice; Nobeli, Irene; Williams, Mark A

2012-03-14

Protein structures provide a valuable resource for rational drug design. For a protein with no known ligand, computational tools can predict surface pockets that are of suitable size and shape to accommodate a complementary small-molecule drug. However, pocket prediction against single static structures may miss features of pockets that arise from proteins' dynamic behaviour. In particular, ligand-binding conformations can be observed as transiently populated states of the apo protein, so it is possible to gain insight into ligand-bound forms by considering conformational variation in apo proteins. This variation can be explored by considering sets of related structures: computationally generated conformers, solution NMR ensembles, multiple crystal structures, homologues or homology models. It is non-trivial to compare pockets, either from different programs or across sets of structures. For a single structure, difficulties arise in defining particular pocket's boundaries. For a set of conformationally distinct structures the challenge is how to make reasonable comparisons between them given that a perfect structural alignment is not possible. We have developed a computational method, Provar, that provides a consistent representation of predicted binding pockets across sets of related protein structures. The outputs are probabilities that each atom or residue of the protein borders a predicted pocket. These probabilities can be readily visualised on a protein using existing molecular graphics software. We show how Provar simplifies comparison of the outputs of different pocket prediction algorithms, of pockets across multiple simulated conformations and between homologous structures. We demonstrate the benefits of use of multiple structures for protein-ligand and protein-protein interface analysis on a set of complexes and consider three case studies in detail: i) analysis of a kinase superfamily highlights the conserved occurrence of surface pockets at the active

Perilipin-related protein regulates lipid metabolism in C. elegans.

PubMed

Chughtai, Ahmed Ali; Kaššák, Filip; Kostrouchová, Markéta; Novotný, Jan Philipp; Krause, Michael W; Saudek, Vladimír; Kostrouch, Zdenek; Kostrouchová, Marta

2015-01-01

Perilipins are lipid droplet surface proteins that contribute to fat metabolism by controlling the access of lipids to lipolytic enzymes. Perilipins have been identified in organisms as diverse as metazoa, fungi, and amoebas but strikingly not in nematodes. Here we identify the protein encoded by the W01A8.1 gene in Caenorhabditis elegans as the closest homologue and likely orthologue of metazoan perilipin. We demonstrate that nematode W01A8.1 is a cytoplasmic protein residing on lipid droplets similarly as human perilipins 1 and 2. Downregulation or elimination of W01A8.1 affects the appearance of lipid droplets resulting in the formation of large lipid droplets localized around the dividing nucleus during the early zygotic divisions. Visualization of lipid containing structures by CARS microscopy in vivo showed that lipid-containing structures become gradually enlarged during oogenesis and relocate during the first zygotic division around the dividing nucleus. In mutant embryos, the lipid containing structures show defective intracellular distribution in subsequent embryonic divisions and become gradually smaller during further development. In contrast to embryos, lipid-containing structures in enterocytes and in epidermal cells of adult animals are smaller in mutants than in wild type animals. Our results demonstrate the existence of a perilipin-related regulation of fat metabolism in nematodes and provide new possibilities for functional studies of lipid metabolism.

Risk prediction for malignant conversion of oral epithelial dysplasia by hypoxia related protein expression.

PubMed

Zhang, Xianglan; Han, Seonhui; Han, Hye-Yeon; Ryu, Mi Heon; Kim, Ki-Yeol; Choi, Eun-Joo; Cha, In-Ho; Kim, Jin

2013-08-01

Increased aerobic glycolysis is a unique finding in cancers and hypoxia-related proteins are associated with aerobic glycolysis. Therefore, we aimed to investigate whether hypoxia-related proteins can be predictive markers for malignant conversion of oral premalignant lesions with epithelial dysplasia (OED). Expression of HIF-1α, Glut-1 and CA9 were detected in clinical samples of eight normal oral mucosa, 85 transitional areas of oral squamous cell carcinoma (OSCC) and 28 OED with or without malignant conversion using immunohistochemistry and were also comparatively detected in immortalised human oral keratinocyte (IHOK) and OSCC cell lines under hypoxia using immunoblotting. Sequential expression of HIF-1α, Glut-1 and CA9 was found both in transitional areas of OSCC and cell lines of IHOK and OSCC under hypoxia, supporting hypoxia-aerobic glycolysis-acidosis axis. Expression of all proteins showed significant association with malignant conversion of OED and CA9 was an independent risk factor of malignant transformation of OED. But the predictability of malignant transformation was improved when all three proteins were applied together. High expression of CA9 was an independent predictive marker of malignant conversion. Moreover, the combined application of these three proteins may be useful to assess the risk of malignant conversion of OED.

Biotechnological Production of Inducible Defense-Related Proteins in Edible Radish (Raphanus Sativus) Found in Nepal

PubMed Central

Khanal, Praval; Karmacharya, Anil; Sharma, Shishir; Nepal, Ashwini K.; Shrestha, Kanti

2014-01-01

Background: Fungal infection in plant leads to use of many hazardous antifungal chemicals. Alternative to these chemicals, defense related antifungal proteins can be used in case of fungal diseases. Aims: An experiment was done in two varieties of edible radish (Raphanus sativus var. Pyuthane Raato and Raphanus sativus var. all season) with aims to produce defense protein within the plant, to identify and perform molecular characterization of those antifungal proteins. The next aim was to compare the antifungal property of those proteins with commercially available synthetic pesticides. Methods: Both varieties of radish were infected with fungi (Alternaria alternata and Fusarium oxysporum). Protein samples were isolated from leaves following the standard protocol as described for β-glucuronidase (GUS) assay and were run along with the standard protein marker of 10-250kDa in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to identify and molecularly characterize them. Results: An additional band in the range of 37-50kDa was observed in the fungal infected samples, which was not seen on uninfected samples. The antifungal assay was carried out for every sample in 96 wells microtitre plate. The extracted protein samples from fungal inoculated plants showed the significant inhibition of fungal growth compared to other samples. On the basis of molecular weight and their antifungal properties, the protein samples from the fungal infected plant were found to be PR2 (Glucanase) and PR3 (Chitinase). Conclusion: Defense related proteins were successfully produced in two varieties of radish found in Nepal. The use of such biologically produced proteins may reduce the use of biologically harmful synthetic pesticides. PMID:24596739

Comparative study of label and label-free techniques using shotgun proteomics for relative protein quantification.

PubMed

Sjödin, Marcus O D; Wetterhall, Magnus; Kultima, Kim; Artemenko, Konstantin

2013-06-01

The analytical performance of three different strategies, iTRAQ (isobaric tag for relative and absolute quantification), dimethyl labeling (DML) and label free (LF) for relative protein quantification using shotgun proteomics have been evaluated. The methods have been explored using samples containing (i) Bovine proteins in known ratios and (ii) Bovine proteins in known ratios spiked into Escherichia coli. The latter case mimics the actual conditions in a typical biological sample with a few differentially expressed proteins and a bulk of proteins with unchanged ratios. Additionally, the evaluation was performed on both QStar and LTQ-FTICR mass spectrometers. LF LTQ-FTICR was found to have the highest proteome coverage while the highest accuracy based on the artificially regulated proteins was found for DML LTQ-FTICR (54%). A varying linearity (k: 0.55-1.16, r(2): 0.61-0.96) was shown for all methods within selected dynamic ranges. All methods were found to consistently underestimate Bovine protein ratios when matrix proteins were added. However, LF LTQ-FTICR was more tolerant toward a compression effect. A single peptide was demonstrated to be sufficient for a reliable quantification using iTRAQ. A ranking system utilizing several parameters important for quantitative proteomics demonstrated that the overall performance of the five different methods was; DML LTQ-FTICR>iTRAQ QStar>LF LTQ-FTICR>DML QStar>LF QStar. Copyright © 2013 Elsevier B.V. All rights reserved.

Expression and Functional Characterization of two Pathogenesis-Related Protein 10 Genes from Zea mays

USDA-ARS?s Scientific Manuscript database

Pathogenesis-related protein 10 (PR10) is one of seventeen PR protein families and plays important roles in plant response to biotic and abiotic stresses. A novel PR10 gene (ZmPR10.1), which shares 89.8% and 85.7% identity to the previous ZmPR10 at the nucleotide and amino acid sequence level, respe...

Functional modules by relating protein interaction networks and gene expression.

PubMed

Tornow, Sabine; Mewes, H W

2003-11-01

Genes and proteins are organized on the basis of their particular mutual relations or according to their interactions in cellular and genetic networks. These include metabolic or signaling pathways and protein interaction, regulatory or co-expression networks. Integrating the information from the different types of networks may lead to the notion of a functional network and functional modules. To find these modules, we propose a new technique which is based on collective, multi-body correlations in a genetic network. We calculated the correlation strength of a group of genes (e.g. in the co-expression network) which were identified as members of a module in a different network (e.g. in the protein interaction network) and estimated the probability that this correlation strength was found by chance. Groups of genes with a significant correlation strength in different networks have a high probability that they perform the same function. Here, we propose evaluating the multi-body correlations by applying the superparamagnetic approach. We compare our method to the presently applied mean Pearson correlations and show that our method is more sensitive in revealing functional relationships.

Functional modules by relating protein interaction networks and gene expression

PubMed Central

Tornow, Sabine; Mewes, H. W.

2003-01-01

Genes and proteins are organized on the basis of their particular mutual relations or according to their interactions in cellular and genetic networks. These include metabolic or signaling pathways and protein interaction, regulatory or co-expression networks. Integrating the information from the different types of networks may lead to the notion of a functional network and functional modules. To find these modules, we propose a new technique which is based on collective, multi-body correlations in a genetic network. We calculated the correlation strength of a group of genes (e.g. in the co-expression network) which were identified as members of a module in a different network (e.g. in the protein interaction network) and estimated the probability that this correlation strength was found by chance. Groups of genes with a significant correlation strength in different networks have a high probability that they perform the same function. Here, we propose evaluating the multi-body correlations by applying the superparamagnetic approach. We compare our method to the presently applied mean Pearson correlations and show that our method is more sensitive in revealing functional relationships. PMID:14576317

The ubiquitin-related protein PLIC-1 regulates heterotrimeric G protein function through association with Gβγ

PubMed Central

N'Diaye, Elsa-Noah; Brown, Eric J.

2003-01-01

PLIC-1, a newly described ubiquitin-related protein, inhibited both Jurkat migration toward SDF-1α and A431 wound healing, but the closely related PLIC-2 did not. PLIC-1 prevented the SDF-1α–induced activation of phospholipase C, decreased ligand-induced internalization of SDF-1α receptor CXCR4 and inhibited chemotaxis signaled by a transfected Gi-coupled receptor. However, PLIC-1 had no effect on Gs-mediated adenylyl cyclase activation, and inhibited only the Gβγ-dependent component of Gq-initiated increase in [Ca2+]i, which is consistent with selective inhibition of Gβγ function. PLIC-1 colocalized with G proteins in lamellae and pseudopods, and precipitated Gβγ in pull downs. Interaction with Gβγ did not require PLIC-1's ubiquitin-like or ubiquitin-associated domains, and proteasome inhibition had no effect on SDF-1α activation of phospholipase C, indicating that PLIC-1's inhibition of Gβγ did not result from effects on proteasome function. Thus, PLIC-1 inhibits Gi signaling by direct association with Gβγ; because it also interacts with CD47, a modulator of integrin function, it likely has a role integrating adhesion and signaling components of cell migration. PMID:14662753

Identification of genes related to proliferative diabetic retinopathy through RWR algorithm based on protein-protein interaction network.

PubMed

Zhang, Jian; Suo, Yan; Liu, Min; Xu, Xun

2018-06-01

Proliferative diabetic retinopathy (PDR) is one of the most common complications of diabetes and can lead to blindness. Proteomic studies have provided insight into the pathogenesis of PDR and a series of PDR-related genes has been identified but are far from fully characterized because the experimental methods are expensive and time consuming. In our previous study, we successfully identified 35 candidate PDR-related genes through the shortest-path algorithm. In the current study, we developed a computational method using the random walk with restart (RWR) algorithm and the protein-protein interaction (PPI) network to identify potential PDR-related genes. After some possible genes were obtained by the RWR algorithm, a three-stage filtration strategy, which includes the permutation test, interaction test and enrichment test, was applied to exclude potential false positives caused by the structure of PPI network, the poor interaction strength, and the limited similarity on gene ontology (GO) terms and biological pathways. As a result, 36 candidate genes were discovered by the method which was different from the 35 genes reported in our previous study. A literature review showed that 21 of these 36 genes are supported by previous experiments. These findings suggest the robustness and complementary effects of both our efforts using different computational methods, thus providing an alternative method to study PDR pathogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

Plasma Protein Pentosidine and Carboxymethyllysine, Biomarkers for Age-related Macular Degeneration*

PubMed Central

Ni, Jiaqian; Yuan, Xianglin; Gu, Jiayin; Yue, Xiuzhen; Gu, Xiaorong; Nagaraj, Ram H.; Crabb, John W.

2009-01-01

Age-related macular degeneration (AMD) causes severe vision loss in the elderly; early identification of AMD risk could help slow or prevent disease progression. Toward the discovery of AMD biomarkers, we quantified plasma protein Nε-carboxymethyllysine (CML) and pentosidine from 58 AMD and 32 control donors. CML and pentosidine are advanced glycation end products that are abundant in Bruch membrane, the extracellular matrix separating the retinal pigment epithelium from the blood-bearing choriocapillaris. We measured CML and pentosidine by LC-MS/MS and LC-fluorometry, respectively, and found higher mean levels of CML (∼54%) and pentosidine (∼64%) in AMD (p < 0.0001) relative to normal controls. Plasma protein fructosyl-lysine, a marker of early glycation, was found by amino acid analysis to be in equal amounts in control and non-diabetic AMD donors, supporting an association between AMD and increased levels of CML and pentosidine independent of other diseases like diabetes. Carboxyethylpyrrole (CEP), an oxidative modification from docosahexaenoate-containing lipids and also abundant in AMD Bruch membrane, was elevated ∼86% in the AMD cohort, but autoantibody titers to CEP, CML, and pentosidine were not significantly increased. Compellingly higher mean levels of CML and pentosidine were present in AMD plasma protein over a broad age range. Receiver operating curves indicate that CML, CEP adducts, and pentosidine alone discriminated between AMD and control subjects with 78, 79, and 88% accuracy, respectively, whereas CML in combination with pentosidine provided ∼89% accuracy, and CEP plus pentosidine provided ∼92% accuracy. Pentosidine levels appeared slightly altered in AMD patients with hypertension and cardiovascular disease, indicating further studies are warranted. Overall this study supports the potential utility of plasma protein CML and pentosidine as biomarkers for assessing AMD risk and susceptibility, particularly in combination with CEP

Electrophoresis and spectrometric analyses of adaptation-related proteins in thermally stressed Chromobacterium violaceum.

PubMed

Cordeiro, I B; Castro, D P; Nogueira, P P O; Angelo, P C S; Nogueira, P A; Gonçalves, J F C; Pereira, A M R F; Garcia, J S; Souza, G H M F; Arruda, M A Z; Eberlin, M N; Astolfi-Filho, S; Andrade, E V; López-Lozano, J L

2013-10-29

Chromobacterium violaceum is a Gram-negative proteobacteria found in water and soil; it is widely distributed in tropical and subtropical regions, such as the Amazon rainforest. We examined protein expression changes that occur in C. violaceum at different growth temperatures using electrophoresis and mass spectrometry. The total number of spots detected was 1985; the number ranged from 99 to 380 in each assay. The proteins that were identified spectrometrically were categorized as chaperones, proteins expressed exclusively under heat stress, enzymes involved in the respiratory and fermentation cycles, ribosomal proteins, and proteins related to transport and secretion. Controlling inverted repeat of chaperone expression and inverted repeat DNA binding sequences, as well as regions recognized by sigma factor 32, elements involved in the genetic regulation of the bacterial stress response, were identified in the promoter regions of several of the genes coding proteins, involved in the C. violaceum stress response. We found that 30 °C is the optimal growth temperature for C. violaceum, whereas 25, 35, and 40 °C are stressful temperatures that trigger the expression of chaperones, superoxide dismutase, a probable small heat shock protein, a probable phasing, ferrichrome-iron receptor protein, elongation factor P, and an ornithine carbamoyltransferase catabolite. This information improves our comprehension of the mechanisms involved in stress adaptation by C. violaceum.

Protein markers for identification of Yersinia pestis and their variation related to culture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wunschel, David S.; Engelmann, Heather E.; Victry, Kristin D.

2013-12-11

The detection of high consequence pathogens, such as Yersinia pestis, is well established in biodefense laboratories for bioterror situations. Laboratory protocols are well established using specified culture media and a growth temperature of 37 °C for expression of specific antigens. Direct detection of Y. pestis protein markers, without prior culture, depends on their expression. Unfortunately protein expression can be impacted by the culture medium which cannot be predicted ahead of time. Furthermore, higher biomass yields are obtained at the optimal growth temperature (i.e. 28 °C–30 °C) and therefore are more likely to be used for bulk production. Analysis of Y.more » pestis grown on several types of media at 30 °C showed that several protein markers were found to be differentially detected in different media. Analysis of the identified proteins against a comprehensive database provided an additional level of organism identification. Peptides corresponding to variable regions of some proteins could separate large groups of strains and aid in organism identification. This work illustrates the need to understand variability of protein expression for detection targets. The potential for relating expression changes of known proteins to specific media factors, even in nutrient rich and chemically complex culture medium, may provide the opportunity to draw forensic information from protein profiles.« less

Signaling Pathways Related to Protein Synthesis and Amino Acid Concentration in Pig Skeletal Muscles Depend on the Dietary Protein Level, Genotype and Developmental Stages

PubMed Central

Liu, Yingying; Li, Fengna; Kong, Xiangfeng; Tan, Bie; Li, Yinghui; Duan, Yehui; Blachier, François; Hu, Chien-An A.; Yin, Yulong

2015-01-01

Muscle growth is regulated by the homeostatic balance of the biosynthesis and degradation of muscle proteins. To elucidate the molecular interactions among diet, pig genotype, and physiological stage, we examined the effect of dietary protein concentration, pig genotype, and physiological stages on amino acid (AA) pools, protein deposition, and related signaling pathways in different types of skeletal muscles. The study used 48 Landrace pigs and 48 pure-bred Bama mini-pigs assigned to each of 2 dietary treatments: lower/GB (Chinese conventional diet)- or higher/NRC (National Research Council)-protein diet. Diets were fed from 5 weeks of age to respective market weights of each genotype. Samples of biceps femoris muscle (BFM, type I) and longissimus dorsi muscle (LDM, type II) were collected at nursery, growing, and finishing phases according to the physiological stage of each genotype, to determine the AA concentrations, mRNA levels for growth-related genes in muscles, and protein abundances of mechanistic target of rapamycin (mTOR) signaling pathway. Our data showed that the concentrations of most AAs in LDM and BFM of pigs increased (P<0.05) gradually with increasing age. Bama mini-pigs had generally higher (P<0.05) muscle concentrations of flavor-related AA, including Met, Phe, Tyr, Pro, and Ser, compared with Landrace pigs. The mRNA levels for myogenic determining factor, myogenin, myocyte-specific enhancer binding factor 2 A, and myostatin of Bama mini-pigs were higher (P<0.05) than those of Landrace pigs, while total and phosphorylated protein levels for protein kinase B, mTOR, and p70 ribosomal protein S6 kinases (p70S6K), and ratios of p-mTOR/mTOR, p-AKT/AKT, and p-p70S6K/p70S6K were lower (P<0.05). There was a significant pig genotype-dependent effect of dietary protein on the levels for mTOR and p70S6K. When compared with the higher protein-NRC diet, the lower protein-GB diet increased (P<0.05) the levels for mTOR and p70S6K in Bama mini-pigs, but

Gadd45 proteins: Relevance to aging, longevity and age-related pathologies

PubMed Central

Moskalev, Alexey A.; Smit-McBride, Zeljka; Shaposhnikov, Mikhail V.; Plyusnina, Ekaterina N.; Zhavoronkov, Alex; Budovsky, Arie; Tacutu, Robi; Fraifeld, Vadim E.

2013-01-01

The Gadd45 proteins have been intensively studied, in view of their important role in key cellular processes. Indeed, the Gadd45 proteins stand at the crossroad of the cell fates by controlling the balance between cell (DNA) repair, eliminating (apoptosis) or preventing the expansion of potentially dangerous cells (cell cycle arrest, cellular senescence), and maintaining the stem cell pool. However, the biogerontological aspects have not thus far received sufficient attention. Here we analyzed the pathways and modes of action by which Gadd45 members are involved in aging, longevity and age-related diseases. Because of their pleiotropic action, a decreased inducibility of Gadd45 members may have far-reaching consequences including genome instability, accumulation of DNA damage, and disorders in cellular homeostasis – all of which may eventually contribute to the aging process and age-related disorders (promotion of tumorigenesis, immune disorders, insulin resistance and reduced responsiveness to stress). Most recently, the dGadd45 gene has been identified as a longevity regulator in Drosophila. Although further wide-scale research is warranted, it is becoming increasingly clear that Gadd45s are highly relevant to aging, age-related diseases (ARDs) and to the control of life span, suggesting them as potential therapeutic targets in ARDs and pro-longevity interventions. PMID:21986581

The protein type within a hypocaloric diet affects obesity-related inflammation: the RESMENA project.

PubMed

Lopez-Legarrea, Patricia; de la Iglesia, Rocio; Abete, Itziar; Navas-Carretero, Santiago; Martinez, J Alfredo; Zulet, M Angeles

2014-04-01

The aim of this study was to compare the effect of two energy-restricted, differing with regard to protein content, on the inflammation state of obese individuals with features of metabolic syndrome. Ninety-six participants completed an 8-wk randomized intervention trial that compared the RESMENA diet (-30% energy, with 30% energy from protein) with a control diet (-30% energy, with 15% energy from protein) that was based on American Heart Association criteria. The mean body weight losses were 7.09 ± 0.82 kg and 6.73 ± 0.71 kg, respectively, with no differences seen between the groups. The endpoint inflammation score-which was based on high-sensitivity C-reactive protein, interleukin-6, tumor necrosis factor-α, and plasminogen activator inhibitor-1 levels-was significantly lower (P = 0.012) in the low-protein group (6.81 ± 2.32 versus 7.94 ± 1.94). The linear regression analyses revealed that total protein intake was positively associated with inflammation (P = 0.007) as well as with animal protein (P = 0.025) and meat protein (P = 0.015), but neither vegetable- nor fish-derived proteins were found to influence inflammatory status. Our results suggest that the type of protein consumed (more than the total protein consumed) within an energy-restricted diet influences the inflammation status associated with obesity-related comorbidities. Copyright © 2014 Elsevier Inc. All rights reserved.

Synthesis and structural characterization of carboxyethylpyrrole-modified proteins: mediators of age-related macular degeneration.

PubMed

Lu, Liang; Gu, Xiaorong; Hong, Li; Laird, James; Jaffe, Keeve; Choi, Jaewoo; Crabb, John; Salomon, Robert G

2009-11-01

Protein modifications in which the epsilon-amino group of lysyl residues is incorporated into a 2-(omega-carboxyethyl)pyrrole (CEP) are mediators of age-related macular degeneration (AMD). They promote both angiogenesis into the retina ('wet AMD') and geographic retinal atrophy ('dry AMD'). Blood levels of CEPs are biomarkers for clinical prognosis of the disease. To enable mechanistic studies of their role in promoting AMD, for example, through the activation of B- and T-cells, interaction with receptors, or binding with complement proteins, we developed an efficient synthesis of CEP derivatives, that is especially effective for proteins. The structures of tryptic peptides derived from CEP-modified proteins were also determined. A key finding is that 4,7-dioxoheptanoic acid 9-fluorenylmethyl ester reacts with primary amines to provide 9-fluorenylmethyl esters of CEP-modified proteins that can be deprotected in situ with 1,8-diazabicyclo[5.4.0]undec-7-ene without causing protein denaturation. The introduction of multiple CEP-modifications with a wide variety of CEP:protein ratios is readily achieved using this strategy.

Histone deacetylase-related protein inhibits AES-mediated neuronal cell death by direct interaction.

PubMed

Zhang, Xiaoguang; Chen, Hsin-Mei; Jaramillo, Eduardo; Wang, Lulu; D'Mello, Santosh R

2008-08-15

Histone deacetylase-related protein (HDRP), an alternatively spliced and truncated form of histone deacetylase-9 that lacks a C-terminal catalytic domain, protects neurons from death. In an effort to understand the mechanism by which HDRP mediates its neuroprotective effect, we screened for proteins in the brain that interact with HDRP by using a yeast two-hybrid assay. One of the HDRP-interacting proteins identified in this screen was amino enhancer of split (AES), a 197-amino acid protein belonging to the Groucho family. Interaction between HDRP and AES was verified by in vitro binding assays, coimmunoprecipitation, and colocalization studies. To investigate the significance of the HDRP-AES association to the regulation of neuronal survival, we used cultured cerebellar granule neurons, which undergo apoptosis when treated with low potassium (LK) medium. We found that in contrast to HDRP, whose expression is markedly reduced by LK treatment, AES expression was not appreciably altered. Forced expression of AES in healthy neurons results in cell death, an action that is blocked by the coexpression of HDRP. AES is a truncated version of larger Groucho-related proteins, one of which is transducin-like enhancer of split (TLE)-1. We found that the expression of TLE1 is reduced in LK-treated neurons and the forced expression of TLE1 blocks LK-induced neuronal death as well as death induced by AES. Our results show that AES has apoptotic activity in neurons and suggest that neuroprotection by HDRP is mediated by the inhibition of this activity through direct interaction.

Differential protein-coding gene and long noncoding RNA expression in smoking-related lung squamous cell carcinoma.

PubMed

Li, Shicheng; Sun, Xiao; Miao, Shuncheng; Liu, Jia; Jiao, Wenjie

2017-11-01

Cigarette smoking is one of the greatest preventable risk factors for developing cancer, and most cases of lung squamous cell carcinoma (lung SCC) are associated with smoking. The pathogenesis mechanism of tumor progress is unclear. This study aimed to identify biomarkers in smoking-related lung cancer, including protein-coding gene, long noncoding RNA, and transcription factors. We selected and obtained messenger RNA microarray datasets and clinical data from the Gene Expression Omnibus database to identify gene expression altered by cigarette smoking. Integrated bioinformatic analysis was used to clarify biological functions of the identified genes, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, the construction of a protein-protein interaction network, transcription factor, and statistical analyses. Subsequent quantitative real-time PCR was utilized to verify these bioinformatic analyses. Five hundred and ninety-eight differentially expressed genes and 21 long noncoding RNA were identified in smoking-related lung SCC. GO and KEGG pathway analysis showed that identified genes were enriched in the cancer-related functions and pathways. The protein-protein interaction network revealed seven hub genes identified in lung SCC. Several transcription factors and their binding sites were predicted. The results of real-time quantitative PCR revealed that AURKA and BIRC5 were significantly upregulated and LINC00094 was downregulated in the tumor tissues of smoking patients. Further statistical analysis indicated that dysregulation of AURKA, BIRC5, and LINC00094 indicated poor prognosis in lung SCC. Protein-coding genes AURKA, BIRC5, and LINC00094 could be biomarkers or therapeutic targets for smoking-related lung SCC. © 2017 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

Characterization of pancreatic lipase-related protein 2 isolated from human pancreatic juice.

PubMed

De Caro, Josiane; Sias, Barbara; Grandval, Philippe; Ferrato, Francine; Halimi, Hubert; Carrière, Frédéric; De Caro, Alain

2004-09-01

Human pancreatic lipase-related protein 2 (HPLRP2) was identified for the first time in pancreatic juice using specific anti-peptide antibodies and purified to homogeneity. Antibodies were raised in the rabbit using a synthetic peptide from the HPLRP2 protein sequence deduced from cDNA. Western blotting analysis showed that these antibodies did not react with classical human pancreatic lipase (HPL) or human pancreatic lipase-related protein 1 (HPLRP1) but cross-reacted with native rat PLRP2 (RPLRP2), as well as with recombinant rat and guinea-pig PLRP2 (GPLRP2). Immunoaffinity chromatography was performed on immobilized anti-recombinant HPLRP2 polyclonal antibodies to purify native HPLRP2 after conventional chromatographic steps including gel filtration and chromatrography on an anion-exchanger. The substrate specificity of HPLRP2 was investigated using various triglycerides, phospholipids and galactolipids as substrates. The lipase activity on triglycerides was inhibited by bile salts and weakly restored by colipase. The phospholipase activity of HPLRP2 on phospholipid micelles was very low. A significant level of galactolipase activity was measured using monogalactosyldiglyceride monomolecular films. These data suggest that the main physiological function of HPLRP2 is the hydrolysis of galactolipids, which are the main lipids present in vegetable food.

Global versus Local Regulatory Roles for Lrp-Related Proteins: Haemophilus influenzae as a Case Study

PubMed Central

Friedberg, Devorah; Midkiff, Michael; Calvo, Joseph M.

2001-01-01

Lrp (leucine-responsive regulatory protein) plays a global regulatory role in Escherichia coli, affecting expression of dozens of operons. Numerous lrp-related genes have been identified in different bacteria and archaea, including asnC, an E. coli gene that was the first reported member of this family. Pairwise comparisons of amino acid sequences of the corresponding proteins shows an average sequence identity of only 29% for the vast majority of comparisons. By contrast, Lrp-related proteins from enteric bacteria show more than 97% amino acid identity. Is the global regulatory role associated with E. coli Lrp limited to enteric bacteria? To probe this question we investigated LrfB, an Lrp-related protein from Haemophilus influenzae that shares 75% sequence identity with E. coli Lrp (highest sequence identity among 42 sequences compared). A strain of H. influenzae having an lrfB null allele grew at the wild-type growth rate but with a filamentous morphology. A comparison of two-dimensional (2D) electrophoretic patterns of proteins from parent and mutant strains showed only two differences (comparable studies with lrp+ and lrp E. coli strains by others showed 20 differences). The abundance of LrfB in H. influenzae, estimated by Western blotting experiments, was about 130 dimers per cell (compared to 3,000 dimers per E. coli cell). LrfB expressed in E. coli replaced Lrp as a repressor of the lrp gene but acted only to a limited extent as an activator of the ilvIH operon. Thus, although LrfB resembles Lrp sufficiently to perform some of its functions, its low abundance is consonant with a more local role in regulating but a few genes, a view consistent with the results of the 2D electrophoretic analysis. We speculate that an Lrp having a global regulatory role evolved to help enteric bacteria adapt to their ecological niches and that it is unlikely that Lrp-related proteins in other organisms have a broad regulatory function. PMID:11395465

Increase of Long-Term ‘Diabesity’ Risk, Hyperphagia, and Altered Hypothalamic Neuropeptide Expression in Neonatally Overnourished ‘Small-For-Gestational-Age’ (SGA) Rats

PubMed Central

Schellong, Karen; Neumann, Uta; Rancourt, Rebecca C.; Plagemann, Andreas

2013-01-01

Background Epidemiological data have shown long-term health adversity in low birth weight subjects, especially concerning the metabolic syndrome and ‘diabesity’ risk. Alterations in adult food intake have been suggested to be causally involved. Responsible mechanisms remain unclear. Methods and Findings By rearing in normal (NL) vs. small litters (SL), small-for-gestational-age (SGA) rats were neonatally exposed to either normal (SGA-in-NL) or over-feeding (SGA-in-SL), and followed up into late adult age as compared to normally reared appropriate-for-gestational-age control rats (AGA-in-NL). SGA-in-SL rats displayed rapid neonatal weight gain within one week after birth, while SGA-in-NL growth caught up only at juvenile age (day 60), as compared to AGA-in-NL controls. In adulthood, an increase in lipids, leptin, insulin, insulin/glucose-ratio (all p<0.05), and hyperphagia under normal chow as well as high-energy/high-fat diet, modelling modern ‘westernized’ lifestyle, were observed only in SGA-in-SL as compared to both SGA-in-NL and AGA-in-NL rats (p<0.05). Lasercapture microdissection (LMD)-based neuropeptide expression analyses in single neuron pools of the arcuate hypothalamic nucleus (ARC) revealed a significant shift towards down-regulation of the anorexigenic melanocortinergic system (proopiomelanocortin, Pomc) in SGA-in-SL rats (p<0.05). Neuropeptide expression within the orexigenic system (neuropeptide Y (Npy), agouti-related-peptide (Agrp) and galanin (Gal)) was not significantly altered. In essence, the ‘orexigenic index’, proposed here as a neuroendocrine ‘net-indicator’, was increased in SGA-in-SL regarding Npy/Pomc expression (p<0.01), correlated to food intake (p<0.05). Conclusion Adult SGA rats developed increased ‘diabesity’ risk only if exposed to neonatal overfeeding. Hypothalamic malprogramming towards decreased anorexigenic activity was involved into the pathophysiology of this neonatally acquired adverse phenotype. Neonatal

Increase of long-term 'diabesity' risk, hyperphagia, and altered hypothalamic neuropeptide expression in neonatally overnourished 'small-for-gestational-age' (SGA) rats.

PubMed

Schellong, Karen; Neumann, Uta; Rancourt, Rebecca C; Plagemann, Andreas

2013-01-01

Epidemiological data have shown long-term health adversity in low birth weight subjects, especially concerning the metabolic syndrome and 'diabesity' risk. Alterations in adult food intake have been suggested to be causally involved. Responsible mechanisms remain unclear. By rearing in normal (NL) vs. small litters (SL), small-for-gestational-age (SGA) rats were neonatally exposed to either normal (SGA-in-NL) or over-feeding (SGA-in-SL), and followed up into late adult age as compared to normally reared appropriate-for-gestational-age control rats (AGA-in-NL). SGA-in-SL rats displayed rapid neonatal weight gain within one week after birth, while SGA-in-NL growth caught up only at juvenile age (day 60), as compared to AGA-in-NL controls. In adulthood, an increase in lipids, leptin, insulin, insulin/glucose-ratio (all p<0.05), and hyperphagia under normal chow as well as high-energy/high-fat diet, modelling modern 'westernized' lifestyle, were observed only in SGA-in-SL as compared to both SGA-in-NL and AGA-in-NL rats (p<0.05). Lasercapture microdissection (LMD)-based neuropeptide expression analyses in single neuron pools of the arcuate hypothalamic nucleus (ARC) revealed a significant shift towards down-regulation of the anorexigenic melanocortinergic system (proopiomelanocortin, Pomc) in SGA-in-SL rats (p<0.05). Neuropeptide expression within the orexigenic system (neuropeptide Y (Npy), agouti-related-peptide (Agrp) and galanin (Gal)) was not significantly altered. In essence, the 'orexigenic index', proposed here as a neuroendocrine 'net-indicator', was increased in SGA-in-SL regarding Npy/Pomc expression (p<0.01), correlated to food intake (p<0.05). Adult SGA rats developed increased 'diabesity' risk only if exposed to neonatal overfeeding. Hypothalamic malprogramming towards decreased anorexigenic activity was involved into the pathophysiology of this neonatally acquired adverse phenotype. Neonatal overfeeding appears to be a critical long-term risk factor in

Computational prediction of protein interactions related to the invasion of erythrocytes by malarial parasites.

PubMed

Liu, Xuewu; Huang, Yuxiao; Liang, Jiao; Zhang, Shuai; Li, Yinghui; Wang, Jun; Shen, Yan; Xu, Zhikai; Zhao, Ya

2014-11-30

The invasion of red blood cells (RBCs) by malarial parasites is an essential step in the life cycle of Plasmodium falciparum. Human-parasite surface protein interactions play a critical role in this process. Although several interactions between human and parasite proteins have been discovered, the mechanism related to invasion remains poorly understood because numerous human-parasite protein interactions have not yet been identified. High-throughput screening experiments are not feasible for malarial parasites due to difficulty in expressing the parasite proteins. Here, we performed computational prediction of the PPIs involved in malaria parasite invasion to elucidate the mechanism by which invasion occurs. In this study, an expectation maximization algorithm was used to estimate the probabilities of domain-domain interactions (DDIs). Estimates of DDI probabilities were then used to infer PPI probabilities. We found that our prediction performance was better than that based on the information of D. melanogaster alone when information related to the six species was used. Prediction performance was assessed using protein interaction data from S. cerevisiae, indicating that the predicted results were reliable. We then used the estimates of DDI probabilities to infer interactions between 490 parasite and 3,787 human membrane proteins. A small-scale dataset was used to illustrate the usability of our method in predicting interactions between human and parasite proteins. The positive predictive value (PPV) was lower than that observed in S. cerevisiae. We integrated gene expression data to improve prediction accuracy and to reduce false positives. We identified 80 membrane proteins highly expressed in the schizont stage by fast Fourier transform method. Approximately 221 erythrocyte membrane proteins were identified using published mass spectral datasets. A network consisting of 205 interactions was predicted. Results of network analysis suggest that SNARE proteins of

Exercise training decreases activation of the mitochondrial fission protein dynamin-related protein-1 in insulin-resistant human skeletal muscle.

PubMed

Fealy, Ciaran E; Mulya, Anny; Lai, Nicola; Kirwan, John P

2014-08-01

Defects in mitochondrial dynamics, the processes of fission, fusion, and mitochondrial autophagy, may contribute to metabolic disease including type 2 diabetes. Dynamin-related protein-1 (Drp1) is a GTPase protein that plays a central role in mitochondrial fission. We hypothesized that aerobic exercise training would decrease Drp1 Ser(616) phosphorylation and increase fat oxidation and insulin sensitivity in obese (body mass index: 34.6 ± 0.8 kg/m(2)) insulin-resistant adults. Seventeen subjects performed supervised exercise for 60 min/day, 5 days/wk at 80-85% of maximal heart rate for 12 wk. Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp, and fat oxidation was determined by indirect calorimetry. Skeletal muscle biopsies were obtained from the vastus lateralis muscle before and after the 12-wk program. The exercise intervention increased insulin sensitivity 2.1 ± 0.2-fold (P < 0.01) and fat oxidation 1.3 ± 0.3-fold (P < 0.01). Phosphorylation of Drp1 at Ser(616) was decreased (pre vs. post: 0.81 ± 0.15 vs. 0.58 ± 0.14 arbitrary units; P < 0.05) following the intervention. Furthermore, reductions in Drp1 Ser(616) phosphorylation were negatively correlated with increases in fat oxidation (r = -0.58; P < 0.05) and insulin sensitivity (rho = -0.52; P < 0.05). We also examined expression of genes related to mitochondrial dynamics. Dynamin1-like protein (DNM1L; P < 0.01), the gene that codes for Drp1, and Optic atrophy 1 (OPA1; P = 0.05) were significantly upregulated following the intervention, while there was a trend towards an increase in expression of both mitofusin protein MFN1 (P = 0.08) and MFN2 (P = 0.07). These are the first data to suggest that lifestyle-mediated improvements in substrate metabolism and insulin sensitivity in obese insulin-resistant adults may be regulated through decreased activation of the mitochondrial fission protein Drp1. Copyright © 2014 the American Physiological Society.

Sperm-binding fibronectin type II-module proteins are genetically linked and functionally related.

PubMed

Ekhlasi-Hundrieser, Mahnaz; Schäfer, Bettina; Philipp, Ute; Kuiper, Heidi; Leeb, Tosso; Mehta, Meenal; Kirchhoff, Christiane; Töpfer-Petersen, Edda

2007-05-01

Fibronectin type II (Fn2) module-containing proteins in the male genital tract are characterized by different numbers of Fn2 modules. Predominantly two classes exist which are distinct by having either two or four Fn2 modules. Minor variants with three Fn2 modules were also found in the human and the porcine epididymis. To reveal their relationship, mRNAs and proteins of representatives of these classes were studied in human, in Sus scrofa, and in rodents. Adult boars expressed members of both classes, i.e. ELSPBP1 and pB1, in subsequent regions of the epididymis, and both were under androgenic control. Human and rodent epididymides, on the other hand, alternatively contained only representatives of one of these two classes, i.e. ELSPBP1 in the human and two different pB1-related counterparts in rodents. ELSPBP1 and pB1-related genomic sequences were closely linked in chromosomal regions HSA 19q and SSC 6 q11-q21; conserved synteny between these regions is well established. On the other hand, in a syntenic region on mouse chromosome 7, ELSPBP1-related sequences were lacking. Tight binding to the sperm membrane via a choline-mediated mechanism was a common feature of the two classes of Fn2-module proteins, suggesting related function(s). However, differences in their regionalized expression patterns along the male genital tract as well as in association sites on the sperm surface suggested a species-specific sequential order in sperm binding.

Protein Secondary Structures (alpha-helix and beta-sheet) at a Cellular Levle and Protein Fractions in Relation to Rumen Degradation Behaviours of Protein: A New Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu,P.

2007-01-01

Studying the secondary structure of proteins leads to an understanding of the components that make up a whole protein, and such an understanding of the structure of the whole protein is often vital to understanding its digestive behaviour and nutritive value in animals. The main protein secondary structures are the {alpha}-helix and {beta}-sheet. The percentage of these two structures in protein secondary structures influences protein nutritive value, quality and digestive behaviour. A high percentage of {beta}-sheet structure may partly cause a low access to gastrointestinal digestive enzymes, which results in a low protein value. The objectives of the present studymore » were to use advanced synchrotron-based Fourier transform IR (S-FTIR) microspectroscopy as a new approach to reveal the molecular chemistry of the protein secondary structures of feed tissues affected by heat-processing within intact tissue at a cellular level, and to quantify protein secondary structures using multicomponent peak modelling Gaussian and Lorentzian methods, in relation to protein digestive behaviours and nutritive value in the rumen, which was determined using the Cornell Net Carbohydrate Protein System. The synchrotron-based molecular chemistry research experiment was performed at the National Synchrotron Light Source at Brookhaven National Laboratory, US Department of Energy. The results showed that, with S-FTIR microspectroscopy, the molecular chemistry, ultrastructural chemical make-up and nutritive characteristics could be revealed at a high ultraspatial resolution ({approx}10 {mu}m). S-FTIR microspectroscopy revealed that the secondary structure of protein differed between raw and roasted golden flaxseeds in terms of the percentages and ratio of {alpha}-helixes and {beta}-sheets in the mid-IR range at the cellular level. By using multicomponent peak modelling, the results show that the roasting reduced (P <0.05) the percentage of {alpha}-helixes (from 47.1% to 36.1%: S

Expression of Tau Pathology-Related Proteins in Different Brain Regions: A Molecular Basis of Tau Pathogenesis.

PubMed

Hu, Wen; Wu, Feng; Zhang, Yanchong; Gong, Cheng-Xin; Iqbal, Khalid; Liu, Fei

2017-01-01

Microtubule-associated protein tau is hyperphosphorylated and aggregated in affected neurons in Alzheimer disease (AD) brains. The tau pathology starts from the entorhinal cortex (EC), spreads to the hippocampus and frontal and temporal cortices, and finally to all isocortex areas, but the cerebellum is spared from tau lesions. The molecular basis of differential vulnerability of different brain regions to tau pathology is not understood. In the present study, we analyzed brain regional expressions of tau and tau pathology-related proteins. We found that tau was hyperphosphorylated at multiple sites in the frontal cortex (FC), but not in the cerebellum, from AD brain. The level of tau expression in the cerebellum was about 1/4 of that seen in the frontal and temporal cortices in human brain. In the rat brain, the expression level of tau with three microtubule-binding repeats (3R-tau) was comparable in the hippocampus, EC, FC, parietal-temporal cortex (PTC), occipital-temporal cortex (OTC), striatum, thalamus, olfactory bulb (OB) and cerebellum. However, the expression level of 4R-tau was the highest in the EC and the lowest in the cerebellum. Tau phosphatases, kinases, microtubule-related proteins and other tau pathology-related proteins were also expressed in a region-specific manner in the rat brain. These results suggest that higher levels of tau and tau kinases in the EC and low levels of these proteins in the cerebellum may accounts for the vulnerability and resistance of these representative brain regions to the development of tau pathology, respectively. The present study provides the regional expression profiles of tau and tau pathology-related proteins in the brain, which may help understand the brain regional vulnerability to tau pathology in neurodegenerative tauopathies.

How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria†

PubMed Central

Deutscher, Josef; Francke, Christof; Postma, Pieter W.

2006-01-01

The phosphoenolpyruvate(PEP):carbohydrate phosphotransferase system (PTS) is found only in bacteria, where it catalyzes the transport and phosphorylation of numerous monosaccharides, disaccharides, amino sugars, polyols, and other sugar derivatives. To carry out its catalytic function in sugar transport and phosphorylation, the PTS uses PEP as an energy source and phosphoryl donor. The phosphoryl group of PEP is usually transferred via four distinct proteins (domains) to the transported sugar bound to the respective membrane component(s) (EIIC and EIID) of the PTS. The organization of the PTS as a four-step phosphoryl transfer system, in which all P derivatives exhibit similar energy (phosphorylation occurs at histidyl or cysteyl residues), is surprising, as a single protein (or domain) coupling energy transfer and sugar phosphorylation would be sufficient for PTS function. A possible explanation for the complexity of the PTS was provided by the discovery that the PTS also carries out numerous regulatory functions. Depending on their phosphorylation state, the four proteins (domains) forming the PTS phosphorylation cascade (EI, HPr, EIIA, and EIIB) can phosphorylate or interact with numerous non-PTS proteins and thereby regulate their activity. In addition, in certain bacteria, one of the PTS components (HPr) is phosphorylated by ATP at a seryl residue, which increases the complexity of PTS-mediated regulation. In this review, we try to summarize the known protein phosphorylation-related regulatory functions of the PTS. As we shall see, the PTS regulation network not only controls carbohydrate uptake and metabolism but also interferes with the utilization of nitrogen and phosphorus and the virulence of certain pathogens. PMID:17158705

Rapid sensing of l-leucine by human and murine hypothalamic neurons: Neurochemical and mechanistic insights.

PubMed

Heeley, Nicholas; Kirwan, Peter; Darwish, Tamana; Arnaud, Marion; Evans, Mark L; Merkle, Florian T; Reimann, Frank; Gribble, Fiona M; Blouet, Clemence

2018-04-01

Dietary proteins are sensed by hypothalamic neurons and strongly influence multiple aspects of metabolic health, including appetite, weight gain, and adiposity. However, little is known about the mechanisms by which hypothalamic neural circuits controlling behavior and metabolism sense protein availability. The aim of this study is to characterize how neurons from the mediobasal hypothalamus respond to a signal of protein availability: the amino acid l-leucine. We used primary cultures of post-weaning murine mediobasal hypothalamic neurons, hypothalamic neurons derived from human induced pluripotent stem cells, and calcium imaging to characterize rapid neuronal responses to physiological changes in extracellular l-Leucine concentration. A neurochemically diverse subset of both mouse and human hypothalamic neurons responded rapidly to l-leucine. Consistent with l-leucine's anorexigenic role, we found that 25% of mouse MBH POMC neurons were activated by l-leucine. 10% of MBH NPY neurons were inhibited by l-leucine, and leucine rapidly reduced AGRP secretion, providing a mechanism for the rapid leucine-induced inhibition of foraging behavior in rodents. Surprisingly, none of the candidate mechanisms previously implicated in hypothalamic leucine sensing (K ATP channels, mTORC1 signaling, amino-acid decarboxylation) were involved in the acute activity changes produced by l-leucine. Instead, our data indicate that leucine-induced neuronal activation involves a plasma membrane Ca 2+ channel, whereas leucine-induced neuronal inhibition is mediated by inhibition of a store-operated Ca 2+ current. A subset of neurons in the mediobasal hypothalamus rapidly respond to physiological changes in extracellular leucine concentration. Leucine can produce both increases and decreases in neuronal Ca 2+ concentrations in a neurochemically-diverse group of neurons, including some POMC and NPY/AGRP neurons. Our data reveal that leucine can signal through novel mechanisms to rapidly

The first report of prion-related protein gene (PRNT) polymorphisms in goat.

PubMed

Kim, Yong-Chan; Jeong, Byung-Hoon

2017-06-01

Prion protein is encoded by the prion protein gene (PRNP). Polymorphisms of several members of the prion gene family have shown association with prion diseases in several species. Recent studies on a novel member of the prion gene family in rams have shown that prion-related protein gene (PRNT) has a linkage with codon 26 of prion-like protein (PRND). In a previous study, codon 26 polymorphism of PRND has shown connection with PRNP haplotype which is strongly associated with scrapie vulnerability. In addition, the genotype of a single nucleotide polymorphism (SNP) at codon 26 of PRND is related to fertilisation capacity. These findings necessitate studies on the SNP of PRNT gene which is connected with PRND. In goat, several polymorphism studies have been performed for PRNP, PRND, and shadow of prion protein gene (SPRN). However, polymorphism on PRNT has not been reported. Hence, the objective of this study was to determine the genotype and allelic distribution of SNPs of PRNT in 238 Korean native goats and compare PRNT DNA sequences between Korean native goats and several ruminant species. A total of five SNPs, including PRNT c.-114G > T, PRNT c.-58A > G in the upstream of PRNT gene, PRNT c.71C > T (p.Ala24Val) and PRNT c.102G > A in the open reading frame (ORF) and c.321C > T in the downstream of PRNT gene, were found in this study. All five SNPs of caprine PRNT gene in Korean native goat are in complete linkage disequilibrium (LD) with a D' value of 1.0. Interestingly, comparative sequence analysis of the PRNT gene revealed five mismatches between DNA sequences of Korean native goats and those of goats deposited in the GenBank. Korean native black goats also showed 5 mismatches in PRNT ORF with cattle. To the best of our knowledge, this is the first genetic research of the PRNT gene in goat.

Constitutive expression of human pancreatic lipase-related protein 1 in Pichia pastoris.

PubMed

Aloulou, Ahmed; Grandval, Philippe; De Caro, Josiane; De Caro, Alain; Carrière, Frédéric

2006-06-01

High-level constitutive expression of the human pancreatic lipase-related protein 1 (HPLRP1) was achieved using the methylotrophic yeast Pichia pastoris. The HPLRP1 cDNA, including its original leader sequence, was subcloned into the pGAPZB vector and further integrated into the genome of P. pastoris X-33 under the control of the glyceraldehyde 3-phosphate dehydrogenase (GAP) constitutive promoter. A major protein with a molecular mass of 50 kDa was found to be secreted into the culture medium and was identified using anti-HPLRP1 polyclonal antibodies as HPLRP1 recombinant protein. The level of expression reached 100-120 mg of HPLRP1 per liter of culture medium after 40 h, as attested by specific and quantitative enzyme-linked immunosorbent assay. A single cation-exchange chromatography sufficed to obtain a highly purified recombinant HPLRP1 after direct batch adsorption onto S-Sepharose of the HPLRP1 present in the culture medium, at pH 5.5. N-terminal sequencing and mass spectrometry analysis were carried out to monitor the production of the mature protein and to confirm that its signal peptide was properly processed.

Discovery of new candidate genes related to brain development using protein interaction information.

PubMed

Chen, Lei; Chu, Chen; Kong, Xiangyin; Huang, Tao; Cai, Yu-Dong

2015-01-01

Human brain development is a dramatic process composed of a series of complex and fine-tuned spatiotemporal gene expressions. A good comprehension of this process can assist us in developing the potential of our brain. However, we have only limited knowledge about the genes and gene functions that are involved in this biological process. Therefore, a substantial demand remains to discover new brain development-related genes and identify their biological functions. In this study, we aimed to discover new brain-development related genes by building a computational method. We referred to a series of computational methods used to discover new disease-related genes and developed a similar method. In this method, the shortest path algorithm was executed on a weighted graph that was constructed using protein-protein interactions. New candidate genes fell on at least one of the shortest paths connecting two known genes that are related to brain development. A randomization test was then adopted to filter positive discoveries. Of the final identified genes, several have been reported to be associated with brain development, indicating the effectiveness of the method, whereas several of the others may have potential roles in brain development.

Mgm101 is a Rad52-related protein required for mitochondrial DNA recombination.

PubMed

Mbantenkhu, MacMillan; Wang, Xiaowen; Nardozzi, Jonathan D; Wilkens, Stephan; Hoffman, Elizabeth; Patel, Anamika; Cosgrove, Michael S; Chen, Xin Jie

2011-12-09

Homologous recombination is a conserved molecular process that has primarily evolved for the repair of double-stranded DNA breaks and stalled replication forks. However, the recombination machinery in mitochondria is poorly understood. Here, we show that the yeast mitochondrial nucleoid protein, Mgm101, is related to the Rad52-type recombination proteins that are widespread in organisms from bacteriophage to humans. Mgm101 is required for repeat-mediated recombination and suppression of mtDNA fragmentation in vivo. It preferentially binds to single-stranded DNA and catalyzes the annealing of ssDNA precomplexed with the mitochondrial ssDNA-binding protein, Rim1. Transmission electron microscopy showed that Mgm101 forms large oligomeric rings of ∼14-fold symmetry and highly compressed helical filaments. Specific mutations affecting ring formation reduce protein stability in vitro. The data suggest that the ring structure may provide a scaffold for stabilization of Mgm101 by preventing the aggregation of the otherwise unstable monomeric conformation. Upon binding to ssDNA, Mgm101 is remobilized from the rings to form distinct nucleoprotein filaments. These studies reveal a recombination protein of likely bacteriophage origin in mitochondria and support the notion that recombination is indispensable for mtDNA integrity.

Structure and stability insights into tumour suppressor p53 evolutionary related proteins.

PubMed

Pagano, Bruno; Jama, Abdullah; Martinez, Pierre; Akanho, Ester; Bui, Tam T T; Drake, Alex F; Fraternali, Franca; Nikolova, Penka V

2013-01-01

The p53 family of genes and their protein products, namely, p53, p63 and p73, have over one billion years of evolutionary history. Advances in computational biology and genomics are enabling studies of the complexities of the molecular evolution of p53 protein family to decipher the underpinnings of key biological conditions spanning from cancer through to various metabolic and developmental disorders and facilitate the design of personalised medicines. However, a complete understanding of the inherent nature of the thermodynamic and structural stability of the p53 protein family is still lacking. This is due, to a degree, to the lack of comprehensive structural information for a large number of homologous proteins and to an incomplete knowledge of the intrinsic factors responsible for their stability and how these might influence function. Here we investigate the thermal stability, secondary structure and folding properties of the DNA-binding domains (DBDs) of a range of proteins from the p53 family using biophysical methods. While the N- and the C-terminal domains of the p53 family show sequence diversity and are normally targets for post-translational modifications and alternative splicing, the central DBD is highly conserved. Together with data obtained from Molecular Dynamics simulations in solution and with structure based homology modelling, our results provide further insights into the molecular properties of evolutionary related p53 proteins. We identify some marked structural differences within the p53 family, which could account for the divergence in biological functions as well as the subtleties manifested in the oligomerization properties of this family.

Agent-based modeling for the landuse change of hunter-gather societies and the impacts on biodiversity in Guyana

NASA Astrophysics Data System (ADS)

Iwamura, T.; Fragoso, J.; Lambin, E.

2012-12-01

The interactions with animals are vital to the Amerindian, indigenous people, of Rupunini savannah-forest in Guyana. Their connections extend from basic energy and protein resource to spiritual bonding through "paring" to a certain animal in the forest. We collected extensive dataset of 23 indigenous communities for 3.5 years, consisting 9900 individuals from 1307 households, as well as animal observation data in 8 transects per communities (47,000 data entries). In this presentation, our research interest is to model the driver of land use change of the indigenous communities and its impacts on the ecosystem in the Rupunini area under global change. Overarching question we would like to answer with this program is to find how and why "tipping-point" from hunting gathering society to the agricultural society occurs in the future. Secondary question is what is the implication of the change to agricultural society in terms of biodiversity and carbon stock in the area, and eventually the well-being of Rupunini people. To answer the questions regarding the society shift in agriculture activities, we built as simulation with Agent-Based Modeling (Multi Agents Simulation). We developed this simulation by using Netlogo, the programming environment specialized for spatially explicit agent-based modeling (ABM). This simulation consists of four different process in the Rupunini landscape; forest succession, animal population growth, hunting of animals, and land clearing for agriculture. All of these processes are carried out by a set of computational unit, called "agents". In this program, there are four types of agents - patches, villages, households, and animals. Here, we describe the impacts of hunting on the biodiversity based on actual demographic data from one village named Crush Water. Animal population within the hunting territory of the village stabilized but Agouti/Paca dominates the landscape with little population of armadillos and peccaries. White-tailed deers

Collagen-binding proteins of Streptococcus mutans and related streptococci.

PubMed

Avilés-Reyes, A; Miller, J H; Lemos, J A; Abranches, J

2017-04-01

The ability of Streptococcus mutans to interact with collagen through the expression of collagen-binding proteins (CBPs) bestows this oral pathogen with an alternative to the sucrose-dependent mechanism of colonization classically attributed to caries development. Based on the abundance and distribution of collagen throughout the human body, stringent adherence to this molecule grants S. mutans with the opportunity to establish infection at different host sites. Surface proteins, such as SpaP, WapA, Cnm and Cbm, have been shown to bind collagen in vitro, and it has been suggested that these molecules play a role in colonization of oral and extra-oral tissues. However, robust collagen binding is not achieved by all strains of S. mutans, particularly those that lack Cnm or Cbm. These observations merit careful dissection of the contribution from these different CBPs towards tissue colonization and virulence. In this review, we will discuss the current understanding of mechanisms used by S. mutans and related streptococci to colonize collagenous tissues, and the possible contribution of CBPs to infections in different sites of the host. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Space-related pharma-motifs for fast search of protein binding motifs and polypharmacological targets

PubMed Central

2012-01-01

Background To discover a compound inhibiting multiple proteins (i.e. polypharmacological targets) is a new paradigm for the complex diseases (e.g. cancers and diabetes). In general, the polypharmacological proteins often share similar local binding environments and motifs. As the exponential growth of the number of protein structures, to find the similar structural binding motifs (pharma-motifs) is an emergency task for drug discovery (e.g. side effects and new uses for old drugs) and protein functions. Results We have developed a Space-Related Pharmamotifs (called SRPmotif) method to recognize the binding motifs by searching against protein structure database. SRPmotif is able to recognize conserved binding environments containing spatially discontinuous pharma-motifs which are often short conserved peptides with specific physico-chemical properties for protein functions. Among 356 pharma-motifs, 56.5% interacting residues are highly conserved. Experimental results indicate that 81.1% and 92.7% polypharmacological targets of each protein-ligand complex are annotated with same biological process (BP) and molecular function (MF) terms, respectively, based on Gene Ontology (GO). Our experimental results show that the identified pharma-motifs often consist of key residues in functional (active) sites and play the key roles for protein functions. The SRPmotif is available at http://gemdock.life.nctu.edu.tw/SRP/. Conclusions SRPmotif is able to identify similar pharma-interfaces and pharma-motifs sharing similar binding environments for polypharmacological targets by rapidly searching against the protein structure database. Pharma-motifs describe the conservations of binding environments for drug discovery and protein functions. Additionally, these pharma-motifs provide the clues for discovering new sequence-based motifs to predict protein functions from protein sequence databases. We believe that SRPmotif is useful for elucidating protein functions and drug discovery

Space-related pharma-motifs for fast search of protein binding motifs and polypharmacological targets.

PubMed

Chiu, Yi-Yuan; Lin, Chun-Yu; Lin, Chih-Ta; Hsu, Kai-Cheng; Chang, Li-Zen; Yang, Jinn-Moon

2012-01-01

To discover a compound inhibiting multiple proteins (i.e. polypharmacological targets) is a new paradigm for the complex diseases (e.g. cancers and diabetes). In general, the polypharmacological proteins often share similar local binding environments and motifs. As the exponential growth of the number of protein structures, to find the similar structural binding motifs (pharma-motifs) is an emergency task for drug discovery (e.g. side effects and new uses for old drugs) and protein functions. We have developed a Space-Related Pharmamotifs (called SRPmotif) method to recognize the binding motifs by searching against protein structure database. SRPmotif is able to recognize conserved binding environments containing spatially discontinuous pharma-motifs which are often short conserved peptides with specific physico-chemical properties for protein functions. Among 356 pharma-motifs, 56.5% interacting residues are highly conserved. Experimental results indicate that 81.1% and 92.7% polypharmacological targets of each protein-ligand complex are annotated with same biological process (BP) and molecular function (MF) terms, respectively, based on Gene Ontology (GO). Our experimental results show that the identified pharma-motifs often consist of key residues in functional (active) sites and play the key roles for protein functions. The SRPmotif is available at http://gemdock.life.nctu.edu.tw/SRP/. SRPmotif is able to identify similar pharma-interfaces and pharma-motifs sharing similar binding environments for polypharmacological targets by rapidly searching against the protein structure database. Pharma-motifs describe the conservations of binding environments for drug discovery and protein functions. Additionally, these pharma-motifs provide the clues for discovering new sequence-based motifs to predict protein functions from protein sequence databases. We believe that SRPmotif is useful for elucidating protein functions and drug discovery.

The p38 mitogen-activated protein kinase signaling pathway is involved in regulating low-density lipoprotein receptor-related protein 1-mediated β-amyloid protein internalization in mouse brain.

PubMed

Ma, Kai-Ge; Lv, Jia; Hu, Xiao-Dan; Shi, Li-Li; Chang, Ke-Wei; Chen, Xin-Lin; Qian, Yi-Hua; Yang, Wei-Na; Qu, Qiu-Min

2016-07-01

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. Recently, increasing evidence suggests that intracellular β-amyloid protein (Aβ) alone plays a pivotal role in the progression of AD. Therefore, understanding the signaling pathway and proteins that control Aβ internalization may provide new insight for regulating Aβ levels. In the present study, the regulation of Aβ internalization by p38 mitogen-activated protein kinases (MAPK) through low-density lipoprotein receptor-related protein 1 (LRP1) was analyzed in vivo. The data derived from this investigation revealed that Aβ1-42 were internalized by neurons and astrocytes in mouse brain, and were largely deposited in mitochondria and lysosomes, with some also being found in the endoplasmic reticulum. Aβ1-42-LRP1 complex was formed during Aβ1-42 internalization, and the p38 MAPK signaling pathway was activated by Aβ1-42 via LRP1. Aβ1-42 and LRP1 were co- localized in the cells of parietal cortex and hippocampus. Furthermore, the level of LRP1-mRNA and LRP1 protein involved in Aβ1-42 internalization in mouse brain. The results of this investigation demonstrated that Aβ1-42 induced an LRP1-dependent pathway that related to the activation of p38 MAPK resulting in internalization of Aβ1-42. These results provide evidence supporting a key role for the p38 MAPK signaling pathway which is involved in the regulation of Aβ1-42 internalization in the parietal cortex and hippocampus of mouse through LRP1 in vivo. Copyright © 2016 Elsevier Ltd. All rights reserved.

[The effect of UV-irradiation on telomerase activity and other stress-related proteins in human lens epithelial cells].

PubMed

Wu, Zhi-hong; Zhang, Jin-song

2005-05-01

To investigate the changes and the role of telomerase activity and other stress-related proteins in the process of UV-induced DNA damage and repair in human lens epithelial cells. Human lens epithelial cells were irradiated at UV-doses 0.0 (control group) and 0.5, 1.5, 2.5, 3.5, 5.0, 7.5, 10.0 mJ/cm(2) (treated 1-7 group). Telomerase activity was determined by Telomerase Repeat Amplification Protocol-Enzyme Linked Immunosorbent Assay (TRAP-ELISA), p53, growth arrest and DNA damage inducible (GADD45), proliferating cell nuclear antigen (PCNA) and p16 protein levels were analyzed by Western blotting. Telomerase activity in control group and treated 1-7 group showed increased tendency, the differences of telomerase activity in 8 groups were significantly (P < 0.01). The expression of p53, GADD45, PCNA, p16 proteins showed increased tendency in experimental group, comparing with the control group, there were significant difference (P < 0.01). During UV-induced DNA damage and repair in human lens epithelial cells, telomerase activity was upregulated and the expression of stress-related proteins levels was increased. Upregulated telomerase activity may play both a protective and a proliferative role in human lens epithelial cells. Increased stress-related proteins level is critic in UV-induced DNA damage and repair in human lens epithelial. Increased telomerase activity is associated with increased levels of the stress-related proteins.

Interactions between whey proteins and salivary proteins as related to astringency of whey protein beverages at low pH.

PubMed

Ye, A; Streicher, C; Singh, H

2011-12-01

Whey protein beverages have been shown to be astringent at low pH. In the present study, the interactions between model whey proteins (β-lactoglobulin and lactoferrin) and human saliva in the pH range from 7 to 2 were investigated using particle size, turbidity, and ζ-potential measurements and sodium dodecyl sulfate-PAGE. The correlation between the sensory results of astringency and the physicochemical data was discussed. Strong interactions between β-lactoglobulin and salivary proteins led to an increase in the particle size and turbidity of mixtures of both unheated and heated β-lactoglobulin and human saliva at pH ∼3.4. However, the large particle size and high turbidity that occurred at pH 2.0 were the result of aggregation of human salivary proteins. The intense astringency in whey protein beverages may result from these increases in particle size and turbidity at these pH values and from the aggregation and precipitation of human salivary proteins alone at pH <3.0. The involvement of salivary proteins in the interaction is a key factor in the perception of astringency in whey protein beverages. At any pH, the increases in particle size and turbidity were much smaller in mixtures of lactoferrin and saliva, which suggests that aggregation and precipitation may not be the only mechanism linked to the perception of astringency in whey protein. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Interaction of the Sliding Clamp β-Subunit and Hda, a DnaA-Related Protein

PubMed Central

Kurz, Mareike; Dalrymple, Brian; Wijffels, Gene; Kongsuwan, Kritaya

2004-01-01

In Escherichia coli, interactions between the replication initiation protein DnaA, the β subunit of DNA polymerase III (the sliding clamp protein), and Hda, the recently identified DnaA-related protein, are required to convert the active ATP-bound form of DnaA to an inactive ADP-bound form through the accelerated hydrolysis of ATP. This rapid hydrolysis of ATP is proposed to be the main mechanism that blocks multiple initiations during cell cycle and acts as a molecular switch from initiation to replication. However, the biochemical mechanism for this crucial step in DNA synthesis has not been resolved. Using purified Hda and β proteins in a plate binding assay and Ni-nitrilotriacetic acid pulldown analysis, we show for the first time that Hda directly interacts with β in vitro. A new β-binding motif, a hexapeptide with the consensus sequence QL[SP]LPL, related to the previously identified β-binding pentapeptide motif (QL[SD]LF) was found in the amino terminus of the Hda protein. Mutants of Hda with amino acid changes in the hexapeptide motif are severely defective in their ability to bind β. A 10-amino-acid peptide containing the E. coli Hda β-binding motif was shown to compete with Hda for binding to β in an Hda-β interaction assay. These results establish that the interaction of Hda with β is mediated through the hexapeptide sequence. We propose that this interaction may be crucial to the events that lead to the inactivation of DnaA and the prevention of excess initiation of rounds of replication. PMID:15150238

Interaction of the sliding clamp beta-subunit and Hda, a DnaA-related protein.