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  1. Article ; Online: Huntingtin-associated protein 1: Eutherian adaptation from a TRAK-like protein, conserved gene promoter elements, and localization in the human intestine.

    Lumsden, Amanda L / Young, Richard L / Pezos, Nektaria / Keating, Damien J

    BMC evolutionary biology

    2016  Volume 16, Issue 1, Page(s) 214

    Abstract: Background: Huntingtin-associated Protein 1 (HAP1) is expressed in neurons and endocrine cells, and is critical for postnatal survival in mice. HAP1 shares a conserved "HAP1_N" domain with TRAfficking Kinesin proteins TRAK1 and TRAK2 (vertebrate), ... ...

    Abstract Background: Huntingtin-associated Protein 1 (HAP1) is expressed in neurons and endocrine cells, and is critical for postnatal survival in mice. HAP1 shares a conserved "HAP1_N" domain with TRAfficking Kinesin proteins TRAK1 and TRAK2 (vertebrate), Milton (Drosophila) and T27A3.1 (C. elegans). HAP1, TRAK1 and TRAK2 have a degree of common function, particularly regarding intracellular receptor trafficking. However, TRAK1, TRAK2 and Milton (which have a "Milt/TRAK" domain that is absent in human and rodent HAP1) differ in function to HAP1 in that they are mitochondrial transport proteins, while HAP1 has emerging roles in starvation response. We have investigated HAP1 function by examining its evolution, and upstream gene promoter sequences. We performed phylogenetic analyses of the HAP1_N domain family of proteins, incorporating HAP1 orthologues (identified by genomic synteny) from 5 vertebrate classes, and also searched the Dictyostelium proteome for a common ancestor. Computational analyses of mammalian HAP1 gene promoters were performed to identify phylogenetically conserved regulatory motifs.
    Results: We found that as recently as marsupials, HAP1 contained a Milt/TRAK domain and was more similar to TRAK1 and TRAK2 than to eutherian HAP1. The Milt/TRAK domain likely arose post multicellularity, as it was absent in the Dictyostelium proteome. It was lost from HAP1 in the eutherian lineage, and also from T27A3.1 in C. elegans. The HAP1 promoter from human, mouse, rat, rabbit, horse, dog, Tasmanian devil and opossum contained common sites for transcription factors involved in cell cycle, growth, differentiation, and stress response. A conserved arrangement of regulatory elements was identified, including sites for caudal-related homeobox transcription factors (CDX1 and CDX2), and myc-associated factor X (MAX) in the region of the TATA box. CDX1 and CDX2 are intestine-enriched factors, prompting investigation of HAP1 protein expression in the human duodenum. HAP1 was localized to singly dispersed mucosal cells, including a subset of serotonin-positive enterochromaffin cells.
    Conclusion: We have identified eutherian HAP1 as an evolutionarily recent adaptation of a vertebrate TRAK protein-like ancestor, and found conserved CDX1/CDX2 and MAX transcription factor binding sites near the TATA box in mammalian HAP1 gene promoters. We also demonstrated that HAP1 is expressed in endocrine cells of the human gut.
    MeSH term(s) Animals ; Base Sequence ; Binding Sites ; Caenorhabditis elegans/genetics ; Conserved Sequence/genetics ; Humans ; Intestines/metabolism ; Mammals/genetics ; Mitochondria/genetics ; Multigene Family ; Nerve Tissue Proteins/metabolism ; Nucleotide Motifs/genetics ; Phylogeny ; Promoter Regions, Genetic ; Protein Binding/genetics ; Protein Domains ; Protein Transport ; Reproducibility of Results ; Sequence Homology, Nucleic Acid ; Serotonin/metabolism ; Transcription Factors/genetics
    Chemical Substances HAP1 protein, human ; Nerve Tissue Proteins ; Transcription Factors ; Serotonin (333DO1RDJY)
    Language English
    Publishing date 2016-10-13
    Publishing country England
    Document type Journal Article
    ISSN 1471-2148
    ISSN (online) 1471-2148
    DOI 10.1186/s12862-016-0780-3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: A Gut-Intrinsic Melanocortin Signaling Complex Augments L-Cell Secretion in Humans.

    Sun, Emily W / Iepsen, Eva W / Pezos, Nektaria / Lumsden, Amanda L / Martin, Alyce M / Schober, Gudrun / Isaacs, Nichole J / Rayner, Christopher K / Nguyen, Nam Q / de Fontgalland, Dayan / Rabbitt, Philippa / Hollington, Paul / Wattchow, David A / Hansen, Torben / Holm, Jens-Christian / Liou, Alice P / Jackson, V Margaret / Torekov, Signe S / Young, Richard L /
    Keating, Damien J

    Gastroenterology

    2021  Volume 161, Issue 2, Page(s) 536–547.e2

    Abstract: Objective: Hypothalamic melanocortin 4 receptors (MC4R) are a key regulator of energy homeostasis. Brain-penetrant MC4R agonists have failed, as concentrations required to suppress food intake also increase blood pressure. However, peripherally located ... ...

    Abstract Objective: Hypothalamic melanocortin 4 receptors (MC4R) are a key regulator of energy homeostasis. Brain-penetrant MC4R agonists have failed, as concentrations required to suppress food intake also increase blood pressure. However, peripherally located MC4R may also mediate metabolic benefits of MC4R activation. Mc4r transcript is enriched in mouse enteroendocrine L cells and peripheral administration of the endogenous MC4R agonist, α-melanocyte stimulating hormone (α-MSH), triggers the release of the anorectic hormones Glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) in mice. This study aimed to determine whether pathways linking MC4R and L-cell secretion exist in humans.
    Design: GLP-1 and PYY levels were assessed in body mass index-matched individuals with or without loss-of-function MC4R mutations following an oral glucose tolerance test. Immunohistochemistry was performed on human intestinal sections to characterize the mucosal MC4R system. Static incubations with MC4R agonists were carried out on human intestinal epithelia, GLP-1 and PYY contents of secretion supernatants were assayed.
    Results: Fasting PYY levels and oral glucose-induced GLP-1 secretion were reduced in humans carrying a total loss-of-function MC4R mutation. MC4R was localized to L cells and regulates GLP-1 and PYY secretion from ex vivo human intestine. α-MSH immunoreactivity in the human intestinal epithelia was predominantly localized to L cells. Glucose-sensitive mucosal pro-opiomelanocortin cells provide a local source of α-MSH that is essential for glucose-induced GLP-1 secretion in small intestine.
    Conclusion: Our findings describe a previously unidentified signaling nexus in the human gastrointestinal tract involving α-MSH release and MC4R activation on L cells in an autocrine and paracrine fashion. Outcomes from this study have direct implications for targeting mucosal MC4R to treat human metabolic disorders.
    MeSH term(s) Autocrine Communication ; Blood Glucose/metabolism ; Case-Control Studies ; Enteroendocrine Cells/drug effects ; Enteroendocrine Cells/metabolism ; Glucagon-Like Peptide 1/metabolism ; Glucose/administration & dosage ; Glucose Tolerance Test ; Humans ; Intestinal Mucosa/drug effects ; Intestinal Mucosa/metabolism ; Loss of Function Mutation ; Paracrine Communication ; Peptide YY/metabolism ; Pro-Opiomelanocortin/genetics ; Pro-Opiomelanocortin/metabolism ; Receptor, Melanocortin, Type 4/agonists ; Receptor, Melanocortin, Type 4/genetics ; Receptor, Melanocortin, Type 4/metabolism ; Secretory Pathway ; Signal Transduction ; Time Factors ; alpha-MSH/metabolism ; alpha-MSH/pharmacology
    Chemical Substances Blood Glucose ; MC4R protein, human ; Receptor, Melanocortin, Type 4 ; Peptide YY (106388-42-5) ; alpha-MSH (581-05-5) ; Pro-Opiomelanocortin (66796-54-1) ; Glucagon-Like Peptide 1 (89750-14-1) ; Glucose (IY9XDZ35W2)
    Language English
    Publishing date 2021-04-20
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 80112-4
    ISSN 1528-0012 ; 0016-5085
    ISSN (online) 1528-0012
    ISSN 0016-5085
    DOI 10.1053/j.gastro.2021.04.014
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Sugar Responses of Human Enterochromaffin Cells Depend on Gut Region, Sex, and Body Mass

    Lumsden, Amanda L / Martin, Alyce M / Sun, Emily W / Schober, Gudrun / Isaacs, Nicole J / Pezos, Nektaria / Wattchow, David A / de Fontgalland, Dayan / Rabbitt, Philippa / Hollington, Paul / Sposato, Luigi / Due, Steven L / Rayner, Christopher K / Nguyen, Nam Q / Liou, Alice P / Jackson, V. Margaret / Young, Richard L / Keating, Damien J

    Nutrients. 2019 Jan. 22, v. 11, no. 2

    2019  

    Abstract: Gut-derived serotonin (5-HT) is released from enterochromaffin (EC) cells in response to nutrient cues, and acts to slow gastric emptying and modulate gastric motility. Rodent studies also evidence a role for gut-derived 5-HT in the control of hepatic ... ...

    Abstract Gut-derived serotonin (5-HT) is released from enterochromaffin (EC) cells in response to nutrient cues, and acts to slow gastric emptying and modulate gastric motility. Rodent studies also evidence a role for gut-derived 5-HT in the control of hepatic glucose production, lipolysis and thermogenesis, and in mediating diet-induced obesity. EC cell number and 5-HT content is increased in the small intestine of obese rodents and human, however, it is unknown whether EC cells respond directly to glucose in humans, and whether their capacity to release 5-HT is perturbed in obesity. We therefore investigated 5-HT release from human duodenal and colonic EC cells in response to glucose, sucrose, fructose and α-glucoside (αMG) in relation to body mass index (BMI). EC cells released 5-HT only in response to 100 and 300 mM glucose (duodenum) and 300 mM glucose (colon), independently of osmolarity. Duodenal, but not colonic, EC cells also released 5-HT in response to sucrose and αMG, but did not respond to fructose. 5-HT content was similar in all EC cells in males, and colonic EC cells in females, but 3 to 4-fold higher in duodenal EC cells from overweight females (p < 0.05 compared to lean, obese). Glucose-evoked 5-HT release was 3-fold higher in the duodenum of overweight females (p < 0.05, compared to obese), but absent here in overweight males. Our data demonstrate that primary human EC cells respond directly to dietary glucose cues, with regional differences in selectivity for other sugars. Augmented glucose-evoked 5-HT release from duodenal EC is a feature of overweight females, and may be an early determinant of obesity.
    Keywords body mass index ; colon ; duodenum ; females ; fructose ; gastric emptying ; glucose ; glucosides ; heat production ; lipolysis ; males ; obesity ; osmolarity ; rodents ; serotonin ; sucrose
    Language English
    Dates of publication 2019-0122
    Publishing place Multidisciplinary Digital Publishing Institute
    Document type Article
    ZDB-ID 2518386-2
    ISSN 2072-6643
    ISSN 2072-6643
    DOI 10.3390/nu11020234
    Database NAL-Catalogue (AGRICOLA)

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  4. Article: Sugar Responses of Human Enterochromaffin Cells Depend on Gut Region, Sex, and Body Mass

    Lumsden, Amanda L / Martin, Alyce M / Sun, Emily W / Schober, Gudrun / Isaacs, Nicole J / Pezos, Nektaria / Wattchow, David A / de Fontgalland, Dayan / Rabbitt, Philippa / Hollington, Paul / Sposato, Luigi / Due, Steven L / Rayner, Christopher K / Nguyen, Nam Q / Liou, Alice P / Jackson, V. Margaret / Young, Richard L / Keating, Damien J

    Nutrients. 2019 Jan. 22, v. 11, no. 2

    2019  

    Abstract: Gut-derived serotonin (5-HT) is released from enterochromaffin (EC) cells in response to nutrient cues, and acts to slow gastric emptying and modulate gastric motility. Rodent studies also evidence a role for gut-derived 5-HT in the control of hepatic ... ...

    Abstract Gut-derived serotonin (5-HT) is released from enterochromaffin (EC) cells in response to nutrient cues, and acts to slow gastric emptying and modulate gastric motility. Rodent studies also evidence a role for gut-derived 5-HT in the control of hepatic glucose production, lipolysis and thermogenesis, and in mediating diet-induced obesity. EC cell number and 5-HT content is increased in the small intestine of obese rodents and human, however, it is unknown whether EC cells respond directly to glucose in humans, and whether their capacity to release 5-HT is perturbed in obesity. We therefore investigated 5-HT release from human duodenal and colonic EC cells in response to glucose, sucrose, fructose and α-glucoside (αMG) in relation to body mass index (BMI). EC cells released 5-HT only in response to 100 and 300 mM glucose (duodenum) and 300 mM glucose (colon), independently of osmolarity. Duodenal, but not colonic, EC cells also released 5-HT in response to sucrose and αMG, but did not respond to fructose. 5-HT content was similar in all EC cells in males, and colonic EC cells in females, but 3 to 4-fold higher in duodenal EC cells from overweight females (p < 0.05 compared to lean, obese). Glucose-evoked 5-HT release was 3-fold higher in the duodenum of overweight females (p < 0.05, compared to obese), but absent here in overweight males. Our data demonstrate that primary human EC cells respond directly to dietary glucose cues, with regional differences in selectivity for other sugars. Augmented glucose-evoked 5-HT release from duodenal EC is a feature of overweight females, and may be an early determinant of obesity.
    Keywords body mass index ; colon ; duodenum ; females ; fructose ; gastric emptying ; glucose ; glucosides ; heat production ; humans ; lipolysis ; males ; obesity ; osmolarity ; rodents ; serotonin ; sucrose
    Language English
    Dates of publication 2019-0122
    Publishing place Multidisciplinary Digital Publishing Institute
    Document type Article
    ZDB-ID 2518386-2
    ISSN 2072-6643
    ISSN 2072-6643
    DOI 10.3390/nu11020234
    Database NAL-Catalogue (AGRICOLA)

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  5. Article ; Online: Sugar Responses of Human Enterochromaffin Cells Depend on Gut Region, Sex, and Body Mass.

    Lumsden, Amanda L / Martin, Alyce M / Sun, Emily W / Schober, Gudrun / Isaacs, Nicole J / Pezos, Nektaria / Wattchow, David A / de Fontgalland, Dayan / Rabbitt, Philippa / Hollington, Paul / Sposato, Luigi / Due, Steven L / Rayner, Christopher K / Nguyen, Nam Q / Liou, Alice P / Jackson, V Margaret / Young, Richard L / Keating, Damien J

    Nutrients

    2019  Volume 11, Issue 2

    Abstract: Gut-derived serotonin (5-HT) is released from enterochromaffin (EC) cells in response to nutrient cues, and acts to slow gastric emptying and modulate gastric motility. Rodent studies also evidence a role for gut-derived 5-HT in the control of hepatic ... ...

    Abstract Gut-derived serotonin (5-HT) is released from enterochromaffin (EC) cells in response to nutrient cues, and acts to slow gastric emptying and modulate gastric motility. Rodent studies also evidence a role for gut-derived 5-HT in the control of hepatic glucose production, lipolysis and thermogenesis, and in mediating diet-induced obesity. EC cell number and 5-HT content is increased in the small intestine of obese rodents and human, however, it is unknown whether EC cells respond directly to glucose in humans, and whether their capacity to release 5-HT is perturbed in obesity. We therefore investigated 5-HT release from human duodenal and colonic EC cells in response to glucose, sucrose, fructose and α-glucoside (αMG) in relation to body mass index (BMI). EC cells released 5-HT only in response to 100 and 300 mM glucose (duodenum) and 300 mM glucose (colon), independently of osmolarity. Duodenal, but not colonic, EC cells also released 5-HT in response to sucrose and αMG, but did not respond to fructose. 5-HT content was similar in all EC cells in males, and colonic EC cells in females, but 3 to 4-fold higher in duodenal EC cells from overweight females (
    MeSH term(s) Body Weight ; Carbohydrates/pharmacology ; Cells, Cultured ; Dose-Response Relationship, Drug ; Enterochromaffin Cells/drug effects ; Female ; Gastrointestinal Tract/cytology ; Humans ; Male ; Sex Factors
    Chemical Substances Carbohydrates
    Language English
    Publishing date 2019-01-22
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2518386-2
    ISSN 2072-6643 ; 2072-6643
    ISSN (online) 2072-6643
    ISSN 2072-6643
    DOI 10.3390/nu11020234
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Augmented capacity for peripheral serotonin release in human obesity.

    Young, Richard L / Lumsden, Amanda L / Martin, Alyce M / Schober, Gudrun / Pezos, Nektaria / Thazhath, Sony S / Isaacs, Nicole J / Cvijanovic, Nada / Sun, Emily W L / Wu, Tongzhi / Rayner, Christopher K / Nguyen, Nam Q / Fontgalland, Dayan de / Rabbitt, Philippa / Hollington, Paul / Sposato, Luigi / Due, Steven L / Wattchow, David A / Liou, Alice P /
    Jackson, V Margaret / Keating, Damien J

    International journal of obesity (2005)

    2018  Volume 42, Issue 11, Page(s) 1880–1889

    Abstract: Background/objectives: Evidence from animal studies highlights an important role for serotonin (5-HT), derived from gut enterochromaffin (EC) cells, in regulating hepatic glucose production, lipolysis and thermogenesis, and promoting obesity and ... ...

    Abstract Background/objectives: Evidence from animal studies highlights an important role for serotonin (5-HT), derived from gut enterochromaffin (EC) cells, in regulating hepatic glucose production, lipolysis and thermogenesis, and promoting obesity and dysglycemia. Evidence in humans is limited, although elevated plasma 5-HT concentrations are linked to obesity.
    Subjects/methods: We assessed (i) plasma 5-HT concentrations before and during intraduodenal glucose infusion (4 kcal/min for 30 min) in non-diabetic obese (BMI 44 ± 4 kg/m
    Results: Plasma 5-HT was twofold higher in obese than control responders prior to (P = 0.025), and during (iAUC, P = 0.009), intraduodenal glucose infusion, and related positively to BMI (R
    Conclusions: Human obesity is characterized by an increased capacity to produce and release 5-HT from the proximal small intestine, which is strongly linked to higher body mass, and glycemic control. Gut-derived 5-HT is likely to be an important driver of pathogenesis in human obesity and dysglycemia.
    MeSH term(s) Adult ; Blood Glucose/metabolism ; Cells, Cultured ; Colon/cytology ; Colon/metabolism ; Endoscopy, Gastrointestinal ; Enterochromaffin Cells/metabolism ; Female ; Humans ; Male ; Middle Aged ; Obesity/metabolism ; Obesity/physiopathology ; Peripheral Nervous System/metabolism ; Peripheral Nervous System/physiology ; Real-Time Polymerase Chain Reaction ; Serotonin/metabolism ; Signal Transduction
    Chemical Substances Blood Glucose ; Serotonin (333DO1RDJY)
    Language English
    Publishing date 2018-03-01
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 752409-2
    ISSN 1476-5497 ; 0307-0565
    ISSN (online) 1476-5497
    ISSN 0307-0565
    DOI 10.1038/s41366-018-0047-8
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