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Li ZH, Li B, Zhang XY, Zhu JN. Neuropeptides and Their Roles in the Cerebellum. Int J Mol Sci 2024; 25:2332. [PMID: 38397008 PMCID: PMC10889816 DOI: 10.3390/ijms25042332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/08/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024] Open
Abstract
Although more than 30 different types of neuropeptides have been identified in various cell types and circuits of the cerebellum, their unique functions in the cerebellum remain poorly understood. Given the nature of their diffuse distribution, peptidergic systems are generally assumed to exert a modulatory effect on the cerebellum via adaptively tuning neuronal excitability, synaptic transmission, and synaptic plasticity within cerebellar circuits. Moreover, cerebellar neuropeptides have also been revealed to be involved in the neurogenetic and developmental regulation of the developing cerebellum, including survival, migration, differentiation, and maturation of the Purkinje cells and granule cells in the cerebellar cortex. On the other hand, cerebellar neuropeptides hold a critical position in the pathophysiology and pathogenesis of many cerebellar-related motor and psychiatric disorders, such as cerebellar ataxias and autism. Over the past two decades, a growing body of evidence has indicated neuropeptides as potential therapeutic targets to ameliorate these diseases effectively. Therefore, this review focuses on eight cerebellar neuropeptides that have attracted more attention in recent years and have significant potential for clinical application associated with neurodegenerative and/or neuropsychiatric disorders, including brain-derived neurotrophic factor, corticotropin-releasing factor, angiotensin II, neuropeptide Y, orexin, thyrotropin-releasing hormone, oxytocin, and secretin, which may provide novel insights and a framework for our understanding of cerebellar-related disorders and have implications for novel treatments targeting neuropeptide systems.
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Affiliation(s)
- Zi-Hao Li
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing 210023, China; (Z.-H.L.); (J.-N.Z.)
| | - Bin Li
- Women and Children’s Medical Research Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Xiao-Yang Zhang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing 210023, China; (Z.-H.L.); (J.-N.Z.)
- Institute for Brain Sciences, Nanjing University, Nanjing 210023, China
| | - Jing-Ning Zhu
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing 210023, China; (Z.-H.L.); (J.-N.Z.)
- Institute for Brain Sciences, Nanjing University, Nanjing 210023, China
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2
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Zhang F, Mak SOK, Liu Y, Ke Y, Rao F, Yung WH, Zhang L, Chow BKC. Secretin receptor deletion in the subfornical organ attenuates the activation of excitatory neurons under dehydration. Curr Biol 2022; 32:4832-4841.e5. [PMID: 36220076 DOI: 10.1016/j.cub.2022.09.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 07/22/2022] [Accepted: 09/19/2022] [Indexed: 11/06/2022]
Abstract
In mammals, thirst is strongly influenced by the subfornical organ (SFO), a forebrain structure that integrates circulating signals including osmotic pressure and sodium contents. Secretin (SCT), a classical gastrointestinal hormone, has been implicated as a humoral factor regulating body-fluid homeostasis. However, the neural mechanism of secretin in the central nervous system in managing thirst remains unclear. In this study, we report that the local ablation of SCT receptor (SCTR) in the SFO reduces water but not salt intake in dehydrated mice and this effect could not be rescued by exogenous SCT administration. Electrophysiology with single-cell RT-PCR indicates that SCT elicits inward currents in the SFO neuronal nitric oxide synthase (SFOnNOS) neurons via SCTR in the presence of glutamate receptor antagonists. We further show that the SCTR in the SFO permits the activation of SFOnNOS neurons under distinct thirst types. Projection-specific gene deletion of SCTR in SFO to the median preoptic nucleus (MnPO) pathway also reduces water intake in dehydrated animals. SCT signaling thus plays an indispensable role in driving thirst. These data not only expand the functional boundaries of SCTR but also provide insights into the central mechanisms of homeostatic regulation.
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Affiliation(s)
- Fengwei Zhang
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Sarah O K Mak
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Yuchu Liu
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Ya Ke
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China; Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Hong Kong, China
| | - Feng Rao
- School of Life Sciences, Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Wing Ho Yung
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China; Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Hong Kong, China.
| | - Li Zhang
- Key Laboratory of CNS Regeneration (Ministry of Education), GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China; Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, China.
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Sugiyama M, Nishijima I, Nakamura W, Nakamura TJ. Secretin receptor-deficient mice exhibit robust food anticipatory activity. Neurosci Lett 2022; 772:136462. [PMID: 35051436 DOI: 10.1016/j.neulet.2022.136462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/20/2021] [Accepted: 01/12/2022] [Indexed: 11/26/2022]
Abstract
In mammals, the suprachiasmatic nucleus (SCN) is a principal circadian pacemaker that optimizes the timing of behavioral rhythms and physiological events. Normally, circadian behavioral rhythms are entrained by the environmental light-dark (LD) cycle via the SCN. However, daily rhythms of other synchronizing signals, such as food availability, also emerge. When food availability is restricted to a single recurring daytime meal in nocturnal rodents, they exhibit increased activity during the hours immediately preceding feeding time; this is called food anticipatory activity (FAA). Many reports suggest that FAA is mediated by the food-entrainable oscillator (FEO) with circadian properties, but not the SCN. However, the neural locus and timekeeping mechanisms of the FEO, including its relationship with gastrointestinal hormone signaling, remain unclear. Herein, to examine whether secretin receptor signaling is necessary for the FEO, the effect of daily food restriction was studied in secretin receptor-deficient (Sctr-/-) mice. Adult wild-type (WT) and Sctr-/- mice were housed in separate cages containing a running wheel, with ad libitum food access and in a LD cycle (12 hours : 12 hours) for at least 2 weeks. After acclimation to the condition, food access times were gradually restricted and 4-hour restricted feeding lasted over 10 days. Subsequently, mice had ad libitum food access for 2 days and then fasted for 2 days. Thereafter, robust FAAs were observed in both WT and Sctr-/- mice during restricted feeding and subsequent fasting. These results indicate that secretin receptor signaling is not essential for the timekeeping mechanism of FEO.
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Affiliation(s)
- Mizuki Sugiyama
- Laboratory of Animal Physiology, School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan
| | - Ichiko Nishijima
- Tohoku Medical Megabank Organization, Tohoku University, Sendai, Miyagi 980-8575, Japan
| | - Wataru Nakamura
- Department of Oral-Chrono Physiology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Nagasaki, 852-8588, Japan
| | - Takahiro J Nakamura
- Laboratory of Animal Physiology, School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan.
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Laurila S, Rebelos E, Honka MJ, Nuutila P. Pleiotropic Effects of Secretin: A Potential Drug Candidate in the Treatment of Obesity? Front Endocrinol (Lausanne) 2021; 12:737686. [PMID: 34671320 PMCID: PMC8522834 DOI: 10.3389/fendo.2021.737686] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 09/15/2021] [Indexed: 12/18/2022] Open
Abstract
Secretin is the first hormone that has been discovered, inaugurating the era and the field of endocrinology. Despite the initial focus, the interest in its actions faded away over the decades. However, there is mounting evidence regarding the pleiotropic beneficial effects of secretin on whole-body homeostasis. In this review, we discuss the evidence from preclinical and clinical studies based on which secretin may have a role in the treatment of obesity.
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Affiliation(s)
- Sanna Laurila
- Turku PET Centre, University of Turku, Turku, Finland
- Heart Center, Turku University Hospital, Turku, Finland
- Department of Cardiology, Satakunta Central Hospital, Pori, Finland
| | - Eleni Rebelos
- Turku PET Centre, University of Turku, Turku, Finland
| | | | - Pirjo Nuutila
- Turku PET Centre, University of Turku, Turku, Finland
- Department of Endocrinology, Turku University Hospital, Turku, Finland
- *Correspondence: Pirjo Nuutila,
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5
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Wang L, Zhang L. Involvement of Secretin in the Control of Cell Survival and Synaptic Plasticity in the Central Nervous System. Front Neurosci 2020; 14:387. [PMID: 32435180 PMCID: PMC7218122 DOI: 10.3389/fnins.2020.00387] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 03/30/2020] [Indexed: 01/30/2023] Open
Abstract
With emerging evidence showing a wide distribution of secretin (SCT) and its receptor (SCTR) in the central nervous system (CNS), the putative neuropeptide role of SCT has become more appreciated since the disruption of SCT/SCTR axis affects various neural functions. This mini review thus focuses on the effects of SCT on cell survival and synaptic plasticity, both of which play critical roles in constructing and maintaining neural circuits with optimal output of behavioral phenotypes. Specifically, SCT-dependent cellular and molecular mechanisms that may regulate these two aspects will be discussed. The potential complementary or synergistical mechanisms between SCT and other peptides of the SCT superfamily will also be discussed for bridging their actions in the brain. A full understanding of functional SCT/SCTR in the brain may lead to future perspectives regarding therapeutic implications of SCT in relieving neural symptoms.
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Affiliation(s)
- Lei Wang
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Li Zhang
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China
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Qi XR, Zhang L. The Potential Role of Gut Peptide Hormones in Autism Spectrum Disorder. Front Cell Neurosci 2020; 14:73. [PMID: 32296309 PMCID: PMC7136424 DOI: 10.3389/fncel.2020.00073] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 03/12/2020] [Indexed: 12/11/2022] Open
Abstract
Gut peptide hormones are one group of secretory factors produced from gastrointestinal endocrine cells with potent functions in modulating digestive functions. In recent decades, they have been found across different brain regions, many of which are involved in autism-related social, emotional and cognitive deficits. Clinical studies have revealed possible correlation between those hormones and autism spectrum disorder pathogenesis. In animal models, gut peptide hormones modulate neurodevelopment, synaptic transmission and neural plasticity, explaining their behavioral relevance. This review article will summarize major findings from both clinical and basic research showing the role of gut peptide hormones in mediating autism-related neurological functions, and their potential implications in autism pathogenesis. The pharmaceutical value of gut hormones in alleviating autism-associated behavioral syndromes will be discussed to provide new insights for future drug development.
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Affiliation(s)
- Xin-Rui Qi
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People’s Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Li Zhang
- Joint International Research Laboratory of CNS Regeneration, Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
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Chakraborty C, Sharma AR, Sharma G, Bhattacharya M, Lee SS. Insight into Evolution and Conservation Patterns of B1-Subfamily Members of GPCR. Int J Pept Res Ther 2020; 26:2505-2517. [PMID: 32421105 PMCID: PMC7223794 DOI: 10.1007/s10989-020-10043-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2020] [Indexed: 11/25/2022]
Abstract
The diverse, evolutionary architectures of proteins can be regarded as molecular fossils, tracing a historical path that marks important milestones across life. The B1-subfamily of GPCRs (G-protein-coupled receptors) are medically significant proteins that comprise 15 transmembrane receptor proteins in Homo sapiens. These proteins control the intracellular concentration of cyclic AMP as well as various vital processes in the body. However, little is known about the evolutionary correlation and conservational blueprint of this GPCR subfamily. We performed a comprehensive analysis to understand the evolutionary architecture among 13 members of the B1-subfamily. Multiple sequence alignment analysis exhibited six multiple sequence aligned blocks and five highly aligned blocks. Molecular phylogenetics indicated that CRHR1 and CRHR2 share a typical ancestral relationship and are siblings in 100% bootstrap replications with a total of 24 nodes observed in the cladogram. CRHR2 has the maximum number of extremely conserved amino acids followed by ADCYAP1R1. The longest continuous number sequence logos (74) were found between sequence location 349 and 423, and consequently, the maximum and minimum logo height recorded was 3.6 bits and 0.18 bits, respectively. Finally, to understand the model and pattern of evolutionary relatedness, the conservation blueprint, and the diversification among the members of a protein family, GPCR distribution from several species throughout the animal kingdom was analysed. Together, the study provides an evolutionary insight and offers a rapid method to explore the potential of depicting the evolutionary relationship, conservation blueprint, and diversification among the B1-subfamily of GPCRs using bioinformatics, algorithm analysis, and mathematical models.
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Affiliation(s)
- Chiranjib Chakraborty
- Adamas University, North, 24 Parganas, Kolkata, 700126 West Bengal India
- Institute for Skeletal Aging & Orthopedic Surgery, Chuncheon Sacred Heart Hospital, Hallym University, Chuncheon, 24252 Republic of Korea
| | - Ashish Ranjan Sharma
- Institute for Skeletal Aging & Orthopedic Surgery, Chuncheon Sacred Heart Hospital, Hallym University, Chuncheon, 24252 Republic of Korea
| | - Garima Sharma
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, 24341 Republic of Korea
| | - Manojit Bhattacharya
- Institute for Skeletal Aging & Orthopedic Surgery, Chuncheon Sacred Heart Hospital, Hallym University, Chuncheon, 24252 Republic of Korea
| | - Sang-Soo Lee
- Institute for Skeletal Aging & Orthopedic Surgery, Chuncheon Sacred Heart Hospital, Hallym University, Chuncheon, 24252 Republic of Korea
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Sugiyama M, Nishijima I, Miyazaki S, Nakamura TJ. Secretin receptor-deficient mice exhibit altered circadian rhythm in wheel-running activity. Neurosci Lett 2020; 722:134814. [PMID: 32027952 DOI: 10.1016/j.neulet.2020.134814] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 01/26/2020] [Accepted: 02/01/2020] [Indexed: 10/25/2022]
Abstract
In mammals, the timing of behavior and physiological activity is controlled by the suprachiasmatic nucleus (SCN) in the hypothalamus. Incidentally, secretin is a peptide hormone that promotes digestive activities and regulates water reabsorption. In recent studies, exogenous administration of secretin has been reported to induce secretion of oxytocin in the supraoptic nucleus of the hypothalamus and modulate social behavior. These results indicate that secretin is involved in the neural network that controls social behavior and plays important roles in the central nervous system. In the present study, we investigated the effects of secretin on circadian rhythms, by assessing circadian rhythms during wheel-running behavior in secretin receptor-deficient (Sctr-/-) mice. Male adult wild-type (WT) and Sctr-/- mice were housed in separate cages containing a wheel. Every minute of the wheel-running activity was monitored during the normal light-dark (LD) cycle (12:12 h) and in constant darkness (DD). Significant differences were observed in the free-running period between the WT and Sctr-/- mice. However, no significant differences were observed in the daily wheel-running revolutions between WT and Sctr-/- mice, in the LD and DD conditions. Moreover, the ratio of the daily activity phase to the rest phase (α/ρ) was significantly smaller in Sctr-/- than that in WT mice in the DD condition. Secretin receptors were expressed in the SCN cells. These findings suggest that secretin receptors are involved in the central circadian clock in the SCN and the circadian system in general.
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Affiliation(s)
- Mizuki Sugiyama
- Laboratory of Animal Physiology, School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan
| | - Ichiko Nishijima
- Tohoku Medical Megabank Organization, Tohoku University, Sendai, Miyagi 980-8575, Japan.
| | - Shota Miyazaki
- Laboratory of Animal Physiology, School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan
| | - Takahiro J Nakamura
- Laboratory of Animal Physiology, School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan.
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Csillag V, Vastagh C, Liposits Z, Farkas I. Secretin Regulates Excitatory GABAergic Neurotransmission to GnRH Neurons via Retrograde NO Signaling Pathway in Mice. Front Cell Neurosci 2019; 13:371. [PMID: 31507377 PMCID: PMC6716020 DOI: 10.3389/fncel.2019.00371] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 07/30/2019] [Indexed: 01/28/2023] Open
Abstract
In mammals, reproduction is regulated by a wide range of metabolic hormones that maintain the proper energy balance. In addition to regulating feeding and energy expenditure, these metabolic messengers also modulate the functional performance of the hypothalamic-pituitary-gonadal (HPG) axis. Secretin, a member of the secretin-glucagon-vasoactive intestinal peptide hormone family, has been shown to alter reproduction centrally, although the underlying mechanisms have not been explored yet. In order to elucidate its central action in the neuroendocrine regulation of reproduction, in vitro electrophysiological slice experiments were carried out on GnRH-GFP neurons in male mice. Bath application of secretin (100 nM) significantly increased the frequency of the spontaneous postsynaptic currents (sPSCs) to 118.0 ± 2.64% compared to the control, and that of the GABAergic miniature postsynaptic currents (mPSCs) to 147.6 ± 19.19%. Resting membrane potential became depolarized by 12.74 ± 4.539 mV after secretin treatment. Frequency of evoked action potentials (APs) also increased to 144.3 ± 10.8%. The secretin-triggered elevation of the frequency of mPSCs was prevented by using either a secretin receptor antagonist (3 μM) or intracellularly applied G-protein-coupled receptor blocker (GDP-β-S; 2 mM) supporting the involvement of secretin receptor in the process. Regarding the actions downstream to secretin receptor, intracellular blockade of protein kinase A (PKA) with KT-5720 (2 μM) or intracellular inhibition of the neuronal nitric oxide synthase (nNOS) by NPLA (1 μM) abolished the stimulatory effect of secretin on mPSCs. These data suggest that secretin acts on GnRH neurons via secretin receptors whose activation triggers the cAMP/PKA/nNOS signaling pathway resulting in nitric oxide release and in the presynaptic terminals this retrograde NO machinery regulates the GABAergic input to GnRH neurons.
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Affiliation(s)
- Veronika Csillag
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.,Roska Tamás Doctoral School of Sciences and Technology, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Csaba Vastagh
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Zsolt Liposits
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.,Department of Neuroscience, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Imre Farkas
- Laboratory of Reproductive Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
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Wang L, Zhang L, Chow BKC. Secretin Prevents Apoptosis in the Developing Cerebellum Through Bcl-2 and Bcl-xL. J Mol Neurosci 2019; 68:494-503. [PMID: 30874970 DOI: 10.1007/s12031-019-01287-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 02/28/2019] [Indexed: 01/30/2023]
Abstract
Secretin (SCT) is involved in a variety of physiological processes and has been implicated in preventing apoptosis during brain development. However, little is known about the molecular mechanism underlying its neuroprotective effects. The B cell lymphoma 2 (Bcl-2) family proteins, such as Bcl-2 and Bcl-xL, determine the commitment of neurons to apoptosis. In SCT knockout mice, we found reduced transcript levels of anti-apoptotic genes Bcl-2 and Bcl-xL, but not of pro-apoptotic gene Bax, in the developing cerebellum. SCT treatment on ex vivo cultured cerebellar slices triggered a time-dependent increase of Bcl-2 and Bcl-xL expression. This SCT-induced transcriptional regulation of Bcl-2 and Bcl-xL was dependent on the cyclic AMP (cAMP) response element-binding protein (CREB), which is a key survival factor at the convergence of multiple signaling cascades. We further demonstrated that activation of CREB by SCT was mediated by cAMP/protein kinase A (PKA) and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase 1/2 (ERK1/2) cascades. These findings, collectively, provide an uncharacterized signaling cascade for SCT-mediated neuronal survival, in which SCT promotes the key anti-apoptotic elements Bcl-2 and Bcl-xL in the intrinsic death pathway through PKA- and ERK-regulated CREB phosphorylation.
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Affiliation(s)
- Lei Wang
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Li Zhang
- GHM Institute for CNS Regeneration, Jinan University, Guangzhou, China.
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong, SAR, Hong Kong.
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Wang R, Chow BKC, Zhang L. Distribution and Functional Implication of Secretin in Multiple Brain Regions. J Mol Neurosci 2018; 68:485-493. [PMID: 29882022 DOI: 10.1007/s12031-018-1089-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 05/11/2018] [Indexed: 12/15/2022]
Abstract
Secretin is a polypeptide hormone initially identified for its gastrointestinal functions. However, emerging evidences show wide distribution of secretin and secretin receptor across various brain regions from cerebral cortex, hippocampus, hypothalamus to cerebellum. In this mini review, we will firstly describe the region-specific expression pattern of secretin and secretin receptor in the brain, followed by a summary of central physiological and neurological functions mediated by secretin. Using genetic manipulation and pharmaceutical approaches, one can elucidate the role of secretin in mediating various neurological functions from simple behaviors, such as water and food intake, to more complex functions including emotion, motor, and learning or memory. At last, current weakness and future perspectives of secretin in the central nervous system will be discussed, aiming to provide the potency of using secretin or its analog for treating various neurological disorders.
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Affiliation(s)
- Ruanna Wang
- Joint International Research Laboratory of CNS Regeneration, GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Billy K C Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China.
| | - Li Zhang
- Joint International Research Laboratory of CNS Regeneration, GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China.
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Wang L, Zhang L, Chow BKC. Secretin Modulates the Postnatal Development of Mouse Cerebellar Cortex Via PKA- and ERK-dependent Pathways. Front Cell Neurosci 2017; 11:382. [PMID: 29249942 PMCID: PMC5714926 DOI: 10.3389/fncel.2017.00382] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/17/2017] [Indexed: 12/14/2022] Open
Abstract
Postnatal development of the cerebellum is critical for its intact function such as motor coordination and has been implicated in the pathogenesis of psychiatric disorders. We previously reported that deprivation of secretin (SCT) from cerebellar Purkinje neurons impaired motor coordination and motor learning function, while leaving the potential role of SCT in cerebellar development to be determined. SCT and its receptor (SCTR) were constitutively expressed in the postnatal cerebellum in a temporal and cell-specific manner. Using a SCT knockout mouse model, we provided direct evidence showing altered developmental patterns of Purkinje cells (PCs) and granular cells (GCs). SCT deprivation reduced the PC density, impaired the PC dendritic formation, induced accelerated GC migration and potentiated cerebellar apoptosis. Furthermore, our results indicated the involvement of protein kinase A (PKA) and extracellular signal regulated kinase (ERK) signaling pathways in SCT-mediated protective effects against neuronal apoptosis. Results of this study illustrated a novel function of SCT in the postnatal development of cerebellum, emphasizing the necessary role of SCT in cerebellar-related functions.
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Affiliation(s)
- Lei Wang
- School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong
| | - Li Zhang
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Billy K. C. Chow
- School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong
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Bai JJ, Tan CD, Chow BKC. Secretin, at the hub of water-salt homeostasis. Am J Physiol Renal Physiol 2016; 312:F852-F860. [PMID: 27279485 DOI: 10.1152/ajprenal.00191.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 06/01/2016] [Indexed: 01/13/2023] Open
Abstract
Water and salt metabolism are tightly regulated processes. Maintaining this milieu intérieur within narrow limits is critical for normal physiological processes to take place. Disturbances to this balance can result in disease and even death. Some of the better-characterized regulators of water and salt homeostasis include angiotensin II, aldosterone, arginine vasopressin, and oxytocin. Although secretin (SCT) was first described >100 years ago, little is known about the role of this classic gastrointestinal hormone in the maintenance of water-salt homeostasis. In recent years, increasing body of evidence suggested that SCT and its receptor play important roles in the central nervous system and kidney to ensure that the mammalian extracellular fluid osmolarity is kept within a healthy range. In this review, we focus on recent advances in our understanding of the molecular, cellular, and network mechanisms by which SCT and its receptor mediate the control of osmotic homeostasis. Implications of hormonal cross talk and receptor-receptor interaction are highlighted.
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Affiliation(s)
- Jenny Juan Bai
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Chong Da Tan
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Billy K C Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
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Bolbecker AR, Petersen IT, Kent JS, Howell JM, O'Donnell BF, Hetrick WP. New Insights into the Nature of Cerebellar-Dependent Eyeblink Conditioning Deficits in Schizophrenia: A Hierarchical Linear Modeling Approach. Front Psychiatry 2016; 7:4. [PMID: 26834653 PMCID: PMC4725217 DOI: 10.3389/fpsyt.2016.00004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 01/11/2016] [Indexed: 11/18/2022] Open
Abstract
Evidence of cerebellar dysfunction in schizophrenia has mounted over the past several decades, emerging from neuroimaging, neuropathological, and behavioral studies. Consistent with these findings, cerebellar-dependent delay eyeblink conditioning (dEBC) deficits have been identified in schizophrenia. While repeated-measures analysis of variance is traditionally used to analyze dEBC data, hierarchical linear modeling (HLM) more reliably describes change over time by accounting for the dependence in repeated-measures data. This analysis approach is well suited to dEBC data analysis because it has less restrictive assumptions and allows unequal variances. The current study examined dEBC measured with electromyography in a single-cue tone paradigm in an age-matched sample of schizophrenia participants and healthy controls (N = 56 per group) using HLM. Subjects participated in 90 trials (10 blocks) of dEBC, during which a 400 ms tone co-terminated with a 50 ms air puff delivered to the left eye. Each block also contained 1 tone-alone trial. The resulting block averages of dEBC data were fitted to a three-parameter logistic model in HLM, revealing significant differences between schizophrenia and control groups on asymptote and inflection point, but not slope. These findings suggest that while the learning rate is not significantly different compared to controls, associative learning begins to level off later and a lower ultimate level of associative learning is achieved in schizophrenia. Given the large sample size in the present study, HLM may provide a more nuanced and definitive analysis of differences between schizophrenia and controls on dEBC.
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Affiliation(s)
- Amanda R Bolbecker
- Department of Psychological and Brain Sciences, Indiana University , Bloomington, IN , USA
| | - Isaac T Petersen
- Department of Psychological and Brain Sciences, Indiana University , Bloomington, IN , USA
| | - Jerillyn S Kent
- Department of Psychological and Brain Sciences, Indiana University , Bloomington, IN , USA
| | - Josselyn M Howell
- Department of Psychological and Brain Sciences, Indiana University , Bloomington, IN , USA
| | - Brian F O'Donnell
- Department of Psychological and Brain Sciences, Indiana University , Bloomington, IN , USA
| | - William P Hetrick
- Department of Psychological and Brain Sciences, Indiana University , Bloomington, IN , USA
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15
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Kimura T, Nishizawa K, Oguma A, Nishimura Y, Sakasegawa Y, Teruya K, Nishijima I, Doh-ura K. Secretin receptor involvement in prion-infected cells and animals. FEBS Lett 2015; 589:2011-8. [PMID: 26037144 DOI: 10.1016/j.febslet.2015.05.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 05/08/2015] [Accepted: 05/19/2015] [Indexed: 12/15/2022]
Abstract
The cellular mechanisms behind prion biosynthesis and metabolism remain unclear. Here we show that secretin signaling via the secretin receptor regulates abnormal prion protein formation in prion-infected cells. Animal studies demonstrate that secretin receptor deficiency slightly, but significantly, prolongs incubation time in female but not male mice. This gender-specificity is consistent with our finding that prion-infected cells are derived from females. Therefore, our results provide initial insights into the reasons why age of disease onset in certain prion diseases is reported to occur slightly earlier in females than males.
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Affiliation(s)
- Tomohiro Kimura
- Department of Neurochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Keiko Nishizawa
- Department of Neurochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Ayumi Oguma
- Department of Neurochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yuki Nishimura
- Department of Neurochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yuji Sakasegawa
- Department of Neurochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kenta Teruya
- Department of Neurochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Ichiko Nishijima
- Department of Biobank Lifescience, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
| | - Katsumi Doh-ura
- Department of Neurochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan.
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16
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Fuchs JR, Robinson GM, Dean AM, Schoenberg HE, Williams MR, Morielli AD, Green JT. Cerebellar secretin modulates eyeblink classical conditioning. ACTA ACUST UNITED AC 2014; 21:668-75. [PMID: 25403455 PMCID: PMC4236411 DOI: 10.1101/lm.035766.114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We have previously shown that intracerebellar infusion of the neuropeptide secretin enhances the acquisition phase of eyeblink conditioning (EBC). Here, we sought to test whether endogenous secretin also regulates EBC and to test whether the effect of exogenous and endogenous secretin is specific to acquisition. In Experiment 1, rats received intracerebellar infusions of the secretin receptor antagonist 5-27 secretin or vehicle into the lobulus simplex of cerebellar cortex immediately prior to sessions 1-3 of acquisition. Antagonist-infused rats showed a reduction in the percentage of eyeblink CRs compared with vehicle-infused rats. In Experiment 2, rats received intracerebellar infusions of secretin or vehicle immediately prior to sessions 1-2 of extinction. Secretin did not significantly affect extinction performance. In Experiment 3, rats received intracerebellar infusions of 5-27 secretin or vehicle immediately prior to sessions 1-2 of extinction. The secretin antagonist did not significantly affect extinction performance. Together, our current and previous results indicate that both exogenous and endogenous cerebellar secretin modulate acquisition, but not extinction, of EBC. We have previously shown that (1) secretin reduces surface expression of the voltage-gated potassium channel α-subunit Kv1.2 in cerebellar cortex and (2) intracerebellar infusions of a Kv1.2 blocker enhance EBC acquisition, much like secretin. Kv1.2 is almost exclusively expressed in cerebellar cortex at basket cell-Purkinje cell pinceaus and Purkinje cell dendrites; we propose that EBC-induced secretin release from PCs modulates EBC acquisition by reducing surface expression of Kv1.2 at one or both of these sites.
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Affiliation(s)
- Jason R Fuchs
- Department of Psychology, University of Vermont, Burlington, Vermont 05405, USA
| | - Gain M Robinson
- Department of Psychology, University of Vermont, Burlington, Vermont 05405, USA
| | - Aaron M Dean
- Department of Psychology, University of Vermont, Burlington, Vermont 05405, USA
| | - Heidi E Schoenberg
- Department of Psychology, University of Vermont, Burlington, Vermont 05405, USA
| | - Michael R Williams
- Department of Pharmacology, University of Vermont, Burlington, Vermont 05405, USA
| | - Anthony D Morielli
- Department of Pharmacology, University of Vermont, Burlington, Vermont 05405, USA
| | - John T Green
- Department of Psychology, University of Vermont, Burlington, Vermont 05405, USA
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17
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Zhang L, Chung SK, Chow BKC. The knockout of secretin in cerebellar Purkinje cells impairs mouse motor coordination and motor learning. Neuropsychopharmacology 2014; 39:1460-8. [PMID: 24356714 PMCID: PMC3988549 DOI: 10.1038/npp.2013.344] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 12/16/2013] [Accepted: 12/16/2013] [Indexed: 11/09/2022]
Abstract
Secretin (SCT) was first considered to be a gut hormone regulating gastrointestinal functions when discovered. Recently, however, central actions of SCT have drawn intense research interest and are supported by the broad distribution of SCT in specific neuronal populations and by in vivo physiological studies regarding its role in water homeostasis and food intake. The direct action of SCT on a central neuron was first discovered in cerebellar Purkinje cells in which SCT from cerebellar Purkinje cells was found to potentiate GABAergic inhibitory transmission from presynaptic basket cells. Because Purkinje neurons have a major role in motor coordination and learning functions, we hypothesize a behavioral modulatory function for SCT. In this study, we successfully generated a mouse model in which the SCT gene was deleted specifically in Purkinje cells. This mouse line was tested together with SCT knockout and SCT receptor knockout mice in a full battery of behavioral tasks. We found that the knockout of SCT in Purkinje neurons did not affect general motor ability or the anxiety level in open field tests. However, knockout mice did exhibit impairments in neuromuscular strength, motor coordination, and motor learning abilities, as shown by wire hanging, vertical climbing, and rotarod tests. In addition, SCT knockout in Purkinje cells possibly led to the delayed development of motor neurons, as supported by the later occurrence of key neural reflexes. In summary, our data suggest a role in motor coordination and motor learning for SCT expressed in cerebellar Purkinje cells.
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Affiliation(s)
- Li Zhang
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China
| | - Sookja Kim Chung
- Department of Anatomy, University of Hong Kong, Hong Kong SAR, China
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18
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Sekar R, Chow BKC. Secretin receptor‐knockout mice are resistant to high‐fat diet‐induced obesity and exhibit impaired intestinal lipid absorption. FASEB J 2014; 28:3494-505. [DOI: 10.1096/fj.13-247536] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Revathi Sekar
- School of Biological Sciences, The University of Hong KongHong KongChina
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong KongHong KongChina
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19
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Zhang L, Chow BKC. The central mechanisms of secretin in regulating multiple behaviors. Front Endocrinol (Lausanne) 2014; 5:77. [PMID: 24904528 PMCID: PMC4033102 DOI: 10.3389/fendo.2014.00077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 05/08/2014] [Indexed: 11/13/2022] Open
Abstract
Secretin (SCT) was firstly discovered as a gut peptide hormone in stimulating pancreatic secretion, while its novel neuropeptide role has drawn substantial research interests in recent years. SCT and its receptor (SCTR) are widely expressed in different brain regions, where they exert multiple cellular functions including neurotransmission, gene expression regulation, neurogenesis, and neural protection. As all these neural functions ultimately can affect behaviors, it is hypothesized that SCT controls multiple behavioral paradigms. Current findings support this hypothesis as SCT-SCTR axis participates in modulating social interaction, spatial learning, water and food intake, motor coordination, and motor learning behaviors. This mini-review focuses on various aspects of SCT and SCTR in hippocampus, hypothalamus, and cerebellum including distribution profiles, cellular functions, and behavioral phenotypes to elucidate the link between cellular mechanisms and behavioral control.
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Affiliation(s)
- Li Zhang
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Billy K. C. Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
- *Correspondence: Billy K. C. Chow, School of Biological Sciences, University of Hong Kong, Kardoorie Biological Science Building, Pokfulam Road 4N-12, Sai Ying Pun, Hong Kong, China e-mail:
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20
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Abstract
Secretin (Sct), a classical gut hormone, is now known to play pleiotropic functions in the body including osmoregulation, digestion, and feeding control. As Sct has long been implicated to regulate metabolism, in this report, we have investigated a potential lipolytic action of Sct. In our preliminary studies, both Sct levels in circulation and Sct receptor (SctR) transcripts in adipose tissue were upregulated during fasting, suggesting a potential physiological relevance of Sct in regulating lipolysis. Using SctR knockout and Sct knockout mice as controls, we show that Sct is able to stimulate lipolysis in vitro in isolated adipocytes dose- and time-dependently, as well as acute lipolysis in vivo. H-89, a protein kinase A (PKA) inhibitor, was found to attenuate lipolytic effects of 1 μM Sct in vitro, while a significant increase in PKA activity upon Sct injection was observed in the adipose tissue in vivo. Sct was also found to stimulate phosphorylation at 660ser of hormone sensitive lipase (HSL) and to bring about the translocation of HSL from cytosol to the lipid droplet. In summary, our data demonstrate for the first time the in vivo and in vitro lipolytic effects of Sct, and that this function is mediated by PKA and HSL.
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Affiliation(s)
- Revathi Sekar
- School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong
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21
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Christian CA, Herbert AG, Holt RL, Peng K, Sherwood KD, Pangratz-Fuehrer S, Rudolph U, Huguenard JR. Endogenous positive allosteric modulation of GABA(A) receptors by diazepam binding inhibitor. Neuron 2013; 78:1063-74. [PMID: 23727119 DOI: 10.1016/j.neuron.2013.04.026] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2013] [Indexed: 11/30/2022]
Abstract
Benzodiazepines (BZs) allosterically modulate γ-aminobutyric acid type-A receptors (GABAARs) to increase inhibitory synaptic strength. Diazepam binding inhibitor (DBI) protein is a BZ site ligand expressed endogenously in the brain, but functional evidence for BZ-mimicking positive modulatory actions has been elusive. We demonstrate an endogenous potentiation of GABAergic synaptic transmission and responses to GABA uncaging in the thalamic reticular nucleus (nRT) that is absent in both nm1054 mice, in which the Dbi gene is deleted, and mice in which BZ binding to α3 subunit-containing GABAARs is disrupted. Viral transduction of DBI into nRT is sufficient to rescue the endogenous potentiation of GABAergic transmission in nm1054 mice. Both mutations enhance thalamocortical spike-and-wave discharges characteristic of absence epilepsy. Together, these results indicate that DBI mediates endogenous nucleus-specific BZ-mimicking ("endozepine") roles to modulate nRT function and suppress thalamocortical oscillations. Enhanced DBI signaling might serve as a therapy for epilepsy and other neurological disorders.
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Affiliation(s)
- Catherine A Christian
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.
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22
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Sekar R, Chow BKC. Metabolic effects of secretin. Gen Comp Endocrinol 2013; 181:18-24. [PMID: 23246720 DOI: 10.1016/j.ygcen.2012.11.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Revised: 11/23/2012] [Accepted: 11/27/2012] [Indexed: 12/25/2022]
Abstract
Secretin (Sct), traditionally a gastrointestinal hormone backed by a century long research, is now beginning to be recognized also as a neuroactive peptide. Substantiation by recent evidence on the functional role of Sct in various regions of the brain, especially on its potential neurosecretion from the posterior pituitary, has revealed Sct's physiological actions in regulating water homeostasis. Recent advances in understanding the functional roles of central and peripheral Sct has been made possible by the development of Sct and Sct receptor (SctR) knockout animal models which have led to novel approaches in research on the physiology of this brain-gut peptide. While research on the role of Sct in appetite regulation and fatty acid metabolism has been initiated recently, its role in glucose homeostasis is unclear. This review focuses mainly on the metabolic role of Sct by discussing data from the last century and recent discoveries, with emphasis on the need for revisiting and elucidating the role of Sct in metabolism and energy homeostasis.
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Affiliation(s)
- Revathi Sekar
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong
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23
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Neuron-restrictive silencer factor functions to suppress Sp1-mediated transactivation of human secretin receptor gene. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1829:231-8. [PMID: 23168245 DOI: 10.1016/j.bbagrm.2012.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 11/09/2012] [Accepted: 11/12/2012] [Indexed: 11/23/2022]
Abstract
In the present study, a functional neuron restrictive silencer element (NRSE) was initially identified in the 5' flanking region (-83 to -67, relative to ATG) of human secretin receptor (hSCTR) gene by promoter assays coupled with scanning mutation analyses. The interaction of neuron restrictive silencer factor (NRSF) with this motif was later indicated via gel mobility shift and ChIP assays. The silencing activity of NRSF was confirmed by over-expression and also by shRNA knock-down of endogenous NRSF. These studies showed an inverse relationship between the expression levels of NRSF and hSCTR in the cells. As hSCTR gene was previously shown to be controlled by two GC-boxes which are regulated by the ratio of Sp1 to Sp3, in the present study, the functional interactions of NRSF and Sp proteins to regulate hSCTR gene was investigated. By co-immunoprecipitation assays, we found that NRSF could be co-precipitated with Sp1 as well as Sp3 in PANC-1 cells. Interestingly, co-expressions of these factors showed that NRSF could suppress Sp1-mediated, but not Sp3-mediated, transactivation of hSCTR. Taken together, we propose here that the down-regulatory effects of NRSF on hSCTR gene expression are mediated via its suppression on Sp1-mediated transactivation.
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24
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Chen XY, Wang H, Xue Y, Chen L. Modulation of paraventricular firing rate by secretin in vivo. Neurosci Lett 2012; 532:29-32. [PMID: 23149133 DOI: 10.1016/j.neulet.2012.10.055] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 08/28/2012] [Accepted: 10/11/2012] [Indexed: 11/29/2022]
Abstract
The paraventricular nucleus (PVN) of hypothalamus is a major integrative center in homeostatic control. Morphological studies have revealed a high level of secretin and secretin receptor expression in the PVN. To investigate the direct electrophysiological effects of secretin in the PVN, in vivo extracellular recordings were performed in the present study. In 24 out of the 46 paraventricular neurons, micro-pressure ejection of secretin increased the firing rate from 3.07±0.43 Hz to 4.86±0.70 Hz. In another 8 out of the 46 paraventricular neurons, secretin decreased the firing rate from 2.61±0.46 Hz to 1.41±0.25 Hz. In the remaining 14 paraventricular neurons, secretin did not alter the firing rate significantly. The present findings provided direct electrophysiological evidence for the possible functions of secretin in the PVN.
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Affiliation(s)
- Xin-Yi Chen
- Department of Physiology, Medical School of Shandong University, Jinan 250012, China
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25
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Todaka H, Tatsukawa T, Hashikawa T, Yanagawa Y, Shibuki K, Nagao S. Heterotrimeric guanosine triphosphate-binding protein-coupled modulatory actions of motilin on K+ channels and postsynaptic γ-aminobutyric acid receptors in mouse medial vestibular nuclear neurons. Eur J Neurosci 2012; 37:339-50. [PMID: 23136934 DOI: 10.1111/ejn.12051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 09/24/2012] [Accepted: 10/01/2012] [Indexed: 11/29/2022]
Abstract
Some central nervous system neurons express receptors of gastrointestinal hormones, but their pharmacological actions are not well known. Previous anatomical and unit recording studies suggest that a group of cerebellar Purkinje cells express motilin receptors, and motilin depresses the spike discharges of vestibular nuclear neurons that receive direct cerebellar inhibition in rats or rabbits. Here, by the slice-patch recording method, we examined the pharmacological actions of motilin on the mouse medial vestibular nuclear neurons (MVNs), which play an important role in the control of ocular reflexes. A small number of MVNs, as well as cerebellar floccular Purkinje cells, were labeled with an anti-motilin receptor antibody. Bath application of motilin (0.1 μm) decreased the discharge frequency of spontaneous action potentials in a group of MVNs in a dose-dependent manner (K(d) , 0.03 μm). The motilin action on spontaneous action potentials was blocked by apamin (100 nm), a blocker of small-conductance Ca(2+) -activated K(+) channels. Furthermore, motilin enhanced the amplitudes of inhibitory postsynaptic currents (IPSCs) and miniature IPSCs, but did not affect the frequencies of miniature IPSCs. Intracellular application of pertussis toxin (PTx) (0.5 μg/μL) or guanosine triphosphate-γ-S (1 mm) depressed the motilin actions on both action potentials and IPSCs. Only 30% of MVNs examined on slices obtained from wild-type mice, but none of the GABAergic MVNs that were studied on slices obtained from vesicular γ-aminobutyric acid transporter-Venus transgenic mice, showed such a motilin response on action potentials and IPSCs. These findings suggest that motilin could modulate small-conductance Ca(2+) -activated K(+) channels and postsynaptic γ-aminobutyric acid receptors through heterotrimeric guanosine triphosphate-binding protein-coupled receptor in a group of glutamatergic MVNs.
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Affiliation(s)
- Hiroshi Todaka
- Laboratory for Motor Learning Control, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-Shi, Saitama, 351-0198, Japan
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26
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Distribution of secretin receptors in the rat central nervous system: an in situ hybridization study. J Mol Neurosci 2012; 50:172-8. [PMID: 23065333 DOI: 10.1007/s12031-012-9895-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 09/24/2012] [Indexed: 10/27/2022]
Abstract
Secretin shows a wide distribution in the brain. Functional significance of central secretin is stressed since it has been associated with autism and schizophrenia. The presence of the secretin receptor was previously demonstrated in the brain by different methods. Neurons in the cerebellum, hypothalamic paraventricular and supraoptic nuclei, and in the vascular organ of lamina terminalis were shown to express secretin receptor mRNA by using in situ hybridization with digoxigenin-labeled probe. In this work, we used a very sensitive radioactive in situ hybridization technique and systematically mapped the expression of secretin receptor mRNA in the brain. The densest labeling was observed in the nucleus of solitary tract and in the laterodorsal thalamic nucleus, where decreasing number of receptors was seen in the vascular organ of lamina terminalis, and the lateral habenular complex, and then in the supraoptic nucleus. Only a few scattered labeled cells were observed in the median frontal gyrus, entorhinal cortex, hypothalamic paraventricular nucleus, perifornical region, lateral hypothalamic area, head of the caudate nucleus, spinal trigeminal nucleus, and cerebellum. Secretin receptor mRNA showed a far wider distribution than was known before, suggesting a more significant functional relevance than thought earlier.
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27
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Banks WA. Brain meets body: the blood-brain barrier as an endocrine interface. Endocrinology 2012; 153:4111-9. [PMID: 22778219 PMCID: PMC3423627 DOI: 10.1210/en.2012-1435] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 06/19/2012] [Indexed: 12/30/2022]
Abstract
The blood-brain barrier (BBB) separates the central nervous system (CNS) from the peripheral tissues. However, this does not prevent hormones from entering the brain, but shifts the main control of entry to the BBB. In general, steroid hormones cross the BBB by transmembrane diffusion, a nonsaturable process resulting in brain levels that reflect blood levels, whereas thyroid hormones and many peptides and regulatory proteins cross using transporters, a saturable process resulting in brain levels that reflect blood levels and transporter characteristics. Protein binding, brain-to-blood transport, and pharmacokinetics modulate BBB penetration. Some hormones have the opposite effect within the CNS than they do in the periphery, suggesting that these hormones cross the BBB to act as their own counterregulators. The cells making up the BBB are also endocrine like, both responding to circulating substances and secreting substances into the circulation and CNS. By dividing a hormone's receptors into central and peripheral pools, the former of which may not be part of the hormone's negative feed back loop, the BBB fosters the development of variable hormone resistance syndromes, as exemplified by evidence that altered insulin action in the CNS can contribute to Alzheimer's disease. In summary, the BBB acts as a regulatory interface in an endocrine-like, humoral-based communication between the CNS and peripheral tissues.
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Affiliation(s)
- William A Banks
- Veterans Affairs Puget Sound Health Care System and Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA.
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28
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Heinzlmann A, Kiss G, Tóth ZE, Dochnal R, Pál Á, Sipos I, Manczinger M, Szabó G, Hashimoto H, Köves K. Intranasal application of secretin, similarly to intracerebroventricular administration, influences the motor behavior of mice probably through specific receptors. J Mol Neurosci 2012; 48:558-64. [PMID: 22752505 DOI: 10.1007/s12031-012-9839-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 06/11/2012] [Indexed: 11/27/2022]
Abstract
Secretin and its receptors show wide distribution in the central nervous system. It was demonstrated previously that intravenous (i.v.) and intracerebroventricular (i.c.v.) application of secretin influenced the behavior of rat, mouse, and human. In our previous experiment, we used a special animal model, Japanese waltzing mice (JWM). These animals run around without stopping (the ambulation distance is very limited) and they do not bother with their environment. The i.c.v. secretin attenuated this hyperactive repetitive movement. In the present work, the effect of i.c.v. and intranasal (i.n.) application of secretin was compared. We have also looked for the presence of secretin receptors in the brain structures related to motor functions. Two micrograms of i.c.v. secretin improved the horizontal movement of JWM, enhancing the ambulation distance. It was nearly threefold higher in treated than in control animals. The i.n. application of secretin to the left nostril once or twice a day or once for 3 days more effectively enhanced the ambulation distance than i.c.v. administration. When secretin was given twice a day for 3 days it had no effect. Secretin did not improve the explorative behavior (the rearing), of JWM. With the use of in situ hybridization, we have found very dense secretin receptor labeling in the cerebellum. In the primary motor cortex and in the striatum, only a few labeled cells were seen. It was supposed that secretin exerted its effect through specific receptors, mainly present in the cerebellum.
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MESH Headings
- Administration, Intranasal
- Animals
- Cerebellum/chemistry
- Cerebellum/drug effects
- Corpus Striatum/chemistry
- Drug Evaluation, Preclinical
- Exploratory Behavior/drug effects
- Female
- Hyperkinesis/drug therapy
- Hyperkinesis/genetics
- In Situ Hybridization
- Injections, Intraventricular
- Male
- Mice
- Mice, Neurologic Mutants
- Motor Activity/drug effects
- Motor Activity/physiology
- Motor Cortex/chemistry
- Nerve Tissue Proteins/agonists
- Nerve Tissue Proteins/analysis
- Nerve Tissue Proteins/physiology
- Rats
- Rats, Sprague-Dawley
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/analysis
- Receptors, G-Protein-Coupled/physiology
- Receptors, Gastrointestinal Hormone/agonists
- Receptors, Gastrointestinal Hormone/analysis
- Receptors, Gastrointestinal Hormone/physiology
- Secretin/administration & dosage
- Secretin/pharmacology
- Secretin/therapeutic use
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Affiliation(s)
- Andrea Heinzlmann
- Department of Human Morphology and Developmental Biology, Semmelweis University, Tűzoltó u. 58, Budapest 1094, Hungary
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29
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Lee VHY, Lam IPY, Choi HS, Chow BKC, Lee LTO. The estrogen-related receptor alpha upregulates secretin expressions in response to hypertonicity and angiotensin II stimulation. PLoS One 2012; 7:e39913. [PMID: 22761926 PMCID: PMC3382582 DOI: 10.1371/journal.pone.0039913] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 06/03/2012] [Indexed: 01/17/2023] Open
Abstract
Osmoregulation via maintenance of water and salt homeostasis is a vital process. In the brain, a functional secretin (SCT) and secretin receptor (SCTR) axis has recently been shown to mediate central actions of angiotensin II (ANGII), including initiation of water intake and stimulation of vasopressin (VP) expression and release. In this report, we provide evidence that estrogen-related receptor α (ERRα, NR3B1), a transcription factor mainly involved in metabolism, acts as an upstream activator of the SCT gene. In vitro studies using mouse hypothalamic cell line N-42 show that ERRα upregulates SCT promoter and gene expression. More importantly, knockdown of endogenous ERRα abolishes SCT promoter activation in response to hypertonic and ANGII stimulations. In mouse brain, ERRα coexpresses with SCT in various osmoregulatory brain regions, including the lamina terminalis and the paraventricular nucleus of the hypothalamus, and its expression is induced by hyperosmotic and ANGII treatments. Based on our data, we propose that both the upregulation of ERRα and/or the increased binding of ERRα to the mouse SCT promoter are two possible mechanisms for the elevated SCT expression upon hyperosmolality and central ANGII stimulation.
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Affiliation(s)
- Vien H. Y. Lee
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Ian P. Y. Lam
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Hueng-Sik Choi
- Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Leo T. O. Lee
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- * E-mail:
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Garcia GL, Dong M, Miller LJ. Differential determinants for coupling of distinct G proteins with the class B secretin receptor. Am J Physiol Cell Physiol 2012; 302:C1202-12. [PMID: 22277758 DOI: 10.1152/ajpcell.00273.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The secretin receptor is a prototypic class B G protein-coupled receptor that is activated by binding of its natural peptide ligand. The signaling effects of this receptor are mediated by coupling with Gs, which activates cAMP production, and Gq, which activates intracellular calcium mobilization. We have explored the molecular basis for the coupling of each of these G proteins to this receptor using systematic site-directed mutagenesis of key residues within each of the intracellular loop regions, and studying ligand binding and secretin-stimulated cAMP and calcium responses. Mutation of a conserved histidine in the first intracellular loop (H157A and H157R) markedly reduced cell surface expression, resulting in marked reduction in cAMP and elimination of measurable calcium responses. Mutation of an arginine (R153A) in the first intracellular loop reduced calcium, but not cAMP responses. Mutation of a dibasic motif in the second intracellular loop (R231A/K232A) had no significant effects on any measured responses. Mutations in the third intracellular loop involving adjacent lysine and leucine residues (K302A/L303A) or two arginine residues separated by a leucine and an alanine (R318A/R321A) significantly reduced cAMP responses, while the latter also reduced calcium responses. Additive effects were elicited by combining the effective mutations, while combining all the effective mutations resulted in a construct that continued to bind secretin normally, but that elicited no significant cAMP or calcium responses. These data suggest that, while some receptor determinants are clearly shared, there are also distinct determinants for coupling with each of these G proteins.
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Affiliation(s)
- Gene L Garcia
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, AZ 85259, USA
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Yuan Y, Lee LTO, Ng SS, Chow BKC. Extragastrointestinal functions and transcriptional regulation of secretin and secretin receptors. Ann N Y Acad Sci 2011; 1220:23-33. [DOI: 10.1111/j.1749-6632.2011.05987.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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32
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Fyk-Kolodziej B, Shimano T, Gong TW, Holt AG. Vesicular glutamate transporters: spatio-temporal plasticity following hearing loss. Neuroscience 2011; 178:218-39. [PMID: 21211553 DOI: 10.1016/j.neuroscience.2010.12.059] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 12/27/2010] [Accepted: 12/28/2010] [Indexed: 12/22/2022]
Abstract
An immunocytochemical comparison of vGluT1 and vGluT3 in the cochlear nucleus (CN) of deafened versus normal hearing rats showed the first example of vGluT3 immunostaining in the dorsal and ventral CN and revealed temporal and spatial changes in vGluT1 localization in the CN after cochlear injury. In normal hearing rats vGluT1 immunostaining was restricted to terminals on CN neurons while vGluT3 immunolabeled the somata of the neurons. This changed in the ventral cochlear nucleus (VCN) 3 days following deafness, where vGluT1 immunostaining was no longer seen in large auditory nerve terminals but was instead found in somata of VCN neurons. In the dorsal cochlear nucleus (DCN), while vGluT1 labeling of terminals decreased, there was no labeling of neuronal somata. Therefore, loss of peripheral excitatory input results in co-localization of vGluT1 and vGluT3 in VCN neuronal somata. Postsynaptic glutamatergic neurons can use retrograde signaling to control their presynaptic inputs and these results suggest vGluTs could play a role in regulating retrograde signaling in the CN under different conditions of excitatory input. Changes in vGluT gene expression in CN neurons were found 3 weeks following deafness using qRT-PCR with significant increases in vGluT1 gene expression in both ventral and dorsal CN while vGluT3 gene expression decreased in VCN but increased in DCN.
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Affiliation(s)
- B Fyk-Kolodziej
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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33
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Bowker A, D’Angelo NM, Hicks R, Wells K. Treatments for Autism: Parental Choices and Perceptions of Change. J Autism Dev Disord 2010; 41:1373-82. [DOI: 10.1007/s10803-010-1164-y] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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34
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Benítez-Burraco A. Neurobiología y neurogenética de la dislexia. Neurologia 2010; 25:563-81. [DOI: 10.1016/j.nrl.2009.12.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Accepted: 12/22/2009] [Indexed: 01/12/2023] Open
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Wink LK, Plawecki MH, Erickson CA, Stigler KA, McDougle CJ. Emerging drugs for the treatment of symptoms associated with autism spectrum disorders. Expert Opin Emerg Drugs 2010; 15:481-94. [PMID: 20470188 PMCID: PMC2923687 DOI: 10.1517/14728214.2010.487860] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD Autism spectrum disorders, or pervasive developmental disorders (PDDs), are neurodevelopmental disorders defined by qualitative impairment in social interaction, impaired communication and stereotyped patterns of behavior. The most common forms of PDD are autistic disorder (autism), Asperger's disorder and PDD not otherwise specified. Recent surveillance studies reveal an increase in the prevalence of autism and related PDDs. The use of pharmacologic agents in the treatment of these disorders can reduce the impact of interfering symptoms, providing relief for affected individuals and their families. AREAS COVERED IN THIS REVIEW This review examines results from neurobiologic research in an attempt to both elucidate the pathophysiology of autism and guide the development of pharmacologic agents for the treatment of associated symptoms. The safety and efficacy data of drugs currently in clinical use for the treatment of these symptoms, as well as pharmaceuticals currently under development, are discussed. WHAT THE READER WILL GAIN This comprehensive review will deepen the reader's current understanding of the research guiding the pharmacologic treatment of symptoms associated with autism and related PDDs. Areas of focus for future research are also discussed. The need for large-scale investigation of some commonly used pharmacologic agents, in addition to the development of drugs with improved efficacy and safety profiles, is made evident. TAKE HOME MESSAGE Despite progress in the development of pharmacologic treatments for a number of interfering symptom domains associated with autism and other PDDs, a great deal of work remains.
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Affiliation(s)
- Logan K Wink
- Indiana University School of Medicine, Department of Psychiatry, Indianapolis, IN 46202, USA
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Lee VHY, Lee LTO, Chu JYS, Lam IPY, Siu FKY, Vaudry H, Chow BKC. An indispensable role of secretin in mediating the osmoregulatory functions of angiotensin II. FASEB J 2010. [DOI: 10.1096/fj.10.165399] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Vien H. Y. Lee
- School of Biological Sciences, The University of Hong Kong Hong Kong China
| | - Leo T. O. Lee
- School of Biological Sciences, The University of Hong Kong Hong Kong China
| | - Jessica Y. S. Chu
- School of Biological Sciences, The University of Hong Kong Hong Kong China
| | - Ian P. Y. Lam
- School of Biological Sciences, The University of Hong Kong Hong Kong China
| | - Francis K Y. Siu
- School of Biological Sciences, The University of Hong Kong Hong Kong China
| | - Hubert Vaudry
- Institut National de la Santé et de la Recherche Médicale, University of Rouen Mont-Saint-Aignan France
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong Kong Hong Kong China
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Lee VHY, Lee LTO, Chu JYS, Lam IPY, Siu FKY, Vaudry H, Chow BKC. An indispensable role of secretin in mediating the osmoregulatory functions of angiotensin II. FASEB J 2010; 24:5024-32. [PMID: 20739612 DOI: 10.1096/fj.10-165399] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Fluid balance is critical to life and hence is tightly controlled in the body. Angiotensin II (ANGII), one of the most important components of this regulatory system, is recognized as a dipsogenic hormone that stimulates vasopressin (VP) expression and release. However, detailed mechanisms regarding how ANGII brings about these changes are not fully understood. In the present study, we show initially that the osmoregulatory functions of secretin (SCT) in the brain are similar to those of ANGII in mice and, more important, we discovered the role of SCT as the link between ANGII and its downstream effects. This was substantiated by the use of two knockout mice, SCTR(-/-) and SCT(-/-), in which we show the absence of an intact SCT/secretin receptor (SCTR) axis resulted in an abolishment or much reduced ANGII osmoregulatory functions. By immunohistochemical staining and in situ hybridization, the proteins and transcripts of SCT and its receptor are found in the paraventricular nucleus (PVN) and lamina terminalis. We propose that SCT produced in the circumventricular organs is transported and released in the PVN to stimulate vasopressin expression and release. In summary, our findings identify SCT and SCTR as novel elements of the ANGII osmoregulatory pathway in maintaining fluid balance in the body.
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Affiliation(s)
- Vien H Y Lee
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
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38
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Köves K, Kiss G, Heinzlmann A, Dochnal R, Manczinger M, Pál A, Sípos I, Szabó G. Secretin attenuates the hereditary repetitive hyperactive movements in a mouse model. J Mol Neurosci 2010; 43:109-14. [PMID: 20607447 DOI: 10.1007/s12031-010-9408-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Accepted: 06/11/2010] [Indexed: 11/30/2022]
Abstract
It was previously demonstrated that secretin influenced the behavior of rats investigated by open-field test. In the present experiment, we have compared the effect of intracerebroventricular administration of 2 μg of secretin on the behavior of CFLP white and Japanese waltzing mice. These latter animals exhibit stereotypic circular movements. The effect of secretin on the horizontal (ambulation) and vertical movements (rearing and jumping) was investigated in open-field test. The ambulation time and distance were shorter, and the number of rearing and jumping were much lower in Japanese waltzing mice than in CFLP white mice during 30 min-experimental period. In white mice, 2 μg of secretin had no effect on the above-mentioned parameters; however, in Japanese waltzing mice, secretin enhanced the ambulation time and distance to the level of CFLP white mice, but did not influence the rearing and jumping. On the basis of the results, it was concluded that intracerebroventricularly administered secretin attenuated the stereotypic (circulating) movement and improved the horizontal movement indicated by the normalization of the ambulation time and distance; however, it did not influence the explorative behavior (rearing and jumping) in our special animal model.
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Affiliation(s)
- Katalin Köves
- Department of Human Morphology and Developmental Biology, Semmelweis University, Tűzoltó u. 58, Budapest H-1094, Hungary.
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39
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Heinzlmann A, Tóth ZE, Köves K. Secretin mRNA in the subdivision of primary sensory neurons in the trigeminal ganglion of rats. J Mol Neurosci 2010; 43:101-8. [PMID: 20582488 DOI: 10.1007/s12031-010-9395-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Accepted: 05/19/2010] [Indexed: 11/26/2022]
Abstract
The primary sensory neurons use glutamate as a major neurotransmitter. Several neuropeptides are also found in these neurons. In our laboratory we demonstrated secretin-like immunoreactivity in primary sensory neurons of several species including human, rat and cat. In the present experiment utilizing in situ hybridization, we have demonstrated for the first time that secretin is not only immunostained but is also expressed in the primary sensory neurons of the trigeminal ganglion of male rats. In intact rats, secretin mRNA was not observed; we had to use intracerebroventricular colchicine administration to induce the expression of secretin. Secretin was expressed in about 5% of the cells in all the three subdivisions of the trigeminal ganglion. The secretin-synthetizing cells were large and medium sized, and their mean diameter was about 50 μm. When we compared the percentage and the size of secretin to that of calcitonin gene-related peptide (CGRP), substance-P (SP) and vasoactive intestinal polypeptide (VIP) cells, it was found that CGRP, SP and VIP are present in about 15-20% of the cells and their mean diameter is about 20-25 μm. The morphometric data indicate that secretin is present in a subdivision of neurons that is different from the subdivision of the CGRP, SP and VIP cells. It is suggested that secretin may modulate the function of the primary neurotransmitter.
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Affiliation(s)
- Andrea Heinzlmann
- Department of Human Morphology and Developmental Biology, Semmelweis University, Tűzoltó u. 58, Budapest 1094, Hungary.
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Abstract
Metabolic pathologies such as Type 2 Diabetes have become a major health problem for worldwide populations. Unfortunately, efforts to cure and especially to prevent these significant global problems have so far been met with disappointment. Recently, the involvement of the gut-derived hormonal dysregulation in the development of obesity-related disturbances has been intensively studied. For instance, studies of gut-derived peptides such as peptide YY 3-36, glucagon-like peptide-1, oxyntomodulin and, more recently, ghrelin have significantly improved our understanding of mechanisms underlying weight and metabolic regulation. Even though early reports of the existence of secretin, the first peptide hormone to be described, date back as far as 1825, so much and yet so little is still known about its physiological role in mammals, including humans. However, recent years have provided a better understanding of how the release of secretin is regulated by enteral secretagogues. On the other hand, most basic questions about its role in the post-prandial regulation of metabolic functions in normal and pathophysiological conditions remain to be elucidated. The present work intends to review the physiology of secretin along with its central and peripheral outcomes on metabolic functions.
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Affiliation(s)
- D H St-Pierre
- Division of Endocrinology, Diabetology and Metabolism, Department of Internal Medicine, Ospedale Molinette, University of Turin, Turin, Italy
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41
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Benítez-Burraco A. Neurobiology and neurogenetics of dyslexia. NEUROLOGÍA (ENGLISH EDITION) 2010. [DOI: 10.1016/s2173-5808(20)70105-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
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42
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Activity-dependent regulation of synapses by retrograde messengers. Neuron 2009; 63:154-70. [PMID: 19640475 DOI: 10.1016/j.neuron.2009.06.021] [Citation(s) in RCA: 205] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Revised: 06/19/2009] [Accepted: 06/26/2009] [Indexed: 01/01/2023]
Abstract
Throughout the brain, postsynaptic neurons release substances from their cell bodies and dendrites that regulate the strength of the synapses they receive. Diverse chemical messengers have been implicated in retrograde signaling from postsynaptic neurons to presynaptic boutons. Here, we provide an overview of the signaling systems that lead to rapid changes in synaptic strength. We consider the capabilities, specializations, and physiological roles of each type of signaling system.
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Chapter MC, White CM, DeRidder A, Chadwick W, Martin B, Maudsley S. Chemical modification of class II G protein-coupled receptor ligands: frontiers in the development of peptide analogs as neuroendocrine pharmacological therapies. Pharmacol Ther 2009; 125:39-54. [PMID: 19686775 DOI: 10.1016/j.pharmthera.2009.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 07/24/2009] [Indexed: 01/08/2023]
Abstract
Recent research and clinical data have begun to demonstrate the huge potential therapeutic importance of ligands that modulate the activity of the secretin-like, Class II, G protein-coupled receptors (GPCRs). Ligands that can modulate the activity of these Class II GPCRs may have important clinical roles in the treatment of a wide variety of conditions such as osteoporosis, diabetes, amyotrophic lateral sclerosis and autism spectrum disorders. While these receptors present important new therapeutic targets, the large glycoprotein nature of their cognate ligands poses many problems with respect to therapeutic peptidergic drug design. These native peptides often exhibit poor bioavailability, metabolic instability, poor receptor selectivity and resultant low potencies in vivo. Recently, increased attention has been paid to the structural modification of these peptides to enhance their therapeutic efficacy. Successful modification strategies have included d-amino acid substitutions, selective truncation, and fatty acid acylation of the peptide. Through these and other processes, these novel peptide ligand analogs can demonstrate enhanced receptor subtype selectivity, directed signal transduction pathway activation, resistance to proteolytic degradation, and improved systemic bioavailability. In the future, it is likely, through additional modification strategies such as addition of circulation-stabilizing transferrin moieties, that the therapeutic pharmacopeia of drugs targeted towards Class II secretin-like receptors may rival that of the Class I rhodopsin-like receptors that currently provide the majority of clinically used GPCR-based therapeutics. Currently, Class II-based drugs include synthesized analogs of vasoactive intestinal peptide for type 2 diabetes or parathyroid hormone for osteoporosis.
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Affiliation(s)
- Megan C Chapter
- Receptor Pharmacology Unit, Laboratory of Neuroscience, National Institute on Aging, Biomedical Research Center, 251 Bayview Blvd., Baltimore MD 21224, USA
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Abstract
Alcohol exposure during brain development induces neuronal cell death in the brain. Several neuroactive peptides have been shown to protect against alcohol-induced cell death. Secretin is a peptide hormone, and the secretin receptor is expressed in the gut and the brain. To explore a potential role of secretin signal against ethanol neurotoxicity during brain development, secretin receptor-deficient mice were exposed to ethanol on postnatal day 4. We identified significant ethanol-induced apoptosis in the external granular layer of the secretin receptor-deficient cerebellum and in the striatum after ethanol treatment. During the early postnatal period, there is a proliferation of granular cell progenitors that reside in the external granular layer. The results suggest that secretin signal plays a neuroprotective role of neuronal progenitor cells against the neurotoxicity of ethanol.
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Yamagata T, Urano H, Weeber E, Nelson D, Nishijima I. Impaired hippocampal synaptic function in secretin deficient mice. Neuroscience 2008; 154:1417-22. [DOI: 10.1016/j.neuroscience.2008.04.037] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Revised: 04/09/2008] [Accepted: 04/10/2008] [Indexed: 10/22/2022]
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Lee LTO, Lam IPY, Chow BKC. A functional variable number of tandem repeats is located at the 5' flanking region of the human secretin gene plays a downregulatory role in expression. J Mol Neurosci 2008; 36:125-31. [PMID: 18566919 DOI: 10.1007/s12031-008-9083-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Accepted: 03/28/2008] [Indexed: 11/26/2022]
Abstract
Secretin is a peptide hormone playing multiple functions in the brain-gut axis. In this report, we investigated, by promoter analysis, the potential function of the variable of tandem repeats (VNTR), located at the 5' upstream region of the human secretin gene, and we demonstrated for the first time that this VNTR could downregulate transcription of the human secretin gene in a promoter-specific manner. The efficiency of VNTR in silencing the promoter was found to be directly related the number of repetitive units residing within. We also showed the deoxyribonucleic acid sequence as well as the length polymorphism of the VNTR of 76 Chinese individuals. These results collectively suggest that VNTR could potentially be a functional regulator to control the expression of the human secretin gene in different individuals.
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Affiliation(s)
- Leo T O Lee
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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47
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Lam IPY, Siu FKY, Chu JYS, Chow BKC. Multiple actions of secretin in the human body. INTERNATIONAL REVIEW OF CYTOLOGY 2008; 265:159-90. [PMID: 18275888 DOI: 10.1016/s0074-7696(07)65004-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The discovery of secretin initiated the field of endocrinology. Over the past century, multiple gastrointestinal functions of secretin have been extensively studied, and it was discovered that the principal function of this peptide in the gastrointestinal system is to facilitate digestion and to provide protection. In view of the late identification of secretin and the secretin receptor in various tissues, including the central nervous system, the pleiotropic functions of secretin have more recently been an area of intense focus. Secretin is a classical hormone, and recent studies clearly showed secretin's involvement in neural and neuroendocrine pathways, although the neuroactivity and neural regulation of its release are yet to be elucidated. This chapter reviews our current understanding of the pleiotropic actions of secretin with a special focus on the hormonal and neural interdependent pathways that mediate these actions.
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Affiliation(s)
- Ian P Y Lam
- Department of Zoology, University of Hong Kong, Hong Kong, China
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48
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Nishijima I, Yamagata T, Spencer CM, Weeber EJ, Alekseyenko O, Sweatt JD, Momoi MY, Ito M, Armstrong DL, Nelson DL, Paylor R, Bradley A. Secretin receptor-deficient mice exhibit impaired synaptic plasticity and social behavior. Hum Mol Genet 2006; 15:3241-50. [PMID: 17008357 PMCID: PMC2593392 DOI: 10.1093/hmg/ddl402] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Secretin is a peptide hormone released from the duodenum to stimulate the secretion of digestive juice by the pancreas. Secretin also functions as a neuropeptide hormone in the brain, and exogenous administration has been reported to alleviate symptoms in some patients with autism. We have generated secretin receptor-deficient mice to explore the relationship between secretin signaling in the brain and behavioral phenotypes. Secretin receptor-deficient mice are overtly normal and fertile; however, synaptic plasticity in the hippocampus is impaired and there are slightly fewer dendritic spines in the CA1 hippocampal pyramidal cells. Furthermore, secretin receptor-deficient mice show abnormal social and cognitive behaviors. These findings suggest that the secretin receptor system has an important role in the central nervous system relating to social behavior.
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Affiliation(s)
- Ichiko Nishijima
- Center for Molecular and Human Genetics, Columbus Children's Research Institute, The Ohio State University, Columbus, OH 43205, USA.
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49
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Siu FKY, Lam IPY, Chu JYS, Chow BKC. Signaling mechanisms of secretin receptor. ACTA ACUST UNITED AC 2006; 137:95-104. [PMID: 16930743 DOI: 10.1016/j.regpep.2006.02.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Revised: 02/14/2006] [Accepted: 02/27/2006] [Indexed: 10/24/2022]
Abstract
Secretin, a 27-amino acid gastrointestinal peptide, was initially discovered based on its activities in stimulating pancreatic juice. In the past 20 years, secretin was demonstrated to exhibit pleiotropic functions in many different tissues and more importantly, its role as a neuropeptide was substantiated. To carry out its activities in the central nervous system and in peripheral organs, secretin interacts specifically with one known receptor. Secretin receptor, a member of guanine nucleotide-binding protein (G protein)-coupled receptor (GPCR) in the secretin/VIP/glucagon subfamily, possesses the characteristics of GPCR with seven conserved transmembrane domains, a relatively large amino-terminal extracellular domain and an intracellular carboxyl terminus. The structural features and signal transduction pathways of the secretin receptor in various tissues are reviewed in this article.
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Affiliation(s)
- Francis K Y Siu
- Department of Zoology, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, PR China
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50
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Abstract
There is increasing interest in the role played by secretin in the central nervous system. Recent evidence suggests that this peptide is widely expressed in the brain but some areas, notably the cerebellum, show a prominent expression of the peptide and its specific receptor. In this article we summarize our current understanding of the expression pattern and action of secretin in the cerebellum. We discuss the findings supporting the endogenous release of this peptide from Purkinje neurons and its role as a retrograde messenger modulating GABAergic synaptic transmission via multiple mechanisms. In addition, we would like to propose other possible, but still to be confirmed, functions of secretin in the cerebellum..
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Affiliation(s)
- Wing-Ho Yung
- Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong.
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