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Yu Y, Tanaka S, Wong TT, Zohar Y, Zmora N. Loss of Function of Vasoactive-intestinal Peptide Alters Sex Ratio and Reduces Male Reproductive Fitness in Zebrafish. Endocrinology 2024; 165:bqae082. [PMID: 38984720 PMCID: PMC11409921 DOI: 10.1210/endocr/bqae082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/21/2024] [Accepted: 07/03/2024] [Indexed: 07/11/2024]
Abstract
Vasoactive-intestinal peptide (Vip) is a pleiotropic peptide with a wide range of distribution and functions. Zebrafish possess 2 isoforms of Vip (a and b), in which Vipa is most homologous to the mammalian form. In female zebrafish, Vipa can stimulate LH secretion from the pituitary but is not essential for female reproduction, as vipa-/- females display normal reproduction. In contrast, we have found that vipa-/- males are severely subfertile and sex ratio of offspring is female-biased. By analyzing all aspects of male reproduction with wild-type (WT) males, we show that the testes of vipa-/- are underdeveloped and contain ∼70% less spermatids compared to WT counterparts. The sperm of vipa-/- males displayed reduced potency in terms of fertilization (by ∼80%) and motility span and duration (by ∼50%). In addition, vipa-/- male attraction to WT females was largely nonexistent, indicating decreased sexual motivation. We show that vipa mRNA and protein is present in Leydig cells and in developing germ cells in the testis of WT, raising the possibility that endogenous Vipa contributes to testicular function. Absence of Vipa in vipa-/- males resulted in downregulation of 3 key genes in the androgen synthesis chain in the testis, 3β-hsd, 17β-hsd1, and cyp11c1 (11β-hydrogenase), associated with a pronounced decrease in 11-ketotestosterone production and, in turn, compromised reproductive fitness. Altogether, this study establishes a crucial role for Vipa in the regulation of male reproduction in zebrafish, like in mammals, with the exception that Vipa is also expressed in zebrafish testis.
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Affiliation(s)
- Yang Yu
- Department of Marine Biotechnology, Institute of Marine & Environmental Technology, University of Maryland Baltimore County, Baltimore, MD 21202, USA
| | - Sakura Tanaka
- Department of Marine Biotechnology, Institute of Marine & Environmental Technology, University of Maryland Baltimore County, Baltimore, MD 21202, USA
| | - Ten-Tsao Wong
- Department of Marine Biotechnology, Institute of Marine & Environmental Technology, University of Maryland Baltimore County, Baltimore, MD 21202, USA
| | - Yonathan Zohar
- Department of Marine Biotechnology, Institute of Marine & Environmental Technology, University of Maryland Baltimore County, Baltimore, MD 21202, USA
| | - Nilli Zmora
- Department of Marine Biotechnology, Institute of Marine & Environmental Technology, University of Maryland Baltimore County, Baltimore, MD 21202, USA
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Traini C, Nistri S, Calosi L, Vannucchi MG. Chronic Exposure to Cigarette Smoke Affects the Ileum and Colon of Guinea Pigs Differently. Relaxin (RLX-2, Serelaxin) Prevents Most Local Damage. Front Pharmacol 2022; 12:804623. [PMID: 35095510 PMCID: PMC8793690 DOI: 10.3389/fphar.2021.804623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/09/2021] [Indexed: 11/13/2022] Open
Abstract
Cigarette smoking (CS) is the cause of several organ and apparatus diseases. The effects of smoke in the gut are partially known. Accumulating evidence has shown a relationship between smoking and inflammatory bowel disease, prompting us to investigate the mechanisms of action of smoking in animal models. Despite the role played by neuropeptides in gut inflammation, there are no reports on their role in animal models of smoking exposure. The hormone relaxin has shown anti-inflammatory properties in the intestine, and it might represent a putative therapy to prevent gut damage caused by smoking. Presently, we investigate the effects of chronic smoke exposure on inflammation, mucosal secretion, and vasoactive intestinal peptide (VIP) and substance P (SP) expressions in the ileum and colon of guinea pigs. We also verify the ability of relaxin to counter the smoke-induced effects. Smoke impacted plasma carbon monoxide (CO). In the ileum, it induced inflammatory infiltrates, fibrosis, and acidic mucin production; reduced the blood vessel area; decreased c-kit-positive mast cells and VIP-positive neurons; and increased the SP-positive nerve fibers. In the colon, it reduced the blood vessel area and the goblet cell area and decreased c-kit-positive mast cells, VIP-positive neurons, and SP-positive nerve fibers. Relaxin prevented most of the smoking-induced changes in the ileum, while it was less effective in the colon. This study shows the diverse sensitivity to CS between the ileum and the colon and demonstrates that both VIP and SP are affected by smoking. The efficacy of relaxin proposes this hormone as a potential anti-inflammatory therapeutic to counteract gut damage in humans affected by inflammatory bowel diseases.
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Affiliation(s)
- Chiara Traini
- Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Florence, Italy
| | - Silvia Nistri
- Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Florence, Italy
| | - Laura Calosi
- Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Florence, Italy
| | - Maria Giuliana Vannucchi
- Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Florence, Italy
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Nitric Oxide: From Gastric Motility to Gastric Dysmotility. Int J Mol Sci 2021; 22:ijms22189990. [PMID: 34576155 PMCID: PMC8470306 DOI: 10.3390/ijms22189990] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/11/2021] [Accepted: 09/13/2021] [Indexed: 12/27/2022] Open
Abstract
It is known that nitric oxide (NO) plays a key physiological role in the control of gastrointestinal (GI) motor phenomena. In this respect, NO is considered as the main non-adrenergic, non-cholinergic (NANC) inhibitory neurotransmitter responsible for smooth muscle relaxation. Moreover, many substances (including hormones) have been reported to modulate NO production leading to changes in motor responses, further underlying the importance of this molecule in the control of GI motility. An impaired NO production/release has indeed been reported to be implicated in some GI dysmotility. In this article we wanted to focus on the influence of NO on gastric motility by summarizing knowledge regarding its role in both physiological and pathological conditions. The main role of NO on regulating gastric smooth muscle motor responses, with particular reference to NO synthases expression and signaling pathways, is discussed. A deeper knowledge of nitrergic mechanisms is important for a better understanding of their involvement in gastric pathophysiological conditions of hypo- or hyper-motility states and for future therapeutic approaches. A possible role of substances which, by interfering with NO production, could prove useful in managing such motor disorders has been advanced.
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Guimaraes de Souza Melo C, Nelisis Zanoni J, Raquel Garcia de Souza S, Zignani I, de Lima Leite A, Domingues Heubel A, Vanessa Colombo Martins Perles J, Afonso Rabelo Buzalaf M. Global Proteomic Profile Integrated to Quantitative and Morphometric Assessment of Enteric Neurons: Investigation of the Mechanisms Involved in the Toxicity Induced by Acute Fluoride Exposure in the Duodenum. Neurotox Res 2021; 39:800-814. [PMID: 33689147 DOI: 10.1007/s12640-020-00296-9] [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: 06/22/2020] [Revised: 09/20/2020] [Accepted: 10/11/2020] [Indexed: 10/21/2022]
Abstract
The enteric nervous system is responsible for controlling the gastrointestinal tract (GIT) functions. Enteric neuropathies are highly correlated to the development of several intestinal disturbances. Fluoride (F) is extensively applied for dental health improvement and its ingestion can promote systemic toxicity with mild to severe GIT symptomatology and neurotoxicity. Although F harmful effects have been published, there is no information regarding noxiousness of a high acute F exposure (25 mg F/kg) on enteric neurons and levels of expression of intestinal proteins in the duodenum. Quantitative proteomics of the duodenum wall associated to morphometric and quantitative analysis of enteric neurons displayed F effects of a high acute exposure. F-induced myenteric neuroplasticity was characterized by a decrease in the density of nitrergic neurons and morphometric alterations in the general populations of neurons, nitrergic neurons, and substance P varicosities. Proteomics demonstrated F-induced alterations in levels of expression of 356 proteins correlated to striated muscle cell differentiation; generation of precursor metabolites and energy; NADH and glutathione metabolic process and purine ribonucleoside triphosphate biosynthesis. The neurochemical role of several intestinal proteins was discussed specially related to the modulation of enteric neuroplasticity. The results provide a new perspective on cell signaling pathways of gastrointestinal symptomatology promoted by acute F toxicity.
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Affiliation(s)
| | | | | | - Isabela Zignani
- Department of Morphophysiological Sciences, State University of Maringá, Paraná, Brazil
| | - Aline de Lima Leite
- Department of Biological Sciences, School of Dentistry, University of São Paulo, Bauru, Brazil
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Martins-Perles JVC, Bossolani GDP, Zignani I, de Souza SRG, Frez FCV, de Souza Melo CG, Barili E, de Souza Neto FP, Guarnier FA, Armani ALC, Cecchini R, Zanoni JN. Quercetin increases bioavailability of nitric oxide in the jejunum of euglycemic and diabetic rats and induces neuronal plasticity in the myenteric plexus. Auton Neurosci 2020; 227:102675. [PMID: 32474374 DOI: 10.1016/j.autneu.2020.102675] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/06/2020] [Accepted: 04/24/2020] [Indexed: 02/08/2023]
Abstract
Considering the antioxidant, neuroprotective, inflammatory and nitric oxide modulatory actions of quercetin, the aim of this study was to test the effect of quercetin administration in drinking water (40 mg/day/rat) on neuronal nitric oxide synthase (nNOS), vasoactive intestinal peptide (VIP), overall population of myenteric neurons (HuC/D) and nitric oxide (NO) levels in the jejunal samples from diabetic rats. Male Wistar rats were distributed into four groups (8 rats per group): euglycemic (E), euglycemic administered with quercetin (E+Q), diabetic (D) and diabetic administered with quercetin (D+Q). Rats were induced to diabetes with streptozotocin (35mg/kg/iv) and, after 120 days, the proximal jejunum were collected and processed for immunohistochemical (VIP, nNOS and HuC/D) and chemiluminescence (quantification of tissue NO levels) techniques. Diabetes mellitus reduced the number of nNOS-IR (immunoreactive) (p <0.05) and HuC/D-IR (p <0.001) neurons, however, promoted an increased morphometric area of nNOS-IR neurons (p <0.001) and VIP-IR varicosities (p <0.05). In D+Q group, neuroplasticity effects were observed on HuC/D-IR neurons, accompanied by a reduction of cell body area of neurons nNOS- and VIP-IR varicosities (p <0.05). The NO levels were increased in the E+Q (p <0.05) and D+Q group (p <0.001) compared to the control group. In conclusion, the results showed that quercetin supplementation increased the bioavailability of NO in the jejunum in euglycemic and mitigate the effects of diabetes on nNOS-IR neurons and VIP-IR varicosities in the myenteric plexus of diabetic rats.
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Affiliation(s)
| | - Gleison Daion Piovezana Bossolani
- Department of Morphological Sciences, Universidade Estadual de Maringá, Avenida Colombo, n 5790 Bloco O-33, Maringá, PR CEP 87020-900, Brazil
| | - Isabela Zignani
- Department of Morphological Sciences, Universidade Estadual de Maringá, Avenida Colombo, n 5790 Bloco O-33, Maringá, PR CEP 87020-900, Brazil
| | - Sara Raquel Garcia de Souza
- Department of Morphological Sciences, Universidade Estadual de Maringá, Avenida Colombo, n 5790 Bloco O-33, Maringá, PR CEP 87020-900, Brazil
| | - Flávia Cristina Vieira Frez
- Department of Morphological Sciences, Universidade Estadual de Maringá, Avenida Colombo, n 5790 Bloco O-33, Maringá, PR CEP 87020-900, Brazil
| | - Carina Guimarães de Souza Melo
- Department of Morphological Sciences, Universidade Estadual de Maringá, Avenida Colombo, n 5790 Bloco O-33, Maringá, PR CEP 87020-900, Brazil
| | - Emerson Barili
- Department of Statistic, Universidade Estadual de Maringá, Avenida Colombo, n 5790, Maringá, PR CEP 87020-900, Brazil
| | - Fernando Pinheiro de Souza Neto
- Department of Pathology Sciences, Universidade Estadual de Londrina (UEL), Rodovia Celso Garcia Cid
- Pr 445 Km 380, Londrina, PR CEP 86.057-970, Brazil
| | - Flávia Alessandra Guarnier
- Department of Pathology Sciences, Universidade Estadual de Londrina (UEL), Rodovia Celso Garcia Cid
- Pr 445 Km 380, Londrina, PR CEP 86.057-970, Brazil
| | - Alessandra Lourenço Cecchini Armani
- Department of Pathology Sciences, Universidade Estadual de Londrina (UEL), Rodovia Celso Garcia Cid
- Pr 445 Km 380, Londrina, PR CEP 86.057-970, Brazil
| | - Rubens Cecchini
- Department of Pathology Sciences, Universidade Estadual de Londrina (UEL), Rodovia Celso Garcia Cid
- Pr 445 Km 380, Londrina, PR CEP 86.057-970, Brazil
| | - Jacqueline Nelisis Zanoni
- Department of Morphological Sciences, Universidade Estadual de Maringá, Avenida Colombo, n 5790 Bloco O-33, Maringá, PR CEP 87020-900, Brazil.
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Kuwahara A, Kuwahara Y, Kato I, Kawaguchi K, Harata D, Asano S, Inui T, Marunaka Y. Xenin-25 induces anion secretion by activating noncholinergic secretomotor neurons in the rat ileum. Am J Physiol Gastrointest Liver Physiol 2019; 316:G785-G796. [PMID: 30978113 DOI: 10.1152/ajpgi.00333.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Xenin-25 is a neurotensin-like peptide that is secreted by enteroendocrine cells in the small intestine. Xenin-8 is reported to augment duodenal anion secretion by activating afferent neural pathways. The intrinsic neuronal circuits mediating the xenin-25-induced anion secretion were characterized using the Ussing-chambered, mucosa-submucosa preparation from the rat ileum. Serosal application of xenin-25 increased the short-circuit current in a concentration-dependent manner. The responses were abolished by the combination of Cl--free and HCO3- -free solutions. The responses were almost completely blocked by TTX (10-6 M) but not by atropine (10-5 M) or hexamethonium (10-4 M). The selective antagonists for neurotensin receptor 1 (NTSR1), neurokinin 1 (NK1), vasoactive intestinal polypeptide (VIP) receptors 1 and 2 (VPAC1 and VPAC2, respectively), and capsaicin, but not 5-hydroxyltryptamine receptors 3 and 4 (5-HT3 and 5-HT4), NTSR2, and A803467, inhibited the responses to xenin-25. The expression of VIP receptors (Vipr) in rat ileum was examined using RT-PCR. The Vipr1 PCR products were detected in the submucosal plexus and mucosa. Immunohistochemical staining showed the colocalization of NTSR1 and NK1 with substance P (SP)- and calbindin-immunoreactive neurons in the submucosal plexus, respectively. In addition, NK1 was colocalized with noncholinergic VIP secretomotor neurons. Based on the results from the present study, xenin-25-induced Cl-/ HCO3- secretion is involved in NTSR1 activation on intrinsic and extrinsic afferent neurons, followed by the release of SP and subsequent activation of NK1 expressed on noncholinergic VIP secretomotor neurons. Finally, the secreted VIP may activate VPAC1 on epithelial cells to induce Cl-/ HCO3- secretion in the rat ileum. Activation of noncholinergic VIP secretomotor neurons by intrinsic primary afferent neurons and extrinsic afferent neurons by postprandially released xenin-25 may account for most of the neurogenic secretory response induced by xenin-25. NEW & NOTEWORTHY This study is the first to investigate the intrinsic neuronal circuit responsible for xenin-25-induced anion secretion in the rat small intestine. We have found that nutrient-stimulated xenin-25 release may activate noncholinergic vasoactive intestinal polypeptide (VIP) secretomotor neurons to promote Cl-/ HCO3- secretion through the activation of VIP receptor 1 on epithelial cells. Moreover, the xenin-25-induced secretory responses are mainly linked with intrinsic primary afferent neurons, which are involved in the activation of neurotensin receptor 1 and neurokinin 1 receptor.
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Affiliation(s)
- Atsukazu Kuwahara
- Research Unit for Epithelial Physiology, Research Organization of Science and Technology, Ritsumeikan University , Kusatsu , Japan.,Department of Molecular Cell Physiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine , Kyoto , Japan.,Research Center for Drug Discovery and Pharmaceutical Development Science, Research Organization of Science and Technology, Ritsumeikan University , Kusatsu , Japan
| | - Yuko Kuwahara
- Department of Molecular Cell Physiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine , Kyoto , Japan
| | - Ikuo Kato
- Department of Medical Biochemistry, Kobe Pharmaceutical University , Kobe , Japan
| | - Kotoku Kawaguchi
- Department of Molecular Physiology, College of Pharmaceutical Sciences, Ritsumeikan University , Kusatsu , Japan
| | - Daiki Harata
- Department of Molecular Physiology, College of Pharmaceutical Sciences, Ritsumeikan University , Kusatsu , Japan
| | - Shinji Asano
- Department of Molecular Physiology, College of Pharmaceutical Sciences, Ritsumeikan University , Kusatsu , Japan
| | | | - Yoshinori Marunaka
- Department of Molecular Cell Physiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine , Kyoto , Japan.,Research Center for Drug Discovery and Pharmaceutical Development Science, Research Organization of Science and Technology, Ritsumeikan University , Kusatsu , Japan.,Research Institute for Clinical Physiology, Kyoto Industrial Health Association , Kyoto , Japan
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Vasoactive Intestinal Polypeptide-Immunoreactive Interneurons within Circuits of the Mouse Basolateral Amygdala. J Neurosci 2018; 38:6983-7003. [PMID: 29954847 PMCID: PMC6070667 DOI: 10.1523/jneurosci.2063-17.2018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 04/20/2018] [Accepted: 05/15/2018] [Indexed: 11/29/2022] Open
Abstract
In cortical structures, principal cell activity is tightly regulated by different GABAergic interneurons (INs). Among these INs are vasoactive intestinal polypeptide-expressing (VIP+) INs, which innervate preferentially other INs, providing a structural basis for temporal disinhibition of principal cells. However, relatively little is known about VIP+ INs in the amygdaloid basolateral complex (BLA). In this study, we report that VIP+ INs have a variable density in the distinct subdivisions of the mouse BLA. Based on different anatomical, neurochemical, and electrophysiological criteria, VIP+ INs could be identified as IN-selective INs (IS-INs) and basket cells expressing CB1 cannabinoid receptors. Whole-cell recordings of VIP+ IS-INs revealed three different spiking patterns, none of which was associated with the expression of calretinin. Genetic targeting combined with optogenetics and in vitro recordings enabled us to identify several types of BLA INs innervated by VIP+ INs, including other IS-INs, basket and neurogliaform cells. Moreover, light stimulation of VIP+ basket cell axon terminals, characterized by CB1 sensitivity, evoked IPSPs in ∼20% of principal neurons. Finally, we show that VIP+ INs receive a dense innervation from both GABAergic inputs (although only 10% from other VIP+ INs) and distinct glutamatergic inputs, identified by their expression of different vesicular glutamate transporters. In conclusion, our study provides a wide-range analysis of single-cell properties of VIP+ INs in the mouse BLA and of their intrinsic and extrinsic connectivity. Our results reinforce the evidence that VIP+ INs are structurally and functionally heterogeneous and that this heterogeneity could mediate different roles in amygdala-dependent functions. SIGNIFICANCE STATEMENT We provide the first comprehensive analysis of the distribution of vasoactive intestinal polypeptide-expressing (VIP+) interneurons (INs) across the entire mouse amygdaloid basolateral complex (BLA), as well as of their morphological and physiological properties. VIP+ INs in the neocortex preferentially target other INs to form a disinhibitory network that facilitates principal cell firing. Our study is the first to demonstrate the presence of such a disinhibitory circuitry in the BLA. We observed structural and functional heterogeneity of these INs and characterized their input/output connectivity. We also identified several types of BLA INs that, when inhibited, may provide a temporal window for principal cell firing and facilitate associative plasticity, e.g., in fear learning.
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Bódi N, Szalai Z, Chandrakumar L, Bagyánszki M. Region-dependent effects of diabetes and insulin-replacement on neuronal nitric oxide synthase- and heme oxygenase-immunoreactive submucous neurons. World J Gastroenterol 2017; 23:7359-7368. [PMID: 29151690 PMCID: PMC5685842 DOI: 10.3748/wjg.v23.i41.7359] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/26/2017] [Accepted: 08/25/2017] [Indexed: 02/07/2023] Open
Abstract
AIM To investigate the intestinal segment-specific effects of diabetes and insulin replacement on the density of different subpopulations of submucous neurons.
METHODS Ten weeks after the onset of type 1 diabetes samples were taken from the duodenum, ileum and colon of streptozotocin-induce diabetic, insulin-treated diabetic and sex- and age-matched control rats. Whole-mount preparations of submucous plexus were prepared from the different gut segments for quantitative fluorescent immunohistochemistry. The following double-immunostainings were performed: neuronal nitric oxide synthase (nNOS) and HuC/D, heme oxygenase (HO) 1 and peripherin, as well as HO2 and peripherin. The density of nNOS-, HO1- and HO2-immunoreactive (IR) neurons was determined as a percentage of the total number of submucous neurons.
RESULTS The total number of submucous neurons and the proportion of nNOS-, HO1- and HO2-IR subpopulations were not affected in the duodenal ganglia of control, diabetic and insulin-treated rats. While the total neuronal number did not change in either the ileum or the colon, the density of nitrergic neurons exhibited a 2- and 3-fold increase in the diabetic ileum and colon, respectively, which was further enhanced after insulin replacement. The presence of HO1- and HO2-IR submucous neurons was robust in the colon of controls (38.4%-50.8%), whereas it was significantly lower in the small intestinal segments (0.0%-4.2%, P < 0.0001). Under pathophysiological conditions the only alteration detected was an increase in the ileum and a decrease in the colon of the proportion of HO-IR neurons in insulin-treated diabetic animals.
CONCLUSION Diabetes and immediate insulin replacement induce the most pronounced region-specific alterations of nNOS-, HO1- and HO2-IR submucous neuronal density in the distal parts of the gut.
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Affiliation(s)
- Nikolett Bódi
- Department of Physiology, Anatomy and Neuroscience, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
| | - Zita Szalai
- Department of Physiology, Anatomy and Neuroscience, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
| | - Lalitha Chandrakumar
- Department of Physiology, Anatomy and Neuroscience, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
| | - Mária Bagyánszki
- Department of Physiology, Anatomy and Neuroscience, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
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Ito J, Uchida H, Machida N, Ohtake K, Saito Y, Kobayashi J. Inducible and neuronal nitric oxide synthases exert contrasting effects during rat intestinal recovery following fasting. Exp Biol Med (Maywood) 2017; 242:762-772. [PMID: 28195513 DOI: 10.1177/1535370217694434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
We investigated the effects of endogenous inducible (iNOS) and neuronal nitric oxide synthase on recovery from intestinal mucosal atrophy caused by fasting-induced apoptosis and decreased cell proliferation during refeeding in rats. Rats were divided into five groups, one of which was fed ad libitum, and four of which underwent 72 h of fasting, followed by refeeding for 0, 6, 24, and 48 h, respectively. iNOS and neuronal nitric oxide synthase mRNA and protein levels in jejunal tissues were measured, and mucosal height was histologically evaluated. Apoptotic indices, interferon-γ (IFN-γ) transcription levels, nitrite levels (as a measure of nitric oxide [NO] production),8-hydroxydeoxyguanosine formation (indicating reactive oxygen species [ROS] levels), crypt cell proliferation, and the motility indices (MI) were also estimated. Associations between mucosal height and NOS protein levels were determined using Spearman's rank correlation test. Notably, we observed significant increases in mucosal height and in neuronal nitric oxide synthase mRNA and protein expression as refeeding time increased. Indeed, there was a significant positive correlation between neuronal nitric oxide synthase protein level and mucosal height during the 48-h refeeding period ( r = 0.725, P < 0.01). Conversely, iNOS mRNA and protein expression decreased according to refeeding time, with a significant negative correlation between iNOS protein level and mucosal height being recorded during the 48-h refeeding period ( r = -0.898, P < 0.01). We also noted a significant negative correlation between jejunal neuronal nitric oxide synthase and iNOS protein concentrations over this same period ( r = -0.734, P < 0.01). Refeeding also restored the decreased jejunal MI caused by fasting. Our finding suggests that refeeding likely repairs fasting-induced jejunal atrophy by suppressing iNOS expression and subsequently inhibiting NO, ROS, and IFN-γ as apoptosis mediators, and by promoting neuronal nitric oxide synthase production and inducing crypt cell proliferation via mechanical stimulation. Impact statement Besides providing new data confirming the involvement of iNOS and nNOS in intestinal mucosal atrophy caused by fasting, this study details their expression and function during recovery from this condition following refeeding. We demonstrate a significant negative correlation between iNOS and nNOS levels during refeeding, and associate this with cell proliferation and apoptosis in crypts and villi. These novel findings elucidate the relationship between these NOS isoforms and its impact on recovery from intestinal injury. A mechanism is proposed comprising the up-regulation of nNOS activity by mechanical stimulation due to the presence of food in the intestine, restricting iNOS-associated apoptosis and promoting cell proliferation and gut motility. Our investigation sheds light on the molecular basis behind the repercussions of total parenteral nutrition on intestinal mucosal integrity, and more importantly, the beneficial effects of early enteral feeding.
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Affiliation(s)
- Junta Ito
- Division of Pathophysiology, Faculty of Pharmaceutical Science, Department of Clinical Dietetics and Human Nutrition, Josai University, Saitama 350-0295, Japan
| | - Hiroyuki Uchida
- Division of Pathophysiology, Faculty of Pharmaceutical Science, Department of Clinical Dietetics and Human Nutrition, Josai University, Saitama 350-0295, Japan
| | - Naomi Machida
- Division of Pathophysiology, Faculty of Pharmaceutical Science, Department of Clinical Dietetics and Human Nutrition, Josai University, Saitama 350-0295, Japan
| | - Kazuo Ohtake
- Division of Pathophysiology, Faculty of Pharmaceutical Science, Department of Clinical Dietetics and Human Nutrition, Josai University, Saitama 350-0295, Japan
| | - Yuki Saito
- Division of Pathophysiology, Faculty of Pharmaceutical Science, Department of Clinical Dietetics and Human Nutrition, Josai University, Saitama 350-0295, Japan
| | - Jun Kobayashi
- Division of Pathophysiology, Faculty of Pharmaceutical Science, Department of Clinical Dietetics and Human Nutrition, Josai University, Saitama 350-0295, Japan
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DUBOC H, TOLSTANOVA G, YUAN PQ, WU V, KAJI I, BIRAUD M, AKIBA Y, KAUNITZ J, MILLION M, TACHE Y, LARAUCHE M. Reduction of epithelial secretion in male rat distal colonic mucosa by bile acid receptor TGR5 agonist, INT-777: role of submucosal neurons. Neurogastroenterol Motil 2016; 28:1663-1676. [PMID: 27259385 PMCID: PMC5083223 DOI: 10.1111/nmo.12866] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/28/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND Recent evidence from rat neuron-free mucosa study suggests that the membrane bile acid receptor TGR5 decreases colonic secretion under basal and stimulated conditions. As submucosal neurons are key players in secretory processes and highly express TGR5, we investigated their role in TGR5 agonist-induced inhibition of secretion and the pathways recruited. METHODS TGR5 expression and localization were assessed in rat proximal (pC) and distal (dC) colon by qPCR and immunohistochemistry with double labeling for cholinergic neurons in whole-mount preparations. The influence of a selective (INT-777) or weak (ursodeoxycholic acid, UDCA) TGR5 agonist on colonic secretion was assessed in Ussing chambers, in dC preparation removing seromuscular ± submucosal tissues, in the presence of different inhibitors of secretion pathways. KEY RESULTS TGR5 mRNA is expressed in full thickness dC and pC and immunoreactivity is located in colonocytes and pChAT-positive neurons. Addition of INT-777, and less potently UDCA, decreased colonic secretion in seromuscular stripped dC by -58.17± 2.6%. INT-777 effect on basal secretion was reduced in neuron-free and TTX-treated mucosal-submucosal preparations. Atropine, hexamethonium, indomethacin, and L-NAME all reduced significantly INT-777's inhibitory effect while the 5-HT4 antagonist, RS-39604, and lidocaine abolished it. INT-777 inhibited stimulated colonic secretion induced by nicotine, but not cisapride, carbachol or PGE2. CONCLUSIONS & INFERENCES TGR5 activation inhibits basal and stimulated distal colonic secretion in rats by acting directly on epithelial cells and also inhibiting submucosal neurons. This could represent a counter-regulatory mechanism, at the submucosal level, of the known prosecretory effect of bile acids in the colon.
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Affiliation(s)
- Henri DUBOC
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA,DHU UNITY, Inserm UMR 1149, and Louis Mourier Hospital, Department of Gastroenterology and Hepatology, AP-HP, University Paris Diderot Sorbonne Paris Cité, Paris, France
| | - Ganna TOLSTANOVA
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA,Educational-Scientific Center “Institute of Biology” Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Pu-Qing YUAN
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Vincent WU
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Izumi KAJI
- Department of Medicine, School of Medicine, UCLA,Brentwood Biomedical Research Institute, Los Angeles, California, USA
| | - Mandy BIRAUD
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Yasutada AKIBA
- VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA,Department of Medicine, School of Medicine, UCLA,Brentwood Biomedical Research Institute, Los Angeles, California, USA
| | - Jonathan KAUNITZ
- VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA,Department of Medicine, School of Medicine, UCLA,Department of Surgery, School of Medicine, UCLA,Brentwood Biomedical Research Institute, Los Angeles, California, USA
| | - Mulugeta MILLION
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Yvette TACHE
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Muriel LARAUCHE
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
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12
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Is L-glutathione more effective than L-glutamine in preventing enteric diabetic neuropathy? Dig Dis Sci 2014; 59:937-48. [PMID: 24370785 DOI: 10.1007/s10620-013-2993-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 12/10/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND Diabetes and its complications appear to be multifactorial. Substances with antioxidant potential have been used to protect enteric neurons in experimental diabetes. AIM This study evaluated the effects of supplementation with L-glutamine and L-glutathione on enteric neurons in the jejunum in diabetic rats. METHODS Rats at 90 days of age were distributed into six groups: normoglycemic, normoglycemic supplemented with 2 % L-glutamine, normoglycemic supplemented with 1 % L-glutathione, diabetic (D), diabetic supplemented with 2 % L-glutamine (DG), and diabetic supplemented with 1 % L-glutathione (DGT). After 120 days, the jejunums were immunohistochemically stained for HuC/D+ neuronal nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP). Western blot was performed to evaluate nNOS and VIP. Submucosal and myenteric neurons were quantitatively and morphometrically analyzed. RESULTS Diabetic neuropathy was observed in myenteric HuC/D, nNOS, and VIP neurons (p < 0.05). In the submucosal plexus, diabetes did not change nitrergic innervation but increased VIPergic neuronal density and body size (p < 0.05). Supplementation with L-glutathione prevented changes in HuC/D neurons in the enteric plexus (p < 0.05), showing that supplementation with L-glutathione was more effective than with L-glutamine. Myenteric nNOS neurons in the DGT group exhibited a reduced density (34.5 %) and reduced area (p < 0.05). Submucosal neurons did not exhibit changes. The increase in VIP-expressing neurons was prevented in the submucosal plexus in the DG and DGT groups (p < 0.05). CONCLUSION Supplementation with L-glutathione exerted a better neuroprotective effect than L-glutamine and may prevent the development of enteric diabetic neuropathy.
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13
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Foong JPP, Tough IR, Cox HM, Bornstein JC. Properties of cholinergic and non-cholinergic submucosal neurons along the mouse colon. J Physiol 2013; 592:777-93. [PMID: 24344165 DOI: 10.1113/jphysiol.2013.265686] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Submucosal neurons are vital regulators of water and electrolyte secretion and local blood flow in the gut. Due to the availability of transgenic models for enteric neuropathies, the mouse has emerged as the research model of choice, but much is still unknown about the murine submucosal plexus. The progeny of choline acetyltransferase (ChAT)-Cre × ROSA26(YFP) reporter mice, ChAT-Cre;R26R-yellow fluorescent protein (YFP) mice, express YFP in every neuron that has ever expressed ChAT. With the aid of the robust YFP staining in these mice, we correlated the neurochemistry, morphology and electrophysiology of submucosal neurons in distal colon. We also examined whether there are differences in neurochemistry along the colon and in neurally mediated vectorial ion transport between the proximal and distal colon. All YFP(+) submucosal neurons also contained ChAT. Two main neurochemical but not electrophysiological groups of neurons were identified: cholinergic (containing ChAT) or non-cholinergic. The vast majority of neurons in the middle and distal colon were non-cholinergic but contained vasoactive intestinal peptide. In the distal colon, non-cholinergic neurons had one or two axons, whereas the cholinergic neurons examined had only one axon. All submucosal neurons exhibited S-type electrophysiology, shown by the lack of long after-hyperpolarizing potentials following their action potentials and fast excitatory postsynaptic potentials (EPSPs). Fast EPSPs were predominantly nicotinic, and somatic action potentials were mediated by tetrodotoxin-resistant voltage-gated channels. The size of submucosal ganglia decreased but the proportion of cholinergic neurons increased distally along the colon. The distal colon had a significantly larger nicotinic ion transport response than the proximal colon. This work shows that the properties of murine submucosal neurons and their control of epithelial ion transport differ between colonic regions. There are several key differences between the murine submucous plexus and that of other animals, including a lack of conventional intrinsic sensory neurons, which suggests there is an incomplete neuronal circuitry within the murine submucous plexus.
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Affiliation(s)
- Jaime Pei Pei Foong
- Department of Physiology, University of Melbourne, Parkville, Vic. 3010, Australia.
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14
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Expression of neuropeptides and anoctamin 1 in the embryonic and adult zebrafish intestine, revealing neuronal subpopulations and ICC-like cells. Cell Tissue Res 2013; 354:355-70. [PMID: 23881406 DOI: 10.1007/s00441-013-1685-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 06/17/2013] [Indexed: 12/12/2022]
Abstract
This immunohistochemical study in zebrafish aims to extend the neurochemical characterization of enteric neuronal subpopulations and to validate a marker for identification of interstitial cells of Cajal (ICC). The expression of neuropeptides and anoctamin 1 (Ano1), a selective ICC marker in mammals, was analyzed in both embryonic and adult intestine. Neuropeptides were present from 3 days postfertilization (dpf). At 3 dpf, galanin-positive nerve fibers were found in the proximal intestine, while calcitonin gene-related peptide (CGRP)- and substance P-expressing fibers appeared in the distal intestine. At 5 dpf, immunoreactive fibers were present along the entire intestinal length, indicating a well-developed peptidergic innervation at the onset of feeding. In the adult intestine, vasoactive intestinal peptide (VIP), pituitary adenylate cyclase-activating peptide (PACAP), galanin, CGRP and substance P were detected in nerve fibers. Colchicine pretreatment enhanced only VIP and PACAP immunoreactivity. VIP and PACAP were coexpressed in enteric neurons. Colocalization stainings revealed three neuronal subpopulations expressing VIP and PACAP: a nitrergic noncholinergic subpopulation, a serotonergic subpopulation and a subpopulation expressing no other markers. Ano1-immunostaining revealed a 3-dimensional network in the adult intestine containing multipolar cells at the myenteric plexus and bipolar cells interspersed between circular smooth muscle cells. Ano1 immunoreactivity first appeared at 3 dpf, indicative of the onset of proliferation of ICC-like cells. It is shown that the Ano1 antiserum is a selective marker of ICC-like cells in the zebrafish intestine. Finally, it is hypothesized that ICC-like cells mediate the spontaneous regular activity of the embryonic intestine.
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15
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Kuramoto H, Kadowaki M, Yoshida N. Morphological demonstration of a vagal inhibitory pathway to the lower esophageal sphincter via nitrergic neurons in the rat esophagus. Neurogastroenterol Motil 2013; 25:e485-94. [PMID: 23634870 DOI: 10.1111/nmo.12146] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Accepted: 04/05/2013] [Indexed: 02/08/2023]
Abstract
BACKGROUND The involvement of vagal parasympathetic efferents in esophageal myenteric neurons in vagal inhibitory pathways to the lower esophageal sphincter (LES) is not clear. Thus, this study was performed to demonstrate morphologically the presence of vagal inhibitory pathways to the LES via esophageal neurons. METHODS Fast Blue (FB) was injected into the LES of Wistar rats, and 3 days after injection, the animals were subjected to electrical stimulation of the vagus nerve. The esophagus was processed for immunohistochemistry for Fos that was an immediate-early gene as a marker of neuronal activity, nitric oxide synthase (NOS), vasoactive intestinal polypeptide (VIP) and choline acetyltransferase (ChAT). The immunoreactivities were then compared with the FB labeling in esophageal neurons. KEY RESULTS Fast Blue-labeled neurons were observed within an esophageal area of 30 mm oral to the LES, with the highest frequency in the esophagus just above the LES. Most of the FB-labeled neurons were positive for NOS and VIP, but a few for ChAT. Following vagal-electrical stimulation, one fourth of the FB-labeled neurons presented nuclei expressing Fos and most of these Fos/FB neurons were NOS-positive. CONCLUSIONS & INFERENCES A majority of the FB-labeled esophageal neurons appeared to be descending motor neurons innervating the LES. Moreover, the colocalization of VIP and NOS in most of the LES-projecting neurons suggests that VIP and NO released from these neurons induce LES relaxation, and the innervation of the vagal efferents to the LES-projecting esophageal neurons in the distal esophagus implies a vagal inhibitory pathway responsible for LES relaxation.
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Affiliation(s)
- H Kuramoto
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan.
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16
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Wang C, Houghton MJ, Gamage PPKM, Collins HE, Patel BA, Yeoman MS, Ranson RN, Saffrey MJ. Changes in the innervation of the mouse internal anal sphincter during aging. Neurogastroenterol Motil 2013; 25:e469-77. [PMID: 23634828 DOI: 10.1111/nmo.12144] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 03/28/2013] [Indexed: 12/20/2022]
Abstract
BACKGROUND The innervation of the mouse internal anal sphincter (IAS) has been little studied, and how it changes during aging has not previously been investigated. The aim of this study was therefore to characterize the distribution and density of subtypes of nerve fibers in the IAS and underlying mucosa in 3-, 12- to 13-, 18- and 24- to 25-month-old male C57BL/6 mice. METHODS Nerve fibers were immunolabeled with antibodies against protein gene product 9.5 (PGP9.5), neuronal nitric oxide synthase (nNOS), vasoactive intestinal polypeptide (VIP), substance P (SP), calcitonin gene-related peptide (CGRP), and calretinin (CR). Immunoreactivity in nerve fibers in the circular muscle and mucosa was quantified using Image J software. KEY RESULTS In young adult (3 month) mice, nNOS-immunoreactive (IR) nerve fibers were densely distributed in the circular muscle, but relatively few in the mucosa; VIP-IR nerve fibers were abundant in the circular muscle and common in the mucosa; SP-IR nerve fibers were common in circular muscle and mucosa; CGRP- and CR-IR nerve fibers were dense in mucosa and sparse in circular muscle. The density of PGP9.5 immunoreactivity (IRY) was not significantly reduced with age, but a significant reduction in nNOS-IRY and SP-IRY with age was found in the IAS circular muscle. Neuronal nitric oxide synthase-, VIP-, and SP-IRY in the anal mucosa were significantly reduced with age. CGRP-IRY in both circular muscle and mucosa was increased in 18-month-old animals. CONCLUSIONS & INFERENCES The density of immunoreactivity of markers for some types of IAS nerve fibers decreases during aging, which may contribute to age-related ano-rectal dysfunction.
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Affiliation(s)
- C Wang
- Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes, UK
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17
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YUAN PQ, MILLION M, WU SV, RIVIER J, TACHÉ Y. Peripheral corticotropin releasing factor (CRF) and a novel CRF1 receptor agonist, stressin1-A activate CRF1 receptor expressing cholinergic and nitrergic myenteric neurons selectively in the colon of conscious rats. Neurogastroenterol Motil 2007; 19:923-36. [PMID: 17973638 PMCID: PMC8086410 DOI: 10.1111/j.1365-2982.2007.00978.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Intraperitoneal (i.p.) corticotropin releasing factor (CRF) induced a CRF(1) receptor-dependent stimulation of myenteric neurons and motility in the rat proximal colon. We characterize the colonic enteric nervous system response to CRF in conscious rats. Laser capture microdissection combined with reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry in longitudinal muscle myenteric plexus whole-mount colonic preparations revealed CRF(1) receptor expression in myenteric neurons. CRF (i.p., 10 microg kg(-1)) induced Fos immunoreactivity (IR) (cells per ganglion) selectively in myenteric plexus of proximal (18.3 +/- 2.4 vs vehicle: 0.0 +/- 0.0) and distal colon (16.8 +/- 1.2 vs vehicle: 0.0 +/- 0.0), but not in that of gastric corpus, antrum, duodenum, jejunum and ileum. The selective CRF(1) agonist, stressin(1)-A (i.p., 10 microg kg(-1)) also induced Fos IR in myenteric but not in submucosal plexus of the proximal and distal colon. Fos IR induced by CRF was located in 55 +/- 1.9% and 53 +/- 5.1% of CRF(1) receptor-IR myenteric neurons and in 44 +/- 2.8% and 40 +/- 3.9% of cholinergic neurons with Dogiel type I morphology, and in 20 +/- 1.6% and 80 +/- 3.3% of nitrergic neurons in proximal and distal colon respectively. CRF and stressin(1)-A elicit defecation and diarrhoea. These data support that one mechanism through which peripherally injected CRF ligands stimulate colonic function involves a direct action on colonic cholinergic and nitrergic myenteric neurons expressing CRF(1) receptor.
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Affiliation(s)
- P.-Q. YUAN
- CURE: Digestive Diseases Research Center, and Center for Neurovisceral Sciences & Womens Health, VA Greater Los Angeles Healthcare System, Digestive Diseases Division, Department of Medicine and Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - M. MILLION
- CURE: Digestive Diseases Research Center, and Center for Neurovisceral Sciences & Womens Health, VA Greater Los Angeles Healthcare System, Digestive Diseases Division, Department of Medicine and Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - S. V. WU
- CURE: Digestive Diseases Research Center, and Center for Neurovisceral Sciences & Womens Health, VA Greater Los Angeles Healthcare System, Digestive Diseases Division, Department of Medicine and Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - J. RIVIER
- The Clayton Foundation Laboratories for Protein Biology, The Salk Institute for Biological Study, La Jolla, CA, USA
| | - Y. TACHÉ
- CURE: Digestive Diseases Research Center, and Center for Neurovisceral Sciences & Womens Health, VA Greater Los Angeles Healthcare System, Digestive Diseases Division, Department of Medicine and Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
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Radford IR, Lobachevsky PN. An enteroendocrine cell-based model for a quiescent intestinal stem cell niche. Cell Prolif 2006; 39:403-14. [PMID: 16987141 PMCID: PMC6496364 DOI: 10.1111/j.1365-2184.2006.00396.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We have shown that the kinetics of conversion of intestinal crypt cell populations to a partially or wholly mutant phenotype are consistent with a model in which each crypt contains an infrequently dividing 'deep' stem cell that is the progenitor of several more frequently dividing 'proximate' stem cells. An assumption of our model is that each deep stem cell exists in a growth inhibitory niche. We have used information from the literature to develop a model for a quiescent intestinal stem cell niche. This niche is postulated to be primarily defined by an enteroendocrine cell type that maintains stem cell quiescence by secretion of growth inhibitory peptides such as somatostatin and guanylin/uroguanylin. Consistent with this model, there is evidence that the proteins postulated as defining a growth-inhibitory stem cell niche can act as intestinal tumour suppressors. Confirmation that a growth-inhibitory niche does exist would have important implications for our understanding of intestinal homeostasis and tumorigenesis.
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Beckett EAH, Takeda Y, Yanase H, Sanders KM, Ward SM. Synaptic specializations exist between enteric motor nerves and interstitial cells of Cajal in the murine stomach. J Comp Neurol 2006; 493:193-206. [PMID: 16255030 DOI: 10.1002/cne.20746] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Autonomic neurotransmission is thought to occur via a loose association between nerve varicosities and smooth muscle cells. In the gastrointestinal tract ultrastructural studies have demonstrated close apposition between enteric nerves and intramuscular interstitial cells of Cajal (ICC-IM) in the stomach and colon and ICC in the deep muscular plexus (ICC-DMP) of the small intestine. In the absence of ICC-IM, postjunctional neural responses are compromised. Although membrane specializations between nerves and ICC-IM have been reported, the molecular identity of these specializations has not been studied. Here we have characterized the expression and distribution of synapse-associated proteins between nerve terminals and ICC-IM in the murine stomach. Transcripts for the presynaptic proteins synaptotagmin, syntaxin, and SNAP-25 were detected. Synaptotagmin and SNAP-25-immunopositive nerve varicosities were concentrated in varicose regions of motor nerves and were closely apposed to ICC-IM but not smooth muscle. W/W(V) mice were used to examine the expression and distribution of synaptic proteins in the absence of ICC-IM. Transcripts encoding synaptotagmin, syntaxin, and SNAP-25 were detected in W/W(V) tissues. In the absence of ICC-IM, synaptotagmin and SNAP-25 were localized to nerve varicosities. Reverse transcriptase polymer chain reaction (RT-PCR) and immunohistochemistry demonstrated the expression of postsynaptic density proteins PSD-93 and PSD-95 in the stomach and expression levels of PSD-93 and PSD-95 were reduced in W/W(V) mutants. These data support the existence of synaptic specializations between enteric nerves and ICC-IM in gastric tissues. In the absence of ICC-IM, components of the synaptic vesicle docking and fusion machinery is trafficked and concentrated in enteric nerve terminals.
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Affiliation(s)
- Elizabeth A H Beckett
- Department of Physiology & Cell Biology, University of Nevada School of Medicine, Reno, Nevada 89557, USA
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20
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Mourad FH, Barada KA, Bou Rached NA, Khoury CI, Saadé NE, Nassar CF. Inhibitory effect of experimental colitis on fluid absorption in rat jejunum: role of the enteric nervous system, VIP, and nitric oxide. Am J Physiol Gastrointest Liver Physiol 2006; 290:G262-8. [PMID: 16123200 DOI: 10.1152/ajpgi.00271.2005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Impairment of small intestinal absorption has been described in patients with ulcerative colitis and in animal models of experimental colitis. The pathophysiology of this dysfunction has not been elucidated. The aim of this study was to investigate the effect of chemical colitis on jejunal fluid absorption and determine the role of the enteric nervous system and some putative neurotransmitters. In a rat model of iodoacetamide-induced colitis, jejunal net fluid absorption was evaluated by the in vivo single-pass perfusion technique. The effects of 1) tetrodotoxin (TTX), 2) benzylalkonium chloride (BAC), 3) capsaicin, 4) vasoactive intestinal polypeptide (VIP) antagonism, 5) nitric oxide (NO) synthase (NOS) inhibition, and 6) 5-hydroxytryptamine type 3 and 4 (5-HT(3) and 5-HT(4)) receptor antagonism on the changes in fluid movement were investigated. A significant decrease in jejunal net fluid absorption was found 2 and 4 days after colitis induction: 26 (SD 14) and 28 (SD 19) microl x min(-1) x g dry intestinal wt(-1), respectively [P < 0.0002 compared with sham rats at 61 (SD 6.5) microl x min(-1) x g dry intestinal wt(-1)]. No histological changes were evident in jejunal sections. TTX and BAC reversed this decrease in fluid absorption: 54 (SD 13) and 44 (SD 14) microl x min(-1) x g dry intestinal wt(-1) (P = 0.0005 and P = 0.019, respectively, compared with colitis). Ablation of capsaicin-sensitive primary afferent fibers had a partial effect: 45 (SD 5) microl x min(-1) x g dry intestinal wt(-1) (P = 0.001 and P = 0.003 compared with colitis and sham, respectively). Constitutive and neuronal NOS inhibition and VIP antagonism returned jejunal net fluid absorption to normal values: 66 (SD 19), 61 (SD 5), and 56 (SD 14) microl x min(-1) x g dry intestinal wt(-1), respectively. 5-HT(3) and 5-HT(4) receptor antagonism had no effect. Chemical colitis is associated with a significant decrease in jejunal net fluid absorption. This decrease is neurally mediated and involves VIP- and NO-related mechanisms.
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Affiliation(s)
- Fadi H Mourad
- American University of Beirut Medical Centre, PO Box 113-6044, Hamra 110-32090, Beirut, Lebanon.
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21
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Harmar AJ, Sheward WJ, Morrison CF, Waser B, Gugger M, Reubi JC. Distribution of the VPAC2 receptor in peripheral tissues of the mouse. Endocrinology 2004; 145:1203-10. [PMID: 14617572 DOI: 10.1210/en.2003-1058] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The neuropeptide vasoactive intestinal peptide (VIP) exerts its actions through two structurally related G protein-coupled receptors (VPAC(1) and VPAC(2)). Pituitary adenylate cyclase-activating polypeptide (PACAP) is also a potent agonist of VPAC(1) and VPAC(2) receptors as well as of a third, PACAP-specific receptor (PAC(1)). We report here the distribution of the VPAC(2) receptor in peripheral tissues of the mouse, determined by receptor autoradiography using [(125)I]VIP and the selective VPAC(2) receptor agonist [(125)I]Ro25-1553 in wild-type and VPAC(2) receptor-null mice. In addition, displacement experiments with the VPAC(2)-selective agonist Ro25-1553 and the VPAC(1)-selective agonist [K(15),R(16),L(27)]VIP(1-7)/GRF(8-27) were performed using the universal radioligand [(125)I]VIP. The VPAC(2) receptor is found predominantly in smooth muscle (in blood vessels and in the smooth muscle layers of the gastrointestinal and reproductive systems), the basal part of the mucosal epithelium in the colon, lung, the vasculature of the kidney, adrenal medulla, and retina. Unexpectedly, the receptor was also present in thyroid follicular cells and acinar cells of the pancreas, tissues that have not been found to express the receptor in other species, and in very large amounts in the lung. Our data suggest novel functions of the VPAC(2) receptor and additional potential therapeutic uses of drugs acting at the receptor (including the treatment of erectile dysfunction), but our results also indicate that caution should be exercised in using the mouse as an animal model for the evaluation of VIP analogs intended for diagnostic or therapeutic use in man.
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MESH Headings
- Animals
- Autoradiography
- Binding, Competitive
- Blood Vessels/metabolism
- Digestive System/metabolism
- Endocrine System/metabolism
- Epithelium/metabolism
- Lymphatic System/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Mutant Strains
- Muscle, Smooth/metabolism
- Peptide Fragments/metabolism
- Peptide Fragments/pharmacology
- Peptides, Cyclic/metabolism
- Peptides, Cyclic/pharmacology
- Radioligand Assay
- Receptors, Vasoactive Intestinal Peptide/agonists
- Receptors, Vasoactive Intestinal Peptide/genetics
- Receptors, Vasoactive Intestinal Peptide/metabolism
- Receptors, Vasoactive Intestinal Peptide, Type II
- Urogenital System/metabolism
- Vasoactive Intestinal Peptide/analogs & derivatives
- Vasoactive Intestinal Peptide/metabolism
- Vasoactive Intestinal Peptide/pharmacokinetics
- Vasoactive Intestinal Peptide/pharmacology
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Affiliation(s)
- Anthony J Harmar
- Division of Neuroscience, School of Biomedical and Clinical Laboratory Sciences, University of Edinburgh, United Kingdom EH8 9JZ.
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22
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Mourad FH, Barada KA, Abdel-Malak N, Bou Rached NA, Khoury CI, Saade NE, Nassar CF. Interplay between nitric oxide and vasoactive intestinal polypeptide in inducing fluid secretion in rat jejunum. J Physiol 2003; 550:863-71. [PMID: 12794180 PMCID: PMC2343080 DOI: 10.1113/jphysiol.2003.043737] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Nitric oxide (NO) and vasoactive intestinal polypeptide (VIP) interact in the regulation of neuromuscular function in the gut. They are also potent intestinal secretogogues that coexist in the enteric nervous system. The aims of this study were: (1) to investigate the interaction between NO and VIP in inducing fluid secretion in the rat jejunum, and (2) to determine whether the NO effect on intestinal fluid movement is neurally mediated. The single pass perfusion technique was used to study fluid movement in a 25 cm segment of rat jejunum in vivo. A solution containing 20 mM L-arginine, a NO precursor, was perfused into the segment. The effect of the NO synthase inhibitors (L-NAME and L-nitroindazole (L-NI)) and the VIP antagonist ([4Cl-D-Phe6,Leu17]VIP (VIPa)) on L-arginine-induced changes in fluid movement, expressed as microl min(-1) (g dry intestinal weight)(-1), was determined. In addition, the effect of neuronal blockade by tetrodotoxin (TTX) and ablation of the myenteric plexus by benzalkonium chloride (BAC) was studied. In parallel groups of rats, the effect of L-NAME and L-NI on VIP-induced intestinal fluid secretion was also examined. Basal fluid absorption in control rats was (median (interquartile range)) 65 (45-78). L-Arginine induced a significant fluid secretion (-14 (-20 to -5); P<0.01). This effect was reversed completely by L-NAME (60 (36-65); P<0.01) and L-NI (46 (39-75); P<0.01) and partially by VIPa (37 (14-47); P<0.01). TTX and BAC partially inhibited the effect of L-arginine (22 (15-32) and 15 (10-26), respectively; P<0.05). The effect of VIP on fluid movement (-23 (-26 to -14)) was partially reversed by L-NAME (24 (8.4-35.5); P<0.01) and L-NI (29 (4-44); P<0.01). The inhibition of VIP or NO synthase prevented L-arginine- and VIP-induced intestinal fluid secretion through a neural mechanism. The data suggest that NO enhances the release of VIP from nerve terminals and vice versa. Subsequently, each potentiates the other's effect in inducing intestinal fluid secretion.
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Affiliation(s)
- F H Mourad
- Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Lebanon.
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