Molecular Medicine Reports Molecular Medicine Reports 1791-2997 1791-3004 D.A. Spandidos 10.3892/mmr.2016.6023 mmr-15-01-0012 Articles Abnormalities in endocrine and immune cells are correlated in dextran-sulfate-sodium-induced colitis in rats El-SalhyMagdy 1 2 3 HatlebakkJan Gunnar 2 3 GiljaOdd Helge 2 3 4 Division of Gastroenterology, Department of Medicine, Stord Hospital, 5416 Stord, Norway Division of Gastroenterology, Department of Clinical Medicine, University of Bergen, 5020 Bergen, Norway National Centre for Functional Gastrointestinal Disorders, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway National Centre for Ultrasound in Gastroenterology, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway Correspondence to: Professor Magdy El-Salhy, Division for Gastroenterology, Department of Medicine, Stord Hospital, Box 4000, 5409 Stord, Norway, E-mail: magdy.el-salhy@helse-fonna.no 012017 12122016 15 1 12 20 13072016 25102016 Copyright: © El-Salhy et al. 2016 This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

The interaction between the gut hormones and the immune system has been suggested to serve an important role in the pathophysiology of inflammatory bowel disease. The aims of the present study were to elucidate the possible abnormalities in the colonic endocrine cells in rats with dextran sodium sulfate (DSS)-induced colitis, and to determine whether they are correlated with alterations in the immune cells. A total of 24 male Wistar rats were divided into two groups: Control and DSS-induced colitis. Colonic tissues were harvested via postmortem laparotomy from all of the animals at the end of the experimental period, and fixed and sectioned for histology. The colonic endocrine and immune cells in those tissue samples were immunostained and their densities quantified by computerized image analysis. The densities of chromogranin A, serotonin, peptide YY and oxyntomodulin cells were significantly higher, and those of pancreatic peptide and somatostatin cells were lower in rats with DSS-induced colitis than in the controls. The densities of mucosal leukocytes, T and B lymphocytes, macrophages/monocytes, and mast cells were significantly higher than in the controls, and these changes were closely associated with the aforementioned changes in all endocrine cell types. These observations indicate an interaction between intestinal hormones and the immune system as represented by immune cells.

 DSS colitis chromogranin A endocrine cells immune cells serotonin PYY Introduction

The etiology of inflammatory bowel disease (IBD) remains unclear (1–3). There are three main forms of IBD, ulcerative colitis (UC), Crohn's disease (CD) and microscopic colitis (MC), which exhibit differences in prevalence, clinical course and prognosis (3–6). While the onset of UC and CD occurs predominantly in individuals <40 years, the onset of MC occurs in those >60 years (3,7). In addition to the morbidity caused by IBD, it considerably reduces the quality of life of patients (3,5,6).

The gastrointestinal endocrine cells are a component of the local regulatory system of the gut, the neuroendocrine system (NES) (8), which also includes the enteric nervous system (8). The NES regulates gastrointestinal motility, secretion, absorption, cell proliferation, visceral sensitivity, local immune defense and appetite (8,9). Abnormalities in several intestinal endocrine cells have been reported in IBD (10–29). It is believed that the interaction between the hormones secreted by the gut endocrine cells and the immune system serve a major role in the pathophysiology of the IBD (30,31).

The primary aim of the present study was to establish the presence of abnormalities in the colonic endocrine cells following dextran sulfate sodium (DSS)-induced colitis in rats, which closely mimics human UC (32). Furthermore, the existence of a correlation between any colonic endocrine cell abnormalities and changes in the densities of various types of immune cells was determined.

 Materials and methods <sec> <title>Rats

A total 24 male Wistar rats (age, 12 weeks; Hannover GALAS; Taconic Biosciences, Lille Skensved, Denmark) with a mean body weight of 280 g (range, 231–380 g) were housed in Macrolon III cages with water and food available ad libitum. They were fed a standard diet (B & K Universal, Nittedal, Norway) consisting of cereal products (88.5%), soy protein (6%), animal protein (2.5%), soy oil (0.5%), and vitamin, mineral and amino-acid supplements (2.5%). The animals were maintained at a temperature of 21±1°C and a relative humidity of 55±5%, and under a 12/12-h light/dark cycle.

The animals were left to acclimatize in the animal house for 7 days prior to the experiment, and were then divided into 2 groups of 12 animals each: Control and DDS-induced colitis (DSS group). Animals in the control group were provided with normal drinking water for 7 days, while those in the DDS-colitis group were instead provided with distilled water containing 5% DSS (molecular weight, 40 kDa; prepared daily; TdB Consultancy AB, Uppsala, Sweden) for 7 days, according to a previously described protocol (33,34). All of the animals were monitored twice daily and were weighed once daily. Animals that showed any signs of pain were given a subcutaneous, 1 ml injection of Temgesic solution (containing 0.3 g/ml Temgesic; Merck Millipore, Darmstadt, Germany).

At the end of the 7-day period, the animals were sacrificed by CO2 inhalation, and the colon was dissected out via a postmortem laparotomy. Tissue samples were collected from the lower part of the colon for further, histopathological and immunohistochemical examinations.

The local ethical committee for the Protection of Vertebrate Animals used for Experimental and Other Scientific Purposes approved the study protocols (project no. 20124629).

 Histopathology and immunohistochemistry

The tissue samples were fixed overnight in 4% buffered paraformaldehyde, embedded in paraffin and then sectioned at a thickness of 5 mm. The sections were deparaffinized and then stained with hematoxylin-eosin, or immunostained using the ultraView Universal DAB Detection kit (version 1.02.0018, Ventana Medical Systems, Inc., Basel, Switzerland) and the BenchMark Ultra IHC/ISH staining module (Ventana Medical Systems, Inc.).

For immunostaining, the sections were incubated with one of the following primary antibodies for 32 min at 37°C: Monoclonal mouse anti-N-terminal of purified chromogranin A (CgA; cat. no. M869; Dako, Glostrup, Denmark) diluted 1:1,000, monoclonal mouse antiserotonin (cat. no. 5HT-209; Dako) diluted 1:1,200, polyclonal antiporcine peptide YY (PYY; cat. no. PYY 11A; Alpha Diagnostic International, San Antonio, TX, USA) diluted 1:1,400, polyclonal rabbit antisynthetic human pancreatic polypeptide (PP; cat. no. #114; Diagnostic BioSystems, Pleasanton, CA, USA) diluted 1:800, polyclonal rabbit antiporcine oxyntomodulin ‘glicentin/enteroglucagon’ (cat. no. BP508; Acris Antibodies GmbH, Herford, Germany) diluted 1:400, polyclonal rabbit antisynthetic human somatostatin (cat. no. A566; Dako) diluted 1:200, monoclonal mouse antihuman CD45 (cat. no. M0701; Dako) diluted 1:100, monoclonal mouse antihuman CD5 (cat. no. IS082; Dako) diluted 1:200, monoclonal mouse antihuman CD57 (cat. no. IS647; Dako) diluted 1:100, monoclonal mouse antihuman CD23 (cat. no. IS781; Dako) diluted 1:100, monoclonal mouse antihuman CD68 (cat. no. M0814; Dako) diluted 1:100 and monoclonal mouse antihuman mast-cell tryptase (cat. no. M7052; Dako) diluted 1:100. CD45 is considered a common leukocyte antigen and is expressed exclusively on cells of the hematopoietic system and their progenitors. CD5 is expressed on B and T lymphocytes, CD57 is expressed by subsets of natural killer cells and CD8+ lymphocytes, and by a small proportion of CD4+/CD45R0+ T lymphocytes, CD23 is expressed on B lymphocytes, CD68 labels human monocytes, macrophages, and myeloid cells, and mast-cell tryptase is expressed predominantly in mast cells (35).

 Quantification of endocrine and immune cells

The endocrine and immune cells were quantified by counting each cell type in 10 randomly chosen microscopic fields. Measurements were performed on a computer linked to a microscope (BX43; Olympus Corporation, Tokyo, Japan) that was equipped with a digital camera (DP26; Olympus Corporation), and using cellSens imaging software (version 1.7; Olympus Corporation). The number of endocrine cells in the epithelial lining of the intestinal lumen and immune cells in the lamina propria of each field were counted on a computer screen, and the area of the epithelial cells was determined by manual drawing using the computer mouse. A 40X objective was used, for which each frame (field) on the monitor represented a tissue area of 0.035 mm2. The data are presented as density measurements (i.e., the number of endocrine cells/mm2 epithelium, and the number of immune cells per field). Immunostained sections were coded and mixed, and measurements were made by the same person (Professor Magdy El-Salhy), who was blind to the identity of the sections.

 Statistical analysis

Differences between the control and DSS groups were tested using the Mann-Whitney nonparametric test. The existence of a correlation between abnormalities/alterations in the densities of endocrine cells and immune cells was determined using the nonparametric Spearman's correlation test. The data are presented as the mean ± standard error, and P<0.05 was considered to indicate a statistically significant difference.

 Results

The histopathological examinations of the colonic tissues produced normal results in the control group, whereas the DSS group had severe-to-moderate inflammation with disturbed mucosal architecture, crypt abscesses, edema, bleeding and infiltration of immune cells into the mucosa and submucosa.

<sec> <title>Endocrine cells

The densities of CgA, serotonin, PYY and enteroglucagon cells were all significantly higher in the DDS group (333.1±34.7, 61.8±6.5, 115.6±5.9 and 85.7±9.0 cells/mm2 epithelium, respectively) than in the control group (117.4±20.7, 40.7±5.5, 86.0±1.5 and 42.9±3.3 cells/mm2 epithelium; P<0.0001, P=0.0006, P=0.002 and P=0.0003, respectively; Figs. 1–3). Conversely, the densities of PP and somatostatin cells were significantly higher in the control group (62.4±3.1 and 43.4±3.2 cells/mm2 epithelium, respectively) than in the DSS group (40.3±3.7 and 28.6±2.7 cells/mm2 epithelium, respectively; P=0.0002 and 0.007, respectively; Figs. 1 and 4).

 Immune cells

The densities of all of the immune cell types were significantly higher in the DDS group than in the control group (Figs. 5–8): Leukocytes, 5.9±0.4 vs. 23.3±2.2 cells/field (P<0.0001); B/T lymphocytes, 7.8±0.8 vs. 23.8±1.6 cells/field (P<0.0001); T lymphocytes, 6.8±0.7 vs. 26.6±2.9 cells/field (P<0.0001); and B lymphocytes, 9.8±0.6 vs. 22.1±2.3 cells/field (P<0.0001).

 Correlation between endocrine and immune cells

The Spearman correlation coefficients and P-values between different endocrine cell types and various immune cells are summarized in Table I. The abnormalities in CgA, serotonin, PYY, and enteroglucagon cells were identified to be positively correlated with the alterations of all types of immune cells, while a negative correlation was observed for PP and somatostatin cells.

 Discussion

Animal models of IBD are either those with chemically induced colitis or mutant (knockout) mice (7,32,36–39). Although neither of these models accurately mimic human IBD, they are useful tools towards understanding the pathophysiological mechanisms underlying IBD (32). DSS-induced colitis is a mixed Th1/Th2 cytokine-mediated colitis (40,41) and is considered be a model for UC with clinical and morphological features similar to that of human UC (32,42,43). However, DSS-induced colitis lacks the chronicity seen in human UC (32).

The present study identified that the densities of all of the colonic endocrine cell types were affected in rats with DSS-induced colitis. Furthermore, the abnormalities in the colonic endocrine cells were closely correlated with the alterations in several immune-cell types following the induction of colitis. These observations lend support to the hypothesized role of gut hormones in immune activation and inflammation (30,31,44).

CgA belongs to the family of granins (45,46), and is localized to the stomach and small and large intestines (47–50). It is commonly used as a marker for gastrointestinal and endocrine tumor cells (51,52). The increase in CgA-immunoreactive cells observed in the present study could reflect an increase in the cell density of the total colonic endocrine cells following the induction of colitis. This observation is in line with the previously reported increases in CgA cells in UC and CD (10,23). However, CgA itself inhibits the vascular leakage caused by tumor necrosis factor α (53). Furthermore, CgA-derived peptides reduce the release of interleukin (IL)-16 and IL-5, hence reducing the number of lymphocytes at inflammatory sites and thus the proinflammatory action of lymphocytes and monocytes (54–56). The increase in the density of CgA cells reported herein was closely associated with the increase in immune cells. Taking into consideration the known interaction between CgA and immune cells, this increase in CgA density is likely a response defense mechanism against inflammation.

Serotonin is a potent hormone that exerts several effects at its numerous receptor types. Thus, it stimulates gastric and intestinal motility, modulates visceral sensitivity, and stimulates intestinal secretion (8,57). The present observation of an increased density of colonic serotonin cells in DSS-induced colitis relative to healthy controls is in agreement with previously published observations in patients with UC, CD and MC, and in animal models of colitis (10,12,58–60). However, additional studies identified that the serotonin cell density reduced in UC and remained unchanged in CD (61,62). It has been reported that serotonin serves an important role in intestinal inflammation (30,54). Thus, the number of serotonin cells has been reported to be reduced in mice lacking the T-lymphocyte receptors (54), IL-13 receptors have been localized on serotonin cells (63), and serotonin receptors have been observed in lymphocytes, monocytes, macrophages and dendritic cells (64). In addition, serotonin affects the proliferation of lymphocytes, protects natural killer cells, inhibits the apoptosis of immune cells, and promotes the recruitment of T cells (65–68). Thus, the fact that the increase in serotonin-cell density in DSS-induced colitis was to be closely associated with the increased densities of the immune-cell types was expected.

PYY and oxyntomodulin are colocalized in the same endocrine cell type (69,70). However, the degree of that colocalization differs according to the animal species (70). PYY delays gastric emptying, and is a key mediator of the ileal brake. It also inhibits gastric and pancreatic secretion, and stimulates the absorption of water and electrolytes (71). Oxyntomodulin has an incretin effect, inhibits gastric and pancreatic secretions, and reduces gastric motility (8). PYY and oxyntomodulin have been previously observed to exhibit anorexigenic effects (72), and the present observation of increased PYY and oxyntomodulin cell densities is in agreement with previous observations in UC and IL-2 gene knockout mice (10,59). Whereas the increase in the oxyntomodulin cell density identified is in line with previous observations in IL-2 knockout mice, it disagrees with observations in UC, where oxyntomodulin cell density was unchanged (10,59). The close correlation between the increase in PYY and oxyntomodulin cell densities with the increase in the densities of the immune cells identified in the current study indicates an interaction between the endocrine and immune systems.

PP stimulates gastric acid secretion and the motility of the stomach and small intestine, and relaxes the gallbladder (8). Somatostatin inhibits intestinal contraction, and gut exocrine and neuroendocrine secretions (8). In addition, somatostatin inhibits lymphocyte proliferation, immunoglobulin synthesis and neutrophil elastase release (73–77). The reduction in PP cell density observed in the present investigation is in line with what has been reported in UC and CD (10). Although the reduction in somatostatin cell density in DSS-induced colitis observed in the current study is also in line with previous publications on UC and CD (28,29), it is in disagreement with a study in which the density of somatostatin cells was observed to be unchanged in these conditions (10). As for the other endocrine cell types assessed in the current study, the correlation between the alterations in the PP and somatostatin cell densities points to their involvement in the inflammatory process.

A potential interaction is suggested between inflammation as indicated by the increase in immune cells and the colonic endocrine cells. It is possible that the increase in serotonin and the reduction in somatostatin cell densities results from inflammation, and that the changes in CgA, PYY, oxyntomodulin and PP cells are secondary responses to the changes in serotonin and somatostatin. Cytokines appear to serve a significant role in the proliferation and differentiation of intestinal stem cells (78–80). It is suggested that inflammation with increased cytokine production increases the serotonin and reduces the somatostatin cell densities by affecting their early progenitors, and that these alterations would result in increased gastrointestinal motility and secretion in addition to visceral hypersensitivity. As a compensatory defense, an increase in PYY and oxyntomodulin, and a reduction in PP would slow gastrointestinal motility and reduce gastrointestinal secretions. The increase in CgA, which appears to have anti-inflammatory effects, may simply reflect the total increase in colonic endocrine cells or another defensive action against inflammation (30).

The induction of colitis by DSS in rats affects all of the colonic endocrine cells. Given the available data on the interactions between hormones and the immune system, it can be hypothesized that inflammation induces the proliferation of serotonin cells and inhibits that of somatostatin cells, in response to which there is a secondary change in the densities of CgA, PYY, oxyntomodulin and PP cells. The close correlation between the changes in all endocrine cell types and immune cells emphasizes the importance of the role of interactions between the intestinal hormone and immune systems in the pathophysiology of intestinal inflammation.

 Acknowledgements

The current study was supported by grants from Helse-Fonna (grant no. 40415), and Helse-Vest (grant no. 911978), Norway.

 References DaneseSFiocchiCEtiopathogenesis of inflammatory bowel diseasesWorld J Gastroenterol12480748122006169374614087613 NunesTFiorinoGDaneseSSansMFamilial aggregation in inflammatory bowel disease: Is it genes or environment?World J Gastroenterol1727152722201110.3748/wjg.v17.i22.2715217347793123468 El-SalhyMGundersenDHatlebakkJGHauskenTClinical presentation, diagnosis, pathogenesis and treatment options for lymphocytic colitis (Review)Int J Mol Med32263270201323695201 PranteraCMarconiSGlucocorticosteroids in the treatment of inflammatory bowel disease and approaches to minimizing systemic activityTherap Adv Gastroenterol6137156201310.1177/1756283X12473675235039683589135 PodolskyDKInflammatory bowel diseaseN Engl J Med347417429200210.1056/NEJMra02083112167685 PodolskyDKThe current future understanding of inflammatory bowel diseaseBest Pract Res Clin Gastroenterol16933943200210.1053/bega.2002.035412473299 CarterMJLoboAJTravisSPIBD Section, British Society of Gastroenterology: Guidelines for the management of inflammatory bowel disease in adultsGut53Suppl 5V116200410.1136/gut.2004.043372153065691867788 El-SalhyMSeimIChopinLGundersenDHatlebakkJGHauskenTIrritable bowel syndrome: The role of gut neuroendocrine peptidesFront Biosci (Elite Ed)427832800201222652678 WuTRaynerCKYoungRLHorowitzMGut motility and enteroendocrine secretionCurr Opin Pharmacol13928934201310.1016/j.coph.2013.09.00224060702 El-SalhyMDanielssonAStenlingRGrimeliusLColonic endocrine cells in inflammatory bowel diseaseJ Intern Med242413419199710.1046/j.1365-2796.1997.00237.x9408072 El-SalhyMGundersenDHatlebakkJGHauskenTChromogranin a cell density as a diagnostic marker for lymphocytic colitisDig Dis Sci5731543159201210.1007/s10620-012-2249-6226993943505499 El-SalhyMGundersenDHatlebakkJGHauskenTHigh densities of serotonin and peptide YY cells in the colon of patients with lymphocytic colitisWorld J Gastroenterol1860706075201210.3748/wjg.v18.i42.6070231553353496883 El-SalhyMLomholt-BeckBGundersenTDHigh chromogranin A cell density in the colon of patients with lymphocytic colitisMol Med Rep4603605201121584496 MoranGWPennockJMcLaughlinJTEnteroendocrine cells in terminal ileal Crohn's diseaseJ Crohns Colitis6871880201210.1016/j.crohns.2012.01.01322398079 MoranGWLeslieFCMcLaughlinJTCrohn's disease affecting the small bowel is associated with reduced appetite and elevated levels of circulating gut peptidesClin Nutr32404411201310.1016/j.clnu.2012.08.02422999064 BestermanHSMallinsonCNModiglianiRChristofidesNDPeraAPontiVSarsonDLBloomSRGut hormones in inflammatory bowel diseaseScand J Gastroenterol18845852198310.3109/003655283091821046374867 El-SalhyMMazzawiTGundersenDHatlebakkJGHauskenTThe role of peptide YY in gastrointestinal diseases and disorders (review)Int J Mol Med312752822013232921454042877 HirotaniYMikajiriKIkedaKMyotokuMKurokawaNChanges of the peptide YY levels in the intestinal tissue of rats with experimental colitis following oral administration of mesalazine and prednisoloneYakugaku Zasshi12813471353200810.1248/yakushi.128.134718758150 Vona-DavisLCMcFaddenDWNPY family of hormones: Clinical relevance and potential use in gastrointestinal diseaseCurr Top Med Chem717101720200710.2174/15680260778234096617979780 El-SalhyMSuhrODanielssonAPeptide YY in gastrointestinal disordersPeptides23397402200210.1016/S0196-9781(01)00617-911825655 TariATeshimaHSumiiKHarumaKOhgoshiHYoshiharaMKajiyamaGMiyachiYPeptide YY abnormalities in patients with ulcerative colitisJpn J Med274955198810.2169/internalmedicine1962.27.493367539 SciolaVMassironiSConteDCaprioliFFerreroSCiafardiniCPeracchiMBardellaMTPiodiLPlasma chromogranin a in patients with inflammatory bowel diseaseInflamm Bowel Dis15867871200910.1002/ibd.2085119090560 BishopAEPietrolettiRTaatCWBrummelkampWHPolakJMIncreased populations of endocrine cells in Crohn's ileitisVirchows Arch A Pathol Anat Histopathol410391396198710.1007/BF007127583103321 ManochaMKhanWISerotonin and GI disorders: An update on clinical and experimental studiesClin Transl Gastroenterol3e13201210.1038/ctg.2012.8232382123365677 StoyanovaIIGulubovaMVMast cells and inflammatory mediators in chronic ulcerative colitisActa Histochem104185192200210.1078/0065-1281-0064112086339 YamamotoHMoriseKKusugamiKFurusawaAKonagayaTNishioYKanekoHUchidaKNagaiHMitsumaTNaguraHAbnormal neuropeptide concentration in rectal mucosa of patients with inflammatory bowel diseaseJ Gastroenterol31525532199610.1007/BF023550528844473 PayerJHuorkaMDurisIMikuleckyMKratochvílováHOndrejkaPLukácLPlasma somatostatin levels in ulcerative colitisHepatogastroenterology4155255319947721243 WatanabeTKubotaYSawadaTMutoTDistribution and quantification of somatostatin in inflammatory diseaseDis Colon Rectum35488494199210.1007/BF020494081348980 KochTRCarneyJAMorrisVAGoVLSomatostatin in the idiopathic inflammatory bowel diseasesDis Colon Rectum31198203198810.1007/BF025525462894935 KhanWIGhiaJEGut hormones: Emerging role in immune activation and inflammationClin Exp Immunol16119272010204088562940144 MargolisKGGershonMDNeuropeptides and inflammatory bowel diseaseCurr Opin Gastroenterol25503511200910.1097/MOG.0b013e328331b69e19816171 ElsonCOSartorRBTennysonGSRiddellRHExperimental models of inflammatory bowel diseaseGastroenterology10913441367199510.1016/0016-5085(95)90599-57557106 GrimstadTBjørndalBCacabelosDAasprongOGOmdalRSvardalABohovPPamplonaRPortero-OtinMBergeRKHauskenTA salmon peptide diet alleviates experimental colitis as compared with fish oilJ Nutr Sci2e2201310.1017/jns.2012.23251915684153328 StucchiAFShoferSLeemanSMaterneOBeerEMcClungJShebaniKMooreFO'BrienMBeckerJMNK-1 antagonist reduces colonic inflammation and oxidative stress in dextran sulfate-induced colitis in ratsAm J Physiol Gastrointest Liver Physiol279G1298G1306200011093954 El-SalhyMMazzawiTUmezawaKGiljaOHEnteroendocrine cells, stem cells and differentiation progenitors in rats with TNBS-induced colitisInt J Mol MedOct242016(Epub ahead of print) SalehMElsonCOExperimental inflammatory bowel disease: Insights into the host-microbiota dialogImmunity34293302201110.1016/j.immuni.2011.03.008214355843108903 SandsBENew therapies for the treatment of inflammatory bowel diseaseSurg Clin North Am8610451064200610.1016/j.suc.2006.05.00916905423 LopezABillioudVPeyrin-BirouletCPeyrin-BirouletLAdherence to anti-TNF therapy in inflammatory bowel diseases: A systematic reviewInflamm Bowel Dis1915281533201310.1097/MIB.0b013e31828132cb23518810 DaneseSSemeraroSArmuzziAPapaAGasbarriniABiological therapies for inflammatory bowel disease: Research drives clinicsMini Rev Med Chem6771784200610.2174/13895570677769862416842127 MotomuraYGhiaJEWangHAkihoHEl-SharkawyRTCollinsMWanYMcLaughlinJTKhanWIEnterochromaffin cell and 5-hydroxytryptamine responses to the same infectious agent differ in Th1 and Th2 dominant environmentsGut57475481200818198200 WirtzSNeufertCWeigmannBNeurathMFChemically induced mouse models of intestinal inflammationNat Protoc2541546200710.1038/nprot.2007.4117406617 DielemanLAPalmenMJAkolHBloemenaEPeñaASMeuwissenSGVan ReesEPChronic experimental colitis induced by dextran sulphate sodium (DSS) is characterized by Th1 and Th2 cytokinesClin Exp Immunol114385391199810.1046/j.1365-2249.1998.00728.x98440471905133 LowDNguyenDDMizoguchiEAnimal models of ulcerative colitis and their application in drug researchDrug Des Devel Ther7134113572013242502233829622 ÖhmanLTornblomHSimrénMCrosstalk at the mucosal border: Importance of the gut microenvironment in IBSNat Rev Gastroenterol Hepatol123649201525446728 BuffaRMaréPGiniASalvadoreMChromogranins A and B and secretogranin II in hormonally identified endocrine cells of the gut and the pancreasBasic Appl Histochem3247148419883223865 EidenLEIs chromogranin a prohormone?Nature325301198710.1038/325301a03808024 BuffaRCapellaCFontanaPUselliniLSolciaETypes of endocrine cells in the human colon and rectumCell Tissue Res1922272401978699014 CurryWJJohnstonCFHuttonJCArdenSDRutherfordNGShawCBuchananKDThe tissue distribution of rat chromogranin A-derived peptides: Evidence for differential tissue processing from sequence specific antiseraHistochemistry96531538199110.1007/BF002670791769862 Portela-GomesGMStridsbergMSelective processing of chromogranin A in the different islet cells in human pancreasJ Histochem Cytochem49483490200110.1177/00221554010490040811259451 Portela-GomesGMStridsbergMChromogranin A in the human gastrointestinal tract: An immunocytochemical study with region-specific antibodiesJ Histochem Cytochem5014871492200210.1177/00221554020500110812417614 TaupenotLHarperKLO'ConnorDTThe chromogranin-secretogranin familyN Engl J Med34811341149200310.1056/NEJMra02140512646671 WiedenmannBHuttnerWBSynaptophysin and chromogranins/secretogranins-widespread constituents of distinct types of neuroendocrine vesicles and new tools in tumor diagnosisVirchows Arch B Cell Pathol Incl Mol Pathol5895121198910.1007/BF028900622575822 FerreroEMagniECurnisFVillaAFerreroMECortiARegulation of endothelial cell shape and barrier function by chromogranin AAnn N Y Acad Sci971355358200210.1111/j.1749-6632.2002.tb04495.x12438151 SpillerRSerotonin and GI clinical disordersNeuropharmacology5510721080200810.1016/j.neuropharm.2008.07.01618687345 EggerMBeerAGTheurlMSchgoerWHotterBTatarczykTVasiljevicDFrauscherSMarksteinerJPatschJRMonocyte migration: A novel effect and signaling pathways of catestatinEur J Pharmacol598104111200810.1016/j.ejphar.2008.09.01618834877 FeistritzerCMosheimerBAColleselliDWiedermannCJKahlerCMEffects of the neuropeptide secretoneurin on natural killer cell migration and cytokine releaseRegul Pept126195201200510.1016/j.regpep.2004.10.00115664667 El-SalhyMGundersenDHatlebakkJGHauskenTIrritable bowel syndrome: Diagnosis, pathogenesis and treatment optionsNova Science Publishers, Inc.New York2012 BertrandPPBertrandRLSerotonin release and uptake in the gastrointestinal tractAuton Neurosci1534757201010.1016/j.autneu.2009.08.00219729349 QianBFEl-SalhyMMelgarSHammarstromMLDanielssonANeuroendocrine changes in colon of mice with a disrupted IL-2 geneClin Exp Immunol120424433200010.1046/j.1365-2249.2000.01255.x108445191905567 OshimaSFujimuraMFukimiyaMChanges in number of serotonin-containing cells and serotonin levels in the intestinal mucosa of rats with colitis induced by dextran sodium sulfateHistochem Cell Biol112257263199910.1007/s00418005044510550609 CoatesMDMahoneyCRLindenDRSampsonJEChenJBlaszykHCrowellMDSharkeyKAGershonMDMaweGMMosesPLMolecular defects in mucosal serotonin content and decreased serotonin reuptake transporter in ulcerative colitis and irritable bowel syndromeGastroenterology12616571664200410.1053/j.gastro.2004.03.01315188158 SjolundKSchaffalitzkyOBMuckadellDEFahrenkrugJHåkansonRPetersonBGSundlerFPeptide-containing nerve fibres in the gut wall in Crohn's diseaseGut24724733198310.1136/gut.24.8.72461920431420237 WangHSteedsJMotomuraYDengYVerma-GandhuMEl-SharkawyRTMcLaughlinJTGrencisRKKhanWICD4+ T cell-mediated immunological control of enterochromaffin cell hyperplasia and 5-hydroxytryptamine production in enteric infectionGut56949957200710.1136/gut.2006.103226173035971994360 Cloëz-TayaraniIChangeuxJPNicotine and serotonin in immune regulation and inflammatory processes: A perspectiveJ Leukoc Biol81599606200717108054 StefuljJCicin-SainLSchauensteinKJernejBSerotonin and immune response: Effect of the amine on in vitro proliferation of rat lymphocytesNeuroimmunomodulation9103108200110.1159/00004901311549892 BettenADahlgrenCHermodssonSHellstrandKSerotonin protects NK cells against oxidatively induced functional inhibition and apoptosisJ Leukoc Biol706572200111435487 LabergeSCruikshankWWBeerDJCenterDMSecretion of IL-16 (lymphocyte chemoattractant factor) from serotonin-stimulated CD8+ T cells in vitroJ Immunol15631031519968598478 SogaFKatohNInoueTKishimotoSSerotonin activates human monocytes and prevents apoptosisJ Invest Dermatol12719471955200710.1038/sj.jid.570082417429435 SpångéusAForsgrenSel-SalhyMDoes diabetic state affect co-localization of peptide YY and enteroglucagon in colonic endocrine cells?Histol Histopathol153741200010668193 PyarokhilAHIshiharaMSasakiMKitamuraNThe developmental plasticity of colocalization pattern of peptide YY and glucagon-like peptide-1 in the endocrine cells of bovine rectumBiomed Res333538201210.2220/biomedres.33.3522361884 El-SalhyMGundersenDGiljaOHHatlebakkJGHauskenTIs irritable bowel syndrome an organic disorder?World J Gastroenterol20384400201410.3748/wjg.v20.i2.384245747083923014 El-SalhyMGundersenDHatlebakkJGHauskenTDiet and irritable bowel syndrome, with a focus on appetite-regulating hormonesNutrition in the prevention and treatment of abdominal obesityWatsonRRElsevierSan Diego516G2014 PayanDGHessCAGoetzlEJInhibition by somatostatin of the proliferation of T-lymphocytes and Molt-4 lymphoblastsCell Immunol84433438198410.1016/0008-8749(84)90117-56142770 AdeyemiEOSavageAPBloomSRHodgsonHJSomatostatin inhibits neutrophil elastase release in vitroPeptides11869871199010.1016/0196-9781(90)90206-K2235686 StaniszAMBefusDBienenstockJDifferential effects of vasoactive intestinal peptide, substance P, and somatostatin on immunoglobulin synthesis and proliferations by lymphocytes from Peyer's patches, mesenteric lymph nodes, and spleenJ Immunol13615215619862415614 ScicchitanoRDazinPBienenstockJPayanDGStaniszAMDistribution of somatostatin receptors on murine spleen and Peyer's patch T and B lymphocytesBrain Behav Immun1173184198710.1016/0889-1591(87)90019-52898266 ScicchitanoRStaniszAMPayanDGKiyonoHMcGheeJRBienenstockJExpression of substance P and somatostatin receptors on a T helper cell lineAdv Exp Med Biol 216A1851901987 MontgomeryRKBreaultDTSmall intestinal stem cell markersJ Anat2135258200810.1111/j.1469-7580.2008.00925.x186380702475558 PottenCSStem cells in gastrointestinal epithelium: Numbers, characteristics and deathPhilos Trans R Soc Lond B Biol Sci353821830199810.1098/rstb.1998.024696842791692280 PottenCSInterleukin-11 protects the clonogenic stem cells in murine small-intestinal crypts from impairment of their reproductive capacity by radiationInt J Cancer62356361199510.1002/ijc.29106203217628879

Densities of various endocrine cell types: (A) Chromogranin A; (B) serotonin; (C) PYY; (D) enteroglucan; (E) PP and (F) somatostatin, in the controls and in rats with DSS-induced colitis. **P<0.01, ***P<0.001, ****P<0.0001 vs. controls. DSS, dextran-sulfate-sodium; SEM, standard error of the mean; PP, pancreatic peptide; PYY, peptide YY.

Chromogranin A (CgA)-immunoreactive-cells in (A) a control and in (B) a rat with DSS-induced colitis.

Peptide YY cells in (A) a control rat and (B) in a rat with DSS-induced colitis.

Somatostatin cells in the colon of (A) a control rat, and (B) in a rat with DSS-induced colitis.

Densities of different types of immune cells: (A) Leukocytes; (B) B and T lymphocytes; (C) T lymphocytes; (D) B lymphocytes; (E) macrophages/monocytes and (F) mast cells in the lamina propria of control rats and rats with DSS-induced colitis. ****P<0.0001 vs. controls. DSS, dextran-sulfate-sodium.

Submucosal leukocytes in (A) a control rat and (B) in a rat with DSS-induced colitis.

B/T lymphocytes in the submucosa of (A) a control rat and in (B) a rat with DSS-induced colitis.

Submucosal mast cells in (A) a control rat and in (B) a rat with DSS-induced colitis.

Summary of the Spearman correlation coefficient (r) and P values between different endocrine cell types and various immune cells.

Immune cell type
Endocrine cell type Leukocytes B/T lymphocytes T lymphocytes B lymphocytes Macrophages/monocytes Mast cells
Chromogranin A r=0.8 r=0.7 r=0.6 r=0.7 r=0.8 r=0.7
P=0.006 P=0.009 P=0.03 P=0.008 P=0.0009 P=0.008
Serotonin r=0.7 r=0.7 r=0.8 r=0.8 r=0.8 r=0.7
P=0.007 P=0.004 P=0.004 P=0.006 P=0.004 P=0.008
Peptide YY r=0.6 r=0.6 r=0.7 r=0.6 r=0.7 r=0.7
P=0.03 P=0.04 P=0.02 P=0.03 P=0.02 P=0.02
Enteroglucagon r=0.6 r=0.8 r=0.8 r=0.7 r=0.7 r=0.9
P=0.04 P=0.006 P=0.006 P=0.02 P=0.02 P=0.0005
Pancreatic peptide r=−0.7 r=−0.7 r=−0.8 r=0.7 r=−0.7 r=0.7
P=0.006 P=0.007 P=0.001 P=0.01 P=0.006 P=0.006
Somatostatin r=−0.7 r=−0.6 r=−0.6 r=−0.8 r=−0.5 r=−0.8
P=0.01 P=0.02 P=0.02 P=0.0009 P=0.006 P=0.0007