Publications by authors named "Iveta Grants"

12 Publications

  • Page 1 of 1

A novel P2X2-dependent purinergic mechanism of enteric gliosis in intestinal inflammation.

EMBO Mol Med 2021 Jan 17;13(1):e12724. Epub 2020 Dec 17.

Department of Surgery, University of Bonn, Bonn, Germany.

Enteric glial cells (EGC) modulate motility, maintain gut homeostasis, and contribute to neuroinflammation in intestinal diseases and motility disorders. Damage induces a reactive glial phenotype known as "gliosis", but the molecular identity of the inducing mechanism and triggers of "enteric gliosis" are poorly understood. We tested the hypothesis that surgical trauma during intestinal surgery triggers ATP release that drives enteric gliosis and inflammation leading to impaired motility in postoperative ileus (POI). ATP activation of a p38-dependent MAPK pathway triggers cytokine release and a gliosis phenotype in murine (and human) EGCs. Receptor antagonism and genetic depletion studies revealed P2X2 as the relevant ATP receptor and pharmacological screenings identified ambroxol as a novel P2X2 antagonist. Ambroxol prevented ATP-induced enteric gliosis, inflammation, and protected against dysmotility, while abrogating enteric gliosis in human intestine exposed to surgical trauma. We identified a novel pathogenic P2X2-dependent pathway of ATP-induced enteric gliosis, inflammation and dysmotility in humans and mice. Interventions that block enteric glial P2X2 receptors during trauma may represent a novel therapy in treating POI and immune-driven intestinal motility disorders.
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http://dx.doi.org/10.15252/emmm.202012724DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7799361PMC
January 2021

Histamine-dependent interactions between mast cells, glia, and neurons are altered following early-life adversity in mice and humans.

Am J Physiol Gastrointest Liver Physiol 2020 12 30;319(6):G655-G668. Epub 2020 Sep 30.

Department of Physiology, Michigan State University, East Lansing, Michigan.

Early-life adversity contributes to the development of functional bowel disorders later in life through unresolved mechanisms. Here, we tested the hypothesis that early-life adversity alters anatomical and functional interactions between mast cells and enteric glia. The effects of early-life stress were studied using the neonatal maternal separation (NMS) stress mouse model. Anatomical relationships between mast cells and enteric glia were assessed using immunohistochemistry and mast cell reporter mice (;). Immunohistochemistry was used to assess the expression of histamine, histamine 1 (H1) receptors, and glial fibrillary acidic protein. Functional responses of glia to mast cell mediators were assessed in calcium imaging experiments using ; mice and cultured human enteric glial cells. NMS increases mast cell numbers at the level of the myenteric plexus and their proximity to myenteric ganglia. Myenteric glia respond to mediators released by activated mast cells that are blocked by H1 receptor antagonists in mice and humans and by blocking neuronal activity with tetrodotoxin in mouse tissue. Histamine replicates the effects of mast cell supernatants on enteric glia, and NMS increases histamine production by mast cells. NMS reduces glial responses to mast cell mediators in mouse tissue, while potentiating responses in cultured human enteric glia. NMS increases myenteric glial fibrillary acidic protein expression and reduces glial process length but does not cause neurodegeneration. Histamine receptor expression is not altered by NMS and is localized to neurons in mice, but glia in humans. Early-life stress increases the potential for interactions between enteric glia and mast cells, and histamine is a potential mediator of mast cell-glial interactions through H1 receptors. We propose that glial-mast cell signaling is a mechanism that contributes to enteric neuroplasticity driven by early-life adversity. Early-life adversity places an individual at risk for developing functional gastrointestinal disorders later in life through unknown mechanisms. Here, we show that interactions between mast cells and glia are disrupted by early-life stress in mice and that histamine is a potential mediator of mast cell-glial interactions.
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http://dx.doi.org/10.1152/ajpgi.00041.2020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7792668PMC
December 2020

Enteric Glia Modulate Macrophage Phenotype and Visceral Sensitivity following Inflammation.

Cell Rep 2020 09;32(10):108100

Department of Physiology and Neuroscience Program, Michigan State University, 567 Wilson Road, East Lansing, MI 48824, USA. Electronic address:

Mechanisms resulting in abdominal pain include altered neuro-immune interactions in the gastrointestinal tract, but the signaling processes that link immune activation with visceral hypersensitivity are unresolved. We hypothesized that enteric glia link the neural and immune systems of the gut and that communication between enteric glia and immune cells modulates the development of visceral hypersensitivity. To this end, we manipulated a major mechanism of glial intercellular communication that requires connexin-43 and assessed the effects on acute and chronic inflammation, visceral hypersensitivity, and immune responses. Deleting connexin-43 in glia protected against the development of visceral hypersensitivity following chronic colitis. Mechanistically, the protective effects of glial manipulation were mediated by disrupting the glial-mediated activation of macrophages through the macrophage colony-stimulating factor. Collectively, our data identified enteric glia as a critical link between gastrointestinal neural and immune systems that could be harnessed by therapies to ameliorate abdominal pain.
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http://dx.doi.org/10.1016/j.celrep.2020.108100DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7518300PMC
September 2020

Clopidogrel IBS Patients Have Higher Incidence of Gastrointestinal Symptoms Influenced by Age and Gender.

Dig Dis Sci 2017 10 24;62(10):2728-2743. Epub 2017 Aug 24.

Department of Anesthesiology, The Wexner Medical Center, The Ohio State University, 420 West 12th Ave, Room 226, Columbus, OH, 43210, USA.

Background: Clopidogrel is an irreversible antagonist of P2Y receptors (P2YRs) used as an antiplatelet drug to reduce risk of thrombosis. P2YRs are expressed in gastrointestinal (GI) tract where they might regulate GI function.

Aim: To evaluate if blockade of P2YRs by clopidogrel is associated with higher incidence of GI symptoms in patients with irritable bowel syndrome (IBS).

Methods: A retrospective analysis of our institutional database was conducted for a 13-year period. IBS patients were identified, and their demographics, GI symptoms and clopidogrel therapy were collected. Logistic regression models were used to characterize symptoms in clopidogrel versus no-clopidogrel IBS-groups, adjusting for Age and Sex differences. An additional study characterized the P2YR distribution in human gut.

Results: The search identified 7217 IBS patients (6761 no-clopidogrel/456 clopidogrel). There were a higher proportion of patients with GI symptoms on clopidogrel (68%) compared to controls (60%, p = 0.0011) that were Females (70 vs. 60%, p = 0.0003) not Males (61 vs. 60%; p = 0.8312). In Females, clopidogrel was associated with higher incidence of GI symptoms (Age adjusted; p < 0.0001) for pain, constipation, gastroparesis (p ≤ 0.0001) and psychogenic pain (p = 0.0006). Age or Sex (adjusted models) influenced one or more GI symptoms (i.e., pain, p < 0.0001; constipation, p < 0.0001/p = 0.008; diarrhea, flatulence, p = 0.01). P2YR immunoreactivity was abundant in human ENS; glial-to-neuron ratio of P2YRs expressed in Females ≫ Males.

Conclusions: Irreversible blockade of P2YR by clopidogrel is associated with higher incidence of GI symptoms in Female IBS patients, although Age or Sex alone contributes to symptomatology. Prospective studies can determine clinical implications of P2YRs in IBS.
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http://dx.doi.org/10.1007/s10620-017-4707-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6075816PMC
October 2017

UTP - Gated Signaling Pathways of 5-HT Release from BON Cells as a Model of Human Enterochromaffin Cells.

Front Pharmacol 2017 13;8:429. Epub 2017 Jul 13.

Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, ColumbusOH, United States.

Enterochromaffin cells (EC) synthesize and release 5-HT and ATP to trigger or modulate gut neural reflexes and transmit information about visceral/pain sensation. Alterations in 5-HT signaling mechanisms may contribute to the pathogenesis of IBD or IBS, but the pharmacologic or molecular mechanisms modulating Ca-dependent 5-HT release are not understood. Previous studies indicated that purinergic signaling via ATP and ADP is an important mechanism in modulation of 5-HT release. However, EC cells also respond to UTP and UDP suggesting uridine triphosphate receptor and signaling pathways are involved as well. We tested the hypothesis that UTP is a regulator of 5-HT release in human EC cells. UTP signaling mechanisms were studied in BON cells, a human EC model, using Fluo-4/Caimaging, patch-clamp, pharmacological analysis, immunohistochemistry, western blots and qPCR. 5-HT release was monitored in BON or EC isolated from human gut surgical specimens (hEC). UTP, UTPγS, UDP or ATP induced Caoscillations in BON. UTP evoked a biphasic concentration-dependent Caresponse. Cells responded in the order of UTP, ATP > UTPγS > UDP >> MRS2768, BzATP, α,β-MeATP > MRS2365, MRS2690, and NF546. Different proportions of cells activated by UTP and ATP also responded to UTPγS (P2Y, 50% cells), UDP (P2Y, 30%), UTPγS and UDP (14%) or MRS2768 (<3%). UTP Caresponses were blocked with inhibitors of PLC, IP3R, SERCA Capump, Lasensitive Cachannels or chelation of intracellular free Ca by BAPTA/AM. Inhibitors of L-type, TRPC, ryanodine-Capools, PI3-Kinase, PKC or SRC-Kinase had no effect. UTP stimulated voltage-sensitive Cacurrents (I), V-depolarization and inhibited I (not I) currents. An I7.2/7.3 K channel blocker XE-991 mimicked UTP-induced V-depolarization and blocked UTP-responses. XE-991 blocked I and UTP caused further reduction. La or PLC inhibitors blocked UTP depolarization; PKC inhibitors, thapsigargin or zero Cabuffer did not. UTP stimulated 5-HT release in hEC expressing TPH1, 5-HT, P2Y/P2YR. Zero-Cabuffer augmented Caresponses and 5-HT release. UTP activates a predominant P2YR pathway to trigger Caoscillations via internal Camobilization through a PLC/IP/IP3R/SERCA Casignaling pathway to stimulate 5-HT release; Cainflux is inhibitory. UTP-induced V-depolarization depends on PLC signaling and an unidentified K channel (which appears independent of Caoscillations or I/VOCC). UTP-gated signaling pathways triggered by activation of P2YR stimulate 5-HT release.
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http://dx.doi.org/10.3389/fphar.2017.00429DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5508028PMC
July 2017

Molecular Signaling and Dysfunction of the Human Reactive Enteric Glial Cell Phenotype: Implications for GI Infection, IBD, POI, Neurological, Motility, and GI Disorders.

Inflamm Bowel Dis 2016 08;22(8):1812-34

*Department of Anesthesiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio;†Gastroenterological Unit, Department of Clinical and Experimental Medicine, "Federico II" University of Naples, Naples, Italy;‡Department of Surgery, Wexner Medical Center, The Ohio State University, Columbus, Ohio;§Department of Internal Medicine, Wexner Medical Center, The Ohio State University, Columbus, Ohio;‖Center for Biostatistics, Wexner Medical Center, The Ohio State University, Columbus, Ohio;¶Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio; and**Nationwide Children's Hospital, Department of Anesthesiology and Pain Medicine, Columbus, Ohio.

Background: Clinical observations or animal studies implicate enteric glial cells in motility disorders, irritable bowel syndrome, inflammatory bowel disease, gastrointestinal (GI) infections, postoperative ileus, and slow transit constipation. Mechanisms underlying glial responses to inflammation in human GI tract are not understood. Our goal was to identify the "reactive human enteric glial cell (rhEGC) phenotype" induced by inflammation, and probe its functional relevance.

Methods: Human enteric glial cells in culture from 15 GI-surgical specimens were used to study gene expression, Ca, and purinergic signaling by Ca/fluo-4 imaging and mechanosensitivity. A nanostring panel of 107 genes was designed as a read out of inflammation, transcription, purinergic signaling, vesicular transport protein, channel, antioxidant, and other pathways. A 24-hour treatment with lipopolysaccharide (200 μg/mL) and interferon-γ (10 μg/mL) was used to induce inflammation and study molecular signaling, flow-dependent Ca responses from 3 mL/min to 10 mL/min, adenosine triphosphate (ATP) release, and ATP responses.

Results: Treatment induced a "rhEGC phenotype" and caused up-regulation in messenger RNA transcripts of 58% of 107 genes analyzed. Regulated genes included inflammatory genes (54%/IP10; IFN-γ; CxCl2; CCL3; CCL2; C3; s100B; IL-1β; IL-2R; TNF-α; IL-4; IL-6; IL-8; IL-10; IL-12A; IL-17A; IL-22; and IL-33), purine-genes (52%/AdoR2A; AdoR2B; P2RY1; P2RY2; P2RY6; P2RX3; P2RX7; AMPD3; ENTPD2; ENTPD3; and NADSYN1), channels (40%/Panx1; CHRNA7; TRPV1; and TRPA1), vesicular transporters (SYT1, SYT2, SNAP25, and SYP), transcription factors (relA/relB, SOCS3, STAT3, GATA_3, and FOXP3), growth factors (IGFBP5 and GMCSF), antioxidant genes (SOD2 and HMOX1), and enzymes (NOS2; TPH2; and CASP3) (P < 0.0001). Treatment disrupted Ca signaling, ATP, and mechanical/flow-dependent Ca responses in human enteric glial cells. ATP release increased 5-fold and s100B decreased 33%.

Conclusions: The "rhEGC phenotype" is identified by a complex cascade of pro-inflammatory pathways leading to alterations of important molecular and functional signaling pathways (Ca, purinergic, and mechanosensory) that could disrupt GI motility. Inflammation induced a "purinergic switch" from ATP to adenosine diphosphate/adenosine/uridine triphosphate signaling. Findings have implications for GI infection, inflammatory bowel disease, postoperative ileus, motility, and GI disorders.
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http://dx.doi.org/10.1097/MIB.0000000000000854DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4993196PMC
August 2016

Purinergic autocrine regulation of mechanosensitivity and serotonin release in a human EC model: ATP-gated P2X3 channels in EC are downregulated in ulcerative colitis.

Inflamm Bowel Dis 2013 Oct;19(11):2366-79

Departments of *Anesthesiology and †Pathology, The Wexner Medical Center at The Ohio State University, Columbus, Ohio; ‡Center for Perinatal Research, §Division of Pediatric Gastroenterology, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio; and ‖Departments of Surgery and **Neuroscience, The Wexner Medical Center at The Ohio State University, Columbus, Ohio.

Background: Alterations in 5-hydroxytryptamine (HT) signaling in inflamed gut may contribute to pathogenesis of inflammatory bowel diseases. Adenosine 5'-triphosphate (ATP) regulates mucosal-mechanosensory reflexes and ATP receptors are sensitive to mucosal inflammation. Yet, it remains unknown whether ATP can modulate 5-HT signaling in enterochromaffin cells (EC). We tested the novel purinergic hypothesis that ATP is a critical autocrine regulator of EC mechanosensitivity and whether EC expression of ATP-gated P2X3-ion channels is altered in inflammatory bowel diseases.

Methods: Laser confocal (fluo-4) Ca imaging was performed in 1947 BON cells. Chemical stimulation or mechanical stimulation (MS) was used to study 5-HT or ATP release in human BON or surgical mucosal specimens, and purine receptors by reverse transcription-polymerase chain reaction, Western Blot, or P2X3-immunoreactivity in BON or 5-HT human EC (hEC) in 11 control and 10 severely inflamed ulcerative colitis (UC) cases.

Results: ATP or MS triggered Ca-transients or 5-HT release in BON. ATP or adenosine diphosphate increased 5-HT release 5-fold. MS caused ATP release, detected after 5'ecto-ATPase inhibition by ARL67156. ARL67156 augmented and apyrase blocked Ca/5-HT mechanosensitive responses. 2-Methyl-thio-adenosine diphosphate 5'-monophosphate-evoked (P2Y1,12) or mechanically-evoked responses were blocked or augmented by a P2Y1,12 antagonist, MRS2179, in different cells or inhibited by U73122. A P2Y12 antagonist, 2MeSAMP, augmented responses. A P2X1,3 agonist, α,β-MeATP, triggered Ca responses, whereas a P2X1,2/3,3 antagonist, 2',3'-O-(2,4,6-trinitrophenyl)-ATP, blocked mechanical responses or cell-surface 5'ATP- labeling. In hEC, α,β-MeATP stimulated 5-HT release. In UC, P2X3-immunoreactivity decreased from 15% to 0.2% of 5-HThECs. Human mucosa and BON expressed P2X1, P2X3, P2X4, P2X5, P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, and P2Y12R-messenger RNA transcripts.

Conclusions: ATP is a critical determinant of mechanosensation and 5-HT release via autocrine activation of slow P2Y1-phospholipase C/inositol-1,4,5-triphosphate-Ca or inhibitory P2Y12-purinergic pathways, and fast ATP-gated P2X3-channels. UC downregulation of P2X3-channels (or A2B) is postulated to mediate abnormal 5-HT signaling.
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http://dx.doi.org/10.1097/MIB.0b013e31829ecf4dDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4037929PMC
October 2013

Impact of disrupting adenosine A₃ receptors (A₃⁻/⁻ AR) on colonic motility or progression of colitis in the mouse.

Inflamm Bowel Dis 2011 Aug 3;17(8):1698-713. Epub 2010 Dec 3.

Department of Anesthesiology, Ohio State University, Columbus, Ohio.

Background: Pharmacological studies suggest that adenosine A₃AR influences motility and colitis. Functional A₃⁻/⁻AR knockout mice were used to prove whether A₃AR activation is involved in modulating either motility or colitis.

Methods: A₃AR was probed by polymerase chain reaction (PCR) genotyping, Western blot, and immunochemistry. Motility was assessed in vivo by artificial bead-expulsion, stool-frequency, and FITC-dextran transit. Colitis was induced with dextran sodium sulfate (DSS) in A₃⁻/⁻AR or wildtype (WT) age- and sex-matched controls. Progression of colitis was evaluated by histopathology, changes in myeloperoxidase (MPO), colon length, CD4(+) -cells, weight-loss, diarrhea, and the guaiac test.

Results: Goat anti-hu-A₃ antiserum identified a 66 kDa immunogenic band in colon. A₃AR-immunoreactivity is expressed in SYN(+) -nerve varicosities, s-100(+) -glia, and crypt cells, but not 5-HT(+) (EC), CD4(+) (T), tryptase(+) (MC), or muscle cells. A₃AR immunoreactivity in myenteric ganglia of distal colon >> proximal colon by a ratio of 2:1. Intestinal transit and bead expulsion were accelerated in A₃⁻/⁻AR mice compared to WT; stool retention was lower by 40%-60% and stool frequency by 67%. DSS downregulated A₃AR in epithelia. DSS histopathology scores indicated less mucosal damage in AA₃⁻/⁻AR mice than WT. A₃⁻/⁻AR phenotype protected against DSS-induced weight loss, neutrophil (MPO), or CD4(+) -T cell infiltration, colon shortening, change in splenic weight, diarrhea, or occult-fecal blood.

Conclusions: Functional disruption of A₃AR in A₃⁻/⁻AR mice alters intestinal motility. We postulate that ongoing release of adenosine and activation of presynaptic-inhibitory A₃AR can slow down transit and inhibit the defecation reflex. A₃AR may be involved in gliotransmission. In separate studies, A₃⁻/⁻AR protects against DSS colitis, consistent with a novel hypothesis that A₃AR activation contributes to development of colitis.
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http://dx.doi.org/10.1002/ibd.21553DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3116114PMC
August 2011

Activation of adenosine low-affinity A3 receptors inhibits the enteric short interplexus neural circuit triggered by histamine.

Am J Physiol Gastrointest Liver Physiol 2009 Dec 1;297(6):G1147-62. Epub 2009 Oct 1.

Dept. of Anesthesiology, The Ohio State Univ., Columbus, 43210, USA.

We tested the novel hypothesis that endogenous adenosine (eADO) activates low-affinity A3 receptors in a model of neurogenic diarrhea in the guinea pig colon. Dimaprit activation of H2 receptors was used to trigger a cyclic coordinated response of contraction and Cl(-) secretion. Contraction-relaxation was monitored by sonomicrometry (via intracrystal distance) simultaneously with short-circuit current (I(sc), Cl(-) secretion). The short interplexus reflex coordinated response was attenuated or abolished by antagonists at H2 (cimetidine), 5-hydroxytryptamine 4 receptor (RS39604), neurokinin-1 receptor (GR82334), or nicotinic (mecamylamine) receptors. The A1 agonist 2-chloro-N(6)-cyclopentyladenosine (CCPA) abolished coordinated responses, and A1 antagonists could restore normal responses. A1-selective antagonists alone [8-cyclopentyltheophylline (CPT), 1,3-dipropyl-8-(2-amino-4-chlorophenyl)xanthine (PACPX), or 8-cyclopentyl-N(3)-[3-(4-(fluorosulfonyl)benzoyloxy)propyl]-xanthine (FSCPX)] caused a concentration-dependent augmentation of crypt cell secretion or contraction and acted at nanomolar concentrations. The A3 agonist N(6)-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (IB-MECA) abolished coordinated responses and the A3 antagonist 3-ethyl-5-benzyl-2-methyl-4-phenylethynyl-6-phenyl-1,4-(+/-)-dihydropyridine-3,5-dicarboxylate (MRS1191) could restore and further augment responses. The IB-MECA effect was resistant to knockdown of adenosine A1 receptor with the irreversible antagonist FSCPX; the IC(50) for IB-MECA was 0.8 microM. MRS1191 alone could augment or unmask coordinated responses to dimaprit, and IB-MECA suppressed them. MRS1191 augmented distension-evoked reflex I(sc) responses. Adenosine deaminase mimicked actions of adenosine receptor antagonists. A3 receptor immunoreactivity was differentially expressed in enteric neurons of different parts of colon. After tetrodotoxin, IB-MECA caused circular muscle relaxation. The data support the novel concept that eADO acts at low-affinity A3 receptors in addition to high-affinity A1 receptors to suppress coordinated responses triggered by immune-histamine H2 receptor activation. The short interplexus circuit activated by histamine involves adenosine, acetylcholine, substance P, and serotonin. We postulate that A3 receptor modulation may occur in gut inflammatory diseases or allergic responses involving mast cell and histamine release.
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http://dx.doi.org/10.1152/ajpgi.00295.2009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2850084PMC
December 2009

New bioinformatics approach to analyze gene expressions and signaling pathways reveals unique purine gene dysregulation profiles that distinguish between CD and UC.

Inflamm Bowel Dis 2009 Jul;15(7):971-84

Department of Bioinformatics, Ohio State University, Columbus, Ohio 43210, USA.

Background: Expression of purine genes is modulated by inflammation or experimental colitis and altered expression leads to disrupted gut function. We studied purine gene dysregulation profiles in inflammatory bowel disease (IBD) and determined whether they can distinguish between Crohn's disease (CD) and ulcerative colitis (UC) using Pathway Analysis and a new Comparative Analysis of Gene Expression and Selection (CAGES) method.

Methods: Raw datasets for 22 purine genes and 36 probe-sets from National Center for Biotechnology Information (NCBI) GEO (Gene Expression Omnibus) (http://www.ncbi.nlm.nih.gov/projects/geo/) were analyzed by National Cancer Institute (NCI) Biological Resources Branch (BRB) array tools for random-variance of multiple/36 t-tests in colonic mucosal biopsies or peripheral blood mononuclear cells (PBMCs) of CD, UC or control subjects. Dysregulation occurs in 59% of purine genes in IBD including ADORA3, CD73, ADORA2A, ADORA2B, ADAR, AMPD2, AMPD3, DPP4, P2RY5, P2RY6, P2RY13, P2RY14, and P2RX5.

Results: In CD biopsies, expression of ADORA3, AMPD3, P2RY13, and P2RY5 were negatively correlated with acute inflammatory score, Crohn's Disease Activity Index (CDAI) or disease chronicity; P2RY14 was positively correlated in UC. In mucosal biopsies or PBMCs, CD and UC were distinguished by unique patterns of dysregulation (up- or downregulation) in purine genes. Purine gene dysregulation differs between PBMCs and biopsies and possibly between sexes for each disease. Ingenuity Pathway Analysis (IPA) revealed significant associations between alterations in the expression of CD73 (upregulation) or ADORA3 (downregulation) and inflammatory or purine genes (
Conclusion: CAGES and Pathway Analysis provided novel evidence that UC and CD have distinct purine gene dysregulation signatures in association with inflammation, cAMP, or other signaling pathways. Disease-specific purine gene signature profiles and pathway associations may be of therapeutic, diagnostic, and functional relevance.
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http://dx.doi.org/10.1002/ibd.20893DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2697273PMC
July 2009

ADOA3R as a therapeutic target in experimental colitis: proof by validated high-density oligonucleotide microarray analysis.

Inflamm Bowel Dis 2006 Aug;12(8):766-89

Departments of Anesthesiology, and Cardiothoracic Surgery, Ball State University, Muncie, Indiana, USA.

Adenosine A3 receptors (ADOA3Rs) are emerging as novel purinergic targets for treatment of inflammatory diseases. Our goal was to assess the protective effect of the ADOA3R agonist N(6)-(3-iodobenzyl)-adenosine-5-N-methyluronamide (IB-MECA) on gene dysregulation and injury in a rat chronic model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)--induced colitis. It was necessary to develop and validate a microarray technique for testing the protective effects of purine-based drugs in experimental inflammatory bowel disease. High-density oligonucleotide microarray analysis of gene dysregulation was assessed in colons from normal, TNBS-treated (7 days), and oral IB-MECA-treated rats (1.5 mg/kg b.i.d.) using a rat RNU34 neural GeneChip of 724 genes and SYBR green polymerase chain reaction. Analysis included clinical evaluation, weight loss assessment, and electron paramagnetic resonance imaging/spin-trap monitoring of free radicals. Remarkable colitis-induced gene dysregulation occurs in the most exceptional cluster of 5.4% of the gene pool, revealing 2 modes of colitis-related dysregulation. Downregulation occurs in membrane transporter, mitogen-activated protein (MAP) kinase, and channel genes. Upregulation occurs in chemokine, cytokine/inflammatory, stress, growth factor, intracellular signaling, receptor, heat shock protein, retinoid metabolism, neural, remodeling, and redox-sensitive genes. Oral IB-MECA prevented dysregulation in 92% of these genes, histopathology, gut injury, and weight loss. IB-MECA or adenosine suppressed elevated free radicals in ex vivo inflamed gut. Oral IB-MECA blocked the colitis-induced upregulation (90% of genes tested (33 of 37 genes). We conclude that our validated high-density oligonucleotide microarray analysis is a powerful technique for molecular gene dysregulation studies to assess the beneficial effects of purine-based or other drugs in experimental colitis. ADOA3R is new potential therapeutic target for inflammatory bowel disease.
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http://dx.doi.org/10.1097/00054725-200608000-00014DOI Listing
August 2006

Endogenous adenosine differentially modulates 5-hydroxytryptamine release from a human enterochromaffin cell model.

Gastroenterology 2004 Jul;127(1):188-202

Department of Anesthesiology, The Ohio State University, Columbus 43210, USA.

Background & Aims: The aim was to determine whether adenosine receptors modulate cAMP, intracellular free calcium ([Ca(2+)](i)), and 5-hydroxytryptamine (5-HT) release in human carcinoid BON cells.

Methods: Adenosine receptor (R) mRNA, proteins, and function were identified by Western blots, immunofluorescent labeling, Fluo-4/AM [Ca(2+)](i) imaging, and pharmacologic/physiologic techniques.

Results: A1, A2, and A3Rs were present in BON cells and carcinoid tumors. Baseline 5-HT levels increased with adenosine deaminase, activation of A2Rs, and inhibition of A3Rs, whereas A3R activation decreased 5-HT. A2R antagonists or blockade of adenosine reuptake that elevates extracellular adenosine reduced mechanically evoked 5-HT release. In single BON cells, touch elevated [Ca(2+)](i) responses were augmented by adenosine deaminase, A1, and A3R antagonists.

Conclusions: Tonic or mechanically evoked release of endogenous adenosine is a critical determinant of differential activation of adenosine receptors and may have important implications for gut mechanosensory reflexes.
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http://dx.doi.org/10.1053/j.gastro.2004.04.070DOI Listing
July 2004
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