TLR2 stimulation, and concordantly, depletion of optineurin in THP-1 cells was associated with reduced TNF release after TLR2 activation. Conclusions: In conclusion, we have developed a successful strategy to identify abnormal expression of genes in individual CD patients relevant to diminished macrophage function. In a wider context, this approach may be equally applicable in delineating the molecular pathogenesis of other complex disorders. 1. A. Franke et al., Nat. Genet. 42, 1118 (2010) 2. A. M. Smith et al., J. Exp. Med. 206, 1883 (2009) Tu1970 Background: The histone deacetylase (HDAC) pan-inhibitor givinostat (ITF2357) currently undergoes clinical phase II trials in juvenile idiopathic arthritis patients. In murine models of colitis, givinostat ameliorates disease activity and protects from colitis-associated carcinogenesis. Recently, the HDAC inhibitors trichostatin A and valproic acid were shown to markedly alter macrophage phenotypes. Here, we studied whether altered macrophage phenotypes and functions might contribute to the diverse clinical effects of givinostat. Methods and Results: Bone marrow-derived macrophages (BMDM) obtained from femurs of C57BL/6 mice were cultured in the presence of macrophage-colony stimulating factor. Mature F4/80+ CD11b+ BMDM were treated with 0 to 200 nM givinostat, followed by stimulation with lipopolysaccharide (LPS). As measured using antibody-based methods, secretion of tumor necrosis factor, IL-6, IL-10, IL-12p70, and the soluble IL-6 receptor (sIL6R) was reduced by givinostat in a dose-dependent manner; contrarily, monocyte chemotactic protein-1 (murine analogue of CCL2) was increased. Cytometric analyses showed that givinostat stifled the LPS-driven up-regulation of IL-6R alpha chain (CD126), while leaving its signal transducer CD130 unchanged. Givinostat reduced the capacity of BMDM for antigen-specific activation of CD4+ T cells without affecting antigen processing, as shown by T cell proliferation and interferon gamma secretion after co-culture of BMDM with naïve CD4+ T cells from OT-II mice in the presence of ovalbumin protein or OVA323-329 peptide. Phagocytosis assay using fluorescent latex spheres revealed significantly impaired phagocytotic activity of givinostat-treated BMDM. Conclusion: We here demonstrate that givinostat treatment alters the phenotype of BMDM, leading to an impairment of major histocompatibility complex class II-dependent T cell activation and of phagocytotic activity. IL-6 signaling is affected at the levels of cytokine secretion, receptor expression and by diminishing IL-6 trans-signalling via sIL 6R. Taken together, our results suggest the induction of an M2-like phenotype by therapeutic levels of givinostat. These effects on central macrophage functions by HDAC pan-inhibition warrant further investigation In Vivo. Tu1968 Increased Sensitivity to TGFβ Results in Defects in T Cell Proliferation and Regulatory T Cell Induction in the Absence of Wiskott-Aldrich Syndrome Protein (WASp) Elisa K. Boden, David Dunkin, Jeremy A. Goettel, Osub Ahmed, Christopher J. Moran, Deanna D. Nguyen, Lloyd Mayer, Scott B. Snapper Background: The Wiskott-Aldrich Syndrome is an immunodeficiency that results from mutations in WASp. WASp transduces cell surface receptor signals to the actin cytoskeleton via interaction with ARP2/3, a known risk allele for ulcerative colitis. Both humans and mice with WASp-deficiency may develop colitis associated with reduced number and function of CD4+CD25+Foxp3+ regulatory T cells (Tregs). Here we demonstrate altered de novo induction of Tregs and reduced T cell proliferation in the absence of WASp that correlates with increased responsiveness to TGFβ. Methods: Naïve T cells from ova-specific TCRtransgenic wild type (WT) or WASp-deficient(WKO) mice were cultured with ova peptide and TGFβ and analyzed for FoxP3 and CFSE dilution at 72h. WT or WKO T cells were exposed to TGFβ for 0-60 minutes and lysates were fractionated by SDS-PAGE. Western blotting was performed for phospho-SMAD2, total SMAD2, CD3ε and TGFβrI/II. Nontransgenic WT and WKO mice were fed ova daily for 5 days followed by immunization and boosting with ova. Delayed-type hypersensitivity (DTH) was assessed by injection of ova into the L footpad and PBS into the right footpad. At 24h DTH was calculated as the difference in size between the left and right footpad. Draining LNs were restimulated with ova and IFNγ from the culture supernatants was measured by ELISA at 48h. Results: Stimulation of naïve WKO T cells resulted in reduced proliferative response to antigen compared with WT. This correlated with an altered threshold for the maximal induction of Tregs, such that the peak induction of Tregs in WKO T cells required 10-fold increased antigen dose. When responsiveness to TGFβ was assessed, WKO T cells demonstrated increased phosphorylation of the TGFβ receptor signaling protein, SMAD2, at early timepoints compared to WT. Expression of TGFβ receptor was not altered in WKO T cells. Surprisingly, oral tolerance to low-dose antigen remained intact in WKO mice. WKO mice fed oral ovalbumin had no DTH response to intradermal ovalbumin. Additionally, following immunization, the draining lymph nodes of tolerized mice had complete suppression of IFNγ response to restimulation with ovalbumin. Conclusions: These data implicate increased sensitivity to TGFβ as a novel mechanism for the reduced Tregs and development of colitis in the absence of WASp. In the setting of oral tolerance, a process known to depend on induction of Tregs and on direct effects of TGFβ, there is no defect in WKO animals. We hypothesize that defects in Treg induction may be compensated by increased sensitivity to the direct effects of TGFβ. Further understanding of the mechanisms that govern Treg homeostasis may allow for the development of Treg-targeted therapies for IBD. Tu1971 Anti-TNF Induced Regulatory Macrophages Display High Levels of Autophagy Anne Christine Vos, Manon Wildenberg, Alon D. Levin, Gijs R. van den Brink, Daniel W. Hommes Background One of the most exciting developments in IBD therapy has been the introduction of anti-TNF agents. Although originally believed to function through neutralization of soluble TNF, we have previously shown that anti-TNF agents induce regulatory macrophages which have immune-suppressive and wound healing capacity (Vos et al, Gastroenterology 2010). How these cells exert their effects has not been established thus far. Over the past few years, genome-wide association studies have shown a correlation between Crohn's Disease (CD) and a number of autophagy-related genes, implicating a role for autophagy dysfunction in the pathogenesis. We evaluated the induction of autophagy in anti-TNF induced macrophages. Methods Mixed lymphocyte reactions were established using PBMC from two healthy donors in a 1:1 ratio and treated with anti-TNF or IgG control. Subsequently, macrophages were isolated from the cultures using CD14-microbeads. Levels of autophagy were determined by enumeration of LC3+ spots and quantification of LC3-I/LC3-II ratio's. In addition, expression levels of various autophagy-related genes were studied by gene array. Results AntiTNF induced regulatory macrophages displayed increased numbers of autophagosomes as indicated by LC3+ spots. In addition, conversion of the autophagosomal protein LC3 was increased in anti-TNF treated cultures compared to IgG treated cultures. Finally, expression of a number of autophagy related genes including atg5, atg7, atg9 and atg16l2 were upregulated in the induced regulatory macrophages in comparison to inflammatory M1 type macrophages. Conclusion Regulatory macrophages induced by anti-TNF therapy display increased levels of autophagy compared to IgG-induced or inflammatory macrophages. Given the role for impaired autophagy in the pathogenesis of CD, this may be an addition mechanism by which anti-TNF compounds exert their beneficial effects. Tu1969 Elevated Expression of the Cytosolic DNA Sensors AIM2 and ZBP1/DAI in Active Ulcerative Colitis but Not Crohn's Disease Colonic Tissue Aine Fanning, Gerard Moloney, John MacSharry, Monica Ambrose, Eamonn M. Quigley, Fergus Shanahan, Silvia Melgar, Kenneth Nally Background: Ulcerative colitis (UC) and Crohn's disease (CD) are chronic remitting and relapsing inflammatory diseases of the gastrointestinal tract. While both are distinct and separate inflammatory conditions, their pathophysiology is still not well defined. For example, while the aetiology of both UC and CD is largely unknown, it is suggested that the interplay between host genetic susceptibility, the external environment, the intestinal microflora and a deregulated immune response in combination, contribute to general disease pathogenesis for both conditions. Pattern recognition receptors (PRRs) are used by the innate immune system to detect common Microbe-Associated Molecular Patterns (MAMPs) and endogenous Danger-Associated Molecular Patterns (DAMPs). Hence, different PRRs can distinguish different MAMPs and DAMPs thereby directing the selectivity of the subsequent immune response to specific exogenous and endogenous triggers. Aims: We profiled the expression of 50 known PRRs including C-type lectin receptors (CLRs), Toll-like Receptors (TLRs), NODlike receptors (NLRs), RIG-I-like receptors (RLRs) and AIM2-like receptors (ALRs) in healthy and IBD tissue to gain further insight into the distinct pathogenesis of UC and CD. Methods: Total RNA was isolated from healthy (n=33), UC active (n=38), UC inactive (n=30), CD active (n=8) and CD inactive (n=10) colonic mucosal biopsy tissue. The expression of a panel of 50 known PRRs were screened by qRT-PCR in a small panel (n=8-12 per disease group) of individual patient samples and differentially expressed genes were subsequently validated in cDNA from remaining tissue samples. Because activation of cytosolic DNA sensor pathways typically leads to a Type I Interferon (IFN) response we screened for expression of a panel of IFN responsive genes by qRT-PCR in the same set of cDNAs. Results: From the initial screen, it was notable that there was a selective up-regulation of the cytosolic DNA sensor genes AIM2 and ZBP-1/DAI in active UC but not inactive UC, active CD or healthy tissue. IFI16 was also strongly up-regulated in active and inactive UC but to a lesser degree than AIM2 and ZBP1/DAI. The differential expression of these genes was confirmed in a larger number of patient samples. In addition, we found several type I IFN responsive genes to be up-regulated in active UC. Conclusion: The expression of the cytosolic DNA sensors - AIM2, ZBP-1/DAI, IFI16 - are selectively and strongly up-regulated in active UC but not active CD or healthy colonic tissue samples. In addition analysis of Type I IFN regulated genes suggests that these DNA sensing pathways are active in UC. Therefore, activation of cytosolic DNA sensors by DNA from viral, bacterial or host genomes could distinguish UC from CD pathogenesis. Tu1972 Mice Overexpressing Wild-Type Human Alpha-Synuclein Display Alterations in Colonic Myenteric Ganglia and Propulsive Colonic Motor Function Lixin Wang, Iddo Magen, Franziska Richter, Pu-Qing Yuan, Marie-Francoise Chesselet, Yvette Tache Background: Gastrointestinal (GI) symptoms are one of the most prevalent non-motor symptoms of Parkinson's disease (PD), and significantly impact patients' quality of life. Despite some recent progress, there remains a paucity of suitable animal models to study the mechanisms of PD-related GI symptoms and test new treatments. Alpha-synulein, a protein associated with both familial and sporadic PD forms pathological neuronal aggregates in PD, including in myenteric neurons. Therefore, mice overexpressing α-synuclein may provide a suitable model for assessing PD-related GI deficits. We have previously shown colonic dysmotility in 12 months old mice overexpressing human wild type α-synuclein under the Thy1 promoter (Thy1-aSyn). Aim: To investigate gut alterations in Thy1-aSyn mice at earlier ages as well as expression of α-synuclein and its relationship to other neurotransmitters in the distal colon. Methods: Defecation, gastric emptying (GE) and immunoreactivity of α-synuclein, peripheral choline acetyl transferase (pChAT), tyrosine hydroxylase (TH), neuronal nitric oxide synthase (nNOS) and vasoactive intestinal peptide (VIP) in distal colon myenteric plexi were assessed in Thy1-aSyn mice. Results: Thy1-aSyn mice aged 2.5-3 or 7-8 months old had 81% and 55% reduction in fecal pellet output, respectively in response to the first 15 min of 2 h in novelty, and 60% and 69% reduction, respectively during the subsequent 1-h refeeding compared with age matched WT littermates. The reduction of fecal pellets was not correlated to food intake during the 1 h of refeeding (r2 = 0.03, p > 0.05). In the early dark phase 8 months old Thy1-aSyn mice showed a 59% S-889 AGA Abstracts AGA Abstracts Givinostat Induces an M2 Macrophage Phenotype and Modulates IL-6 Signaling Martin Wetzel, Marco Gerling, Rainer Glauben, Thorsten Stroh, Ulrike Erben, Martin Zeitz, Britta Siegmund AGA Abstracts reduction of fecal pellets also occurred in the first 15 min of novel environment. Thy1-aSyn mice (8-10 months) displayed increased α-synuclein in myenteric plexi with abundant varicose terminals surrounding pChAT-immunoreactive (ir) neurons and only a few, nNOSir neurons. There were no conspicuous changes in pChAT- and nNOS-ir neurons, and THand VIP-ir nerve fibers, or proteinase K-resistant α-synuclein aggregates at the ages examined. GE was not altered in Thy1-aSyn mice aged 4 to 18 months. Conclusions: The occurrence of colonic dysfunction in Thy1-aSyn mice several months before the loss of striatal dopamine together with the histological data support the hypothesis that over-production of presynaptic α-synuclein in colonic myenteric ganglia could interfere with cholinergic neuronal activation, causing early functional bowel symptoms in PD. Supported by Michael J. Fox Foundation (Target validation grant), the Morris K. Udall Parkinson's Disease Research Center of Excellence at UCLA (P50NS38367), center grant NIHDDK 41301 (Animal Core), RO1 DK 57238; center grant P50 DK064539 for Oppenheimer Family Center for Neurobiology of Stress and VA Career Scientist Award capable of inhibiting gastric motility in conscious rats and that endogenously released IL-1 may mediate the LPS-evoked inhibition of gastric antral motility. These evidence also led us speculate that IL-1Ra may be a therapeutic tool for patients with disturbed gastrointestinal functions under septic conditions. Effects of intraperitoneal injection of LPS and IL-1Ra on gastric antral motility in conscious rats Each data represents the mean ±S.E. †P< 0.05, when compared with saline ‡P< 0.05, when compared with LPS alone Tu1973 Tu1975 Gut Microbiota Regulate Murine Gastrointestinal Motility Through a Toll-Like Receptor 4 Dependent Pathway Mallappa Anitha, Matam Vijay-Kumar, Andrew T. Gewirtz, Shanthi Srinivasan Daikenchuto, a Kampo (Japanese Herbal) Medicine, Ameliorates Postoperative Ileus by Anti-Inflammatory Action Through Nach Receptor Mari Endo, Toshihiko Hanawa, Tetsuro Oikawa, Hiroshi Ozaki, Masatoshi Hori Background: Toll-like receptors play a pivotal role in intestinal homeostasis. The role of TLR4 signaling on the development and survival of enteric neurons and its influence on gastrointestinal motility is not known. Aim: We examined the role of Toll-like receptor 4 (TLR4) on the development of enteric neurons and influence on gastrointestinal motility. Methods: We assessed changes in intestinal motility (stool frequency, bead expulsion test, and isometric muscle recording of colonic longitudinal muscle strips) using mice lacking TLR4 signaling (Tlr4Lps-d and TLR4-/-), Myd88 knockout mice (Myd88-/-), germ free mice, WT mice with altered microbiota, and mice with a neural crest specific deletion of Myd88 (Wnt1Cre+/−/Myd88fl/fl) that we generated. In Vitro, the role of TLR4 signaling on enteric neuronal cell survival was studied in immorto fetal enteric neurons (IM-FEN) and enteric neuronal cells isolated from E13.5, WT and Tlr4Lps-d mice, treated with low dose TLR4 agonist, lipopolysaccharide (LPS). Results: We found a significant delay in motility in Tlr4Lpsd , TLR4-/-, and Myd88-/- mice. The intestinal transit as measured by geometric center was significantly delayed in Tlr4Lps-d mice (WT: 9.6 + 0.4; Tlr4Lps-d: 7.7 + 0.3, n=5, P<0.01). The stool frequency, wet and dry weight was much lower in the Tlr4Lps-d mice (No. of pellets/hr, WT: 18 + 1; Tlr4Lps-d: 9 + 1, n=10, P<0.001). Proximal colon motility as measured by isometric muscle recording showed a reduction in electric field stimulation (EFS) induced relaxation in Tlr4Lps-d mice (P<0.05). Consistent with this there was a reduction in the number of nNOS neurons in the myenteric plexus of Tlr4Lps-d, TLR4-/- and Myd88-/- mice compared to WT mice (number of neurons per unit area, WT: 58.8 + 4; Tlr4Lps-d: 29.6 + 1.6, n=8, P<0.001) but no difference in cholinergic neurons. A similar phenotype was seen with germ free mice, WT mice with altered microbiota, and Wnt1Cre+/−/Myd88fl/fl mice. Colonic motility assessed by the bead expulsion time was delayed in Wnt1Cre+/−/Myd88fl/fl mice compared to WT mice (P<0.01). The stool frequency was lower in the Wnt1Cre+/−/ Myd88fl/fl mice (No. of pellets/hr, WT: 12 + 4; Wnt1Cre+/−/Myd88fl/fl: 5 + 1, P<0.05). Proximal colon motility as measured by isometric muscle recording showed a reduction in EFS induced relaxation in Wnt1Cre+/−/Myd88fl/fl mice (P<0.05). In Vitro, enteric neuronal cells treated with LPS demonstrated NF-κB activation and improved neuronal survival (P<0.001). Conclusions: Our findings suggest that for the proper post natal development of the enteric nervous system, microbial-neuronal interaction is essential. One potential mechanism we propose is through LPS induction of NF-κB and resulting activation of prosurvival pathways. These results support a novel role of bacterial-neuronal interaction in the pathophysiology of gastrointestinal motility. Introduction: Daikenchuto (DKT) is a gastrointestinal prokinetic Japanese herbal medicine. DKT is widely prescribed for patients with postoperative ileus and adhesive bowel obstruction following abdominal surgery. Main mechanism is considered as gastrointestinal prokinetic ability via 5-HT3 and 5-HT4 receptor stimulations. Indeed, DKT has a clinically significant promotility effect in small bowel and ascending colon transit. However, detailed mechanisms of DKT for amelioration of these gut dysfunction disorders remain unclear. Aim: In the present study, we investigated effects of DKT on postoperative ileus and clarified the detailed mechanisms. Method: Intestinal manipulation (IM) was applied to distal ileum of Balb/c mouse to make postoperative ileus model. DKT (95 mg/kg) was orally administrated to the animals at 3, 2 and 1 day before and 6 h after IM. Alpha7-nicotinic acetylcholine (α7nACh) receptor antagonist methyllycaconitine citrate (MLA; 0.0125 mg/kg, s.c.) was also applied 30 min before each DKT administration in some experiments. At 24 h after IM, small intestine was isolated and whole mount smooth muscle layer was prepared. Immunohistochemistry, cytokine mRNA expression, myeloperoxidase activity were performed. Gastric emptying ability was also measured by 13C-acetate breath test. Results: IM significantly decayed rate of gastric emptying. DKT showed a tendency to recover the decayed gastric emptying induced by IM. In the muscle layer treated with IM, many CD68 positive macrophages and MPO expressed neutrophils were infiltrated. MPO activity also increased after IM. DKT significantly inhibited the infiltrations of macrophages and neutrophils and decreased the MPO activity. At 3 h after the IM, mRNA expressions of proinflammatory cytokines or chemokines, such as TNF-α, IL-1β, IL-6 and MCP-1, were significantly upregulated. DKT inhibited mRNA expression of TNF-α and MCP-1 but not IL-6 and IL-1β. These results indicated that DKT has an anti-inflammatory action. Recent our work suggested that 5-HT4 receptor agonist, mosapride citrate, which is a clinically useful gastroprokinetic agent, has an anti-inflammatory action by activating α7nACh receptors in macrophages via ACh release from myenteric plexus nerve (Gut 60:638, 2011). Therefore, we investigated effects of MLA on DKT-mediated anti-inflammatory reaction. Results indicated that MLA partially but significantly reduced the anti-inflammatory action of DKT. Conclusion: Stimulating the 5-HT4 receptor by DKT accelerates ACh release from cholinergic myenteric neurons, which subsequently activates α7nACh receptors possibly on activated monocytes/macrophages, resulted in inhibited IMinduced inflammation. In addition to the gastrointestinal prokinetic action, DKT serves as novel therapeutic agent for POI characterized by anti-inflammatory potency. Tu1974 Endogenous IL-1 Mediates the LPS-Induced Inhibition of Gastric Motility in Conscious Rats Yoshihiro Tsuchiya, Tsukasa Nozu, Shima Kumei, Masumi Ohhira, Toshikatsu Okumura Sepsis induces the disturbance of gastrointestinal motility. A therapeutic approach to improve gastrointestinal motility could break the intestinal cycle of sepsis and prevent the development of a sepsis-induced systemic inflammatory response syndrome and multiple organ failure. Regrettably, very limited knowledge exists regarding the pathogenesis of sepsis-induced gastrointestinal motility disturbance and it remains to be fully elucidated, whether mechanistically microbial-mediated alterations in gut motility. Exogenous lipopolysaccharide (LPS) from gram-negative bacteria is known to be a causative factor of sepsis-induced pathophysiological changes. Although studies suggested that LPS decreased gastric acid secretion and gastric emptying in conscious animals, little is known whether LPS could change gastric antral contractility in freely moving conscious animals. We tried to clarify the above problem and the mechanisms. In this study, we recorded intraluminal gastric pressure waves in freely moving conscious rats by manometric catheter located in the antrum according to our recent publication (Nozu et al., J Gastroenterol in press). Area under the manometric trace was evaluated as motor index (MI). Intraperitoneal injection of LPS at doses of 0.2 mg/kg or more significantly inhibited MI. The inhibition started immediately after the administration of LPS and lasted over 1 h. Next, we examined the effects of cytolines, possibly induced by LPS, on gastric motility. Intraperitoneal injection of IL-1β potently decreased MI while neither IL-6 nor TNF-α inhibited gastric motility, suggesting IL-1β specifically reduced gastric motility. Finally, we examined the hypothesis that endogenous IL-1 mediates the LPS-induced inhibition of gastric motility. To address the speculation, a human recombinant IL-1 receptor antagonist (IL-1Ra) was used to block IL-1 signaling. The biological activity of IL-1 is mediated by two different gene products, IL-1α and IL-1β. These two proteins bind to IL-1 receptor-1 (IL-1R1). The effects of IL-1 are tightly controlled by several naturally occurring inhibitors, such as IL-1 receptor antagonist (IL-1Ra). It has been established that IL-1Ra binds to IL-1R1 and thus antagonizes biological effects of IL-1. IL-1Ra at a dose of 20 mg/kg by itself failed to change gastric antral pressure. On the ther hand, pretreatment with IL-1Ra at a dose of 20 mg/kg significantly blocked the inhibition of gastric contractility by LPS at a dose of 0.2 mg/kg. These results suggest for the first time that LPS or IL-1β is AGA Abstracts Administration of DKT significantly decreased MPO activity as shown in panel A. * indicates significantly different from IM (vehicle) at P<0.05. Panel B shows typical results of MPOstaining in whole-mount preparation of intestinal muscle region. Treatment with DKT significantly inhibited infiltration of neutrophils induced by intestinal manipulation (IM). S-890