Increased Mucin Production Research Articles

The Tmem16a chloride channel is required for mucin maturation after secretion from goblet-like cells in the Xenopus tropicalis tadpole skin

The TMEM16A chloride channel is proposed as a therapeutic target in cystic fibrosis, where activation of this ion channel might restore airway surface hydration and mitigate respiratory symptoms. While TMEM16A is associated with increased mucin production under stimulated or pro-inflammatory conditions, its role in baseline mucin production, secretion and/or maturation is less well understood. Here, we use the Xenopus tadpole skin mucociliary surface as a model of human upper airway epithelium to study Tmem16a function in mucus production. We found that Xenopus tropicalis Tmem16a is present at the apical membrane surface of tadpole skin small secretory cells that express canonical markers of mammalian “goblet cells” such as Foxa1 and spdef. X. tropicalis Tmem16a functions as a voltage-gated, calcium-activated chloride channel when transfected into mammalian cells in culture. Depletion of Tmem16a from the tadpole skin results in dysregulated mucin maturation post-secretion, with secreted mucins having a disrupted molecular size distribution and altered morphology assessed by sucrose gradient centrifugation and electron microscopy, respectively. Our results show that in the Xenopus tadpole skin, Tmem16a is necessary for normal mucus barrier formation and demonstrate the utility of this model system to discover new biology relevant to human mucosal biology in health and disease.

Protective Effect of Probiotics against Pseudomonas aeruginosa Infection of Human Corneal Epithelial Cells.

Probiotic therapy needs consideration as an alternative strategy to prevent and possibly treat corneal infection. This study aimed to assess the preventive effect of Lactobacillus reuteri and Bifidobacterium longum subsp. infantis on reducing the infection of human corneal epithelial (HCE) cells caused by Pseudomonas aeruginosa. The probiotics' preventive effect against infection was evaluated in cell monolayers pretreated with each probiotic 1 h and 24 h prior to P. aeruginosa challenge followed by 1 h and 24 h of growth in combination. Cell adhesion, cytotoxicity, anti-inflammatory, and antinitrosative activities were evaluated. L. reuteri and B. longum adhered to HCE cells, preserved occludin tight junctions' integrity, and increased mucin production on a SkinEthicTM HCE model. Pretreatment with L. reuteri or B. longum significantly protected HCE cells from infection at 24 h, increasing cell viability at 110% (110.51 ± 5.15; p ≤ 0.05) and 137% (137.55 ± 11.97; p ≤ 0.05), respectively. Each probiotic showed anti-inflammatory and antinitrosative activities, reducing TNF-α level (p ≤ 0.001) and NOx amount (p ≤ 0.001) and reestablishing IL-10 level (p ≤ 0.001). In conclusion, this study demonstrated that L. reuteri and B. longum exert protective effects in the context of corneal infection caused by P. aeruginosa by restoring cell viability and modulating inflammatory cytokine release.

The relationship between the gut microbiome and resistance training: a rapid review

The human gut microbiome is attracting increasing attention because of its overall effect on health. Several reviews have investigated the impact of physical activity on the gut microbiome; however, these predominantly concentrate on either endurance or a combination of physical activities. This study aims to describe the effect of resistance or strength training on the gut microbiome of a human population. This rapid review follows the guidelines of the Cochrane Rapid Reviews Guidance along with PRISMA. A review of the literature was carried out using articles indexed by PubMed, Scopus, and Web of Science published in the last 12 years. None of the seven studies included find significant change in the gut microbiome in terms of bacterial taxa composition or overall diversity, though the results show that resistance training might decrease the zonulin level and increase mucin production and thereby reduce inflammation in the gut. Interestingly, two studies point to a gut-muscle axis connection and this is discussed in our paper. However, due to the small number of existing studies and certain methodological disagreements, it was hard to find a consensus on the relationship between the gut microbiome and resistance training.

Association between neuropeptides and mucins in Crohn’s disease mucous cells

Crohn’s disease (CD) and ulcerative colitis (UC) are both inflammatory bowel diseases (IBD). Unlike UC, which is limited to the mucosa of the colon, CD inflammation is characterized by chronic mucosal ulcerations affecting the entire gastrointestinal tract. Goblet cells (GCs) can be found in some lining epithelia, particularly in the respiratory and digestive tracts. GCs represent the main source of mucin that are the significant components of the mucus layer; hypertrophy of GCs and an increase in mucin production are observed in many enteric infections. The cytoplasm of goblet cells may also contain neuropeptides, such as serotonin, that can be altered in inflammatory bowel disease (IBD). The defense system of the gut is represented by the intestinal mucosal barrier, its protective function is strictly connected to the regulation of the mucus layer and the coordination of the neuro-immune response. Paraformaldehyde-fixed intestinal tissues, obtained from fifteen patients with Crohn’s disease, were analyzed by immunostaining for MUC2, MUC4, 5-HT, and VAChT. This study aims to define the link between neuropeptides and mucins in mucous cells and their involvement in the inflammation process. Our results showed in mucous cells of Crohn’s disease (CD) patients a high expression of MUC4 and a decrease in the expression of vesicular acetylcholine transporter (VAChT) demonstrating the presence of an inflammatory state.

Gut microbiota-derived butyrate regulates gut mucus barrier repair by activating the macrophage/WNT/ERK signaling pathway.

Ulcerative colitis (UC) is majorly associated with dysregulation of the dynamic cross-talk among microbial metabolites, intestinal epithelial cells, and macrophages. Several studies have reported the significant role of butyrate in host-microbiota communication. However, whether butyrate provides anti-inflammatory profiles in macrophages, thus contributing to UC intestinal mucus barrier protection, has currently remained elusive. In the current study, we found that butyrate increased mucin production and the proportion of mucin-secreting goblet cells in the colon crypt in a macrophage-dependent manner by using clodronate liposomes. Furthermore, in vivo and in vitro studies were conducted, validating that butyrate facilitates M2 macrophage polarization with the elevated expressions of CD206 and arginase-1 (Arg1). In macrophages/goblet-like LS174T cells co-culture systems, butyrate-primed M2 macrophages significantly enhanced the expression of mucin-2 (MUC2) and SPDEF (goblet cell marker genes) than butyrate alone, while blockade of WNTs secretion or ERK1/2 activation significantly decreased the beneficial effect of butyrate-primed macrophages on goblet cell function. Additionally, the adoptive transfer of butyrate-induced M2 macrophages facilitated the generation of goblet cells and mucus restoration following dextran sulfate sodium (DSS) insult. Taken together, our results revealed a novel mediator of macrophage-goblet cell cross-talk associated with the regulation of epithelial barrier integrity, implying that the microbial metabolite butyrate may serve as a candidate therapeutic target for UC.

A pan-cancer analysis of MUC family genes as potential biomarkers for immune checkpoint therapy.

2598 Background: Mucin (MUC) is a family of high-molecular weight glycoproteins and increased mucin production occurs in many malignant tumors. Recent studies have found relationship between mutations of some MUC family genes and efficacy of immunotherapy. Here, we explored the associations of MUC family genes (MUC2, MUC3A, MUC4, MUC5B, MUC6, MUC12, MUC16, MUC17, MUC19) mutation with ICI response based on multidimensional data from multiple solid tumors. Methods: 15 solid tumor types of TCGA genomic data for 6138 patients was used to evaluate tumor mutational burden (TMB) differences between MUC family genes mutation group and wildtype group. TMB was calculated as the total count of nonsynonymous mutations in coding sequence. Neoantigens of 3039 samples across 11 solid tumor types were obtained from The Cancer Immunome Atlas. A pan-cancer immunotherapy cohort (Broad/Dana-Farber, Nat Genet 2018, N = 249) was used to explore the relationship between mutations of MUC family genes and its efficacy of immunotherapy. Results: The most common mutated MUC genes (frequency > 5%) were MUC16 (25.3%), MUC17 (10.8%), MUC5B (10.5%), MUC4 (8.6%), and MUC2 (5.1%). The data between MUC mutation group and wild type group showed a significant difference (P < 0.01) in TMB. Median TMB across fifteen tumors in MUC mutation group and wild type group is 7.04 mutations per Mb and 2.07 mutations per Mb, separately. The TNB between two group is also showed a significant difference (P < 0.01). Median TNB across nine types tumor in MUC mutation group and wild type group is 121.5 neoantigens and 34.0 neoantigens, separately. A multivariable analysis across the pan-cancer cohort using Cox proportional-hazards regression demonstrated that KMT2C mutation was associated with better OS (hazard ratio, 0.66; 95%CI, 0.45-0.99; P = 0.042), adjusting for sex and cancer type. Conclusions: The results indicated that MUC family genes mutation was associated with a higher TMB and TNB. Analysis of immunotherapy cohort data showed MUC family was associated with better OS. These findings indicate that these genes mutation may serve as a predictive biomarker for ICI in solid tumor patients.

Effects of empagliflozin against indomethacin induced gastric mucosa.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors (SGLT2i) are considered a new class antidiabetic agent, as well as lowering blood sugar, it has many positive effects. This study aimed to investigate the effects of SLGT2i on the gastric mucosa. We investigated the effects of empagliflozin on indomethacin-induced gastritis using 48 male Wistar Albino rats. We performed histopathological evaluations of gastric mucosa tissue. And we studied the levels of serum disulfide, native thiol, total thiol, and ischemia modified albumin, disulfide/native thiol ratio (SSSH), native thiol/total thiol percent ratio (SH total SH), and disulfide/total thiol percent ratio (SS total SH). We found that empagliflozin increased mucin production in rat gastric mucosa. Besides, we observed milder inflammation findings and lower gastritis scores in the empagliflozin receiving groups than the placebo groups. Native thiol, total thiol, and disulfide levels were lower in the indomethacin-induced gastritis groups. This study is the first to investigate the effect of empagliflozin on the gastrointestinal tract in a rat model. We concluded that empagliflozin increased mucin production and revealed positive effects in an indomethacin-induced gastritis model.

A51 ENTERIC PARASITE INFECTION-INDUCED ALTERATION OF THE GUT MICROBIOTA REGULATES INTESTINAL GOBLET CELL BIOLOGY AND MUCIN PRODUCTION VIA TLR2 SIGNALING

Abstract Background Goblet cells (GCs) are the major source of mucin which are the main components of the mucus layer that represents the front line of innate defense in the gastrointestinal (GI) tract. Hyperplasia of GCs and increased mucin production are observed in many enteric nematode infections such as Trichuris muris infection. Increased mucin production contributes to parasite clearance by trapping in mucus and inhibiting motility. The GI tract contains trillions of commensal microbes, and these microbes control mucin production from GCs by activating different signaling cascades. During nematode parasite infection due to the coexistence of parasites and microbiota in close proximity of GCs in gut, it is likely that this nematode-microbiota interaction plays an important role in mucin production. Toll-like receptors (TLRs), components of the innate immune system, sense gut microbiota stimuli. The human GC-like cell line, LS174T, expresses TLR2 mRNA which was enhanced by stimulation with synthetic TLR2 ligands. We hypothesize T. muris-induced altered microbiota modulates GC response and mucin production via TLR2 signaling. Aims To elucidate the role of T. muris-induced altered gut microbiota in the regulation of intestinal GC response and mucin production via host TLR2 signaling. Methods C57BL/6 mice were infected by gavage with ~300 T. muris eggs and infectivity was confirmed by worm burden. Microbiota was analyzed by 16s rRNA sequencing. Colonic GCs response, mucins and TLR2 expression and cytokines production were assessed in germ-free (GF) mice receiving non-infected and T. muris-infected microbiota (collected on day 36 post-infection to exclude worms). Muc2 and Muc5ac expression were assessed in wild-type (WT) and TLR2 deficient (TLR2-/-) mice transplanted with T. muris-infected microbiota following antibiotic treatment. Results We observed a difference in microbial composition between non-infected and T. muris infected mice. Transfer of T. muris-infected microbiota into GF mice significantly increased GC numbers and TLR2 expression as well as up-regulated Muc2 and Muc5ac expression and IL-4, IL-13 production compared to GF mice with non-infected microbiota. Antibiotic-treated TLR2-/- mice after receiving microbiota from T. muris-infected mice showed significantly decreased expression of Muc2 and Muc5ac compared to antibiotic-treated WT mice receiving the same microbiota. Conclusions T. muris-induced altered microbiota influences intestinal GC response and mucin production via TLR2. In addition to enhancing our understanding on the interaction of parasite with resident microbiota in host defense, this study provides new information on TLR2 based innate signaling in the regulation of GC biology and mucin production. Funding Agencies NSERC

The Effect of Formula-based Nutritional Treatment on Colitis in a Murine Model

BackgroundExclusive enteral nutrition (EEN) induces remission in pediatric Crohn's disease (CD). The exact mechanism of EEN therapy in CD is unknown, but alteration of the intestinal microflora after EEN is thought to affect mucosal healing. To determine the link between EEN therapy and therapeutic efficacy in CD, we established a murine model of dextran sulfate sodium (DSS)-induced colitis and applied EEN therapy.MethodsEight-week-old C57BL/6 mice were administered DSS for 4 days to induce colitis, and either normal chow (NC) or EEN was administered for the following 4 days. The mice were grouped according to the feeding pattern after DSS administration: DSS/NC and DSS/EEN groups. The clinical course was confirmed via daily observation of the weight and stool. Fecal samples were collected and 16sRNA sequencing was used. The mice were sacrificed to confirm colonic histopathology.ResultsWeight reduction and increase in disease activity were observed as the day progressed for 4 days after DSS administration. There was significant weight recovery and improvement in disease activity in the EEN group compared to that in the NC group. Verrucomicrobia and Proteobacteria abundances tended to increase and Bacteroidetes abundance decreased in the EEN group. In the EEN group, significant changes in the β-diversity of the microbiota were observed. In the analysis of microbiome species, abundances of Akkermansia muciniphila, Clostridium cocleatum, mucin-degrading bacteria, Flintibacter butyricus, and Parabacteroides goldsteinii, which are beneficial microbiota, were significantly increased in the EEN group compared to those in the NC group. More abundant mucins were confirmed in the colonic histopathology of the EEN group. These microbial and histopathological differences suggested that EEN might improve colitis symptoms in a murine colitis model by promoting mucin recycling and subsequently inducing the healing effect of the gut barrier.ConclusionEEN showed clinical efficacy in a murine model of colitis. Based on the increase in mucin-degrading bacteria and the pathological increase in mucin production after EEN administration, it can be observed that mucin plays an important role in the therapeutic effect of EEN.

Early pathogenesis of cystic fibrosis gallbladder disease in a porcine model

AbstractHepatobiliary disease causes significant morbidity in people with cystic fibrosis (CF), yet this problem remains understudied. We previously found that newborn CF pigs have microgallbladders with significant luminal obstruction in the absence of infection and consistent inflammation. In this study, we sought to better understand the early pathogenesis of CF pig gallbladder disease. We hypothesized that loss of CFTR would impair gallbladder epithelium anion/liquid secretion and increase mucin production. CFTR was expressed apically in non-CF pig gallbladder epithelium but was absent in CF. CF pig gallbladders lacked cAMP-stimulated anion transport. Using a novel gallbladder epithelial organoid model, we found that Cl− or HCO3− was sufficient for non-CF organoid swelling. This response was absent for non-CF organoids in Cl−/HCO3−-free conditions and in CF. Single-cell RNA-sequencing revealed a single epithelial cell type in non-CF gallbladders that coexpressed CFTR, MUC5AC, and MUC5B. Despite CF gallbladders having increased luminal MUC5AC and MUC5B accumulation, there was no significant difference in the epithelial expression of gel-forming mucins between non-CF and CF pig gallbladders. In conclusion, these data suggest that loss of CFTR-mediated anion transport and fluid secretion contribute to microgallbladder development and luminal mucus accumulation in CF.In this study, the authors assess the early pathogenesis of cystic fibrosis (CF) pig gallbladder disease. The CF pig gallbladder epithelium lacks cAMP-stimulated anion and fluid transport. CF pig gallbladders also demonstrate increased luminal mucins MUC5AC and MUC5B accumulation without significant changes in the epithelial expression of gel-forming mucins compared to non-CF pigs.

Pediococcus acidilactici intake decreases the clinical severity of atopic dermatitis along with increasing mucin production and improving the gut microbiome in Nc/Nga mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease that is associated with intestinal microflora. Since specific probiotics may have better efficacy for AD, we determined the efficacy of Pediococcus acidilactici SRCM102024 (PA) for treating AD in HaCaT cells and NC/Nga mice and explored the mechanism of action. AD-like pathology was induced in HaCaT cells and the dorsal skin of Nc/Nga mice by local exposure to 2,4-dinitrochlorobenzene (DNCB). In AD-lesion induced mice, PA in low-, medium- and high-dosages (5 × 10E6, 5 × 10E7 and 5 × 10E8 CFU/kg bw, respectively) and dexamethasone (3 mg/kg bw, positive-control) were orally administered for 5 weeks. The clinical AD severity, serum immunoglobulin E (IgE) and TNF-α, gene expressions of interleukin (IL)-4, IL-13, and TNF-α and gut microflora were measured. PA treatment (100–300 CFU/mL) dose-dependently increased cell survival in DNCB-induced HACAT cells. PA reduced the relative mRNA expression of PAR-2, TNF-α, IL-4 and IL-13 in the cells. In dorsal skin of Nc/Nga mice applied with DNCB, PA dose-dependently attenuated erythema, hemorrhage, edema, excoriation, dryness and scratching behavior and PA-H improved the clinical symptoms similar to the positive-control. PA-M and PA-H treatment significantly prevented the disturbance of the dorsal skin tissues and decreased the inflammatory cellular infiltrate of mast cells, compared to the control. PA dose-dependently reduced serum IgE and TNF-α concentrations and the mRNA expression of TNF-α, IL-4, and IL-13 in dorsal skin. In gut microflora, relative counts of Lactobacillales, Butyricicoccus and Ruminococcus were decreased in the AD-control compared to the positive-control and the PA-M and PA-H prevented their decrease. However, the positive-control increased serum AST and ALT activities, indicating liver damage as an adverse effect. In conclusion, oral treatment of PA (human equivalent 1 × 10E9-1 × 10E10) relieved the AD symptoms by dose-dependently preventing over-activation of the immune response. Oral PA intake may be a safe and effective alternative therapy for AD.

Prebiotic, antioxidant and anti-inflammatory properties of edible Amazon fruits

Dietary products with prebiotic and antioxidant properties may be used to protect against chronic diseases, including inflammatory bowel diseases. Assai berry, burity palm and cupuassu from the Amazon are functional foods because of their high level of dietary fiber and polyphenols, which have an important role in the prevention of inflammatory processes. Their activity as a dietary supplement was measured using fruit pulp flours in a trinitrobenzenesulphonic acid model of intestinal inflammation. The intestinal anti-inflammatory effects were evaluated using clinical parameters and biochemical analysis of pro-inflammatory cytokines (IL-6, IL-1β and TNF-α), whereas antioxidant activity was studied using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, mieloperoxidase (MPO) and alkaline phosphatase (ALP) activities, glutathione (GSH) level and phenolic content. The effects of dietary supplementation on the mucin release and short-chain fatty acid (SCFA) production were studied. Assai berry and burity palm reduced MPO and ALP activities, counteracted GSH and propionate reductions induced by the inflammatory process as well as decreased IL-6, IL-1β and TNF-α levels and increased mucin production. Cupuassu reduced MPO and ALP activities, IL-6 and IL-1β levels and increased colonic mucin, without effects on the SCFA production and TNF-α colonic level. In vitro studies showed the antioxidant properties, which were associated with the presence of polyphenol compounds and scavenging activity using the DPPH assay. The results indicated the possible benefits of using assai berry and burity palm fruits as dietary antioxidant, prebiotic, immune modulators and anti-inflammatory complementary products to treat intestinal inflammation.

Effect of dietary fiber and threonine content on intestinal barrier function in pigs challenged with either systemic E. coli lipopolysaccharide or enteric Salmonella Typhimurium

BackgroundThe independent and interactive effects of dietary fiber (DF) and threonine (Thr) were investigated in growing pigs challenged with either systemic E. coli lipopolysaccharide (LPS) or enteric Salmonella Typhimurium (ST) to characterise their effect on intestinal barrier function.ResultsIn experiment 1, intestinal barrier function was assessed via oral lactulose and mannitol (L:M) gavage and fecal mucin analysis in pigs challenged with E. coli LPS and fed low fiber (LF) or high fiber (HF) diets with graded dietary Thr. Urinary lactulose recovery and L:M ratio increased (P < 0.05) during the LPS inoculation period in LF fed pigs but not in HF fed pigs. Fecal mucin output was increased (P < 0.05) in pigs fed HF compared to LF fed pigs. In experiment 2, RT-qPCR, ileal morphology, digesta volatile fatty acid (VFA) content, and fecal mucin output were measured in Salmonella Typhimurium challenged pigs, fed LF or HF diets with standard or supplemented dietary Thr. Salmonella inoculation increased (P < 0.05) fecal mucin output compared to the unchallenged period. Supplemental Thr increased fecal mucin output in the HF-fed pigs (Fib × Thr; P < 0.05). Feeding HF increased (P < 0.05) VFA concentration in cecum and colon. No effect of either Thr or fiber on expression of gene markers was observed except a tendency (P = 0.06) for increased MUC2 expression with the HF diet. Feeding HF increased goblet cell numbers (P < 0.05).ConclusionDietary fiber appears to improve barrier function through increased mucin production capacity (i.e., goblet cell numbers, MUC2 gene expression) and secretion (i.e., fecal mucin output). The lack of effect of dietary Thr in Salmonella-challenged pigs provides further evidence that mucin secretion in the gut is conserved and, therefore, Thr may be limiting for growth under conditions of increased mucin production.

P071 MODULATION OF THE MUCUS LAYER BY BIFIDOBACTERIUM DENTIUM PROVIDES PROTECTION IN A MODEL OF COLITIS

Abstract Background The intestinal mucus layer serves as a critical interface between the environment and the host. Patients with inflammatory bowel disease (IBD), particularly ulcerative colitis, exhibit reduced synthesis and secretion of the mucus protein MUC2 and decreased mucus thickness. This in turn promotes immune activation and inflammation. The clinical relevance of the mucus layer emphasizes the need to address strategies to modulate this barrier. Although bifidobacteria represent only 3–6% of the healthy adult fecal microbiota, their presence has been associated with numerous health benefits, including bolstering mucus production. However, the molecular mechanisms that underlie these positive effects appear to be strain-specific and are not well defined. We hypothesized that the human-derived Bifidobacterium dentium would increase intestinal mucus synthesis and expulsion via specific metabolites. We also speculated that modulation of goblet cells would be beneficial during colitis. Methods &amp; Results In silico genome analysis revealed that B. dentium lacked the enzymatic repertoire required for degradation of mucin glycans. Consistent with these findings, we found that B. dentium could not use mucin glycans as a primary carbon source in vitro. To examine mucus modulation in vivo, germ-free mice were mono-associated with live or heat-killed B. dentium. Live B. dentium mono-associated mice exhibited increased colonic expression of goblet cell markers Krüppel-Like Factor 4 (Klf4), Relmβ, trefoil factor 3 (Tff3), Muc2, and several mucin glycosyltransferases compared to both heat-killed B. dentium and germ-free counterparts. Likewise, live B. dentium mono-associated colon had increased acidic mucin-filled goblet cells as denoted by MUC2 and PAS-AB staining. In vitro, B. dentium secreted products, including acetate, were able to increase MUC2 levels in T84 cells, mouse colonoids and human colonoids. We also identified that B. dentium secreted products, such as GABA, stimulated autophagy-mediated calcium signaling and MUC2 release. To identify whether B. dentium could enhance MUC2 production in mice harboring a complete microbiota, specific pathogen free mice were treated with live B. dentium by oral gavage. Administration of B. dentium increased the inner mucus layer compared to controls. Moreover, in a TNBS model of colitis, B. dentium treated mice had increased goblet cell numbers and MUC2 mRNA. Mirroring these findings, B. dentium treated mice lost less weight, had improved histology and had decreased levels of TNF, KC (IL-8), and IL-6. Conclusions This work illustrates that B. dentium enhances the intestinal mucus layer and goblet cell function via upregulation of gene expression and autophagy signaling pathways with a net increase in mucin production. Ultimately, these pathways may be targeted for the development of novel therapeutics.

P420 A randomised, observer-blinded phase Ib multiple, ascending dose study of UTTR1147A, an IL-22Fc fusion protein, in healthy volunteers and ulcerative colitis patients

Abstract Background Inflammatory bowel disease (IBD) is characterised by gut dysbiosis, weakened epithelial barrier, and a dysregulated immune system. Interleukin-22 (IL-22), an IL-10 family cytokine, has demonstrated efficacy in animal IBD models by promoting intestinal epithelial repair, increasing antimicrobial peptide production, and increasing mucin production via goblet cells1. UTTR1147A is a fusion protein in which IL-22 is linked with the Fc portion of IgG4 to improve the pharmacokinetic (PK) characteristics. Methods A phase I study (NCT02749630) was conducted to evaluate the safety, tolerability, PK, and pharmacodynamics (PD) of repeat IV dosing of UTTR1147A in healthy volunteers (HV) and UC patients with centrally read Mayo endoscopic score ≥ 2. 38 HVs and 24 UC patients were given UTTR1147A or placebo at doses ranging from 30 to 90 µg/kg either biweekly or monthly (6:2 UTTR1147A: placebo per cohort). PK and serum PD (REG3A and CRP) were studied across multiple time points and the Mayo Clinic Score was evaluated at baseline, day 30 and day 85. Results Overall, UTTR1147A was safe and adequately tolerated in HV and UC patients. The most common adverse events were on-target dermatological effects (dry skin, erythema, and pruritus) that were manageable, monitorable and reversible. Dose-limiting non-serious dermatological toxicities (severe dry skin, erythema, exfoliation, and discomfort) were seen in two HVs and 1 UC patient dosed with 90ug/kg Q2wk. There were 2 unrelated serious adverse events (ankle fracture and cytomegalovirus infection) that eventually resolved. PK analyses showed that UTTR1147A exposures were, in general, dose proportional within HVs and within UC patients, with a mean elimination half-life of ~16 days and ~12 days, respectively. At the same dose level, UC patients showed relatively lower drug exposures than HVs, possibly due to faster drug clearance. Consistent with the Phase Ia2, UTTR1147A directly induced production of serum PD biomarkers REG3A and CRP at all dose cohorts tested compared with placebo. Notably, UC patients appear to have attenuated serum PD responses compared with HV. Clinical response was observed in 7/18 patients, and clinical remission in 5/18 patients treated with UTTR1147A compared with 1/6 and 0/6 placebo patients, respectively. Conclusion UTTR1147A demonstrated adequate safety and PK profile in healthy volunteers and UC patients. PD biomarker data demonstrated pharmacological activity of UTTR1147A providing evidence of IL-22R pathway activation. Together with the preliminary signals of efficacy, these data support further investigation of this potential, novel non-immunosuppressive therapy in IBD.

LKB1 Represses ATOH1 via PDK4 and Energy Metabolism and Regulates Intestinal Stem Cell Fate

In addition to the Notch and Wnt signaling pathways, energy metabolism also regulates intestinal stem cell (ISC) function. Tumor suppressor and kinase STK11 (also called LKB1) regulates stem cells and cell metabolism. We investigated whether loss of LKB1 alters ISC homeostasis in mice. We deleted LKB1 from ISCs in mice using Lgr5-regulated CRE-ERT2 (Lkb1Lgr5-KO mice) and the traced lineages by using a CRE-dependent TdTomato reporter. Intestinal tissues were collected and analyzed by immunohistochemical and immunofluorescence analyses. We purified ISCs and intestinal progenitors using flow cytometry and performed RNA-sequencing analysis. We measured organoid-forming capacity and ISC percentages using intestinal tissues from Lkb1Lgr5-KO mice. We analyzed human Ls174t cells with knockdown of LKB1 or other proteins by immunoblotting, real-time quantitative polymerase chain reaction, and the Seahorse live-cell metabolic assay. Some intestinal crypts from Lkb1Lgr5-KO mice lost ISCs compared with crypts from control mice. However, most crypts from Lkb1Lgr5-KO mice contained functional ISCs that expressed increased levels of Atoh1 messenger RNA (mRNA), acquired a gene expression signature associated with secretory cells, and generated more cells in the secretory lineage compared with control mice. Knockdown of LKB1 in Ls174t cells induced expression of Atoh1 mRNA and a phenotype of increased mucin production; knockdown of ATOH1 prevented induction of this phenotype. The increased expression of Atoh1 mRNA after LKB1 loss from ISCs or Ls174t cells did not involve Notch or Wnt signaling. Knockdown of pyruvate dehydrogenase kinase 4 (PDK4) or inhibition with dichloroacetate reduced the up-regulation of Atoh1 mRNA after LKB1 knockdown in Ls174t cells. Cells with LKB1 knockdown had a reduced rate of oxygen consumption, which was partially restored by PDK4 inhibition with dichloroacetate. ISCs with knockout of LKB1 increased the expression of PDK4 and had an altered metabolic profile. LKB1 represses transcription of ATOH1, via PDK4, in ISCs, restricting their differentiation into secretory lineages. These findings provide a connection between metabolism and the fate determination of ISCs.

Role of the antioxidant properties in the gastroprotective and gastric healing activity promoted by Brazilian green propolis and the healing efficacy of Artepillin C.

Green propolis is a resinous substance used in folk medicine given its anti-inflammatory, antibacterial, and anti-ulcer effects. Our research group has already confirmed the gastroprotective activity of hydroalcoholic extract from green propolis (HEGP), as well as of its main isolated compounds. In continuity, this study evaluated the antioxidant mode of action involved in the preventive effect induced by HEGP, and its therapeutic gastric healing potential on installed ulcers. In addition, the healing effect of its main compound Artepillin C was also investigated. Acute and chronic ulcers were induced in rats by given ethanol or acetic acid, respectively. In acute model, the rats were orally pre-treated with vehicle (water plus 1% Tween, 1mL/kg), HEGP (30-300mg/kg), or carbenoxolone (200mg/kg) 1h prior the ulcer induction. In the chronic ulcer protocol, the rats received vehicle (water plus 1% Tween, 1mL/kg), HEGP (300mg/kg), or omeprazole (20mg/kg) twice a day by 7days, whereas groups of mice received vehicle (water plus 1% Tween, 1mL/kg), Artepillin C (18mg/kg), or ranitidine (20mg/kg) twice a day by 4days. Ulcerated tissue was collected for histological, histochemical, immunostaining, oxidative, and inflammatory analyses. The in vitro scavenger activity of HEGP was also verified using the DPPH assay. The oral pre-treatment with HEGP (100 and 300mg/kg) prevented the gastric epithelial damage promoted by ethanol. Besides, HEGP (100 and 300mg/kg) reduced SOD activity about 11% and 26%, respectively, and increased the activity of GST around 20% and CAT in 80%. HEGP (300mg/kg) also reduced the production of reactive oxygen species, as well as lipoperoxidation levels in the ethanol-ulcerated tissue. In the acetic acid-induced chronic ulcer, the daily treatment with HEGP (300mg/kg) accelerates the healing process by 71%. In this model, HEGP normalized SOD and CAT activity and increased GST activity by 109% when compared to non-ulcerated rats. In both models, the extract administration increased the mucin PAS staining and reduced the myeloperoxidase activity at the ulcer site. Moreover, the treatment with HEGP enhanced the PCNA immunostaining, but did not alter the concentration of collagen in the acetic acid-ulcerated tissue. The extract had a direct DPPH radical-scavenging ability (LogIC50: 0.56). Besides, as expected, HPLC analysis showed Artepillin C as a major compound and its administration at 18mg/kg also accelerated the gastric healing ulcer process in mice. Our findings confirm that HEGP displays both gastroprotective and gastric healing properties, contributing to the validation of its popular use as preventive and therapeutic approaches. These actions occur through the increase in mucin production and the reestablishment of the oxidative balance due to a reduction in gastric inflammation.

HEAT KILLED LB. PARACASEI OR CELL WALL LIPOTEICHOIC ACID AMELIORATES AGE-RELATED LEAKY GUT AND INFLAMMATION

Increased inflammation associated with leaky gut is a major risk factor for morbidity and mortality in older adults; however, successful preventive and therapeutic strategies are not available to ameliorate these conditions. In this study, we demonstrate that a human-origin Lactobacillus paracasei D3-5 strain (D3-5), even when dead, extended life span of C. elegans. In addition, feeding D3-5 to older mice (>79 weeks) prevented high fat diet (HFD)-induced metabolic dysfunction and decreased leaky gut and inflammation, which were associated with improved physical and cognitive function. D3-5 feeding significantly increased mucin production and proportionately, the abundance of mucin-degrading bacteria Akkermansia muciniphila was also increased. Mechanistically, we show that the cell wall of D3-5 contains lipoteichoic acid (LTA), which enhanced mucin (Muc2) expression via TLR-2/p38-MAPK pathway, which in turn reduced age-related leaky gut and inflammation. This study indicates that the D3-5 and its LTA can prevent/treat age-related leaky gut and inflammation.

ILC2s mediate systemic innate protection by priming mucus production at distal mucosal sites.

Host immunity to parasitic nematodes requires the generation of a robust type 2 cytokine response, characterized by the production of interleukin 13 (IL-13), which drives expulsion. Here, we show that infection with helminths in the intestine also induces an ILC2-driven, IL-13-dependent goblet cell hyperplasia and increased production of mucins (Muc5b and Muc5ac) at distal sites, including the lungs and other mucosal barrier sites. Critically, we show that type 2 priming of lung tissue through increased mucin production inhibits the progression of a subsequent lung migratory helminth infection and limits its transit through the airways. These data show that infection by gastrointestinal-dwelling helminths induces a systemic innate mucin response that primes peripheral barrier sites for protection against subsequent secondary helminth infections. These data suggest that innate-driven priming of mucus barriers may have evolved to protect from subsequent infections with multiple helminth species, which occur naturally in endemic areas.

Abstract 2333: Aspirin may extend biliary tract cancer survival: Results from population-based cohort

Abstract Background: Biliary tract cancers (BTCs) are rare, but lethal cancers with a median survival of &amp;lt;12 months. Because of this poor prognosis, there is a critical need for treatments that extend survival. Cyclooxygenase-2 (COX-2) is an enzyme responsible for producing prostaglandin E (PGE). PGEs increase mucin production and reduce bile flow in the gallbladder, leading to gallstones, a precursor to gallbladder cancer. Overexpression of COX-2 due to chronic inflammation from cholangiocarcinoma has been found to enhance PGE production and promote tumor growth. Previous research suggests that COX-2 inhibitors, such as aspirin, may slow cancer cell growth. We investigated aspirin use following diagnosis and overall survival in a large cohort of patients with BTCs. Methods: All patients diagnosed with incident biliary tract cancer between 1990 to 2017 were selected from the population-based United Kingdom’s Clinical Practice Research Datalink. Site-specific associations between aspirin use after BTC diagnosis and overall survival was analyzed using Cox proportional hazards models with aspirin use modeled as time-dependent, adjusting for age at diagnosis, sex, comorbidities, history of aspirin use, and use of statins, using follow-up time as the time scale. Results: We identified 3,211 biliary tract cancer cases in which 2,694 (84%) deaths occurred after an overall median follow-up time of 5 months. The table presents the number of cases by cancer subtype, deaths, and median survival time. Aspirin use following a diagnosis of BTC was associated with a reduction in mortality for each of the BTC sites: gallbladder, HR 0.41 (95% CI: 0.28, 0.61); cholangiocarcinoma, HR 0.46 (95% CI: 0.36, 0.60); ampulla of Vater, HR 0.24 (95% CI: 0.11, 0.51); and mixed, HR: 0.51 (95% CI: 0.33, 0.78). Conclusions: The use of aspirin after BTC diagnosis was associated with a lower risk of overall mortality. These results warrant additional studies to understand the mechanisms underlying improved survival with aspirin use. Table.Association between post-BTC diagnosis aspirin use versus no use and survival in the UK CPRD datasetCancer siteBTC patients N (%)Mortality N (%)Median survival time in months (interquartile range)HR (95% CI)*Gallbladder668 (23)555 (83)3.9 (2 - 11)0.41 (0.28, 0.61)Cholangiocarcinoma1,560 (53)1321 (85)4.8 (2 - 12)0.46 (0.36, 0.60)Ampulla of Vater224 (8)142 (63)9 (4 - 21)0.24 (0.11, 0.51)Mixed484 (16)401 (83)5 (2 - 13)0.51 (0.33, 0.78)*Adjusted for age at diagnosis, comorbidities, prior aspirin use, and use of statins.Abbreviations: CPRD, Clinical Practice Research Datalink; CI, confidence interval; HR, hazard ratio; N, number; and UK, United Kingdom. Citation Format: Sarah S. Jackson, Bin Zhu, Ruth Pfeiffer, Zhiwei Liu, Shahinaz Gadalla, Jill Koshiol. Aspirin may extend biliary tract cancer survival: Results from population-based cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2333.