Stimulation Of Mucus Secretion Research Articles

Sex-Dependent Regulation of Mucin Gene Transcription and Goblet Cell Secretion Machinery Following Intra-Airway IL-13 in Mice with Conditional Loss of Club Cell Creb1

IL-13 is an important effector molecule in allergic asthma, converting secretoglobin-positive club cells into mucin-secreting goblet cells and promoting mucin hypersecretion. IL-13-mediated conversion of club cells to goblet cells requires decreased gene expression of forkhead box A2 ( FOXA2) and increased gene expression of SAM pointed domain containing ETS transcription factor ( SPDEF). In addition, IL-13-mediated mucin hypersecretion may include modulation of purinergic and muscarinic receptors that control basal and stimulated mucus secretion, respectively. We recently found that the cAMP response element-binding protein (CREB), a ubiquitous transcription factor, directly binds to FOXA2 and modulates mucus secretion mechanisms in mice. Here we tested the hypothesis that conditional loss of club cell Creb1 in murine airways modulates the pro-mucin effects of IL-13. Loss of club cell Creb1 augmented IL-13-mediated increases in gene expression of the major gel-forming secreted mucins Muc5ac and Muc5b in male murine airways, with no effect on IL-13-mediated increases in Muc5ac and Muc5b in female murine airways. Examination of mucin secretion mechanisms revealed that IL-13 decreased muscarinic 3 receptor ( M3R) mRNA expression in male murine airways, whereas loss of club cell Creb1 prevented this, resulting in a significant treatment by genotype interaction. Interestingly, in female airways, a main effect of genotype was observed, with loss of club cell Creb1 reducing M3R mRNA expression in the airway. Examination of the purinergic receptor P2Y ( P2ry2) mRNA revealed a main treatment effect for IL-13 to increase P2ry2 expression in male murine airways with no impact of loss of club cell Creb1. In the females, IL-13 increased P2ry2 mRNA in both genotypes, with loss of club cell Creb1 significantly blunting the effect of IL-13 on P2ry2 mRNA. Lastly, we examined goblet cell density and mucin secretion mechanisms using Alcian Blue-PAS staining post in vivo stimulation with a muscarinic agent. We found no major effect of treatment or genotype in the density of goblet cells containing acidic mucins in either male or female airways. In contrast, both males and females showed IL-13-mediated increases in the density of goblet cells containing neutral mucins that was not impacted by genotype. Our preliminary findings suggest that loss of club cell Creb1 decreases molecular mucin secretion mechanisms in male and female airways, and increases Muc5ac and Muc5b mRNA in male airways, though a corresponding genotype-dependent increase in goblet cell density post cholinergic stimulation was not observed. Thus, we conclude that loss of club cell Creb1 causes changes to molecules important for IL-13-mediated mucin hypersecretion, without apparent functional benefit or detriment to the murine airway. This work was supported by the National Institutes of Health (OD026582, HL152101), the Cystic Fibrosis Foundation (REZNIKO20I0, REZNIKO19I0), the Katie Rose Foundation (AWD08203), and the University of Florida McKnight Career Accelerator Award. Angelina Bonilla was funded by the National institutes of Health (R25GM115298). Pedro Trevizan Bau receives the University of Florida McKnight Brain Institute Gator NeuroScholar Fellowship. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Phytochemical Properties of Crataegus azarolus Berries Decoction Extract and Evaluation of its Protective Activity Against Acetic Acid-Induced Ulcerative Colitis in Rats.

The present study aims to evaluate the protective effect of Crataegus azarolus berries decoction extract (CAB-DE) against acetic acid-induced ulcerative colitis as well as the mechanisms implicated in such protection. Adult male Wistar rats were separated into seven groups: Control (H2O), acetic acid (AA), AA + various doses of CAB-DE (100, 200, and 400mg/kg, b.w.,p.o.), and AA + sulfasalazine (100mg/kg, b.w.,p.o.) or gallic acid (50mg/kg, b.w.,p.o.) during 10days. All rats were kept fasting overnight and ulcerative colitis was induced by rectal infusion of AA (300mg kg-1, b.w.) (3%, v/v, 5mL kg-1 b.w), for 30s. The colon was rapidly excised and macroscopically examined to measure ulcerated surfaces and the ulcer index. In vitro, we found that CAB-DE exhibited a high antioxidant activity against DPPH radical (IC50 = 164.17 ± 4.78μg/mL). In vivo, pretreatment with CAB-DE significantly protected the colonic mucosa against AA-induced damage by stimulating mucus secretion, reducing ulcer index as well as histopathological changes. Also, CAB-DE limited the oxidative status induced by AA in the colonic mucosa, as assessed by MDA and H2O2 increased levels and the depletion of both enzymatic activities and non-enzymatic levels. In addition, AA intoxication increased iron and calcium levels in colonic mucosa and plasma, while CAB-DE pretreatment regulated all intracellular mediators deregulation and significantly reduced inflammatory markers such as CRP (1.175 ± .04 ─ .734 ± .06μg/dl) and ALP (161.53 ± 5.02 ─ 98.60 ± 4.21 UI/L) levels. We suggest that CAB-DE protected against AA-induced ulcerative colitis due in part to its antioxidant and anti-inflammatory properties.

Bei Mu Gua Lou San facilitates mucus expectoration by increasing surface area and hydration levels of airway mucus in an air-liquid-interface cell culture model of the respiratory epithelium

BackgroundBei Mu Gua Lou San (BMGLS) is an ancient formulation known for its moisturizing and expectorant properties, but the underlying mechanisms remain unknown. We investigated concentration-dependent effects of BMGLS on its rehydrating and mucus-modulating properties using an air-liquid-interface (ALI) cell culture model of the Calu-3 human bronchial epithelial cell line and primary normal human bronchial epithelial cells (NHBE), and specifically focused on quantity and composition of the two major mucosal proteins MUC5AC and MUC5B.MethodsALI cultures were treated with BMGLS at different concentrations over three weeks and evaluated by means of histology, immunostaining and electron microscopy. MUC5AC and MUC5B mRNA levels were assessed and quantified on protein level using an automated image-based approach. Additionally, expression levels of the major mucus-stimulating enzyme 15-lipoxygenase (ALOX15) were evaluated.ResultsBMGLS induced concentration-dependent morphological changes in NHBE but not Calu-3 ALI cultures that resulted in increased surface area via the formation of herein termed intra-epithelial structures (IES). While cellular rates of proliferation, apoptosis or degeneration remained unaffected, BMGLS caused swelling of mucosal granules, increased the area of secreted mucus, decreased muco-glycoprotein density, and dispensed MUC5AC. Additionally, BMGLS reduced expression levels of MUC5AC, MUC5B and the mucus-stimulating enzyme 15-lipoxygenase (ALOX15).ConclusionsOur studies suggest that BMGLS rehydrates airway mucus while stimulating mucus secretion by increasing surface areas and regulating goblet cell differentiation through modulating major mucus-stimulating pathways.

Enhancement of prostaglandin D2-D prostanoid 1 signaling reduces intestinal permeability by stimulating mucus secretion

IntroductionThe intestinal barrier plays a crucial role in distinguishing foods from toxins. Prostaglandin D2 (PGD2) is one of the lipid-derived autacoids synthesized from cell membrane-derived arachidonic acid. We previously reported that pharmacological stimulation of PGD2 receptor, D prostanoid 1 (DP1) attenuated the symptoms of azoxymethane/dextran sodium sulfate-induced colitis and ovalbumin-induced food allergy in mouse models. These observations suggested that DP1 stimulation protects the intestinal barrier. The present study aimed to uncover the effects of DP1 stimulation on intestinal barrier function and elucidate the underlying mechanisms.Materials and methodsIntestinal permeability was assessed in mice by measuring the transfer of orally administered fluorescein isothiocyanate-dextran (40 kDa) into the blood. The DP1 agonist BW245C (1 mg/kg) was administered 10 min prior to dextran administration. The intestinal permeability was confirmed using the ex vivo everted sac method. Tight junction integrity was evaluated in vitro by measuring the transepithelial electrical resistance (TER) in the human intestinal epithelial cell line Caco-2. Mucus secretion was assessed by observing Alcian Blue-stained intestinal sections.ResultsPharmacological DP1 stimulation reduced intestinal permeability both in vivo and ex vivo. Immunohistochemical staining showed that DP1 was strongly expressed on the apical side of the epithelial cells. DP1 stimulation did not affect TER in vitro but induced mucus secretion from goblet cells. Mucus removal by a mucolytic agent N-acetyl-l-cysteine canceled the inhibition of intestinal permeability by DP1 stimulation.ConclusionThese observations suggest that pharmacological DP1 stimulation decreases intestinal permeability by stimulating mucus secretion.

Gut homeostasis, injury, and healing: New therapeutic targets.

The integrity of the gastrointestinal mucosa plays a crucial role in gut homeostasis, which depends upon the balance between mucosal injury by destructive factors and healing via protective factors. The persistence of noxious agents such as acid, pepsin, nonsteroidal anti-inflammatory drugs, or Helicobacter pylori breaks down the mucosal barrier and injury occurs. Depending upon the size and site of the wound, it is healed by complex and overlapping processes involving membrane resealing, cell spreading, purse-string contraction, restitution, differentiation, angiogenesis, and vasculogenesis, each modulated by extracellular regulators. Unfortunately, the gut does not always heal, leading to such pathology as peptic ulcers or inflammatory bowel disease. Currently available therapeutics such as proton pump inhibitors, histamine-2 receptor antagonists, sucralfate, 5-aminosalicylate, antibiotics, corticosteroids, and immunosuppressants all attempt to minimize or reduce injury to the gastrointestinal tract. More recent studies have focused on improving mucosal defense or directly promoting mucosal repair. Many investigations have sought to enhance mucosal defense by stimulating mucus secretion, mucosal blood flow, or tight junction function. Conversely, new attempts to directly promote mucosal repair target proteins that modulate cytoskeleton dynamics such as tubulin, talin, Ehm2, filamin-a, gelsolin, and flightless I or that proteins regulate focal adhesions dynamics such as focal adhesion kinase. This article summarizes the pathobiology of gastrointestinal mucosal healing and reviews potential new therapeutic targets.

A randomised study of evaluation of antiulcerogenic activity of quercetin in rats

Background: Peptic ulcer is very common disease. Peptic ulcer results probably due to an imbalance between aggressive factors (acid, pepsin, H. pylori) and defensive factors (gastric mucus, prostaglandins and bicarbonate secretion). Whatever may be the cause of peptic ulcer, it is the gastric acid that prevents ulcer healing and maintain the ulcer. Therefore, most of the drugs available for treatment of peptic ulcer either neutralize the secreted acid or decrease the acid secretion.Methods: The study was conducted on albino rats (Wistar) of 200-250g and maintained under standard conditions (room temperature 24-27oC and humidity 60-65%) with 12h light and dark cycle. The food in the form of dry pellets (Amrut Lab., hyd) and water were available ad libitum. The animal experiments were approved by the ethics committee of the institute.Results: In pyloric ligation model, the rats pre-treated with quercetin showed highly significant protection (p <0.001) when compared to control group and significant protection when compared to ranitidine pre-treated group (p <0.05). In indomethacin model, both quercetin and ranitidine pre-treated groups showed significant protection when compared to control group (p <0.01).Conclusions: In conclusion, it appears that quercetin possess anti-ulcerogenic principles like flavanoids, phenolic compound and caratinoid. These phytoconstituents provides protection against gastric mucosal damage induced by pylorus ligation, aspirin and ethanol, through inhibition of gastric acid, pepsin, histamine and free radical and stimulation of mucus secretion.

Stress-Induced Mucus Secretion and Its Composition by a Combination of Proteomics and Metabolomics of the Jellyfish Aurelia coerulea.

Background: Jellyfish respond quickly to external stress that stimulates mucus secretion as a defense. Neither the composition of secreted mucus nor the process of secretion are well understood. Methods: Aurelia coerulea jellyfish were stimulated by removing them from environmental seawater. Secreted mucus and tissue samples were then collected within 60 min, and analyzed by a combination of proteomics and metabolomics using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS), respectively. Results: Two phases of sample collection displayed a quick decrease in volume, followed by a gradual increase. A total of 2421 and 1208 proteins were identified in tissue homogenate and secreted mucus, respectively. Gene Ontology (GO) analysis showed that the mucus-enriched proteins are mainly located in extracellular or membrane-associated regions, while the tissue-enriched proteins are distributed throughout intracellular compartments. Tryptamine, among 16 different metabolites, increased with the largest-fold change value of 7.8 in mucus, which is consistent with its involvement in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway ‘tryptophan metabolism’. We identified 11 metalloproteinases, four serpins, three superoxide dismutases and three complements, and their presence was speculated to be related to self-protective defense. Conclusions: Our results provide a composition profile of proteins and metabolites in stress-induced mucus and tissue homogenate of A. coerulea. This provides insight for the ongoing endeavors to discover novel bioactive compounds. The large increase of tryptamine in mucus may indicate a strong stress response when jellyfish were taken out of seawater and the active self-protective components such as enzymes, serpins and complements potentially play a key role in innate immunity of jellyfish.

Beneficial effects of the commercial lactic acid bacteria product, Vigiis 101, on gastric mucosa and intestinal bacterial flora in rats

Gastric mucosal integrity is maintained through achieving a balance between potentially detrimental and protective factors. This study aimed to evaluate the effects of Vigiis 101 powder, a product consisting of dried Lactobacillus paracasei subsp. paracasei NTU 101 bacteria, on intestinal bacterial flora and acute damage to the gastric mucosa induced by pylorus ligation. Acute gastric injury were induced by pylorus ligation. Rats were orally treated with the vehicle or 0.15, 0.30, 1.50g/kg (0.5-, 1-, and 5-x) Vigiis 101 for 8 weeks. We analyzed the intestinal microflora, short-chain fatty acids, antioxidant enzyme levels and gastric lesion. Daily treatment of rats with Vigiis 101 increased the levels of beneficial Bifidobacterium spp. and Lactobacillus spp., and reduced those of detrimental Clostridium perfringens and Enterobacteriaceae. Vigiis 101 treatment also markedly reduced gastric lesion areas by between 1.7 and 11.4%, and significantly increased the levels of the short-chain fatty acids (SCFAs): acetic acid, propionic acid, and butyric acid in cecal samples by 45-86%, 127-158%, and 20-211%, respectively, compared to non-treated controls. In the gastric mucosa of rats treated with Vigiis 101, the activity of superoxide dismutase and levels of prostaglandin E2 (PGE2) were enhanced, and the activity of lipid peroxidase reduced, relative to controls. The up-regulation of PGE2 and SCFAs in the gastric mucosa is likely to stimulate mucus secretion and increase transmucosal resistance, thereby contributing to Vigiis 101-mediated protection from gastric mucosal lesions induced by pylorus ligation.

Serum Biochemical Profile of Nile Tilapias (Oreochromis niloticus) Bred in Net Cages during Summer and Winter

Background: The growth of fish farming in Brazil has been noticeable over the past few years, and the Nile tilapia (Oreochromis niloticus) is the most bred species in the country. Studies on the physiology of these animals are necessary so that the production continues to grow and to improve its rates. However, very discrepant data are still found in the area of blood biochemistry. The aim of this study was to evaluate the physiological variations in serum concentrations of proteins, metabolites, electrolytes and serum enzymes in Nile tilapias bred in net cages in Cachoeira Dourada, state of Minas Gerais, Brazil, during summer and winter.Materials, Methods & Results: During the year of 2016, samples from 100 Nile tilapias were collected during summer (January and February) and samples from 100 Nile tilapias were also collected during winter (July and August). Only one blood sample was collected by caudal venipuncture of each fish, just before the slaughter, always in the morning. The serum samples obtained were then analyzed for serum concentrations of proteins, metabolites, electrolytes, lipids and serum enzymes. Serum concentrations of total proteins, globulins, triglycerides, high density lipoprotein (HDL), alkaline phosphatase, sodium and chloride were significantly higher during winter in comparison to summer, while the serum concentration of uric acid was significantly lower during winter in comparison to summer.Discussion: Due to the lower temperature of water during winter, tilapias reduced food intake and became more susceptible to diseases, which led to an increase in circulating globulins. In that same season, there was an increase in serum concentrations of sodium and chloride as a result of adding sodium chloride to the water in order to stimulate mucus secretion on the fishes’ skin and gills to prevent pathologies. Triglycerides, HDL, and uric acid are considered indicators of nutritional status of animals. The increase in serum concentrations of triglycerides and HDL indicates that tilapias are mobilizing energy reserves, however, when the increase in serum concentrations of uric acid is observed, it is fair to assume there has been an increase in food intake, raising protein catabolism. The increase of serum concentration in alkaline phosphatase is caused by the presence of multiple forms of enzymes that are induced by the action of endogenous corticosteroids, which are produced as a result of the stress suffered by tilapias during the fishing process and during winter, when the water temperature is lower than the ideal for this species. It can be concluded that the season has influence on some serum biochemical constituents of Nile tilapias bred in net cages, and that the predominant variations happen during winter due to immunity decline and during summer due to the increase in food intake and, consequently, in the metabolism of tilapias.

Corticotrophin Releasing Hormone Regulates NLRP6 and Disrupts Mucosal Homeostasis in Functional Dyspepsia

BackgroundFunctional dyspepsia (FD) affects 15% of the population and is characterised by recurring upper gastrointestinal (GI) symptoms occurring in the absence of clinically identifiable pathology. The pathophysiology of FD is poorly understood, however recent work has demonstrated increased numbers of mucosal mast cells and eosinophils in patients with FD. Psychological stress is a key factor associated with the onset of FD and is a trigger of symptom exacerbations, however the biological mechanisms through which stress may lead to FD symptoms have not yet been defined. Recent pre‐clinical work identified that psychological stress downregulates the innate epithelial immune protein NLRP6. NLRP6 has been shown to regulate GI mucus secretion and is responsible for activation of Interleukin 18 (IL‐18). IL‐18 is potently chemotactic for mast cells and eosinophils. We hypothesised that stress hormone levels are altered in patients with FD, leading to alterations in GI mucosal homeostasis and immune cell recruitment.MethodsGoblet cell‐like HT29‐MTX‐E12 (E12) cells were grown on permeable membranes over 21 days to form monolayers with apical‐basolateral polarity. Cells were treated basolaterally with the stress hormone corticotrophin releasing hormone (CRH) (0.05μM or 0.5μM) for 16 hours. mRNA was extracted for qPCR analysis and immunoblots were performed on whole protein lysates. For mucous‐layer analysis, monolayers were snap frozen and stained with alcian blue. FD patients were identified by the Rome III criteria; asymptomatic individuals were recruited as controls. Serum CRH levels were measured by ELISA. Pinch biopsies were collected from the duodenum of FD patients and non‐FD controls. Biopsies were either formalin fixed and stained immunohistochemically or mRNA was extracted from enriched epithelial cell preparations for qPCR analysis.ResultsNLRP6 expression was increased in monolayers treated with 0.05μM CRH and decreased in monolayers treated with 0.5μM CRH (n=3, p=0.02), suggesting a dynamic regulation. CRH treatment at both 0.05μM and 0.5μM significantly increased mucus secretion in monolayers (n=3, p=0.05 and p<0.0001 respectively). Levels of CRH were significantly reduced in both duodenal tissue (n=6, p=0.001) and serum (n=10, p=0.013) of FD patients compared to non‐FD controls. Duodenal NLRP6 was significantly increased in patients with FD compared to non‐FD controls (n=6, p=0.007) and epithelial expression of NLRP6 was positively correlated with expression of IL‐18 (r=0.95, p=0.015) in FD patients, but not non‐FD controls.ConclusionThis study has identified that CRH dynamically regulates NLRP6 in vitro and stimulates mucus secretion. Therefore, the concurrent decrease in CRH and increase in NLRP6 observed in FD patients provides a potential pathway through which psychological stress may lead to disruption of GI mucosal homeostasis and disease.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Year in review 2017: Chronic obstructive pulmonary disease and asthma.

Year in review 2017: Chronic obstructive pulmonary disease and asthma.

Aniseed (Pimpinella anisum L.) essential oil reduces pro-inflammatory cytokines and stimulates mucus secretion in primary airway bronchial and tracheal epithelial cell lines

Aniseed (Pimpinella anisum L., Apiaceae) is a medicinal and aromatic plant widely cultivated in the Mediterranean area and used in foodstuffs, as ingredient of famous liqueurs, confectionery and bakery products. Its essential oil is one of the most selled on the market and used on an industrial level. In addition, aniseed is exploited as an herbal remedy to threat respiratory disorders. However, little information is available about its effect on respiratory tissues during inflammation. In the present work, we evaluated the anti-inflammatory activity and the effect on mucin secretion of aniseed essential oil in primary airway bronchial and tracheal epithelial cells (HBEpC and HTEpC, respectively) in a model of lung inflammation induced by lypopolysaccharide (LPS). The aniseed essential oil was obtained by hydrodistillation of the fruits from plants cultivated in central Italy, and analysed by gas chromatography-mass spectrometry (GC–MS). HBEpC and HTEpC lines were treated with LPS and then incubated with 0.3% of aniseed essential oil. Levels of pro-inflammatory cytokines, IL-8 and IL-1 beta were assessed by RT/PCR and Western Blot analysis. Muc5ac protein release was determined in culture medium of HBEpC- and HTEpC- LPS-treated lines by Western Blot analysis. Aniseed essential oil showed a very high level of (E)-anethole (97.9%). At non-toxic doses, it significantly decreased the expression levels of IL-1 and IL-8 and increased the Muc5ac secretion in LPS-treated HBEpC and HTEpC lines. These results provide new evidence supporting the ethnobotanical use of aniseed in the treatment of respiratory diseases. In particular, aniseed essential oil showed a significant anti-inflammatory effect on both HBEpC and HTEpC cells together with mucus hypersecretion.

Tiotropium inhibits mucin production stimulated by neutrophil elastase but not by IL-13

Tiotropium, a muscarinic antagonist, is approved for the treatment of chronic obstructive pulmonary disease and poorly controlled asthma. Because mucus hypersecretion is characteristic of both of these diseases, and muscarinic agonists stimulate mucus secretion, we hypothesized that tiotropium would attenuate airway MUC5AC expression. We grew normal human bronchial epithelial (NHBE) cells to a goblet cell phenotype with 1 or 5 ng/mL of IL-13 and exposed these cells to 10 nM tiotropium or excipient for the full 14 days. Normally differentiated NHBE cells (without IL-13) were exposed to neutrophil elastase (NE) 1 × 10−7 or 5 × 10−7 M for 1 h. MUC5AC was measured by quantitative PCR and ELISA. Acetylcholine production by the epithelium was evaluated by quantitative PCR and by choline/acetylcholine quantification. Tiotropium had no effect on IL-13-stimulated MUC5AC, but attenuated MUC5AC stimulated by NE (p = 0.007 at 5 × 10−7 M). IL-13 increased CarAT mRNA (p < 0.001 at 5 ng/mL) and acetylcholine concentration in the medium (p = 0.018 at 5 ng/mL), while NE had no effect. Tiotropium had no direct effect on IL-13 or NE-induced CarAT or acetylcholine concentration. Tiotropium decreased MUC5AC stimulated by NE, but had no effect on MUC5AC stimulated by IL-13. These results may be due to IL-13, but not NE, increasing acetylcholine production.

Prophylactic effects of Clausena excavata Burum. f. leaf extract in ethanol-induced gastric ulcers.

Clausena excavata is a natural herb with both antioxidant and anti-inflammatory properties. It has been used for decades in folkloric practice for the amelioration of various ailments. In this study, the gastroprotective activity of methanolic extract of C. excavata leaves (MECE) was determined in the Sprague Dawley rat ethanol-induced gastric ulcer model. Rats were pretreated with a single dose of vehicle (5% Tween 20), 20 mg/mL omeprazole, 400 and 200 mg/mL of MECE dissolved in 5% Tween 20. Ulcer was induced with 5 mL/kg of ethanol and stomach tissue was obtained after 1 hour. Histological examination was done on hematoxylin and eosin, periodic acid-Schiff, and immunochemically stained gastric mucosal tissues. Prostaglandin E2, superoxide dismutase, catalase, glutathione peroxidase, and lipid peroxidation levels of the gastric tissue homogenates were also determined. Significantly (P<0.05) smaller ulcer areas, less intense edema, and fewer leukocytes’ infiltration were observed in MECE- and omeprazole-treated than in untreated gastric mucosa with ulcer. The gastric pH, mucus production, superoxide dismutase, catalase, and glutathione peroxidase contents increased, while the lipid peroxidation content decreased as a result of MECE treatment. Bcl-2-associated X protein was underexpressed, while heat shock protein 70 and transforming growth factor-beta protein were overexpressed in the ulcerated gastric mucosa tissues treated with omeprazole and MECE. Similarly, there was a reduction in the levels of tumor necrotic factor-alpha and interleukin-6, while the level of interleukin-10 was increased. This study showed that the gastroprotective effect of MECE is achieved through inhibition of gastric juice secretion and ulcer lesion development, stimulation of mucus secretion, elevation of gastric pH, reduction of reactive oxygen species production, inhibition of apoptosis in the gastric mucosa, and modulation of inflammatory cytokines.

Investigating the role of MRGPRC11 and capsaicin-sensitive afferent nerves in the anti-influenza effects exerted by SLIGRL-amide in murine airways.

BackgroundThe hexapeptide SLIGRL-amide activates protease-activated receptor-2 (PAR-2) and mas-related G protein-coupled receptor C11 (MRGPRC11), both of which are known to be expressed on populations of sensory nerves. SLIGRL-amide has recently been reported to inhibit influenza A (IAV) infection in mice independently of PAR-2 activation, however the explicit roles of MRGPRC11 and sensory nerves in this process are unknown. Thus, the principal aim of this study was to determine whether SLIGRL-amide-induced inhibition of influenza infection is mediated by MRGPRC11 and/or by capsaicin-sensitive sensory nerves.MethodsThe inhibitory effect of SLIGRL-amide on IAV infection observed in control mice in vivo was compared to effects produced in mice that did not express MRGPRC11 (mrgpr-cluster∆−/− mice) or had impaired sensory nerve function (induced by chronic pre-treatment with capsaicin). Complementary mechanistic studies using both in vivo and ex vivo approaches investigated whether the anti-IAV activity of SLIGRL-amide was (1) mimicked by either activators of MRGPRC11 (BAM8-22) or by activators (acute capsaicin) or selected mediators (substance P, CGRP) of sensory nerve function, or (2) suppressed by inhibitors of sensory nerve function (e.g. NK1 receptor antagonists).ResultsSLIGRL-amide and BAM8-22 dose-dependently inhibited IAV infection in mrgpr-cluster∆−/− mice that do not express MRGPRC11. In addition, SLIGRL-amide and BAM8-22 each inhibited IAV infection in capsaicin-pre-treated mice that lack functional sensory nerves. Furthermore, the anti-IAV activity of SLIGRL-amide was not mimicked by the sensory neuropeptides substance P or CGRP, nor blocked by either NK1 (L-703,606, RP67580) and CGRP receptor (CGRP8-37) antagonists. Direct stimulation of airway sensory nerves through acute exposure to the TRPV1 activator capsaicin also failed to mimic SLIGRL-amide-induced inhibition of IAV infectivity. The anti-IAV activity of SLIGRL-amide was mimicked by the purinoceptor agonist ATP, a direct activator of mucus secretion from airway epithelial cells. Additionally, both SLIGRL-amide and ATP stimulated mucus secretion and inhibited IAV infectivity in mouse isolated tracheal segments.ConclusionsSLIGRL-amide inhibits IAV infection independently of MRGPRC11 and independently of capsaicin-sensitive, neuropeptide-releasing sensory nerves, and its secretory action on epithelial cells warrants further investigation.

Histamine stimulates mucus secretion through IL‐4 induced TMEM16A in human nasal epithelium

BackgroundHistamine released from mast cells is an important mediator of allergic reaction, and mucus hypersecretion is a major allergic symptom.ObjectiveWe studied whether histamine directly induces mucus secretion from epithelial cells or submucosal glands (SMG) in human and pig nasal epithelium.MethodsThe short circuit current (Isc) change in response was determined in cultured primary human nasal epithelial (HNE) cells using Ussing chamber experiment. Freshly excised nasal mucosae were harvested from patients who were classified into AR and non‐AR group to quantify mucus secretion from individual SMGs using bubble method. The expression of H1R, H2R, and H3R in human nasal turbinates was identified using in situ hybridization. Pig nasal and tracheal tissues were also investigated.ResultsHistamine induced a modest alteration of Isc in HNE cells with increasing intracellular calcium but no gland secretion. Pretreatment of IL‐4 augmented histamine response that was suppressed by TMEM16A inhibitor. The expression of H1R, H2R, and H3R was identified in human nasal epithelium by in situ hybridization. However, H1R or H2R was not noted in SMG. In pig airway tissues, histamine was a potent secretagogue that directly induced robust responses, indicating a species‐difference from human.ConclusionH1R agonist induces modest anion secretion under normal condition but the response was enhanced under IL‐4 stimulation that might be related to mucus hypersecretion in allergic rhinitis. We first elucidated histamine‐induced mucus secretion in synergy with IL‐4 through TMEM16A in human nasal epithelium.Support or Funding InformationSupported by grants NRF‐2013R1A1A 1010151 to H. J. Cho from the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education, Science and Technology.

Modulation and adherence of intestinal mucus by commensal bacteria and the pathogen C. difficile

Gut pathogens initially encounter the host at the gastrointestinal (GI) mucus layer making its regulation a crucial aspect of gut health. Few studies have addressed bacteria‐mucus adherence or mucus oligosaccharide utilization by commensal or pathogenic bacteria. To address this gap in knowledge, the interaction between mucus (human stool, HT‐29‐MTX cells and human ileal enteroids) and commensal bacteria (B. thetaiotaomicron, C. coccoides, C. butryicum, B. producta, A. muciniphila, F. prausnitzii, R. torques, L. reuteri) or the pathogen C. difficile was examined. In vitro cultures in tryptone‐yeast extract media revealed that C. difficile and B. producta were capable of using multiple types of oligosaccharides (fucose, mannose, galactose, GlcNAc, GalNAC, sialic acid) as a sole carbon source, while other commensal bacteria exhibited specific oligosaccharide preferences. Commensal bacteria had enhanced adherence to mucus from human stool compared to HT‐29‐MTX mucus. Additionally, FITC‐labeled oligosaccharide specific lectins demonstrated that all tested commensal bacteria were capable of altering mucus oligosaccharide composition. Select commensal species were also able to stimulate mucus secretion. In contrast, the pathogen C. difficile adhered to multiple oligosaccharides in human stool mucus, but had limited adherence to HT‐29‐MTX mucus. C. difficile did not stimulate mucus secretion in HT‐29‐MTX cells and decreased secretion in enteroids. Together this data demonstrates that commensal and pathogenic bacteria adhere directly to GI mucus, but this interaction is mucin type and composition dependent. Manipulation or adherence to intestinal mucus may represent a method of bacterial‐host modulation. T32DK07644

LEUKOTRIENE RECEPTOR ANTAGONISTS IN DIFFERENT PHENOTYPES OF BRONCHIAL ASTHMA

Cysteinyl leukotrienes which are products of lipoxygenase pathway of arachidonic acid metabolism play an important role in all phenotypes of bronchial asthma (BA). They are involved in immune and non-immune stimulation of different cells and inflammatory mechanisms in BA. Leukotrienes cause bronchoconstriction, increase vascular permeability and bronchial mucosa oedema, stimulate mucus secretion. Knowledge of leukotriene as inflammation mediators has allowed development leukotriene receptor antagonists and their implementation in clinical practice. Antiinflammatory properties of leukotriene receptor antagonists facilitate achievement asthma control while using both as monotherapy in mild asthma and in combinations with other antiasthmatic drugs in more severe disease. Currently, ongoing research of asthma phenotypes could define certain phenotypes with more important role of leukotrienes.

Antiulcerogenic and mucogenic activity of xylopia aethiopica fruit extract in rat

Prolong administration of non steroidal anti-inflammatory drugs, alcohol, irritants and stress can cause peptic ulcer. In the present investigation, the effect of indomethacin, alcohol and hypothermia induced stress on Xylopia aethiopicafed rats was studied. Peptic ulcers were induced by oral administration of indomethacin (50mg/kg) or alcohol (10ml/kg) or 2-hour exposure to cold (15-20oC). The animals were anaesthetized, their abdomens opened and stomachs removed for macroscopic assessment of ulcers, and mucus secretion. The fruit extract of Xylopia aethiopica reduced the induced gastric ulcers caused by indomethacin and increased mucus secretion dose dependently when compared with control. Likewise, the mean gastric ulcer indexes were significantly reduced and mucus secretionincreased in the ethanol induced model when compared with control. In the hypothermic stress induced gastric ulcers, the values of the mean ulcers were also reduced significantly, but mucus secretion was only significantly higher in the high dose extract-treated group than in control. These results show that consumption of the fruit of xylopia aethiopica could reduce incidence of peptic ulcer. The increased secretion of mucus in the test animals suggests that prostaglandins might have been produced since they are known to stimulate mucus secretion. It is concluded that thefruit extract of Xylopia aethiopica stimulated mucus secretion and reduced peptic ulceration in the rat.KEYWORDS: Xylopia aethiopica, ulcer, indomethacin, alcohol, stress.

Anti-gastric Actions of Eugenol and Cinnamic Acid Isolated from Cinnamomi Ramulus

We investigated the evidence of gastric protection for ulcer and gastritis by Cinnamomi Ramulus (Cinnamomum cassia Blume, Geiji, CR) extract and its several constituents. CR ethanolic extract showed the potent antioxidant activity and cytotoxicity of Helicobacter pylori (H. pylori) and acid-neutralizing capacity. Especially, eugenol exerted a significant antioxidant activity and inhibited the colonization of H. pylori. In vivo test, eugenol and cinnamic acid significantly inhibited HCl/ethanol-induced gastric lesions and increased the mucus content though they didn't inhibit gastric secretion effectively. Taken together, eugenol and cinnamic acid, which were isolated from CR, exhibited the antioxidant activity in vitro and protective effect against gastric damage in vivo through stimulation of mucus secretion and so on. It suggested that they are useful as the neutraceuticals for gastritis.