Goblet Cell Mucus Research Articles

Fmo5 plays a sex-specific role in goblet cell maturation and mucus barrier formation.

The intestine plays a key role in metabolism, nutrient and water absorption, and provides both physical and immunological defense against dietary and luminal antigens. The protective mucosal lining in the intestine is a critical component of intestinal barrier that when compromised, can lead to increased permeability, a defining characteristic of inflammatory bowel disease (IBD), among other intestinal diseases. Here, we define a new role for the flavin-containing monooxygenase (FMO) family of enzymes in maintaining a healthy intestinal epithelium. Using Caenorhabditis elegans we measure intestinal barrier function, actin expression, and intestinal damage response. In mice, we utilize an intestine-specific, tamoxifen- inducible knockout model of the mammalian homolog of Cefmo-2 , Fmo5, and assess histology, mucus barrier thickness, and goblet cell physiology. We also treat mice with the ER chaperone Tauroursodeoxycholic acid (TUDCA). In nematodes, we find Cefmo-2 is necessary and sufficient for intestinal barrier function, intestinal actin expression, and is induced by intestinal damage. In mice, we find striking changes to the intestine within two weeks following Fmo5 disruption. Alterations include sex-dependent changes in colon epithelial histology, goblet cell localization, and mucus barrier formation. These changes are significantly more severe in female mice, mirroring differences observed in IBD patients. Furthermore, we find increased protein folding stress in Fmo5 knockout animals and successfully rescue the severe female phenotype with addition of a chemical ER chaperone. Together, our results identify a highly conserved and novel role for Fmo5 in the mammalian intestine and support a key role for Fmo5 in maintenance of ER/protein homeostasis and proper mucus barrier formation.

YiQi GuBen formula alleviates airway inflammation and airway remodeling in OVA-induced asthma mice through TLR4/NF-κB signaling pathway.

We aim to investigate the effect of YiQi GuBen formula (YQGB) on airway inflammation and airway remodeling in the ovalbumin (OVA)-induced asthma model to further explore the potential mechanisms of YQGB in treating allergic asthma. Mice were divided into five groups randomly (n = 10): the control group, OVA group, OVA + Dex (0.1 mg/kg) group, OVA + low-dose (1.1 g/kg) YQGB group, and OVA + high-dose (2.2 g/kg) YQGB group. Inflammatory cell count and IgE were detected in bronchoalveolar lavage fluid (BALF). Lung tissue histopathology was observed by using H&E, PAS, Masson, and immunohistochemistry staining. qRT-PCR and western blot were applied to analyze key genes and proteins associated with TLR4 and NF-κB signaling pathways. In OVA-induced asthma mice, YQGB decreased eosinophils and IgE in BALF. YQGB alleviated the OVA-induced inflammatory infiltration and declined IL-4, IL-5, IL-13, Eotaxin, ECP, GM-CSF, LTC4, and LTD4. YQGB attenuated the OVA-induced goblet cell metaplasia and mucus hypersecretion. YQGB mitigated the OVA-induced subepithelial fibrosis and lowered TGF-β1, E-Cadherin, Vimentin, and Fibronectin. YQGB ameliorated the OVA-induced airway smooth muscle thickening and lessened α-SMA and PDGF levels. YQGB reduced the expression of TLR4, MyD88, TRAF6, IκBα, and p65 mRNAs, and IκBα and p-p65 protein levels were also reduced. YQGB exhibits the anti-asthma effect by reducing airway inflammation and airway remodeling through suppressing TLR4/NF-κB signaling pathway, and is worth promoting clinically.

The hydro-ethanolic extract of Scoparia dulcis Linn inhibits allergic airway inflammatory responses in murine asthma models

BackgroundInflammatory responses, including airway inflammation, hyper-responsiveness, mucus hyper-secretion, prostaglandins and Th2 cytokines infiltration in the airway submucosa, frequently occur in allergic respiratory disorders. This study sought to investigate the effects of the hydro-ethanolic extract of Scoparia dulcis (SDE) on allergic airway inflammation, airway hyper-responsiveness, goblet cell hyperplasia, mucus hypersecretion, Th2 cytokines and prostaglandin (PG)-D2 using murine asthma models. MethodsAllergic asthma was induced in healthy guinea-pigs, and mice, by exposing them to ovalbumin (OVA) sensitization and challenge, and treatment with either 2 ml/kg normal saline, 10 mg/kg salbutamol, 10 mg/kg prednisolone, 50, 100, or 250 mg/kg of SDE per os. The percentage protection against pre-convulsive dyspnoea after methacholine challenge in OVA-induced asthmatic guinea-pigs was determined for each treatment regime, and histopathological examinations thereafter conducted on the excised lungs. Periodic acid-Schiff staining was also performed to identify goblet cell hyperplasia and mucus hypersecretion in these lung tissues. Lung tissue homogenates and serum from OVA-induced asthmatic mice were also assayed for PGD2, interleukins (IL)-5 and -13 levels using monoclonal antibody-based mouse ELISA kits. ResultsSDE treatments prolonged the time taken for pre-convulsive dyspnoea to occur after methacholine challenge in OVA-induced asthmatic guinea-pigs; indicative of a positive activity against airway hyper-responsiveness. Histopathological studies also showed that SDE significantly inhibited (p ≤ 0.05) pulmonary infiltration of leukocytes, inflammatory cell accumulation, airway smooth muscle thickening and goblet cell hyperplasia. Serum and lung tissue concentrations of PGD2, IL-5 and IL-13, significantly elevated (p ≤ 0.001) following allergic asthma induction in mice, were significantly reduced (p ≤ 0.01) back to within normal levels after SDE treatments. ConclusionThe plant extract exhibited anti-asthmatic and anti-inflammatory properties, as it reduced the severity of allergic inflammation and hyper-reactivity, as well as PGD2 and Th2 cytokines infiltration in the airway; and these effects could be exploited for future management of asthma.

Surgical Management of Allergic Rhinitis

The inferior turbinate is composed of a central bony structure surrounded by ciliated pseudostratified columnar epithelium. Underneath the epithelium, there are mucous glands, goblet cells and venous sinusoids in the submucosa, The inferior turbinate is supplied by the inferior turbinate branch of the posterior lateral nasal artery from the sphenopalatine artery. The inferior turbinates humidify the air, trap particles and direct airflow throughout the nasal cavity. Due to these functions, the inferior turbinates are often the first point of contact for allergens in the inspired air. With immune responses prompted by a cascade of inflammatory mediators such as immunoglobulin E, mast cells, histamine, and leukotrienes, mucous glands become stimulated and the vasculature within the inferior turbinate engorges. This results in inferior turbinate hypertrophy, leading to increased nasal discharge and nasal obstruction. For individuals refractory to medical therapy for nasal obstruction, surgical inferior turbinate reduction techniques can be employed to help alleviate the symptoms. For those with rhinorrhea refractory to medical therapy, surgical management aimed at reducing parasympathetic innervation to the nasal cavity to reduce nasal discharge production can be also option.

GSDMD protects intestinal epithelial cells against bacterial infections through its N-terminal activity impacting intestinal immune homeostasis.

The intestinal mucosal barrier serves as a vital guardian for gut health, maintaining a delicate equilibrium between gut microbiota and host immune homeostasis. Recent studies have found the intricate roles of Gasdermin D (GSDMD), a key executioner of pyroptosis downstream of the inflammasome, within the intestine, including controlling colitis in intestinal macrophage and the regulatory function in goblet cell mucus secretion. Thus, the exact role and nature of GSDMD's regulatory function in maintaining intestinal immune homeostasis and defending against pathogens remain elucidation. Here, we uncover that GSDMD plays a key role in defending against intestinal Citrobacter rodentium infection, with high expression in intestinal epithelial and lamina propria myeloid cells. Our results show that GSDMD specifically acts in intestinal epithelial cells to fight the infection, independently of its effects on antimicrobial peptides or mucin secretion. Instead, the resistance is mediated through GSDMD's N-terminal fragments, highlighting its importance in intestinal immunity. However, the specific underlying mechanism of GSDMD N-terminal activity in protection against intestinal bacterial infections still needs further study to clarify in the future.

Anoctamin pharmacology

TMEM16 proteins, also known as anoctamins, are a family of ten membrane proteins with various tissue expression and subcellular localization. TMEM16A (anoctamin 1) is a plasma membrane protein that acts as a calcium-activated chloride channel. It is expressed in many types of epithelial cells, smooth muscle cells and some neurons. In airway epithelial cells, TMEM16A expression is particularly enhanced by inflammatory stimuli that also promote goblet cell metaplasia and mucus hypersecretion. Therefore, pharmacological modulation of TMEM16A could be beneficial to improve mucociliary clearance in chronic obstructive respiratory diseases. However, the correct approach to modulate TMEM16A activity (activation or inhibition) is still debated. Pharmacological inhibitors of TMEM16A could also be useful as anti-hypertensive agents given the TMEM16A role in smooth muscle contraction.In contrast to TMEM16A, TMEM16F (anoctamin 6) behaves as a calcium-activated phospholipid scramblase, responsible for the externalization of phosphatidylserine on cell surface. Inhibitors of TMEM16F could be useful as anti-coagulants and anti-viral agents. The role of other anoctamins as therapeutic targets is still unclear since their physiological role is still to be defined.

Developmental events in the mandibular salivary gland of Indian sheep (Ovis aries): Morphological and histochemical studies.

At 22nd day of fetal development, the primordial anlage of mandibular gland was first noticed as a solid epithelial bud from oral epithelium. The terminal buds were arranged in the form of clusters with undifferentiated epithelial cells and terminated in a bulb like structure in 28-day-old fetus. The lumenization and branching of the main cord was noticed at 35th day. The primary septa, which divide the glandular mass into lobes was observed from 53rd day onwards which resulted in the formation of distinct lobulation at 58th day. At 61st day, the capsule formation was initiated by the aggregation of mesenchymal tissue. The terminal tubules differentiated to form the secretory end pieces and the tubular portion leads to the formation of intercalated and striated ducts at 98th day. Predominantly mucous types of acinar cells were seen from 108th day onwards. The number of lobules increased with steep increase in parenchyma from 128th day onwards. Micrometrical studies revealed that the mean diameter of acinar cells and all ducts was increased with the advancement of age and the significant differences were observed between groups. Localization of acidic and neutral mucopolysaccharides was observed in mucous cells and goblet cells. RESEARCH HIGHLIGHTS: The primordial anlage of mandibular salivary gland was seen at 22nd day. Lobulation of gland was appeared at 53rd day of development, however; it was completed at 58th day. At 98th day, the terminal tubules differentiated to form the secretory end pieces. The parenchyma of the gland showed predominantly mucous type of cells from 108th day onwards. Myoepithelial cells were first appeared as flattened basal cells initially around the developing acinar cells at 132nd day. Localization of acidic as well as neutral mucopolysaccharides was observed in mucous cells and goblet cells. Fine lipid droplets were observed in intralobular as well as interlobular connective tissue, however; phospholipids were observed in the cell membrane of secretory cells and ducts.

Myeloid A20 is critical for alternative macrophage polarization and type-2 immune-mediated helminth resistance.

Protective immunity against intestinal helminths requires induction of robust type-2 immunity orchestrated by various cellular and soluble effectors which promote goblet cell hyperplasia, mucus production, epithelial proliferation, and smooth muscle contractions to expel worms and re-establish immune homeostasis. Conversely, defects in type-2 immunity result in ineffective helminth clearance, persistent infection, and inflammation. Macrophages are highly plastic cells that acquire an alternatively activated state during helminth infection, but they were previously shown to be dispensable for resistance to Trichuris muris infection. We use the in vivo mouse model A20myel-KO, characterized by the deletion of the potent anti-inflammatory factor A20 (TNFAIP3) specifically in the myeloid cells, the excessive type-1 cytokine production, and the development of spontaneous arthritis. We infect A20myel-KO mice with the gastrointestinal helminth Trichuris muris and we analyzed the innate and adaptive responses. We performed RNA sequencing on sorted myeloid cells to investigate the role of A20 on macrophage polarization and type-2 immunity. Moreover, we assess in A20myel-KO mice the pharmacological inhibition of type-1 cytokine pathways on helminth clearance and the infection with Salmonella typhimurium. We show that proper macrophage polarization is essential for helminth clearance, and we identify A20 as an essential myeloid factor for the induction of type-2 immune responses against Trichuris muris. A20myel-KO mice are characterized by persistent Trichuris muris infection and intestinal inflammation. Myeloid A20 deficiency induces strong classical macrophage polarization which impedes anti-helminth type-2 immune activation; however, it promotes detrimental Th1/Th17 responses. Antibody-mediated neutralization of the type-1 cytokines IFN-γ, IL-18, and IL-12 prevents myeloid-orchestrated Th1 polarization and re-establishes type-2-mediated protective immunity against T. muris in A20myel-KO mice. In contrast, the strong Th1-biased immunity in A20myel-KO mice offers protection against Salmonella typhimurium infection. We hereby identify A20 as a critical myeloid factor for correct macrophage polarization and appropriate adaptive mucosal immunity in response to helminth and enteric bacterial infection.

Time-dependent impact of a high-fat diet on the intestinal barrier of male mice.

Excessive saturated fat intake compromises the integrity of the intestinal mucosa, leading to low-grade inflammation, impaired mucosal integrity, and increased intestinal permeability, resulting in the migration of lipopolysaccharide (LPS) to other tissues. To evaluate the chronic effects (at 10 and 16 wk) of a high-fat diet (HFD) (with 50% energy as fat) on the phylogenetic gut microbiota distribution and intestinal barrier structure and protection in C57BL/6 mice. Forty adult male mice were divided into four nutritional groups, where the letters refer to the type of diet (control and HFD or HF) and the numbers refer to the period (in weeks) of diet administration: Control diet for 10 wk, HFD for 10 wk, control diet for 16 wk, and HFD for 16 wk. After sacrifice, biochemical, molecular, and stereological analyses were performed. The HF groups were overweight, had gut dysbiosis, had a progressive decrease in occludin immunostaining, and had increased LPS concentrations. Dietary progression reduced the number of goblet cells per large intestine area and Mucin2 expression in the HF16 group, consistent with a completely disarranged intestinal ultrastructure after 16 wk of HFD intake. Chronic HFD intake causes overweight, gut dysbiosis, and morphological and functional alterations of the intestinal barrier after 10 or 16 wk. Time-dependent reductions in goblet cell numerical density and mucus production have emerged as targets for countering obesity-driven intestinal damage.

A32 CATHELICIDIN REGULATES GOBLET CELL MUCUS SECRETION DURING CITROBACTER RODENTIUM-INDUCED COLITIS

Abstract Background Colonic goblet cells by secreting Muc2 mucin and specific proteins is critical for physically entrapping and expelling invading enteropathogens. Thus, is not surprising that Muc2-/- littermates exhibit increased susceptibility to attaching/effacing Citrobacter rodentium colonization. The colonic epithelium also secretes small cathelicidin peptide, which potentially interacts intimately with goblet cells and was presumed to accumulate within the sterile inner mucus layer as a simple antimicrobial peptide defense. Aims To determine the effects of cathelicidin on mucin secretion in goblet cells during C. rodentium-induced colitis and the impact on the mucus barrier defense. Methods We used cathelicidin-deficient (Camp-/-) mice, mouse colonoids and human colonic LS174T like-goblet epithelial cells to elucidate the mechanisms by which cathelicidin regulates goblet cell secretions. Results Camp -/- littermates infected with C. rodentium displayed increased fecal shedding and epithelial colonization. Camp-/- littermates at the peak of C. rodentium infection (7 dpi) showed a deficient mucin layer with fewer Alcian blue/PAS filled goblet cells and a reduction in fucose (UEA-1+) and N-acetylglucosamine (WGA+) glycoproteins. By transmission electron microscopy (TEM), goblet cells in Camp-/- colons were swollen and retained a large number of mucus granules during C. rodentium infection. C. rodentium infected Camp-/- littermates showed impaired reactive oxygen species (ROS) production and a transcriptomic profiling associated with decreased ROS biosynthesis and an increase in ROS negative regulators. In mucin producing LS174T colonic epithelial cells, human cathelicidin LL-37 promptly induced the secretion of goblet cell-associated TFF3 and RELMβ, via a ROS-dependent mechanism. Conclusions These findings revealed that mice lacking cathelicidin (Camp-/-) were more susceptible to C. rodentium colonization caused by defective goblet cell mucus and mucin-associated protein secretion via a ROS-dependent mechanism. Importantly, cathelicidin regulated mucus secretion revealing a non microbicidal action of this peptide with homeostatic properties on the colonic mucus barrier, critical in excluding luminal microbiota away from the epithelia to clear bacterial infections and restore gut homeostasis. Funding Agencies NSERC

Seihaito, a Kampo medicine, attenuates IL-13-induced mucus production and goblet cell metaplasia

Goblet cell hyperplasia and increased mucus production are features of airway diseases, including asthma, and excess airway mucus often worsens these conditions. Even steroids are not uniformly effective in mucus production in severe asthma, and new therapeutic options are needed. Seihaito is a Japanese traditional medicine that is used clinically as an antitussive and expectorant. In the present study, we examined the effect of Seihaito on goblet cell differentiation and mucus production. In in vitro studies, using air–liquid interface culture of guinea-pig tracheal epithelial cells, Seihaito inhibited IL-13-induced proliferation of goblet cells and MUC5AC, a major component of mucus production. Seihaito suppressed goblet cell-specific gene expression, without changing ciliary cell-specific genes, suggesting that it inhibits goblet cell differentiation. In addition, Seihaito suppressed MUC5AC expression in cells transfected with SPDEF, a transcription factor activated by IL-13. Furthermore, Seihaito attenuated in vivo goblet cell proliferation and MUC5AC mRNA expression in IL-13-treated mouse lungs. Collectively, these findings demonstrated that Seihaito has an inhibitory effect on goblet cell differentiation and mucus production, which is at least partly due to the inhibition of SPDEF.

Fine particulate matter contributes to COPD-like pathophysiology: experimental evidence from rats exposed to diesel exhaust particles

BackgroundAmbient fine particulate matter (PM2.5) is considered a plausible contributor to the onset of chronic obstructive pulmonary disease (COPD). Mechanistic studies are needed to augment the causality of epidemiologic findings. In this study, we aimed to test the hypothesis that repeated exposure to diesel exhaust particles (DEP), a model PM2.5, causes COPD-like pathophysiologic alterations, consequently leading to the development of specific disease phenotypes. Sprague Dawley rats, representing healthy lungs, were randomly assigned to inhale filtered clean air or DEP at a steady-state concentration of 1.03 mg/m3 (mass concentration), 4 h per day, consecutively for 2, 4, and 8 weeks, respectively. Pulmonary inflammation, morphologies and function were examined.ResultsBlack carbon (a component of DEP) loading in bronchoalveolar lavage macrophages demonstrated a dose-dependent increase in rats following DEP exposures of different durations, indicating that DEP deposited and accumulated in the peripheral lung. Total wall areas (WAt) of small airways, but not of large airways, were significantly increased following DEP exposures, compared to those following filtered air exposures. Consistently, the expression of α-smooth muscle actin (α-SMA) in peripheral lung was elevated following DEP exposures. Fibrosis areas surrounding the small airways and content of hydroxyproline in lung tissue increased significantly following 4-week and 8-week DEP exposure as compared to the filtered air controls. In addition, goblet cell hyperplasia and mucus hypersecretions were evident in small airways following 4-week and 8-week DEP exposures. Lung resistance and total lung capacity were significantly increased following DEP exposures. Serum levels of two oxidative stress biomarkers (MDA and 8-OHdG) were significantly increased. A dramatical recruitment of eosinophils (14.0-fold increase over the control) and macrophages (3.2-fold increase) to the submucosa area of small airways was observed following DEP exposures.ConclusionsDEP exposures over the courses of 2 to 8 weeks induced COPD-like pathophysiology in rats, with characteristic small airway remodeling, mucus hypersecretion, and eosinophilic inflammation. The results provide insights on the pathophysiologic mechanisms by which PM2.5 exposures cause COPD especially the eosinophilic phenotype.

Reprogramming of arachidonic acid metabolism using α-terpineol to alleviate asthma: insights from metabolomics.

Asthma is a chronic inflammatory disorder in airways with typical pathologic features of airway inflammation and mucus hypersecretion. α-Terpineol is a monocyclic terpene found in many natural plants and foods. It has been reported to possess a wide range of pharmacological activities including anti-inflammatory and expectorant effects. However, the role of α-terpineol in asthma and its potential protective mechanism have not been well elucidated. This study is designed to investigate the pharmacological effect and mechanism of α-terpineol on asthmatic mice using the metabolomics platform. A murine model of asthma was established using ovalbumin (OVA) sensitization and then challenged for one week. The leukocyte count and inflammatory cytokines in the bronchoalveolar lavage fluid (BALF), lung histopathology, inflammatory infiltrate and mucus secretion were evaluated. An ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)-based metabolomics study was performed on lung tissues and serum to explore endogenous small molecule metabolites affected by α-terpineol in asthmatic mice. After α-terpineol treatment, leukocyte count, inflammatory cytokines in the BALF, and peribronchial inflammation infiltration were significantly downregulated. Goblet cell hyperplasia and mucus secretion were attenuated, with the level of Muc5ac in BALF decreased. These results proved the protective effect of α-terpineol against airway inflammation, mucus hypersecretion and Th1/Th2 immune imbalance. To further investigate the underlying mechanisms of α-terpineol in asthma treatment, UPLC-MS/MS-based metabolomics analysis was performed. 26 and 15 identified significant differential metabolites were found in the lung tissues and serum of the control, model and α-terpineol groups, respectively. Based on the above differential metabolites, enrichment analysis showed that arachidonic acid (AA) metabolism was reprogrammed in both mouse lung tissues and serum. 5-Lipoxygenase (5-LOX) and cysteinyl leukotrienes (CysLTs) are the key enzyme and the end product of AA metabolism, respectively. In-depth studies have shown that pretreatment with α-terpineol can alleviate asthma by decreasing the AA level, downregulating the expression of 5-LOX and reducing the accumulation of CysLTs in mouse lung tissues. In summary, this study demonstrates that α-terpineol is a potential agent that can prevent asthma via regulating disordered AA metabolism.

Effect of laxative polyherbal paste for loperamide induced constipation in rats.

The goal of this study was to find out if polyherbal paste (PHP) with Rosadamascena, Terminalia chebula, and Trachyspermumammi in honey could help rats that were constipated because of loperamide. Thirty male rats were divided into 6 groups: a control group receiving saline, a model group receiving loperamide at 10 mg/kg and saline, a phenolphthalein group (positive control) receiving loperamide at 10 mg/kg and phenolphthalein at 10 mg/kg, and low (20 mg/kg), medium (40 mg/kg), and high (60 mg/kg) doses of PHP, via intragastric administration for 7 days. Various parameters, including food consumption, water consumption, body weight, fecal characteristics, gastrointestinal transit rate, histological changes, serum biomarkers, and aquaporin-3 (AQP3) and C-kit protein expression levels, were assessed. Administering PHP at a dose of 60 mg/kg resulted in a 16.89% increase in fecal water content, a 12.14% increase in the amount of feces, and a 23.67% increase in gastrointestinal transit rate, while also reducing the time to black stool and restoring appearance by 23.41%. At the 40 mg/kg dose, PHP increased motilin levels in the blood by 31.22%, gastrin by 52.78%, and substance P by 19.45% while decreasing somatostatin by 20.17%. Furthermore, at the 60 mg/kg dose, PHP decreased mucous membrane damage and goblet cell function in the colon, reduced AQP3 protein production by 33.39%, and increased c-kit protein production by 12.14%. The PHP showed promising therapeutic potential for loperamide-induced constipation in rats.

PH Sensitive Quercetin Nanoparticles Ameliorate DSS-Induced Colitis in Mice by Colon-Specific Delivery.

Ulcerative colitis (UC) is a classic inflammatory bowel disease (IBD) that represents a serious threat to human health. As a natural flavonoid with multiple biological activities, quercetin (QCT) suffers from low bioavailability through limitations in chemical stability. Here, the study investigates the regulatory effects of quercetin nanoparticles (QCT NPs) on dextran sulfate sodium (DSS) induced colitis mice. Chitosan is modified to obtain N-succinyl chitosan (NSC) with superior water solubility. Nanoparticles composed of sodium alginate (SA) and NSC can encapsulate QCT after cross-linking, forming QCT NPs. In vitro drug release assays demonstrate the pH sensitivity of QCT NPs. Compared with free quercetin, QCT NPs have better therapeutic efficacy in modulating gut microbiota and its metabolites short chain fatty acid (SCFAs) to relieve DSS-induced colitis in mice, thereby alleviating colon inflammatory infiltration, increasing goblet cells density and mucus protein, ameliorating TNF-α, IL-1β, IL-6, IL-10, and Myeloperoxidase (MPO) levels, and recovering intestinal barrier integrity. pH sensitive QCT nanoparticles can reduce inflammatory reaction, improve gut microbiota, and repair intestinal barrier by targeting colon, thus improving DSS induced colitis in mice, providing reference for the treatment of colitis.

Reduced miR-513a-5p expression in COPD may regulate airway mucous cell hyperplasia through TFR1-dependent signaling.

Airway mucous cell metaplasia and mucous hypersecretion is one of the key characteristic pathophysiological status of chronic obstructive pulmonary disease (COPD). micro(mi)RNAs are acknowledged as non-encoding RNA molecules playing important roles in gene expression regulation. In this study, we searched the Gene Expression Omnibus (GEO) database for the differentially expressed miRNAs between COPD and non-COPD controls with bioinformatics analysis. Finally, we focused on miR-513a-5p and investigated the potential mechanism by which miR-513a-5p regulates airway mucous hypersecretion and goblet cell metaplasia. A dual-luciferase reporter assay was then showing that miR-513a-5p targeted the 3'-UTR of TFR1 and inhibited its expression in vitro. In vivo transfection demonstrated that TFR1 downregulation partially blocked MUC5AC hypersecretion and goblet cell hyperplasia in COPD model rats. In vitro study, CSE increased the intracellular expression and secretion of MUC5AC by BEAS-2B branchial epithelial cells in the BEAS-2B cell and THP-1 cell coculture system. Coculture with either miR-513a-5p mimic-pretreated or TFR1-deficient THP-1 cells attenuated intracellular MUC5AC expression in BEAS-2B cells exposed to CSE. ELISA demonstrated that transfection of TFR1 siRNA or pretreatment with miR-513a-5p mimic reduced the secretion of inflammatory factors that are responsible for airway goblet cell hyperplasia, such as IL-1β, IL-13, and IL-17, by THP-1 cells after CSE stimulation. Our findings supported that miR-513a-5p/TFR1 signaling axis might activate macrophages as well as promote airway inflammation and airway mucous cell hyperplasia in COPD.

Targeting the translationally controlled tumor protein by a monoclonal antibody improves allergic airway inflammation in mice

Secretion of translationally controlled tumor protein (TCTP) was found in body fluids during the late phase of allergic reactions, implicating TCTP in allergic diseases. Furthermore, blocking TCTP has been shown to be helpful in treating asthma and allergies in animal models. The objectives of this study were to produce anti-TCTP monoclonal antibodies (mAbs), test their ability to inhibit the cytokine-like function of dimeric TCTP (dTCTP) in vitro and to assess their therapeutic effects in a murine model of ovalbumin (OVA)-induced airway inflammation. We first verified the inhibitory effects of 4 anti-TCTP mAbs on dTCTP-induced secretion of IL-8 in BEAS-2B cells. To investigate the anti-inflammatory effect of anti-TCTP mAbs on allergic airway inflammation, we treated OVA-sensitized mice with anti-TCTP mAbs before OVA challenge. The changes in bronchoalveolar lavage fluid (BALF) cells, IL-4, IL-5, and IL-13 levels in both BALF and lung homogenates, plasma levels of OVA-specific IgE, and lung tissues were analyzed. We found that JEW-M449 anti-TCTP mAb bound to the flexible loop of TCTP and significantly inhibited dTCTP-induced IL-8 release, making it the most effective inhibitor in our study. We also found that treatment with JEW-M449 significantly reduced the infiltration of inflammatory cells and suppressed the OVA-induced upregulation of type 2 cytokines in both BALF and lung homogenates in a dose-dependent manner. In addition, JEW-M449 significantly attenuated the degree of goblet cell hyperplasia and mucus secretion. Our results demonstrate that specific targeting of the flexible loop of TCTP is a potent strategy for treating airway inflammatory diseases.

Stability and emetic activity of enterotoxin like X (SElX) with high carrier rate of food poisoning Staphylococcus aureus

In order to analyze and clarify the thermal stability of food poisoning Staphylococcus aureus (S. aureus) enterotoxin-like X (SElX) and the biological characteristics of digestive enzymes, and to evaluate the risk of S. aureus carrying selx gene in food poisoning, the selx gene carrying rates of 165 strains isolated from 95 food poisoning events from 2006 to 2019 were first statistically analyzed. Subsequently, the purified recombinant SElX protein was digested and heated, and the superantigen activity was verified with mouse spleen cells and peripheral blood mononuclear cells of kittens. At the same time, the emetic activity and toxicity of SElX were evaluated using the kitten vomiting animal model, mice toxin model and in vitro cell models. The results showed the selx gene carrying rate of 165 food poisoning S. aureus strains was 90.30 %. SElX had significant resistance to heat treatment and pepsin digestion (pH = 4.0 and pH = 4.5), and had good superantigen activity and emetic activity. However, there is no significant lethal effect on mice and no significant toxicity to cells. Importantly, we found that SElX had an inhibitory effect on acidic mucus of goblet cells in various segments of the small intestine. The present study investigated the stability of SElX, and confirmed the emetic activity of SElX by establishing a kitten vomiting model for the first time, suggesting that SElX is a high risk toxin of food poisoning, which will provide new ideas for the prevention and control of S. aureus food poisoning.

Succinate signaling attenuates high-fat diet-induced metabolic disturbance and intestinal barrier dysfunction

Succinate is a vital signaling metabolite produced by the host and gut microbiota. Succinate has been shown to regulate host metabolic homeostasis and inhibit obesity-associated inflammation in macrophages by engaging its cognate receptor, SUCNR1. However, the contribution of the succinate-SUCNR1 axis to intestinal barrier dysfunction in obesity remains unclear. In the present study, we explored the effects of succinate-SUCNR1 signaling on high-fat diet (HFD)-induced intestinal barrier dysfunction. Using a SUCNR1-deficient mouse model under HFD feeding conditions, we identified the effects of succinate-SUCNR1 axis on obesity-associated intestinal barrier impairment. Our results showed that HFD administration decreased goblet cell numbers and mucus production, promoted intestinal pro-inflammatory responses, induced gut microbiota composition imbalance, increased intestinal permeability, and caused mucosal barrier dysfunction. Dietary succinate supplementation was sufficient to activate a type 2 immune response, trigger the differentiation of barrier-promoting goblet cells, suppress intestinal inflammation, restore HFD-induced mucosal barrier impairment and intestinal dysbiosis, and eventually exert anti-obesity effects. However, SUNNR1-deficient mice failed to improve the intestinal barrier function and metabolic phenotype in HFD mice. Our data indicate the protective role of the succinate-SUCNR1 axis in HFD-induced intestinal barrier dysfunction.

Nootkatone attenuates airway inflammation in asthmatic mice through repressing ROS-induced NLRP3 inflammasome activation.

Nootkatone (NKT) exhibits potential pharmacological activities including anti-oxidation and anti-inflammation. Nevertheless, little is known about the roles of NKT in asthmatic airway inflammation. In the study, mice were sensitized and challenged with ovalbumin (OVA) to establish experimental allergic asthma model. After treatment with NKT, lung tissues, peripheral blood, and bronchoalveolar lavage fluid (BALF) were collected to assess inflammatory cytokines, oxidative stress, and pathological alternations. The effects of NKT on regulating reactive oxygen species (ROS)-induced NLR family pyrin domain containing 3 (NLRP3) inflammasome activation was assessed in IL-13-treated BEAS-2B cell model. We found that NKT treatment decreased the production of Th2 inflammatory cytokines (IL-4, IL-5, and IL-13) in BALF and IgE levels in serum, and alleviated inflammatory cell penetration, goblet cell proliferation, collagen accumulation, and mucus hypersecretion in lung tissues. NKT treatment mitigated oxidative stress and NLRP3 inflammasome activation in asthmatic mice. IL-13 treatment induced oxidative stress and NLRP3-mediated pyroptosis in BEAS-2B bronchial epithelial cells, whereas these effects were blocked by NKT. NKT protected against airway remodeling, as indicated by decreased epithelial-mesenchymal transition. Taken together, these results demonstrate that NKT mitigates asthmatic airway inflammation by inhibiting ROS-triggered NLRP3 activation and may be a potential agent for treating asthma.