Mucin Secretion Research Articles

Generation of human gastric assembloids from primary fetal organoids

PurposeUnderstanding human gastric epithelium homeostasis remains partial, motivating the exploration of innovative in vitro models. Recent literature showcases the potential of fetal stem cell-derived organoids in developmental and disease modelling and translational therapies. To scale the complexity of the model, we propose to generate assembloids, aiming to increase gastric maturation to provide new structural and functional insights.MethodsHuman fetal gastric organoids (fGOs) were expanded in 3D Matrigel cultures. Confluent organoid cultures were released from the Matrigel dome and resuspended in a collagen I hydrogel. Subsequently, the organoid mixture was seeded in a ring shape within a 24-well plate and allowed to gelate. The structure was lifted in the medium and cultured in floating conditions, allowing for organoid self-assembling into a gastric assembloid. After 10 days of maturation, the assembloids were characterized by immunostaining and RT-PCR, comparing different fetal developmental stages.ResultsSuccessful generation of human fetal gastric assembloids (fGAs) was achieved using spontaneous self-aggregation within the collagen I hydrogel. Immunostaining analysis of early and late fGAs showed the establishment of apico-basal cell polarity, secretion of gastric mucins, and the presence of chromogranin A in both samples. Transcriptional markers analysis revealed distinct disparities in markers associated with mature cell types between late and early fetal stages.ConclusionsfGOs can reliably be generated from human fetal samples. This pioneering assembloid approach paves the way for advancing our comprehension of human gastric epithelium homeostasis and its perturbation, offering a better in vitro platform for the study of gastric epithelial development and therapeutic translation.

PSIV-30 Exploring the Prebiotic Activities of Proanthocyanidins on a Platform Using the Three-Dimensionally (3D)-Cultured Organoids

Abstract Using antibiotics, the antimicrobial substance active against bacteria and promoting growth efficiency, in feedstuffs and food supply has been attracting great attention due to its side effects and contribution to antibiotic resistance. Therefore, exploring talternatives to antibiotics is of great significance and urgent need for human health and animal industries with a sustainable high efficiency. The objective of this study is to evaluate the biological and medicinal activities of the monomers of proanthocyanidins (PAs), such as epicatechin, epigallocatechin gallate, and flavanols such as quercetin, isoquercetrin, and rutin generated from engineered plants. The evaluations were performed in intestinal organoids isolated from ileum of neonatal piglets. The organoids after expended in vitro were incubated with or without the candidate compounds for 24 hours, and then treated with or without polyinosinic-polycytidylic acid [Poly (I:C), 10 µg/mL] for another 24 hours, a synthetic analog of double-stranded RNA (can induce a molecular pattern associated with viral infections). Cell proliferation, barrier function, toll-like receptor pathway and apoptosis as well as organic cation transporters were assessed by measuring the abundance of the corresponding genes. Concentration gradient (0 to 200 µM) measurements showed that isoquercetrin and epigallocatechin gallate might stimulate the intestinal cell proliferation, promote the uptake of L-carnitine, and increase barrier function and mucin secretion (P < 0.05). Epigallocatechin gallate and epicatechin might affect the inflammation responses via modifying expression of Interleukins but not induce apoptosis. Interactions between the examined these compounds and Poly (I: C) were not observed (P > 0.05), but the influence on the challenged pattern were tested for some of the measured genes (P < 0.05). Based on the data collected from this in vitro study, we conclude that epigallocatechin gallate is a potential PA monomer with all prebiotic characteristics and its applicable values in feedstuff and food supply should be studied in vivo studies in domestic (food) animals with and without antigen challenges. Supported by NC Biotechnology Center project (1107)2022-3082 and the North Carolina Agricultural Research Hatch Projects 02780.

Mechanism Underlying the Regulation of Mucin Secretion in the Uterus during Pregnancy

The function of endometrial epithelial cells is to secrete various substances that are rich in growth factors and nutrients. These substances support both embryo implantation and its subsequent development into a fetus. A vast number of mucins are expressed in endometrial epithelial cells, and they play an important role in regulating the processes of embryo implantation, pregnancy, and parturition. Previous studies have shown that mucin forms a mucus layer covering endometrial epithelial cells, which helps resist damage from foreign bacteria and their toxins. Therefore, this article aims to investigate the location of mucins in the endometrium, the mechanism of mucin secretion by the endometrium, and the regulation of mucins in the uterine epithelium by reproductive hormones, as well as the role of mucins in the protection of the epithelium’s structure. This research aims to provide a foundational understanding for future studies on the role and mechanism of endometrial mucins throughout the pregnancy cycle.

Complement C3-Deficiency-Induced Constipation in FVB/N-C3em1Hlee/Korl Knockout Mice Was Significantly Relieved by Uridine and Liriope platyphylla L. Extracts.

Complement component 3 (C3) deficiency has recently been known as a cause of constipation, without studies on the therapeutic efficacy. To evaluate the therapeutic agents against C3-deficiency-induced constipation, improvements in the constipation-related parameters and the associated molecular mechanisms were examined in FVB/N-C3em1Hlee/Korl knockout (C3 KO) mice treated with uridine (Urd) and the aqueous extract of Liriope platyphylla L. (AEtLP) with laxative activity. The stool parameters and gastrointestinal (GI) transit were increased in Urd- and AEtLP-treated C3 KO mice compared with the vehicle (Veh)-treated C3 KO mice. Urd and AEtLP treatment improved the histological structure, junctional complexes of the intestinal epithelial barrier (IEB), mucin secretion ability, and water retention capacity. Also, an improvement in the composition of neuronal cells, the regulation of excitatory function mediated via the 5-hydroxytryptamine (5-HT) receptors and muscarinic acetylcholine receptors (mAChRs), and the regulation of the inhibitory function mediated via the neuronal nitric oxide synthase (nNOS) and inducible NOS (iNOS) were detected in the enteric nervous system (ENS) of Urd- and AEtLP-treated C3 KO mice. Therefore, the results of the present study suggest that C3-deficiency-induced constipation can improve with treatment with Urd and AEtLP via the regulation of the mucin secretion ability, water retention capacity, and ENS function.

Silkworm pupa protein peptide improved DSS-induced colitis in C57BL/6 mice through the MAPK/NF-κB signaling pathway

Numerous studies have revealed the multifunctional activities of silkworm pupa peptides (SPP). In this study, we investigated the protective effects of SPP on dextran sulfate sodium (DSS)-induced colitis in mice. The results showed that SPP improved the clinical symptoms of colitis in mice, including increased colon length, slowed weight loss, and reduced disease activity index (DAI) scores. Furthermore, SPP significantly alleviated DSS-induced colonic injury by reducing the expression of myeloperoxidase (MPO) in colonic tissues, enhancing mucin secretion in the colon, and decreasing colonic cell apoptosis. SPP also mitigated the severity of colitis by modulating serum inflammatory factors and improving colonic oxidative stress levels. Western blot analysis revealed that SPP suppressed the activation of the MAPK and NF-κB signaling pathways. In conclusion, SPP protected against DSS-induced colitis in mice by reducing cell apoptosis, attenuating inflammatory responses, and improving oxidative stress levels, potentially through the inhibition of MAPK and NF-κB signaling pathways.

Пропіонова кислота відновлює секрецію муцину у шлунку при експериментальному цукровому діабеті

Type 2 diabetes mellitus (T2DM) is associated with a number of complications, in particular, gastrointestinal tract dysfunction. Impaired mucin secretion by the gastric mucosa in rats with T2DM may affect the absorption of drugs in the stomach and may explain the poor efficacy of treatment and correction of the condition. The aim of our work was to study changes in mucin secretion by the mucous membrane of the gastric fundus in rats with T2DM and the administration of metformin in combination with propionate. T2DM was modelled in rats by a high-fat diet for 3 months with a single administration of streptozotocin (25 mg/kg). Pharmacological correction was performed by intragastric administration of metformin (60 mg/ kg), propionate (60 mg/kg), and combined administration of the mentioned drugs for 14 days. Structural changes in the gastric mucosa and mucopolysaccharide secretion activity were assessed by histochemistry. Western blot analysis of MUC5AC expression was performed. A significant decrease in mucin production was observed in the lower stomach of rats, which was associated with a decrease in the density of cells actively producing acidic mucopolysaccharides. Metformin administration to animals with T2DM did not restore mucin production in the gastric fundus, whereas propionate administration increased acid mucopolysaccharide secretion. An increase in the neutral component of mucus and MUC5AC was found in T2DM. The combined administration of metformin and propionate helped to reduce the content of this mucin. The identified morphofunctional changes in the gastric fundus require further research and should be taken into account when using oral hypoglycaemic drugs because the loss of the mucin barrier layer may affect the state of the gastric mucosa and the absorption of drugs.

Green carbon dots derived from Atractylodes macrocephala: A potential nanodrug for treating alcoholic gastric ulcer.

Alcoholic gastric ulcer is a common acute gastric injury disease. The drugs currently used in clinical practice not only cannot fundamentally treat gastric injury, but also have serious side effects. There is an urgent demand for the discovery of a mild drug to treat alcoholic gastric ulcers. Herein, the green carbon dots derived from charred Atractylodes macrocephala (CAM-CDs) were acquired and have been proven to be safe and effective in alleviating alcoholic gastric ulcers at an inhibition rate up to 60%. CAM-CDs can markedly attenuate the gastric mucosa damage such as mucosal defect, bleeding and inflammatory cell infiltration by histopathological examination. Serum and tissue inflammatory cytokine measurements, as well as immunohistochemistry results, indicate that its mechanism of gastric mucosal protection may involve the reduction of IL-1β and TNF-α by regulating inflammatory signaling pathway of the NF-κB/NLRP3 axis, as well as elevation of IL-10 levels. CAM-CDs also can reduce oxidative stress markers (MDA), increase PGE2 and mucin secretion (MUC5AC), and it simultaneously exerts slight inhibition of hydrogen potassium ATPase and pepsin activity to protect gastric mucosa, as well as increases the microbial diversity and regulates species composition of gut microbiota in rats with gastric ulcer. Our work provides a new perspective on utilizing carbon-based nanomaterials in the development of new mild drugs.

Interaction of the Gut Microbiome and Immunity in Multiple Sclerosis: Impact of Diet and Immune Therapy.

The bidirectional communication between the gut and central nervous system (CNS) through microbiota is known as the microbiota-gut-brain axis. The brain, through the enteric neural innervation and the vagus nerve, influences the gut physiological activities (motility, mucin, and peptide secretion), as well as the development of the mucosal immune system. Conversely, the gut can influence the CNS via intestinal microbiota, its metabolites, and gut-homing immune cells. Growing evidence suggests that gut immunity is critically involved in gut-brain communication during health and diseases, including multiple sclerosis (MS). The gut microbiota can influence the development and function of gut immunity, and conversely, the innate and adaptive mucosal immunity can influence microbiota composition. Gut and systemic immunity, along with gut microbiota, are perturbed in MS. Diet and disease-modifying therapies (DMTs) can affect the composition of the gut microbial community, leading to changes in gut and peripheral immunity, which ultimately affects MS. A high-fat diet is highly associated with gut dysbiosis-mediated inflammation and intestinal permeability, while a high-fiber diet/short-chain fatty acids (SCFAs) can promote the development of Foxp3 Tregs and improvement in intestinal barrier function, which subsequently suppress CNS autoimmunity in the animal model of MS (experimental autoimmune encephalomyelitis or EAE). This review will address the role of gut immunity and its modulation by diet and DMTs via gut microbiota during MS pathophysiology.

Inflammatory Activity of Epithelial Stem Cell Variants from Cystic Fibrosis Lungs Is Not Resolved by CFTR Modulators.

Rationale: CFTR (cystic fibrosis transmembrane conductance regulator) modulator drugs restore function to mutant channels in patients with cystic fibrosis (CF) and lead to improvements in body mass index and lung function. Although it is anticipated that early childhood treatment with CFTR modulators will significantly delay or even prevent the onset of advanced lung disease, lung neutrophils and inflammatory cytokines remain high in patients with CF with established lung disease despite modulator therapy, underscoring the need to identify and ultimately target the sources of this inflammation in CF lungs. Objectives: To determine whether CF lungs, like chronic obstructive pulmonary disease (COPD) lungs, harbor potentially pathogenic stem cell "variants" distinct from the normal p63/Krt5 lung stem cells devoted to alveolar fates, to identify specific variants that might contribute to the inflammatory state of CF lungs, and to assess the impact of CFTR genetic complementation or CFTR modulators on the inflammatory variants identified herein. Methods: Stem cell cloning technology developed to resolve pathogenic stem cell heterogeneity in COPD and idiopathic pulmonary fibrosis lungs was applied to end-stage lungs of patients with CF (three homozygous CFTR:F508D, one CFTR F508D/L1254X; FEV1, 14-30%) undergoing therapeutic lung transplantation. Single-cell-derived clones corresponding to the six stem cell clusters resolved by single-cell RNA sequencing of these libraries were assessed by RNA sequencing and xenografting to monitor inflammation, fibrosis, and mucin secretion. The impact of CFTR activity on these variants after CFTR gene complementation or exposure to CFTR modulators was assessed by molecular and functional studies. Measurements and Main Results: End-stage CF lungs display a stem cell heterogeneity marked by five predominant variants in addition to the normal lung stem cell, of which three are proinflammatory both at the level of gene expression and their ability to drive neutrophilic inflammation in xenografts in immunodeficient mice. The proinflammatory functions of these three variants were unallayed by genetic or pharmacological restoration of CFTR activity. Conclusions: The emergence of three proinflammatory stem cell variants in CF lungs may contribute to the persistence of lung inflammation in patients with CF with advanced disease undergoing CFTR modulator therapy.

Shen-Ling-Bai-Zhu-San alleviates the imbalance of intestinal homeostasis in dextran sodium sulfate-induced colitis mice by regulating gut microbiota and inhibiting the NLRP3 inflammasome activation

Ethnopharmacological relevanceShen-Ling-Bai-Zhu-San (SLBZS) is a classic formula for strengthening the spleen and dispelling dampness, which has shown excellent efficacy in inflammatory bowel disease (IBD) in traditional Chinese medicine clinical studies. However, its exact pharmacological mechanism needs to be further elucidated. Aim of the studyThis study aims to investigate the restorative effect and mechanism of SLBZS on disturbed intestinal homeostasis in DSS-induced colitis mice. Materials and methodsA colitis model was induced by 3% dextran sulfate sodium (DSS) for seven days, and SLBZS was administered by gavage. The influence of SLBZS on DSS-induced clinical symptoms and disease activity index (DAI) was monitored and analyzed. Alcian blue and fluorescein isothiocyanate-conjugated wheat germ agglutinin (FITC-WGA) staining were used to assess intestinal mucus changes. The expression of intestinal barrier function indexes and immune-associated indexes were determined by H&E staining, real-time quantitative PCR (RT-qPCR), and Western blot. And gut microbiota changes were detected by 16S rDNA sequencing technology. The antibiotic experiment was used to explore the role of gut microbiota in SLBZS treatment. ResultsThe results showed that SLBZS significantly improved the physiological indexes including body weight, DAI score, and colon length of colitis mice. We focused on the effects of SLBZS on intestinal homeostasis in colitis mice. First, SLBZS could enhance the secretion of intestinal mucin and the expression levels of tight junctions and adhesive junctions. Second, SLBZS inhibited the expression level of inflammatory factors and reduced the protein expression level of NLRP3 inflammasome. Third, 16S rDNA sequencing analysis revealed that SLBZS repaired the dysfunctional gut microbiota of colitis mice, such as enhancing the abundance of short-chain fatty acid-producing bacteria including Faecalibaculum, Colidextribacter, and Coprococcus. Further, by gut microbiota-depleted mice, we found that SLBZS could not exert an anti-colitis effect when gut microbiota was absent. ConclusionsSLBZS restored intestinal environmental homeostasis by enhancing intestinal barrier function, inhibiting NLRP3 inflammasome, and restoring disturbed gut microbiota. And SLBZS could not ameliorate colitis mice with depleted gut microbiota. Our finding provided a theoretical basis for the clinical application of SLBZS in IBD.

Melatonin Alleviates Intestinal Barrier Damaging Effects Induced by Polyethylene Microplastics in Albino Rats.

There have been concerns about the potential health risks posed by microplastics (MP). The detection of MP in a variety of food products revealed that humans are ingesting MP. Nevertheless, there is a paucity of data about their impacts, as well as their uptake, on intestinal barrier integrity. This study examined the toxic effects of oral administration of two doses of polyethylene microplastics (PE-MP) (3.75 or 15 mg/kg/day for 5 weeks; mean particle size: 4.0-6.0 µm) on the intestinal barrier integrity in rats. Moreover, the effect of melatonin treatment with MP exposure was also assessed. The PE-MP particle uptake, histopathological changes, Alcian blue staining, Muc2 mRNA, proinflammatory cytokines (IL-1β and TNF-α), and cleaved caspase-3, as well as tight junction proteins (claudin-1, myosin light-chain kinase (MLCK), occludin, and zonula occludens-1 (ZO-1)) were assessed. Oral administration of PE-MP resulted in apparent jejunal histopathological alterations; significantly decreased mucin secretion, occludin, ZO-1, and claudin-1 expression; and significantly upregulated MLCK mRNA, IL-1β concentration, and cleaved caspase-3 expression. Melatonin reversed these altered parameters and improved the PE-MP-induced histopathological and ultrastructure changes. This study highlighted the PE-MP's toxic effect on intestinal barrier integrity and revealed the protective effect of melatonin.

Virus-Like Particles Assembled Using Respiratory Syncytial Virus Matrix Protein Elicit Protective Immunity in Mice.

Heterologous virus-like particle (VLP) assembly involving influenza or the Newcastle disease virus matrix protein (M) has been extensively used to explore the efficacies of VLP vaccines against the respiratory syncytial virus (RSV). Here, we attempted to generate homologous RSV VLPs by expressing the pre-fusion (pre-F) or the glycoprotein (G) on the RSV M protein and evaluated their protective efficacy in mice. We generated VLPs using the baculovirus expression system in Spodoptera frugiperda (Sf9) insect cells. Recombinant baculoviruses expressing the RSV pre-F, G, and M antigens were inoculated into Sf9 cells, and particles were self-assembled. Mice were immunized with either pre-F or G-expressing VLPs, and immune parameters were assessed to determine protection. Our findings show that successful VLP assembly can be achieved by utilizing recombinant baculoviruses expressing the RSV pre-F or G proteins with the native matrix protein. Mice immunized with either pre-F or the G antigen-expressing VLPs elicited robust serum-mediated virus neutralization. VLP immunization evoked Th1-biased RSV-specific antibody responses in the sera of mice. Following challenge infection with the RSV A2 strain, immunized mice experienced lesser eosinophil and IL-4 accumulation in the lungs, though a substantial increase in TNF-α secretion was observed from CD4+ T cells. Interestingly, splenic antibody-secreting cell responses were substantially enhanced against RSV F antigen, but not against the RSV G antigen following immunization and challenge infection. Immunizing mice with the VLPs significantly inhibited pulmonary histopathology development, as indicated by the diminished inflammatory immune cell influx and mucin secretion. Combined, these vaccine-induced immune responses contributed to successfully inhibiting the RSV replication in the lungs of mice and demonstrated that RSV VLP assembly using insect cell-derived homologous RSV matrix protein is a feasible approach.

Purinergic 2X 4 (P2X4), but not P2X7, receptors increase cytosolic [Ca2+] and stimulate mucin secretion in rat conjunctival goblet cells to maintain ocular surface health

Ionotropic purinergic receptors (P2XRs) are activated by ATP and ATP analogs. ATP can be released through ATP-permeable channels such as the pannexin hemichannels. Upon activation, the P2XRs become permeable to Ca2+, a potent stimulator of mucin secretion in conjunctival goblet cells (CGCs). The purpose of this study was to investigate the presence and function of P2XRs in CGCs. We also examined the presence of pannexin hemichannels. Rat first passage CGCs were stained with the goblet cell marker anti-cytokeratin 7 antibody and specific antibodies to P2X1-7 receptors and pannexin 1-3. mRNA expression was determined by RT-PCR using primers specific to P2XRs and pannexins. Proteins were identified with Western blotting (WB) using the same antibodies as for immunofluorescence (IF) microscopy. To study receptor function, CGCs were incubated with Fura 2-AM, exposed to agonists and antagonists, and intracellular [Ca2+] ([Ca2+]i) measured. [Ca2+]i was also measured after knock down of P2X4 and P2X7 receptor expression, and when exploiting P2XR specific characteristics. Lastly, mucin secretion was measured after the addition of several P2XR agonists. All P2XRs and pannexins were visualized with IF microscopy, and identified with RT-PCR and WB. [Ca2+]i was significantly increased when stimulated with ATP (10−7-10−4 M). Suramin, a non-selective P2XR antagonist at 10−4 M did not reduce ATP-induced peak [Ca2+]i. The potent P2X7 agonist, BzATP (10−7-10−4 M) increased the [Ca2+]i, although to a lesser extent than ATP. When measuring [Ca2+]i the effect of repeated applications of ATP at 10−5 or 10−6 M the response “desensitized” after 30–60 s. The P2X4 specific antagonist 5-BDBD decreased the P2X4 agonist, 2MeSATP,-induced [Ca2+]i increase. Furthermore, siRNA against the P2X4R, but not the P2X7R, decreased agonist-induced peak [Ca2+]i. ATP (10−5 M), BzATP (10−4 M) and 2MeSATP (10−5 M) induced mucin secretion. We conclude that all seven P2XRs are present in cultured rat CGCs. Of the P2XRs, only activation of the homotrimeric P2X4R appears to increase [Ca2+]i and induce mucin secretion. The P2X4R in CGCs offers a new therapeutic target for protective mucin secretion.

C-C Motif Chemokine Receptor 3-Mediated Extracellular Signal-Regulated Kinase 1/2 and p38 Mitogen-Activated Protein Kinase Signaling: Promising Targets for Human Airway Epithelial Mucin 5AC Induction by Eotaxin-2 and Eotaxin-3

Introduction: Eotaxin-2 and -3 of the C-C chemokine subfamily function as potent chemoattractant factors for eosinophil recruitment and various immune responses in allergic and inflammatory airway diseases. Mucin 5AC (MUC5AC), a major gel-forming secretory mucin, is overexpressed in airway inflammation. However, the association between mucin secretion and eotaxin-2/3 expression in the upper and lower airway epithelial cells has not been fully elucidated. Therefore, in this study, we investigated the effects of eotaxin-2/3 on MUC5AC expression and its potential signaling mediators. Methods: We analyzed the effects of eotaxin-2 and -3 on NCI-H292 human airway epithelial cells and primary human nasal epithelial cells (HNEpCs) via reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, and western blotting. Along with immunoblot analyses with specific inhibitors and small interfering RNA (siRNA), we explored the signaling pathway involved in MUC5AC expression following eotaxin-2/3 treatment. Results: In HCI-H292 cells, eotaxin-2/3 activated the mRNA expression and protein production of MUC5AC. A specific inhibitor of C-C motif chemokine receptor 3 (CCR3), SB328437, suppressed eotaxin-2/3-induced MUC5AC expression at both the mRNA and protein levels. Eotaxin-2/3 induced the phosphorylation of extracellular signal-regulated kinase (ERK)-1/2 and p38, whereas pretreatment with a CCR3 inhibitor significantly attenuated this effect. Induction of MUC5AC expression with eotaxin-2/3 was decreased by U0126 and SB203580, specific inhibitors of ERK1/2 and p38 mitogen-activated protein kinase (MAPK), respectively. In addition, cell transfection with ERK1/2 and p38 siRNAs inhibited eotaxin-2/3-induced MUC5AC expression. Moreover, specific inhibitors (SB328437, U0126, and SB203580) attenuated eotaxin-2/3-induced MUC5AC expression in HNEpCs. Conclusion: Our results imply that CCR3-mediated ERK1/2 and p38 MAPK are involved in the signal transduction of eotaxin-2/3-induced MUC5AC overexpression.

Allergic Mucin in Allergic Fungal Rhinosinusitis.

A previously healthy 67-year-old man visited the otorhinolaryngologist’s office reporting mucinous nasal secretion, postnasal drip, and right nasal stuffiness for 8 months. On the initial visit, the nasal endoscopy revealed only sparsely pooled mucinous discharge in the right middle meatus with no mass lesion or nasal polyps. A computed tomography image revealed diffusely thickened mucosa of the right maxillary sinus partially filled with a dense secretion showing areas of hyperattenuation in the bone window setting (Figure 1, arrowhead). No focal microcalcifications, bony destructions, or bony remodeling were identified in the maxillary sinus. The patient had serum eosinophilia of 598 eosinophils/μL (9.7% total white blood cells). The radioallergosorbent test showed an elevated total IgE concentration of 915.60 IU/mL and the multiple allergen simultaneous test revealed type I hypersensitization (atopy) to Aspergillus spp. (class 3), Cladosporium spp. (2+), weak sensitization to Penicillium spp. (1+), and none to Alternaria spp.

Effects of soluble glucomannan and insoluble cellulose treatment on mucin secretion and mucin glycosylation-related gene expression in the colons of mice.

Fiber added to the diet can promote intestinal mucin secretion, relieve intestinal inflammation, and enhance the intestinal barrier function. Glycosylation is the key to mucin function. However, there are few studies on the correlation between dietary fiber and mucin glycosylation, especially two kinds of dietary fiber with different solubility. The aim of this study was to investigate the effects of soluble glucomannan (GM) and insoluble cellulose (CL) treatment on mucin secretion and mucin glycosylation-related gene expression in the colons of mice. The GM group significantly increased the goblet cell number, crypt depth, and the expression of mucin 2 (Muc2) and mucin 3a (Muc3a) genes in the colon. At the same time, the analysis of the colon transcriptome showed that the GM group changed the expression of genes related to the mucin glycosylation process, and the GM group up-regulated the expression of Gcnt3, Gcnt4, St3gal1, Galnt13, and B3gnt6 genes involved in the O-glycosylation process. Similarly, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that differentially glycosylated genes in the GM group were mainly related to the biosynthesis of mucin type O-glycans, while the genes in the CL group were related to the biosynthesis of various types of N-glycans. The correlation analysis between colonic microbes and differentially glycosylated genes also showed that the abundance of Alistipes in the GM group was significantly associated with the expression of Gcnt3, a key glycosylation gene. Glucomannan treatment was more favorable for colonic Muc2 and Muc3a secretion and mucin O-glycosylation gene expression. © 2023 Society of Chemical Industry.

Cinnamaldehyde alleviates zearalenone-induced LS174T cell apoptosis, barrier dysfunction and mucin reduction through JNK/NF-κB signaling pathway

As a natural aldehyde organic compound, cinnamaldehyde (CA) is one of the main components of cinnamon essential oil with multiple bioactivities. In this study, we investigated the protective effects of CA on zearalenone (ZEA)-induced apoptosis, barrier dysfunction and mucin reduction, as well as underlying mechanisms in LS174T cells. In the present study, cells pre-treated with or without CA for 24 h were left untreated or subjected to ZEA for indicated time points Our results showed that 10 μM CA significantly prevented ZEA-induced cell viability decline, reversed ZEA-induced increase of the LDH level, cell cycle disruption and apoptosis in LS174T cells. Periodic acid-schiff (PAS) staining analysis showed that CA significantly alleviated the reduction of mucin secretion in LS174T cells caused by ZEA exposure. Western blot analysis showed that CA significantly reversed ZEA-induced reduction of the expression of mucin 2 (MUC2) and tight junction (TJ) proteins (claudin-1, claudin-3, ZO-1 and ZO-2) in LS174T cells. Notably, CA can significantly reduce the upregulation of the main effector of MAPK and NF-κB signaling pathways in LS174T cells. Further study showed that CA protects cells against ZEA-induced cellular damage through JNK/NF-κB signaling pathway in LS174T cells. Supplementation with CA might be an potential strategy to alleviate the damaging effect of ZEA on epithelial cells.

Moringa oleifera Lam. Leaf improves constipation of rats induced by low-fiber-diet: A proteomics study

Ethnopharmacological relevanceThe leaf of Moringa oleifera Lam., a medicinal and edible herb for thousands of years in Ayurveda, is used as Pancha (na) karma (purgative) during and after the body cleansing process, to treat constipation, reduce cholesterol and body weight. Aim of studyThe aim was to investigate the diarrhea effects and possible mechanism of M. oleifera leaves in constipation rats. Materials and methodsThe hot water extract of M. oleifera leaves (WEMOL) was prepared and analyzed using LC-20AT HPLC system. The constipated rat model was induced by feeding with low fiber diet for 21 days. After oral administration of WEMOL for 7 days, the excretion parameter analysis, gastro-intestinal propulsion, histological analysis by HE and Alcian blue staining, and gastrointestinal hormone in rat's digestive tract through ELISA were used to evaluate the laxative effect of WEMOL. Label-free quantitation (LFQ) with LC-MS/MS, bioinformatics and Western blot were used to discover and verify the signal pathways and key proteins of WEMOL related to diarrhea. ResultsThe contents of isoquercitrin and astragalin were 2.7 mg/g and 1.7 mg/g, respectively in WEMOL. The stool number, weight, and water content of constipation rats were significantly reduced, indicating model had been established successfully. WEMOL (1.25 and 2.5 g/kg) increased water content of feces and the levels of Gas, MTL, NPY in gastric antrum and VIP, SP in colon of constipation rats, improved the muscle layer thickness and mucin secretion of colon. The proteomics revealed a total of 1731 differential proteins and 9 signaling pathways, WEMOL increased the expression of Vamp2, Gnai3, and Prkacb. ConclusionsThe laxative mechanism of WEMOL maybe modulate the signaling pathways mediated by 5-HT and Ach receptors, related to gastrointestinal motility and intestinal fluid secretion. It can be considered as the scientific connotation of Pancha (na) karma of M. oleifera leaves in ayurveda.

Impact of Western Diet and Ultra-Processed Food on the Intestinal Mucus Barrier.

The intestinal epithelial barrier plays a key role in the absorption of nutrients and water, in the regulation of the interactions between luminal contents and the underlying immune cells, and in the defense against enteric pathogens. Additionally, the intestinal mucus layer provides further protection due to mucin secretion and maturation by goblet cells, thus representing a crucial player in maintaining intestinal homeostasis. However, environmental factors, such as dietary products, can disrupt this equilibrium, leading to the development of inflammatory intestinal disorders. In particular, ultra-processed food, which is broadly present in the Western diet and includes dietary components containing food additives and/or undergoing multiple industrial processes (such as dry heating cooking), was shown to negatively impact intestinal health. In this review, we summarize and discuss current knowledge on the impact of a Western diet and, in particular, ultra-processed food on the mucus barrier and goblet cell function, as well as potential therapeutic approaches to maintain and restore the mucus layer under pathological conditions.

Akkermansia muciniphila-directed polyphenol chlorogenic acid intervention for obesity in mice

Akkermansia muciniphila play an important in ameliorating obesity but is not allowed for direct consumption in most countries. To date, microbiota-directed foods selectively promote the targeted human gut microbes, providing a strategy for A. muciniphila enhancement. Multiple studies have indicated the potential regulation of the polyphenol on A. muciniphila. Therefore, a polyphenol screening based on A. muciniphila upregulation was performed in mice. Chlorogenic acid (CGA) exhibited a greater response to A. muciniphila upregulation. Furthermore, we found that CGA did not directly promote A. muciniphila growth or mucin secretion. Microbiome and metabolomics revealed that the increased abundance of A. muciniphila resulted from the inhibition of CGA on Desulfovibrio and Alistipes and the influence of docosahexaenoic acid, β-hydroxybutyrate, and N-acetyl-lactosamine. Finally, to confirm the regulation of CGA on A. muciniphila under disease conditions, high-fat diet-fed mice were established. The results showed CGA promoted A. muciniphila growth, and we expectedly found that CGA suppressed the augment in body weight of mice, significantly attenuated adipose tissue abnormality, provided liver protection and improved gut barrier integrity. These results suggest that CGA inhibits the development of obesity. Overall, our results indicate that microbiota-directed food is a promising approach for the treatment of obesity.