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Simple Summary: It is generally reported that the prognostic factors for ampulla of Vater cancer include T stage, N stage, and lymphovascular invasion and subtype, and the meaning of MUC stain is controversial. This retrospective study by the authors evaluated the significance of various MUC stains in AoV cancer using single-center clinicopathological data. The results showed that MUC5AC was significant for lymph node metastasis and was furthermore valuable as a prognostic factor for predicting overall survival. If this is evaluated in addition to the hematoxylin and eosin stain, which is commonly performed in preoperative biopsy, it is expected to be a method to select groups that require more extensive LN dissection and further prevent locoregional recurrence. Introduction: Mucins play a pivotal role in epithelial carcinogenesis; however, their role remains elusive in ampulla of Vater (AoV) cancer, regardless of histological subtype. Therefore, we investigated the clinical significance of MUC1, MUC2, MUC5AC, and MUC6 expression in AoV cancer. Methods: Using samples from 68 patients with AoV cancer, we performed immunohistochemical staining for MUC1, MUC2, MUC5AC, and MUC6 using a tissue microarray. Subsequently, we analyzed their expression patterns in relation to clinicopathological parameters and patient outcomes. Results: Of the patients, 98.5% exhibited positive expression for MUC1, while MUC2, MUC5AC, and MUC6 were expressed in 44.1%, 47.1%, and 41.2% of the patients, respectively. Correlation analyses between mucin expression and clinicopathological factors revealed no significant associations, except between MUC5AC expression and N stage. Univariate analysis demonstrated significant associations between MUC5AC expression and overall survival (OS). Multivariate analysis further confirmed that MUC5AC expression was a significant predictor of OS, along with the N stage. However, MUC5AC expression was not meaningfully associated with recurrence-free survival (RFS). The patients positive for MUC5AC expression had a considerably shorter OS than those with negative expression. Conclusions: Our study provides insights into the clinical impact of mucins on AoV cancer, regardless of the histological subtype. Although MUC1 expression is universal, MUC5AC expression is a significant prognostic indicator that correlates with lymph node metastasis and poor OS. These results emphasize the possible utility of MUC5AC as a biomarker for extensive lymph node dissection and the prognostic evaluation of patients with AoV cancer. [ABSTRACT FROM AUTHOR]

This study was the first attempt to visualize pulmonary retention of nanocarriers (NCs) with the use of the P2 probe, a new water-initiated aggregation-caused fluorescent-quenching (ACQ) dye, for the development of NCs with long-lasting retention in the respiratory system (RS). Flash nanoprecipitation was used to fabricate mucopenetrating NCs (MP/NCs) and mucoadhesive NCs (MA/NCs). Both NCs were labeled with the P2 probe, and their distribution and retention in RS were visualized after intratracheal administration to rats. MP/NCs and MA/NCs had a mean diameter below 200 nm and ζ-potential of 0 and 48 mV, respectively. MA/NCs showed three times stronger interactions with mucin than MP/NCs, resulting in significantly lower diffusiveness in mucus. The P2 probe exhibited an ACQ effect with negligible rekindling in simulated lung fluid, and the spectroscopic data suggested applicability to reliable imaging of insufflated NCs. In confocal laser scanning microscopic and in vivo imaging system images of the rat RS, MA/NCs were locally deposited in the respiratory tract and transported toward the pharynx by mucocilliary clearance (MCC). In contrast, MP/NCs diffused in the respiratory mucus were less subject to the influence of MCC. Based on the results from the bioimaging study using the P2 probe, MP/NCs could offer enhanced pulmonary retention of drugs compared with MA/NCs. [ABSTRACT FROM AUTHOR]

A great interest is placed on the influence of probiotic, prebiotic and synbiotic preparations on animals in accordance with the principle of One health. The small intestine mucosa represents a complex ecosystem ensuring the homeostasis of the animal organism. The effect of Lacto-Immuno-Vital synbiotic preparation on the quantity of mucin produced in the broiler chicken small intestine was studied. The chickens (7 days old Hybrid ROSS 308) were divided into 3 equal size (n = 16) groups, housed in separate halls: control group (CG), and two experimental groups that received syn-biotic preparation Lacto-Immuno-Vital, – one with continuous synbiotic administration (EGC), and another with pulsed synbiotic administration (EGP). The preparation was administered to EGC group from the experimental day 1 to day 7 continuously every day (500 g per 1000 l of drinking water.day−1), and to EGP group from experimental day 8 to day 22 in a pulsed manner (every third day) at a dose of 300 g per 1000 l of drinking water. The experiment lasted 22 days. A significant effect on mucus production quantity was found in the duodenum (P < 0.001), in EG after both types of synbiotic supplementation compared to CG. The comparison of continuous and pulsed supplementation was as follows: a significant effect (P < 0.001) was observed after continuous supplementation of the synbiotic preparation, compared to pulsed supplementation in EG. [ABSTRACT FROM AUTHOR]

Background and Objectives: Mucin has been implicated via various mechanisms in the development and growth of tumour cells. However, mucin expression studies in salivary gland tumours are limited, especially with samples from minor salivary glands. This study aims to investigate and compare mucin expression in benign and malignant salivary gland tumours of minor and major salivary gland origins. Materials and Methods: Special stains were used to stain neutral mucin (Periodic acid Schiff), sialomucin (Alcian Blue) and sulfomucin (Aldehyde Fuschin) within tissues from six normal salivary glands and 73 salivary gland tumours including 31 pleomorphic adenomas, 27 mucoepidermoid carcinomas, and 15 adenoid cystic carcinomas. A semi-quantitative approach was used to evaluate mucin expression within ductal lumens. Sialomucin was the most expressed mucin in all salivary gland tumours, regardless of origin. Results: A significant difference was observed in the mucin expression between benign and malignant salivary gland tumours, as pleomorphic adenoma showed three times significantly higher expression of sialomucin compared to mucoepidermoid carcinoma and adenoid cystic carcinoma (p = 0.028). Pleomorphic adenomas of major glands showed 42 times significantly higher expression of sialomucin compared to those of minor glands (p = 0.000). Conclusions: Sialomucin content in pleomorphic adenomas of major glands was vastly increased compared to that in minor glands. Differential sialomucin expression in benign and malignant salivary gland tumours suggests a role in diagnosing of borderline salivary gland tumours. [ABSTRACT FROM AUTHOR]

Introduction: Signet-ring cells are typically associated with mucin-secreting epithelium; thus, they are most commonly found in the gastrointestinal tract, but not exclusively. Primary signet-ring cell carcinoma of the prostate is a rare and poorly differentiated, aggressive acinar adenocarcinoma variant with a grim prognosis. Clinical Case: In June of 2023, a 54-year-old Caucasian male presented with a complaint of lower urinary tract obstructive symptoms with occasional macrohematuria, non-specific body aches, and shortness of breath. A prostate specimen obtained in transurethral resection of the prostate was sent for histopathological examination. After a series of extraprostatic diagnostic workups, including fibrogastroduodenoscopy, colonoscopy computed tomography imaging, and immunohistochemical studies, the patient was diagnosed with primary prostatic signet-ring cell adenocarcinoma stage IV. Unfortunately, due to the advanced stage of the disease, PE, and third-degree thrombocytopenia, the patient was not a candidate for chemotherapy and died of cardiopulmonary insufficiency later that week. Discussion: Prostatic signet-ring cell carcinoma accounts for 0.02% of all prostate adenocarcinoma cases. Due to its nature and epidemiology, a diligent extraprostatic investigation has to be carried out. The disease often presents with unremarkable clinical symptoms and variable serum prostate-specific antigen results, which may contribute to its late diagnosis. Inconsistent immunohistochemical findings and an unpredictable response to hormonal treatment together pose both diagnostic and therapeutic challenges that negatively affect the prognosis. Conclusions: This study highlights the importance of a multidisciplinary approach and the need for diagnostic and therapeutic consensus within the research community in search of the primary site of the disease, which may positively influence the prognosis. [ABSTRACT FROM AUTHOR]

Microbial community function depends on both taxonomic composition and spatial organization. While composition of the human gut microbiome has been deeply characterized, less is known about the organization of microbes between regions such as lumen and mucosa and the microbial genes regulating this organization. Using a defined 117 strain community for which we generate high-quality genome assemblies, we model mucosa/lumen organization with in vitro cultures incorporating mucin hydrogel carriers as surfaces for bacterial attachment. Metagenomic tracking of carrier cultures reveals increased diversity and strain-specific spatial organization, with distinct strains enriched on carriers versus liquid supernatant, mirroring mucosa/lumen enrichment in vivo. A comprehensive search for microbial genes associated with this spatial organization identifies candidates with known adhesion-related functions, as well as novel links. These findings demonstrate that carrier cultures of defined communities effectively recapitulate fundamental aspects of gut spatial organization, enabling identification of key microbial strains and genes.

It is imperative to preserve the integrity of the gastrointestinal system in spite of the persistent existence of harmful chemicals and microbial flora in the gut. This is made possible by essential healing initiators called Trefoil factors which helps in mucosal reconstitution and tissue development on the gastrointestinal surface. The trefoil factors are a class of abundant secreted proteins that are essential for epithelial continuity (TFFs). Trefoil factor family (TFF) proteins are biologically active peptides that play significant role in safeguarding, restoring and continuity of the gastrointestinal tract (GIT) epithelium, through collaborative modulations with mucins in the mucosal layer. These peptides are readily produced in reaction to epithelial damage in the digestive tract, thereby contributing to the healing and restituting of the epithelial layers of the intestine. In addition, considerable evidence indicated that TFF peptides trigger proliferation, migration and angiogenesis, all which are crucial processes for wound healing. There is also increasing evidence that TFF peptides modulate the mucosal immune system. These protective properties, suggest that dietary manipulation strategies targeted at enhancing the expression and synthesis of TFF peptides at optimal levels in the GIT epithelium, may constitute a plausible alternative strategy to the use of in-feed antibiotic growth promoters to maintain epithelial integrity and promote resistance to enteric pathogens. This review describes TFF peptides, with importance to their biological functions and involvement in gastrointestinal mucosal protection and repair in food animals.

Background & aims: Older people experience a greater incidence of lower bowel disorders, including constipation. Causes can include factors associated with growing older, such as use of medications or disease, but compounded by degenerative changes within the bowel wall. It has been suggested that the latter is exacerbated by loss of an effective mucosal barrier to luminal contents. In human colon, little is known about the impact of ageing on key components of this barrier, namely the goblet cells and mucin content. Methods: Changes in the number of goblet cells and density of mucin content were investigated in macroscopically normal human ascending (AC; n = 13) and descending (DC; n = 14) colon from elderly (≥ 67 years) and younger adults (60 years and below). Samples were serially sectioned and stained for haematoxylin and eosin to assess tissue morphology, and alcian blue periodic acid Schiff (ABPAS) and MUC-2 antibody to identify goblet cells producing mucins. New procedures in visualization and identification of goblet cells and mucin contents were employed to ensure unbiased counting and densitometric analysis. Results: Compared with the younger adults, the numbers of goblet cells per crypt were significantly lower in the elderly AC (72 ± 1.2 vs 51 ± 0.5) and DC (75 ± 2.6 vs. 54 ± 1.9), although this reduction did not reach statistical significance when assessed per mucosal area (AC: P = 0.068; DC: P = 0.096). In both regions from the elderly, numerous empty vesicles (normally containing mucins) were observed, and some areas of epithelium were devoid of goblet cells. Thus, the density of mucin content per unit mucosal area were significantly reduced with age. Conclusions: Ageing could result in a reduced number of goblet cells and development of degenerative changes in mucin production. Together, these have implications for the mucus barrier function in the colon of elderly individuals.

Pancreatic cancer is difficult to resect due to its unique challenges, often leading to incomplete tumor resections. Fluorescence-guided surgery (FGS), also known as intraoperative molecular imaging and optical surgical navigation, is an intraoperative tool that can aid surgeons in complete tumor resection through an increased ability to detect the tumor. To target the tumor, FGS contrast agents rely on biomarkers aberrantly expressed in malignant tissue compared to normal tissue. These biomarkers allow clinicians to identify the tumor and its stage before surgical resection and provide a contrast agent target for intraoperative imaging. Mucins, a family of glycoproteins, are upregulated in malignant tissue compared to normal tissue. Therefore, these proteins may serve as biomarkers for surgical resection. Intraoperative imaging of mucin expression in pancreatic cancer can potentially increase the number of complete resections. While some mucins have been studied for FGS, the potential ability to function as a biomarker target extends to the entire mucin family. Therefore, mucins are attractive proteins to investigate more broadly as FGS biomarkers. This review summarizes the biomarker traits of mucins and their potential use in FGS for pancreatic cancer.

Abstract Heart surgery may be complicated by acute lung injury and adult respiratory distress syndrome. Expression and release of mucins MUC5AC and MUC5B in the lungs has been reported to be increased in acute lung injury. The aim of our study was to [1] investigate the perioperative changes of MUC5AC, MUC5B and other biomarkers in mini-bronchoalveolar lavage (minBAL), and [2] relate these to clinical outcomes after cardiac surgery. In this prospective cohort study in 49 adult cardiac surgery patients pre- and post-surgery non-fiberscopic miniBAL fluids were analysed for MUC5AC, MUC5B, IL-8, human neutrophil elastase, and neutrophils. All measured biomarkers increased after surgery. Perioperative MUC5AC-change showed a significant negative association with postoperative P/F ratio (p = 0.018), and a positive association with ICU stay (p = 0.027). In conclusion, development of lung injury after cardiac surgery and prolonged ICU stay are associated with an early increase of MUC5AC as detected in mini-BAL.

Pandemic and endemic strains of Vibrio cholerae arise from toxigenic conversion by the CTXφ bacteriophage, a process by which CTXφ infects nontoxigenic strains of V. cholerae. CTXφ encodes the cholera toxin, an enterotoxin responsible for the watery diarrhea associated with cholera infections. Despite the critical role of CTXφ during infections, signals that affect CTXφ-driven toxigenic conversion or expression of the CTXφ-encoded cholera toxin remain poorly characterized, particularly in the context of the gut mucosa. Here, we identify mucin polymers as potent regulators of CTXφ-driven pathogenicity in V. cholerae. Our results indicate that mucin-associated O-glycans block toxigenic conversion by CTXφ and suppress the expression of CTXφ-related virulence factors, including the toxin co-regulated pilus and cholera toxin, by interfering with the TcpP/ToxR/ToxT virulence pathway. By synthesizing individual mucin glycan structures de novo, we identify the Core 2 motif as the critical structure governing this virulence attenuation. Overall, our results highlight a novel mechanism by which mucins and their associated O-glycan structures affect CTXφ-mediated evolution and pathogenicity of V. cholerae, underscoring the potential regulatory power housed within mucus.

Mucins (MUC1-MUC24) are a family of glycoproteins involved in cell signaling and barrier protection. They have been implicated in the progression of numerous malignancies including gastric, pancreatic, ovarian, breast, and lung cancer. Mucins have also been extensively studied with respect to colorectal cancer. They have been found to have diverse expression profiles amongst the normal colon, benign hyperplastic polyps, pre-malignant polyps, and colon cancers. Those expressed in the normal colon include MUC2, MUC3, MUC4, MUC11, MUC12, MUC13, MUC15 (at low levels), and MUC21. Whereas MUC5, MUC6, MUC16, and MUC20 are absent from the normal colon and are expressed in colorectal cancers. MUC1, MUC2, MUC4, MUC5AC, and MUC6 are currently the most widely covered in the literature regarding their role in the progression from normal colonic tissue to cancer.

The gastrointestinal tract relies on the production, maturation, and transit of mucin to protect against pathogens and to lubricate the epithelial lining. Although the molecular and cellular mechanisms that regulate mucin production and movement are beginning to be understood, the upstream epithelial signals that contribute to mucin regulation remain unclear. Here, we report that the inflammatory cytokine tumor necrosis factor (TNF), generated by the epithelium, contributes to mucin homeostasis by regulating both cell differentiation and cystic fibrosis transmembrane conductance regulator (CFTR) activity. We used genetic mouse models and noninflamed samples from patients with inflammatory bowel disease (IBD) undergoing anti-TNF therapy to assess the effect of in vivo perturbation of TNF. We found that inhibition of epithelial TNF promotes the differentiation of secretory progenitor cells into mucus-producing goblet cells. Furthermore, TNF treatment and CFTR inhibition in intestinal organoids demonstrated that TNF promotes ion transport and luminal flow via CFTR. The absence of TNF led to slower gut transit times, which we propose results from increased mucus accumulation coupled with decreased luminal fluid pumping. These findings point to a TNF/CFTR signaling axis in the adult intestine and identify epithelial cell-derived TNF as an upstream regulator of mucin homeostasis.

The intestinal anaerobic bacterium Akkermansia muciniphila is specialized in the degradation of mucins, which are heavily O-glycosylated proteins that constitute the major components of the mucus lining the intestine. Despite that adhesion to mucins is considered critical for the persistence of A. muciniphila in the human intestinal tract, our knowledge of how this intestinal symbiont recognizes and binds to mucins is still limited. Here, we first show that the mucin-binding properties of A. muciniphila are independent of environmental oxygen concentrations and not abolished by pasteurization. We then dissected the mucin-binding properties of pasteurized A. muciniphila by use of a recently developed cell-based mucin array that enables display of the tandem repeats of human mucins with distinct O-glycan patterns and structures. We found that A. muciniphila recognizes the unsialylated LacNAc (Galβ1-4GlcNAcβ1-R) disaccharide selectively on core2 and core3 O-glycans. This disaccharide epitope is abundantly found on human colonic mucins capped by sialic acids, and we demonstrated that endogenous A. muciniphila neuraminidase activity can uncover the epitope and promote binding. In summary, our study provides insights into the mucin-binding properties important for colonization of a key mucin-foraging bacterium. Intestinal mucus consists of densely O-glycosylated mucins, serving as a nutrient source for bacteria. Elzinga et al. show that mucin-degrading Akkermansia muciniphila selectively binds to O-glycan structures found on human colonic mucins. [ABSTRACT FROM AUTHOR]

Background: Pseudomyxoma peritonei (PMP) is a rare peritoneal mucinous carcinomatosis with largely unknown underlying molecular mechanisms. Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy is the only therapeutic option; however, despite its use, recurrence with a fatal outcome is common. The lack of molecular characterisation of PMP and other mucinous tumours is mainly due to the physicochemical properties of mucin. Results: This manuscript describes the first protocol capable of breaking the mucin barrier and isolating proteins from mucinous tumours. Briefly, mucinous tumour samples were homogenised and subjected to liquid chromatography using two specific columns to reduce mainly glycoproteins, albumins and immunoglobulin G. The protein fractions were then subjected to mass spectrometry analysis and the proteomic profile obtained was analysed using various bioinformatic tools. Thus, we present here the first proteome analysed in PMP and identified a distinct mucin isoform profile in soft compared to hard mucin tumour tissues as well as key biological processes/pathways altered in mucinous tumours. Importantly, this protocol also allowed us to identify MUC13 as a potential tumour cell marker in PMP. Conclusions: In sum, our results demonstrate that this protein isolation protocol from mucin will have a high impact, allowing the oncology research community to more rapidly advance in the knowledge of PMP and other mucinous neoplasms, as well as develop new and effective therapeutic strategies. [ABSTRACT FROM AUTHOR]

Mucin, a glycoprotein with viscoelastic properties, and silk fibroin, a protein excreted from silkworms with properties of thermal and mechanical resistance, have been probed as building blocks in the design of biomaterials. Aiming to evaluate the interaction and miscibility between mucin and fibroin, we synthesized silk fibroin and mucin (SF/MU) blends for biomedical applications. The morphological analysis of the SF/MU blends showed the presence of two phases, suggesting a partial miscibility between the polymers. The degradation temperature of the SF/MU blends increased with an increase in the silk fibroin content, indicating that silk fibroin contributed to the thermal stability of the blends. The glass transition temperature of the SF/MU blends lay between the values of the pure polymers. The Fourier‐transform infrared spectroscopy results pointed out that the interaction between fibroin and mucin occurred between the amine group of silk fibroin and mucin carboxyl and hydroxyl groups. The outcomes of this work provided essential information on the miscibility of the SF/MU blends. These findings will be critical for further studies with fibroin and mucin‐based biomaterials, especially in mucoadhesive systems and wound healing applications. [ABSTRACT FROM AUTHOR]

The immune system employs soluble effectors to shape luminal spaces. Antibodies are soluble molecules that effect immunological responses, including neutralization, opsonization, antibody-dependent cytotoxicity and complement activation. These molecules are comprised of immunoglobulin (Ig) domains. The N-terminal Ig domains recognize antigen, and the C-terminal domains facilitate their elimination through phagocytosis (opsonization). A less-recognized function mediated by the C-terminal Ig domains of the IgG class of antibodies (Fc region) involves the formation of multiple low-affinity bonds with the mucus matrix. This association anchors the antibody molecule to the matrix to entrap potential pathogens. Even though invertebrates are not known to have antibodies, protochordates have a class of secreted molecules containing Ig domains that can bind bacteria and potentially serve a similar purpose. The VCBPs (V region-containing chitin-binding proteins) possess a C-terminal chitin-binding domain that helps tether them to chitin-rich mucus gels, mimicking the IgG-mediated Fc trapping of microbes in mucus. The broad functional similarity of these structurally divergent, Ig-containing, secreted effectors makes a case for a unique form of convergent evolution within chordates. This opinion essay highlights emerging evidence that divergent secreted immune effectors with Ig-like domains evolved to manage immune recognition at mucosal surfaces in strikingly similar ways. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'. [ABSTRACT FROM AUTHOR]

Mucins released from epithelial tumors have been proposed to play a role in cancer-associated thrombosis. Mucin1 (MUC1) is a transmembrane mucin that is overexpressed in a variety of human malignancies, including breast and pancreatic cancer. We analyzed the association of MUC1 and venous thrombosis in a mouse tumor model and in patients with cancer. We used a human pancreatic cancer cell line HPAF-II that expresses a high level of MUC1. We grew HPAF-II tumors in the pancreas of Crl:NU- Foxn1 nu male mice. MUC1 in plasma and extracellular vesicles (EVs) isolated from plasma was measured using an enzyme-linked immunosorbent assay. MUC1 in EVs and venous thrombi from tumor-bearing mice was assessed by western blotting. We measured MUC1 in plasma from healthy controls and patients with stomach, colorectal or pancreatic cancer with or without venous thromboembolism. MUC1 was detected in the plasma of mice bearing HPAF-II tumors and was associated with EVs. MUC1 was present in venous thrombi from mice bearing HFAP-II tumors. Recombinant MUC1 did not induce platelet aggregation. Levels of MUC1 were higher in patients with pancreatic cancer compared with healthy controls. In contrast to the mouse model, MUC1 was present in EV-free plasma in samples from healthy controls and patients with cancer. There was no significant difference in the levels of MUC1 in cancer patients with or without VTE. Our data did not find any evidence that MUC1 contributed to VTE in patients with cancer. • Circulating MUC1 was present in the plasma of tumor-bearing mice. • MUC1 was present in venous thrombi isolated from tumor-bearing mice. • There was no difference in levels of MUC1 in cancer patients with or without VTE [ABSTRACT FROM AUTHOR]

Saliva is vital to oral health, fulfilling multiple functions in the oral cavity. Three pairs of major salivary glands and hundreds of minor salivary glands contribute to saliva production. The secretory acinar cells within these glands include two distinct populations. Serous acinar cells secrete a watery saliva containing enzymes, while mucous acinar cells secrete a more viscous fluid containing highly glycosylated mucins. Despite their shared developmental origins, the parotid gland (PG) is comprised of only serous acinar cells, while the sublingual gland (SLG) contains predominantly mucous acinar cells. The instructive signals that govern the identity of serous versus mucous acinar cell phenotypes are not yet known. The homeobox transcription factor Nkx2.3 is uniquely expressed in the SLG. Disruption of the Nkx2.3 gene was reported to delay the maturation of SLG mucous acinar cells. To examine whether Nkx2.3 plays a role in directing the mucous cell phenotype, we analyzed SLG from Nkx2.3−/− mice using RNAseq, immunostaining and proteomic analysis of saliva. Our results indicate that Nkx2.3, most likely in concert with other transcription factors uniquely expressed in the SLG, is a key regulator of the molecular program that specifies the identity of mucous acinar cells. [Display omitted] • Nkx2.3 transcription factor is a key regulator specifying mucous acinar cell identity. • Nkx2.3 KO SLG transcriptome is intermediate between mucous and serous acinar cells. • The Nkx2.3 transcription factor has both activating and repressive activities. [ABSTRACT FROM AUTHOR]

Carcinomas of the head-and-neck region with squamous and glandular/mucinous features constitute a heterogeneous group, with a significant minority of tumors showing an human papillomavirus (HPV) association. The differential diagnosis is usually between mucoepidermoid carcinoma (MEC) and adenosquamous carcinoma. We present here two tumors that exemplify both the challenges of diagnostic classification, as well as the complex relationship to HPV: (a) a low risk HPV positive/p16 negative carcinoma that is most consistent with a relatively typical intermediate grade mucoepidermoid type carcinoma with complete MEC phenotype (three cell types), originating from intranasal sinonasal papillomas with exophytic and inverted patterns, and invading surrounding maxillary compartments, and (b) a p16 and keratin 7 (KRT7) positive carcinoma of the right tonsil, characterized by stratified squamous and mucinous cell (mucocyte) features. Whereas the first tumor represents a typical MEC ex-Schneiderian papilloma, the second is morphologically most consistent with the, novel for this anatomic location, diagnosis of "invasive stratified mucin producing carcinoma" (ISMC), pointing to an analogy to similar, high-risk HPV-driven malignancies recently described in the gynecologic (GYN) and genitourinary (GU) areas. Both tumors, despite their mucoepidermoid-like features had no connection to salivary glands and lacked the MAML2 translocation typical of salivary gland MEC, pointing to a mucosal/non-salivary gland origin. Using these two carcinomas as examples, we attempt to address questions related to: (a) the histological distinction between MEC, adenosquamous carcinoma, and ISMC, (b) similarities and differences between these histological entities in mucosal sites versus morphologically similar salivary gland tumors, and (c) the role of HPV in these tumors. [ABSTRACT FROM AUTHOR]

Cyanidin 3-O-glucoside (C3G) is believed to combine with oral mucin, thus impairing oral lubrication and leading to the development of oral astringency. When C3G is oxidized into cyanidin 3-O-glucoside quinone (C3GQ), it might covalently interact with cysteine of mucin to enhance astringency. Herein, their detailed interactions at the molecule level were characterized through spectroscopy, isothermal titration calorimetry and determination of free amino and sulfhydryl groups. The results showed that hydrogen bond and van der Waals force were the predominant non-covalent interactions. Furthermore, C3GQ could additionally bind to mucin by forming C-N and C-S bonds since the amino and sulfhydryl groups of mucin decreased by 0.48 mmol/g and 4.14 µmol/g after reacting with C3GQ. Besides, C3GQ had stronger interaction with mucin as the exothermic value of Muc-C3GQ (2513 KJ/mol) was larger than Muc-C3G (60.4 KJ/mol). These findings may explain the phenomenon of increased astringency of anthocyanins after being oxidized into quinones. [ABSTRACT FROM AUTHOR]

Cystic echinococcosis is caused by the tissue‐dwelling larva (hydatid) of Echinococcus granulosus sensu lato. A salient feature is that this larva is protected by the acellular laminated layer (LL). As the parasite grows, the LL sheds abundant particles that can accumulate in the parasite's vicinity. The potential of LL particles to induce inflammation in vivo has not been specifically analysed. It is not known how each of its two major components, namely highly glycosylated mucins and calcium inositol hexakisphosphate (InsP6) deposits, impacts inflammation induced by the LL as a whole. In this work, we show that LL particles injected intraperitoneally cause infiltration of eosinophils, neutrophils and monocytes/macrophages as well as the disappearance of resident (large peritoneal) macrophages. Strikingly, the absence of calcium InsP6 enhanced the recruitment of all the inflammatory cell types analysed. In contrast, oxidation of the mucin carbohydrates caused decreased recruitment of neutrophils. The carbohydrate‐oxidised particles caused cell influx nonetheless, which may be explained by possible receptor‐independent effects of LL particles on innate immune cells, as suggested by previous works from our group. In summary, LL particles can induce acute inflammatory cell recruitment partly dependent on its mucin glycans, and this recruitment is attenuated by the calcium InsP6 component. [ABSTRACT FROM AUTHOR]

Key Clinical Massage: In extradigital glomus tumors, (1) noncontact and (2) contact dermoscopy show (1) a central purplish‐white area corresponding to tumor nests surrounding enlarged vessels, a peripheral yellow‐white area corresponding to mucin deposition, melanin granules, and fibrous tissue, and (2) white reticular and linear cord areas corresponding to pseudocapsules and collagen fibers. [ABSTRACT FROM AUTHOR]

Background: Non-neoplastic and neoplastic diseases of gallbladder are most prevalent in northern and north-eastern states of Uttar Pradesh, Bihar, Orissa, West Bengal, and Assam in India. Chronic cholecystitis, the most common pathology of gallbladder is often associated with metaplasia of epithelium, leading to increased susceptibility to malignant transformation. Along with histopathological examination, mucin histochemistry is useful in early detection of metaplasia and thereby predicting metaplasia-dysplasia-carcinoma sequence. Aims and Objectives: The objective of this study was to estimate the prevalence of neoplastic and non-neoplastic diseases of gallbladder and to determine the usefulness of mucin histochemistry in early diagnosis of metaplasia and carcinoma of gallbladder. Materials and Methods: A cross-sectional observational study was conducted in R. G. Kar Medical College, Kolkata, over a period of 18 months. Total 401 cholecystectomy specimens were studied. In every case, following sequence of examinations was performedgross examinations, histopathological examination, and mucin histochemistry. Results: All the available information was meticulously documented in tables and charts, software was used to calculate the statistical significance and efficacy of mucin histochemistry as a diagnostic tool. Conclusion: We found that mucin histochemistry is statistically significant and has positive predictive value in early diagnosis of metaplasia and carcinoma of gallbladder. [ABSTRACT FROM AUTHOR]

Role of the Mucin 1 gene in thyroid cancer and its relationship with the adenosine-monophosphate activatedprotein kinase-mammalian target of rapamycin signaling pathway were investigated in this work. The ACT-1 thyroid cancer cell lines were employed as the research models and enrolled into three groups based on treatment viz., a control group (no intervention), a small interfering ribonucleic acid-negative control group (transfection of negative control small interfering ribonucleic acid at 100 nM/l into ACT-1 thyroid cancer cells), and a Mucin 1-small interfering ribonucleic acid group (transfection of Mucin 1-small interfering ribonucleic acid at 100 nM/l into ACT-1 cells). The impacts of interfering with Mucin 1 gene on thyroid cancer cell proliferation, apoptosis, adenosine-monophosphate activated-protein kinase, mammalian target of rapamycin, and autophagy-related proteins (light chain 3I and light chain 3II) were observed. The results indicated that the cell survival rate in Mucin 1-small interfering ribonucleic acid group (53.15±8.23) % was lower to that in control group (95.13±6.42) % (p<0.05), resulting a higher cell apoptosis rate of (15.79±1.36) %, which was (3.11±0.68) % in control group (p<0.05). p-Mammalian target of rapamycin in control group (0.13±0.02) was elevated based on that in Mucin 1-small interfering ribonucleic acid group (0.05±0.01) (p<0.05), while p-adenosine-monophosphate activated-protein kinase in control group (0.16±0.02) was downshifted in contrast to that in Mucin 1-small interfering ribonucleic acid group (0.46±0.03) (p<0.05). Light chain 3I/light chain 3II in control group was (0.28±0.02), being lower in comparison to that in Mucin 1-small interfering ribonucleic acid group (0.46±0.03) (p<0.05). Interference with Mucin 1 gene regulated the biological behaviors of thyroid cancer cells by modulating the adenosine-monophosphate activated-protein kinase-mammalian target of rapamycin signaling pathway. [ABSTRACT FROM AUTHOR]

Gallbladder disorders encompass a spectrum from congenital anomalies to inflammatory and neoplastic conditions, frequently requiring surgical intervention. Epithelial abnormalities like adenoma and metaplasia have the potential to progress to carcinoma, emphasizing the importance of histopathological assessment for early detection of malignancy. Gallbladder cancer (GBC) may be incidentally discovered during cholecystectomy for presumed benign conditions, underscoring the need for a thorough examination. However, the lack of clarity regarding the molecular mechanisms of GBC has impeded diagnostic and therapeutic advancements. Timely detection is crucial due to GBC's aggressive nature and poor prognosis. Chronic inflammation plays a central role in carcinogenesis, causing DNA damage and oncogenic alterations due to persistent insults. Inflammatory cytokines and microRNAs are among the various mediators contributing to this process. Gallbladder calcifications, particularly stippled ones, may signal malignancy and warrant preemptive removal. Molecular pathways involving mutations in oncogenes and tumor suppressor genes drive GBC pathogenesis, with proposed sequences such as gallstone-induced inflammation leading to carcinoma formation. Understanding these mechanisms, alongside evaluating mucin characteristics and gene mutations, can deepen comprehension of GBC's pathophysiology. This, in turn, facilitates the identification of high-risk individuals and the development of improved treatment strategies, ultimately enhancing patient outcomes. Thus, in this review, our aim has been to underscore the primary mechanisms underlying the development of gallbladder dysplasia and neoplasia. [ABSTRACT FROM AUTHOR]

Introduction: Secreted mucins are highly O-glycosylated glycoproteins produced by goblet cells in mucosal epithelia. They constitute the protective viscous gel layer overlying the epithelia and are involved in pathogen recognition, adhesion and expulsion. The gill polyopisthocotylidan ectoparasite Sparicotyle chrysophrii, feeds on gilthead seabream (Sparus aurata) blood eliciting severe anemia. Methods: Control unexposed and recipient (R) gill samples of gilthead seabream experimentally infected with S. chrysophrii were obtained at six consecutive times (0, 11, 20, 32, 41, and 61 days post-exposure (dpe)). In histological samples, goblet cell numbers and their intensity of lectin labelling was registered. Expression of nine mucin genes (muc2, muc2a, muc2b, muc5a/c, muc4, muc13, muc18, muc19, imuc) and three regulatory factors involved in goblet cell differentiation (hes1, elf3, agr2) was studied by qPCR. In addition, differential expression of glycosyltransferases and glycosidases was analyzed in silico from previously obtained RNAseq datasets of S. chrysophrii-infected gilthead seabream gills with two different infection intensities. Results and Discussion: Increased goblet cell differentiation (up-regulated elf3 and agr2) leading to neutral goblet cell hyperplasia on gill lamellae of R fish gills was found from 32 dpe on, when adult parasite stages were first detected. At this time point, acute increased expression of both secreted (muc2a, muc2b, muc5a/c) and membrane-bound mucins (imuc, muc4, muc18) occurred in R gills. Mucins did not acidify during the course of infection, but their glycosylation pattern varied towards more complex glycoconjugates with sialylated, fucosylated and branched structures, according to lectin labelling and the shift of glycosyltransferase expression patterns. Gilthead seabream gill mucosal response against S. chrysophrii involved neutral mucus hypersecretion, which could contribute to worm expulsion and facilitate gas exchange to counterbalance parasite-induced hypoxia. Stress induced by the sparicotylosis condition seems to lead to changes in glycosylation characteristic of more structurally complex mucins. [ABSTRACT FROM AUTHOR]

Background: Low-grade appendiceal mucinous neoplasms (LAMNs) are benign non-invasive epithelial proliferations of the appendix. These usually present clinically as mucoceles and these rarely exceed 2 cm in diameter. Lesions confined to the lumen are labelled as LAMN; however those in which mucin spreads outside the peritoneum are labeled as pseudomyxoma peritonei (PMP). Aims and Objective: A retrospective study was conducted over a period of three years and all cases of appendectomies were studied. Twelve cases of LAMN were identified, which is a diagnostic dilemma for the pathologists and clinicians. Results: LAMN was identified based on the histopathological features. Out of the 12 cases, 9 were classified as LAMN and 3 as appendiceal neoplasm with PMP. There was villous or flat proliferation of epithelial lining, loss lymphoid aggregates, and dissecting mucin within muscularis. Conclusion: LAMNs are rare neoplasms of the appendix, with clinical presentation similar to acute appendicitis. Mucinous collections within the appendiceal wall should be extensively searched for mucosal changes and, if found, should prompt a careful search for pushing invasion of LAMNs. A thorough and vigilant gross examination can be of great help. Appendicectomy is the treatment of benign and grossly intact mucinous neoplasm. [ABSTRACT FROM AUTHOR]

A key component of amphibian antipredator strategies is the chemical defenses that make them toxic and/or distasteful, like the cardiotoxic bufadienolides synthesized by the true toads and stored in granular skin glands. The morphology of adult toad glands is well-described, but the ontogenetic timing and distribution of glands during larval stages are poorly understood. A comparative understanding of granular gland development is needed to elucidate the mechanisms underlying the diversification of toad chemical defenses and their ecological roles across lineages and ontogeny. Herein, we analyzed gland morphology before and after metamorphosis of Rhinella horribilis, Incilius melanochlorus, and I. luetkenii. We hypothesized that granular gland development would begin earlier and progress faster in relatively more toxic Rhinella species. Our results showed that the timeline of skin development, the relative dimensions and quantity of structures, and the appearance of protein and mucin content in granular and mucous glands did not vary among Rhinella and Incilius. Furthermore, epidermal mucus and/or giant cells in larval toads may act as sources of chemical defenses prior to gland development. Our findings suggest that gland development is well-conserved among these genera; it is possible that reported differences in toxin profiles are not due to divergent morphogenesis during larval or metamorphic stages, but rather to differences in molecular function or structural differentiation in juveniles or adults. Therefore, complementary studies using integrative techniques such as immunohistochemistry and comparative transcriptomics are needed to uncover the mechanisms responsible for the diversity of chemical defenses found in bufonid toads across development. [ABSTRACT FROM AUTHOR]

Aims Indole and mucin are compounds found in the host environment as they are produced by the host or by the host-associated microbiota. This study investigated whether indole and mucin impact Clostridium perfringens growth and sporulation, as well as enterotoxin production and biofilm formation. Methods and results There was no impact on growth of Cl. perfringens for up to 400 µM indole and 240 mg/l mucin, and neither indole nor mucin affected sporulation. Reverse-transcriptase qPCR showed that mucin strongly upregulated the expression of Cl. perfringens enterotoxin (up to 121-fold increase), whereas indole had a much more modest effect (2-fold). This was also reflected in increased Cl. perfringens enterotoxin levels in mucin-treated Cl. perfringens (as assessed by a reversed passive latex agglutination assay). Finally, mucin and indole significantly increased biofilm formation of Cl. perfringens , although the effect size was relatively small (less than 1.5 fold). Conclusion These results indicate that Cl. perfringens can sense its presence in a host environment by responding to mucin, and thereby markedly increased enterotoxin production. [ABSTRACT FROM AUTHOR]

Background: Snail mucin is becoming increasingly popular for its wide range of ingredients and potential benefits. Snail extract's widespread appearance in cosmetic formulations encourages an investigation into the medical and cosmetic benefits. Aims: This study aims to explore current literature on the variety of snail mucin applications. Specifically, we present a review of the uses, global market estimates and projects, and limitations to snail mucin. Methods: A literature search was conducted on PubMed reviewing snail mucin and their application in medical and dermatologic fields examining their uses. Economic reports were also investigated for Global Market estimates. Results: The therapeutic use of snail mucin in medical fields has been studied as antimicrobial agents, drug delivery vehicles, antitumor agents, wound healing agents, and biomaterial coatings among others. Additionally, the use in cosmetic fields includes antiaging, hydrating, anti‐acne, scarring, and hyperpigmentation treatments. It is important to highlight that most studies conducted were preclinical or small clinical studies, stressing the need for additional large‐scale clinical trials to support these claims. Investigations into the global market found estimates ranging from $457 million to $1.2 billion with upward projections in the upcoming decade. Limitations include ethical habitats for collection, allergy investigation, and missing clinical studies. Conclusions: The findings presented here emphasize the expanding uses of snail mucin and its ingredients alongside a growing market cosmetic industry should consider. We also emphasize the need for appropriate clinical trials into the stated benefits of snail mucin to ensure consumer safety and ethical extraction of mucin. [ABSTRACT FROM AUTHOR]

Inflammation and mucus production are prevalent characteristics of chronic respiratory conditions, such as asthma and chronic chronic obstructive pulmonary disease (COPD). Biological co-factors, including bacteria, viruses, and fungi, may exacerbate these diseases by activating various pathways associated with airway diseases. An example is the fungus Pneumocystis, which is linked to severe COPD in human patients. Recent evidence has demonstrated that Pneumocystis significantly enhanced inflammation and mucus hypersecretion in a rat model of elastase-induced COPD. The present study specifically aims to investigate two additional aspects associated with the pathology induced by Pneumocystis infection: inflammation and collagen deposition around airways. To this end, the focus was to investigate the role of the IL-1β pro-inflammatory pathway during Pneumocystis infection in COPD rats. Several airway pathology-related features, such as inflammation, mucus hypersecretion, and fibrosis, were evaluated using histological and molecular techniques. COPD animals infected with Pneumocystis exhibited elevated inflammation levels, including a synergistic increase in IL-1β and Cox-2. Furthermore, protein levels of the IL-1β-dependent transcription factor cAMP response element-binding (CREB) showed a synergistic elevation of their phosphorylated version in the lungs of COPD animals infected with Pneumocystis, while mucus levels were notably higher in the airways of COPD-infected animals. Interestingly, a CREB responsive element (CRE) was identified in the Muc5b promoter. The presence of CREB in the Muc5b promoter was synergistically increased in COPD animals infected with Pneumocystis compared to other experimental groups. Finally, an increment of deposited collagen was identified surrounding the airways of COPD animals infected with Pneumocystis compared with the other experimental animal groups and correlated with the increase of Tgfβ1 mRNA levels. These findings emphasize the role of Pneumocystis as a potential biological co-factor in chronic respiratory diseases like COPD or asthma, warranting new perspectives in the treatment of chronic respiratory diseases. [ABSTRACT FROM AUTHOR]

Heart surgery may be complicated by acute lung injury and adult respiratory distress syndrome. Expression and release of mucins MUC5AC and MUC5B in the lungs has been reported to be increased in acute lung injury. The aim of our study was to [1] investigate the perioperative changes of MUC5AC, MUC5B and other biomarkers in mini-bronchoalveolar lavage (minBAL), and [2] relate these to clinical outcomes after cardiac surgery. In this prospective cohort study in 49 adult cardiac surgery patients pre- and post-surgery non-fiberscopic miniBAL fluids were analysed for MUC5AC, MUC5B, IL-8, human neutrophil elastase, and neutrophils. All measured biomarkers increased after surgery. Perioperative MUC5AC-change showed a significant negative association with postoperative P/F ratio (p = 0.018), and a positive association with ICU stay (p = 0.027). In conclusion, development of lung injury after cardiac surgery and prolonged ICU stay are associated with an early increase of MUC5AC as detected in mini-BAL. [ABSTRACT FROM AUTHOR]

Introduction: Allergic airway diseases are one of the serious health problems in worldwide and allergic airway inflammation is a prerequisite led to the exacerbated situation such as mucus hypersecretion, epithelial barrier damage and microbiota dysbiosis. Because of side effects and low efficiencies of current therapeutics, the need for novel alternatives has been urged. Probiotics in which have diverse and beneficial modulatory effects have been applied to the airway inflammation model and the underlying mechanism needs to be investigated. Methods: We aimed to evaluate whether our target strain, Lactiplantibacillus plantarum APsulloc331261 (GTB1TM) isolated from green tea, can ameliorate allergic airway inflammation in mice and to figure out the mechanism. We induced allergic airway inflammation to mice by ovalbumin (OVA) and administered GTB1 orally and the immune and epithelial barrier markers were assessed. The gut metabolite and microbiota were also analysed, and the in vitro cell-line experiment was introduced to confirm the hypothesis of the study. Results: GTB1 ameliorated type 2 inflammation and suppressed mucin hypersecretion with the inhibition of MUC5AC in inflamed mice. Moreover, GTB1 increased the butyrate production and the relative abundance of butyrate producer, Clostridium cluster IV. We assumed that butyrate may have a potential role and investigated the effect of butyrate in mucin regulation via human airway epithelial cell line, A549. Butyrate significantly reduced the gene expression of MUC5AC in A549 cells suggesting its regulatory role in mucus production. Conclusion: Therefore, our study demonstrates that the oral administration of GTB1 can ameliorate allergic airway inflammation and mucin hypersecretion by butyrate production. [ABSTRACT FROM AUTHOR]

Background and Aims: Mucin disfunction is a critical event in the pathogenesis of inflammatory bowel disease (IBD). Although hyper mucinous conditions have a still debated implication in the clinical evolution of this disorder, hyper mucinous villous proliferations were found to have a preneoplastic biologic potential. We studied morphologic and immunophenotypic characteristics of these lesions in ileocolonic resections for IBD to add evidence about the evolutive potential of these lesions in samples with well oriented wall structures. Methods: Morphologic characteristics of bowel samples from 20 patients resected for IBD and with raised lesions at gross examination were studied and sections from cases with hyper mucinous lesions were stained with the following antibodies: Ki 67, p21, and p27, which were employed to evaluate the characteristics of the proliferative and differentiative activity of the epithelial structures; mismatch repair proteins and p53 have been studied as proteins implicated in carcinogenesis in IBD-affected mucosa; mucins subtypes in hyper mucinous structures were evaluated with MUC-2 and MUC-6. The results in 11 cases of saplings were that they harbored hyper mucinous proliferations. The occurrence of hyper mucinous structures was not related to dysplastic lesions, pseudo pyloric metaplasia, subtype of disease, or activity. In only one of our cases, mild cytologic atypia in the proliferative compartment was detected. Proliferation markers (Ki 67, p53) were expressed in the proliferative compartments of mucosal crypts and antiproliferative proteins p21 and p27 were expressed in differentiated epithelium. MMR proteins expression was limited to the proliferative compartment of the hyper mucinous projections. Mucin subtypes distribution was regular in the epithelium of hyper mucinous proliferations. Conclusions: The present monocentric retrospective study was conducted on surgical samplings with well oriented crypts. Collected data show that hyper mucinous features are frequent occurrences in raised lesions in IBD patients. In hyper mucinous proliferations of the selected cases, the status of the proliferative cycle, the expression of the proteins most frequently involved in carcinogenetic pathways of mucosa affected by IBD, and the mucins subtypes expression have no evident anomalies. Findings are not consistent with the increased risk of neoplastic evolution observed in other studies; rather, they suggest a hyperplastic nature. However, the capacity of hyper mucinous raised lesions for neoplastic evolution should be ruled out with more extensive prospective studies to identify functional defects that could explain the hypothesized neoplastic potential. [ABSTRACT FROM AUTHOR]

Introduction: In this study, the relationship between the spinnbarkeit, i.e., the stretchability of saliva, and dental caries was investigated. Methods: Dentistry students were divided into a group with more than 2 decayed, missed, and filled teeth (DMFT ≥2, n = 30) and caries-free group (DMFT = 0, n = 36). Results: Unstimulated saliva flow rate, pH, and spinnbarkeit were determined. Salivary spinnbarkeit was significantly lower in the caries-prone group compared to the caries-free group (5.4 ± 3.9 mm vs. 13.5 ± 7.6 mm, respectively, p < 0.001). Conclusion: This suggests that saliva with high spinnbarkeit protects better against dental caries. [ABSTRACT FROM AUTHOR]

Problem: Excisional surgery for cervical intraepithelial neoplasia is a risk factor for preterm birth in subsequent pregnancies. However, the underlying mechanisms of this association remain unclear. We previously showed that cervical MUC5B, a mucin protein, may be a barrier to ascending pathogens during pregnancy. We thus hypothesized that hyposecretion of cervical MUC5B is associated with preterm birth after cervical excisional surgery. Method of study: This prospective nested case‐control study (Study 1) included pregnant women who had previously undergone cervical excisional surgery across 11 hospitals. We used proteomics to compare cervicovaginal fluid at 18–22 weeks of gestation between the preterm and term birth groups. In another case‒control analysis (Study 2), we compared MUC5B expression in nonpregnant uterine tissues between 15 women with a history of cervical excisional surgery and 26 women without a history of cervical surgery. Results: The abundance of MUC5B in cervicovaginal fluid was significantly decreased in the preterm birth group (fold change = 0.41, p =.035). Among the 480 quantified proteins, MUC5B had the second highest positive correlation with gestational age at delivery in the combined preterm and term groups. The cervicovaginal microbiome composition was not significantly different between the two groups. Cervical length was not correlated with gestational age at delivery (r = 0.18, p =.079). Histologically, the MUC5B‐positive area in the nonpregnant cervix was significantly decreased in women with a history of cervical excisional surgery (0.85‐fold, p =.048). The distribution of MUC5B‐positive areas in the cervical tissues of 26 women without a history of cervical excisional surgery differed across individuals. Conclusions: This study suggests that the primary mechanism by which cervical excisional surgery causes preterm birth is the hyposecretion of MUC5B due to loss of the cervical glands. [ABSTRACT FROM AUTHOR]

Mucus is an integral polydisperse molecule around the epithelium layer throughout the gastrointestinal tract and acts as a nutrition source for gut microbiota. In the present study, three Enterococcus strains, i.e., Enterococcus faecium KS2, Enterococcus faecium KS3, and Enterococcus gallinarum KS4, having mucin degrading ability, were isolated from human feces and identified by metagenomic technique. The cultures exhibited halos when grown in a mucin-containing medium, whereas quantitative data indicated a decrease in oligosaccharide concentration ranging between 28.74 and 73.05%, further confirming its degradation behavior. The physiological properties revealed that E. gallinarum KS4 lacks virulence, whereas E. faecium KS2 and E. faecium KS3 had the virulence factors. All identified isolates could tolerate pH 2.0 for up to three hours and exhibited survivability ranging between 75 and 111%. They also exhibited more than 70% survivability after eight hours against 0.5% (w/v) bile concentration. Antibiotic susceptibility data revealed that the KS2 strain showed susceptibility against 12 out of 26 antibiotics, including tetracycline, chloramphenicol, gentamicin, and kanamycin. At the same time, KS3 did not show susceptibility against ceftazidime, cefixime, and nalidixic, while E. gallinarum KS4 strain was susceptible to all tested antibiotics except cefixime and nalidixic. The study highlights mucin degrading behavior of human-derived Enterococcus strains and physiological traits specifically depicted E. faecium KS2 and KS3 as opportunistic pathogens. However, E. gallinarum KS4 showed promising functional attributes and required to be corroborated using a suitable in-vivo model. [ABSTRACT FROM AUTHOR]

Intestinal goblet cells are secretory cells specialized in the production of mucins, and as such are challenged by the need for efficient protein folding. Goblet cells express Inositol-Requiring Enzyme-1β (IRE1β), a unique sensor in the unfolded protein response (UPR), which is part of an adaptive mechanism that regulates the demands of mucin production and secretion. However, how IRE1β activity is tuned to mucus folding load remains unknown. We identified the disulfide isomerase and mucin chaperone AGR2 as a goblet cell-specific protein that crucially regulates IRE1β-, but not IRE1α-mediated signaling. AGR2 binding to IRE1β disrupts IRE1β oligomerization, thereby blocking its downstream endonuclease activity. Depletion of endogenous AGR2 from goblet cells induces spontaneous IRE1β activation, suggesting that alterations in AGR2 availability in the endoplasmic reticulum set the threshold for IRE1β activation. We found that AGR2 mutants lacking their catalytic cysteine, or displaying the disease-associated mutation H117Y, were no longer able to dampen IRE1β activity. Collectively, these results demonstrate that AGR2 is a central chaperone regulating the goblet cell UPR by acting as a rheostat of IRE1β endonuclease activity. Synopsis: IRE1β is specifically expressed in mucin-secreting goblet cells of the mammalian gut. Here, the mucin chaperone AGR2 is identified as master regulator of IRE1β oligomerization and endonuclease activity. The protein disulfide isomerase AGR2 acts as a specific interactor of the unfolded protein response sensor IRE1β in colon epithelial cells. AGR2 inhibits IRE1β endonuclease activity by promoting IRE1β monomerization. The inflammatory bowel disease-associated AGR2H117Y mutant loses its repressive activity on IRE1β. AGR2 regulates IRE1β UPR sensor activity by holding it in a monomeric inactive state. [ABSTRACT FROM AUTHOR]

Effector mechanisms of the unfolded protein response (UPR) in the endoplasmic reticulum (ER) are well-characterised, but how ER proteostasis is sensed is less well understood. Here, we exploited the beta isoform of the UPR transducer IRE1, that is specific to mucin-producing cells in order to gauge the relative regulatory roles of activating ligands and repressing chaperones of the specialised ER of goblet cells. Replacement of the stress-sensing luminal domain of endogenous IRE1α in CHO cells (normally expressing neither mucin nor IRE1β) with the luminal domain of IRE1β deregulated basal IRE1 activity. The mucin-specific chaperone AGR2 repressed IRE1 activity in cells expressing the domain-swapped IRE1β/α chimera, but had no effect on IRE1α. Introduction of the goblet cell-specific client MUC2 reversed AGR2-mediated repression of the IRE1β/α chimera. In vitro, AGR2 actively de-stabilised the IRE1β luminal domain dimer and formed a reversible complex with the inactive monomer. These features of the IRE1β-AGR2 couple suggest that active repression of IRE1β by a specialised mucin chaperone subordinates IRE1 activity to a proteostatic challenge unique to goblet cells, a challenge that is otherwise poorly recognised by the pervasive UPR transducers. Synopsis: Stress recognition by the unfolded protein response (UPR) of the ER is incompletely understood. Here, negative regulation of a goblet-cell selective isoform of the UPR transducer IRE1β by the mucin chaperone AGR2 shows how UPR signalling can be coupled to the load of abundant, cell-specific, secreted proteins via specialised chaperone titration. In heterologous CHO cell cultures, the specialised UPR transducer IRE1β is constitutively active despite the absence of the ER client proteins normally co-expressed with it. Coexpression of AGR2, a mucin chaperone normally present together with IRE1β, selectively represses the stress-sensing IRE1β luminal domain in CHO cells. Introduction of the secreted client protein mucin into CHO cells reverses AGR2-mediated repression of IRE1β. In vitro, AGR2 promotes a monomeric pool of IRE1β's luminal stress-sensing domain. Mucin-secreting goblet cells in the gut have evolved a specialised unfolded protein response signalling pathway. [ABSTRACT FROM AUTHOR]

Optogenetics is a powerful approach in neuroscience research. However, other tissues of the body may benefit from controlled ion currents and neuroscience may benefit from more precise optogenetic expression. The present work constructs three subcellularly‐targeted optogenetic actuators based on the channelrhodopsin ChR2‐XXL, utilizing 5, 10, or 15 tandem repeats (TR) from mucin as N‐terminal targeting motifs and evaluates expression in several polarized and non‐polarized cell types. The modified channelrhodopsin maintains its electrophysiological properties, which can be used to produce continuous membrane depolarization, despite the expected size of the repeats. This work then shows that these actuators are subcellularly localized in polarized cells. In polarized epithelial cells, all three actuators localize to just the lateral membrane. The TR‐tagged constructs also express subcellularly in cortical neurons, where TR5‐ChR2XXL and TR10‐ChR2XXL mainly target the somatodendrites. Moreover, the transfection efficiencies are shown to be dependent on cell type and tandem repeat length. Overall, this work verifies that the targeting motifs from epithelial cells can be used to localize optogenetic actuators in both epithelia and neurons, opening epithelia processes to optogenetic manipulation and providing new possibilities to target optogenetic tools. [ABSTRACT FROM AUTHOR]

We previously demonstrated that monosodium glutamate (MSG) consumption increases trimethylamine (TMA) level in the renal tissue as well as dimethylamine and methylamine levels in urine of rats, suggesting the effects of MSG on humans. To better define the findings, we investigated whether MSG consumption alters serum trimethylamine N-oxide (TMAO) level, and as a consequence, induces kidney injury in the rat model. Adult male Wistar rats (n = 40) were randomized to be fed with a standard diet (control group) or a standard diet with 0.5, 1.5 or 3.0 g% MSG corresponding to 7, 21, or 42 g/day in 60 kg man, respectively in drinking water (MSG-treated groups), or a standard diet with 3.0 g% MSG in drinking water which was withdrawn after 4 weeks (MSG-withdrawal group). Blood and urine samples were collected to analyze the TMAO levels using 1H NMR and markers of kidney injury. Fecal samples were also collected for gut microbiota analysis. We found serum TMAO levels increased and urinary TMAO excretion decreased during MSG consumption, in parallel with the increase of the neutrophil gelatinase-associated lipocalin (NGAL) excretion which subsided with the withdrawal of MSG. The fecal 16 S rRNA analysis during MSG consumption showed gut microbiota changes with a consistent suppression of Akkermansia muciniphila, a mucin producing bacteria, but not of TMA-producing bacteria. In conclusions, our findings suggested that prolonged high dose MSG consumption may cause TMAO accumulation in the blood via reduction of renal excretion associated with acute kidney injury. The mechanisms by which MSG reduced TMAO excretion require further investigation.

Context.--The tumor-host interaction in the tumor microenvironment (TME) affects the prognosis of patients with malignant tumors. TME assessed via tumor budding (BD) and tumor-infiltrating lymphocyte (TIL) had a prognostic impact in patients with nonampullary small intestinal and colorectal carcinomas. In ampullary carcinoma (AC), MUC5AC was recently revealed as a significant prognosticator, but studies about the TME have not been conducted. Objective.--To assess TME-based prognostic risk in AC. Design.--We generated a collective TME risk index based on high-grade BD at the invasive front (BD3) and high density of stromal-TIL (>5%) in 64 surgically resected ACs. We evaluated its predictive values for overall survival (OS) and recurrence-free survival (RFS). We also investigated the relationship of TME to MUC5AC expression. Results.--TME prognostic risk index was classified into low-risk ([BD.sup.Low]/[TIL.sup.High]; 26 of 64; 41%), intermediate-risk ([BD.sup.Low]/[TIL.sup.Low] or [BD.sup.High]/[TIL.sup.High]; 23; 36%), and high-risk ([BD.sup.High]/[TIL.sup.Low]; 15; 23%) groups. Higher TME prognostic risk was associated with higher tumor grade (P = .03), lymphovascular invasion (P = .05), and MUC5AC immunopositivity (P = .02). TME prognostic risk index displayed better predictive ability for both OS (53.9 versus 46.1 versus 42.2) and RFS (24.8 versus 16.9 versus 15.3) than BD or TIL alone. In multivariate analysis, TME prognostic risk index was an independent prognosticator for OS (P = .003) and RFS (P = .03). Conclusions.--TME risk index in combination with BD and TIL was a stronger predictor of prognostic risk stratification than either BD or TIL alone for both OS and RFS in patients with AC. MUC5AC may modulate the interaction between tumor cells and immunity toward enhancing invasiveness in TME., Ampullary carcinoma (AC) is a rare cancer, constituting less than 0.5% of all gastrointestinal (GI) cancers. (1,2) The ampulla has an anatomically complex structure; it is located at the junction [...]