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Mucus plugs occlude airways to obstruct airflow in asthma. Studies in patients and in mouse models show that mucus plugs occur in the context of type 2 inflammation, and studies in human airway epithelial cells (HAECs) show that IL-13-activated cells generate pathologic mucus independently of immune cells. To determine how HAECs autonomously generate pathologic mucus, we used a magnetic microwire rheometer to characterize the viscoelastic properties of mucus secreted under varying conditions. We found that normal HAEC mucus exhibited viscoelastic liquid behavior and that mucus secreted by IL-13-activated HAECs exhibited solid-like behavior caused by mucin cross-linking. In addition, IL-13-activated HAECs shows increased peroxidase activity in apical secretions, and an overlaid thiolated polymer (thiomer) solution shows an increase in solid behavior that was prevented by peroxidase inhibition. Furthermore, gene expression for thyroid peroxidase (TPO), but not lactoperoxidase (LPO), was increased in IL-13-activated HAECs and both TPO and LPO catalyze the formation of oxidant acids that cross-link thiomer solutions. Finally, gene expression for TPO in airway epithelial brushings was increased in patients with asthma with high airway mucus plug scores. Together, our results show that IL-13-activated HAECs autonomously generated pathologic mucus via peroxidase-mediated cross-linking of mucin polymers.

Modulation of the cervix by steroid hormones and commensal microbiome play a central role in the health of the female reproductive tract. Here we describe organ-on-a-chip (Organ Chip) models that recreate the human cervical epithelial-stromal interface with a functional epithelial barrier and production of mucus with biochemical and hormone-responsive properties similar to living cervix. When Cervix Chips are populated with optimal healthy versus dysbiotic microbial communities (dominated by Lactobacillus crispatus and Gardnerella vaginalis, respectively), significant differences in tissue innate immune responses, barrier function, cell viability, proteome, and mucus composition are observed that are similar to those seen in vivo. Thus, human Cervix Organ Chips represent physiologically relevant in vitro models to study cervix physiology and host-microbiome interactions, and hence may be used as a preclinical testbed for development of therapeutic interventions to enhance womens health.

INTRODUCTION: While localized inflammation has been implicated in the pathophysiology of acute coronavirus disease of 2019 (COVID-19) olfactory dysfunction (OD), persistent COVID-19 OD remains poorly understood with limited therapeutics. Our prospective study evaluated olfactory cleft (OC) biomarkers as predictors of persistent OD in mucus sampling. METHODS: COVID-19 subjects with persistent OD >3 months confirmed by psychophysical olfaction tests were compared to COVID-19 subjects with no OD and those with no prior infection. OC mucus samples were evaluated for 13 anti-viral and inflammatory biomarkers. Cohorts were compared using analysis of variance (ANOVA) and Mann-Whitney tests with multi-comparison adjustment. Viral RNA was assessed through RT-PCR using the COVID-19 N2 primer. RESULTS: Thirty-five samples were collected (20 COVID persistent OD, 8 COVID no OD, and 7 non-COVID no OD). Significant differences in IFN-λ1 (p = 0.007) and IFN-γ (p = 0.006) expression in OC mucus were found across all three groups, with the highest cytokine concentrations corresponding to COVID OD. IFN-α2 levels were elevated in COVID OD versus no OD (p = 0.026). Mean IFN-γ levels were the highest in COVID OD, but there were higher levels found in COVID no OD compared to non-COVID no OD (p = 0.008). No difference was seen in IL6. No N2 gene expression was detected in all cohorts. CONCLUSION: IFN pathway cytokines were found elevated in the olfactory microenvironment of COVID-19 persistent OD compared to those with no OD and no prior history of COVID-19 infection.

By incompletely understood mechanisms, type 2 (T2) inflammation present in the airways of severe asthmatics drives the formation of pathologic mucus which leads to airway mucus plugging. Here we investigate the molecular role and clinical significance of intelectin-1 (ITLN-1) in the development of pathologic airway mucus in asthma. Through analyses of human airway epithelial cells we find that ITLN1 gene expression is highly induced by interleukin-13 (IL-13) in a subset of metaplastic MUC5AC+ mucus secretory cells, and that ITLN-1 protein is a secreted component of IL-13-induced mucus. Additionally, we find ITLN-1 protein binds the C-terminus of the MUC5AC mucin and that its deletion in airway epithelial cells partially reverses IL-13-induced mucostasis. Through analysis of nasal airway epithelial brushings, we find that ITLN1 is highly expressed in T2-high asthmatics, when compared to T2-low children. Furthermore, we demonstrate that both ITLN-1 gene expression and protein levels are significantly reduced by a common genetic variant that is associated with protection from the formation of mucus plugs in T2-high asthma. This work identifies an important biomarker and targetable pathways for the treatment of mucus obstruction in asthma.

BACKGROUNDInformation about the size, airway location, and longitudinal behavior of mucus plugs in asthma is needed to understand their role in mechanisms of airflow obstruction and to rationally design muco-active treatments.METHODSCT lung scans from 57 patients with asthma were analyzed to quantify mucus plug size and airway location, and paired CT scans obtained 3 years apart were analyzed to determine plug behavior over time. Radiologist annotations of mucus plugs were incorporated in an image-processing pipeline to generate size and location information that was related to measures of airflow.RESULTSThe length distribution of 778 annotated mucus plugs was multimodal, and a 12 mm length defined short ("stubby", ≤12 mm) and long ("stringy", >12 mm) plug phenotypes. High mucus plug burden was disproportionately attributable to stringy mucus plugs. Mucus plugs localized predominantly to airway generations 6-9, and 47% of plugs in baseline scans persisted in the same airway for 3 years and fluctuated in length and volume. Mucus plugs in larger proximal generations had greater effects on spirometry measures than plugs in smaller distal generations, and a model of airflow that estimates the increased airway resistance attributable to plugs predicted a greater effect for proximal generations and more numerous mucus plugs.CONCLUSIONPersistent mucus plugs in proximal airway generations occur in asthma and demonstrate a stochastic process of formation and resolution over time. Proximal airway mucus plugs are consequential for airflow and are in locations amenable to treatment by inhaled muco-active drugs or bronchoscopy.TRIAL REGISTRATIONClinicaltrials.gov; NCT01718197, NCT01606826, NCT01750411, NCT01761058, NCT01761630, NCT01716494, and NCT01760915.FUNDINGAstraZeneca, Boehringer-Ingelheim, Genentech, GlaxoSmithKline, Sanofi-Genzyme-Regeneron, and TEVA provided financial support for study activities at the Coordinating and Clinical Centers beyond the third year of patient follow-up. These companies had no role in study design or data analysis, and the only restriction on the funds was that they be used to support the SARP initiative.

Infecting humans with controlled doses of small intestinal helminths, such as human hookworm, is proposed as a therapy for the colonic inflammatory disease ulcerative colitis. Strengthening the colonic mucus barrier is a potential mechanism by which small intestinal helminths could treat ulcerative colitis. In this study, we compare C57BL/6 mice infected with the small intestinal helminth Heligmosomoides polygyrus and uninfected controls to investigate changes in colonic mucus. Histology, gene expression, and immunofluorescent analysis demonstrate that this helminth induces goblet cell hyperplasia, and an upregulation of mucin sialylation, and goblet-cell-derived functional proteins resistin-like molecule-beta (RELM-β) and trefoil factors (TFFs), in the colon. Using IL-13 knockout mice, we reveal that these changes are predominantly IL-13-dependent. The assessment of the colonic mucus microbiome demonstrates that H. polygyrus infection increases the abundance of Ruminococcus gnavus, a commensal bacterium capable of utilising sialic acid as an energy source. This study also investigates a human cohort experimentally challenged with human hookworm. It demonstrates that TFF blood levels increase in individuals chronically infected with small intestinal helminths, highlighting a conserved mucus response between humans and mice. Overall, small intestinal helminths modify colonic mucus, highlighting this as a plausible mechanism by which human hookworm therapy could treat ulcerative colitis. [ABSTRACT FROM AUTHOR]

Cnidarians are the first phylum of metazoans to exhibit a functional mucus layer. In evolution, mucous cells perform the classical secretory function of mucus and act as sentinels for external insults, particularly in mammals. However, this topic has not been much analysed in the lower metazoans. This study aims to investigate the role of mucous cells in Actinia equina (Anthozoa, Hexacorallia) (Linnaeus, 1758) by using confocal microscopy and bioinformatics. The results show colocalization of Toll‐like receptor 2 (TLR2) and Mucin2 (MUC2) on these cells, suggesting a crosstalk between defence response and mucus secretion in cnidarians. Furthermore, the presence of TLR2 on the surface of mucous cells suggests their involvement in host defence responses, as occurs in vertebrates. Moreover, through in silico analysis, we confirmed the presence of orthologous genes for the tested antibodies, providing additional evidence to support our results from an evolutionary perspective. These data suggest that mucous cells play a defensive role throughout evolution, helping us understand how these cells have developed and adapted across phylogenesis. This information also provides new insights into the defensive strategies of invertebrates and clarifies their evolutionary history. [ABSTRACT FROM AUTHOR]

Mucus is a hydrated, viscoelastic, and adhesive gel that lubricates and protects the body from pathogens; however, its protective function hinders drug/nanomedicine diffusion and treatment efficiency. Therefore, novel drug delivery strategies are required to overcome challenging mucosal barriers. Here, multi‐responsive nanogels (NGs) are developed and explored their interaction with mucus. Specific NG features (e.g., surface charge, temperature responsiveness, and redox response) are evaluated in a typical mucus‐associated environment (i.e., mucin proteins and high glutathione concentrations). The results demonstrate that biocompatibility and the capacity to deliver a protein through mucosal barriers in different in vitro and in vivo models highlight the importance of specific NG design elements. Disulfide bonds are highlighted as redox‐sensitive cross‐linkers within the NG structure as critical for drug delivery performance; they function as degradation points that enable NG degradation and subsequent drug release and anchoring points to adhere to mucin, thereby enhancing their residence time at the desired site of action. Additionally, it is confirmed that surface charges impact interactions with mucin; positively charged NGs exhibit improved interactions with mucin compared to negatively charged and neutral NGs. Overall, the findings underline the importance of redox response and surface charge in NG design for reaching efficient mucosal drug delivery. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The study aimed to investigate the impact of mucus plugs on the localization of clots in pulmonary embolisms among chronic obstructive pulmonary disease (COPD) patients. MATERIAL AND METHODS: The retrospective study examined 200 participants diagnosed with both COPD and pulmonary embolism. Of these, 100 patients exhibited mucus plugs in the segmental and subsegmental branches of the pulmonary bronchial tree, while the remaining 100 did not, using computed tomography images for diagnosis. Data collection encompassed a comprehensive review of patient records, including medical history and imaging reports, to determine the presence of mucus plugs and the localization of clots in pulmonary embolism cases. RESULTS: Patients with mucus plugs exhibited a notably longer duration of COPD (P = .021) and a higher mean pulmonary arterial occlusion index (23 vs. 12, P = .001). Moreover, the prevalence of clots in major pulmonary arteries was significantly elevated in the mucus plug group compared to the non-mucus plug group (P < .05). Conversely, patients without mucus plugs displayed a higher incidence of clots in segmental and subsegmental arteries (P < .001). Strong positive correlations existed between mucus plugs in segmental branches and clots in major pulmonary arteries, with moderate to strong correlation coefficients (0.51 to 0.62, P < .05). Additionally, strong negative correlations were observed between mucus plugs in segmental branches and clots in segmental and subsegmental arteries, with correlation coefficients (CC) ranging from -0.74 to -0.76 (P < .05). Similarly, a significant negative correlation was noted between mucus plugs in subsegmental branches and clots in subsegmental arteries (CC: -0.68 and -0.71, P < .05). CONCLUSION: The results suggest that mucus plugs may be associated with increased severity of COPD, higher pulmonary arterial occlusion index, and altered clot distribution within the pulmonary artery tree. These findings emphasize the importance of recognizing mucus plugs as a key consideration in COPD assessment and management, potentially influencing disease severity, vascular remodeling, and thrombotic risk management. [ABSTRACT FROM AUTHOR]

The skin is covered by a protective mucus layer, which is essential to the innate defense mechanism of fish. Investigating the response of skin mucus to various toxic stresses is crucial for enhancing its ability to tackle environmental challenges and developing strategies to mitigate toxic effects. Alkalinity stress assays (50 mmol/L NaHCO3) were conducted on crucian carp (Carassius auratus) from Lake Dali Nur (pH = 9.6) and Ping Xiang red crucian carp from freshwater (pH = 7) over 7 days. The expression of skin mucous proteins was analyzed using the liquid chromatography (LC)-spectrometry (MS)/MS Analysis-Data-independent acquisition (DIA) mode. A total of 12,537 proteins were identified across 20 samples from four groups, with 12,025 quantified. In the alkaline water population, high alkali stress resulted in the up-regulation of 139 proteins and the down-regulation of 500 proteins. In contrast, the freshwater population showed an increase in 112 proteins and a decrease in 120; both populations had a total of 23 genes up-regulated and 21 down-regulated. The protein regulatory network for the alkaline water group included 3146 pairwise interactions among 464 nodes, with only 20 being differentially expressed proteins. Conversely, the freshwater group's network comprised just 1027 specific interactions across 337 nodes, with 6 corresponding to differentially expressed proteins. A common protein regulatory network responding to high alkali stress was extracted and visualized for both populations. Based on their regulatory relationships and expression levels, these proteins are hypothesized to play similar roles under high alkali stress. Notably, the alpha-globin fragment and keratin type I cytoskeletal 13-like proteins showed markedly up-regulated expression, with the alpha-globin fragment increasing nearly a thousandfold from an extremely low level. This suggests it could serve as a potential biomarker for alkali tolerance, warranting further investigation. [ABSTRACT FROM AUTHOR]

The tree frog is a prominent amphibian among terrestrial vertebrates known for its ability to adhere to various surfaces through the capillary forces of water in the microchannels between micropillars on its disc‐shaped toe pads, a phenomenon known as wet adhesion. However, the secretion pattern of mucus on the attachment surface of living tree frog toe pads and the distribution of active mucus pores (AMPs) have not yet been fully elucidated. In this study, we utilized synchrotron X‐ray micro‐computed tomography and interference reflection microscopy to obtain the spatial distribution of the entire population of ventral mucus glands on the toe pads of living tree frogs and the real‐time mucus secretion patterns from the ventral mucus pores on the contact surface under different environmental conditions. We observed that the number and secretion frequency of AMPs on the toe pad are regulated according to environmental conditions. Such dynamic mucus secretion on the tree frog's toe pad could contribute to the understanding of capillary force regulation for wet adhesion and the development of adhesive surfaces by mimicking the mucus‐secreting toe pad. [ABSTRACT FROM AUTHOR]

Human respiratory mucus (HRM) is extremely soft, compelling passive microrheology for linear viscoelastic characterization. We focus this study on the use of passive microrheology to characterize HRM heterogeneity, a phenomenon in normal HRM that becomes extreme during cystic fibrosis (CF) disease. Specifically, a fraction of the mucin polymers comprising HRM phase-separate into insoluble structures, called flakes, dispersed in mucin-depleted solution. We first reconstitute HRM samples to the MUC5B:MUC5AC mucin ratios consistent with normal and CF clinical samples, which we show recapitulate progressive flake formation and heterogeneity. We then employ passive particle tracking with 200 nm and 1 μm diameter beads in each reconstituted sample. To robustly analyze the tracking data, we introduce statistical denoising methods for low signal-to-noise tracking data within flakes, tested and verified using model-generated synthetic data. These statistical methods provide a fractional Brownian motion classifier of all successfully denoised, tracked beads in flakes and the dilute solution. From the ensemble of classifier data, per bead diameter and mucus sample, we then employ clustering methods to learn and infer multiple levels of heterogeneity: (i) tracked bead data within vs. outside flakes and (ii) within-flake data buried within or distinguishable from the experimental noise floor. Simulated data consistent with experimental data (within and outside flakes) are used to explore form(s) of the generalized Stokes–Einstein relation (GSER) that recover the dynamic moduli of homogeneous and heterogeneous truth sets of purely flakelike, dilute solution, and mixture samples. The appropriate form of GSER is applied to experimental data to show (i) flakes are heterogeneous with gel and sol domains; (ii) dilute solutions are heterogeneous with only sol domains; and (iii) flake and dilute solution properties vary with probe diameter. [ABSTRACT FROM AUTHOR]

Airway mucus plugs are frequently identified on CT scans of patients with COPD with a smoking history without mucus-related symptoms (ie, cough, phlegm [silent mucus plugs]). In patients with COPD, what are the risk and protective factors associated with silent airway mucus plugs? Are silent mucus plugs associated with functional, structural, and clinical measures of disease? We identified mucus plugs on chest CT scans of participants with COPD from the COPDGene study. The mucus plug score was defined as the number of pulmonary segments with mucus plugs, ranging from 0 to 18, and categorized into three groups (0, 1-2, and ≥ 3). We determined risk and protective factors for silent mucus plugs and the associations of silent mucus plugs with measures of disease severity using multivariable linear and logistic regression models. Of 4,363 participants with COPD, 1,739 had no cough or phlegm. Among the 1,739 participants, 627 (36%) had airway mucus plugs identified on CT scan. Risk factors of silent mucus plugs (compared with symptomatic mucus plugs) were older age (OR, 1.02), female sex (OR, 1.40), and Black race (OR, 1.93) (all P values <.01). Among those without cough or phlegm, silent mucus plugs (vs absence of mucus plugs) were associated with worse 6-min walk distance, worse resting arterial oxygen saturation, worse FEV 1 % predicted, greater emphysema, thicker airway walls, and higher odds of severe exacerbation in the past year in adjusted models. Mucus plugs are common in patients with COPD without mucus-related symptoms. Silent mucus plugs are associated with worse functional, structural, and clinical measures of disease. CT scan-identified mucus plugs can complement the evaluation of patients with COPD. [Display omitted] [ABSTRACT FROM AUTHOR]

Background and Objective: Mucus plugs and underlying airway tree structure can affect airflow limitation and prognosis in patients with chronic obstructive pulmonary disease (COPD), but their relative roles are unclear. This study used two COPD cohorts to examine whether mucus plugs on computed tomography (CT) were associated with airflow limitation and clinical outcomes independent of other airway structural changes and emphysema. Methods: Based on visual CT assessment, patients with mucus plugs in 0, 1–2 and ≥3 lung segments were assigned to no‐, low‐ and high‐mucus groups. Loss of health‐related independence and mortality were prospectively recorded for 3 and 10 years in the Kyoto–Himeji and Hokkaido cohorts, respectively. The percentages of the wall area of the central airways (WA%), total airway count (TAC) and emphysema were quantified on CT. Results: Of 199 and 96 patients in the Kyoto–Himeji and Hokkaido cohorts, 34% and 30%, respectively, had high mucus scores. In both cohorts, TAC was lower in the high‐mucus group than in the no‐mucus group, whereas their emphysema severity did not differ. High mucus score and low TAC were independently associated with airflow limitation after adjustment for WA% and emphysema. In multivariable models adjusted for WA% and emphysema, TAC, rather than mucus score, was associated with a greater rate of loss of independence, whereas high mucus score, rather than TAC, was associated with increased mortality. Conclusion: Mucus plugs and lower airway branch count on CT had distinct roles in airflow limitation, health‐related independence and mortality in patients with COPD. [ABSTRACT FROM AUTHOR]

Proteins and peptides have been increasingly developed as pharmaceuticals owing to their high potency and low side effects. However, their administration routes are confined to injections, such as intra-muscular and intra-venous injections, making patient compliance a challenge. Hence, non-injectable delivery systems are crucial to expanding the clinical use of proteins and peptides. In this context, two choline-based ionic liquids (ILs), namely, choline geranic acid ([Ch][Ger]) and choline citric acid ([Ch][Cit]), have been identified as promising agents for enhancing the permeation and prolonging the retention time of glucagon (GC) after intra-nasal administration. Notably, intra-nasal delivery of GC via ILs (GC/ILs) elicited rapid and smooth reversal of acute hypoglycaemia without leading to rebound hyperglycaemia in type 1 diabetic rats subjected to insulin induction. In addition, ILs could improve the transcellular transport of GC through electrostatic interaction. ILs could also transiently open inter-cellular tight junctions transiently to facilitate the paracellular transport of GC. Safety tests indicated that continuous intra-nasal delivery of ILs led to reversible changes, such as epithelial cell inflammation, goblet cell overgrowth, and impacts on the distribution of nasal cilia. However, these changes could be alleviated by the innate self-repair ability of mucosal epithelial cells. This study highlights the considerable potential of ILs for long-term nasal delivery of biomacromolecules. [Display omitted] • Intra-nasal delivery of glucagon in ionic liquids (GC/ILs) for acute hypoglycaemia rescue • ILs improved the stability and solubility of GC through hydrogen bonding interactions. • ILs enhanced the paracellular transport of GC as a novel transient permeation enhancer. • The water content of ILs significantly affected the nasal retention and efficacy of GC/ILs. • The long-term regimen of nasal delivery of GC/ILs showed a favourable safety profile. [ABSTRACT FROM AUTHOR]

SARS-CoV-2 initiates infection in the conducting airways, where mucociliary clearance inhibits pathogen penetration. However, it is unclear how mucociliary clearance impacts SARS-CoV-2 spread after infection is established. To investigate viral spread at this site, we perform live imaging of SARS-CoV-2 infected differentiated primary human bronchial epithelium cultures for up to 12 days. Using a fluorescent reporter virus and markers for cilia and mucus, we longitudinally monitor mucus motion, ciliary motion, and infection. Infected cell numbers peak at 4 days post infection, forming characteristic foci that tracked mucus movement. Inhibition of MCC using physical and genetic perturbations limits foci. Later in infection, mucociliary clearance deteriorates. Increased mucus secretion accompanies ciliary motion defects, but mucociliary clearance and vectorial infection spread resume after mucus removal, suggesting that mucus secretion may mediate MCC deterioration. Our work shows that while MCC can facilitate SARS-CoV-2 spread after initial infection, subsequent MCC decreases inhibit spread, revealing a complex interplay between SARS-CoV-2 and MCC. Becker et al. use live imaging of SARS-CoV-2 infected airway epithelium cultures to demonstrate a dual role for mucociliary clearance in viral spread. Initially, virus goes with the mucus flow, facilitating local spread; later, increased mucus secretion and ciliary motion defects limit spread. [ABSTRACT FROM AUTHOR]

The blood–brain barrier is one of the serious challenges in the treatment of Parkinson's disease (PD), which severely hinders the drug's brain bioavailability. In this study, a lyotropic liquid crystalline (LLC) based in situ gel nasal spray loaded with the first‐line drug Levodopa (LDA) for PD is developed to resolve this issue based on a nose‐to‐brain drug delivery approach. Specifically, the two key stages of LLC‐based in situ gel nasal spray, droplet deposition, and drug retention are tailored. By adjusting LLC's precursor solution's viscosity, the droplet deposition on the superior nasal tract can be increased by 18 times. Through nasal mucus‐triggered sol–gel transition, the LDA nasal cavity retention is prolonged by three times. The epigallocatechin gallate is incorporated into the LLC‐based in situ gel nasal spray to inhibit the autoxidation of LDA and alleviate the oxidative stress response in PD. The results show that the LLC‐based in situ gel nasal spray has a 26‐fold higher brain bioavailability of LDA compared to oral administration. The PD rats show a significant improvement in behavioral and cognitive disorders after administration. The LLC‐based in situ gel nasal spray is proved to work by reducing oxidative damage. This study is anticipated to offer a promising strategy for the clinical application of LDA. [ABSTRACT FROM AUTHOR]

AbstractAkkermansia muciniphila (A. muciniphila) has gained recognition as a pioneering probiotic, exhibiting considerable potential to enhance immune conditions across both humans and animals. The health benefits of A. muciniphila are attributed to its various components, including outer membrane proteins (PilQ and Amuc_1100), secreted proteins (P9 and AmTARS), extracellular vesicles, and metabolites such as SCFAs, ornithine lipids, γ-aminobutyric acid, cobalamin, and inosine. The dynamic control of the mucus layer by A. muciniphila plays a crucial role in regulating intestinal mucosal immunity. Furthermore, A. muciniphila modulates immune function by interacting with macrophages, dendritic cells, T lymphocytes, and Paneth cells. Increasing the abundance of A. muciniphila in the gut through nutritional strategies represents a safe and effective means to augment immune function. Various polyphenols, oligosaccharides, and polysaccharides have been shown to elevate the levels of this bacterium, thereby contributing to favorable immunoregulatory outcomes. This paper delves into the latest research advancements related to the probiotic mechanisms of A. muciniphila and provides an overview of the current understanding of how its abundance responds to nutrients. These insights offer a theoretical foundation for the utilization of A. muciniphila in immunoregulation. [ABSTRACT FROM AUTHOR]

Walking is a locomotion mode in which animals move over the ground using their appendages. Walking is observed in both terrestrial and aquatic animals, but the morphology and diversity of appendages in the latter group have been less extensively studied. The present paper reports on the "adhesive areas," which may represent morphological and physiological adaptations for stable aquatic walking, in the paintpot cuttlefish, Ascarosepion tullbergi. This animal employs arm IV as a forelimb and an ambulatory flap as a hindlimb for walking, resulting in a gait‐like manner of movement. The structure of the adhesive area is exclusively located on the ventral skin surface of arm IV and the ambulatory flap, which are in contact with the ground during walking. The "adhesive areas" are characterized by a dense population of adhesive mucus‐secreting cells and the development of numerous wrinkles on the surface. These features may enhance the gripping and sticking capacity of the ground‐contact area, thus improving walking stability. The use of adhesive areas for walking is a unique feature of A. tullbergi, as other cuttlefish with adhesive areas primarily use them for attaching to substrata in strong currents. Our results contribute to the understanding of the locomotion strategy of cuttlefish. [ABSTRACT FROM AUTHOR]

A healthy mucus is essential for maintaining intestinal homeostasis and overall well‐being. In recent years, extensive research focused on understanding the intricate interactions between mucus and the gut microbiota. Mucus‐adhering bacteria play crucial roles in preserving barrier integrity, epithelial permeability and mucus architecture, as well as in the colonization resistance against pathogens. Unravelling the significance of these microorganisms in human health and disease is challenging, primarily because most of the studies on the human gut microbiota rely on faecal samples, which do not fully represent the microecological complexity found in the intestinal mucosa. This review discusses novel strategies to specifically target and evaluate the mucosal microbiota, such as culturomics applied to mucosal biopsies or brushings, intestinal organoids and artificial in vitro models incorporating mucus. [ABSTRACT FROM AUTHOR]

Cystic fibrosis (CF) is a genetic disorder characterized by recurrent airway infections, inflammation, impaired mucociliary clearance, and progressive decline in lung function. The disease may start in the small airways; however, this is difficult to prove due to the limited accessibility of the small airways with the current single-photon mucociliary clearance assay. Here, we developed a dynamic positron emission tomography assay with high spatial and temporal resolution. We tested that mucociliary clearance is abnormal in the small airways of newborn cystic fibrosis pigs. Clearance of [68Ga]-tagged macroaggregated albumin from small airways started immediately after delivery and continued for the duration of the study. Initial clearance was fast but slowed down a few minutes after delivery. Cystic fibrosis pigs' small airways cleared significantly less than non-CF pigs' small airways (non-CF 25.1 ± 3.1% vs. CF 14.6 ± 0.1%). Stimulation of the cystic fibrosis airways with the purinergic secretagogue uridine-5′-triphosphate (UTP) further impaired clearance (non-CF with UTP 20.9 ± 0.3% vs. CF with UTP 13.0 ± 1.8%). None of the cystic fibrosis pigs treated with UTP (n = 6) cleared more than 20% of the delivered dose. These data indicate that mucociliary clearance in the small airways is fast and can easily be missed if the assay is not sensitive enough. The data also indicate that mucociliary clearance is impaired in the small airways of cystic fibrosis pigs. This defect is exacerbated by stimulation of mucus secretions with purinergic agonists. NEW & NOTEWORTHY: We developed a novel positron emission tomography scan assay with unprecedented temporal and spatial resolution to measure mucociliary clearance in the small airways. We proved a long-standing but unproven assertion that mucociliary clearance is inherently abnormal in the small airways of newborn cystic fibrosis piglets that are otherwise free of infection or inflammation. This technique can be easily extended to other airway diseases such as asthma, idiopathic pulmonary fibrosis, or chronic obstructive pulmonary disease. [ABSTRACT FROM AUTHOR]

Elysia crispata (Sacoglossa, Gastropoda) is a tropical sea slug known for its ability to incorporate functional chloroplasts from a variety of green macroalgae, a phenomenon termed kleptoplasty. This sea slug, amenable to laboratory cultivation, produces mucus, a viscous secretion that serves diverse purposes including protection, locomotion, and reproduction. In this study, we profiled the antimicrobial, antioxidant, and anti-inflammatory activities of the mucus of this sea slug. Results revealed inhibitory activity against several bacterial strains, more pronounced for Gram–negative bacteria. Particularly interesting was the strong inhibitory effect against Pseudomonas aeruginosa, a bacterial species classified by the WHO as a high-priority pathogen and associated with high-risk infections due to its frequent multidrug-resistant profile. Similar inhibitory effects were observed for the mucus native protein extracts, indicating that proteins present in the mucus contributed significantly to the antimicrobial activity. The mucus also showed both antioxidant and anti-inflammatory activities. The latter activities were associated with the low molecular weight (<10 kDa) fraction of the mucus rather than the native protein extracts. This study opens the way to further research on the biotechnological applications of the mucus secreted by this unique marine organism, particularly as an antimicrobial agent. [ABSTRACT FROM AUTHOR]

Mucocele formation in dogs is a unique and enigmatic muco-obstructive disease of the gallbladder caused by the amassment of abnormal mucus that bears striking pathological similarity to cystic fibrosis. We investigated the role of cystic fibrosis transmembrane conductance regulatory protein (CFTR) in the pathogenesis of this disease. The location and frequency of disease-associated variants in the coding region of CFTR were compared using whole genome sequence data from 2,642 dogs representing breeds at low-risk, high-risk, or with confirmed disease. Expression, localization, and ion transport activity of CFTR were quantified in control and mucocele gallbladders by NanoString, Western blotting, immunofluorescence imaging, and studies in Ussing chambers. Our results establish a significant loss of CFTR-dependent anion secretion by mucocele gallbladder mucosa. A significantly lower quantity of CFTR protein was demonstrated relative to E-cadherin in mucocele compared with control gallbladder mucosa. Immunofluorescence identified CFTR along the apical membrane of epithelial cells in control gallbladders but not in mucocele gallbladder epithelium. Decreases in mRNA copy number for CFTR were accompanied by decreases in mRNA for the Cl−/ HCO 3 − exchanger SLC26A3, K+ channels (KCNQ1, KCNN4), and vasoactive intestinal polypeptide receptor (VIPR1), which suggest a driving force for change in secretory function of gallbladder epithelial cells in the pathogenesis of mucocele formation. There were no significant differences in CFTR gene variant frequency, type, or predicted impact comparing low-risk, high-risk, and definitively diagnosed groups of dogs. This study describes a unique, naturally occurring muco-obstructive disease of the canine gallbladder, with uncanny similarity to cystic fibrosis, and driven by the underlying failure of CFTR function. NEW & NOTEWORTHY: Cystic fibrosis transmembrane conductance regulatory protein (CFTR) genomic variants and expression of mRNA, protein, and electrogenic anion secretory activity of CFTR were characterized in dog gallbladder. Acquired inhibition of CFTR expression by gallbladder epithelium was identified as underpinning a naturally occurring muco-obstructive disease of the dog gallbladder that bears striking pathological similarity to animal models of cystic fibrosis. [ABSTRACT FROM AUTHOR]

Objectives: Exposure to benzo[α]pyrene (BaP) increases the incidence and severity of allergic rhinitis (AR), but the underlying mechanisms remain unclear. Thus, we investigated the in vivo effects of BaP exposure on mucus hypersecretion and tissue remodeling in a rat model of AR. Methods: Female Sprague–Dawley rats were randomly divided into 4 groups: a negative control group, a group of healthy rats exposed to BaP, a group of rats with ovalbumin (OVA)-induced AR, and a group of AR model rats exposed to BaP. Nasal symptoms and levels of OVA-specific serum immunoglobulin E (IgE) were measured in each individual rat. Moreover, examination of goblet cell hyperplasia and collagen deposition was carried out with periodic acid-Schiff (PAS) staining and Masson trichrome (MT) staining. Mucin 5AC (MUC5AC) expression was assessed by immunohistochemistry. Results: BaP significantly increased the number of sneezes, the number of nasal rubs and the levels of OVA-specific serum IgE in rats with AR. Statistically significant differences in goblet cell hyperplasia and collagen deposition were observed between the BaP-exposed AR model group and the AR model group. Immunohistochemical results showed that the nasal mucosa of AR model rats displayed markedly elevated MUC5AC expression after BaP exposure. Conclusion: Our data indicate that mucus hypersecretion and the development of nasal remodeling might be pathophysiologic mechanisms underlying increased susceptibility to AR after exposure to BaP. [ABSTRACT FROM AUTHOR]

A 71-year-old man with a history of recurrent tonsillar squamous cell carcinoma was admitted to the hospital with oropharyngeal bleeding. He received high-dose radiation therapy with curative intent. On day 4 of hospitalization, he demonstrated hypoxia resulting from an airway mucus plug and was brought to the medical ICU. [ABSTRACT FROM AUTHOR]

Background: The utility of two disease-severity indices, namely bronchiectasis severity index (BSI) and FACED score in allergic bronchopulmonary aspergillosis (ABPA) remains unknown. Objective: To correlate the BSI and FACED scores with immunological parameters (serum IgE [total and A. fumigatus-specific], A. fumigatus-specific IgG, blood eosinophil count), and high-attenuation mucus on chest computed tomography in ABPA. The secondary objectives were to evaluate the correlation between BSI and FACED scores and correlate the BSI/FACED scores with the bronchiectasis health questionnaire (BHQ) and Saint George's Respiratory Questionnaire (SGRQ). Methods: We included treatment-naïve ABPA subjects with bronchiectasis in a prospective observational study. We computed the BSI and FACED scores for each subject before initiating treatment. The subjects also completed two quality-of-life questionnaires (BHQ and SGRQ). Results: We included 91 subjects. The mean (standard deviation) BSI and FACED scores were 3.43 (3.39) and 1.43 (1.27). We found no correlation between BSI or FACED with any immunological parameter or high-attenuation mucus. There was a strong correlation between BSI and FACED scores (r = 0.76, p < 0.001). We found a weak correlation between BSI and BHQ/SGRQ and FACED and SGRQ. Conclusion: We found no correlation between BSI and FACED with immunological parameters in ABPA. However, we found a significant correlation between BSI and FACED and a weak correlation between SGRQ and BHQ. ABPA likely requires a separate disease-severity scoring system. [ABSTRACT FROM AUTHOR]

Despite clinical implications, the pathogenesis of mucus plugging in asthma, chronic obstructive pulmonary disease (COPD), and asthma-COPD overlap (ACO) remains unclear. We hypothesized that distinct airway microbiomes might affect mucus plugging differently among ACO, asthma, and COPD and among different extents of airway eosinophilic inflammation. The sputum microbiome, sputum cell differential count, and mucus plug score on computed tomography were cross-sectionally evaluated in patients with chronic airflow limitation. Patients with ACO, asthma, or COPD were enrolled (n = 56, 10, and 25). Higher mucus plug scores were associated with a greater relative abundance of the phylum Proteobacteria (rho = 0.29) only in patients with ACO and a greater relative abundance of the phylum Actinobacteria (rho = 0.46) only in patients with COPD. In multivariable models including only patients with ACO, the presence of mucus plugs was associated with a greater relative abundance of the phylum Proteobacteria and the genus Haemophilus, independent of smoking status, airflow limitation, and emphysema severity. Moreover, the mucus score was associated with a greater relative abundance of the genus Streptococcus (rho = 0.46) in patients with a high sputum eosinophil count (n = 22) and with that of the genus Haemophilus (rho = 0.46) in those with a moderate sputum eosinophil count (n = 26). The associations between mucus plugging and the microbiome in ACO differed from those in COPD and asthma. Greater relative abundances of the phylum Proteobacteria and genus Haemophilus may be involved in mucus plugging in patients with ACO and moderate airway eosinophilic inflammation. [ABSTRACT FROM AUTHOR]

The intestinal barrier is a selective interface between the body´s external and the internal environment. Its layer of epithelial cells is joined together by tight junction proteins. In intestinal permeability (IP), the barrier is compromised, leading to increased translocation of luminal contents such as large molecules, toxins and even microorganisms. Numerous diseases including Inflammatory Bowel Disease (IBD), Coeliac disease (CD), autoimmune disorders, and diabetes are believed to be associated with IP. Dietary interventions, such as prebiotics, may improve the intestinal barrier. Prebiotics are non-digestible food compounds, that promote the growth and activity of beneficial bacteria in the gut. This systematic review assesses the connection between prebiotic usage and IP. PubMed and Trip were used to identify relevant studies conducted between 2010–2023. Only six studies were found, which all varied in the characteristics of the population, study design, and types of prebiotics interventions. Only one study showed a statistically significant effect of prebiotics on IP. Alteration of intestinal barrier function was measured by lactulose/mannitol, chromium-labelled Ethylenediaminetetraacetic acid (51Cr-EDTA), lactulose/rhamnose, and sucralose/erythritol excretion as well as zonulin and glucagon-like peptide 2 levels. Three studies also conducted gut microbiota assessment, and one of them showed statistically significant improvement of the gut microbiome. This study also reported a decrease in zonulin level. The main conclusion from this review is that there is a lack of human studies in this important field. Futhermore, large population studies and using standardized protocols, would be required to properly assess the impact of prebiotic intervention and improvement on IP. [ABSTRACT FROM AUTHOR]

Abstract The mucociliary clearance (MC) system is a vital host defense against infection in the lung. MC system function is dependent on ciliary density, structure, and function and airway surface liquid (ASL) composition and hydration. Animal and human studies indicate that MC rate decreases with age which may contribute to the increased rates of pulmonary infection experienced by older people. The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene encodes an anion channel on epithelial surfaces that plays a key role in maintaining ASL hydration. Failure or dysfunction of CFTR could result in the dehydration of airway mucus, depressing MC. Here we use two available databases including bulk (GTEx) and single-cell (CELLxGENE) sequencing data from the lung to determine if CFTR expression decreases with age. Bulk expression data and single-cell expression data from goblet, club, and respiratory basal cells all demonstrated patterns of decreasing CFTR expression with age. Ciliated airway cells did not. Secretory cells (including club and goblet cells) and basal cells are the largest source of CFTR expression in the airway. This indicates that changes in CFTR expression and ASL dehydration may contribute to the decreasing MC associated with aging.

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

Background: Despite clinical implications, the pathogenesis of mucus plugging in asthma, chronic obstructive pulmonary disease (COPD), and asthma-COPD overlap (ACO) remains unclear. We hypothesized that distinct airway microbiomes might affect mucus plugging differently among ACO, asthma, and COPD and among different extents of airway eosinophilic inflammation. Methods: The sputum microbiome, sputum cell differential count, and mucus plug score on computed tomography were cross-sectionally evaluated in patients with chronic airflow limitation. Results: Patients with ACO, asthma, or COPD were enrolled (n = 56, 10, and 25). Higher mucus plug scores were associated with a greater relative abundance of the phylum Proteobacteria (rho = 0.29) only in patients with ACO and a greater relative abundance of the phylum Actinobacteria (rho = 0.46) only in patients with COPD. In multivariable models including only patients with ACO, the presence of mucus plugs was associated with a greater relative abundance of the phylum Proteobacteria and the genus Haemophilus, independent of smoking status, airflow limitation, and emphysema severity. Moreover, the mucus score was associated with a greater relative abundance of the genus Streptococcus (rho = 0.46) in patients with a high sputum eosinophil count (n = 22) and with that of the genus Haemophilus (rho = 0.46) in those with a moderate sputum eosinophil count (n = 26). Conclusions: The associations between mucus plugging and the microbiome in ACO differed from those in COPD and asthma. Greater relative abundances of the phylum Proteobacteria and genus Haemophilus may be involved in mucus plugging in patients with ACO and moderate airway eosinophilic inflammation.

Intestinal mucus serves as the first line barrier within the mucosa to protect against microbiota attack due to its water-repellent properties, which are the result of the high abundance of phosphatidylcholine bound to mucins. A deficiency of mucus phosphatidylcholine predisposes it to mucosal inflammation by the attack of commensal microbiota, as it is intrinsically low in ulcerative colitis. However, for precipitation of an acute inflammatory episode, mucus phosphatidylcholine has to fall below the critical level required for mucosal protection. Bacterial ectophospholipase could be a candidate for further thinning of the mucus phosphatidylcholine shield as shown, for example, with the ectophospholipase containing Helicobacter pylori bacterium. Despite supporting evidence for this mechanism in the intestine, the responsible ectophospholipase-carrying bacteria species are still to be defined. Applying phosphatidylcholine to the lumen can serve to fill up empty mucin-binding sites in ulcerative colitis as well as provide a substrate for the ectophospholipase-carrying bacteria preventing their attacks on the mucus phosphatidylcholine layer. Evidence supporting this concept comes from clinical trials in humans with ulcerative colitis as well as from colitis mouse models where phosphatidylcholine was substituted in the lumen. An alternative strategy could involve adding non-absorbable phospholipase inhibitors to the intestinal lumen, which has been shown to be effective in a mouse model of ulcerative colitis. Bacterial phospholipase should be considered a pathogenetic factor of the intestinal microbiota and therapeutic strategies should be developed to prevent their hyperactivity for clinical improvement of intestinal inflammation.

Abstract The colonic epithelium is comprised of three-dimensional crypts (3D) lined with mucus secreted by a heterogeneous population of goblet cells. In this study, we report the formation of a long-lived, and self-renewing replica of human 3D crypts with a mucus layer patterned in the X–Y–Z dimensions. Primary colon cells were cultured on a shaped scaffold under an air–liquid interface to yield architecturally accurate crypts with a mucus bilayer (605 ± 180 μm thick) possessing an inner (149 ± 50 μm) and outer (435 ± 111 μm) region. Lectins with distinct carbohydrate-binding preferences demonstrated that the mucus in the intercrypt regions was chemically distinct from that above and within the crypts replicating in vivo chemical patterning. Constitutive mucus secretion ejected beads from crypt lumens in 8–10 days, while agonist-stimulated secretion increased mucus thickness by 17-fold in 8 h. The tissue was long-lived, > 50 days, the longest time assessed. In conclusion, the in vitro mucus replicated key physiology of the human mucus, including the bilayer (Z) structure and intercrypt-crypt (X–Y) zones, constitutive mucus flow, spatially complex chemical attributes, and mucus secretion response to stimulation, with the potential to reveal local and global determinants of mucus function and its breakdown in disease.

Eosinophilic inflammation is primarily characterized by type 2 immune responses against parasitic organisms. In the contemporary human being especially in developed countries, eosinophilic inflammation is strongly associated with allergic/sterile inflammation, and constitutes an undesired immune reaction. This situation is in stark contrast to neutrophilic inflammation, which is indispensable for the host defense against bacterial infections. Among eosinophilic inflammatory disorders, massive accumulation of eosinophils within mucus is observed in certain cases, and is often linked to the distinctive clinical finding of mucus with high viscosity. Eosinophilic mucus is found in a variety of diseases, including chronic allergic keratoconjunctivitis, chronic rhinosinusitis encompassing allergic fungal sinusitis, eosinophilic otitis media, eosinophilic sialodochitis, allergic bronchopulmonary aspergillosis/mycosis, eosinophilic plastic bronchitis, and eosinophilic asthma. In these pathological conditions, chronic inflammation and tissue remodeling coupled with irreversible organ damage due to persistent adhesion of toxic substances and luminal obstruction may impose a significant burden on the body. Eosinophils aggregate in the hyperconcentrated mucus together with cell-derived crystals, macromolecules, and polymers, thereby affecting the biophysical properties of the mucus. This review focuses on the clinically significant challenges of mucus and discusses the consequences of activated eosinophils on the mucosal surface that impact mucus and persistent inflammation.

Airway mucus is a hydrogel with unique biophysical properties due to its primary water composition and a small proportion of large anionic glycoproteins or mucins. The predominant mucins in human mucus, MUC5AC and MUC5B, are secreted by specialized cells within the airway epithelium both in normal conditions and in response to various stimuli. Their relative proportions are correlated with specific inflammatory responses and disease mechanisms. The dysregulation of mucin expression is implicated in numerous respiratory diseases, including asthma, COPD, and cystic fibrosis, where the pathogenic role of mucus has been extensively described yet often overlooked. In airway diseases, excessive mucus production or impaired mucus clearance leads to mucus plugging, with secondary airway occlusion that contribute to airflow obstruction, asthma severity and poor control. Eosinophils and Charcot Leyden crystals in sputum contribute to the mucus burden and tenacity. Mucin may also contribute to eosinophil survival. Other mechanisms, including eosinophil-independent IL-13 release, mast-cell activation and non-type-2 (T2) cytokines, are also likely to participate in mucus pathobiology. An accurate assessment of mucus and its clinical and functional consequences require a thorough approach that includes evaluation of cellular predominance in sputum, airway cytokines and other inflammatory markers, mucus characteristics and composition and structural and functional impact measured by advanced lung imaging. This review, illustrated with clinical scenarios, provides an overview of current methods to assess mucus and its relevance to the choice of biologics to treat patients with severe asthma.

Mucus provides a protective barrier that is crucial for host defense in the lungs. However, excessive or abnormal mucus can have pathophysiological consequences in many pulmonary diseases, including asthma. Patients with asthma are treated with agents that relax airway smooth muscle and reduce airway inflammation, but responses are often inadequate. In part, this is due to the inability of existing therapeutic agents to directly target mucus. Accordingly, there is a critical need to better understand how mucus hypersecretion and airway plugging are affected by the epithelial cells that synthesize, secrete, and transport mucus components. This review highlights recent advances in the biology of mucin glycoproteins with a specific focus on MUC5AC and MUC5B, the chief macromolecular components of airway mucus. An improved mechanistic understanding of key steps in mucin production and secretion will help reveal novel potential therapeutic strategies.

The human colon is home to trillions of microorganisms that modulate gastrointestinal physiology. The understanding of how this gut ecosystem impacts human health, although evolving, is slowed by the lack of accessible tools suitable to studying complex host‐mucus‐microbe interactions. Here, a synthetic gel‐like material capable of recapitulating the varied structural, mechanical, and biochemical profiles of native human colonic mucus is reported to develop compositionally simple microbiome screening platforms with utility in microbiology and drug discovery. The viscous fibrillar material is realized through templated assembly of a fluorine‐rich amino acid at liquid‐liquid interphases. The fluorine‐assisted mucus surrogate (FAMS) can be decorated with mucins to serve as a habitat for microbial colonization and integrated with human colorectal cells to generate artificial mucosae, referred to as a microbiome organoid. Notably, FAMS are made with inexpensive and commercially available materials and can be generated using simple protocols and standard laboratory hardware. As a result, this platform can be broadly incorporated into various laboratory settings to advance probiotic research and inform in vivo approaches. If implemented into high throughput screening approaches, FAMS may represent a valuable tool to study compound metabolism and gut permeability, with an exemplary demonstration of this utility presented here. [ABSTRACT FROM AUTHOR]

Intravesical therapy (IT) is widely used to tackle various urological diseases. However, its clinical efficacy is decreased by the impermeability of various barriers presented on the bladder luminal surface, including the urinary mucus layer and the densely packed tissue barrier. In this study, we report a mucoadhesive-to-penetrating nanomotors-in-hydrogel system for urothelium-oriented intravesical drug delivery. Upon intravesical instillation, its poloxamer 407 (PLX) hydrogel gelated and adhered to the urothelium to prolong its intravesical retention. The urea afterwards diffused into the hydrogel, thus generating a concentration gradient. Urease-powered membrane nanomotors (UMN) without asymmetric surface engineering could catalyze the urea and migrate down this concentration gradient to deeply and unidirectionally penetrate the urothelial barrier. Moreover, the intravesical hybrid system-delivered gemcitabine could effectively inhibit the bladder tumor growth without inducing any side effect. Therefore, our mucoadhesive-to-penetrating nanomotors-in-hydrogel system could serve as an alternative to IT to meet the clinical need for more efficacious therapeutics for urological diseases. [ABSTRACT FROM AUTHOR]

Antibiotic use is a risk factor for development of inflammatory bowel diseases (IBDs). IBDs are characterized by a damaged mucus layer, which does not separate the intestinal epithelium from the microbiota. Here, we hypothesized that antibiotics affect the integrity of the mucus barrier, which allows bacterial penetrance and predisposes to intestinal inflammation. We found that antibiotic treatment led to breakdown of the colonic mucus barrier and penetration of bacteria into the mucus layer. Using fecal microbiota transplant, RNA sequencing followed by machine learning, ex vivo mucus secretion measurements, and antibiotic treatment of germ-free mice, we determined that antibiotics induce endoplasmic reticulum stress in the colon that inhibits colonic mucus secretion in a microbiota-independent manner. This antibiotic-induced mucus secretion flaw led to penetration of bacteria into the colonic mucus layer, translocation of microbial antigens into circulation, and exacerbation of ulcerations in a mouse model of IBD. Thus, antibiotic use might predispose to intestinal inflammation by impeding mucus production. [ABSTRACT FROM AUTHOR]

PurposeMethodsResultsConclusionsTo emphasise the importance of “soft” observations during lacrimal irrigation in diagnosing lacrimal outflow dysfunction and reporting outcomes of soft factors post-DCR.A retrospective study of patients with ≤ 20% of regurgitation on lacrimal irrigation who underwent DCR surgery. A comparative analysis of percentage reflux of saline (RFX), initial mucus in reflux (IMR), patient-reported transit time of saline (PR-TTS), and resistance encountered (RES) during LS was performed. Validated TEARS score was used. Subjective success was defined as ≥ 2-point improvement in T subscale of TEARS score. Objective success, as a decrease in RFX, RES, PR-TTS and absence of IMR, post-operatively.From a total of 253 patients who underwent DCR surgery, 8 patients met the inclusion criteria. All patients were T4 (wiping >10× daily) indoors and outdoors. TEARS score improved after surgery with a mean reduction of T = 2.62, E = 1.63 and A = 1.35 (p < .05) with no significant change in R scores (p = .10). A mean reduction in RFX of 11.75 ± 6.74% and a median improvement of 1 point in PR-TTS and 2 point in RES was observed (p < .05). No significant changes of these parameters occurred in the contralateral side during this period. Subjective and objective success of DCR was 75% and 100%, respectively.This study is the first to attempt to combine qualitative “soft” observations during lacrimal irrigation such as IMR, RES and PR-TTS for identifying nasolacrimal outflow dysfunction and reporting outcomes using these parameters of DCR in patients with epiphora and ≤ 20% of fluid regurgitation. These parameters were greater in the more symptomatic side and successfully improved after DCR, making them a valuable tool to reach a provisional diagnosis. [ABSTRACT FROM AUTHOR]

The impact of ustekinumab (UST) on mucosal- and fistula healing and extraintestinal manifestations (EIM) in Crohn's disease (CD) were not fully elucidated in the registration trials. In this prospective, multicenter study (EudraCT number: 2017-005151-83) we evaluated the German label real-world-effectiveness of UST to achieve the primary endpoint of combined clinical and endoscopic response at week 52 and several secondary endpoints. Of 79 screened we enrolled 52 patients (female n = 28, bionaïve n = 13, biologic n = 39). At week 52 (per protocol analysis), 52% (n = 13/25) of patients achieved the primary endpoint [50% (n = 3/6) in the bionaïve, 45.5% (n = 5/11) biologic, 62.5% (n = 5/8) multiple biologics cohorts, respectively with age as independent predictor [OR 95% CI 0.933 (0.873, 0.998) p = 0.043], 60% (n = 15/25) achieved endoscopic response [50% (n = 3/6) in the bionaïve, 54.5% (n = 6/11) biologic, 75% (n = 6/8) multiple biologics cohorts, respectively], 36% (n = 9/25) achieved endoscopic remission [50% (n = 3/6) in the bionaïve, 27.3% (n = 3/11) biologic, 37.5% (n = 3/8) multiple biologics cohorts, respectively], 48% (n = 12/25) achieved mucosal healing [50% (n = 3/6) in the bionaïve, 36.4% (n = 4/11) biologic, 62.5% (n = 5/8) multiple biologics cohorts, respectively]. All achieved a fistula response and 33.3% (n = 1/3) in the multiple biologics group fistula remission at week 52. EIM decreased (week 0 28.2% vs. week 52 8%). CRP, FCP, PRO-2, EQ-5D-5L improved throughout. 36 patients (69.2%) experienced ≥ 1 treatment emergent adverse event, in 8 (15.4%) cases rated as severe and in 5 (9.6%) leading to UST discontinuation, but no very severe events or deaths. The effectiveness of UST was better than in the registration trials. [ABSTRACT FROM AUTHOR]

We examined the morphology and taxonomy of specimens of the genus Nitella, collected from the main island of Okinawa, Japan. Based on their vegetative and reproductive characteristics, the samples were most similar to Nitella tumulosa, as the two species have a large monoicous thallus without mucus, an abbreviated two-celled dactyl and papillate oospore walls. Nevertheless, the two species can be differentiated based on variations in the overall appearance of thalli and the size of oogonia. Moreover, scanning electron microscopy observations revealed the detailed structures of oospores of specimens collected from Okinawa, and their oospore characteristics were clearly distinguishable from those of N. tumulosa and other related taxa. Additionally, molecular phylogenetic analyses demonstrated that the specimens collected from the main island of Okinawa were phylogenetically separated from a clade comprising specimens of N. tumulosa. Therefore, we propose a new species from the specimen collected from the main island of Okinawa as, Nitella pluripapillifera sp. nov. [ABSTRACT FROM AUTHOR]

Snails exhibit remarkable adaptability, allowing them to flourish in diverse environmental conditions and resulting in thriving populations in specific regions. This abundance has led communities to harness snails for various purposes, including their use as animal feed, daily dietary source, and in traditional wound-healing practices with historical roots. The primary objective of this systematic review is to identify the snail species commonly employed in wound healing and evaluate the bioactivity of compounds derived from different snail species. This review was conducted using literature review method, drawing from international databases such as Scopus, and encompassed publications from 2013 to 2023. A total of 22 articles met the inclusion and exclusion criteria. Snail body parts that have been explored for wound-healing purposes include both the body and the shell, along with snail secretions, particularly their mucus. Various methods have been employed to extract mucus, involving manual stimulation of the snail's body, spraying with a saline solution (NaCl), application of electric shock, and the use of ozone gas through nebulisation. Prominent snail species found to be beneficial for wound healing include Achatina fulica, Helix aspersa, Eobania desertorum, Helix lucurus, Cornu bistrialis, Theba pisana, and Megalobulimus lopesi. These snail species demonstrate potential applications in the treatment of burns, excision wounds, incision wounds, and diabetic ulcers. Key compounds within snail secretions encompass mucopolysaccharides, polyphenols, peptides, and glycosaminoglycans. These compounds exert significant effects on haemostasis, inflammation control, cellular proliferation, and re-epithelialisation, significantly contributing to the wound healing process. [ABSTRACT FROM AUTHOR]

Biological evolution has generated a vast array of natural compounds produced by organisms across all domains. Among these, secondary metabolites, selected to enhance an organism's competitiveness in its natural environment, make them a reservoir for discovering new compounds with cytotoxic activity, potentially useful as novel anticancer agents. Slime secretions, the first barrier between epithelial surfaces and the surrounding environment, frequently contain cytotoxic molecules to limit the growth of parasitic organisms. Planarians, freshwater Triclads, continuously secrete a viscous mucus with multiple physiological functions. The chemical composition of planarian mucus has been only partially elucidated, and there are no studies reporting its cytotoxic or cytostatic effects. In this study, we developed a protocol for collecting mucus from Dugesia japonica specimens and we demonstrated that it inhibits the growth of cancer cells by activating cytostatic and ROS-dependent cytotoxic mechanisms inducing lipid droplet accumulation and mitochondrial membrane reorganization. Although further research is needed to identify the specific chemicals responsible for the anticancer activity of planarian mucus, this work opens up numerous research avenues aimed at better understanding the mechanisms of action of this product for potential therapeutic applications. [ABSTRACT FROM AUTHOR]

Despite the safety and convenience of oral administration, poorly water-soluble drugs compromise absorption and bioavailability. These drugs can exhibit low dissolution rates, variability between fed and fasted states, difficulty permeating the mucus layer, and P-glycoprotein efflux. Drug nanocrystals offer a promising strategy to address these challenges. This review focuses on the opportunities to develop orally administered nanocrystals based on pharmacokinetic outcomes. The impacts of the drug particle size, morphology, dissolution rate, crystalline state on oral bioavailability are discussed. The potential of the improved dissolution rate to eliminate food effects during absorption is also addressed. This review also explores whether permeation or dissolution drives nanocrystal absorption. Additionally, it addresses the functional roles of stabilizers. Drug nanocrystals may result in prolonged concentrations in the bloodstream in some cases. Therefore, nanocrystals represent a promising strategy to overcome the challenges of poorly water-soluble drugs, thus encouraging further investigation into unclear mechanisms during oral administration. [ABSTRACT FROM AUTHOR]

Asthma is a chronic lung disease with persistent airway inflammation, bronchial hyper-reactivity, mucus overproduction, and airway remodeling. Antagonizing T2 responses by triggering the immune system with microbial components such as Toll-like receptors (TLRs) has been suggested as a therapeutic concept for allergic asthma. The aim of this study was to evaluate the effect of a TLR2/6 agonist, FSL-1 (Pam2CGDPKHPKSF), administered by intranasal instillation after an allergic airway reaction was established in the ovalbumin (OVA) mouse model and to analyze the role of natural killer (NK) cells in this effect. We showed that FSL-1 decreased established OVA-induced airway hyper-responsiveness and eosinophilic inflammation but did not reduce the T2 or T17 response. FSL-1 increased the recruitment and activation of NK cells in the lung parenchyma and modified the repartition of NK cell subsets in lung compartments. Finally, the transfer or depletion of NK cells did not modify airway hyper-responsiveness and eosinophilia after OVA and/or FSL-1 treatment. Thus, the administration of FSL-1 reduces airway hyper-responsiveness and bronchoalveolar lavage eosinophilia. However, despite modifications of their functions following OVA sensitization, NK cells play no role in OVA-induced asthma and its inhibition by FSL-1. Therefore, the significance of NK cell functions and localization in the airways remains to be unraveled in asthma. [ABSTRACT FROM AUTHOR]

This study investigated the effects of adding earthworm mucus on the changes in sludge compost bacterial community structure and its response to environmental factors. The results showed that adding earthworm mucus improved the composting effect of sludge, reducing nitrogen loss and increasing nutrients; nitrogen loss decreased by 5.55%, and potassium and phosphorus increased by 10.23 and 16.28%, respectively. Firmicutes, Chloroflexi, Actinobacteria, and Proteobacteria were the main bacterial phyla in the sludge, with a combined relative abundance of over 60%. The addition of earthworm mucus significantly impacted bacterial community structure and composting activity, increasing the relative abundance of dominant bacteria during the process. Redundancy analysis showed that environmental factors significantly impacted the changes in bacterial community structure during composting. The results indicate that the addition of earthworm mucus increases the relative abundance of advantageous bacteria playing essential roles in sludge composting, enhancing the fertility and maturity of sludge composting products by significantly reducing nitrogen loss and increasing potassium and phosphorus. Based on the response relationship between environmental factors and bacterial communities, the bacterial community structure in sludge composting can be improved by regulating environmental factors (such as pH and moisture content), enhancing the effectiveness of sludge composting. [ABSTRACT FROM AUTHOR]

Coculture of intestinal bacteria with primary human intestinal epithelium provides a valuable tool for investigating host‐colon bacterial interactions and for testing and screening therapeutics. However, most current intestinal model systems lack key physiological features of the in vivo colon, such as both a proper oxygen microenvironment and a mucus layer. In this work, a new in vitro colonic microphysiological system is demonstrated with a cell‐derived, functional mucus that closely resembles the in vivo colonic mucosa and apical microenvironment by employing an anaerobic air‐liquid interface culture. The human primary colon epithelial cells in this new in vitro system exhibit high cell viability (>98%) with ≈100 µm thick functional mucus layer on average. Successful coculture of model anaerobic gut bacterial strains Lactobacillus rhamnosus GG and Anaerobutyricum hallii without loss in human cell viability demonstrates that this new model can be an invaluable tool for future studies of the impact of commensal and pathogenic bacteria on the colon. [ABSTRACT FROM AUTHOR]

Intestinal mucus serves as the first line barrier within the mucosa to protect against microbiota attack due to its water-repellent properties, which are the result of the high abundance of phosphatidylcholine bound to mucins. A deficiency of mucus phosphatidylcholine predisposes it to mucosal inflammation by the attack of commensal microbiota, as it is intrinsically low in ulcerative colitis. However, for precipitation of an acute inflammatory episode, mucus phosphatidylcholine has to fall below the critical level required for mucosal protection. Bacterial ectophospholipase could be a candidate for further thinning of the mucus phosphatidylcholine shield as shown, for example, with the ectophospholipase containing Helicobacter pylori bacterium. Despite supporting evidence for this mechanism in the intestine, the responsible ectophospholipase-carrying bacteria species are still to be defined. Applying phosphatidylcholine to the lumen can serve to fill up empty mucin-binding sites in ulcerative colitis as well as provide a substrate for the ectophospholipase-carrying bacteria preventing their attacks on the mucus phosphatidylcholine layer. Evidence supporting this concept comes from clinical trials in humans with ulcerative colitis as well as from colitis mouse models where phosphatidylcholine was substituted in the lumen. An alternative strategy could involve adding non-absorbable phospholipase inhibitors to the intestinal lumen, which has been shown to be effective in a mouse model of ulcerative colitis. Bacterial phospholipase should be considered a pathogenetic factor of the intestinal microbiota and therapeutic strategies should be developed to prevent their hyperactivity for clinical improvement of intestinal inflammation. [ABSTRACT FROM AUTHOR]