To overcome the critical challenge in drug inhalation for pulmonary diseases, we innovatively proposed that polydopamine (PDA) as a surface modification material had great potential to improve the mucus permeation and pulmonary retention of inhalable lipid-based nanocarriers. We prepared PDA coated lipid nanoemulsions/solid lipid nanoparticles/liposomes and systematically evaluated their interactions with mucin and pulmonary retention after inhalation. PDA-coated lipid-based nanocarriers exhibited weaker interactions with mucins, higher mucus permeability and cellular uptake by the respiratory epithelium cells compared to PEGylated lipid-based nanocarriers. However, the pulmonary retention advantage of PDA coating was shown in lipid nanoemulsions (< 50 nm) and solid lipid nanoparticles (< 100 nm). Liposomes (∼ 150 nm) with PEGylation possessed higher pulmonary retention than that coated by PDA. It was suggested that PEGylated liposomes were liable to be phagocytosed by alveolar macrophages due to binding with specific antibodies. Overall, this work suggests that PDA as a surface modification material of inhalable lipid-based nanocarriers holds promise for effective mucus penetration and pulmonary retention.

Pathological mucus hypersecretion is an important clinical hallmark of chronic airway inflammatory diseases and yet there is a lack of effective therapeutic medicine. Resveratrol, a dietary polyphenol, has been shown to possess anti‑aging, antioxidation, anti‑inflammation and tumor prevention effects. However, the effect and underlying mechanism of resveratrol in lipopolysaccharide (LPS) induced‑mucus hypersecretion remain to be elucidated. Among more than 20 mucin family members, mucin 5ac (MUC5AC) is a major glycoprotein in airway mucus. The present study investigated the therapeutic effects and mechanisms of resveratrol in LPS‑induced MUC5AC expression in human bronchial epithelial (NCI‑H292) cells and an acute inflammatory murine model. It found that resveratrol markedly attenuated LPS‑induced MUC5AC expression and reactive oxygen species production in NCI‑H292 cells. Moreover, resveratrol increased activation of nuclear factor erythroid‑2‑related factor 2 (Nrf2) and phosphorylation of mitogen‑activated protein kinase (MAPK). Notably, compared with negative control, knockdown of Nrf2 by small interfering RNA and specific inhibitors of ERK/p38 MAPK markedly abrogated the downregulative effect of resveratrol on LPS‑induced MUC5AC expression in NCI‑H292 cells. Additionally, in vivo effects on histopathology and gene expression were assessed in lung tissues collected after intratracheal instillation of LPS with or without resveratrol treatment. Western blotting of lung tissue samples confirmed that administration of resveratrol inhibited MUC5AC expression in LPS‑induced acute inflammatory mice, but increased Nrf2 expression along with phosphorylation of ERK and p38. Periodic acid‑Schiff's staining also showed that resveratrol suppressed mucin production. Compared with the LPS group, administration of resveratrol effectively decreased the numbers of inflammatory cells and neutrophils in bronchoalveolar lavage fluid, as well as markedly alleviating the infiltration of exacerbated inflammatory cells in lung tissue. In conclusion, resveratrol exerted protective effects against LPS‑induced MUC5AC overexpression, inflammation and oxidative stress by activating ERK/p38 MAPK and Nrf2 pathway. Furthermore, the results suggested that resveratrol might be a potential therapeutic agent to inhibit airway mucus hyperproduction.

Emerging evidence suggests that electroacupuncture (EA) could cause autonomic reflexes to modulate visceral functions. However, the efficacy and underlying mechanisms for somatic stimulation on allergic pulmonary inflammation (API) remain elusive.

Mice were administered intranasal Papain to induce API. Distinct current (0,0.1, 0.2 and 0.5 mA) of EA at the back BL13, hindlimb ST36 and forelimb LU5 acupoint were then carried out. The control group underwent the same procedure but without current stimulation. Changes in API was assessed using immunohistochemistry, flow cytometry and haematoxylin and eosin (H&E) staining. Pharmacological approaches were used to investigate the underlying mechanisms of EA effects on API.

EA at the back region but not limb regions, in a current intensity-dependent manner, exacerbated API, primarily causing a decrease in the survival rate and intensified inflammation in the lung, including the infiltration of lung type 2 innate lymphoid cells and eosinophils, and lung pathology scores. Blocking local thoracic sensory nerves with lidocaine or lung-innervated autonomic nerves with hexamethonium eliminates the EA-produced detrimental effects. Chemical pulmonary sympathectomy with 6-OHDA further enhanced lung pathology scores, but inhibiting the activity of pulmonary muscarinic receptors was sufficient to prevent the exacerbation of API induced by EA.

Our findings suggest that BL13 EA induces a somatic-autonomic reflex involving the pulmonary muscarinic receptors, thereby exacerbating API. The selective and intensity-dependency activation of body thoracic regions in driving pulmonary autonomic pathways could help optimise stimulation parameters, enhancing both efficacy and safety in modulating API.

Nasal drug administration constitutes an efficient and non-invasive modality of drug delivery, and its distinctive physiological structure offers potentialities for treating a variety of diseases. To elevate the drug absorption and delivery efficiency, it is of paramount importance to delineate the transport routes and their enhancement mechanisms. Nevertheless, drug absorption pathways vary depending on the disease target, these variations present opportunities for targeted delivery and challenges for achieving precision. Hence, this review outlines the anatomical structure of the nasal cavity, and subsequently elaborates on the drug transport pathways within the nasal cavity and their influencing factors. Based on the distinct sites of drug action, diseases suitable for nasal drug administration are categorized into three types: systemic diseases, local nasal diseases, and central nervous system diseases. Grounded on multiple transport routes and their influencing factors, this review proposes strategies like optimizing formulation viscosity, using penetration enhancers, adding mucosal adhesives and improving delivery device, offering insights into future advancements in nasal drug delivery systems.

The porcine colon epithelium plays a crucial role in nutrient absorption, ion transport, and barrier function. However ethical concerns necessitate the development of alternatives to animal models for its study. The objective of this study was to develop and characterize a two-dimensional (2D) in vitro model of porcine colonic organoids that closely mimics native colon tissue, thereby supporting in vitro research in gastrointestinal physiology, pathology, and pharmacology. Porcine colonic crypts were isolated and cultured in three-dimensional (3D) organoid systems, which were subsequently disaggregated to form 2D monolayers on transwell inserts. The integrity of the monolayers was evaluated through the measurement of transepithelial electrical resistance (TEER) and electron microscopy. The functional prerequisites of the model were evaluated through the measurement of the mRNA expression of key ion channels and transporters, using quantitative RT-PCR. Ussing chamber experiments were performed to verify physiological activity. The 2D monolayer displayed robust TEER values and retained structural characteristics, including microvilli and mucus-secreting goblet cells, comparable to those observed in native colon tissue. Gene expression analysis revealed no significant differences between the 2D organoid model and native tissue with regard to critical transporters. Ussing chamber experiments demonstrated physiological responses that were consistent with those observed in native colonic tissue. In conclusion, 2D porcine colonic organoid model can be recommended as an accurate representation of the physiological and functional attributes of the native colon epithelium. This model offers a valuable tool for investigating intestinal barrier properties, ion transport, and the pathophysiology of gastrointestinal diseases, while adhering to the 3R principles.

Rainbow trout (Oncorhynchus mykiss) is an important fish species raised in aquaculture, but it is susceptible to stress, infections diseases. The present study aimed to determine the effects of fulvic acid feed addition on the systemic and mucosal protective mechanisms of juvenile rainbow trout and to elucidate the underlying molecular mechanisms of changes in the gut. Rainbow trout (4.30 ± 0.6 g) diet was supplemented with different levels of fulvic acid: 0% (Control), 0.5%, 1% and 2%. At the end of 8-week feeding trial, growth parameters such as final weight gained weight (%), SGR (F1%) increased, and FCR (all levels) decreased significantly compared to the control group. We found that the activity of lysozyme, glutathione peroxidase, and catalase in the serum were significantly improved, especially after the addition of 0.5% and 1% of fulvic acid. At the same time, the immunoglobulin concentration in the skin mucus was increased with 0.5% supplementation. However, the expression of tnf-α, il-6 and gpx in the intestine was strongly upregulated after supplementation with 2%, indicating oxidative stress and inflammation with this level of fulvic acid inclusion. Furthermore, the mucus lysozyme activity was reduced at this concentration, which can increase the susceptibility to pathogen invasion. The results suggest that adding 0.5%-1% of fulvic acid to the feed of juvenile rainbow trout can help to improve their immune and antioxidative defenses and thereby support the wellbeing of fish.

Undaria pinnatifida, an edible brown seaweed that is widely consumed in East Asia, has gained increasing recognition for its health benefits. Among its bioactive compounds, polysaccharides have attracted significant attention due to their diverse biological activity. This review provides a comprehensive overview of recent advancements in the extraction, purification, structural characterization, and bioactivity of U. pinnatifida polysaccharides. We discuss state-of-the-art extraction techniques, including ultrasound-assisted, microwave-assisted, and enzyme-assisted extraction, as well as purification strategies such as membrane separation and chromatographic methods. Furthermore, we highlight their potential biological activity, including antioxidant, immunomodulatory, anticancer, gut health-promoting, and anti-hyperglycemic effects, along with their underlying mechanisms of action. By summarizing the latest research, this review aims to provide valuable insights into the development and application of U. pinnatifida polysaccharides in functional foods and pharmaceuticals.

Radiation-induced xerostomia (RIX) is a common and debilitating side effect of head and neck cancer radiotherapy, significantly impacting patients' quality of life. This review comprehensively summarizes the current understanding of RIX, encompassing its clinical quantification, underlying pathophysiology, and established and emerging treatment modalities. We explore various objective and subjective measures used to quantify salivary flow and assess the severity of xerostomia in clinical settings. The pathophysiological mechanisms leading to RIX are elucidated, including radiation damage to salivary glands, alterations in saliva composition, and the role of inflammatory processes. Current treatment strategies, such as saliva substitutes and stimulants, are discussed alongside their limitations. Furthermore, we delve into novel investigational approaches, including gene therapy, stem cell transplantation, and pharmacologic interventions, offering promising avenues for future RIX management. This review provides clinicians and researchers with a comprehensive overview of RIX, highlighting the need for continued research to develop more effective preventative and therapeutic strategies to alleviate this burdensome condition.

Our understanding of the airway epithelium's role in driving asthma pathogenesis has evolved over time. From being regarded primarily as a physical barrier that could be damaged via inflammation, the epithelium is now known to actively contribute to asthma development through interactions with the immune system. The airway epithelium contains multiple cell types with specialized functions spanning barrier action, mucociliary clearance, immune cell recruitment, and maintenance of tissue homeostasis. Environmental insults may cause direct or indirect injury to the epithelium leading to impaired barrier function, epithelial remodelling, and increased release of inflammatory mediators. In severe asthma, the epithelial barrier repair process is inhibited and the response to insults is exaggerated, driving downstream inflammation. Genetic and epigenetic mechanisms also maintain dysregulation of the epithelial barrier, adding to disease chronicity. Here, we review the role of the airway epithelium in severe asthma and how targeting the epithelium can contribute to asthma treatment.

To investigate the relationship between the type 2 inflammatory response associated with asthma and lower respiratory tract infection (LRTI) caused by respiratory syncytial virus (RSV).

Sixty-seven children with RSV infection hospitalized in our hospital from October 2023 to December 2023 and 27 healthy children undergoing medical examination were included. The study population was divided into the RSV LRTI group (n = 67) and the control group (n = 27). Interleukin-13 (IL-13), serum total immunoglobulin E (IgE), mucin 5AC (MUC5AC), and blood eosinophil count (EOS) were tested and compared between the two groups. The presence or absence of specificity between the two groups was analyzed using the rank sum test and subject operating characteristic curves (Receiver Operating Characteristic curves, ROC curves).

The levels of IL-13, IgE, MUC5AC, and EOS were higher in children with RSV LRTI compared to healthy children. These differences were statistically significant (P < .05). The ROC curve analysis results showed that IL-13, IgE, MUC5AC, and EOS predicted type 2 inflammation with areas under the curve of 0.687, 0.762, 0.764, and 0.646, respectively.

A type 2 inflammatory response associated with asthma may be observed after RSV-induced LRTIs.

Pseudomonas aeruginosa is a prevalent opportunistic Gram-negative bacterial pathogen. One of its key virulence factors is pyocyanin, a redox-active phenazine secondary metabolite that plays a crucial role in the establishment and persistence of chronic infections. This review provides a synopsis of the mechanisms through which pyocyanin exacerbates pulmonary infections. Pyocyanin induces oxidative stress by generating reactive oxygen and nitrogen species which disrupt essential defense mechanisms in respiratory epithelium. Pyocyanin increases airway barrier permeability and facilitates bacterial invasion. Pyocyanin also impairs mucociliary clearance by damaging ciliary function, resulting in mucus accumulation and airway obstruction. Furthermore, it modulates immune responses by promoting the production of pro-inflammatory cytokines, accelerating neutrophil apoptosis, and inducing excessive neutrophil extracellular trap formation, which exacerbates lung tissue damage. Additionally, pyocyanin disrupts macrophage phagocytic function, hindering the clearance of apoptotic cells and perpetuating inflammation. It also triggers mucus hypersecretion by inactivating the transcription factor FOXA2 and enhancing the IL-4/IL-13-STAT6 and EGFR-AKT/ERK1/2 signaling pathways, leading to goblet cell metaplasia and increased mucin production. Insights into the role of pyocyanin in P. aeruginosa infections may reveal potential therapeutic strategies to alleviate the severity of infections in chronic respiratory diseases including cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD).

Nonsteroidal anti-inflammatory drug (NSAID) enteropathy is a serious clinical complication with no effective treatments available. Modulating the intestinal microbiota through dietary and nutritional targets is a promising strategy for preventing NSAID enteropathy. This study aimed to investigate the protective effect and underlying mechanisms of the probiotic Clostridium butyricum (CB) on indomethacin (IND)-induced enteropathy. C57BL/6J mice received CB treatment for 14 days along with concurrent IND gavage for the final 7 days. Caco2 cells were stimulated with IND to evaluate the effect of CB supernatant (CBS) on the intestinal barrier function, and LS174T cells were used to validate the modulatory action of CBS on the Notch signaling pathway. Our findings revealed that CB treatment prevented anorexia and weight loss, reduced the severity of enteropathy, and decreased the inflammatory response of the small intestine. CB also increased the expression of tight junction proteins and reduced permeability in mice and Caco2 cells. Additionally, CB suppressed apoptosis and promoted proliferation in the small intestine. Further research found that CB increased the number of goblet cells and MUC2 secretion. Mechanistically, CB may promote MUC2 secretion by suppressing the Notch signaling pathway, consistent with the results of intervention in LS174T cells with CBS. In conclusion, CB might prevent NSAID enteropathy by increasing MUC2 secretion through the inhibition of the Notch pathway. Our study identified the potential efficacy of CB as a preventive strategy against NSAID enteropathy and showed promising prospects for CB as a food supplement.

To explore the role of the miR-146a-5p-mediated regulation of the EGFR/MEK/ERK pathway in the effect of effective-component compatibility of Bufei Yishen Formula III (ECC-BYF III) on ameliorating mucus hypersecretion by bronchial epithelial cells (BEAS-2B cells).

BEAS-2B cells exposed to cigarette smoke extract (CSE) were used to establish a mucus hypersecretion model of BEAS-2B cells. The optimal intervention concentration of ECC-BYF III was screened by CCK-8, qRT-PCR and ELISA, the effects of ECC-BYF III on MUC5AC, MUC5B, IL-4, IL-8, TNF-α, IL-1α, miR-146a-5p and EGFR/MEK/ERK pathway expression were assessed. Furthermore, dual luciferase reporter gene was used to verify the relationship between miR-146a-5p and EGFR/MEK/ERK, and to observe the effect of down-regulating miR-146a-5p on ECC-BYF III ameliorating mucus hypersecretion and EGFR/MEK/ERK pathway.

ECC-BYF III reduced the expression of MUC5AC and MUC5B, decreased the mRNA expression of IL-1α, IL-8 and TNF-α, increased the mRNA expression of IL-4, and decreased the protein expression of TNF-α. Moreover, ECC-BYF III ameliorated CSE induced mucus hypersecretion in BEAS-2B cells through EGFR/MEK/ERK pathway. Finally, our results indicated that ECC-BYF III ameliorated the model by targeting miR-146a-5p and downregulating the EGFR/MEK/ERK pathway.

ECC-BYF III can ameliorate CSE induced mucus hypersecretion by BEAS-2B cells and reduce the inflammatory response. The underlying mechanism may be related to the regulation of miR-146a-5p and the EGFR/MEK/ERK pathway. ECC-BYF III can inhibit activation of the EGFR/MEK/ERK pathway by upregulating the expression of miR-146a-5p, thereby ameliorating mucus hypersecretion by BEAS-2B cells.

Pulmonary inflammation is the main cause of lung injury. Phosphodiesterase 4 (PDE4) is a promising anti-inflammatory target for the treatment of respiratory diseases. Herein, we designed and synthesized 43 compounds in two novel series of benzimidazole derivatives as PDE4 inhibitors. Among them, compound A5 showed highly selective inhibition of PDE4, good safety, and liver microsomal stability in vitro. A5 administration remarkably attenuated inflammatory infiltration and pathologic injury of the lung in models of acute lung injury in mice and chronic obstructive pulmonary disease (COPD) in mice. In addition, A5 enhanced sputum secretion, relieved cough in mice, and inhibited phosphorylation of p38 MAP kinase, an important protein in the regulation of lung injury. Overall, A5, as an effective PDE4 inhibitor without acute toxicity and gastrointestinal reaction, may be a potent candidate for the treatment of pulmonary injury.

The present study aimed to evaluate the effect of consumption of milk fermented by Lacticaseibacillus (Lc.) casei SJRP38 and Limosilactobacillus (Lm.) fermentum SJRP43 on bacterial translocation, stool analysis, and intestinal morphology of healthy BALB/c mice. Potentially probiotic lactic acid bacteria, Lc. casei SJRP38, and Lm. fermentum SJRP43 were evaluated and analyzed for translocation, fecal analysis, and intestinal morphology of four groups of mice: water control (WC), milk control (MC), milk fermented by Lc. casei SJRP38 (FMLC), and milk fermented by Lm. fermentum SJRP43 (FMLF), in co-culture with Streptococcus thermophilus ST080. The results of the animal assay indicate that the population of Lactobacilli and Bidobacterium sp. in the gastrointestinal tract of BALB/c mice was greater than 6.0 log10 CFU/g, and there was no evidence of bacteremia due to the low incidence of bacterial translocation. Ingesting fermented milk containing Lc. casei SJRP38 and Lm. fermentum SJRP43 was found to promote a healthier microbiota, as it led to a reduction in Clostridium sp. and an increase in Lactobacilli and Bifidobacterium sp. in feces. Furthermore, the dairy treatments (MC, FMLC, and FMLF) resulted in taller intestinal villi and an increase in the frequency of goblet cells in the intestines. Overall, the consumption of fermented milk containing Lc. casei SJRP38 and Lm. fermentum SJRP43 strains was deemed safe and demonstrated beneficial effects on the intestines of BALB/c mice.

Mucus plays an integral role for the barrier function of many epithelial tissues. In the human airways, mucus is constantly secreted to capture inhaled microbes and pollutants and cleared away through concerted ciliary motion. Many important respiratory diseases exhibit altered mucus flowability and impaired clearance, contributing to respiratory distress and increased risk of infections. Understanding how mucus rheology changes during disease progression and in response to treatments is thus of great interest for subtyping patients and tailoring treatments, probing disease mechanisms, and tailoring therapies; however, basic research of mucus rheology is greatly hampered by the lack of scalable and user-friendly rheometry assays for the small volumes of mucus typically produced by in vitro respiratory models and in clinical ex vivo settings. To address this challenge, we developed a streamlined, high-throughput protocol leveraging Differential Dynamic Microscopy (DDM) to reliably measure the frequency-dependent microrheology of minuscule (3-10 μL) mucus samples using standard epifluorescence microscopy. Our method does not require time-consuming user-interventions common in particle tracking routines and measures microrheology at the time scale of mucus relaxation (1-20s), hence greatly reducing assay time. We demonstrate the successful application of our method in mucus samples harvested from state-of-the-art air-liquid-interface (ALI) human respiratory cultures to assess mucus rheology in airway disease models and different culture conditions. To show that our approach equally applies to other types and sources of human mucus, we also validated our method with clinical samples of cervical mucus. We envision that our method can be seamlessly adopted by non-expert users, without the need for specialized equipment or extensive training, to study diseases and their treatments in the respiratory, intestinal, reproductive and other mucosal organ systems. This advancement opens up new avenues for large-scale studies, providing new insights into the role of mucus rheology which was previously limited by data accessibility and resource constraints.

The mucosal immune system, as the most extensive peripheral immune network, serves as the frontline defense against a myriad of microbial and dietary antigens. It is crucial in preventing pathogen invasion and establishing immune tolerance. A comprehensive understanding of mucosal immunity is essential for developing treatments that can effectively target diseases at their entry points, thereby minimizing the overall impact on the body. Despite its importance, our knowledge of mucosal immunity remains incomplete, necessitating further research. The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has underscored the critical role of mucosal immunity in disease prevention and treatment. This systematic review focuses on the dynamic interactions between mucosa-associated lymphoid structures and related diseases. We delve into the basic structures and functions of these lymphoid tissues during disease processes and explore the intricate regulatory networks and mechanisms involved. Additionally, we summarize novel therapies and clinical research advances in the prevention of mucosal immunity-related diseases. The review also addresses the challenges in developing mucosal vaccines, which aim to induce specific immune responses while maintaining tolerance to non-pathogenic microbes. Innovative therapies, such as nanoparticle vaccines and inhalable antibodies, show promise in enhancing mucosal immunity and offer potential for improved disease prevention and treatment.

Heart failure (HF) threatens tens of millions of people's health worldwide, which is the terminal stage in the development of majority cardiovascular diseases. Recently, an increasing number of studies have demonstrated that bioinformatics and machine learning (ML) algorithms can offer new insights into the diagnosing and treating HF. To further discover HF diagnostic genes, we utilized least absolute shrinkage and selection operator (LASSO) and Support Vector Machine (SVM) to identify novel immune-related genes. The HF dataset was obtained from the gene expression omnibus (GEO) database and three candidate genes (LCN6, MUC4, and TNFRSF13C) were finally screened. In addition, the myocardial infarction (MI) modeling experiments on mice were performed to validate the expression of LCN6, MUC4, and TNFRSF13C on experimental HF mice. Altogether, these three candidate genes are promising targets for the prediction of HF with immunological perspective.

Loss of surface sialic acid by neuraminidases is known as 'desialylation'. Platelets are desialylated in bacterial or viral infections, during storage, senescence, various mutations, platelet auto antibodies, hemostasis and shear stress. In this review the recent literature on the different sialic acid capped glycan structures will be covered as well as platelet desialylation in inherited glycan disorders and induced by external neuraminidases.

Neuraminidases are released from platelet intracellular stores and translocated to the platelet surface. Apart from clearance, loss of surface sialic acid by neuraminidases ('desialylation') affects platelet signaling including ligand binding and their procoagulant function. Platelets are also desialylated in infections, various mutations, presence of platelet auto antibodies.

Since platelet desialylation occurs in various healthy and pathological conditions, measuring desialylation might be a new diagnostic tool.

Clearance of airway secretions and treatment of respiratory tract infections (RTIs) are two common problems caregivers face in the neonatal intensive care unit (NICU). Mucolytics degrade crosslinks in mucus gel, reducing mucus viscosity and facilitating their removal by cough or endotracheal suctioning. While such medications have been studied in older children and adults, their use is not as well described in the NICU. For RTIs, systemic antibiotics are usually prescribed, although their use is often associated with adverse effects. Inhaled antibiotics may provide increased drug concentrations to the infected airways while minimizing systemic toxicity. The use of inhaled antibiotics in the NICU has been described in small case series. As underlying physiologic differences will lend to inaccuracies when extrapolating data obtained from older children, there is an urgent need to determine the safety, efficacy, and optimal dosing of inhaled mucolytics and antibiotics in infants of varying gestational and post-natal ages.

Eosinophilic chronic rhinosinusitis (ECRS), a CRS with nasal polyps (CRSwNP), is characterized by eosinophilic infiltration with type 2 inflammation and is highly associated with bronchial asthma. Intractable ECRS with poorly controlled asthma is recognized as a difficult-to-treat eosinophilic airway inflammation. Although eosinophils are activated and coincubation with airway epithelial cells prolongs their survival, the interaction mechanism between eosinophils and epithelial cells is unclear. This study examined the effect of eosinophils on mucin glycoprotein 1 (MUC1), a member of membrane-bound mucin, in the airway epithelial cells, to elucidate the mechanisms of the eosinophil-airway epithelial cell interaction. Nasal polyp samples from patients with CRSwNP and BEAS-2B airway epithelial cells, coincubated with purified eosinophils, were stained with two MUC1 antibodies. To confirm the involvement of CCL4, an anti-CCL4 neutralizing antibody or recombinant CCL4 was used as needed. The immunofluorescence results revealed a negative correlation between the expression of full-length MUC1 and eosinophil count in nasal polyps. In BEAS-2B coincubated with eosinophils, full-length MUC1, but not the C-terminal domain, was reduced, and eosinophil survival was prolonged, which was concomitant with CCL4 increase, whereas the anti-CCL4 neutralizing antibody decreased these reactions. The survival of eosinophils that contacted recombinant MUC1 without the N-terminal domain was prolonged, and recombinant CCL4 increased the expression of metalloproteases. Increased CCL4 induces the contact between eosinophils and airway epithelial cells by shedding the MUC1 N-terminal domain and enhances eosinophil survival in eosinophilic airway inflammation. This novel mechanism may be a therapeutic target for difficult-to-treat eosinophilic airway inflammation.

Using primary airway epithelial cells (AEC) is essential to mimic more closely different types and stages of lung disease in humans while reducing or even replacing animal experiments. Access to lung tissue remains limited because these samples are generally obtained from patients who undergo lung transplantation for end-stage lung disease or thoracic surgery for (mostly) lung cancer. We investigated whether forceps or cryo biopsies are a viable alternative source of AEC compared to the conventional technique.

AECs were obtained ex vivo from healthy donor lung tissue using the conventional method and two biopsy procedures (forceps, cryo). The influence of the isolation method on the quality and function of AEC was investigated at different time-points during expansion and differentiation in air-liquid interface cultures. In addition, fully-differentiated AECs were stimulated with house dust mite extract (HDM) to allow functional analyses in an allergic in vitro model. Vitality or differentiation capacity were determined using flow cytometry, scanning electron microscope, periodic acid-Schiff reaction, immunofluorescence staining, and proteomics.

As anticipated, no significant differences between each of the sampling methods were detected for any of the measured outcomes. The proteome composition was comparable for each isolation method, while donor-dependent effects were observed. Treatment with HDM led to minor differences in mucociliary differentiation.

Our findings confirmed the adequacy of these alternative approaches for attaining primary AECs, which can now expand the research for a broader range of lung diseases and for studies at an earlier stage not requiring lung surgery.

Mucins 5AC (MUC5AC) and 5B (MUC5B) are the major mucins providing the organizing framework for the airway's mucus gel. We retrieved bronchial mucosal biopsies and bronchial wash (BW) samples through bronchoscopy from patients with chronic obstructive pulmonary disease (n = 38), healthy never-smokers (n = 40), and smokers with normal lung function (n = 40). The expression of MUC5AC and MUC5B was assessed immunohistochemically. The mucin concentrations in BW were determined using the slot-blot technique. The immunohistochemical expression of MUC5AC and MUC5B was localized to goblet cells and submucosal glands. Smokers had higher MUC5AC and lower MUC5B goblet cell expression and higher concentrations of soluble MUC5AC in BW than never-smokers. The MUC5B expression in goblet cells correlated positively with expiratory air flows, diffusing capacity, and the dyspnoea score. Chronic bronchitis, emphysema, and the progression of chronic airflow limitation during a median follow-up time of 8.4 years were associated with higher MUC5AC and lower MUC5B expression in goblet cells. Sustainers, slow progressors, and rapid progressors of airflow obstruction differed in their MUC5B expression at baseline. Emphysema and bronchial wall thickening on CT at a follow-up visit were associated with lower MUC5B expression at baseline. Our findings strengthen the hypothesis that MUC5AC and MUC5B are yet another contributing factor to smoking-associated lung disease progression.

Inflammatory bowel disease is triggered by abnormalities in epithelial barrier function and immunological responses, although its pathogenesis is poorly understood. The dextran sodium sulphate (DSS)-induced colitis model has been used to examine inflammation in the colon. Damage to mucosa primality occurs in the large intestine and scarcely in the small intestine. To evaluate the effect on the ileum, we histologically analyzed the inflammatory and recovery phases in DSS model mice, and 40 kDa FITC-dextran was used to investigate barrier function. In the inflammatory phase, histological damage was insignificant. However, expanded crypts, hypertrophic goblet and Paneth cells, increased mucus production and secretion were observed. The cellular morphology was restored to that of the control in the recovery phase. According to in situ hybridization and lectin histochemistry, the expression of intestinal stem cell markers, secretory cell differentiation factors, and glycosylation of secretory granules in Paneth cells differed in the DSS model. DSS-treatment did not influence the barrier function in the ileum, and FITC-dextran did not diffuse via the paracellular pathway into the mucosa. However, cells incorporating FITC appeared even under normal conditions. The number of FITC-positive Paneth cells was lower in the DSS group than the control group. Our results showed morphological and functional alterations in ileal epithelial cells, especially secretory cells, in the DSS colitis model.

Natural and synthetic biopolymers are gaining popularity in the development of inhaled drug formulations. Their highly tunable properties and ability to sustain drug release allow for the incorporation of attributes not achieved in dry powder inhaler formulations composed only of micronized drugs, standard excipients, and/or carriers. There are multiple physiological barriers to the penetration of inhaled drugs to the epithelial surface, such as the periciliary layer mucus mesh, pulmonary macrophages, and inflammation and mucus compositional changes resulting from respiratory diseases. Biopolymers may facilitate transport to the epithelial surface despite such barriers. A variety of categories of biopolymers have been assessed for their potential in inhaled drug formulations throughout the research literature, ranging from natural biopolymers (e.g., chitosan, alginate, hyaluronic acid) to those synthesized in a laboratory setting (e.g., polycaprolactone, poly(lactic-co-glycolic acid)) with varying structures and compositions. To date, no biopolymers have been approved as a commercial dry powder inhaler product. However, advances may be possible in the treatment of respiratory diseases and infections upon further investigation and evaluation. Herein, this review will provide a thorough foundation of reported research utilizing biopolymers in dry powder inhaler formulations. Furthermore, insight and considerations for the future development of dry powder formulations will be proposed.

Asian sand dust (ASD), a seasonal dust storm originating from the deserts of China and Mongolia, affects Korea and Japan during the spring, carrying soil particles and a variety of biochemical components. Exposure to ASD has been associated with the onset and exacerbation of respiratory disorders, although the underlying mechanisms remain unclear. This study investigates ASD-induced pulmonary toxicity and its mechanistic pathways, focusing on the role of thioredoxin-interacting protein (TXNIP). Using TXNIP knock-out (KO) mice and adeno-associated virus (AAV)-mediated TXNIP overexpression transgenic mice, we explored how TXNIP modulates ASD-induced pulmonary inflammation. Mice were exposed to ASD via intranasal administration on days 1, 3, and 5 to induce inflammation. ASD exposure led to significant pulmonary inflammation, evidenced by increased inflammatory cell counts and elevated cytokine levels in bronchoalveolar lavage fluid, as well as heightened protein expression of the TXNIP/NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome. TXNIP KO mice exhibited attenuated airway inflammation and downregulation of the NLRP3 inflammasome compared to wild-type controls, while AAV-mediated TXNIP overexpression mice showed exacerbated inflammatory responses, including elevated NLRP3 inflammasome expression, compared to AAV-GFP controls. These findings suggest that TXNIP is a key regulator of ASD-induced pulmonary inflammation.

To evaluate the phytobiotic effect of Anacardium occidentale leaf powder (AOLP) on growth performance, diarrhea incidence, blood biochemistry, and intestinal traits, seventy-two weaned piglets were randomly distributed into four groups (six replicates/group and three pigs/replicate) for 28 days, receiving a control diet (T0) or being supplemented with 5 (T1), 10 (T2), or 15 (T3) g/kg of AOLP. The diets did not affect the growth performance (p > 0.05); however, the AOLP groups had a decreased diarrhea incidence and malondialdehyde concentration (p < 0.05; 28 days). However, the AOLP groups had increased immunoglobulins (G and M) and villus heights (p < 0.05) in the duodenum. Likewise, T3 improved the number of goblet cells in the villi and the whole intestine (p < 0.01), the Mucin2 area in the jejunum and ileum (p < 0.05), occludin gene expression in the jejunum (p < 0.01), and acetic and valeric acid production (p < 0.05). Microbial diversity at the genus level was not different (p > 0.05); however, T3 increased the abundance of the Lactobacillus genus. These findings suggest that dietary supplementation with AOLP improved intestinal health by increasing antioxidant, immune, anti-inflammatory, and antidiarrheal activity in the weaned piglets.

Inositol-requiring enzyme 1 (IRE1), a mediator of the unfolded protein response, shows the highest degree of evolutionary conservation. Vertebrates express two IRE1 paralogs: IRE1α, which is universally expressed and IRE1β, which shows specific expression within mucus secreted cells in respiratory and gastrointestinal tracts. The biological properties and regulation of the two IRE1 duplicates show evolutionary differences. As recently suggested, IRE1β-deficient mice display impairment in secreted protein expression and mucosal homeostasis. Abnormal changes in IRE1β caused by external and internal factors can disrupt mucosal homeostasis and further lead to respiratory and gastrointestinal diseases. Here, we highlight the physiological functions of IRE1β in the respiratory and gastrointestinal tracts in response to environmental microbes, viruses, toxins, and food components.

Rotavirus (RV) is a major cause of diarrhea in young children and animals, especially piglets, leading to substantial economic losses in the global pig industry. Isoleucine (Ile), a branched-chain amino acid, plays an important role in regulating nutrient metabolism and has been shown to improve diarrhea. This study aimed to evaluate the effects of Ile supplementation on the mucosal immune barrier of the small intestine in RV-infected weaned piglets.

Forty-eight 21-day-old weaned piglets were randomly divided into three dietary treatments (each treatment was subdivided into two groups, eight replicates per group), with 0%, 0.5%, or 1% Ile added for 15 days, and then, one group from each treatment was challenged with RV.

The results showed that 1% Ile added to the diet promoted the healthy development of the intestinal mucosa. Ile could restore the reduced villus height in the ileum and the goblet cell number in the duodenum and ileum to normal levels, improving the intestinal epithelial tight junctions in RV-infected piglets. Additionally, Ile increased the activity of lipase, amylase, and sucrase, as well as superoxide dismutase (SOD) and glutathione (GSH), along with the expression of SIgA, DEFβ1, and DEFβ2 in parts of the small intestine.

The addition of Ile to the diet mitigated the effects of RV infection on intestinal morphology and mucosal barrier function, as well as the physiological functions of weaned piglets, and improved the antioxidant and immune functions of the piglets to some extent. These findings offer valuable insights, contributing to a deeper understanding of the role of Ile in supporting intestinal health.

In cystic fibrosis, the airway gel-forming mucin MUC5B accumulates in the airways, preventing clearance of pathogens like Pseudomonas aeruginosa (PA). The cystic fibrosis transmembrane conductance regulator (CFTR)-/- (KO) rat model exhibits a similar accumulation of Muc5b. Our lab has shown that increased Muc5b precipitates the development of chronic PA infection. We hypothesized that reducing Muc5b in the KO rat airway would prevent occlusive mucus plugs and development of persistent PA infection. Six-month-old KO rats received Muc5b or scramble siRNA via intratracheal instillation. Rats were then inoculated with 106 colony-forming units of mucoid P. aeruginosa isolate PAM57-15 and euthanized at 3- or 14-days post infection (dpi) to assess acute and persistent infection. At 14 dpi, Muc5b siRNA-treated KO rats had increased weight, decreased neutrophilic inflammation, and reduced mucus plugging in the small airways compared with scramble-treated KO and WT rats. These results indicate that pharmacological intervention of Muc5b reduces mucus plugging during persistent PA infection.NEW & NOTEWORTHY Although highly effective modulator therapies for cystic fibrosis (CF) have improved mucus-related outcomes of disease for people with CF, eradication of Pseudomonas aeruginosa (PA) infection has not been achieved in this population. In addition, current therapies for CF do not target mucin hypersecretion directly. Here, we show that a novel approach of normalizing airway Muc5b hypersecretion ameliorates infection-induced mucus plugging and neutrophilic inflammation during persistent PA infection in CFTR-/- rats.

To observe the complications and inflammatory responses caused by the different types of metal stents in the trachea of rabbits.

79 rabbits were randomly divided into 4 groups and were implanted with the customized nickel-titanium alloy metal stents(fully covered metal stent: group A, bare metal stent: group B, segmented covered metal stent: group C and control group: group D). The complications (tracheal deformation, granulation tissue hyperplasia, scar hyperplasia and secretion retention) of different types of metal stents were compared by observing the anatomical and pathological specimens of dead rabbits; And the expression of inflammatory factors of different types of metal stents were compared by detecting the tissue of tracheas of dead rabbits.

(1)There were significant differences in the above four complications among groups A, B and C(p < 0.01). The incidences of tracheal deformation, scar hyperplasia and secretion retention in group A were significantly higher than that in group B(p < 0.0167), however, the incidence of granulation tissue hyperplasia in group A was significantly lower than that in group B(p < 0.0167). The incidence of scar hyperplasia in group A was significantly lower than that in group C(p < 0.0167) and there were no significant differences in other complications between these two groups(p > 0.0167). The incidences of tracheal deformation, scar hyperplasia and secretion retention in group B were significantly lower than that in group C(p < 0.0167), however, the incidence of granulation tissue hyperplasia in group B was significantly higher than that in group C(p < 0.0167). (2)The concentration of IL-1β in group A was higher than that in group B (p < 0.05 and foldchange>1.2).

(1)There are significant differences in complications between the fully covered metal stent, bare metal stent and segmented covered metal stent; the incidences of complications between the segmented covered metal stent and fully covered metal stent are similar. (2)Changes in different inflammatory factors can be observed between the fully covered and bare metal stent.

The challenge of the treatment of end-stage lung disease poses an urgent clinical demand for lung tissue engineering. Over the past few years, various lung tissue-engineered constructs are developed for lung tissue regeneration and respiratory pathology study. In this review, an overview of recent achievements in the field of lung tissue engineering is proposed. The introduction of lung structure and lung injury are stated briefly at first. After that, the lung tissue-engineered constructs are categorized into three types: acellular, monocellular, and multicellular systems. The different bioengineered constructs included in each system that can be applied to the reconstruction of the trachea, airway epithelium, alveoli, and even whole lung are described in detail, followed by the highlight of relevant representative research. Finally, the challenges and future directions of biomaterials, manufacturing technologies, and cells involved in lung tissue engineering are discussed. Overall, this review can provide referable ideas for the realization of functional lung regeneration and permanent lung substitution.

Although research on the role of iron in host immunity has a history spanning decades, it is only relatively recently that attention has been directed toward the biological effects of iron on the intestinal mucus layer, prompted by an evolving understanding of the role of this material in immune defense. The mucus layer, secreted by intestinal goblet cells, covers the intestinal epithelium, and given its unique location, interactions between the host and gut microbiota, as well as among constituent microbiota, occur frequently within the mucus layer. Iron, as an essential nutrient for the vast majority of life forms, regulates immune responses from both the host and microbial perspectives. In this review, we summarize the iron metabolism of both the host and gut microbiota and describe how iron contributes to intestinal mucosal homeostasis via the intestinal mucus layer with respect to both host and constituent gut microbiota. The findings described herein offer a new perspective on iron-mediated intestinal mucosal barrier function.

Mucus clearance is crucial for airway protection, and its dysfunction leads to chronic obstructive pulmonary disease (COPD) characterized by mucus hypersecretion (MHS) and impaired clearance. MUC5AC and MUC5B mucin proteins are key components of airway mucus, with MUC5AC being particularly responsive to environmental stimuli, making it a potential COPD biomarker. N-acetylcysteine (NAC) is a mucolytic agent with known effects on mucus viscosity and clearance, but its precise mechanisms in COPD remain unclear. This systematic review evaluated the impact of NAC on MHS in the airways, reporting significant inhibitory effects on MUC5AC and MUC5B gene and protein expression, as well as a reduction in the number of goblet cells. NAC has demonstrated efficacy in vitro and in animal models of MHS, including COPD models, but data on human bronchial tissue are lacking. This systematic review suggests that NAC acts as a mucolytic and a mucoregulator, directly inhibiting mucus secretion and goblet cell hyperplasia. Given the critical role of MHS in COPD progression, exacerbations, and mortality, these findings highlight the potential of NAC as a targeted therapy for hypersecretion COPD phenotypes. However, further studies are needed to confirm the results of this systematic review, even in human bronchial tissue, to provide translatable evidence in clinical settings. Understanding the intimate mechanism of NAC versus MHS regulation may pave the way for more effective treatments targeting airway mucus dysfunction in COPD, ultimately improving patient outcomes and reducing morbidity and mortality associated with chronic mucus hypersecretion.

Artemisia argyi polysaccharide (AAP) is a homogeneous polysaccharide with a molecular weight of 16 kDa, displaying anti-inflammatory, antioxidant, and anti-tumorigenic properties, and potential protective effects on intestinal barrier function. It is anticipated to serve as an efficient component in diarrhea treatment. This study aims to examine the impact of AAP on diarrhea severity, intestinal barrier function, and inflammation in diarrhea-induced rats. The results demonstrated that AAP treatment notably decreased the incidence of diarrhea, reduced its severity, and lowered the disease activity score in rats, while also increasing body weight. Oral administration of AAP augmented goblet cell counts and elevated mucin-2 expression, aiding in the restoration of the mucus barrier. Additionally, AAP treatment enhanced colonic microbial diversity by increasing the abundance of S24-7 and Lactobacillus, while decreasing the levels of Bacteroides, Clostridium, and Sutterella. Moreover, the AAP administration elevated the levels of steroid hormones, prostaglandins, and their derivatives. By inhibiting the TLR4/MyD88/NF-κB pathway, AAP mitigated the release of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and increased the secretion of anti-inflammatory factor (IL-10). Overall, oral AAP administration effectively combats osmotic diarrhea by fortifying mucus barrier integrity and exerting anti-inflammatory effects, suggesting its potential use as an adjunctive agent in oral rehydration therapy.

Hydrogen peroxide (H2O2), a novel water treatment agent, can be used for disinfection, water quality adjustment, and disease prevention, while excessive H2O2 can injure farm animals, even leading to death. Hydrogen peroxide is a recommended disinfectant and bactericide for treating gill diseases and vibriosis in the greenfin horse-faced filefish Thamnaconus septentrionalis. However, its cumulative effect, toxic molecular mechanism and relevant signal transduction/metabolic networks in marine fishes are largely unknown.

We employed a multi-omics approach to investigate the detrimental effects of 50 mg/L H2O2 exposure (2 h/d) on filefish for 2 d, 4 d, and 6 d. Transcriptome sequencing showed that differentially expressed genes (DEGs) were mainly classified into functions such as signal transduction, nervous system, liver and bile acid metabolism, energy metabolism, cell adhesion and communication, inflammation and immune response. Metabolomic analysis found that the significantly changed metabolites (SCMs) were involved in phenylalanine metabolism, inflammatory mediator regulation, linoleic acid metabolism, and necroptosis. The main SCMs were cholic acid, carnitine C12:1, dimethylmalonic acid, glutamic acid, L-lactic acid, shikimic acid, 2-methylsuccinic acid, and others. Moreover, H2O2-induced oxidative stress also disturbs the balance of the gut microbiota, altering the microbial composition and affecting digestive processes.

Integrated multiomics analysis revealed that H2O2-induced detrimental impacts include mucosal damage, inflammatory and immune responses, altered energy metabolism, and gut microbiota disorders. These findings offer novel insights into the harmful effects and signal transduction/metabolic pathways triggered by H2O2 exposure in marine fishes.

Indole, a compound in Chinese stinky tofu (ST), acts as a ligand for the aryl hydrocarbon receptor (AHR). Despite extensive research on prebiotic compounds, indole's specific role in ST remains unexplored. This study used an ethanol gavage method to create an ALD (alcoholic liver disease) mouse model and investigate dietary indole's effects on the intestinal barrier. Our findings indicate that after 6 weeks of being fed ST, the indole present (2 mg/day) robustly activated the intestinal AHR, upregulating its target gene, CYP1A1 (cytochrome P450 1A1 enzyme). This activation significantly reduced intestinal permeability, mitigated alcohol-induced oxidative stress and inflammation, and restored intestinal barrier function. Consequently, the study demonstrates that foodborne indole substantially reduces alcohol absorption and lowers the expression levels of liver inflammation-related factors, thereby slowing the progression of ALD. These results highlight indole's therapeutic potential for treating ALD and its role in developing functional foods.

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.

Airway mucus hypersecretion, a crucial pathological feature of chronic obstructive pulmonary disease (COPD), contributes to the initiation, progression, and exacerbation of this disease. As a macromolecular mucin, the secretory behaviour of Mucin5AC (MUC5AC) is highly dependent on a series of modifying and folding processes that occur in the endoplasmic reticulum (ER). In this study, we focused on the ER quality control protein KDEL receptor (KDELR) and demonstrated that KDELR2 and MUC5AC were colocalized in the airway epithelium of COPD patients and COPD model rats. In addition, knockdown of KDELR2 markedly reduced the expression of MUC5AC both in vivo and in vitro and knockdown of ATF6 further decreased the levels of KDELR2. Furthermore, pretreatment with 4μ8C, an IRE1α inhibitor, led to a partial reduction in the expression of KDELR2 and MUC5AC both in vivo and in vitro, which indicated the involvement of IRE1α/XBP-1s in the upstream signalling cascade. Our study revealed that KDELR2 plays a crucial role in airway MUC5AC hypersecretion in COPD, which might be dependent on ATF6 and IRE1α/XBP-1s upstream signalling.