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1.
Iran J Allergy Asthma Immunol ; 21(2): 119-127, 2022 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-35490266

RESUMO

Asthma is a respiratory disease; involving millions of people worldwide. The main cause of asthma is allergy and immune response dysregulation. The effects of azithromycin and doxycycline as asthma-controlling drugs were evaluated in this study. Mice asthma model was produced and asthmatic mice were treated with azithromycin (75 mg/kg, orally) and doxycycline (20 mg/kg, orally). Eosinophils and neutrophils count, interleukin (IL)-4, IL-5, IL-12, IL-13, and total immunoglobulin E (IgE) levels were measured. Histological study and evaluating the genes expression of Muc5ac, Muc5b, IL-33, COX2, MYD88, and TRAF6 were performed. Azithromycin and doxycycline did not affect eosinophil and neutrophil percentage, IL-4, IL-5, IL-12, and total IgE levels, peribronchial and perivascular inflammation, goblet cell hyperplasia, and gene expression of MYD88, TRAF6, and COX2. Treatment with azithromycin significantly decreased IL-13 level, mucus secretion, and gene expression of IL-33, Muc5ac, and Muc5b; compared to the non-treated asthma group. Azithromycin administration controls mucus secretion and inflammation. Azithromycin therapy and not doxycycline might be an effective adjuvant option in asthma with reducing mucus in the airway.


Assuntos
Asma , Azitromicina , Animais , Azitromicina/farmacologia , Azitromicina/uso terapêutico , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Doxiciclina/farmacologia , Doxiciclina/uso terapêutico , Humanos , Imunoglobulina E/metabolismo , Inflamação/tratamento farmacológico , Interleucina-12 , Interleucina-13/metabolismo , Interleucina-13/uso terapêutico , Interleucina-33 , Interleucina-5/metabolismo , Interleucina-5/uso terapêutico , Camundongos , Muco/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Transdução de Sinais , Fator 6 Associado a Receptor de TNF
2.
Sci Adv ; 8(13): eabm9718, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35363522

RESUMO

Cystic fibrosis (CF) is characterized by abnormal transepithelial ion transport. However, a description of CF lung disease pathophysiology unifying superficial epithelial and submucosal gland (SMG) dysfunctions has remained elusive. We hypothesized that biophysical abnormalities associated with CF mucus hyperconcentration provide a unifying mechanism. Studies of the anion secretion-inhibited pig airway model of CF revealed elevated SMG mucus concentrations, osmotic pressures, and SMG mucus accumulation. Human airway studies revealed hyperconcentrated CF SMG mucus with raised osmotic pressures and cohesive forces predicted to limit SMG mucus secretion/release. Using proline-rich protein 4 (PRR4) as a biomarker of SMG secretion, CF sputum proteomics analyses revealed markedly lower PRR4 levels compared to healthy and bronchiectasis controls, consistent with a failure of CF SMGs to secrete mucus onto airway surfaces. Raised mucus osmotic/cohesive forces, reflecting mucus hyperconcentration, provide a unifying mechanism that describes disease-initiating mucus accumulation on airway surfaces and in SMGs of the CF lung.


Assuntos
Fibrose Cística , Animais , Fibrose Cística/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Muco/metabolismo , Sistema Respiratório/metabolismo , Escarro/metabolismo , Suínos
3.
Sci Rep ; 12(1): 5515, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35365684

RESUMO

The human mucus layer plays a vital role in maintaining health by providing a physical barrier to pathogens. This biological hydrogel also provides the microenvironment for commensal bacteria. Common models used to study host-microbe interactions include gnotobiotic animals or mammalian-microbial co-culture platforms. Many of the current in vitro models lack a sufficient mucus layer to host these interactions. In this study, we engineered a mucus-like hydrogel Consisting of a mixed alginate-mucin (ALG-MUC) hydrogel network by using low concentration calcium chloride (CaCl2) as crosslinker. We demonstrated that the incorporation of ALG-MUC hydrogels into an aqueous two-phase system (ATPS) co-culture platform can support the growth of a mammalian monolayer and pathogenic bacteria. The ALG-MUC hydrogels displayed selective diffusivity against macromolecules and stability with ATPS microbial patterning. Additionally, we showed that the presence of mucin within hydrogels contributed to an increase in antimicrobial resistance in ATPS patterned microbial colonies. By using common laboratory chemicals to generate a mammalian-microbial co-culture system containing a representative mucus microenvironment, this model can be readily adopted by typical life science laboratories to study host-microbe interaction and drug discovery.


Assuntos
Interações entre Hospedeiro e Microrganismos , Muco , Alginatos/química , Animais , Hidrogéis/química , Mamíferos/metabolismo , Mucinas/metabolismo , Muco/metabolismo
4.
Gut Microbes ; 14(1): 2052699, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35380912

RESUMO

Over the past two decades, our appreciation of the gut mucus has moved from a static lubricant to a dynamic and essential component of the gut ecosystem that not only mediates the interface between host tissues and vast microbiota, but regulates how this ecosystem functions to promote mutualistic symbioses and protect from microbe-driven diseases. By delving into the complex chemistry and biology of the mucus, combined with innovative in vivo and ex vivo approaches, recent studies have revealed novel insights into the formation and function of the mucus system, the O-glycans that make up this system, and how they mediate two major host-defense strategies - resistance and tolerance - to reduce damage caused by indigenous microbes and opportunistic pathogens. This current review summarizes these findings by highlighting the emerging roles of mucus and mucin-type O-glycans in influencing host and microbial physiology with an emphasis on host defense strategies against bacteria in the gastrointestinal tract.


Assuntos
Microbioma Gastrointestinal , Microbiota , Glicosilação , Mucosa Intestinal/microbiologia , Mucinas/metabolismo , Muco/metabolismo , Simbiose
5.
FASEB J ; 36(5): e22297, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35394686

RESUMO

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder for which dietary interventions can be a useful treatment. In recent years, the low-FODMAP approach is gaining traction in this regard. The fermentation of these non-absorbed carbohydrates by the gut microbiota can generate toxic glycating metabolites, such as methylglyoxal. These metabolites can have harmful effects by their role in the generation of advanced glycation end products (AGEs), which activates Receptor for AGEs (AGER). Mast cells can be stimulated by AGEs and play a role in IBS. We have treated mice with lactose or fructo-oligosaccharides (FOS), with or without co-administration of pyridoxamine and investigated the colonic mucus barrier. We have found that an increased intake of lactose and fructo-oligosaccharides induces a dysregulation of the colonic mucus barrier, increasing mucus discharge in empty colon, while increasing variability and decreasing average thickness mucus layer covering the fecal pellet. Changes were correlated with increased mast cell counts, pointing to a role for the crosstalk between these and goblet cells. Additionally, AGE levels in colonic epithelium were increased by treatment with the selected fermentable carbohydrates. Observed effects were prevented by co-treatment with anti-glycation agent pyridoxamine, implicating glycation processes in the negative impact of fermentable carbohydrate ingestion. This study shows that excessive intake of fermentable carbohydrates can cause colonic mucus barrier dysregulation in mice, by a process that involves glycating agents and increased mucosal mast cell counts.


Assuntos
Síndrome do Intestino Irritável , Animais , Contagem de Células , Lactose/farmacologia , Camundongos , Muco/metabolismo , Oligossacarídeos/metabolismo , Piridoxamina
6.
Sci Rep ; 12(1): 6153, 2022 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35418571

RESUMO

Cyclic peptides are good candidates for orally delivered therapeutics, however, issues remain in their development due to low intestinal permeability. Although some of the biological factors have been reported that regulate intestinal permeation of cyclic peptides, the influence of the mucus barrier, a major hurdle to epithelial drug delivery, on cyclic peptide bioavailability is unclear. In this study, we show that the lipophilic cyclic peptide, cyclosporin A (CsA), interacted with, and likely induced aggregation, of polymeric, gel-forming mucins (MUC2, MUC5AC and MUC5B) which underpin the mucus gel-networks in the gastrointestinal tract. Under similar conditions, two other cyclic peptides (daptomycin and polymyxin B) did not cause mucin aggregation. Using rate-zonal centrifugation, purified MUC2, MUC5AC and MUC5B mucins sedimented faster in the presence of CsA, with a significant increase in mucins in the pellet fraction. In contrast, mucin sedimentation profiles were largely unaltered after treatment with daptomycin or polymyxin B. CsA increased MUC5B sedimentation was concentration-dependent, and sedimentation studies using recombinant mucin protein domains suggests CsA most likely causes aggregation of the relatively non-O-glycosylated N-terminal and C-terminal regions of MUC5B. Furthermore, the aggregation of the N-terminal region, but not the C-terminal region, was affected by pH. CsA has partially N-methylated amide groups, this unique molecular structure, not present in daptomycin and polymyxin B, may potentially be involved in interaction with gel-forming mucin. Taken together, our results indicate that the interaction of gel-forming mucins with the cyclic peptide CsA is mediated at the N- and C-terminal domains of mucin polymers under physiological conditions. Our findings demonstrate that the mucus barrier is an important physiological factor regulating the intestinal permeation of cyclic peptides in vivo.


Assuntos
Ciclosporina , Daptomicina , Ciclosporina/metabolismo , Ciclosporina/farmacologia , Mucina-5AC/metabolismo , Mucina-2/metabolismo , Mucina-5B/metabolismo , Muco/metabolismo , Peptídeos Cíclicos/metabolismo , Polimixina B
7.
Eur J Pharm Biopharm ; 174: 106-110, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35364256

RESUMO

Porcine intestinal mucus (PIM) is often utilized as an ex vivo mucus model in mucus interaction studies. However, numerous isolation procedures and storage conditions for PIM are reported, yet their potential impact on preserving the critical properties of PIM remains unknown. This study investigated the effect of isolation procedures (rinsing and anatomical site of mucus isolation) and storage conditions (-20 °C, -80 °C, snap frozen in li-quid nitrogen prior to storage at -80 °C, or freeze-dried followed by storage at room temperature and reconstitution) of PIM in regard to the permeation of fluorescein-isothiocyanate-labelled dextran (FD) macromolecules of 4, 40 and 150 kDa, rheological properties as well as pH, osmolality, protein and water content. Rinsing intestines with tap water or phosphate-buffered saline as well as isolating PIM from different regions of the first five meters of the proximal jejunum did not affect the pH or osmolality of isolated PIM. The permeation of FD4, FD40 and FD150 through stored PIM was similar to permeation through fresh PIM. The rheological properties of stored PIM were similar to properties of fresh PIM. Osmolality, protein and water content were similar in stored and fresh PIM whereas pH decreased with 0.3 unit for all stored PIM. Overall, PIM samples stored at -20 °C, -80 °C, snap frozen or freeze-dried were found to have similar properties to freshly isolated PIM and can all be consi-dered good alternatives to fresh PIM for mucus studies.


Assuntos
Intestinos , Muco , Animais , Congelamento , Muco/metabolismo , Permeabilidade , Proteínas/metabolismo , Suínos , Água/metabolismo
8.
Ecotoxicol Environ Saf ; 236: 113428, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35366562

RESUMO

The objective of this study was to characterize vitellogenin (VTG) protein in male fathead minnow (Pimephales promelas) mucus compared with more conventional measures in plasma and mRNA isolated from liver. To assess the intensity and duration of changes in mucus VTG concentrations, male fathead minnows were exposed to 17α-ethinylestradiol (EE2) for 7 days with a subsequent depuration period of 14 days. The experiment was conducted in a flow-through system to maintain a consistent concentration of EE2 at a nominal EC50 concentration of 2.5 ng/L and high concentration of 10 ng/L as a positive control. Mucus, plasma and liver were sampled at regular intervals throughout the study. Relative abundance of vtg mRNA increased after 2 days of exposure and returned to control levels after 4 days of depuration. VTG protein concentration displayed similar induction kinetics in both mucus and plasma, however, it was found to be significantly increased after 2 days of exposure using the mucus-based assays and 7 days with the plasma-based assay. Significantly elevated levels of VTG were detected by both assays throughout the 14-day depuration period. The elimination of the laborious plasma collection step in the mucus-based workflow allowed sampling of smaller organisms where blood volume is limiting. It also resulted in significant gains in workflow efficiency, decreasing sampling time without loss of performance.


Assuntos
Cyprinidae , Vitelogeninas , Animais , Cyprinidae/metabolismo , Fígado/metabolismo , Masculino , Muco/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Vitelogeninas/metabolismo
9.
Nat Commun ; 13(1): 1632, 2022 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-35347136

RESUMO

To identify genetic determinants of airway dysfunction, we performed a transcriptome-wide association study for asthma by combining RNA-seq data from the nasal airway epithelium of 681 children, with UK Biobank genetic association data. Our airway analysis identified 95 asthma genes, 58 of which were not identified by transcriptome-wide association analyses using other asthma-relevant tissues. Among these genes were MUC5AC, an airway mucin, and FOXA3, a transcriptional driver of mucus metaplasia. Muco-ciliary epithelial cultures from genotyped donors revealed that the MUC5AC risk variant increases MUC5AC protein secretion and mucus secretory cell frequency. Airway transcriptome-wide association analyses for mucus production and chronic cough also identified MUC5AC. These cis-expression variants were associated with trans effects on expression; the MUC5AC variant was associated with upregulation of non-inflammatory mucus secretory network genes, while the FOXA3 variant was associated with upregulation of type-2 inflammation-induced mucus-metaplasia pathway genes. Our results reveal genetic mechanisms of airway mucus pathobiology.


Assuntos
Asma , Transcriptoma , Asma/genética , Asma/metabolismo , Criança , Epitélio/metabolismo , Humanos , Metaplasia/metabolismo , Mucina-5AC/genética , Mucina-5AC/metabolismo , Muco/metabolismo
10.
J Clin Invest ; 132(8)2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35239513

RESUMO

The respiratory tract surface is protected from inhaled pathogens by a secreted layer of mucus rich in mucin glycoproteins. Abnormal mucus accumulation is a cardinal feature of chronic respiratory diseases, but the relationship between mucus and pathogens during exacerbations is poorly understood. We identified elevations in airway mucin 5AC (MUC5AC) and MUC5B concentrations during spontaneous and experimentally induced chronic obstructive pulmonary disease (COPD) exacerbations. MUC5AC was more sensitive to changes in expression during exacerbation and was therefore more predictably associated with viral load, inflammation, symptom severity, decrements in lung function, and secondary bacterial infections. MUC5AC was functionally related to inflammation, as Muc5ac-deficient (Muc5ac-/-) mice had attenuated RV-induced (RV-induced) airway inflammation, and exogenous MUC5AC glycoprotein administration augmented inflammatory responses and increased the release of extracellular adenosine triphosphate (ATP) in mice and human airway epithelial cell cultures. Hydrolysis of ATP suppressed MUC5AC augmentation of RV-induced inflammation in mice. Therapeutic suppression of mucin production using an EGFR antagonist ameliorated immunopathology in a mouse COPD exacerbation model. The coordinated virus induction of MUC5AC and MUC5B expression suggests that non-Th2 mechanisms trigger mucin hypersecretion during exacerbations. Our data identified a proinflammatory role for MUC5AC during viral infection and suggest that MUC5AC inhibition may ameliorate COPD exacerbations.


Assuntos
Mucina-5AC , Doença Pulmonar Obstrutiva Crônica , Trifosfato de Adenosina/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Inflamação/metabolismo , Camundongos , Mucina-5AC/genética , Mucina-5AC/metabolismo , Mucina-5B/genética , Mucina-5B/metabolismo , Muco/metabolismo , Doença Pulmonar Obstrutiva Crônica/metabolismo , Doença Pulmonar Obstrutiva Crônica/virologia , Mucosa Respiratória/metabolismo , Mucosa Respiratória/patologia
11.
Cell ; 185(7): 1172-1188.e28, 2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-35303419

RESUMO

Intestinal mucus forms the first line of defense against bacterial invasion while providing nutrition to support microbial symbiosis. How the host controls mucus barrier integrity and commensalism is unclear. We show that terminal sialylation of glycans on intestinal mucus by ST6GALNAC1 (ST6), the dominant sialyltransferase specifically expressed in goblet cells and induced by microbial pathogen-associated molecular patterns, is essential for mucus integrity and protecting against excessive bacterial proteolytic degradation. Glycoproteomic profiling and biochemical analysis of ST6 mutations identified in patients show that decreased sialylation causes defective mucus proteins and congenital inflammatory bowel disease (IBD). Mice harboring a patient ST6 mutation have compromised mucus barriers, dysbiosis, and susceptibility to intestinal inflammation. Based on our understanding of the ST6 regulatory network, we show that treatment with sialylated mucin or a Foxo3 inhibitor can ameliorate IBD.


Assuntos
Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Sialiltransferases/genética , Animais , Homeostase , Humanos , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Camundongos , Muco/metabolismo , Sialiltransferases/metabolismo , Simbiose
12.
Food Funct ; 13(8): 4399-4420, 2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35297435

RESUMO

Background: Ulcerative colitis (UC) is a chronic inflammatory disorder of the colon with a continuously remitting and relapsing course. Its etiology is closely related to abnormal interactions between host and gut microbiota. The mucus barrier lining the gastrointestinal tract is necessary to coordinate host and gut microbiota interaction by nourishing and modulating the microbiota. Differential effects of the anti-inflammatory fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on UC progression in mice were firstly addressed by our previous work; here, the mechanism for their respective effects were further uncovered from host-microbiome crosstalk based on mucus barrier modulation to pave the way for UC therapy. Methods: Assessment of the disease activity index and histopathology score was conducted in mice with dextran sodium sulfate (DSS)-induced colitis pre-treated with different doses of EPA and DHA. Mucin generation, glycosylation and secretion were evaluated by a combination of electron microscopy, specific mucous staining, and qPCR. Western blotting was used to analyze the underlying molecular events. Fecal short chain fatty acids were detected using gas chromatography, and the gut microbial composition was analyzed using 16S rRNA sequencing. Results: Compared with DHA, the more potent inhibitory effect of high dose EPA on DSS-induced colitis was reconfirmed, which was underlain by a reinforced mucus layer as indicated by increased mucin granule release, mucus layer stratification and markedly upregulated expression of the key modulators involved in goblet cell differentiation. In turn a remarkably enhanced mucus barrier in the EPA group functioned to modulate the gut microbiome, as demonstrated by the enriched abundance of the phylum Bacteroidetes and mucin-degrading bacterium Akkermansia muciniphila producing acetic and propionic acids. Conclusions: EPA and DHA differentially coordinate the interaction between the host and the gut microbiota and relieve mucus barrier disruption in DSS-induced colitis. EPA may develop into a promising adjunctive therapy for UC.


Assuntos
Colite Ulcerativa , Colite , Microbioma Gastrointestinal , Animais , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/microbiologia , Colite Ulcerativa/tratamento farmacológico , Colo/metabolismo , Sulfato de Dextrana/efeitos adversos , Modelos Animais de Doenças , Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Mucinas/metabolismo , Muco/metabolismo , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Verrucomicrobia
13.
Eur J Pharm Biopharm ; 173: 92-102, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35227857

RESUMO

Gastrointestinal (GI) mucus is continuously secreted and lines the entire length of the GI tract. Essential for health, it keeps the noxious luminal content away from the epithelium. Our aim was to characterize the composition and structure of mucus throughout the various GI segments in dog. Mucus was collected from the stomach, small intestine (duodenum, jejunum, ileum), and large intestine (cecum, proximal and distal colon) from dogs. Composition was determined by multi-omics. Structural properties were investigated using cryoSEM and rheology. GI mucus contained 74-95% water and maintained a pH around 6.5. The proteome was similar across the different GI segments. The highest abundant secreted gel-forming mucin in the gastric mucus was mucin 5AC, whether mucin 2 had highest abundance in the intestinal mucus. Lipid and metabolite abundance was generally higher in the jejunal mucus than the colonic mucus. CryoSEM microscopy revealed smaller pore size in small intestinal mucus, which increased in the large intestine. All mucus samples showed shear-thinning behavior and characteristics of gel-like structure. In conclusion, the mucus is a highly viscous and hydrated material. These data provide an important baseline for future studies on human and canine intestinal diseases and the dog model in drug absorption.


Assuntos
Intestino Delgado , Muco , Animais , Colo/metabolismo , Cães , Trato Gastrointestinal/metabolismo , Mucosa Intestinal/metabolismo , Intestino Delgado/metabolismo , Muco/metabolismo , Estômago
14.
Adv Drug Deliv Rev ; 184: 114182, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35278522

RESUMO

The secreted mucus layer that lines and protects epithelial cells is conserved across diverse species. While the exact composition of this protective layer varies between organisms, certain elements are conserved, including proteins that are heavily decorated with N-acetylgalactosamine-based sugars linked to serines or threonines (O-linked glycosylation). These heavily O-glycosylated proteins, known as mucins, exist in many forms and are able to form hydrated gel-like structures that coat epithelial surfaces. In vivo studies in diverse organisms have highlighted the importance of both the mucin proteins as well as their constituent O-glycans in the protection and health of internal epithelia. Here, we summarize in vivo approaches that have shed light on the synthesis and function of these essential components of mucus.


Assuntos
Mucinas , Muco , Células Epiteliais/metabolismo , Glicosilação , Humanos , Mucinas/química , Mucinas/metabolismo , Muco/metabolismo , Polissacarídeos
15.
Mol Pharm ; 19(5): 1309-1324, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35333535

RESUMO

Nucleic acids, both DNA and small RNAs, have emerged as potential therapeutics for the treatment of various lung disorders. However, delivery of nucleic acids to the lungs is challenging due to the barrier property imposed by mucus, which is further reinforced in disease conditions such as chronic obstructive pulmonary disease and asthma. The presence of negatively charged mucins imparts the electrostatic barrier property, and the mesh network structure of mucus provides steric hindrance to the delivery system. To overcome this, the delivery system either needs to be muco-inert with a low positive charge such that the interactions with mucus are minimized or should have the ability to transiently dismantle the mucus structure for effective penetration. We have developed a mucus penetrating system for the delivery of both small RNA and plasmid DNA independently. The nucleic acid core consists of a nucleic acid (pDNA/siRNA) and a cationic/amphipathic cell penetrating peptide. The mucus penetrating coating consists of the hydrophilic biopolymer chondroitin sulfate A (CS-A) conjugated with a mucolytic agent, mannitol. We hypothesize that the hydrophilic coating of CS-A would reduce the surface charge and decrease the interaction with negatively charged mucins, while the conjugated mannitol residues would disrupt the mucin-mucin interaction or decrease the viscosity of mucus by increasing the influx of water into the mucus. Our results indicate that CS-A-mannitol-coated nanocomplexes possess reduced surface charge, reduced viscosity of artificial mucus, and increased diffusion in mucin suspension as well as increased penetration through the artificial mucus layer as compared to the non-coated ones. Further, the coated nanocomplexes showed low cytotoxicity as well as higher transfection in A-549 and BEAS-2B cells as compared to the non-coated ones.


Assuntos
Peptídeos Penetradores de Células , Nanopartículas , Ácidos Nucleicos , Peptídeos Penetradores de Células/metabolismo , Portadores de Fármacos/química , Pulmão/metabolismo , Manitol/metabolismo , Mucinas/metabolismo , Muco/metabolismo , Nanopartículas/química , Ácidos Nucleicos/metabolismo
16.
ACS Biomater Sci Eng ; 8(4): 1396-1426, 2022 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-35294187

RESUMO

Mucus is a complex viscoelastic gel and acts as a barrier covering much of the soft tissue in the human body. High vascularization and accessibility have motivated drug delivery to various mucosal surfaces; however, these benefits are hindered by the mucus layer. To overcome the mucus barrier, many nanomedicines have been developed, with the goal of improving the efficacy and bioavailability of drug payloads. Two major nanoparticle-based strategies have emerged to facilitate mucosal drug delivery, namely, mucoadhesion and mucopenetration. Generally, mucoadhesive nanoparticles promote interactions with mucus for immobilization and sustained drug release, whereas mucopenetrating nanoparticles diffuse through the mucus and enhance drug uptake. The choice of strategy depends on many factors pertaining to the structural and compositional characteristics of the target mucus and mucosa. While there have been promising results in preclinical studies, mucus-nanoparticle interactions remain poorly understood, thus limiting effective clinical translation. This article reviews nanomedicines designed with mucoadhesive or mucopenetrating properties for mucosal delivery, explores the influence of site-dependent physiological variation among mucosal surfaces on efficacy, transport, and bioavailability, and discusses the techniques and models used to investigate mucus-nanoparticle interactions. The effects of non-homeostatic perturbations on protein corona formation, mucus composition, and nanoparticle performance are discussed in the context of mucosal delivery. The complexity of the mucosal barrier necessitates consideration of the interplay between nanoparticle design, tissue-specific differences in mucus structure and composition, and homeostatic or disease-related changes to the mucus barrier to develop effective nanomedicines for mucosal delivery.


Assuntos
Sistemas de Liberação de Medicamentos , Nanopartículas , Humanos , Membrana Mucosa/metabolismo , Muco/química , Muco/metabolismo , Preparações Farmacêuticas/análise , Preparações Farmacêuticas/química , Preparações Farmacêuticas/metabolismo
17.
Commun Biol ; 5(1): 249, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35318436

RESUMO

Mucus in the lung plays an essential role as a barrier to infection by viral pathogens such as influenza A virus (IAV). Previous work determined mucin-associated sialic acid acts as a decoy receptor for IAV hemagglutinin (HA) binding and the sialic-acid cleaving enzyme, neuraminidase (NA), facilitates virus passage through mucus. However, it has yet to be fully addressed how the physical structure of the mucus gel influences its barrier function and its ability to trap viruses via glycan mediated interactions to prevent infection. To address this, IAV and nanoparticle diffusion in human airway mucus and mucin-based hydrogels is quantified using fluorescence video microscopy. We find the mobility of IAV in mucus is significantly influenced by the mesh structure of the gel and in contrast to prior reports, these effects likely influence virus passage through mucus gels to a greater extent than HA and NA activity. In addition, an analytical approach is developed to estimate the binding affinity of IAV to the mucus meshwork, yielding dissociation constants in the mM range, indicative of weak IAV-mucus binding. Our results provide important insights on how the adhesive and physical barrier properties of mucus influence the dissemination of IAV within the lung microenvironment.


Assuntos
Vírus da Influenza A , Géis , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Humanos , Vírus da Influenza A/fisiologia , Mucinas/metabolismo , Muco/metabolismo , Ácido N-Acetilneuramínico/metabolismo
18.
Cells ; 11(3)2022 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-35159335

RESUMO

We recently identified microRNAs (miRNAs) associated with chronic mucus hypersecretion (CMH) in chronic obstructive pulmonary disease (COPD), which were expressed in both airway epithelial cells and fibroblasts. We hypothesized that these miRNAs are involved in communication between fibroblasts and epithelium, contributing to airway remodeling and CMH in COPD. Primary bronchial epithelial cells (PBECs) differentiated at the air-liquid interface, and airway fibroblasts (PAFs) from severe COPD patients with CMH were cultured alone or together. RNA was isolated and miRNA expression assessed. miRNAs differentially expressed after co-culturing were studied functionally using overexpression with mimics in mucus-expressing human lung A549 epithelial cells or normal human lung fibroblasts. In PBECs, we observed higher miR-708-5pexpression upon co-culture with fibroblasts, and miR-708-5p expression decreased upon mucociliary differentiation. In PAFs, let-7a-5p, miR-31-5p and miR-146a-5p expression was significantly increased upon co-culture. miR-708-5p overexpression suppressed mucin 5AC (MUC5AC) secretion in A549, while let-7a-5poverexpression suppressed its target gene COL4A1 in lung fibroblasts. Our findings suggest that let-7a-5p, miR-31-5p and miR-146a-5p may be involved in CMH via fibroblasts-epithelium crosstalk, including extracellular matrix gene regulation, while airway epithelial expression of miR-708-5p may be involved directly, regulating mucin production. These findings shed light on miRNA-mediated mechanisms underlying CMH, an important symptom in COPD.


Assuntos
MicroRNAs , Doença Pulmonar Obstrutiva Crônica , Epitélio/metabolismo , Fibroblastos/metabolismo , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Muco/metabolismo , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/metabolismo
19.
Digestion ; 103(3): 232-243, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35184056

RESUMO

BACKGROUND: The pathophysiology of ulcerative colitis (UC) remains unclear, but early lesions on the colorectal mucosal surface may play an important role in its etiology. Intestinal mucus samples, including inner and outer layers, are collected by net or brush catheters, but the quality of the samples obtained by each method has not been fully investigated. OBJECTIVE: The purpose of this study was to compare the microbiome and protein content of intestinal mucus collected by net and brush catheters during colonoscopy. METHODS: Intestinal mucus samples from the lower rectum of 4 patients with UC were collected using a net catheter, a brush catheter, and intestinal fluid suction. Microbiome and protein content were analyzed using 16S rRNA gene sequencing and mass spectrometry. RESULTS: The patients demonstrated significant differences in microbiome alpha diversity (p < 0.05), but this difference was not observed between the sampling methods. Net catheter samples demonstrated higher total protein concentrations than brush catheter samples. The brush catheter group had more Lachnospira, a butyrate-producing bacterium, when compared to the net group. The brush catheter group also had more oral bacteria of Staphylococcus and Dialister in those with active phase when compared to the net group. CONCLUSIONS: Brush catheters are more likely to collect the intestinal mucus inner layer, whereas net catheters are more likely to collect larger samples that include the outer mucus layer, as well as the intestinal fluid. Two sampling methods with different types of collection of the mucosa may lead to different results among patients with mucosal vulnerabilities.


Assuntos
Colite Ulcerativa , Cateteres , Colite Ulcerativa/patologia , Humanos , Mucosa Intestinal/metabolismo , Muco/metabolismo , Muco/microbiologia , RNA Ribossômico 16S/genética , Reto/patologia
20.
Food Funct ; 13(6): 3098-3109, 2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35226005

RESUMO

As a broadly defined member of lactic acid bacteria (LAB), the Lactobacillus strain is well characterized in food fermentation and specific strains can enhance the intestinal barrier function and be recognized as the probiotic strain. In recent years, many molecules of the cell surface are thought to be related to the adhesion property in the gastrointestinal mucosa. Mucus layer-related proteins, extracellular matrix proteins, and immunoglobulins also exhibit immunity regulation and protection of the intestinal epithelial barrier function. Meanwhile, the effects of bile and the low pH of the gastrointestinal tract (GIT) on Lactobacillus colonization are also needed to be considered. Furthermore, LAB can adhere and aggregate in the GIT to promote the maturity of biofilm and the extracellular matrix secreting through the signal molecules in the quorum sensing (QS) system. Therefore, it is of great interest to use the QS system to regulate the initial adhesion ability of Lactobacillus and further enhance the probiotic effect of the biofilm formation of beneficial bacteria. This review summarizes the adhesion properties of cell surface proteins derived from Lactobacillus strains in recent studies and provides valuable information on the QS effect on the adhesion property of Lactobacillus strains in the GIT environment.


Assuntos
Aderência Bacteriana , Proteínas de Bactérias/metabolismo , Trato Gastrointestinal/microbiologia , Lactobacillales/fisiologia , Lactobacillus/fisiologia , Proteínas de Membrana/metabolismo , Percepção de Quorum , Fímbrias Bacterianas/fisiologia , Flagelos/fisiologia , Humanos , Lactobacillus/ultraestrutura , Glicoproteínas de Membrana/metabolismo , Muco/metabolismo , Muco/microbiologia , Peptidoglicano/química , Peptidoglicano/metabolismo , Probióticos , Ácidos Teicoicos/química , Ácidos Teicoicos/metabolismo
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