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1.
Nat Commun ; 15(1): 4764, 2024 Jun 04.
Article En | MEDLINE | ID: mdl-38834561

Bacteriophage are sophisticated cellular parasites that can not only parasitize bacteria but are increasingly recognized for their direct interactions with mammalian hosts. Phage adherence to mucus is known to mediate enhanced antimicrobial effects in vitro. However, little is known about the therapeutic efficacy of mucus-adherent phages in vivo. Here, using a combination of in vitro gastrointestinal cell lines, a gut-on-a-chip microfluidic model, and an in vivo murine gut model, we demonstrated that a E. coli phage, øPNJ-6, provided enhanced gastrointestinal persistence and antimicrobial effects. øPNJ-6 bound fucose residues, of the gut secreted glycoprotein MUC2, through domain 1 of its Hoc protein, which led to increased intestinal mucus production that was suggestive of a positive feedback loop mediated by the mucus-adherent phage. These findings extend the Bacteriophage Adherence to Mucus model into phage therapy, demonstrating that øPNJ-6 displays enhanced persistence within the murine gut, leading to targeted depletion of intestinal pathogenic bacteria.


Escherichia coli Infections , Escherichia coli , Intestinal Mucosa , Mucin-2 , Animals , Escherichia coli/virology , Mice , Intestinal Mucosa/microbiology , Intestinal Mucosa/virology , Mucin-2/metabolism , Humans , Escherichia coli Infections/microbiology , Escherichia coli Infections/therapy , Phage Therapy/methods , Bacterial Adhesion , Female , Mucus/metabolism , Mucus/virology , Coliphages/physiology , Fucose/metabolism , Mice, Inbred C57BL
2.
Aging (Albany NY) ; 16(10): 8472-8483, 2024 May 26.
Article En | MEDLINE | ID: mdl-38809424

OBJECTIVE: To investigate the role of the EGFR/MAPK signaling pathway in PM2.5 in promoting the MUC5AC hypersecretion in airway and exacerbating airway inflammation. METHODS: By establishing rat model exposed to PM2.5, overexpressing miR-133b-5p and Claudin1, the content of IL-1 and TNF-α in serum were detected by ELISA, the pathology of lung tissue was observed by HE staining, p-EGFR, Claudin1, MUC5AC, p-ERK1/2, p-JNK, p-p38 in rats lung tissue were detected by immunohistochemical and WB, the expression level of miR-133b-5p in rats lung tissue were detected by qPCR. RESULTS: After the rats were exposed to PM2.5, the content of inflammatory factors in serum increased, the inflammatory damage of lung tissues occurred, the expression of miR-133b-5p was down-regulated, and the expression of MUC5AC protein was increased. The ELISA test results showed that the expression of IL-1 and TNF-α in the model group was significantly higher than that in the control group, and the model +AG1478 treatment group was down-regulated compared with the model group, and the +miR-133b-5p agomir treatment group was significantly lower than that in the control group, the model group and the model +Claudin1 overexpression blank load group, and the model +Claudin1 overexpression group was down-regulated compared with the model group and the model +Claudin1 overexpression blank load group. The protein detection results showed that the expression of p-EGFR, MUC5AC, p-ERK1/2, p-JNK and p-p38 proteins was increased and the expression of Claudin1 protein was decreased in the model group compared with the control group. In the model + AG1478 treatment group, model + miR-133b-5p agomir treatment group and model + Claudin1 overexpression group, compared with the model group, p-EGFR, MUC5AC, p-ERK1/2, p-JNK, p-p38 protein expression was down-regulated, and Claudin1 protein expression was up-regulated. CONCLUSIONS: PM2.5 inhibited the expression of miR-133b-5p to activate the EGFR/MAPK signal pathway, induce the hypersecretion of MUC5AC, thus aggravating PM2.5-related airway inflammation in rats.


Claudin-1 , ErbB Receptors , MicroRNAs , Mucin 5AC , Particulate Matter , Animals , MicroRNAs/metabolism , MicroRNAs/genetics , Mucin 5AC/metabolism , Mucin 5AC/genetics , Rats , ErbB Receptors/metabolism , ErbB Receptors/genetics , Particulate Matter/toxicity , Claudin-1/metabolism , Claudin-1/genetics , Male , Rats, Sprague-Dawley , Lung/metabolism , Lung/pathology , Mucus/metabolism , Signal Transduction , Tumor Necrosis Factor-alpha/metabolism , MAP Kinase Signaling System
3.
Toxicol In Vitro ; 98: 105841, 2024 Jun.
Article En | MEDLINE | ID: mdl-38729454

3D cell culture models exposed at the air-liquid interface (ALI) represent a potential alternative to animal experiments for hazard and risk assessment of inhaled compounds. This study compares cocultures composed of either Calu-3, A549 or HBEC3-KT lung epithelial cells, cultured together with THP-1-derived macrophages and EA.hy926 endothelial cells, in terms of barrier capacity and responses to a standard reference sample of fine particulate matter (SRM 2786). High-content imaging analysis revealed a similar cellular composition between the different cell models. The 3D cell cultures with Calu-3 cells showed the greatest barrier capacity, as measured by transepithelial electrical resistance and permeability to Na-fluorescein. Mucus production was detected in 3D cell cultures based on Calu-3 and A549 cells. Exposure to SRM 2786 at ALI increased cytokine release and expression of genes associated with inflammation and xenobiotic metabolism. Moreover, the presence of THP-1-derived macrophages was central to the cytokine responses in all cell models. While the different 3D cell culture models produced qualitatively similar responses, more pronounced pro-inflammatory responses were observed in the basolateral compartment of the A549 and HBEC3-KT models compared to the Calu-3 model, likely due to their reduced barrier capacity and lower retention of secreted mediators in the apical compartment.


Cytokines , Lung , Particulate Matter , Humans , Particulate Matter/toxicity , Lung/drug effects , Lung/cytology , Cytokines/metabolism , Cytokines/genetics , Cell Line , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Cell Culture Techniques , Macrophages/drug effects , Coculture Techniques , Air Pollutants/toxicity , Mucus/metabolism
4.
Aging (Albany NY) ; 16(9): 7902-7914, 2024 May 03.
Article En | MEDLINE | ID: mdl-38709270

BACKGROUND: Traditional bandages, gauze, and cotton balls are increasingly insufficient for addressing complex war injuries characterized by severe bleeding and diverse wound conditions. The giant salamander, a species of high medical value, secretes a unique mucus when stimulated, which has potential applications in wound care. MATERIALS: Giant salamander skin mucus gel dressing wrapped with bone marrow mesenchymal stem cells (BMSCs-GSSM-gel) was prepared and validated. Skin wound injury of rabbit and mouse models were established. Hematoxylin and Eosin, Masson's trichrome, and Sirius red staining were performed. The platelet aggregation rate and coagulation items were measured. Transcriptome sequencing was performed to find potential differential expression genes. RESULTS: Preparation and characterization of BMSCs-GSSM-gel were performed, and BMSCs-GSSM-gel particles with a diameter of about 200 nm were obtained. BMSCs-GSSM-gel accelerated wound healing in both rabbit and mouse models. BMSCs-GSSM-gel significantly promoted hemostasis via increasing platelet aggregation rate and fibrinogen, but decreasing activated partial thromboplastin time, thrombin time, and prothrombin time. BMSCs-GSSM-gel treatment significantly impacted several genes associated with cell adhesion, inflammatory response, collagen-containing extracellular matrix, and the positive regulation of cell migration based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Integrin Subunit Beta 4 (ITGB4), Integrin Subunit Alpha 3 (ITGA3), and Laminin Subunit Beta 3 (LAMB3) might be involved in the wound healing process by BMSCs-GSSM-gel. CONCLUSIONS: We proved the BMSCs-GSSM-gel greatly improved the skin wound healing, and it might play a crucial role in the application fields of skin damage repair.


Mesenchymal Stem Cells , Skin , Wound Healing , Animals , Rabbits , Mesenchymal Stem Cells/metabolism , Skin/injuries , Skin/metabolism , Mice , Mucus/metabolism , Integrins/metabolism , Integrins/genetics , Gels , Mesenchymal Stem Cell Transplantation/methods , Male
5.
Comput Biol Med ; 176: 108540, 2024 Jun.
Article En | MEDLINE | ID: mdl-38728996

Colonic motility plays a vital role in maintaining proper digestive function. The rhythmic contractions and relaxations facilitate various types of motor functions that generate both propulsive and non-propulsive motility modes which in turn generate shear stresses on the epithelial surface. However, the interplay between colonic mucus, shear stress, and epithelium remains poorly characterized. Here, we present a colonic computational model that describes the potential roles of mucus and shear stress in both homeostasis and ulcerative colitis (UC). Our model integrates several key features, including the properties of the mucus bilayer and faeces, intraluminal pressure, and crypt characteristics to predict the time-space mosaic of shear stress. We show that the mucus thickness which could vary based on the severity of UC, may significantly reduce the amount of shear stress applied to the colonic crypts and effect faecal velocity. Our model also reveals an important spatial shear stress variance in homeostatic colonic crypts that suggests shear stress may have a modulatory role in epithelial cell migration, differentiation, apoptosis, and immune surveillance. Together, our study uncovers the rather neglected roles of mucus and shear stress in intestinal cellular processes during homeostasis and inflammation.


Colon , Gastrointestinal Motility , Homeostasis , Models, Biological , Mucus , Humans , Colon/physiology , Gastrointestinal Motility/physiology , Mucus/metabolism , Mucus/physiology , Homeostasis/physiology , Inflammation/metabolism , Inflammation/physiopathology , Computer Simulation , Stress, Mechanical , Colitis, Ulcerative/physiopathology , Colitis, Ulcerative/metabolism
6.
J Biomed Opt ; 29(4): 046004, 2024 Apr.
Article En | MEDLINE | ID: mdl-38690122

Significance: Assessing the nanostructure of polymer solutions and biofluids is broadly useful for understanding drug delivery and disease progression and for monitoring therapy. Aim: Our objective is to quantify bronchial mucus solids concentration (wt. %) during hypertonic saline (HTS) treatment in vitro via nanostructurally constrained diffusion of gold nanorods (GNRs) monitored by polarization-sensitive optical coherence tomography (PS-OCT). Approach: Using PS-OCT, we quantified GNR translational (DT) and rotational (DR) diffusion coefficients within polyethylene oxide solutions (0 to 3 wt. %) and human bronchial epithelial cell (hBEC) mucus (0 to 6.4 wt. %). Interpolation of DT and DR data is used to develop an assay to quantify mucus concentration. The assay is demonstrated on the mucus layer of an air-liquid interface hBEC culture during HTS treatment. Results: In polymer solutions and mucus, DT and DR monotonically decrease with increasing concentration. DR is more sensitive than DT to changes above 1.5 wt. % of mucus and exhibits less intrasample variability. Mucus on HTS-treated hBEC cultures exhibits dynamic mixing from cilia. A region of hard-packed mucus is revealed by DR measurements. Conclusions: The extended dynamic range afforded by simultaneous measurement of DT and DR of GNRs using PS-OCT enables resolving concentration of the bronchial mucus layer over a range from healthy to disease in depth and time during HTS treatment in vitro.


Gold , Mucus , Nanotubes , Tomography, Optical Coherence , Tomography, Optical Coherence/methods , Humans , Nanotubes/chemistry , Gold/chemistry , Mucus/chemistry , Mucus/metabolism , Diffusion , Bronchi/diagnostic imaging , Epithelial Cells/chemistry , Epithelial Cells/metabolism , Saline Solution, Hypertonic/pharmacology , Saline Solution, Hypertonic/chemistry , Cells, Cultured
7.
Expert Opin Drug Deliv ; 21(4): 553-572, 2024 Apr.
Article En | MEDLINE | ID: mdl-38720439

INTRODUCTION: Intranasal administration is an effective drug delivery routes in modern pharmaceutics. However, unlike other in vivo biological barriers, the nasal mucosal barrier is characterized by high turnover and selective permeability, hindering the diffusion of both particulate drug delivery systems and drug molecules. The in vivo fate of administrated nanomedicines is often significantly affected by nano-biointeractions. AREAS COVERED: The biological barriers that nanomedicines encounter when administered intranasally are introduced, with a discussion on the factors influencing the interaction between nanomedicines and the mucus layer/mucosal barriers. General design strategies for nanomedicines administered via the nasal route are further proposed. Furthermore, the most common methods to investigate the characteristics and the interactions of nanomedicines when in presence of the mucus layer/mucosal barrier are briefly summarized. EXPERT OPINION: Detailed investigation of nanomedicine-mucus/mucosal interactions and exploration of their mechanisms provide solutions for designing better intranasal nanomedicines. Designing and applying nanomedicines with mucus interaction properties or non-mucosal interactions should be customized according to the therapeutic need, considering the target of the drug, i.e. brain, lung or nose. Then how to improve the precise targeting efficiency of nanomedicines becomes a difficult task for further research.


Administration, Intranasal , Drug Delivery Systems , Mucus , Nanomedicine , Nasal Mucosa , Nasal Mucosa/metabolism , Humans , Animals , Mucus/metabolism , Permeability , Pharmaceutical Preparations/administration & dosage , Pharmaceutical Preparations/metabolism , Drug Design , Nanoparticles
8.
Food Res Int ; 187: 114343, 2024 Jul.
Article En | MEDLINE | ID: mdl-38763636

Human breast milk promotes maturation of the infant gastrointestinal barrier, including the promotion of mucus production. In the quest to produce next generation infant milk formula (IMF), we have produced IMF by membrane filtration (MEM-IMF). With a higher quantity of native whey protein, MEM-IMF more closely mimics human breast milk than IMF produced using conventional heat treatment (HT-IMF). After a 4-week dietary intervention in young pigs, animals fed a MEM-IMF diet had a higher number of goblet cells, acidic mucus and mucin-2 in the jejunum compared to pigs fed HT-IMF (P < 0.05). In the duodenum, MEM-IMF fed pigs had increased trypsin activity in the gut lumen, increased mRNA transcript levels of claudin 1 in the mucosal scrapings and increased lactase activity in brush border membrane vesicles than those pigs fed HT-IMF (P < 0.05). In conclusion, MEM-IMF is superior to HT-IMF in the promotion of mucus production in the young gut.


Filtration , Infant Formula , Mucus , Animals , Infant Formula/chemistry , Mucus/metabolism , Swine , Whey Proteins/metabolism , Intestine, Small/metabolism , Trypsin/metabolism , Humans , Goblet Cells/metabolism , Claudin-1/metabolism , Claudin-1/genetics , Lactase/metabolism , Lactase/genetics , Mucin-2/metabolism , Mucin-2/genetics , Intestinal Mucosa/metabolism , Duodenum/metabolism , Jejunum/metabolism , RNA, Messenger/metabolism , RNA, Messenger/genetics , Milk Proteins/metabolism , Milk Proteins/analysis
9.
Nat Commun ; 15(1): 3900, 2024 May 09.
Article En | MEDLINE | ID: mdl-38724552

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


Asthma , GPI-Linked Proteins , Interleukin-13 , Lectins , Mucin 5AC , Mucus , Child , Humans , Asthma/genetics , Asthma/metabolism , Cytokines , Epithelial Cells/metabolism , GPI-Linked Proteins/genetics , GPI-Linked Proteins/metabolism , Interleukin-13/genetics , Interleukin-13/metabolism , Lectins/genetics , Lectins/metabolism , Mucin 5AC/genetics , Mucin 5AC/metabolism , Mucus/metabolism , Nasal Mucosa/metabolism , Polymorphism, Genetic , Respiratory Mucosa/metabolism
10.
Int J Mol Sci ; 25(9)2024 Apr 30.
Article En | MEDLINE | ID: mdl-38732126

Enterohemorrhagic Escherichia coli (EHEC) is a critical public health concern due to its role in severe gastrointestinal illnesses in humans, including hemorrhagic colitis and the life-threatening hemolytic uremic syndrome. While highly pathogenic to humans, cattle, the main reservoir for EHEC, often remain asymptomatic carriers, complicating efforts to control its spread. Our study introduces a novel method to investigate EHEC using organoid-derived monolayers from adult bovine ileum and rectum. These polarized epithelial monolayers were exposed to EHEC for four hours, allowing us to perform comparative analyses between the ileal and rectal tissues. Our findings mirrored in vivo observations, showing a higher colonization rate in the rectum compared with the ileum (44.0% vs. 16.5%, p < 0.05). Both tissues exhibited an inflammatory response with increased expression levels of TNF-a (p < 0.05) and a more pronounced increase of IL-8 in the rectum (p < 0.01). Additionally, the impact of EHEC on the mucus barrier varied across these gastrointestinal regions. Innovative visualization techniques helped us study the ultrastructure of mucus, revealing a net-like mucin glycoprotein organization. While further cellular differentiation could enhance model accuracy, our research significantly deepens understanding of EHEC pathogenesis in cattle and informs strategies for the preventative measures and therapeutic interventions.


Enterohemorrhagic Escherichia coli , Ileum , Organoids , Rectum , Animals , Cattle , Ileum/microbiology , Ileum/metabolism , Ileum/ultrastructure , Rectum/microbiology , Enterohemorrhagic Escherichia coli/pathogenicity , Organoids/metabolism , Organoids/microbiology , Mucus/metabolism , Escherichia coli Infections/microbiology , Intestinal Mucosa/microbiology , Intestinal Mucosa/metabolism , Intestinal Mucosa/ultrastructure
11.
Nat Commun ; 15(1): 4578, 2024 May 29.
Article En | MEDLINE | ID: mdl-38811586

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


Cervix Uteri , Host Microbial Interactions , Immunity, Innate , Microbiota , Humans , Female , Cervix Uteri/microbiology , Cervix Uteri/immunology , Microbiota/immunology , Host Microbial Interactions/immunology , Gardnerella vaginalis/immunology , Lactobacillus crispatus/immunology , Mucus/immunology , Mucus/microbiology , Mucus/metabolism , Lab-On-A-Chip Devices
12.
Gut Microbes ; 16(1): 2356270, 2024.
Article En | MEDLINE | ID: mdl-38797998

High-fat diets alter gut barrier integrity, leading to endotoxemia by impacting epithelial functions and inducing endoplasmic reticulum (ER) stress in intestinal secretory goblet cells. Indeed, ER stress, which is an important contributor to many chronic diseases such as obesity and obesity-related disorders, leads to altered synthesis and secretion of mucins that form the protective mucus barrier. In the present study, we investigated the relative contribution of omega-3 polyunsaturated fatty acid (PUFAs)-modified microbiota to alleviating alterations in intestinal mucus layer thickness and preserving gut barrier integrity. Male fat-1 transgenic mice (exhibiting endogenous omega-3 PUFAs tissue enrichment) and wild-type (WT) littermates were fed either an obesogenic high-fat diet (HFD) or a control diet. Unlike WT mice, HFD-fed fat-1 mice were protected against mucus layer alterations as well as an ER stress-mediated decrease in mucin expression. Moreover, cecal microbiota transferred from fat-1 to WT mice prevented changes in the colonic mucus layer mainly through colonic ER stress downregulation. These findings highlight a novel feature of the preventive effects of omega-3 fatty acids against intestinal permeability in obesity-related conditions.


Colon , Diet, High-Fat , Endoplasmic Reticulum Stress , Fatty Acids, Omega-3 , Gastrointestinal Microbiome , Intestinal Mucosa , Mice, Transgenic , Animals , Diet, High-Fat/adverse effects , Mice , Male , Fatty Acids, Omega-3/metabolism , Colon/microbiology , Colon/metabolism , Intestinal Mucosa/metabolism , Intestinal Mucosa/microbiology , Obesity/metabolism , Obesity/microbiology , Mucus/metabolism , Mice, Inbred C57BL , Mucins/metabolism , Goblet Cells/metabolism , Fecal Microbiota Transplantation
14.
Sci Rep ; 14(1): 11779, 2024 05 23.
Article En | MEDLINE | ID: mdl-38783070

Most terrestrial mammals have a vomeronasal system to detect specific chemicals. The peripheral organ of this system is a vomeronasal organ (VNO) opening to the incisive duct, and its primary integrative center is an accessory olfactory bulb (AOB). The VNO in seals is thought to be degenerated like whales and manatees, unlike otariids, because of the absence of the AOB. However, olfaction plays pivotal roles in seals, and thus we conducted a detailed morphological evaluation of the vomeronasal system of three harbor seals (Phoca vitulina). The VNO lumen was not found, and the incisive duct did not open into the oral cavity but was recognized as a fossa on the anteroventral side of the nasal cavity. This fossa is rich in mucous glands that secrete acidic mucopolysaccharides, which might originate from the vomeronasal glands. The olfactory bulb consisted only of a main olfactory bulb that received projections from the olfactory mucosa, but an AOB region was not evident. These findings clarified that harbor seals do not have a VNO to detect some chemicals, but the corresponding region is a specialized secretory organ.


Nasal Cavity , Olfactory Bulb , Phoca , Vomeronasal Organ , Animals , Vomeronasal Organ/metabolism , Vomeronasal Organ/anatomy & histology , Phoca/metabolism , Phoca/anatomy & histology , Nasal Cavity/anatomy & histology , Nasal Cavity/metabolism , Olfactory Bulb/metabolism , Olfactory Bulb/anatomy & histology , Mucus/metabolism , Olfactory Mucosa/metabolism , Olfactory Mucosa/anatomy & histology , Male , Smell/physiology , Female
15.
BMC Biotechnol ; 24(1): 28, 2024 May 04.
Article En | MEDLINE | ID: mdl-38702622

Scientists know very little about the mechanisms underlying fish skin mucus, despite the fact that it is a component of the immune system. Fish skin mucus is an important component of defence against invasive infections. Recently, Fish skin and its mucus are gaining interest among immunologists. Characterization was done on the obtained silver nanoparticles Ag combined with Clarias gariepinus catfish epidermal mucus proteins (EMP-Ag-NPs) through UV-vis, FTIR, XRD, TEM, and SEM. Ag-NPs ranged in size from 4 to 20 nm, spherical in form and the angles were 38.10°, 44.20°, 64.40°, and 77.20°, Where wavelength change after formation of EMP-Ag-NPs as indicate of dark brown, the broad band recorded at wavelength at 391 nm. Additionally, the antimicrobial, antibiofilm and anticancer activities of EMP-Ag-NPs was assessed. The present results demonstrate high activity against unicellular fungi C. albicans, followed by E. faecalis. Antibiofilm results showed strong activity against both S. aureus and P. aeruginosa pathogens in a dose-dependent manner, without affecting planktonic cell growth. Also, cytotoxicity effect was investigated against normal cells (Vero), breast cancer cells (Mcf7) and hepatic carcinoma (HepG2) cell lines at concentrations (200-6.25 µg/mL) and current results showed highly anticancer effect of Ag-NPs at concentrations 100, 5 and 25 µg/mL exhibited rounding, shrinkage, deformation and granulation of Mcf7 and HepG2 with IC50 19.34 and 31.16 µg/mL respectively while Vero cells appeared rounded at concentration 50 µg/mL and normal shape at concentration 25, 12.5 and 6.25 µg/ml with IC50 35.85 µg/mL. This study evidence the potential efficacy of biologically generated Ag-NPs as a substitute medicinal agent against harmful microorganisms. Furthermore, it highlights their inhibitory effect on cancer cell lines.


Biofilms , Catfishes , Metal Nanoparticles , Silver , Metal Nanoparticles/chemistry , Biofilms/drug effects , Biofilms/growth & development , Silver/chemistry , Silver/pharmacology , Animals , Humans , Mucus/metabolism , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Vero Cells , Fish Proteins/pharmacology , Fish Proteins/chemistry , Fish Proteins/metabolism , Chlorocebus aethiops , Cell Line, Tumor , Microbial Sensitivity Tests , Pseudomonas aeruginosa/drug effects , Anti-Infective Agents/pharmacology , Anti-Infective Agents/chemistry , Staphylococcus aureus/drug effects , Staphylococcus aureus/physiology , Candida albicans/drug effects , Epidermis/metabolism
16.
Toxins (Basel) ; 16(5)2024 Apr 30.
Article En | MEDLINE | ID: mdl-38787061

Peptide toxins from marine invertebrates have found use as drugs and in biotechnological applications. Many marine habitats, however, remain underexplored for natural products, and the Southern Ocean is among them. Here, we report toxins from one of the top predators in Antarctic waters: the nemertean worm Parborlasia corrugatus (McIntosh, 1876). Transcriptome mining revealed a total of ten putative toxins with a cysteine pattern similar to that of alpha nemertides, four nemertide-beta-type sequences, and two novel full-length parborlysins. Nemertean worms express toxins in the epidermal mucus. Here, the expression was determined by liquid chromatography combined with mass spectrometry. The findings include a new type of nemertide, 8750 Da, containing eight cysteines. In addition, we report the presence of six cysteine-containing peptides. The toxicity of tissue extracts and mucus fractions was tested in an Artemia assay. Notably, significant activity was observed both in tissue and the high-molecular-weight mucus fraction, as well as in a parborlysin fraction. Membrane permeabilization experiments display the membranolytic activity of some peptides, most prominently the parborlysin fraction, with an estimated EC50 of 70 nM.


Peptides , Animals , Antarctic Regions , Peptides/toxicity , Peptides/chemistry , Marine Toxins/toxicity , Marine Toxins/chemistry , Marine Toxins/analysis , Mucus/metabolism , Mucus/chemistry , Artemia
17.
Nat Commun ; 15(1): 3502, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38664378

Beneficial gut bacteria are indispensable for developing colonic mucus and fully establishing its protective function against intestinal microorganisms. Low-fiber diet consumption alters the gut bacterial configuration and disturbs this microbe-mucus interaction, but the specific bacteria and microbial metabolites responsible for maintaining mucus function remain poorly understood. By using human-to-mouse microbiota transplantation and ex vivo analysis of colonic mucus function, we here show as a proof-of-concept that individuals who increase their daily dietary fiber intake can improve the capacity of their gut microbiota to prevent diet-mediated mucus defects. Mucus growth, a critical feature of intact colonic mucus, correlated with the abundance of the gut commensal Blautia, and supplementation of Blautia coccoides to mice confirmed its mucus-stimulating capacity. Mechanistically, B. coccoides stimulated mucus growth through the production of the short-chain fatty acids propionate and acetate via activation of the short-chain fatty acid receptor Ffar2, which could serve as a new target to restore mucus growth during mucus-associated lifestyle diseases.


Colon , Dietary Fiber , Fatty Acids, Volatile , Gastrointestinal Microbiome , Intestinal Mucosa , Receptors, Cell Surface , Animals , Dietary Fiber/metabolism , Fatty Acids, Volatile/metabolism , Mice , Colon/metabolism , Colon/microbiology , Humans , Intestinal Mucosa/metabolism , Intestinal Mucosa/microbiology , Male , Receptors, G-Protein-Coupled/metabolism , Receptors, G-Protein-Coupled/genetics , Female , Mice, Inbred C57BL , Mucus/metabolism , Fecal Microbiota Transplantation , Symbiosis , Propionates/metabolism , Clostridiales/metabolism , Acetates/metabolism , Adult
18.
Biomaterials ; 309: 122577, 2024 Sep.
Article En | MEDLINE | ID: mdl-38677221

The relationship between the mechanical forces associated with bowel movement and colonic mucosal physiology is understudied. This is partly due to the limited availability of physiologically relevant fecal models that can exert these mechanical stimuli in in vitro colon models in a simple-to-implement manner. In this report, we created a mucus-coated fecal surrogate that was magnetically propelled to produce a controllable sweeping mechanical stimulation on primary intestinal epithelial cell monolayers. The mucus layer was derived from purified porcine stomach mucins, which were first modified with reactive vinyl sulfone (VS) groups followed by reaction with a thiol crosslinker (PEG-4SH) via a Michael addition click reaction. Formation of mucus hydrogel network was achieved at the optimal mixing ratio at 2.5 % w/v mucin-VS and 0.5 % w/v PEG-4SH. The artificial mucus layer possessed similar properties as the native mucus in terms of its storage modulus (66 Pa) and barrier function (resistance to penetration by 1-µm microbeads). This soft, but mechanically resilient mucus layer was covalently linked to a stiff fecal hydrogel surrogate (based on agarose and magnetic particles, with a storage modulus of 4600 Pa). The covalent bonding between the mucus and agarose ensured its stability in the subsequent fecal sliding movement when tested at travel distances as long as 203 m. The mucus layer served as a lubricant and protected epithelial cells from the moving fecal surrogate over a 1 h time without cell damage. To demonstrate its utility, this mucus-coated fecal surrogate was used to mechanically stimulate a fully differentiated, in vitro primary colon epithelium, and the physiological stimulated response of mucin-2 (MUC2), interleukin-8 (IL-8) and serotonin (5HT) secretion was quantified. Compared with a static control, mechanical stimulation caused a significant increase in MUC2 secretion into luminal compartment (6.4 × ), a small but significant increase in IL-8 secretion (2.5 × and 3.5 × , at both luminal and basal compartments, respectively), and no detectable alteration in 5HT secretion. This mucus-coated fecal surrogate is expected to be useful in in vitro colon organ-on-chips and microphysiological systems to facilitate the investigation of feces-induced mechanical stimulation on intestinal physiology and pathology.


Colon , Feces , Intestinal Mucosa , Mucus , Mucus/metabolism , Animals , Colon/physiology , Intestinal Mucosa/metabolism , Intestinal Mucosa/cytology , Feces/chemistry , Swine , Hydrogels/chemistry , Shear Strength , Sulfones/chemistry , Stress, Mechanical , Polyethylene Glycols/chemistry
19.
J Trace Elem Med Biol ; 84: 127459, 2024 Jul.
Article En | MEDLINE | ID: mdl-38640745

Trace elements such as zinc, manganese, copper, or iron are essential for a wide range of physiological functions. It is therefore crucial to ensure an adequate supply of these elements to the body. Many previous investigations have dealt with the role of transport proteins, in particular their selectivity for, and competition between, different ions. Another so far less well investigated major factor influencing the absorption of trace elements seems to be the intestinal mucus layer. This gel-like substance covers the entire gastrointestinal tract and its physiochemical properties can be mainly assigned to the glycoproteins it contains, so-called mucins. Interaction with mucins has already been demonstrated for some metals. However, knowledge about the impact on the respective bioavailability and competition between those metals is still sketchy. This review therefore aims to summarize the findings and knowledge gaps about potential effects regarding the interaction between gastrointestinal mucins and the trace elements iron, zinc, manganese, and copper. Mucins play an indispensable role in the absorption of these trace elements in the neutral to slightly alkaline environment of the intestine, by keeping them in a soluble form that can be absorbed by enterocytes. Furthermore, the studies so far indicate that the competition between these trace elements for uptake already starts at the intestinal mucus layer, yet further research is required to completely understand this interaction.


Copper , Intestinal Absorption , Intestinal Mucosa , Iron , Manganese , Zinc , Copper/metabolism , Humans , Zinc/metabolism , Manganese/metabolism , Iron/metabolism , Intestinal Absorption/physiology , Animals , Intestinal Mucosa/metabolism , Mucins/metabolism , Mucus/metabolism , Trace Elements/metabolism
20.
J Theor Biol ; 587: 111824, 2024 Jun 21.
Article En | MEDLINE | ID: mdl-38604595

The human gut microbiota relies on complex carbohydrates (glycans) for energy and growth, primarily dietary fiber and host-derived mucins. We introduce a mathematical model of a glycan generalist and a mucin specialist in a two-compartment chemostat model of the human colon. Our objective is to characterize the influence of dietary fiber and mucin supply on the abundance of mucin-degrading species within the gut ecosystem. Current mathematical gut reactor models that include the enzymatic degradation of glycans do not differentiate between glycan types and their degraders. The model we present distinguishes between a generalist that can degrade both dietary fiber and mucin, and a specialist species that can only degrade mucin. The integrity of the colonic mucus barrier is essential for overall human health and well-being, with the mucin specialist Akkermanisa muciniphila being associated with a healthy mucus layer. Competition, particularly between the specialist and generalists like Bacteroides thetaiotaomicron, may lead to mucus layer erosion, especially during periods of dietary fiber deprivation. Our model treats the colon as a gut reactor system, dividing it into two compartments that represent the lumen and the mucus of the gut, resulting in a complex system of ordinary differential equations with a large and uncertain parameter space. To understand the influence of model parameters on long-term behavior, we employ a random forest classifier, a supervised machine learning method. Additionally, a variance-based sensitivity analysis is utilized to determine the sensitivity of steady-state values to changes in model parameter inputs. By constructing this model, we can investigate the underlying mechanisms that control gut microbiota composition and function, free from confounding factors.


Dietary Fiber , Gastrointestinal Microbiome , Models, Biological , Mucins , Mucus , Mucins/metabolism , Dietary Fiber/metabolism , Humans , Gastrointestinal Microbiome/physiology , Mucus/metabolism , Colon/metabolism , Colon/microbiology , Polysaccharides/metabolism
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