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Gut Microbes Dec 2023The intestinal epithelium is constantly exposed to microbes residing in the lumen. Traditionally, the response to microbial interactions has been studied in cell lines...
The intestinal epithelium is constantly exposed to microbes residing in the lumen. Traditionally, the response to microbial interactions has been studied in cell lines derived from cancerous tissues, e.g. Caco-2. It is, however, unclear how the responses in these cancer cell lines reflect the responses of a normal epithelium and whether there might be microbial strain-specific effects. To address these questions, we derived organoids from the small intestine from a cohort of healthy individuals. Culturing intestinal epithelium on a flat laminin matrix induced their differentiation, facilitating analysis of microbial responses via the apical membrane normally exposed to the luminal content. Here, it was evident that the healthy epithelium across multiple individuals ( = 9) demonstrates robust acute both common and strain-specific responses to a range of probiotic bacterial strains (BB-12, LGG, DSM33361, and Bif195). Importantly, parallel experiments using the Caco-2 cell line provide no acute response. Collectively, we demonstrate that primary epithelial cells maintained as organoids represent a valuable resource for assessing interactions between the epithelium and luminal microbes across individuals, and that these models are likely to contribute to a better understanding of host microbe interactions.
Topics: Humans; Caco-2 Cells; Gastrointestinal Microbiome; Epithelial Cells; Organoids; Epithelium; Intestinal Mucosa
PubMed: 37992398
DOI: 10.1080/19490976.2023.2281012 -
Biophysical Journal Aug 2023Membrane surface reconstruction at the nanometer scale is required for understanding mechanisms of subcellular shape change. This historically has been the domain of...
Membrane surface reconstruction at the nanometer scale is required for understanding mechanisms of subcellular shape change. This historically has been the domain of electron microscopy, but extraction of surfaces from specific labels is a difficult task in this imaging modality. Existing methods for extracting surfaces from fluorescence microscopy have poor resolution or require high-quality super-resolution data that are manually cleaned and curated. Here, we present NanoWrap, a new method for extracting surfaces from generalized single-molecule localization microscopy data. This makes it possible to study the shape of specifically labeled membranous structures inside cells. We validate NanoWrap using simulations and demonstrate its reconstruction capabilities on single-molecule localization microscopy data of the endoplasmic reticulum and mitochondria. NanoWrap is implemented in the open-source Python Microscopy Environment.
Topics: Mitochondria; Membranes; Nanotechnology; Endoplasmic Reticulum; Microscopy, Fluorescence
PubMed: 37355772
DOI: 10.1016/j.bpj.2023.06.010 -
Mucosal Immunology Jun 2024The microbiome has emerged as a crucial modulator of host-immune interactions and clearly impacts tumor development and therapy efficacy. The microbiome is a... (Review)
Review
The microbiome has emerged as a crucial modulator of host-immune interactions and clearly impacts tumor development and therapy efficacy. The microbiome is a double-edged sword in cancer development and therapy as both pro-tumorigenic and anti-tumorigenic bacterial taxa have been identified. The staggering number of association-based studies in various tumor types has led to an enormous amount of data that makes it difficult to identify bacteria that promote tumor development or modulate therapy efficacy from bystander bacteria. Here we aim to comprehensively summarize the current knowledge of microbiome-host immunity interactions and cancer therapy in various mucosal tissues to find commonalities and thus identify potential functionally relevant bacterial taxa. Moreover, we also review recent studies identifying specific bacteria and mechanisms through which the microbiome modulates cancer development and therapy efficacy.
Topics: Humans; Immunotherapy; Animals; Neoplasms; Microbiota; Mucous Membrane; Host-Pathogen Interactions; Gastrointestinal Microbiome; Immunity, Mucosal
PubMed: 38521413
DOI: 10.1016/j.mucimm.2024.03.007 -
STAR Protocols Dec 2023Renewable energy-driven bipolar membrane water electrolyzers (BPMWEs) are a promising technology for sustainable production of hydrogen from seawater and other impure...
Renewable energy-driven bipolar membrane water electrolyzers (BPMWEs) are a promising technology for sustainable production of hydrogen from seawater and other impure water sources. Here, we present a protocol for assembling BPMWEs and operating them in a range of water feedstocks, including ultra-pure deionized water and seawater. We describe steps for membrane electrode assembly preparation, electrolyzer assembly, and electrochemical evaluation. For complete details on the use and execution of this protocol, please refer to Marin et al. (2023)..
Topics: Water; Membranes
PubMed: 37924520
DOI: 10.1016/j.xpro.2023.102606 -
The Journal of Physical Chemistry. B Oct 2023Mechanosensitive ion channels are present in the plasma membranes of all cells. They play a fundamental role in converting mechanical stimuli into biochemical signals...
Mechanosensitive ion channels are present in the plasma membranes of all cells. They play a fundamental role in converting mechanical stimuli into biochemical signals and are involved in several physiological processes such as touch sensation, hearing, and blood pressure regulation. This protein family includes TWIK-related arachidonic acid-stimulated K channel (TRAAK), which is specifically implicated in the maintenance of the resting membrane potential and in the regulation of a variety of important neurobiological functions. Dysregulation of these channels has been linked to various diseases, including blindness, epilepsy, cardiac arrhythmia, and chronic pain. For these reasons, mechanosensitive channels are targets for the treatment of several diseases. Here, we propose a new approach to investigate TRAAK ion channel modulation that is based on nongenetic photostimulation. We employed an amphiphilic azobenzene, named Ziapin2. In the dark, Ziapin2 preferentially dwells in the plasma membrane, causing a thinning of the membrane. Upon light irradiation, an isomerization occurs, breaking the dimers and inducing membrane relaxation. To study the effect of Ziapin2 on the mechanosensitive channels, we expressed human TRAAK (hTRAAK) channels in HEK293T cells. We observed that Ziapin2 insertion in the membrane is able per se to recruit hTRAAK, permitting the exit of K ions outside the cells with a consequent hyperpolarization of the cell membrane. During light stimulation, membrane relaxation induces hTRAAK closure, generating a consistent and compensatory depolarization. These results add information to the Ziapin2 mechanism and suggest that membrane deformation can be a tool for the nonselective modulation of mechanosensitive channels.
Topics: Humans; Potassium Channels; HEK293 Cells; Ion Channels; Cell Membrane; Membranes
PubMed: 37815392
DOI: 10.1021/acs.jpcb.3c04551 -
Cytometry. Part a : the Journal of the... Nov 2023There is a great need to understand human immune cells within tissue, where disease manifests and infection occurs. Tissue-resident memory T cells (TRMs) were discovered...
There is a great need to understand human immune cells within tissue, where disease manifests and infection occurs. Tissue-resident memory T cells (TRMs) were discovered over a decade ago, there is a great need to understand their role in human disease. We developed a 24-color flow cytometry panel to comprehensively interrogate CD4 and CD8 TRMs isolated from human tissues. When interrogating cells within human tissue, enzymatic methods used to liberate cells from within the tissue can cause cleavage of cell surface markers needed to phenotype these cells. Here we carefully select antibody clones and evaluate the effect of enzymatic digestion on the expression of markers relevant to the identification of T cell residency, as well as markers relevant to the activation and immunoregulation status of these cells. We have designed this panel to be applicable across a range of human tissues including skin, intestine, and type II mucosae such as the vagina.
Topics: Female; Humans; Flow Cytometry; CD8-Positive T-Lymphocytes; Intestines; CD4-Positive T-Lymphocytes; Mucous Membrane; Immunologic Memory
PubMed: 37772977
DOI: 10.1002/cyto.a.24782 -
Journal of Genetics and Genomics = Yi... Oct 2023Interactions between diet and the intestinal microbiome play an important role in human health and disease development. It is well known that such interactions, whether... (Review)
Review
Interactions between diet and the intestinal microbiome play an important role in human health and disease development. It is well known that such interactions, whether direct or indirect, trigger a series of metabolic reactions in the body. Evidence suggests that intestinal stem cells (ISCs), which are phenotypic precursors of various intestinal epithelial cells, play a significant role in the regulation of intestinal barrier function and homeostasis. The advent and evolution of intestinal organoid culture techniques have presented a key opportunity to study the association between the intestinal microenvironment and ISCs. As a result, the effects exerted by dietary factors, intestinal microbiomes, and their metabolites on the metabolic regulation of ISCs and the potential mechanisms underlying such effects are being gradually revealed. This review summarises the effects of different dietary patterns on the behaviour and functioning of ISCs and focuses on the crosstalk between intestinal microbiota, related metabolites, and ISCs, with the aim of fully understanding the relationship between these three factors and providing further insights into the complex mechanisms associated with ISCs in the human body. Gaining an understanding of these mechanisms may lead to the development of novel dietary interventions or drugs conducive to intestinal health.
Topics: Humans; Gastrointestinal Microbiome; Stem Cells; Diet; Animals; Intestines; Intestinal Mucosa; Homeostasis
PubMed: 36566949
DOI: 10.1016/j.jgg.2022.12.002 -
Nutrients Aug 2023Thanks to their valuable assessment possibilities (subjective complaints and changes in nasal patency during the examination), nasal provocation tests may serve as an...
Thanks to their valuable assessment possibilities (subjective complaints and changes in nasal patency during the examination), nasal provocation tests may serve as an alternative tool for oral food challenges in the future. However, this test requires successive attempts to regulate its methodology in order to develop a standardized lyophilisate form and determine the threshold dose for a positive result. The study objective was to present the methodological foundation for nasal food allergen provocation tests induced by freeze-dried powdered chicken egg whites. A control group of 25 individuals with no history of allergy to chicken eggs or any other allergy was included in the study. Optical rhinometry and visual analog scales were used to assess the response of nasal mucosa to local allergen challenges. Minor variations in nasal flows, as measured by optical rhinometry, were observed in the provocation tests. The mean optical density measurements (as measured regardless of the allergen dose used) varied from positive to negative values and vice versa, e.g., amounting to 0.018 OD (standard deviation 0.095) at 15 min and -0.011 OD (standard deviation 0.090) at 30 min. No significant differences were observed concerning the perceived nasal discomfort using the visual analog scale. Due to the absence of nasal mucosal reactivity, nasal challenge is an excellent methodological tool for implementing food allergen tests.
Topics: Humans; Nasal Provocation Tests; Hypersensitivity; Food; Nasal Mucosa; Allergens
PubMed: 37686848
DOI: 10.3390/nu15173816 -
International Journal of Molecular... Sep 2023This is an attempt to briefly summarize the contributions to this second Special Issue of the on the barrier function of the skin and the oral mucosa [...].
This is an attempt to briefly summarize the contributions to this second Special Issue of the on the barrier function of the skin and the oral mucosa [...].
Topics: Mouth Mucosa; Skin
PubMed: 37761991
DOI: 10.3390/ijms241813690 -
Nature Communications Apr 2024The organization of membrane proteins between and within membrane-bound compartments is critical to cellular function. Yet we lack approaches to regulate this...
The organization of membrane proteins between and within membrane-bound compartments is critical to cellular function. Yet we lack approaches to regulate this organization in a range of membrane-based materials, such as engineered cells, exosomes, and liposomes. Uncovering and leveraging biophysical drivers of membrane protein organization to design membrane systems could greatly enhance the functionality of these materials. Towards this goal, we use de novo protein design, molecular dynamic simulations, and cell-free systems to explore how membrane-protein hydrophobic mismatch could be used to tune protein cotranslational integration and organization in synthetic lipid membranes. We find that membranes must deform to accommodate membrane-protein hydrophobic mismatch, which reduces the expression and co-translational insertion of membrane proteins into synthetic membranes. We use this principle to sort proteins both between and within membranes, thereby achieving one-pot assembly of vesicles with distinct functions and controlled split-protein assembly, respectively. Our results shed light on protein organization in biological membranes and provide a framework to design self-organizing membrane-based materials with applications such as artificial cells, biosensors, and therapeutic nanoparticles.
Topics: Cell Membrane; Membranes; Membrane Proteins; Liposomes; Artificial Cells; Lipid Bilayers
PubMed: 38605024
DOI: 10.1038/s41467-024-47163-1