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Frontiers in Immunology 2018Amphibian skin is a mucosal surface in direct and continuous contact with a microbially diverse and laden aquatic and/or terrestrial environment. As such, frog skin is... (Review)
Review
Amphibian skin is a mucosal surface in direct and continuous contact with a microbially diverse and laden aquatic and/or terrestrial environment. As such, frog skin is an important innate immune organ and first line of defence against pathogens in the environment. Critical to the innate immune functions of frog skin are the maintenance of physical, chemical, cellular, and microbiological barriers and the complex network of interactions that occur across all the barriers. Despite the global decline in amphibian populations, largely as a result of emerging infectious diseases, we understand little regarding the cellular and molecular mechanisms that underlie the innate immune function of amphibian skin and defence against pathogens. In this review, we discuss the structure, cell composition and cellular junctions that contribute to the skin physical barrier, the antimicrobial peptide arsenal that, in part, comprises the chemical barrier, the pattern recognition receptors involved in recognizing pathogens and initiating innate immune responses in the skin, and the contribution of commensal microbes on the skin to pathogen defence. We briefly discuss the influence of environmental abiotic factors (natural and anthropogenic) and pathogens on the immunocompetency of frog skin defences. Although some aspects of frog innate immunity, such as antimicrobial peptides are well-studied; other components and how they contribute to the skin innate immune barrier, are lacking. Elucidating the complex network of interactions occurring at the interface of the frog's external and internal environments will yield insight into the crucial role amphibian skin plays in host defence and the environmental factors leading to compromised barrier integrity, disease, and host mortality.
Topics: Amphibians; Animals; Antimicrobial Cationic Peptides; Anura; Bacteria; Disease Resistance; Epithelial Cells; Host-Pathogen Interactions; Immunity, Innate; Microbial Sensitivity Tests; Microbiota; Mucous Membrane; Receptors, Pattern Recognition; Skin; Skin Physiological Phenomena; Viruses
PubMed: 30692997
DOI: 10.3389/fimmu.2018.03128 -
Frontiers in Immunology 2021Type 3 Innate lymphoid cells (ILC3s) have been described as tissue-resident cells and characterized throughout the body, especially in mucosal sites and classical first... (Review)
Review
Type 3 Innate lymphoid cells (ILC3s) have been described as tissue-resident cells and characterized throughout the body, especially in mucosal sites and classical first barrier organs such as skin, gut and lungs, among others. A significant part of the research has focused on their role in combating pathogens, mainly extracellular pathogens, with the gut as the principal organ. However, some recent discoveries in the field have unveiled their activity in other organs, combating intracellular pathogens and as part of the response to viruses. In this review we have compiled the latest studies on the role of ILC3s and the molecular mechanisms involved in defending against different microbes at the mucosal surface, most of these studies have made use of conditional transgenic mice. The present review therefore attempts to provide an overview of the function of ILC3s in infections throughout the body, focusing on their specific activity in different organs.
Topics: Animals; Gastrointestinal Tract; Host-Pathogen Interactions; Humans; Immunity, Innate; Infections; Lung; Lymphocytes; Mouth Mucosa; Skin
PubMed: 34659248
DOI: 10.3389/fimmu.2021.748851 -
Italian Journal of Dermatology and... Oct 2023The oral mucosa can be involved in a wide variety of mucocutaneous conditions that may present primarily in the mouth or affect other cutaneous or mucosal sites. Many of... (Review)
Review
The oral mucosa can be involved in a wide variety of mucocutaneous conditions that may present primarily in the mouth or affect other cutaneous or mucosal sites. Many of these conditions are immune mediated and typically present as inflammatory mucosal pathology. Patients experiencing such conditions usually seek medical evaluation and treatment due to the associated pain and discomfort and occasionally taste disturbance or dysphagia and the overall deterioration in the oral health-related quality of life. These conditions share some common features and there could be some overlapping in their clinical presentation, which can lead to delays in diagnosis and proper management of patients. Clinicians dealing with such disorders, including dermatologists, need to be aware of the oral manifestations of mucocutaneous conditions, their clinical features, underlying mechanisms, diagnostic approaches, and treatment options, as well as the recent advances in the research on these conditions. This review provides a comprehensive, evidence-based reference for clinicians, with updated insights into a group of immune mediated conditions known to cause oral mucosal pathology. Part one will cover oral lichen planus, erythema multiforme and systemic lupus erythematosus, while part two will cover pemphigus vulgaris and mucous membrane pemphigoid, recurrent aphthous stomatitis, in addition to the less common disorders linear IgA disease, dermatitis herpetiformis and epidermolysis bullosa.
Topics: Humans; Mouth Mucosa; Mouth Diseases; Quality of Life; Stomatitis, Aphthous; Pemphigus
PubMed: 37916401
DOI: 10.23736/S2784-8671.23.07676-4 -
World Journal of Gastroenterology Feb 2019During the past decades, endoscopic resection techniques have gradually improved and gained more importance for the management of premalignant lesions and early cancers.... (Review)
Review
During the past decades, endoscopic resection techniques have gradually improved and gained more importance for the management of premalignant lesions and early cancers. These endoscopic resection techniques can be divided in 3 major groups: snare polipectomy, endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). The use of submucosal injection is essential for the majority of EMR techniques and is an integral part of ESD, whereas during polipectomy it is not crucial in most cases except to prevent bleeding in large polyps and/or those with large stalks as an alternative to mechanical methods. Injection provides a lifting up effect of the lesion separating it from the muscular layer, thereby reducing thermal injury and the risk of perforation and bleeding while also facilitating resection by improving technical feasibility. With this work, we aim to review the most common endoscopic resection techniques and the importance of submucosal injection in each one of them. For that, we present some of the most commonly used submucosal injection solutions, taking into account their advantages and disadvantages. We also discuss, based on current recommendations and our own experience, how and when to preform submucosal injection, depending on lesions features and endoscopic resection technique that´s being used, to assure complete resection and to prevent associated adverse events. Finally, we also present and discuss some new proposed submucosal injection solutions, endoscopic resection techniques and devices that may have a major impact on the future of therapeutic endoscopy.
Topics: Endoscopic Mucosal Resection; Gastric Mucosa; Gastrointestinal Diseases; Humans; Injections; Intestinal Mucosa; Neoplasms; Precancerous Conditions
PubMed: 30809079
DOI: 10.3748/wjg.v25.i7.777 -
Proceedings of the National Academy of... Feb 2023Lysosomal exocytosis is involved in many key cellular processes but its spatiotemporal regulation is poorly known. Using total internal reflection fluorescence...
Lysosomal exocytosis is involved in many key cellular processes but its spatiotemporal regulation is poorly known. Using total internal reflection fluorescence microscopy (TIRFM) and spatial statistics, we observed that lysosomal exocytosis is not random at the adhesive part of the plasma membrane of RPE1 cells but clustered at different scales. Although the rate of exocytosis is regulated by the actin cytoskeleton, neither interfering with actin or microtubule dynamics by drug treatments alters its spatial organization. Exocytosis events partially co-appear at focal adhesions (FAs) and their clustering is reduced upon removal of FAs. Changes in membrane tension following a hypo-osmotic shock or treatment with methyl-β-cyclodextrin were found to increase clustering. To investigate the link between FAs and membrane tension, cells were cultured on adhesive ring-shaped micropatterns, which allow to control the spatial organization of FAs. By using a combination of TIRFM and fluorescence lifetime imaging microscopy (FLIM), we revealed the existence of a radial gradient in membrane tension. By changing the diameter of micropatterned substrates, we further showed that this gradient as well as the extent of exocytosis clustering can be controlled. Together, our data indicate that the spatial clustering of lysosomal exocytosis relies on membrane tension patterning controlled by the spatial organization of FAs.
Topics: Cell Membrane; Exocytosis; Membranes; Cell Physiological Phenomena; Lysosomes
PubMed: 36800388
DOI: 10.1073/pnas.2207425120 -
Biochemical Society Transactions Oct 2022The mucus layer covering the gastrointestinal (GI) tract plays a critical role in maintaining gut homeostasis. In the colon, the inner mucus layer ensures commensal... (Review)
Review
The mucus layer covering the gastrointestinal (GI) tract plays a critical role in maintaining gut homeostasis. In the colon, the inner mucus layer ensures commensal microbes are kept at a safe distance from the epithelium while mucin glycans in the outer mucus layer provide microbes with nutrients and binding sites. Microbes residing in the mucus form part of the so-called 'mucosa-associated microbiota' (MAM), a microbial community which, due to its close proximity to the epithelium, has a profound impact on immune and metabolic health by directly impacting gut barrier function and the immune system. Alterations in GI microbial communities have been linked to human diseases. Although most of this knowledge is based on analysis of the faecal microbiota, a growing number of studies show that the MAM signature differs from faecal or luminal microbiota and has the potential to be used to distinguish between diseased and healthy status in well-studied conditions such as IBD, IBS and CRC. However, our knowledge about spatial microbial alterations in pathogenesis remains severely hampered by issues surrounding access to microbial communities in the human gut. In this review, we provide state-of-the-art information on how to access MAM in humans, the composition of MAM, and how changes in MAM relate to changes in human health and disease. A better understanding of interactions occurring at the mucosal surface is essential to advance our understanding of diseases affecting the GI tract and beyond.
Topics: Humans; Gastrointestinal Microbiome; Intestinal Mucosa; Colon; Mucus; Microbiota
PubMed: 36214382
DOI: 10.1042/BST20201201 -
International Journal of Molecular... Nov 2019Epicardial adipose tissue (EAT) is part of the visceral adipose tissue (VAT) that surrounds the heart and it is a quantifiable, modifiable, and multifaceted tissue that... (Review)
Review
Epicardial adipose tissue (EAT) is part of the visceral adipose tissue (VAT) that surrounds the heart and it is a quantifiable, modifiable, and multifaceted tissue that has both local and systemic effects. When EAT is enlarged, EAT contributes to atherosclerotic cardiovascular disease (ASCVD) risk and plays a role in the development of metabolic syndrome (MetS). In this review, we will discuss the role of EAT in various facets of MetS, including type 2 diabetes mellitus (T2DM) and insulin resistance. We examine the association between EAT and liver steatosis. We also address the correlations of EAT with HIV therapy and with psoriasis. We discuss racial differences in baseline EAT thickness. We conclude that EAT measurement serves as a powerful potential diagnostic tool in assessing cardiovascular and metabolic risk. Measurement of EAT is made less costly, more convenient, and yet accurate and reliable by transthoracic echocardiography. Furthermore, modification of EAT thickness has therapeutic implications for ASCVD, T2DM, and MetS.
Topics: Biomarkers; Cardiovascular Diseases; Humans; Intra-Abdominal Fat; Lipid Metabolism; Metabolic Syndrome; Pericardium
PubMed: 31795098
DOI: 10.3390/ijms20235989 -
Communications Biology Aug 2021The position of abdominal organs, and mechanisms by which these are centrally connected, are currently described in peritoneal terms. As part of the peritoneal model of...
The position of abdominal organs, and mechanisms by which these are centrally connected, are currently described in peritoneal terms. As part of the peritoneal model of abdominal anatomy, there are multiple mesenteries. Recent findings point to an alternative model in which digestive organs are connected to a single mesentery. Given that direct evidence of this is currently lacking, we investigated the development and shape of the entire mesentery. Here we confirm that, within the abdomen, there is one mesentery in which all abdominal digestive organs develop and remain connected to. We show that all abdominopelvic organs are organised into two, discrete anatomical domains, the mesenteric and non-mesenteric domain. A similar organisation occurs across a range of animal species. The findings clarify the anatomical foundation of the abdomen; at the foundation level, the abdomen comprises a visceral (i.e. mesenteric) and somatic (i.e. musculoskeletal) frame. The organisation at that level is a fundamental order that explains the positional anatomy of all abdominopelvic organs, vasculature and peritoneum. Collectively, the findings provide a novel start point from which to systemically characterise the abdomen and its contents.
Topics: Humans; Mesentery; Peritoneum
PubMed: 34408242
DOI: 10.1038/s42003-021-02496-1 -
Clinical and Experimental Immunology Oct 2016This literature review assesses the current knowledge about the immunological aspects of the vermiform appendix in health and disease. An essential part of its... (Review)
Review
This literature review assesses the current knowledge about the immunological aspects of the vermiform appendix in health and disease. An essential part of its immunological function is the interaction with the intestinal bacteria, a trait shown to be preserved during its evolution. The existence of the appendiceal biofilm in particular has proved to have a beneficial effect for the entire gut. In assessing the influence of acute appendicitis and the importance of a normally functioning gut flora, however, multiple immunological aspects point towards the appendix as a priming site for ulcerative colitis. Describing the immunological and microbiotical changes in the appendix during acute and chronic inflammation of the appendix, this review suggests that this association becomes increasingly plausible. Sustained by the distinct composition of cells, molecules and microbiota, as well as by the ever more likely negative correlation between the appendix and ulcerative colitis, the idea of the appendix being a vestigial organ should therefore be discarded.
Topics: Animals; Appendicitis; Appendix; Biological Evolution; Humans; Inflammatory Bowel Diseases; Intestinal Mucosa; Lymphocytes; Microbiota
PubMed: 27271818
DOI: 10.1111/cei.12821 -
Expert Review of Gastroenterology &... Mar 2018Nano-scale formulations are being developed to improve the delivery of orally administered medicines, and the interactions between nanoformulations and the... (Review)
Review
Nano-scale formulations are being developed to improve the delivery of orally administered medicines, and the interactions between nanoformulations and the gastrointestinal luminal, mucosal and epithelial environment is currently being investigated. The mucosal surface of the gastrointestinal tract is capable of trapping and eliminating large particles and pathogens as part of the natural defences of the body, it is becoming clearer that nanoformulation properties such as particle size, charge, and shape, as well as mucous properties such as viscoelasticity, thickness, density, and turn-over time are all relevant to these interactions. However, progress has been slow to utilise this information to produce effective mucous-penetrating particles. Areas covered: This review focuses on delivery method of nanomedicines both into and across the gastrointestinal mucosal surface, and aims to summarise the biological barriers that exist to successful oral nanomedicine delivery and how these barriers may be investigated and overcome. Expert commentary: Despite successes in the laboratory, no nanotechnology-enabled products are currently in clinical use which either specifically target the intestinal mucous surface or cross the epithelial barrier intact. New nanomedicine-based treatments of local diseases (intestinal cancer, inflammation, infection) and systemic diseases are advancing towards clinical use, and offer genuine opportunities to improve therapy.
Topics: Administration, Oral; Animals; Bile; Cell Membrane; Drug Delivery Systems; Endocytosis; Exocytosis; Gastric Juice; Humans; Intestinal Absorption; Intestinal Mucosa; Mucus; Nanoparticles; Permeability; Saliva; Tight Junctions; Transcytosis
PubMed: 29088978
DOI: 10.1080/17474124.2018.1399794