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Ambrogi M, Vezina CM. Roles of airway and intestinal epithelia in responding to pathogens and maintaining tissue homeostasis. Front Cell Infect Microbiol 2024; 14:1346087. [PMID: 38736751 PMCID: PMC11082347 DOI: 10.3389/fcimb.2024.1346087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 04/10/2024] [Indexed: 05/14/2024] Open
Abstract
Epithelial cells form a resilient barrier and orchestrate defensive and reparative mechanisms to maintain tissue stability. This review focuses on gut and airway epithelia, which are positioned where the body interfaces with the outside world. We review the many signaling pathways and mechanisms by which epithelial cells at the interface respond to invading pathogens to mount an innate immune response and initiate adaptive immunity and communicate with other cells, including resident microbiota, to heal damaged tissue and maintain homeostasis. We compare and contrast how airway and gut epithelial cells detect pathogens, release antimicrobial effectors, collaborate with macrophages, Tregs and epithelial stem cells to mount an immune response and orchestrate tissue repair. We also describe advanced research models for studying epithelial communication and behaviors during inflammation, tissue injury and disease.
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Affiliation(s)
| | - Chad M. Vezina
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, United States
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Engel L, Zaoralová M, Zhou M, Dunn AR, Oliver SL. Extracellular filaments revealed by affinity capture cryo-electron tomography of lymphocytes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.05.552110. [PMID: 37577490 PMCID: PMC10418515 DOI: 10.1101/2023.08.05.552110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Cryogenic-electron tomography (cryo-ET) has provided an un-precedented glimpse into the nanoscale architecture of cells by combining cryogenic preservation of biological structures with electron tomography. Micropatterning of extracellular matrix proteins is increasingly used as a method to prepare adherent cell types for cryo-ET as it promotes optimal positioning of cells and subcellular regions of interest for vitrification, cryo-focused ion beam (cryo-FIB) milling, and data acquisition. Here we demonstrate a micropatterning workflow for capturing minimally adherent cell types, human T-cells and Jurkat cells, for cryo-FIB and cryo-ET. Our affinity capture system facilitated the nanoscale imaging of Jurkat cells, revealing extracellular filamentous structures. It improved workflow efficiency by consistently producing grids with a sufficient number of well-positioned cells for an entire cryo-FIB session. Affinity capture can be extended to facilitate high resolution imaging of other adherent and non-adherent cell types with cryo-ET.
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Abstract
Biogeography is the study of species distribution and diversity within an ecosystem and is at the core of how we understand ecosystem dynamics and interactions at the macroscale. In gut microbial communities, a historical reliance on bulk sequencing to probe community composition and dynamics has overlooked critical processes whereby microscale interactions affect systems-level microbiota function and the relationship with the host. In recent years, higher-resolution sequencing and novel single-cell level data have uncovered an incredible heterogeneity in microbial composition and have enabled a more nuanced spatial understanding of the gut microbiota. In an era when spatial transcriptomics and single-cell imaging and analysis have become key tools in mammalian cell and tissue biology, many of these techniques are now being applied to the microbiota. This fresh approach to intestinal biogeography has given important insights that span temporal and spatial scales, from the discovery of mucus encapsulation of the microbiota to the quantification of bacterial species throughout the gut. In this Review, we highlight emerging knowledge surrounding gut biogeography enabled by the observation and quantification of heterogeneity across multiple scales.
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Affiliation(s)
- Giselle McCallum
- Department of Biology, Concordia University, Montreal, Quebec, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Carolina Tropini
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada.
- School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, Canada.
- Humans and the Microbiome Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, Canada.
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Kunnathattil M, Rahul P, Skaria T. Soluble vascular endothelial glycocalyx proteoglycans as potential therapeutic targets in inflammatory diseases. Immunol Cell Biol 2024; 102:97-116. [PMID: 37982607 DOI: 10.1111/imcb.12712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 10/30/2023] [Accepted: 10/30/2023] [Indexed: 11/21/2023]
Abstract
Reducing the activity of cytokines and leukocyte extravasation is an emerging therapeutic strategy to limit tissue-damaging inflammatory responses and restore immune homeostasis in inflammatory diseases. Proteoglycans embedded in the vascular endothelial glycocalyx, which regulate the activity of cytokines to restrict the inflammatory response in physiological conditions, are proteolytically cleaved in inflammatory diseases. Here we critically review the potential of proteolytically shed, soluble vascular endothelial glycocalyx proteoglycans to modulate pathological inflammatory responses. Soluble forms of the proteoglycans syndecan-1, syndecan-3 and biglycan exert beneficial anti-inflammatory effects by the removal of chemokines, suppression of proinflammatory cytokine expression and leukocyte migration, and induction of autophagy of proinflammatory M1 macrophages. By contrast, soluble versikine and decorin enhance proinflammatory responses by increasing inflammatory cytokine synthesis and leukocyte migration. Endogenous syndecan-2 and mimecan exert proinflammatory effects, syndecan-4 and perlecan mediate beneficial anti-inflammatory effects and glypican regulates Hh and Wnt signaling pathways involved in systemic inflammatory responses. Taken together, targeting the vascular endothelial glycocalyx-derived, soluble syndecan-1, syndecan-2, syndecan-3, syndecan-4, biglycan, versikine, mimecan, perlecan, glypican and decorin might be a potential therapeutic strategy to suppress overstimulated cytokine and leukocyte responses in inflammatory diseases.
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Affiliation(s)
- Maneesha Kunnathattil
- Department of Zoology, Government College Madappally, University of Calicut, Calicut, Kerala, India
| | - Pedapudi Rahul
- School of Biotechnology, National Institute of Technology Calicut, Calicut, Kerala, India
| | - Tom Skaria
- School of Biotechnology, National Institute of Technology Calicut, Calicut, Kerala, India
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Toepfer S, Toth S, Zupan T, Bogataj U, Žnidaršič N, Ladanyi M, Sabotič J. Diabrotica v. virgifera Seems Not Affected by Entomotoxic Protease Inhibitors from Higher Fungi. INSECTS 2024; 15:60. [PMID: 38249066 PMCID: PMC10816698 DOI: 10.3390/insects15010060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 12/15/2023] [Accepted: 12/24/2023] [Indexed: 01/23/2024]
Abstract
Certain soil insects, such as the root-damaging larvae of the maize pest Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae), are increasingly difficult to control because of recent bans of some insecticides. An alternative and safer approach may be the development of biopesticides based on entomotoxic defense proteins of higher fungi. Many of these potentially interesting proteins are protease inhibitors, and some have been shown to adversely affect insects. We examined the effects of the cysteine protease inhibitors macrocypin 1, 3, and 4 from Macrolepiota procera, clitocypin from Clitocybe nebularis, and cocaprin 1 and the serine protease inhibitor cospin 1 from Coprinopsis cinerea on D. v. virgifera. We confirmed the inhibition by mycocypins of the cysteine catalytic-type proteolytic activities in gut extracts of larvae and adults. The inhibition of pGlu-Phe-Leu-hydrolyzing activity was stronger than that of Z-Phe-Arg-hydrolyzing activity. Mycocypins and cospin resisted long-term proteolytic digestion, whereas cocaprin 1 was digested. Bioassays with overlaid artificial diet revealed no effects of proteins on neonatal mortality or stunting, and no effects on adult mortality. Immersion of eggs in protein solutions had little effect on egg hatching or mortality of hatching neonates. Microscopic analysis of the peritrophic matrix and apical surface of the midguts revealed the similarity between larvae of D. v. virgifera and the chrysomelid Leptinotarsa decemlineata, which are sensitive to these inhibitors. The resistance of D. v. virgifera to fungal protease inhibitors is likely due to effective adaptation of digestive enzyme expression to dietary protease inhibitors. We continue to study unique protein complexes of higher fungi for the development of new approaches to pest control.
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Affiliation(s)
- Stefan Toepfer
- Department of Integrated Plant Protection, Plant Protection Institute, Hungarian University of Agriculture and Life Sciences (MATE), 2100 Godollo, Hungary;
- CABI, 2800 Delemont, Switzerland
| | - Szabolcs Toth
- Department of Integrated Plant Protection, Plant Protection Institute, Hungarian University of Agriculture and Life Sciences (MATE), 2100 Godollo, Hungary;
| | - Tanja Zupan
- Department of Biotechnology, Jožef Stefan Institute, 1000 Ljubljana, Slovenia; (T.Z.); (J.S.)
| | - Urban Bogataj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (U.B.); (N.Ž.)
| | - Nada Žnidaršič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (U.B.); (N.Ž.)
| | - Marta Ladanyi
- Department of Applied Statistics, Institute of Mathematics and Basic Science, Hungarian University of Agriculture and Life Sciences (MATE), 1118 Budapest, Hungary;
| | - Jerica Sabotič
- Department of Biotechnology, Jožef Stefan Institute, 1000 Ljubljana, Slovenia; (T.Z.); (J.S.)
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Niazi A, Kim JA, Kim DK, Lu D, Sterin I, Park J, Park S. Microvilli regulate the release modes of alpha-tectorin to organize the domain-specific matrix architecture of the tectorial membrane. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.04.574255. [PMID: 38260557 PMCID: PMC10802356 DOI: 10.1101/2024.01.04.574255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The tectorial membrane (TM) is an apical extracellular matrix (ECM) in the cochlea essential for auditory transduction. The TM exhibits highly ordered domain-specific architecture. Alpha-tectorin/TECTA is a glycosylphosphatidylinositol (GPI)-anchored ECM protein essential for TM organization. Here, we identified that TECTA is released by distinct modes: proteolytic shedding by TMPRSS2 and GPI-anchor-dependent release from the microvillus tip. In the medial/limbal domain, proteolytically shed TECTA forms dense fibers. In the lateral/body domain produced by the supporting cells displaying dense microvilli, the proteolytic shedding restricts TECTA to the microvillus tip and compartmentalizes the collagen-binding site. The tip-localized TECTA, in turn, is released in a GPI-anchor-dependent manner to form collagen-crosslinking fibers, required for maintaining the spacing and parallel organization of collagen fibrils. Overall, we showed that distinct release modes of TECTA determine the domain-specific organization pattern, and the microvillus coordinates the release modes along its membrane to organize the higher-order ECM architecture.
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Affiliation(s)
- Ava Niazi
- Department of Neurobiology, University of Utah, Salt Lake City, Utah, USA
- Neuroscience Program, University of Utah, Salt Lake City, Utah, USA
| | - Ju Ang Kim
- Department of Neurobiology, University of Utah, Salt Lake City, Utah, USA
- Current affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Dong-Kyu Kim
- Department of Neurobiology, University of Utah, Salt Lake City, Utah, USA
- Current affiliation: Genetics & Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Di Lu
- Department of Neurobiology, University of Utah, Salt Lake City, Utah, USA
| | - Igal Sterin
- Department of Neurobiology, University of Utah, Salt Lake City, Utah, USA
| | - Joosang Park
- Department of Neurobiology, University of Utah, Salt Lake City, Utah, USA
| | - Sungjin Park
- Department of Neurobiology, University of Utah, Salt Lake City, Utah, USA
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Jäverfelt S, Hellsén G, Kaji I, Goldenring JR, Pelaseyed T. The MYO1B and MYO5B motor proteins and the SNX27 sorting nexin regulate membrane mucin MUC17 trafficking in enterocytes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.06.530313. [PMID: 36945389 PMCID: PMC10028800 DOI: 10.1101/2023.03.06.530313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
A dense glycocalyx, composed of the megaDalton-sized membrane mucin MUC17, coats the microvilli in the apical brush border of transporting intestinal epithelial cells, called enterocytes. The establishment of the MUC17-based glycocalyx in the mouse small intestine occurs at the critical suckling-weaning transition. The enterocytic glycocalyx extends 1 µm into the intestinal lumen and prevents the gut bacteria from directly attaching to the enterocytes. To date, the mechanism behind apical targeting of MUC17 to the brush border remains unknown. Here, we show that the actin-based motor proteins MYO1B and MYO5B, and the sorting nexin SNX27 regulate the intracellular trafficking of MUC17 in enterocytes. We demonstrate that MUC17 turnover at the brush border is slow and controlled by MYO1B and SNX27. Furthermore, we report that MYO1B regulates MUC17 protein levels in enterocytes, whereas MYO5B specifically governs MUC17 levels at the brush border. Together, our results extend our understanding of the intracellular trafficking of membrane mucins and provide mechanistic insights into how defective trafficking pathways render enterocytes sensitive to bacterial invasion.
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Lysyl oxidase-like 1 deficiency alters ultrastructural and biomechanical properties of the peripapillary sclera in mice. Matrix Biol Plus 2022; 16:100120. [PMID: 36060791 PMCID: PMC9436796 DOI: 10.1016/j.mbplus.2022.100120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 08/17/2022] [Indexed: 11/30/2022] Open
Abstract
Lysyl oxidate-like 1 knockout (Loxl1-/-) mice have decreased vision without elevated intraocular pressure. Loxl1-/- mice exhibit biometric changes of the anterior segment of the eye. Loxl1-/- mice have altered elastin and collagen structure in peripapillary sclera. Structural alternations of peripapillary sclera correlate with its increased stiffness in Loxl1-/- mice.
Lysyl oxidase-like 1 encoded by the LOXL1 gene is a member of the lysyl oxidase family of enzymes that are important in the maintenance of extracellular matrix (ECM)-rich tissue. LOXL1 is important for proper elastic fiber formation and mice lacking LOXL1 (Loxl1−/−) exhibit systemic elastic fiber disorders, such as pelvic organ prolapse, a phenotype associated with exfoliation syndrome (XFS) in humans. Patients with XFS have a significant risk of developing exfoliation glaucoma (XFG), a severe form of glaucoma, which is a neurodegenerative condition leading to irreversible blindness if not detected and treated in a timely fashion. Although Loxl1−/− mice have been used extensively to investigate mechanisms of pelvic organ prolapse, studies of eyes in those mice are limited and some showed inconsistent ocular phenotypes. In this study we demonstrate that Loxl1−/− mice have significant anterior segment biometric abnormalities which recapitulate some human XFS features. We then focused on the peripapillary sclera (PPS), a critical structure for maintaining optic nerve health. We discovered quantitative and qualitive changes in ultrastructure of PPS, such as reduced elastic fibers, enlarged collagen fibrils, and transformed collagen lamella organization detected by transmission electron microscopy (TEM). Importantly, these changes corelate with altered tissue biomechanics detected by Atomic Force Microscopy (AFM) of PPS in mice. Together, our results support a crucial role for LOXL1 in ocular tissue structure and biomechanics, and Loxl1−/− mice could be a valuable resource for understanding the role of scleral tissue biomechanics in ocular disease.
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Intrarectal Capsazepine Administration Modulates Colonic Mucosal Health in Mice. Int J Mol Sci 2022; 23:ijms23179577. [PMID: 36076974 PMCID: PMC9455796 DOI: 10.3390/ijms23179577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/10/2022] [Accepted: 08/16/2022] [Indexed: 11/16/2022] Open
Abstract
Antagonism of transient receptor potential vanniloid-1 (TRPV1) and desensitization of transient receptor potential ankyrin-1 (TRPA1) nociceptors alleviate inflammatory bowel diseases (IBD)-associated chronic pain. However, there is limited literature available about their role in regulating the mucosal layer, its interaction with host physiology, and luminal microbial community. The present study focuses on the effects’ intra rectal administration of capsazepine (modulator of TRPA1/TRPV1 expressing peptidergic sensory neurons) on colonic mucus production and gut health. We performed histological analysis, gut permeability alteration, gene expression changes, metabolite profiling, and gut microbial abundance in the ileum, colon, and cecum content of these animals. Intra rectal administration of capsazepine modulates TRPA1/TRPV1-positive nociceptors (behavioral pain assays) and resulted in damaged mucosal lining, increased gut permeability, and altered transcriptional profile of genes for goblet cell markers, mucus regulation, immune response, and tight junction proteins. The damage to mucosal lining prevented its role in enterosyne (short chain fatty acids) actions. These results suggest that caution must be exercised before employing TRPA1/TRPV1 modulation as a therapeutic option to alleviate pain caused due to IBD.
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Mucosal Plasma Cell Activation and Proximity to Nerve Fibres Are Associated with Glycocalyx Reduction in Diarrhoea-Predominant Irritable Bowel Syndrome: Jejunal Barrier Alterations Underlying Clinical Manifestations. Cells 2022; 11:cells11132046. [PMID: 35805133 PMCID: PMC9265332 DOI: 10.3390/cells11132046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/19/2022] [Accepted: 06/22/2022] [Indexed: 12/12/2022] Open
Abstract
Irritable bowel syndrome (IBS) is a disorder of brain-gut interaction characterised by abdominal pain and changes in bowel habits. In the diarrhoea subtype (IBS-D), altered epithelial barrier and mucosal immune activation are associated with clinical manifestations. We aimed to further evaluate plasma cells and epithelial integrity to gain understanding of IBS-D pathophysiology. One mucosal jejunal biopsy and one stool sample were obtained from healthy controls and IBS-D patients. Gastrointestinal symptoms, stress, and depression scores were recorded. In the jejunal mucosa, RNAseq and gene set enrichment analyses were performed. A morphometric analysis by electron microscopy quantified plasma cell activation and proximity to enteric nerves and glycocalyx thickness. Immunoglobulins concentration was assessed in the stool. IBS-D patients showed differential expression of humoral pathways compared to controls. Activation and proximity of plasma cells to nerves and IgG concentration were also higher in IBS-D. Glycocalyx thickness was lower in IBS-D compared to controls, and this reduction correlated with plasma cell activation, proximity to nerves, and clinical symptoms. These results support humoral activity and loss of epithelial integrity as important contributors to gut dysfunction and clinical manifestations in IBS-D. Additional studies are needed to identify the triggers of these alterations to better define IBS-D pathophysiology.
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Ornelas A, Dowdell AS, Lee JS, Colgan SP. Microbial Metabolite Regulation of Epithelial Cell-Cell Interactions and Barrier Function. Cells 2022; 11:cells11060944. [PMID: 35326394 PMCID: PMC8946845 DOI: 10.3390/cells11060944] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/04/2022] [Accepted: 03/07/2022] [Indexed: 02/04/2023] Open
Abstract
Epithelial cells that line tissues such as the intestine serve as the primary barrier to the outside world. Epithelia provide selective permeability in the presence of a large constellation of microbes, termed the microbiota. Recent studies have revealed that the symbiotic relationship between the healthy host and the microbiota includes the regulation of cell–cell interactions at the level of epithelial tight junctions. The most recent findings have identified multiple microbial-derived metabolites that influence intracellular signaling pathways which elicit activities at the epithelial apical junction complex. Here, we review recent findings that place microbiota-derived metabolites as primary regulators of epithelial cell–cell interactions and ultimately mucosal permeability in health and disease.
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Affiliation(s)
- Alfredo Ornelas
- Mucosal Inflammation Program, Department of Medicine, University of Colorado Anschutz Medical Campus, 12700 E. 19th Ave, Mailstop B146, Aurora, CO 80045, USA; (A.O.); (A.S.D.); (J.S.L.)
| | - Alexander S. Dowdell
- Mucosal Inflammation Program, Department of Medicine, University of Colorado Anschutz Medical Campus, 12700 E. 19th Ave, Mailstop B146, Aurora, CO 80045, USA; (A.O.); (A.S.D.); (J.S.L.)
| | - J. Scott Lee
- Mucosal Inflammation Program, Department of Medicine, University of Colorado Anschutz Medical Campus, 12700 E. 19th Ave, Mailstop B146, Aurora, CO 80045, USA; (A.O.); (A.S.D.); (J.S.L.)
| | - Sean P. Colgan
- Mucosal Inflammation Program, Department of Medicine, University of Colorado Anschutz Medical Campus, 12700 E. 19th Ave, Mailstop B146, Aurora, CO 80045, USA; (A.O.); (A.S.D.); (J.S.L.)
- Rocky Mountain Regional Veterans Affairs Medical Center, 1700 N. Wheeling St., Aurora, CO 80045, USA
- Correspondence:
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Burclaff J, Bliton RJ, Breau KA, Ok MT, Gomez-Martinez I, Ranek JS, Bhatt AP, Purvis JE, Woosley JT, Magness ST. A Proximal-to-Distal Survey of Healthy Adult Human Small Intestine and Colon Epithelium by Single-Cell Transcriptomics. Cell Mol Gastroenterol Hepatol 2022; 13:1554-1589. [PMID: 35176508 PMCID: PMC9043569 DOI: 10.1016/j.jcmgh.2022.02.007] [Citation(s) in RCA: 72] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/04/2022] [Accepted: 02/07/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND & AIMS Single-cell transcriptomics offer unprecedented resolution of tissue function at the cellular level, yet studies analyzing healthy adult human small intestine and colon are sparse. Here, we present single-cell transcriptomics covering the duodenum, jejunum, ileum, and ascending, transverse, and descending colon from 3 human beings. METHODS A total of 12,590 single epithelial cells from 3 independently processed organ donors were evaluated for organ-specific lineage biomarkers, differentially regulated genes, receptors, and drug targets. Analyses focused on intrinsic cell properties and their capacity for response to extrinsic signals along the gut axis across different human beings. RESULTS Cells were assigned to 25 epithelial lineage clusters. Multiple accepted intestinal stem cell markers do not specifically mark all human intestinal stem cells. Lysozyme expression is not unique to human Paneth cells, and Paneth cells lack expression of expected niche factors. Bestrophin 4 (BEST4)+ cells express Neuropeptide Y (NPY) and show maturational differences between the small intestine and colon. Tuft cells possess a broad ability to interact with the innate and adaptive immune systems through previously unreported receptors. Some classes of mucins, hormones, cell junctions, and nutrient absorption genes show unappreciated regional expression differences across lineages. The differential expression of receptors and drug targets across lineages show biological variation and the potential for variegated responses. CONCLUSIONS Our study identifies novel lineage marker genes, covers regional differences, shows important differences between mouse and human gut epithelium, and reveals insight into how the epithelium responds to the environment and drugs. This comprehensive cell atlas of the healthy adult human intestinal epithelium resolves likely functional differences across anatomic regions along the gastrointestinal tract and advances our understanding of human intestinal physiology.
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Affiliation(s)
- Joseph Burclaff
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - R Jarrett Bliton
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill/North Carolina State University, Chapel Hill, North Carolina
| | - Keith A Breau
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Meryem T Ok
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill/North Carolina State University, Chapel Hill, North Carolina
| | - Ismael Gomez-Martinez
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jolene S Ranek
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Aadra P Bhatt
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jeremy E Purvis
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - John T Woosley
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Scott T Magness
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill/North Carolina State University, Chapel Hill, North Carolina; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
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Gieryńska M, Szulc-Dąbrowska L, Struzik J, Mielcarska MB, Gregorczyk-Zboroch KP. Integrity of the Intestinal Barrier: The Involvement of Epithelial Cells and Microbiota-A Mutual Relationship. Animals (Basel) 2022; 12:ani12020145. [PMID: 35049768 PMCID: PMC8772550 DOI: 10.3390/ani12020145] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/28/2021] [Accepted: 01/05/2022] [Indexed: 02/07/2023] Open
Abstract
Simple Summary The gastrointestinal tract is a complex organization of various types of epithelial cells forming a single layer of the mucosal barrier, the host mucosal immune system, and microorganisms termed as gut microbiota inhabiting this area. The mucosal barrier, including physical and chemical factors, spatially segregates gut microbiota and the host immune system preventing the development of immune response directed towards non-pathogenic commensals and dietary antigens. However, for the maintenance of the integrity of the mucosal surfaces, cross-talk between epithelial cells and microbiota is required. The microbiome and the intestinal epithelium developed a complex dependence necessary for sustaining intestinal homeostasis. In this review, we highlight the role of specific epithelial cell subtypes and their role in barrier arrangement, the mechanisms employed by them to control intestinal microbiota as well as the mechanisms utilized by the microbiome to regulate intestinal epithelial function. This review will provide information regarding the development of inflammatory disorders dependent on the loss of intestinal barrier function and composition of the intestinal microbiota. Abstract The gastrointestinal tract, which is constantly exposed to a multitude of stimuli, is considered responsible for maintaining the homeostasis of the host. It is inhabited by billions of microorganisms, the gut microbiota, which form a mutualistic relationship with the host. Although the microbiota is generally recognized as beneficial, at the same time, together with pathogens, they are a permanent threat to the host. Various populations of epithelial cells provide the first line of chemical and physical defense against external factors acting as the interface between luminal microorganisms and immunocompetent cells in lamina propria. In this review, we focus on some essential, innate mechanisms protecting mucosal integrity, thus responsible for maintaining intestine homeostasis. The characteristics of decisive cell populations involved in maintaining the barrier arrangement, based on mucus secretion, formation of intercellular junctions as well as production of antimicrobial peptides, responsible for shaping the gut microbiota, are presented. We emphasize the importance of cross-talk between gut microbiota and epithelial cells as a factor vital for the maintenance of the homeostasis of the GI tract. Finally, we discuss how the imbalance of these regulations leads to the compromised barrier integrity and dysbiosis considered to contribute to inflammatory disorders and metabolic diseases.
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Arkill KP. A Reinterpretation of Evidence for the Endothelial Glycocalyx Filtration Structure. Front Cell Dev Biol 2021; 9:734661. [PMID: 34540847 PMCID: PMC8442954 DOI: 10.3389/fcell.2021.734661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/13/2021] [Indexed: 11/17/2022] Open
Abstract
The endothelial glycocalyx (eGlx) is thought to be the primary macromolecular filter for fluid flux out of the vasculature. This filter maintains the higher protein concentration within the vessel lumen relative to the tissue. Whilst the arguments for the eGlx being the size filter are convincing the structural evidence has been limited to specialized stains of perfusion fixed tissue, which are further processed for resin embedding for transmission electron microscopy. The staining and processing of the delicate pore structure has left many researchers struggling to interpret the observed surface coat. Previous work has alluded to a 19.5 nm spacing between fibers; however, whilst repeatable it does not give an eGlx pore size consistent with known glycosaminoglycan (GAG) molecular structure due to the required fiber thickness of >10 nm. Here a new interpretation is proposed based on the likelihood that the electron micrographs of are often of collapsed eGlx. The 19.5 nm spacing measured may therefore be the core protein of the proteoglycans (PGs) with the GAGs wrapped up around them rather than in an expanded in vivo state. The concept is explored to determine that this is indeed consistent with experimental measurements of permeability if the syndecans are predominately dimerized. Further an alteration of core protein lattice from hexagonal packing to square packing dramatically changes the permeability which could be facilitated via known mechanisms such as transient actin binding.
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Affiliation(s)
- Kenton P. Arkill
- School of Medicine, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom
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15
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Onnainty R, Usseglio N, Bonafé Allende JC, Granero GE. Exploring a new free-standing polyelectrolyte (PEM) thin film as a predictive tool for drug-mucin interactions: Insights on drug transport through mucosal surfaces. Int J Pharm 2021; 604:120764. [PMID: 34087412 DOI: 10.1016/j.ijpharm.2021.120764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/27/2021] [Accepted: 05/30/2021] [Indexed: 11/29/2022]
Abstract
The main objective of the present work was to design a biomimetic free-standing multilayered PEM film, constructed by the layer-by-layer (LbL) assembly approach, based on natural biopolymers and intended to recreate the complex mucus-mimetic matrices in order to provide mechanistic insights into biophysical interactions between drugs and the physiological gel-forming mucin network of mucus that covers the mucosal epithelia named as(CS/ALG)/(PGM) PEM film. The obtained results indicate that mucin may delay or increase drug precipitation on the mucus layer, depending on specific drug-mucin interactions driving drug supersaturation or drug crystallization phenomena. It was found that the drug lipophilicity characteristics governed the mucin binding degree, which had an influencing role on the drug translocation across this gel-like hydrogel. Moreover, the ionization of these drugs did not have a significant role on the drug binding ability to mucin as much as the lipophilicity properties did. The (CS/ALG)/(PGM) PEM film may be a promising tool to routine testing drug-mucus interactions to evaluate biophysical interactions between this protective barrier of the organism against different drug therapeutic products or external aggressive agents, leading to the optimization of drug delivery products or drugs for particular disease states.
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Affiliation(s)
- R Onnainty
- Unidad de Investigación y Desarrollo en TecnologíaFarmacéutica (UNITEFA), CONICET and Departamento de CienciasFarmacéuticas, Facultad de CienciasQuímicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000-HUA Córdoba, Argentina
| | - N Usseglio
- Unidad de Investigación y Desarrollo en TecnologíaFarmacéutica (UNITEFA), CONICET and Departamento de CienciasFarmacéuticas, Facultad de CienciasQuímicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000-HUA Córdoba, Argentina
| | - J C Bonafé Allende
- Departamento de QuímicaOrgánica, Facultad de CienciasQuímicas (Universidad Nacional de Córdoba), IPQA-CONICET, Haya de la Torre y Av. Medina Allende, 5000 Córdoba, Argentina
| | - G E Granero
- Unidad de Investigación y Desarrollo en TecnologíaFarmacéutica (UNITEFA), CONICET and Departamento de CienciasFarmacéuticas, Facultad de CienciasQuímicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000-HUA Córdoba, Argentina.
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16
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Andretto V, Rosso A, Briançon S, Lollo G. Nanocomposite systems for precise oral delivery of drugs and biologics. Drug Deliv Transl Res 2021; 11:445-470. [PMID: 33534107 DOI: 10.1007/s13346-021-00905-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/08/2021] [Indexed: 12/15/2022]
Abstract
Oral delivery is considered the favoured route of administration for both local and systemic delivery of active molecules. Formulation of drugs in conventional systems and nanoparticles has provided opportunities for targeting the gastrointestinal (GI) tract, increasing drug solubility and bioavailability. Despite the achievements of these delivery approaches, the development of a product with the ability of delivering drug molecules at a specific site and according to patients' needs remains a challenging endeavour. The complexity of the physicochemical properties of colloidal systems, their stability in different regions of the gastrointestinal tract, and interaction with the restrictive biological barriers hampered their success for oral precise medicine. To overcome these issues, nanoparticles have been combined with polymers to create hybrid nanosystems, namely nanocomposites. They offer enormous possibilities of structural and mechanical modifications to both nanoparticles and polymeric matrixes to generate systems with new properties, functions, and applications for oral delivery. In this review, nanocomposites' physicochemical and functional properties intended to target specific regions of the GI tract-oral cavity, stomach, small bowel, and colon-are analysed. In parallel, it is provided an insight in the nanocomposite solutions for oral delivery intended for systemic and local absorption, together with a focus on inflammatory bowel diseases (IBDs). Additional difficulties in managing IBD related to the alteration in the physiology of the intestine are described. Finally, future perspectives and opportunities for advancement in this field are discussed.
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Affiliation(s)
- Valentina Andretto
- LAGEPP UMR 5007, Univ Lyon, Université Claude Bernard Lyon 1, CNRS, 43 Boulevard du 11 Novembre 1918, 69100, Villeurbanne, France
| | - Annalisa Rosso
- LAGEPP UMR 5007, Univ Lyon, Université Claude Bernard Lyon 1, CNRS, 43 Boulevard du 11 Novembre 1918, 69100, Villeurbanne, France
| | - Stéphanie Briançon
- LAGEPP UMR 5007, Univ Lyon, Université Claude Bernard Lyon 1, CNRS, 43 Boulevard du 11 Novembre 1918, 69100, Villeurbanne, France
| | - Giovanna Lollo
- LAGEPP UMR 5007, Univ Lyon, Université Claude Bernard Lyon 1, CNRS, 43 Boulevard du 11 Novembre 1918, 69100, Villeurbanne, France.
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17
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Graves MJ, Matoo S, Choi MS, Storad ZA, El Sheikh Idris RA, Pickles BK, Acharya P, Shinder PE, Arvay TO, Crawley SW. A cryptic sequence targets the adhesion complex scaffold ANKS4B to apical microvilli to promote enterocyte brush border assembly. J Biol Chem 2020; 295:12588-12604. [PMID: 32636301 DOI: 10.1074/jbc.ra120.013790] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/30/2020] [Indexed: 12/31/2022] Open
Abstract
Nutrient-transporting enterocytes interact with their luminal environment using a densely packed collection of apical microvilli known as the brush border. Assembly of the brush border is controlled by the intermicrovillar adhesion complex (IMAC), a protocadherin-based complex found at the tips of brush border microvilli that mediates adhesion between neighboring protrusions. ANKS4B is known to be an essential scaffold within the IMAC, although its functional properties have not been thoroughly characterized. We report here that ANKS4B is directed to the brush border using a noncanonical apical targeting sequence that maps to a previously unannotated region of the scaffold. When expressed on its own, this sequence targeted to microvilli in the absence of any direct interaction with the other IMAC components. Sequence analysis revealed a coiled-coil motif and a putative membrane-binding basic-hydrophobic repeat sequence within this targeting region, both of which were required for the scaffold to target and mediate brush border assembly. Size-exclusion chromatography of the isolated targeting sequence coupled with in vitro brush border binding assays suggests that it functions as an oligomer. We further show that the corresponding sequence found in the closest homolog of ANKS4B, the scaffold USH1G that operates in sensory epithelia as part of the Usher complex, lacks the inherent ability to target to microvilli. This study further defines the underlying mechanism of how ANKS4B targets to the apical domain of enterocytes to drive brush border assembly and identifies a point of functional divergence between the ankyrin repeat-based scaffolds found in the IMAC and Usher complex.
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Affiliation(s)
- Maura J Graves
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, USA
| | - Samaneh Matoo
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, USA
| | - Myoung Soo Choi
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, USA
| | - Zachary A Storad
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, USA
| | | | - Brooke K Pickles
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, USA
| | - Prashun Acharya
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, USA
| | - Paula E Shinder
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, USA
| | - Taylen O Arvay
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, USA
| | - Scott W Crawley
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, USA
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