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Liu Y, Zhang S, Deng H, Chen A, Chai L. Lead and copper influenced bile acid metabolism by changing intestinal microbiota and activating farnesoid X receptor in Bufo gargarizans. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 863:160849. [PMID: 36521604 DOI: 10.1016/j.scitotenv.2022.160849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 12/06/2022] [Accepted: 12/07/2022] [Indexed: 06/17/2023]
Abstract
Lead (Pb) and copper (Cu) are ubiquitous metal contaminants and can pose a threat to ecosystem and human health. Bile acids have recently received considerable attention for their role in the maintenance of health. However, there were few studies on whether Pb and Cu affect bile acid metabolism in amphibians. In this study, a combination approach of histological analysis, targeted metabolomics, 16S rDNA sequencing and qPCR was used to explore the impacts of Pb, Cu and their mixture (Mix) on bile acid in Bufo gargarizans tadpoles. The results showed that Pb, Cu, and Mix resulted in intestinal damage and altered the bile acid profiles. Specifically, Pb and Mix exposure decreased total bile acid concentrations while increased toxic bile acid levels; in contrast, Cu exposure increased total bile acid levels. And hydrophilic bile acids were reduced in all treated tadpoles. Moreover, Pb and/or Cu changed the composition of intestinal microbiota, especially Clostridia, Bacteroides and Eubacterium involved in bile acid biotransformation. qPCR revealed that the decreased total bile acid concentrations in Pb- and Mix-treated tadpoles were most likely attributed to the activation of intestinal farnesoid X receptor (Fxr), which suppressed bile acid synthesis and reabsorption. While activated fxr in the Cu treatment group may be a regulatory mechanism in response to increased bile excretion, which is a detoxification route of tadpoles under Cu stress. Collectively, Pb, Cu and Mix changed bile acid profiles by affecting intestinal microbial composition and activating Fxr signaling. This study provided insight into the impacts of Pb and Cu on bile acid metabolism and contributed to the assessment of the potential ecotoxicity of heavy metals on amphibians.
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Affiliation(s)
- Yutian Liu
- School of Water and Environment, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an 710054, China
| | - Siliang Zhang
- School of Water and Environment, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an 710054, China
| | - Hongzhang Deng
- School of Water and Environment, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an 710054, China
| | - Aixia Chen
- School of Water and Environment, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an 710054, China
| | - Lihong Chai
- School of Water and Environment, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an 710054, China.
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2
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Sharkova M, Chow E, Erickson T, Hocking JC. The morphological and functional diversity of apical microvilli. J Anat 2023; 242:327-353. [PMID: 36281951 PMCID: PMC9919547 DOI: 10.1111/joa.13781] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/03/2022] [Accepted: 10/05/2022] [Indexed: 11/30/2022] Open
Abstract
Sensory neurons use specialized apical processes to perceive external stimuli and monitor internal body conditions. The apical apparatus can include cilia, microvilli, or both, and is adapted for the functions of the particular cell type. Photoreceptors detect light through a large, modified cilium (outer segment), that is supported by a surrounding ring of microvilli-like calyceal processes (CPs). Although first reported 150 years ago, CPs remain poorly understood. As a basis for future study, we therefore conducted a review of existing literature about sensory cell microvilli, which can act either as the primary sensory detector or as support for a cilia-based detector. While all microvilli are finger-like cellular protrusions with an actin core, the processes vary across cell types in size, number, arrangement, dynamics, and function. We summarize the current state of knowledge about CPs and the characteristics of the microvilli found on inner ear hair cells (stereocilia) and cerebral spinal fluid-contacting neurons, with comparisons to the brush border of the intestinal and renal epithelia. The structure, stability, and dynamics of the actin core are regulated by a complement of actin-binding proteins, which includes both common components and unique features when compared across cell types. Further, microvilli are often supported by lateral links, a glycocalyx, and a defined extracellular matrix, each adapted to the function and environment of the cell. Our comparison of microvillar features will inform further research into how CPs support photoreceptor function, and also provide a general basis for investigations into the structure and functions of apical microvilli found on sensory neurons.
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Affiliation(s)
- Maria Sharkova
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Erica Chow
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Timothy Erickson
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Jennifer C Hocking
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Division of Anatomy, Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
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3
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Ali Q, Ma S, La S, Guo Z, Liu B, Gao Z, Farooq U, Wang Z, Zhu X, Cui Y, Li D, Shi Y. Microbial short-chain fatty acids: a bridge between dietary fibers and poultry gut health. Anim Biosci 2022; 35:1461-1478. [PMID: 35507857 PMCID: PMC9449382 DOI: 10.5713/ab.21.0562] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 03/18/2022] [Indexed: 11/27/2022] Open
Abstract
The maintenance of poultry gut health is complex depending on the intricate balance among diet, the commensal microbiota, and the mucosa, including the gut epithelium and the superimposing mucus layer. Changes in microflora composition and abundance can confer beneficial or detrimental effects on fowl. Antibiotics have devastating impacts on altering the landscape of gut microbiota, which further leads to antibiotic resistance or spread the pathogenic populations. By eliciting the landscape of gut microbiota, strategies should be made to break down the regulatory signals of pathogenic bacteria. The optional strategy of conferring dietary fibers (DFs) can be used to counterbalance the gut microbiota. DFs are the non-starch carbohydrates indigestible by host endogenous enzymes but can be fermented by symbiotic microbiota to produce short-chain fatty acids (SCFAs). This is one of the primary modes through which the gut microbiota interacts and communicate with the host. The majority of SCFAs are produced in the large intestine (particularly in the caecum), where they are taken up by the enterocytes or transported through portal vein circulation into the bloodstream. Recent shreds of evidence have elucidated that SCFAs affect the gut and modulate the tissues and organs either by activating G-protein-coupled receptors or affecting epigenetic modifications in the genome through inducing histone acetylase activities and inhibiting histone deacetylases. Thus, in this way, SCFAs vastly influence poultry health by promoting energy regulation, mucosal integrity, immune homeostasis, and immune maturation. In this review article, we will focus on DFs, which directly interact with gut microbes and lead to the production of SCFAs. Further, we will discuss the current molecular mechanisms of how SCFAs are generated, transported, and modulated the pro-and anti-inflammatory immune responses against pathogens and host physiology and gut health.
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4
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Gray ME, Johnson ZR, Modak D, Tamilselvan E, Tyska MJ, Sotomayor M. Heterophilic and homophilic cadherin interactions in intestinal intermicrovillar links are species dependent. PLoS Biol 2021; 19:e3001463. [PMID: 34871294 PMCID: PMC8691648 DOI: 10.1371/journal.pbio.3001463] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/21/2021] [Accepted: 10/30/2021] [Indexed: 11/19/2022] Open
Abstract
Enterocytes are specialized epithelial cells lining the luminal surface of the small intestine that build densely packed arrays of microvilli known as brush borders. These microvilli drive nutrient absorption and are arranged in a hexagonal pattern maintained by intermicrovillar links formed by 2 nonclassical members of the cadherin superfamily of calcium-dependent cell adhesion proteins: protocadherin-24 (PCDH24, also known as CDHR2) and the mucin-like protocadherin (CDHR5). The extracellular domains of these proteins are involved in heterophilic and homophilic interactions important for intermicrovillar function, yet the structural determinants of these interactions remain unresolved. Here, we present X-ray crystal structures of the PCDH24 and CDHR5 extracellular tips and analyze their species-specific features relevant for adhesive interactions. In parallel, we use binding assays to identify the PCDH24 and CDHR5 domains involved in both heterophilic and homophilic adhesion for human and mouse proteins. Our results suggest that homophilic and heterophilic interactions involving PCDH24 and CDHR5 are species dependent with unique and distinct minimal adhesive units.
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Affiliation(s)
- Michelle E. Gray
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio, United States of America
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
| | - Zachary R. Johnson
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
| | - Debadrita Modak
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
| | - Elakkiya Tamilselvan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
- Biophysics Program, The Ohio State University, Columbus, Ohio, United States of America
| | - Matthew J. Tyska
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Marcos Sotomayor
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio, United States of America
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
- Biophysics Program, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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5
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Shini S, Aland RC, Bryden WL. Avian intestinal ultrastructure changes provide insight into the pathogenesis of enteric diseases and probiotic mode of action. Sci Rep 2021; 11:167. [PMID: 33420315 PMCID: PMC7794591 DOI: 10.1038/s41598-020-80714-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 12/24/2020] [Indexed: 01/27/2023] Open
Abstract
Epithelial damage and loss of barrier integrity occur following intestinal infections in humans and animals. Gut health was evaluated by electron microscopy in an avian model that exposed birds to subclinical necrotic enteritis (NE) and fed them a diet supplemented with the probiotic Bacillus amyloliquefaciens strain H57 (H57). Scanning electron microscopy of ileal mucosa revealed significant villus damage, including focal erosions of epithelial cells and villous atrophy, while transmission electron microscopy demonstrated severe enterocyte damage and loss of cellular integrity in NE-exposed birds. In particular, mitochondria were morphologically altered, appearing irregular in shape or swollen, and containing electron-lucent regions of matrix and damaged cristae. Apical junctional complexes between adjacent enterocytes were significantly shorter, and the adherens junction was saccular, suggesting loss of epithelial integrity in NE birds. Segmented filamentous bacteria attached to villi, which play an important role in intestinal immunity, were more numerous in birds exposed to NE. The results suggest that mitochondrial damage may be an important initiator of NE pathogenesis, while H57 maintains epithelium and improves the integrity of intestinal mucosa. Potential actions of H57 are discussed that further define the mechanisms responsible for probiotic bacteria’s role in maintaining gut health.
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Affiliation(s)
- Shaniko Shini
- School of Agriculture and Food Sciences, University of Queensland, Gatton, QLD, 4343, Australia.
| | - R Claire Aland
- School of Biomedical Sciences, University of Queensland, St Lucia, QLD, 4071, Australia
| | - Wayne L Bryden
- School of Agriculture and Food Sciences, University of Queensland, Gatton, QLD, 4343, Australia
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Alix M, Gasset E, Bardon-Albaret A, Noel J, Pirot N, Perez V, Coves D, Saulnier D, Lignot JH, Cucchi PN. Description of the unusual digestive tract of Platax orbicularis and the potential impact of Tenacibaculum maritimum infection. PeerJ 2020; 8:e9966. [PMID: 33024633 PMCID: PMC7520087 DOI: 10.7717/peerj.9966] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 08/26/2020] [Indexed: 12/11/2022] Open
Abstract
Background Ephippidae fish are characterized by a discoid shape with a very small visceral cavity. Among them Platax orbicularis has a high economic potential due to its flesh quality and flesh to carcass ratio. Nonetheless, the development of its aquaculture is limited by high mortality rates, especially due to Tenacibaculum maritimum infection, occurring one to three weeks after the transfer of fishes from bio-secure land-based aquaculture system to the lagoon cages for growth. Among the lines of defense against this microbial infection, the gastrointestinal tract (GIT) is less studied. The knowledge about the morphofunctional anatomy of this organ in P. orbicularis is still scarce. Therefore, the aims of this study are to characterize the GIT in non-infected P. orbicularis juveniles to then investigate the impact of T. maritimum on this multifunctional organ. Methods In the first place, the morpho-anatomy of the GIT in non-infected individuals was characterized using various histological techniques. Then, infected individuals, experimentally challenged by T. maritimum were analysed and compared to the previously established GIT reference. Results The overlapped shape of the GIT of P. orbicularis is probably due to its constrained compaction in a narrow visceral cavity. Firstly, the GIT was divided into 10 sections, from the esophagus to the rectum. For each section, the structure of the walls was characterized, with a focus on mucus secretions and the presence of the Na+/K+ ATPase pump. An identification key allowing the characterization of the GIT sections using in toto histology is given. Secondly, individuals challenged with T. maritimum exhibited differences in mucus type and proportion and, modifications in the mucosal and muscle layers. These changes could induce an imbalance in the trade-off between the GIT functions which may be in favour of protection and immunity to the disadvantage of nutrition capacities.
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Affiliation(s)
- Maud Alix
- MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Montpellier, France.,Institute of Marine Research, Bergen, Norway
| | - Eric Gasset
- MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - Agnes Bardon-Albaret
- Ifremer, UMR Ecosystèmes Insulaires Océaniens, UPF, ILM, IRD, Tahiti, French Polynesia
| | - Jean Noel
- BCM, Université de Montpellier, CNRS, INSERM, Montpellier, France.,IRCM, Université de Montpellier, ICM, INSERM, Montpellier, France
| | - Nelly Pirot
- BCM, Université de Montpellier, CNRS, INSERM, Montpellier, France.,IRCM, Université de Montpellier, ICM, INSERM, Montpellier, France
| | - Valérie Perez
- MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - Denis Coves
- MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - Denis Saulnier
- Ifremer, UMR Ecosystèmes Insulaires Océaniens, UPF, ILM, IRD, Tahiti, French Polynesia
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7
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Cytoskeletal Organization and Cell Polarity in the Pathogenesis of Crohn’s Disease. Clin Rev Allergy Immunol 2020; 60:164-174. [DOI: 10.1007/s12016-020-08795-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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8
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Heath M, Buckley R, Gerber Z, Davis P, Linneman L, Gong Q, Barkemeyer B, Fang Z, Good M, Penn D, Kim S. Association of Intestinal Alkaline Phosphatase With Necrotizing Enterocolitis Among Premature Infants. JAMA Netw Open 2019; 2:e1914996. [PMID: 31702803 PMCID: PMC6902776 DOI: 10.1001/jamanetworkopen.2019.14996] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 09/19/2019] [Indexed: 12/21/2022] Open
Abstract
Importance Necrotizing enterocolitis (NEC) in preterm infants is an often-fatal gastrointestinal tract emergency. A robust NEC biomarker that is not confounded by sepsis could improve bedside management, lead to lower morbidity and mortality, and permit patient selection in randomized clinical trials of possible therapeutic approaches. Objective To evaluate whether aberrant intestinal alkaline phosphatase (IAP) biochemistry in infant stool is a molecular biomarker for NEC and not associated with sepsis. Design, Setting, and Participants This multicenter diagnostic study enrolled 136 premature infants (gestational age, <37 weeks) in 2 hospitals in Louisiana and 1 hospital in Missouri. Data were collected and analyzed from May 2015 to November 2018. Exposures Infant stool samples were collected between 24 and 40 or more weeks postconceptual age. Enrolled infants underwent abdominal radiography at physician and hospital site discretion. Main Outcomes and Measures Enzyme activity and relative abundance of IAP were measured using fluorometric detection and immunoassays, respectively. After measurements were performed, biochemical data were evaluated against clinical entries from infants' hospital stay. Results Of 136 infants, 68 (50.0%) were male infants, median (interquartile range [IQR]) birth weight was 1050 (790-1350) g, and median (IQR) gestational age was 28.4 (26.0-30.9) weeks. A total of 25 infants (18.4%) were diagnosed with severe NEC, 19 (14.0%) were suspected of having NEC, and 92 (66.9%) did not have NEC; 26 patients (19.1%) were diagnosed with late-onset sepsis, and 14 (10.3%) had other non-gastrointestinal tract infections. For severe NEC, suspected NEC, and no NEC samples, median (IQR) fecal IAP content, relative to the amount of IAP in human small intestinal lysate, was 99.0% (51.0%-187.8%) (95% CI, 54.0%-163.0%), 123.0% (31.0%-224.0%) (95% CI, 31.0%-224.0%), and 4.8% (2.4%-9.8%) (95% CI, 3.4%-5.9%), respectively. For severe NEC, suspected NEC, and no NEC samples, median (IQR) enzyme activity was 183 (56-507) μmol/min/g (95% CI, 63-478 μmol/min/g) of stool protein, 355 (172-608) μmol/min/g (95% CI, 172-608 μmol/min/g) of stool protein, and 613 (210-1465) μmol/min/g (95% CI, 386-723 μmol/min/g) of stool protein, respectively. Mean (SE) area under the receiver operating characteristic curve values for IAP content measurements were 0.97 (0.02) (95% CI, 0.93-1.00; P < .001) at time of severe NEC, 0.97 (0.02) (95% CI, 0.93-1.00; P < .001) at time of suspected NEC, 0.52 (0.07) (95% CI, 0.38-0.66; P = .75) at time of sepsis, and 0.58 (0.08) (95% CI, 0.42-0.75; P = .06) at time of other non-gastrointestinal tract infections. Mean (SE) area under the receiver operating characteristic curve values for IAP activity were 0.76 (0.06) (95% CI, 0.64-0.86; P < .001), 0.62 (0.07) (95% CI, 0.48-0.77; P = .13), 0.52 (0.07) (95% CI, 0.39-0.67; P = .68), and 0.57 (0.08) (95% CI, 0.39-0.69; P = .66), respectively. Conclusions and Relevance In this diagnostic study, high amounts of IAP protein in stool and low IAP enzyme activity were associated with diagnosis of NEC and may serve as useful biomarkers for NEC. Our findings indicated that IAP biochemistry was uniquely able to distinguish NEC from sepsis.
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Affiliation(s)
- Maya Heath
- Department of Pediatrics and Neonatology, Louisiana State University School of Medicine, Children’s Hospital of New Orleans, New Orleans
| | - Rebecca Buckley
- Department of Biochemistry and Molecular Biology, Louisiana State University School of Medicine and Health Sciences Center, New Orleans
| | - Zeromeh Gerber
- Department of Pediatrics and Neonatology, Louisiana State University School of Medicine, Children’s Hospital of New Orleans, New Orleans
| | - Porcha Davis
- Department of Biochemistry and Molecular Biology, Louisiana State University School of Medicine and Health Sciences Center, New Orleans
| | - Laura Linneman
- Division of Newborn Medicine, Department of Pediatrics, Washington University School of Medicine in St Louis, St Louis Children’s Hospital, St Louis, Missouri
| | - Qingqing Gong
- Division of Newborn Medicine, Department of Pediatrics, Washington University School of Medicine in St Louis, St Louis Children’s Hospital, St Louis, Missouri
| | - Brian Barkemeyer
- Department of Pediatrics and Neonatology, Louisiana State University School of Medicine, Children’s Hospital of New Orleans, New Orleans
| | - Zhide Fang
- Department of Biostatistics, Louisiana State University School of Public Health, New Orleans
| | - Misty Good
- Division of Newborn Medicine, Department of Pediatrics, Washington University School of Medicine in St Louis, St Louis Children’s Hospital, St Louis, Missouri
| | - Duna Penn
- Department of Pediatrics and Neonatology, Louisiana State University School of Medicine, Children’s Hospital of New Orleans, New Orleans
| | - Sunyoung Kim
- Department of Biochemistry and Molecular Biology, Louisiana State University School of Medicine and Health Sciences Center, New Orleans
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Probing the Action of Permeation Enhancers Sodium Cholate and N-dodecyl-β-D-maltoside in a Porcine Jejunal Mucosal Explant System. Pharmaceutics 2018; 10:pharmaceutics10040172. [PMID: 30279382 PMCID: PMC6320951 DOI: 10.3390/pharmaceutics10040172] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 09/27/2018] [Accepted: 09/28/2018] [Indexed: 11/18/2022] Open
Abstract
The small intestinal epithelium constitutes a major permeability barrier for the oral administration of therapeutic drugs with poor bioavailability, and permeation enhancers (PEs) are required to increase the paracellular and/or transcellular uptake of such drugs. Many PEs act as surfactants by perturbing cell membrane integrity and causing permeabilization by leakage or endocytosis. The aim of the present work was to study the action of sodium cholate (NaC) and N-dodecyl-β-D-maltoside (DDM), using a small intestinal mucosal explant system. At 2 mM, both NaC and DDM caused leakage into the enterocyte cytosol of the fluorescent probe Lucifer Yellow, but they also blocked the constitutive endocytotic pathway from the brush border. In addition, an increased paracellular passage of 3-kDa Texas Red Dextran into the lamina propria was observed. By electron microscopy, both PEs disrupted the hexagonal organization of microvilli of the brush border and led to the apical extrusion of vesicle-like and amorphous cell debris to the lumen. In conclusion, NaC and DDM acted in a multimodal way to increase the permeability of the jejunal epithelium both by paracellular and transcellular mechanisms. However, endocytosis, commonly thought to be an uptake mechanism that may be stimulated by PEs, was not involved in the transcellular process.
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10
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Schneeberger K, Roth S, Nieuwenhuis EES, Middendorp S. Intestinal epithelial cell polarity defects in disease: lessons from microvillus inclusion disease. Dis Model Mech 2018; 11:11/2/dmm031088. [PMID: 29590640 PMCID: PMC5894939 DOI: 10.1242/dmm.031088] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The intestinal epithelium is a highly organized tissue. The establishment of epithelial cell polarity, with distinct apical and basolateral plasma membrane domains, is pivotal for both barrier formation and for the uptake and vectorial transport of nutrients. The establishment of cell polarity requires a specialized subcellular machinery to transport and recycle proteins to their appropriate location. In order to understand and treat polarity-associated diseases, it is necessary to understand epithelial cell-specific trafficking mechanisms. In this Review, we focus on cell polarity in the adult mammalian intestine. We discuss how intestinal epithelial polarity is established and maintained, and how disturbances in the trafficking machinery can lead to a polarity-associated disorder, microvillus inclusion disease (MVID). Furthermore, we discuss the recent developments in studying MVID, including the creation of genetically manipulated cell lines, mouse models and intestinal organoids, and their uses in basic and applied research. Summary: Microvillus inclusion disease serves as a useful model to enhance our understanding of the intestinal trafficking and polarity machinery in health and disease.
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Affiliation(s)
- Kerstin Schneeberger
- Division of Paediatrics, Department of Paediatric Gastroenterology, Wilhelmina Children's Hospital, 3584 CT, Utrecht, The Netherlands
| | - Sabrina Roth
- Division of Paediatrics, Department of Paediatric Gastroenterology, Wilhelmina Children's Hospital, 3584 CT, Utrecht, The Netherlands
| | - Edward E S Nieuwenhuis
- Division of Paediatrics, Department of Paediatric Gastroenterology, Wilhelmina Children's Hospital, 3584 CT, Utrecht, The Netherlands
| | - Sabine Middendorp
- Division of Paediatrics, Department of Paediatric Gastroenterology, Wilhelmina Children's Hospital, 3584 CT, Utrecht, The Netherlands .,Regenerative Medicine Center Utrecht, University Medical Centre (UMC) Utrecht, 3584 CT, Utrecht, The Netherlands
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11
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Klunder LJ, Faber KN, Dijkstra G, van IJzendoorn SCD. Mechanisms of Cell Polarity-Controlled Epithelial Homeostasis and Immunity in the Intestine. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a027888. [PMID: 28213466 DOI: 10.1101/cshperspect.a027888] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Intestinal epithelial cell polarity is instrumental to maintain epithelial homeostasis and balance communications between the gut lumen and bodily tissue, thereby controlling the defense against gastrointestinal pathogens and maintenance of immune tolerance to commensal bacteria. In this review, we highlight recent advances with regard to the molecular mechanisms of cell polarity-controlled epithelial homeostasis and immunity in the human intestine.
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Affiliation(s)
- Leon J Klunder
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, the Netherlands
| | - Klaas Nico Faber
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, the Netherlands
| | - Gerard Dijkstra
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, the Netherlands
| | - Sven C D van IJzendoorn
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, the Netherlands
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12
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Abstract
The brush border on the apical surface of enterocytes is a highly specialized structure well-adapted for efficient digestion and nutrient transport, whilst at the same time providing a protective barrier for the intestinal mucosa. The brush border is constituted of a densely ordered array of microvilli, protrusions of the plasma membrane, which are supported by actin-based microfilaments and interacting proteins and anchored in an apical network of actomyosin and intermediate filaments, the so-called terminal web. The highly dynamic, specialized apical domain is both an essential partner for the gut microbiota and an efficient signalling platform that enables adaptation to physiological stimuli from the external and internal milieu. Nevertheless, genetic alterations or various pathological stresses, such as infection, inflammation, and mechanical or nutritional alterations, can jeopardize this equilibrium and compromise intestinal functions. Long-time neglected, the intestinal brush-border shall be enlightening again as the central actor of the complex but essential intestinal homeostasis. Here, we review the processes and components involved in brush border organization and discuss pathological mechanisms that can induce brush border defects and their physiological consequences.
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Crawley SW, Shifrin DA, Grega-Larson NE, McConnell RE, Benesh AE, Mao S, Zheng Y, Zheng QY, Nam KT, Millis BA, Kachar B, Tyska MJ. Intestinal brush border assembly driven by protocadherin-based intermicrovillar adhesion. Cell 2014; 157:433-446. [PMID: 24725409 DOI: 10.1016/j.cell.2014.01.067] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Revised: 12/19/2013] [Accepted: 01/28/2014] [Indexed: 12/17/2022]
Abstract
Transporting epithelial cells build apical microvilli to increase membrane surface area and enhance absorptive capacity. The intestinal brush border provides an elaborate example with tightly packed microvilli that function in nutrient absorption and host defense. Although the brush border is essential for physiological homeostasis, its assembly is poorly understood. We found that brush border assembly is driven by the formation of Ca(2+)-dependent adhesion links between adjacent microvilli. Intermicrovillar links are composed of protocadherin-24 and mucin-like protocadherin, which target to microvillar tips and interact to form a trans-heterophilic complex. The cytoplasmic domains of microvillar protocadherins interact with the scaffolding protein, harmonin, and myosin-7b, which promote localization to microvillar tips. Finally, a mouse model of Usher syndrome lacking harmonin exhibits microvillar protocadherin mislocalization and severe defects in brush border morphology. These data reveal an adhesion-based mechanism for brush border assembly and illuminate the basis of intestinal pathology in patients with Usher syndrome. PAPERFLICK:
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Affiliation(s)
- Scott W Crawley
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - David A Shifrin
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Nathan E Grega-Larson
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Russell E McConnell
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Andrew E Benesh
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Suli Mao
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Yuxi Zheng
- Department of Otolaryngology-HNS, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Qing Yin Zheng
- Department of Otolaryngology-HNS, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Ki Taek Nam
- Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul 120-752, Korea
| | - Bryan A Millis
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bechara Kachar
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Matthew J Tyska
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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