1
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Nascimento RR, Aquino CC, Sousa JK, Gadelha KL, Cajado AG, Schiebel CS, Dooley SA, Sousa PA, Rocha JA, Medeiros JR, Magalhães PC, Maria-Ferreira D, Gois MB, C P Lima-Junior R, V T Wong D, Lima AM, Engevik AC, Nicolau LD, Vale ML. SARS-CoV-2 Spike protein triggers gut impairment since mucosal barrier to innermost layers: From basic science to clinical relevance. Mucosal Immunol 2024; 17:565-583. [PMID: 38555027 DOI: 10.1016/j.mucimm.2024.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 03/12/2024] [Accepted: 03/23/2024] [Indexed: 04/02/2024]
Abstract
Studies have reported the occurrence of gastrointestinal (GI) symptoms, primarily diarrhea, in COVID-19. However, the pathobiology regarding COVID-19 in the GI tract remains limited. This work aimed to evaluate SARS-CoV-2 Spike protein interaction with gut lumen in different experimental approaches. Here, we present a novel experimental model with the inoculation of viral protein in the murine jejunal lumen, in vitro approach with human enterocytes, and molecular docking analysis. Spike protein led to increased intestinal fluid accompanied by Cl- secretion, followed by intestinal edema, leukocyte infiltration, reduced glutathione levels, and increased cytokine levels [interleukin (IL)-6, tumor necrosis factor-α, IL-1β, IL-10], indicating inflammation. Additionally, the viral epitope caused disruption in the mucosal histoarchitecture with impairment in Paneth and goblet cells, including decreased lysozyme and mucin, respectively. Upregulation of toll-like receptor 2 and toll-like receptor 4 gene expression suggested potential activation of local innate immunity. Moreover, this experimental model exhibited reduced contractile responses in jejunal smooth muscle. In barrier function, there was a decrease in transepithelial electrical resistance and alterations in the expression of tight junction proteins in the murine jejunal epithelium. Additionally, paracellular intestinal permeability increased in human enterocytes. Finally, in silico data revealed that the Spike protein interacts with cystic fibrosis transmembrane conductance regulator (CFTR) and calcium-activated chloride conductance (CaCC), inferring its role in the secretory effect. Taken together, all the events observed point to gut impairment, affecting the mucosal barrier to the innermost layers, establishing a successful experimental model for studying COVID-19 in the GI context.
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Affiliation(s)
- Renata R Nascimento
- Post Graduation Program in Pharmacology, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Brazil
| | - Cristhyane C Aquino
- Institute of Biomedicine for Brazilian Semi-Arid and Clinical Research Unit, Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza, Brazil
| | - José K Sousa
- Institute of Biomedicine for Brazilian Semi-Arid and Clinical Research Unit, Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza, Brazil; Division of Infectious Diseases & International Health, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Kalinne L Gadelha
- Post Graduation Program in Pharmacology, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Brazil
| | - Aurilene G Cajado
- Post Graduation Program in Pharmacology, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Brazil
| | - Carolina S Schiebel
- Instituto de Pesquisa Pelé Pequeno Príncipe, Faculdades Pequeno Príncipe, Programa de Pós-graduação em Biotecnologia Aplicada à Saúde da Criança e do Adolescente, Curitiba, Brazil
| | - Sarah A Dooley
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Paulo A Sousa
- Biotechnology and Biodiversity Center Research, Lab of Inflammation and Translational Gastroenterology (LIGAT), Parnaíba Delta Federal University, Parnaíba, Brazil
| | - Jefferson A Rocha
- Biotechnology and Biodiversity Center Research, Lab of Inflammation and Translational Gastroenterology (LIGAT), Parnaíba Delta Federal University, Parnaíba, Brazil
| | - Jand R Medeiros
- Biotechnology and Biodiversity Center Research, Lab of Inflammation and Translational Gastroenterology (LIGAT), Parnaíba Delta Federal University, Parnaíba, Brazil
| | - Pedro C Magalhães
- Post Graduation Program in Pharmacology, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Brazil
| | - Daniele Maria-Ferreira
- Instituto de Pesquisa Pelé Pequeno Príncipe, Faculdades Pequeno Príncipe, Programa de Pós-graduação em Biotecnologia Aplicada à Saúde da Criança e do Adolescente, Curitiba, Brazil
| | - Marcelo B Gois
- Faculty of Health Sciences, Federal University of Rondonópolis, Rondonópolis, Brazil
| | - Roberto C P Lima-Junior
- Post Graduation Program in Pharmacology, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Brazil
| | - Deysi V T Wong
- Post Graduation Program in Pharmacology, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Brazil
| | - Aldo M Lima
- Institute of Biomedicine for Brazilian Semi-Arid and Clinical Research Unit, Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza, Brazil; Division of Infectious Diseases & International Health, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Amy C Engevik
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Lucas D Nicolau
- Institute of Biomedicine for Brazilian Semi-Arid and Clinical Research Unit, Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza, Brazil; Biotechnology and Biodiversity Center Research, Lab of Inflammation and Translational Gastroenterology (LIGAT), Parnaíba Delta Federal University, Parnaíba, Brazil; Department of Biochemistry and Pharmacology, Federal University of Piauí, Teresina, Brazil.
| | - Mariana L Vale
- Post Graduation Program in Pharmacology, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Brazil
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Lueschow-Guijosa SR, Stanford AH, Berger JN, Gong H, Boly TJ, Jensen BA, Nordkild P, Leegwater AJ, Wehkamp J, Underwood MA, McElroy SJ. Host defense peptides human β defensin 2 and LL-37 ameliorate murine necrotizing enterocolitis. iScience 2024; 27:109993. [PMID: 38846005 PMCID: PMC11154634 DOI: 10.1016/j.isci.2024.109993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 03/13/2024] [Accepted: 05/13/2024] [Indexed: 06/09/2024] Open
Abstract
Necrotizing enterocolitis (NEC) is a leading cause of preterm infant morbidity and mortality. Treatment for NEC is limited and non-targeted, which makes new treatment and prevention strategies critical. Host defense peptides (HDPs) are essential components of the innate immune system and have multifactorial mechanisms in host defense. LL-37 and hBD2 are two HDPs that have been shown in prior literature to protect from neonatal sepsis-induced mortality or adult inflammatory bowel disease, respectively. Therefore, this article sought to understand if these two HDPs could influence NEC severity in murine preclinical models. NEC was induced in P14-16 C57Bl/6 mice and HDPs were provided as a pretreatment or treatment. Both LL-37 and hBD2 resulted in decreased NEC injury scores as a treatment and hBD2 as a pretreatment. Our data suggest LL-37 functions through antimicrobial properties, while hBD2 functions through decreases in inflammation and improvement of intestinal barrier integrity.
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Affiliation(s)
| | - Amy H. Stanford
- Department of Pediatrics, University of Iowa, Iowa City, IA 52242, USA
| | - Jennifer N. Berger
- Department of Pediatrics, Children’s Minnesota, Minneapolis, MN 55404, USA
| | - Huiyu Gong
- Department of Pediatrics, University of Iowa, Iowa City, IA 52242, USA
| | - Timothy J. Boly
- Department of Pediatrics, University of Iowa, Iowa City, IA 52242, USA
| | - Benjamin A.H. Jensen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark
| | | | | | - Jan Wehkamp
- Department of Internal Medicine, University of Tübingen, 72074 Tübingen, Germany
| | - Mark A. Underwood
- Department of Pediatrics, University of California Davis, Sacramento, CA 95616, USA
| | - Steven J. McElroy
- Department of Pediatrics, University of California Davis, Sacramento, CA 95616, USA
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3
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Reyes EA, Castillo-Azofeifa D, Rispal J, Wald T, Zwick RK, Palikuqi B, Mujukian A, Rabizadeh S, Gupta AR, Gardner JM, Boffelli D, Gartner ZJ, Klein OD. Epithelial TNF controls cell differentiation and CFTR activity to maintain intestinal mucin homeostasis. J Clin Invest 2023; 133:e163591. [PMID: 37643009 PMCID: PMC10575728 DOI: 10.1172/jci163591] [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: 07/14/2022] [Accepted: 08/22/2023] [Indexed: 08/31/2023] Open
Abstract
The gastrointestinal tract relies on the production, maturation, and transit of mucin to protect against pathogens and to lubricate the epithelial lining. Although the molecular and cellular mechanisms that regulate mucin production and movement are beginning to be understood, the upstream epithelial signals that contribute to mucin regulation remain unclear. Here, we report that the inflammatory cytokine tumor necrosis factor (TNF), generated by the epithelium, contributes to mucin homeostasis by regulating both cell differentiation and cystic fibrosis transmembrane conductance regulator (CFTR) activity. We used genetic mouse models and noninflamed samples from patients with inflammatory bowel disease (IBD) undergoing anti-TNF therapy to assess the effect of in vivo perturbation of TNF. We found that inhibition of epithelial TNF promotes the differentiation of secretory progenitor cells into mucus-producing goblet cells. Furthermore, TNF treatment and CFTR inhibition in intestinal organoids demonstrated that TNF promotes ion transport and luminal flow via CFTR. The absence of TNF led to slower gut transit times, which we propose results from increased mucus accumulation coupled with decreased luminal fluid pumping. These findings point to a TNF/CFTR signaling axis in the adult intestine and identify epithelial cell-derived TNF as an upstream regulator of mucin homeostasis.
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Affiliation(s)
- Efren A. Reyes
- Department of Orofacial Sciences and Program in Craniofacial Biology, and
- Department of Pharmaceutical Chemistry and TETRAD Program, UCSF, San Francisco, California, USA
| | - David Castillo-Azofeifa
- Department of Orofacial Sciences and Program in Craniofacial Biology, and
- Department of Regenerative Medicine, Genentech, Inc., South San Francisco, California, USA
| | - Jérémie Rispal
- Department of Orofacial Sciences and Program in Craniofacial Biology, and
| | - Tomas Wald
- Department of Orofacial Sciences and Program in Craniofacial Biology, and
| | - Rachel K. Zwick
- Department of Orofacial Sciences and Program in Craniofacial Biology, and
| | - Brisa Palikuqi
- Department of Orofacial Sciences and Program in Craniofacial Biology, and
| | - Angela Mujukian
- F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Shervin Rabizadeh
- F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
- Department of Pediatrics, Cedars-Sinai Guerin Children’s, Los Angeles, California, USA
| | | | - James M. Gardner
- Department of Surgery, and
- Diabetes Center, UCSF, San Francisco, California, USA
- Chan-Zuckerberg Biohub, San Francisco, California, USA
- The Center for Cellular Construction, San Francisco, California, USA
| | - Dario Boffelli
- Department of Pediatrics, Cedars-Sinai Guerin Children’s, Los Angeles, California, USA
| | - Zev J. Gartner
- Department of Pharmaceutical Chemistry and TETRAD Program, UCSF, San Francisco, California, USA
| | - Ophir D. Klein
- Department of Orofacial Sciences and Program in Craniofacial Biology, and
- Department of Pediatrics, Cedars-Sinai Guerin Children’s, Los Angeles, California, USA
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Hosic S, Lake W, Stas E, Koppes R, Breault DT, Murthy SK, Koppes AN. Cholinergic Activation of Primary Human Derived Intestinal Epithelium Does Not Ameliorate TNF-α Induced Injury. Cell Mol Bioeng 2020; 13:487-505. [PMID: 33184579 DOI: 10.1007/s12195-020-00633-0] [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: 02/28/2020] [Accepted: 06/19/2020] [Indexed: 02/08/2023] Open
Abstract
Introduction The intestinal epithelium contains specialized cells including enterocytes, goblet, Paneth, enteroendocrine, and stem cells. Impaired barrier integrity in Inflammatory Bowel Disease is characterized by elevated levels of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α). Prior studies in immortalized lines such as Caco-2, without native epithelial heterogeneity, demonstrate the amelioration of TNF-α compromised barrier integrity via nicotinic (nAChR) or muscarinic (mAChR) acetylcholine receptor activation. Methods A tissue-engineered model of primary human small intestinal epithelium was derived from dissociated organoids cultured on collagen-coated Transwells. Differentiation was accomplished with serum-containing media and compared to Caco-2 and HT-29 regarding alkaline phosphatase expression, transepithelial electrical resistance (TEER), and IL-8 secretion. Inflammation was modeled via basal stimulation with TNF-α (25 ng/mL) with or without nicotine (nAChR agonist) or bethanechol (mAChR agonist). Apoptosis, density (cells/cm2), TEER, lucifer yellow permeability, 70 kDa dextran transport, cell morphology, and IL-8 secretion were characterized. Results Primary intestinal epithelium demonstrates significant functional differences compared to immortalized cells, including increased barrier integrity, IL-8 expression, mucus production, and the presence of absorptive and secretory cells. Exposure to TNF-α impaired barrier integrity, increased apoptosis, altered morphology, and increased secretion of IL-8. Stimulation of nAChR with nicotine did not ameliorate TNF-α induced permeability nor alter 70 kDa dextran transport. However, stimulation of mAChR with bethanechol decreased transport of 70 kDa dextran but did not ameliorate TNF-α induced paracellular permeability. Conclusions A primary model of intestinal inflammation was evaluated, demonstrating nAChR or mAChR activation does not have the same protective effects compared to immortalized epithelium. Inclusion of other native stromal support cells are underway.
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Affiliation(s)
- Sanjin Hosic
- Department of Chemical Engineering, Northeastern University, 360 Huntington Ave., 313 Snell Engineering, Boston, MA 02115 USA
| | - Will Lake
- Department of Chemical Engineering, Northeastern University, 360 Huntington Ave., 313 Snell Engineering, Boston, MA 02115 USA
| | - Eric Stas
- Division of Endocrinology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115 USA
| | - Ryan Koppes
- Department of Chemical Engineering, Northeastern University, 360 Huntington Ave., 313 Snell Engineering, Boston, MA 02115 USA
| | - David T Breault
- Division of Endocrinology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115 USA.,Department of Pediatrics, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 USA.,Harvard Stem Cell Institute, 7 Divinity Ave, Cambridge, MA 02138 USA
| | - Shashi K Murthy
- Department of Chemical Engineering, Northeastern University, 360 Huntington Ave., 313 Snell Engineering, Boston, MA 02115 USA
| | - Abigail N Koppes
- Department of Chemical Engineering, Northeastern University, 360 Huntington Ave., 313 Snell Engineering, Boston, MA 02115 USA.,Department of Biology, Northeastern University, 360 Huntington Ave., 313 Snell Engineering, Boston, MA 02115 USA
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5
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Lueschow SR, McElroy SJ. The Paneth Cell: The Curator and Defender of the Immature Small Intestine. Front Immunol 2020; 11:587. [PMID: 32308658 PMCID: PMC7145889 DOI: 10.3389/fimmu.2020.00587] [Citation(s) in RCA: 123] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 03/13/2020] [Indexed: 12/14/2022] Open
Abstract
Paneth cells were first described in the late 19th century by Gustav Schwalbe and Josef Paneth as columnar epithelial cells possessing prominent eosinophilic granules in their cytoplasm. Decades later there is continued interest in Paneth cells as they play an integral role in maintaining intestinal homeostasis and modulating the physiology of the small intestine and its associated microbial flora. Paneth cells are highly specialized secretory epithelial cells located in the small intestinal crypts of Lieberkühn. The dense granules produced by Paneth cells contain an abundance of antimicrobial peptides and immunomodulating proteins that function to regulate the composition of the intestinal flora. This in turn plays a significant role in secondary regulation of the host microvasculature, the normal injury and repair mechanisms of the intestinal epithelial layer, and the levels of intestinal inflammation. These critical functions may have even more importance in the immature intestine of premature infants. While Paneth cells begin to develop in the middle of human gestation, they do not become immune competent or reach their adult density until closer to term gestation. This leaves preterm infants deficient in normal Paneth cell biology during the greatest window of susceptibility to develop intestinal pathology such as necrotizing enterocolitis (NEC). As 10% of infants worldwide are currently born prematurely, there is a significant population of infants contending with an inadequate cohort of Paneth cells. Infants who have developed NEC have decreased Paneth cell numbers compared to age-matched controls, and ablation of murine Paneth cells results in a NEC-like phenotype suggesting again that Paneth cell function is critical to homeostasis to the immature intestine. This review will provide an up to date and comprehensive look at Paneth cell ontogeny, the impact Paneth cells have on the host-microbial axis in the immature intestine, and the repercussions of Paneth cell dysfunction or loss on injury and repair mechanisms in the immature gut.
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Affiliation(s)
- Shiloh R Lueschow
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, United States
| | - Steven J McElroy
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, United States.,Stead Family Department of Pediatrics, University of Iowa, Iowa City, IA, United States
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6
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Dithizone-induced Paneth cell disruption significantly decreases intestinal perfusion in the murine small intestine. J Pediatr Surg 2019; 54:2402-2407. [PMID: 30857731 PMCID: PMC6707906 DOI: 10.1016/j.jpedsurg.2019.02.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/06/2019] [Accepted: 02/17/2019] [Indexed: 02/06/2023]
Abstract
PURPOSE Necrotizing enterocolitis is associated with decreased intestinal perfusion and ischemia. Paneth cells, specialized epithelial cells, have been shown to regulate the intestinal vasculature and disruption of these cells has been associated with NEC. We hypothesized that Paneth cell disruption in immature mice intestine would decrease the perfusion of the intestinal microvasculature. METHODS Paneth cells were disrupted in P14-16 mice using chemical (dithizone) and transgenic (diphtheria toxin) methodology. Six hours after Paneth cell disruption, Dylight 488 was injected directly into the left ventricle and allowed to perfuse for 5 minutes prior to intestinal harvesting. Tissue samples were evaluated with confocal fluorescence microscopy to quantify intestinal perfusion and samples were quantified by real time RT-PCR for gene expression. RESULTS Dithizone treatment significantly decreased intestinal perfusion compared to controls (p < 0.01). However, diphtheria toxin treatment demonstrated no significant difference in perfusion (p > 0.21). Intestines from all treatment groups had similar PECAM staining, but intestines treated with dithizone had significantly decreased nNOS and iNOS gene expression compared to controls (p < 0.007). CONCLUSIONS Paneth cell disruption significantly decreases the perfusion of the small intestinal microvasculature in a dithizone-specific manner. Dithizone has no effect on the amount of microvasculature, but does impact genes critical to nitric oxide signaling likely contributing to mesenteric vasoconstriction.
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7
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Lueschow SR, Stumphy J, Gong H, Kern SL, Elgin TG, Underwood MA, Kalanetra KM, Mills DA, Wong MH, Meyerholz DK, Good M, McElroy SJ. Loss of murine Paneth cell function alters the immature intestinal microbiome and mimics changes seen in neonatal necrotizing enterocolitis. PLoS One 2018; 13:e0204967. [PMID: 30273395 PMCID: PMC6166990 DOI: 10.1371/journal.pone.0204967] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 09/16/2018] [Indexed: 01/06/2023] Open
Abstract
Necrotizing enterocolitis (NEC) remains the leading cause of gastrointestinal morbidity and mortality in premature infants. Human and animal studies suggest a role for Paneth cells in NEC pathogenesis. Paneth cells play critical roles in host-microbial interactions and epithelial homeostasis. The ramifications of eliminating Paneth cell function on the immature host-microbial axis remains incomplete. Paneth cell function was depleted in the immature murine intestine using chemical and genetic models, which resulted in intestinal injury consistent with NEC. Paneth cell depletion was confirmed using histology, electron microscopy, flow cytometry, and real time RT-PCR. Cecal samples were analyzed at various time points to determine the effects of Paneth cell depletion with and without Klebsiella gavage on the microbiome. Deficient Paneth cell function induced significant compositional changes in the cecal microbiome with a significant increase in Enterobacteriacae species. Further, the bloom of Enterobacteriaceae species that occurs is phenotypically similar to what is seen in human NEC. This further strengthens our understanding of the importance of Paneth cells to intestinal homeostasis in the immature intestine.
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Affiliation(s)
- Shiloh R. Lueschow
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
| | - Jessica Stumphy
- Stead Family Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States of America
| | - Huiyu Gong
- Stead Family Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States of America
| | - Stacy L. Kern
- Stead Family Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States of America
| | - Timothy G. Elgin
- Stead Family Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States of America
| | - Mark A. Underwood
- Departments of Pediatrics and Food Science and Technology, University of California Davis, Sacramento, California, United States of America
| | - Karen M. Kalanetra
- Departments of Pediatrics and Food Science and Technology, University of California Davis, Sacramento, California, United States of America
| | - David A. Mills
- Departments of Pediatrics and Food Science and Technology, University of California Davis, Sacramento, California, United States of America
| | - Melissa H. Wong
- Department of Cell, Developmental, and Cancer Biology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - David K. Meyerholz
- Department of Pathology, University of Iowa, Iowa City, Iowa, United States of America
| | - Misty Good
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Steven J. McElroy
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
- Stead Family Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States of America
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8
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White JR, Gong H, Pope B, Schlievert P, McElroy SJ. Paneth-cell-disruption-induced necrotizing enterocolitis in mice requires live bacteria and occurs independently of TLR4 signaling. Dis Model Mech 2017; 10:727-736. [PMID: 28450472 PMCID: PMC5483007 DOI: 10.1242/dmm.028589] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 04/07/2017] [Indexed: 12/18/2022] Open
Abstract
Necrotizing enterocolitis (NEC) remains a leading cause of morbidity and mortality in premature infants. Both human surgical specimens and animal models suggest a potential involvement of Paneth cells in NEC pathogenesis. Paneth cells play critical roles in epithelial homeostasis, innate immunity and host-microbial interactions. Yet, the complex interplay between Paneth cell disruption, epithelial barrier dysfunction and microbial-driven inflammation remains unclear in the immature intestine. In this study, mucosal intestinal injury consistent with human NEC was induced in postnatal day 14-16 (P14-P16) mice by disrupting Paneth cells, followed by gavage with Klebsiella pneumonia. Mucosal injury was determined by histology, serum cytokine levels and epithelial barrier dysfunction. Toll-like receptor 4 (TLR4) activation was examined using protein expression, gene expression, and TLR4−/− mice. Finally, the role of bacteria was evaluated using heat-killed bacteria, conditioned media, Bacillus cereus and cecal slurries. We found that live bacteria were required to induce injury; however, TLR4 activation was not required. NEC induced by Paneth cell disruption results in altered localization of tight junction proteins and subsequent loss of barrier function. Prior research has shown a requirement for TLR4 activation to induce NEC-like damage. However, many infants develop NEC in the absence of Gram-negative rod bacteremia, raising the possibility that alternative pathways to intestinal injury exist. In this study, we show a previously unknown mechanism for the development of intestinal injury equivalent to that seen in human NEC and that is not dependent on TLR4 pathways. These data are congruent with the new hypothesis that NEC may be the consequence of several disease processes ending in a final common inflammatory pathway. Summary: Paneth cell disruption and bacterial exposure in immature murine intestine induces NEC-like pathology. Importantly, this occurs independently of TLR4 activation, presenting an alternative mechanism for disease development.
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Affiliation(s)
| | - Huiyu Gong
- Pediatrics, University of Iowa, Iowa City, IA 54424, USA
| | - Brock Pope
- Pediatrics, University of Iowa, Iowa City, IA 54424, USA
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9
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Fung CM, White JR, Brown AS, Gong H, Weitkamp JH, Frey MR, McElroy SJ. Intrauterine Growth Restriction Alters Mouse Intestinal Architecture during Development. PLoS One 2016; 11:e0146542. [PMID: 26745886 PMCID: PMC4706418 DOI: 10.1371/journal.pone.0146542] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 12/18/2015] [Indexed: 12/31/2022] Open
Abstract
Infants with intrauterine growth restriction (IUGR) are at increased risk for neonatal and lifelong morbidities affecting multiple organ systems including the intestinal tract. The underlying mechanisms for the risk to the intestine remain poorly understood. In this study, we tested the hypothesis that IUGR affects the development of goblet and Paneth cell lineages, thus compromising the innate immunity and barrier functions of the epithelium. Using a mouse model of maternal thromboxane A2-analog infusion to elicit maternal hypertension and resultant IUGR, we tested whether IUGR alters ileal maturation and specifically disrupts mucus-producing goblet and antimicrobial-secreting Paneth cell development. We measured body weights, ileal weights and ileal lengths from birth to postnatal day (P) 56. We also determined the abundance of goblet and Paneth cells and their mRNA products, localization of cellular tight junctions, cell proliferation, and apoptosis to interrogate cellular homeostasis. Comparison of the murine findings with human IUGR ileum allowed us to verify observed changes in the mouse were relevant to clinical IUGR. At P14 IUGR mice had decreased ileal lengths, fewer goblet and Paneth cells, reductions in Paneth cell specific mRNAs, and decreased cell proliferation. These findings positively correlated with severity of IUGR. Furthermore, the decrease in murine Paneth cells was also seen in human IUGR ileum. IUGR disrupts the normal trajectory of ileal development, particularly affecting the composition and secretory products of the epithelial surface of the intestine. We speculate that this abnormal intestinal development may constitute an inherent “first hit”, rendering IUGR intestine susceptible to further injury, infection, or inflammation.
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Affiliation(s)
- Camille M. Fung
- Division of Neonatology, Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Jessica R. White
- Division of Neonatology, Pediatrics, University of Iowa, Iowa City, Iowa, United States of America
| | - Ashley S. Brown
- Division of Neonatology, Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Huiyu Gong
- Division of Neonatology, Pediatrics, University of Iowa, Iowa City, Iowa, United States of America
| | - Jörn-Hendrik Weitkamp
- Division of Neonatology, Pediatrics, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Mark R. Frey
- Department of Pediatrics and Department of Biochemistry and Molecular Biology, University of Southern California Keck School of Medicine and The Saban Research Institute at Children's Hospital Los Angeles, Los Angeles, California, United States of America
| | - Steven J. McElroy
- Division of Neonatology, Pediatrics, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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10
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Halpern MD, Denning PW. The role of intestinal epithelial barrier function in the development of NEC. Tissue Barriers 2015; 3:e1000707. [PMID: 25927016 DOI: 10.1080/21688370.2014.1000707] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 12/16/2014] [Indexed: 12/12/2022] Open
Abstract
The intestinal epithelial barrier plays an important role in maintaining host health. Breakdown of intestinal barrier function is known to play a role in many diseases such as infectious enteritis, idiopathic inflammatory bowel disease, and neonatal inflammatory bowel diseases. Recently, increasing research has demonstrated the importance of understanding how intestinal epithelial barrier function develops in the premature neonate in order to develop strategies to promote its maturation. Optimizing intestinal barrier function is thought to be key to preventing neonatal inflammatory bowel diseases such as necrotizing enterocolitis. In this review, we will first summarize the key components of the intestinal epithelial barrier, what is known about its development, and how this may explain NEC pathogenesis. Finally, we will review what therapeutic strategies may be used to promote optimal development of neonatal intestinal barrier function in order to reduce the incidence and severity of NEC.
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Key Words
- AJ, adherens junctions
- AJC, apical junction complex
- BAs, bile acids; EGF, epidermal growth factor
- Bb, Bifidobacterium bifidum
- Bi, Bifidobacterium infantis
- EPO, erythropoietin; IFNγ, interferon gamma
- IEL, intestinal epithelial lymphocytes
- NEC, necrotizing enterocolitis
- NICU, neonatal intensive care unit
- Necrotizing enterocolitis (NEC)
- TCRγδ, T-cell receptor gamma-delta
- TGF-β, transforming growth factor-beta
- TJ, tight junctions
- TNFα, tumor necrosis factor alpha
- TPN, total parenteral nutrition
- apical junctional complex
- commensal bacteria
- intestinal epithelial barrier
- prematurity
- probiotics
- tight junctions
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Affiliation(s)
- Melissa D Halpern
- Department of Pediatrics; The University of Arizona ; Tucson, AZ USA
| | - Patricia W Denning
- Department of Pediatrics; Emory University School of Medicine ; Atlanta, GA USA
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