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Gomart A, Vallée A, Lecarpentier Y. Necrotizing Enterocolitis: LPS/TLR4-Induced Crosstalk Between Canonical TGF-β/Wnt/β-Catenin Pathways and PPARγ. Front Pediatr 2021; 9:713344. [PMID: 34712628 PMCID: PMC8547806 DOI: 10.3389/fped.2021.713344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 09/13/2021] [Indexed: 12/13/2022] Open
Abstract
Necrotizing enterocolitis (NEC) represents one of the major causes of morbidity and mortality in premature infants. Several recent studies, however, have contributed to a better understanding of the pathophysiology of this dreadful disease. Numerous intracellular pathways play a key role in NEC, namely: bacterial lipopolysaccharide (LPS), LPS toll-like receptor 4 (TLR4), canonical Wnt/β-catenin signaling and PPARγ. In a large number of pathologies, canonical Wnt/β-catenin signaling and PPARγ operate in opposition to one another, so that when one of the two pathways is overexpressed the other is downregulated and vice-versa. In NEC, activation of TLR4 by LPS leads to downregulation of the canonical Wnt/β-catenin signaling and upregulation of PPARγ. This review aims to shed light on the complex intracellular mechanisms involved in this pathophysiological profile by examining additional pathways such as the GSK-3β, NF-κB, TGF-β/Smads, and PI3K-Akt pathways.
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Affiliation(s)
- Alexia Gomart
- Département de Pédiatrie et Médecine de l'adolescent, Centre Hospitalier Intercommunal de Créteil, Créteil, France
| | - Alexandre Vallée
- Department of Clinical Research and Innovation, Foch Hospital, Suresnes, France
| | - Yves Lecarpentier
- Centre de Recherche Clinique, Grand Hôpital de l'Est Francilien, Meaux, France
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2
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Ladd MR, Costello CM, Gosztyla C, Werts AD, Johnson B, Fulton WB, Martin LY, Redfield EJ, Crawford B, Panaparambil R, Sodhi CP, March JC, Hackam DJ. Development of Intestinal Scaffolds that Mimic Native Mammalian Intestinal Tissue. Tissue Eng Part A 2019; 25:1225-1241. [PMID: 30652526 PMCID: PMC6760185 DOI: 10.1089/ten.tea.2018.0239] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 12/05/2018] [Indexed: 12/27/2022] Open
Abstract
IMPACT STATEMENT This study is significant because it demonstrates an attempt to design a scaffold specifically for small intestine using a novel fabrication method, resulting in an architecture that resembles intestinal villi. In addition, we use the versatile polymer poly(glycerol sebacate) (PGS) for artificial intestine, which has tunable mechanical and degradation properties that can be harnessed for further fine-tuning of scaffold design. Moreover, the utilization of PGS allows for future development of growth factor and drug delivery from the scaffolds to promote artificial intestine formation.
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Affiliation(s)
- Mitchell R. Ladd
- Department of Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Cait M. Costello
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York
| | - Carolyn Gosztyla
- Department of Surgery, Walter Reed National Military Medical Center, Bethesda, Maryland
| | - Adam D. Werts
- Department of Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Blake Johnson
- Department of Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - William B. Fulton
- Department of Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Laura Y. Martin
- Department of Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Elizabeth J. Redfield
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York
| | - Bryan Crawford
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland
| | - Rohan Panaparambil
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland
| | - Chhinder P. Sodhi
- Department of Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - John C. March
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York
| | - David J. Hackam
- Department of Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland
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3
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Pelletier RM, Akpovi CD, Chen L, Kumar NM, Vitale ML. Complementary expression and phosphorylation of Cx46 and Cx50 during development and following gene deletion in mouse and in normal and orchitic mink testes. Am J Physiol Regul Integr Comp Physiol 2015; 309:R255-76. [PMID: 26017495 PMCID: PMC4525330 DOI: 10.1152/ajpregu.00152.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 05/23/2015] [Indexed: 01/11/2023]
Abstract
Gap junction-mediated communication helps synchronize interconnected Sertoli cell activities. Besides, coordination of germ cell and Sertoli cell activities depends on gap junction-mediated Sertoli cell-germ cell communication. This report assesses mechanisms underlying the regulation of connexin 46 (Cx46) and Cx50 in mouse testis and those accompanying a "natural" seasonal and a pathological arrest of spermatogenesis, resulting from autoimmune orchitis (AIO) in mink. Furthermore, the impact of deleting Cx46 or Cx50 on the expression, phosphorylation of junction proteins, and spermatogenesis is evaluated. Cx46 mRNA and protein expression increased, whereas Cx50 decreased with adulthood in normal mice and mink. Cx46 mRNA and protein expression increased, whereas Cx50 decreased with adulthood in normal mice and mink. During the mink active spermatogenic phase, Cx50 became phosphorylated and localized to the site of the blood-testis barrier. By contrast, Cx46 was dephosphorylated and associated with annular junctions, suggesting phosphorylation/dephosphorylation of Cx46 and Cx50 involvement in the barrier dynamics. Cx46-positive annular junctions in contact with lipid droplets were found. Cx46 and Cx50 expression and localization were altered in mink with AIO. The deletion of Cx46 or Cx50 impacted on other connexin expression and phosphorylation and differently affected tight and adhering junction protein expression. The level of apoptosis, determined by ELISA, and a number of Apostain-labeled spermatocytes and spermatids/tubules were higher in mice lacking Cx46 (Cx46-/-) than wild-type and Cx50-/- mice, arguing for life-sustaining Cx46 gap junction-mediated exchanges in late-stage germ cells secluded from the blood by the barrier. The data show that expression and phosphorylation of Cx46 and Cx50 are complementary in seminiferous tubules.
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Affiliation(s)
- R-Marc Pelletier
- Department of Pathology and Cell Biology, Université de Montréal, Québec, Canada; and
| | - Casimir D Akpovi
- Department of Pathology and Cell Biology, Université de Montréal, Québec, Canada; and
| | - Li Chen
- Department of Pathology and Cell Biology, Université de Montréal, Québec, Canada; and
| | - Nalin M Kumar
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois
| | - María L Vitale
- Department of Pathology and Cell Biology, Université de Montréal, Québec, Canada; and
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4
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Darwich AS, Aslam U, Ashcroft DM, Rostami-Hodjegan A. Meta-analysis of the turnover of intestinal epithelia in preclinical animal species and humans. Drug Metab Dispos 2014; 42:2016-22. [PMID: 25233858 DOI: 10.1124/dmd.114.058404] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Due to the rapid turnover of the small intestinal epithelia, the rate at which enterocyte renewal occurs plays an important role in determining the level of drug-metabolizing enzymes in the gut wall. Current physiologically based pharmacokinetic (PBPK) models consider enzyme and enterocyte recovery as a lumped first-order rate. An assessment of enterocyte turnover would enable enzyme and enterocyte renewal to be modeled more mechanistically. A literature review together with statistical analysis was employed to establish enterocyte turnover in human and preclinical species. A total of 85 studies was identified reporting enterocyte turnover in 1602 subjects in six species. In mice, the geometric weighted combined mean (WX) enterocyte turnover was 2.81 ± 1.14 days (n = 169). In rats, the weighted arithmetic mean enterocyte turnover was determined to be 2.37 days (n = 501). Humans exhibited a geometric WX enterocyte turnover of 3.48 ± 1.55 days for the gastrointestinal epithelia (n = 265), displaying comparable turnover to that of cytochrome P450 enzymes in vitro (0.96-4.33 days). Statistical analysis indicated humans to display longer enterocyte turnover as compared with preclinical species. Extracted data were too sparse to support regional differences in small intestinal enterocyte turnover in humans despite being indicated in mice. The utilization of enterocyte turnover data, together with in vitro enzyme turnover in PBPK modeling, may improve the predictions of metabolic drug-drug interactions dependent on enzyme turnover (e.g., mechanism-based inhibition and enzyme induction) as well as absorption of nanoparticle delivery systems and intestinal metabolism in special populations exhibiting altered enterocyte turnover.
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Affiliation(s)
- Adam S Darwich
- Centre for Applied Pharmacokinetic Research, Manchester Pharmacy School, University of Manchester, Manchester, United Kingdom (A.S.D., U.A., D.M.A., A.R.-H.); and Simcyp (a Certara company), Sheffield, United Kingdom (A.R.-H.)
| | - Umair Aslam
- Centre for Applied Pharmacokinetic Research, Manchester Pharmacy School, University of Manchester, Manchester, United Kingdom (A.S.D., U.A., D.M.A., A.R.-H.); and Simcyp (a Certara company), Sheffield, United Kingdom (A.R.-H.)
| | - Darren M Ashcroft
- Centre for Applied Pharmacokinetic Research, Manchester Pharmacy School, University of Manchester, Manchester, United Kingdom (A.S.D., U.A., D.M.A., A.R.-H.); and Simcyp (a Certara company), Sheffield, United Kingdom (A.R.-H.)
| | - Amin Rostami-Hodjegan
- Centre for Applied Pharmacokinetic Research, Manchester Pharmacy School, University of Manchester, Manchester, United Kingdom (A.S.D., U.A., D.M.A., A.R.-H.); and Simcyp (a Certara company), Sheffield, United Kingdom (A.R.-H.)
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5
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Abstract
Curcumin is a polyphenol which is extracted from the plant Curcuma longa. Recent studies showed that curcumin has therapeutic effects on ulcerative colitis. The mechanisms underlying such therapeutic effects on ulcerative colitis include anti-inflammatory, anti-oxidative stress, anti-apoptosis and so on. Curcumin can inhibit the nuclear factor-κB (NF-κB) signaling pathway, mitogen-activated protein kinase (MAPK), signal transducers and activators of transcription-3 (STAT3), and Toll-like receptor 4 (TLR4) signaling pathway, reduce cytokines such as interleukin-23 (IL-23), tumor necrosis factor (TNF)-alpha and interferon gamma, enhance the expression of peroxisome proliferator-activated receptor γ involved in inflammation and immune response regulation, and down-regulate the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), thereby making nitrites returning to basal levels. In this paper, we will review the recent progress in understanding the mechanisms underlying the therapeutic effects of curcumin on ulcerative colitis.
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Update in pathogenesis and prospective in treatment of necrotizing enterocolitis. BIOMED RESEARCH INTERNATIONAL 2014; 2014:543765. [PMID: 25147804 PMCID: PMC4124648 DOI: 10.1155/2014/543765] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 06/24/2014] [Indexed: 02/02/2023]
Abstract
Necrotizing enterocolitis (NEC) is among the most common and devastating diseases in neonates and, despite the significant advances in neonatal clinical and basic science investigations, its etiology is largely understood, specific treatment strategies are lacking, and morbidity and mortality remain high. Improvements in the understanding of pathogenesis of NEC may have therapeutic consequences. Pharmacologic inhibition of toll-like receptor signaling, the use of novel nutritional strategies, and microflora modulation may represent novel promising approaches to the prevention and treatment of NEC. This review, starting from the recent acquisitions in the pathogenic mechanisms of NEC, focuses on current and possible therapeutic perspectives.
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Hunter CJ, De Plaen IG. Inflammatory signaling in NEC: Role of NF-κB, cytokines and other inflammatory mediators. ACTA ACUST UNITED AC 2013; 21:55-65. [PMID: 24388163 DOI: 10.1016/j.pathophys.2013.11.010] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Catherine J Hunter
- Department of Surgery, Division of Pediatric Surgery, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, United States
| | - Isabelle G De Plaen
- Department of Pediatrics, Division of Neonatology, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Avenue, Box 45, Chicago, IL 60611, United States.
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8
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Innate immune signaling in the pathogenesis of necrotizing enterocolitis. Clin Dev Immunol 2013; 2013:475415. [PMID: 23762089 PMCID: PMC3677005 DOI: 10.1155/2013/475415] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 05/01/2013] [Accepted: 05/07/2013] [Indexed: 01/01/2023]
Abstract
Necrotizing enterocolitis (NEC) is a challenging disease to treat, and caring for patients afflicted by it remains both frustrating and difficult. While NEC may develop quickly and without warning, it may also develop slowly, insidiously, and appear to take the caregiver by surprise. In seeking to understand the molecular and cellular processes that lead to NEC development, we have identified a critical role for the receptor for bacterial lipopolysaccharide (LPS) toll like receptor 4 (TLR4) in the pathogenesis of NEC, as its activation within the intestinal epithelium of the premature infant leads to mucosal injury and reduced epithelial repair. The expression and function of TLR4 were found to be particularly elevated within the intestinal mucosa of the premature as compared with the full-term infant, predisposing to NEC development. Importantly, factors within both the enterocyte itself, such as heat shock protein 70 (Hsp70), and in the extracellular environment, such as amniotic fluid, can curtail the extent of TLR4 signaling and reduce the propensity for NEC development. This review will highlight the critical TLR4-mediated steps that lead to NEC development, with a focus on the proinflammatory responses of TLR4 signaling that have such devastating consequences in the premature host.
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Do KH, Choi HJ, Kim J, Park SH, Kim KH, Moon Y. SOCS3 Regulates BAFF in Human Enterocytes under Ribosomal Stress. THE JOURNAL OF IMMUNOLOGY 2013; 190:6501-10. [DOI: 10.4049/jimmunol.1203004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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10
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Abstract
The pathogenesis of necrotizing enterocolitis (NEC) is complex and its speed of progression is variable. To gain understanding of the disease, researchers have examined tissues resected from patients with NEC; however, as these are obtained at late stages of the disease, they do not yield clues about the early pathogenic events leading to NEC. Therefore, animal models are used and have helped identify a role for several mediators of the inflammatory network in NEC. In this article, we discuss the evidence for the role of these inflammatory mediators and conclude with a current unifying hypothesis regarding NEC pathogenesis.
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Affiliation(s)
- Isabelle G. De Plaen
- Associate Professor of Pediatrics, Department of Pediatrics, Division of Neonatology, Northwestern University Feinberg School of Medicine, Children’s Hospital of Chicago Research Center, Ann and Robert H. Lurie Children’s Hospital of Chicago, 225 E. Chicago Ave, Box 45, Chicago, IL 60611-2605, U.S.A., Tel: (773)-755-6379; fax: (312)-227-9758
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11
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Brink PR, Valiunas V, Gordon C, Rosen MR, Cohen IS. Can gap junctions deliver? BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1818:2076-81. [PMID: 21986484 DOI: 10.1016/j.bbamem.2011.09.025] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 09/09/2011] [Accepted: 09/23/2011] [Indexed: 01/08/2023]
Abstract
In vivo delivery of small interfering RNAs (siRNAs) to target cells via the extracellular space has been hampered by dilution effects and immune responses. Gap junction-mediated transfer between cells avoids the extracellular space and its associated limitations. Because of these advantages cell based delivery via gap junctions has emerged as a viable alternative for siRNA or miRNA delivery. Here we discuss the advantages and disadvantages of extracellular delivery and cell to cell delivery via gap junction channels composed of connexins. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
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Affiliation(s)
- Peter R Brink
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, USA.
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12
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Thomson ABR, Chopra A, Clandinin MT, Freeman H. Recent advances in small bowel diseases: Part I. World J Gastroenterol 2012; 18:3336-52. [PMID: 22807604 PMCID: PMC3396187 DOI: 10.3748/wjg.v18.i26.3336] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 04/05/2012] [Accepted: 04/13/2012] [Indexed: 02/06/2023] Open
Abstract
As is the case in all parts of gastroenterology and hepatology, there have been many advances in our knowledge and understanding of small intestinal diseases. Over 1000 publications were reviewed for 2008 and 2009, and the important advances in basic science as well as clinical applications were considered. In Part I of this Editorial Review, seven topics are considered: intestinal development; proliferation and repair; intestinal permeability; microbiotica, infectious diarrhea and probiotics; diarrhea; salt and water absorption; necrotizing enterocolitis; and immunology/allergy. These topics were chosen because of their importance to the practicing physician.
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13
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Midura-Kiela MT, Radhakrishnan VM, Larmonier CB, Laubitz D, Ghishan FK, Kiela PR. Curcumin inhibits interferon-γ signaling in colonic epithelial cells. Am J Physiol Gastrointest Liver Physiol 2012; 302:G85-96. [PMID: 22038826 PMCID: PMC3345961 DOI: 10.1152/ajpgi.00275.2011] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Curcumin (diferulolylmethane) is an anti-inflammatory phenolic compound found effective in preclinical models of inflammatory bowel diseases (IBD) and in ulcerative colitis patients. Pharmacokinetics of curcumin and its poor systemic bioavailability suggest that it targets preferentially intestinal epithelial cells. The intestinal epithelium, an essential component of the gut innate defense mechanisms, is profoundly affected by IFN-γ, which can disrupt the epithelial barrier function, prevent epithelial cell migration and wound healing, and prime epithelial cells to express major histocompatibility complex class II (MHC-II) molecules and to serve as nonprofessional antigen-presenting cells. In this report we demonstrate that curcumin inhibits IFN-γ signaling in human and mouse colonocytes. Curcumin inhibited IFN-γ-induced gene transcription, including CII-TA, MHC-II genes (HLA-DRα, HLA-DPα1, HLA-DRβ1), and T cell chemokines (CXCL9, 10, and 11). Acutely, curcumin inhibited Stat1 binding to the GAS cis-element, prevented Stat1 nuclear translocation, and reduced Jak1 phosphorylation and phosphorylation of Stat1 at Tyr(701). Longer exposure to curcumin led to endocytic internalization of IFNγRα followed by lysosomal fusion and degradation. In summary, curcumin acts as an IFN-γ signaling inhibitor in colonocytes with biphasic mechanisms of action, a phenomenon that may partially account for the beneficial effects of curcumin in experimental colitis and in human IBD.
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Affiliation(s)
| | | | | | - Daniel Laubitz
- 1Department of Pediatrics, Steele Children's Research Center and ,2Institute of Biochemistry and Biophysics Polish Academy of Sciences, Warsaw, Poland; and
| | - Fayez K. Ghishan
- 1Department of Pediatrics, Steele Children's Research Center and
| | - Pawel R. Kiela
- 1Department of Pediatrics, Steele Children's Research Center and ,3Department of Immunobiology, University of Arizona Health Sciences Center, Tucson, Arizona
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Defamie N, Mesnil M. The modulation of gap-junctional intercellular communication by lipid rafts. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:1866-9. [PMID: 21986485 DOI: 10.1016/j.bbamem.2011.09.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 09/15/2011] [Accepted: 09/24/2011] [Indexed: 01/24/2023]
Abstract
Lipid rafts are specific microdomains of plasma membrane which are enriched in cholesterol and sphingolipids. These domains seem to favour the interactions of particular proteins and the regulation of signalling pathways in the cells. Recent data have shown that among the proteins, which are preferentially localized in lipid rafts, are connexins that are the structural proteins of gap junctions. Since gap junctional intercellular communication is involved in various cellular processes and pathologies such as cancer, we were interested to review the various observations concerning this specific localization of connexins in lipid rafts and its consequences on gap junctional intercellular communication capacity. In particular, we will focus our discussion on the role of the lipid raft-connexin connection in cancer progression. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
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15
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Strale PO, Clarhaut J, Lamiche C, Cronier L, Mesnil M, Defamie N. Down-regulation of connexin43 expression reveals the involvement of caveolin-1 containing lipid rafts in human U251 glioblastoma cell invasion. Mol Carcinog 2011; 51:845-60. [DOI: 10.1002/mc.20853] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 06/29/2011] [Accepted: 08/10/2011] [Indexed: 01/15/2023]
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Koval M, Billaud M, Straub AC, Johnstone SR, Zarbock A, Duling BR, Isakson BE. Spontaneous lung dysfunction and fibrosis in mice lacking connexin 40 and endothelial cell connexin 43. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:2536-46. [PMID: 21641379 PMCID: PMC3124229 DOI: 10.1016/j.ajpath.2011.02.045] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2010] [Revised: 12/30/2010] [Accepted: 02/01/2011] [Indexed: 12/31/2022]
Abstract
Gap junction proteins (connexins) facilitate intercellular communication and serve several roles in regulation of tissue function and remodeling. To examine the physiologic effects of depleting two prominent endothelial connexins, Cx40 and Cx43, transgenic mice were generated by breeding Cx40-deficient mice (Cx40(-/-)) with a vascular endothelial cell (VEC)-specific Cx43-deficient mouse strain (VEC Cx43(-/-)) to produce double-connexin knockout mice (VEC Cx43(-/-)/Cx40(-/-)). The life span in VEC Cx43(-/-)/Cx40(-/-) mice was dramatically shortened, which correlated with severe spontaneous lung abnormalities as the mice aged including increased fibrosis, aberrant alveolar remodeling, and increased lung fibroblast content. Moreover, VEC Cx43(-/-)/Cx40(-/-) mice exhibited cardiac hypertrophy and hypertension. Because VEC Cx43(-/-)/Cx40(-/-) mice demonstrated phenotypic hallmarks that were remarkably similar to those in mice deficient in caveolin-1, pulmonary caveolin expression was examined. Lungs from VEC Cx43(-/-)/Cx40(-/-) mice demonstrated significantly decreased expression of caveolin-1 and caveolin-2. This suggests that expression of caveolin-1 may be linked to expression of Cx40 and endothelial Cx43. Moreover, the phenotype of caveolin-1(-/-) mice and VEC Cx43(-/-)/Cx40(-/-) mice may arise via a common mechanism.
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Affiliation(s)
- Michael Koval
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Marie Billaud
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Adam C. Straub
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Scott R. Johnstone
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Alexander Zarbock
- Department of Anesthesiology and Critical Care Medicine, University of Münster, Münster, Germany
- Max-Planck-Institute of Molecular Biomedicine, Münster, Germany
| | - Brian R. Duling
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Brant E. Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia
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17
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Schalper KA, Sánchez HA, Lee SC, Altenberg GA, Nathanson MH, Sáez JC. Connexin 43 hemichannels mediate the Ca2+ influx induced by extracellular alkalinization. Am J Physiol Cell Physiol 2010; 299:C1504-15. [PMID: 20881238 DOI: 10.1152/ajpcell.00015.2010] [Citation(s) in RCA: 133] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Although alkaline pH is known to trigger Ca(2+) influx in diverse cells, no pH-sensitive Ca(2+) channel has been identified. Here, we report that extracellular alkalinization induces opening of connexin 43 hemichannels (Cx43 HCs). Increasing extracellular pH from 7.4 to 8.5, in the presence of physiological Ca(2+)/Mg(2+) concentrations, rapidly increased the ethidium uptake rate and open probability of HCs in Cx43 and Cx43EGFP HeLa transfectants (HeLa-Cx3 and HeLa-Cx43EGFP, respectively) but not in parental HeLa cells (HeLa-parental) lacking Cx43 HCs. The increase in ethidium uptake induced by pH 8.5 was not affected by raising the extracellular Ca(2+) concentration from 1.8 to 10 mM but was inhibited by a connexin HC inhibitor (La(3+)). Probenecid, a pannexin HC blocker, had no effect. Extracellular alkalinization increased the intracellular Ca(2+) levels only in cells expressing HCs. The above changes induced by extracellular alkalinization did not change the cellular distribution of Cx43, suggesting that HC activation occurs through a gating mechanism. Experiments on cells expressing a COOH-terminal truncated Cx43 mutant indicated that the effects of alkalinization on intracellular Ca(2+) and ethidium uptake did not depend on the Cx43 C terminus. Moreover, purified dephosphorylated Cx43 HCs reconstituted in liposomes were Ca(2+) permeable, suggesting that Ca(2+) influx through Cx43 HCs could account for the elevation in intracellular Ca(2+) elicited by extracellular alkalinization. These studies identify a membrane pathway for Ca(2+) influx and provide a potential explanation for the activation of cellular events induced by extracellular alkalinization.
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Affiliation(s)
- Kurt A Schalper
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Alameda 340, 4 to Piso, Santiago, 8331150 Chile.
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Langelier B, Linard A, Bordat C, Lavialle M, Heberden C. Long chain-polyunsaturated fatty acids modulate membrane phospholipid composition and protein localization in lipid rafts of neural stem cell cultures. J Cell Biochem 2010; 110:1356-64. [DOI: 10.1002/jcb.22652] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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19
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Peng HY, Chen GD, Tung KC, Chien YW, Lai CY, Hsieh MC, Chiu CH, Lai CH, Lee SD, Lin TB. Estrogen-dependent facilitation on spinal reflex potentiation involves the Cdk5/ERK1/2/NR2B cascade in anesthetized rats. Am J Physiol Endocrinol Metab 2009; 297:E416-26. [PMID: 19531642 DOI: 10.1152/ajpendo.00129.2009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Cyclin-dependent kinase-5 (Cdk5), a proline-directed serine/threonine kinase, may alter pain-related neuronal plasticity by regulating extracellular signal-related kinase-1/2 (ERK1/2) activation. This study investigated whether Cdk5-dependent ERK activation underlies the estrogen-elicited facilitation on the repetitive stimulation-induced spinal reflex potentiaton (SRP) that is presumed to be involved in postinflammatory/neuropathic hyperalgesia and allodynia. Reflex activity of the external urethra sphincter electromyogram evoked by pelvic afferent nerve test stimulation (TS; 1 stimulation/30 s for 10 min) and repetitive stimulation (RS; 1 stimulation/1 s for 10 min) was recorded in anesthetized rats. TS evoked a baseline reflex activity, whereas RS produced SRP. Intrathecal (it) beta-estradiol facilitated the repetitive stimulation-induced SRP that was reversed by pretreatment with the estrogen receptor anatogonist ICI 182,780 (10 nM, 10 microl it), Cdk5 inhibitor roscovitine (100 nM, 10 microl it), ERK inhibitor (U-0126; 100 microM, 10 microl it) and N-methyl-D-aspartate (NMDA) NR2B subunit antagonist (Co-101244; 100 nM, 10 microl it). Moreover, ERalpha (propylpyrazoletriol; 100 nM, 10 microl it) and ERbeta (diarylpropionitrile; 100 microM, 10 microl it) agonists both facilitated the SRP, similar to results with a beta-estradiol injection. In association with the facilitated RS-induced SRP, an intrathecal beta-estradiol injection elicited ERK1/2 and NR2B subunit phosphorylation that were both reversed by intrathecal roscovitine and U-0126. These results indicated that the Cdk/ERK cascade, which is activated by ERalpha and ERbeta, may subsequently phosphorylate the NR2B subunit to develop NMDA-dependent postinflammatory hyperalgesia and allodynia to maintain the protective mechanisms of the body.
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Affiliation(s)
- Hsien-Yu Peng
- Department of Physiology, Chung-Shan Medical University Hospital, Chung-Shan Medical University, Taichung, Taiwan
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20
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Anand RJ, Dai S, Gribar SC, Richardson W, Kohler JW, Hoffman RA, Branca MF, Li J, Shi XH, Sodhi CP, Hackam DJ. A role for connexin43 in macrophage phagocytosis and host survival after bacterial peritoneal infection. THE JOURNAL OF IMMUNOLOGY 2009; 181:8534-8543. [PMID: 19050272 DOI: 10.4049/jimmunol.181.12.8534] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The pathways that lead to the internalization of pathogens via phagocytosis remain incompletely understood. We now demonstrate a previously unrecognized role for the gap junction protein connexin43 (Cx43) in the regulation of phagocytosis by macrophages and in the host response to bacterial infection of the peritoneal cavity. Primary and cultured macrophages were found to express Cx43, which localized to the phagosome upon the internalization of IgG-opsonized particles. The inhibition of Cx43 using small interfering RNA or by obtaining macrophages from Cx43 heterozygous or knockout mice resulted in significantly impaired phagocytosis, while transfection of Cx43 into Fc-receptor expressing HeLa cells, which do not express endogenous Cx43, conferred the ability of these cells to undergo phagocytosis. Infection of macrophages with adenoviruses expressing wild-type Cx43 restored phagocytic ability in macrophages from Cx43 heterozygous or deficient mice, while infection with viruses that expressed mutant Cx43 had no effect. In understanding the mechanisms involved, Cx43 was required for RhoA-dependent actin cup formation under adherent particles, and transfection with constitutively active RhoA restored a phagocytic phenotype after Cx43 inactivation. Remarkably, mortality was significantly increased in a mouse model of bacterial peritonitis after Cx43 inhibition and in Cx43 heterozygous mice compared with untreated and wild-type counterparts. These findings reveal a novel role for Cx43 in the regulation of phagocytosis and rearrangement of the F-actin cytoskeleton, and they implicate Cx43 in the regulation of the host response to microbial infection.
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Affiliation(s)
- Rahul J Anand
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, and University of Pittsburgh School of Medicine, Pittsburgh, PA 15213.,Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213
| | - Shipan Dai
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, and University of Pittsburgh School of Medicine, Pittsburgh, PA 15213.,Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213
| | - Steven C Gribar
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, and University of Pittsburgh School of Medicine, Pittsburgh, PA 15213.,Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213
| | - Ward Richardson
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, and University of Pittsburgh School of Medicine, Pittsburgh, PA 15213.,Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213
| | - Jeff W Kohler
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, and University of Pittsburgh School of Medicine, Pittsburgh, PA 15213.,Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213
| | - Rosemary A Hoffman
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213
| | - Maria F Branca
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, and University of Pittsburgh School of Medicine, Pittsburgh, PA 15213.,Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213
| | - Jun Li
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, and University of Pittsburgh School of Medicine, Pittsburgh, PA 15213.,Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213
| | - Xiao-Hua Shi
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, and University of Pittsburgh School of Medicine, Pittsburgh, PA 15213.,Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213
| | - Chhinder P Sodhi
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, and University of Pittsburgh School of Medicine, Pittsburgh, PA 15213.,Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213
| | - David J Hackam
- Division of Pediatric Surgery, Children's Hospital of Pittsburgh, and University of Pittsburgh School of Medicine, Pittsburgh, PA 15213.,Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213
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