1
|
Bhargava A. Unraveling corticotropin-releasing factor family-orchestrated signaling and function in both sexes. VITAMINS AND HORMONES 2023; 123:27-65. [PMID: 37717988 DOI: 10.1016/bs.vh.2023.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Stress responses to physical, psychological, environmental, or cellular stressors, has two arms: initiation and recovery. Corticotropin-releasing factor (CRF) is primarily responsible for regulating and/or initiating stress responses via, whereas urocortins (UCNs) are involved in the recovery response to stress via feedback inhibition. Stress is a loaded, polysemous word and is experienced in a myriad of ways. Some stressors are good for an individual, in fact essential, whereas other stressors are associated with bad outcomes. Perceived stress, like beauty, lies in the eye of the beholder, and hence the same stressor can result in individual-specific outcomes. In mammals, there are two main biological sexes with reproduction as primary function. Reproduction and nutrition can also be viewed as stressors; based on a body of work from my laboratory, we propose that the functions of all other organs have co-evolved to optimize and facilitate an individual's nutritional and reproductive functions. Hence, sex differences in physiologically relevant outcomes are innate and occur at all levels- molecular, endocrine, immune, and (patho)physiological. CRF and three UCNs are peptide hormones that mediate their physiological effects by binding to two known G protein-coupled receptors (GPCRs), CRF1 and CRF2. Expression and function of CRF family of hormones and their receptors is likely to be sexually dimorphic in all organs. In this chapter, based on the large body of work from others and my laboratory, an overview of the CRF family with special emphasis on sex-specific actions of peripherally expressed CRF2 receptor in health and disease is provided.
Collapse
Affiliation(s)
- Aditi Bhargava
- Center for Reproductive Sciences, Department of Obstetrics and Gynecology, University of California San Francisco, San Francisco, CA, United States.
| |
Collapse
|
2
|
Varadarajan S, Chumki SA, Stephenson RE, Misterovich ER, Wu JL, Dudley CE, Erofeev IS, Goryachev AB, Miller AL. Mechanosensitive calcium flashes promote sustained RhoA activation during tight junction remodeling. J Cell Biol 2022; 221:213049. [PMID: 35254388 PMCID: PMC8906493 DOI: 10.1083/jcb.202105107] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 12/03/2021] [Accepted: 02/02/2022] [Indexed: 11/22/2022] Open
Abstract
Epithelial cell–cell junctions remodel in response to mechanical stimuli to maintain barrier function. Previously, we found that local leaks in tight junctions (TJs) are rapidly repaired by local, transient RhoA activation, termed “Rho flares,” but how Rho flares are regulated is unknown. Here, we discovered that intracellular calcium flashes and junction elongation are early events in the Rho flare pathway. Both laser-induced and naturally occurring TJ breaks lead to local calcium flashes at the site of leaks. Additionally, junction elongation induced by optogenetics increases Rho flare frequency, suggesting that Rho flares are mechanically triggered. Depletion of intracellular calcium or inhibition of mechanosensitive calcium channels (MSCs) reduces the amplitude of calcium flashes and diminishes the sustained activation of Rho flares. MSC-dependent calcium influx is necessary to maintain global barrier function by regulating reinforcement of local TJ proteins via junction contraction. In all, we uncovered a novel role for MSC-dependent calcium flashes in TJ remodeling, allowing epithelial cells to repair local leaks induced by mechanical stimuli.
Collapse
Affiliation(s)
| | - Shahana A Chumki
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI
| | - Rachel E Stephenson
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
| | - Eileen R Misterovich
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
| | - Jessica L Wu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
| | - Claire E Dudley
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
| | - Ivan S Erofeev
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, Scotland
| | - Andrew B Goryachev
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, Scotland
| | - Ann L Miller
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI.,Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI
| |
Collapse
|
3
|
Lactobacillus casei and Epidermal Growth Factor Prevent Osmotic Stress-Induced Tight Junction Disruption in Caco-2 Cell Monolayers. Cells 2021; 10:cells10123578. [PMID: 34944085 PMCID: PMC8700399 DOI: 10.3390/cells10123578] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 01/08/2023] Open
Abstract
Osmotic stress plays a crucial role in the pathogenesis of many gastrointestinal diseases. Lactobacillus casei and epidermal growth factor (EGF) effects on the osmotic stress-induced epithelial junctional disruption and barrier dysfunction were investigated. Caco-2 cell monolayers were exposed to osmotic stress in the presence or absence of L. casei or EGF, and the barrier function was evaluated by measuring inulin permeability. Tight junction (TJ) and adherens junction integrity were assessed by immunofluorescence confocal microscopy. The role of signaling molecules in the L. casei and EGF effects was determined by using selective inhibitors. Data show that pretreatment of cell monolayers with L. casei or EGF attenuates osmotic stress-induced TJ and adherens junction disruption and barrier dysfunction. EGF also blocked osmotic stress-induced actin cytoskeleton remodeling. U0126 (MEK1/2 inhibitor), the MAP kinase inhibitor, blocked EGF-mediated epithelial protection from osmotic stress. In contrast, the L. casei-mediated epithelial protection from osmotic stress was unaffected by U0126, AG1478 (EGFR tyrosine kinase inhibitor), SP600125 (JNK1/2 inhibitor), or SB202190 (P38 MAP kinase inhibitor). On the other hand, Ro-32-0432 (PKC inhibitor) blocked the L. casei-mediated prevention of osmotic stress-induced TJ disruption and barrier dysfunction. The combination of EGF and L. casei is more potent in protecting the barrier function from osmotic stress. These findings suggest that L. casei and EGF ameliorate osmotic stress-induced disruption of apical junctional complexes and barrier dysfunction in the intestinal epithelium by distinct signaling mechanisms.
Collapse
|
4
|
Yokoo K, Yamamoto Y, Suzuki T. Ammonia impairs tight junction barriers by inducing mitochondrial dysfunction in Caco-2 cells. FASEB J 2021; 35:e21854. [PMID: 34597422 DOI: 10.1096/fj.202100758r] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/12/2021] [Accepted: 07/29/2021] [Indexed: 12/13/2022]
Abstract
Ammonia is one of the major metabolites produced by intestinal microorganisms; however, its role in intestinal homeostasis is poorly understood. The present study investigated the regulation of intestinal tight junction (TJ) proteins by ammonia and the underlying mechanisms in human intestinal Caco-2 cells. Ammonia (15, 30, and 60 mM) increased the permeability of the cells in a dose-dependent manner, as indicated by reduced transepithelial electrical resistance and increased dextran flux. Immunoblot and immunofluorescence analyses revealed that the ammonia-induced increase in TJ permeability reduced the membrane localization of TJ proteins such as zonula occludens (ZO)1, ZO2, occludin, claudin-1, and claudin-3. DNA microarray analysis identified a biological pathway "response to reactive oxygen species" enriched by ammonia treatment, indicating the induction of oxidative stress in the cells. Ammonia treatment also increased the malondialdehyde content and decreased the ratio of reduced to oxidized glutathione. Meanwhile, ammonia treatment-induced mitochondrial dysfunction, as indicated by the downregulation of genes associated with the electron transport chain, reduction of the cellular ATP, NADH, and tricarboxylic acid cycle intermediate content, and suppression of the mitochondrial membrane potential. In contrast, N-acetyl cysteine reversed the ammonia-induced impairment of TJ permeability and structure without affecting the mitochondrial parameters. Collectively, ammonia impaired the TJ barrier by increasing oxidative stress in Caco-2 cells. A mitochondrial dysfunction is possibly an event preceding ammonia-induced oxidative stress. The findings of this study could potentially improve our understanding of the interplay between intestinal microorganisms and their hosts.
Collapse
Affiliation(s)
- Kana Yokoo
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Japan
| | - Yoshinari Yamamoto
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Japan
| | - Takuya Suzuki
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Japan.,Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Japan
| |
Collapse
|
5
|
Monaco A, Ovryn B, Axis J, Amsler K. The Epithelial Cell Leak Pathway. Int J Mol Sci 2021; 22:ijms22147677. [PMID: 34299297 PMCID: PMC8305272 DOI: 10.3390/ijms22147677] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/13/2021] [Accepted: 07/15/2021] [Indexed: 01/08/2023] Open
Abstract
The epithelial cell tight junction structure is the site of the transepithelial movement of solutes and water between epithelial cells (paracellular permeability). Paracellular permeability can be divided into two distinct pathways, the Pore Pathway mediating the movement of small ions and solutes and the Leak Pathway mediating the movement of large solutes. Claudin proteins form the basic paracellular permeability barrier and mediate the movement of small ions and solutes via the Pore Pathway. The Leak Pathway remains less understood. Several proteins have been implicated in mediating the Leak Pathway, including occludin, ZO proteins, tricellulin, and actin filaments, but the proteins comprising the Leak Pathway remain unresolved. Many aspects of the Leak Pathway, such as its molecular mechanism, its properties, and its regulation, remain controversial. In this review, we provide a historical background to the evolution of the Leak Pathway concept from the initial examinations of paracellular permeability. We then discuss current information about the properties of the Leak Pathway and present current theories for the Leak Pathway. Finally, we discuss some recent research suggesting a possible molecular basis for the Leak Pathway.
Collapse
Affiliation(s)
- Ashley Monaco
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Boulevard, Old Westbury, NY 11568, USA; (A.M.); (J.A.)
| | - Ben Ovryn
- Department of Physics, New York Institute of Technology, Northern Boulevard, Old Westbury, NY 11568, USA;
| | - Josephine Axis
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Boulevard, Old Westbury, NY 11568, USA; (A.M.); (J.A.)
| | - Kurt Amsler
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Boulevard, Old Westbury, NY 11568, USA; (A.M.); (J.A.)
- Correspondence: ; Tel.: +1-516-686-3716
| |
Collapse
|
6
|
McCarty MF, Lerner A. Perspective: Prospects for Nutraceutical Support of Intestinal Barrier Function. Adv Nutr 2020; 12:316-324. [PMID: 33126251 PMCID: PMC8243597 DOI: 10.1093/advances/nmaa139] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/28/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022] Open
Abstract
Impairment of intestinal barrier function is linked to certain pathologies and to aging, and can be a cause of bacterial infections, systemic and hepatic inflammation, food allergies, and autoimmune disorders. The formation and maintenance of intestinal tight junctions is supported by glucagon-like peptide-2 (GLP-2), which via insulin-like growth factor I activity boosts phosphoinositide 3-kinase/Akt/mammalian target of rapamycin complex 1 (PI3K/Akt/mTORC1) signaling in enterocytes. 5'-AMP-activated protein kinase (AMPK) activity as well as estrogen receptor-β (ERβ) activity are also protective in this regard. Conversely, activation of mitogen-activated protein kinases (MAPKs) and cellular Src (c-Src) under inflammatory conditions can induce dissociation of tight junctions. Hence, nutraceuticals that promote GLP-2 secretion from L cells-effective pre/probiotics, glycine, and glutamine-as well as diets rich in soluble fiber or resistant starch, can support intestinal barrier function. AMPK activators-notably berberine and the butyric acid produced by health-promoting microflora-are also beneficial in this regard, as are soy isoflavones, which function as selective agonists for ERβ. The adverse impact of MAPK and c-Src overactivation on the intestinal barrier can be combatted with various antioxidant measures, including phycocyanobilin, phase 2-inducer nutraceuticals, and N-acetylcysteine. These considerations suggest that rationally designed functional foods or complex supplementation programs could have clinical potential for supporting and restoring healthful intestinal barrier function.
Collapse
|
7
|
Liu JQ, Hu TY, Diao KY, Yu D, Song YN, Mo LH, Yang G, Liu ZQ, Liu ZG, Yang PC. Cold stress promotes IL-33 expression in intestinal epithelial cells to facilitate food allergy development. Cytokine 2020; 136:155295. [PMID: 32977238 DOI: 10.1016/j.cyto.2020.155295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/23/2020] [Accepted: 09/08/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND The causative factors and pathogenesis of food allergy (FA) is not fully understood yet. Cold stress (CS) occurs frequently in human life that influences physiological activities in the body. In this study, we aimed to investigate the chronic CS (CS) effects on promoting the expression of IL-33 in intestinal epithelial cells. METHODS CS was carried out by placing mice at 4 °C for 1 h daily for 7 consecutive days. We developed a mouse model used to test the effects of CS on the FA development. RESULTS We found that, similar to conventional FA mouse model, CS induced the core body temperature to drop markedly in mice, increased intestinal epithelial barrier permeability and facilitated FA development. CS promoted interleukin (IL)-33 expression in intestinal epithelial cells through the adrenocorticotropic hormone (ACTH)/cortisol axis and via inducing the Il33 promoter methylation. CS facilitated the FA development in mice, that could be blocked by depletion of IL-33 expression in intestinal epithelial cells. CONCLUSIONS CS induces IL-33 expression in intestinal epithelial cells to promote Th2 polarization in the intestinal tissues and facilitates FA development.
Collapse
Affiliation(s)
- Jiang-Qi Liu
- Department of Allergy, Longgang ENT Hospital and Shenzhen ENT Institute, Shenzhen, China; Research Center of Allergy & Immunology, Shenzhen University School of Medicine, Shenzhen, China
| | - Tian-Yong Hu
- Department of Allergy, Longgang ENT Hospital and Shenzhen ENT Institute, Shenzhen, China; Research Center of Allergy & Immunology, Shenzhen University School of Medicine, Shenzhen, China
| | - Kai-Yuan Diao
- Department of Pediatric Otolaryngology, Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Dian Yu
- Department of Allergy, Longgang ENT Hospital and Shenzhen ENT Institute, Shenzhen, China
| | - Yan-Nan Song
- Department of Allergy, Longgang ENT Hospital and Shenzhen ENT Institute, Shenzhen, China
| | - Li-Hua Mo
- Department of Allergy, Longgang ENT Hospital and Shenzhen ENT Institute, Shenzhen, China; Department of Pediatric Otolaryngology, Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Gui Yang
- Department of Otolaryngology, Longgagn Central Hospital, Shenzhen, China
| | - Zhi-Qiang Liu
- Department of Allergy, Longgang ENT Hospital and Shenzhen ENT Institute, Shenzhen, China; Research Center of Allergy & Immunology, Shenzhen University School of Medicine, Shenzhen, China.
| | - Zhi-Gang Liu
- Department of Allergy, Longgang ENT Hospital and Shenzhen ENT Institute, Shenzhen, China.
| | - Ping-Chang Yang
- Department of Allergy, Longgang ENT Hospital and Shenzhen ENT Institute, Shenzhen, China; Guangdong Provincial Key Laboratory of Regional Immunity and Diseases, Shenzhen, China.
| |
Collapse
|
8
|
Konno T, Kohno T, Kikuchi S, Shimada H, Satohisa S, Saito T, Kondoh M, Kojima T. Epithelial barrier dysfunction and cell migration induction via JNK/cofilin/actin by angubindin-1. Tissue Barriers 2019; 8:1695475. [PMID: 31782346 DOI: 10.1080/21688370.2019.1695475] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Angulin-1/LSR is a tricellular tight junction molecule, that plays an important role in maintaining the epithelial and endothelial barriers. The actin cytoskeleton at tricellular contacts also contributes to the maintenance of the epithelial barrier. Loss of angulin-1/LSR enhances the migration of various cancer cells. Angubindin-1 is a novel binder to angulin-1/LSR and angulin-3. It is a peptide generated from the angulin-1 binding site of Clostridium perfringens iota toxin, which affects the actin cytoskeleton and decreases the epithelial and endothelial barrier functions. However, its regulatory mechanisms are not well understood. To investigate the regulatory mechanisms of the epithelial barrier dysfunction and cell migration induction by angubindin-1, we used human endometrial cancer cell line Sawano, which has high LSR expression and the epithelial barrier function. Angubindin-1 decreased LSR expression and the epithelial barrier function and increased cell migration. It inhibited the recovery of the epithelial barrier function in a Ca-switch model. At tricellular contacts, sinking of the membrane and an increase of actin fibers near the junctions were caused by angubindin-1. It dynamically changed F-actin from lines to dot-like structures at tricellular contacts. Angubindin-1 transiently increased the phosphorylation of cofilin and JNK, which are involved in the regulation of the intracellular actin cytoskeleton. Furthermore, knockdown of JNK and the JNK inhibitor SP600125 prevented the decrease of the epithelial barrier function and the increase of cell migration induced by angubindin-1. These findings suggest that angubindin-1 might reversibly regulate the epithelial barrier and cell migration at tricellular contacts via JNK/cofilin/actin cytoskeleton dynamics.
Collapse
Affiliation(s)
- Takumi Konno
- Department of Cell Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Takayuki Kohno
- Department of Cell Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Shin Kikuchi
- Department of Anatomy, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hiroshi Shimada
- Department of Cell Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.,Department of Obstetrics and Gynecology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Seiro Satohisa
- Department of Obstetrics and Gynecology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Tsuyoshi Saito
- Department of Obstetrics and Gynecology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Masuo Kondoh
- Drug discovery Center, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Japan
| | - Takashi Kojima
- Department of Cell Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| |
Collapse
|
9
|
Grauso M, Lan A, Andriamihaja M, Bouillaud F, Blachier F. Hyperosmolar environment and intestinal epithelial cells: impact on mitochondrial oxygen consumption, proliferation, and barrier function in vitro. Sci Rep 2019; 9:11360. [PMID: 31388052 PMCID: PMC6684637 DOI: 10.1038/s41598-019-47851-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 07/22/2019] [Indexed: 01/01/2023] Open
Abstract
The aim of the present study was to elucidate the in vitro short-term (2-h) and longer-term (24-h) effects of hyperosmolar media (500 and 680 mOsm/L) on intestinal epithelial cells using the human colonocyte Caco-2 cell line model. We found that a hyperosmolar environment slowed down cell proliferation compared to normal osmolarity (336 mOsm/L) without inducing cell detachment or necrosis. This was associated with a transient reduction of cell mitochondrial oxygen consumption, increase in proton leak, and decrease in intracellular ATP content. The barrier function of Caco-2 monolayers was also transiently affected since increased paracellular apical-to-basal permeability and modified electrolyte permeability were measured, allowing partial equilibration of the trans-epithelial osmotic difference. In addition, hyperosmotic stress induced secretion of the pro-inflammatory cytokine IL-8. By measuring expression of genes involved in energy metabolism, tight junction forming, electrolyte permeability and intracellular signaling, different response patterns to hyperosmotic stress occurred depending on its intensity and duration. These data highlight the potential impact of increased luminal osmolarity on the intestinal epithelium renewal and barrier function and point out some cellular adaptive capacities towards luminal hyperosmolar environment.
Collapse
Affiliation(s)
- Marta Grauso
- UMR PNCA, AgroParisTech, INRA, Université Paris-Saclay, 75005, Paris, France.
| | - Annaïg Lan
- UMR PNCA, AgroParisTech, INRA, Université Paris-Saclay, 75005, Paris, France
| | | | - Frédéric Bouillaud
- Institut Cochin, INSERM U1016, CNRS UMR8104, Université Paris Descartes, 75014, Paris, France
| | - François Blachier
- UMR PNCA, AgroParisTech, INRA, Université Paris-Saclay, 75005, Paris, France
| |
Collapse
|
10
|
Thompson KE, Ray RM, Alli S, Ge W, Boler A, Shannon McCool W, Meena AS, Shukla PK, Rao R, Johnson LR, Miller MA, Tigyi GJ. Prevention and treatment of secretory diarrhea by the lysophosphatidic acid analog Rx100. Exp Biol Med (Maywood) 2018; 243:1056-1065. [PMID: 30253666 DOI: 10.1177/1535370218803349] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
IMPACT STATEMENT A critical barrier in treating diarrheal disease is easy-to-use effective treatments. Rx100 is a first in class, novel small molecule that has shown efficacy after both subcutaneous and oral administration in a mouse cholera-toxin- and Citrobacter rodentium infection-induced diarrhea models. Our findings indicate that Rx100 a metabolically stable analog of the lipid mediator lysophosphatidic acid blocks activation of CFTR-mediated secretion responsible for fluid discharge in secretory diarrhea. Rx100 represents a new treatment modality which does not directly block CFTR but attenuates its activation by bacterial toxins. Our results provide proof-of-principle that Rx100 can be developed for use as an effective oral or injectable easy-to-use drug for secretory diarrhea which could significantly improve care by eliminating the need for severely ill patients to regularly consume large quantities of oral rehydration therapies and offering options for pediatric patients.
Collapse
Affiliation(s)
- Karin E Thompson
- 1 RxBio, Inc., Johnson City, TN 37604, USA.,*These authors contributed equally to this paper
| | - Ramesh M Ray
- 1 RxBio, Inc., Johnson City, TN 37604, USA.,*These authors contributed equally to this paper
| | | | - Wenbo Ge
- 1 RxBio, Inc., Johnson City, TN 37604, USA
| | | | | | - Avtar S Meena
- 2 Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Pradeep K Shukla
- 2 Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Radakrishna Rao
- 2 Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Leonard R Johnson
- 1 RxBio, Inc., Johnson City, TN 37604, USA.,2 Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Mark A Miller
- 3 Microbiology Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Gabor J Tigyi
- 1 RxBio, Inc., Johnson City, TN 37604, USA.,2 Department of Physiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| |
Collapse
|
11
|
Cho YE, Yu LR, Abdelmegeed MA, Yoo SH, Song BJ. Apoptosis of enterocytes and nitration of junctional complex proteins promote alcohol-induced gut leakiness and liver injury. J Hepatol 2018; 69:142-153. [PMID: 29458168 PMCID: PMC6008177 DOI: 10.1016/j.jhep.2018.02.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 02/07/2018] [Accepted: 02/07/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Binge alcohol exposure causes gut leakiness, contributing to increased endotoxemia and inflammatory liver injury, although the molecular mechanisms are still elusive. This study was aimed at investigating the roles of apoptosis of enterocytes and nitration followed by degradation of intestinal tight junction (TJ) and adherens junction (AJ) proteins in binge alcohol-induced gut leakiness. METHODS The levels of intestinal (ileum) junctional complex proteins, oxidative stress markers and apoptosis-related proteins in rodents, T84 colonic cells and autopsied human ileums were determined by immunoblot, immunoprecipitation, immunofluorescence, and mass-spectral analyses. RESULTS Binge alcohol exposure caused apoptosis of gut enterocytes with elevated serum endotoxin and liver injury. The levels of intestinal CYP2E1, iNOS, nitrated proteins and apoptosis-related marker proteins were significantly elevated in binge alcohol-exposed rodents. Differential, quantitative mass-spectral analyses of the TJ-enriched fractions of intestinal epithelial layers revealed that several TJ, AJ and desmosome proteins were decreased in binge alcohol-exposed rats compared to controls. Consistently, the levels of TJ proteins (claudin-1, claudin-4, occludin and zonula occludens-1), AJ proteins (β-catenin and E-cadherin) and desmosome plakoglobin were very low in binge alcohol-exposed rats, wild-type mice, and autopsied human ileums but not in Cyp2e1-null mice. Additionally, pretreatment with specific inhibitors of CYP2E1 and iNOS prevented disorganization and/or degradation of TJ proteins in alcohol-exposed T84 colonic cells. Furthermore, immunoprecipitation followed by immunoblot confirmed that intestinal TJ and AJ proteins were nitrated and degraded via ubiquitin-dependent proteolysis, resulting in their decreased levels. CONCLUSIONS These results demonstrated for the first time the critical roles of CYP2E1, apoptosis of enterocytes, and nitration followed by ubiquitin-dependent proteolytic degradation of the junctional complex proteins, in promoting binge alcohol-induced gut leakiness and endotoxemia, contributing to inflammatory liver disease. LAY SUMMARY Binge alcohol exposure causes gut leakiness, contributing to increased endotoxemia and inflammatory liver injury. Our results demonstrated for the first time the critical roles of apoptosis of enterocytes and nitration followed by ubiquitin-dependent proteolytic degradation of the junctional complex proteins in promoting this gut leakiness and endotoxemia. These results provide insight into the molecular mechanisms of alcohol-induced inflammatory liver disease.
Collapse
Affiliation(s)
- Young-Eun Cho
- Section of Molecular Pharmacology & Toxicology, Laboratory of Membrane Biochemistry, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892 USA
| | - Li-Rong Yu
- Biomarkers and Alternative Models Branch, Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079, USA
| | - Mohamed A. Abdelmegeed
- Section of Molecular Pharmacology & Toxicology, Laboratory of Membrane Biochemistry, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892 USA
| | - Seong-Ho Yoo
- Department of Forensic Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Byoung-Joon Song
- Section of Molecular Pharmacology & Toxicology, Laboratory of Membrane Biochemistry, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892, USA.
| |
Collapse
|
12
|
Jinhong Tablet Reduces Damage of Intestinal Mucosal Barrier in Rats with Acute Biliary Infection via Bcl-2/Bax mRNA and Protein Regulation. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 2017:4985926. [PMID: 29234407 PMCID: PMC5646335 DOI: 10.1155/2017/4985926] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 08/23/2017] [Indexed: 12/22/2022]
Abstract
Objective To explore the effects and mechanism of Jinhong Tablet on intestinal mucosal barrier function and SIRS in rats with acute biliary infection. Methods 36 SD male rats were divided into three groups: sham operation (control), acute biliary infection (ABI) model, and Jinhong Tablet (Jinhong) group. Jinhong group were force-fed with Jinhong Tablet, while the other two groups received oral saline. At days 3 and 5, morphological changes of intestinal mucosa were assessed. Serum diamine oxidase (DAO), D-lactate, and endotoxin levels were measured. And the genes bcl-2 and bax in intestinal tissues were tested by real-time PCR and Western blotting. Results Intestinal damage was significantly less severe in Jinhong group compared with ABI group, as indicated by Chiu's scoring, TUNEL analysis, and serum DAO, D-lactic acid, and endotoxin levels. Additionally, the expression of bax mRNA and protein was decreased and the ratio of bcl-2/bax mRNA and protein was increased compared with ABI group. Conclusion Jinhong Tablet had a positive intervention on acute biliary infection through improving inflammation and intestinal mucosal barrier, inhibiting excessive apoptosis of intestinal epithelial cells via bax and bcl-2 gene, and protein regulation.
Collapse
|
13
|
c-Jun N-terminal kinase 2 promotes enterocyte survival and goblet cell differentiation in the inflamed intestine. Mucosal Immunol 2017; 10:1211-1223. [PMID: 28098247 DOI: 10.1038/mi.2016.125] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 11/15/2016] [Indexed: 02/06/2023]
Abstract
c-Jun N-terminal kinases (JNKs) contribute to immune signaling but their functional role during intestinal mucosal inflammation has remained ill defined. Using genetic mouse models, we characterized the role of JNK1 and JNK2 during homeostasis and acute colitis. Epithelial apoptosis, regeneration, differentiation, and barrier function were analyzed in intestinal epithelium-specific (ΔIEC) or complete JNK1 and bone marrow chimeric or complete JNK2 deficient mice as well as double-knockout animals (JNK1ΔIECJNK2-/-) during homeostasis and acute dextran sulfate sodium (DSS)-induced colitis. Results were confirmed using human HT-29 cells and wild-type or JNK2-deficient mouse intestinal organoid cultures. We show that nonhematopoietic JNK2 but not JNK1 expression confers protection from DSS-induced intestinal inflammation reducing epithelial barrier dysfunction and enterocyte apoptosis. JNK2 additionally enhanced Atonal homolog 1 expression, goblet cell and enteroendocrine cell differentiation, and mucus production under inflammatory conditions. Our results identify a protective role of epithelial JNK2 signaling to maintain mucosal barrier function, epithelial cell integrity, and mucus layer production in the event of inflammatory tissue damage.
Collapse
|
14
|
Calcium-mediated oxidative stress: a common mechanism in tight junction disruption by different types of cellular stress. Biochem J 2017; 474:731-749. [PMID: 28057718 DOI: 10.1042/bcj20160679] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 08/10/2016] [Accepted: 01/05/2017] [Indexed: 02/07/2023]
Abstract
The role of reactive oxygen species (ROS) in osmotic stress, dextran sulfate sodium (DSS) and cyclic stretch-induced tight junction (TJ) disruption was investigated in Caco-2 cell monolayers in vitro and restraint stress-induced barrier dysfunction in mouse colon in vivo Live cell imaging showed that osmotic stress, cyclic stretch and DSS triggered rapid production of ROS in Caco-2 cell monolayers, which was blocked by depletion of intracellular Ca2+ by 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. Knockdown of CaV1.3 or TRPV6 channels blocked osmotic stress and DSS-induced ROS production and attenuated TJ disruption and barrier dysfunction. N-Acetyl l-cysteine (NAC) and l-NG-Nitroarginine methyl ester (l-NAME) blocked stress-induced TJ disruption and barrier dysfunction. NAC and l-NAME also blocked stress-induced activation of c-Jun N-terminal kinase (JNK) and c-Src. ROS was colocalized with the mitochondrial marker in stressed cells. Cyclosporin A blocked osmotic stress and DSS-induced ROS production, barrier dysfunction, TJ disruption and JNK activation. Mitochondria-targeted Mito-TEMPO blocked osmotic stress and DSS-induced barrier dysfunction and TJ disruption. Chronic restraint stress in mice resulted in the elevation of intracellular Ca2+, activation of JNK and c-Src, and disruption of TJ in the colonic epithelium. Furthermore, corticosterone administration induced JNK and c-Src activation, TJ disruption and protein thiol oxidation in colonic mucosa. The present study demonstrates that oxidative stress is a common signal in the mechanism of TJ disruption in the intestinal epithelium by different types of cellular stress in vitro and bio behavioral stress in vivo.
Collapse
|
15
|
Evaluation of soman-induced extracranial histopathology in the context of clinical biochemistry, mitotic and apoptotic activity and morphometric analysis. J Appl Biomed 2017. [DOI: 10.1016/j.jab.2016.09.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
16
|
Samak G, Gangwar R, Meena AS, Rao RG, Shukla PK, Manda B, Narayanan D, Jaggar JH, Rao R. Calcium Channels and Oxidative Stress Mediate a Synergistic Disruption of Tight Junctions by Ethanol and Acetaldehyde in Caco-2 Cell Monolayers. Sci Rep 2016; 6:38899. [PMID: 27958326 PMCID: PMC5153649 DOI: 10.1038/srep38899] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/14/2016] [Indexed: 12/13/2022] Open
Abstract
Ethanol is metabolized into acetaldehyde in most tissues. In this study, we investigated the synergistic effect of ethanol and acetaldehyde on the tight junction integrity in Caco-2 cell monolayers. Expression of alcohol dehydrogenase sensitized Caco-2 cells to ethanol-induced tight junction disruption and barrier dysfunction, whereas aldehyde dehydrogenase attenuated acetaldehyde-induced tight junction disruption. Ethanol up to 150 mM did not affect tight junction integrity or barrier function, but it dose-dependently increased acetaldehyde-mediated tight junction disruption and barrier dysfunction. Src kinase and MLCK inhibitors blocked this synergistic effect of ethanol and acetaldehyde on tight junction. Ethanol and acetaldehyde caused a rapid and synergistic elevation of intracellular calcium. Calcium depletion by BAPTA or Ca2+-free medium blocked ethanol and acetaldehyde-induced barrier dysfunction and tight junction disruption. Diltiazem and selective knockdown of TRPV6 or CaV1.3 channels, by shRNA blocked ethanol and acetaldehyde-induced tight junction disruption and barrier dysfunction. Ethanol and acetaldehyde induced a rapid and synergistic increase in reactive oxygen species by a calcium-dependent mechanism. N-acetyl-L-cysteine and cyclosporine A, blocked ethanol and acetaldehyde-induced barrier dysfunction and tight junction disruption. These results demonstrate that ethanol and acetaldehyde synergistically disrupt tight junctions by a mechanism involving calcium, oxidative stress, Src kinase and MLCK.
Collapse
Affiliation(s)
- Geetha Samak
- Department of Physiology, University of Tennessee Health Science Center, 894 Union Avenue, Memphis TN 38163, USA
| | - Ruchika Gangwar
- Department of Physiology, University of Tennessee Health Science Center, 894 Union Avenue, Memphis TN 38163, USA
| | - Avtar S Meena
- Department of Physiology, University of Tennessee Health Science Center, 894 Union Avenue, Memphis TN 38163, USA
| | - Roshan G Rao
- Department of Physiology, University of Tennessee Health Science Center, 894 Union Avenue, Memphis TN 38163, USA
| | - Pradeep K Shukla
- Department of Physiology, University of Tennessee Health Science Center, 894 Union Avenue, Memphis TN 38163, USA
| | - Bhargavi Manda
- Department of Physiology, University of Tennessee Health Science Center, 894 Union Avenue, Memphis TN 38163, USA
| | - Damodaran Narayanan
- Department of Physiology, University of Tennessee Health Science Center, 894 Union Avenue, Memphis TN 38163, USA
| | - Jonathan H Jaggar
- Department of Physiology, University of Tennessee Health Science Center, 894 Union Avenue, Memphis TN 38163, USA
| | - RadhaKrishna Rao
- Department of Physiology, University of Tennessee Health Science Center, 894 Union Avenue, Memphis TN 38163, USA
| |
Collapse
|
17
|
Tokuda S, Hirai T, Furuse M. Effects of Osmolality on Paracellular Transport in MDCK II Cells. PLoS One 2016; 11:e0166904. [PMID: 27855213 PMCID: PMC5113991 DOI: 10.1371/journal.pone.0166904] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 11/04/2016] [Indexed: 12/20/2022] Open
Abstract
Epithelia separate apical and basal compartments, and movement of substances via the paracellular pathway is regulated by tight junctions. Claudins are major constituents of tight junctions and involved in the regulation of tight junction permeability. On the other hand, the osmolality in the extracellular environment fluctuates in association with life activity. However, effects of osmotic changes on the permeaibility of claudins are poorly understood. Therefore, we investigated the effects of osmotic changes on the paracellular transport in MDCK II cells. Interestingly, apical hyposmolality decreased cation selectivity in the paracellular pathway gradually with time, and the elimination of the osmotic gradient promptly restored the cation selectivity. Apical hyposmolality also induced bleb formation at cell-cell contacts and changed the shape of cell-cell contacts from a jagged pattern to a slightly linear pattern. In claudin-2 knockout MDCK II cells, the decrease of cation selectivity, the bleb formation, nor the changes in the shape of cell-cell contacts was observed under the apical hyposmolality. Our findings in this study indicate that osmotic gradient between apical and basal sides is involved in the acute regulation of the cation selective property of claudin-2 channels.
Collapse
Affiliation(s)
- Shinsaku Tokuda
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- * E-mail:
| | - Toyohiro Hirai
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Mikio Furuse
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki, Japan
- Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444–8585, Japan
| |
Collapse
|
18
|
JNK Signaling: Regulation and Functions Based on Complex Protein-Protein Partnerships. Microbiol Mol Biol Rev 2016; 80:793-835. [PMID: 27466283 DOI: 10.1128/mmbr.00043-14] [Citation(s) in RCA: 309] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The c-Jun N-terminal kinases (JNKs), as members of the mitogen-activated protein kinase (MAPK) family, mediate eukaryotic cell responses to a wide range of abiotic and biotic stress insults. JNKs also regulate important physiological processes, including neuronal functions, immunological actions, and embryonic development, via their impact on gene expression, cytoskeletal protein dynamics, and cell death/survival pathways. Although the JNK pathway has been under study for >20 years, its complexity is still perplexing, with multiple protein partners of JNKs underlying the diversity of actions. Here we review the current knowledge of JNK structure and isoforms as well as the partnerships of JNKs with a range of intracellular proteins. Many of these proteins are direct substrates of the JNKs. We analyzed almost 100 of these target proteins in detail within a framework of their classification based on their regulation by JNKs. Examples of these JNK substrates include a diverse assortment of nuclear transcription factors (Jun, ATF2, Myc, Elk1), cytoplasmic proteins involved in cytoskeleton regulation (DCX, Tau, WDR62) or vesicular transport (JIP1, JIP3), cell membrane receptors (BMPR2), and mitochondrial proteins (Mcl1, Bim). In addition, because upstream signaling components impact JNK activity, we critically assessed the involvement of signaling scaffolds and the roles of feedback mechanisms in the JNK pathway. Despite a clarification of many regulatory events in JNK-dependent signaling during the past decade, many other structural and mechanistic insights are just beginning to be revealed. These advances open new opportunities to understand the role of JNK signaling in diverse physiological and pathophysiological states.
Collapse
|
19
|
Thakre-Nighot M, Blikslager AT. Indomethacin induces increase in gastric epithelial tight junction permeability via redistribution of occludin and activation of p38 MAPK in MKN-28 Cells. Tissue Barriers 2016; 4:e1187325. [PMID: 27583191 DOI: 10.1080/21688370.2016.1187325] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/26/2016] [Accepted: 05/02/2016] [Indexed: 12/21/2022] Open
Abstract
Tight Junctions (TJ) create a paracellular barrier that is compromised when nonsteriodal anti-inflammatory drugs (NSAIDs) injure the gastric epithelium, leading to increased permeability. However, the mechanism of NSAID-induced gastric injury is unclear. Here, we examined the effect of indomethacin on barrier function and TJ in gastric MKN-28 cells. In concentration response studies, 500 µm indomethacin induced a significant decrease in transepithelial resistance (TER; 380 vs. 220 Ω·cm(2) for control and indomethacin-treated cells respectively, p < 0.05), and increased dextran permeability by 0.2 vs 1.2 g/l (p < 0.05). These changes in barrier function were completely ameliorated by the p38 MAPK inhibitor (SB-203580) but not by JNK inhibitor (SP-600125) or MEK/ERK inhibitor (PD-98059). SiRNA knock down of p38 MAPK prevented the loss of barrier function caused by indomethacin in MKN-28 cells. Western analyses of TJ proteins revealed that expression of occludin was reduced by indomethacin, whereas there was no change in other TJ proteins. The loss of occludin expression induced by indomethacin was prevented by inhibition of p38 MAPK but not JNK or ERK and also by siRNA of p38 MAPK. Immunofluorescence revealed disruption of occludin localization at the site of the tight junction in indomethacin-treated cells, and this was attenuated by inhibition of p38 MAPK. NSAID injury to murine gastric mucosa on Ussing chambers revealed that indomethacin caused a significant drop in TER and increased paracellular permeability. Pretreatment with the p38 MAPK inhibitor significantly attenuated the disruption of barrier function, but JNK and MEK/ERK inhibition had no effect. Western blot analysis on gastric mucosa reveled loss of TJ protein occludin by indomethacin, which was prevented by inhibition of p38 MAPK. This data suggests that indomethacin compromises the gastric epithelial barrier via p38 MAPK inducing occludin alterations in the TJs.
Collapse
Affiliation(s)
- Meghali Thakre-Nighot
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University , Raleigh, NC, USA
| | - Anthony T Blikslager
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University , Raleigh, NC, USA
| |
Collapse
|
20
|
Fish oil enhances intestinal barrier function and inhibits corticotropin-releasing hormone/corticotropin-releasing hormone receptor 1 signalling pathway in weaned pigs after lipopolysaccharide challenge. Br J Nutr 2016; 115:1947-57. [PMID: 27080003 DOI: 10.1017/s0007114516001100] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Stress induces injury in intestinal barrier function in piglets. Long-chain n-3 PUFA have been shown to exhibit potential immunomodulatory and barrier protective effects in animal models and clinical trials. In addition, corticotropin-releasing hormone (CRH)/CRH receptor (CRHR) signalling pathways play an important role in stress-induced alterations of intestinal barrier function. We hypothesised that fish oil could affect intestinal barrier function and CRH/CRHR signalling pathways. In total, thirty-two weaned pigs were allocated to one of four treatments. The experiment consisted of a 2×2 factorial design, and the main factors included immunological challenge (saline or lipopolysaccharide (LPS)) and diet (5 % maize oil or 5 % fish oil). On d 19 of the trial, piglets were treated with saline or LPS. At 4 h after injection, all pigs were killed, and the mesenteric lymph nodes (MLN), liver, spleen and intestinal samples were collected. Fish oil decreased bacterial translocation incidence and the number of translocated micro-organisms in the MLN. Fish oil increased intestinal claudin-1 protein relative concentration and villus height, as well as improved the intestinal morphology. In addition, fish oil supplementation increased intestinal intraepithelial lymphocyte number and prevented elevations in intestinal mast cell and neutrophil numbers induced by LPS challenge. Moreover, fish oil tended to decrease the mRNA expression of intestinal CRHR1, CRH and glucocorticoid receptors. These results suggest that fish oil supplementation improves intestinal barrier function and inhibits CRH/CRHR1 signalling pathway and mast cell tissue density.
Collapse
|
21
|
Mir H, Meena AS, Chaudhry KK, Shukla PK, Gangwar R, Manda B, Padala MK, Shen L, Turner JR, Dietrich P, Dragatsis I, Rao R. Occludin deficiency promotes ethanol-induced disruption of colonic epithelial junctions, gut barrier dysfunction and liver damage in mice. Biochim Biophys Acta Gen Subj 2015; 1860:765-74. [PMID: 26721332 DOI: 10.1016/j.bbagen.2015.12.013] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 12/05/2015] [Accepted: 12/18/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND Disruption of epithelial tight junctions (TJ), gut barrier dysfunction and endotoxemia play crucial role in the pathogenesis of alcoholic tissue injury. Occludin, a transmembrane protein of TJ, is depleted in colon by alcohol. However, it is unknown whether occludin depletion influences alcoholic gut and liver injury. METHODS Wild type (WT) and occludin deficient (Ocln(-/-)) mice were fed 1-6% ethanol in Lieber-DeCarli diet. Gut permeability was measured by vascular-to-luminal flux of FITC-inulin. Junctional integrity was analyzed by confocal microscopy. Liver injury was assessed by plasma transaminase, histopathology and triglyceride analyses. The effect of occludin depletion on acetaldehyde-induced TJ disruption was confirmed in Caco-2 cell monolayers. RESULTS Ethanol feeding significantly reduced body weight gain in Ocln(-/-) mice. Ethanol increased inulin permeability in colon of both WT and Ocln(-/-) mice, but the effect was 4-fold higher in Ocln(-/-) mice. The gross morphology of colonic mucosa was unaltered, but ethanol disrupted the actin cytoskeleton, induced redistribution of occludin, ZO-1, E-cadherin and β-catenin from the junctions and elevated TLR4, which was more severe in Ocln(-/-) mice. Occludin knockdown significantly enhanced acetaldehyde-induced TJ disruption and barrier dysfunction in Caco-2 cell monolayers. Ethanol significantly increased liver weight and plasma transaminase activity in Ocln(-/-) mice, but not in WT mice. Histological analysis indicated more severe lesions and fat deposition in the liver of ethanol-fed Ocln(-/-) mice. Ethanol-induced elevation of liver triglyceride was also higher in Ocln(-/-) mice. CONCLUSION This study indicates that occludin deficiency increases susceptibility to ethanol-induced colonic mucosal barrier dysfunction and liver damage in mice.
Collapse
Affiliation(s)
- Hina Mir
- Department of Physiology, University of Tennessee, Memphis, TN, United States
| | - Avtar S Meena
- Department of Physiology, University of Tennessee, Memphis, TN, United States
| | - Kamaljit K Chaudhry
- Department of Physiology, University of Tennessee, Memphis, TN, United States
| | - Pradeep K Shukla
- Department of Physiology, University of Tennessee, Memphis, TN, United States
| | - Ruchika Gangwar
- Department of Physiology, University of Tennessee, Memphis, TN, United States
| | - Bhargavi Manda
- Department of Physiology, University of Tennessee, Memphis, TN, United States
| | - Mythili K Padala
- Department of Physiology, University of Tennessee, Memphis, TN, United States
| | - Le Shen
- Department of Pathology, University of Chicago, Chicago, IL, United States
| | - Jerrold R Turner
- Department of Pathology, University of Chicago, Chicago, IL, United States
| | - Paula Dietrich
- Department of Physiology, University of Tennessee, Memphis, TN, United States
| | - Ioannis Dragatsis
- Department of Physiology, University of Tennessee, Memphis, TN, United States
| | - RadhaKrishna Rao
- Department of Physiology, University of Tennessee, Memphis, TN, United States.
| |
Collapse
|
22
|
Bidmon-Fliegenschnee B, Lederhuber HC, Csaicsich D, Pichler J, Herzog R, Memaran-Dadgar N, Huber WD, Aufricht C, Kratochwill K. Overexpression of Hsp70 confers cytoprotection during gliadin exposure in Caco-2 cells. Pediatr Res 2015; 78:358-64. [PMID: 26086640 DOI: 10.1038/pr.2015.112] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 03/10/2015] [Indexed: 12/22/2022]
Abstract
BACKGROUND In Celiac disease (CD), cytoskeletal integrity of intestinal cells is disrupted by gliadin exposure. This study investigates the role of heat shock protein (Hsp)70 during cytoskeletal recovery in CD by assessing its induction and effects on junctional proteins. METHODS Using an in-vitro model of CD, cytoskeletal injury and recovery was assessed in gliadin-exposed Caco-2 cells by measuring cellular distribution of ezrin, E-cadherin, and Hsp70 by differential centrifugation. Effects of Hsp70 were tested by an in-vitro repair assay, based on the incubation of injured or recovered cytoskeletal cellular fractions in noncytoskeletal supernatants containing low or high levels of Hsp70, or by transient transfection of Caco-2 cells with Hsp70. RESULTS Cytoskeletal disruption of ezrin and E-cadherin was demonstrated in gliadin-exposed Caco-2 cells by their significant shift from the cytoskeletal pellet into the noncytoskeletal supernatant fraction. Recovery from gliadin exposure was associated with induction and cytoskeletal redistribution of Hsp70. The in-vitro repair assay delineated direct evidence for HSP-mediated repair by stabilization of junctional proteins by Hsp70. Overexpression of Hsp70 resulted in significantly increased cytoskeletal integrity. CONCLUSION Our results establish an essential role of HSP-mediated cytoskeletal repair in Caco-2 cells during recovery from in-vitro gliadin exposure.
Collapse
Affiliation(s)
| | - Hans Ch Lederhuber
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Dagmar Csaicsich
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Judith Pichler
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Rebecca Herzog
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Nima Memaran-Dadgar
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Wolf-Dietrich Huber
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Christoph Aufricht
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Klaus Kratochwill
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
23
|
Song BJ, Akbar M, Jo I, Hardwick JP, Abdelmegeed MA. Translational Implications of the Alcohol-Metabolizing Enzymes, Including Cytochrome P450-2E1, in Alcoholic and Nonalcoholic Liver Disease. ADVANCES IN PHARMACOLOGY 2015; 74:303-72. [PMID: 26233911 DOI: 10.1016/bs.apha.2015.04.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Fat accumulation (hepatic steatosis) in alcoholic and nonalcoholic fatty liver disease is a potentially pathologic condition which can progress to steatohepatitis (inflammation), fibrosis, cirrhosis, and carcinogenesis. Many clinically used drugs or some alternative medicine compounds are also known to cause drug-induced liver injury, which can further lead to fulminant liver failure and acute deaths in extreme cases. During liver disease process, certain cytochromes P450 such as the ethanol-inducible cytochrome P450-2E1 (CYP2E1) and CYP4A isozymes can be induced and/or activated by alcohol and/or high-fat diets and pathophysiological conditions such as fasting, obesity, and diabetes. Activation of these P450 isozymes, involved in the metabolism of ethanol, fatty acids, and various drugs, can produce reactive oxygen/nitrogen species directly and/or indirectly, contributing to oxidative modifications of DNA/RNA, proteins and lipids. In addition, aldehyde dehydrogenases including the mitochondrial low Km aldehyde dehydrogenase-2 (ALDH2), responsible for the metabolism of acetaldehyde and lipid aldehydes, can be inactivated by various hepatotoxic agents. These highly reactive acetaldehyde and lipid peroxides, accumulated due to ALDH2 suppression, can interact with cellular macromolecules DNA/RNA, lipids, and proteins, leading to suppression of their normal function, contributing to DNA mutations, endoplasmic reticulum stress, mitochondrial dysfunction, steatosis, and cell death. In this chapter, we specifically review the roles of the alcohol-metabolizing enzymes including the alcohol dehydrogenase, ALDH2, CYP2E1, and other enzymes in promoting liver disease. We also discuss translational research opportunities with natural and/or synthetic antioxidants, which can prevent or delay the onset of inflammation and liver disease.
Collapse
Affiliation(s)
- Byoung-Joon Song
- Section of Molecular Pharmacology and Toxicology, Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA.
| | - Mohammed Akbar
- Section of Molecular Pharmacology and Toxicology, Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA
| | - Inho Jo
- Department of Molecular Medicine, Ewha Womans University School of Medicine, Seoul, South Korea
| | - James P Hardwick
- Biochemistry and Molecular Pathology in Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Mohamed A Abdelmegeed
- Section of Molecular Pharmacology and Toxicology, Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA
| |
Collapse
|
24
|
Calcium/Ask1/MKK7/JNK2/c-Src signalling cascade mediates disruption of intestinal epithelial tight junctions by dextran sulfate sodium. Biochem J 2015; 465:503-15. [PMID: 25377781 DOI: 10.1042/bj20140450] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Disruption of intestinal epithelial tight junctions is an important event in the pathogenesis of ulcerative colitis. Dextran sodium sulfate (DSS) induces colitis in mice with symptoms similar to ulcerative colitis. However, the mechanism of DSS-induced colitis is unknown. We investigated the mechanism of DSS-induced disruption of intestinal epithelial tight junctions and barrier dysfunction in Caco-2 cell monolayers in vitro and mouse colon in vivo. DSS treatment resulted in disruption of tight junctions, adherens junctions and actin cytoskeleton leading to barrier dysfunction in Caco-2 cell monolayers. DSS induced a rapid activation of c-Jun N-terminal kinase (JNK), and the inhibition or knockdown of JNK2 attenuated DSS-induced tight junction disruption and barrier dysfunction. In mice, DSS administration for 4 days caused redistribution of tight junction and adherens junction proteins from the epithelial junctions, which was blocked by JNK inhibitor. In Caco-2 cell monolayers, DSS increased intracellular Ca(2+) concentration, and depletion of intracellular Ca(2+) by 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid tetrakis(acetoxymethyl ester) (BAPTA/AM) or thapsigargin attenuated DSS-induced JNK activation, tight junction disruption and barrier dysfunction. Knockdown of apoptosis signal-regulated kinase 1 (Ask1) or MKK7 blocked DSS-induced tight junction disruption and barrier dysfunction. DSS activated c-Src by a Ca2+ and JNK-dependent mechanism. Inhibition of Src kinase activity or knockdown of c-Src blocked DSS-induced tight junction disruption and barrier dysfunction. DSS increased tyrosine phosphorylation of occludin, zonula occludens-1 (ZO-1), E-cadherin and β-catenin. SP600125 abrogated DSS-induced tyrosine phosphorylation of junctional proteins. Recombinant JNK2 induced threonine phosphorylation and auto-phosphorylation of c-Src. The present study demonstrates that Ca(2+)/Ask1/MKK7/JNK2/cSrc signalling cascade mediates DSS-induced tight junction disruption and barrier dysfunction.
Collapse
|
25
|
Konno T, Ninomiya T, Kohno T, Kikuchi S, Sawada N, Kojima T. c-Jun N-terminal kinase inhibitor SP600125 enhances barrier function and elongation of human pancreatic cancer cell line HPAC in a Ca-switch model. Histochem Cell Biol 2014; 143:471-9. [PMID: 25511417 DOI: 10.1007/s00418-014-1300-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/2014] [Indexed: 12/11/2022]
Abstract
c-Jun N-terminal kinase (JNK), known as a stress-activated protein kinase, regulates normal epithelial biological processes, including assembly of adherens and tight junctions, and it is involved in the development of several cancers. The JNK inhibitor SP600125 enhances epithelial barrier function through modulation of tight junction molecules in normal human pancreatic epithelial cells. Furthermore, this JNK inhibitor suppresses the growth of human pancreatic cancer cells. However, the effects of SP600125 on the epithelial barrier in human pancreatic cancer cells remain unknown. In the present study, the JNK inhibitor SP600125 markedly enhanced the barrier function and cell elongation of well-differentiated human pancreatic cancer cell line HPAC in a Ca-switch model. The epithelial barrier function induced by SP600125 was regulated by phosphorylated β-catenin without changes in the tight junction molecules. The cell elongation induced by SP600125 was closely related to the expression of the F-actin-binding protein DrebrinE. These findings suggest that JNK is involved in the regulation of the epithelial barrier function and cell shape during remodeling of pancreatic cancer cells. The JNK inhibitor SP600125 may have potential as a therapeutic drug for pancreatic cancer via induction of differentiation.
Collapse
Affiliation(s)
- Takumi Konno
- Department of Cell Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, S1. W17., Sapporo, 060-8556, Japan
| | | | | | | | | | | |
Collapse
|
26
|
Butyrate protects rat liver against total hepatic ischemia reperfusion injury with bowel congestion. PLoS One 2014; 9:e106184. [PMID: 25171217 PMCID: PMC4149529 DOI: 10.1371/journal.pone.0106184] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 07/28/2014] [Indexed: 12/19/2022] Open
Abstract
Hepatic ischemia/reperfusion (I/R) injury is an unavoidable consequence of major liver surgery, especially in liver transplantation with bowel congestion, during which endotoxemia is often evident. The inflammatory response aggravated by endotoxin after I/R contributes to liver dysfunction and failure. The purpose of the present study was to investigate the protective effect of butyrate, a naturally occurring four-carbon fatty acid in the body and a dietary component of foods such as cheese and butter, on hepatic injury complicated by enterogenous endotoxin, as well as to examine the underlying mechanisms involved. SD rats were subjected to a total hepatic ischemia for 30 min after pretreatment with either vehicle or butyrate, followed by 6 h and 24 h of reperfusion. Butyrate preconditioning markedly improved hepatic function and histology, as indicated by reduced transaminase levels and ameliorated tissue pathological changes. The inflammatory factors levels, macrophages activation, TLR4 expression, and neutrophil infiltration in live were attenuated by butyrate. Butyrate also maintained the intestinal barrier structures, reversed the aberrant expression of ZO-1, and decreased the endotoxin translocation. We conclude that butyrate inhibition of endotoxin translocation, macrophages activation, inflammatory factors production, and neutrophil infiltration is involved in the alleviation of total hepatic I/R liver injury in rats. This suggests that butyrate should potentially be utilized in liver transplantation.
Collapse
|
27
|
Zhao L, Luo L, Chen J, Xiao J, Jia W, Xiao Y. Utilization of Extracorporeal Membrane Oxygenation Alleviates Intestinal Ischemia–Reperfusion Injury in Prolonged Hemorrhagic Shock Animal Model. Cell Biochem Biophys 2014; 70:1733-40. [DOI: 10.1007/s12013-014-0121-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
28
|
Samak G, Gangwar R, Crosby LM, Desai LP, Wilhelm K, Waters CM, Rao R. Cyclic stretch disrupts apical junctional complexes in Caco-2 cell monolayers by a JNK-2-, c-Src-, and MLCK-dependent mechanism. Am J Physiol Gastrointest Liver Physiol 2014; 306:G947-58. [PMID: 24722904 PMCID: PMC4042113 DOI: 10.1152/ajpgi.00396.2013] [Citation(s) in RCA: 44] [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
The intestinal epithelium is subjected to various types of mechanical stress. In this study, we investigated the impact of cyclic stretch on tight junction and adherens junction integrity in Caco-2 cell monolayers. Stretch for 2 h resulted in a dramatic modulation of tight junction protein distribution from a linear organization into wavy structure. Continuation of cyclic stretch for 6 h led to redistribution of tight junction proteins from the intercellular junctions into the intracellular compartment. Disruption of tight junctions was associated with redistribution of adherens junction proteins, E-cadherin and β-catenin, and dissociation of the actin cytoskeleton at the actomyosin belt. Stretch activates JNK2, c-Src, and myosin light-chain kinase (MLCK). Inhibition of JNK, Src kinase or MLCK activity and knockdown of JNK2 or c-Src attenuated stretch-induced disruption of tight junctions, adherens junctions, and actin cytoskeleton. Paracellular permeability measured by a novel method demonstrated that cyclic stretch increases paracellular permeability by a JNK, Src kinase, and MLCK-dependent mechanism. Stretch increased tyrosine phosphorylation of occludin, ZO-1, E-cadherin, and β-catenin. Inhibition of JNK or Src kinase attenuated stretch-induced occludin phosphorylation. Immunofluorescence localization indicated that phospho-MLC colocalizes with the vesicle-like actin structure at the actomyosin belt in stretched cells. On the other hand, phospho-c-Src colocalizes with the actin at the apical region of cells. This study demonstrates that cyclic stretch disrupts tight junctions and adherens junctions by a JNK2, c-Src, and MLCK-dependent mechanism.
Collapse
Affiliation(s)
| | | | | | | | | | | | - RadhaKrishna Rao
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee
| |
Collapse
|
29
|
Nakatsu D, Kano F, Taguchi Y, Sugawara T, Nishizono T, Nishikawa K, Oda Y, Furuse M, Murata M. JNK1/2-dependent phosphorylation of angulin-1/LSR is required for the exclusive localization of angulin-1/LSR and tricellulin at tricellular contacts in EpH4 epithelial sheet. Genes Cells 2014; 19:565-81. [PMID: 24889144 DOI: 10.1111/gtc.12158] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 03/27/2014] [Indexed: 01/16/2023]
Abstract
Tricellular tight junctions (tTJs) are specialized structural variants of tight junctions within tricellular contacts of an epithelial sheet and comprise several transmembrane proteins including lipolysis-stimulated lipoprotein receptor (angulin-1/LSR) and tricellulin. To elucidate the mechanism of its formation, we carried out stepwise screening of kinase inhibitors followed by RNAi screening to identify kinases that regulate intracellular localization of angulin-1/LSR to the tTJs using a fluorescence image-based screen. We found that the activity of JNK1 and JNK2, but not JNK3, was required for the exclusive localization of angulin-1/LSR at the tTJs. Based on a bioinformatics approach, we estimated the potential phosphorylation site of angulin-1/LSR by JNK1 to be serine 288 and experimentally confirmed that JNK1 directly phosphorylates angulin-1/LSR at this site. We found that JNK2 was also involved in the phosphorylation of angulin-1/LSR. Furthermore, GFP-tagged angulin-1/LSR(S288A), in which serine 288 was substituted by alanine, was observed to be dispersed to bicellular junctions, indicating that phosphorylation of Ser288 is crucial for the exclusive localization of angulin-1/LSR and tricellulin at tTJs. Our fluorescence image-based screening for kinases inhibitor or siRNAs combined with the phosphorylation site prediction could become a versatile and useful tool to elucidate the mechanisms underlying the maintenance of tTJs regulated by kinase networks.
Collapse
Affiliation(s)
- Daiki Nakatsu
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Chung HK, Rao JN, Zou T, Liu L, Xiao L, Gu H, Turner DJ, Yang P, Wang JY. Jnk2 deletion disrupts intestinal mucosal homeostasis and maturation by differentially modulating RNA-binding proteins HuR and CUGBP1. Am J Physiol Cell Physiol 2014; 306:C1167-75. [PMID: 24740539 DOI: 10.1152/ajpcell.00093.2014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Homeostasis and maturation of the mammalian intestinal epithelium are preserved through strict regulation of cell proliferation, apoptosis, and differentiation, but the exact mechanism underlying this process remains largely unknown. c-Jun NH2-terminal kinase 2 (JNK2) is highly expressed in the intestinal mucosa, and its activation plays an important role in proliferation and also mediates apoptosis in cultured intestinal epithelial cells (IECs). Here, we investigated the in vivo function of JNK2 in the regulation of intestinal epithelial homeostasis and maturation by using a targeted gene deletion approach. Targeted deletion of the jnk2 gene increased cell proliferation within the crypts in the small intestine and disrupted mucosal maturation as indicated by decreases in the height of villi and the villus-to-crypt ratio. JNK2 deletion also decreased susceptibility of the intestinal epithelium to apoptosis. JNK2-deficient intestinal epithelium was associated with an increase in the level of the RNA-binding protein HuR and with a decrease in the abundance of CUG-binding protein 1 (CUGBP1). In studies in vitro, JNK2 silencing protected intestinal epithelial cell-6 (IEC-6) cells against apoptosis and this protection was prevented by inhibiting HuR. Ectopic overexpression of CUGBP1 repressed IEC-6 cell proliferation, whereas CUGBP1 silencing enhanced cell growth. These results indicate that JNK2 is essential for maintenance of normal intestinal epithelial homeostasis and maturation under biological conditions by differentially modulating HuR and CUGBP1.
Collapse
Affiliation(s)
- Hee Kyoung Chung
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jaladanki N Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Tongtong Zou
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Lan Liu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Hui Gu
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland
| | - Douglas J Turner
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Peixin Yang
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland
| | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland; and Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| |
Collapse
|
31
|
Liang HY, Chen T, Yan HT, Huang Z, Tang LJ. Berberine ameliorates severe acute pancreatitis‑induced intestinal barrier dysfunction via a myosin light chain phosphorylation‑dependent pathway. Mol Med Rep 2014; 9:1827-33. [PMID: 24584406 DOI: 10.3892/mmr.2014.1996] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 02/21/2014] [Indexed: 11/05/2022] Open
Abstract
Berberine is a traditional drug used to treat gastrointestinal disorders in China and has been demonstrated to attenuate intestinal barrier dysfunction in certain animal models. However, the effects of berberine on pancreatitis-induced intestinal barrier dysfunction are yet to be fully elucidated. This study aimed to investigate the effect of berberine pretreatment on the attenuation of intestinal barrier dysfunction induced by severe acute pancreatitis (SAP). A total of 36 rats were randomly divided into Sham, SAP and SAP plus berberine groups. Pancreatitis was induced using retrograde injection of 3% Na-taurocholate into the pancreatic duct. Histological examinations of the pancreas were performed and intestinal barrier dysfunction was characterized by histological measurements and the assessment of serum diamine oxidase activity and endotoxin levels. Zonula occludens-1 and occludin mRNA and protein expression, as well as myosin light chain (MLC) phosphorylation, were assessed. SAP rat models were successfully established. Berberine treatment was found to have no significant effect on the histological changes in the pancreas, but was observed to ameliorate the intestinal mucosal barrier damage and membrane permeability associated with SAP. Although berberine exerted minimal effects on tight junction proteins in the ilea of SAP rats, it was observed to significantly inhibit SAP-induced MLC phosphorylation. To the best of our knowledge, this is the first study to demonstrate that berberine attenuates SAP‑induced intestinal barrier dysfunction in vivo. In addition, this study shows that the effect of berberine on intestinal barrier function may be associated with the inhibition of SAP‑induced upregulation of MLC phosphorylation.
Collapse
Affiliation(s)
- Hong-Yin Liang
- PLA Center of General Surgery, General Hospital of Chengdu Military Command, Chengdu, Sichuan 610083, P.R. China
| | - Tao Chen
- PLA Center of General Surgery, General Hospital of Chengdu Military Command, Chengdu, Sichuan 610083, P.R. China
| | - Hong-Tao Yan
- PLA Center of General Surgery, General Hospital of Chengdu Military Command, Chengdu, Sichuan 610083, P.R. China
| | - Zhu Huang
- PLA Center of General Surgery, General Hospital of Chengdu Military Command, Chengdu, Sichuan 610083, P.R. China
| | - Li-Jun Tang
- PLA Center of General Surgery, General Hospital of Chengdu Military Command, Chengdu, Sichuan 610083, P.R. China
| |
Collapse
|
32
|
Modeling long-term host cell-Giardia lamblia interactions in an in vitro co-culture system. PLoS One 2013; 8:e81104. [PMID: 24312526 PMCID: PMC3849038 DOI: 10.1371/journal.pone.0081104] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 10/09/2013] [Indexed: 12/30/2022] Open
Abstract
Globally, there are greater than 700,000 deaths per year associated with diarrheal disease. The flagellated intestinal parasite, Giardia lamblia, is one of the most common intestinal pathogens in both humans and animals throughout the world. While attached to the gastrointestinal epithelium, Giardia induces epithelial cell apoptosis, disrupts tight junctions, and increases intestinal permeability. The underlying cellular and molecular mechanisms of giardiasis, including the role lamina propria immune cells, such as macrophages, play in parasite control or clearance are poorly understood. Thus far, one of the major obstacles in ascertaining the mechanisms of Giardia pathology is the lack of a functionally relevant model for the long-term study of the parasite in vitro. Here we report on the development of an in vitro co-culture model which maintains the basolateral-apical architecture of the small intestine and allows for long-term survival of the parasite. Using transwell inserts, Caco-2 intestinal epithelial cells and IC-21 macrophages are co-cultured in the presence of Giardia trophozoites. Using the developed model, we show that Giardia trophozoites survive over 21 days and proliferate in a combination media of Caco-2 cell and Giardia medium. Giardia induces apoptosis of epithelial cells through caspase-3 activation and macrophages do not abrogate this response. Additionally, macrophages induce Caco-2 cells to secrete the pro-inflammatory cytokines, GRO and IL-8, a response abolished by Giardia indicating parasite induced suppression of the host immune response. The co-culture model provides additional complexity and information when compared to a single-cell model. This model will be a valuable tool for answering long-standing questions on host-parasite biology that may lead to discovery of new therapeutic interventions.
Collapse
|
33
|
Du MH, Luo HM, Hu S, Lv Y, Lin ZL, Ma L. Electroacupuncture improves gut barrier dysfunction in prolonged hemorrhagic shock rats through vagus anti-inflammatory mechanism. World J Gastroenterol 2013; 19:5988-5999. [PMID: 24106399 PMCID: PMC3785620 DOI: 10.3748/wjg.v19.i36.5988] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 07/11/2013] [Accepted: 08/17/2013] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate whether electroacupuncture (EA) at Zusanli (ST36) prevents intestinal barrier and remote organ dysfunction following prolonged hemorrhagic shock through a vagus anti-inflammatory mechanism.
METHODS: Sprague-Dawley rats were subjected to about 45% of total blood volume loss followed by delayed fluid replacement (DFR) with Ringer lactate 3h after hemorrhage. In a first study, rats were randomly divided into six groups: (1) EAN: EA at non-channel acupoints followed by DFR; (2) EA: EA at ST36 after hemorrhage followed by DFR; (3) VGX/EA: vagotomy (VGX) before EA at ST36 and DFR; (4) VGX/EAN: VGX before EAN and DFR; (5) α-bungarotoxin (α-BGT)/EA: intraperitoneal injection of α-BGT before hemorrhage, followed by EA at ST36 and DFR; and (6) α-BGT/EAN group: α-BGT injection before hemorrhage followed by EAN and DFR. Survival and mean arterial pressure (MAP) were monitored over the next 12 h. In a second study, with the same grouping and treatment, cytokine levels in plasma and intestine, organ parameters, gut injury score, gut permeability to 4 kDa FITC-dextran, and expression and distribution of tight junction protein ZO-1 were evaluated.
RESULTS: MAP was significantly lowered after blood loss; EA at ST36 improved the blood pressure at corresponding time points 3 and 12 h after hemorrhage. EA at ST36 reduced tumor necrosis factor-α and interleukin (IL)-6 levels in both plasma and intestine homogenates after blood loss and DFR, while vagotomy or intraperitoneal injection of α-BGT before EA at ST36 reversed its anti-inflammatory effects, and EA at ST36 did not influence IL-10 levels in plasma and intestine. EA at ST36 alleviated the injury of intestinal villus, the gut injury score being significantly lower than that of EAN group (1.85 ± 0.33 vs 3.78 ± 0.59, P < 0.05). EA at ST36 decreased intestinal permeability to FITC-dextran compared with EAN group (856.95 ng/mL ± 90.65 ng/mL vs 2305.62 ng/mL ± 278.32 ng/mL, P < 0.05). EA at ST36 significantly preserved ZO-1 protein expression and localization at 12 h after hemorrhage. However, EA at non-channel acupoints had no such effect, and abdominal vagotomy and α-BGT treatment could weaken or eliminate the effects of EA at ST36. Besides, EA at ST36 decreased blood aminotransferase, MB isoenzyme of creatine kinase and creatinine vs EAN group at corresponding time points. At the end of 12-h experiment, the survival rate of the EA group was significantly higher than that of the other groups.
CONCLUSION: EA at ST36 attenuates the systemic inflammatory response, protects intestinal barrier integrity, improves organ function and survival rate after hemorrhagic shock via activating the cholinergic anti-inflammatory mechanism.
Collapse
|
34
|
Miyashita SI, Sagane Y, Inui K, Hayashi S, Miyata K, Suzuki T, Ohyama T, Watanabe T, Niwa K. Botulinum toxin complex increases paracellular permeability in intestinal epithelial cells via activation of p38 mitogen-activated protein kinase. J Vet Med Sci 2013; 75:1637-42. [PMID: 23884081 PMCID: PMC3942962 DOI: 10.1292/jvms.13-0164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Clostridium botulinum produces a large toxin complex (L-TC) that increases paracellular
permeability in intestinal epithelial cells by a mechanism that remains unclear. Here, we
show that mitogen-activated protein kinases (MAPKs) are involved in this permeability
increase. Paracellular permeability was measured by FITC-dextran flux through a monolayer
of rat intestinal epithelial IEC-6 cells, and MAPK activation was estimated from western
blots. L-TC of C. botulinum serotype D strain 4947 increased paracellular
dextran flux and activated extracellular signal-regulated kinase (ERK), p38, but not c-Jun
N-terminal kinase (JNK) in IEC-6 cells. The permeability increase induced by L-TC was
abrogated by the p38 inhibitor SB203580. These results indicate that L-TC increases
paracellular permeability by activating p38, but not JNK and ERK.
Collapse
Affiliation(s)
- Shin-Ichiro Miyashita
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, Hokkaido 099-2493, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Electroacupuncture at Zusanli (ST36) Prevents Intestinal Barrier and Remote Organ Dysfunction following Gut Ischemia through Activating the Cholinergic Anti-Inflammatory-Dependent Mechanism. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:592127. [PMID: 23662144 PMCID: PMC3638586 DOI: 10.1155/2013/592127] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 03/18/2013] [Indexed: 02/08/2023]
Abstract
This study investigated the protective effect and mechanism of electroacupuncture at ST36 points on the intestinal barrier dysfunction and remote organ injury after intestinal ischemia and reperfusion injury in rats. Rats were subjected to gut ischemia for 30 min, and then received electroacupuncture for 30 min with or without abdominal vagotomy or intraperitoneal administration of cholinergic α 7 nicotinic acetylcholine receptor ( α 7nAChR) inhibitor. Then we compared its effects with electroacupuncture at nonchannel points, vagal nerve stimulation, or intraperitoneal administration of cholinergic agonist. Cytokine levels in plasma and tissue of intestine, lung, and liver were assessed 60 min after reperfusion. Intestinal barrier injury was detected by histology, gut injury score, the permeability to 4 kDa FITC-dextran, and changes in tight junction protein ZO-1 using immunofluorescence and Western blot. Electroacupuncture significantly lowered the levels of tumor necrosis factor- α and interleukin-8 in plasma and organ tissues, decreased intestinal permeability to FITC-dextran, and prevented changes in ZO-1 protein expression and localization. However, abdominal vagotomy or intraperitoneal administration of cholinergic α 7nAChR inhibitor reversed these effects of electroacupuncture. These findings suggest that electroacupuncture attenuates the systemic inflammatory response through protection of intestinal barrier integrity after intestinal ischemia injury in the presence of an intact vagus nerve.
Collapse
|
36
|
Rao RK, Samak G. Protection and Restitution of Gut Barrier by Probiotics: Nutritional and Clinical Implications. CURRENT NUTRITION & FOOD SCIENCE 2013; 9:99-107. [PMID: 24353483 DOI: 10.2174/1573401311309020004] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Probiotics are beneficial bacteria present in various dietary components and many of these colonize in the human and animal intestine. In the gut probiotics help the host by assisting in maintenance of normal mucosal homeostasis. Probiotics not only help maintain normal function of the gut mucosa, but also protect mucosa from injurious factors such as toxins, allergens and pathogens. The beneficial effect of probiotics is mediated by multiple mechanisms, including cytoprotection, cell proliferation, cell migration, resistance to apoptosis, synthesis of proteins and gene expression. One of the important cytoprotective effects of probiotics in the intestinal mucosa is to strengthen the epithelial tight junctions and preservation of mucosal barrier function. Probiotics not only enhance barrier function by inducing synthesis and assembly of tight junction proteins, but also preventing disruption of tight junctions by injurious factors. Bioactive factors released by probiotics trigger activation of various cell signaling pathways that lead to strengthening of tight junctions and the barrier function. This article reviews and summarizes the current understanding of various probiotics that are involved in the protection of gut barrier function, highlights the cellular and molecular mechanisms involved in the protective effect and addresses the clinical implications of probiotic supplementation.
Collapse
Affiliation(s)
- R K Rao
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - G Samak
- DVS College of Arts and Science, Shimoga, India
| |
Collapse
|
37
|
Cai Y, Wang W, Liang H, Sun L, Teitelbaum DH, Yang H. Keratinocyte growth factor pretreatment prevents radiation-induced intestinal damage in a mouse model. Scand J Gastroenterol 2013; 48:419-26. [PMID: 23464848 DOI: 10.3109/00365521.2013.772227] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Radiation-induced gastrointestinal syndrome is usually severe in clinical practice. Keratinocyte growth factor (KGF) plays an important role in the intestinal mucosal growth and repair of intestinal injury. This study was to investigate the effects of KGF on radiation-induced intestinal damage, especially the barrier dysfunction, in a mouse model. METHODS Adult C57BL/6J mice were randomized into three groups: normal control, irradiation group, and KGF-treated group. Mice in the later two groups received irradiation with a dose of 6 Gy from Co-60 source. In the KGF-treated group, KGF was intraperitoneally given once daily (5 mg/kg/day) for 5 consecutive days before irradiation. Mice were killed at 3 days after irradiation and the small bowel was collected for histology. Epithelial cell proliferation was studied by immunohistochemistry for proliferating cell nuclear antigen. Claudin-1 and ZO-1 expressions were determined by western blot assay and immunohistochemistry. Epithelial barrier function was assessed with transepithelial resistance. RESULTS KGF significantly promoted the recovery of mucosa from radiation-induced injury demonstrated by mucosal histology, villus height, crypt depth, and crypt cell proliferation. KGF also improved the disrupted distribution of tight junction proteins and the epithelial barrier dysfunction after irradiation. CONCLUSION KGF pretreatment could improve radiation-induced intestinal injury including the epithelial structure and function in a mouse model.
Collapse
Affiliation(s)
- Yujiao Cai
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | | | | | | | | | | |
Collapse
|
38
|
Gonzalez Pardo V, Russo de Boland A. Age-related changes in the response of intestinal cells to 1α,25(OH)2-vitamin D3. Ageing Res Rev 2013; 12:76-89. [PMID: 22706185 DOI: 10.1016/j.arr.2012.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 06/01/2012] [Accepted: 06/06/2012] [Indexed: 12/14/2022]
Abstract
The hormonally active form of vitamin D(3), 1α,25(OH)(2)-vitamin D(3), acts in intestine, its major target tissue, where its actions are of regulatory and developmental importance: regulation of intracellular calcium through modulation of second messengers and activation of mitogenic cascades leading to cell proliferation. Several causes have been postulated to modify the hormone response in intestinal cells with ageing, among them, alterations of vitamin D receptor (VDR) levels and binding sites, reduced expression of G-proteins and hormone signal transduction changes. The current review summarizes the actual knowledge regarding the molecular and biochemical basis of age-impaired 1α,25(OH)(2)-vitamin D(3) receptor-mediated signaling in intestinal cells. A fundamental understanding why the hormone functions are impaired with age will enhance our knowledge of its importance in intestinal cell physiology.
Collapse
Affiliation(s)
- Verónica Gonzalez Pardo
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Consejo Nacional de Investigaciones Científicas y Técnicas, Bahía Blanca, Argentina
| | | |
Collapse
|
39
|
Cai Y, Wang W, Liang H, Sun L, Teitelbaum DH, Yang H. Keratinocyte growth factor improves epithelial structure and function in a mouse model of intestinal ischemia/reperfusion. PLoS One 2012; 7:e44772. [PMID: 23028616 PMCID: PMC3441439 DOI: 10.1371/journal.pone.0044772] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 08/07/2012] [Indexed: 12/16/2022] Open
Abstract
Background Intestinal ischemia/reperfusion (I/R) induces the desquamation of the intestinal epithelium, increases the intestinal permeability, and in patients often causes fatal conditions including sepsis and multiple organ failure. Keratinocyte growth factor (KGF) increases intestinal growth, although little is known about KGF activity on intestinal function after intestinal I/R. We hypothesized that KGF administration would improve the intestinal function in a mouse model of intestinal I/R. Methods Adult C57BL/6J mice were randomized to three groups: Sham, I/R group and I/R+KGF group. Mice were killed on day 5, and the small bowel was harvested for histology, wet weight, RNA and protein content analysis. Epithelial cell (EC) proliferation was detected by immunohistochemistry for PCNA, and apoptosis was determined by TUNEL staining. The expressions of Claudin-1 and ZO-1 were detected by immunohistochemistry. Epithelial barrier function was assessed with transepithelial resistance (TER). Results KGF significantly increased the intestinal wet weight, contents of intestinal protein and RNA, villus height, crypt depth and crypt cell proliferation, while KGF resulted in the decrease of epithelial apoptosis. KGF also stimulated the recovery of mucosal structures and attenuated the disrupted distribution of TJ proteins. Moreover, KGF attenuated the intestinal I/R-induced decrease in TER and maintained the intestinal barrier function. Conclusion KGF administration improves the epithelial structure and barrier function in a mouse model of intestinal I/R. This suggests that KGF may have clinical applicability.
Collapse
Affiliation(s)
- Yujiao Cai
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Wensheng Wang
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Hongying Liang
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Lihua Sun
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Daniel H. Teitelbaum
- Department of Surgery, the University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Hua Yang
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
- Department of Surgery, the University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail:
| |
Collapse
|
40
|
Oltean M, Joshi M, Björkman E, Oltean S, Casselbrant A, Herlenius G, Olausson M. Intraluminal polyethylene glycol stabilizes tight junctions and improves intestinal preservation in the rat. Am J Transplant 2012; 12:2044-51. [PMID: 22548829 DOI: 10.1111/j.1600-6143.2012.04067.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Rapidly progressing mucosal breakdown limits the intestinal preservation time below 10 h. Recent studies indicate that intraluminal solutions containing polyethylene glycol (PEG) alleviate preservation injury of intestines stored in UW-Viaspan. We investigated whether a low-sodium PEG solution is beneficial for intestines stored in histidine-tryptophane-ketoglutarate (HTK) preservation solution. Rat intestines used as control tissue (group 1) were perfused with HTK, groups 2 and 3 received either a customized PEG-3350 (group 2) or an electrolyte solution (group 3) intraluminally before cold storage. Tissue injury, brush-border maltase activity, zonula occludens-1 (ZO-1) and claudin-3 expression in the tight junctions (TJ) were analyzed after 8, 14 and 20 h. We measured epithelial resistance and permeability (Ussing chamber) after 8 and 14 h. Group 2 had superior morphology while maltase activity was similar in all groups. TJ proteins rapidly decreased and decolocalized in groups 1 3; these negative events were delayed in group 2, where colocalization persisted for about 14 h. Intestines in group 2 had higher epithelial resistance and lower permeability than the other groups. These results suggest that a customized PEG solution intraluminally reduces the intestinal preservation injury by improving several major epithelial characteristics without negatively affecting the brush-border enzymes or promoting edema.
Collapse
Affiliation(s)
- M Oltean
- The Transplant Institute, Sahlgrenska University Hospital, Sweden.
| | | | | | | | | | | | | |
Collapse
|
41
|
C-Jun N-Terminal Kinase 2 Promotes Liver Injury via the Mitochondrial Permeability Transition after Hemorrhage and Resuscitation. HPB SURGERY : A WORLD JOURNAL OF HEPATIC, PANCREATIC AND BILIARY SURGERY 2012; 2012:641982. [PMID: 22791932 PMCID: PMC3390051 DOI: 10.1155/2012/641982] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 03/24/2012] [Indexed: 12/11/2022]
Abstract
Hemorrhagic shock leads to hepatic hypoperfusion and activation of mitogen-activated stress kinases (MAPK) like c-Jun N-terminal kinase (JNK) 1 and 2. Our aim was to determine whether mitochondrial dysfunction leading to hepatic necrosis and apoptosis after hemorrhage/resuscitation (H/R) was dependent on JNK2. Under pentobarbital anesthesia, wildtype (WT) and JNK2 deficient (KO) mice were hemorrhaged to 30 mm Hg for 3 h and then resuscitated with shed blood plus half the volume of lactated Ringer's solution. Serum alanine aminotransferase (ALT), necrosis, apoptosis and oxidative stress were assessed 6 h after resuscitation. Mitochondrial polarization was assessed by intravital microscopy. After H/R, ALT in WT-mice increased from 130 U/L to 4800 U/L. In KO-mice, ALT after H/R was blunted to 1800 U/l (P < 0.05). Necrosis, caspase-3 activity and ROS were all substantially decreased in KO compared to WT mice after H/R. After sham operation, intravital microscopy revealed punctate mitochondrial staining by rhodamine 123 (Rh123), indicating normal mitochondrial polarization. At 4 h after H/R, Rh123 staining became dim and diffuse in 58% of hepatocytes, indicating depolarization and onset of the mitochondrial permeability transition (MPT). By contrast, KO mice displayed less depolarization after H/R (23%, P < 0.05). In conclusion, JNK2 contributes to MPT-mediated liver injury after H/R.
Collapse
|
42
|
Abstract
OBJECTIVES Chemotherapy often induces intestinal mucositis, which is associated with an increase in intestinal permeability; however, underlying mechanisms remain incompletely understood. Thus, we aimed to study the regulation of 3 tight junction (TJ) proteins, claudin-1, occludin, and zonula occludens-1, after anticancer treatment. METHODS Methotrexate (MTX) was subcutaneously injected for 3 consecutive days in Sprague-Dawley rats to induce intestinal mucositis and was applied on Caco-2 cell monolayers. TJ protein expression and cellular distribution were studied by Western blot and microscopy, respectively. In Caco-2 cells, the paracellular permeability was evaluated by both transepithelial electrical resistance and flux of fluorescein isothiocyanate-dextran marker. Cytokine production and signaling pathways were also assessed. RESULTS In MTX-treated rats, the cellular distribution of the 3 TJ proteins was altered and claudin-1 and occludin expression was reduced during the acute phase of mucositis compared with controls. During the recovery phase, these parameters were restored. In vitro, MTX treatment led to an increase in proinflammatory cytokine production at the apical side but did not affect Caco-2 cell apoptosis and necrosis. Increase in paracellular permeability was associated with altered occludin and zonula occludens-1 expression and cellular distribution. All of these alterations were prevented by MEK1 and 2, JNK, and NF-κB inhibitors. CONCLUSIONS MTX treatment induced an increase in intestinal permeability partially related to alteration of TJs protein expression and cellular distribution that may be mediated by MAPK and NF-κB pathways. These are potential targets to limit the adverse effects of chemotherapy.
Collapse
|
43
|
Reinecke K, Eminel S, Dierck F, Roessner W, Kersting S, Chromik AM, Gavrilova O, Laukevicience A, Leuschner I, Waetzig V, Rosenstiel P, Herdegen T, Sina C. The JNK inhibitor XG-102 protects against TNBS-induced colitis. PLoS One 2012; 7:e30985. [PMID: 22427801 PMCID: PMC3302790 DOI: 10.1371/journal.pone.0030985] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 12/30/2011] [Indexed: 12/19/2022] Open
Abstract
The c-Jun N-terminal kinase (JNK)-inhibiting peptide D-JNKI-1, syn. XG-102 was tested for its therapeutic potential in acute inflammatory bowel disease (IBD) in mice. Rectal instillation of the chemical irritant trinitrobenzene sulfonic acid (TNBS) provoked a dramatic acute inflammation in the colon of 7–9 weeks old mice. Coincident subcutaneous application of 100 µg/kg XG-102 significantly reduced the loss of body weight, rectal bleeding and diarrhoea. After 72 h, the end of the study, the colon was removed and immuno-histochemically analysed. XG-102 significantly reduced (i) pathological changes such as ulceration or crypt deformation, (ii) immune cell pathology such as infiltration and presence of CD3- and CD68-positive cells, (iii) the production of tumor necrosis factor (TNF)-α in colon tissue cultures from TNBS-treated mice, (iv) expression of Bim, Bax, FasL, p53, and activation of caspase 3, (v) complexation of JNK2 and Bim, and (vi) expression and activation of the JNK substrate and transcription factor c-Jun. A single application of subcutaneous XG-102 was at least as effective or even better depending on the outcome parameter as the daily oral application of sulfasalazine used for treatment of IBD. The successful and substantial reduction of the severe, TNBS-evoked intestinal damages and clinical symptoms render the JNK-inhibiting peptide XG-102 a powerful therapeutic principle of IBD.
Collapse
Affiliation(s)
- Kirstin Reinecke
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Sevgi Eminel
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | | | - Wibke Roessner
- Pharmaceutical Institute, University of Kiel, Kiel, Germany
| | - Sabine Kersting
- Department of Visceral and General Surgery, St. Josef Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Ansgar Michael Chromik
- Department of Visceral and General Surgery, St. Josef Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Olga Gavrilova
- Institute for Clinical Molecular Biology, University of Kiel, University Hospital Schleswig-Holstein, Kiel, Campus Kiel, Kiel, Germany
| | - Ale Laukevicience
- Department of Physiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Ivo Leuschner
- Institute of Pathology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Vicki Waetzig
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Philip Rosenstiel
- Institute for Clinical Molecular Biology, University of Kiel, University Hospital Schleswig-Holstein, Kiel, Campus Kiel, Kiel, Germany
| | - Thomas Herdegen
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
- * E-mail:
| | - Christian Sina
- Institute for Clinical Molecular Biology, University of Kiel, University Hospital Schleswig-Holstein, Kiel, Campus Kiel, Kiel, Germany
| |
Collapse
|
44
|
Modulation of tight junction structure and function by kinases and phosphatases targeting occludin. J Biomed Biotechnol 2012; 2012:807356. [PMID: 22315516 PMCID: PMC3270569 DOI: 10.1155/2012/807356] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 08/22/2011] [Indexed: 01/20/2023] Open
Abstract
Tight junctions (TJs) typically represent the most apical contacts in epithelial and endothelial cell layers where they play an essential role in the separation of extracellular or luminal spaces from underlying tissues in the body. Depending on the protein composition, TJs define the barrier characteristics and in addition maintain cell polarity. Two major families of integral membrane proteins form the typical TJ strand network, the tight junction-associated MARVEL protein (TAMP) family members occludin, tricellulin, and MarvelD3 as well as a specific set of claudins. Occludin was the first identified member of these tetraspanins and is now widely accepted as a regulator of TJ assembly and function. Therefore, occludin itself has to be tightly regulated. Phosphorylation of occludin appears to be of central importance in this context. Here we want to summarize current knowledge on the kinases and phosphatases directly modifying occludin, and their role in the regulation of TJ structure, function, and dynamics.
Collapse
|
45
|
Pflugfelder SC. Tear dysfunction and the cornea: LXVIII Edward Jackson Memorial Lecture. Am J Ophthalmol 2011; 152:900-909.e1. [PMID: 22019306 DOI: 10.1016/j.ajo.2011.08.023] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 08/22/2011] [Accepted: 08/23/2011] [Indexed: 11/29/2022]
Abstract
PURPOSE To describe the cause and consequence of tear dysfunction-related corneal disease. DESIGN Perspective on effects of tear dysfunction on the cornea. METHODS Evidence is presented on the effects of tear dysfunction on corneal morphology, function, and health, as well as efficacy of therapies for tear dysfunction-related corneal disease. RESULTS Tear dysfunction is a prevalent eye disease and the most frequent cause for superficial corneal epithelial disease that results in corneal barrier disruption, an irregular optical surface, light scattering, optical aberrations, and exposure and sensitization of pain-sensing nerve endings (nociceptors). Tear dysfunction-related corneal disease causes irritation and visual symptoms such as photophobia and blurred and fluctuating vision that may decrease quality of life. Dysfunction of 1 or more components of the lacrimal functional unit results in changes in tear composition, including elevated osmolarity and increased concentrations of matrix metalloproteinases, inflammatory cytokines, and chemokines. These tear compositional changes promote disruption of tight junctions, alter differentiation, and accelerate death of corneal epithelial cells. CONCLUSIONS Corneal epithelial disease resulting from tear dysfunction causes eye irritation and decreases visual function. Clinical and basic research has improved understanding of the pathogenesis of tear dysfunction-related corneal epithelial disease, as well as treatment outcomes.
Collapse
Affiliation(s)
- Stephen C Pflugfelder
- Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA.
| |
Collapse
|
46
|
Samak G, Narayanan D, Jaggar JH, Rao R. CaV1.3 channels and intracellular calcium mediate osmotic stress-induced N-terminal c-Jun kinase activation and disruption of tight junctions in Caco-2 CELL MONOLAYERS. J Biol Chem 2011; 286:30232-43. [PMID: 21737448 DOI: 10.1074/jbc.m111.240358] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We investigated the role of a Ca(2+) channel and intracellular calcium concentration ([Ca(2+)](i)) in osmotic stress-induced JNK activation and tight junction disruption in Caco-2 cell monolayers. Osmotic stress-induced tight junction disruption was attenuated by 1,2-bis(2-aminophenoxyl)ethane-N,N,N',N'-tetraacetic acid (BAPTA)-mediated intracellular Ca(2+) depletion. Depletion of extracellular Ca(2+) at the apical surface, but not basolateral surface, also prevented tight junction disruption. Similarly, thapsigargin-mediated endoplasmic reticulum (ER) Ca(2+) depletion attenuated tight junction disruption. Thapsigargin or extracellular Ca(2+) depletion partially reduced osmotic stress-induced rise in [Ca(2+)](i), whereas thapsigargin and extracellular Ca(2+) depletion together resulted in almost complete loss of rise in [Ca(2+)](i). L-type Ca(2+) channel blockers (isradipine and diltiazem) or knockdown of the Ca(V)1.3 channel abrogated [Ca(2+)](i) rise and disruption of tight junction. Osmotic stress-induced JNK2 activation was abolished by BAPTA and isradipine, and partially reduced by extracellular Ca(2+) depletion, thapsigargin, or Ca(V)1.3 knockdown. Osmotic stress rapidly induced c-Src activation, which was significantly attenuated by BAPTA, isradipine, or extracellular Ca(2+) depletion. Tight junction disruption by osmotic stress was blocked by tyrosine kinase inhibitors (genistein and PP2) or siRNA-mediated knockdown of c-Src. Osmotic stress induced a robust increase in tyrosine phosphorylation of occludin, which was attenuated by BAPTA, SP600125 (JNK inhibitor), or PP2. These results demonstrate that Ca(V)1.3 and rise in [Ca(2+)](i) play a role in the mechanism of osmotic stress-induced tight junction disruption in an intestinal epithelial monolayer. [Ca(2+)](i) mediate osmotic stress-induced JNK activation and subsequent c-Src activation and tyrosine phosphorylation of tight junction proteins. Additionally, inositol 1,4,5-trisphosphate receptor-mediated release of ER Ca(2+) also contributes to osmotic stress-induced tight junction disruption.
Collapse
Affiliation(s)
- Geetha Samak
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
| | | | | | | |
Collapse
|
47
|
Samak G, Aggarwal S, Rao RK. ERK is involved in EGF-mediated protection of tight junctions, but not adherens junctions, in acetaldehyde-treated Caco-2 cell monolayers. Am J Physiol Gastrointest Liver Physiol 2011; 301:G50-9. [PMID: 21474650 PMCID: PMC3129938 DOI: 10.1152/ajpgi.00494.2010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The role of mitogen-activated protein kinases (MAPK) in the mechanism of EGF-mediated prevention of acetaldehyde-induced tight junction disruption was evaluated in Caco-2 cell monolayers. Pretreatment of cell monolayers with EGF attenuated acetaldehyde-induced decrease in resistance and increase in inulin permeability and redistribution of occludin, zona occludens-1 (ZO-1), E-cadherin, and β-catenin from the intercellular junctions. EGF rapidly increased the levels of phospho-ERK1/2, phospho-p38 MAPK, and phospho-JNK1. Pretreatment of cell monolayers with U-0126 (inhibitor of ERK activation), but not SB-202190 and SP-600125 (p38 MAPK and JNK inhibitors), significantly attenuated EGF-mediated prevention of acetaldehyde-induced changes in resistance, inulin permeability, and redistribution of occludin and ZO-1. U-0126, but not SB-202190 and SP-600125, also attenuated EGF-mediated prevention of acetaldehyde effect on the midregion F-actin ring. However, EGF-mediated preservation of junctional distribution of E-cadherin and β-catenin was unaffected by all three inhibitors. Expression of wild-type or constitutively active MEK1 attenuated acetaldehyde-induced redistribution of occludin and ZO-1, whereas dominant-negative MEK1 prevented EGF-mediated preservation of occludin and ZO-1 in acetaldehyde-treated cells. MEK1 expression did not alter E-cadherin distribution in acetaldehyde-treated cells in the presence or absence of EGF. Furthermore, EGF attenuated acetaldehyde-induced tyrosine-phosphorylation of occludin, ZO-1, claudin-3, and E-cadherin. U-0126, but not SB-202190 and SP-600125, prevented EGF effect on tyrosine-phosphorylation of occludin and ZO-1, but not claudin-3, E-cadherin, or β-catenin. These results indicate that EGF-mediated protection of tight junctions from acetaldehyde requires the activity of ERK1/2, but not p38 MAPK or JNK1/2, and that EGF-mediated protection of adherens junctions is independent of MAPK activities.
Collapse
Affiliation(s)
- G. Samak
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee
| | - S. Aggarwal
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee
| | - R. K. Rao
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee
| |
Collapse
|