1
|
Ran X, Müller S, Brunssen C, Huhle R, Scharffenberg M, Schnabel C, Koch T, Gama de Abreu M, Morawietz H, Ferreira JMC, Wittenstein J. Modulation of the hippo-YAP pathway by cyclic stretch in rat type 2 alveolar epithelial cells-a proof-of-concept study. Front Physiol 2023; 14:1253810. [PMID: 37877098 PMCID: PMC10591329 DOI: 10.3389/fphys.2023.1253810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 09/28/2023] [Indexed: 10/26/2023] Open
Abstract
Background: Mechanical ventilation (MV) is a life supporting therapy but may also cause lung damage. This phenomenon is known as ventilator-induced lung injury (VILI). A potential pathomechanisms of ventilator-induced lung injury may be the stretch-induced production and release of cytokines and pro-inflammatory molecules from the alveolar epithelium. Yes-associated protein (YAP) might be regulated by mechanical forces and involved in the inflammation cascade. However, its role in stretch-induced damage of alveolar cells remains poorly understood. In this study, we explored the role of YAP in the response of alveolar epithelial type II cells (AEC II) to elevated cyclic stretch in vitro. We hypothesize that Yes-associated protein activates its downstream targets and regulates the interleukin-6 (IL-6) expression in response to 30% cyclic stretch in AEC II. Methods: The rat lung L2 cell line was exposed to 30% cyclic equibiaxial stretch for 1 or 4 h. Non-stretched conditions served as controls. The cytoskeleton remodeling and cell junction integrity were evaluated by F-actin and Pan-cadherin immunofluorescence, respectively. The gene expression and protein levels of IL-6, Yes-associated protein, Cysteine-rich angiogenic inducer 61 (Cyr61/CCN1), and connective tissue growth factor (CTGF/CCN2) were studied by real-time polymerase chain reaction (RT-qPCR) and Western blot, respectively. Verteporfin (VP) was used to inhibit Yes-associated protein activation. The effects of 30% cyclic stretch were assessed by two-way ANOVA. Statistical significance as accepted at p < 0.05. Results: Cyclic stretch of 30% induced YAP nuclear accumulation, activated the transcription of Yes-associated protein downstream targets Cyr61/CCN1 and CTGF/CCN2 and elevated IL-6 expression in AEC II after 1 hour, compared to static control. VP (2 µM) inhibited Yes-associated protein activation in response to 30% cyclic stretch and reduced IL-6 protein levels. Conclusion: In rat lung L2 AEC II, 30% cyclic stretch activated YAP, and its downstream targets Cyr61/CCN1 and CTGF/CCN2 and proinflammatory IL-6 expression. Target activation was blocked by a Yes-associated protein inhibitor. This novel YAP-dependent pathway could be involved in stretch-induced damage of alveolar cells.
Collapse
Affiliation(s)
- Xi Ran
- Department of Intensive Care Medicine, Chongqing General Hospital, Changqing, China
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus Dresden, TUD Dresden University of Technology, Dresden, Germany
| | - Sabine Müller
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus Dresden, TUD Dresden University of Technology, Dresden, Germany
| | - Coy Brunssen
- Division of Vascular Endothelium and Microcirculation, Department of Medicine III, University Hospital and Medical Faculty Carl Gustav Carus, TUD Dresden University of Technology, Dresden, Germany
| | - Robert Huhle
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus Dresden, TUD Dresden University of Technology, Dresden, Germany
| | - Martin Scharffenberg
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus Dresden, TUD Dresden University of Technology, Dresden, Germany
| | - Christian Schnabel
- Department of Anesthesiology and Intensive Care Medicine, Clinical Sensoring and Monitoring Group, University Hospital Carl Gustav Carus Dresden, TUD Dresden University of Technology, Dresden, Germany
| | - Thea Koch
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus Dresden, TUD Dresden University of Technology, Dresden, Germany
| | - Marcelo Gama de Abreu
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus Dresden, TUD Dresden University of Technology, Dresden, Germany
- Department of Intensive Care and Resuscitation, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, United States
- Department of Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Henning Morawietz
- Division of Vascular Endothelium and Microcirculation, Department of Medicine III, University Hospital and Medical Faculty Carl Gustav Carus, TUD Dresden University of Technology, Dresden, Germany
| | - Jorge M. C. Ferreira
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus Dresden, TUD Dresden University of Technology, Dresden, Germany
| | - Jakob Wittenstein
- Department of Anesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus Dresden, TUD Dresden University of Technology, Dresden, Germany
| |
Collapse
|
2
|
Fang X, Ni K, Guo J, Li Y, Zhou Y, Sheng H, Bu B, Luo M, Ouyang M, Deng L. FRET Visualization of Cyclic Stretch-Activated ERK via Calcium Channels Mechanosensation While Not Integrin β1 in Airway Smooth Muscle Cells. Front Cell Dev Biol 2022; 10:847852. [PMID: 35663392 PMCID: PMC9162487 DOI: 10.3389/fcell.2022.847852] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 04/05/2022] [Indexed: 12/19/2022] Open
Abstract
Mechanical stretch is one type of common physiological activities such as during heart beating, lung breathing, blood flow through the vessels, and physical exercise. The mechanical stimulations regulate cellular functions and maintain body homeostasis. It still remains to further characterize the mechanical-biomechanical coupling mechanism. Here we applied fluorescence resonance energy transfer (FRET) technology to visualize ERK activity in airway smooth muscle (ASM) cells under cyclic stretch stimulation in airway smooth muscle (ASM) cells, and studied the mechanosensing pathway. FRET measurements showed apparent ERK activation by mechanical stretch, which was abolished by ERK inhibitor PD98059 pretreatment. Inhibition of extracellular Ca2+ influx reduced ERK activation, and selective inhibition of inositol 1,4,5-trisphosphate receptor (IP3R) Ca2+ channel or SERCA Ca2+ pump on endoplasmic reticulum (ER) blocked the activation. Chemical inhibition of the L-type or store-operated Ca2+ channels on plasma membrane, or inhibition of integrin β1 with siRNA had little effect on ERK activation. Disruption of actin cytoskeleton but not microtubule one inhibited the stretch-induced ERK activation. Furthermore, the ER IP3R-dependent ERK activation was not dependent on phospholipase C-IP3 signal, indicating possibly more mechanical mechanism for IP3R activation. It is concluded from our study that the mechanical stretch activated intracellular ERK signal in ASM cells through membrane Ca2+ channels mechanosensation but not integrin β1, which was mediated by actin cytoskeleton.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Linhong Deng
- *Correspondence: Mingxing Ouyang, ; Linhong Deng,
| |
Collapse
|
3
|
Live imaging approach of dynamic multicellular responses in ERK signaling during vertebrate tissue development. Biochem J 2022; 479:129-143. [PMID: 35050327 PMCID: PMC8883488 DOI: 10.1042/bcj20210557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/28/2021] [Accepted: 01/05/2022] [Indexed: 11/17/2022]
Abstract
The chemical and mechanical responses of cells via the exchange of information during growth and development result in the formation of biological tissues. Information processing within the cells through the signaling pathways and networks inherent to the constituent cells has been well-studied. However, the cell signaling mechanisms responsible for generating dynamic multicellular responses in developing tissues remain unclear. Here, I review the dynamic multicellular response systems during the development and growth of vertebrate tissues based on the extracellular signal-regulated kinase (ERK) pathway. First, an overview of the function of the ERK signaling network in cells is provided, followed by descriptions of biosensors essential for live imaging of the quantification of ERK activity in tissues. Then adducing four examples, I highlight the contribution of live imaging techniques for studying the involvement of spatio-temporal patterns of ERK activity change in tissue development and growth. In addition, theoretical implications of ERK signaling are also discussed from the viewpoint of dynamic systems. This review might help in understanding ERK-mediated dynamic multicellular responses and tissue morphogenesis.
Collapse
|
4
|
Blázquez-Prieto J, Huidobro C, López-Alonso I, Amado-Rodriguez L, Martín-Vicente P, López-Martínez C, Crespo I, Pantoja C, Fernandez-Marcos PJ, Serrano M, Sznajder JI, Albaiceta GM. Activation of p21 limits acute lung injury and induces early senescence after acid aspiration and mechanical ventilation. Transl Res 2021; 233:104-116. [PMID: 33515780 PMCID: PMC7838583 DOI: 10.1016/j.trsl.2021.01.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/13/2020] [Accepted: 01/21/2021] [Indexed: 12/27/2022]
Abstract
The p53/p21 pathway is activated in response to cell stress. However, its role in acute lung injury has not been elucidated. Acute lung injury is associated with disruption of the alveolo-capillary barrier leading to acute respiratory distress syndrome (ARDS). Mechanical ventilation may be necessary to support gas exchange in patients with ARDS, however, high positive airway pressures can cause regional overdistension of alveolar units and aggravate lung injury. Here, we report that acute lung injury and alveolar overstretching activate the p53/p21 pathway to maintain homeostasis and avoid massive cell apoptosis. A systematic pooling of transcriptomic data from animal models of lung injury demonstrates the enrichment of specific p53- and p21-dependent gene signatures and a validated senescence profile. In a clinically relevant, murine model of acid aspiration and mechanical ventilation, we observed changes in the nuclear envelope and the underlying chromatin, DNA damage and activation of the Tp53/p21 pathway. Absence of Cdkn1a decreased the senescent response, but worsened lung injury due to increased cell apoptosis. Conversely, treatment with lopinavir and/or ritonavir led to Cdkn1a overexpression and ameliorated cell apoptosis and lung injury. The activation of these mechanisms was associated with early markers of senescence, including expression of senescence-related genes and increases in senescence-associated heterochromatin foci in alveolar cells. Autopsy samples from lungs of patients with ARDS revealed increased senescence-associated heterochromatin foci. Collectively, these results suggest that acute lung injury activates p53/p21 as an antiapoptotic mechanism to ameliorate damage, but with the side effect of induction of senescence.
Collapse
Affiliation(s)
| | - Covadonga Huidobro
- Instituto de Investigación Sanitaria del Principado de Asturias. Oviedo, Spain; Centro de Investigación Biomédica en Red (CIBER)-Enfermedades Respiratorias. Madrid, Spain
| | - Inés López-Alonso
- Instituto de Investigación Sanitaria del Principado de Asturias. Oviedo, Spain; Centro de Investigación Biomédica en Red (CIBER)-Enfermedades Respiratorias. Madrid, Spain; Instituto Universitario de Oncología del Principado de Asturias. Oviedo, Spain
| | - Laura Amado-Rodriguez
- Instituto de Investigación Sanitaria del Principado de Asturias. Oviedo, Spain; Centro de Investigación Biomédica en Red (CIBER)-Enfermedades Respiratorias. Madrid, Spain; Instituto Universitario de Oncología del Principado de Asturias. Oviedo, Spain; Unidad de Cuidados Intensivos Cardiológicos. Hospital Universitario Central de Asturias. Oviedo, Spain
| | - Paula Martín-Vicente
- Instituto de Investigación Sanitaria del Principado de Asturias. Oviedo, Spain; Centro de Investigación Biomédica en Red (CIBER)-Enfermedades Respiratorias. Madrid, Spain; Instituto Universitario de Oncología del Principado de Asturias. Oviedo, Spain
| | - Cecilia López-Martínez
- Instituto de Investigación Sanitaria del Principado de Asturias. Oviedo, Spain; Centro de Investigación Biomédica en Red (CIBER)-Enfermedades Respiratorias. Madrid, Spain; Instituto Universitario de Oncología del Principado de Asturias. Oviedo, Spain
| | - Irene Crespo
- Departamento de Biología Funcional. Universidad de Oviedo. Oviedo, Spain
| | - Cristina Pantoja
- Metabolic Syndrome Group - BIOPROMET, Madrid Institute for Advanced Studies - IMDEA Food, CEI UAM+CSIC. Madrid, Spain
| | - Pablo J Fernandez-Marcos
- Metabolic Syndrome Group - BIOPROMET, Madrid Institute for Advanced Studies - IMDEA Food, CEI UAM+CSIC. Madrid, Spain
| | - Manuel Serrano
- Institute for Research in Biomedicine (IRB Barcelona); Barcelona Institute of Science and Technology (BIST); Catalan Institution for Research and Advanced Studies (ICREA); Barcelona, Spain
| | - Jacob I Sznajder
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Guillermo M Albaiceta
- Instituto de Investigación Sanitaria del Principado de Asturias. Oviedo, Spain; Centro de Investigación Biomédica en Red (CIBER)-Enfermedades Respiratorias. Madrid, Spain; Instituto Universitario de Oncología del Principado de Asturias. Oviedo, Spain; Unidad de Cuidados Intensivos Cardiológicos. Hospital Universitario Central de Asturias. Oviedo, Spain; Departamento de Biología Funcional. Universidad de Oviedo. Oviedo, Spain.
| |
Collapse
|
5
|
Baltanás FC, Zarich N, Rojas-Cabañeros JM, Santos E. SOS GEFs in health and disease. Biochim Biophys Acta Rev Cancer 2020; 1874:188445. [PMID: 33035641 DOI: 10.1016/j.bbcan.2020.188445] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 10/01/2020] [Accepted: 10/01/2020] [Indexed: 12/11/2022]
Abstract
SOS1 and SOS2 are the most universal and widely expressed family of guanine exchange factors (GEFs) capable or activating RAS or RAC1 proteins in metazoan cells. SOS proteins contain a sequence of modular domains that are responsible for different intramolecular and intermolecular interactions modulating mechanisms of self-inhibition, allosteric activation and intracellular homeostasis. Despite their homology, analyses of SOS1/2-KO mice demonstrate functional prevalence of SOS1 over SOS2 in cellular processes including proliferation, migration, inflammation or maintenance of intracellular redox homeostasis, although some functional redundancy cannot be excluded, particularly at the organismal level. Specific SOS1 gain-of-function mutations have been identified in inherited RASopathies and various sporadic human cancers. SOS1 depletion reduces tumorigenesis mediated by RAS or RAC1 in mouse models and is associated with increased intracellular oxidative stress and mitochondrial dysfunction. Since WT RAS is essential for development of RAS-mutant tumors, the SOS GEFs may be considered as relevant biomarkers or therapy targets in RAS-dependent cancers. Inhibitors blocking SOS expression, intrinsic GEF activity, or productive SOS protein-protein interactions with cellular regulators and/or RAS/RAC targets have been recently developed and shown preclinical and clinical effectiveness blocking aberrant RAS signaling in RAS-driven and RTK-driven tumors.
Collapse
Affiliation(s)
- Fernando C Baltanás
- Centro de Investigación del Cáncer - IBMCC (CSIC-USAL) and CIBERONC, Universidad de Salamanca, 37007 Salamanca, Spain
| | - Natasha Zarich
- Unidad Funcional de Investigación de Enfermedades Crónicas (UFIEC) and CIBERONC, Instituto de Salud Carlos III, 28220, Majadahonda, Madrid, Spain
| | - Jose M Rojas-Cabañeros
- Unidad Funcional de Investigación de Enfermedades Crónicas (UFIEC) and CIBERONC, Instituto de Salud Carlos III, 28220, Majadahonda, Madrid, Spain
| | - Eugenio Santos
- Centro de Investigación del Cáncer - IBMCC (CSIC-USAL) and CIBERONC, Universidad de Salamanca, 37007 Salamanca, Spain.
| |
Collapse
|
6
|
Kim D, Kwon S. Vibrational stress affects extracellular signal-regulated kinases activation and cytoskeleton structure in human keratinocytes. PLoS One 2020; 15:e0231174. [PMID: 32267880 PMCID: PMC7141684 DOI: 10.1371/journal.pone.0231174] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 03/17/2020] [Indexed: 01/22/2023] Open
Abstract
As the outermost organ, the skin can be damaged following injuries such as wounds and bacterial or viral infections, and such damage should be rapidly restored to defend the body against physical, chemical, and microbial assaults. However, the wound healing process can be delayed or prolonged by health conditions, including diabetes mellitus, venous stasis disease, ischemia, and even stress. In this study, we developed a vibrational cell culture model and investigated the effects of mechanical vibrations on human keratinocytes. The HaCaT cells were exposed to vibrations at a frequency of 45 Hz with accelerations of 0.8g for 2 h per day. The applied mechanical vibration did not affect cell viability or cell proliferation. Cell migratory activity did increase following exposure to vibration, but the change was not statistically significant. The results of immunostaining (F-actin), western blot (ERK1/2), and RT-qPCR (FGF-2, PDGF-B, HB-EGF, TGF-β1, EGFR, and KGFR) analyses demonstrated that the applied vibration resulted in rearrangement of the cytoskeleton, leading to activation of ERK1/2, one of the MAPK signaling pathways, and upregulation of the gene expression levels of HB-EGF and EGFR. The results suggest that mechanical vibration may have wound healing potential and could be used as a mechanical energy-based treatment for enhancing wound healing efficiency.
Collapse
Affiliation(s)
- Dongjoo Kim
- Department of Biological Engineering, Inha University, Incheon, Korea
- Biology and Medical Device Evaluation Team, Korea Testing & Research Institute, Gwacheon, Korea
| | - Soonjo Kwon
- Department of Biological Engineering, Inha University, Incheon, Korea
- * E-mail:
| |
Collapse
|
7
|
Meza D, Musmacker B, Steadman E, Stransky T, Rubenstein DA, Yin W. Endothelial Cell Biomechanical Responses are Dependent on Both Fluid Shear Stress and Tensile Strain. Cell Mol Bioeng 2019; 12:311-325. [PMID: 31719917 DOI: 10.1007/s12195-019-00585-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 06/28/2019] [Indexed: 12/15/2022] Open
Abstract
Introduction The goal of this study was to investigate how concurrent shear stress and tensile strain affect endothelial cell biomechanical responses. Methods Human coronary artery endothelial cells were exposed to concurrent pulsatile shear stress and cyclic tensile strain in a programmable shearing and stretching device. Three shear stress-tensile strain conditions were used: (1) pulsatile shear stress at 1 Pa and cyclic tensile strain at 7%, simulating normal stress/strain conditions in a healthy coronary artery; (2) shear stress at 3.7 Pa and tensile strain at 3%, simulating pathological stress/strain conditions near a stenosis; (3) shear stress at 0.7 Pa and tensile strain at 5%, simulating pathological stress/strain conditions in a recirculation zone. Cell morphology was quantified using immunofluorescence microscopy. Cell surface PECAM-1 phosphorylation, ICAM-1 expression, ERK1/2 and NF-κB activation were measured using ELISA or Western blot. Results Simultaneous stimulation from pulsatile shear stress and cyclic tensile strain induced a significant increase in cell area, compared to that induced by shear stress or tensile strain alone. The combined stimulation caused significant increases in PECAM-1 phosphorylation. The combined stimulation also significantly enhanced EC surface ICAM-1 expression (compared to that under shear stress alone) and transcriptional factor NF-κB activation (compared to that under control conditions). Conclusion Pulsatile shear stress and cyclic tensile strain could induce increased but not synergistic effect on endothelial cell morphology or activation. The combined mechanical stimulation can be relayed from cell membrane to nucleus. Therefore, to better understand how mechanical conditions affect endothelial cell mechanotransduction and cardiovascular disease development, both shear stress and tensile strain need to be considered.
Collapse
Affiliation(s)
- Daphne Meza
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - Bryan Musmacker
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - Elisabeth Steadman
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - Thomas Stransky
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - David A Rubenstein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - Wei Yin
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
- Stony Brook University, Bioengineering Building, Room 109, Stony Brook, NY 11794 USA
| |
Collapse
|
8
|
Aschner Y, Downey GP. The Importance of Tyrosine Phosphorylation Control of Cellular Signaling Pathways in Respiratory Disease: pY and pY Not. Am J Respir Cell Mol Biol 2019; 59:535-547. [PMID: 29812954 DOI: 10.1165/rcmb.2018-0049tr] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Reversible phosphorylation of proteins on tyrosine residues is an essential signaling mechanism by which diverse cellular processes are closely regulated. The tight temporal and spatial control of the tyrosine phosphorylation status of proteins by protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs) is critical to cellular homeostasis as well as to adaptations to the external environment. Via regulation of cellular signaling cascades involving other protein kinases and phosphatases, receptors, adaptor proteins, and transcription factors, PTKs and PTPs closely control diverse cellular processes such as proliferation, differentiation, migration, inflammation, and maintenance of cellular barrier function. Given these key regulatory roles, it is not surprising that dysfunction of PTKs and PTPs is important in the pathogenesis of human disease, including many pulmonary diseases. The roles of various PTKs and PTPs in acute lung injury and repair, pulmonary fibrosis, pulmonary vascular disease, and inflammatory airway disease are discussed in this review. It is important to note that although there is overlap among many of these proteins in various disease states, the mechanisms by which they influence the pathogenesis of these conditions differ, suggesting wide-ranging roles for these enzymes and their potential as therapeutic targets.
Collapse
Affiliation(s)
- Yael Aschner
- 1 Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, and
| | - Gregory P Downey
- 1 Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, and.,2 Department of Immunology and Microbiology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado; and.,3 Department of Medicine.,4 Department of Pediatrics, and.,5 Department of Biomedical Research, National Jewish Health, Denver, Colorado
| |
Collapse
|
9
|
Dolinay T, Aonbangkhen C, Zacharias W, Cantu E, Pogoriler J, Stablow A, Lawrence GG, Suzuki Y, Chenoweth DM, Morrisey E, Christie JD, Beers MF, Margulies SS. Protein kinase R-like endoplasmatic reticulum kinase is a mediator of stretch in ventilator-induced lung injury. Respir Res 2018; 19:157. [PMID: 30134920 PMCID: PMC6106739 DOI: 10.1186/s12931-018-0856-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 08/06/2018] [Indexed: 12/22/2022] Open
Abstract
Background Acute respiratory distress syndrome (ARDS) is a severe form of lung injury characterized by damage to the epithelial barrier with subsequent pulmonary edema and hypoxic respiratory failure. ARDS is a significant medical problem in intensive care units with associated high care costs. There are many potential causes of ARDS; however, alveolar injury associated with mechanical ventilation, termed ventilator-induced lung injury (VILI), remains a well-recognized contributor. It is thus critical to understand the mechanism of VILI. Based on our published preliminary data, we hypothesized that the endoplasmic reticulum (ER) stress response molecule Protein Kinase R-like Endoplasmic Reticulum Kinase (PERK) plays a role in transmitting mechanosensory signals the alveolar epithelium. Methods ER stress signal responses to mechanical stretch were studied in ex-vivo ventilated pig lungs. To explore the effect of PERK inhibition on VILI, we ventilated live rats and compared lung injury parameters to non-ventilated controls. The effect of stretch-induced epithelial ER Ca2+ signaling on PERK was studied in stretched alveolar epithelial monolayers. To confirm the activation of PERK in human disease, ER stress signaling was compared between ARDS and non-ARDS lungs. Results Our studies revealed increased PERK-specific ER stress signaling in response to overstretch. PERK inhibition resulted in dose-dependent improvement of alveolar inflammation and permeability. Our data indicate that stretch-induced epithelial ER Ca2+ release is an activator of PERK. Experiments with human lung tissue confirmed PERK activation by ARDS. Conclusion Our study provides evidences that PERK is a mediator stretch signals in the alveolar epithelium.
Collapse
Affiliation(s)
- Tamás Dolinay
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA.,Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of California Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA
| | - Chanat Aonbangkhen
- Department of Chemistry University of Pennsylvania, 231 S 34th St, Philadelphia, PA, 19104, USA
| | - William Zacharias
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA
| | - Edward Cantu
- Department of Surgery, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA
| | - Jennifer Pogoriler
- Department of Pathology, Children's Hospital of Philadelphia, 3400 S 34th St, Philadelphia, PA, 19104, USA
| | - Alec Stablow
- Department of Bioengineering, University of Pennsylvania, 210 South 33rd St, Suite 240 Skirkanich Hall Philadelphia, Philadelphia, PA, 19104, USA
| | - Gladys G Lawrence
- Department of Bioengineering, University of Pennsylvania, 210 South 33rd St, Suite 240 Skirkanich Hall Philadelphia, Philadelphia, PA, 19104, USA
| | - Yoshikazu Suzuki
- Department of Surgery, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA
| | - David M Chenoweth
- Department of Chemistry University of Pennsylvania, 231 S 34th St, Philadelphia, PA, 19104, USA
| | - Edward Morrisey
- Department of Medicine, Division of Cardiovascular Medicine, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA
| | - Jason D Christie
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA
| | - Michael F Beers
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA
| | - Susan S Margulies
- Department of Bioengineering, University of Pennsylvania, 210 South 33rd St, Suite 240 Skirkanich Hall Philadelphia, Philadelphia, PA, 19104, USA. .,Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University, University School of Medicine, U.A. Whitaker Building, 313 Ferst Drive, Suite 2116, Atlanta, GA, 30332-0535, USA.
| |
Collapse
|
10
|
Kothe TB, Royse E, Kemp MW, Usuda H, Saito M, Musk GC, Jobe AH, Hillman NH. Epidermal growth factor receptor inhibition with Gefitinib does not alter lung responses to mechanical ventilation in fetal, preterm lambs. PLoS One 2018; 13:e0200713. [PMID: 30005089 PMCID: PMC6044532 DOI: 10.1371/journal.pone.0200713] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 07/02/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Epidermal growth factor receptor (EGFR) is important for airway branching and lung maturation. Mechanical ventilation of preterm lambs causes increases in EGFR and EGFR ligand mRNA in the lung. Abnormal EGFR signaling may contribute to the development of bronchopulmonary dysplasia. HYPOTHESIS Inhibition of EGFR signaling will decrease airway epithelial cell proliferation and lung inflammation caused by mechanical ventilation in preterm, fetal sheep. METHODS Following exposure of the fetal head and chest at 123±1 day gestational age and with placental circulation intact, fetal lambs (n = 4-6/group) were randomized to either: 1) Gefitinib 15 mg IV and 1 mg intra-tracheal or 2) saline IV and IT. Lambs were further assigned to 15 minutes of either: a) Injurious mechanical ventilation (MV) or b) Continuous positive airway pressure (CPAP) 5 cmH2O. After the 15 minute intervention, the animals were returned to the uterus and delivered after i) 6 or ii) 24 hours in utero. RESULTS MV caused lung injury and inflammation, increased lung mRNA for cytokines and EGFR ligands, caused airway epithelial cell proliferation, and decreased airway epithelial phosphorylated ERK1/2. Responses to MV were unchanged by Gefitinib. Gefitinib altered expression of EGFR mRNA in the lung and liver of both CPAP and MV animals. Gefitinib decreased the liver SAA3 mRNA response to MV at 6 hours. There were no differences in markers of lung injury or inflammation between CPAP animals receiving Gefitinib or saline. CONCLUSION Inhibition of the EGFR pathway did not alter acute lung inflammation or injury from mechanical ventilation in preterm sheep.
Collapse
Affiliation(s)
- T. Brett Kothe
- Division of Neonatology, Cardinal Glennon Children’s Hospital, Saint Louis University, Saint Louis, Missouri, United States of America
| | - Emily Royse
- Division of Neonatology, Cardinal Glennon Children’s Hospital, Saint Louis University, Saint Louis, Missouri, United States of America
| | - Matthew W. Kemp
- School of Women’s and Infants’ Health, University of Western Australia, Perth, Western Australia, Australia
| | - Haruo Usuda
- School of Women’s and Infants’ Health, University of Western Australia, Perth, Western Australia, Australia
| | - Masatoshi Saito
- Centre for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan
| | - Gabrielle C. Musk
- Animal Care Services, University of Western Australia, Perth, Western Australia, Australia
| | - Alan H. Jobe
- School of Women’s and Infants’ Health, University of Western Australia, Perth, Western Australia, Australia
- Division of Pulmonary Biology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Noah H. Hillman
- Division of Neonatology, Cardinal Glennon Children’s Hospital, Saint Louis University, Saint Louis, Missouri, United States of America
| |
Collapse
|
11
|
Lecuona E, Sznajder JI. Stretching to Understand How Proteostasis and the Unfolded Protein Response Regulate Lung Injury. Am J Respir Cell Mol Biol 2018; 57:143-144. [PMID: 28762764 DOI: 10.1165/rcmb.2017-0170ed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Emilia Lecuona
- 1 Pulmonary and Critical Care Medicine Northwestern University Chicago, Illinois
| | - Jacob I Sznajder
- 1 Pulmonary and Critical Care Medicine Northwestern University Chicago, Illinois
| |
Collapse
|
12
|
Liu J, Wang W, Liu F, Li Z. Pediatric acute respiratory distress syndrome - current views. Exp Ther Med 2018; 15:1775-1780. [PMID: 29434764 PMCID: PMC5776650 DOI: 10.3892/etm.2017.5628] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 11/29/2017] [Indexed: 12/18/2022] Open
Abstract
Acute respiratory distress syndrome (ARDS) mainly involves acute respiratory failure. In addition to this affected patients feel progressive arterial hypoxemia, dyspnea, and a marked increase in the work of breathing. The only clinical solution for the above pathological state is ventilation. Mechanical ventilation is necessary to support life in ARDs but it itself worsen lung injury and the term is known clinically as ‘ventilation induced lung injury’ (VILI). At the cellular level, respiratory epithelial cells are subjected to cyclic stretch, i.e. repeated cycles of positive and negative strain, during normal tidal ventilation. In aerated areas of diseased lungs, or even normal lungs subjected to injurious positive pressure mechanical ventilation, the cells are at risk of being over distended, and worsening injury by disrupting the alveolar epithelial barrier. Further, hypercapnic acidosis (HCA) in itself confers protection from stretch injury, potentially via a mechanisms involving inhibition of nuclear factor κB (NF-κB), a transcription factor central to inflammation, injury and repair. Mesenchymal stem cells are the latest in the field and are being investigated as a possible therapy for ARDS.
Collapse
Affiliation(s)
- Jinfeng Liu
- Department of Neonatology, Xuzhou Chlidren's Hospital, Xuzhou, Jiangsu 221002, P.R. China
| | - Wei Wang
- Department of Neonatology, Xuzhou Chlidren's Hospital, Xuzhou, Jiangsu 221002, P.R. China
| | - Fengli Liu
- Department of Neonatology, Xuzhou Chlidren's Hospital, Xuzhou, Jiangsu 221002, P.R. China
| | - Zhenguang Li
- Department of Neonatology, Xuzhou Chlidren's Hospital, Xuzhou, Jiangsu 221002, P.R. China
| |
Collapse
|
13
|
Toumpanakis D, Vassilakopoulou V, Sigala I, Zacharatos P, Vraila I, Karavana V, Theocharis S, Vassilakopoulos T. The role of Src & ERK1/2 kinases in inspiratory resistive breathing induced acute lung injury and inflammation. Respir Res 2017; 18:209. [PMID: 29237457 PMCID: PMC5729404 DOI: 10.1186/s12931-017-0694-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 12/05/2017] [Indexed: 01/08/2023] Open
Abstract
Background Inspiratory resistive breathing (IRB), a hallmark of obstructive airway diseases, is associated with large negative intrathoracic pressures, due to strenuous contractions of the inspiratory muscles. IRB is shown to induce lung injury in previously healthy animals. Src is a multifunctional kinase that is activated in the lung by mechanical stress. ERK1/2 kinase is a downstream target of Src. We hypothesized that Src is activated in the lung during IRB, mediates ERK1/2 activation and IRB-induced lung injury. Methods Anaesthetized, tracheostomized adult rats breathed spontaneously through a 2-way non-rebreathing valve. Resistance was added to the inspiratory port to provide a peak tidal inspiratory pressure of 50% of maximum (inspiratory resistive breathing). Activation of Src and ERK1/2 in the lung was estimated during IRB. Following 6 h of IRB, respiratory system mechanics were measured by the forced oscillation technique and bronchoalveolar lavage (BAL) was performed to measure total and differential cell count and total protein levels. IL-1b and MIP-2a protein levels were measured in lung tissue samples. Wet lung weight to total body weight was measured and Evans blue dye extravasation was estimated to measure lung permeability. Lung injury was evaluated by histology. The Src inhibitor, PP-2 or the inhibitor of ERK1/2 activation, PD98059 was administrated 30 min prior to IRB. Results Src kinase was activated 30 min after the initiation of IRB. Src inhibition ameliorated the increase in BAL cellularity after 6 h IRB, but not the increase of IL-1β and MIP-2a in the lung. The increase in BAL total protein and lung injury score were not affected. The increase in tissue elasticity was partly inhibited. Src inhibition blocked ERK1/2 activation at 3 but not at 6 h of IRB. ERK1/2 inhibition ameliorated the increase in BAL cellularity after 6 h of IRB, blocked the increase of IL-1β and returned Evans blue extravasation and wet lung weight to control values. BAL total protein and the increase in elasticity were partially affected. ERK1/2 inhibition did not significantly change total lung injury score compared to 6 h IRB. Conclusions Src and ERK1/2 are activated in the lung following IRB and participate in IRB-induced lung injury.
Collapse
Affiliation(s)
- Dimitrios Toumpanakis
- 1st Department of Critical Care and Pulmonary Medicine and "Marianthi Simou" Applied Biomedical Research and Training Center, Medical School, University of Athens, 45-47 Ispilandou str, 10676, Athens, Greece
| | - Vyronia Vassilakopoulou
- 1st Department of Critical Care and Pulmonary Medicine and "Marianthi Simou" Applied Biomedical Research and Training Center, Medical School, University of Athens, 45-47 Ispilandou str, 10676, Athens, Greece
| | - Ioanna Sigala
- 1st Department of Critical Care and Pulmonary Medicine and "Marianthi Simou" Applied Biomedical Research and Training Center, Medical School, University of Athens, 45-47 Ispilandou str, 10676, Athens, Greece
| | - Panagiotis Zacharatos
- 1st Department of Critical Care and Pulmonary Medicine and "Marianthi Simou" Applied Biomedical Research and Training Center, Medical School, University of Athens, 45-47 Ispilandou str, 10676, Athens, Greece
| | - Ioanna Vraila
- 1st Department of Critical Care and Pulmonary Medicine and "Marianthi Simou" Applied Biomedical Research and Training Center, Medical School, University of Athens, 45-47 Ispilandou str, 10676, Athens, Greece
| | - Vassiliki Karavana
- 1st Department of Critical Care and Pulmonary Medicine and "Marianthi Simou" Applied Biomedical Research and Training Center, Medical School, University of Athens, 45-47 Ispilandou str, 10676, Athens, Greece
| | | | - Theodoros Vassilakopoulos
- 1st Department of Critical Care and Pulmonary Medicine and "Marianthi Simou" Applied Biomedical Research and Training Center, Medical School, University of Athens, 45-47 Ispilandou str, 10676, Athens, Greece.
| |
Collapse
|
14
|
Rentzsch I, Santos CL, Huhle R, Ferreira JMC, Koch T, Schnabel C, Koch E, Pelosi P, Rocco PRM, Gama de Abreu M. Variable stretch reduces the pro-inflammatory response of alveolar epithelial cells. PLoS One 2017; 12:e0182369. [PMID: 28813446 PMCID: PMC5557541 DOI: 10.1371/journal.pone.0182369] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 07/17/2017] [Indexed: 11/18/2022] Open
Abstract
Mechanical ventilation has the potential to increase inflammation in both healthy and injured lungs. Several animal studies have shown that variable ventilation recruits the lungs and reduces inflammation. However, it is unclear which cellular mechanisms are involved in those findings. We hypothesized that variable stretch of LPS-stimulated alveolar epithelial cells (AECs) reduces the production of pro-inflammatory cytokines compared to non-variable stretch. AECs were subjected to non-variable or variable cyclic stretch (sinusoidal pattern), with and without LPS stimulation. The expression and release of interleukin-6, CXCL-2 and CCL-2 mRNA were analyzed after 4 hours. The phosphorylation of the MAPKs ERK1/2 and SAPK/JNK was determined by Western Blot analysis at 0, 15, 30, 45 and 60 min of cyclic stretch. In LPS-stimulated AECs, variable cyclic cell stretching led to reduced cytokine expression and release compared to non-variable cell stretching. Furthermore, the phosphorylation of the MAPK ERK1/2 was increased after 30 minutes in non-variable stretched AECs, whereas variable stretched cells demonstrated only the non-stretched level of phosphorylation. After the 4h period of cyclic cell stretch and inhibition of the ERK1/2, but not the SAPK/JNK, signaling pathway, the gene expression of investigated cytokines increased in variable stretched, and decreased in non-variable stretched AECs. We conclude that in LPS-stimulated AECs, variable stretch reduced the pro-inflammatory response compared to non-variable stretch. This effect was mediated by the ERK1/2 signaling pathway, and might partly explain the findings of reduced lung inflammation during mechanical ventilation modes that enhance breath-by-breath variability of the respiratory pattern.
Collapse
Affiliation(s)
- Ines Rentzsch
- Department of Anesthesiology and Intensive Care Therapy, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Cíntia L. Santos
- Department of Anesthesiology and Intensive Care Therapy, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Robert Huhle
- Department of Anesthesiology and Intensive Care Therapy, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Jorge M. C. Ferreira
- Department of Anesthesiology and Intensive Care Therapy, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Thea Koch
- Department of Anesthesiology and Intensive Care Therapy, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Christian Schnabel
- Department of Anesthesiology and Intensive Care Therapy, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Edmund Koch
- Department of Anesthesiology and Intensive Care Therapy, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Paolo Pelosi
- Department of Surgical Sciences and Integrated Diagnostics, AOU IRCCS San Martino –IST, University of Genoa, Genoa, Italy
| | - Patricia R. M. Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcelo Gama de Abreu
- Department of Anesthesiology and Intensive Care Therapy, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- * E-mail:
| |
Collapse
|
15
|
Wang T, Gross C, Desai AA, Zemskov E, Wu X, Garcia AN, Jacobson JR, Yuan JXJ, Garcia JGN, Black SM. Endothelial cell signaling and ventilator-induced lung injury: molecular mechanisms, genomic analyses, and therapeutic targets. Am J Physiol Lung Cell Mol Physiol 2016; 312:L452-L476. [PMID: 27979857 DOI: 10.1152/ajplung.00231.2016] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 12/08/2016] [Accepted: 12/11/2016] [Indexed: 12/13/2022] Open
Abstract
Mechanical ventilation is a life-saving intervention in critically ill patients with respiratory failure due to acute respiratory distress syndrome (ARDS). Paradoxically, mechanical ventilation also creates excessive mechanical stress that directly augments lung injury, a syndrome known as ventilator-induced lung injury (VILI). The pathobiology of VILI and ARDS shares many inflammatory features including increases in lung vascular permeability due to loss of endothelial cell barrier integrity resulting in alveolar flooding. While there have been advances in the understanding of certain elements of VILI and ARDS pathobiology, such as defining the importance of lung inflammatory leukocyte infiltration and highly induced cytokine expression, a deep understanding of the initiating and regulatory pathways involved in these inflammatory responses remains poorly understood. Prevailing evidence indicates that loss of endothelial barrier function plays a primary role in the development of VILI and ARDS. Thus this review will focus on the latest knowledge related to 1) the key role of the endothelium in the pathogenesis of VILI; 2) the transcription factors that relay the effects of excessive mechanical stress in the endothelium; 3) the mechanical stress-induced posttranslational modifications that influence key signaling pathways involved in VILI responses in the endothelium; 4) the genetic and epigenetic regulation of key target genes in the endothelium that are involved in VILI responses; and 5) the need for novel therapeutic strategies for VILI that can preserve endothelial barrier function.
Collapse
Affiliation(s)
- Ting Wang
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Christine Gross
- Vascular Biology Center, Augusta University, Augusta, Georgia
| | - Ankit A Desai
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Evgeny Zemskov
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Xiaomin Wu
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Alexander N Garcia
- Department of Pharmacology University of Illinois at Chicago, Chicago, Illinois; and
| | - Jeffrey R Jacobson
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Jason X-J Yuan
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Joe G N Garcia
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Stephen M Black
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona;
| |
Collapse
|
16
|
Abstract
The loss of vision in the human eye disease, glaucoma, is due to degeneration of the axons of the retinal ganglion cells. In glaucoma, reactive astrocytes in the optic nerve head contain inducible nitric oxide synthase, which apparently produces excessive nitric oxide that damages the axons. The astrocytes respond to the elevated intraocular pressure that is characteristic of the disease. An important signal transduction pathway for the induction of nitric oxide synthase in response to pressure is the epidermal growth factor receptor tyrosine kinase. Pharmacological inhibition of the activity or the induction of inducible nitric oxide synthase may provide neuroprotection for the treatment of glaucoma.
Collapse
Affiliation(s)
- Arthur H Neufeld
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
| | | |
Collapse
|
17
|
Periodic mechanical stress activates EGFR-dependent Rac1 mitogenic signals in rat nucleus pulpous cells via ERK1/2. Biochem Biophys Res Commun 2015; 469:723-30. [PMID: 26707876 DOI: 10.1016/j.bbrc.2015.12.056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 12/15/2015] [Indexed: 01/14/2023]
Abstract
The mitogenic effects of periodic mechanical stress on nucleus pulpous cells have been studied extensively but the mechanisms whereby nucleus pulpous cells sense and respond to mechanical stimulation remain a matter of debate. We explored this question by performing cell culture experiments in our self-developed periodic stress field and perfusion culture system. Under periodic mechanical stress, rat nucleus pulpous cell proliferation was significantly increased (p < 0.05 for each) and was associated with increases in the phosphorylation and activation of EGFR, Rac1, and ERK1/2 (p < 0.05 for each). Pretreatment with the ERK1/2 selective inhibitor PD98059 reduced periodic mechanical stress-induced nucleus pulpous cell proliferation (p < 0.05 for each), while the activation levels of EGFR and Rac1 were not inhibited. Proliferation and phosphorylation of ERK1/2 were inhibited after pretreatment with the Rac1 inhibitor NSC23766 in nucleus pulpous cells in response to periodic mechanical stress (p < 0.05 for each), while the phosphorylation site of EGFR was not affected. Inhibition of EGFR activity with AG1478 abrogated nucleus pulpous cell proliferation (p < 0.05 for each) and attenuated Rac1 and ERK1/2 activation in nucleus pulpous cells subjected to periodic mechanical stress (p < 0.05 for each). These findings suggest that periodic mechanical stress promotes nucleus pulpous cell proliferation in part through the EGFR-Rac1-ERK1/2 signaling pathway, which links these three important signaling molecules into a mitogenic cascade.
Collapse
|
18
|
Nagre N, Wang S, Kellett T, Kanagasabai R, Deng J, Nishi M, Shilo K, Oeckler RA, Yalowich JC, Takeshima H, Christman J, Hubmayr RD, Zhao X. TRIM72 modulates caveolar endocytosis in repair of lung cells. Am J Physiol Lung Cell Mol Physiol 2015; 310:L452-64. [PMID: 26637632 DOI: 10.1152/ajplung.00089.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 12/01/2015] [Indexed: 01/11/2023] Open
Abstract
Alveolar epithelial and endothelial cell injury is a major feature of the acute respiratory distress syndrome, in particular when in conjunction with ventilation therapies. Previously we showed [Kim SC, Kellett T, Wang S, Nishi M, Nagre N, Zhou B, Flodby P, Shilo K, Ghadiali SN, Takeshima H, Hubmayr RD, Zhao X. Am J Physiol Lung Cell Mol Physiol 307: L449-L459, 2014.] that tripartite motif protein 72 (TRIM72) is essential for amending alveolar epithelial cell injury. Here, we posit that TRIM72 improves cellular integrity through its interaction with caveolin 1 (Cav1). Our data show that, in primary type I alveolar epithelial cells, lack of TRIM72 led to significant reduction of Cav1 at the plasma membrane, accompanied by marked attenuation of caveolar endocytosis. Meanwhile, lentivirus-mediated overexpression of TRIM72 selectively increases caveolar endocytosis in rat lung epithelial cells, suggesting a functional association between these two. Further coimmunoprecipitation assays show that deletion of either functional domain of TRIM72, i.e., RING, B-box, coiled-coil, or PRY-SPRY, abolishes the physical interaction between TRIM72 and Cav1, suggesting that all theoretical domains of TRIM72 are required to forge a strong interaction between these two molecules. Moreover, in vivo studies showed that injurious ventilation-induced lung cell death was significantly increased in knockout (KO) TRIM72(KO) and Cav1(KO) lungs compared with wild-type controls and was particularly pronounced in double KO mutants. Apoptosis was accompanied by accentuation of gross lung injury manifestations in the TRIM72(KO) and Cav1(KO) mice. Our data show that TRIM72 directly and indirectly modulates caveolar endocytosis, an essential process involved in repair of lung epithelial cells through removal of plasma membrane wounds. Given TRIM72's role in endomembrane trafficking and cell repair, we consider this molecule an attractive therapeutic target for patients with injured lungs.
Collapse
Affiliation(s)
- Nagaraja Nagre
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia; Division of Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio
| | - Shaohua Wang
- Thoracic Diseases Research Unit, Mayo Clinic, Rochester, Minnesota
| | - Thomas Kellett
- Division of Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio
| | - Ragu Kanagasabai
- Division of Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio
| | - Jing Deng
- Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, College of Medicine, The Ohio State University, Columbus, Ohio
| | - Miyuki Nishi
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan; and
| | - Konstantin Shilo
- Division of Pulmonary Pathology, Department of Pathology, College of Medicine, The Ohio State University, Columbus, Ohio
| | | | - Jack C Yalowich
- Division of Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio
| | - Hiroshi Takeshima
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan; and
| | - John Christman
- Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, College of Medicine, The Ohio State University, Columbus, Ohio
| | - Rolf D Hubmayr
- Thoracic Diseases Research Unit, Mayo Clinic, Rochester, Minnesota
| | - Xiaoli Zhao
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia; Division of Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio; Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, College of Medicine, The Ohio State University, Columbus, Ohio;
| |
Collapse
|
19
|
Abstract
PURPOSE OF REVIEW Multiple clinical and laboratory studies have been conducted to illustrate the effects of hypercapnia in a range of injuries, and to understand the mechanisms underlying these effects. The aim of this review is to highlight and interpret information obtained from these recent reports and discuss how they may inform the clinical context. RECENT FINDINGS In the last decade, several important articles have addressed key elements of how carbon dioxide interacts in critical illness states. Among them the most important insights relate to how hypercapnia affects critical illness and include the effects and mechanisms of carbon dioxide in pulmonary hypertension, infection, inflammation, diaphragm dysfunction, and cerebral ischemia. In addition, we discuss molecular insights that apply to multiple aspects of critical illness. SUMMARY Experiments involving hypercapnia have covered a wide range of illness models with varying degrees of success. It is becoming evident that deliberate hypercapnia in the clinical setting should seldom be used, except wherever necessitated to avoid ventilator-associated lung injury. A more complete understanding of the molecular mechanisms must be established.
Collapse
|
20
|
Aschner Y, Zemans RL, Yamashita CM, Downey GP. Matrix metalloproteinases and protein tyrosine kinases: potential novel targets in acute lung injury and ARDS. Chest 2014; 146:1081-1091. [PMID: 25287998 DOI: 10.1378/chest.14-0397] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Acute lung injury (ALI) and ARDS fall within a spectrum of pulmonary disease that is characterized by hypoxemia, noncardiogenic pulmonary edema, and dysregulated and excessive inflammation. While mortality rates have improved with the advent of specialized ICUs and lung protective mechanical ventilation strategies, few other therapies have proven effective in the management of ARDS, which remains a significant clinical problem. Further development of biomarkers of disease severity, response to therapy, and prognosis is urgently needed. Several novel pathways have been identified and studied with respect to the pathogenesis of ALI and ARDS that show promise in bridging some of these gaps. This review will focus on the roles of matrix metalloproteinases and protein tyrosine kinases in the pathobiology of ALI in humans, and in animal models and in vitro studies. These molecules can act independently, as well as coordinately, in a feed-forward manner via activation of tyrosine kinase-regulated pathways that are pivotal in the development of ARDS. Specific signaling events involving proteolytic processing by matrix metalloproteinases that contribute to ALI, including cytokine and chemokine activation and release, neutrophil recruitment, transmigration and activation, and disruption of the intact alveolar-capillary barrier, will be explored in the context of these novel molecular pathways.
Collapse
Affiliation(s)
- Yael Aschner
- Division of Pulmonary, Critical Care, and Sleep Medicine, Departments of Medicine and Pediatrics, National Jewish Health, Denver, CO; Division of Pulmonary Sciences and Critical Care Medicine, Departments of Medicine, University of Colorado Denver, Aurora, CO
| | - Rachel L Zemans
- Division of Pulmonary, Critical Care, and Sleep Medicine, Departments of Medicine and Pediatrics, National Jewish Health, Denver, CO; Division of Pulmonary Sciences and Critical Care Medicine, Departments of Medicine, University of Colorado Denver, Aurora, CO
| | - Cory M Yamashita
- Department of Medicine, University of Western Ontario, London, ON, Canada
| | - Gregory P Downey
- Division of Pulmonary, Critical Care, and Sleep Medicine, Departments of Medicine and Pediatrics, National Jewish Health, Denver, CO; Division of Pulmonary Sciences and Critical Care Medicine, Departments of Medicine, University of Colorado Denver, Aurora, CO; Immunology, University of Colorado Denver, Aurora, CO.
| |
Collapse
|
21
|
Otulakowski G, Engelberts D, Gusarova GA, Bhattacharya J, Post M, Kavanagh BP. Hypercapnia attenuates ventilator-induced lung injury via a disintegrin and metalloprotease-17. J Physiol 2014; 592:4507-21. [PMID: 25085885 DOI: 10.1113/jphysiol.2014.277616] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Hypercapnic acidosis, common in mechanically ventilated patients, has been reported to exert both beneficial and harmful effects in models of lung injury. Understanding its effects at the molecular level may provide insight into mechanisms of injury and protection. The aim of this study was to establish the effects of hypercapnic acidosis on mitogen‐activated protein kinase (MAPK) activation, and determine the relevant signalling pathways. p44/42 MAPK activation in a murine model of ventilator‐induced lung injury (VILI) correlated with injury and was reduced in hypercapnia. When cultured rat alveolar epithelial cells were subjected to cyclic stretch, activation of p44/42 MAPK was dependent on epidermal growth factor receptor (EGFR) activity and on shedding of EGFR ligands; exposure to 12% CO2 without additional buffering blocked ligand shedding, as well as EGFR and p44/42 MAPK activation. The EGFR ligands are known substrates of the matrix metalloprotease ADAM17, suggesting stretch activates and hypercapnic acidosis blocks stretch‐mediated activation of ADAM17. This was corroborated in the isolated perfused mouse lung, where elevated CO2 also inhibited stretch‐activated shedding of the ADAM17 substrate TNFR1 from airway epithelial cells. Finally, in vivo confirmation was obtained in a two‐hit murine model of VILI where pharmacological inhibition of ADAM17 reduced both injury and p44/42 MAPK activation. Thus, ADAM17 is an important proximal mediator of VILI; its inhibition is one mechanism of hypercapnic protection and may be a target for clinical therapy.
Collapse
Affiliation(s)
- Gail Otulakowski
- Physiology and Experimental Medicine Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, Canada
| | - Doreen Engelberts
- Physiology and Experimental Medicine Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, Canada
| | - Galina A Gusarova
- Departments of Medicine and Physiology, Columbia University, New York, NY, USA
| | - Jahar Bhattacharya
- Departments of Medicine and Physiology, Columbia University, New York, NY, USA
| | - Martin Post
- Physiology and Experimental Medicine Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, Canada
| | - Brian P Kavanagh
- Physiology and Experimental Medicine Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, Canada Departments of Critical Care Medicine and Anaesthesia, Hospital for Sick Children, University of Toronto, Toronto, Canada
| |
Collapse
|
22
|
Kaniaris E, Vaporidi K, Vergadi E, Theodorakis EE, Kondili E, Lagoudaki E, Tsatsanis C, Georgopoulos D. Genetic and pharmacologic inhibition of Tpl2 kinase is protective in a mouse model of ventilator-induced lung injury. Intensive Care Med Exp 2014; 2:15. [PMID: 26266915 PMCID: PMC4513004 DOI: 10.1186/2197-425x-2-15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 03/26/2014] [Indexed: 12/17/2022] Open
Abstract
Background Mechanical stress induced by injurious ventilation leads to pro-inflammatory cytokine production and lung injury. The extracellular-signal-regulated-kinase, ERK1/2, participates in the signaling pathways activated upon mechanical stress in the lungs to promote the inflammatory response. Tumor progression locus 2 (Tpl2) is a MAP3kinase that activates ERK1/2 upon cytokine or TLR signaling, to induce pro-inflammatory cytokine production. The role of Tpl2 in lung inflammation, and specifically in the one caused by mechanical stress has not been investigated. The aim of the study was to examine if genetic or pharmacologic inhibition of Tpl2 could ameliorate ventilator-induced lung injury. Methods Adult male wild-type and Tpl2-deficient mice were ventilated with normal or high tidal volume for 4 h. Additional wild-type mice were treated with a Tpl2 inhibitor either before or 30 min after initiation of high tidal ventilation. Non-ventilated mice of both genotypes served as controls. The development of lung injury was evaluated by measuring lung mechanics, arterial blood gases, concentrations of proteins, IL-6, and MIP-2 in bronchoalveolar lavage fluid (BALF) and by lung histology. Data were compared by Kruskal-Wallis non-parametric test and significance was defined as p < 0.05. Results Mechanical ventilation with normal tidal volume induced a mild increase of IL-6 in BALF in both strains. High tidal volume ventilation induced lung injury in wild-type mice, characterized by decreased lung compliance, increased concentrations of proteins, IL-6 and MIP-2 in BALF, and inflammatory cell infiltration on histology. All indices of lung injury were ameliorated in Tpl2-deficient mice. Wild-type mice treated with the Tpl2 inhibitor, either prior of after the initiation of high tidal volume ventilation were protected from the development of lung injury, as indicated by preserved lung compliance and lower BALF concentrations of proteins and IL-6, than similarly ventilated, untreated wild-type mice. Conclusions Genetic and pharmacologic inhibition of Tpl2 is protective in a mouse model of ventilator-induced lung injury, ameliorating both high-permeability pulmonary edema and lung inflammation.
Collapse
Affiliation(s)
- Evangelos Kaniaris
- Department of Intensive Care Medicine, Experimental Intensive Care Medicine Laboratory, University of Crete, School of Medicine, Heraklio, Crete, 71003, Greece,
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Nava MM, Raimondi MT, Pietrabissa R. Bio-chemo-mechanical models for nuclear deformation in adherent eukaryotic cells. Biomech Model Mechanobiol 2014; 13:929-43. [DOI: 10.1007/s10237-014-0558-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 01/30/2014] [Indexed: 12/12/2022]
|
24
|
Abstract
Mechanical ventilation (MV) is, by definition, the application of external forces to the lungs. Depending on their magnitude, these forces can cause a continuum of pathophysiological alterations ranging from the stimulation of inflammation to the disruption of cell-cell contacts and cell membranes. These side effects of MV are particularly relevant for patients with inhomogeneously injured lungs such as in acute lung injury (ALI). These patients require supraphysiological ventilation pressures to guarantee even the most modest gas exchange. In this situation, ventilation causes additional strain by overdistension of the yet non-injured region, and additional stress that forms because of the interdependence between intact and atelectatic areas. Cells are equipped with elaborate mechanotransduction machineries that respond to strain and stress by the activation of inflammation and repair mechanisms. Inflammation is the fundamental response of the host to external assaults, be they of mechanical or of microbial origin and can, if excessive, injure the parenchymal tissue leading to ALI. Here, we will discuss the forces generated by MV and how they may injure the lungs mechanically and through inflammation. We will give an overview of the mechanotransduction and how it leads to inflammation and review studies demonstrating that ventilator-induced lung injury can be prevented by blocking pathways of mechanotransduction or inflammation.
Collapse
Affiliation(s)
- Ulrike Uhlig
- Department of Pharmacology & Toxicology, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | | |
Collapse
|
25
|
|
26
|
Jacques P, Lambrecht S, Verheugen E, Pauwels E, Kollias G, Armaka M, Verhoye M, Van der Linden A, Achten R, Lories RJ, Elewaut D. Proof of concept: enthesitis and new bone formation in spondyloarthritis are driven by mechanical strain and stromal cells. Ann Rheum Dis 2013; 73:437-45. [PMID: 23921997 DOI: 10.1136/annrheumdis-2013-203643] [Citation(s) in RCA: 283] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVES Spondyloarthritides (SpA) are characterised by both peripheral and axial arthritis. The hallmarks of peripheral SpA are the development of enthesitis, most typically of the Achilles tendon and plantar fascia, and new bone formation. This study was undertaken to unravel the mechanisms leading towards enthesitis and new bone formation in preclinical models of SpA. RESULTS First, we demonstrated that TNF(ΔARE) mice show typical inflammatory features highly reminiscent of SpA. The first signs of inflammation were found at the entheses. Importantly, enthesitis occurred equally in the presence or absence of mature T and B cells, underscoring the importance of stromal cells. Hind limb unloading in TNF(ΔARE) mice significantly suppressed inflammation of the Achilles tendon compared with weight bearing controls. Erk1/2 signalling plays a crucial role in mechanotransduction-associated inflammation. Furthermore, new bone formation is strongly promoted at entheseal sites by biomechanical stress and correlates with the degree of inflammation. CONCLUSIONS These findings provide a formal proof of the concept that mechanical strain drives both entheseal inflammation and new bone formation in SpA.
Collapse
Affiliation(s)
- Peggy Jacques
- Laboratory for Molecular Immunology and Inflammation, Department of Rheumatology, University Hospital, , Ghent, Belgium
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Mechanisms of acute respiratory distress syndrome in children and adults: a review and suggestions for future research. Pediatr Crit Care Med 2013; 14:631-43. [PMID: 23823199 DOI: 10.1097/pcc.0b013e318291753f] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVES To provide a current overview of the epidemiology and pathophysiology of acute respiratory distress syndrome in adults and children, and to identify research questions that will address the differences between adults and children with acute respiratory distress syndrome. DATA SOURCES Narrative literature review and author-generated data. DATA SELECTION The epidemiology of acute respiratory distress syndrome in adults and children, lung morphogenesis, and postnatal lung growth and development are reviewed. The pathophysiology of acute respiratory distress syndrome is divided into eight categories: alveolar fluid transport, surfactant, innate immunity, apoptosis, coagulation, direct alveolar epithelial injury by bacterial products, ventilator-associated lung injury, and repair. DATA EXTRACTION AND SYNTHESIS Epidemiologic data suggest significant differences in the prevalence and mortality of acute respiratory distress syndrome between children and adults. Postnatal lung development continues through attainment of adult height, and there is overlap between the regulation of postnatal lung development and inflammatory, apoptotic, alveolar fluid clearance, and repair mechanisms. Therefore, there is a different biological baseline network of gene and protein expression in children as compared with adults. CONCLUSIONS There are significant obstacles to performing research on children with acute respiratory distress syndrome. However, epidemiologic, clinical, and animal studies suggest age-dependent differences in the pathophysiology of acute respiratory distress syndrome. In order to reduce the prevalence and improve the outcome of patients with acute respiratory distress syndrome, translational studies of inflammatory, apoptotic, alveolar fluid clearance, and repair mechanisms are needed. Understanding the differences in pathophysiologic mechanisms in acute respiratory distress syndrome between children and adults should facilitate identification of novel therapeutic interventions to prevent or modulate lung injury and improve lung repair.
Collapse
|
28
|
Chen G, Chen X, Sukumar A, Gao B, Curley J, Schnaper HW, Ingram AJ, Krepinsky JC. TGFβ receptor I transactivation mediates stretch-induced Pak1 activation and CTGF upregulation in mesangial cells. J Cell Sci 2013; 126:3697-712. [PMID: 23781022 DOI: 10.1242/jcs.126714] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Increased intraglomerular pressure is an important pathogenic determinant of kidney fibrosis in the progression of chronic kidney disease, and can be modeled by exposing glomerular mesangial cells (MC) to mechanical stretch. MC produce extracellular matrix and profibrotic cytokines, including connective tissue growth factor (CTGF) when stretched. We show that p21-activated kinase 1 (Pak1) is activated by stretch in MC in culture and in vivo in a process marked by elevated intraglomerular pressures. Its activation is essential for CTGF upregulation. Rac1 is an upstream regulator of Pak1 activation. Stretch induces transactivation of the type I transforming growth factor β1 receptor (TβRI) independently of ligand binding. TβRI transactivation is required not only for Rac1/Pak1 activation, but also for activation of the canonical TGFβ signaling intermediate Smad3. We show that Smad3 activation is an essential requirement for CTGF upregulation in MC under mechanical stress. Pak1 regulates Smad3 C-terminal phosphorylation and transcriptional activation. However, a second signaling pathway, that of RhoA/Rho-kinase and downstream Erk activation, is also required for stretch-induced CTGF upregulation in MC. Importantly, this is also regulated by Pak1. Thus, Pak1 serves as a novel central mediator in the stretch-induced upregulation of CTGF in MC.
Collapse
Affiliation(s)
- Guang Chen
- Division of Nephrology, St. Joseph's Hospital, McMaster University, Hamilton, ON L8N 4A6, Canada
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Ji HL, Zhao RZ, Chen ZX, Shetty S, Idell S, Matalon S. δ ENaC: a novel divergent amiloride-inhibitable sodium channel. Am J Physiol Lung Cell Mol Physiol 2012; 303:L1013-26. [PMID: 22983350 DOI: 10.1152/ajplung.00206.2012] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The fourth subunit of the epithelial sodium channel, termed delta subunit (δ ENaC), was cloned in human and monkey. Increasing evidence shows that this unique subunit and its splice variants exhibit biophysical and pharmacological properties that are divergent from those of α ENaC channels. The widespread distribution of epithelial sodium channels in both epithelial and nonepithelial tissues implies a range of physiological functions. The altered expression of SCNN1D is associated with numerous pathological conditions. Genetic studies link SCNN1D deficiency with rare genetic diseases with developmental and functional disorders in the brain, heart, and respiratory systems. Here, we review the progress of research on δ ENaC in genomics, biophysics, proteomics, physiology, pharmacology, and clinical medicine.
Collapse
Affiliation(s)
- Hong-Long Ji
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas, USA.
| | | | | | | | | | | |
Collapse
|
30
|
CHOLEWA JASONMICHAEL, PAOLONE VINCENTJ. Influence of Exercise on Airway Epithelia in Cystic Fibrosis. Med Sci Sports Exerc 2012; 44:1219-26. [DOI: 10.1249/mss.0b013e31824bd436] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
31
|
Cohen TS, DiPaolo BC, Gray Lawrence G, Margulies SS. Sepsis enhances epithelial permeability with stretch in an actin dependent manner. PLoS One 2012; 7:e38748. [PMID: 22723883 PMCID: PMC3378620 DOI: 10.1371/journal.pone.0038748] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 05/11/2012] [Indexed: 01/11/2023] Open
Abstract
Ventilation of septic patients often leads to the development of edema and impaired gas exchange. We hypothesized that septic alveolar epithelial monolayers would experience stretch-induced barrier dysfunction at a lower magnitude of stretch than healthy alveolar epithelial monolayers. Alveolar epithelial cells were isolated from rats 24 hours after cecal ligation and double puncture (2CLP) or sham surgery. Following a 5-day culture period, monolayers were cyclically stretched for 0, 10, or 60 minutes to a magnitude of 12% or 25% change in surface area (ΔSA). Barrier function, MAPk and myosin light chain (MLC) phosphorylation, tight junction (TJ) protein expression and actin cytoskeletal organization were examined after stretch. Significant increases in epithelial permeability were observed only in 2CLP monolayers at the 12% ΔSA stretch level, and in both 2CLP and sham monolayers at the 25% ΔSA stretch level. Increased permeability in 2CLP monolayers was not associated with MAPk signaling or alterations in expression of TJ proteins. 2CLP monolayers had fewer actin stress fibers before stretch, a more robust stretch-induced actin redistribution, and reduced phosphorylated MLCK than sham monolayers. Jasplakinolide stabilization of the actin cytoskeleton in 2CLP monolayers prevented significant increases in permeability following 60 minutes of stretch to 12% ΔSA. We concluded that septic alveolar epithelial monolayers are more susceptible to stretch-induced barrier dysfunction than healthy monolayers due to actin reorganization.
Collapse
Affiliation(s)
- Taylor S. Cohen
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Brian C. DiPaolo
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Gladys Gray Lawrence
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Susan S. Margulies
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
32
|
Finigan JH, Downey GP, Kern JA. Human epidermal growth factor receptor signaling in acute lung injury. Am J Respir Cell Mol Biol 2012. [PMID: 22652197 DOI: 10.1165/rcmb.2012‐0100tr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Acute lung injury (ALI) is a syndrome marked by increased permeability across the pulmonary epithelium resulting in pulmonary edema. Recent evidence suggests that members of the human epidermal growth factor receptor (HER) family are activated in alveolar epithelial cells during ALI and regulate alveolar epithelial barrier function. These tyrosine kinase receptors, which also participate in the pathophysiology of pulmonary epithelial malignancies, regulate cell growth, differentiation, and migration as well as cell-cell adhesion, all processes that influence epithelial injury and repair. In this review we outline mechanisms of epithelial injury and repair in ALI, activation patterns of this receptor family in pulmonary epithelial cells as a consequence injury, how receptor activation alters alveolar permeability, and the possible intracellular signaling pathways involved. Finally, we propose a theoretical model for how HER-mediated modulation of alveolar permeability might affect lung injury and repair. Understanding how these receptors signal has direct therapeutic implications in lung injury and other diseases characterized by altered epithelial barrier function.
Collapse
Affiliation(s)
- James H Finigan
- Department of Medicine, National Jewish Health, 1400 Jackson Street, K736A, Denver, CO 80206, USA.
| | | | | |
Collapse
|
33
|
Finigan JH, Downey GP, Kern JA. Human epidermal growth factor receptor signaling in acute lung injury. Am J Respir Cell Mol Biol 2012; 47:395-404. [PMID: 22652197 DOI: 10.1165/rcmb.2012-0100tr] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Acute lung injury (ALI) is a syndrome marked by increased permeability across the pulmonary epithelium resulting in pulmonary edema. Recent evidence suggests that members of the human epidermal growth factor receptor (HER) family are activated in alveolar epithelial cells during ALI and regulate alveolar epithelial barrier function. These tyrosine kinase receptors, which also participate in the pathophysiology of pulmonary epithelial malignancies, regulate cell growth, differentiation, and migration as well as cell-cell adhesion, all processes that influence epithelial injury and repair. In this review we outline mechanisms of epithelial injury and repair in ALI, activation patterns of this receptor family in pulmonary epithelial cells as a consequence injury, how receptor activation alters alveolar permeability, and the possible intracellular signaling pathways involved. Finally, we propose a theoretical model for how HER-mediated modulation of alveolar permeability might affect lung injury and repair. Understanding how these receptors signal has direct therapeutic implications in lung injury and other diseases characterized by altered epithelial barrier function.
Collapse
Affiliation(s)
- James H Finigan
- Department of Medicine, National Jewish Health, 1400 Jackson Street, K736A, Denver, CO 80206, USA.
| | | | | |
Collapse
|
34
|
Martins RP, Finan JD, Guilak F, Lee DA. Mechanical regulation of nuclear structure and function. Annu Rev Biomed Eng 2012; 14:431-55. [PMID: 22655599 DOI: 10.1146/annurev-bioeng-071910-124638] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Mechanical loading induces both nuclear distortion and alterations in gene expression in a variety of cell types. Mechanotransduction is the process by which extracellular mechanical forces can activate a number of well-studied cytoplasmic signaling cascades. Inevitably, such signals are transduced to the nucleus and induce transcription factor-mediated changes in gene expression. However, gene expression also can be regulated through alterations in nuclear architecture, providing direct control of genome function. One putative transduction mechanism for this phenomenon involves alterations in nuclear architecture that result from the mechanical perturbation of the cell. This perturbation is associated with direct mechanical strain or osmotic stress, which is transferred to the nucleus. This review describes the current state of knowledge relating the nuclear architecture and the transfer of mechanical forces to the nucleus mediated by the cytoskeleton, the nucleoskeleton, and the LINC (linker of the nucleoskeleton and cytoskeleton) complex. Moreover, remodeling of the nucleus induces alterations in nuclear stiffness, which may be associated with cell differentiation. These phenomena are discussed in relation to the potential influence of nuclear architecture-mediated mechanoregulation of transcription and cell fate.
Collapse
Affiliation(s)
- Rui P Martins
- Institute of Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, United Kingdom
| | | | | | | |
Collapse
|
35
|
Yehya N, Yerrapureddy A, Tobias J, Margulies SS. MicroRNA modulate alveolar epithelial response to cyclic stretch. BMC Genomics 2012; 13:154. [PMID: 22537220 PMCID: PMC3425319 DOI: 10.1186/1471-2164-13-154] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2011] [Accepted: 04/26/2012] [Indexed: 12/14/2022] Open
Abstract
Background MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression implicated in multiple cellular processes. Cyclic stretch of alveoli is characteristic of mechanical ventilation, and is postulated to be partly responsible for the lung injury and inflammation in ventilator-induced lung injury. We propose that miRNAs may regulate some of the stretch response, and therefore hypothesized that miRNAs would be differentially expressed between cyclically stretched and unstretched rat alveolar epithelial cells (RAECs). Results RAECs were isolated and cultured to express type I epithelial characteristics. They were then equibiaxially stretched to 25% change in surface area at 15 cycles/minute for 1 hour or 6 hours, or served as unstretched controls, and miRNAs were extracted. Expression profiling of the miRNAs with at least 1.5-fold change over controls revealed 42 miRNAs were regulated (34 up and 8 down) with stretch. We validated 6 of the miRNAs using real-time PCR. Using a parallel mRNA array under identical conditions and publicly available databases, target genes for these 42 differentially regulated miRNAs were identified. Many of these genes had significant up- or down-regulation under the same stretch conditions. There were 362 down-regulated genes associated with up-regulated miRNAs, and 101 up-regulated genes associated with down-regulated miRNAs. Specific inhibition of two selected miRNAs demonstrated a reduction of the increased epithelial permeability seen with cyclic stretch. Conclusions We conclude that miRNA expression is differentially expressed between cyclically stretched and unstretched alveolar epithelial cells, and may offer opportunities for therapeutic intervention to ameliorate stretch-associated alveolar epithelial cell dysfunction.
Collapse
Affiliation(s)
- Nadir Yehya
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 South 33rd Street, Philadelphia, PA 19104-6321, USA
| | | | | | | |
Collapse
|
36
|
Schmitt S, Hendricks P, Weir J, Somasundaram R, Sittampalam GS, Nirmalanandhan VS. Stretching mechanotransduction from the lung to the lab: approaches and physiological relevance in drug discovery. Assay Drug Dev Technol 2012; 10:137-47. [PMID: 22352900 DOI: 10.1089/adt.2011.418] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recent years have shown a great deal of interest and research into the understanding of the biological and physiological roles of mechanical forces on cellular behavior. Despite these reports, in vitro screening of new molecular entities for lung ailments is still performed in static cell culture models. Failure to incorporate the effects of mechanical forces during early stages of screening could significantly reduce the success rate of drug candidates in the highly expensive clinical phases of the drug discovery pipeline. The objective of this review is to expand our current understanding of lung mechanotransduction and extend its applicability to cellular physiology and new drug screening paradigms. This review covers early in vivo studies and the importance of mechanical forces in normal lung development, use of different types of bioreactors that simulate in vivo movements in a controlled in vitro cell culture environment, and recent research using dynamic cell culture models. The cells in lungs are subjected to constant stretching (mechanical forces) in regular cycles due to involuntary expansion and contraction during respiration. The effects of stretch on normal and abnormal (disease) lung cells under pathological conditions are discussed. The potential benefits of extending dynamic cell culture models (screening in the presence of forces) and the associated challenges are also discussed in this review. Based on this review, the authors advocate the development of dynamic high throughput screening models that could facilitate the rapid translation of in vitro biology to animal models and clinical efficacy. These concepts are translatable to cardiovascular, digestive, and musculoskeletal tissues and in vitro cell systems employed routinely in drug-screening applications.
Collapse
Affiliation(s)
- Sarah Schmitt
- School of Engineering, The University of Kansas, Lawrence, Kansas 66160, USA.
| | | | | | | | | | | |
Collapse
|
37
|
The role of purinergic signaling on deformation induced injury and repair responses of alveolar epithelial cells. PLoS One 2011; 6:e27469. [PMID: 22087324 PMCID: PMC3210789 DOI: 10.1371/journal.pone.0027469] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 10/17/2011] [Indexed: 01/11/2023] Open
Abstract
Cell wounding is an important driver of the innate immune response of ventilator-injured lungs. We had previously shown that the majority of wounded alveolus resident cells repair and survive deformation induced insults. This is important insofar as wounded and repaired cells may contribute to injurious deformation responses commonly referred to as biotrauma. The central hypothesis of this communication states that extracellular adenosine-5′ triphosphate (ATP) promotes the repair of wounded alveolus resident cells by a P2Y2-Receptor dependent mechanism. Using primary type 1 alveolar epithelial rat cell models subjected to micropuncture injury and/or deforming stress we show that 1) stretch causes a dose dependent increase in cell injury and ATP media concentrations; 2) enzymatic depletion of extracellular ATP reduces the probability of stretch induced wound repair; 3) enriching extracellular ATP concentrations facilitates wound repair; 4) purinergic effects on cell repair are mediated by ATP and not by one of its metabolites; and 5) ATP mediated cell salvage depends at least in part on P2Y2-R activation. While rescuing cells from wounding induced death may seem appealing, it is possible that survivors of membrane wounding become governors of a sustained pro-inflammatory state and thereby perpetuate and worsen organ function in the early stages of lung injury syndromes. Means to uncouple P2Y2-R mediated cytoprotection from P2Y2-R mediated inflammation and to test the preclinical efficacy of such an undertaking deserve to be explored.
Collapse
|
38
|
Letsiou E, Kitsiouli E, Nakos G, Lekka ME. Mild stretch activates cPLA2 in alveolar type II epithelial cells independently through the MEK/ERK and PI3K pathways. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1811:370-6. [PMID: 21185392 DOI: 10.1016/j.bbalip.2010.12.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 12/15/2010] [Accepted: 12/16/2010] [Indexed: 10/18/2022]
Abstract
Alveolar epithelial type II cells (AT II) in which lung surfactant synthesis and secretion take place, are subjected to low magnitude stretch during normal breathing. The aim of the study was to explore the effect of mild stretch on phospholipase A(2) (PLA(2)) activation, an enzyme known to be involved in surfactant secretion. In A549 cells (a model of AT II cells), we showed, using a fluorometric assay, that stretch triggers an increase of total PLA(2) activity. Western blot experiments revealed that the cytosolic isoform cPLA(2) is rapidly phosphorylated under stretch, in addition to a modest increase in cPLA(2) mRNA levels. Treatment of A549 cells with selective inhibitors of the MEK/ERK pathway significantly attenuated the stretch-induced cPLA(2) phosphorylation. A strong interaction of cPLA(2) and pERK enzymes was demonstrated by immunoprecipitation. We also found that inhibition of PI3K pathway attenuated cPLA(2) activation after stretch, without affecting pERK levels. Our results suggest that low magnitude stretch can induce cPLA(2) phosphorylation through the MEK/ERK and PI3K-Akt pathways, independently.
Collapse
Affiliation(s)
- Eleftheria Letsiou
- Biochemistry Laboratory, Chemistry Department, University of Ioannina, 45110, Ioannina, Greece
| | | | | | | |
Collapse
|
39
|
Takawira D, Budinger GRS, Hopkinson SB, Jones JCR. A dystroglycan/plectin scaffold mediates mechanical pathway bifurcation in lung epithelial cells. J Biol Chem 2010; 286:6301-10. [PMID: 21149456 DOI: 10.1074/jbc.m110.178988] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In alveolar epithelial cells (AECs), the membrane-anchored proteoglycan dystroglycan (DG) is a mechanoreceptor that transmits mechanical stretch forces to activate independently the ERK1/2 and the adenosine 5'-monophosphate-activated protein kinase (AMPK) signaling cascades in a process called pathway bifurcation. We tested the hypothesis that the cytoskeleton cross-linker plectin, known to bind both DG and AMPK in muscle cells, acts as a scaffold to regulate DG-mediated mechanical stimulation and pathway bifurcation. We demonstrate that plectin and DG form a complex in AECs and that this complex interacts with ERK1/2 and AMPK. Plectin knockdown reduces DG interaction with AMPK but not with ERK1/2. Despite this, mechanoactivation of both signaling pathways is significantly attenuated in AECs deficient in plectin. Thus, DG has the dual role of mechanical receptor and scaffold for ERK1/2, whereas plectin acts as a scaffold for AMPK signaling but is also required for DG-mediated ERK1/2 activation. We conclude that the DG-plectin complex plays a central role in transmitting mechanical stress from the extracellular matrix to the cytoplasm.
Collapse
Affiliation(s)
- Desire Takawira
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | | | | | | |
Collapse
|
40
|
dos Santos CCD, Shan Y, Akram A, Slutsky AS, Haitsma JJ. Neuroimmune regulation of ventilator-induced lung injury. Am J Respir Crit Care Med 2010; 183:471-82. [PMID: 20870758 DOI: 10.1164/rccm.201002-0314oc] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
RATIONALE Ventilator-induced lung injury (VILI) contributes to the mortality in patients with acute lung injury by increasing inflammation. Recent evidence suggests that stimulation of the cholinergic antiinflammatory pathway may be an attractive way to attenuate inflammatory injury. OBJECTIVES To determine the role of vagus nerve signaling in VILI and establish whether stimulation of the vagus reflex can mitigate VILI. METHODS We performed bilateral vagotomy in a mouse model of high-tidal volume-induced lung injury. We performed pharmacological and electrical vagus nerve stimulation in a rat model of VILI following ischemia/reperfusion injury. To determine the contribution of the alpha 7 acetylcholine nicotinic receptor to pulmonary cell injury, we exposed human bronchial epithelial cells to cyclic stretch in the presence of specific agonist or antagonist of the alpha 7 receptor. MEASUREMENTS AND MAIN RESULTS Vagotomy exacerbates lung injury from VILI in mice as demonstrated by increased wet-to-dry ratio, infiltration of neutrophils, and increased IL-6. Vagal stimulation attenuates lung injury in rats after ischemia/reperfusion injury ventilated with high-volume strategies. Treatment of both mice and rats with the vagus mimetic drug semapimod resulted in decreased lung injury. Vagotomy also increased pulmonary apoptosis, whereas vagus stimulation (electrical and pharmacological) attenuated VILI-induced apoptosis. In vitro studies suggest that vagus-dependent effects on inflammation and apoptosis are mediated via the α7 nicotinc acetylcholine receptor-dependent effects on cyclic stretch-dependent signaling pathways c-jun N-terminal kinase and tumor necrosis factor receptor superfamily, member 6. CONCLUSIONS Stimulation of the cholinergic antiinflammatory reflex may represent a promising alternative for the treatment of VILI.
Collapse
Affiliation(s)
- Claudia C dos dos Santos
- Keenan Research Centre of the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada.
| | | | | | | | | |
Collapse
|
41
|
Wang S, Hubmayr RD. Type I alveolar epithelial phenotype in primary culture. Am J Respir Cell Mol Biol 2010; 44:692-9. [PMID: 20616357 DOI: 10.1165/rcmb.2009-0359oc] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Type I alveolar epithelial cells (ATIs) are very large, thin cells, which extend across several air sacs and cover more than 95% of the alveolar surface area. ATIs are the target of many insults, including ventilator-induced lung injury, and are generally considered terminally differentiated cells arising from type II cell (ATII) lineage. ATIs have proven difficult to harvest and maintain in primary culture, which is why much of ATI biology has been inferred from studies on ex vivo, ATII-derived, so-called ATI-like cells. We report on a modified approach to rat ATI harvest and primary culture, which yielded the following observations: (1) rat ATI can be harvested and maintained with a high degree of purity in primary culture; (2) in vitro growth characteristics of primary ATIs differ from those of ATII-derived ATI-like cells; ATIs, but not ex vivo, ATII-derived ATI-like cells, are capable of cell division; (3) ATIs readily repair plasma membrane wounds without the subsequent loss of their ability to divide; (4) ATI monolayers heal scratch wounds primarily by cell spreading and migration. Although the ability of ATIs to divide may be limited to the in vitro environment, we do believe that their role in alveolar wound repair deserves to be revisited, and the molecular control of ATI-ATII plasticity further explored.
Collapse
Affiliation(s)
- Shaohua Wang
- Thoracic Diseases Research Unit, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | | |
Collapse
|
42
|
Ngiam N, Peltekova V, Engelberts D, Otulakowski G, Post M, Kavanagh BP. Early growth response-1 worsens ventilator-induced lung injury by up-regulating prostanoid synthesis. Am J Respir Crit Care Med 2010; 181:947-56. [PMID: 20110555 DOI: 10.1164/rccm.200908-1297oc] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Ventilator-induced lung injury (VILI) is common and serious and may be mediated in part by prostanoids. We have demonstrated increased expression of the early growth response-1 (Egr1) gene by injurious ventilation, but whether-or how-such up-regulation contributes to injury is unknown. OBJECTIVES We sought to define the role of Egr1 in the pathogenesis of VILI. METHODS An in vivo murine model of VILI was used, and Egr1(+/+) (wild-type) and Egr1(-/-) mice were studied; the effects of prostaglandin E receptor subtype 1 (EP1) inhibition were assessed. MEASUREMENTS AND MAIN RESULTS Injurious ventilation caused lung injury in wild-type mice, but less so in Egr1(-/-) mice. The injury was associated with expression of EGR1 protein, which was localized to type II cells and macrophages and was concentrated in nuclear extracts. There was a concomitant increase in expression of phosphorylated p44/p42 mitogen-activated protein kinases. The prostaglandin E synthase (mPGES-1) gene has multiple EGR1 binding sites on its promoter, and induction of mPGES-1 mRNA (as well as the prostanoid product, PGE2) by injurious ventilation was highly dependent on the presence of the Egr1 gene. PGE2 mediates many lung effects via EP1 receptors, and EP1 blockade (with ONO-8713) lessened lung injury. CONCLUSIONS This is the first demonstration of a mechanism whereby expression of a novel gene (Egr1) can contribute to VILI via a prostanoid-mediated pathway.
Collapse
Affiliation(s)
- Nicola Ngiam
- Physiology and Experimental Medicine, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8
| | | | | | | | | | | |
Collapse
|
43
|
Mechanical stretch-induced RhoA activation is mediated by the RhoGEF Vav2 in mesangial cells. Cell Signal 2009; 22:34-40. [PMID: 19755152 DOI: 10.1016/j.cellsig.2009.09.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 09/03/2009] [Accepted: 09/04/2009] [Indexed: 11/20/2022]
Abstract
Increased intraglomerular pressure is an important hemodynamic determinant of glomerulosclerosis, and can be modelled in vitro by exposing mesangial cells (MC) to cyclic mechanical stretch. We have previously shown that the GTPase RhoA mediates stretch-induced fibronectin production. Here we investigate the role of the RhoGEF Vav2 in the activation of RhoA by stretch. Primary rat MC were exposed to 1 Hz cyclic stretch, previously shown to induce maximal RhoA activation at 1 min. Total Vav2 tyrosine phosphorylation and specific phosphorylation on Y172, required for activation, were increased by 1 min of stretch. Overexpression of dominant-negative Vav2 Y172/159F in COS-1 cells or downregulation of Vav2 by siRNA in MC prevented stretch-induced RhoA activation. Vav2 is known to be activated in response to growth factors, and we have previously shown the epidermal growth factor receptor (EGFR) to be transactivated by stretch in MC. Both Vav2 Y172 phosphorylation and RhoA activation were blocked by the EGFR inhibitor AG1478 and prevented in MC overexpressing kinase inactive EGFR. Stretch led to physical association between the EGFR and Vav2, and this was dependent on EGFR activation. EGFR Y992 phosphorylation, required for growth factor-induced Vav2 phosphorylation, was also induced by stretch. Activation of both Src and PI3K were necessary upstream mediators of stretch-induced Vav2 Y172 phosphorylation and RhoA activation. In summary, stretch-induced RhoA activation is dependent on transactivation of the EGFR and activation of the RhoGEF Vav2. Src and PI3K are both required upstream of Vav2 and RhoA activation.
Collapse
|
44
|
Boudreault F, Tschumperlin DJ. Stretch-induced mitogen-activated protein kinase activation in lung fibroblasts is independent of receptor tyrosine kinases. Am J Respir Cell Mol Biol 2009; 43:64-73. [PMID: 19684308 DOI: 10.1165/rcmb.2009-0092oc] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Lung growth and remodeling are modulated by mechanical stress, with fibroblasts thought to play a leading role. Little mechanistic information is available about how lung fibroblasts respond to mechanical stress. We exposed cultured lung fibroblasts to tonic stretch and measured changes in phosphorylation status of mitogen-activated protein kinases (MAPKs), selected receptor tyrosine kinases (RTKs), and phospholipase Cgamma1 (PLCgamma1) and activation of the small G-protein Ras. Human lung fibroblasts (LFs) were seeded on matrix-coated silicone membranes and exposed to equibiaxial 10 to 40% static stretch or 20% contraction. LFs were stimulated with EGF, FGF2, or PDGF-BB or exposed to stretch in the presence of inhibitors of EGFR (AG1478), FGFR (PD173074), and PDGFR (AG1296). Phospho-MAPK, phospho-RTK, and phospho-PLCgamma1 levels were measured by Western blotting. Active GTP-Ras was quantified by immunoblotting after pull-down with a glutathione S-transferase-Raf-RBD construct. Normalized p-ERK1/2, p-JNK, and p-p38 levels increased after stretch but not contraction. Ligands to RTKs broadly stimulated MAPKs, with the responses to EGF and PDGF most similar to stretch in terms of magnitude and rank order of MAPK responses. Stretching cells failed to elicit measurable activation of EGFR, FGFR (FRS2alpha phosphorylation), or PDGFR. Potent inhibitors of the kinase activity of each receptor failed to attenuate stretch-induced MAPK activation. PLCgamma1 and Ras, prominent effectors downstream of RTKs, were not activated by stretch. Our findings demonstrate that MAPKs are potently activated by stretch in lung fibroblasts, but, in contrast to stress responses observed in other cell types, RTKs are not necessary for stretch-induced MAPK activation in LFs.
Collapse
Affiliation(s)
- Francis Boudreault
- Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
| | | |
Collapse
|
45
|
Ingram KR, Wann AKT, Wingate RM, Coleman PJ, McHale N, Levick JR. Signal pathways regulating hyaluronan secretion into static and cycled synovial joints of rabbits. J Physiol 2009; 587:4361-76. [PMID: 19622607 PMCID: PMC2754372 DOI: 10.1113/jphysiol.2009.175620] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Joint lubrication, synovial fluid conservation and many pathophysiological processes depend on hyaluronan (HA). Intra-articular HA injection and exercise, which stimulates articular HA production, ameliorate osteoarthritis. We therefore investigated the pathways regulating movement-stimulated articular HA secretion rate ( ) in vivo. Endogenous HA was removed from the knee joint cavity of anaesthetised rabbits by washout. Joints were then cycled passively or remained static for 5 h, with/without intra-articular agonist/inhibitor, after which newly secreted HA was harvested for analysis. Movement almost doubled . Similar or larger increases were elicited in static joints by the intra-articular Ca(2+) ionophore ionomycin, prostaglandin E(2), cAMP-raising agents, serine/threonine phosphatase inhibitor and activation of protein kinase C (PKC). PKC-stimulated secretion was inhibited by the PKC inhibitor bisindolylmaleimide I and inhibitors of the downstream kinases MEK-ERK (U0126, PD98059). These agents inhibited movement-stimulated secretion of HA (MSHA) only when the parallel p38 kinase path was simultaneously inhibited by SB203580 (ineffective alone). The phospholipase C inhibitor U73122 almost fully blocked MSHA (P = 0.001, n = 10), without affecting static . The ENaC channel blocker amiloride inhibited MSHA, whereas other inhibitors of stretch-activated channels (Gd(3+), ruthenium red, SKF96365) did not. It is proposed that MSHA may be mediated by PLC activation, leading to activation of parallel PKC-MEK-ERK and p38 kinase pathways.
Collapse
Affiliation(s)
- K R Ingram
- Physiology, Basic Medical Sciences, St George's Hospital Medical School, University of London, London SW17 0RE, UK
| | | | | | | | | | | |
Collapse
|
46
|
Sivaramakrishnan S, Schneider JL, Sitikov A, Goldman RD, Ridge KM. Shear stress induced reorganization of the keratin intermediate filament network requires phosphorylation by protein kinase C zeta. Mol Biol Cell 2009; 20:2755-65. [PMID: 19357195 DOI: 10.1091/mbc.e08-10-1028] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Keratin intermediate filaments (KIFs) form a fibrous polymer network that helps epithelial cells withstand external mechanical forces. Recently, we established a correlation between the structure of the KIF network and its local mechanical properties in alveolar epithelial cells. Shear stress applied across the cell surface resulted in the structural remodeling of KIF and a substantial increase in the elastic modulus of the network. This study examines the mechanosignaling that regulates the structural remodeling of the KIF network. We report that the shear stress-mediated remodeling of the KIF network is facilitated by a twofold increase in the dynamic exchange rate of KIF subunits, which is regulated in a PKC zeta and 14-3-3-dependent manner. PKC zeta phosphorylates K18pSer33, and this is required for the structural reorganization because the KIF network in A549 cells transfected with a dominant negative PKC zeta, or expressing the K18Ser33Ala mutation, is unchanged. Blocking the shear stress-mediated reorganization results in reduced cellular viability and increased apoptotic levels. These data suggest that shear stress mediates the phosphorylation of K18pSer33, which is required for the reorganization of the KIF network, resulting in changes in mechanical properties of the cell that help maintain the integrity of alveolar epithelial cells.
Collapse
|
47
|
Pulmonary atelectasis during low stretch ventilation: "open lung" versus "lung rest" strategy. Crit Care Med 2009; 37:1046-53. [PMID: 19237916 DOI: 10.1097/ccm.0b013e3181968e7e] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Limiting tidal volume (VT) may minimize ventilator-induced lung injury (VILI). However, atelectasis induced by low VT ventilation may cause ultrastructural evidence of cell disruption. Apoptosis seems to be involved as protective mechanisms from VILI through the involvement of mitogen-activated protein kinases (MAPKs). We examined the hypothesis that atelectasis may influence the response to protective ventilation through MAPKs. DESIGN Prospective randomized study. SETTING University animal laboratory. SUBJECTS Adult male 129/Sv mice. INTERVENTIONS Isolated, nonperfused lungs were randomized to VILI: VT of 20 mL/kg and positive end-expiratory pressure (PEEP) zero; low stretch/lung rest: VT of 6 mL/kg and 8-10 cm H2O of PEEP; low stretch/open lung: VT of 6 mL/kg, two recruitment maneuvers and 14-16 cm H2O of PEEP. Ventilator settings were adjusted using the stress index. MEASUREMENT AND MAIN RESULT Both low stretch strategies equally blunted the VILI-induced derangement of respiratory mechanics (static volume-pressure curve), lung histology (hematoxylin and eosin), and inflammatory mediators (interleukin-6, macrophage inflammatory protein-2 [enzyme-linked immunosorbent assay], and inhibitor of nuclear factor-kB[Western blot]). VILI caused nuclear swelling and membrane disruption of pulmonary cells (electron microscopy). Few pulmonary cells with chromatin condensation and fragmentation were seen during both low stretch strategies. However, although cell thickness during low stretch/open lung was uniform, low stretch/lung rest demonstrated thickening of epithelial cells and plasma membrane bleb formation. Compared with the low stretch/open lung, low stretch/lung rest caused a significant decrease in apoptotic cells (terminal deoxynucleotidyl transferase mediated deoxyuridine-triphosphatase nick end-labeling) and tissue expression of caspase-3 (Western blot). Both low stretch strategies attenuated the activation of MAPKs. Such reduction was larger during low stretch/open lung than during low stretch/lung rest (p < 0.001). CONCLUSION Low stretch strategies provide similar attenuation of VILI. However, low stretch/lung rest strategy is associated to less apoptosis and more ultrastructural evidence of cell damage possibly through MAPKs-mediated pathway.
Collapse
|
48
|
Finan JD, Chalut KJ, Wax A, Guilak F. Nonlinear osmotic properties of the cell nucleus. Ann Biomed Eng 2008; 37:477-91. [PMID: 19107599 DOI: 10.1007/s10439-008-9618-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Accepted: 12/03/2008] [Indexed: 12/20/2022]
Abstract
In the absence of active volume regulation processes, cell volume is inversely proportional to osmolarity, as predicted by the Boyle Van't Hoff relation. In this study, we tested the hypothesis that nuclear volume has a similar relationship with extracellular osmolarity in articular chondrocytes, cells that are exposed to changes in the osmotic environment in vivo. Furthermore, we explored the mechanism of the relationships between osmolarity and nuclear size and shape. Nuclear size was quantified using two independent techniques, confocal laser scanning microscopy and angle-resolved low coherence interferometry. Nuclear volume was osmotically sensitive but this relationship was not linear, showing a decline in the osmotic sensitivity in the hypo-osmotic range. Nuclear shape was also influenced by extracellular osmolarity, becoming smoother as the osmolarity decreased. The osmotically induced changes in nuclear size paralleled the changes in nuclear shape, suggesting that shape and volume are interdependent. The osmotic sensitivity of shape and volume persisted after disruption of the actin cytoskeleton. Isolated nuclei contracted in response to physiologic changes in macromolecule concentration but not in response to physiologic changes in ion concentration, suggesting solute size has an important influence on the osmotic pressurization of the nucleus. This finding in turn implies that the diffusion barrier that causes osmotic effects is not a semi-permeable membrane, but rather due to size constraints that prevent large solute molecules from entering small spaces in the nucleus. As nuclear morphology has been associated previously with cell phenotype, these findings may provide new insight into the role of mechanical and osmotic signals in regulating cell physiology.
Collapse
Affiliation(s)
- John D Finan
- Department of Surgery, Duke University Medical Center, 375 MSRB, Box 3093, Durham, NC 27710, USA
| | | | | | | |
Collapse
|
49
|
Bierman A, Yerrapureddy A, Reddy NM, Hassoun PM, Reddy SP. Epidermal growth factor receptor (EGFR) regulates mechanical ventilation-induced lung injury in mice. Transl Res 2008; 152:265-72. [PMID: 19059161 PMCID: PMC2646043 DOI: 10.1016/j.trsl.2008.10.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 10/01/2008] [Accepted: 10/03/2008] [Indexed: 12/29/2022]
Abstract
Mechanical ventilation (MV) is used as therapy to support critically ill patients; however, the mechanisms by which MV induces lung injury and inflammation remain unclear. Epidermal growth factor receptor (EGFR)-mediated signaling plays a key role in various physiologic and pathologic processes, which include those modulated by mechanical and shear forces, in various cell types. We hypothesized that EGFR-activated signaling plays a key role in ventilator-induced lung injury and inflammation (VILI). To test this hypothesis, we assessed lung vascular and alveolar permeability as well as inflammation, which are cardinal features of VILI, in mice treated with the EGFR inhibitor AG1478. Inhibition of EGFR activity greatly diminished MV-induced lung alveolar permeability and neutrophil accumulation in the bronchoalveolar lavage (BAL) fluid, as compared with vehicle-treated controls. Similarly, AG1478 inhibition diminished lung vascular leak (as assessed by Evans blue extravasation), but it did not affect interstitial neutrophil accumulation. Inhibition of the EGFR pathway also blocked expression of genes induced by MV. However, intratracheal instillation of EGF alone failed to induce lung injury. Collectively, our findings suggest that EGFR-activated signaling is necessary but not sufficient to produce acute lung injury in mice.
Collapse
Affiliation(s)
- Alexis Bierman
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Division of Pulmonary and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | | | | | | | | |
Collapse
|
50
|
Birukova AA, Rios A, Birukov KG. Long-term cyclic stretch controls pulmonary endothelial permeability at translational and post-translational levels. Exp Cell Res 2008; 314:3466-77. [PMID: 18824167 DOI: 10.1016/j.yexcr.2008.09.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Revised: 08/22/2008] [Accepted: 09/10/2008] [Indexed: 11/17/2022]
Abstract
We have previously described differential effects of physiologic (5%) and pathologic (18%) cyclic stretch (CS) on agonist-induced pulmonary endothelial permeability. This study examined acute and chronic effects of CS on agonist-induced intracellular signaling and cell morphology in the human lung macro- and microvascular endothelial cell (EC) monolayers. Endothelial permeability was assessed by analysis of morphological changes, parameters of cell contraction and measurements of transendothelial electrical resistance. Exposure of both microvascular and macrovascular EC to 18% CS for 2-96 h increased thrombin-induced permeability and monolayer disruption. Interestingly, the ability to promote thrombin responses was present in EC cultures exposed to 48-96 h of CS even after replating onto non-elastic substrates. In turn, physiologic CS preconditioning (72 h) attenuated thrombin-induced paracellular gap formation and MLC phosphorylation in replated EC cultures. Long-term preconditioning at 18% CS (72 h) increased the content of signaling and contractile proteins including Rho GTPase, MLC, MLC kinase, ZIP kinase, PAR1, caldesmon and HSP27 in the pulmonary microvascular and macrovascular cells. We conclude that short term CS regulates EC permeability via modulation of agonist-induced signaling, whereas long-term CS controls endothelial barrier at both post-translational level and via magnitude-dependent regulation of pulmonary EC phenotype, signaling and contractile protein expression.
Collapse
Affiliation(s)
- Anna A Birukova
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | | | | |
Collapse
|