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Hu Q, Zhang S, Yang Y, Yao JQ, Tang WF, Lyon CJ, Hu TY, Wan MH. Extracellular vesicles in the pathogenesis and treatment of acute lung injury. Mil Med Res 2022; 9:61. [PMID: 36316787 PMCID: PMC9623953 DOI: 10.1186/s40779-022-00417-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 09/19/2022] [Indexed: 11/05/2022] Open
Abstract
Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common life-threatening lung diseases associated with acute and severe inflammation. Both have high mortality rates, and despite decades of research on clinical ALI/ARDS, there are no effective therapeutic strategies. Disruption of alveolar-capillary barrier integrity or activation of inflammatory responses leads to lung inflammation and injury. Recently, studies on the role of extracellular vesicles (EVs) in regulating normal and pathophysiologic cell activities, including inflammation and injury responses, have attracted attention. Injured and dysfunctional cells often secrete EVs into serum or bronchoalveolar lavage fluid with altered cargoes, which can be used to diagnose and predict the development of ALI/ARDS. EVs secreted by mesenchymal stem cells can also attenuate inflammatory reactions associated with cell dysfunction and injury to preserve or restore cell function, and thereby promote cell proliferation and tissue regeneration. This review focuses on the roles of EVs in the pathogenesis of pulmonary inflammation, particularly ALI/ARDS.
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Affiliation(s)
- Qian Hu
- Department of Integrated Traditional Chinese and Western Medicine, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Shu Zhang
- Department of Emergency Medicine, Emergency Medical Laboratory, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Yue Yang
- Department of Integrated Traditional Chinese and Western Medicine, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Jia-Qi Yao
- Department of Integrated Traditional Chinese and Western Medicine, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Wen-Fu Tang
- Department of Integrated Traditional Chinese and Western Medicine, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Christopher J Lyon
- Center of Cellular and Molecular Diagnosis, Tulane University School of Medicine, 1430 Tulane Ave., New Orleans, LA, 70112, USA.,Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, 1430 Tulane Ave., New Orleans, LA, 70112, USA
| | - Tony Ye Hu
- Center of Cellular and Molecular Diagnosis, Tulane University School of Medicine, 1430 Tulane Ave., New Orleans, LA, 70112, USA. .,Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, 1430 Tulane Ave., New Orleans, LA, 70112, USA.
| | - Mei-Hua Wan
- Department of Integrated Traditional Chinese and Western Medicine, West China Hospital of Sichuan University, Chengdu, 610041, China. .,West China Hospital (Airport) of Sichuan University, Chengdu, 610299, China.
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2
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Lin C, Zheng X, Lin S, Zhang Y, Wu J, Li Y. Mechanotransduction Regulates the Interplays Between Alveolar Epithelial and Vascular Endothelial Cells in Lung. Front Physiol 2022; 13:818394. [PMID: 35250619 PMCID: PMC8895143 DOI: 10.3389/fphys.2022.818394] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/28/2022] [Indexed: 12/22/2022] Open
Abstract
Mechanical stress plays a critical role among development, functional maturation, and pathogenesis of pulmonary tissues, especially for the alveolar epithelial cells and vascular endothelial cells located in the microenvironment established with vascular network and bronchial-alveolar network. Alveolar epithelial cells are mainly loaded by cyclic strain and air pressure tension. While vascular endothelial cells are exposed to shear stress and cyclic strain. Currently, the emerging evidences demonstrated that non-physiological mechanical forces would lead to several pulmonary diseases, including pulmonary hypertension, fibrosis, and ventilation induced lung injury. Furthermore, a series of intracellular signaling had been identified to be involved in mechanotransduction and participated in regulating the physiological homeostasis and pathophysiological process. Besides, the communications between alveolar epithelium and vascular endothelium under non-physiological stress contribute to the remodeling of the pulmonary micro-environment in collaboration, including hypoxia induced injuries, endothelial permeability impairment, extracellular matrix stiffness elevation, metabolic alternation, and inflammation activation. In this review, we aim to summarize the current understandings of mechanotransduction on the relation between mechanical forces acting on the lung and biological response in mechanical overloading related diseases. We also would like to emphasize the interplays between alveolar epithelium and vascular endothelium, providing new insights into pulmonary diseases pathogenesis, and potential targets for therapy.
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Affiliation(s)
- Chuyang Lin
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Xiaolan Zheng
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Sha Lin
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Yue Zhang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Jinlin Wu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Yifei Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
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3
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Bonfanti A, Duque J, Kabla A, Charras G. Fracture in living tissues. Trends Cell Biol 2022; 32:537-551. [DOI: 10.1016/j.tcb.2022.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/08/2022] [Accepted: 01/10/2022] [Indexed: 10/19/2022]
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4
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Xu X, Nie Y, Wang W, Ma N, Lendlein A. Periodic thermomechanical modulation of toll-like receptor expression and distribution in mesenchymal stromal cells. MRS COMMUNICATIONS 2021; 11:425-431. [PMID: 34258101 PMCID: PMC8265727 DOI: 10.1557/s43579-021-00049-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 05/25/2021] [Indexed: 06/13/2023]
Abstract
ABSTRACT Toll-like receptor (TLR) can trigger an immune response against virus including SARS-CoV-2. TLR expression/distribution is varying in mesenchymal stromal cells (MSCs) depending on their culture environments. Here, to explore the effect of periodic thermomechanical cues on TLRs, thermally controlled shape-memory polymer sheets with programmable actuation capacity were created. The proportion of MSCs expressing SARS-CoV-2-associated TLRs was increased upon stimulation. The TLR4/7 colocalization was promoted and retained in the endoplasmic reticula. The TLR redistribution was driven by myosin-mediated F-actin assembly. These results highlight the potential of boosting the immunity for combating COVID-19 via thermomechanical preconditioning of MSCs. GRAPHIC ABSTRACT Periodic thermal and synchronous mechanical stimuli provided by polymer sheet actuators selectively promoted the expression of SARS-CoV-2-associated TLRs 4 and 7 in adipose-derived MSCs and recruited TLR4 to Endoplasmic reticulum region where TLR7 was located via controlling myosin-mediated F-actin cytoskeleton assembly.
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Affiliation(s)
- Xun Xu
- Institute of Active Polymers and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Hereon, 14513 Teltow, Germany
| | - Yan Nie
- Institute of Active Polymers and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Hereon, 14513 Teltow, Germany
- Institute of Chemistry, University of Potsdam, 14476 Potsdam, Germany
| | - Weiwei Wang
- Institute of Active Polymers and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Hereon, 14513 Teltow, Germany
| | - Nan Ma
- Institute of Active Polymers and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Hereon, 14513 Teltow, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Andreas Lendlein
- Institute of Active Polymers and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Hereon, 14513 Teltow, Germany
- Institute of Chemistry, University of Potsdam, 14476 Potsdam, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
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5
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Iverson E, Kaler L, Agostino EL, Song D, Duncan GA, Scull MA. Leveraging 3D Model Systems to Understand Viral Interactions with the Respiratory Mucosa. Viruses 2020; 12:E1425. [PMID: 33322395 PMCID: PMC7763686 DOI: 10.3390/v12121425] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/27/2020] [Accepted: 12/02/2020] [Indexed: 02/07/2023] Open
Abstract
Respiratory viruses remain a significant cause of morbidity and mortality in the human population, underscoring the importance of ongoing basic research into virus-host interactions. However, many critical aspects of infection are difficult, if not impossible, to probe using standard cell lines, 2D culture formats, or even animal models. In vitro systems such as airway epithelial cultures at air-liquid interface, organoids, or 'on-chip' technologies allow interrogation in human cells and recapitulate emergent properties of the airway epithelium-the primary target for respiratory virus infection. While some of these models have been used for over thirty years, ongoing advancements in both culture techniques and analytical tools continue to provide new opportunities to investigate airway epithelial biology and viral infection phenotypes in both normal and diseased host backgrounds. Here we review these models and their application to studying respiratory viruses. Furthermore, given the ability of these systems to recapitulate the extracellular microenvironment, we evaluate their potential to serve as a platform for studies specifically addressing viral interactions at the mucosal surface and detail techniques that can be employed to expand our understanding.
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Affiliation(s)
- Ethan Iverson
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA; (E.I.); (E.L.A.)
| | - Logan Kaler
- Biophysics Program, University of Maryland, College Park, MD 20742, USA; (L.K.); (G.A.D.)
| | - Eva L. Agostino
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA; (E.I.); (E.L.A.)
| | - Daniel Song
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA;
| | - Gregg A. Duncan
- Biophysics Program, University of Maryland, College Park, MD 20742, USA; (L.K.); (G.A.D.)
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA;
| | - Margaret A. Scull
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA; (E.I.); (E.L.A.)
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6
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Wang J, He Y, Yang G, Li N, Li M, Zhang M. Transient receptor potential canonical 1 channel mediates the mechanical stress‑induced epithelial‑mesenchymal transition of human bronchial epithelial (16HBE) cells. Int J Mol Med 2020; 46:320-330. [PMID: 32319532 PMCID: PMC7255483 DOI: 10.3892/ijmm.2020.4568] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 03/17/2020] [Indexed: 01/16/2023] Open
Abstract
Airway remodeling is a central event in the pathology of chronic obstructive pulmonary disease (COPD) that leads to airway narrowing and subsequently, to increased mechanical pressure. High mechanical pressure can exacerbate airway remodeling. Thus, a treatment regimen aimed at disrupting this high-pressure airway remodeling vicious cycle may improve the prognosis of patients with COPD. Recent studies have demonstrated that mechanical stress induces lung epithelial-mesenchymal transition (EMT), which is commonly present in airway epithelial cells of patients with COPD. As TRPC1 functions as a mechanosensitive channel that mediates non-selective cation entry in response to increased membrane stretch, the present study investigated the role of TRPC1 in the occurrence of EMT induced by mechanical stress. In the present study, the expression of TRPC1 in the bronchial epithelium was examined in vivo by immunohistochemistry. In vitro, human bronchial epithelial (16HBE) cells were subjected to mechanical stretching for up to 48 h, and TRPC1 expression was then examined by RT-qPCR and western blot analysis. In addition, TRPC1 receptor function was assessed by Ca2+ imaging and siRNA transfection. EMT was identified using immunofluorescence, western blot analysis and RT-qPCR. It was found that TRPC1 expression was upregulated in patients with COPD and in 16HBE cells subjected to mechanical stretch. The mechanical stress-induced activation of TRPC1 in 16HBE cells increased the intracellular calcium concentration and subsequently decreased the expression of cytokeratin 8 and E-cadherin, and increased the expression of α-smooth muscle actin, indicating the occurrence of EMT. On the whole, the findings of the present study demonstrate that TRPC1 plays a key role in the occurrence of EMT in human lung epithelial cells in response to mechanical stretch; thus, this protein may serve as a novel therapeutic target for progressive airway remodeling in COPD.
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Affiliation(s)
- Jing Wang
- Department of Respiratory Medicine, The Second Clinical Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Ye He
- Department of Geriatrics, Sichuan Provincial People's Hospital, Sichuan Academy of Medical Science, Chengdu, Sichuan 610072, P.R. China
| | - Gang Yang
- Department of Neurosurgery, The First Clinical Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Na Li
- Division of Nephrology, The Seventh Affiliated Hospital, Sun Yat‑sen University, Shenzhen, Guangdong 518107, P.R. China
| | - Minchao Li
- Department of Respiratory Medicine, The Second Clinical Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Min Zhang
- Department of Geriatrics, Sichuan Provincial People's Hospital, Sichuan Academy of Medical Science, Chengdu, Sichuan 610072, P.R. China
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7
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Plazyo O, Sheng JJ, Jin JP. Downregulation of calponin 2 contributes to the quiescence of lung macrophages. Am J Physiol Cell Physiol 2019; 317:C749-C761. [PMID: 31365293 PMCID: PMC6850996 DOI: 10.1152/ajpcell.00036.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 07/08/2019] [Accepted: 07/23/2019] [Indexed: 12/14/2022]
Abstract
Calponin 2 is an actin cytoskeleton-associated regulatory protein that inhibits the activity of myosin-ATPase and cytoskeleton dynamics. Recent studies have demonstrated that deletion of calponin 2 restricts the proinflammatory activation of macrophages in atherosclerosis and arthritis to attenuate the disease progression in mice. Here we demonstrate that the levels of calponin 2 vary among different macrophage populations, which may reflect their adaptation to specific tissue microenvironment corresponding to specific functional states. Interestingly, lung resident macrophages express significantly lower calponin 2 than peritoneal resident macrophages, which correlates with decreased substrate adhesion and reduced expression of proinflammatory cytokines and a proresolution phenotype. Deletion of calponin 2 in peritoneal macrophages also decreased substrate adhesion and downregulated the expression of proinflammatory cytokines. Providing the first line of defense against microbial invasion while receiving constant exposure to extrinsic antigens, lung macrophages need to maintain a necessary level of activity while limiting exaggerated inflammatory reaction. Therefore, their low level of calponin 2 may reflect an important physiological adaption. Downregulation of calponin 2 in macrophages may be targeted as a cytoskeleton-based novel mechanism, possibly via endoplasmic reticulum stress altering the processing and secretion of cytokines, to regulate immune response and promote quiescence for the treatment of inflammatory diseases.
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Affiliation(s)
- Olesya Plazyo
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Juan-Juan Sheng
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - J-P Jin
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
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8
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Morton SE, Knopp JL, Chase JG, Docherty P, Howe SL, Möller K, Shaw GM, Tawhai M. Optimising mechanical ventilation through model-based methods and automation. ANNUAL REVIEWS IN CONTROL 2019; 48:369-382. [PMID: 36911536 PMCID: PMC9985488 DOI: 10.1016/j.arcontrol.2019.05.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 04/09/2019] [Accepted: 05/01/2019] [Indexed: 06/11/2023]
Abstract
Mechanical ventilation (MV) is a core life-support therapy for patients suffering from respiratory failure or acute respiratory distress syndrome (ARDS). Respiratory failure is a secondary outcome of a range of injuries and diseases, and results in almost half of all intensive care unit (ICU) patients receiving some form of MV. Funding the increasing demand for ICU is a major issue and MV, in particular, can double the cost per day due to significant patient variability, over-sedation, and the large amount of clinician time required for patient management. Reducing cost in this area requires both a decrease in the average duration of MV by improving care, and a reduction in clinical workload. Both could be achieved by safely automating all or part of MV care via model-based dynamic systems modelling and control methods are ideally suited to address these problems. This paper presents common lung models, and provides a vision for a more automated future and explores predictive capacity of some current models. This vision includes the use of model-based methods to gain real-time insight to patient condition, improve safety through the forward prediction of outcomes to changes in MV, and develop virtual patients for in-silico design and testing of clinical protocols. Finally, the use of dynamic systems models and system identification to guide therapy for improved personalised control of oxygenation and MV therapy in the ICU will be considered. Such methods are a major part of the future of medicine, which includes greater personalisation and predictive capacity to both optimise care and reduce costs. This review thus presents the state of the art in how dynamic systems and control methods can be applied to transform this core area of ICU medicine.
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Affiliation(s)
- Sophie E Morton
- Department of Mechanical Engineering, University of Canterbury, New Zealand
| | - Jennifer L Knopp
- Department of Mechanical Engineering, University of Canterbury, New Zealand
| | - J Geoffrey Chase
- Department of Mechanical Engineering, University of Canterbury, New Zealand
| | - Paul Docherty
- Department of Mechanical Engineering, University of Canterbury, New Zealand
| | - Sarah L Howe
- Department of Mechanical Engineering, University of Canterbury, New Zealand
| | - Knut Möller
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Geoffrey M Shaw
- Department of Intensive Care, Christchurch Hospital, Christchurch, New Zealand
| | - Merryn Tawhai
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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9
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Predictive Virtual Patient Modelling of Mechanical Ventilation: Impact of Recruitment Function. Ann Biomed Eng 2019; 47:1626-1641. [PMID: 30927170 DOI: 10.1007/s10439-019-02253-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/22/2019] [Indexed: 10/27/2022]
Abstract
Mechanical ventilation is a life-support therapy for intensive care patients suffering from respiratory failure. To reduce the current rate of ventilator-induced lung injury requires ventilator settings that are patient-, time-, and disease-specific. A common lung protective strategy is to optimise the level of positive end-expiratory pressure (PEEP) through a recruitment manoeuvre to prevent alveolar collapse at the end of expiration and to improve gas exchange through recruitment of additional alveoli. However, this process can subject parts of the lung to excessively high pressures or volumes. This research significantly extends and more robustly validates a previously developed pulmonary mechanics model to predict lung mechanics throughout recruitment manoeuvres. In particular, the process of recruitment is more thoroughly investigated and the impact of the inclusion of expiratory data when estimating peak inspiratory pressure is assessed. Data from the McREM trial and CURE pilot trial were used to test model predictive capability and assumptions. For PEEP changes of up to and including 14 cmH2O, the parabolic model was shown to improve peak inspiratory pressure prediction resulting in less than 10% absolute error in the CURE cohort and 16% in the McREM cohort. The parabolic model also better captured expiratory mechanics than the exponential model for both cohorts.
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10
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Morton SE, Dickson J, Chase JG, Docherty P, Desaive T, Howe SL, Shaw GM, Tawhai M. A virtual patient model for mechanical ventilation. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2018; 165:77-87. [PMID: 30337083 DOI: 10.1016/j.cmpb.2018.08.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 07/24/2018] [Accepted: 08/08/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND AND OBJECTIVES Mechanical ventilation (MV) is a primary therapy for patients with acute respiratory failure. However, poorly selected ventilator settings can cause further lung damage due to heterogeneity of healthy and damaged alveoli. Varying positive-end-expiratory-pressure (PEEP) to a point of minimum elastance is a lung protective ventilator strategy. However, even low levels of PEEP can lead to ventilator induced lung injury for individuals with highly inflamed pulmonary tissue. Hence, models that could accurately predict peak inspiratory pressures after changes to PEEP could improve clinician confidence in attempting potentially beneficial treatment strategies. METHODS This study develops and validates a physiologically relevant respiratory model that captures elastance and resistance via basis functions within a well-validated single compartment lung model. The model can be personalised using information available at a low PEEP to predict lung mechanics at a higher PEEP. Proof of concept validation is undertaken with data from four patients and eight recruitment manoeuvre arms. RESULTS Results show low error when predicting upwards over the clinically relevant pressure range, with the model able to predict peak inspiratory pressure with less than 10% error over 90% of the range of PEEP changes up to 12 cmH2O. CONCLUSIONS The results provide an in-silico model-based means of predicting clinically relevant responses to changes in MV therapy, which is the foundation of a first virtual patient for MV.
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Affiliation(s)
- S E Morton
- Department of Mechanical Engineering, University of Canterbury, New Zealand.
| | - J Dickson
- Department of Mechanical Engineering, University of Canterbury, New Zealand.
| | - J G Chase
- Department of Mechanical Engineering, University of Canterbury, New Zealand.
| | - P Docherty
- Department of Mechanical Engineering, University of Canterbury, New Zealand.
| | - T Desaive
- GIGA Cardiovascular Science, University of Liege, Liege, Belgium.
| | - S L Howe
- Department of Mechanical Engineering, University of Canterbury, New Zealand.
| | - G M Shaw
- Department of Intensive Care, Christchurch Hospital, Christchurch, New Zealand.
| | - M Tawhai
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.
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11
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Development of a Predictive Pulmonary Elastance Model to Describe Lung Mechanics throughout Recruitment Manoeuvres. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.ifacol.2018.11.640] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Papaioannou AI, Herodotou Y, Tomos I, Apollonatou V, Verykokou G, Papathanasiou E, Manali ED, Loukides S, Papiris SA. Ability of using different dry powder inhalers during COPD exacerbations. Pulm Pharmacol Ther 2017; 48:211-216. [PMID: 29277688 DOI: 10.1016/j.pupt.2017.12.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/03/2017] [Accepted: 12/18/2017] [Indexed: 11/18/2022]
Abstract
BACKGROUND Guidelines suggest that patients hospitalized for acute COPD exacerbations (AECOPD) are treated with short acting bronchodilators. Long acting bronchodilators, offer longer symptom relief but since they are usually administered via Dry Powder Inhalers (DPIs) it is considered that during AECOPD patients would not be able to achieve appropriate inspiratory flow (IF) to receive appropriate drug doses. The aim of the present study was to evaluate whether patients admitted to the hospital for AECOPD, are able to achieve the necessary IF using different DPIs. METHODS IF was measured daily in patients admitted for AECOPD with a portable IF meter (In-Check Oral inhaler assessment kit), containing a series of adapters that simulate the resistance of 4 DPIs [Turbuhaler (T), Breezhaler/Aerolizer (B/F), Discus (A/A/D) and Handinhaler (HH)]. Dyspnea, spirometry and arterial blood gases were also recorded daily. RESULTS 44 consecutive patients were included in the study. The majority of patients were able to achieve an IF over 30 L/min with all four device resistances. This minimum required IF was achieved in 90.9%, 100%, 95.5% and 81.8% of patients on admission and in 100%, 100%, 97.7%, and 95.5% of patients on discharge for T, B/F, A/A/D and HH respectively. No functional characteristic was able to predict the achievement of this minimum necessary IF. CONCLUSION Most patients hospitalized for AECOPD, are able to receive treatment with long acting bronchodilators administered via DPIs. The possible beneficial effects of such an intervention should be tested in further studies.
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Affiliation(s)
- Andriana I Papaioannou
- 2nd Respiratory Medicine Department, "Attikon" University Hospital, Athens Medical School, National and Kapodistrian University of Athens, Greece.
| | - Yiolanda Herodotou
- 2nd Respiratory Medicine Department, "Attikon" University Hospital, Athens Medical School, National and Kapodistrian University of Athens, Greece
| | - Ioannis Tomos
- 2nd Respiratory Medicine Department, "Attikon" University Hospital, Athens Medical School, National and Kapodistrian University of Athens, Greece
| | - Vasiliki Apollonatou
- 2nd Respiratory Medicine Department, "Attikon" University Hospital, Athens Medical School, National and Kapodistrian University of Athens, Greece
| | - Galateia Verykokou
- 2nd Respiratory Medicine Department, "Attikon" University Hospital, Athens Medical School, National and Kapodistrian University of Athens, Greece
| | - Evgenia Papathanasiou
- 2nd Respiratory Medicine Department, "Attikon" University Hospital, Athens Medical School, National and Kapodistrian University of Athens, Greece
| | - Effrosyni D Manali
- 2nd Respiratory Medicine Department, "Attikon" University Hospital, Athens Medical School, National and Kapodistrian University of Athens, Greece
| | - Stelios Loukides
- 2nd Respiratory Medicine Department, "Attikon" University Hospital, Athens Medical School, National and Kapodistrian University of Athens, Greece
| | - Spyros A Papiris
- 2nd Respiratory Medicine Department, "Attikon" University Hospital, Athens Medical School, National and Kapodistrian University of Athens, Greece
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13
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Beeh KM, Burgel PR, Franssen FME, Lopez-Campos JL, Loukides S, Hurst JR, Fležar M, Ulrik CS, Di Marco F, Stolz D, Valipour A, Casserly B, Ställberg B, Kostikas K, Wedzicha JA. How Do Dual Long-Acting Bronchodilators Prevent Exacerbations of Chronic Obstructive Pulmonary Disease? Am J Respir Crit Care Med 2017; 196:139-149. [PMID: 27922741 DOI: 10.1164/rccm.201609-1794ci] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Decreasing the frequency and severity of exacerbations is one of the main goals of treatment for patients with chronic obstructive pulmonary disease. Several studies have documented that long-acting bronchodilators can reduce exacerbation rate and/or severity, and others have shown that combinations of long-acting β2-adrenergic agonists (LABAs) and long-acting muscarinic antagonists (LAMAs) provide greater reductions in exacerbation frequency than either their monocomponents or LABA/inhaled corticosteroid combinations in patients at low and high risk for these events. In this review, small groups of experts critically evaluated mechanisms potentially responsible for the increased benefit of LABA/LAMA combinations over single long-acting bronchodilators or LABA/inhaled corticosteroids in decreasing exacerbation. These included effects on lung hyperinflation and mechanical stress, inflammation, excessive mucus production with impaired mucociliary clearance, and symptom severity. The data assembled and analyzed by each group were reviewed by all authors and combined into this manuscript. Available clinical results support the possibility that effects of LABA/LAMA combinations on hyperinflation, mucociliary clearance, and symptom severity may all contribute to decreasing exacerbations. Although preclinical studies suggest LABAs and LAMAs have antiinflammatory effects, such effects have not been demonstrated yet in patients with chronic obstructive pulmonary disease.
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Affiliation(s)
- Kai M Beeh
- 1 insaf Respiratory Research Institute, Wiesbaden, Germany
| | - Pierre-Regis Burgel
- 2 Department of Respiratory Diseases and Adult Cystic Fibrosis Centre, Hôpital Cochin, AP-HP and Paris Descartes University, Paris, France
| | - Frits M E Franssen
- 3 Department of Research and Education, Centre of Expertise for Chronic Organ Failure, Horn, the Netherlands
| | - Jose Luis Lopez-Campos
- 4 Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío, Sevilla, Spain.,5 Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Stelios Loukides
- 6 2nd Respiratory Medicine Department, National and Kapodistrian University of Athens Medical School, Attiko University Hospital, Athens, Greece
| | - John R Hurst
- 7 University College London Respiratory, University College London, London, United Kingdom
| | - Matjaž Fležar
- 8 University Clinic of Respiratory and Allergic Diseases, Golnik, Slovenia
| | | | - Fabiano Di Marco
- 10 Dipartimento di Scienze della Salute, Università degli Studi di Milano, Ospedale San Paolo, Milan, Italy
| | - Daiana Stolz
- 11 Clinic of Respiratory Medicine and Pulmonary Cell Research, University Hospital Basel, Basel, Switzerland
| | - Arschang Valipour
- 12 Ludwig-Boltzmann-Institute for Chronic Obstructive Pulmonary Disease and Respiratory Epidemiology, Otto-Wagner-Spital, Vienna, Austria
| | - Brian Casserly
- 13 University Hospital, Limerick, Ireland.,14 Graduate Entry Medical School, University of Limerick, Limerick, Ireland
| | - Björn Ställberg
- 15 Department of Public Health and Caring Science, Family Medicine and Preventive Medicine, Uppsala University, Uppsala, Sweden
| | | | - Jadwiga A Wedzicha
- 17 Airways Disease Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
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Pulmonary Hypoplasia Induced by Oligohydramnios: Findings from Animal Models and a Population-Based Study. Pediatr Neonatol 2017; 58:3-7. [PMID: 27324123 DOI: 10.1016/j.pedneo.2016.04.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Revised: 11/26/2015] [Accepted: 04/21/2016] [Indexed: 10/21/2022] Open
Abstract
Pulmonary hypoplasia is a substantial cause of death in newborn infants, and oligohydramnios is one of the most commonly associated abnormalities. Lung growth is influenced by physical factors such as the intrauterine space, lung liquid volume and pressure, and fetal breathing movements. During lung development, the main physical force experienced by the lungs is stretching induced by breathing movements and the lung fluid in the airspaces. Oligohydramnios reduces the intrathoracic cavity size, thus disrupting fetal lung growth and leading to pulmonary hypoplasia. The exact mechanism by which oligohydramnios alters the respiratory system structure and the effect of oligohydramnios on long-term respiratory outcomes remain unknown. In this review, we summarize the effects of oligohydramnios on lung development, discuss the mechanisms of oligohydramnios-induced pulmonary hypoplasia identified in various animal studies, and describe the long-term respiratory outcomes in childhood of oligohydramnios-exposed fetuses reported by a population-based study.
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15
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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.
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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;
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17
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Liu C, Li Q, Zhou X, Kolosov VP, Perelman JM. Cortactin mediates elevated shear stress-induced mucin hypersecretion via actin polymerization in human airway epithelial cells. Int J Biochem Cell Biol 2013; 45:2756-63. [DOI: 10.1016/j.biocel.2013.09.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 09/12/2013] [Accepted: 09/28/2013] [Indexed: 11/25/2022]
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18
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Perino MG, Moldobaeva A, Jenkins J, Wagner EM. Chemokine localization in bronchial angiogenesis. PLoS One 2013; 8:e66432. [PMID: 23776670 PMCID: PMC3679055 DOI: 10.1371/journal.pone.0066432] [Citation(s) in RCA: 5] [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: 01/16/2013] [Accepted: 05/09/2013] [Indexed: 12/20/2022] Open
Abstract
Angiogenesis in the lung involves the systemic bronchial vasculature and becomes prominent when chronic inflammation prevails. Mechanisms for neovascularization following pulmonary ischemia include growth factor transit from ischemic parenchyma to upstream bronchial arteries, inflammatory cell migration/recruitment through the perfusing artery, and paracrine effects of lung cells within the left bronchus, the niche where arteriogenesis takes place. We analyzed left lung bronchoalveolar lavage (BAL) fluid and left bronchus homogenates after left pulmonary artery ligation (LPAL) in rats, immediately after the onset of ischemia (0 h), 6 h and 24 h later. Additionally, we tested the effectiveness of dexamethasone on decreasing inflammation (0–24 h LPAL) and angiogenesis at early (3 d LPAL; bronchial endothelial proliferation) and late (14 d LPAL; blood flow) stages. After LPAL (6 h), BAL protein, total inflammatory cells, macrophages, and polymorphonuclear cells increased significantly. In parallel, pro-angiogenic CXC chemokines increased in BAL and the left main-stem bronchus (CXCL1) or only within the bronchus (CXCL2). Dexamethasone treatment reduced total BAL protein, inflammatory cells (total and polymorphonuclear cells), and CXCL1 but not CXCL2 in BAL. By contrast, no decrease was seen in either chemokine within the bronchial tissue, in proliferating bronchial endothelial cells, or in systemic perfusion of the left lung. Our results confirm the presence of CXC chemokines within BAL fluid as well as within the left mainstem bronchus. Despite significant reduction in lung injury and inflammation with dexamethasone treatment, chemokine expression within the bronchial tissue as well as angiogenesis were not affected. Our results suggest that early changes within the bronchial niche contribute to subsequent neovascularization during pulmonary ischemia.
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Affiliation(s)
- Maria Grazia Perino
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Aigul Moldobaeva
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - John Jenkins
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Elizabeth M. Wagner
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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Birukova AA, Tian Y, Meliton A, Leff A, Wu T, Birukov KG. Stimulation of Rho signaling by pathologic mechanical stretch is a "second hit" to Rho-independent lung injury induced by IL-6. Am J Physiol Lung Cell Mol Physiol 2012; 302:L965-75. [PMID: 22345573 DOI: 10.1152/ajplung.00292.2011] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Most patients with acute lung injury (ALI) and acute respiratory distress syndrome of septic and nonseptic nature require assisted ventilation with positive pressure, which at suboptimal range may further exacerbate lung dysfunction. Previous studies described enhancement of agonist-induced Rho GTPase signaling and endothelial cell (EC) permeability in EC cultures exposed to pathologically relevant cyclic stretch (CS) magnitudes. This study examined a role of pathologic CS in modulation of pulmonary EC permeability caused by IL-6, a cytokine increased in sepsis and acting in a Rho-independent manner. IL-6 increased EC permeability, which was associated with activation of Jak/signal transducers and activators of transcription, p38 MAP kinase, and NF-κB signaling and was augmented by EC exposure to 18% CS. Rho kinase inhibitor Y-27632 suppressed the synergistic effect of 18% CS on IL-6-induced EC monolayer disruption but did not alter the IL-6 effects on static EC culture. 18% CS also increased IL-6-induced ICAM-1 expression by pulmonary EC and neutrophil adhesion, which was attenuated by Y-27632. Intratracheal IL-6 administration in C57BL/6J mice increased protein content and cell count in bronchoalveolar lavage fluid. These changes were augmented by high tidal volume mechanical ventilation (HTV; 30 ml/kg, 4 h). Intravenous injection of Y-27632 suppressed IL6/HTV-induced lung injury. In conclusion, this study proposes a novel mechanism contributing to two-hit model of ALI: in addition to synergistic effects on Rho-dependent endothelial hyper-permeability triggered by thrombin, TNFα, LPS, or other agonists, ventilator-induced lung injury-relevant CS may also exacerbate Rho-independent mechanisms of EC permeability induced by other inflammatory mediators such as IL-6 via mechanisms involving Rho activity.
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Affiliation(s)
- Anna A Birukova
- Lung Injury Center, Section of Pulmonary and Critical Medicine, Dept. of Medicine, Univ. of Chicago, Chicago, IL 60637, USA
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Wu M, Fannin J, Rice KM, Wang B, Blough ER. Effect of aging on cellular mechanotransduction. Ageing Res Rev 2011; 10:1-15. [PMID: 19932197 DOI: 10.1016/j.arr.2009.11.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 11/11/2009] [Accepted: 11/16/2009] [Indexed: 12/27/2022]
Abstract
Aging is becoming a critical heath care issue and a burgeoning economic burden on society. Mechanotransduction is the ability of the cell to sense, process, and respond to mechanical stimuli and is an important regulator of physiologic function that has been found to play a role in regulating gene expression, protein synthesis, cell differentiation, tissue growth, and most recently, the pathophysiology of disease. Here we will review some of the recent findings of this field and attempt, where possible, to present changes in mechanotransduction that are associated with the aging process in several selected physiological systems, including musculoskeletal, cardiovascular, neuronal, respiratory systems and skin.
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Merrien J, Gras D, Robert P, Chanez P. [Mechanotransduction and the bronchoalveolar epithelium]. Rev Mal Respir 2010; 27:1164-74. [PMID: 21163395 DOI: 10.1016/j.rmr.2010.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Accepted: 06/08/2010] [Indexed: 11/25/2022]
Abstract
The bronchoalveolar epithelium is submitted to numerous mechanical strains. These strains induce a specific cellular activity at the tissue level. This type of activation has been studied in respiratory medicine, mainly in the context of mechanical ventilation and asthma. The phenomenon of mechanotransduction is linked to various epithelial cellular activities such as epithelium repair, extracellular matrix remodelling, inflammatory mediator release and mucociliary regulation. In this review, the main studies related to bronchoalveolar epithelial mechanotransduction are reported to bring a new perspective on this little known biological phenomenon. A better understanding of the physiological and pathological aspects will potentially offer new treatment approaches for bronchial diseases.
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Affiliation(s)
- J Merrien
- Département des Maladies Respiratoires, AP-HM, Université de la Méditerranée, 270 Boulevard de Sainte-Marguerite, 13009 Marseille, France.
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Rauch C, Pluen A, Foster N, Loughna P, Mobasheri A, Lagadic-Gossmann D, Counillon L. On some aspects of the thermodynamic of membrane recycling mediated by fluid phase endocytosis: evaluation of published data and perspectives. Cell Biochem Biophys 2010; 56:73-90. [PMID: 20013072 DOI: 10.1007/s12013-009-9072-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The theoretical and experimental description of fluid phase endocytosis (FPE) requires an asymmetry in phospholipid number between the two leaflets of the cell membrane, which provides the biomechanical torque needed to generate membrane budding. Although the motor force behind FPE is defined, its kinetic has yet to be determined. Based on a body of evidences suggesting that the mean surface tension is unlikely to be involved in endocytosis we decided to determine whether the cytosolic hydrostatic pressure could be involved, by considering a constant energy exchanged between the cytosol and the cell membrane. The theory is compared to existing experimental data obtained from FPE kinetic studies in living cells where altered phospholipid asymmetry or changes in the extracellular osmotic pressure have been investigated. The model demonstrates that FPE is dependent on the influx and efflux of vesicular volumes (i.e. vesicular volumes recycling) rather than the membrane tension of cells. We conclude that: (i) a relationship exists between membrane lipid number asymmetry and resting cytosolic pressure and (ii) the validity of Laplace's law is limited to cells incubated in a definite hypotonic regime. Finally, we discuss how the model could help clarifying elusive observations obtained from different fields and including: (a) the non-canonical shuttling of aquaporin in cells, (b) the relationship between high blood pressure and inflammation and (c) the mechanosensitivity of the sodium/proton exchanger.
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Affiliation(s)
- Cyril Rauch
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, UK.
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Cyclic hydrostatic pressure and cotton particles stimulate synthesis by human lung macrophages of cytokines in vitro. Respir Res 2009; 10:44. [PMID: 19490623 PMCID: PMC2708140 DOI: 10.1186/1465-9921-10-44] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Accepted: 06/02/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Inhalation of particulates is a leading cause of the development of lung diseases and current understanding of the complex relationship between lung metabolism and airborne particulates is incomplete. It is well established that mechanical load is important in the development of the lung and in lung cell differentiation. The interaction between particle exposure and physical forces on alveolar macrophages is a physiologically relevant issue, but as yet understudied. This study examines the effect of cyclic hydrostatic pressure and cotton particles on synthesis of cytokines by human alveolar macrophages. METHODS Alveolar macrophages were obtained from patients with lung disease, either from lavage samples or from lung tissue resection. The commonly used cell line THP-1 was included in the experiments. Cell cultures were exposed to cotton particles and/cyclic hydrostatic pressure (3 or 5 psi); control cultures were exposed to medium only. TNFalpha, IL-1beta and IL-6 were assayed in the culture media using specific ELISAs. Cells were characterized using morphology and markers specific for macrophages (Jenner/Giemsa staining, CD14 and CD68). RESULTS Exposure to cotton particles stimulated cytokine synthesis by macrophages from all three sources; exposure to cyclic hydrostatic pressure alone did not stimulate cytokine synthesis significantly. However, the combination of both particles and cyclic hydrostatic pressure increased the simulation of cytokine synthesis still further. Cell characterization demonstrated that the large majority of cells had a macrophage morphology and were positive for CD14 and CD68. CONCLUSION These data suggest an interaction between cyclic hydrostatic pressure and particulate exposure, which increases alveolar macrophage cytokine production. This interaction was only observed at the higher cyclic hydrostatic pressure. However, in patient samples, there was considerable variation in the amount by which secretion of an individual cytokine increased and there was also variation in the mechanosensitivity of cells from the three different sources. Cyclic hydrostatic pressure, therefore, may be an important modulator of the response of alveolar macrophages to cotton particles, but the source of the cells may be a confounding factor which demands further investigation.
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Abstract
OBJECTIVE Uncertainties about the numerous degrees of freedom in ventilator settings leave many unanswered questions about the biophysical determinants of lung injury. We investigated whether mechanical ventilation with high air flow could yield lung mechanical stress even in normal animals. DESIGN Prospective, randomized, controlled experimental study. SETTING University research laboratory. SUBJECTS Thirty normal male Wistar rats (180-230 g). INTERVENTIONS Rats were ventilated for 2 hrs with tidal volume of 10 mL/kg and either with normal inspiratory air flow (V') of 10 mL/s (F10) or high V' of 30 mL/s (F30). In the control group, animals did not undergo mechanical ventilation. Because high flow led to elevated respiratory rate (200 breaths/min) and airway peak inspiratory pressure (PIP,aw = 17 cm H2O), two additional groups were established to rule out the potential contribution of these variables: a) normal respiratory rate = 100 breaths/min and V' = 30 mL/sec; and b) PIP,aw = 17 cm H2O and V' = 10 mL/sec. MEASUREMENTS AND MAIN RESULTS Lung mechanics and histology (light and electron microscopy), arterial blood gas analysis, and type III procollagen messenger RNA expression in lung tissue were analyzed. Ultrastructural microscopy was similar in control and F10 groups. High air flow led to increased lung plateau and peak pressures, hypoxemia, alveolar hyperinflation and collapse, pulmonary neutrophilic infiltration, and augmented type III procollagen messenger RNA expression compared with control rats. The reduction of respiratory rate did not modify the morphofunctional behavior observed in the presence of increased air flow. Even though the increase in peak pressure yielded mechanical and histologic changes, type III procollagen messenger RNA expression remained unaltered. CONCLUSIONS Ventilation with high inspiratory air flow may lead to high tensile and shear stresses resulting in lung functional and morphologic compromise and elevation of type III procollagen messenger RNA expression.
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The Extracellular Matrix of the Lung: The Forgotten Friend! Intensive Care Med 2007. [DOI: 10.1007/978-0-387-49518-7_29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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