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Ren C, Chang Z, Li K, Wang X, Wang D, Xu Y, Li X, Li Q. Impact of uniaxial cyclic stretching on matrix-associated endothelial cell responses. Mater Today Bio 2024; 27:101152. [PMID: 39104901 PMCID: PMC11298614 DOI: 10.1016/j.mtbio.2024.101152] [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: 04/09/2024] [Revised: 06/07/2024] [Accepted: 07/08/2024] [Indexed: 08/07/2024] Open
Abstract
Uniaxial cyclic stretching plays a pivotal role in the fields of tissue engineering and regenerative medicine, influencing cell behaviors and functionality based on physical properties, including matrix morphology and mechanical stimuli. This study delves into the response of endothelial cells to uniaxial cyclic strain within the geometric constraints of micro-nano fibers. Various structural scaffold forms of poly(l-lactide-co-caprolactone) (PLCL), such as flat membranes, randomly oriented fiber membranes, and aligned fiber membranes, were fabricated through solvent casting and electrospinning methods. Our investigation focuses on the morphological variation of endothelial cells under diverse geometric constraints and the mechanical-dependent release of nitric oxide (NO) on oriented fibrous membranes. Our results indicate that while uniaxial cyclic stretching promotes endothelial cell spreading, the anisotropy of the matrix morphology remains the primary driving factor for cell alignment. Additionally, uniaxial cyclic stretching significantly enhances NO release, with a notably stronger effect correlated to the increasing strain amplitude. Importantly, this study reveals that uniaxial cyclic stretching enhances the mRNA expression of key proteins, including talin, vinculin, rac, and nitric oxide synthase (eNOS).
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Affiliation(s)
- Cuihong Ren
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou, 450001, PR China
- National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou, 450001, PR China
| | - Zhonghua Chang
- Institute of Laser Manufacturing, Henan Academy of Sciences, Zhengzhou, 450046, PR China
| | - Kecheng Li
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou, 450001, PR China
- National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou, 450001, PR China
| | - Xiaofeng Wang
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou, 450001, PR China
- National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou, 450001, PR China
| | - Dongfang Wang
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou, 450001, PR China
- National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou, 450001, PR China
| | - Yiyang Xu
- National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou, 450001, PR China
| | - Xiaomeng Li
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou, 450001, PR China
- National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou, 450001, PR China
| | - Qian Li
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou, 450001, PR China
- National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou, 450001, PR China
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Ketelhut S, Oechslin L, Zehnder C, Kubica C, Nigg CR. Acute self-myofascial release modulates cardiac autonomic function and hemodynamic parameters at rest and reduces cardiovascular stress reaction. Eur J Appl Physiol 2024; 124:1535-1545. [PMID: 38157043 PMCID: PMC11055748 DOI: 10.1007/s00421-023-05382-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 11/22/2023] [Indexed: 01/03/2024]
Abstract
PURPOSE Self-myofascial release (SMR) is a form of self-massage aiming to release tension, improve blood flow, and alleviate muscle soreness. This study aimed to determine whether a single session of SMR could impact cardiovascular parameters at rest and during a cold pressor test (CPT). METHODS Twenty male participants (aged 26 ± 2 years) underwent a 20-min SMR and a 20-min seated control condition (CON) on two separate test days in a randomized order. Peripheral and central blood pressure (BP), total peripheral resistance (TPR), pulse wave velocity (PWV), heart rate (HR), root mean square of successive RR interval differences (RMSSD), and the quotient of low-frequency power and high-frequency power (LF/HF) were measured both at rest and during a CPT before (t0), 2 min (t1), and 20 min (t2) after the SMR and CON. RESULTS Time × condition interactions could be detected for peripheral and central diastolic BP, TPR, HR, and RMSSD. Following the SMR, peripheral diastolic BP, central diastolic BP, TPR, and RMSSD were reduced, while HR was increased compared to the CON. Regarding the CPT time × condition interactions could be detected for peripheral, and central diastolic BP, with lower values after SMR. CONCLUSION The results of the present study suggest that a single bout of SMR confers favorable cardiovascular benefits in healthy normotensive individuals. Furthermore, SMR can attenuate the hemodynamic reactivity to a stress test. Future research should address whether regular SMR leads to chronic adaptations similar to regular, moderate aerobic exercise, massage therapy, and static stretching.
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Affiliation(s)
- Sascha Ketelhut
- Institute of Sports Science, University of Bern, Bremgartenstrasse 145, 3013, Bern, Switzerland.
| | - Livia Oechslin
- Institute of Sports Science, University of Bern, Bremgartenstrasse 145, 3013, Bern, Switzerland
| | - Cäcilia Zehnder
- Institute of Sports Science, University of Bern, Bremgartenstrasse 145, 3013, Bern, Switzerland
| | - Claudia Kubica
- Institute of Sports Science, University of Bern, Bremgartenstrasse 145, 3013, Bern, Switzerland
| | - Claudio R Nigg
- Institute of Sports Science, University of Bern, Bremgartenstrasse 145, 3013, Bern, Switzerland
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Dalton C, Ahn J, Jeyarajan G, Krigolson OE, Heath M. Distinct cortical haemodynamics during squat-stand and continuous aerobic exercise do not influence the magnitude of a postexercise executive function benefit. J Sports Sci 2023; 41:1459-1470. [PMID: 37884880 DOI: 10.1080/02640414.2023.2275086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 10/18/2023] [Indexed: 10/28/2023]
Abstract
A single bout of aerobic exercise benefits executive function (EF). A potential mechanism for this benefit is an exercise-mediated increase in cerebral blood flow (CBF) that elicits vascular endothelial shear-stress improving EF efficiency. Moderate intensity continuous aerobic exercise (MCE) asymptotically increases CBF, whereas continuous body weight squat-stand exercise (SSE) provides a large amplitude oscillatory response. Some work has proposed that an increase in CBF oscillation amplitude provides the optimal shear-stress for improving EF and brain health. We examined whether a large amplitude oscillatory CBF response associated with a single bout of SSE imparts a larger postexercise EF benefit than an MCE cycle ergometer protocol. Exercise changes in middle cerebral artery velocity (MCAv) were measured via transcranial Doppler ultrasound to estimate CBF, and pre- and postexercise EF was assessed via the antisaccade task. MCE produced a steady state increase in MCAv, whereas SSE produced a large amplitude MCAv oscillation. Both conditions produced a postexercise EF benefit that null hypothesis and equivalence tests showed to be comparable in magnitude. Accordingly, we provide a first demonstration that a single bout of SSE benefits EF; however, the condition's oscillatory CBF response does not impart a larger benefit than a time- and intensity-matched MCE protocol.
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Affiliation(s)
- Connor Dalton
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, London, ON, Canada
| | - Joshua Ahn
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, London, ON, Canada
| | - Gianna Jeyarajan
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, London, ON, Canada
| | - Olave E Krigolson
- Centre for Biomedical Research, University of Victoria, Victoria, BC, Canada
| | - Matthew Heath
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, London, ON, Canada
- Canadian Centre for Activity and Aging, University of Western Ontario, London, ON, Canada
- Graduate Program in Neuroscience, University of Western Ontario, London, ON, Canada
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Ernst BP, Heinrich UR, Fries M, Meuser R, Rader T, Eckrich J, Stauber RH, Strieth S. Cochlear implantation impairs intracochlear microcirculation and counteracts iNOS induction in guinea pigs. Front Cell Neurosci 2023; 17:1189980. [PMID: 37448696 PMCID: PMC10336219 DOI: 10.3389/fncel.2023.1189980] [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: 03/20/2023] [Accepted: 06/06/2023] [Indexed: 07/15/2023] Open
Abstract
Introduction Preservation of residual hearing remains a great challenge during cochlear implantation. Cochlear implant (CI) electrode array insertion induces changes in the microvasculature as well as nitric oxide (NO)-dependent vessel dysfunction which have been identified as possible mediators of residual hearing loss after cochlear implantation. Methods A total of 24 guinea pigs were randomized to receive either a CI (n = 12) or a sham procedure (sham) by performing a cochleostomy without electrode array insertion (n = 12). The hearing threshold was determined using frequency-specific compound action potentials. To gain visual access to the stria vascularis, a microscopic window was created in the osseous cochlear lateral wall. Cochlear blood flow (CBF) and cochlear microvascular permeability (CMP) were evaluated immediately after treatment, as well as after 1 and 2 h, respectively. Finally, cochleae were resected for subsequent immunohistochemical analysis of the iNOS expression. Results The sham control group showed no change in mean CBF after 1 h (104.2 ± 0.7%) and 2 h (100.8 ± 3.6%) compared to baseline. In contrast, cochlear implantation resulted in a significant continuous decrease in CBF after 1 h (78.8 ± 8.1%, p < 0.001) and 2 h (60.6 ± 11.3%, p < 0.001). Additionally, the CI group exhibited a significantly increased CMP (+44.9% compared to baseline, p < 0.0001) and a significant increase in median hearing threshold (20.4 vs. 2.5 dB SPL, p = 0.0009) compared to sham after 2 h. Intriguingly, the CI group showed significantly lower iNOS-expression levels in the organ of Corti (329.5 vs. 54.33 AU, p = 0.0003), stria vascularis (596.7 vs. 48.51 AU, p < 0.0001), interdental cells (564.0 vs. 109.1 AU, p = 0.0003) and limbus fibrocytes (119.4 vs. 18.69 AU, p = 0.0286). Conclusion Mechanical and NO-dependent microvascular dysfunction seem to play a pivotal role in residual hearing loss after CI electrode array insertion. This may be facilitated by the implantation associated decrease in iNOS expression. Therefore, stabilization of cochlear microcirculation could be a therapeutic strategy to preserve residual hearing.
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Affiliation(s)
| | - Ulf-Rüdiger Heinrich
- Department of Otorhinolaryngology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Mathias Fries
- Department of Otorhinolaryngology, University Medical Center Bonn (UKB), Bonn, Germany
| | - Regina Meuser
- Institute for Medical Biometry, Epidemiology and Informatics (IMBEI), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Tobias Rader
- Division of Audiology, Department of Otorhinolaryngology, University Hospital, Ludwig-Maximilians-Universität München (LMU), Munich, Germany
| | - Jonas Eckrich
- Department of Otorhinolaryngology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Roland H. Stauber
- Department of Otorhinolaryngology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Sebastian Strieth
- Department of Otorhinolaryngology, University Medical Center Bonn (UKB), Bonn, Germany
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Yuan Y. Clinical Translation of Engineered Pulmonary Vascular Models. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1413:273-288. [PMID: 37195536 DOI: 10.1007/978-3-031-26625-6_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Diseases in pulmonary vasculature remain a major cause of morbidity and mortality worldwide. Numerous pre-clinical animal models were developed to understand lung vasculature during diseases and development. However, these systems are typically limited in their ability to represent human pathophysiology for the study of disease and drug mechanisms. In recent years, a growing number of studies have focused on developing in vitro experimental platforms that mimic human tissues/organs. In this chapter, we discuss the key components involved in developing engineered pulmonary vascular modeling systems and provide perspectives on ways to improve the translational potential of existing models.
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Affiliation(s)
- Yifan Yuan
- Department of Medicine (Pulmonary), Department of Anesthesiology, Yale University, New Haven, CT, USA.
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Gorgisen G, Aydin M, Mboma O, Gökyildirim MY, Chao CM. The Role of Insulin Receptor Substrate Proteins in Bronchopulmonary Dysplasia and Asthma: New Potential Perspectives. Int J Mol Sci 2022; 23:ijms231710113. [PMID: 36077511 PMCID: PMC9456457 DOI: 10.3390/ijms231710113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 01/12/2023] Open
Abstract
Insulin receptor substrates (IRSs) are proteins that are involved in signaling through the insulin receptor (IR) and insulin-like growth factor (IGFR). They can also interact with other receptors including growth factor receptors. Thus, they represent a critical node for the transduction and regulation of multiple signaling pathways in response to extracellular stimuli. In addition, IRSs play a central role in processes such as inflammation, growth, metabolism, and proliferation. Previous studies have highlighted the role of IRS proteins in lung diseases, in particular asthma. Further, the members of the IRS family are the common proteins of the insulin growth factor signaling cascade involved in lung development and disrupted in bronchopulmonary dysplasia (BPD). However, there is no study focusing on the relationship between IRS proteins and BPD yet. Unfortunately, there is still a significant gap in knowledge in this field. Thus, in this review, we aimed to summarize the current knowledge with the major goal of exploring the possible roles of IRS in BPD and asthma to foster new perspectives for further investigations.
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Affiliation(s)
- Gokhan Gorgisen
- Department of Medical Genetics, Faculty of Medicine, Van Yüzüncü Yil University, Van 65080, Turkey
| | - Malik Aydin
- Laboratory of Experimental Pediatric Pneumology and Allergology, Center for Biomedical Education and Research, School of Life Sciences (ZBAF), Faculty of Health, Witten/Herdecke University, 58455 Witten, Germany
- Center for Child and Adolescent Medicine, Center for Clinical and Translational Research (CCTR), Helios University Hospital Wuppertal, Witten/Herdecke University, 42283 Wuppertal, Germany
| | - Olivier Mboma
- Laboratory of Experimental Pediatric Pneumology and Allergology, Center for Biomedical Education and Research, School of Life Sciences (ZBAF), Faculty of Health, Witten/Herdecke University, 58455 Witten, Germany
- Center for Child and Adolescent Medicine, Center for Clinical and Translational Research (CCTR), Helios University Hospital Wuppertal, Witten/Herdecke University, 42283 Wuppertal, Germany
| | - Mira Y. Gökyildirim
- Department of Pediatrics, University Medical Center Rostock, University of Rostock, 18057 Rostock, Germany
| | - Cho-Ming Chao
- Department of Pediatrics, University Medical Center Rostock, University of Rostock, 18057 Rostock, Germany
- Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus Liebig University Giessen, 35390 Giessen, Germany
- Correspondence: ; Tel.: +49-641-9946735
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Electrochemical microwell sensor with Fe-N co-doped carbon catalyst to monitor nitric oxide release from endothelial cell spheroids. ANAL SCI 2022; 38:1297-1304. [PMID: 35895213 DOI: 10.1007/s44211-022-00160-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 06/23/2022] [Indexed: 11/01/2022]
Abstract
Endothelial cells have been widely used for vascular biology studies; recent progress in tissue engineering have offered three-dimensional (3D) culture systems for vascular endothelial cells which can be considered as physiologically relevant models. To facilitate the studies, we developed an electrochemical device to detect nitric oxide (NO), a key molecule in the vasculature, for the evaluation of 3D cultured endothelial cells. Using an NO-sensitive catalyst composed of Fe-N co-doped reduced graphene oxide, the real-time monitoring of NO release from the endothelial cell spheroids was demonstrated.
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Abstract
Pulmonary hypertension (PH) due to left heart disease (LHD; group 2 PH) is a common complication of heart failure with reduced ejection fraction and heart failure with preserved ejection fraction and is often related to disease severity and duration of these diseases. PH due to LHD is associated with negative impact on outcomes in addition to worse symptoms and exercise capacity. Risk factors for group 2 PH are older age, hypertension, atrial fibrillation, and features of metabolic syndrome. The main mechanisms for group 2 PH are believed to be vascular remodeling secondary to sustained elevated intravascular pressure.
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Affiliation(s)
- Ayedh K Alamri
- Department of Medicine, University of Utah, University of Utah School of Medicine, 30 North 1900 East, Room 4C116, Salt Lake City, UT 84132, USA
| | - Christy L Ma
- Division of Cardiovascular Medicine, Department of Medicine, University of Utah, University of Utah School of Medicine, 30 North 1900 East, Room 4A100, Salt Lake City, UT 84132, USA
| | - John J Ryan
- Division of Cardiovascular Medicine, Department of Medicine, University of Utah, University of Utah School of Medicine, 30 North 1900 East, Room 4A100, Salt Lake City, UT 84132, USA.
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Hollósi A, Pászty K, Kellermayer M, Charras G, Varga A. BRAF Modulates Stretch-Induced Intercellular Gap Formation through Localized Actin Reorganization. Int J Mol Sci 2021; 22:ijms22168989. [PMID: 34445693 PMCID: PMC8396467 DOI: 10.3390/ijms22168989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/17/2021] [Accepted: 08/17/2021] [Indexed: 01/02/2023] Open
Abstract
Mechanical forces acting on cell–cell adhesion modulate the barrier function of endothelial cells. The actively remodeled actin cytoskeleton impinges on cell–cell adhesion to counteract external forces. We applied stress on endothelial monolayers by mechanical stretch to uncover the role of BRAF in the stress-induced response. Control cells responded to external forces by organizing and stabilizing actin cables in the stretched cell junctions. This was accompanied by an increase in intercellular gap formation, which was prevented in BRAF knockdown monolayers. In the absence of BRAF, there was excess stress fiber formation due to the enhanced reorganization of actin fibers. Our findings suggest that stretch-induced intercellular gap formation, leading to a decrease in barrier function of blood vessels, can be reverted by BRAF RNAi. This is important when the endothelium experiences changes in external stresses caused by high blood pressure, leading to edema, or by immune or cancer cells in inflammation or metastasis.
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Affiliation(s)
- Anna Hollósi
- Department of Biophysics and Radiation Biology, Semmelweis University, H-1094 Budapest, Hungary; (A.H.); (K.P.); (M.K.)
| | - Katalin Pászty
- Department of Biophysics and Radiation Biology, Semmelweis University, H-1094 Budapest, Hungary; (A.H.); (K.P.); (M.K.)
| | - Miklós Kellermayer
- Department of Biophysics and Radiation Biology, Semmelweis University, H-1094 Budapest, Hungary; (A.H.); (K.P.); (M.K.)
| | - Guillaume Charras
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK;
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Andrea Varga
- Department of Biophysics and Radiation Biology, Semmelweis University, H-1094 Budapest, Hungary; (A.H.); (K.P.); (M.K.)
- Correspondence:
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Stretching is Superior to Brisk Walking for Reducing Blood Pressure in People With High-Normal Blood Pressure or Stage I Hypertension. J Phys Act Health 2021; 18:21-28. [PMID: 33338988 DOI: 10.1123/jpah.2020-0365] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 09/29/2020] [Accepted: 10/06/2020] [Indexed: 01/12/2023]
Abstract
BACKGROUND Aerobic exercise is recommended for reducing blood pressure; however, recent studies indicate that stretching may also be effective. The authors compared 8 weeks of stretching versus walking exercise in men and women with high-normal blood pressure or stage 1 hypertension (ie, 130/85-159/99 mm Hg). METHODS Forty men and women (61.6 y) were randomized to a stretching or brisk walking exercise program (30 min/d, 5 d/wk for 8 wk). Blood pressure was assessed during sitting and supine positions and for 24 hours using a portable monitor before and after the training programs. RESULTS The stretching program elicited greater reductions than the walking program (P < .05) for sitting systolic (146 [9] to 140 [12] vs 139 [9] to 142 [12] mm Hg), supine diastolic (85 [7] to 78 [8] vs 81 [7] to 82 [7] mm Hg), and nighttime diastolic (67 [8] to 65 [10] vs 68 [8] to 73 [12] mm Hg) blood pressures. The stretching program elicited greater reductions than the walking program (P < .05) for mean arterial pressure assessed in sitting (108 [7] to 103 [6] vs 105 [6] vs 105 [8] mm Hg), supine (102 [9] to 96 [9] vs 99 [6] to 99 [7] mm Hg), and at night (86 [9] to 83 [10] vs 88 [9] to 93 [12] mm Hg). CONCLUSIONS An 8-week stretching program was superior to brisk walking for reducing blood pressure in individuals with high-normal blood pressure or stage 1 hypertension.
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Dull RO, Chignalia AZ. The Glycocalyx and Pressure-Dependent Transcellular Albumin Transport. Cardiovasc Eng Technol 2020; 11:655-662. [PMID: 33006050 PMCID: PMC7782381 DOI: 10.1007/s13239-020-00489-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/24/2020] [Indexed: 12/17/2022]
Abstract
Purpose Acute increases in hydrostatic pressure activate endothelial signaling pathways that modulate barrier function and vascular permeability. We investigated the role the glycocalyx and established mechanotransduction pathways in pressure-induced albumin transport across rat lung microvascular endothelial cells.
Methods Rat lung microvascular endothelial cells (RLMEC) were cultured on Costar Snapwell chambers. Cell morphology was assessed using silver nitrate staining. RLMEC were exposed to zero pressure (Control) or 30 cmH2O (Pressure) for 30 or 60 min. Intracellular albumin uptake and transcellular albumin transport was quantified. Transcellular transport was reported as solute flux (Js) and an effective permeability coefficient (Pe). The removal of cell surface heparan sulfates (heparinase), inhibition of NOS (L-NAME) and reactive oxygen species (apocynin, Apo) was investigated. Results Acute increase in hydrostatic pressure augmented albumin uptake by 30–40% at 60 min and Js and Pe both increased significantly. Heparinase increased albumin uptake but attenuated transcellular transport while L-NAME attenuated both pressure-dependent albumin uptake and transport. Apo interrupted albumin uptake under both control and pressure conditions, leading to a near total lack of transcellular transport, suggesting a different mechanism and/or site of action. Conclusion Pressure-dependent albumin uptake and transcellular transport is another component of endothelial mechanotransduction and associated regulation of solute flux. This novel albumin uptake and transport pathway is regulated by heparan sulfates and eNOS. Albumin uptake is sensitive to ROS. The physiological and clinical implications of this albumin transport are discussed.
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Affiliation(s)
- Randal O Dull
- Department of Anesthesiology, University of Illinois College of Medicine, Chicago, IL, USA. .,Department of Anesthesiology, Banner-University Medical Center, University of Arizona College of Medicine, Suite 4401, 1501 N. Campbell Avenue, Tucson, AZ, 85724-5114, USA. .,Department of Pathology, Banner-University Medical Center, University of Arizona College of Medicine, Tucson, AZ, USA. .,Department of Surgery, Banner-University Medical Center, University of Arizona College of Medicine, Tucson, AZ, USA.
| | - Andreia Z Chignalia
- Department of Anesthesiology, University of Illinois College of Medicine, Chicago, IL, USA.,Department of Anesthesiology, Banner-University Medical Center, University of Arizona College of Medicine, Suite 4401, 1501 N. Campbell Avenue, Tucson, AZ, 85724-5114, USA.,Department of Physiology, Banner-University Medical Center, University of Arizona College of Medicine, Tucson, AZ, USA.,Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ, USA
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Jin ZH, Liu YL, Fan WT, Huang WH. Integrating Flexible Electrochemical Sensor into Microfluidic Chip for Simulating and Monitoring Vascular Mechanotransduction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1903204. [PMID: 31402582 DOI: 10.1002/smll.201903204] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Indexed: 05/20/2023]
Abstract
As an interface between the blood flow and vessel wall, endothelial cells (ECs) are exposed to hemodynamic forces, and the biochemical molecules released from ECs-blood flow interaction are important determinants of vascular homeostasis. Versatile microfluidic chips have been designed to simulate the biological and physiological parameters of the human vascular system, but in situ and real-time monitoring of the mechanical force-triggered signals during vascular mechanotransduction still remains a significant challenge. Here, such challenge is fulfilled for the first time, by preparation of a flexible and stretchable electrochemical sensor and its incorporation into a microfluidic vascular chip. This allows simulating of in vivo physiological and biomechanical parameters of blood vessels, and simultaneously monitoring the mechanically induced biochemical signals in real time. Specifically, the cyclic circumferential stretch that is actually exerted on endothelium but is hard to reproduce in vitro is successfully recapitulated, and nitric oxide signals under normal blood pressure, as well as reactive oxygen species signals under hypertensive states, are well documented. Here, the first integration of a flexible electrochemical sensor into a microfluidic chip is reported, therefore paving a way to evaluate in vitro organs by built-in flexible sensors.
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Affiliation(s)
- Zi-He Jin
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
| | - Yan-Ling Liu
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
| | - Wen-Ting Fan
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
| | - Wei-Hua Huang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
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Arishe OO, Ebeigbe AB, Webb RC. Mechanotransduction and Uterine Blood Flow in Preeclampsia: The Role of Mechanosensing Piezo 1 Ion Channels. Am J Hypertens 2020; 33:1-9. [PMID: 31545339 PMCID: PMC7768673 DOI: 10.1093/ajh/hpz158] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 09/13/2019] [Accepted: 09/19/2019] [Indexed: 12/31/2022] Open
Abstract
There is a large increase in uterine arterial blood flow during normal pregnancy. Structural and cellular adjustments occur in the uterine vasculature during pregnancy to accommodate this increased blood flow through a complex adaptive process that is dependent on multiple coordinated and interactive influences and this process is known as "vascular remodeling." The etiology of preeclampsia involves aberrant placentation and vascular remodeling leading to reduced uteroplacental perfusion. The placental ischemia leads to development of hypertension and proteinuria in the mother, intrauterine growth restriction, and perinatal death in the fetus. However, the underlying source of the deficient vascular remodeling and the subsequent development of preeclampsia remain to be fully understood. Mechanoreceptors in the vascular system convert mechanical force (shear stress) to biochemical signals and feedback mechanisms. This review focuses on the Piezo 1 channel, a mechanosensitive channel that is sensitive to shear stress in the endothelium; it induces Ca2+ entry which is linked to endothelial nitric oxide synthase (eNOS) activation as the mechanoreceptor responsible for uterine vascular dilatation during pregnancy. Here we describe the downstream signaling pathways involved in this process and the possibility of a deficiency in expression of Piezo 1 in preeclampsia leading to the abnormal vascular dysfunction responsible for the pathophysiology of the disease. The Piezo 1 ion channel is expressed in the endothelium and vascular smooth muscle cells (VSMCs) of small-diameter arteries. It plays a role in the structural remodeling of arteries and is involved in mechanotransduction of hemodynamic shear stress by endothelial cells (ECs).
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Affiliation(s)
- Olufunke O Arishe
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
- Department of Physiology, College of Medical Sciences, University of Benin, Benin City, Nigeria
| | - Anthony B Ebeigbe
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
- Department of Physiology, College of Medical Sciences, University of Benin, Benin City, Nigeria
| | - R Clinton Webb
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
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14
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Wu CS, Chou HC, Huang LT, Lin CM, Lin YK, Chen CM. High amplitude bubble continuous positive airway pressure decreases lung injury in rats with ventilator-induced lung injury. J Chin Med Assoc 2019; 82:795-801. [PMID: 30893255 DOI: 10.1097/jcma.0000000000000070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Bubble continuous positive airway pressure (BCPAP) has been used in neonates with respiratory distress for decades; however, the optimal setting for BCPAP circuits remains unknown. This study compared the gas exchange efficiency and lung protection efficacy between conventional and high-amplitude BCPAP devices. METHODS We compared gas exchange, lung volume, and pulmonary inflammation severity among rats with ventilator-induced lung injury (VILI) that were treated with conventional BCPAP (BCPAP with an expiratory limb at 0°), high-amplitude BCPAP (BCPAP with an expiratory limb at 135°), or spontaneous breathing (SB). After mechanical ventilation for 90 minutes, the rats were randomly divided into four groups: a control group (euthanized immediately; n = 3), an SB group (n = 8), and two BCPAP groups that received BCPAP with the expiratory limb at either 0° (n = 8) or 135° (n = 7) for 90 minutes. RESULTS The high-amplitude BCPAP group exhibited significantly lower alveolar protein, lung volume, and Interleukin-6 (IL-6) levels than did the SB group. The high-amplitude BCPAP group exhibited significantly lower IL-6 levels than did the conventional BCPAP group. The two BCPAP groups demonstrated no difference in gas exchange efficiency. CONCLUSION High-amplitude BCPAP reduced lung inflammation and alveolar overdistension in rats with VILI after mechanical ventilation was ceased. Thus high-amplitude BCPAP may offer a superior lung protective effect than conventional BCPAP.
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Affiliation(s)
- Chun-Shan Wu
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC
- Department of Pediatrics, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan, Taiwan, ROC
| | - Hsiu-Chu Chou
- Department of Anatomy and Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC
| | - Liang-Ti Huang
- Department of Pediatrics, Wan Fang Hospital, Taipei, Taiwan, ROC
- Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC
| | - Chun-Mao Lin
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC
| | - Yen-Kuang Lin
- Biostatistics Research Center, Taipei Medical University, Taipei, Taiwan, ROC
- Graduate Institute of Nursing, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC
| | - Chung-Ming Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC
- Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC
- Department of Pediatrics, Taipei Medical University Hospital, Taipei, Taiwan, ROC
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15
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Grune J, Tabuchi A, Kuebler WM. Alveolar dynamics during mechanical ventilation in the healthy and injured lung. Intensive Care Med Exp 2019; 7:34. [PMID: 31346797 PMCID: PMC6658629 DOI: 10.1186/s40635-019-0226-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 02/13/2019] [Indexed: 02/12/2023] Open
Abstract
Mechanical ventilation is a life-saving therapy in patients with acute respiratory distress syndrome (ARDS). However, mechanical ventilation itself causes severe co-morbidities in that it can trigger ventilator-associated lung injury (VALI) in humans or ventilator-induced lung injury (VILI) in experimental animal models. Therefore, optimization of ventilation strategies is paramount for the effective therapy of critical care patients. A major problem in the stratification of critical care patients for personalized ventilation settings, but even more so for our overall understanding of VILI, lies in our limited insight into the effects of mechanical ventilation at the actual site of injury, i.e., the alveolar unit. Unfortunately, global lung mechanics provide for a poor surrogate of alveolar dynamics and methods for the in-depth analysis of alveolar dynamics on the level of individual alveoli are sparse and afflicted by important limitations. With alveolar dynamics in the intact lung remaining largely a "black box," our insight into the mechanisms of VALI and VILI and the effectiveness of optimized ventilation strategies is confined to indirect parameters and endpoints of lung injury and mortality.In the present review, we discuss emerging concepts of alveolar dynamics including alveolar expansion/contraction, stability/instability, and opening/collapse. Many of these concepts remain still controversial, in part due to limitations of the different methodologies applied. We therefore preface our review with an overview of existing technologies and approaches for the analysis of alveolar dynamics, highlighting their individual strengths and limitations which may provide for a better appreciation of the sometimes diverging findings and interpretations. Joint efforts combining key technologies in identical models to overcome the limitations inherent to individual methodologies are needed not only to provide conclusive insights into lung physiology and alveolar dynamics, but ultimately to guide critical care patient therapy.
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Affiliation(s)
- Jana Grune
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Berlin, 10117 Berlin, Germany
| | - Arata Tabuchi
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Wolfgang M. Kuebler
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Berlin, 10117 Berlin, Germany
- The Keenan Research Centre for Biomedical Science at St. Michael’s, Toronto, Canada
- Departments of Surgery and Physiology, University of Toronto, Toronto, Canada
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16
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Park BH, Shin MH, Douglas IS, Chung KS, Song JH, Kim SY, Kim EY, Jung JY, Kang YA, Chang J, Kim YS, Park MS. Erythropoietin-Producing Hepatoma Receptor Tyrosine Kinase A2 Modulation Associates with Protective Effect of Prone Position in Ventilator-induced Lung Injury. Am J Respir Cell Mol Biol 2019; 58:519-529. [PMID: 29216437 DOI: 10.1165/rcmb.2017-0143oc] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The erythropoietin-producing hepatoma (Eph) receptor tyrosine kinase A2 (EphA2) and its ligand, ephrinA1, play a pivotal role in inflammation and tissue injury by modulating the epithelial and endothelial barrier integrity. Therefore, EphA2 receptor may be a potential therapeutic target for modulating ventilator-induced lung injury (VILI). To support this hypothesis, here, we analyzed EphA2/ephrinA1 signaling in the process of VILI and determined the role of EphA2/ephrinA1 signaling in the protective mechanism of prone positioning in a VILI model. Wild-type mice were ventilated with high (24 ml/kg; positive end-expiratory pressure, 0 cm; 5 h) tidal volume in a supine or prone position. Anti-EphA2 receptor antibody or IgG was administered to the supine position group. Injury was assessed by analyzing the BAL fluid, lung injury scoring, and transmission electron microscopy. Lung lysates were evaluated using cytokine/chemokine ELISA and Western blotting of EphA2, ephrinA1, PI3Kγ, Akt, NF-κB, and P70S6 kinase. EphA2/ephrinA1 expression was higher in the supine high tidal volume group than in the control group, but it did not increase upon prone positioning or anti-EphA2 receptor antibody treatment. EphA2 antagonism reduced the extent of VILI and downregulated the expression of PI3Kγ, Akt, NF-κB, and P70S6 kinase. These findings demonstrate that EphA2/ephrinA1 signaling is involved in the molecular mechanism of VILI and that modulation of EphA2/ehprinA1 signaling by prone position or EphA2 antagonism may be associated with the lung-protective effect. Our data provide evidence for EphA2/ehprinA1 as a promising therapeutic target for modulating VILI.
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Affiliation(s)
- Byung Hoon Park
- 1 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Gyeonggi Provincial Medical Center Paju Hospital, Paju City, Gyeonggi-Do, Republic of Korea
| | - Mi Hwa Shin
- 2 Division of Pulmonology, The Institute of Chest Diseases, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Ivor S Douglas
- 3 Division of Pulmonary Sciences and Critical Care Medicine, Denver Health Medical Center, University of Colorado School of Medicine, Denver, Colorado
| | - Kyung Soo Chung
- 2 Division of Pulmonology, The Institute of Chest Diseases, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Joo Han Song
- 2 Division of Pulmonology, The Institute of Chest Diseases, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Song Yee Kim
- 2 Division of Pulmonology, The Institute of Chest Diseases, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Eun Young Kim
- 2 Division of Pulmonology, The Institute of Chest Diseases, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Ji Ye Jung
- 2 Division of Pulmonology, The Institute of Chest Diseases, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Young Ae Kang
- 2 Division of Pulmonology, The Institute of Chest Diseases, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Joon Chang
- 2 Division of Pulmonology, The Institute of Chest Diseases, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Young Sam Kim
- 2 Division of Pulmonology, The Institute of Chest Diseases, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; and
| | - Moo Suk Park
- 2 Division of Pulmonology, The Institute of Chest Diseases, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; and
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17
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Fang Y, Wu D, Birukov KG. Mechanosensing and Mechanoregulation of Endothelial Cell Functions. Compr Physiol 2019; 9:873-904. [PMID: 30873580 PMCID: PMC6697421 DOI: 10.1002/cphy.c180020] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Vascular endothelial cells (ECs) form a semiselective barrier for macromolecules and cell elements regulated by dynamic interactions between cytoskeletal elements and cell adhesion complexes. ECs also participate in many other vital processes including innate immune reactions, vascular repair, secretion, and metabolism of bioactive molecules. Moreover, vascular ECs represent a unique cell type exposed to continuous, time-dependent mechanical forces: different patterns of shear stress imposed by blood flow in macrovasculature and by rolling blood cells in the microvasculature; circumferential cyclic stretch experienced by the arterial vascular bed caused by heart propulsions; mechanical stretch of lung microvascular endothelium at different magnitudes due to spontaneous respiration or mechanical ventilation in critically ill patients. Accumulating evidence suggests that vascular ECs contain mechanosensory complexes, which rapidly react to changes in mechanical loading, process the signal, and develop context-specific adaptive responses to rebalance the cell homeostatic state. The significance of the interactions between specific mechanical forces in the EC microenvironment together with circulating bioactive molecules in the progression and resolution of vascular pathologies including vascular injury, atherosclerosis, pulmonary edema, and acute respiratory distress syndrome has been only recently recognized. This review will summarize the current understanding of EC mechanosensory mechanisms, modulation of EC responses to humoral factors by surrounding mechanical forces (particularly the cyclic stretch), and discuss recent findings of magnitude-specific regulation of EC functions by transcriptional, posttranscriptional and epigenetic mechanisms using -omics approaches. We also discuss ongoing challenges and future opportunities in developing new therapies targeting dysregulated mechanosensing mechanisms to treat vascular diseases. © 2019 American Physiological Society. Compr Physiol 9:873-904, 2019.
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Affiliation(s)
- Yun Fang
- Department of Medicine, University of Chicago, Chicago, Illinois, USA,Correspondence to
| | - David Wu
- Department of Medicine, University of Chicago, Chicago, Illinois, USA
| | - Konstantin G. Birukov
- Department of Anesthesiology, University of Maryland Baltimore School of Medicine, Baltimore, Maryland, USA
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18
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Modulators of Transient Receptor Potential (TRP) Channels as Therapeutic Options in Lung Disease. Pharmaceuticals (Basel) 2019; 12:ph12010023. [PMID: 30717260 PMCID: PMC6469169 DOI: 10.3390/ph12010023] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 12/25/2022] Open
Abstract
The lungs are essential for gas exchange and serve as the gateways of our body to the external environment. They are easily accessible for drugs from both sides, the airways and the vasculature. Recent literature provides evidence for a role of Transient Receptor Potential (TRP) channels as chemosensors and essential members of signal transduction cascades in stress-induced cellular responses. This review will focus on TRP channels (TRPA1, TRPC6, TRPV1, and TRPV4), predominantly expressed in non-neuronal lung tissues and their involvement in pathways associated with diseases like asthma, cystic fibrosis, chronic obstructive pulmonary disease (COPD), lung fibrosis, and edema formation. Recently identified specific modulators of these channels and their potential as new therapeutic options as well as strategies for a causal treatment based on the mechanistic understanding of molecular events will also be evaluated.
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19
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Chignalia AZ, Isbatan A, Patel M, Ripper R, Sharlin J, Shosfy J, Borlaug BA, Dull RO. Pressure-dependent NOS activation contributes to endothelial hyperpermeability in a model of acute heart failure. Biosci Rep 2018; 38:BSR20181239. [PMID: 30355657 PMCID: PMC6250809 DOI: 10.1042/bsr20181239] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 10/11/2018] [Accepted: 10/21/2018] [Indexed: 12/12/2022] Open
Abstract
Aims: Acute increases in left ventricular end diastolic pressure (LVEDP) can induce pulmonary edema (PE). The mechanism(s) for this rapid onset edema may involve more than just increased fluid filtration. Lung endothelial cell permeability is regulated by pressure-dependent activation of nitric oxide synthase (NOS). Herein, we demonstrate that pressure-dependent NOS activation contributes to vascular failure and PE in a model of acute heart failure (AHF) caused by hypertension.Methods and results: Male Sprague-Dawley rats were anesthetized and mechanically ventilated. Acute hypertension was induced by norepinephrine (NE) infusion and resulted in an increase in LVEDP and pulmonary artery pressure (Ppa) that were associated with a rapid fall in PaO2, and increases in lung wet/dry ratio and injury scores. Heart failure (HF) lungs showed increased nitrotyrosine content and ROS levels. L-NAME pretreatment mitigated the development of PE and reduced lung ROS concentrations to sham levels. Apocynin (Apo) pretreatment inhibited PE. Addition of tetrahydrobiopterin (BH4) to AHF rats lung lysates and pretreatment of AHF rats with folic acid (FA) prevented ROS production indicating endothelial NOS (eNOS) uncoupling.Conclusion: Pressure-dependent NOS activation leads to acute endothelial hyperpermeability and rapid PE by an increase in NO and ROS in a model of AHF. Acute increases in pulmonary vascular pressure, without NOS activation, was insufficient to cause significant PE. These results suggest a clinically relevant role of endothelial mechanotransduction in the pathogenesis of AHF and further highlights the concept of active barrier failure in AHF. Therapies targetting the prevention or reversal of endothelial hyperpermeability may be a novel therapeutic strategy in AHF.
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Affiliation(s)
- Andreia Z Chignalia
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A.
| | - Ayman Isbatan
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A
| | - Milan Patel
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A
| | - Richard Ripper
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A
- Research and Development Service, Jesse Brown Veterans Affairs Medical Center, 820 S Damen Ave., Chicago, IL 60612, U.S.A
| | - Jordan Sharlin
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A
| | - Joelle Shosfy
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A
| | - Barry A Borlaug
- Department of Cardiovascular Medicine, Mayo Clinic and Foundation, 200 First St SW, Rochester, MN 55905, U.S.A
| | - Randal O Dull
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL 60612, U.S.A
- Department of Anesthesiology, University of Arizona College of Medicine and Banner-University Medical Center, Tucson, AZ 85724, U.S.A
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20
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Kohn JC, Abdalrahman T, Sack KL, Reinhart-King CA, Franz T. Endothelial cells on an aged subendothelial matrix display heterogeneous strain profiles in silico. Biomech Model Mechanobiol 2018; 17:1405-1414. [PMID: 29802577 DOI: 10.1007/s10237-018-1034-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 05/16/2018] [Indexed: 10/24/2022]
Abstract
Within the artery intima, endothelial cells respond to mechanical cues and changes in subendothelial matrix stiffness. Recently, we found that the aging subendothelial matrix stiffens heterogeneously and that stiffness heterogeneities are present on the scale of one cell length. However, the impacts of these complex mechanical micro-heterogeneities on endothelial cells have not been fully understood. Here, we simulate the effects of matrices that mimic young and aged vessels on single- and multi-cell endothelial cell models and examine the resulting cell basal strain profiles. Although there are limitations to the model which prohibit the prediction of intracellular strain distributions in alive cells, this model does introduce mechanical complexities to the subendothelial matrix material. More heterogeneous basal strain distributions are present in the single- and multi-cell models on the matrix mimicking an aged artery over those exhibited on the young artery. Overall, our data indicate that increased heterogeneous strain profiles in endothelial cells are displayed in silico when there is an increased presence of microscale arterial mechanical heterogeneities in the matrix.
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Affiliation(s)
- J C Kohn
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, College of Engineering, Cornell University, Ithaca, NY, USA.,Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Observatory, South Africa
| | - T Abdalrahman
- Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Observatory, South Africa
| | - K L Sack
- Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Observatory, South Africa
| | - C A Reinhart-King
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, College of Engineering, Cornell University, Ithaca, NY, USA.,Department of Biomedical Engineering, School of Engineering, Vanderbilt University, Nashville, TN, USA
| | - T Franz
- Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Observatory, South Africa. .,Bioengineering Science Research Group, Engineering Sciences, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK.
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21
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Hotta K, Behnke BJ, Arjmandi B, Ghosh P, Chen B, Brooks R, Maraj JJ, Elam ML, Maher P, Kurien D, Churchill A, Sepulveda JL, Kabolowsky MB, Christou DD, Muller-Delp JM. Daily muscle stretching enhances blood flow, endothelial function, capillarity, vascular volume and connectivity in aged skeletal muscle. J Physiol 2018; 596:1903-1917. [PMID: 29623692 DOI: 10.1113/jp275459] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 02/19/2018] [Indexed: 01/04/2023] Open
Abstract
KEY POINTS In aged rats, daily muscle stretching increases blood flow to skeletal muscle during exercise. Daily muscle stretching enhanced endothelium-dependent vasodilatation of skeletal muscle resistance arterioles of aged rats. Angiogenic markers and capillarity increased in response to daily stretching in muscles of aged rats. Muscle stretching performed with a splint could provide a feasible means of improving muscle blood flow and function in elderly patients who cannot perform regular aerobic exercise. ABSTRACT Mechanical stretch stimuli alter the morphology and function of cultured endothelial cells; however, little is known about the effects of daily muscle stretching on adaptations of endothelial function and muscle blood flow. The present study aimed to determine the effects of daily muscle stretching on endothelium-dependent vasodilatation and muscle blood flow in aged rats. The lower hindlimb muscles of aged Fischer rats were passively stretched by placing an ankle dorsiflexion splint for 30 min day-1 , 5 days week-1 , for 4 weeks. Blood flow to the stretched limb and the non-stretched contralateral limb was determined at rest and during treadmill exercise. Endothelium-dependent/independent vasodilatation was evaluated in soleus muscle arterioles. Levels of hypoxia-induced factor-1α, vascular endothelial growth factor A and neuronal nitric oxide synthase were determined in soleus muscle fibres. Levels of endothelial nitric oxide synthase and superoxide dismutase were determined in soleus muscle arterioles, and microvascular volume and capillarity were evaluated by microcomputed tomography and lectin staining, respectively. During exercise, blood flow to plantar flexor muscles was significantly higher in the stretched limb. Endothelium-dependent vasodilatation was enhanced in arterioles from the soleus muscle from the stretched limb. Microvascular volume, number of capillaries per muscle fibre, and levels of hypoxia-induced factor-1α, vascular endothelial growth factor and endothelial nitric oxide synthase were significantly higher in the stretched limb. These results indicate that daily passive stretching of muscle enhances endothelium-dependent vasodilatation and induces angiogenesis. These microvascular adaptations may contribute to increased muscle blood flow during exercise in muscles that have undergone daily passive stretch.
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Affiliation(s)
- Kazuki Hotta
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA.,Department of Engineering Science, University of Electro-communications, Tokyo, Japan
| | - Bradley J Behnke
- Department of Kinesiology, Kansas State University College of Human Ecology, Manhattan, KS, USA
| | - Bahram Arjmandi
- Department of Nutrition, Food and Exercise Sciences, College of Human Sciences, Florida State University, Tallahassee, FL, USA
| | - Payal Ghosh
- Department of Nutrition, Food and Exercise Sciences, College of Human Sciences, Florida State University, Tallahassee, FL, USA
| | - Bei Chen
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Rachael Brooks
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA
| | - Joshua J Maraj
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Marcus L Elam
- Department of Nutrition, Food and Exercise Sciences, College of Human Sciences, Florida State University, Tallahassee, FL, USA
| | - Patrick Maher
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Daniel Kurien
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Alexandra Churchill
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA
| | - Jaime L Sepulveda
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA
| | - Max B Kabolowsky
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA
| | - Demetra D Christou
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, USA
| | - Judy M Muller-Delp
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA
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22
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Gangoda SVS, Avadhanam B, Jufri NF, Sohn EH, Butlin M, Gupta V, Chung R, Avolio AP. Pulsatile stretch as a novel modulator of amyloid precursor protein processing and associated inflammatory markers in human cerebral endothelial cells. Sci Rep 2018; 8:1689. [PMID: 29374229 PMCID: PMC5786097 DOI: 10.1038/s41598-018-20117-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 01/15/2018] [Indexed: 01/22/2023] Open
Abstract
Amyloid β (Aβ) deposition is a hallmark of Alzheimer’s disease (AD). Vascular modifications, including altered brain endothelial cell function and structural viability of the blood-brain barrier due to vascular pulsatility, are implicated in AD pathology. Pulsatility of phenomena in the cerebral vasculature are often not considered in in vitro models of the blood-brain barrier. We demonstrate, for the first time, that pulsatile stretch of brain vascular endothelial cells modulates amyloid precursor protein (APP) expression and the APP processing enzyme, β-secretase 1, eventuating increased-Aβ generation and secretion. Concurrent modulation of intercellular adhesion molecule 1 and endothelial nitric oxide synthase (eNOS) signaling (expression and phosphorylation of eNOS) in response to pulsatile stretch indicates parallel activation of endothelial inflammatory pathways. These findings mechanistically support vascular pulsatility contributing towards cerebral Aβ levels.
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Affiliation(s)
- Sumudu V S Gangoda
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Bhargava Avadhanam
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Nurul F Jufri
- Programme of Biomedical Science, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 50300, Kuala Lumpur, Malaysia
| | - Eun Hwa Sohn
- Department of Herbal Medicine Resources, Kangwon National University, Samcheok, 25949, Republic of Korea
| | - Mark Butlin
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia.
| | - Vivek Gupta
- Department of Clinical Medicine, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Roger Chung
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Alberto P Avolio
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
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23
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Xiong PY, Potus F, Chan W, Archer SL. Models and Molecular Mechanisms of World Health Organization Group 2 to 4 Pulmonary Hypertension. Hypertension 2018; 71:34-55. [PMID: 29158355 PMCID: PMC5777609 DOI: 10.1161/hypertensionaha.117.08824] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Ping Yu Xiong
- From the Department of Medicine and Queen's Cardiopulmonary Unit (QCPU) (P.Y.X., F.P., W.C., S.L.A.) and Biomedical and Molecular Sciences (P.Y.X.), Queen's University, Kingston, Ontario, Canada
| | - Francois Potus
- From the Department of Medicine and Queen's Cardiopulmonary Unit (QCPU) (P.Y.X., F.P., W.C., S.L.A.) and Biomedical and Molecular Sciences (P.Y.X.), Queen's University, Kingston, Ontario, Canada
| | - Winnie Chan
- From the Department of Medicine and Queen's Cardiopulmonary Unit (QCPU) (P.Y.X., F.P., W.C., S.L.A.) and Biomedical and Molecular Sciences (P.Y.X.), Queen's University, Kingston, Ontario, Canada
| | - Stephen L Archer
- From the Department of Medicine and Queen's Cardiopulmonary Unit (QCPU) (P.Y.X., F.P., W.C., S.L.A.) and Biomedical and Molecular Sciences (P.Y.X.), Queen's University, Kingston, Ontario, Canada.
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Bommakanti N, Isbatan A, Bavishi A, Dharmavaram G, Chignalia AZ, Dull RO. Hypercapnic acidosis attenuates pressure-dependent increase in whole-lung filtration coefficient (K f). Pulm Circ 2017; 7:719-726. [PMID: 28727979 PMCID: PMC5841912 DOI: 10.1177/2045893217724414] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Hypercapnic acidosis (HCA) has beneficial effects in experimental models of lung injury by attenuating inflammation and decreasing pulmonary edema. However, HCA increases pulmonary vascular pressure that will increase fluid filtration and worsen edema development. To reconcile these disparate effects, we tested the hypothesis that HCA inhibits endothelial mechanotransduction and protects against pressure-dependent increases in the whole lung filtration coefficient (Kf). Isolated perfused rat lung preparation was used to measure whole lung filtration coefficient (Kf) at two levels of left atrial pressure (PLA = 7.5 versus 15 cm H2O) and at low tidal volume (LVt) versus standard tidal volume (STVt) ventilation. The ratio of Kf2/Kf1 was used as the index of whole lung permeability. Double occlusion pressure, pulmonary artery pressure, pulmonary capillary pressures, and zonal characteristics (ZC) were measured to assess effects of HCA on hemodynamics and their relationship to Kf2/Kf1. An increase in PLA2 from 7.5 to 15 cm H2O resulted in a 4.9-fold increase in Kf2/Kf1 during LVt and a 4.8-fold increase during STVt. During LVt, HCA reduced Kf2/Kf1 by 2.7-fold and reduced STVt Kf2/Kf1 by 5.2-fold. Analysis of pulmonary hemodynamics revealed no significant differences in filtration forces in response to HCA. HCA interferes with lung vascular mechanotransduction and prevents pressure-dependent increases in whole lung filtration coefficient. These results contribute to a further understanding of the lung protective effects of HCA.
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Affiliation(s)
- Nikhil Bommakanti
- 1 Department of Anesthesiology, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,2 Department of Bioengineering, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA
| | - Ayman Isbatan
- 1 Department of Anesthesiology, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,3 Lung Vascular Biology Laboratory, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA
| | - Avni Bavishi
- 1 Department of Anesthesiology, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,3 Lung Vascular Biology Laboratory, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA
| | - Gourisree Dharmavaram
- 1 Department of Anesthesiology, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,3 Lung Vascular Biology Laboratory, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA
| | - Andreia Z Chignalia
- 1 Department of Anesthesiology, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,3 Lung Vascular Biology Laboratory, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA
| | - Randal O Dull
- 1 Department of Anesthesiology, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,2 Department of Bioengineering, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.,3 Lung Vascular Biology Laboratory, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA
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25
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Zhang X, Wang W, Li F, Voiculescu I. Stretchable impedance sensor for mammalian cell proliferation measurements. LAB ON A CHIP 2017; 17:2054-2066. [PMID: 28513702 DOI: 10.1039/c7lc00375g] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This paper presents the fabrication and testing of a novel stretchable electric cell-substrate impedance sensing (ECIS) lab on a chip device. This is the first time that ECIS electrodes were fabricated on a stretchable polydimethylsiloxane (PDMS) substrate and ECIS measurements were performed on mammalian cells exposed to cyclic strain. The stretchable ECIS biosensors simulate in vitro the dynamic environment of organisms, such as pulsation, bending and stretching, which enables investigations on cell behavior that undergoes mechanical stimuli in biological tissue. Usually cell-based assays used in cell mechanobiology rely on endpoint cell tests, which provide a limited view on dynamic cellular mechanisms. The ECIS technique is a label-free, real-time and noninvasive method to monitor the cellular response to mechanical stimuli. Bovine aortic endothelial cells (BAECs) have been used in this research because the BAECs are exposed in vivo to cyclic physiologic elongation produced by blood circulation in the arteries. These innovative stretchable ECIS biosensors were used to analyze the proliferation of BAECs under different cyclic mechanical stimulations. The results of fluorescence based cell proliferation assays confirmed that the stretchable ECIS sensors were able to analyze in real-time the BAEC proliferation. The novel stretchable ECIS sensor has the ability to analyse cell proliferation, determine the cell number and density, and apply mechanical stimulation at the same time.
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Affiliation(s)
- Xudong Zhang
- The City College of New York, Mechanical Engineering Department, USA.
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26
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Dietrich A, Steinritz D, Gudermann T. Transient receptor potential (TRP) channels as molecular targets in lung toxicology and associated diseases. Cell Calcium 2017; 67:123-137. [PMID: 28499580 DOI: 10.1016/j.ceca.2017.04.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 04/21/2017] [Accepted: 04/21/2017] [Indexed: 12/24/2022]
Abstract
The lungs as the gateways of our body to the external environment are essential for gas exchange. They are also exposed to toxicants from two sides, the airways and the vasculature. Apart from naturally produced toxic agents, millions of human made chemicals were produced since the beginning of the industrial revolution whose toxicity still needs to be determined. While the knowledge about toxic substances is increasing only slowly, a paradigm shift regarding the proposed mechanisms of toxicity at the plasma membrane emerged. According to their broad-range chemical reactivity, the mechanism of lung injury evoked by these agents has long been described as rather unspecific. Consequently, therapeutic options are still restricted to symptomatic treatment. The identification of molecular down-stream effectors in cells was a major step forward in the mechanistic understanding of the action of toxic chemicals and will pave the way for more causal and specific toxicity testing as well as therapeutic options. In this context, the involvement of Transient Receptor Potential (TRP) channels as chemosensors involved in the detection and effectors of toxicant action is an attractive concept intensively discussed in the scientific community. In this review we will summarize recent evidence for an involvement of TRP channels (TRPA1, TRPC4, TRPC6, TRPV1, TRPV4, TRPM2 and TRPM8) expressed in the lung in pathways of toxin sensing and as mediators of lung inflammation and associated diseases like asthma, COPD, lung fibrosis and edema formation. Specific modulators of these channels may offer new therapeutic options in the future and will endorse strategies for a causal, specifically tailored treatment based on the mechanistic understanding of molecular events induced by lung-toxic agents.
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Affiliation(s)
- Alexander Dietrich
- Walther-Straub-Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL), LMU Munich, Germany.
| | - Dirk Steinritz
- Walther-Straub-Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL), LMU Munich, Germany; Bundeswehr-Institute of Pharmacology and Toxicology, Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institute of Pharmacology and Toxicology, Member of the German Center for Lung Research (DZL), LMU Munich, Germany
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Bravo B, García de Durango C, González Á, Gortázar AR, Santos X, Forteza-Vila J, Vidal-Vanaclocha F. Opposite Effects of Mechanical Action of Fluid Flow on Proangiogenic Factor Secretion From Human Adipose-Derived Stem Cells With and Without Oxidative Stress. J Cell Physiol 2017; 232:2158-2167. [PMID: 27925206 DOI: 10.1002/jcp.25712] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 11/29/2016] [Indexed: 12/30/2022]
Abstract
Mechanical forces, hypoxia, and oxidative stress contribute to skin renewal, perfusion, and wound healing, but how are they regulating subcutaneous adipose-derived stem cells (ASCs) in the inflammatory microenvironment associated to skin repair and disorders is unknown. In this study, ASCs were isolated from lipoaspirate samples from plastic surgery patients, primary cultured and their differentiation and secretion of a panel of cytokines with pronounced effects on skin repair and angiogenesis were studied under mechanical stimulation by intermittent fluid flow, 1% hypoxia and oxidative stress by glutathione (GSH) depletion with buthionine sulfoximine (BSO) treatment. Mechanical action of fluid flow did not alter mesenchymal phenotype of CD90+ /CD29+ /CD44+ /CD34- /CD106- /CD45- ASCs; however, it remarkably induced ASC secretion of human umbilical vein endothelial cell (HUVEC) migration-stimulating factors. Multiplex Luminex assay further confirmed an increased secretion of VEGF, G-CSF, HGF, Leptin, IL-8, PDGF-BB, Angiopoietin-2, and Follistatin from mechanically-stimulated ASCs via cyclooxygenase-2. Consistent with this mechanism, GSH depletion and hypoxia also increased ASC secretion of VEGF, IL-8, leptin, Angiopoitein-2, and PDGF-BB. However, mechanical action of fluid flow abrogated VEGF and HUVEC migration-stimulating activity from GSH-depleted and hypoxic ASCs. Conversely, GSH depletion and hypoxia abrogated VEGF and HUVEC migration-stimulating activity from mechano-stimulated ASCs. Although mechanical action of fluid flow, hypoxia, and GSH-depletion had independent proangiogenic-stimulating activity on ASCs, mechanical stimulation had opposite effects on proangiogenic factor secretion from ASCs with and without oxidative stress. These data uncover the role of hypoxia and endogenous redox balance during the proangiogenic response of ASCs and other mesenchymal-derived cell types to mechanical action of interstitial fluid flow. J. Cell. Physiol. 232: 2158-2167, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Beatriz Bravo
- Institute of Applied Molecular Medicine (IMMA), CEU-San Pablo University School of Medicine, Boadilla del Monte, Madrid, Spain
| | - Cira García de Durango
- Institute of Applied Molecular Medicine (IMMA), CEU-San Pablo University School of Medicine, Boadilla del Monte, Madrid, Spain
| | - Álvaro González
- Department of Molecular and Cellular Oncology Houston, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Arancha R Gortázar
- Institute of Applied Molecular Medicine (IMMA), CEU-San Pablo University School of Medicine, Boadilla del Monte, Madrid, Spain
| | - Xavier Santos
- Institute of Applied Molecular Medicine (IMMA), CEU-San Pablo University School of Medicine, Boadilla del Monte, Madrid, Spain
| | - Jerónimo Forteza-Vila
- Valencia Institute of Pathology (IVP), Catholic University of Valencia School of Medicine and Odontology, Valencia, Spain
| | - Fernando Vidal-Vanaclocha
- Valencia Institute of Pathology (IVP), Catholic University of Valencia School of Medicine and Odontology, Valencia, Spain
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Aghasafari P, Bin M Ibrahim I, Pidaparti R. Strain-induced inflammation in pulmonary alveolar tissue due to mechanical ventilation. Biomech Model Mechanobiol 2017; 16:1103-1118. [PMID: 28194537 DOI: 10.1007/s10237-017-0879-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/19/2016] [Indexed: 10/20/2022]
Abstract
Inflammation is the body's attempt at self-protection to remove harmful stimuli, including damaged cells, irritants, or pathogens and begin the healing process. In this study, strain-induced inflammation in pulmonary alveolar tissue under high tidal volume is investigated through a combination of an inflammation model and fluid structure interaction (FSI) analysis. A realistic three-dimensional organ model for alveolar sacs is built, and FSI is employed to evaluate strain distribution in alveolar tissue for different tidal volume (TV) values under the mechanical ventilation (MV) condition. The alveolar tissue is treated as a hyperelastic solid and provides the environment for the tissue constituents. The influence of different strain distributions resulting from different tidal volumes is investigated. It is observed that strain is highly distributed in the inlet area. In addition, strain versus time curves in different locations through the alveolar model reveals that middle layers in the alveolar region would undergo higher levels of strain during breathing under the MV condition. Three different types of strain distributions in the alveolar region from the FSI simulation are transferred to the CA model to study population dynamics of cell constituents under MV for different TVs; 200, 500 and 1000 mL, respectively. The CA model results suggests that strain distribution plays a significant role in population dynamics. An interplay between strain magnitude and distribution appears to influence healing capability. Results suggest that increasing TV leads to an exponential rise in tissue damage by inflammation.
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Affiliation(s)
- Parya Aghasafari
- College of Engineering, UGA, 132A Paul D. Coverdell Center, Athens, GA, 30602, USA
| | - Israr Bin M Ibrahim
- College of Engineering, UGA, 132A Paul D. Coverdell Center, Athens, GA, 30602, USA
| | - Ramana Pidaparti
- College of Engineering, UGA, 132A Paul D. Coverdell Center, Athens, GA, 30602, USA.
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29
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Jin ZH, Liu YL, Chen JJ, Cai SL, Xu JQ, Huang WH. Conductive Polymer-Coated Carbon Nanotubes To Construct Stretchable and Transparent Electrochemical Sensors. Anal Chem 2017; 89:2032-2038. [DOI: 10.1021/acs.analchem.6b04616] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Zi-He Jin
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), College
of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Yan-Ling Liu
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), College
of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Jing-Jing Chen
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), College
of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Si-Liang Cai
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), College
of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Jia-Quan Xu
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), College
of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Wei-Hua Huang
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), College
of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
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Abstract
In the United States trauma is the leading cause of mortality among those under the age of 45, claiming approximately 192,000 lives each year. Significant personal disability, lost productivity, and long-term healthcare needs are common and contribute 580 billion dollars in economic impact each year. Improving resuscitation strategies and the early acute care of trauma patients has the potential to reduce the pathological sequelae of combined exuberant inflammation and immune suppression that can co-exist, or occur temporally, and adversely affect outcomes. The endothelial and epithelial glycocalyx has emerged as an important participant in both inflammation and immunomodulation. Constituents of the glycocalyx have been used as biomarkers of injury severity and have the potential to be target(s) for therapeutic interventions aimed at immune modulation. In this review, we provide a contemporary understanding of the physiologic structure and function of the glycocalyx and its role in traumatic injury with a particular emphasis on lung injury.
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Johansson MJ, Kvitting JPE, Flatebø T, Nicolaysen A, Nicolaysen G, Walther SM. Inhibition of Constitutive Nitric Oxide Synthase Does Not Influence Ventilation-Perfusion Matching in Normal Prone Adult Sheep With Mechanical Ventilation. Anesth Analg 2016; 123:1492-1499. [PMID: 27622722 DOI: 10.1213/ane.0000000000001556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Local formation of nitric oxide in the lung induces vasodilation in proportion to ventilation and is a putative mechanism behind ventilation-perfusion matching. We hypothesized that regional ventilation-perfusion matching occurs in part due to local constitutive nitric oxide formation. METHODS Ventilation and perfusion were analyzed in lung regions (≈1.5 cm) before and after inhibition of constitutive nitric oxide synthase with N-nitro-L-arginine methyl ester (L-NAME) (25 mg/kg) in 7 prone sheep ventilated with 10 cm H2O positive end-expiratory pressure. Ventilation and perfusion were measured by the use of aerosolized fluorescent and infused radiolabeled microspheres, respectively. The animals were exsanguinated while deeply anesthetized; then, lungs were excised, dried at total lung capacity, and divided into cube units. The spatial location for each cube was tracked and fluorescence and radioactivity per unit weight determined. RESULTS After administration of L-NAME, pulmonary artery pressure increased from a mean of 16.6-23.6 mm Hg, P = .007 but PaO2, PaCO2, and SD log(V/Q) did not change. Distribution of ventilation was not influenced by L-NAME, but a small redistribution of perfusion from ventral to dorsal lung regions was observed. Perfusion to regions with the highest ventilation (fifth quintile of the ventilation distribution) remained unchanged after L-NAME. CONCLUSIONS We found minimal or no influence of constitutive nitric oxide synthase inhibition by L-NAME on the distributions of ventilation and perfusion, and ventilation-perfusion in prone, anesthetized, ventilated, and healthy adult sheep with normal gas exchange.
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Affiliation(s)
- Mats J Johansson
- From the *Department of Cardiothoracic Anesthesia and Intensive Care; †Division of Cardiovascular Medicine, Department of Medical and Health Sciences; ‡Department of Cardiothoracic Surgery, Linköping University Hospital, Linköping, Sweden; and §Department of Physiology, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
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Song MJ, Davidovich N, Lawrence GG, Margulies SS. Superoxide mediates tight junction complex dissociation in cyclically stretched lung slices. J Biomech 2016; 49:1330-1335. [PMID: 26592435 PMCID: PMC4864146 DOI: 10.1016/j.jbiomech.2015.10.032] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 10/20/2015] [Accepted: 10/21/2015] [Indexed: 12/25/2022]
Abstract
We found that stretching Type I rat alveolar epithelial cell (RAEC) monolayers at magnitudes that correspond to high tidal-volume mechanical ventilation results in the production of reactive oxygen species, including nitric oxide and superoxide. Scavenging superoxide with Tiron eliminated the stretch-induced increase in cell monolayer permeability, and similar results were reported for rats ventilated at large tidal volumes, suggesting that oxidative stress plays an important role in barrier impairment in ventilator-induced lung injury associated with large stretch and tidal volumes. In this communication we show that mechanisms that involve oxidative injury are also present in a novel precision cut lung slices (PCLS) model under identical mechanical loads. PCLSs from healthy rats were stretched cyclically to 37% change in surface area for 1 hour. Superoxide was visualized using MitoSOX. To evaluate functional relationships, in separate stretch studies superoxide was scavenged using Tiron or mito-Tempo. PCLS and RAEC permeability was assessed as tight junction (TJ) protein (occludin, claudin-4 and claudin-7) dissociation from zona occludins-1 (ZO-1) via co-immunoprecipitation and Western blot, after 1h (PCLS) or 10min (RAEC) of stretch. Superoxide was increased significantly in PCLS, and Tiron and mito-Tempo dramatically attenuated the response, preventing claudin-4 and claudin-7 dissociation from ZO-1. Using a novel PCLS model for ventilator-induced lung injury studies, we have shown that uniform, biaxial, cyclic stretch generates ROS in the slices, and that superoxide scavenging that can protect the lung tissue under stretch conditions. We conclude that PCLS offer a valuable platform for investigating antioxidant treatments to prevent ventilation-induced lung injury.
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Affiliation(s)
- Min Jae Song
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Nurit Davidovich
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Gladys G Lawrence
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Susan S Margulies
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.
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Lu X, Kassab GS. Integrins mediate mechanical compression-induced endothelium-dependent vasodilation through endothelial nitric oxide pathway. ACTA ACUST UNITED AC 2016; 146:221-32. [PMID: 26324675 PMCID: PMC4555471 DOI: 10.1085/jgp.201411350] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Integrins mediate endothelial NO production and vasodilation in response to the compression of muscle arterioles. Cardiac and skeletal muscle contraction lead to compression of intramuscular arterioles, which, in turn, leads to their vasodilation (a process that may enhance blood flow during muscle activity). Although endothelium-derived nitric oxide (NO) has been implicated in compression-induced vasodilation, the mechanism whereby arterial compression elicits NO production is unclear. We cannulated isolated swine (n = 39) myocardial (n = 69) and skeletal muscle (n = 60) arteriole segments and exposed them to cyclic transmural pressure generated by either intraluminal or extraluminal pressure pulses to simulate compression in contracting muscle. We found that the vasodilation elicited by internal or external pressure pulses was equivalent; moreover, vasodilation in response to pressure depended on changes in arteriole diameter. Agonist-induced endothelium-dependent and -independent vasodilation was used to verify endothelial and vascular smooth muscle cell viability. Vasodilation in response to cyclic changes in transmural pressure was smaller than that elicited by pharmacological activation of the NO signaling pathway. It was attenuated by inhibition of NO synthase and by mechanical removal of the endothelium. Stemming from previous observations that endothelial integrin is implicated in vasodilation in response to shear stress, we found that function-blocking integrin α5β1 or αvβ3 antibodies attenuated cyclic compression–induced vasodilation and NOx (NO−2 and NO−3) production, as did an RGD peptide that competitively inhibits ligand binding to some integrins. We therefore conclude that integrin plays a role in cyclic compression–induced endothelial NO production and thereby in the vasodilation of small arteries during cyclic transmural pressure loading.
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Affiliation(s)
- Xiao Lu
- Department of Biomedical Engineering, Department of Cellular and Integrative Physiology, Department of Surgery, and Indiana Center for Vascular Biology and Medicine, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202
| | - Ghassan S Kassab
- Department of Biomedical Engineering, Department of Cellular and Integrative Physiology, Department of Surgery, and Indiana Center for Vascular Biology and Medicine, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202 Department of Biomedical Engineering, Department of Cellular and Integrative Physiology, Department of Surgery, and Indiana Center for Vascular Biology and Medicine, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202 Department of Biomedical Engineering, Department of Cellular and Integrative Physiology, Department of Surgery, and Indiana Center for Vascular Biology and Medicine, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202 Department of Biomedical Engineering, Department of Cellular and Integrative Physiology, Department of Surgery, and Indiana Center for Vascular Biology and Medicine, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202
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Wu CS, Chou HC, Huang LT, Lin YK, Chen CM. Bubble CPAP Support after Discontinuation of Mechanical Ventilation Protects Rat Lungs with Ventilator-Induced Lung Injury. Respiration 2016; 91:171-179. [DOI: 10.1159/000443528] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
Abstract
<b><i>Background:</i></b> Bubble continuous positive airway pressure (BCPAP) has been used in neonates with respiratory distress for decades, but its lung-protective effect and underlying mechanism has not been investigated. <b><i>Objectives:</i></b> To test the hypothesis that BCPAP use after extubation decreases lung injury and that alterations to lung nitric oxide synthase (NOS) 3 expression may be one of the underlying mechanisms. <b><i>Methods:</i></b> We compared gas exchange, lung injury severity, and lung NOS expression among rats with ventilator-induced lung injury (VILI) treated with either BCPAP or spontaneous breathing. After high tidal volume ventilation for 30 min, the rats were randomly divided to three groups: a control group underwent spontaneous breathing (n = 7), and two BCPAP groups were treated with the bubble technique with either a 2.5-mm-diameter (n = 7) or a 5.5-mm-diameter (n = 7) expiratory limb for 2 h. <b><i>Results:</i></b> The bubble technique (2.5 and 5.5 mm diameter combined) resulted in a significantly higher Pa<smlcap>O</smlcap><sub>2</sub>, decreased alveolar protein levels (1.01 vs. 1.43 mg/kg, p < 0.05), a lower lung injury score (3.87 vs. 4.86, p < 0.05), and decreased NOS3 expression (1.99 vs. 3.32, p < 0.05) compared to spontaneous breathing in the control group. BCPAP with a 2.5-mm-diameter and with a 5.5-mm-diameter expiratory limb was not different with regard to gas exchange, alveolar protein levels, and lung injury scores, but there was a trend for lower NOS3 expression in the 5.5-mm group (1.41 vs. 2.56, p = 0.052). <b><i>Conclusions:</i></b> BCPAP decreases lung injury in rats with VILI after stopping mechanical ventilation. Attenuation of lung NOS3 expression may be one of the underlying mechanisms.
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Breitling S, Ravindran K, Goldenberg NM, Kuebler WM. The pathophysiology of pulmonary hypertension in left heart disease. Am J Physiol Lung Cell Mol Physiol 2015; 309:L924-41. [DOI: 10.1152/ajplung.00146.2015] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 08/20/2015] [Indexed: 12/17/2022] Open
Abstract
Pulmonary hypertension (PH) is characterized by elevated pulmonary arterial pressure leading to right-sided heart failure and can arise from a wide range of etiologies. The most common cause of PH, termed Group 2 PH, is left-sided heart failure and is commonly known as pulmonary hypertension with left heart disease (PH-LHD). Importantly, while sharing many clinical features with pulmonary arterial hypertension (PAH), PH-LHD differs significantly at the cellular and physiological levels. These fundamental pathophysiological differences largely account for the poor response to PAH therapies experienced by PH-LHD patients. The relatively high prevalence of this disease, coupled with its unique features compared with PAH, signal the importance of an in-depth understanding of the mechanistic details of PH-LHD. The present review will focus on the current state of knowledge regarding the pathomechanisms of PH-LHD, highlighting work carried out both in human trials and in preclinical animal models. Adaptive processes at the alveolocapillary barrier and in the pulmonary circulation, including alterations in alveolar fluid transport, endothelial junctional integrity, and vasoactive mediator secretion will be discussed in detail, highlighting the aspects that impact the response to, and development of, novel therapeutics.
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Affiliation(s)
- Siegfried Breitling
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, Germany
| | - Krishnan Ravindran
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Neil M. Goldenberg
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
- Department of Anesthesia, University of Toronto, Toronto, Ontario, Canada
| | - Wolfgang M. Kuebler
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Germany
- Departments of Surgery and Physiology, University of Toronto, Toronto, Ontario, Canada; and
- German Heart Institute Berlin, Berlin, Germany
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36
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Woods SJ, Waite AAC, O'Dea KP, Halford P, Takata M, Wilson MR. Kinetic profiling of in vivo lung cellular inflammatory responses to mechanical ventilation. Am J Physiol Lung Cell Mol Physiol 2015; 308:L912-21. [PMID: 25770178 PMCID: PMC4421782 DOI: 10.1152/ajplung.00048.2015] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 03/07/2015] [Indexed: 02/07/2023] Open
Abstract
Mechanical ventilation, through overdistension of the lung, induces substantial inflammation that is thought to increase mortality among critically ill patients. The mechanotransduction processes involved in converting lung distension into inflammation during this ventilator-induced lung injury (VILI) remain unclear, although many cell types have been shown to be involved in its pathogenesis. This study aimed to identify the profile of in vivo lung cellular activation that occurs during the initiation of VILI. This was achieved using a flow cytometry-based method to quantify the phosphorylation of several markers (p38, ERK1/2, MAPK-activated protein kinase 2, and NF-κB) of inflammatory pathway activation within individual cell types. Anesthetized C57BL/6 mice were ventilated with low (7 ml/kg), intermediate (30 ml/kg), or high (40 ml/kg) tidal volumes for 1, 5, or 15 min followed by immediate fixing and processing of the lungs. Surprisingly, the pulmonary endothelium was the cell type most responsive to in vivo high-tidal-volume ventilation, demonstrating activation within just 1 min, followed by the alveolar epithelium. Alveolar macrophages were the slowest to respond, although they still demonstrated activation within 5 min. This order of activation was specific to VILI, since intratracheal lipopolysaccharide induced a very different pattern. These results suggest that alveolar macrophages may become activated via a secondary mechanism that occurs subsequent to activation of the parenchyma and that the lung cellular activation mechanism may be different between VILI and lipopolysaccharide. Our data also demonstrate that even very short periods of high stretch can promote inflammatory activation, and, importantly, this injury may be immediately manifested within the pulmonary vasculature.
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Affiliation(s)
- Samantha J. Woods
- Section of Anaesthetics, Pain Medicine and Intensive Care, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital, London, United Kingdom
| | - Alicia A. C. Waite
- Section of Anaesthetics, Pain Medicine and Intensive Care, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital, London, United Kingdom
| | - Kieran P. O'Dea
- Section of Anaesthetics, Pain Medicine and Intensive Care, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital, London, United Kingdom
| | - Paul Halford
- Section of Anaesthetics, Pain Medicine and Intensive Care, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital, London, United Kingdom
| | - Masao Takata
- Section of Anaesthetics, Pain Medicine and Intensive Care, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital, London, United Kingdom
| | - Michael R. Wilson
- Section of Anaesthetics, Pain Medicine and Intensive Care, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital, London, United Kingdom
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Goldenberg NM, Ravindran K, Kuebler WM. TRPV4: physiological role and therapeutic potential in respiratory diseases. Naunyn Schmiedebergs Arch Pharmacol 2014; 388:421-36. [PMID: 25342095 DOI: 10.1007/s00210-014-1058-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 10/10/2014] [Indexed: 01/11/2023]
Abstract
Members of the family of transient receptor potential (TRP) channels have been implicated in the pathophysiology of a host of lung diseases. The role of these multimodal cation channels in lung homeostasis is thought to stem from their ability to respond to changes in mechanical stimuli (i.e., shear and stretch), as well as to various protein and lipid mediators. The vanilloid subfamily member, TRPV4, which is highly expressed in the majority of lung cell types, is well positioned for critical involvement in several pulmonary conditions, including edema formation, control of pulmonary vascular tone, and the lung response to local or systemic inflammatory insults. In recent years, several pharmacological inhibitors of TRPV4 have been developed, and the current generation of compounds possess high affinity and specificity for TRPV4. As such, we have now entered a time where the therapeutic potential of TRPV4 inhibitors can be systematically examined in a variety of lung diseases. Due to this fact, this review seeks to describe the current state of the art with respect to the role of TRPV4 in pulmonary homeostasis and disease, and to highlight the current and future roles of TRPV4 inhibitors in disease treatment. We will first focus on genera aspects of TRPV4 structure and function, and then will discuss known roles for TRPV4 in pulmonary diseases, including pulmonary edema formation, pulmonary hypertension, and acute lung injury. Finally, both promising aspects and potential pitfalls of the clinical use of TRPV4 inhibitors will be examined.
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Affiliation(s)
- Neil M Goldenberg
- Department of Anesthesia, University of Toronto, Toronto, ON, Canada
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Morty RE, Kuebler WM. TRPV4: an exciting new target to promote alveolocapillary barrier function. Am J Physiol Lung Cell Mol Physiol 2014; 307:L817-21. [PMID: 25281637 DOI: 10.1152/ajplung.00254.2014] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Transient receptor potential (TRP) channels are emerging as important players and drug targets in respiratory disease. Amongst the vanilloid-type TRP channels (which includes the six members of the TRPV family), target diseases include cough, asthma, cancer, and more recently, pulmonary edema associated with acute respiratory distress syndrome. Here, we critically evaluate a recent report that addresses TRPV4 as a candidate target for the management of acute lung injury that develops as a consequence of aspiration of gastric contents, or acute chlorine gas exposure. By use of two new TRPV4 inhibitors (GSK2220691 or GSK2337429A) and a trpv4(-/-) mouse strain, TRPV4 was implicated as a key mediator of pulmonary inflammation after direct chemical insult. Additionally, applied therapeutically, TRPV4 inhibitors exhibited vasculoprotective effects after chlorine gas exposure, inhibiting vascular leakage, and improving blood oxygenation. These observations underscore TRPV4 channels as candidate therapeutic targets in the management of lung injury, with the added need to balance these against the potential drawbacks of TRPV4 inhibition, such as the danger of limiting the immune response in settings of pathogen-provoked injury.
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Affiliation(s)
- Rory E Morty
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Giessen, Germany;
| | - Wolfgang M Kuebler
- Institute of Physiology, Charité Universitätsmedizin Berlin, Germany; Departments of Surgery and Physiology, University of Toronto, Toronto, Ontario, Canada; and The Keenan Research Center for Biomedical Science of St. Michael's, Toronto, Ontario, Canada
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Moldobaeva A, Rentsendorj O, Jenkins J, Wagner EM. Nitric oxide synthase promotes distension-induced tracheal venular leukocyte adherence. PLoS One 2014; 9:e106092. [PMID: 25181540 PMCID: PMC4152173 DOI: 10.1371/journal.pone.0106092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/28/2014] [Indexed: 12/24/2022] Open
Abstract
The process of leukocyte recruitment to the airways in real time has not been extensively studied, yet airway inflammation persists as a major contributor to lung pathology. We showed previously in vivo, that neutrophils are recruited acutely to the large airways after periods of airway distension imposed by the application of positive end-expiratory pressure (PEEP). Given extensive literature implicating products of nitric oxide synthase (NOS) in lung injury after ventilatory over-distension, we questioned whether similar mechanisms exist in airway post-capillary venules. Yet, endothelial nitric oxide has been shown to be largely anti-inflammatory in other systemic venules. Using intravital microscopy to visualize post-capillary tracheal venules in anesthetized, ventilated mice, the number of adherent leukocytes was significantly decreased in eNOS-/- mice under baseline conditions (2±1 cell/60 min observation) vs wild type (WT) C57BL/6 mice (7±2 cells). After exposure to PEEP (8 cmH2O for 1 min; 5 times), adherent cells increased significantly (29±5 cells) in WT mice while eNOS-/- mice demonstrated a significantly decreased number of adherent cells (11±4 cells) after PEEP. A similar response was seen when thrombin was used as the pro-inflammatory stimulus. In addition, mouse tracheal venular endothelial cells studied in vitro after exposure to cyclic stretch (18% elongation) or thrombin both demonstrated increased p-selectin expression that was significantly attenuated by NG-nitro-L-arginine methyl ester, N-acetylcysteine amide (NACA) and excess BH4. In vivo treatment with the ROS inhibitor NACA or co-factor BH4 abolished completely the PEEP-induced leukocyte adherence. These results suggest that pro-inflammatory stimuli cause leukocyte recruitment to tracheal endothelium in part due to eNOS uncoupling.
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Affiliation(s)
- Aigul Moldobaeva
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Otgonchimeg Rentsendorj
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - John Jenkins
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Elizabeth M. Wagner
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail:
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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.
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Affiliation(s)
- Ulrike Uhlig
- Department of Pharmacology & Toxicology, Medical Faculty, RWTH Aachen University, Aachen, Germany
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Parker JC. Acute lung injury and pulmonary vascular permeability: use of transgenic models. Compr Physiol 2013; 1:835-82. [PMID: 23737205 DOI: 10.1002/cphy.c100013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Acute lung injury is a general term that describes injurious conditions that can range from mild interstitial edema to massive inflammatory tissue destruction. This review will cover theoretical considerations and quantitative and semi-quantitative methods for assessing edema formation and increased vascular permeability during lung injury. Pulmonary edema can be quantitated directly using gravimetric methods, or indirectly by descriptive microscopy, quantitative morphometric microscopy, altered lung mechanics, high-resolution computed tomography, magnetic resonance imaging, positron emission tomography, or x-ray films. Lung vascular permeability to fluid can be evaluated by measuring the filtration coefficient (Kf) and permeability to solutes evaluated from their blood to lung clearances. Albumin clearances can then be used to calculate specific permeability-surface area products (PS) and reflection coefficients (σ). These methods as applied to a wide variety of transgenic mice subjected to acute lung injury by hyperoxic exposure, sepsis, ischemia-reperfusion, acid aspiration, oleic acid infusion, repeated lung lavage, and bleomycin are reviewed. These commonly used animal models simulate features of the acute respiratory distress syndrome, and the preparation of genetically modified mice and their use for defining specific pathways in these disease models are outlined. Although the initiating events differ widely, many of the subsequent inflammatory processes causing lung injury and increased vascular permeability are surprisingly similar for many etiologies.
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Affiliation(s)
- James C Parker
- Department of Physiology, University of South Alabama, Mobile, Alabama, USA.
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Davidovich N, DiPaolo BC, Lawrence GG, Chhour P, Yehya N, Margulies SS. Cyclic stretch-induced oxidative stress increases pulmonary alveolar epithelial permeability. Am J Respir Cell Mol Biol 2013; 49:156-64. [PMID: 23526210 DOI: 10.1165/rcmb.2012-0252oc] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Mechanical ventilation with high tidal volumes has been associated with pulmonary alveolar flooding. Understanding the mechanisms underlying cyclic stretch-induced increases in alveolar epithelial permeability may be important in designing preventive measures for acute lung injury. In this work, we assessed whether cyclic stretch leads to the generation of reactive oxygen species in type I-like alveolar epithelial cells, which increase monolayer permeability via activation of NF-κB and extracellular signal-regulated kinase (ERK). We cyclically stretched type I-like rat primary alveolar epithelial cells at magnitudes of 12, 25, and 37% change in surface area (ΔSA) for 10 to 120 minutes. High levels of reactive oxygen species and of superoxide and NO specifically were detected in cells stretched at 37% ΔSA for 10 to 120 minutes. Exogenous superoxide and NO stimulation increased epithelial permeability in unstretched cells, which was preventable by the NF-κB inhibitor MG132. The cyclic stretch-induced increase in permeability was decreased by the superoxide scavenger tiron and by MG132. Furthermore, tiron had a dramatic protective effect on in vivo lung permeability under mechanical ventilation conditions. Cyclic stretch increased the activation of the NF-κB signaling pathway, which was significantly decreased with the ERK inhibitor U0126. Altogether, our in vitro and in vivo data demonstrate the sensitivity of permeability to stretch- and ventilation-induced superoxide production, suggesting that using antioxidants may be helpful in the prevention and treatment of ventilator-induced lung injury.
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Affiliation(s)
- Nurit Davidovich
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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Collins SR, Blank RS, Deatherage LS, Dull RO. Special article: the endothelial glycocalyx: emerging concepts in pulmonary edema and acute lung injury. Anesth Analg 2013; 117:664-674. [PMID: 23835455 PMCID: PMC3790575 DOI: 10.1213/ane.0b013e3182975b85] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The endothelial glycocalyx is a dynamic layer of macromolecules at the luminal surface of vascular endothelium that is involved in fluid homeostasis and regulation. Its role in vascular permeability and edema formation is emerging but is still not well understood. In this special article, we highlight key concepts of endothelial dysfunction with regards to the glycocalyx and provide new insights into the glycocalyx as a mediator of processes central to the development of pulmonary edema and lung injury.
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Affiliation(s)
- Stephen R Collins
- From the Department of Anesthesiology, University of Virginia Health System, Charlottesville, Virginia; Department of Anesthesiology, University of Utah, Salt Lake City, Utah; and Department of Anesthesiology and Bioengineering, University of Illinois at Chicago College of Medicine, Chicago, Illinois
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Hu Z, Xiong Y, Han X, Geng C, Jiang B, Huo Y, Luo J. Acute mechanical stretch promotes eNOS activation in venous endothelial cells mainly via PKA and Akt pathways. PLoS One 2013; 8:e71359. [PMID: 23977025 PMCID: PMC3743752 DOI: 10.1371/journal.pone.0071359] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 06/28/2013] [Indexed: 11/19/2022] Open
Abstract
In the vasculature, physiological levels of nitric oxide (NO) protect against various stressors, including mechanical stretch. While endothelial NO production in response to various stimuli has been studied extensively, the precise mechanism underlying stretch-induced NO production in venous endothelial cells remains incompletely understood. Using a model of continuous cellular stretch, we found that stretch promoted phosphorylation of endothelial NO synthase (eNOS) at Ser1177, Ser633 and Ser615 and NO production in human umbilical vein endothelial cells. Although stretch activated the kinases AMPKα, PKA, Akt, and ERK1/2, stretch-induced eNOS activation was only inhibited by kinase-specific inhibitors of PKA and PI3K/Akt, but not of AMPKα and Erk1/2. Similar results were obtained with knockdown by shRNAs targeting the PKA and Akt genes. Furthermore, inhibition of PKA preferentially attenuated eNOS activation in the early phase, while inhibition of the PI3K/Akt pathway reduced eNOS activation in the late phase, suggesting that the PKA and PI3K/Akt pathways play distinct roles in a time-dependent manner. Finally, we investigated the role of these pathways in stretch-induced endothelial exocytosis and leukocyte adhesion. Interestingly, we found that inhibition of the PI3K/Akt pathway increased stretch-induced Weibel-Palade body exocytosis and leukocyte adhesion, while inhibition of the PKA pathway had the opposite effects, suggesting that the exocytosis-promoting effect of PKA overwhelms the inhibitory effect of PKA-mediated NO production. Taken together, the results suggest that PKA and Akt are important regulators of eNOS activation in venous endothelial cells under mechanical stretch, while playing different roles in the regulation of stretch-induced endothelial exocytosis and leukocyte adhesion.
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Affiliation(s)
- Zhenqian Hu
- Laboratory of Vascular Biology, Institute of Molecular Medicine, Peking University, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Beijing, China
| | - Yan Xiong
- Laboratory of Vascular Biology, Institute of Molecular Medicine, Peking University, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Beijing, China
| | - Xiaofan Han
- Laboratory of Vascular Biology, Institute of Molecular Medicine, Peking University, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Beijing, China
| | - Chenyang Geng
- Laboratory of Vascular Biology, Institute of Molecular Medicine, Peking University, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Beijing, China
| | - Beibei Jiang
- Laboratory of Vascular Biology, Institute of Molecular Medicine, Peking University, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Beijing, China
| | - Yingqing Huo
- Laboratory of Vascular Biology, Institute of Molecular Medicine, Peking University, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Beijing, China
| | - Jincai Luo
- Laboratory of Vascular Biology, Institute of Molecular Medicine, Peking University, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Beijing, China
- * E-mail:
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Hotta K, Kamiya K, Shimizu R, Yokoyama M, Nakamura-Ogura M, Tabata M, Kamekawa D, Akiyama A, Kato M, Noda C, Matsunaga A, Masuda T. Stretching exercises enhance vascular endothelial function and improve peripheral circulation in patients with acute myocardial infarction. Int Heart J 2013; 54:59-63. [PMID: 23676363 DOI: 10.1536/ihj.54.59] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The purpose of this study was to clarify the acute effects of a single session of stretching exercises on vascular endothelial function and peripheral circulation in patients with acute myocardial infarction. This study evaluated 32 patients (mean age, 66 ± 9 years) who received phase I cardiac rehabilitation after acute myocardial infarction. Five types of stretching exercises were performed on the floor: wrist dorsiflexion, close-legged trunk flexion, open-legged trunk flexion, open-legged lateral trunk bending, and cross-legged trunk flexion. Each exercise entailed a 30-second stretching followed by a 30-second relaxation, and was repeated twice. Low- and high-frequency components (LF and HF) of heart rate variability (LF, 0.04-0.15 Hz; HF, 0.15-0.40 Hz) were analyzed, and HF and LF/HF were used as indices of parasympathetic and sympathetic nervous activities, respectively. Reactive hyperemia peripheral arterial tonometry (RH-PAT) index was measured and used as a parameter for vascular endothelial function. Transcutaneous oxygen pressure (tcPO2) on the right foot and chest was also measured, and the Foot-tcPO2/Chest-tcPO2 ratio was used as a parameter for peripheral circulation. The HF, RH-PAT index, and Foot-tcPO2/Chest-tcPO2 ratio were significantly higher after the exercises than before (P < 0.05, P < 0.01, and P < 0.05, respectively). There was no significant difference in the LF/HF ratio measured before and after stretching exercises. These findings demonstrate that stretching exercises improve vascular endothelial function and peripheral circulation in patients with acute myocardial infarction.
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Affiliation(s)
- Kazuki Hotta
- Department of Angiology and Cardiology, Kitasato University Graduate School of Medical Sciences, Kitasato, Sagamihara, Japan
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Chloride transport-driven alveolar fluid secretion is a major contributor to cardiogenic lung edema. Proc Natl Acad Sci U S A 2013; 110:E2308-16. [PMID: 23645634 DOI: 10.1073/pnas.1216382110] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Alveolar fluid clearance driven by active epithelial Na(+) and secondary Cl(-) absorption counteracts edema formation in the intact lung. Recently, we showed that impairment of alveolar fluid clearance because of inhibition of epithelial Na(+) channels (ENaCs) promotes cardiogenic lung edema. Concomitantly, we observed a reversal of alveolar fluid clearance, suggesting that reversed transepithelial ion transport may promote lung edema by driving active alveolar fluid secretion. We, therefore, hypothesized that alveolar ion and fluid secretion may constitute a pathomechanism in lung edema and aimed to identify underlying molecular pathways. In isolated perfused lungs, alveolar fluid clearance and secretion were determined by a double-indicator dilution technique. Transepithelial Cl(-) secretion and alveolar Cl(-) influx were quantified by radionuclide tracing and alveolar Cl(-) imaging, respectively. Elevated hydrostatic pressure induced ouabain-sensitive alveolar fluid secretion that coincided with transepithelial Cl(-) secretion and alveolar Cl(-) influx. Inhibition of either cystic fibrosis transmembrane conductance regulator (CFTR) or Na(+)-K(+)-Cl(-) cotransporters (NKCC) blocked alveolar fluid secretion, and lungs of CFTR(-/-) mice were protected from hydrostatic edema. Inhibition of ENaC by amiloride reproduced alveolar fluid and Cl(-) secretion that were again CFTR-, NKCC-, and Na(+)-K(+)-ATPase-dependent. Our findings show a reversal of transepithelial Cl(-) and fluid flux from absorptive to secretory mode at hydrostatic stress. Alveolar Cl(-) and fluid secretion are triggered by ENaC inhibition and mediated by NKCC and CFTR. Our results characterize an innovative mechanism of cardiogenic edema formation and identify NKCC1 as a unique therapeutic target in cardiogenic lung edema.
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Aubry E, Fayoux P, Jani J, Deprest J, Deruelle P, Houfflin-Debarge V, Storme L. Tracheal occlusion alters pulmonary circulation in the fetal lamb with normally developing lungs. J Pediatr Surg 2013; 48:481-7. [PMID: 23480900 DOI: 10.1016/j.jpedsurg.2012.08.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 07/17/2012] [Accepted: 08/14/2012] [Indexed: 11/25/2022]
Abstract
BACKGROUND Tracheal occlusion (TO) promotes fetal lung growth through an increase in intraluminal pressure. Although evidence suggests that fetal TO (FETO) decreases the occurrence of pulmonary hypertension in severe congenital diaphragmatic hernia, controversies on its effect on the pulmonary circulation remain. Therefore, we investigated the effects of FETO on the lung hemodynamics in a chronically catheterized fetal lamb model. METHODS Fifteen pregnant ewes were operated on between 125 and 128 days of gestation (term: 145 days). Catheters and ultrasonic flow transducer were placed through a left thoracotomy in the lamb fetus to determine aortic, pulmonary and left atrial pressures, and left pulmonary artery blood flow. A balloon was positioned between the carina and vocal cords under fetoscopic control. The animals were assigned to either control (n=6) or FETO (n=9) groups. TO was performed by inflating the balloon. We studied the acute effects of temporary (2-h) and prolonged (4-day) TO on basal pulmonary vascular tone and on the pulmonary vascular reactivity to acetylcholine and to increased fetal oxygen tension. RESULTS We found that left pulmonary blood flow (LPA) increased and pulmonary vascular resistance (PVR) decreased by 20% during brief TO (p<0.05). After balloon deflation, LPA blood flow further increased by 40%, and PVR decreased by 50% compared to baseline values (p<0.05). In contrast, no change in LPA blood flow or PVR was observed during prolonged TO. Moreover, the vasodilator responses to acetylcholine and to increased fetal PaO2 were blunted during TO. CONCLUSIONS These data indicate that antenatal tracheal occlusion promotes active pulmonary vasodilation, which is partly blunted by the mechanical effects of elevation of the intraluminal pressure.
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Affiliation(s)
- Estelle Aubry
- EA4489, Environnement Périnatal et Croissance, Faculté de Médecine, IFR 114, Université de Lille 2, France
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Sriram K, Salazar Vázquez BY, Tsai AG, Cabrales P, Intaglietta M, Tartakovsky DM. Autoregulation and mechanotransduction control the arteriolar response to small changes in hematocrit. Am J Physiol Heart Circ Physiol 2012; 303:H1096-106. [PMID: 22923620 DOI: 10.1152/ajpheart.00438.2012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Here, we present an analytic model of arteriolar mechanics that accounts for key autoregulation mechanisms, including the myogenic response and the vasodilatory effects of nitric oxide (NO) in the vasculature. It couples the fluid mechanics of blood flow in arterioles with solid mechanics of the vessel wall and includes the effects of wall shear stress- and stretch-induced endothelial NO production. The model can be used to describe the regulation of blood flow and NO transport under small changes in hematocrit and to analyze the regulatory response of arterioles to small changes in hematocrit. Our analysis revealed that the experimentally observed paradoxical increase in cardiac output with small increases in hematocrit results from the combination of increased NO production and the effects of a strong myogenic response modulated by elevated levels of WSS. Our findings support the hypothesis that vascular resistance varies inversely with blood viscosity for small changes in hematocrit in a healthy circulation that responds to shear stress stimuli. They also suggest beneficial effects independent of changes in O(2) carrying capacity associated with the postsurgical transfusion of one or two units of blood.
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Affiliation(s)
- Krishna Sriram
- Department of Mechanical and Aerospace Engineering, University of California-San Diego, La Jolla, California 92093-0412, USA
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Contractile Activity Regulates Inducible Nitric Oxide Synthase Expression and NO(i) Production in Cardiomyocytes via a FAK-Dependent Signaling Pathway. JOURNAL OF SIGNAL TRANSDUCTION 2012; 2012:473410. [PMID: 22900166 PMCID: PMC3412095 DOI: 10.1155/2012/473410] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 06/06/2012] [Accepted: 06/06/2012] [Indexed: 11/18/2022]
Abstract
Intracellular nitric oxide (NOi) is a physiological regulator of excitation-contraction coupling, but is also involved in the development of cardiac dysfunction during hypertrophy and heart failure. To determine whether contractile activity regulates nitric oxide synthase (NOS) expression, spontaneously contracting, neonatal rat ventricular myocytes (NRVM) were treat with L-type calcium channel blockers (nifedipine and verapamil) or myosin II ATPase inhibitors (butanedione monoxime (BDM) and blebbistatin) to produce contractile arrest. Both types of inhibitors significantly reduced iNOS but not eNOS expression, and also reduced NOi production. Inhibiting contractile activity also reduced focal adhesion kinase (FAK) and AKT phosphorylation. Contraction-induced iNOS expression required FAK and phosphatidylinositol 3-kinase (PI(3)K), as both PF573228 and LY294002 (10 μM, 24 h) eliminated contraction-induced iNOS expression. Similarly, shRNAs specific for FAK (shFAK) caused FAK knockdown, reduced AKT phosphorylation at T308 and S473, and reduced iNOS expression. In contrast, shRNA-mediated knockdown of PYK2, the other member of the FAK-family of protein tyrosine kinases, had much less of an effect. Conversely, overexpression of a constitutively active form of FAK (CD2-FAK) or AKT (Myr-AKT) reversed the inhibitory effect of BDM on iNOS expression and NOi production. Thus, contraction-induced iNOS expression and NOi production in NRVM are mediated via a FAK-PI(3)K-AKT signaling pathway.
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Siegl S, Uhlig S. Using the one-lung method to link p38 to pro-inflammatory gene expression during overventilation in C57BL/6 and BALB/c mice. PLoS One 2012; 7:e41464. [PMID: 22848503 PMCID: PMC3404097 DOI: 10.1371/journal.pone.0041464] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 06/21/2012] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION The mechanisms of ventilator-induced lung injury (VILI), including the role of MAP kinases, are frequently studied in different mouse strains. A useful model for such studies is the isolated perfused mouse lung. As a further development we present the one-lung method that permits to continue perfusion and ventilation of the right lung after removal of the left lung. This method was used to compare the effect of high pressure ventilation (HPV) on pro-inflammatory signaling events in two widely used mouse strains (C57BL/6, BALB/c) and to further define the role of p38 in VILI. METHODS Lungs were perfused and ventilated for 30 min under control conditions before they were randomized to low (8 cm H(2)O) or high (25 cm H(2)O) pressure ventilation (HPV) for 210 min, with the left lung being removed after 180 min. In the left lung we measured the phosphorylation of p38, JNK, ERK and Akt kinase, and in the right lung gene expression and protein concentrations of Il1b, Il6, Tnf, Cxcl1, Cxcl2, and Areg. RESULTS Lung mechanics and kinase activation were similar in both mouse strains. HPV increased all genes (except Tnf in BALB/c) and all mediators in both strains. The gene expression of mRNA for Il1b, Il6, Cxcl1 and Cxcl2 was higher in BALB/c mice. Backward regression of the kinase data at t = 180 min with the gene and protein expression data at t = 240 min suggested that p38 controls HPV-induced gene expression, but not protein production. This hypothesis was confirmed in experiments with the p38-kinase inhibitor SB203580. CONCLUSIONS The one-lung method is useful for mechanistic studies in the lungs. While C57BL/6 show diminished pro-inflammatory responses during HPV, lung mechanics and mechanotransduction processes appear to be similar in both mouse strains. Finally, the one-lung method allowed us to link p38 to gene expression during VILI.
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Affiliation(s)
- Stephanie Siegl
- Institute of Pharmacology and Toxicology, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Stefan Uhlig
- Institute of Pharmacology and Toxicology, Medical Faculty, RWTH Aachen University, Aachen, Germany
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