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1.
J Cell Physiol ; 237(2): 1521-1531, 2022 02.
Article in English | MEDLINE | ID: covidwho-1490820

ABSTRACT

Mechanical forces can modulate the immune response, mostly described as promoting the activation of immune cells, but the role and mechanism of pathological levels of mechanical stress in lymphocyte activation have not been focused on before. By an ex vivo experimental approach, we observed that mechanical stressing of murine spleen lymphocytes with 50 mmHg for 3 h induced the nuclear localization of NFAT1, increased C-Jun, and increased the expression of early activation marker CD69 in resting CD8+ cells. Interestingly, 50 mmHg mechanical stressing induced the nuclear localization of NFAT1; but conversely decreased C-Jun and inhibited the expression of CD69 in lymphocytes under lipopolysaccharide or phorbol 12-myristate 13-acetate/ionomycin stimulation. Additionally, we observed similar changes trends when comparing RNA-seq data of hypertensive and normotensive COVID-19 patients. Our results indicate a biphasic effect of mechanical stress on lymphocyte activation, which provides insight into the variety of immune responses in pathologies involving elevated mechanical stress.


Subject(s)
Lymphocyte Activation/immunology , Stress, Mechanical , Animals , Antigens, CD/metabolism , Antigens, Differentiation, T-Lymphocyte/metabolism , Biomarkers/metabolism , CD8-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/immunology , COVID-19/complications , Cell Nucleus/drug effects , Cell Nucleus/metabolism , Comorbidity , Gene Expression Regulation/drug effects , Humans , Hypertension/complications , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Ion Channels/metabolism , Lectins, C-Type/metabolism , Lipopolysaccharides/pharmacology , Lymphocyte Activation/drug effects , Lymphocyte Activation/genetics , Male , Mice, Inbred C57BL , NFATC Transcription Factors/metabolism , Protein Transport/drug effects , Proto-Oncogene Proteins c-jun/metabolism , Signal Transduction/drug effects , Tetradecanoylphorbol Acetate/pharmacology
2.
Biomolecules ; 11(11)2021 10 27.
Article in English | MEDLINE | ID: covidwho-1488477

ABSTRACT

The COVID-19 pandemic has escalated the occurrence of hypoxia including thrombotic stroke worldwide, for which nitric oxide (NO) therapy seems very promising and translatable. Therefore, various modes/routes of NO-delivery are now being tested in different clinical trials for safer, faster, and more effective interventions against ischemic insults. Intravenous (IV) infusion of S-Nitrosoglutathione (GSNO), the major endogenous molecular pool of NO, has been reported to protect against mechanical cerebral ischemia-reperfusion (IR); however, it has been never tested in any kind of "clinically" relevant thromboembolic stroke models with or without comorbidities and in combination with the thrombolytic reperfusion therapy. Moreover, "IV-effects" of higher dose of GSNO following IR-injury have been contradicted to augment stroke injury. Herein, we tested the hypothesis that nebulization of low-dose GSNO will not alter blood pressure (BP) and will mitigate stroke injury in diabetic mice via enhanced cerebral blood flow (CBF) and brain tissue oxygenation (PbtO2). GSNO-nebulization (200 µg/kgbwt) did not alter BP, but augmented the restoration of CBF, improved behavioral outcomes and reduced stroke injury. Moreover, GSNO-nebulization increased early reoxygenation of brain tissue/PbtO2 as measured at 6.5 h post-stroke following thrombolytic reperfusion, and enervated unwanted effects of late thrombolysis in diabetic stroke. We conclude that the GSNO-nebulization is safe and effective for enhancing collateral microvascular perfusion in the early hours following stroke. Hence, nebulized-GSNO therapy has the potential to be developed and translated into an affordable field therapy against ischemic events including strokes, particularly in developing countries with limited healthcare infrastructure.


Subject(s)
Diabetes Complications/drug therapy , Diabetes Mellitus/drug therapy , Hemorrhage/prevention & control , S-Nitrosoglutathione/administration & dosage , Stroke/complications , Thrombolytic Therapy/adverse effects , Animals , Behavior, Animal , Blood Pressure , Blood-Brain Barrier , COVID-19/epidemiology , Hemorrhage/complications , Hypoxia , Infusions, Intravenous , Laser-Doppler Flowmetry , Male , Mice , Mice, Inbred C57BL , Microcirculation , Nebulizers and Vaporizers , Neuroprotective Agents/pharmacology , Perfusion , Reperfusion Injury/drug therapy , Risk , Stress, Mechanical
3.
Nat Commun ; 11(1): 3749, 2020 07 27.
Article in English | MEDLINE | ID: covidwho-1376193

ABSTRACT

xrRNAs from flaviviruses survive in host cells because of their exceptional dichotomic response to the unfolding action of different enzymes. They can be unwound, and hence copied, by replicases, and yet can resist degradation by exonucleases. How the same stretch of xrRNA can encode such diverse responses is an open question. Here, by using atomistic models and translocation simulations, we uncover an elaborate and directional mechanism for how stress propagates when the two xrRNA ends, [Formula: see text] and [Formula: see text], are driven through a pore. Pulling the [Formula: see text] end, as done by replicases, elicits a progressive unfolding; pulling the [Formula: see text] end, as done by exonucleases, triggers a counterintuitive molecular tightening. Thus, in what appears to be a remarkable instance of intra-molecular tensegrity, the very pulling of the [Formula: see text] end is what boosts resistance to translocation and consequently to degradation. The uncovered mechanistic principle might be co-opted to design molecular meta-materials.


Subject(s)
RNA, Viral/metabolism , Zika Virus/genetics , Base Sequence , Nucleic Acid Conformation , RNA Transport , RNA, Viral/chemistry , RNA, Viral/genetics , Stress, Mechanical , Thermodynamics
4.
BMC Anesthesiol ; 21(1): 145, 2021 05 12.
Article in English | MEDLINE | ID: covidwho-1225757

ABSTRACT

BACKGROUND: Flow-controlled ventilation (FCV) is a novel ventilation method increasingly being used clinically, particularly during the current COVID-19 pandemic. However, the continuous flow pattern in FCV during inspiration and expiration has a significant impact on respiratory parameters and ventilatory settings compared to conventional ventilation modes. In addition, the constant flow combined with direct intratracheal pressure measurement allows determination of dynamic compliance and ventilation settings can be adjusted accordingly, reflecting a personalized ventilation approach. CASE PRESENTATION: A 50-year old women with confirmed SARS-CoV-2 infection suffering from acute respiratory distress syndrome (ARDS) was admitted to a tertiary medical center. Initial ventilation occurred with best standard of care pressure-controlled ventilation (PCV) and was then switched to FCV, by adopting PCV ventilator settings. This led to an increase in oxygenation by 30 %. Subsequently, to reduce invasiveness of mechanical ventilation, FCV was individualized by dynamic compliance guided adjustment of both, positive end-expiratory pressure and peak pressure; this intervention reduced driving pressure from 18 to 12 cm H2O. However, after several hours, compliance further deteriorated which resulted in a tidal volume of only 4.7 ml/kg. CONCLUSIONS: An individualized FCV approach increased oxygenation parameters in a patient suffering from severe COVID-19 related ARDS. Direct intratracheal pressure measurements allow for determination of dynamic compliance and thus optimization of ventilator settings, thereby reducing applied and dissipated energy. However, although desirable, this personalized ventilation strategy may reach its limits when lung function is so severely impaired that patient's oxygenation has to be ensured at the expense of lung protective ventilation concepts.


Subject(s)
COVID-19/therapy , Respiration, Artificial/methods , Air Pressure , COVID-19/complications , Compliance , Female , Humans , Intubation, Intratracheal , Middle Aged , Positive-Pressure Respiration , Precision Medicine , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/therapy , Respiratory Mechanics , Stress, Mechanical , Tomography, X-Ray Computed , Ventilators, Mechanical
5.
Transl Res ; 233: 104-116, 2021 07.
Article in English | MEDLINE | ID: covidwho-1051128

ABSTRACT

The p53/p21 pathway is activated in response to cell stress. However, its role in acute lung injury has not been elucidated. Acute lung injury is associated with disruption of the alveolo-capillary barrier leading to acute respiratory distress syndrome (ARDS). Mechanical ventilation may be necessary to support gas exchange in patients with ARDS, however, high positive airway pressures can cause regional overdistension of alveolar units and aggravate lung injury. Here, we report that acute lung injury and alveolar overstretching activate the p53/p21 pathway to maintain homeostasis and avoid massive cell apoptosis. A systematic pooling of transcriptomic data from animal models of lung injury demonstrates the enrichment of specific p53- and p21-dependent gene signatures and a validated senescence profile. In a clinically relevant, murine model of acid aspiration and mechanical ventilation, we observed changes in the nuclear envelope and the underlying chromatin, DNA damage and activation of the Tp53/p21 pathway. Absence of Cdkn1a decreased the senescent response, but worsened lung injury due to increased cell apoptosis. Conversely, treatment with lopinavir and/or ritonavir led to Cdkn1a overexpression and ameliorated cell apoptosis and lung injury. The activation of these mechanisms was associated with early markers of senescence, including expression of senescence-related genes and increases in senescence-associated heterochromatin foci in alveolar cells. Autopsy samples from lungs of patients with ARDS revealed increased senescence-associated heterochromatin foci. Collectively, these results suggest that acute lung injury activates p53/p21 as an antiapoptotic mechanism to ameliorate damage, but with the side effect of induction of senescence.


Subject(s)
Acute Lung Injury/metabolism , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Acids/administration & dosage , Acids/toxicity , Acute Lung Injury/etiology , Acute Lung Injury/pathology , Animals , Apoptosis , Cellular Senescence , Cyclin-Dependent Kinase Inhibitor p21/deficiency , Cyclin-Dependent Kinase Inhibitor p21/genetics , DNA Damage , Disease Models, Animal , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Respiration, Artificial/adverse effects , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/metabolism , Respiratory Distress Syndrome/pathology , Signal Transduction , Stress, Mechanical , Tumor Suppressor Protein p53/deficiency , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
7.
Biomed Eng Online ; 19(1): 91, 2020 Dec 03.
Article in English | MEDLINE | ID: covidwho-958037

ABSTRACT

Most critically ill Covid-19 patients succumb to multiple organ failure and/or sudden cardiac arrest (SCA) as a result of comorbid endothelial dysfunction disorders which had probably aggravated by conventional mechanical assist devices. Even worse, mechanical ventilators prevent the respiratory pump from performing its crucial function as a potential generator of endothelial shear stress (ESS) which controls microcirculation and hemodynamics since birth. The purpose of this work is to bring our experience with ESS enhancement and pulmonary vascular resistance (PVR) management as a potential therapeutic solution in acute respiratory distress syndrome (ARDS). We propose a non-invasive device composed of thoracic and infradiaphragmatic compartments that will be pulsated in an alternating frequency (20/40 bpm) with low-pressure pneumatic generator (0.1-0.5 bar). Oxygen supply, nasogastric with, or without endotracheal tubes are considered.


Subject(s)
COVID-19/physiopathology , COVID-19/therapy , Endothelium, Vascular/pathology , Respiration, Artificial/instrumentation , Respiratory Distress Syndrome/physiopathology , Shear Strength , Animals , COVID-19/complications , Critical Illness , Dogs , Equipment Design , Female , Heart Arrest , Hemodynamics , Male , Oxygen/therapeutic use , Respiratory Distress Syndrome/complications , Respiratory Distress Syndrome/therapy , Stress, Mechanical , Swine
8.
Emerg Top Life Sci ; 4(4): 379-387, 2020 12 11.
Article in English | MEDLINE | ID: covidwho-927716

ABSTRACT

There has not been any means to inhibit replication of the SARS-CoV-2 virus responsible for the rapid, deadly spread of the COVID-19 pandemic and an effective, safe, tested across diverse populations vaccine still requires extensive investigation. This review deals with the repurpose of a wellness technology initially fabricated for combating physical inactivity by increasing muscular activity. Its action increases pulsatile shear stress (PSS) to the endothelium such that the bioavailability of nitric oxide (NO) and other mediators are increased throughout the body. In vitro evidence indicates that NO inhibits SARS-CoV-2 virus replication but there are no publications of NO delivery to the virus in vivo. It will be shown that increased PSS has potential in vivo to exert anti-viral properties of NO as well as to benefit endothelial manifestations of COVID-19 thereby serving as a safe and effective backstop.


Subject(s)
COVID-19/therapy , Endothelium/metabolism , Nitric Oxide/metabolism , Physical Stimulation , Accelerometry , COVID-19/physiopathology , Exercise , Humans , Physical Stimulation/methods , Stress, Mechanical
9.
Stroke ; 52(1): 260-270, 2021 01.
Article in English | MEDLINE | ID: covidwho-916325

ABSTRACT

BACKGROUND AND PURPOSE: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is associated with an increased rate of cerebrovascular events including ischemic stroke and intracerebral hemorrhage. The mechanisms underlying cerebral endothelial susceptibility and response to SARS-CoV-2 are unknown yet critical to understanding the association of SARS-CoV-2 infection with cerebrovascular events. METHODS: Endothelial cells were isolated from human brain and analyzed by RNA sequencing. Human umbilical vein and human brain microvascular cells were used in both monolayer culture and endothelialized within a 3-dimensional printed vascular model of the middle cerebral artery. Gene expression levels were measured by quantitative polymerase chain reaction and direct RNA hybridization. Recombinant SARS-CoV-2 S protein and S protein-containing liposomes were used to measure endothelial binding by immunocytochemistry. RESULTS: ACE2 (angiotensin-converting enzyme-2) mRNA levels were low in human brain and monolayer endothelial cell culture. Within the 3-dimensional printed vascular model, ACE2 gene expression and protein levels were progressively increased by vessel size and flow rates. SARS-CoV-2 S protein-containing liposomes were detected in human umbilical vein endothelial cells and human brain microvascular endothelial cells in 3-dimensional middle cerebral artery models but not in monolayer culture consistent with flow dependency of ACE2 expression. Binding of SARS-CoV-2 S protein triggered 83 unique genes in human brain endothelial cells including upregulation of complement component C3. CONCLUSIONS: Brain endothelial cells are susceptible to direct SARS-CoV-2 infection through flow-dependent expression of ACE2. Viral S protein binding triggers a unique gene expression profile in brain endothelia that may explain the association of SARS-CoV-2 infection with cerebrovascular events.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/virology , Endothelial Cells/virology , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Transcriptome , Brain/metabolism , Brain/virology , COVID-19/metabolism , Cells, Cultured , Cerebrovascular Circulation/physiology , Endothelial Cells/metabolism , Humans , Models, Anatomic , Stress, Mechanical
10.
Mol Med ; 26(1): 95, 2020 10 14.
Article in English | MEDLINE | ID: covidwho-873932

ABSTRACT

Pulmonary fibrosis arises from the repeated epithelial mild injuries and insufficient repair lead to over activation of fibroblasts and excessive deposition of extracellular matrix, which result in a mechanical stretched niche. However, increasing mechanical stress likely exists before the establishment of fibrosis since early micro injuries increase local vascular permeability and prompt cytoskeletal remodeling which alter cellular mechanical forces. It is noteworthy that COVID-19 patients with severe hypoxemia will receive mechanical ventilation as supportive treatment and subsequent pathology studies indicate lung fibrosis pattern. At advanced stages, mechanical stress originates mainly from the stiff matrix since boundaries between stiff and compliant parts of the tissue could generate mechanical stress. Therefore, mechanical stress has a significant role in the whole development process of pulmonary fibrosis. The alveoli are covered by abundant capillaries and function as the main gas exchange unit. Constantly subject to variety of damages, the alveolar epithelium injuries were recently recognized to play a vital role in the onset and development of idiopathic pulmonary fibrosis. In this review, we summarize the literature regarding the effects of mechanical stress on the fundamental cells constituting the alveoli in the process of pulmonary fibrosis, particularly on epithelial cells, capillary endothelial cells, fibroblasts, mast cells, macrophages and stem cells. Finally, we briefly review this issue from a more comprehensive perspective: the metabolic and epigenetic regulation.


Subject(s)
Coronavirus Infections/immunology , Epigenesis, Genetic/immunology , Idiopathic Pulmonary Fibrosis/immunology , Mechanotransduction, Cellular/immunology , Pneumonia, Viral/immunology , Pulmonary Embolism/immunology , Respiratory Insufficiency/immunology , Alveolar Epithelial Cells/immunology , Alveolar Epithelial Cells/pathology , Betacoronavirus/immunology , Betacoronavirus/pathogenicity , Biomechanical Phenomena , COVID-19 , Coronavirus Infections/genetics , Coronavirus Infections/pathology , Coronavirus Infections/virology , Cytokines/genetics , Cytokines/immunology , Endothelial Cells/immunology , Endothelial Cells/pathology , Fibroblasts/immunology , Fibroblasts/pathology , Humans , Idiopathic Pulmonary Fibrosis/genetics , Idiopathic Pulmonary Fibrosis/pathology , Idiopathic Pulmonary Fibrosis/virology , Lung/blood supply , Lung/immunology , Lung/pathology , Macrophages/immunology , Macrophages/pathology , Mechanotransduction, Cellular/genetics , Pandemics , Pneumonia, Viral/genetics , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Pulmonary Embolism/genetics , Pulmonary Embolism/pathology , Pulmonary Embolism/virology , Respiratory Insufficiency/genetics , Respiratory Insufficiency/pathology , Respiratory Insufficiency/virology , SARS-CoV-2 , Stress, Mechanical
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