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1.
J Gen Virol ; 102(10)2021 10.
Article in English | MEDLINE | ID: covidwho-1490495

ABSTRACT

The highly pathogenic Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a severe respiratory virus. Recent reports indicate additional central nervous system (CNS) involvement. In this study, human DPP4 transgenic mice were infected with MERS-CoV, and viral antigens were first detected in the midbrain-hindbrain 4 days post-infection, suggesting the virus may enter the brainstem via peripheral nerves. Neurons and astrocytes throughout the brain were infected, followed by damage of the blood brain barrier (BBB), as well as microglial activation and inflammatory cell infiltration, which may be caused by complement activation based on the observation of deposition of complement activation product C3 and high expression of C3a receptor (C3aR) and C5a receptor (C5aR1) in neurons and glial cells. It may be concluded that these effects were mediated by complement activation in the brain, because of their reduction resulted from the treatment with mouse C5aR1-specific mAb. Such mAb significantly reduced nucleoprotein expression, suppressed microglial activation and decreased activation of caspase-3 in neurons and p38 phosphorylation in the brain. Collectively, these results suggest that MERS-CoV infection of CNS triggers complement activation, leading to inflammation-mediated damage of brain tissue, and regulating of complement activation could be a promising intervention and adjunctive treatment for CNS injury by MERS-CoV and other coronaviruses.


Subject(s)
Brain/pathology , Complement System Proteins/immunology , Coronavirus Infections/pathology , Dipeptidyl Peptidase 4/genetics , Middle East Respiratory Syndrome Coronavirus/pathogenicity , Animals , Blood-Brain Barrier/immunology , Blood-Brain Barrier/pathology , Brain/blood supply , Brain/immunology , Brain/virology , Complement Activation/drug effects , Complement Inactivating Agents/therapeutic use , Coronavirus Infections/drug therapy , Coronavirus Infections/immunology , Coronavirus Infections/virology , Disease Models, Animal , Humans , Inflammation , Mice , Mice, Transgenic , Microglia/immunology , Microglia/pathology
2.
Proc Natl Acad Sci U S A ; 118(41)2021 10 12.
Article in English | MEDLINE | ID: covidwho-1486398

ABSTRACT

The COVID-19 pandemic led to widespread mandates requiring the wearing of face masks, which led to debates on their benefits and possible adverse effects. To that end, the physiological effects at the systemic and at the brain level are of interest. We have investigated the effect of commonly available face masks (FFP2 and surgical) on cerebral hemodynamics and oxygenation, particularly microvascular cerebral blood flow (CBF) and blood/tissue oxygen saturation (StO2), measured by transcranial hybrid near-infrared spectroscopies and on systemic physiology in 13 healthy adults (ages: 23 to 33 y). The results indicate small but significant changes in cerebral hemodynamics while wearing a mask. However, these changes are comparable to those of daily life activities. This platform and the protocol provides the basis for large or targeted studies of the effects of mask wearing in different populations and while performing critical tasks.


Subject(s)
Brain/physiology , Masks , Activities of Daily Living , Adult , Brain/blood supply , Brain/metabolism , COVID-19/prevention & control , Female , Healthy Volunteers , Hemodynamics , Humans , Male , Microcirculation , Monitoring, Physiologic , Oxygen/metabolism , SARS-CoV-2 , Spectroscopy, Near-Infrared , Young Adult
3.
Methods Mol Biol ; 2311: 185-193, 2021.
Article in English | MEDLINE | ID: covidwho-1482181

ABSTRACT

Studies of blood-brain barrier (BBB) require developing of a novel and convenient in vitro endothelial cell model. We isolated primary human and rodent brain microvascular endothelial cells and developed methods for culturing, characterization, and high-efficiency transfection of endothelial cells. Here, we describe the improved methods to obtain in vitro human and rodent BBB models to study expression of endogenous and exogenous genes of interest.


Subject(s)
Blood-Brain Barrier/physiology , Brain/blood supply , Cell Separation , Endothelial Cells/physiology , Microvessels/cytology , Transfection , Animals , Blood-Brain Barrier/metabolism , Cell Culture Techniques , Cell Differentiation , Cell Proliferation , Cells, Cultured , Endothelial Cells/metabolism , Fetus , Gestational Age , Humans , Mice , Rats
4.
PLoS One ; 15(6): e0233981, 2020.
Article in English | MEDLINE | ID: covidwho-1456053

ABSTRACT

We aimed to examine aneurysm hemodynamics with intra-saccular pressure measurement, and compare the effects of coiling, stenting and stent-assisted coiling in proximal segments of intracranial circulation. A cohort of 45 patients underwent elective endovascular coil embolization (with or without stent) for intracranial aneurysm at our department. Arterial pressure transducer was used for all measurements. It was attached to proximal end of the microcatheter. Measurements were taken in the parent artery before and after embolization, at the aneurysm dome before embolization, after stent implantation, and after embolization. Stent-assisted coiling was performed with 4 different stents: LVIS and LVIS Jr (Microvention, Tustin, CA, USA), Leo (Balt, Montmorency, France), Barrel VRD (Medtronic/ Covidien, Irvine, CA, USA). Presence of the stent showed significant reverse correlation with intra-aneurysmal pressure-both systolic and diastolic-after its implantation (r = -0.70 and r = -0.75, respectively), which was further supported by correlations with stent cell size-r = 0.72 and r = 0.71, respectively (P<0.05). Stent implantation resulted in significant decrease in diastolic intra-aneurysmal pressure (p = 0.046). Systolic or mean intra-aneurysmal pressure did not differ significantly. Embolization did not significantly change the intra-aneurysmal pressure in matched pairs, regardless of the use of stent (p>0.05). In conclusion, low-profile braided stents show a potential to divert blood flow, there was significant decrease in diastolic pressure after stent placement. Flow-diverting properties were related to stent porosity. Coiling does not significantly change the intra-aneurysmal pressure, regardless of packing density.


Subject(s)
Blood Pressure , Intracranial Aneurysm/physiopathology , Stents , Aged , Arterial Pressure , Blood Circulation , Blood Vessel Prosthesis , Brain/blood supply , Brain/physiopathology , Embolization, Therapeutic , Female , Hemodynamics , Humans , Intracranial Aneurysm/therapy , Male , Middle Aged
5.
Proc Natl Acad Sci U S A ; 118(41)2021 10 12.
Article in English | MEDLINE | ID: covidwho-1450314

ABSTRACT

The COVID-19 pandemic led to widespread mandates requiring the wearing of face masks, which led to debates on their benefits and possible adverse effects. To that end, the physiological effects at the systemic and at the brain level are of interest. We have investigated the effect of commonly available face masks (FFP2 and surgical) on cerebral hemodynamics and oxygenation, particularly microvascular cerebral blood flow (CBF) and blood/tissue oxygen saturation (StO2), measured by transcranial hybrid near-infrared spectroscopies and on systemic physiology in 13 healthy adults (ages: 23 to 33 y). The results indicate small but significant changes in cerebral hemodynamics while wearing a mask. However, these changes are comparable to those of daily life activities. This platform and the protocol provides the basis for large or targeted studies of the effects of mask wearing in different populations and while performing critical tasks.


Subject(s)
Brain/physiology , Masks , Activities of Daily Living , Adult , Brain/blood supply , Brain/metabolism , COVID-19/prevention & control , Female , Healthy Volunteers , Hemodynamics , Humans , Male , Microcirculation , Monitoring, Physiologic , Oxygen/metabolism , SARS-CoV-2 , Spectroscopy, Near-Infrared , Young Adult
6.
Microvasc Res ; 138: 104232, 2021 11.
Article in English | MEDLINE | ID: covidwho-1446976

ABSTRACT

The mechanisms by which the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) induces neurological complications remain to be elucidated. We aimed to identify possible effects of hypoxia on the expression of SARS-CoV-2 cell entry mediators, angiotensin-converting enzyme 2 (ACE2) receptor and transmembrane protease serine 2 (TMPRSS2) protein, in human brain endothelial cells, in vitro. hCMEC/D3 cells were exposed to different oxygen tensions: 20% (Control group), 8% or 2% O2 (Hypoxia groups). Cells were harvested 6-, 24- and 48 h following hypoxic challenge for assessment of mRNA and protein, using qPCR and Western Blot. The response of the brain endothelial cells to hypoxia was replicated using modular incubator chambers. We observed an acute increase (6 h, p < 0.05), followed by a longer-term decrease (48 h, p < 0.05) in ACE2 mRNA and protein expression, accompanied by reduced expression of TMPRSS2 protein levels (48 h, p < 0.05) under the more severe hypoxic condition (2% O2). No changes in levels of von Willebrand Factor (vWF - an endothelial cell damage marker) or interleukin 6 (IL-6 - a pro-inflammatory cytokine) mRNA were observed. We conclude that hypoxia regulates brain endothelial cell ACE2 and TMPRSS2 expression in vitro, which may indicate human brain endothelial susceptibility to SARS-CoV-2 infection and subsequent brain sequelae.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Brain/blood supply , COVID-19/virology , Endothelial Cells/virology , SARS-CoV-2/pathogenicity , Serine Endopeptidases/metabolism , Virus Internalization , Angiotensin-Converting Enzyme 2/genetics , COVID-19/enzymology , Cell Hypoxia , Cell Line , Endothelial Cells/enzymology , Gene Expression Regulation , Host-Pathogen Interactions , Humans , Serine Endopeptidases/genetics
7.
Cells ; 10(9)2021 09 04.
Article in English | MEDLINE | ID: covidwho-1403545

ABSTRACT

Stroke is the third leading cause of mortality in women and it kills twice as many women as breast cancer. A key role in the pathophysiology of stroke plays the disruption of the blood-brain barrier (BBB) within the neurovascular unit. While estrogen induces vascular protective actions, its influence on stroke remains unclear. Moreover, experiments assessing its impact on endothelial cells to induce barrier integrity are non-conclusive. Since pericytes play an active role in regulating BBB integrity and function, we hypothesize that estradiol may influence BBB by regulating their activity. In this study using human brain vascular pericytes (HBVPs) we investigated the impact of estradiol on key pericyte functions known to influence BBB integrity. HBVPs expressed estrogen receptors (ER-α, ER-ß and GPER) and treatment with estradiol (10 nM) inhibited basal cell migration but not proliferation. Since pericyte migration is a hallmark for BBB disruption following injury, infection and inflammation, we investigated the effects of estradiol on TNFα-induced PC migration. Importantly, estradiol prevented TNFα-induced pericyte migration and this effect was mimicked by PPT (ER-α agonist) and DPN (ER-ß agonist), but not by G1 (GPR30 agonist). The modulatory effects of estradiol were abrogated by MPP and PHTPP, selective ER-α and ER-ß antagonists, respectively, confirming the role of ER-α and ER-ß in mediating the anti-migratory actions of estrogen. To delineate the intracellular mechanisms mediating the inhibitory actions of estradiol on PC migration, we investigated the role of AKT and MAPK activation. While estradiol consistently reduced the TNFα-induced MAPK and Akt phosphorylation, only the inhibition of MAPK, but not Akt, significantly abrogated the migratory actions of TNFα. In transendothelial electrical resistance measurements, estradiol induced barrier function (TEER) in human brain microvascular endothelial cells co-cultured with pericytes, but not in HBMECs cultured alone. Importantly, transcriptomics analysis of genes modulated by estradiol in pericytes showed downregulation of genes known to increase cell migration and upregulation of genes known to inhibit cell migration. Taken together, our findings provide the first evidence that estradiol modulates pericyte activity and thereby improves endothelial integrity.


Subject(s)
Brain/blood supply , Cell Movement/drug effects , Estradiol/pharmacology , Gene Expression Profiling , Pericytes/cytology , Cell Movement/genetics , Cell Proliferation/drug effects , Cells, Cultured , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Gene Expression Regulation/drug effects , Humans , Mitogen-Activated Protein Kinases/metabolism , Pericytes/drug effects , Pericytes/metabolism , Phosphorylation/drug effects , Proto-Oncogene Proteins c-akt/metabolism , Receptors, Estrogen/metabolism , Tumor Necrosis Factor-alpha/metabolism
9.
J Clin Invest ; 131(8)2021 04 15.
Article in English | MEDLINE | ID: covidwho-1291498

ABSTRACT

BACKGROUNDThe coronavirus disease 2019 (COVID-19) rapidly progressed to a global pandemic. Although some patients totally recover from COVID-19 pneumonia, the disease's long-term effects on the brain still need to be explored.METHODSWe recruited 51 patients with 2 subtypes of COVID-19 (19 mild and 32 severe) with no specific neurological manifestations at the acute stage and no obvious lesions on the conventional MRI 3 months after discharge. Changes in gray matter morphometry, cerebral blood flow (CBF), and white matter (WM) microstructure were investigated using MRI. The relationship between brain imaging measurements and inflammation markers was further analyzed.RESULTSCompared with healthy controls, the decrease in cortical thickness/CBF and the changes in WM microstructure were more severe in patients with severe disease than in those with mild disease, especially in the frontal and limbic systems. Furthermore, changes in brain microstructure, CBF, and tract parameters were significantly correlated (P < 0.05) with the inflammatory markers C-reactive protein, procalcitonin, and interleukin 6.CONCLUSIONIndirect injury related to inflammatory storm may damage the brain, altering cerebral volume, CBF, and WM tracts. COVID-19-related hypoxemia and dysfunction of vascular endothelium may also contribute to neurological changes. The abnormalities in these brain areas need to be monitored during recovery, which could help clinicians understand the potential neurological sequelae of COVID-19.FUNDINGNatural Science Foundation of China.


Subject(s)
COVID-19/diagnostic imaging , Cerebrovascular Circulation/physiology , SARS-CoV-2 , Aged , Brain/blood supply , Brain/diagnostic imaging , Brain/pathology , C-Reactive Protein/metabolism , COVID-19/epidemiology , COVID-19/physiopathology , Case-Control Studies , China/epidemiology , Diffusion Tensor Imaging , Echo-Planar Imaging , Female , Follow-Up Studies , Gray Matter/diagnostic imaging , Gray Matter/pathology , Humans , Imaging, Three-Dimensional , Inflammation Mediators/blood , Interleukin-6/blood , Male , Middle Aged , Neuroimaging , Pandemics , Procalcitonin/blood , Severity of Illness Index , Time Factors , White Matter/diagnostic imaging , White Matter/pathology
10.
Int Rev Cell Mol Biol ; 363: 203-269, 2021.
Article in English | MEDLINE | ID: covidwho-1212320

ABSTRACT

An increase in intracellular Ca2+ concentration ([Ca2+]i) regulates a plethora of functions in the cardiovascular (CV) system, including contraction in cardiomyocytes and vascular smooth muscle cells (VSMCs), and angiogenesis in vascular endothelial cells and endothelial colony forming cells. The sarco/endoplasmic reticulum (SR/ER) represents the largest endogenous Ca2+ store, which releases Ca2+ through ryanodine receptors (RyRs) and/or inositol-1,4,5-trisphosphate receptors (InsP3Rs) upon extracellular stimulation. The acidic vesicles of the endolysosomal (EL) compartment represent an additional endogenous Ca2+ store, which is targeted by several second messengers, including nicotinic acid adenine dinucleotide phosphate (NAADP) and phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2], and may release intraluminal Ca2+ through multiple Ca2+ permeable channels, including two-pore channels 1 and 2 (TPC1-2) and Transient Receptor Potential Mucolipin 1 (TRPML1). Herein, we discuss the emerging, pathophysiological role of EL Ca2+ signaling in the CV system. We describe the role of cardiac TPCs in ß-adrenoceptor stimulation, arrhythmia, hypertrophy, and ischemia-reperfusion injury. We then illustrate the role of EL Ca2+ signaling in VSMCs, where TPCs promote vasoconstriction and contribute to pulmonary artery hypertension and atherosclerosis, whereas TRPML1 sustains vasodilation and is also involved in atherosclerosis. Subsequently, we describe the mechanisms whereby endothelial TPCs promote vasodilation, contribute to neurovascular coupling in the brain and stimulate angiogenesis and vasculogenesis. Finally, we discuss about the possibility to target TPCs, which are likely to mediate CV cell infection by the Severe Acute Respiratory Disease-Coronavirus-2, with Food and Drug Administration-approved drugs to alleviate the detrimental effects of Coronavirus Disease-19 on the CV system.


Subject(s)
COVID-19/complications , COVID-19/drug therapy , Calcium Signaling/physiology , Cardiovascular Diseases/etiology , Cardiovascular Diseases/metabolism , Cardiovascular System/metabolism , Lysosomes/metabolism , SARS-CoV-2 , ADP-ribosyl Cyclase 1/metabolism , Animals , Brain/blood supply , Brain/metabolism , COVID-19/metabolism , Calcium Channels/metabolism , Cardiovascular Diseases/drug therapy , Endoplasmic Reticulum/metabolism , Endothelial Cells/metabolism , Humans , Models, Cardiovascular , Myocytes, Cardiac/metabolism , NADP/analogs & derivatives , NADP/metabolism , Receptors, Adrenergic, beta/metabolism , Sarcoplasmic Reticulum/metabolism , Transient Receptor Potential Channels/metabolism
11.
Stroke ; 52(7): 2422-2426, 2021 07.
Article in English | MEDLINE | ID: covidwho-1195875

ABSTRACT

BACKGROUND AND PURPOSE: Stroke may complicate coronavirus disease 2019 (COVID-19) infection based on clinical hypercoagulability. We investigated whether transcranial Doppler ultrasound has utility for identifying microemboli and clinically relevant cerebral blood flow velocities (CBFVs) in COVID-19. METHODS: We performed transcranial Doppler for a consecutive series of patients with confirmed or suspected COVID-19 infection admitted to 2 intensive care units at a large academic center including evaluation for microembolic signals. Variables specific to hypercoagulability and blood flow including transthoracic echocardiography were analyzed as a part of routine care. RESULTS: Twenty-six patients were included in this analysis, 16 with confirmed COVID-19 infection. Of those, 2 had acute ischemic stroke secondary to large vessel occlusion. Ten non-COVID stroke patients were included for comparison. Two COVID-negative patients had severe acute respiratory distress syndrome and stroke due to large vessel occlusion. In patients with COVID-19, relatively low CBFVs were observed diffusely at median hospital day 4 (interquartile range, 3-9) despite low hematocrit (29.5% [25.7%-31.6%]); CBFVs in comparable COVID-negative stroke patients were significantly higher compared with COVID-positive stroke patients. Microembolic signals were not detected in any patient. Median left ventricular ejection fraction was 60% (interquartile range, 60%-65%). CBFVs were correlated with arterial oxygen content, and C-reactive protein (Spearman ρ=0.28 [P=0.04]; 0.58 [P<0.001], respectively) but not with left ventricular ejection fraction (ρ=-0.18; P=0.42). CONCLUSIONS: In this cohort of critically ill patients with COVID-19 infection, we observed lower than expected CBFVs in setting of low arterial oxygen content and low hematocrit but not associated with suppression of cardiac output.


Subject(s)
Blood Flow Velocity , Brain/diagnostic imaging , COVID-19/diagnostic imaging , Cerebrovascular Circulation , Ischemic Stroke/diagnostic imaging , Adult , Aged , Blood Gas Analysis , Brain/blood supply , C-Reactive Protein/metabolism , COVID-19/physiopathology , Case-Control Studies , Critical Illness , Female , Humans , Ischemic Stroke/physiopathology , Male , Middle Aged , Oxygen/blood , Respiratory Distress Syndrome/diagnostic imaging , Respiratory Distress Syndrome/physiopathology , SARS-CoV-2 , Stroke Volume/physiology , Ultrasonography, Doppler, Transcranial
12.
J Clin Invest ; 131(8)2021 04 15.
Article in English | MEDLINE | ID: covidwho-1186424

ABSTRACT

BACKGROUNDThe coronavirus disease 2019 (COVID-19) rapidly progressed to a global pandemic. Although some patients totally recover from COVID-19 pneumonia, the disease's long-term effects on the brain still need to be explored.METHODSWe recruited 51 patients with 2 subtypes of COVID-19 (19 mild and 32 severe) with no specific neurological manifestations at the acute stage and no obvious lesions on the conventional MRI 3 months after discharge. Changes in gray matter morphometry, cerebral blood flow (CBF), and white matter (WM) microstructure were investigated using MRI. The relationship between brain imaging measurements and inflammation markers was further analyzed.RESULTSCompared with healthy controls, the decrease in cortical thickness/CBF and the changes in WM microstructure were more severe in patients with severe disease than in those with mild disease, especially in the frontal and limbic systems. Furthermore, changes in brain microstructure, CBF, and tract parameters were significantly correlated (P < 0.05) with the inflammatory markers C-reactive protein, procalcitonin, and interleukin 6.CONCLUSIONIndirect injury related to inflammatory storm may damage the brain, altering cerebral volume, CBF, and WM tracts. COVID-19-related hypoxemia and dysfunction of vascular endothelium may also contribute to neurological changes. The abnormalities in these brain areas need to be monitored during recovery, which could help clinicians understand the potential neurological sequelae of COVID-19.FUNDINGNatural Science Foundation of China.


Subject(s)
COVID-19/diagnostic imaging , Cerebrovascular Circulation/physiology , SARS-CoV-2 , Aged , Brain/blood supply , Brain/diagnostic imaging , Brain/pathology , C-Reactive Protein/metabolism , COVID-19/epidemiology , COVID-19/physiopathology , Case-Control Studies , China/epidemiology , Diffusion Tensor Imaging , Echo-Planar Imaging , Female , Follow-Up Studies , Gray Matter/diagnostic imaging , Gray Matter/pathology , Humans , Imaging, Three-Dimensional , Inflammation Mediators/blood , Interleukin-6/blood , Male , Middle Aged , Neuroimaging , Pandemics , Procalcitonin/blood , Severity of Illness Index , Time Factors , White Matter/diagnostic imaging , White Matter/pathology
13.
J Neurol Sci ; 421: 117308, 2021 02 15.
Article in English | MEDLINE | ID: covidwho-1033825

ABSTRACT

We evaluated the incidence, distribution, and histopathologic correlates of microvascular brain lesions in patients with severe COVID-19. Sixteen consecutive patients admitted to the intensive care unit with severe COVID-19 undergoing brain MRI for evaluation of coma or neurologic deficits were retrospectively identified. Eleven patients had punctate susceptibility-weighted imaging (SWI) lesions in the subcortical and deep white matter, eight patients had >10 SWI lesions, and four patients had lesions involving the corpus callosum. The distribution of SWI lesions was similar to that seen in patients with hypoxic respiratory failure, sepsis, and disseminated intravascular coagulation. Brain autopsy in one patient revealed that SWI lesions corresponded to widespread microvascular injury, characterized by perivascular and parenchymal petechial hemorrhages and microscopic ischemic lesions. Collectively, these radiologic and histopathologic findings add to growing evidence that patients with severe COVID-19 are at risk for multifocal microvascular hemorrhagic and ischemic lesions in the subcortical and deep white matter.


Subject(s)
Brain Injuries/diagnostic imaging , COVID-19/diagnostic imaging , Magnetic Resonance Imaging/methods , Microvessels/diagnostic imaging , Severity of Illness Index , Brain/blood supply , Brain/diagnostic imaging , Brain Injuries/etiology , COVID-19/complications , Humans , Intensive Care Units/trends , Male , Microvessels/injuries , Middle Aged , Retrospective Studies
16.
ACS Chem Neurosci ; 11(22): 3732-3740, 2020 11 18.
Article in English | MEDLINE | ID: covidwho-910316

ABSTRACT

This Article summarizes the likely benefits of central nervous system oxidative preconditioning in the reduction of COVID-19 based on its putative pathogenesis. The current COVID-19 outbreak caused a pandemic with millions of infected patients and death cases worldwide. The clinical features of severe acute respiratory syndrome coronavirus (SARS-CoV) was initially linked with respiratory disorders, but recent studies have reported alterations of neurological and cerebrovascular functions in COVID-19 patients. The main viral infection features are related to cell death, inflammation, and cytokine generation, which can be associated with the dysregulation of redox systems or oxidative stress. However, until now, there is no available and effective therapeutic approach. Thus, it is necessary to search for care and adequate protection against the disease, especially for susceptible and vulnerable groups. Preconditioning, a well-known antioxidative stress and anti-inflammatory approach, is protective against many neurological age-related disorders. COVID-19 severity and morbidity have been observed in elderly patients. The aim of the present study is to elucidate the possible protective role of oxidative preconditioning in aged patients at high risk of developing severe COVID-19 complications.


Subject(s)
Betacoronavirus , Brain/blood supply , Coronavirus Infections/therapy , Ischemic Preconditioning/methods , Oxidative Stress/physiology , Pneumonia, Viral/therapy , Betacoronavirus/metabolism , Brain/metabolism , Brain/virology , COVID-19 , Coronavirus Infections/metabolism , Humans , Ischemic Preconditioning/trends , Pandemics , Pneumonia, Viral/metabolism , SARS-CoV-2
17.
Eur Rev Med Pharmacol Sci ; 24(19): 10267-10278, 2020 Oct.
Article in English | MEDLINE | ID: covidwho-890962

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) uses Angiotensin- converting enzyme 2 (ACE2) receptors to infect host cells which may lead to coronavirus disease (COVID-19). Given the presence of ACE2 receptors in the brain and the critical role of the renin-angiotensin system (RAS) in brain functions, special attention to brain microcirculation and neuronal inflammation is warranted during COVID-19 treatment. Neurological complications reported among COVID-19 patients range from mild dizziness, headache, hypogeusia, hyposmia to severe like encephalopathy, stroke, Guillain-Barre Syndrome (GBS), CNS demyelination, infarcts, microhemorrhages and nerve root enhancement. The pathophysiology of these complications is likely via direct viral infection of the CNS and PNS tissue or through indirect effects including post- viral autoimmune response, neurological consequences of sepsis, hyperpyrexia, hypoxia and hypercoagulability among critically ill COVID-19 patients. Further, decreased deformability of red blood cells (RBC) may be contributing to inflammatory conditions and hypoxia in COVID-19 patients. Haptoglobin, hemopexin, heme oxygenase-1 and acetaminophen may be used to maintain the integrity of the RBC membrane.


Subject(s)
Brain/physiopathology , COVID-19/physiopathology , Erythrocytes/pathology , Hemolysis , Nervous System Diseases/physiopathology , Brain/blood supply , COVID-19/complications , Erythrocytes/drug effects , Hemolysis/drug effects , Humans , Models, Neurological , Molecular Targeted Therapy/methods , Nervous System Diseases/complications , Nervous System Diseases/drug therapy , Pandemics , SARS-CoV-2
18.
Neuromolecular Med ; 23(1): 184-198, 2021 03.
Article in English | MEDLINE | ID: covidwho-871558

ABSTRACT

Ergothioneine (ET) is a naturally occurring antioxidant that is synthesized by non-yeast fungi and certain bacteria. ET is not synthesized by animals, including humans, but is avidly taken up from the diet, especially from mushrooms. In the current study, we elucidated the effect of ET on the hCMEC/D3 human brain endothelial cell line. Endothelial cells are exposed to high levels of the cholesterol oxidation product, 7-ketocholesterol (7KC), in patients with cardiovascular disease and diabetes, and this process is thought to mediate pathological inflammation. 7KC induces a dose-dependent loss of cell viability and an increase in apoptosis and necrosis in the endothelial cells. A relocalization of the tight junction proteins, zonula occludens-1 (ZO-1) and claudin-5, towards the nucleus of the cells was also observed. These effects were significantly attenuated by ET. In addition, 7KC induces marked increases in the mRNA expression of pro-inflammatory cytokines, IL-1ß IL-6, IL-8, TNF-α and cyclooxygenase-2 (COX2), as well as COX2 enzymatic activity, and these were significantly reduced by ET. Moreover, the cytoprotective and anti-inflammatory effects of ET were significantly reduced by co-incubation with an inhibitor of the ET transporter, OCTN1 (VHCL). This shows that ET needs to enter the endothelial cells to have a protective effect and is unlikely to act via extracellular neutralizing of 7KC. The protective effect on inflammation in brain endothelial cells suggests that ET might be useful as a nutraceutical for the prevention or management of neurovascular diseases, such as stroke and vascular dementia. Moreover, the ability of ET to cross the blood-brain barrier could point to its usefulness in combatting 7KC that is produced in the CNS during neuroinflammation, e.g. after excitotoxicity, in chronic neurodegenerative diseases, and possibly COVID-19-related neurologic complications.


Subject(s)
Antioxidants/pharmacology , COVID-19/complications , Endothelial Cells/drug effects , Ergothioneine/pharmacology , Ketocholesterols/toxicity , Nervous System Diseases/prevention & control , Neuroprotective Agents/pharmacology , Antioxidants/pharmacokinetics , Apoptosis/drug effects , Biological Transport , Blood-Brain Barrier , Brain/blood supply , Brain/cytology , Cell Line , Cholesterol/metabolism , Claudin-5 , Cyclooxygenase 2/biosynthesis , Cyclooxygenase 2/genetics , Cytokines/biosynthesis , Cytokines/genetics , Drug Evaluation, Preclinical , Ergothioneine/pharmacokinetics , Humans , Microvessels/cytology , Nervous System Diseases/etiology , Neuroprotective Agents/pharmacokinetics , Nitric Oxide Synthase Type II/metabolism , Nitric Oxide Synthase Type III/metabolism , Organic Cation Transport Proteins , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Symporters , Zonula Occludens-1 Protein
19.
J Neurovirol ; 26(5): 631-641, 2020 10.
Article in English | MEDLINE | ID: covidwho-739689

ABSTRACT

A subset of patients with coronavirus 2 disease (COVID-19) experience neurological complications. These complications include loss of sense of taste and smell, stroke, delirium, and neuromuscular signs and symptoms. The etiological agent of COVID-19 is SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), an RNA virus with a glycoprotein-studded viral envelope that uses ACE2 (angiotensin-converting enzyme 2) as a functional receptor for infecting the host cells. Thus, the interaction of the envelope spike proteins with ACE2 on host cells determines the tropism and virulence of SARS-CoV-2. Loss of sense of taste and smell is an initial symptom of COVID-19 because the virus enters the nasal and oral cavities first and the epithelial cells are the receptors for these senses. Stroke in COVID-19 patients is likely a consequence of coagulopathy and injury to cerebral vascular endothelial cells that cause thrombo-embolism and stroke. Delirium and encephalopathy in acute and post COVID-19 patients are likely multifactorial and secondary to hypoxia, metabolic abnormalities, and immunological abnormalities. Thus far, there is no clear evidence that coronaviruses cause inflammatory neuromuscular diseases via direct invasion of peripheral nerves or muscles or via molecular mimicry. It appears that most of neurologic complications in COVID-19 patients are indirect and as a result of a bystander injury to neurons.


Subject(s)
Betacoronavirus/pathogenicity , Brain Diseases/complications , Coronavirus Infections/complications , Olfaction Disorders/complications , Pneumonia, Viral/complications , Pulmonary Embolism/complications , Stroke/complications , Angiotensin-Converting Enzyme 2 , Brain/blood supply , Brain/pathology , Brain/virology , Brain Diseases/immunology , Brain Diseases/pathology , Brain Diseases/virology , Bystander Effect , COVID-19 , Coronavirus Infections/immunology , Coronavirus Infections/pathology , Coronavirus Infections/virology , Epithelial Cells/pathology , Epithelial Cells/virology , Gene Expression Regulation , Host-Pathogen Interactions/genetics , Host-Pathogen Interactions/immunology , Humans , Lung/blood supply , Lung/pathology , Lung/virology , Neurons/pathology , Neurons/virology , Olfaction Disorders/immunology , Olfaction Disorders/pathology , Olfaction Disorders/virology , Pandemics , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/immunology , Pneumonia, Viral/immunology , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Pulmonary Embolism/immunology , Pulmonary Embolism/pathology , Pulmonary Embolism/virology , SARS-CoV-2 , Signal Transduction/genetics , Signal Transduction/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Stroke/immunology , Stroke/pathology , Stroke/virology
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