Vascular dysfunction in the brain; implications for heavy metals exposure

2021 ◽  
Vol 17 ◽  
Author(s):  
Nzube F. Olung ◽  
Oritoke M. Aluko ◽  
Sikirullai O. Jeje ◽  
Ayotunde S. Adeagbo ◽  
Omamuyovwi M. Ijomone
Keyword(s):  
Risk Factors ◽  
Heavy Metals ◽  
Vascular Dysfunction ◽  
Neurovascular Unit ◽  
Neurovascular Coupling ◽  
The Brain ◽  
Neurovascular Damage ◽  
Metals Exposure ◽  
Neurovascular Dysfunction

: Normal or diseased conditions that alter the brain’s requirement for oxygen and nutrients via alterations to neurovascular coupling act at the level of the neurovascular unit; comprising neuronal, glial and vascular components. The communications between the components of the neurovascular unit are precise and accurate for its functions, hence a minute disturbance can result in neurovascular dysfunction. Heavy metals such as cadmium, mercury, and lead have been identified to increase the vulnerability of the neurovascular unit to damage. This review examines the role of heavy metals in neurovascular dysfunctions and the possible mechanisms by which these metals act. Risk factors ranging from lifestyle, environment, genetics, infections, and physiologic ageing involved in neurological dysfunctions were highlighted, while stroke, was discussed as the prevalent consequence of neurovascular dysfunctions. Furthermore, the role of these heavy metals in the pathogenesis of stroke consequently pinpoints the importance of understanding the mechanisms of neurovascular damage in a bid to curb the occurrence of neurovascular dysfunctions.

scholarly journals Mesenchymal Stem Cell Derived Extracellular Vesicles for Repairing the Neurovascular Unit after Ischemic Stroke

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 767
Author(s):  
Courtney Davis ◽  
Sean I. Savitz ◽  
Nikunj Satani
Keyword(s):  
Ischemic Stroke ◽  
Extracellular Vesicles ◽  
Neurovascular Unit ◽  
Culture Conditions ◽  
Therapeutic Effects ◽  
Stroke Treatment ◽  
Inflammatory Molecules ◽  
The Brain

Ischemic stroke is a debilitating disease and one of the leading causes of long-term disability. During the early phase after ischemic stroke, the blood-brain barrier (BBB) exhibits increased permeability and disruption, leading to an influx of immune cells and inflammatory molecules that exacerbate the damage to the brain tissue. Mesenchymal stem cells have been investigated as a promising therapy to improve the recovery after ischemic stroke. The therapeutic effects imparted by MSCs are mostly paracrine. Recently, the role of extracellular vesicles released by these MSCs have been studied as possible carriers of information to the brain. This review focuses on the potential of MSC derived EVs to repair the components of the neurovascular unit (NVU) controlling the BBB, in order to promote overall recovery from stroke. Here, we review the techniques for increasing the effectiveness of MSC-based therapeutics, such as improved homing capabilities, bioengineering protein expression, modified culture conditions, and customizing the contents of EVs. Combining multiple techniques targeting NVU repair may provide the basis for improved future stroke treatment paradigms.

scholarly journals Association between Risk Factors for Vascular Dementia and Adiponectin

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Juhyun Song ◽  
Won Taek Lee ◽  
Kyung Ah Park ◽  
Jong Eun Lee
Keyword(s):  
Risk Factors ◽  
Cardiovascular Disease ◽  
Signal Transduction ◽  
Vascular Dementia ◽  
Case Control ◽  
Case Control Studies ◽  
Insulin Signal Transduction ◽  
Increased Risk ◽  
The Brain

Vascular dementia is caused by various factors, including increased age, diabetes, hypertension, atherosclerosis, and stroke. Adiponectin is an adipokine secreted by adipose tissue. Adiponectin is widely known as a regulating factor related to cardiovascular disease and diabetes. Adiponectin plasma levels decrease with age. Decreased adiponectin increases the risk of cardiovascular disease and diabetes. Adiponectin improves hypertension and atherosclerosis by acting as a vasodilator and antiatherogenic factor. Moreover, adiponectin is involved in cognitive dysfunction via modulation of insulin signal transduction in the brain. Case-control studies demonstrate the association between low adiponectin and increased risk of stroke, hypertension, and diabetes. This review summarizes the recent findings on the association between risk factors for vascular dementia and adiponectin. To emphasize this relationship, we will discuss the importance of research regarding the role of adiponectin in vascular dementia.

scholarly journals Apolipoprotein E Antibodies Affect the Retention of Passive Avoidance Memory in the Chick

1998 ◽  
Vol 6 (3) ◽  
pp. 29-40 ◽  
Author(s):  
Chris Lancashire ◽  
Radmila Mileusnic ◽  
Steven P.R. Rose
Keyword(s):  
Risk Factors ◽  
Apolipoprotein E ◽  
Passive Avoidance ◽  
Residence Time ◽  
Memory Formation ◽  
Avoidance Task ◽  
Brain Distribution ◽  
The Brain ◽  
Avoidance Memory

Isoforms of apolipoprotein E (ApoE) have been implicated as risk factors in Alzheimer’s disease. We have, therefore, examined the possible role of ApoE in memory formation, using a one-trial passive avoidance task in day-old chicks. Birds were trained on the task and then at various times pre or post-training were injected intracerebrally with anti-ApoE. Immunofluorescence staining demonstrated the presence of the antibody bound to the neuropil, close to the injection site and adjacent to the ventricle, with a residence time in the brain of up to 30 min. Chicks that were injected 30 min pre-training or just post-training with 5μg/ hemisphere of the antibody learned the task, but were amnesic when tested at 30 min or at subsequent times up to 24 hr Post-training. When tested at 24 hr, birds injected 5.5 hr post-training showed unimpaired retention. Birds injected with 5μg/hemisphere of anti-ApoA-I (which has a brain distribution similar to that of anti-ApoE) at 30 min pretraining showed no amnesia, indicating the specificity of the effect to the ApoE. Possible mechanisms for this effect are discussed.

scholarly journals Concentrations of the Selected Biomarkers of Endothelial Dysfunction in Response to Antiepileptic Drugs: A Literature Review

2019 ◽  
Vol 25 ◽  
pp. 107602961985942 ◽  
Author(s):  
Beata Sarecka-Hujar ◽  
Izabela Szołtysek-Bołdys ◽  
Ilona Kopyta ◽  
Barbara Dolińska ◽  
Andrzej Sobczak
Keyword(s):  
Risk Factors ◽  
Cardiovascular Diseases ◽  
Endothelial Dysfunction ◽  
Literature Review ◽  
Antiepileptic Drug ◽  
Asymmetric Dimethylarginine ◽  
The Body ◽  
Biochemical Processes ◽  
The Brain

Epilepsy is a disease arising from morphological and metabolic changes in the brain. Approximately 60% of patients with seizures can be controlled with 1 antiepileptic drug (AED), while in others, polytherapy is required. The AED treatment affects a number of biochemical processes in the body, including increasing the risk of cardiovascular diseases (CVDs). It is indicated that the duration of AED therapy with some AEDs significantly accelerates the process of atherosclerosis. Most of AEDs increase levels of homocysteine (HCys) as well as may affect concentrations of new, nonclassical risk factors for atherosclerosis, that is, asymmetric dimethylarginine (ADMA) and homoarginine (hArg). Because of the role of these parameters in the pathogenesis of CVD, knowledge of HCys, ADMA, and hArg concentrations in patients with epilepsia treated with AED, both pediatric and adult, appears to be of significant importance.

scholarly journals Vascular dysfunction and atherosclerosis in chronic kidney disease; A distinct entity

2019 ◽  
Vol 8 (2) ◽  
pp. 17-17 ◽  
Author(s):  
Eranga Harshani Silva ◽  
Chandima Madhu Wickramatilake ◽  
Sarath Lekamwasam ◽  
Lakmini Kumari Boralugoda Mudduwa ◽  
Ranjuka Arushana Ubayasiri
Keyword(s):  
Risk Factors ◽  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Vascular Dysfunction ◽  
Therapeutic Interventions ◽  
Cvd Risk ◽  
Unexplored Area ◽  
Calcium And Phosphate Metabolism ◽  
Conventional Risk Factors

Cardiovascular disease (CVD) is prevalent among patients with chronic kidney disease (CKD) and its occurrence and severity cannot be fully defined by the conventional cardiovascular risk factors namely age, hypertension, dyslipidaemia, diabetes mellitus and obesity. Contemporary studies have examined the role of non-conventional risk factors such as anemia, hyperhomocysteinemia, calcium and phosphate metabolism, vascular stiffness due to endothelial dysfunction ( ED), oxidative injury, and inflammation in the causation of CVD in CKD. Therapeutic interventions used in non-CKD patients are found to be less effective on patients with CKD. The purpose of this review was to gather available evidence on the CVD risk among CKD patients. Numerous mechanisms have been postulated to describe the increased atherogenicity in CKD patients. We discuss these mechanisms especially arterial stiffness, ED and inflammation in detail. In conclusion, CVD in CKD is still an unexplored area which needs further studies to uncover the possible mechanisms. Identifying newer therapies to improve health among this group of patients is of paramount importance.

scholarly journals Role of astroglial Connexin 43 in pneumolysin cytotoxicity and during pneumococcal meningitis

2020 ◽  
Vol 16 (12) ◽  
pp. e1009152
Author(s):  
Chakir Bello ◽  
Yasmine Smail ◽  
Vincent Sainte-Rose ◽  
Isabelle Podglajen ◽  
Alice Gilbert ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Connexin 43 ◽  
Critical Role ◽  
Neurovascular Unit ◽  
Brain Slices ◽  
Host Cells ◽  
Intermediate Filament Protein ◽  
Young Infants ◽  
The Brain

Streptococcus pneumoniae or pneumococcus (PN) is a major causative agent of bacterial meningitis with high mortality in young infants and elderly people worldwide. The mechanism underlying PN crossing of the blood brain barrier (BBB) and specifically, the role of non-endothelial cells of the neurovascular unit that control the BBB function, remains poorly understood. Here, we show that the astroglial connexin 43 (aCx43), a major gap junctional component expressed in astrocytes, plays a predominant role during PN meningitis. Following intravenous PN challenge, mice deficient for aCx43 developed milder symptoms and showed severely reduced bacterial counts in the brain. Immunofluorescence analysis of brain slices indicated that PN induces the aCx43–dependent destruction of the network of glial fibrillary acid protein (GFAP), an intermediate filament protein specifically expressed in astrocytes and up-regulated in response to brain injury. PN also induced nuclear shrinkage in astrocytes associated with the loss of BBB integrity, bacterial translocation across endothelial vessels and replication in the brain cortex. We found that aCx4-dependent astrocyte damages could be recapitulated using in vitro cultured cells upon challenge with wild-type PN but not with a ply mutant deficient for the pore-forming toxin pneumolysin (Ply). Consistently, we showed that purified Ply requires Cx43 to promote host cell plasma membrane permeabilization in a process involving the Cx43-dependent release of extracellular ATP and prolonged increase of cytosolic Ca2+ in host cells. These results point to a critical role for astrocytes during PN meningitis and suggest that the cytolytic activity of the major virulence factor Ply at concentrations relevant to bacterial infection requires co-opting of connexin plasma membrane channels.

Neuroprotection for Aortic Surgery and Stenting

2017 ◽  
Author(s):  
Jared W. Feinman ◽  
John G. Augoustides
Keyword(s):  
Risk Factors ◽  
Spinal Cord ◽  
Best Practices ◽  
Clinical Setting ◽  
Aortic Surgery ◽  
Surgical Techniques ◽  
Significant Risk ◽  
Severe Injury ◽  
The Brain

Despite recent advances, aortic surgery and stenting for an array of diseases still pose a significant risk of permanent and severe injury to the brain and/or spinal cord. These neurological risks are best understood in terms of the primary disease pathology, the extent of aortic involvement, mechanisms and risk factors, the role of neuromonitoring modalities, and the surgical techniques required for repair. This chapter will present an overview of perioperative practice in aortic surgery and stenting based on this framework and the latest guidelines and trials in order to describe best practices and promising options for neuroprotection in this challenging clinical setting.

scholarly journals Lead, Manganese, and Methylmercury as Risk Factors for Neurobehavioral Impairment in Advanced Age

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Bernard Weiss
Keyword(s):  
Risk Factors ◽  
Adverse Effects ◽  
Neurodegenerative Disease ◽  
Early Development ◽  
Neurodegenerative Disorders ◽  
Advanced Age ◽  
Metal Contaminants ◽  
Aging Populations ◽  
The Brain

Contamination of the environment by metals is recognized as a threat to health. One of their targets is the brain, and the adverse functional effects they induce are reflected by neurobehavioral assessments. Lead, manganese, and methylmercury are the metal contaminants linked most comprehensively to such disorders. Because many of these adverse effects can appear later in life, clues to the role of metals as risk factors for neurodegenerative disorders should be sought in the exposure histories of aging populations. A review of the available literature offers evidence that all three metals can produce, in advanced age, manifestations of neurobehavioral dysfunction associated with neurodegenerative disease. Among the critical unresolved questions is timing; that is, during which periods of the lifespan, including early development, do environmental exposures lay the foundations for their ultimate effects?

scholarly journals Mechanisms Mediating Functional Hyperemia in the Brain

2017 ◽  
Vol 24 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Amy R. Nippert ◽  
Kyle R. Biesecker ◽  
Eric A. Newman
Keyword(s):  
Nitric Oxide ◽  
Arachidonic Acid ◽  
Final Section ◽  
Neurovascular Coupling ◽  
Functional Hyperemia ◽  
Generating Functional ◽  
Signaling Mechanisms ◽  
The Brain ◽  
Astrocyte Endfeet

Neuronal activity within the brain evokes local increases in blood flow, a response termed functional hyperemia. This response ensures that active neurons receive sufficient oxygen and nutrients to maintain tissue function and health. In this review, we discuss the functions of functional hyperemia, the types of vessels that generate the response, and the signaling mechanisms that mediate neurovascular coupling, the communication between neurons and blood vessels. Neurovascular coupling signaling is mediated primarily by the vasoactive metabolites of arachidonic acid (AA), by nitric oxide, and by K+. While much is known about these pathways, many contentious issues remain. We highlight two controversies, the role of glial cell Ca2+ signaling in mediating neurovascular coupling and the importance of capillaries in generating functional hyperemia. We propose signaling pathways that resolve these controversies. In this scheme, capillary dilations are generated by Ca2+ increases in astrocyte endfeet, leading to production of AA metabolites. In contrast, arteriole dilations are generated by Ca2+ increases in neurons, resulting in production of nitric oxide and AA metabolites. Arachidonic acid from neurons also diffuses into astrocyte endfeet where it is converted into additional vasoactive metabolites. While this scheme resolves several discrepancies in the field, many unresolved challenges remain and are discussed in the final section of the review.

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