scholarly journals When the Blood Hits Your Brain: The Neurotoxicity of Extravasated Blood

2021 ◽  
Vol 22 (10) ◽  
pp. 5132
Author(s):  
Jesse A. Stokum ◽  
Gregory J. Cannarsa ◽  
Aaron P. Wessell ◽  
Phelan Shea ◽  
Nicole Wenger ◽  
...  

Hemorrhage in the central nervous system (CNS), including intracerebral hemorrhage (ICH), intraventricular hemorrhage (IVH), and aneurysmal subarachnoid hemorrhage (aSAH), remains highly morbid. Trials of medical management for these conditions over recent decades have been largely unsuccessful in improving outcome and reducing mortality. Beyond its role in creating mass effect, the presence of extravasated blood in patients with CNS hemorrhage is generally overlooked. Since trials of surgical intervention to remove CNS hemorrhage have been generally unsuccessful, the potent neurotoxicity of blood is generally viewed as a basic scientific curiosity rather than a clinically meaningful factor. In this review, we evaluate the direct role of blood as a neurotoxin and its subsequent clinical relevance. We first describe the molecular mechanisms of blood neurotoxicity. We then evaluate the clinical literature that directly relates to the evacuation of CNS hemorrhage. We posit that the efficacy of clot removal is a critical factor in outcome following surgical intervention. Future interventions for CNS hemorrhage should be guided by the principle that blood is exquisitely toxic to the brain.

2002 ◽  
Vol 12 (6) ◽  
pp. 1-7 ◽  
Author(s):  
George A. Alsina ◽  
J. Patrick Johnson ◽  
Duncan Q. McBride ◽  
Patrick R. L. Rhoten ◽  
C. Mark Mehringer ◽  
...  

Worldwide, cysticercosis is the most common parasitic infection of the central nervous system. In endemic regions, the incidence of neurocysticercosis (NCC) approaches 4% of the general population. The disease is predominantly intracranial, the authors of most series generally report the incidence of spinal NCC as only 1.5 to 3% of all cases. Although spinal NCC is relatively rare, it represents a distinct clinical entity that can have devastating consequences for the patient. Because of the limited size of the spinal canal, the mass effect of these lesions is poorly tolerated. Most spinal NCC occurs in the subarachnoid space where mass effect can cause spinal cord compression, although obstruction of cerebrospinal fluid pathways due to scarring of the subarachnoid space can also cause symptoms. The authors treated six patients with spinal NCC. In five cases the lesions were located in the subarachnoid space, and in one the lesion was intramedullary. All patients with subarachnoid spinal NCC required excision of the symptomatic lesions; in two cases initial medical therapy had failed. The patient with intramedullary spinal NCC experienced mild symptoms and underwent steroid therapy. All patients experienced variably improved outcomes and were eventually ambulatory. Medical therapy should be carefully considered in selected patients in whom symptoms are stable and nonprogressive. Surgical intervention is required when severe or progressive deficits occur to prevent permanent injury. In some patients recovery may be limited as a result of inflammatory injury to the spinal cord or arachnoidal adhesions.


2020 ◽  
Vol 19 (7) ◽  
pp. 483-494
Author(s):  
Tyler J. Wenzel ◽  
Evan Kwong ◽  
Ekta Bajwa ◽  
Andis Klegeris

: Glial cells, including microglia and astrocytes, facilitate the survival and health of all cells within the Central Nervous System (CNS) by secreting a range of growth factors and contributing to tissue and synaptic remodeling. Microglia and astrocytes can also secrete cytotoxins in response to specific stimuli, such as exogenous Pathogen-Associated Molecular Patterns (PAMPs), or endogenous Damage-Associated Molecular Patterns (DAMPs). Excessive cytotoxic secretions can induce the death of neurons and contribute to the progression of neurodegenerative disorders, such as Alzheimer’s disease (AD). The transition between various activation states of glia, which include beneficial and detrimental modes, is regulated by endogenous molecules that include DAMPs, cytokines, neurotransmitters, and bioactive lipids, as well as a diverse group of mediators sometimes collectively referred to as Resolution-Associated Molecular Patterns (RAMPs). RAMPs are released by damaged or dying CNS cells into the extracellular space where they can induce signals in autocrine and paracrine fashions by interacting with glial cell receptors. While the complete range of their effects on glia has not been described yet, it is believed that their overall function is to inhibit adverse CNS inflammatory responses, facilitate tissue remodeling and cellular debris removal. This article summarizes the available evidence implicating the following RAMPs in CNS physiological processes and neurodegenerative diseases: cardiolipin (CL), prothymosin α (ProTα), binding immunoglobulin protein (BiP), heat shock protein (HSP) 10, HSP 27, and αB-crystallin. Studies on the molecular mechanisms engaged by RAMPs could identify novel glial targets for development of therapeutic agents that effectively slow down neuroinflammatory disorders including AD.


2020 ◽  
Vol 21 (15) ◽  
pp. 5475 ◽  
Author(s):  
Manuela Pennisi ◽  
Giuseppe Lanza ◽  
Luca Falzone ◽  
Francesco Fisicaro ◽  
Raffaele Ferri ◽  
...  

Increasing evidence suggests that Severe Acute Respiratory Syndrome-coronavirus-2 (SARS-CoV-2) can also invade the central nervous system (CNS). However, findings available on its neurological manifestations and their pathogenic mechanisms have not yet been systematically addressed. A literature search on neurological complications reported in patients with COVID-19 until June 2020 produced a total of 23 studies. Overall, these papers report that patients may exhibit a wide range of neurological manifestations, including encephalopathy, encephalitis, seizures, cerebrovascular events, acute polyneuropathy, headache, hypogeusia, and hyposmia, as well as some non-specific symptoms. Whether these features can be an indirect and unspecific consequence of the pulmonary disease or a generalized inflammatory state on the CNS remains to be determined; also, they may rather reflect direct SARS-CoV-2-related neuronal damage. Hematogenous versus transsynaptic propagation, the role of the angiotensin II converting enzyme receptor-2, the spread across the blood-brain barrier, the impact of the hyperimmune response (the so-called “cytokine storm”), and the possibility of virus persistence within some CNS resident cells are still debated. The different levels and severity of neurotropism and neurovirulence in patients with COVID-19 might be explained by a combination of viral and host factors and by their interaction.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Talita A. M. Vrechi ◽  
Anderson H. F. F. Leão ◽  
Ingrid B. M. Morais ◽  
Vanessa C. Abílio ◽  
Antonio W. Zuardi ◽  
...  

AbstractAutophagy is a lysosomal catabolic process essential to cell homeostasis and is related to the neuroprotection of the central nervous system. Cannabidiol (CBD) is a non-psychotropic phytocannabinoid present in Cannabis sativa. Many therapeutic actions have been linked to this compound, including autophagy activation. However, the precise underlying molecular mechanisms remain unclear, and the downstream functional significance of these actions has yet to be determined. Here, we investigated CBD-evoked effects on autophagy in human neuroblastoma SH-SY5Y and murine astrocyte cell lines. We found that CBD-induced autophagy was substantially reduced in the presence of CB1, CB2 and TRPV1 receptor antagonists, AM 251, AM 630 and capsazepine, respectively. This result strongly indicates that the activation of these receptors mediates the autophagic flux. Additionally, we demonstrated that CBD activates autophagy through ERK1/2 activation and AKT suppression. Interestingly, CBD-mediated autophagy activation is dependent on the autophagy initiator ULK1, but mTORC1 independent. Thus, it is plausible that a non-canonical pathway is involved. Our findings collectively provide evidence that CBD stimulates autophagy signal transduction via crosstalk between the ERK1/2 and AKT kinases, which represent putative regulators of cell proliferation and survival. Furthermore, our study sheds light on potential therapeutic cannabinoid targets that could be developed for treating neurodegenerative disorders.


Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 573
Author(s):  
Matjaž Stenovec

Ketamine, a non-competitive N–methyl–d–aspartate receptor (NMDAR) antagonist, exerts a rapid, potent and long-lasting antidepressant effect, although the cellular and molecular mechanisms of this action are yet to be clarified. In addition to targeting neuronal NMDARs fundamental for synaptic transmission, ketamine also affects the function of astrocytes, the key homeostatic cells of the central nervous system that contribute to pathophysiology of major depressive disorder. Here, I review studies revealing that (sub)anesthetic doses of ketamine elevate intracellular cAMP concentration ([cAMP]i) in astrocytes, attenuate stimulus-evoked astrocyte calcium signaling, which regulates exocytotic secretion of gliosignaling molecules, and stabilize the vesicle fusion pore in a narrow configuration, possibly hindering cargo discharge or vesicle recycling. Next, I discuss how ketamine affects astrocyte capacity to control extracellular K+ by reducing vesicular delivery of the inward rectifying potassium channel (Kir4.1) to the plasmalemma that reduces the surface density of Kir4.1. Modified astroglial K+ buffering impacts upon neuronal firing pattern as demonstrated in lateral habenula in a rat model of depression. Finally, I highlight the discovery that ketamine rapidly redistributes cholesterol in the astrocyte plasmalemma, which may alter the flux of cholesterol to neurons. This structural modification may further modulate a host of processes that synergistically contribute to ketamine’s rapid antidepressant action.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1548
Author(s):  
Mustafa N. Mithaiwala ◽  
Danielle Santana-Coelho ◽  
Grace A. Porter ◽  
Jason C. O’Connor

Diseases of the central nervous system (CNS) remain a significant health, social and economic problem around the globe. The development of therapeutic strategies for CNS conditions has suffered due to a poor understanding of the underlying pathologies that manifest them. Understanding common etiological origins at the cellular and molecular level is essential to enhance the development of efficacious and targeted treatment options. Over the years, neuroinflammation has been posited as a common link between multiple neurological, neurodegenerative and neuropsychiatric disorders. Processes that precipitate neuroinflammatory conditions including genetics, infections, physical injury and psychosocial factors, like stress and trauma, closely link dysregulation in kynurenine pathway (KP) of tryptophan metabolism as a possible pathophysiological factor that ‘fuel the fire’ in CNS diseases. In this study, we aim to review emerging evidence that provide mechanistic insights between different CNS disorders, neuroinflammation and the KP. We provide a thorough overview of the different branches of the KP pertinent to CNS disease pathology that have therapeutic implications for the development of selected and efficacious treatment strategies.


2021 ◽  
pp. 107385842199226
Author(s):  
Stellina Y. H. Lee ◽  
Nathanael J. Yates ◽  
Susannah J. Tye

Inflammation is a critical factor contributing to the progressive neurodegenerative process observed in Parkinson’s disease (PD). Microglia, the immune cells of the central nervous system, are activated early in PD pathogenesis and can both trigger and propagate early disease processes via innate and adaptive immune mechanisms such as upregulated immune cells and antibody-mediated inflammation. Downstream cytokines and gene regulators such as microRNA (miRNA) coordinate later disease course and mediate disease progression. Biomarkers signifying the inflammatory and neurodegenerative processes at play within the central nervous system are of increasing interest to clinical teams. To be effective, such biomarkers must achieve the highest sensitivity and specificity for predicting PD risk, confirming diagnosis, or monitoring disease severity. The aim of this review was to summarize the current preclinical and clinical evidence that suggests that inflammatory processes contribute to the initiation and progression of neurodegenerative processes in PD. In this article, we further summarize the data about main inflammatory biomarkers described in PD to date and their potential for regulation as a novel target for disease-modifying pharmacological strategies.


2021 ◽  
Vol 22 (6) ◽  
pp. 3238
Author(s):  
Ho-Wei Hsu ◽  
Ting-Yi Lin ◽  
Yi-Ching Liu ◽  
Jwu-Lai Yeh ◽  
Jong-Hau Hsu

The ductus arteriosus (DA) is a physiologic vessel crucial for fetal circulation. As a major regulating factor, the prostaglandin pathway has long been the target for DA patency maintenance or closure. However, the adverse effect of prostaglandins and their inhibitors has been a major unsolved clinical problem. Furthermore, a significant portion of patients with patent DA fail to respond to cyclooxygenase inhibitors that target the prostaglandin pathway. These unresponsive medical patients ultimately require surgical intervention and highlight the importance of exploring pathways independent from this well-recognized prostaglandin pathway. The clinical limitations of prostaglandin-targeting therapeutics prompted us to investigate molecules beyond the prostaglandin pathway. Thus, this article introduces molecules independent from the prostaglandin pathway based on their correlating mechanisms contributing to vascular remodeling. These molecules may serve as potential targets for future DA patency clinical management.


2019 ◽  
Vol 131 (5) ◽  
pp. 1615-1619
Author(s):  
Anthony M. Alvarado ◽  
Kyle A. Smith ◽  
Roukoz B. Chamoun

Glioependymal cysts are rare congenital lesions of the central nervous system. Reported surgical treatments of these lesions have varied and yielded mixed results, and the optimal surgical strategy is still controversial. The authors here report the clinical and surgical outcomes for three adult patients successfully treated with neuroendoscopic fenestration into the ventricular system. The patients had presented with symptomatic glioependymal cysts in the period from 2013 to 2016 at the authors’ institution. All underwent minimally invasive neuroendoscopic fenestration of the glioependymal cyst into the lateral ventricle via a stereotactically guided burr hole. Presenting clinical and radiological findings, operative courses, and postintervention outcomes were evaluated.All three patients initially presented with symptoms related to regional mass effect of the underlying glioependymal cyst, including headaches, visual disturbances, and hemiparesis. All patients were successfully treated with endoscopic fenestration of the cyst wall into the lateral ventricle, where the wall was thinnest. Postoperatively, all patients reported improvement in their presenting symptoms, and neuroimaging demonstrated decompression of the cyst. Clinical follow-up ranged from 4 months to 5 years without evidence of reexpansion of the cyst or shunt requirement.Compared to open resection and shunting of the cyst contents, minimally invasive endoscopic fenestration of a glioependymal cyst into the ventricular system is a safe and effective surgical option. This approach is practical, is less invasive than open resection, and appears to provide a long-term solution.


2021 ◽  
Vol 49 (4) ◽  
pp. 1779-1790 ◽  
Author(s):  
Lorenzo Ceccarelli ◽  
Chiara Giacomelli ◽  
Laura Marchetti ◽  
Claudia Martini

Extracellular vesicles (EVs) are a heterogeneous family of cell-derived lipid bounded vesicles comprising exosomes and microvesicles. They are potentially produced by all types of cells and are used as a cell-to-cell communication method that allows protein, lipid, and genetic material exchange. Microglia cells produce a large number of EVs both in resting and activated conditions, in the latter case changing their production and related biological effects. Several actions of microglia in the central nervous system are ascribed to EVs, but the molecular mechanisms by which each effect occurs are still largely unknown. Conflicting functions have been ascribed to microglia-derived EVs starting from the neuronal support and ending with the propagation of inflammation and neurodegeneration, confirming the crucial role of these organelles in tuning brain homeostasis. Despite the increasing number of studies reported on microglia-EVs, there is also a lot of fragmentation in the knowledge on the mechanism at the basis of their production and modification of their cargo. In this review, a collection of literature data about the surface and cargo proteins and lipids as well as the miRNA content of EVs produced by microglial cells has been reported. A special highlight was given to the works in which the EV molecular composition is linked to a precise biological function.


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