scholarly journals The Normal and Brain Tumor Vasculature: Morphological and Functional Characteristics and Therapeutic Targeting

2021 ◽  
Vol 12 ◽  
Author(s):  
Joris Guyon ◽  
Candice Chapouly ◽  
Laetitia Andrique ◽  
Andreas Bikfalvi ◽  
Thomas Daubon

Glioblastoma is among the most common tumor of the central nervous system in adults. Overall survival has not significantly improved over the last decade, even with optimizing standard therapeutic care including extent of resection and radio- and chemotherapy. In this article, we review features of the brain vasculature found in healthy cerebral tissue and in glioblastoma. Brain vessels are of various sizes and composed of several vascular cell types. Non-vascular cells such as astrocytes or microglia also interact with the vasculature and play important roles. We also discuss in vitro engineered artificial blood vessels which may represent useful models for better understanding the tumor–vessel interaction. Finally, we summarize results from clinical trials with anti-angiogenic therapy alone or in combination, and discuss the value of these approaches for targeting glioblastoma.

2007 ◽  
Vol 38 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Céline Callewaere ◽  
Ghazal Banisadr ◽  
William Rostène ◽  
Stéphane Mélik Parsadaniantz

Chemokines are small secreted proteins that chemoattract and activate immune and non-immune cells both in vivo and in vitro. In addition to their well-established role in the immune system, several recent reports have suggested that chemokines and their receptors may also play a role in the central nervous system (CNS). The best known central action is their ability to act as immunoinflammatory mediators. Indeed, these proteins regulate leukocyte infiltration in the brain during inflammatory and infectious diseases. However, we and others recently demonstrated that they are expressed not only in neuroinflammatory conditions, but also constitutively by different cell types including neurons in the normal brain, suggesting that they may act as modulators of neuronal functions. The goal of this review is to highlight the role of chemokines in the control of neuroendocrine functions. First, we will focus on the expression of chemokines and their receptors in the CNS, with the main spotlight on the neuronal expression in the hypothalamo–pituitary system. Secondly, we will discuss the role – we can now suspect – of chemokines and their receptors in the regulation of neuroendocrine functions. In conclusion, we propose that chemokines can be added to the well-described neuroendocrine regulatory mechanisms, providing an additional fine modulatory tuning system in physiological conditions.


Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2104 ◽  
Author(s):  
Eleonora Ficiarà ◽  
Shoeb Anwar Ansari ◽  
Monica Argenziano ◽  
Luigi Cangemi ◽  
Chiara Monge ◽  
...  

Magnetic Oxygen-Loaded Nanobubbles (MOLNBs), manufactured by adding Superparamagnetic Iron Oxide Nanoparticles (SPIONs) on the surface of polymeric nanobubbles, are investigated as theranostic carriers for delivering oxygen and chemotherapy to brain tumors. Physicochemical and cyto-toxicological properties and in vitro internalization by human brain microvascular endothelial cells as well as the motion of MOLNBs in a static magnetic field were investigated. MOLNBs are safe oxygen-loaded vectors able to overcome the brain membranes and drivable through the Central Nervous System (CNS) to deliver their cargoes to specific sites of interest. In addition, MOLNBs are monitorable either via Magnetic Resonance Imaging (MRI) or Ultrasound (US) sonography. MOLNBs can find application in targeting brain tumors since they can enhance conventional radiotherapy and deliver chemotherapy being driven by ad hoc tailored magnetic fields under MRI and/or US monitoring.


Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1468
Author(s):  
Yashika S. Kamte ◽  
Manisha N. Chandwani ◽  
Alexa C. Michaels ◽  
Lauren A. O’Donnell

Viruses that infect the central nervous system (CNS) are associated with developmental abnormalities as well as neuropsychiatric and degenerative conditions. Many of these viruses such as Zika virus (ZIKV), cytomegalovirus (CMV), and herpes simplex virus (HSV) demonstrate tropism for neural stem cells (NSCs). NSCs are the multipotent progenitor cells of the brain that have the ability to form neurons, astrocytes, and oligodendrocytes. Viral infections often alter the function of NSCs, with profound impacts on the growth and repair of the brain. There are a wide spectrum of effects on NSCs, which differ by the type of virus, the model system, the cell types studied, and the age of the host. Thus, it is a challenge to predict and define the consequences of interactions between viruses and NSCs. The purpose of this review is to dissect the mechanisms by which viruses can affect survival, proliferation, and differentiation of NSCs. This review also sheds light on the contribution of key antiviral cytokines in the impairment of NSC activity during a viral infection, revealing a complex interplay between NSCs, viruses, and the immune system.


2021 ◽  
Vol 10 (11) ◽  
pp. 2358
Author(s):  
Maria Grazia Giovannini ◽  
Daniele Lana ◽  
Chiara Traini ◽  
Maria Giuliana Vannucchi

The microbiota–gut system can be thought of as a single unit that interacts with the brain via the “two-way” microbiota–gut–brain axis. Through this axis, a constant interplay mediated by the several products originating from the microbiota guarantees the physiological development and shaping of the gut and the brain. In the present review will be described the modalities through which the microbiota and gut control each other, and the main microbiota products conditioning both local and brain homeostasis. Much evidence has accumulated over the past decade in favor of a significant association between dysbiosis, neuroinflammation and neurodegeneration. Presently, the pathogenetic mechanisms triggered by molecules produced by the altered microbiota, also responsible for the onset and evolution of Alzheimer disease, will be described. Our attention will be focused on the role of astrocytes and microglia. Numerous studies have progressively demonstrated how these glial cells are important to ensure an adequate environment for neuronal activity in healthy conditions. Furthermore, it is becoming evident how both cell types can mediate the onset of neuroinflammation and lead to neurodegeneration when subjected to pathological stimuli. Based on this information, the role of the major microbiota products in shifting the activation profiles of astrocytes and microglia from a healthy to a diseased state will be discussed, focusing on Alzheimer disease pathogenesis.


2021 ◽  
Vol 22 (11) ◽  
pp. 5818
Author(s):  
Gaylia Jean Harry

A change in microglia structure, signaling, or function is commonly associated with neurodegeneration. This is evident in the patient population, animal models, and targeted in vitro assays. While there is a clear association, it is not evident that microglia serve as an initiator of neurodegeneration. Rather, the dynamics imply a close interaction between the various cell types and structures in the brain that orchestrate the injury and repair responses. Communication between microglia and neurons contributes to the physiological phenotype of microglia maintaining cells in a surveillance state and allows the cells to respond to events occurring in their environment. Interactions between microglia and astrocytes is not as well characterized, nor are interactions with other members of the neurovascular unit; however, given the influence of systemic factors on neuroinflammation and disease progression, such interactions likely represent significant contributes to any neurodegenerative process. In addition, they offer multiple target sites/processes by which environmental exposures could contribute to neurodegenerative disease. Thus, microglia at least play a role as a significant other with an equal partnership; however, claiming a role as an initiator of neurodegeneration remains somewhat controversial.


1976 ◽  
Vol 230 (4) ◽  
pp. 1101-1107 ◽  
Author(s):  
R Spector

Total thiamine (free thiamine and thiamine phosphates) transport into the cerebrospinal fluid (CSF), brain, and choroid plexus and out of the CSF was measured in rabbits. In vivo, total thiamine transport into CSF, choroid plexus, and brain was saturable. At the normal plasma total thiamine concentration, less than 5% of total thiamine entry into CSF, choroid plexus, and brain was by simple diffusion. The relative turnovers of total thiamine in choroid plexus, whole brain, and CSF were 5, 2, and 14% per h, respectively, when measured by the penetration of 35S-labeled thiamine injected into blood. From the CSF, clearance of [35S]thiamine relative to mannitol was not saturable after the intraventricular injection of various concentrations of thiamine. However, a portion of the [35S]thiamine cleared from the CSF entered brain by a saturable mechanism. In vitro, choroid plexuses, isolated from rabbits and incubated in artificial CSF, accumulated [35S]thiamine against a concentration gradient by an active saturable process that did not depend on pyrophosphorylation of the [35S]thiamine. The [35S]thiamine accumulated within the choroid plexus in vitro was readily released. These results were interpreted as showing that the entry of total thiamine into the brain and CSF from blood is regulated by a saturable transport system, and that the locus of this system may be, in part, in the choroid plexus.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Song Cao ◽  
Daniel W. Fisher ◽  
Guadalupe Rodriguez ◽  
Tian Yu ◽  
Hongxin Dong

Abstract Background The role of microglia in Alzheimer’s disease (AD) pathogenesis is becoming increasingly important, as activation of these cell types likely contributes to both pathological and protective processes associated with all phases of the disease. During early AD pathogenesis, one of the first areas of degeneration is the locus coeruleus (LC), which provides broad innervation of the central nervous system and facilitates norepinephrine (NE) transmission. Though the LC-NE is likely to influence microglial dynamics, it is unclear how these systems change with AD compared to otherwise healthy aging. Methods In this study, we evaluated the dynamic changes of neuroinflammation and neurodegeneration in the LC-NE system in the brain and spinal cord of APP/PS1 mice and aged WT mice using immunofluorescence and ELISA. Results Our results demonstrated increased expression of inflammatory cytokines and microglial activation observed in the cortex, hippocampus, and spinal cord of APP/PS1 compared to WT mice. LC-NE neuron and fiber loss as well as reduced norepinephrine transporter (NET) expression was more evident in APP/PS1 mice, although NE levels were similar between 12-month-old APP/PS1 and WT mice. Notably, the degree of microglial activation, LC-NE nerve fiber loss, and NET reduction in the brain and spinal cord were more severe in 12-month-old APP/PS1 compared to 12- and 24-month-old WT mice. Conclusion These results suggest that elevated neuroinflammation and microglial activation in the brain and spinal cord of APP/PS1 mice correlate with significant degeneration of the LC-NE system.


2019 ◽  
Vol 20 (10) ◽  
pp. 2435 ◽  
Author(s):  
Tetsuya Takahashi ◽  
Takayoshi Shimohata

Methylmercury (MeHg) causes severe damage to the central nervous system, and there is increasing evidence of the association between MeHg exposure and vascular dysfunction, hemorrhage, and edema in the brain, but not in other organs of patients with acute MeHg intoxication. These observations suggest that MeHg possibly causes blood–brain barrier (BBB) damage. MeHg penetrates the BBB into the brain parenchyma via active transport systems, mainly the l-type amino acid transporter 1, on endothelial cell membranes. Recently, exposure to mercury has significantly increased. Numerous reports suggest that long-term low-level MeHg exposure can impair endothelial function and increase the risks of cardiovascular disease. The most widely reported mechanism of MeHg toxicity is oxidative stress and related pathways, such as neuroinflammation. BBB dysfunction has been suggested by both in vitro and in vivo models of MeHg intoxication. Therapy targeted at both maintaining the BBB and suppressing oxidative stress may represent a promising therapeutic strategy for MeHg intoxication. This paper reviews studies on the relationship between MeHg exposure and vascular dysfunction, with a special emphasis on the BBB.


1998 ◽  
Vol 119 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Norbert Dieringer ◽  
Hans Straka

Removal of the labyrinthine organs on one side results in a number of severe postural and dynamic reflex deficits. Over time some of these behavioral deficits normalize again. At a chronic stage the brain of frogs exhibits a number of changes in vestibular and propriospinal circuits on the operated side that were studied in vitro. The onset of changes in the vestibular nuclear complex was delayed, became evident only after head posture had recovered by more than 50%, and was independent of the presence or absence of a degeneration of vestibular nerve afferent fibers. The time course of changes measured in the isolated spinal cord paralleled the time course of normalization of head and body posture. Results obtained after selective lesions of individual labyrinthine nerve branches show that unilateral inactivation of utricular afferent inputs is a necessary and sufficient condition to provoke postural deficits and propriospinal changes similar to those after the removal of all labyrinthine organs. The presence of multiple synaptic changes at distributed anatomic sites over different periods of time suggests that different parts of the central nervous system are involved in the normalization of different manifestations of the vestibular lesion syndrome. (Otolaryngol Head Neck Surg 1998;119:27–33.)


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