Seizures Are Associated with Blood-Brain Barrier Disruption in a Piglet Model of Neonatal Hypoxic-Ischaemic Encephalopathy

2018 ◽  
Vol 40 (5-6) ◽  
pp. 560-575 ◽  
Author(s):  
Kate Goasdoue ◽  
Kirat Kishore Chand ◽  
Stephanie Melita Miller ◽  
Kah Meng Lee ◽  
Paul Bernard Colditz ◽  
...  

Seizures in the neonatal period are most often symptomatic of central nervous system (CNS) dysfunction and the most common cause is hypoxic-ischaemic encephalopathy (HIE). Seizures are associated with poor long-term outcomes and increased neuropathology. Blood-brain barrier (BBB) disruption and inflammation may contribute to seizures and increased neuropathology but are incompletely understood in neonatal HIE. The aim of this study was to investigate the impact of seizures on BBB integrity in a preclinical model of neonatal hypoxic-ischaemic (HI) injury. Piglets (age: <24 h) were subjected to a 30-min HI insult followed by recovery to 72 h post-insult. Amplitude-integrated electroencephalography (aEEG) was performed and seizure burden and background aEEG pattern were analysed. BBB disruption was evaluated in the parietal cortex and hippocampus by means of immunohistochemistry and Western blot. mRNA and protein expression of tight-junction proteins (zonula-occludens 1 [ZO1], occludin [OCLN], and claudin-5 [CLDN5]) was assessed using quantitative polymerase chain reaction (qPCR) and Western blot. In addition, mRNA from genes associated with BBB disruption vascular endothelial growth factor (VEGF) and matrix metalloproteinase 2 (MMP2) as well as inflammatory cytokines and chemokines was assessed with qPCR. Piglets that developed seizures following HI (HI-Sz) had significantly greater injury, as demonstrated by poorer aEEG background pattern scores, lower neurobehavioural scores, and greater histopathology. HI-Sz animals had severe IgG extravasation into brain tissue and uptake into neurons as well as significantly greater levels of IgG in both brain regions as assessed by Western blot. IgG protein in both brain regions was significantly associated with seizure burden, aEEG pattern scores, and neurobehavioural scores. There was no difference in mRNA expression of the tight junctions, however a significant loss of ZO1 and OCLN protein was observed in the parietal cortex. The inflammatory genes TGFβ, IL1β, IL8, IL6, and TNFα were significantly upregulated in HI-Sz animals. MMP2 was significantly increased in animals with seizures compared with animals without seizures. Increasing our understanding of neuropathology associated with seizure is vital because of the association between seizure and poor outcomes. Investigating the BBB is a major untapped area of research and a potential avenue for novel treatments.

2021 ◽  
Vol 23 (Supplement_1) ◽  
pp. i19-i19
Author(s):  
Caitlin Ung ◽  
Dannielle Upton ◽  
Maria Tsoli ◽  
David Ziegler

Abstract Diffuse Intrinsic Pontine Glioma (DIPG) is the most aggressive pediatric high-grade glioma with median survival of only 12 months from diagnosis. Current therapies are essentially palliative. The blood-brain barrier (BBB) is a major obstacle, limiting delivery of effective chemotherapeutics into the brain. We hypothesized that tumors in the brainstem region have a BBB less permeable than tumors in other brain regions. We have confirmed the presence of an intact BBB in three orthotopic models of DIPG by Evans Blue extravasation assay. Immunohistochemical staining of CD13+ pericytes and CD34+ endothelial cells in healthy mouse brain compared to orthotopic DIPG model showed higher levels of both components in brainstem compared to cortical region. Single-cell RNA sequencing experiments are currently being undertaken to investigate region-specific differences in BBB cell populations and the impact of DIPG on signaling pathways that govern permeability. To determine if tumor location impacts therapeutic outcome, we performed in vivo efficacy studies with DIPG orthotopically injected into cortical region or brainstem region and treated with SAHA, HDAC inhibitor, or temsirolimus, mTOR inhibitor. Temsirolimus or SAHA was ineffective at extending survival in mice injected with DIPG in the brainstem compared to control. However, temsirolimus led to a significant improvement in survival in mice injected with DIPG cells in cortical region (median survival 85 days) compared to control (median survival 69 days (P≤0.01)). This suggests that the same tumor in cortical region may respond to systemic therapy that is ineffective in the brainstem and that the intact BBB in the brainstem is a major reason for treatment failure in DIPG. In conclusion, the BBB in the brainstem and in the presence of DIPG may be altered, changing signaling pathways that affect permeability. Understanding the brainstem cerebrovasculature may potentially lead to a novel strategy to treat DIPG as well as other brain tumors.


Cephalalgia ◽  
2017 ◽  
Vol 38 (4) ◽  
pp. 674-689 ◽  
Author(s):  
Nathan T Fried ◽  
Christina R Maxwell ◽  
Melanie B Elliott ◽  
Michael L Oshinsky

Background The blood-brain barrier (BBB) has been hypothesized to play a role in migraine since the late 1970s. Despite this, limited investigation of the BBB in migraine has been conducted. We used the inflammatory soup rat model of trigeminal allodynia, which closely mimics chronic migraine, to determine the impact of repeated dural inflammatory stimulation on BBB permeability. Methods The sodium fluorescein BBB permeability assay was used in multiple brain regions (trigeminal nucleus caudalis (TNC), periaqueductal grey, frontal cortex, sub-cortex, and cortex directly below the area of dural activation) during the episodic and chronic stages of repeated inflammatory dural stimulation. Glial activation was assessed in the TNC via GFAP and OX42 immunoreactivity. Minocycline was tested for its ability to prevent BBB disruption and trigeminal sensitivity. Results No astrocyte or microglial activation was found during the episodic stage, but BBB permeability and trigeminal sensitivity were increased. Astrocyte and microglial activation, BBB permeability, and trigeminal sensitivity were increased during the chronic stage. These changes were only found in the TNC. Minocycline treatment prevented BBB permeability modulation and trigeminal sensitivity during the episodic and chronic stages. Discussion Modulation of BBB permeability occurs centrally within the TNC following repeated dural inflammatory stimulation and may play a role in migraine.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 892
Author(s):  
Elisa L. J. Moya ◽  
Elodie Vandenhaute ◽  
Eleonora Rizzi ◽  
Marie-Christine Boucau ◽  
Johan Hachani ◽  
...  

Central nervous system (CNS) diseases are one of the top causes of death worldwide. As there is a difficulty of drug penetration into the brain due to the blood–brain barrier (BBB), many CNS drugs treatments fail in clinical trials. Hence, there is a need to develop effective CNS drugs following strategies for delivery to the brain by better selecting them as early as possible during the drug discovery process. The use of in vitro BBB models has proved useful to evaluate the impact of drugs/compounds toxicity, BBB permeation rates and molecular transport mechanisms within the brain cells in academic research and early-stage drug discovery. However, these studies that require biological material (animal brain or human cells) are time-consuming and involve costly amounts of materials and plastic wastes due to the format of the models. Hence, to adapt to the high yields needed in early-stage drug discoveries for compound screenings, a patented well-established human in vitro BBB model was miniaturized and automated into a 96-well format. This replicate met all the BBB model reliability criteria to get predictive results, allowing a significant reduction in biological materials, waste and a higher screening capacity for being extensively used during early-stage drug discovery studies.


2021 ◽  
Vol 22 (3) ◽  
pp. 1068
Author(s):  
Katarzyna Dominika Kania ◽  
Waldemar Wagner ◽  
Łukasz Pułaski

Two immortalized brain microvascular endothelial cell lines (hCMEC/D3 and RBE4, of human and rat origin, respectively) were applied as an in vitro model of cellular elements of the blood–brain barrier in a nanotoxicological study. We evaluated the impact of CdSe/ZnS core-shell-type quantum dot nanoparticles on cellular homeostasis, using gold nanoparticles as a largely bioorthogonal control. While the investigated nanoparticles had surprisingly negligible acute cytotoxicity in the evaluated models, a multi-faceted study of barrier-related phenotypes and cell condition revealed a complex pattern of homeostasis disruption. Interestingly, some features of the paracellular barrier phenotype (transendothelial electrical resistance, tight junction protein gene expression) were improved by exposure to nanoparticles in a potential hormetic mechanism. However, mitochondrial potential and antioxidant defences largely collapsed under these conditions, paralleled by a strong pro-apoptotic shift in a significant proportion of cells (evidenced by apoptotic protein gene expression, chromosomal DNA fragmentation, and membrane phosphatidylserine exposure). Taken together, our results suggest a reactive oxygen species-mediated cellular mechanism of blood–brain barrier damage by quantum dots, which may be toxicologically significant in the face of increasing human exposure to this type of nanoparticles, both intended (in medical applications) and more often unintended (from consumer goods-derived environmental pollution).


Neurosurgery ◽  
1984 ◽  
Vol 15 (3) ◽  
pp. 362-366 ◽  
Author(s):  
Edward A. Neuwelt ◽  
Suellen A. Hill ◽  
Eugene P. Frenkel

Abstract Chemotherapeutic drug delivery can be enhanced by administering drugs into the internal carotid or vertebral artery circulation after osmotic opening of the blood-brain barrier (BBB). As evidence of the clinical implications of this technique, radiographic documentation of central nervous system (CNS) tumor regression was observed in three patients concurrent with the development of new tumor nodule(s) in portions of the brain distant from the region of osmotic blood-brain barrier opening. These three patients, one with metastatic carcinoma of the breast, one with glioblastoma, and one with primary CNS lymphoma, highlight the importance of drug delivery to CNS malignancies.


2021 ◽  
Vol 22 (18) ◽  
pp. 10045
Author(s):  
Phuong Thao Do ◽  
Chung-Che Wu ◽  
Yung-Hsiao Chiang ◽  
Chaur-Jong Hu ◽  
Kai-Yun Chen

Ischemic stroke is the leading cause of mortality and long-term disability worldwide. Disruption of the blood–brain barrier (BBB) is a prominent pathophysiological mechanism, responsible for a series of subsequent inflammatory cascades that exacerbate the damage to brain tissue. However, the benefit of recanalization is limited in most patients because of the narrow therapeutic time window. Recently, mesenchymal stem cells (MSCs) have been assessed as excellent candidates for cell-based therapy in cerebral ischemia, including neuroinflammatory alleviation, angiogenesis and neurogenesis promotion through their paracrine actions. In addition, accumulating evidence on how MSC therapy preserves BBB integrity after stroke may open up novel therapeutic targets for treating cerebrovascular diseases. In this review, we focus on the molecular mechanisms of MSC-based therapy in the ischemia-induced prevention of BBB compromise. Currently, therapeutic effects of MSCs for stroke are primarily based on the fundamental pathogenesis of BBB breakdown, such as attenuating leukocyte infiltration, matrix metalloproteinase (MMP) regulation, antioxidant, anti-inflammation, stabilizing morphology and crosstalk between cellular components of the BBB. We also discuss prospective studies to improve the effectiveness of MSC therapy through enhanced migration into defined brain regions of stem cells. Targeted therapy is a promising new direction and is being prioritized for extensive research.


Author(s):  
Zhuqing Jin ◽  
Jian Liang ◽  
Jiaqi Li ◽  
Pappachan E. Kolattukudy

Focal cerebral ischemia can lead to blood-brain barrier (BBB) breakdown, which is implicated in neuroinflammation and elevation of matrix metalloproteinases (MMPs). The role of the anti-inflammatory protein, monocyte chemotactic protein&ndash;induced protein 1 (MCPIP1) plays in the injury of BBB in stroke has not yet been reported. This study was conducted to identify and characterize the role MCPIP1 plays in BBB breakdown. Transient middle cerebral artery occlusion (MCAO) is induced in both wild-type and Mcpip1-/- mice for 2 hours of occlusion periods followed by reperfusion for 24 or 48 hours. BBB permeability was measured by FITC-dextran extravasation, MMP-9/3 expression was analyzed by western blot, and claudin-5 and zonula occludens-1 (ZO-1) were analyzed by immunohistochemistry and western blot. After MCAO in wild type mouse is induced, there is significantly increase in MCPIP1 mRNA and protein levels. Absence of MCPIP1 leaded to significant increase in FITC-dextran leakage in peri-infarct brain, significant upregulation of MMP-9, MMP-3 and reduced levels of tight junction components, claudin-5 and ZO-1 in the brain after MCAO. Our data demonstrate that absence of MCPIP1 exacerbates ischemia-induced blood-brain barrier disruption by enhancing the expression of matrix metalloproteinases and degradation of tight junction proteins. Overall data indicate that MCPIP1 is important protective role against BBB disruption in cerebral ischemia.


Author(s):  
Ghaith A. Bahadar ◽  
Zahoor A Shah

: There is a surge in diabetes incidence with an estimated 463 million individuals been diagnosed worldwide. Diabetes Mellitus (DM) is a major stroke-related comorbid condition that increases the susceptibility of disabling post-stroke outcomes. Although less common, intracerebral hemorrhage (ICH) is the most dramatic subtype of stroke that is associated with higher mortality, particularly in DM population. Previous studies have focused mainly on the impact of DM on ischemic stroke. Few studies have focused on impact of DM on ICH and discussed the blood-brain barrier disruption, brain edema, and hematoma formation. However, more recently, investigating the role of oxidative damage and reactive oxygen species (ROS) production in preclinical studies involving DM-ICH animal models has gained attention. But, little is known about the correlation between neuroinflammatory processes, glial cells activation, and peripheral immune cell invasion with DM-ICH injury. DM and ICH patients experience impaired abilities in multiple cognitive domains by relatively comparable mechanisms, which could get exacerbated in the setting of comorbidities. In this review, we discuss both the pathology of DM as a comorbid condition for ICH and the potential molecular therapeutic targets for the clinical management of the ICH and its recovery.


2019 ◽  
Vol 171 (2) ◽  
pp. 485-500 ◽  
Author(s):  
Bartosz Pomierny ◽  
Weronika Krzyżanowska ◽  
Żaneta Broniowska ◽  
Beata Strach ◽  
Beata Bystrowska ◽  
...  

Abstract Benzophenone-3 is the most commonly used UV filter. It is well absorbed through the skin and gastrointestinal tract. Its best-known side effect is the impact on the function of sex hormones. Little is known about the influence of BP-3 on the brain. The aim of this study was to show whether BP-3 crosses the blood-brain barrier (BBB), to determine whether it induces nerve cell damage in susceptible brain structures, and to identify the mechanism of its action in the central nervous system. BP-3 was administered dermally during the prenatal period and adulthood to rats. BP-3 effect on short-term and spatial memory was determined by novel object and novel location recognition tests. BP-3 concentrations were assayed in the brain and peripheral tissues. In brain structures, selected markers of brain damage were measured. The study showed that BP-3 is absorbed through the rat skin, passes through the BBB. BP-3 raised oxidative stress and induced apoptosis in the brain. BP-3 increased the concentration of extracellular glutamate in examined brain structures and changed the expression of glutamate transporters. BP-3 had no effect on short-term memory but impaired spatial memory. The present study showed that dermal BP-3 exposure may cause damage to neurons what might be associated with the increase in the level of extracellular glutamate, most likely evoked by changes in the expression of GLT-1 and xCT glutamate transporters. Thus, exposure to BP-3 may be one of the causes that increase the risk of developing neurodegenerative diseases.


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