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Sample records for brain barrier breakdown

  1. Vascular Cell Senescence Contributes to Blood-Brain Barrier Breakdown

    NARCIS (Netherlands)

    Yamazaki, Y.; Baker, D.J.; Tachibana, M.; Liu, C.C.; Deursen, J.M.A. van; Brott, T.G.; Bu, G.; Kanekiyo, T.

    2016-01-01

    BACKGROUND AND PURPOSE: Age-related changes in the cerebrovasculature, including blood-brain barrier (BBB) disruption, are emerging as potential risks for diverse neurological conditions. Because the accumulation of senescent cells in tissues is increasingly recognized as a critical step leading to

  2. Blood–brain barrier breakdown as a novel mechanism underlying cerebral hyperperfusion syndrome

    Science.gov (United States)

    Ivens, Sebastian; Gabriel, Szendro; Greenberg, George; Shelef, Ilan

    2013-01-01

    Cerebral hyperperfusion syndrome (CHS) may occur as a severe complication following surgical treatment of carotid stenosis. However, the mechanism inducing neurological symptoms in CHS remains unknown. We describe a patient with CHS presenting with seizures 24 h following carotid endarterectomy. Imaging demonstrated early ipsilateral blood–brain barrier (BBB) breakdown with electroencephalographic evidence of cortical dysfunction preceding brain edema. Using in vitro experiments on rat cortical tissue, we show that direct exposure of isolated brain slices to a serum-like medium induces spontaneous epileptiform activity, and that neuronal dysfunction is triggered by albumin. We propose BBB breakdown and subsequent albumin extravasation as a novel pathogenic mechanism underlying CHS and a potential target for therapy. PMID:20361293

  3. Blood-brain barrier breakdown in reversible cerebral vasoconstriction syndrome: Implications for pathophysiology and diagnosis.

    Science.gov (United States)

    Lee, Mi Ji; Cha, Jihoon; Choi, Hyun Ah; Woo, Sook-Young; Kim, Seonwoo; Wang, Shuu-Jiun; Chung, Chin-Sang

    2017-03-01

    Diagnosis of reversible cerebral vasoconstriction syndrome (RCVS) is currently based on luminographic findings of vasoconstriction. In addition to vasoconstriction, the blood-brain barrier (BBB) breakdown has been postulated as a central mechanism of RCVS. Our aim was to document BBB breakdown in patients with RCVS and its role for the pathophysiology-based diagnosis of RCVS. We prospectively recruited 72 consecutive patients with thunderclap headache who did not have aneurysmal subarachnoid hemorrhage from April 2015 to July 2016 at the Samsung Medical Center. Based on the International Classification of Headache Disorders-3 beta criteria and neuroimaging, patients were classified as having RCVS (n = 41; "definite" in 29 imaging-proven patients and "probable" in 12 imaging-negative patients), other secondary causes (n = 7), and thunderclap headache of undetermined cause (n = 24). BBB breakdown was evaluated using contrast-enhanced fluid-attenuated inversion recovery magnetic resonance imaging. BBB breakdown was documented in 20 (69.0%) patients with definite RCVS, 3 (25.0%) patients with probable RCVS, and none with other secondary causes. BBB breakdown was present in RCVS patients with (n = 4) and without (n = 19) concomitant posterior reversible encephalopathy syndrome. In patients with RCVS, the extent of BBB breakdown was independently associated with neurological complications (multivariate odds ratio = 1.48 per 1 territorial increase, 95% confidence interval = 1.04-2.12, adjusted p = 0.032). Three (12.5%) patients with thunderclap headache of undetermined cause were newly classified as having RCVS by the presence of BBB breakdown. This is the first study to show BBB breakdown in patients with RCVS. This finding might broaden our understanding of the pathophysiology and clinical spectrum of RCVS. Ann Neurol 2017;81:454-466. © 2017 American Neurological Association.

  4. Blood-brain barrier breakdown after embolic stroke in rats occurs without ultrastructural evidence for disrupting tight junctions.

    Directory of Open Access Journals (Sweden)

    Martin Krueger

    Full Text Available The term blood-brain barrier (BBB relates to the ability of cerebral vessels to hold back hydrophilic and large molecules from entering the brain, thereby crucially contributing to brain homeostasis. In fact, experimental opening of endothelial tight junctions causes a breakdown of the BBB evidenced as for instance by albumin leakage. This and similar observations led to the conclusion that BBB breakdown is predominantly mediated by damage to tight junction complexes, but evidentiary ultrastructural data are rare. Since functional deficits of the BBB contribute to an increased risk of hemorrhagic transformation and brain edema after stroke, which both critically impact on the clinical outcome, we studied the mechanism of BBB breakdown using an embolic model of focal cerebral ischemia in Wistar rats to closely mimic the essential human pathophysiology. Ischemia-induced BBB breakdown was detected using intravenous injection of FITC-albumin and tight junctions in areas of FITC-albumin extravasation were subsequently studied using fluorescence and electron microscopy. Against our expectation, 25 hours after ischemia induction the morphology of tight junction complexes (identified ultrastructurally and using antibodies against the transcellular proteins occludin and claudin-5 appeared to be regularly maintained in regions where FITC-albumin massively leaked into the neuropil. Furthermore, occludin signals along pan-laminin-labeled vessels in the affected hemisphere equaled the non-affected contralateral side (ratio: 0.966 vs. 0.963; P = 0.500. Additional ultrastructural analyses at 5 and 25 h after ischemia induction clearly indicated FITC-albumin extravasation around vessels with intact tight junctions, while the endothelium exhibited enhanced transendothelial vesicle trafficking and signs of degeneration. Thus, BBB breakdown and leakage of FITC-albumin cannot be correlated with staining patterns for common tight junction proteins alone

  5. Accelerated pericyte degeneration and blood-brain barrier breakdown in apolipoprotein E4 carriers with Alzheimer's disease.

    Science.gov (United States)

    Halliday, Matthew R; Rege, Sanket V; Ma, Qingyi; Zhao, Zhen; Miller, Carol A; Winkler, Ethan A; Zlokovic, Berislav V

    2016-01-01

    The blood–brain barrier (BBB) limits the entry of neurotoxic blood-derived products and cells into the brain that is required for normal neuronal functioning and information processing. Pericytes maintain the integrity of the BBB and degenerate in Alzheimer’s disease (AD). The BBB is damaged in AD, particularly in individuals carrying apolipoprotein E4 (APOE4) gene, which is a major genetic risk factor for late-onset AD. The mechanisms underlying the BBB breakdown in AD remain, however, elusive. Here, we show accelerated pericyte degeneration in AD APOE4 carriers >AD APOE3 carriers >non-AD controls, which correlates with the magnitude of BBB breakdown to immunoglobulin G and fibrin. We also show accumulation of the proinflammatory cytokine cyclophilin A (CypA) and matrix metalloproteinase-9 (MMP-9) in pericytes and endothelial cells in AD (APOE4 >APOE3), previously shown to lead to BBB breakdown in transgenic APOE4 mice. The levels of the apoE lipoprotein receptor, low-density lipoprotein receptor-related protein-1 (LRP1), were similarly reduced in AD APOE4 and APOE3 carriers. Our data suggest that APOE4 leads to accelerated pericyte loss and enhanced activation of LRP1-dependent CypA–MMP-9 BBB-degrading pathway in pericytes and endothelial cells, which can mediate a greater BBB damage in AD APOE4 compared with AD APOE3 carriers.

  6. Sustained pharmacological inhibition of δPKC protects against hypertensive encephalopathy through prevention of blood-brain barrier breakdown in rats

    OpenAIRE

    Qi, Xin; Inagaki, Koichi; Sobel, Raymond A.; Mochly-Rosen, Daria

    2007-01-01

    Hypertensive encephalopathy is a potentially fatal condition associated with cerebral edema and the breakdown of the blood-brain barrier (BBB). The molecular pathways leading to this condition, however, are unknown. We determined the role of δPKC, which is thought to regulate microvascular permeability, in the development of hypertensive encephalopathy using δV1-1 — a selective peptide inhibitor of δPKC. As a model of hypertensive encephalopathy, Dahl salt-sensitive rats were fed an 8% high-s...

  7. Pressure passive cerebral blood flow and breakdown of the blood-brain barrier in experimental fetal asphyxia

    DEFF Research Database (Denmark)

    Lou, H C; Lassen, N A; Tweed, W A

    1979-01-01

    reaching CBF values up to 6 times normal at normal MABP of about 60 to 70 mmHg, and severe ischemia reaching CBF values close to zero in large cortical areas at MABP of 30 mmHg. CVP remained essentially unchanged at 10--15 mmHg. The severe and prolonged asphyxia rendered the blood-brain barrier leaky...... to the albumin tracer Evans blue. In four other fetuses umbilical cord clamping was omitted. However, only in one of these cases was acidosis completely avoided, and CBF autoregulation maintained. The three other fetuses were acidotic at the end of the surgical procedure and had impaired autoregulation....

  8. Sustained pharmacological inhibition of deltaPKC protects against hypertensive encephalopathy through prevention of blood-brain barrier breakdown in rats.

    Science.gov (United States)

    Qi, Xin; Inagaki, Koichi; Sobel, Raymond A; Mochly-Rosen, Daria

    2008-01-01

    Hypertensive encephalopathy is a potentially fatal condition associated with cerebral edema and the breakdown of the blood-brain barrier (BBB). The molecular pathways leading to this condition, however, are unknown. We determined the role of deltaPKC, which is thought to regulate microvascular permeability, in the development of hypertensive encephalopathy using deltaV1-1 - a selective peptide inhibitor of deltaPKC. As a model of hypertensive encephalopathy, Dahl salt-sensitive rats were fed an 8% high-salt diet from 6 weeks of age and then were infused s.c. with saline, control TAT peptide, or deltaV1-1 using osmotic minipumps. The mortality rate and the behavioral symptoms of hypertensive encephalopathy decreased significantly in the deltaV1-1-treated group relative to the control-treated group, and BBB permeability was reduced by more than 60%. Treatment with deltaV1-1 was also associated with decreased deltaPKC accumulation in capillary endothelial cells and in the endfeet of capillary astrocytes, which suggests decreased microvasculature disruption. Treatment with deltaV1-1 prevented hypertension-induced tight junction disruption associated with BBB breakdown, which suggests that deltaPKC may specifically act to dysregulate tight junction components. Together, these results suggest that deltaPKC plays a role in the development of hypertension-induced encephalopathy and may be a therapeutic target for the prevention of BBB disruption.

  9. Circulating angiotensin II gains access to the hypothalamus and brain stem during hypertension via breakdown of the blood-brain barrier.

    Science.gov (United States)

    Biancardi, Vinicia Campana; Son, Sook Jin; Ahmadi, Sahra; Filosa, Jessica A; Stern, Javier E

    2014-03-01

    Angiotensin II-mediated vascular brain inflammation emerged as a novel pathophysiological mechanism in neurogenic hypertension. However, the precise underlying mechanisms and functional consequences in relation to blood-brain barrier (BBB) integrity and central angiotensin II actions mediating neurohumoral activation in hypertension are poorly understood. Here, we aimed to determine whether BBB permeability within critical hypothalamic and brain stem regions involved in neurohumoral regulation was altered during hypertension. Using digital imaging quantification after intravascularly injected fluorescent dyes and immunohistochemistry, we found increased BBB permeability, along with altered key BBB protein constituents, in spontaneously hypertensive rats within the hypothalamic paraventricular nucleus, the nucleus of the solitary tract, and the rostral ventrolateral medulla, all critical brain regions known to contribute to neurohumoral activation during hypertension. BBB disruption, including increased permeability and downregulation of constituent proteins, was prevented in spontaneously hypertensive rats treated with the AT1 receptor antagonist losartan, but not with hydralazine, a direct vasodilator. Importantly, we found circulating angiotensin II to extravasate into these brain regions, colocalizing with neurons and microglial cells. Taken together, our studies reveal a novel angiotensin II-mediated feed-forward mechanism during hypertension, by which circulating angiotensin II evokes increased BBB permeability, facilitating in turn its access to critical brain regions known to participate in blood pressure regulation.

  10. Sleep Deprivation-Induced Blood-Brain Barrier Breakdown and Brain Dysfunction are Exacerbated by Size-Related Exposure to Ag and Cu Nanoparticles. Neuroprotective Effects of a 5-HT3 Receptor Antagonist Ondansetron.

    Science.gov (United States)

    Sharma, Aruna; Muresanu, Dafin F; Lafuente, José V; Patnaik, Ranjana; Tian, Z Ryan; Buzoianu, Anca D; Sharma, Hari S

    2015-10-01

    Military personnel are often subjected to sleep deprivation (SD) during combat operations. Since SD is a severe stress and alters neurochemical metabolism in the brain, a possibility exists that acute or long-term SD will influence blood-brain barrier (BBB) function and brain pathology. This hypothesis was examined in young adult rats (age 12 to 14 weeks) using an inverted flowerpot model. Rats were placed over an inverted flowerpot platform (6.5 cm diameter) in a water pool where the water levels are just 3 cm below the surface. In this model, animals can go to sleep for brief periods but cannot achieve deep sleep as they would fall into water and thus experience sleep interruption. These animals showed leakage of Evans blue in the cerebellum, hippocampus, caudate nucleus, parietal, temporal, occipital, cingulate cerebral cortices, and brain stem. The ventricular walls of the lateral and fourth ventricles were also stained blue, indicating disruption of the BBB and the blood-cerebrospinal fluid barrier (BCSFB). Breakdown of the BBB or the BCSFB fluid barrier was progressive in nature from 12 to 48 h but no apparent differences in BBB leakage were seen between 48 and 72 h of SD. Interestingly, rats treated with metal nanoparticles, e.g., Cu or Ag, showed profound exacerbation of BBB disruption by 1.5- to 4-fold, depending on the duration of SD. Measurement of plasma and brain serotonin showed a close correlation between BBB disruption and the amine level. Repeated treatment with the serotonin 5-HT3 receptor antagonist ondansetron (1 mg/kg, s.c.) 4 and 8 h after SD markedly reduced BBB disruption and brain pathology after 12 to 24 h SD but not following 48 or 72 h after SD. However, TiO2-nanowired ondansetron (1 mg/kg, s.c) in an identical manner induced neuroprotection in rats following 48 or 72 h SD. However, plasma and serotonin levels were not affected by ondansetron treatment. Taken together, our observations are the first to show that (i) SD could induce BBB

  11. Dielectric breakdown in AlO{sub x} tunnelling barriers

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, D M; Carara, M; Schelp, L F; Dorneles, L S [Universidade Federal de Santa Maria, Departamento de Fisica, Av. Roraima, 1000, Santa Maria 97105-900, RS (Brazil); Fichtner, P F P, E-mail: lsdorneles@gmail.com [Universidade Federal do Rio Grande do Sul, Instituto de Fisica, Av. Bento Goncalves, 9500, Caixa Postal 15051, Porto Alegre 91501-970, RS (Brazil)

    2011-04-06

    We studied the dielectric breakdown in tunnelling barriers produced by plasma-assisted oxidation of an aluminium surface. The barrier mean height, thickness and the effective tunnelling area were extracted from current versus voltage curves measured at room temperature. The effective tunnelling area ranged from 10{sup -10} to 10{sup -5} cm{sup 2}, corresponding to less than 1% of the geometrical surface of the samples. The estimated electrical field to breakdown agreed with predictions from thermochemical models, and decreased exponentially with the effective tunnelling area.

  12. Breakdown of blood-brain barrier function in the murine lymphocytic choriomeningitis virus infection mediated by virus-specific CD8+ T cells

    DEFF Research Database (Denmark)

    Andersen, I H; Marker, O; Thomsen, Allan Randrup

    1991-01-01

    Intracerebral inoculation of lymphocytic choriomeningitis virus (LCMV) generally results in a fatal T cell-mediated meningitis. In a previous study we have demonstrated a compromised blood-brain barrier (BBB) under such conditions. Using semi-quantitative radiography and the low molecular tracer 2......-amino-[1-14C]isobutyric acid we now demonstrate an uncompromised BBB in i.c. infected T cell-deficient nu/nu mice, but serious dysfunction in heterozygous littermates. Transfer experiments were used to characterize and compare the cell subset(s) involved in inducing BBB dysfunction and fatal disease....... It was demonstrated that Thy-1+, CD8+ class I-restricted T cells were mandatory for the increase in BBB permeability as well as for mortality. In addition, depletion of class II-restricted CD4+ cells significantly weakened both effects of cell transfer. These results support the idea of a causal relationship between...

  13. Cerebral Oedema, Blood-Brain Barrier Breakdown and the Decrease in Na(+),K(+)-ATPase Activity in the Cerebral Cortex and Hippocampus are Prevented by Dexamethasone in an Animal Model of Maple Syrup Urine Disease.

    Science.gov (United States)

    Rosa, Luciana; Galant, Leticia S; Dall'Igna, Dhébora M; Kolling, Janaina; Siebert, Cassiana; Schuck, Patrícia F; Ferreira, Gustavo C; Wyse, Angela T S; Dal-Pizzol, Felipe; Scaini, Giselli; Streck, Emilio L

    2016-08-01

    Maple syrup urine disease (MSUD) is a rare metabolic disorder associated with acute and chronic brain dysfunction. This condition has been shown to lead to macroscopic cerebral alterations that are visible on imaging studies. Cerebral oedema is widely considered to be detrimental for MSUD patients; however, the mechanisms involved are still poorly understood. Therefore, we investigated whether acute administration of branched-chain amino acids (BCAA) causes cerebral oedema, modifies the Na(+),K(+)-ATPase activity, affects the permeability of the blood-brain barrier (BBB) and alters the levels of cytokines in the hippocampus and cerebral cortex of 10-day-old rats. Additionally, we investigated the influence of concomitant administration of dexamethasone on the alterations caused by BCAA. Our results showed that the animals submitted to the model of MSUD exhibited an increase in the brain water content, both in the cerebral cortex and in the hippocampus. By investigating the mechanism of cerebral oedema, we discovered an association between H-BCAA and the Na(+),K(+)-ATPase activity and the permeability of the BBB to small molecules. Moreover, the H-BCAA administration increases Il-1β, IL-6 and TNF-α levels in the hippocampus and cerebral cortex, whereas IL-10 levels were decreased in the hippocampus. Interestingly, we showed that the administration of dexamethasone successfully reduced cerebral oedema, preventing the inhibition of Na(+),K(+)-ATPase activity, BBB breakdown and the increase in the cytokines levels. In conclusion, these findings suggest that dexamethasone can improve the acute cerebral oedema and brain injury associated with high levels of BCAA, either through a direct effect on brain capillary Na(+),K(+)-ATPase or through a generalized effect on the permeability of the BBB to all compounds.

  14. Spinal cord compression injury in guinea pigs: structural changes of endothelium and its perivascular cell associations after blood-brain barrier breakdown and repair.

    Science.gov (United States)

    Jaeger, C B; Blight, A R

    1997-04-01

    This study examines morphological changes of the blood-brain barrier (BBB) after spinal cord compression. The lowest thoracic segment (T13) of female guinea pigs was injured and the BBB was tested from 7 days to 5.5 months postinjury using intravenously injected horseradish peroxidase (HRP) as a tracer. Tracer leakage in the injured segment was verified with the light microscope and the fine structure of capillaries was examined. Diffuse tissue staining was observed at T13 up to 2 weeks following injury. A leaky BBB correlated with expected changes in the fine structure of endothelial cell junctions. These were predominantly nonoverlapping cell junctions which, in many instances, were separated by clefts between adjacent cells. At early survival times, numerous capillary profiles with juxtaposed astrocyte foot processes were noted in addition to altered cell associations. Complete sealing of the BBB against interstitial HRP leakage was not observed until 17 days postinjury. After the first week, some of the endothelial cells were contacted by macrophages, processes of perivascular microglia, and processes of swollen and degenerating astrocytes. Perivascular spaces varied in extent and contained amorphous deposits of extracellular materials in addition to supernumerary layers of basal lamina. The early changes were followed by profound tissue restructuring due to loss of both neurons and glia. At longer survival times the BBB to HRP repaired. Endothelial cells formed complex overlapping junctions with zonulae occludentes. Most of the capillaries in the injured segment were no longer in direct contact with astrocyte foot processes, although reactive astrocytes constituted the predominant cell type in the remaining gray matter. Substantial expansion of perivascular spaces was evident. The cytoplasm of endothelial cells had numerous pinocytotic vesicles. Perivascular spaces contained layers of assembled collagen arranged perpendicularly to each other in addition to

  15. Barrier mechanisms in the Drosophila blood-brain barrier

    Directory of Open Access Journals (Sweden)

    Samantha Jane Hindle

    2014-12-01

    Full Text Available The invertebrate blood-brain barrier field is growing at a rapid pace and, in recent years, studies have shown a physiologic and molecular complexity that has begun to rival its vertebrate counterpart. Novel mechanisms of paracellular barrier maintenance through GPCR signaling were the first demonstrations of the complex adaptive mechanisms of barrier physiology. Building upon this work, the integrity of the invertebrate blood-brain barrier has recently been shown to require coordinated function of all layers of the compound barrier structure, analogous to signaling between the layers of the vertebrate neurovascular unit. These findings strengthen the notion that many blood-brain barrier mechanisms are conserved between vertebrates and invertebrates, and suggest that novel findings in invertebrate model organisms will have a significant impact on the understanding of vertebrate BBB functions. In this vein, important roles in coordinating localized and systemic signaling to dictate organism development and growth are beginning to show how the blood-brain barrier can govern whole animal physiologies. This includes novel functions of blood-brain barrier gap junctions in orchestrating synchronized neuroblast proliferation, and of blood-brain barrier secreted antagonists of insulin receptor signaling. These advancements and others are pushing the field forward in exciting new directions. In this review, we provide a synopsis of invertebrate blood-brain barrier anatomy and physiology, with a focus on insights from the past 5 years, and highlight important areas for future study.

  16. The blood-brain barrier in systemic lupus erythematosus.

    Science.gov (United States)

    Abbott, N J; Mendonça, L L F; Dolman, D E M

    2003-01-01

    Central nervous system (CNS) involvement may occur in 20-70% of systemic lupus erythematosus (SLE) patients where neurological symptoms are overt; this is termed neuropsychiatric lupus or NPSLE. This review summarizes evidence that damage to the brain endothelium forming the blood-brain barrier (BBB) is a contributory factor in NPSLE. The normal CNS is protected by blood-tissue barriers at three sites, the brain endothelium (BBB), the choroid plexus epithelium (blood-CSF barrier) and the arachnoid epithelium. The tight junctions of the barrier layers severely restrict entry of plasma constituents including proteins, so that the CSF and brain interstitial fluid contain low levels of protein. Methods for diagnosing BBB damage include imaging (CT, MRI) using contrast agents, and analysing protein content and profiles of CSF Changes in the albumin quotient Qalbumin show evidence for barrier damage, while changes in the immunoglobulin (Ig) index can indicate intrathecal antibody production. However, BBB damage may be transient, and hence undetected or underestimated. Few mechanistic studies exist, but the two main candidate mechanisms for BBB damage are microthrombi in cerebral vessels leading to ischaemia, and immune-mediated attack and activation of the endothelium leading to local cytokine production. Both can result in barrier breakdown. Neurological syndromes could then be secondary to damage to the BBB. The implications for treatment of NPSLE are discussed.

  17. Fabrication of 4H-SiC Schottky barrier diodes with high breakdown voltages

    CERN Document Server

    Kum, B H; Shin, M W; Park, J D

    1999-01-01

    This paper discusses the fabrication and the breakdown characteristics of 4H-SiC Schottky barrier diodes (SBDs). Optimal processing conditions for the ohmic contacts were extracted using the transmission-line method (TLM) and were applied to the device fabrication. The Ti/4H-SiC SBDs with Si sub x B sub y passivation showed a maximum reverse breakdown voltage of 268 V with a forward current density as high as 70 mA/cm sup 2 at a forward voltage of 2 V. The breakdown of the Pt. 4H-SiC SBDs without any passivation occurred at near 110 V. It is concluded that the breakdown enhancement in the Ti/4H-SiC SBDs can be attributed to the passivation; otherwise, excess surface charge near the edge of the Schottky contact would lead to electric fields of sufficient magnitude to cause field emission.

  18. Breakdown of the Blood-Ocular Barrier as a Strategy for the Systemic Use of Nanosystems

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    Vital P. Costa

    2012-05-01

    Full Text Available Several drug delivery systems have been proposed to overcome physiological barriers, improving ocular bioavailability. Systemic routes are seldom used due to the blood-ocular barrier. Novel drug delivery systems based on nanotechnology techniques have been developed to overcome ocular physiological barriers. This non-systematic review suggests the utilization of a transitory blood-ocular breakdown to allow the access of drugs by nanotechnology drug delivery systems via the systemic route. We discuss the possible ways to cause the breakdown of the blood-ocular barrier: acute inflammation caused by intraocular surgery, induced ocular hypotony, and the use of inflammatory mediators. The suitability of use of the systemic route and its toxic effects are also discussed in this article.

  19. Permeability of the blood-brain barrier predicts conversion from optic neuritis to multiple sclerosis

    DEFF Research Database (Denmark)

    Cramer, Stig P; Modvig, Signe; Simonsen, Helle Juhl

    2015-01-01

    in the permeability of the blood-brain barrier in normal-appearing white matter of patients with multiple sclerosis and here, for the first time, we present a study on the capability of blood-brain barrier permeability in predicting conversion from optic neuritis to multiple sclerosis and a direct comparison...... with cerebrospinal fluid markers of inflammation, cellular trafficking and blood-brain barrier breakdown. To this end, we applied dynamic contrast-enhanced magnetic resonance imaging at 3 T to measure blood-brain barrier permeability in 39 patients with monosymptomatic optic neuritis, all referred for imaging...... fluid as well as levels of CXCL10 and MMP9 in the cerebrospinal fluid. These findings suggest that blood-brain barrier permeability, as measured by magnetic resonance imaging, may provide novel pathological information as a marker of neuroinflammation related to multiple sclerosis, to some extent...

  20. Markers for blood-brain barrier integrity

    DEFF Research Database (Denmark)

    Saunders, Norman R; Dziegielewska, Katarzyna M; Møllgård, Kjeld

    2015-01-01

    known when first introduced, but seem to have been forgotten since. Understanding these limitations is important because Evans blue is still the most commonly used marker of brain barrier integrity and those using it seem oblivious to problems arising from its in vivo application. The introduction......In recent years there has been a resurgence of interest in brain barriers and various roles their intrinsic mechanisms may play in neurological disorders. Such studies require suitable models and markers to demonstrate integrity and functional changes at the interfaces between blood, brain......, and cerebrospinal fluid. Studies of brain barrier mechanisms and measurements of plasma volume using dyes have a long-standing history, dating back to the late nineteenth-century. Their use in blood-brain barrier studies continues in spite of their known serious limitations in in vivo applications. These were well...

  1. The biological significance of brain barrier mechanisms

    DEFF Research Database (Denmark)

    Saunders, Norman R; Habgood, Mark D; Møllgård, Kjeld

    2016-01-01

    Barrier mechanisms in the brain are important for its normal functioning and development. Stability of the brain's internal environment, particularly with respect to its ionic composition, is a prerequisite for the fundamental basis of its function, namely transmission of nerve impulses....... In addition, the appropriate and controlled supply of a wide range of nutrients such as glucose, amino acids, monocarboxylates, and vitamins is also essential for normal development and function. These are all cellular functions across the interfaces that separate the brain from the rest of the internal...... environment of the body. An essential morphological component of all but one of the barriers is the presence of specialized intercellular tight junctions between the cells comprising the interface: endothelial cells in the blood-brain barrier itself, cells of the arachnoid membrane, choroid plexus epithelial...

  2. Protection of the Blood-Brain Barrier as a Therapeutic Strategy for Brain Damage.

    Science.gov (United States)

    Michinaga, Shotaro; Koyama, Yutaka

    2017-01-01

    Severe brain damage by trauma, ischemia, and hemorrhage lead to fatal conditions including sudden death, subsequent complications of the extremities and cognitive dysfunctions. Despite the urgent need for treatments for these complications, currently available therapeutic drugs are limited. Blood-brain barrier (BBB) disruption is a common pathogenic feature in many types of brain damage. The characteristic pathophysiological conditions caused by BBB disruption are brain edema resulting from an excessive increase of brain water content, inflammatory damage caused by infiltrating immune cells, and hemorrhage caused by the breakdown of microvessel structures. Because these pathogenic features induced by BBB disruption cause fatal conditions, their improvement is a desirable strategy. Many studies using experimental animal models have focused on molecules involved in BBB disruption, including vascular endothelial growth factors (VEGFs), matrix metalloproteinases (MMPs) and endothelins (ETs). The inhibition of these factors in several experimental animals was protective against BBB disruption caused by several types of brain damage, and ameliorated brain edema, inflammatory damage, and hemorrhagic transformation. In patients with brain damage, the up-regulation of these factors was observed and was related to brain damage severity. Thus, BBB protection by targeting VEGFs, MMPs, and ETs might be a novel strategy for the treatment of brain damage.

  3. Barrier discharges driven by sub-microsecond pulses at atmospheric pressure: Breakdown manipulation by pulse width

    Energy Technology Data Exchange (ETDEWEB)

    Hoder, Tomas; Hoeft, Hans; Kettlitz, Manfred; Weltmann, Klaus-Dieter; Brandenburg, Ronny [Leibniz Institute for Plasma Science and Technology, INP Greifswald, Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany)

    2012-07-15

    Barrier discharges at atmospheric pressure in nitrogen-oxygen mixture powered by high voltage pulses of widths between 10 {mu}s and 200 ns were investigated. The development of the microdischarges on rising and falling slopes was recorded by streak and intensified CCD cameras simultaneously. The breakdown on the falling slope strongly depends on the pulse width. As a result of pulse width variation the starting point of ignition changes and positive and negative streamers occur simultaneously in the falling slope. The observed effect is caused by the electric field rearrangement in the gap due to the different positive ion densities related to their gap crossing times.

  4. High breakdown voltage GaN-on-insulator based heterojunction field effect transistor with a partial back barrier layer

    Science.gov (United States)

    Du, Jiangfeng; Li, Ruonan; Bai, Zhiyuan; Liu, Yong; Yu, Qi

    2017-11-01

    A high breakdown voltage GaN-on-Insulator based heterojunction field effect transistor with a partial back barrier (PB-GOI HFET) is proposed in this paper. The partial back barrier (PB) formed by AlGaN is located in the GaN channel layer, which can make the breakdown voltage improved significantly by modulating the distribution of electric field along the channel. PB-GOI HFET can not only maintain the original advantages of GOI structure, but also improve the breakdown voltage without degradation of frequency performance. Compared with a conventional GOI HFET, the proposed PB-GOI HFET with gate-drain distance of 5 μm possesses the breakdown voltage of 1200 V and the FOM of 3.12 GW/cm2, which increased by more than 353% and 976%. The novel PB-GOI HFET shows great prospects in power electronics applications.

  5. Inflammation at the Blood–Brain Barrier in Multiple Sclerosis

    NARCIS (Netherlands)

    Mizee, M.R.; van Doorn, R.P.; Prat, A.; de Vries, H.E.; Fricker, G.; Ott, M.; Mahringer, A.

    2014-01-01

    The blood–brain barrier is specialized to function as a barrier to protect the central nervous system (CNS) by restricting entry of unwanted molecules and immune cells into the brain and inversely, to prevent CNS-born agents from reaching the systemic circulation. The blood–brain barrier

  6. Ruptura da barreira hematoencefálica após injeção de droga gliotóxica no tronco encefálico de ratos wistar Blood-brain barrier breakdown following gliotoxic drug injection in the brainstem of Wistar rats

    Directory of Open Access Journals (Sweden)

    Eduardo Fernandes Bondan

    2002-09-01

    Full Text Available O brometo de etídio (BE determina desaparecimento astrocitário local, com ruptura da glia limitans e suposto dano na barreira hematoencefálica (BBB. Este estudo visou avaliar a integridade da BBB após injeção de solução de BE a 0,1% (grupo E ou de salina a 0,9% (grupo C na cisterna pontis de ratos Wistar. Fragmentos do tronco encefálico foram coletados das 24 horas aos 31 dias pós-injeção para estudo ultra-estrutural e marcação imuno-histoquímica para a GFAP. Alguns animais receberam carvão coloidal por via intravenosa nos mesmos períodos. Nos ratos do grupo C, não houve sinal de perda astrocitária, nem extravasamento vascular de carvão no sítio da injeção. No grupo E, o desaparecimento astrocitário começou às 48 horas e algumas áreas estavam ainda destituídas de processos astrocíticos 31 dias após. Extravasamento de partículas de carvão nas lesões foi visto de 48 horas até 7 dias, não sendo detectada qualquer alteração ultra-estrutural das junções oclusivas pela falta de astrócitos perivasculares.Ethidium bromide (EB causes local astrocytic disappearance, with glia limitans disruption and supposed blood-brain barrier (BBB breakdown The aim of this study was to investigate the BBB integrity after the injection of 0.1% EB (group E or 0.9% saline solution (group C into cisterna pontis of Wistar rats. Brainstem fragments were collected from 24 hours to 31 days post-injection for ultrastructural study and GFAP immuno-histochemical staining. Some animals received colloidal carbon ink by intravenous route at the same periods. In rats from group C, there was no sign of astrocyte loss and no leakage of ink from blood vessels in the injection site. In group E, astrocyte disappearance began at 48 hours and some areas were still devoid of astrocytic processes 31 days after. Leakage of carbon particles was seen from 48 hours to 7 days in the EB-induced lesions. Tight junctions did not show any detectable

  7. Breakdown of the brain's functional network modularity with awareness

    National Research Council Canada - National Science Library

    Godwin, Douglass; Barry, Robert L; Marois, René

    2015-01-01

    ... performed a simple masked target detection task. We found that awareness of a visual target is associated with a degradation of the modularity of the brain's functional networks brought about by an increase in intermodular functional connectivity...

  8. Molecular basis of the inner blood-retinal barrier and its breakdown in diabetic macular edema and other pathological conditions

    NARCIS (Netherlands)

    Klaassen, Ingeborg; van Noorden, Cornelis J. F.; Schlingemann, Reinier O.

    2013-01-01

    Breakdown of the inner endothelial blood-retinal barrier (BRB), as occurs in diabetic retinopathy, age-related macular degeneration, retinal vein occlusions, uveitis and other chronic retinal diseases, results in vasogenic edema and neural tissue damage, causing loss of vision. The central mechanism

  9. Medulloblastoma Genotype Dictates Blood Brain Barrier Phenotype.

    Science.gov (United States)

    Phoenix, Timothy N; Patmore, Deanna M; Boop, Scott; Boulos, Nidal; Jacus, Megan O; Patel, Yogesh T; Roussel, Martine F; Finkelstein, David; Goumnerova, Liliana; Perreault, Sebastien; Wadhwa, Elizabeth; Cho, Yoon-Jae; Stewart, Clinton F; Gilbertson, Richard J

    2016-04-11

    The childhood brain tumor, medulloblastoma, includes four subtypes with very different prognoses. Here, we show that paracrine signals driven by mutant β-catenin in WNT-medulloblastoma, an essentially curable form of the disease, induce an aberrant fenestrated vasculature that permits the accumulation of high levels of intra-tumoral chemotherapy and a robust therapeutic response. In contrast, SHH-medulloblastoma, a less curable disease subtype, contains an intact blood brain barrier, rendering this tumor impermeable and resistant to chemotherapy. The medulloblastoma-endothelial cell paracrine axis can be manipulated in vivo, altering chemotherapy permeability and clinical response. Thus, medulloblastoma genotype dictates tumor vessel phenotype, explaining in part the disparate prognoses among medulloblastoma subtypes and suggesting an approach to enhance the chemoresponsiveness of other brain tumors. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Hormones and the blood-brain barrier.

    Science.gov (United States)

    Hampl, Richard; Bičíková, Marie; Sosvorová, Lucie

    2015-03-01

    Hormones exert many actions in the brain, and brain cells are also hormonally active. To reach their targets in brain structures, hormones must overcome the blood-brain barrier (BBB). The BBB is a unique device selecting desired/undesired molecules to reach or leave the brain, and it is composed of endothelial cells forming the brain vasculature. These cells differ from other endothelial cells in their almost impermeable tight junctions and in possessing several membrane structures such as receptors, transporters, and metabolically active molecules, ensuring their selection function. The main ways how compounds pass through the BBB are briefly outlined in this review. The main part concerns the transport of major classes of hormones: steroids, including neurosteroids, thyroid hormones, insulin, and other peptide hormones regulating energy homeostasis, growth hormone, and also various cytokines. Peptide transporters mediating the saturable transport of individual classes of hormones are reviewed. The last paragraph provides examples of how hormones affect the permeability and function of the BBB either at the level of tight junctions or by various transporters.

  11. Blood-brain barrier permeability imaging using perfusion computed tomography

    Directory of Open Access Journals (Sweden)

    Avsenik Jernej

    2015-06-01

    Full Text Available Background. The blood-brain barrier represents the selective diffusion barrier at the level of the cerebral microvascular endothelium. Other functions of blood-brain barrier include transport, signaling and osmoregulation. Endothelial cells interact with surrounding astrocytes, pericytes and neurons. These interactions are crucial to the development, structural integrity and function of the cerebral microvascular endothelium. Dysfunctional blood-brain barrier has been associated with pathologies such as acute stroke, tumors, inflammatory and neurodegenerative diseases.

  12. Peptide Transport through the Blood-Brain Barrier

    Science.gov (United States)

    1991-01-01

    cause glomerular nephropathies , (c) the potential antigenicity of the vector, i.e., some cationized heterologous proteins are highly immunogenic, (d...I diabetes . N. Enctl. J. Med. 312:1078-1084. 12. Pardridge, W.M. (1988): Recent advances in blood-brain barrier transport. Ann. Rev. Pharmacol...barrier. In: Pathophysiology of the Blood-Brain Barrier: Long Term Consequences of Barrier Dysfunction for the Brain (B.B. Johansson, C. Owman, and H

  13. Splenectomy attenuates severe thermal trauma-induced intestinal barrier breakdown in rats.

    Science.gov (United States)

    Liu, Xiang-dong; Chen, Zhen-yong; Yang, Peng; Huang, Wen-guang; Jiang, Chun-fang

    2015-12-01

    The severe local thermal trauma activates a number of systemic inflammatory mediators, such as TNF-α, NF-κB, resulting in a disruption of gut barrier. The gastrointestinal tight junction (TJ) is highly regulated by membrane-associated proteins including zonula occludens protein-1 (ZO-1) and occludin, which can be modulated by inflammatory cytokines. As splenectomy has been shown to reduce secretion of cytokines, we hypothesized that (1) severe scald injury up-regulates TNF-α and NF-κB, meanwhile down-regulates expression of ZO-1 and occludin, leading to the increased intestinal permeability, and (2) splenectomy can prevent the burn-induced decrease in ZO-1 and occludin expression, resulting in improved intestinal barrier. Wistar rats undergoing a 30% total body surface area (TBSA) thermal trauma were randomized to receive an accessorial splenectomy meanwhile or not. Intestinal injury was assessed by histological morphological analysis, and serum endotoxin levels, TNF-α, NF-κB, ZO-1 and occludin levels were detected by Western blotting in the terminal ileum mucosal tissue. 30% TBSA burn caused a significant increase in serum endotoxin levels, but NF-κB, and TNF-α, and the average intestinal villus height and mucosal thickness were decreased significantly. Burn injury could also markedly decrease the levels of ZO-1 and occludin in terminal ileum mucosal tissue (all PSplenectomy at 7th day after burn significantly reversed the burn-induced breakdown of ZO-1 and occludin (all PSplenectomy may provide a therapeutic benefit in restoring burn-induced intestinal barrier by decreasing the release of inflammatory cytokines and recovering TJ proteins.

  14. Mechanisms of microbial traversal of the blood-brain barrier.

    Science.gov (United States)

    Kim, Kwang Sik

    2008-08-01

    Central nervous system (CNS) infections continue to be an important cause of morbidity and mortality. Microbial invasion and traversal of the blood-brain barrier is a prerequisite for CNS infections. Pathogens can cross the blood-brain barrier transcellularly, paracellularly and/or in infected phagocytes (the so-called Trojan-horse mechanism). Consequently, pathogens can cause blood-brain barrier dysfunction, including increased permeability, pleocytosis and encephalopathy. A more complete understanding of the microbial-host interactions that are involved in microbial traversal of the blood-brain barrier and the associated barrier dysfunction should help to develop new strategies to prevent CNS infections.

  15. The blood-brain barrier in psychoneuroimmunology.

    Science.gov (United States)

    Banks, William A

    2009-05-01

    The term ''psychoneuroimmunology'' connotes separate compartments that interact. The blood-brain barrier (BBB) is both the dividing line, physical and physiologic, between the immune system and the central nervous system (CNS) and the locale for interaction. The BBB restricts unregulated mixing of immune substances in the blood with those in the CNS, directly transports neuroimmune-active substances between the blood and CNS, and itself secretes neuroimmune substances. These normal functions of the BBB can be altered by neuroimmune events. As such, the BBB is an important conduit in the communication between the immune system and the CNS.

  16. Brain Extracellular Space as a Diffusion Barrier.

    Science.gov (United States)

    Nicholson, Charles; Kamali-Zare, Padideh; Tao, Lian

    2011-10-01

    The extracellular space (ECS) consists of the narrow channels between brain cells together with their geometrical configuration and contents. Despite being only 20-60 nm in width, the ECS typically occupies 20% of the brain volume. Numerous experiments over the last 50 years have established that molecules moving through the ECS obey the laws of diffusion but with an effective diffusion coefficient reduced by a factor of about 2.6 compared to free diffusion. This review considers the origins of the diffusion barrier arising from the ECS and its properties. The paper presents a brief overview of software for implementing two point-source paradigms for measurements of localized diffusion properties: the real-time iontophoresis or pressure method for small ions and the integrative optical imaging method for macromolecules. Selected results are presented. This is followed by a discussion of the application of the MCell Monte Carlo simulation program to determining the importance of geometrical constraints, especially dead-space microdomains, and the possible role of interaction with the extracellular matrix. It is concluded that we can predict the impediment to diffusion of many molecules of practical importance and also use studies of the diffusion of selected molecular probes to reveal the barrier properties of the ECS.

  17. The blood-brain barrier and glutamate.

    Science.gov (United States)

    Hawkins, Richard A

    2009-09-01

    Glutamate concentrations in plasma are 50-100 micromol/L; in whole brain, they are 10,000-12,000 micromol/L but only 0.5-2 micromol/L in extracellular fluids (ECFs). The low ECF concentrations, which are essential for optimal brain function, are maintained by neurons, astrocytes, and the blood-brain barrier (BBB). Cerebral capillary endothelial cells form the BBB that surrounds the entire central nervous system. Tight junctions connect endothelial cells and separate the BBB into luminal and abluminal domains. Molecules entering or leaving the brain thus must pass 2 membranes, and each membrane has distinct properties. Facilitative carriers exist only in luminal membranes, and Na(+)-dependent glutamate cotransporters (excitatory amino acid transporters; EAATs) exist exclusively in abluminal membranes. The EAATs are secondary transporters that couple the Na(+) gradient between the ECF and the endothelial cell to move glutamate against the existing electrochemical gradient. Thus, the EAATs in the abluminal membrane shift glutamate from the ECF to the endothelial cell where glutamate is free to diffuse into blood on facilitative carriers. This organization does not allow net glutamate entry to the brain; rather, it promotes the removal of glutamate and the maintenance of low glutamate concentrations in the ECF. This explains studies that show that the BBB is impermeable to glutamate, even at high concentrations, except in a few small areas that have fenestrated capillaries (circumventricular organs). Recently, the question of whether the BBB becomes permeable in diabetes has arisen. This issue was tested in rats with diet-induced obesity and insulin resistance or with streptozotocin-induced diabetes. Neither condition produced any detectable effect on BBB glutamate transport.

  18. Alteration of blood-brain barrier integrity by retroviral infection.

    Directory of Open Access Journals (Sweden)

    Philippe V Afonso

    2008-11-01

    Full Text Available The blood-brain barrier (BBB, which forms the interface between the blood and the cerebral parenchyma, has been shown to be disrupted during retroviral-associated neuromyelopathies. Human T Lymphotropic Virus (HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP is a slowly progressive neurodegenerative disease associated with BBB breakdown. The BBB is composed of three cell types: endothelial cells, pericytes and astrocytes. Although astrocytes have been shown to be infected by HTLV-1, until now, little was known about the susceptibility of BBB endothelial cells to HTLV-1 infection and the impact of such an infection on BBB function. We first demonstrated that human cerebral endothelial cells express the receptors for HTLV-1 (GLUT-1, Neuropilin-1 and heparan sulfate proteoglycans, both in vitro, in a human cerebral endothelial cell line, and ex vivo, on spinal cord autopsy sections from HAM/TSP and non-infected control cases. In situ hybridization revealed HTLV-1 transcripts associated with the vasculature in HAM/TSP. We were able to confirm that the endothelial cells could be productively infected in vitro by HTLV-1 and that blocking of either HSPGs, Neuropilin 1 or Glut1 inhibits this process. The expression of the tight-junction proteins within the HTLV-1 infected endothelial cells was altered. These cells were no longer able to form a functional barrier, since BBB permeability and lymphocyte passage through the monolayer of endothelial cells were increased. This work constitutes the first report of susceptibility of human cerebral endothelial cells to HTLV-1 infection, with implications for HTLV-1 passage through the BBB and subsequent deregulation of the central nervous system homeostasis. We propose that the susceptibility of cerebral endothelial cells to retroviral infection and subsequent BBB dysfunction is an important aspect of HAM/TSP pathogenesis and should be considered in the design of future therapeutics strategies.

  19. Tick-borne encephalitis virus infects human brain microvascular endothelial cells without compromising blood-brain barrier integrity.

    Science.gov (United States)

    Palus, Martin; Vancova, Marie; Sirmarova, Jana; Elsterova, Jana; Perner, Jan; Ruzek, Daniel

    2017-07-01

    Alteration of the blood-brain barrier (BBB) is a hallmark of tick-borne encephalitis (TBE), a life-threating human viral neuroinfection. However, the mechanism of BBB breakdown during TBE, as well as TBE virus (TBEV) entry into the brain is unclear. Here, primary human microvascular endothelial cells (HBMECs) were infected with TBEV to study interactions with the BBB. Although the number of infected cells was relatively low in culture (10 6 pfu/ml). Infection did not induce any significant changes in the expression of key tight junction proteins or upregulate the expression of cell adhesion molecules, and did not alter the highly organized intercellular junctions between HBMECs. In an in vitro BBB model, the virus crossed the BBB via a transcellular pathway without compromising the integrity of the cell monolayer. The results indicate that HBMECs may support TBEV entry into the brain without altering BBB integrity. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Outer brain barriers in rat and human development

    DEFF Research Database (Denmark)

    Brøchner, Christian B; Holst, Camilla Bjørnbak; Møllgård, Kjeld

    2015-01-01

    Complex barriers at the brain's surface, particularly in development, are poorly defined. In the adult, arachnoid blood-cerebrospinal fluid (CSF) barrier separates the fenestrated dural vessels from the CSF by means of a cell layer joined by tight junctions. Outer CSF-brain barrier provides...... diffusion restriction between brain and subarachnoid CSF through an initial radial glial end feet layer covered with a pial surface layer. To further characterize these interfaces we examined embryonic rat brains from E10 to P0 and forebrains from human embryos and fetuses (6-21st weeks post...

  1. The Blood-Brain Barrier: An Engineering Perspective

    Directory of Open Access Journals (Sweden)

    Andrew eWong

    2013-08-01

    Full Text Available It has been more than 100 years since Paul Ehrlich reported that various water-soluble dyes injected into the circulation did not enter the brain. Since Ehrlich’s first experiments, only a small number of molecules, such as alcohol and caffeine have been found to cross the blood-brain barrier, and it remains the major roadblock to treatment of many central nervous system diseases. At the same time, many central nervous system diseases are associated with disruption of the blood-brain barrier that can lead to changes in permeability, modulation of immune cell transport, and trafficking of pathogens into the brain. Therefore advances in our understanding of the structure and function of the blood-brain barrier are key to advances in treatment of a wide range of central nervous system diseases. Over the past 10 years it has become recognized that the blood-brain barrier is a complex dynamic system that involves biomechanical and biochemical signaling between the vascular system and the brain. Here we reconstruct the structure, function, and transport properties of the blood-brain barrier from an engineering perspective. New insight into the physics of the blood-brain barrier could ultimately lead to clinical advances in the treatment of central nervous system diseases.

  2. Glutamate Transporters in the Blood-Brain Barrier

    DEFF Research Database (Denmark)

    Helms, Hans Christian Cederberg; Nielsen, Carsten Uhd; Waagepetersen, Helle Sønderby

    2017-01-01

    concentration of L-glutamate causes excitotoxicity. A tight control of the brain interstitial fluid L-glutamate levels is therefore imperative, in order to maintain optimal neurotransmission and to avoid such excitotoxicity. The blood-brain barrier, i.e., the endothelial lining of the brain capillaries...... cells. The mechanisms underlying transendothelial L-glutamate transport are however still not well understood. The present chapter summarizes the current knowledge on blood-brain barrier L-glutamate transporters and the suggested pathways for the brain-to-blood L-glutamate efflux....

  3. The blood-brain barrier in migraine treatment

    DEFF Research Database (Denmark)

    Edvinsson, L.; Tfelt-Hansen, P.

    2008-01-01

    Salient aspects of the anatomy and function of the blood-barrier barrier (BBB) are reviewed in relation to migraine pathophysiology and treatment. The main function of the BBB is to limit the access of circulating substances to the neuropile. Smaller lipophilic substances have some access...... vascular beds also. We discuss how this can be related to genuine migraine attacks. Our view is that there exists no clear proof of breakdown or leakage of the BBB during migraine attacks, and that antimigraine drugs need to pass the BBB for efficacy Udgivelsesdato: 2008/12...

  4. CD146 coordinates brain endothelial cell-pericyte communication for blood-brain barrier development.

    Science.gov (United States)

    Chen, Jianan; Luo, Yongting; Hui, Hui; Cai, Tanxi; Huang, Hongxin; Yang, Fuquan; Feng, Jing; Zhang, Jingjing; Yan, Xiyun

    2017-09-05

    The blood-brain barrier (BBB) establishes a protective interface between the central neuronal system and peripheral blood circulation and is crucial for homeostasis of the CNS. BBB formation starts when the endothelial cells (ECs) invade the CNS and pericytes are recruited to the nascent vessels during embryogenesis. Despite the essential function of pericyte-EC interaction during BBB development, the molecular mechanisms coordinating the pericyte-EC behavior and communication remain incompletely understood. Here, we report a single cell receptor, CD146, that presents dynamic expression patterns in the cerebrovasculature at the stages of BBB induction and maturation, coordinates the interplay of ECs and pericytes, and orchestrates BBB development spatiotemporally. In mouse brain, CD146 is first expressed in the cerebrovascular ECs of immature capillaries without pericyte coverage; with increased coverage of pericytes, CD146 could only be detected in pericytes, but not in cerebrovascular ECs. Specific deletion of Cd146 in mice ECs resulted in reduced brain endothelial claudin-5 expression and BBB breakdown. By analyzing mice with specific deletion of Cd146 in pericytes, which have defects in pericyte coverage and BBB integrity, we demonstrate that CD146 functions as a coreceptor of PDGF receptor-β to mediate pericyte recruitment to cerebrovascular ECs. Moreover, we found that the attached pericytes in turn down-regulate endothelial CD146 by secreting TGF-β1 to promote further BBB maturation. These results reveal that the dynamic expression of CD146 controls the behavior of ECs and pericytes, thereby coordinating the formation of a mature and stable BBB.

  5. Immune responses at brain barriers and implications for brain development and neurological function in later life

    Directory of Open Access Journals (Sweden)

    Helen B. Stolp

    2013-08-01

    Full Text Available For a long time the brain has been considered an immune-privileged site due to a muted inflammatory response and the presence of protective brain barriers. It is now recognised that neuroinflammation may play an important role in almost all neurological disorders and that the brain barriers may be contributing through either normal immune signalling, or disruption of their basic physiological mechanisms. The distinction between normal function and dysfunction at the barriers is difficult to dissect, partly due to a lack of understanding of normal barrier function and partly because of physiological changes that occur as part of normal development and ageing. Brain barriers consist of a number of interacting structural and physiological elements including tight junctions between adjacent barrier cells and an array of influx and efflux transporters. Despite these protective mechanisms, the capacity for immune-surveillance of the brain is maintained, and there is evidence of inflammatory signalling at the brain barriers that may be an important part of the body’s response to damage or infection. This signalling system appears to change both with normal ageing, and during disease. Changes may affect diapedesis of immune cells and active molecular transfer, or cause rearrangement of the tight junctions and an increase in passive permeability across barrier interfaces. Here we review the many elements that contribute to brain barrier functions and how they respond to inflammation, particularly during development and aging. The implications of inflammation–induced barrier dysfunction for brain development and subsequent neurological function are also discussed.

  6. [Blood-brain barrier transport of opioid analgesics].

    Science.gov (United States)

    Suzuki, Toyofumi

    2011-01-01

    Opioid analgesics exhibit cationic properties under physiological conditions, and the mechanism underlying permeation of the blood-brain barrier thus cannot be fully explained by simple diffusion alone. Various types of transporters that exhibit substrate specificity are localized on the blood-brain barrier, and play a role in transporting substances from circulating blood and from brain interstitial fluid. Progress is being made in explaining the mechanisms, functions, and physiological roles of polyspecific organic cation transporters, but little evidence has indicated that these previously identified organic cation transporters are involved in the transport of opioid analgesics across the blood-brain barrier. Consequently, clarifying the role of transporters in the distribution of opioid analgesics into the brain and determining their transport molecule will not only provide clues to effective drug delivery to the brain, but will also contribute to optimizing pain relief treatment, and by extension play a role in drug discovery for analgesics. Currently there are enthusiastic discussions in the literature regarding the existence of putative transporters involved in the transport of opioid analgesics across the blood-brain barrier. This review article introduces the results of our research as well as recent findings on the involvement of transporters in the blood-brain barrier transport of opioid analgesics such as morphine, morphine metabolites, oxycodone, fentanyl, codeine, and pentazocine.

  7. Ocular pharmacokinetics of intravitreally administered brimonidine and dexamethasone in animal models with and without blood-retinal barrier breakdown.

    Science.gov (United States)

    Shen, Jie; Durairaj, Chandra; Lin, Ton; Liu, Yan; Burke, James

    2014-02-20

    We compared ocular and systemic pharmacokinetics of brimonidine and dexamethasone following a single intravitreal dose in animals with blood-retinal barrier (BRB) breakdown and in healthy controls. We induced BRB breakdown in rabbits by intravitreal injection of recombinant human VEGF165 and choroidal neovascularization (CNV) in monkeys with laser. Control and disease animals then received single intravitreal injections of brimonidine alone, dexamethasone alone, or brimonidine in combination with dexamethasone. Ocular tissues and plasma were collected and quantified for drug concentration using LC-MS/MS assays. Statistical analysis was performed to compare the pharmacokinetic parameters between the control and disease animal models. In rabbits, brimonidine and dexamethasone exposure, as assessed by area under the drug concentration-time curve (AUC) in aqueous humor, retina, and choroid, was lower in disease than control animals, with a greater difference observed for dexamethasone than brimonidine. In monkeys, dexamethasone exposure was lower in disease than control animals for the central retina/choroid and peripheral choroid, whereas brimonidine exposure was lower in disease animals only in the central retina/choroid. Plasma exposure to both drugs was comparable between control and disease animals in both species. In animal models with a breakdown of the blood-retina barrier, drug clearance could be increased, resulting in lower drug concentration in ocular tissues compared to normal animals. However, the extent of difference may be compound- and disease model-specific. Therefore, extrapolation of ocular pharmacokinetic data obtained in normal animals to disease models for the purpose of pharmacokinetic/pharmacodynamic data analysis should be performed with caution.

  8. Blood-brain barrier dysfunction after primary blast injury in vitro.

    Science.gov (United States)

    Hue, Christopher D; Cao, Siqi; Haider, Syed F; Vo, Kiet V; Effgen, Gwen B; Vogel, Edward; Panzer, Matthew B; Bass, Cameron R Dale; Meaney, David F; Morrison, Barclay

    2013-10-01

    The incidence of blast-induced traumatic brain injury (bTBI) has increased substantially in recent military conflicts. However, the consequences of bTBI on the blood-brain barrier (BBB), a specialized cerebrovascular structure essential for brain homeostasis, remain unknown. In this study, we utilized a shock tube driven by compressed gas to generate operationally relevant, ideal pressure profiles consistent with improvised explosive devices (IEDs). By multiple measures, the barrier function of an in vitro BBB model was disrupted following exposure to a range of controlled blast loading conditions. Trans-endothelial electrical resistance (TEER) decreased acutely in a dose-dependent manner that was most strongly correlated with impulse, as opposed to peak overpressure or duration. Significantly increased hydraulic conductivity and solute permeability post-injury further confirmed acute alterations in barrier function. Compromised ZO-1 immunostaining identified a structural basis for BBB breakdown. After blast exposure, TEER remained significantly depressed 2 days post-injury, followed by spontaneous recovery to pre-injury control levels at day 3. This study is the first to report immediate disruption of an in vitro BBB model following primary blast exposure, which may be important for the development of novel helmet designs to help mitigate the effects of blast on the BBB.

  9. Retinoic Acid Induces Blood-Brain Barrier Development

    NARCIS (Netherlands)

    Mizee, M.R.; Wooldrik, D.; Lakeman, K.A.M.; van het Hof, B.; Drexhage, J.A.R.; Geerts, D.; Bugiani, M.; Aronica, E.; Mebius, R.E.; Prat, A.; de Vries, H.E.; Reijerkerk, A.

    2013-01-01

    The blood- brain barrier (BBB) is crucial in the maintenance of a controlled environment within the brain to safeguard optimal neuronal function. The endothelial cells (ECs) of theBBBpossess specific properties that restrict the entry of cells and metabolites into the CNS. The specialized BBB

  10. Retinoic acid induces blood-brain barrier development

    NARCIS (Netherlands)

    Mizee, Mark R.; Wooldrik, Desiree; Lakeman, Kim A. M.; van het Hof, Bert; Drexhage, Joost A. R.; Geerts, Dirk; Bugiani, Marianna; Aronica, Eleonora; Mebius, Reina E.; Prat, Alexandre; de Vries, Helga E.; Reijerkerk, Arie

    2013-01-01

    The blood-brain barrier (BBB) is crucial in the maintenance of a controlled environment within the brain to safeguard optimal neuronal function. The endothelial cells (ECs) of the BBB possess specific properties that restrict the entry of cells and metabolites into the CNS. The specialized BBB

  11. Routes for drug translocation across the blood-brain barrier

    DEFF Research Database (Denmark)

    Kristensen, Mie; Brodin, Birger

    2017-01-01

    A number of potent drugs for the treatment of brain diseases are available. However, in order for them to reach their target site of action, they must pass the blood-brain barrier (BBB). The capillary endothelium comprises the major barrier of the BBB and allows only passive permeation of some...... small lipophilic molecules. Brain delivery of the larger biopharmaceuticals, which today includes an increasing number of novel drug entities, is therefore restricted; both due to their molecular size and their hydrophilic nature. Thus, the development of novel drug entities intended for the treatment...... of brain diseases such as neurodegenerative diseases or brain cancers, require a delivery strategy for overcoming the BBB before reaching its final target within the brain. Peptide-based delivery vectors is an emerging tool as shuttles for drug delivery across the BBB and one may explore receptor...

  12. The complementary membranes forming the blood-brain barrier.

    Science.gov (United States)

    Hawkins, Richard A; Peterson, Darryl R; Viña, Juan R

    2002-09-01

    Brain capillary endothelial cells form the blood-brain barrier. They are connected by extensive tight junctions, and are polarized into luminal (blood-facing) and abluminal (brain-facing) plasma membrane domains. The polar distribution of transport proteins allows for active regulation of brain extracellular fluid. Experiments on isolated membrane vesicles from capillary endothelial cells of bovine brain demonstrated the polar arrangement of amino acid and glucose transporters, and the utility of such arrangements have been proposed. For instance, passive carriers for glutamine and glutamate have been found only in the luminal membrane of blood-brain barrier cells, while Na-dependent secondary active transporters are at the abluminal membrane. This organization could promote the net removal of nitrogen-rich amino acids from brain, and account for the low level of glutamate penetration into the central nervous system. Furthermore, the presence of a gamma-glutamyl cycle at the luminal membrane and Na-dependent amino acid transporters at the abluminal membrane may serve to modulate movement of amino acids from blood-to-brain. Passive carriers facilitate amino acid transport into brain. However, activation of the gamma-glutamyl cycle by increased plasma amino acids is expected to generate oxoproline within the blood-brain barrier. Oxoproline stimulates secondary active amino acid transporters (Systems A and B(o)+) at the abluminal membrane, thereby reducing net influx of amino acids to brain. Finally, passive glucose transporters are present in both the luminal and abluminal membranes of the blood-brain barrier. Interestingly, a high affinity Na-dependent glucose carrier has been described only in the abluminal membrane. This raises the question whether glucose entry may be regulated to some extent. Immunoblotting studies suggest more than one type of passive glucose transporter exist in the blood-brain barrier, each with an asymmetrical distribution. In conclusion, it

  13. Targeted liposomes for drug delivery across the blood-brain barrier

    NARCIS (Netherlands)

    van Rooy, I.|info:eu-repo/dai/nl/304823074

    2011-01-01

    Our brain is protected by the blood-brain barrier (BBB). This barrier is formed by specialized endothelial cells of the brain vasculature and prevents toxic substances from entering the brain. The downside of this barrier is that many drugs that have been developed to cure brain diseases cannot

  14. The emerging roles of clusterin on reduction of both blood retina barrier breakdown and neural retina damage in diabetic retinopathy.

    Science.gov (United States)

    Zhang, Conghui; Nie, Jing; Feng, Le; Luo, Wentao; Yao, Jun; Wang, Fang; Wang, Hao

    2016-04-01

    Previous proteomic studies revealed that intravitreous clusterin was decreased in diabetic retinopathy (DR) patients. We explored the role of clusterin in reduction of both blood retina barrier (BRB) breakdown and neural retina damage in early DR. Immunofluorescent staining of proliferated diabetic retinopathy (PDR) membranes was performed to detect endogenous clusterin, and intravitreous injection of clusterin (CLU group) or PBS (DR group) to streptozotocin-induced diabetic rats was conducted. Both qPCR and immunofluorescent staining were employed to investigate tight junction (TJ) protein. Fundus fluorescein angiography (FFA) and electroretinogram (ERG) were examined. Finally, HE and TUNEL stainings were used for neural retina assessment. Clusterin was expressed in the endothelial cells of PDR membranes. The expressions of several TJ protein genes were decreased in the retina of DR group (pretina showed that both dropouts and apoptotic death of neural retina cells in diabetic rats were attenuated in CLU group. Clusterin had a promising role in reducing both BRB breakdown and neural retina damage under high glucose; the mechanism might be keeping TJ protein integrated and maintaining anti-apoptosis in early diabetic rats.

  15. Effects of GSM modulated radio-frequency electromagnetic radiation on permeability of blood-brain barrier in male & female rats.

    Science.gov (United States)

    Sırav, Bahriye; Seyhan, Nesrin

    2016-09-01

    With the increased use of mobile phones, their biological and health effects have become more important. Usage of mobile phones near the head increases the possibility of effects on brain tissue. This study was designed to investigate the possible effects of pulse modulated 900MHz and 1800MHz radio-frequency radiation on the permeability of blood-brain barrier of rats. Study was performed with 6 groups of young adult male and female wistar albino rats. The permeability of blood-brain barrier to intravenously injected evans blue dye was quantitatively examined for both control and radio-frequency radiarion exposed groups. For male groups; Evans blue content in the whole brain was found to be 0.08±0.01mg% in the control, 0.13±0.03mg% in 900MHz exposed and 0.26±0.05mg% in 1800MHz exposed animals. In both male radio-frequency radiation exposed groups, the permeability of blood-brain barrier found to be increased with respect to the controls (pradiation exposure was found more effective on the male animals (p0.01). However 900MHz pulse modulated radio-frequency exposure was found effective on the permeability of blood-brain barrier of female animals. Results have shown that 20min pulse modulated radio-frequency radiation exposure of 900MHz and 1800MHz induces an effect and increases the permeability of blood-brain barrier of male rats. For females, 900MHz was found effective and it could be concluded that this result may due to the physiological differences between female and male animals. The results of this study suggest that mobile phone radation could lead to increase the permeability of blood-brain barrier under non-thermal exposure levels. More studies are needed to demonstrate the mechanisms of that breakdown. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Anatomy and physiology of the blood-brain barrier.

    Science.gov (United States)

    Serlin, Yonatan; Shelef, Ilan; Knyazer, Boris; Friedman, Alon

    2015-02-01

    Essential requisite for the preservation of normal brain activity is to maintain a narrow and stable homeostatic control in the neuronal environment of the CNS. Blood flow alterations and altered vessel permeability are considered key determinants in the pathophysiology of brain injuries. We will review the present-day literature on the anatomy, development and physiological mechanisms of the blood-brain barrier, a distinctive and tightly regulated interface between the CNS and the peripheral circulation, playing a crucial role in the maintenance of the strict environment required for normal brain function. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Histamine Induces Alzheimer's Disease-Like Blood Brain Barrier Breach and Local Cellular Responses in Mouse Brain Organotypic Cultures

    Science.gov (United States)

    Sedeyn, Jonathan C.; Wu, Hao; Hobbs, Reilly D.; Levin, Eli C.; Nagele, Robert G.; Venkataraman, Venkat

    2015-01-01

    Among the top ten causes of death in the United States, Alzheimer's disease (AD) is the only one that cannot be cured, prevented, or even slowed down at present. Significant efforts have been exerted in generating model systems to delineate the mechanism as well as establishing platforms for drug screening. In this study, a promising candidate model utilizing primary mouse brain organotypic (MBO) cultures is reported. For the first time, we have demonstrated that the MBO cultures exhibit increased blood brain barrier (BBB) permeability as shown by IgG leakage into the brain parenchyma, astrocyte activation as evidenced by increased expression of glial fibrillary acidic protein (GFAP), and neuronal damage-response as suggested by increased vimentin-positive neurons occur upon histamine treatment. Identical responses—a breakdown of the BBB, astrocyte activation, and neuronal expression of vimentin—were then demonstrated in brains from AD patients compared to age-matched controls, consistent with other reports. Thus, the histamine-treated MBO culture system may provide a valuable tool in combating AD. PMID:26697497

  18. Dimethyl fumarate attenuates cerebral edema formation by protecting the blood-brain barrier integrity.

    Science.gov (United States)

    Kunze, Reiner; Urrutia, Andrés; Hoffmann, Angelika; Liu, Hui; Helluy, Xavier; Pham, Mirko; Reischl, Stefan; Korff, Thomas; Marti, Hugo H

    2015-04-01

    Brain edema is a hallmark of various neuropathologies, but the underlying mechanisms are poorly understood. We aim to characterize how tissue hypoxia, together with oxidative stress and inflammation, leads to capillary dysfunction and breakdown of the blood-brain barrier (BBB). In a mouse stroke model we show that systemic treatment with dimethyl fumarate (DMF), an antioxidant drug clinically used for psoriasis and multiple sclerosis, significantly prevented edema formation in vivo. Indeed, DMF stabilized the BBB by preventing disruption of interendothelial tight junctions and gap formation, and decreased matrix metalloproteinase activity in brain tissue. In vitro, DMF directly sustained endothelial tight junctions, inhibited inflammatory cytokine expression, and attenuated leukocyte transmigration. We also demonstrate that these effects are mediated via activation of the redox sensitive transcription factor NF-E2 related factor 2 (Nrf2). DMF activated the Nrf2 pathway as shown by up-regulation of several Nrf2 target genes in the brain in vivo, as well as in cerebral endothelial cells and astrocytes in vitro, where DMF also increased protein abundance of nuclear Nrf2. Finally, Nrf2 knockdown in endothelial cells aggravated subcellular delocalization of tight junction proteins during ischemic conditions, and attenuated the protective effect exerted by DMF. Overall, our data suggest that DMF protects from cerebral edema formation during ischemic stroke by targeting interendothelial junctions in an Nrf2-dependent manner, and provide the basis for a completely new approach to treat brain edema. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. The inner CSF-brain barrier

    DEFF Research Database (Denmark)

    Whish, Sophie; Dziegielewska, Katarzyna M; Møllgård, Kjeld

    2015-01-01

    In the adult the interface between the cerebrospinal fluid and the brain is lined by the ependymal cells, which are joined by gap junctions. These intercellular connections do not provide a diffusional restrain between the two compartments. However, during development this interface, initially...... of plasma proteins (70 kDa) diffuse freely. Transcriptomic analysis of junctional proteins present in the cerebrospinal fluid-brain interface showed expression of adherens junctional proteins, actins, cadherins and catenins changing in a development manner consistent with the observed changes...... outlining the inner CSF-brain interface from E16; most of these markers were not present in the adult ependyma. Claudin-5 was present in the apical-most part of radial glial cells and in endothelial cells in embryos, but only in endothelial cells including plexus endothelial cells in adults. Claudin-11...

  20. Self-stabilized discharge filament in plane-parallel barrier discharge configuration: formation, breakdown mechanism, and memory effects

    Science.gov (United States)

    Tschiersch, R.; Nemschokmichal, S.; Bogaczyk, M.; Meichsner, J.

    2017-10-01

    Single self-stabilized discharge filaments were investigated in the plane-parallel electrode configuration. The barrier discharge was operated inside a gap of 3 mm shielded by glass plates to both electrodes, using helium-nitrogen mixtures and a square-wave feeding voltage at a frequency of 2 kHz. The combined application of electrical measurements, ICCD camera imaging, optical emission spectroscopy and surface charge diagnostics via the electro-optic Pockels effect allowed the correlation of the discharge development in the volume and on the dielectric surfaces. The formation criteria and existence regimes were found by systematic variation of the nitrogen admixture to helium, the total pressure and the feeding voltage amplitude. Single self-stabilized discharge filaments can be operated over a wide parameter range, foremost, by significant reduction of the voltage amplitude after the operation in the microdischarge regime. Here, the outstanding importance of the surface charge memory effect on the long-term stability was pointed out by the recalculated spatio-temporally resolved gap voltage. The optical emission revealed discharge characteristics that are partially reminiscent of both the glow-like barrier discharge and the microdischarge regime, such as a Townsend pre-phase, a fast cathode-directed ionization front during the breakdown and radially propagating surface discharges during the afterglow.

  1. Revisiting blood-brain barrier: a chromatographic approach

    OpenAIRE

    Subirats i Vila, Xavier; Muñoz-Pascual, Laura; Abraham, Michael H.; Rosés Pascual, Martí

    2017-01-01

    Drugs designed to reach a pharmacological CNS target must be effectively transported across the blood-brain barrier (BBB), a thin monolayer of endothelial cells tightly attached together between the blood and the brain parenchyma. Because of the lipidic nature of the BBB, several physicochemical partition models have been studied as surrogates for the passive permeation of potential drug candidates across the BBB (octanol-water, alkane-water, PAMPA...). In the last years, biopartition chromat...

  2. Iron uptake and transport at the blood-brain barrier

    DEFF Research Database (Denmark)

    Larsen, Annette Burkhart; Thomsen, Louiza Bohn; Moos, Torben

    The mechanism by which iron is transported across the blood-brain barrier (BBB) remains controversial, and in this study we aimed to further clarify mechanisms by which iron is transported into the brain. We analyzed and compared the mRNA and protein expression of a variety of proteins involved...... in the transport of iron (transferrin receptor, divalent metal transporter I (DMT1), steap 2, steap 3, ceruloplasmin, hephaestin and ferroportin) in both primary rat brain capillary endothelial cells (BCEC) and immortalized rat brain capillary endothelial cell line (RBE4) grown in co-culture with defined polarity....... The mRNA expression of the iron-related molecules was also investigated in isolated brain capillaries from iron deficiency, iron reversible and normal rats. We also performed iron transport studies to analyze the routes by which iron is transported through the brain capillary endothelial cells: i) We...

  3. Caveolin-1 increases proinflammatory chemoattractants and blood-retinal barrier breakdown but decreases leukocyte recruitment in inflammation.

    Science.gov (United States)

    Li, Xiaoman; Gu, Xiaowu; Boyce, Timothy M; Zheng, Min; Reagan, Alaina M; Qi, Hui; Mandal, Nawajes; Cohen, Alex W; Callegan, Michelle C; Carr, Daniel J J; Elliott, Michael H

    2014-08-26

    Caveolin-1 (Cav-1), the signature protein of caveolae, modulates inflammatory responses, and innate immunity. However, Cav-1's role in retinal inflammation has not been rigorously tested. In this study, we examined the effect of Cav-1 ablation on the sensitivity of the retina to inflammation. Cav-1 knockout (KO) mice were challenged by intravitreal injection of lipopolysaccharide (LPS) and inflammatory cell recruitment was assessed by flow cytometry and immunohistochemistry. Leukostasis was assessed in retinal flatmounts after perfusion with FITC-labeled Concanavalin A (FITC-ConA). Chemoattractants were measured by multiplex immunoassays. Blood-retinal barrier (BRB) breakdown was assessed quantitatively by a FITC-dextran permeability assay. The ratio of extravascular to total immune cells was determined by CD45 immunohistochemistry of retinal flatmounts. Inflammatory challenge resulted in significant blunting of proinflammatory cytokine (monocyte chemoattractant protein-1 [MCP-1/CCL2], CXCL1/KC, IL-6, and IL-1β) responses as well as reduced inflammatory BRB breakdown in Cav-1 KO retinas. Paradoxically, Cav-1 deficiency resulted in significantly increased recruitment of immune cells compared with controls as well as increased leukostasis. A similar ratio of extravascular/total leukocytes were found in Cav-1 KO and wild-type (WT) retinas suggesting that Cav-1 deficient leukocytes were as competent to extravasate as those from WT mice. We found increased levels of circulating immune cells in naïve (not challenged with LPS) Cav-1 KO mice compared with controls. Caveolin-1 paradoxically modulates inflammatory signaling and leukocyte infiltration through distinct mechanisms. We hypothesize that Cav-1 expression may enhance inflammatory signaling while at the same time supporting the physical properties of the BRB. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  4. Blood-brain barrier disruption by continuous-wave radio frequency radiation.

    Science.gov (United States)

    Sirav, Bahriye; Seyhan, Nesrin

    2009-01-01

    The increasing use of cellular phones and the increasing number of associated base stations are becoming a widespread source of non ionizing electromagnetic radiation. Some biological effects are likely to occur even at low-level EM fields. This study was designed to investigate the effects of 900 and 1,800 MHz Continuous Wave Radio Frequency Radiation (CW RFR) on the permeability of Blood Brain Barrier (BBB) of rats. Results have shown that 20 min RFR exposure of 900 and 1,800 MHz induces an effect and increases the permeability of BBB of male rats. There was no change in female rats. The scientific evidence on RFR safety or harm remains inconclusive. More studies are needed to demonstrate the effects of RFR on the permeability of BBB and the mechanisms of that breakdown.

  5. Purinergic receptor P2RY12-dependent microglial closure of the injured blood-brain barrier

    DEFF Research Database (Denmark)

    Lou, Nanhong; Takano, Takahiro; Pei, Yong

    2016-01-01

    Microglia are integral functional elements of the central nervous system, but the contribution of these cells to the structural integrity of the neurovascular unit has not hitherto been assessed. We show here that following blood-brain barrier (BBB) breakdown, P2RY12 (purinergic receptor P2Y, G......-protein coupled, 12)-mediated chemotaxis of microglia processes is required for the rapid closure of the BBB. Mice treated with the P2RY12 inhibitor clopidogrel, as well as those in which P2RY12 was genetically ablated, exhibited significantly diminished movement of juxtavascular microglial processes and failed...... and cerebrovascular disease. As such, these observations suggest the need for caution in the postincident continuation of P2RY12-targeted platelet inhibition....

  6. Approaches to transport therapeutic drugs across the blood-brain barrier to treat brain diseases.

    Science.gov (United States)

    Gabathuler, Reinhard

    2010-01-01

    The central nervous system is protected by barriers which control the entry of compounds into the brain, thereby regulating brain homeostasis. The blood-brain barrier, formed by the endothelial cells of the brain capillaries, restricts access to brain cells of blood-borne compounds and facilitates nutrients essential for normal metabolism to reach brain cells. This very tight regulation of the brain homeostasis results in the inability of some small and large therapeutic compounds to cross the blood-brain barrier (BBB). Therefore, various strategies are being developed to enhance the amount and concentration of therapeutic compounds in the brain. In this review, we will address the different approaches used to increase the transport of therapeutics from blood into the brain parenchyma. We will mainly concentrate on the physiologic approach which takes advantage of specific receptors already expressed on the capillary endothelial cells forming the BBB and necessary for the survival of brain cells. Among all the approaches used for increasing brain delivery of therapeutics, the most accepted method is the use of the physiological approach which takes advantage of the transcytosis capacity of specific receptors expressed at the BBB. The low density lipoprotein receptor related protein (LRP) is the most adapted for such use with the engineered peptide compound (EPiC) platform incorporating the Angiopep peptide in new therapeutics the most advanced with promising data in the clinic.

  7. Endothelial progenitor cells physiology and metabolic plasticity in brain angiogenesis and blood-brain barrier modeling

    Directory of Open Access Journals (Sweden)

    Natalia Malinovskaya

    2016-12-01

    Full Text Available Currently, there is a considerable interest to the assessment of blood-brain barrier (BBB development as a part of cerebral angiogenesis developmental program. Embryonic and adult angiogenesis in the brain is governed by the coordinated activity of endothelial progenitor cells, brain microvascular endothelial cells, and non-endothelial cells contributing to the establishment of the BBB (pericytes, astrocytes, neurons. Metabolic and functional plasticity of endothelial progenitor cells controls their timely recruitment, precise homing to the brain microvessels, and efficient support of brain angiogenesis. Deciphering endothelial progenitor cells physiology would provide novel engineering approaches to establish adequate microfluidically-supported BBB models and brain microphysiological systems for translational studies.

  8. Galectin-1 suppresses methamphetamine induced neuroinflammation in human brain microvascular endothelial cells: Neuroprotective role in maintaining blood brain barrier integrity.

    Science.gov (United States)

    Parikh, Neil U; Aalinkeel, R; Reynolds, J L; Nair, B B; Sykes, D E; Mammen, M J; Schwartz, S A; Mahajan, S D

    2015-10-22

    Methamphetamine (Meth) abuse can lead to the breakdown of the blood-brain barrier (BBB) integrity leading to compromised CNS function. The role of Galectins in the angiogenesis process in tumor-associated endothelial cells (EC) is well established; however no data are available on the expression of Galectins in normal human brain microvascular endothelial cells and their potential role in maintaining BBB integrity. We evaluated the basal gene/protein expression levels of Galectin-1, -3 and -9 in normal primary human brain microvascular endothelial cells (BMVEC) that constitute the BBB and examined whether Meth altered Galectin expression in these cells, and if Galectin-1 treatment impacted the integrity of an in-vitro BBB. Our results showed that BMVEC expressed significantly higher levels of Galectin-1 as compared to Galectin-3 and -9. Meth treatment increased Galectin-1 expression in BMVEC. Meth induced decrease in TJ proteins ZO-1, Claudin-3 and adhesion molecule ICAM-1 was reversed by Galectin-1. Our data suggests that Galectin-1 is involved in BBB remodeling and can increase levels of TJ proteins ZO-1 and Claudin-3 and adhesion molecule ICAM-1 which helps maintain BBB tightness thus playing a neuroprotective role. Galectin-1 is thus an important regulator of immune balance from neurodegeneration to neuroprotection, which makes it an important therapeutic agent/target in the treatment of drug addiction and other neurological conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Brain metastatic cancer cells release microRNA-181c-containing extracellular vesicles capable of destructing blood-brain barrier.

    Science.gov (United States)

    Tominaga, Naoomi; Kosaka, Nobuyoshi; Ono, Makiko; Katsuda, Takeshi; Yoshioka, Yusuke; Tamura, Kenji; Lötvall, Jan; Nakagama, Hitoshi; Ochiya, Takahiro

    2015-04-01

    Brain metastasis is an important cause of mortality in breast cancer patients. A key event during brain metastasis is the migration of cancer cells through blood-brain barrier (BBB). However, the molecular mechanism behind the passage through this natural barrier remains unclear. Here we show that cancer-derived extracellular vesicles (EVs), mediators of cell-cell communication via delivery of proteins and microRNAs (miRNAs), trigger the breakdown of BBB. Importantly, miR-181c promotes the destruction of BBB through the abnormal localization of actin via the downregulation of its target gene, PDPK1. PDPK1 degradation by miR-181c leads to the downregulation of phosphorylated cofilin and the resultant activated cofilin-induced modulation of actin dynamics. Furthermore, we demonstrate that systemic injection of brain metastatic cancer cell-derived EVs promoted brain metastasis of breast cancer cell lines and are preferentially incorporated into the brain in vivo. Taken together, these results indicate a novel mechanism of brain metastasis mediated by EVs that triggers the destruction of BBB.

  10. Brain metastatic cancer cells release microRNA-181c-containing extracellular vesicles capable of destructing blood–brain barrier

    Science.gov (United States)

    Tominaga, Naoomi; Kosaka, Nobuyoshi; Ono, Makiko; Katsuda, Takeshi; Yoshioka, Yusuke; Tamura, Kenji; Lötvall, Jan; Nakagama, Hitoshi; Ochiya, Takahiro

    2015-01-01

    Brain metastasis is an important cause of mortality in breast cancer patients. A key event during brain metastasis is the migration of cancer cells through blood–brain barrier (BBB). However, the molecular mechanism behind the passage through this natural barrier remains unclear. Here we show that cancer-derived extracellular vesicles (EVs), mediators of cell–cell communication via delivery of proteins and microRNAs (miRNAs), trigger the breakdown of BBB. Importantly, miR-181c promotes the destruction of BBB through the abnormal localization of actin via the downregulation of its target gene, PDPK1. PDPK1 degradation by miR-181c leads to the downregulation of phosphorylated cofilin and the resultant activated cofilin-induced modulation of actin dynamics. Furthermore, we demonstrate that systemic injection of brain metastatic cancer cell-derived EVs promoted brain metastasis of breast cancer cell lines and are preferentially incorporated into the brain in vivo. Taken together, these results indicate a novel mechanism of brain metastasis mediated by EVs that triggers the destruction of BBB. PMID:25828099

  11. The blood brain barrier: Insights from development and ageing.

    Science.gov (United States)

    Delaney, Conor; Campbell, Matthew

    2017-10-02

    The blood brain barrier is a necessity for cerebral homeostasis and response to environmental insult, thus loss in functionality with age creates opportunities for disease to arise in the aged brain. Understanding how the barrier is developed and maintained throughout the earlier years of adult life can identify key processes that may have beneficial applications in the restoration of the aged brain. With an unprecedented increasing global aged population, the prevention and treatment of age-associated disorders has become a rising healthcare priority demanding novel approaches for the development of therapeutic strategies. The aging cardiovascular system has long been recognised to be a major factor in age-associated diseases such as stroke, atherosclerosis and cardiac arrest. Changes in the highly specialised cerebral vasculature may similarly drive neurodegenerative and neuropsychiatric disease.

  12. Estrogen protects the blood-brain barrier from inflammation-induced disruption and increased lymphocyte trafficking.

    Science.gov (United States)

    Maggioli, E; McArthur, S; Mauro, C; Kieswich, J; Kusters, D H M; Reutelingsperger, C P M; Yaqoob, M; Solito, E

    2016-01-01

    Sex differences have been widely reported in neuroinflammatory disorders, focusing on the contributory role of estrogen. The microvascular endothelium of the brain is a critical component of the blood-brain barrier (BBB) and it is recognized as a major interface for communication between the periphery and the brain. As such, the cerebral capillary endothelium represents an important target for the peripheral estrogen neuroprotective functions, leading us to hypothesize that estrogen can limit BBB breakdown following the onset of peripheral inflammation. Comparison of male and female murine responses to peripheral LPS challenge revealed a short-term inflammation-induced deficit in BBB integrity in males that was not apparent in young females, but was notable in older, reproductively senescent females. Importantly, ovariectomy and hence estrogen loss recapitulated an aged phenotype in young females, which was reversible upon estradiol replacement. Using a well-established model of human cerebrovascular endothelial cells we investigated the effects of estradiol upon key barrier features, namely paracellular permeability, transendothelial electrical resistance, tight junction integrity and lymphocyte transmigration under basal and inflammatory conditions, modeled by treatment with TNFα and IFNγ. In all cases estradiol prevented inflammation-induced defects in barrier function, action mediated in large part through up-regulation of the central coordinator of tight junction integrity, annexin A1. The key role of this protein was then further confirmed in studies of human or murine annexin A1 genetic ablation models. Together, our data provide novel mechanisms for the protective effects of estrogen, and enhance our understanding of the beneficial role it plays in neurovascular/neuroimmune disease. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  13. Gliomas and the vascular fragility of the blood brain barrier

    Directory of Open Access Journals (Sweden)

    Luiz Gustavo eDubois

    2014-12-01

    Full Text Available Astrocytes, members of the glial family, interact through the exchange of soluble factors or by directly contacting neurons and other brain cells, such as microglia and endothelial cells. Astrocytic projections interact with vessels and act as additional elements of the Blood Brain Barrier (BBB. By mechanisms not fully understood, astrocytes can undergo oncogenic transformation and give rise to gliomas. The tumors take advantage of the BBB to ensure survival and continuous growth. A glioma can develop into a very aggressive tumor, the glioblastoma (GBM, characterized by a highly heterogeneous cell population (including tumor stem cells, extensive proliferation and migration. Nevertheless, gliomas can also give rise to slow growing tumors and in both cases, the afflux of blood, via BBB is crucial. Glioma cells migrate to different regions of the brain guided by the extension of blood vessels, colonizing the healthy adjacent tissue. In the clinical context, GBM can lead to tumor-derived seizures, which represent a challenge to patients and clinicians, since drugs used for its treatment must be able to cross the BBB. Uncontrolled and fast growth also leads to the disruption of the chimeric and fragile vessels in the tumor mass resulting in peritumoral edema. Although hormonal therapy is currently used to control the edema, it is not always efficient. In this review we comment the points cited above, considering the importance of the blood brain barrier and the concerns that arise when this barrier is affected.

  14. Intestinal barrier function and the brain-gut axis.

    Science.gov (United States)

    Alonso, Carmen; Vicario, María; Pigrau, Marc; Lobo, Beatriz; Santos, Javier

    2014-01-01

    The luminal-mucosal interface of the intestinal tract is the first relevant location where microorganism-derived antigens and all other potentially immunogenic particles face the scrutiny of the powerful mammalian immune system. Upon regular functioning conditions, the intestinal barrier is able to effectively prevent most environmental and external antigens to interact openly with the numerous and versatile elements that compose the mucosal-associated immune system. This evolutionary super system is capable of processing an astonishing amount of antigens and non-immunogenic particles, approximately 100 tons in one individual lifetime, only considering food-derived components. Most important, to develop oral tolerance and proper active immune responses needed to prevent disease and inflammation, this giant immunogenic load has to be managed in a way that physiological inflammatory balance is constantly preserved. Adequate functioning of the intestinal barrier involves local and distant regulatory networks integrating the so-called brain-gut axis. Along this complex axis both brain and gut structures participate in the processing and execution of response signals to external and internal changes coming from the digestive tract, using multidirectional pathways to communicate. Dysfunction of brain-gut axis facilitates malfunctioning of the intestinal barrier, and vice versa, increasing the risk of uncontrolled immunological reactions that may trigger mucosal and brain low-grade inflammation, a putative first step to the initiation of more permanent gut disorders. In this chapter, we describe the structure, function and interactions of intestinal barrier, microbiota and brain-gut axis in both healthy and pathological conditions.

  15. Vascular Pathology and Blood-Brain Barrier Disruption in Cognitive and Psychiatric Complications of Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Yonatan Serlin

    2011-01-01

    Full Text Available Vascular pathology is recognized as a principle insult in type 2 diabetes mellitus (T2DM. Co-morbidities such as structural brain abnormalities, cognitive, learning and memory deficits are also prevailing in T2DM patients. We previously suggested that microvascular pathologies involving blood-brain barrier (BBB breakdown results in leakage of serum-derived components into the brain parenchyma, leading to neuronal dysfunction manifested as psychiatric illnesses. The current postulate focuses on the molecular mechanisms controlling BBB permeability in T2DM, as key contributors to the pathogenesis of mental disorders in patients. Revealing the mechanisms underlying BBB dysfunction and inflammatory response in T2DM and their role in metabolic disturbances, abnormal neurovascular coupling and neuronal plasticity, would contribute to the understanding of the mechanisms underlying psychopathologies in diabetic patients. Establishing this link would offer new targets for future therapeutic interventions.

  16. Migration of African trypanosomes across the blood-brain barrier.

    Science.gov (United States)

    Masocha, Willias; Rottenberg, Martin E; Kristensson, Krister

    2007-09-10

    Subspecies of the extracellular parasite, Trypanosoma brucei, which are spread by the tsetse fly in sub-Saharan Africa, cause in humans Sleeping Sickness. In experimental rodent models the parasite can at a certain stage of disease pass through the blood-brain barrier across or between the endothelial cells and the vessel basement membranes. The laminin composition of the basement membranes determines whether they are permissive to parasite penetration. One cytokine, interferon-gamma, plays an important role in regulating the trypanosome trafficking into the brain. Treatment strategies aim at developing drugs that can impede penetration of trypanosomes into the brain and/or that can eliminate trypanosomes once they are inside the brain parenchyma, but have lower toxicity than the ones presently in use.

  17. Blood-Brain Barrier Imaging in Human Neuropathologies

    Science.gov (United States)

    Veksler, Ronel; Shelef, Ilan; Friedman, Alon

    2014-01-01

    The blood–brain barrier (BBB) is essential for normal function of the brain, and its role in many brain pathologies has been the focus of numerous studies during the last decades. Dysfunction of the BBB is not only being shown in numerous brain diseases, but animal studies have indicated that it plays a direct key role in the genesis of neurovascular dysfunction and associated neurodegeneration. As such evidence accumulates, the need for robust and clinically applicable methods for minimally invasive assessment of BBB integrity is becoming urgent. This review provides an introduction to BBB imaging methods in the clinical scenario. First, imaging modalities are reviewed, with a focus on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). We then proceed to review image analysis methods, including quantitative and semi-quantitative methods. The advantages and limitations of each approach are discussed, and future directions and questions are highlighted. PMID:25453223

  18. Targeted liposomes for drug delivery across the blood-brain barrier

    OpenAIRE

    van Rooy, I.

    2011-01-01

    Our brain is protected by the blood-brain barrier (BBB). This barrier is formed by specialized endothelial cells of the brain vasculature and prevents toxic substances from entering the brain. The downside of this barrier is that many drugs that have been developed to cure brain diseases cannot cross this barrier and do not reach the brain in therapeutic concentrations. An innovative way to help these drugs to reach the brain is by encapsulating them into nanoparticles (e.g. liposomes). A tar...

  19. Translocating the blood-brain barrier using electrostatics

    Directory of Open Access Journals (Sweden)

    Marta eRibeiro

    2012-10-01

    Full Text Available Mammalian cell membranes regulate homeostasis, protein activity and cell signaling. The charge at the membrane surface has been correlated with these key events.Although mammalian cells are known to be slightly anionic, quantitative information on the membrane charge and the importance of electrostatic interactions in pharmacokinetics and pharmacodynamics remain elusive. Recently, we reported for the first time that brain endothelial cells are more negatively charged than human umbilical cord cells, using zeta-potential dynamic light scattering. Here, we hypothesize that anionicity is a key feature of the blood-brain barrier and contributes to select which compounds cross into the brain. For the sake of comparison, we also studied the membrane surface charge of blood components – red blood cells, platelets and peripheral blood mononuclear cells. To further quantitatively correlate the negative zeta-potential values with membrane charge density, model membranes with different percentages of anionic lipids were also evaluated.From all the cells tested, brain cell membranes are the most anionic and the ones having their lipids mostly exposed, which explains why lipophilic cationic compounds are more prone to cross the blood-brain barrier.

  20. Neuro-inflammation, blood-brain barrier, seizures and autism

    Directory of Open Access Journals (Sweden)

    Theoharides Theoharis C

    2011-11-01

    Full Text Available Abstract Many children with Autism Spectrum Diseases (ASD present with seizure activity, but the pathogenesis is not understood. Recent evidence indicates that neuro-inflammation could contribute to seizures. We hypothesize that brain mast cell activation due to allergic, environmental and/or stress triggers could lead to focal disruption of the blood-brain barrier and neuro-inflammation, thus contributing to the development of seizures. Treating neuro-inflammation may be useful when anti-seizure medications are ineffective.

  1. The vasopressin receptor of the blood-brain barrier in the rat hippocampus is linked to calcium signalling

    DEFF Research Database (Denmark)

    Hess, J.; Jensen, Claus V.; Diemer, Nils Henrik

    1991-01-01

    Neuropathology, vasopressin receptor, VI subtype, blood-brain barrier, cerebral endothelium, hippocampus, Fura-2......Neuropathology, vasopressin receptor, VI subtype, blood-brain barrier, cerebral endothelium, hippocampus, Fura-2...

  2. The role of the blood-brain barrier in hypertension.

    Science.gov (United States)

    Setiadi, Anthony; Korim, Willian S; Elsaafien, Khalid; Yao, Song T

    2017-10-06

    What is the topic of this review? This review highlights the importance of the blood-brain barrier in the context of diseases involving autonomic dysfunction, such as hypertension and heart failure. What advances does it highlight? It highlights the potential role of pro-inflammatory cytokines, leucocytes and angiotensin II in disrupting the blood-brain barrier in cardiovascular diseases. Advances are highlighted in our understanding of neurovascular unit cells, astrocytes and microglia, with a specific emphasis on their pathogenic roles within the brain. The blood-brain barrier (BBB) is a crucial barrier that provides both metabolic and physical protection to an immune-privileged CNS. The BBB has been shown to be disrupted in hypertension. This review addresses the importance of the BBB in maintaining homeostasis in the context of diseases related to autonomic dysfunction, such as hypertension. We highlight the potentially important roles of the immune system and neurovascular unit in the maintenance of the BBB, whereby dysregulation may lead to autonomic dysfunction in diseases such as heart failure and hypertension. Circulating leucocytes and factors such as angiotensin II and pro-inflammatory cytokines are thought ultimately to downregulate endothelial tight junction proteins that are a crucial component of the BBB. The specific mechanisms underlying BBB disruption and their role in contributing to autonomic dysfunction are not yet fully understood but are a growing area of interest. A greater understanding of these systems and advances in our knowledge of the molecular mechanisms causing BBB disruption will allow for the development of future therapeutic interventions in the treatment of autonomic imbalance associated with diseases such as heart failure and hypertension. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

  3. Blood-brain barrier transcytosis of insulin in developing rabbits.

    Science.gov (United States)

    Duffy, K R; Pardridge, W M

    1987-09-08

    Previous studies with isolated brain microvessels have suggested that blood insulin is selectively transported through the brain capillary, i.e. the blood-brain barrier (BBB), by receptor-mediated transcytosis. The purpose of the present study is to demonstrate in vivo the uptake of circulating 125I-insulin by brain using thaw-mount autoradiography. However, metabolism of systemic 125I-insulin to 125I-tyrosine would allow for brain uptake of 125I-tyrosine and this would preclude interpretation of the autoradiogram. Therefore, the present studies were performed in developing rabbits, since plasma protein degradation of peptides is greatly reduced in developing animals. 125I-insulin was infused via the carotid artery at a rate of 0.25 ml/min for 1, 5, or 10 min, and the mean brain uptake, relative to a [3H]albumin reference, was 99.3 +/- 5.5%, 110.1 +/- 4.3%, and 143.6 +/- 7.9%, respectively. This uptake was saturable by simultaneously infusing unlabeled insulin. Thaw-mount autoradiography of rabbit brain after a 10-min infusion of 125I-insulin revealed silver grains in the pericapillary space and well within the brain parenchyma. HPLC analysis of acid-ethanol extracts of rabbit blood after a 10-min infusion showed virtually all of the 125I-radioactivity co-migrated with a known insulin standard on a reverse-phase column, indicating minimal degradation of infused 125I-insulin. HPLC analysis of brain radioactivity showed the major peak co-migrated with 125I-insulin and this peak was precipitated by an anti-insulin antiserum. The correlation of the transport data, the autoradiography, and the HPLC analysis support the model that brain insulin originates from blood via receptor-mediated transport of the peptide at the BBB.

  4. Barrier Functionality of Porcine and Bovine Brain Capillary Endothelial Cells

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    Ailar Nakhlband

    2011-09-01

    Full Text Available Introduction: To date, isolated cell based blood-brain barrier (BBB models have been widely used for brain drug delivery and targeting, due to their relatively proper bioelectrical and permeability properties. However, primary cultures of brain capillary endothelial cells (BCECs isolated from different species vary in terms of bioelectrical and permeability properties. Methods: To pursue this, in the current investigation, primary porcine and bovine BCECs (PBCECs and BBCECs, respectively were isolated and used as an in vitro BBB model. The bioelectrical and permeability properties were assessed in BCECs co-cultured with C6 cells with/without hydrocortisone (550 nM. The bioelectrical properties were further validated by means of the permeability coefficients of transcellular and paracellular markers. Results: The primary PBCECs displayed significantly higher trans-endothelial electrical resistance (~900 W.cm2 than BBCECs (~700 W.cm2 - both co-cultured with C6 cells in presence of hydrocortisone. Permeability coefficients of propranolol/diazepam and mannitol/sucrose in PBCECs were ~21 and ~2 (×10-6 cm.sec-1, where these values for BBCECs were ~25 and ~5 (×10-6 cm.sec-1. Conclusion: Upon our bioelectrical and permeability findings, both models display discriminative barrier functionality but porcine BCECs seem to provide a better platform than bovine BCECs for drug screening and brain targeting.

  5. Nanotechnologies: a strategy to overcome blood-brain barrier.

    Science.gov (United States)

    De Rosa, Giuseppe; Salzano, Giuseppina; Caraglia, Michele; Abbruzzese, Alberto

    2012-01-01

    The possibility to treat central nervous system (CNS) disorders is strongly limited by the poor access of many therapeutic agent to the target tissues. This is mainly due to the presence of the blood-brain barrier (BBB), formed by a complex interplay of endothelial cells, astrocyte and pericytes, through which only selected molecules can passively diffuse to reach CNS. Drug pharmacokinetics and biodistribution can be changed by using nanotechnology, in order to improve drug accumulation into the action site and to limit the drug release in the healthy tissues. When the CNS diseases are characterised by BBB altered permeability, an enhanced drug delivery into the brain can be achieved by using nanocarriers. Moreover, modification of nanocarrier surface with specific endogenous or exogenous ligands can promote enhanced BBB crossing, also in case of unaltered endothelium. This review summarizes the most meaningful advances in the field of nanotechnology for brain delivery of therapeutics.

  6. How Glutamate Is Managed by the Blood–Brain Barrier

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    Richard A. Hawkins

    2016-10-01

    Full Text Available A facilitative transport system exists on the blood–brain barrier (BBB that has been tacitly assumed to be a path for glutamate entry to the brain. However, glutamate is a non-essential amino acid whose brain content is much greater than plasma, and studies in vivo show that glutamate does not enter the brain in appreciable quantities except in those small regions with fenestrated capillaries (circumventricular organs. The situation became understandable when luminal (blood facing and abluminal (brain facing membranes were isolated and studied separately. Facilitative transport of glutamate and glutamine exists only on the luminal membranes, whereas Na+-dependent transport systems for glutamate, glutamine, and some other amino acids are present only on the abluminal membrane. The Na+-dependent cotransporters of the abluminal membrane are in a position to actively transport amino acids from the extracellular fluid (ECF into the endothelial cells of the BBB. These powerful secondary active transporters couple with the energy of the Na+-gradient to move glutamate and glutamine into endothelial cells, whereupon glutamate can exit to the blood on the luminal facilitative glutamate transporter. Glutamine may also exit the brain via separate facilitative transport system that exists on the luminal membranes, or glutamine can be hydrolyzed to glutamate within the BBB, thereby releasing ammonia that is freely diffusible. The γ-glutamyl cycle participates indirectly by producing oxoproline (pyroglutamate, which stimulates almost all secondary active transporters yet discovered in the abluminal membranes of the BBB.

  7. Blood-brain barrier permeability and brain uptake mechanism of kainic Acid and dihydrokainic Acid

    DEFF Research Database (Denmark)

    Gynther, Mikko; Petsalo, Aleksanteri; Hansen, Steen Honoré

    2015-01-01

    tools in various in vivo central nervous system disease models in rodents, as well as being templates in the design of novel ligands affecting the glutamatergic system. Both molecules are highly polar but yet capable of crossing the blood-brain barrier (BBB). We used an in situ rat brain perfusion...... technique to determine the brain uptake mechanism and permeability across the BBB. To determine KA and DHK concentrations in the rat brain, simple and rapid sample preparation and liquid chromatography mass spectrometer methods were developed. According to our results the BBB permeability of KA and DHK...... is low, 0.25 × 10(-6) and 0.28 × 10(-6) cm/s for KA and DHK, respectively. In addition, the brain uptake is mediated by passive diffusion, and not by active transport. Furthermore, the non-specific plasma and brain protein binding of KA and DHK was determined to be low, which means that the unbound drug...

  8. Impacts of Blood-Brain Barrier in Drug Delivery and Targeting of Brain Tumors

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    Yadollah Omidi

    2012-02-01

    Full Text Available Introduction: Entry of blood circulating agents into the brain is highly selectively controlled by specific transport machineries at the blood brain barrier (BBB, whose excellent barrier restrictiveness make brain drug delivery and targeting very challenging. Methods: Essential information on BBB cellular microenvironment were reviewed and discussed towards impacts of BBB on brain drug delivery and targeting. Results: Brain capillary endothelial cells (BCECs form unique biological structure and architecture in association with astrocytes and pericytes, in which microenvironment the BCECs express restrictive tight junctional complexes that block the paracellular inward/outward traverse of biomolecules/compounds. These cells selectively/specifically control the transportation process through carrier and/or receptor mediated transport machineries that can also be exploited for the delivery of pharmaceuticals into the brain. Intelligent molecular therapies should be designed using such transport machineries for the efficient delivery of designated drugs into the brain. For better clinical outcomes, these smart pharmaceuticals should be engineered as seamless nanosystems to provide simultaneous imaging and therapy (multimodal theranostics. Conclusion: The exceptional functional presence of BBB selectively controls inward and outward transportation mechanisms, thus advanced smart multifunctional nanomedicines are needed for the effective brain drug delivery and targeting. Fully understanding the biofunctions of BBB appears to be a central step for engineering of intelligent seamless therapeutics consisting of homing device for targeting, imaging moiety for detecting, and stimuli responsive device for on-demand liberation of therapeutic agent.

  9. Involvement of the Blood-Brain Barrier in Metabolic Regulation.

    Science.gov (United States)

    Kastin, Abba J; Pan, Weihong

    2016-01-01

    Pertinent to pandemic obesity, the discovery of endogenous peptides that affect the ingestion of food has led to the question of how these ingestive peptides exert their actions in the brain. Whereas peripheral sources provide a ready reserve, the availability of ingestive peptides to their central nervous system targets can be regulated by the blood-brain barrier (BBB). Some of the peptides/polypeptides are transported by saturable mechanisms from blood to brain. Examples include leptin, insulin, mahogany, and pancreatic polypeptide. Some enter the brain by passive diffusion, such as neuropeptide Y, orexin A, cocaine- and amphetamine-regulated transcript, cyclo His-Pro, and amylin. Some others may have essentially no penetration of the BBB; this class includes agouti-related protein, melanin-concentrating hormone, and urocortin. The regulatory function of the BBB can be seen in various physiological states. Hyperglycemia may upregulate transport systems for leptin, urocortin, and galanin-like peptide, whereas fasting can down-regulate those for leptin and galanin-like peptide. Thus, the BBB plays a dynamic role in modulating the passage of ingestive peptides from blood to brain.

  10. Tesmilifene modifies brain endothelial functions and opens the blood-brain/blood-glioma barrier.

    Science.gov (United States)

    Walter, Fruzsina R; Veszelka, Szilvia; Pásztói, Mária; Péterfi, Zoltán A; Tóth, András; Rákhely, Gábor; Cervenak, László; Ábrahám, Csongor S; Deli, Mária A

    2015-09-01

    Tesmilifene, a tamoxifen analog with antihistamine action, has chemopotentiating properties in experimental and clinical cancer studies. In our previous works, tesmilifene increased the permeability of the blood-brain barrier (BBB) in animal and culture models. Our aim was to investigate the effects of tesmilifene on brain microvessel permeability in the rat RG2 glioma model and to reveal its mode of action in brain endothelial cells. Tesmilifene significantly increased fluorescein extravasation in the glioma. Short-term treatment with tesmilifene reduced the resistance and increased the permeability for marker molecules in a rat triple co-culture BBB model. Tesmilifene also affected the barrier integrity in brain endothelial cells co-cultured with RG2 glioblastoma cells. Tesmilifene inhibited the activity of P-glycoprotein and multidrug resistance-associated protein-1 efflux pumps and down-regulated the mRNA expression of tight junction proteins, efflux pumps, solute carriers, and metabolic enzymes important for BBB functions. Among the possible signaling pathways that regulate BBB permeability, tesmilifene activated the early nuclear translocation of NFκB. The MAPK/ERK and PI3K/Akt kinase pathways were also involved. We demonstrate for the first time that tesmilifene increases permeability marker molecule extravasation in glioma and inhibits efflux pump activity in brain endothelial cells, which may have therapeutic relevance. Tesmilifene, a chemopotentiator in experimental and clinical cancer studies increases vascular permeability in RG2 glioma in rats and permeability for marker molecules in a culture model of the blood-brain barrier. Tesmilifene inhibits the activity of efflux pumps and down-regulates the mRNA expression of tight junction proteins, transporters, and metabolic enzymes important for the blood-brain barrier functions, which may have therapeutic relevance. © 2015 International Society for Neurochemistry.

  11. Physical insights into the blood-brain barrier translocation mechanisms

    Science.gov (United States)

    Theodorakis, Panagiotis E.; Müller, Erich A.; Craster, Richard V.; Matar, Omar K.

    2017-08-01

    The number of individuals suffering from diseases of the central nervous system (CNS) is growing with an aging population. While candidate drugs for many of these diseases are available, most of these pharmaceutical agents cannot reach the brain rendering most of the drug therapies that target the CNS inefficient. The reason is the blood-brain barrier (BBB), a complex and dynamic interface that controls the influx and efflux of substances through a number of different translocation mechanisms. Here, we present these mechanisms providing, also, the necessary background related to the morphology and various characteristics of the BBB. Moreover, we discuss various numerical and simulation approaches used to study the BBB, and possible future directions based on multi-scale methods. We anticipate that this review will motivate multi-disciplinary research on the BBB aiming at the design of effective drug therapies.

  12. The NR1 subunit of NMDA receptor regulates monocyte transmigration through the brain endothelial cell barrier

    NARCIS (Netherlands)

    Reijerkerk, A.; Kooij, G.; van der Pol, S.M.A.; Leyen, T.A.; Lakeman, K.; Van Het Hof, B; Vivien, D.; de Vries, H.E.

    2010-01-01

    Normal neuronal functioning is dependent on the blood-brain barrier. This barrier is confined to specialized brain endothelial cells lining the inner vessel wall, and tightly controlling transport of nutrients, efflux of potentially harmful molecules and entry of immune cells into the brain. Loss of

  13. Perlecan and the Blood-Brain Barrier: Beneficial Proteolysis?

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    Jill eRoberts

    2012-08-01

    Full Text Available The cerebral microvasculature is important for maintaining brain homeostasis. This is achieved via the blood-brain barrier (BBB, composed of endothelial cells with specialized tight junctions, astrocytes and a basement membrane. Prominent components of the basement membrane extracellular matrix (ECM include fibronectin, laminin, collagen IV and perlecan, all of which regulate cellular processes via signal transduction through various cell membrane bound ECM receptors. Expression and proteolysis of these ECM components can be rapidly altered during pathological states of the central nervous system. In particular, proteolysis of perlecan, a heparan sulfate proteoglycan, occurs within hours following ischemia induced by experimental stroke. Proteolysis of ECM components following stroke results in the degradation of the basement membrane and further disruption of the BBB. While it is clear that such proteolysis has negative consequences for the BBB, we propose that it also may lead to generation of ECM protein fragments, including the C-terminal domain V (DV of perlecan, that potentially have a positive influence on other aspects of CNS health. Indeed, perlecan DV has been shown to be persistently generated after stroke and beneficial as a neuroprotective molecule and promoter of post-stroke brain repair. This mini-review will discuss beneficial roles of perlecan protein fragment generation within the brain during stroke.

  14. Sorting Tubules Regulate Blood-Brain Barrier Transcytosis

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    Roberto Villaseñor

    2017-12-01

    Full Text Available Transcytosis across the blood-brain barrier (BBB regulates key processes of the brain, but the intracellular sorting mechanisms that determine successful receptor-mediated transcytosis in brain endothelial cells (BECs remain unidentified. Here, we used Transferrin receptor-based Brain Shuttle constructs to investigate intracellular transport in BECs, and we uncovered a pathway for the regulation of receptor-mediated transcytosis. By combining live-cell imaging and mathematical modeling in vitro with super-resolution microscopy of the BBB, we show that intracellular tubules promote transcytosis across the BBB. A monovalent construct (sFab sorted for transcytosis was localized to intracellular tubules, whereas a bivalent construct (dFab sorted for degradation formed clusters with impaired transport along tubules. Manipulating tubule biogenesis by overexpressing the small GTPase Rab17 increased dFab transport into tubules and induced its transcytosis in BECs. We propose that sorting tubules regulate transcytosis in BECs and may be a general mechanism for receptor-mediated transport across the BBB.

  15. Sleep restriction impairs blood-brain barrier function.

    Science.gov (United States)

    He, Junyun; Hsuchou, Hung; He, Yi; Kastin, Abba J; Wang, Yuping; Pan, Weihong

    2014-10-29

    The blood-brain barrier (BBB) is a large regulatory and exchange interface between the brain and peripheral circulation. We propose that changes of the BBB contribute to many pathophysiological processes in the brain of subjects with chronic sleep restriction (CSR). To achieve CSR that mimics a common pattern of human sleep loss, we quantified a new procedure of sleep disruption in mice by a week of consecutive sleep recording. We then tested the hypothesis that CSR compromises microvascular function. CSR not only diminished endothelial and inducible nitric oxide synthase, endothelin1, and glucose transporter expression in cerebral microvessels of the BBB, but it also decreased 2-deoxy-glucose uptake by the brain. The expression of several tight junction proteins also was decreased, whereas the level of cyclooxygenase-2 increased. This coincided with an increase of paracellular permeability of the BBB to the small tracers sodium fluorescein and biotin. CSR for 6 d was sufficient to impair BBB structure and function, although the increase of paracellular permeability returned to baseline after 24 h of recovery sleep. This merits attention not only in neuroscience research but also in public health policy and clinical practice. Copyright © 2014 the authors 0270-6474/14/3414697-10$15.00/0.

  16. Magnetic Nanoparticles Cross the Blood-Brain Barrier: When Physics Rises to a Challenge

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    Maria Antònia Busquets

    2015-12-01

    Full Text Available The blood-brain barrier is a physical and physiological barrier that protects the brain from toxic substances within the bloodstream and helps maintain brain homeostasis. It also represents the main obstacle in the treatment of many diseases of the central nervous system. Among the different approaches employed to overcome this barrier, the use of nanoparticles as a tool to enhance delivery of therapeutic molecules to the brain is particularly promising. There is special interest in the use of magnetic nanoparticles, as their physical characteristics endow them with additional potentially useful properties. Following systemic administration, a magnetic field applied externally can mediate the capacity of magnetic nanoparticles to permeate the blood-brain barrier. Meanwhile, thermal energy released by magnetic nanoparticles under the influence of radiofrequency radiation can modulate blood-brain barrier integrity, increasing its permeability. In this review, we present the strategies that use magnetic nanoparticles, specifically iron oxide nanoparticles, to enhance drug delivery to the brain.

  17. Blood-brain barrier and cerebral blood flow: Age differences in hemorrhagic stroke

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    Semyachkina-Glushkovskaya Oxana

    2015-11-01

    Full Text Available Neonatal stroke is similar to the stroke that occurs in adults and produces a significant morbidity and long-term neurologic and cognitive deficits. There are important differences in the factors, clinical events and outcomes associated with the stroke in infants and adults. However, mechanisms underlying age differences in the stroke development remain largely unknown. Therefore, treatment guidelines for neonatal stroke must extrapolate from the adult data that is often not suitable for children. The new information about differences between neonatal and adult stroke is essential for identification of significant areas for future treatment and effective prevention of neonatal stroke. Here, we studied the development of stress-induced hemorrhagic stroke and possible mechanisms underlying these processes in newborn and adult rats. Using histological methods and magnetic resonance imaging, we found age differences in the type of intracranial hemorrhages. Newborn rats demonstrated small superficial bleedings in the cortex while adult rats had more severe deep bleedings in the cerebellum. Using Doppler optical coherent tomography, we found higher stress-reactivity of the sagittal sinus to deleterious effects of stress in newborn vs. adult rats suggesting that the cerebral veins are more vulnerable to negative stress factors in neonatal vs. adult brain in rats. However, adult but not newborn rats demonstrated the stroke-induced breakdown of blood brain barrier (BBB permeability. The one of possible mechanisms underlying the higher resistance to stress-related stroke injures of cerebral vessels in newborn rats compared with adult animals is the greater expression of two main tight junction proteins of BBB (occludin and claudin-5 in neonatal vs. mature brain in rats.

  18. The blood-brain barrier as a cause of obesity.

    Science.gov (United States)

    Banks, William A

    2008-01-01

    The dramatic increase in the number of obese and overweight persons has spurred interest in control of appetite, body weight, and adiposity. Leptin is the humoral component of a negative feedback loop between adipose tissue and brain. Leptin is secreted from fat in proportion to the degree of adiposity, is transported across the blood-brain barrier (BBB), and acts in the brain to decrease appetite and increase thermogenesis, actions that ultimately decrease adiposity. However, leptin fails as an adipostat because leptin resistance arises in obesity. The BBB transporter is the first part of the feedback loop to fail, producing the so called "peripheral resistance" to leptin. In this sense, obesity is a disease of the BBB. Failure of leptin as an adipostat raises the question of what its primary role is as does its effects on reproduction, bone, immunity, breathing, cognition, and neurogenesis. Kinetics analysis shows that the BBB transporter performs most efficiently at low serum levels of leptin, suggesting that the feedback loop evolved to operate at lower leptin levels than those seen in ideal body weight. We suggest that low levels of serum leptin inform the brain that adipose reserves are adequate to expend calories on functions other than feeding, such as reproduction and the immune system. This feedback loop is short-circuited when an animal enters starvation. Hallmarks of starvation include decreased secretion of leptin by adipose tissue and hypertriglyceridemia. Triglycerides inhibit the transport of leptin across the BBB, thus attenuating the leptin signal across the BBB and providing a mechanism for peripheral leptin resistance. Triglycerides are elevated in both starvation and obesity. We postulate that hypertriglyceridemia evolved as a starvation signal to the brain that acts in part to inhibit the transport of the leptin across the BBB. The hypertriglyceridemia of obesity invokes this aspect of the starvation response, inducing leptin resistance at the

  19. Transport across the blood-brain barrier of pluronic leptin.

    Science.gov (United States)

    Price, Tulin O; Farr, Susan A; Yi, Xiang; Vinogradov, Serguei; Batrakova, Elena; Banks, William A; Kabanov, Alexander V

    2010-04-01

    Leptin is a peptide hormone produced primarily by adipose tissue that acts as a major regulator of food intake and energy homeostasis. Impaired transport of leptin across the blood-brain barrier (BBB) contributes to leptin resistance, which is a cause of obesity. Leptin as a candidate for the treatment of this obesity is limited because of the short half-life in circulation and the decreased BBB transport that arises in obesity. Chemical modification of polypeptides with amphiphilic poly(ethylene oxide)-poly(propylene oxide) block copolymers (Pluronic) is a promising technology to improve efficiency of delivery of polypeptides to the brain. In the present study, we determined the effects of Pluronic P85 (P85) with intermediate hydrophilic-lipophilic balance conjugated with leptin via a degradable SS bond [leptin(ss)-P85] on food intake, clearance, stability, and BBB uptake. The leptin(ss)-P85 exhibited biological activity when injected intracerebroventricularly after overnight food deprivation and 125I-leptin(ss)-P85 was stable in blood, with a half-time clearance of 32.3 min (versus 5.46 min for leptin). 125I-Leptin(ss)-P85 crossed the BBB [blood-to-brain unidirectional influx rate (K(i)) = 0.272 +/- 0.037 microl/g x min] by a nonsaturable mechanism unrelated to the leptin transporter. Capillary depletion showed that most of the 125I-leptin(ss)-P85 taken up by the brain reached the brain parenchyma. Food intake was reduced when 3 mg of leptin(ss)-P85 was administered via tail vein in normal body weight mice [0-30 min, p penetration by a mechanism-independent BBB leptin transporter.

  20. Pharmacological modulation of blood-brain barrier increases permeability of doxorubicin into the rat brain

    Science.gov (United States)

    Sardi, Iacopo; la Marca, Giancarlo; Cardellicchio, Stefania; Giunti, Laura; Malvagia, Sabrina; Genitori, Lorenzo; Massimino, Maura; de Martino, Maurizio; Giovannini, Maria G

    2013-01-01

    Our group recently demonstrated in a rat model that pretreatment with morphine facilitates doxorubicin delivery to the brain in the absence of signs of increased acute systemic toxicity. Morphine and other drugs such as dexamethasone or ondansetron seem to inhibit MDR proteins localized on blood-brain barrier, neurons and glial cells increasing the access of doxorubicin to the brain by efflux transporters competition. We explored the feasibility of active modification of the blood-brain barrier protection, by using morphine dexamethasone or ondansetron pretreatment, to allow doxorubicin accumulation into the brain in a rodent model. Rats were pretreated with morphine (10 mg/kg, i.p.), dexamethasone (2 mg/kg, i.p.) or ondansetron (2 mg/kg, i.p.) before injection of doxorubicin (12 mg/kg, i.p.). Quantitative analysis of doxorubicin was performed by mass spectrometry. Acute hearth and kidney damage was analyzed by measuring doxorubicin accumulation, LDH activity and malondialdehyde plasma levels. The concentration of doxorubicin was significantly higher in all brain areas of rats pretreated with morphine (P < 0.001) or ondansetron (P < 0.05) than in control tissues. The concentration of doxorubicin was significantly higher in cerebral hemispheres and brainstem (P < 0.05) but not in cerebellum of rats pretreated with dexamethasone than in control tissues. Pretreatment with any of these drugs did not increase LDH activity or lipid peroxidation compared to controls. Our data suggest that morphine, dexamethasone or ondansetron pretreatment is able to allow doxorubicin penetration inside the brain by modulating the BBB. This effect is not associated with acute cardiac or renal toxicity. This finding might provide the rationale for clinical applications in the treatment of refractory brain tumors and pave the way to novel applications of active but currently inapplicable chemotherapeutic drugs. PMID:23977451

  1. Blood-brain barrier transport machineries and targeted therapy of brain diseases

    Directory of Open Access Journals (Sweden)

    Jaleh Barar

    2016-12-01

    Full Text Available Introduction: Desired clinical outcome of pharmacotherapy of brain diseases largely depends upon the safe drug delivery into the brain parenchyma. However, due to the robust blockade function of the blood-brain barrier (BBB, drug transport into the brain is selectively controlled by the BBB formed by brain capillary endothelial cells and supported by astrocytes and pericytes. Methods: In the current study, we have reviewed the most recent literature on the subject to provide an insight upon the role and impacts of BBB on brain drug delivery and targeting. Results: All drugs, either small molecules or macromolecules, designated to treat brain diseases must adequately cross the BBB to provide their therapeutic properties on biological targets within the central nervous system (CNS. However, most of these pharmaceuticals do not sufficiently penetrate into CNS, failing to meet the intended therapeutic outcomes. Most lipophilic drugs capable of penetrating BBB are prone to the efflux functionality of BBB. In contrast, all hydrophilic drugs are facing severe infiltration blockage imposed by the tight cellular junctions of the BBB. Hence, a number of strategies have been devised to improve the efficiency of brain drug delivery and targeted therapy of CNS disorders using multimodal nanosystems (NSs. Conclusion: In order to improve the therapeutic outcomes of CNS drug transfer and targeted delivery, the discriminatory permeability of BBB needs to be taken under control. The carrier-mediated transport machineries of brain capillary endothelial cells (BCECs can be exploited for the discovery, development and delivery of small molecules into the brain. Further, the receptor-mediated transport systems can be recruited for the delivery of macromolecular biologics and multimodal NSs into the brain.

  2. Excitotoxicity triggered by neonatal monosodium glutamate treatment and blood-brain barrier function.

    Science.gov (United States)

    Gudiño-Cabrera, Graciela; Ureña-Guerrero, Monica E; Rivera-Cervantes, Martha C; Feria-Velasco, Alfredo I; Beas-Zárate, Carlos

    2014-11-01

    It is likely that monosodium glutamate (MSG) is the excitotoxin that has been most commonly employed to characterize the process of excitotoxicity and to improve understanding of the ways that this process is related to several pathological conditions of the central nervous system. Excitotoxicity triggered by neonatal MSG treatment produces a significant pathophysiological impact on adulthood, which could be due to modifications in the blood-brain barrier (BBB) permeability and vice versa. This mini-review analyzes this topic through brief descriptions about excitotoxicity, BBB structure and function, role of the BBB in the regulation of Glu extracellular levels, conditions that promote breakdown of the BBB, and modifications induced by neonatal MSG treatment that could alter the behavior of the BBB. In conclusion, additional studies to better characterize the effects of neonatal MSG treatment on excitatory amino acids transporters, ionic exchangers, and efflux transporters, as well as the role of the signaling pathways mediated by erythropoietin and vascular endothelial growth factor in the cellular elements of the BBB, should be performed to identify the mechanisms underlying the increase in neurovascular permeability associated with excitotoxicity observed in several diseases and studied using neonatal MSG treatment. Copyright © 2015 IMSS. Published by Elsevier Inc. All rights reserved.

  3. Permeability of the blood-brain barrier to lead.

    Science.gov (United States)

    Bradbury, M W; Deane, R

    1993-01-01

    This review examines the kinetics and possible mechanisms of lead transport into brain across the microvessel endothelium (the blood-brain barrier). Although severe lead poisoning both in neonatal rats and in young children may cause microvessel damage, there is little evidence that there is either damage or even disturbance of specific transport mechanisms at blood leads linear with time up to 4 hours, reaching spaces in relation to plasma of 6.6 - 8.2 ml/100 g in cerebral tissues at one hour. The concentration of free Pb+ in serum is of the order of 10(-12)M, the majority of lead being bound to protein and to sulfhydryl compounds, such as L-cysteine. Transport into brain has been further studied during short vascular perfusion of one cerebral hemisphere of the rat with oxygenated and buffered physiological saline. This allows total control of the fluid perfusing the cerebral microvessels. In the absence of organic ligands for lead, 203Pb entered brain very fast, with a space of 9.7 ml/100 g in frontal cortex at one min. The presence of albumin, L-cysteine or EDTA abolished measurable uptake. Experiments designed to reveal a role for the anion exchanger or calcium channels gave negative results. However, the effects of potassium depolarization and of varying pH indicated that the lead species passively entering the endothelium might be PbOH+. Experiments with various metabolic inhibitors, including vanadate, suggested that Pb uptake in the endothelium is mitigated by active back transport of lead into blood by the Ca-ATPase pump.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Blood-brain barrier damage in vascular dementia.

    Science.gov (United States)

    Ueno, Masaki; Chiba, Yoichi; Matsumoto, Koichi; Murakami, Ryuta; Fujihara, Ryuji; Kawauchi, Machi; Miyanaka, Hiroshi; Nakagawa, Toshitaka

    2016-04-01

    New findings on flow or drainage pathways of brain interstitial fluid and cerebrospinal fluid have been made. The interstitial fluid flow has an effect on the passage of blood-borne substances in the brain parenchyma, especially in areas near blood-brain barrier (BBB)-free regions. Actually, blood-borne substances can be transferred in areas with intact BBB function, such as the hippocampus, the corpus callosum, periventricular areas, and medial portions of the amygdala, presumably through leaky vessels in the subfornical organs or the choroid plexus. Increasing evidence indicates that dysfunction of the BBB function may play a significant role in the pathogenesis of vascular dementia. Accordingly, we have examined which insults seen in patients suffering from vascular dementia have an effect on the BBB using experimental animal models exhibiting some phenotypes of vascular dementia. The BBB in the hippocampus was clearly deteriorated in Mongolian gerbils exposed to acute ischemia followed by reperfusion and also in stroke-prone spontaneously hypertensive rats (SHRSP) showing hypertension. The BBB in the corpus callosum was clearly deteriorated in Wistar rats with permanent ligation of the bilateral common carotid arteries showing chronic hypoperfusion. The BBB in the hippocampus and the olfactory bulb was mildly deteriorated in aged senescence accelerated prone mice (SAMP8) showing cognitive dysfunction. The BBB in the hippocampus was mildly deteriorated in aged animals with hydrocephalus. Mild endothelial damage was seen in hyperglycemic db/db mice. In addition, mRNA expression of osteopontin, matrix metalloproteinase-13 (MMP-13), and CD36 was increased in vessels showing BBB damage in hypertensive SHRSP. As osteopontin, MMP-13 and CD36 are known to be related to brain injury and amyloid β accumulation or clearance, BBB damage followed by increased gene expression of these molecules not only contributes to the pathogenesis of vascular dementia, but also bridges

  5. Endocannabinoids modulate human blood–brain barrier permeability in vitro

    Science.gov (United States)

    Hind, William H; Tufarelli, Cristina; Neophytou, Maria; Anderson, Susan I; England, Timothy J; O'Sullivan, Saoirse E

    2015-01-01

    Background and Purpose Endocannabinoids alter permeability at various epithelial barriers, and cannabinoid receptors and endocannabinoid levels are elevated by stroke, with potential neuroprotective effects. We therefore explored the role of endocannabinoids in modulating blood–brain barrier (BBB) permeability in normal conditions and in an ischaemia/reperfusion model. Experimental Approach Human brain microvascular endothelial cell and astrocyte co-cultures modelled the BBB. Ischaemia was modelled by oxygen-glucose deprivation (OGD) and permeability was measured by transepithelial electrical resistance. Endocannabinoids or endocannabinoid-like compounds were assessed for their ability to modulate baseline permeability or OGD-induced hyperpermeability. Target sites of action were investigated using receptor antagonists and subsequently identified with real-time PCR. Key Results Anandamide (10 μM) and oleoylethanolamide (OEA, 10 μM) decreased BBB permeability (i.e. increased resistance). This was mediated by cannabinoid CB2 receptors, transient receptor potential vanilloid 1 (TRPV1) channels, calcitonin gene-regulated peptide (CGRP) receptor (anandamide only) and PPARα (OEA only). Application of OEA, palmitoylethanolamide (both PPARα mediated) or virodhamine (all 10 μM) decreased the OGD-induced increase in permeability during reperfusion. 2-Arachidonoyl glycerol, noladin ether and oleamide did not affect BBB permeability in normal or OGD conditions. N-arachidonoyl-dopamine increased permeability through a cytotoxic mechanism. PPARα and γ, CB1 receptors, TRPV1 channels and CGRP receptors were expressed in both cell types, but mRNA for CB2 receptors was only present in astrocytes. Conclusion and Implication The endocannabinoids may play an important modulatory role in normal BBB physiology, and also afford protection to the BBB during ischaemic stroke, through a number of target sites. PMID:25651941

  6. Endocannabinoids modulate human blood-brain barrier permeability in vitro.

    Science.gov (United States)

    Hind, William H; Tufarelli, Cristina; Neophytou, Maria; Anderson, Susan I; England, Timothy J; O'Sullivan, Saoirse E

    2015-06-01

    Endocannabinoids alter permeability at various epithelial barriers, and cannabinoid receptors and endocannabinoid levels are elevated by stroke, with potential neuroprotective effects. We therefore explored the role of endocannabinoids in modulating blood-brain barrier (BBB) permeability in normal conditions and in an ischaemia/reperfusion model. Human brain microvascular endothelial cell and astrocyte co-cultures modelled the BBB. Ischaemia was modelled by oxygen-glucose deprivation (OGD) and permeability was measured by transepithelial electrical resistance. Endocannabinoids or endocannabinoid-like compounds were assessed for their ability to modulate baseline permeability or OGD-induced hyperpermeability. Target sites of action were investigated using receptor antagonists and subsequently identified with real-time PCR. Anandamide (10 μM) and oleoylethanolamide (OEA, 10 μM) decreased BBB permeability (i.e. increased resistance). This was mediated by cannabinoid CB2 receptors, transient receptor potential vanilloid 1 (TRPV1) channels, calcitonin gene-regulated peptide (CGRP) receptor (anandamide only) and PPARα (OEA only). Application of OEA, palmitoylethanolamide (both PPARα mediated) or virodhamine (all 10 μM) decreased the OGD-induced increase in permeability during reperfusion. 2-Arachidonoyl glycerol, noladin ether and oleamide did not affect BBB permeability in normal or OGD conditions. N-arachidonoyl-dopamine increased permeability through a cytotoxic mechanism. PPARα and γ, CB1 receptors, TRPV1 channels and CGRP receptors were expressed in both cell types, but mRNA for CB2 receptors was only present in astrocytes. The endocannabinoids may play an important modulatory role in normal BBB physiology, and also afford protection to the BBB during ischaemic stroke, through a number of target sites. © 2015 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of The British Pharmacological Society.

  7. Rapidly profiling blood-brain barrier penetration with liposome EKC.

    Science.gov (United States)

    Wang, Yongjun; Sun, Jin; Liu, Hongzhuo; He, Zhonggui

    2007-07-01

    This report intended to study the potential of liposome EKC (LEKC) as a convenient and high-throughput screening tool to assess drug penetration across the blood-brain barrier (BBB). The retention factors (k) of 24 structurally diverse compounds were determined with LEKC and vesicle EKC (VEKC), respectively. Principal component analysis of the steady-state concentrations ratio of compounds in the brain and in the blood expressed as log BB, log k(LEKC), log k(VEKC), and other lipophilic descriptors including octanol/water partition coefficient (Clog P), octanol/water distribution coefficients (log D(7.4)), and polar surface area (PSA), showed the maximum similarity of partitioning processes in LEKC to drug penetration across the BBB. Furthermore, the log BB were correlated with the above five lipophilic descriptors, and the results showed that log k(LEKC) gave the better correlation coefficient (r(2) = 0.811, p <0.0001) than those of log D(7.4), Clog P, PSA, and log k(VEKC) (r(2) = 0.730, 0.672, 0.627, and 0.620, p <0.0001). This is the first report of the use of LEKC as a promising rapid tool to profile drug penetration across the BBB.

  8. Neurosurgical Techniques for Disruption of the Blood–Brain Barrier for Glioblastoma Treatment

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    Analiz Rodriguez

    2015-08-01

    Full Text Available The blood–brain barrier remains a main hurdle to drug delivery to the brain. The prognosis of glioblastoma remains grim despite current multimodal medical management. We review neurosurgical technologies that disrupt the blood–brain barrier (BBB. We will review superselective intra-arterial mannitol infusion, focused ultrasound, laser interstitial thermotherapy, and non-thermal irreversible electroporation (NTIRE. These technologies can lead to transient BBB and blood–brain tumor barrier disruption and allow for the potential of more effective local drug delivery. Animal studies and preliminary clinical trials show promise for achieving this goal.

  9. Characterization of a novel brain barrier ex vivo insect-based P-glycoprotein screening model

    DEFF Research Database (Denmark)

    Andersson, O.; Badisco, L.; Hansen, A. H.

    2014-01-01

    In earlier studies insects were proposed as suitable models for vertebrate blood–brain barrier (BBB) permeability prediction and useful in early drug discovery. Here we provide transcriptome and functional data demonstrating the presence of a P-glycoprotein (Pgp) efflux transporter in the brain....... As in vertebrates, the locust brain–barrier function is morphologically confined to one specific cell layer and by using a whole-brain ex vivo drug exposure technique our locust model may retain the major cues that maintain and modulate the physiological function of the brain barrier. We show that the locust model...

  10. Vascular Endothelial Growth Factor Increases during Blood-Brain Barrier-Enhanced Permeability Caused by Phoneutria nigriventer Spider Venom

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    Monique C. P. Mendonça

    2014-01-01

    Full Text Available Phoneutria nigriventer spider accidental envenomation provokes neurotoxic manifestations, which when critical, results in epileptic-like episodes. In rats, P. nigriventer venom (PNV causes blood-brain barrier breakdown (BBBb. The PNV-induced excitotoxicity results from disturbances on Na+, K+ and Ca2+ channels and glutamate handling. The vascular endothelial growth factor (VEGF, beyond its angiogenic effect, also, interferes on synaptic physiology by affecting the same ion channels and protects neurons from excitotoxicity. However, it is unknown whether VEGF expression is altered following PNV envenomation. We found that adult and neonates rats injected with PNV showed immediate neurotoxic manifestations which paralleled with endothelial occludin, β-catenin, and laminin downregulation indicative of BBBb. In neonate rats, VEGF, VEGF mRNA, and Flt-1 receptors, glutamate decarboxylase, and calbindin-D28k increased in Purkinje neurons, while, in adult rats, the BBBb paralleled with VEGF mRNA, Flk-1, and calbindin-D28k increases and Flt-1 decreases. Statistically, the variable age had a role in such differences, which might be due to age-related unequal maturation of blood-brain barrier (BBB and thus differential cross-signaling among components of the glial neurovascular unit. The concurrent increases in the VEGF/Flt-1/Flk-1 system in the cerebellar neuron cells and the BBBb following PNV exposure might imply a cytokine modulation of neuronal excitability consequent to homeostatic perturbations induced by ion channels-acting PNV neuropeptides. Whether such modulation represents neuroprotection needs further investigation.

  11. Pathological changes in the structures of the blood-brain barrier in acute cerebral circulatory disorders

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    S. І. Tertyshny

    2012-04-01

    Full Text Available Morphological changes of the blood-brain barrier were investigated in case of an acute brain disturbed circulation. Autocontrol of vessels with their dilatation and formation of aggregation from formal elements were shown from the onset of the disease. Distructive changes of the endothelium, basement membranes, pericytes, asrtocytosal processes are marked in the microvessels with formation of the perivascular edema. Increase permeability of the blood-brain barrier promotes hemorrhagic transformation and lymphomicrophagical infi ltration of the perivascular zones.

  12. Protection of Glial Müller Cells by Dexamethasone in a Mouse Model of Surgically Induced Blood-Retinal Barrier Breakdown.

    Science.gov (United States)

    Siqueiros-Marquez, Lourdes; Bénard, Romain; Vacca, Ophélie; Charles-Messance, Hugo; Bolaños-Jimenez, Rodrigo; Guilloneau, Xavier; Sennlaub, Florian; Montañez, Cecilia; Sahel, José Alain; Rendon, Alvaro; Tadayoni, Ramin; Giocanti-Aurégan, Audrey

    2017-02-01

    Breakdown of the inner blood-retinal barrier (iBRB) occurs in many retinal disorders and may cause retinal edema often responsible for vision loss. Dexamethasone is used in clinical practice to restore iBRB. The aim of this study was to characterize the impact of a surgically induced iBRB breakdown on retinal homeostatic changes due to dystrophin Dp71, aquaporin-4 (AQP4), and Kir4.1 alterations in Müller glial cells (MGC) in a mouse model. The protective effect of dexamethasone was assessed in this model. Moreover, retinal explants were used to control MGC exposure to a hypoosmotic solution containing barium. Partial lens surgery was performed in C57BL6/J mice. Dystrophin Dp71, AQP4, and Kir4.1 expression was analyzed by quantitative RT-PCR, Western blot, and immunohistochemistry. Twenty-four hours after surgery, mice received a single intravitreal injection of dexamethasone or of vehicle. After partial lens surgery, iBRB permeability increased while Dp71 and AQP4 were downregulated and Kir4.1 was delocalized. These effects were partially prevented by dexamethasone injection. In the retinal explant model, MGC were swollen and Dp71, AQP4, and Kir4.1 were downregulated after exposure to a hypoosmotic solution containing barium, but not in the presence of dexamethasone. Heat shock factor protein 1 (HSF1) was overexpressed in dexamethasone-treated retinas. Partial lens surgery induces iBRB breakdown and molecular changes in MGC, including a downregulation of Dp71 and AQP4 and the delocalization of Kir4.1. Dexamethasone seems to protect retina from these molecular changes by upregulating HSF1.

  13. The blood-brain barrier and cancer: transporters, treatment, and Trojan horses.

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    Deeken, John F; Löscher, Wolfgang

    2007-03-15

    Despite scientific advances in understanding the causes and treatment of human malignancy, a persistent challenge facing basic and clinical investigators is how to adequately treat primary and metastatic brain tumors. The blood-brain barrier is a physiologic obstruction to the delivery of systemic chemotherapy to the brain parenchyma and central nervous system (CNS). A number of physiologic properties make the endothelium in the CNS distinct from the vasculature found in the periphery. Recent evidence has shown that a critical aspect of this barrier is composed of xenobiotic transporters which extrude substrates from the brain into the cerebrospinal fluid and systemic circulation. These transporters also extrude drugs and toxins if they gain entry into the cytoplasm of brain endothelial cells before they enter the brain. This review highlights the properties of the blood-brain barrier, including the location, function, and relative importance of the drug transporters that maintain this barrier. Primary and metastatic brain malignancy can compromise this barrier, allowing some access of chemotherapy treatment to reach the tumor. The responsiveness of brain tumors to systemic treatment found in past clinical research is discussed, as are possible explanations as to why CNS tumors are nonetheless able to evade therapy. Finally, strategies to overcome this barrier and better deliver chemotherapy into CNS tumors are presented.

  14. Consumption of Polyphenol-Rich Zingiber Zerumbet Rhizome Extracts Protects against the Breakdown of the Blood-Retinal Barrier and Retinal Inflammation Induced by Diabetes

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    Thing-Fong Tzeng

    2015-09-01

    Full Text Available The present study investigates the amelioration of diabetic retinopathy (DR by Zingiber zerumbet rhizome ethanol extracts (ZZRext in streptozotocin-induced diabetic rats (STZ-diabetic rats. ZZRext contains high phenolic and flavonoid contents. STZ-diabetic rats were treated orally with ZZRext (200, 300 mg/kg per day for three months. Blood-retinal barrier (BRB breakdown and increased vascular permeability were found in diabetic rats, with downregulation of occludin, and claudin-5. ZZRext treatment effectively preserved the expression of occludin, and claudin-5, leading to less BRB breakdown and less vascular permeability. Retinal histopathological observation showed that the disarrangement and reduction in thickness of retinal layers were reversed in ZZRext-treated diabetic rats. Retinal gene expression of tumor necrosis factor-α, interleukin (IL-1β, IL-6, vascular endothelial growth factor, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 were all decreased in ZZRext-treated diabetic rats. Moreover, ZZRext treatment not only inhibited the nuclear factor κB (NF-κB activation, but also downregulated the protein expression of p38 mitogen-activated protein kinase (MAPK in diabetic retina. In conclusion, the results suggest that the retinal protective effects of ZZRext occur through improved retinal structural change and inhibiting retinal inflammation. The antiretinopathy property of ZZRext might be related to the downregulation of p38 MAPK and NF-κB signal transduction induced by diabetes.

  15. Revisiting blood-brain barrier: A chromatographic approach.

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    Subirats, Xavier; Muñoz-Pascual, Laura; Abraham, Michael H; Rosés, Martí

    2017-10-25

    Drugs designed to reach a pharmacological CNS target must be effectively transported across the blood-brain barrier (BBB), a thin monolayer of endothelial cells tightly attached together between the blood and the brain parenchyma. Because of the lipidic nature of the BBB, several physicochemical partition models have been studied as surrogates for the passive permeation of potential drug candidates across the BBB (octanol-water, alkane-water, PAMPA...). In the last years, biopartition chromatography is gaining importance as a noncellular system for the estimation of biological properties in early stages of drug development. Microemulsions (ME) are suitable mobile phases, because of their ease of formulation, stability and adjustability to a large number of compositions mimicking biological structures. In the present work, several microemulsion liquid chromatographic (MELC) systems have been characterized by means of the Abraham's solvation parameter model, in order to assess their suitability as BBB distribution or permeability surrogates. In terms of similarity between BBB and MELC systems (dispersion forces arising from solute non-bonded electrons, dipolarity/polarizability, hydrogen-bond acidity and basicity, and molecular volume), the passive permeability surface area product (log PS) for neutral (including zwitterions), fully and partially ionized drugs was found to be well correlated with the ME made of 3.3% SDS (w/v; surfactant) 0.8% heptane (w/v; oil phase) and 6.6% 1-butanol (w/v; co-surfactant) in 50mM aqueous phosphate buffer, pH 7.4. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. In vitro models of the blood-brain barrier

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    Helms, Hans Christian Cederberg; Abbott, N Joan; Burek, Malgorzata

    2016-01-01

    components of plasma and xenobiotics. This "blood-brain barrier" function is a major hindrance for drug uptake into the brain parenchyma. Cell culture models, based on either primary cells or immortalized brain endothelial cell lines, have been developed, in order to facilitate in vitro studies of drug...

  17. Smuggling Drugs into the Brain: An Overview of Ligands Targeting Transcytosis for Drug Delivery across the Blood-Brain Barrier

    NARCIS (Netherlands)

    Zuhorn, Inge; Georgieva, Julia V.; Hoekstra, Dick

    2015-01-01

    The blood-brain barrier acts as a physical barrier that prevents free entry of blood-derived substances, including those intended for therapeutic applications. The development of molecular Trojan horses is a promising drug targeting technology that allows for non-invasive delivery of therapeutics

  18. Impairment of brain endothelial glucose transporter by methamphetamine causes blood-brain barrier dysfunction

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    Murrin L Charles

    2011-03-01

    Full Text Available Abstract Background Methamphetamine (METH, an addictive psycho-stimulant drug with euphoric effect is known to cause neurotoxicity due to oxidative stress, dopamine accumulation and glial cell activation. Here we hypothesized that METH-induced interference of glucose uptake and transport at the endothelium can disrupt the energy requirement of the blood-brain barrier (BBB function and integrity. We undertake this study because there is no report of METH effects on glucose uptake and transport across the blood-brain barrier (BBB to date. Results In this study, we demonstrate that METH-induced disruption of glucose uptake by endothelium lead to BBB dysfunction. Our data indicate that a low concentration of METH (20 μM increased the expression of glucose transporter protein-1 (GLUT1 in primary human brain endothelial cell (hBEC, main component of BBB without affecting the glucose uptake. A high concentration of 200 μM of METH decreased both the glucose uptake and GLUT1 protein levels in hBEC culture. Transcription process appeared to regulate the changes in METH-induced GLUT1 expression. METH-induced decrease in GLUT1 protein level was associated with reduction in BBB tight junction protein occludin and zonula occludens-1. Functional assessment of the trans-endothelial electrical resistance of the cell monolayers and permeability of dye tracers in animal model validated the pharmacokinetics and molecular findings that inhibition of glucose uptake by GLUT1 inhibitor cytochalasin B (CB aggravated the METH-induced disruption of the BBB integrity. Application of acetyl-L-carnitine suppressed the effects of METH on glucose uptake and BBB function. Conclusion Our findings suggest that impairment of GLUT1 at the brain endothelium by METH may contribute to energy-associated disruption of tight junction assembly and loss of BBB integrity.

  19. Aggressive Antioxidant Reductive Stress Impairs Brain Endothelial Cell Angiogenesis and Blood Brain Barrier Function.

    Science.gov (United States)

    Mentor, Shireen; Fisher, David

    2017-01-01

    Oxidative stress in the brain microvasculature is a common characteristic in models of cerebrovascular disease. Considering the effects of reactive oxygen species activity in vascular-derived insults, it is naturally prudent to hypothesize those interventions inhibiting reactive oxygen species activity, such as antioxidant supplementation, may be beneficial for cerebrovascular disease. Hyper doses of antioxidant supplements, and foods with high antioxidant concentrations, are commonly used as an ongoing remedial and 'over-the-counter' treatments for most seasonal ailments. For the first time, this study reports the adverse effects of excess antioxidants on angiogenic properties of the blood-brain barrier (BBB) which have clinical implications. A medicinal tea, known as Rooibos, commonly used in South Africa and marketed globally, for its prominent antioxidant profile, demonstrated its effects on brain endothelial cellular proliferation, toxicology, mitochondrial activity and permeability. Mouse brain endothelial cells were seeded at cell densities ranging from 103-106 cells/ml and were incubated at pre-determined time intervals of 24 to120 hours. Daily exposure of a selected concentration range of fermented Rooibos tea caused dose-related decreases in cellular proliferation, and unequivocally decreased permeability across our in vitro BBB model. Despite the negative effects on cellular proliferation, no toxicity was observed for all selected fermented Rooibos concentrations. Our data conclusively shows that the use of excess antioxidants perturbs BBB functionality and angiogenic properties, adversely implicating the homeostatic regulation of the brain microenvironment, while suppression in cellular proliferation impacts both the maintenance and repair function of brain capillaries. Our study indicates that excess antioxidants will lead to an impaired response to mechanical-induced injury and pathogenic infection of the BBB, compromising patient recovery. Copyright

  20. Tracer kinetic modelling for DCE-MRI quantification of subtle blood-brain barrier permeability.

    Science.gov (United States)

    Heye, Anna K; Thrippleton, Michael J; Armitage, Paul A; Valdés Hernández, Maria Del C; Makin, Stephen D; Glatz, Andreas; Sakka, Eleni; Wardlaw, Joanna M

    2016-01-15

    There is evidence that subtle breakdown of the blood-brain barrier (BBB) is a pathophysiological component of several diseases, including cerebral small vessel disease and some dementias. Dynamic contrast-enhanced MRI (DCE-MRI) combined with tracer kinetic modelling is widely used for assessing permeability and perfusion in brain tumours and body tissues where contrast agents readily accumulate in the extracellular space. However, in diseases where leakage is subtle, the optimal approach for measuring BBB integrity is likely to differ since the magnitude and rate of enhancement caused by leakage are extremely low; several methods have been reported in the literature, yielding a wide range of parameters even in healthy subjects. We hypothesised that the Patlak model is a suitable approach for measuring low-level BBB permeability with low temporal resolution and high spatial resolution and brain coverage, and that normal levels of scanner instability would influence permeability measurements. DCE-MRI was performed in a cohort of mild stroke patients (n=201) with a range of cerebral small vessel disease severity. We fitted these data to a set of nested tracer kinetic models, ranking their performance according to the Akaike information criterion. To assess the influence of scanner drift, we scanned 15 healthy volunteers that underwent a "sham" DCE-MRI procedure without administration of contrast agent. Numerical simulations were performed to investigate model validity and the effect of scanner drift. The Patlak model was found to be most appropriate for fitting low-permeability data, and the simulations showed vp and K(Trans) estimates to be reasonably robust to the model assumptions. However, signal drift (measured at approximately 0.1% per minute and comparable to literature reports in other settings) led to systematic errors in calculated tracer kinetic parameters, particularly at low permeabilities. Our findings justify the growing use of the Patlak model in low

  1. Blood-Brain Barrier Effects of the Fusarium Mycotoxins Deoxynivalenol, 3 Acetyldeoxynivalenol, and Moniliformin and Their Transfer to the Brain.

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    Matthias Behrens

    Full Text Available Secondary metabolites produced by Fusarium fungi frequently contaminate food and feed and have adverse effects on human and animal health. Fusarium mycotoxins exhibit a wide structural and biosynthetic diversity leading to different toxicokinetics and toxicodynamics. Several studies investigated the toxicity of mycotoxins, focusing on very specific targets, like the brain. However, it still remains unclear how fast mycotoxins reach the brain and if they impair the integrity of the blood-brain barrier. This study investigated and compared the effects of the Fusarium mycotoxins deoxynivalenol, 3-acetyldeoxynivalenol and moniliformin on the blood-brain barrier. Furthermore, the transfer properties to the brain were analyzed, which are required for risk assessment, including potential neurotoxic effects.Primary porcine brain capillary endothelial cells were cultivated to study the effects of the examined mycotoxins on the blood-brain barrier in vitro. The barrier integrity was monitored by cellular impedance spectroscopy and 14C radiolabeled sucrose permeability measurements. The distribution of the applied toxins between blood and brain compartments of the cell monolayer was analyzed by high performance liquid chromatography-mass spectrometry to calculate transfer rates and permeability coefficients.Deoxynivalenol reduced the barrier integrity and caused cytotoxic effects at 10 μM concentrations. Slight alterations of the barrier integrity were also detected for 3-acetyldeoxynivalenol. The latter was transferred very quickly across the barrier and additionally cleaved to deoxynivalenol. The transfer of deoxynivalenol and moniliformin was slower, but clearly exceeded the permeability of the negative control. None of the compounds was enriched in one of the compartments, indicating that no efflux transport protein is involved in their transport.

  2. Fragmentation: Loss of global coherence or breakdown of modularity in functional brain architecture?

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    Daan evan den Berg

    2012-03-01

    Full Text Available Psychiatric illnesses characterised by disorganized cognition, such as schizophrenia, have been described in terms of fragmentation and hence understood as reduction in functional brain connectivity, particularly in prefrontal and parietal areas. However, as graph-theory shows, relatively small numbers of nonlocal connections are sufficient to ensure global coherence in the modular small world network structure of the brain. We reconsider fragmentation in this perspective. Computational studies have shown that for a given level of connectivity in a model of coupled nonlinear oscillators, modular small-world networks evolve from an initially random organization. Here we demonstrate that with decreasing connectivity, the probability of evolving into a modular small-world network breaks down at a critical point, which scales to the percolation function of random networks with a universal exponent of α=1.17. Thus, according to the model, local modularity systematically breaks down before there is loss of global coherence in network connectivity. We therefore propose that fragmentation may involve, at least in its initial stages, the inability of a dynamically evolving network to sustain a modular small-world structure. The result is in a shift in the balance in schizophrenia from local to global functional connectivity.

  3. Growth inhibition in a brain metastasis model by antibody delivery using focused ultrasound-mediated blood-brain barrier disruption

    NARCIS (Netherlands)

    Kobus, T.; Zervantonakis, I.K.; Zhang, Y; McDannold, N.J.

    2016-01-01

    HER2-targeting antibodies (i.e. trastuzumab and pertuzumab) prolong survival in HER2-positive breast cancer patients with extracranial metastases. However, the response of brain metastases to these drugs is poor, and it is hypothesized that the blood-brain barrier (BBB) limits drug delivery to the

  4. Immortalized endothelial cell lines for in vitro blood-brain barrier models: A systematic review.

    Science.gov (United States)

    Rahman, Nurul Adhwa; Rasil, Alifah Nur'ain Haji Mat; Meyding-Lamade, Uta; Craemer, Eva Maria; Diah, Suwarni; Tuah, Ani Afiqah; Muharram, Siti Hanna

    2016-07-01

    Endothelial cells play the most important role in construction of the blood-brain barrier. Many studies have opted to use commercially available, easily transfected or immortalized endothelial cell lines as in vitro blood-brain barrier models. Numerous endothelial cell lines are available, but we do not currently have strong evidence for which cell lines are optimal for establishment of such models. This review aimed to investigate the application of immortalized endothelial cell lines as in vitro blood-brain barrier models. The databases used for this review were PubMed, OVID MEDLINE, ProQuest, ScienceDirect, and SpringerLink. A narrative systematic review was conducted and identified 155 studies. As a result, 36 immortalized endothelial cell lines of human, mouse, rat, porcine and bovine origins were found for the establishment of in vitro blood-brain barrier and brain endothelium models. This review provides a summary of immortalized endothelial cell lines as a guideline for future studies and improvements in the establishment of in vitro blood-brain barrier models. It is important to establish a good and reproducible model that has the potential for multiple applications, in particular a model of such a complex compartment such as the blood-brain barrier. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Rapid breakdown of microvascular barriers and subsequent hemorrhagic transformation after delayed recombinant tissue plasminogen activator treatment in a rat embolic stroke model.

    Science.gov (United States)

    Dijkhuizen, Rick M; Asahi, Minoru; Wu, Ona; Rosen, Bruce R; Lo, Eng H

    2002-08-01

    Thrombolytic therapy with recombinant tissue plasminogen activator (rtPA) after stroke increases risk of hemorrhagic transformation, particularly in areas with blood-brain barrier leakage. Our aim was to characterize acute effects of rtPA administration on the integrity of microvascular barriers. Stroke was induced in spontaneously hypertensive rats by unilateral embolic middle cerebral artery occlusion. Six hours after stroke, rtPA was intravenously administered (n=10). Controls received saline (n=4). Extravasation of the large-diameter contrast agent monocrystalline iron oxide nanocolloid (MION) was assessed with susceptibility contrast-enhanced MRI during rtPA injection. In addition, we performed perfusion MRI and diffusion-weighted MRI. After MRI, 2 hours after rtPA treatment, intracerebral hemorrhage was quantified with a spectrophotometric hemoglobin assay. Late rtPA treatment resulted in increased hemorrhage volume (8.4+/-1.7 versus 2.9+/-0.9 micro L in controls; Pcerebral blood flow index was 22.8+/-19.7% [of contralateral] at 0.5 hours before and 22.4+/-18.0% at 1 hour after rtPA administration). The DeltaR2* changes during rtPA delivery in MION-injected animals indicate extravasation of MION, which reflects increased permeability of the blood-brain barrier. This implies that late rtPA treatment rapidly aggravates early ischemia-induced damage to microvascular barriers, thereby enhancing hemorrhagic transformation.

  6. Stress plays provoking role in hypertension-related stroke: injuries of blood-brain barrier function

    Science.gov (United States)

    Semyachkina-Glushkovskaya, O.; Shirokov, A.; Gekalyuk, A.; Abakumov, M.; Navolokin, N.; Abdurashitov, A.; Pavlov, A.; Ulanova, M.; Fedorova, V.; Razubaeva, V.; Saranceva, E.; Li, P.; Huang, Q.; Zhu, D.; Luo, Q.; Tuchin, V.; Kurths, J.

    2017-02-01

    Chronic hypertension itself does not cause stroke but significantly decreases the resistant to stroke induced by stress due to exhausting of adaptive capacity of cerebral endothelium and decrease resistance of blood-brain barrier to stress.

  7. A quantitative MRI method for imaging blood-brain barrier leakage in experimental traumatic brain injury.

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    Wei Li

    Full Text Available Blood-brain barrier (BBB disruption is common following traumatic brain injury (TBI. Dynamic contrast enhanced (DCE MRI can longitudinally measure the transport coefficient Ktrans which reflects BBB permeability. Ktrans measurements however are not widely used in TBI research because it is generally considered to be noisy and possesses low spatial resolution. We improved spatiotemporal resolution and signal sensitivity of Ktrans MRI in rats by using a high-sensitivity surface transceiver coil. To overcome the signal drop off profile of the surface coil, a pre-scan module was used to map the flip angle (B1 field and magnetization (M0 distributions. A series of T1-weighted gradient echo images were acquired and fitted to the extended Kety model with reversible or irreversible leakage, and the best model was selected using F-statistics. We applied this method to study the rat brain one hour following controlled cortical impact (mild to moderate TBI, and observed clear depiction of the BBB damage around the impact regions, which matched that outlined by Evans Blue extravasation. Unlike the relatively uniform T2 contrast showing cerebral edema, Ktrans shows a pronounced heterogeneous spatial profile in and around the impact regions, displaying a nonlinear relationship with T2. This improved Ktrans MRI method is also compatible with the use of high-sensitivity surface coil and the high-contrast two-coil arterial spin-labeling method for cerebral blood flow measurement, enabling more comprehensive investigation of the pathophysiology in TBI.

  8. Dehydroepiandrosterone sulfate augments blood-brain barrier and tight junction protein expression in brain endothelial cells.

    Science.gov (United States)

    Papadopoulos, Dimitrios; Scheiner-Bobis, Georgios

    2017-08-01

    Tight junctions (TJ) between brain endothelial cells are essential for formation and maintenance of the blood-brain barrier (BBB). Although loss of BBB integrity is associated with several neuropathological disorders, treatments that augment or stabilise the BBB are scarce. Here we show that physiological concentrations of dehydroepiandrosterone sulfate (DHEAS) stimulate the expression of the TJ proteins zonula occludens-1 (ZO-1) and claudin-3 in the brain-derived endothelial cell line bEnd.3 and promote TJ formation between neighbouring cells, demonstrated by augmented transendothelial resistance across cell monolayers. Silencing androgen receptor expression by siRNA does not prevent DHEAS-induced stimulation of ZO-1 expression, indicating that conversion of DHEAS into testosterone is not required for its actions. Suppression of Gnα11 expression by siRNA prevents DHEAS actions, pointing towards a G-protein-coupled receptor as being a mediator of the DHEAS effects. These results are consistent with the idea that DHEAS, acting as a hormone in its own right, supports the integrity of the BBB. The current findings might help in developing new strategies for the prevention or treatment of neurological disorders associated with BBB defects. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Protozoa traversal of the blood-brain barrier to invade the central nervous system.

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    Elsheikha, Hany M; Khan, Naveed Ahmed

    2010-07-01

    Neuropathogenic protozoa have evolved strategies to breach the blood-brain barrier and invade the central nervous system. These include transcellular, paracellular and the Trojan horse routes but the associated molecular mechanisms remain incompletely understood. Here, we summarize the current understanding of protozoa penetration across the blood-brain barrier, focusing on Plasmodium, Babesia, Trypanosoma, Toxoplasma, Acanthamoeba and Balamuthia. Advances in understanding the molecular pathways will offer opportunities for the rational development of novel therapeutic interventions.

  10. Brain pericytes from stress-susceptible pigs increase blood-brain barrier permeability in vitro

    Directory of Open Access Journals (Sweden)

    Vandenhaute Elodie

    2012-06-01

    Full Text Available Abstract Background The function of pericytes remains questionable but with improved cultured technique and the use of genetically modified animals, it has become increasingly clear that pericytes are an integral part of blood–brain barrier (BBB function, and the involvement of pericyte dysfunction in certain cerebrovascular diseases is now emerging. The porcine stress syndrome (PSS is the only confirmed, homologous model of malignant hyperthermia (MH in veterinary medicine. Affected animals can experience upon slaughter a range of symptoms, including skeletal muscle rigidity, metabolic acidosis, tachycardia and fever, similar to the human syndrome. Symptoms are due to an enhanced calcium release from intracellular stores. These conditions are associated with a point mutation in ryr1/hal gene, encoding the ryanodine receptor, a calcium channel. Important blood vessel wall muscle modifications have been described in PSS, but potential brain vessel changes have never been documented in this syndrome. Methods In the present work, histological and ultrastructural analyses of brain capillaries from wild type and ryr1 mutated pigs were conducted to investigate the potential impairment of pericytes, in this pathology. In addition, brain pericytes were isolated from the three porcine genotypes (wild-type NN pigs; Nn and nn pigs, bearing one or two (n mutant ryr1/hal alleles, respectively, and tested in vitro for their influence on the permeability of BBB endothelial monolayers. Results Enlarged perivascular spaces were observed in ryr1-mutant samples, corresponding to a partial or total detachment of the astrocytic endfeet. These spaces were electron lucent and sometimes filled with lipid deposits and swollen astrocytic feet. At the ultrastructural level, brain pericytes did not seem to be affected because they showed regular morphology and characteristics, so we aimed to check their ability to maintain BBB properties in vitro. Our results indicated

  11. Stroke and Drug Delivery--In Vitro Models of the Ischemic Blood-Brain Barrier

    DEFF Research Database (Denmark)

    Tornabene, Erica; Brodin, Birger

    2016-01-01

    and Drug Administration-approved tissue plasminogen activator for treatment of acute ischemic stroke being the most prominent example. A large number of potential drug candidates for treatment of ischemic brain tissue have been developed and subsequently failed in clinical trials. A deeper understanding......Stroke is a major cause of death and disability worldwide. Both cerebral hypoperfusion and focal cerebral infarcts are caused by a reduction of blood flow to the brain, leading to stroke and subsequent brain damage. At present, only few medical treatments of stroke are available, with the Food...... of permeation pathways across the barrier in ischemic and postischemic brain endothelium is important for development of new medical treatments. The blood-brain barrier, that is, the endothelial monolayer lining the brain capillaries, changes properties during an ischemic event. In vitro models of the blood-brain...

  12. Confocal imaging of xenobiotic transport across the blood-brain barrier.

    Science.gov (United States)

    Miller, David S

    2003-11-01

    The brain capillary endothelium is a formidable barrier to entry of foreign chemicals into the central nervous system (CNS). For the most part it poorly distinguishes between therapeutics and neurotoxins and thus the blood-brain barrier both protects the brain from toxic chemicals and limits our ability to treat a variety of CNS disorders. Two elements underlie the barrier function of the brain capillary endothelium: 1). a physical barrier comprised of tight junctions, which form an effective seal to intercellular diffusion, and the cells themselves, which exhibit a low rate of endocytosis, and 2). a metabolic/active barrier, comprised of specific membrane transporters expressed by the endothelial cells. We have recently developed an experimental system based on confocal microscopy to study mechanisms of transport in freshly isolated brain capillaries. Here I review studies demonstrating a major role for the ATP-driven, xenobiotic export pump, p-glycoprotein, in barrier function and recent experiments showing that transient inhibition of pump function can have substantial benefit for chemotherapy in an animal model of brain cancer. Copyright 2003 Wiley-Liss, Inc.

  13. Regulation of brain copper homeostasis by the brain barrier systems: Effects of Fe-overload and Fe-deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Monnot, Andrew D.; Behl, Mamta; Ho, Sanna; Zheng, Wei, E-mail: wzheng@purdue.edu

    2011-11-15

    Maintaining brain Cu homeostasis is vital for normal brain function. The role of systemic Fe deficiency (FeD) or overload (FeO) due to metabolic diseases or environmental insults in Cu homeostasis in the cerebrospinal fluid (CSF) and brain tissues remains unknown. This study was designed to investigate how blood-brain barrier (BBB) and blood-SCF barrier (BCB) regulated Cu transport and how FeO or FeD altered brain Cu homeostasis. Rats received an Fe-enriched or Fe-depleted diet for 4 weeks. FeD and FeO treatment resulted in a significant increase (+ 55%) and decrease (- 56%) in CSF Cu levels (p < 0.05), respectively; however, neither treatment had any effect on CSF Fe levels. The FeD, but not FeO, led to significant increases in Cu levels in brain parenchyma and the choroid plexus. In situ brain perfusion studies demonstrated that the rate of Cu transport into the brain parenchyma was significantly faster in FeD rats (+ 92%) and significantly slower (- 53%) in FeO rats than in controls. In vitro two chamber Transwell transepithelial transport studies using primary choroidal epithelial cells revealed a predominant efflux of Cu from the CSF to blood compartment by the BCB. Further ventriculo-cisternal perfusion studies showed that Cu clearance by the choroid plexus in FeD animals was significantly greater than control (p < 0.05). Taken together, our results demonstrate that both the BBB and BCB contribute to maintain a stable Cu homeostasis in the brain and CSF. Cu appears to enter the brain primarily via the BBB and is subsequently removed from the CSF by the BCB. FeD has a more profound effect on brain Cu levels than FeO. FeD increases Cu transport at the brain barriers and prompts Cu overload in the CNS. The BCB plays a key role in removing the excess Cu from the CSF.

  14. Safety Validation of Repeated Blood-Brain Barrier Disruption Using Focused Ultrasound

    NARCIS (Netherlands)

    Kobus, T.; Vykhodtseva, N.; Pilatou, M.; Zhang, Y.; McDannold, N.

    2016-01-01

    The purpose of this study was to investigate the effects on the brain of multiple sessions of blood-brain barrier (BBB) disruption using focused ultrasound (FUS) in combination with micro-bubbles over a range of acoustic exposure levels. Six weekly sessions of FUS, using acoustical pressures between

  15. The immune system mediates blood-brain barrier damage; Possible implications for pathophysiology of neuropsychiatric illnesses

    NARCIS (Netherlands)

    VanderWerf, YD; DeJongste, MJL; terHorst, GJ

    1995-01-01

    The immune system mediates blood-brain barrier damage; possible implications for pathophysiology of neuropsychiatric illnesses. In this investigation the effects of immune activation on the brain are characterized In order to study this, we used a model for chronic immune activation, the myocardial

  16. Change in blood– brain barrier permeability during pediatric diabetic ketoacidosis treatment*

    Science.gov (United States)

    Vavilala, Monica S.; Richards, Todd L.; Roberts, Joan S.; Chiu, Harvey; Pihoker, Catherine; Bradford, Heidi; Deeter, Kristina; Marro, Ken I.; Shaw, Dennis

    2010-01-01

    Objective Cerebral edema is a devastating complication of pediatric diabetic ketoacidosis. We aimed to examine blood– brain barrier permeability during treatment of diabetic ketoacidosis in children. Design Prospective observational study. Setting Seattle Children’s Hospital, Seattle, WA. Patients Children admitted with diabetic ketoacidosis (pH 300 mg/dL, and ketosis). Interventions None. Measurements and Main Results Subjects underwent two serial paired contrast-enhanced perfusion (gadolinium) and diffusion magnetic resonance imaging scans. Change in whole brain and regional blood– brain barrier permeability (permeability ratio*100 and % permeability ratio change) between illness and recovery were determined. Time 0 reflects start of insulin treatment. Thirteen children (median age 10.0 ± 1.1 yrs; seven female) with diabetic ketoacidosis were enrolled. Permeability ratio increased from time 1 (first magnetic resonance image after time 0) to time 2 (second magnetic resonance image after time 0) in the frontal cortex (ten of 13 subjects), occipital cortex (ten of 13 subjects), and basal ganglia (nine of 13). Whole brain permeability ratio increased from time 1 to time 2 (160%) and regional increase in permeability ratio was greatest in the frontal cortex (148%) compared with the occipital cortex (128%) and basal ganglia (112%). Conclusions Overall, whole brain and regional blood– brain barrier permeability increased in most subjects during diabetic ketoacidosis treatment. The frontal region had more blood– brain barrier permeability than other brain regions examined. PMID:19838141

  17. The rights and wrongs of blood-brain barrier permeability studies

    DEFF Research Database (Denmark)

    Saunders, Norman R; Dreifuss, Jean-Jacques; Dziegielewska, Katarzyna M

    2014-01-01

    . The original concept of a blood-brain barrier is often attributed to Ehrlich; however, he did not accept that permeability of cerebral vessels was different from other organs. Goldmann is often credited with the first experiments showing dye (trypan blue) exclusion from the brain when injected systemically...

  18. Exosome delivered anticancer drugs across the blood-brain barrier for brain cancer therapy in Danio rerio.

    Science.gov (United States)

    Yang, Tianzhi; Martin, Paige; Fogarty, Brittany; Brown, Alison; Schurman, Kayla; Phipps, Roger; Yin, Viravuth P; Lockman, Paul; Bai, Shuhua

    2015-06-01

    The blood-brain barrier (BBB) essentially restricts therapeutic drugs from entering into the brain. This study tests the hypothesis that brain endothelial cell derived exosomes can deliver anticancer drug across the BBB for the treatment of brain cancer in a zebrafish (Danio rerio) model. Four types of exosomes were isolated from brain cell culture media and characterized by particle size, morphology, total protein, and transmembrane protein markers. Transport mechanism, cell uptake, and cytotoxicity of optimized exosome delivery system were tested. Brain distribution of exosome delivered anticancer drugs was evaluated using transgenic zebrafish TG (fli1: GFP) embryos and efficacies of optimized formations were examined in a xenotransplanted zebrafish model of brain cancer model. Four exosomes in 30-100 diameters showed different morphologies and exosomes derived from brain endothelial cells expressed more CD63 tetraspanins transmembrane proteins. Optimized exosomes increased the uptake of fluorescent marker via receptor mediated endocytosis and cytotoxicity of anticancer drugs in cancer cells. Images of the zebrafish showed exosome delivered anticancer drugs crossed the BBB and entered into the brain. In the brain cancer model, exosome delivered anticancer drugs significantly decreased fluorescent intensity of xenotransplanted cancer cells and tumor growth marker. Brain endothelial cell derived exosomes could be potentially used as a carrier for brain delivery of anticancer drug for the treatment of brain cancer.

  19. Brain barriers and functional interfaces with sequential appearance of ABC efflux transporters during human development

    DEFF Research Database (Denmark)

    Møllgård, Kjeld; Dziegielewska, Katarzyna M.; Holst, Camilla B.

    2017-01-01

    Adult brain is protected from entry of drugs and toxins by specific mechanisms such as ABC (ATP-binding Cassette) efflux transporters. Little is known when these appear in human brain during development. Cellular distribution of three main ABC transporters (ABCC1, ABCG2, ABCB1) was determined...... at blood-brain barriers and interfaces in human embryos and fetuses in first half of gestation. Antibodies against claudin-5 and-11 and antibodies to α-fetoprotein were used to describe morphological and functional aspects of brain barriers. First exchange interfaces to be established, probably at 4...... three transporters. Results provide evidence for sequential establishment of brain exchange interfaces and spatial and temporal timetable for three main ABC transporters in early human brain....

  20. Smuggling Drugs into the Brain: An Overview of Ligands Targeting Transcytosis for Drug Delivery across the Blood-Brain Barrier.

    Science.gov (United States)

    Georgieva, Julia V; Hoekstra, Dick; Zuhorn, Inge S

    2014-11-17

    The blood-brain barrier acts as a physical barrier that prevents free entry of blood-derived substances, including those intended for therapeutic applications. The development of molecular Trojan horses is a promising drug targeting technology that allows for non-invasive delivery of therapeutics into the brain. This concept relies on the application of natural or genetically engineered proteins or small peptides, capable of specifically ferrying a drug-payload that is either directly coupled or encapsulated in an appropriate nanocarrier, across the blood-brain barrier via receptor-mediated transcytosis. Specifically, in this process the nanocarrier-drug system ("Trojan horse complex") is transported transcellularly across the brain endothelium, from the blood to the brain interface, essentially trailed by a native receptor. Naturally, only certain properties would favor a receptor to serve as a transporter for nanocarriers, coated with appropriate ligands. Here we briefly discuss brain microvascular endothelial receptors that have been explored until now, highlighting molecular features that govern the efficiency of nanocarrier-mediated drug delivery into the brain.

  1. Smuggling Drugs into the Brain: An Overview of Ligands Targeting Transcytosis for Drug Delivery across the Blood–Brain Barrier

    Directory of Open Access Journals (Sweden)

    Julia V. Georgieva

    2014-11-01

    Full Text Available The blood–brain barrier acts as a physical barrier that prevents free entry of blood-derived substances, including those intended for therapeutic applications. The development of molecular Trojan horses is a promising drug targeting technology that allows for non-invasive delivery of therapeutics into the brain. This concept relies on the application of natural or genetically engineered proteins or small peptides, capable of specifically ferrying a drug-payload that is either directly coupled or encapsulated in an appropriate nanocarrier, across the blood–brain barrier via receptor-mediated transcytosis. Specifically, in this process the nanocarrier–drug system (“Trojan horse complex” is transported transcellularly across the brain endothelium, from the blood to the brain interface, essentially trailed by a native receptor. Naturally, only certain properties would favor a receptor to serve as a transporter for nanocarriers, coated with appropriate ligands. Here we briefly discuss brain microvascular endothelial receptors that have been explored until now, highlighting molecular features that govern the efficiency of nanocarrier-mediated drug delivery into the brain.

  2. A dynamic in vivo-like organotypic blood-brain barrier model to probe metastatic brain tumors

    Science.gov (United States)

    Xu, Hui; Li, Zhongyu; Yu, Yue; Sizdahkhani, Saman; Ho, Winson S.; Yin, Fangchao; Wang, Li; Zhu, Guoli; Zhang, Min; Jiang, Lei; Zhuang, Zhengping; Qin, Jianhua

    2016-11-01

    The blood-brain barrier (BBB) restricts the uptake of many neuro-therapeutic molecules, presenting a formidable hurdle to drug development in brain diseases. We proposed a new and dynamic in vivo-like three-dimensional microfluidic system that replicates the key structural, functional and mechanical properties of the blood-brain barrier in vivo. Multiple factors in this system work synergistically to accentuate BBB-specific attributes-permitting the analysis of complex organ-level responses in both normal and pathological microenvironments in brain tumors. The complex BBB microenvironment is reproduced in this system via physical cell-cell interaction, vascular mechanical cues and cell migration. This model possesses the unique capability to examine brain metastasis of human lung, breast and melanoma cells and their therapeutic responses to chemotherapy. The results suggest that the interactions between cancer cells and astrocytes in BBB microenvironment might affect the ability of malignant brain tumors to traverse between brain and vascular compartments. Furthermore, quantification of spatially resolved barrier functions exists within a single assay, providing a versatile and valuable platform for pharmaceutical development, drug testing and neuroscientific research.

  3. Paving the way towards complex blood-brain barrier models using pluripotent stem cells

    DEFF Research Database (Denmark)

    Lauschke, Karin; Frederiksen, Lise; Hall, Vanessa Jane

    2017-01-01

    A tissue with great need to be modelled in vitro is the blood-brain barrier (BBB). The BBB is a tight barrier that covers all blood vessels in the brain and separates the brain microenvironment from the blood system. It consists of three cell types (neurovascular unit (NVU)) that contribute......, it is now possible to produce many cell types from the BBB and even partially recapitulate this complex tissue in vitro. In this review, we summarize the most recent developments in PSC differentiation and modelling of the BBB. We also suggest how patient-specific human induced PSCs could be used to model...

  4. Electroconvulsive therapy, hypertensive surge, blood-brain barrier breach, and amnesia

    DEFF Research Database (Denmark)

    Andrade, Chittaranjan; Bolwig, Tom G

    2014-01-01

    Preclinical and clinical evidence show that electroconvulsive therapy (ECT)-induced intraictal surge in blood pressure may result in a small, transient breach in the blood-brain barrier, leading to mild cerebral edema and a possible leach of noxious substances from blood into brain tissues...... convincing evidence of benefits. It is concluded that there is insufficient support, at present, for the hypothesis that the hypertensive surge during ECT and the resultant blood-brain barrier breach contribute meaningfully to ECT-induced cognitive deficits. Future research should address the subset...

  5. The diffusion permeability to water of the rat blood-brain barrier

    DEFF Research Database (Denmark)

    Bolwig, T G; Lassen, N A

    1975-01-01

    The diffusion permeability to water of the rat blood-brain-barrier (BBB) was studied. Preliminary data obtained with the Oldendorf tissue uptake method (Oldendorf 1970) in seizure experiments suggested that the transfer from blood to brain of labelled water is diffusion-limited. More definite evi...... passage increased from 0.26 to 0.67 when the arterial carbon dioxide tension was changed from 15 to 85 mm Hg, a change increasing the cerebral blood flow about sixfold. This finding suggests that water does not pass the blood-brain barrier as freely as lipophilic gases....

  6. Imaging blood-brain barrier dysfunction as a biomarker for epileptogenesis.

    Science.gov (United States)

    Bar-Klein, Guy; Lublinsky, Svetlana; Kamintsky, Lyn; Noyman, Iris; Veksler, Ronel; Dalipaj, Hotjensa; Senatorov, Vladimir V; Swissa, Evyatar; Rosenbach, Dror; Elazary, Netta; Milikovsky, Dan Z; Milk, Nadav; Kassirer, Michael; Rosman, Yossi; Serlin, Yonatan; Eisenkraft, Arik; Chassidim, Yoash; Parmet, Yisrael; Kaufer, Daniela; Friedman, Alon

    2017-06-01

    A biomarker that will enable the identification of patients at high-risk for developing post-injury epilepsy is critically required. Microvascular pathology and related blood-brain barrier dysfunction and neuroinflammation were shown to be associated with epileptogenesis after injury. Here we used prospective, longitudinal magnetic resonance imaging to quantitatively follow blood-brain barrier pathology in rats following status epilepticus, late electrocorticography to identify epileptic animals and post-mortem immunohistochemistry to confirm blood-brain barrier dysfunction and neuroinflammation. Finally, to test the pharmacodynamic relevance of the proposed biomarker, two anti-epileptogenic interventions were used; isoflurane anaesthesia and losartan. Our results show that early blood-brain barrier pathology in the piriform network is a sensitive and specific predictor (area under the curve of 0.96, P brain barrier pathology as a clinically relevant predictive, diagnostic and pharmaco!dynamics biomarker for acquired epilepsy. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Effects of deferoxamine on blood-brain barrier disruption after subarachnoid hemorrhage

    OpenAIRE

    Yanjiang Li; Heng Yang; Wei Ni; Yuxiang Gu

    2017-01-01

    Blood brain barrier (BBB) disruption is a key mechanism of subarachnoid hemorrhage (SAH)-induced brain injury. This study examined the mechanism of iron-induced BBB disruption after SAH and investigated the potential therapeutic effect of iron chelation on SAH. Male adult Sprague-Dawley rats had an endovascular perforation of left internal carotid artery bifurcation or sham operation. The rats were treated with deferoxamine (DFX) or vehicle (100mg/kg) for a maximum of 7 days. Brain edema, BBB...

  8. Α-Melanocyte-Stimulating Hormone Protects Early Diabetic Retina from Blood-Retinal Barrier Breakdown and Vascular Leakage via MC4R.

    Science.gov (United States)

    Cai, Siwei; Yang, Qianhui; Hou, Mengzhu; Han, Qian; Zhang, Hanyu; Wang, Jiantao; Qi, Chen; Bo, Qiyu; Ru, Yusha; Yang, Wei; Gu, Zhongxiu; Wei, Ruihua; Cao, Yunshan; Li, Xiaorong; Zhang, Yan

    2018-01-01

    Blood-retinal barrier (BRB) breakdown and vascular leakage is the leading cause of blindness of diabetic retinopathy (DR). Hyperglycemia-induced oxidative stress and inflammation are primary pathogenic factors of this severe DR complication. An effective interventional modality against the pathogenic factors during early DR is needed to curb BRB breakdown and vascular leakage. This study sought to examine the protective effects of α-Melanocyte-stimulating hormone (α-MSH) on early diabetic retina against vascular hyperpermeability, electrophysiological dysfunction, and morphological deterioration in a rat model of diabetes and probe the mechanisms underlying the α-MSH's anti-hyperpermeability in both rodent retinas and simian retinal vascular endothelial cells (RF6A). Sprague Dawley rats were injected through tail vein with streptozotocin to induce diabetes. The rats were intravitreally injected with α-MSH or saline at Week 1 and 3 after hyperglycemia. In another 2 weeks, Evans blue assay, transmission electron microscopy, electroretinogram (ERG), and hematoxylin and eosin (H&E) staining were performed to examine the protective effects of α-MSH in diabetic retinas. The expression of pro-inflammatory factors and tight junction at mRNA and protein levels in retinas was analyzed. Finally, the α-MSH's anti-hyperpermeability was confirmed in a high glucose (HG)-treated RF6A cell monolayer transwell culture by transendothelial electrical resistance (TEER) measurement and a fluorescein isothiocyanate-Dextran assay. Universal or specific melanocortin receptor (MCR) blockers were also employed to elucidate the MCR subtype mediating α-MSH's protection. Evans blue assay showed that BRB breakdown and vascular leakage was detected, and rescued by α-MSH both qualitatively and quantitatively in early diabetic retinas; electron microscopy revealed substantially improved retinal and choroidal vessel ultrastructures in α-MSH-treated diabetic retinas; scotopic ERG suggested

  9. Glutamate Efflux at the Blood-Brain Barrier

    DEFF Research Database (Denmark)

    Cederberg-Helms, Hans Christian; Uhd-Nielsen, Carsten; Brodin, Birger

    2014-01-01

    L-Glutamate is considered the most important excitatory amino acid in the mammalian brain. Strict control of its concentration in the brain interstitial fluid is important to maintain neurotransmission and avoid excitotoxicity. The role of astrocytes in handling L-glutamate transport and metaboli...

  10. Transfection of brain capillary endothelial cells in primary culture with defined blood-brain barrier properties.

    Science.gov (United States)

    Burkhart, Annette; Thomsen, Louiza Bohn; Thomsen, Maj Schneider; Lichota, Jacek; Fazakas, Csilla; Krizbai, István; Moos, Torben

    2015-08-07

    Primary brain capillary endothelial cells (BCECs) are a promising tool to study the blood-brain barrier (BBB) in vitro, as they maintain many important characteristics of the BBB in vivo, especially when co-cultured with pericytes and/or astrocytes. A novel strategy for drug delivery to the brain is to transform BCECs into protein factories by genetic modifications leading to secretion of otherwise BBB impermeable proteins into the central nervous system. However, a huge challenge underlying this strategy is to enable transfection of non-mitotic BCECs, taking a non-viral approach. We therefore aimed to study transfection in primary, non-mitotic BCECs cultured with defined BBB properties without disrupting the cells' integrity. Primary cultures of BCECs, pericytes and astrocytes were generated from rat brains and used in three different in vitro BBB experimental arrangements, which were characterised based on a their expression of tight junction proteins and other BBB specific proteins, high trans-endothelial electrical resistance (TEER), and low passive permeability to radiolabeled mannitol. Recombinant gene expression and protein synthesis were examined in primary BCECs. The BCECs were transfected using a commercially available transfection agent Turbofect™ to express the red fluorescent protein HcRed1-C1. The BCECs were transfected at different time points to monitor transfection in relation to mitotic or non-mitotic cells, as indicated by fluorescence-activated cell sorting analysis after 5-and 6-carboxylfluorescein diacetate succinidyl ester incorporation. The cell cultures exhibited important BBB characteristics judged from their expression of BBB specific proteins, high TEER values, and low passive permeability. Among the three in vitro BBB models, co-culturing with BCECs and astrocytes was well suited for the transfection studies. Transfection was independent of cell division and with equal efficacy between the mitotic and non-mitotic BCECs. Importantly

  11. Blood brain barrier and Alzheimer's disease: Similarity and dissimilarity of molecular alerts.

    Science.gov (United States)

    Toropova, Alla P; Toropov, Andrey A; Begum, S; Achary, P G R

    2017-10-16

    Blood brain barrier and Alzheimer's disease are interrelated. This interrelation is detected by physicochemical methods, pharmacological and electrophysiological analyses. Nature of the phenomenon is extremely complex. The description of this interrelation in mathematical terms is very important task. The systematization of facts, which are described in the literature and related to interaction between processes, which influence on Alzheimer's disease and blood brain barrier is object of this work. In addition, the establishing of correlations between molecular features and endpoints, which are related to treatment of Alzheimer's disease and blood brain barrier using the CORAL software are objects study in this work. The logically structural analysis of information available in the literature; and building up quantitative structure - activity relationships (QSARs) by the Monte Carlo method has been used to solve the task of systematization of facts related to "treatment Alzheimer's disease vs. blood brain barrier". Comparison of agreements and disagreements of available published papers together with the statistical quality of built up QSARs are results of this work. The facts from published papers; and technical details of QSAR built up in this study give possibility to formulate the following rules: (i) there are molecular alerts, which are promoters of increase of blood brain barrier and therapeutic activity of anti-Alzheimer disease agents; (ii) there are molecular alerts, which contradict each other. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. In vitro screening of nanomedicines through the blood brain barrier: A critical review.

    Science.gov (United States)

    Aparicio-Blanco, Juan; Martín-Sabroso, Cristina; Torres-Suárez, Ana-Isabel

    2016-10-01

    The blood-brain barrier accounts for the high attrition rate of the treatments of most brain disorders, which therefore remain one of the greatest health-care challenges of the twenty first century. Against this background of hindrance to brain delivery, nanomedicine takes advantage of the assembly at the nanoscale of available biomaterials to provide a delivery platform with potential to raising brain levels of either imaging or therapeutic agents. Nevertheless, to prevent later failure due to ineffective drug levels at the target site, researchers have been endeavoring to develop a battery of in vitro screening procedures that can predict earlier in the drug discovery process the ability of these cutting-edge drug delivery platforms to cross the blood-brain barrier for biomedical purposes. This review provides an in-depth analysis of the currently available in vitro blood-brain barrier models (both cell-based and non-cell-based) with the focus on their suitability for understanding the biological brain distribution of forthcoming nanomedicines. The relationship between experimental factors and underlying physiological assumptions that would ultimately lead to a more predictive capacity of their in vivo performance, and those methods already assayed for the evaluation of the brain distribution of nanomedicines are comprehensively discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Long-term reliable physically unclonable function based on oxide tunnel barrier breakdown on two-transistors two-magnetic-tunnel-junctions cell-based embedded spin transfer torque magnetoresistive random access memory

    Science.gov (United States)

    Takaya, Satoshi; Tanamoto, Tetsufumi; Noguchi, Hiroki; Ikegami, Kazutaka; Abe, Keiko; Fujita, Shinobu

    2017-04-01

    Among the diverse applications of spintronics, security for internet-of-things (IoT) devices is one of the most important. A physically unclonable function (PUF) with a spin device (spin transfer torque magnetoresistive random access memory, STT-MRAM) is presented. Oxide tunnel barrier breakdown is used to realize long-term stability for PUFs. A secure PUF has been confirmed by evaluating the Hamming distance of a 32-bit STT-MRAM-PUF fabricated using 65 nm CMOS technology.

  14. New frontiers in translational research in neuro-oncology and the blood-brain barrier: report of the tenth annual Blood-Brain Barrier Disruption Consortium Meeting.

    Science.gov (United States)

    Doolittle, Nancy D; Abrey, Lauren E; Bleyer, W Archie; Brem, Steven; Davis, Thomas P; Dore-Duffy, Paula; Drewes, Lester R; Hall, Walter A; Hoffman, John M; Korfel, Agnieszka; Martuza, Robert; Muldoon, Leslie L; Peereboom, David; Peterson, Darryl R; Rabkin, Samuel D; Smith, Quentin; Stevens, Glen H J; Neuwelt, Edward A

    2005-01-15

    The blood-brain barrier (BBB) presents a major obstacle to the treatment of malignant brain tumors and other central nervous system (CNS) diseases. For this reason, a meeting partially funded by an NIH R13 grant was convened to discuss recent advances and future directions in translational research in neuro-oncology and the BBB. Cell biology and transport across the BBB, delivery of agents to the CNS, neuroimaging, angiogenesis, immunotherapy, and gene therapy, as well as glioma, primary CNS lymphoma, and metastases to the CNS were discussed. Transport across the BBB relates to the neurovascular unit, which consists not only of endothelial cells but also of pericyte, glia, and neuronal elements.

  15. Modeling the ischemic blood-brain barrier; the effects of oxygen-glucose deprivation (OGD) on endothelial cells in culture

    DEFF Research Database (Denmark)

    Tornabene, Erica; Helms, Hans Christian Cederberg; Berndt, Philipp

    Introduction - The blood-brain barrier (BBB) is a physical, transport and metabolic barrier which plays a key role in preventing uncontrolled exchanges between blood and brain, ensuring an optimal environment for neurons activity. This extent interface is created by the endothelial cells forming...... pathways across the barrier in ischemic and postischemic brain endothelium is important for developing new medical therapies capable to exploit the barrier changes occurring during/after ischemia to permeate in the brain and treat this devastating disease. Materials and Methods - Primary cultures...

  16. Uptake mechanism of ApoE-modified nanoparticles on brain capillary endothelial cells as a blood-brain barrier model.

    Science.gov (United States)

    Wagner, Sylvia; Zensi, Anja; Wien, Sascha L; Tschickardt, Sabrina E; Maier, Wladislaw; Vogel, Tikva; Worek, Franz; Pietrzik, Claus U; Kreuter, Jörg; von Briesen, Hagen

    2012-01-01

    The blood-brain barrier (BBB) represents an insurmountable obstacle for most drugs thus obstructing an effective treatment of many brain diseases. One solution for overcoming this barrier is a transport by binding of these drugs to surface-modified nanoparticles. Especially apolipoprotein E (ApoE) appears to play a major role in the nanoparticle-mediated drug transport across the BBB. However, at present the underlying mechanism is incompletely understood. In this study, the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells was investigated to differentiate between active and passive uptake mechanism by flow cytometry and confocal laser scanning microscopy. Furthermore, different in vitro co-incubation experiments were performed with competing ligands of the respective receptor. This study confirms an active endocytotic uptake mechanism and shows the involvement of low density lipoprotein receptor family members, notably the low density lipoprotein receptor related protein, on the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells. This knowledge of the uptake mechanism of ApoE-modified nanoparticles enables future developments to rationally create very specific and effective carriers to overcome the blood-brain barrier.

  17. Trojan Horse Transit Contributes to Blood-Brain Barrier Crossing of a Eukaryotic Pathogen.

    Science.gov (United States)

    Santiago-Tirado, Felipe H; Onken, Michael D; Cooper, John A; Klein, Robyn S; Doering, Tamara L

    2017-01-31

    The blood-brain barrier (BBB) protects the central nervous system (CNS) by restricting the passage of molecules and microorganisms. Despite this barrier, however, the fungal pathogen Cryptococcus neoformans invades the brain, causing a meningoencephalitis that is estimated to kill over 600,000 people annually. Cryptococcal infection begins in the lung, and experimental evidence suggests that host phagocytes play a role in subsequent dissemination, although this role remains ill defined. Additionally, the disparate experimental approaches that have been used to probe various potential routes of BBB transit make it impossible to assess their relative contributions, confounding any integrated understanding of cryptococcal brain entry. Here we used an in vitro model BBB to show that a "Trojan horse" mechanism contributes significantly to fungal barrier crossing and that host factors regulate this process independently of free fungal transit. We also, for the first time, directly imaged C. neoformans-containing phagocytes crossing the BBB, showing that they do so via transendothelial pores. Finally, we found that Trojan horse crossing enables CNS entry of fungal mutants that cannot otherwise traverse the BBB, and we demonstrate additional intercellular interactions that may contribute to brain entry. Our work elucidates the mechanism of cryptococcal brain invasion and offers approaches to study other neuropathogens. The fungal pathogen Cryptococcus neoformans invades the brain, causing a meningoencephalitis that kills hundreds of thousands of people each year. One route that has been proposed for this brain entry is a Trojan horse mechanism, whereby the fungus crosses the blood-brain barrier (BBB) as a passenger inside host phagocytes. Although indirect experimental evidence supports this intriguing mechanism, it has never been directly visualized. Here we directly image Trojan horse transit and show that it is regulated independently of free fungal entry, contributes

  18. Iron transport across the blood-brain barrier; Development, neurovascular regulation and cerebral amyloid angiopathy

    Science.gov (United States)

    McCarthy, Ryan C; Kosman, Daniel J

    2014-01-01

    There are two barriers for iron entry into the brain: 1) the brain-cerebrospinal fluid (CSF) barrier and 2) the blood-brain barrier (BBB). Here, we review the literature on developmental iron accumulation by the brain, focusing on the transport of iron through the brain microvascular endothelial cells (BMVEC) of the BBB. We review the iron trafficking proteins which may be involved in the iron flux across BMVEC and discuss the plausible mechanisms of BMVEC iron uptake and efflux. We suggest a model for how BMVEC iron uptake and efflux are regulated and a mechanism by which the majority of iron is trafficked across the developing BBB under the direct guidance of neighboring astrocytes. Thus, we place brain iron uptake in the context of the neurovascular unit of the adult brain. Last, we propose that BMVEC iron is involved in the aggregation of amyloid-β peptides leading to the progression of cerebral amyloid angiopathy which often occurs prior to dementia and the onset of Alzheimer's disease. PMID:25355056

  19. Potential Use of Nanomedicine for Drug Delivery Across the Blood-Brain Barrier in Healthy and Diseased Brain.

    Science.gov (United States)

    Ruozi, Barbara; Belletti, Daniela; Pederzoli, Francesca; Forni, Flavio; Vandelli, Maria Angela; Tosi, Giovanni

    2016-01-01

    The research of efficacious non-invasive therapies for the treatment of brain diseases represents a huge challenge, as people affected by disorders of the central nervous system (CNS) will significantly increase. Moreover, the blood-brain barrier is a key factor in hampering a number of effective drugs to reach the CNS. This review is therefore focusing on possible interventions of nanomedicine-based approaches in selected diseases affecting the CNS. A wide overview of the most outstanding results on preclinical evaluations of the potential of nanomedicine in brain diseases (i.e. brain tumor, Alzheimer, Parkinson, epilepsy and others) is given, with highlights on the data with relevant interest and real possibility in translation from bench-to-bedside. Moreover, a critical evaluation on the rationale in planning nanosystems to target specific brain pathologies is described, opening the path to a more structured and pathology-tailored design of nanocarriers.

  20. The effect of aging on brain barriers and the consequences for Alzheimer's disease development.

    Science.gov (United States)

    Gorlé, Nina; Van Cauwenberghe, Caroline; Libert, Claude; Vandenbroucke, Roosmarijn E

    2016-08-01

    Life expectancy has increased in most developed countries, which has led to an increase in the proportion of elderly people in the world's population. However, this increase in life expectancy is not accompanied by a lengthening of the health span since aging is characterized with progressive deterioration in cellular and organ functions. The brain is particularly vulnerable to disease, and this is reflected in the onset of age-related neurodegenerative diseases such as Alzheimer's disease. Research shows that dysfunction of two barriers in the central nervous system (CNS), the blood-brain barrier (BBB) and the blood-cerebrospinal fluid (CSF) barrier (BCSFB), plays an important role in the progression of these neurodegenerative diseases. The BBB is formed by the endothelial cells of the blood capillaries, whereas the BCSFB is formed by the epithelial cells of the choroid plexus (CP), both of which are affected during aging. Here, we give an overview of how these barriers undergo changes during aging and in Alzheimer's disease, thereby disturbing brain homeostasis. Studying these changes is needed in order to gain a better understanding of the mechanisms of aging at the brain barriers, which might lead to the development of new therapies to lengthen the health span (including mental health) and reduce the chances of developing Alzheimer's disease.

  1. The blood-brain barrier in migraine treatment

    DEFF Research Database (Denmark)

    Edvinsson, L; Tfelt-Hansen, P

    2008-01-01

    Salient aspects of the anatomy and function of the blood-barrier barrier (BBB) are reviewed in relation to migraine pathophysiology and treatment. The main function of the BBB is to limit the access of circulating substances to the neuropile. Smaller lipophilic substances have some access...... to the central nervous system by diffusion, whereas other substances can cross the BBB by carrier-mediated influx transport, receptor-mediated transcytosis and absorptive-mediated transcytosis. Studies of drugs relevant to migraine pathophysiology and treatment have been examined with the pressurized...... with special emphasize on the triptans and calcitonin gene-related peptide (CGRP). The human experimental headache model, especially the use of glycerol trinitrate (the nitric oxide model), and experiences with CGRP administrations utilize the systemic administration of the agonists with effects on other...

  2. Interferon-λ restricts West Nile virus neuroinvasion by tightening the blood-brain barrier.

    Science.gov (United States)

    Lazear, Helen M; Daniels, Brian P; Pinto, Amelia K; Huang, Albert C; Vick, Sarah C; Doyle, Sean E; Gale, Michael; Klein, Robyn S; Diamond, Michael S

    2015-04-22

    Although interferon-λ [also known as type III interferon or interleukin-28 (IL-28)/IL-29] restricts infection by several viruses, its inhibitory mechanism has remained uncertain. We used recombinant interferon-λ and mice lacking the interferon-λ receptor (IFNLR1) to evaluate the effect of interferon-λ on infection with West Nile virus, an encephalitic flavivirus. Cell culture studies in mouse keratinocytes and dendritic cells showed no direct antiviral effect of exogenous interferon-λ, even though expression of interferon-stimulated genes was induced. We observed no differences in West Nile virus burden between wild-type and Ifnlr1(-/-) mice in the draining lymph nodes, spleen, or blood. We detected increased West Nile virus infection in the brain and spinal cord of Ifnlr1(-/-) mice, yet this was not associated with a direct antiviral effect in mouse neurons. Instead, we observed an increase in blood-brain barrier permeability in Ifnlr1(-/-) mice. Treatment of mice with pegylated interferon-λ2 resulted in decreased blood-brain barrier permeability, reduced West Nile virus infection in the brain without affecting viremia, and improved survival against lethal virus challenge. An in vitro model of the blood-brain barrier showed that interferon-λ signaling in mouse brain microvascular endothelial cells increased transendothelial electrical resistance, decreased virus movement across the barrier, and modulated tight junction protein localization in a protein synthesis- and signal transducer and activator of transcription 1 (STAT1)-independent manner. Our data establish an indirect antiviral function of interferon-λ in which noncanonical signaling through IFNLR1 tightens the blood-brain barrier and restricts viral neuroinvasion and pathogenesis. Copyright © 2015, American Association for the Advancement of Science.

  3. Resuscitation of Hypotensive Traumatic Brain Injured Animals With Spray-Dried Plasma Does Not Adversely Alter Physiology and Improves Blood-Brain Barrier Function.

    Science.gov (United States)

    McDaniel, Steven; Golla, Stephanie; Moore, Anthony N; DaCorta, Joe; Bode, Arthur; Pati, Shibani; Dash, Pramod K; Zhao, Jing

    2017-07-01

    According to the Defense and Veterans Brain Injury Center and the Armed Forces Health Surveillance Center, the number of soldiers who have sustained a traumatic brain injury (TBI) has risen dramatically over the past decade. Studies have shown that brain damage can be exacerbated if blood loss occurs (often occurring in polytrauma). As blood supply is critical for brain function and survival, TBI patients must be properly resuscitated to maintain blood volume, blood pressure, and cerebral perfusion. Recent studies have suggested that blood loss can damage the vascular endothelium and enhance blood-brain barrier (BBB) permeability. Brain endothelial cells and the tight junctions between them are key structural components of the BBB. As the BBB is critical for isolating the brain from potential pathogens and for regulating the influx of molecules into the brain, evaluation of resuscitation fluids for their efficacy to improve BBB function has clinical relevance. Although whole blood and fresh frozen plasma (FFP) contain the essential coagulation factors, ions, and other factors, the transport and storage of these products in remote, austere environments can be challenging. The use of spray-dried plasma (SDP) has several advantages including storage at ambient temperature, can be readily reconstituted before use, and infectious materials can be inactivated during the drying process. In this study, we compared FFP and SDP for their effects on blood pressure, cerebral blood flow, BBB integrity, and markers of endothelial cells and tight junction proteins, in TBI animals with blood loss. All procedures were reviewed and approved by the UTHealth animal welfare committee. Sprague Dawley rats received controlled cortical impact brain injury followed by removal of 25% blood volume. Animals were resuscitated 40 minutes later with either FFP or concentrated SDP (Resusix) Heart rate and blood pressure were monitored continuously using catheters implanted into the femoral artery

  4. Restraint stress-induced morphological changes at the blood-brain barrier in adult rats

    Directory of Open Access Journals (Sweden)

    Petra eSántha

    2016-01-01

    Full Text Available Stress is well known to contribute to the development of both neurological and psychiatric diseases. While the role of the blood-brain barrier is increasingly recognised in the development of neurodegenerative disorders, such as Alzheimer’s disease, dysfunction of the blood-brain barrier has been linked to stress-related psychiatric diseases only recently. In the present study the effects of restraint stress with different duration (1, 3 and 21 days were investigated on the morphology of the blood-brain barrier in male adult Wistar rats. Frontal cortex and hippocampus sections were immunostained for markers of brain endothelial cells (claudin-5, occludin and glucose transporter-1 and astroglia (GFAP. Staining pattern and intensity were visualized by confocal microscopy and evaluated by several types of image analysis. The ultrastructure of brain capillaries was investigated by electron microscopy. Morphological changes and intensity alterations in brain endothelial tight junction proteins claudin-5 and occludin were induced by stress. Following restraint stress significant increases in the fluorescence intensity of glucose transporter-1 were detected in brain endothelial cells in the frontal cortex and hippocampus. Significant reductions in GFAP fluorescence intensity were observed in the frontal cortex in all stress groups. As observed by electron microscopy, one-day acute stress induced morphological changes indicating damage in capillary endothelial cells in both brain regions. After 21 days of stress thicker and irregular capillary basal membranes in the hippocampus and edema in astrocytes in both regions were seen. These findings indicate that stress exerts time-dependent changes in the staining pattern of tight junction proteins occludin, claudin-5 and glucose transporter-1 at the level of brain capillaries and in the ultrastructure of brain endothelial cells and astroglial endfeet, which may contribute to neurodegenerative processes

  5. Increased brainstem perfusion, but no blood-brain barrier disruption, during attacks of migraine with aura.

    Science.gov (United States)

    Hougaard, Anders; Amin, Faisal M; Christensen, Casper E; Younis, Samaira; Wolfram, Frauke; Cramer, Stig P; Larsson, Henrik B W; Ashina, Messoud

    2017-06-01

    See Moskowitz (doi:10.1093/brain/awx099) for a scientific commentary on this article.The migraine aura is characterized by transient focal cortical disturbances causing dramatic neurological symptoms that are usually followed by migraine headache. It is currently not understood how the aura symptoms are related to the headache phase of migraine. Animal studies suggest that cortical spreading depression, the likely mechanism of migraine aura, causes disruption of the blood-brain barrier and noxious stimulation of trigeminal afferents leading to activation of brainstem nuclei and triggering of migraine headache. We used the sensitive and validated technique of dynamic contrast-enhanced high-field magnetic resonance imaging to simultaneously investigate blood-brain barrier permeability and tissue perfusion in the brainstem (at the level of the lower pons), visual cortex, and brain areas of the anterior, middle and posterior circulation during spontaneous attacks of migraine with aura. Patients reported to our institution to undergo magnetic resonance imaging during the headache phase after presenting with typical visual aura. Nineteen patients were scanned during attacks and on an attack-free day. The mean time from attack onset to scanning was 7.6 h. We found increased brainstem perfusion bilaterally during migraine with aura attacks. Perfusion also increased in the visual cortex and posterior white matter following migraine aura. We found no increase in blood-brain barrier permeability in any of the investigated regions. There was no correlation between blood-brain barrier permeability, brain perfusion, and time from symptom onset to examination or pain intensity. Our findings demonstrate hyperperfusion in brainstem during the headache phase of migraine with aura, while the blood-brain barrier remains intact during attacks of migraine with aura. These data thus contradict the preclinical hypothesis of cortical spreading depression-induced blood-brain barrier

  6. Astrocytes and pericytes differentially modulate blood–brain barrier characteristics during development and hypoxic insult

    OpenAIRE

    Al Ahmad, A; Taboada, C B; Gassmann, M.; Ogunshola, O O

    2010-01-01

    Understanding regulation of blood-brain barrier (BBB) is crucial to reduce/prevent its disruption during injury. As high brain complexity makes interpretation of in vivo data challenging, BBB studies are frequently performed using simplified in vitro models. However, many models fail to address the three-dimensional (3D) cellular interactions that occur in vivo, an important feature that may explain discrepancies in translation of in vitro data to the in vivo situation. We have designed and c...

  7. [Changes in the permeability of the blood-brain barrier to oxythiamine].

    Science.gov (United States)

    Ostrovskiĭ, Iu M; Zimatkina, T I; Oparin, D A

    1985-01-01

    Activity of transketolase was distinctly inhibited in mice brain after simultaneous administration of hydroxythiamine and 3,3-dimethyl-l-phenyl-l-phthalyl acetic acid. The rate of the enzyme inhibition correlated with an increase of the acid concentration in the mixture studied. The data obtained suggest that permeability of blood-brain barrier for hydroxythiamine was altered in simultaneous administration of the vitamin with some biologically active preparations.

  8. Physiologic and anatomic characterization of the brain surface glia barrier of Drosophila.

    Science.gov (United States)

    DeSalvo, Michael K; Mayer, Nasima; Mayer, Fahima; Bainton, Roland J

    2011-09-01

    Central nervous system (CNS) physiology requires special chemical, metabolic, and cellular privileges for normal function, and blood-brain barrier (BBB) structures are the anatomic and physiologic constructs that arbitrate communication between the brain and body. In the vertebrate BBB, two primary cell types create CNS exclusion biology, a polarized vascular endothelium (VE), and a tightly associated single layer of astrocytic glia (AG). Examples of direct action by the BBB in CNS disease are constantly expanding, including key pathophysiologic roles in multiple sclerosis, stroke, and cancer. In addition, its role as a pharmacologic treatment obstacle to the brain is long standing; thus, molecular model systems that can parse BBB functions and understand the complex integration of sophisticated cellular anatomy and highly polarized chemical protection physiology are desperately needed. Compound barrier structures that use two primary cell types (i.e., functional bicellularity) are common to other humoral/CNS barrier structures. For example, invertebrates use two cell layers of glia, perineurial and subperineurial, to control chemical access to the brain, and analogous glial layers, fenestrated and pseudocartridge, to maintain the blood-eye barrier. In this article, we summarize our current understanding of brain-barrier glial anatomy in Drosophila, demonstrate the power of live imaging as a screening methodology for identifying physiologic characteristics of BBB glia, and compare the physiologies of Drosophila barrier layers to the VE/AG interface of vertebrates. We conclude that many unique BBB physiologies are conserved across phyla and suggest new methods for modeling CNS physiology and disease. Copyright © 2011 Wiley-Liss, Inc.

  9. What is the blood-brain barrier? A molecular perspective. Cerebral vascular biology.

    Science.gov (United States)

    Drewes, L R

    1999-01-01

    The term "blood-brain barrier" was coined over one hundred years ago as a result of the observation that vital dyes introduced into the circulation quickly penetrated and stained nearly all organs and tissues of the mammalian body except the brain which retained its pale creamy appearance. Advances in microscopy revealed that, in contrast to other vascular beds, the brain endothelial cells lining the vascular wall are tightly linked with junctional complexes that eliminate gaps or spaces between cells and prevent any free diffusion of blood-borne substances into the brain parenchymal space. The endothelial cells, situated at the interface between blood and brain, therefore, play a critical role in performing essential biological functions including transport of micro- and macronutrients, receptor-mediated signaling, leukocyte trafficking, and osmoregulation. A number of molecular components responsible for some of these unique properties have now been identified and are being characterized under physiological and disease conditions. These include the proteins involved in formation and assembly of tight junctions; the plasma membrane-embedded proteins that are responsible for transport of brain energy substrates and nutrients (glucose, monocarboxylic acids, nucleosides, amino acids, others); the multi-drug transporter protein, p-glycoprotein, and other drug-rejecting proteins that protect the brain from foreign, potentially disruptive chemicals. These and other recent findings, taken as a whole, reveal the brain endothelium as a complex and dynamic biological system, in contrast to the simple, inert and rigid barrier initially perceived.

  10. The blood-brain barrier in vitro using primary culture

    DEFF Research Database (Denmark)

    Larsen, Annette Burkhart

    and transport of iron across the BBB. Expression of iron-related proteins was investigated at the BBB and it was possible to show expression of the essential iron transport protein; transferrin receptor, ferrireductases, divalent metal transporter 1 (DMT1), ferroportin and ferrooxidases, which was additionally...... obstacle for the treatment of central nervous system (CNS) diseases, as many potentially CNS active drugs are unable to reach their site of action within the brain. In vitro BBB models are, therefore, being developed to investigate the BBB permeability of a drug early in its development. The first part...... to demonstrate protein secretion of recombinant therapeutic polypeptides from BCECs. The third part of the thesis involves iron transport at BCECs, and the study of the transferrin receptor as a carrier for transport into the brain. The transferrin receptor is expressed by the BCECs and is involved in the uptake...

  11. Enhanced brain distribution of carboplatin in a primate model after blood-brain barrier disruption using an implantable ultrasound device.

    Science.gov (United States)

    Goldwirt, Lauriane; Canney, Michael; Horodyckid, Catherine; Poupon, Joel; Mourah, Samia; Vignot, Alexandre; Chapelon, Jean-Yves; Carpentier, Alexandre

    2016-01-01

    Glioblastoma is both the most common and aggressive primary brain tumor in adults. Carboplatin chemotherapy has shown only modest efficacy in progressive high-grade gliomas. The limited clinical efficacy of carboplatin may be due to its low concentration in tissue when the drug is delivered intravenously. The aim of this study was to assess whether the tissue concentration of intravenously administered carboplatin could be enhanced by ultrasound-induced blood-brain disruption in a primate model. Carboplatin was administered intravenously for 60 min to a single primate following blood-brain barrier opening induced by an implantable ultrasound device. Blood and brain samples were collected after animal killing, which occurred 60 min after the end of carboplatin administration. Platinum quantification in ultrafiltrate plasma and brain samples was performed using inductively coupled plasma mass spectrometry. The brain concentration of platinum was highly enhanced (5.2×) in the 3.9 cm(3) region sonicated by the US beam, with a higher concentration in more vascularized anatomical structures. At 5 and 10 mm from the US beam axis, platinum concentrations were slightly enhanced (2.2× and 1.3× respectively). This study demonstrates that BBB opening using an implantable ultrasound transducer enhances the brain distribution of carboplatin in a loco-regional manner. Such a treatment approach is of significant interest for the treatment of primary brain tumors and is under current evaluation in a phase 1 clinical trial (NCT02253212).

  12. Blood-brain barrier molecular trojan horse enables imaging of brain uptake of radioiodinated recombinant protein in the rhesus monkey.

    Science.gov (United States)

    Boado, Ruben J; Hui, Eric K-W; Lu, Jeff Zhiqiang; Sumbria, Rachita K; Pardridge, William M

    2013-10-16

    Recombinant proteins are large molecule drugs that do not cross the blood-brain barrier (BBB). However, BBB-penetration of protein therapeutics is enabled by re-engineering the recombinant protein as IgG fusion proteins. The IgG domain is a monoclonal antibody (mAb) against an endogenous BBB receptor-mediated transport system, such as the human insulin receptor (HIR), and acts as a molecular Trojan horse to ferry the fused protein across the BBB. In the present study, a recombinant lysosomal enzyme, iduronate 2-sulfatase (IDS), is fused to the HIRMAb, and BBB penetration of the IDS alone vs the HIRMAb-IDS fusion protein is compared in the Rhesus monkey. Recombinant IDS and the HIRMAb-IDS fusion protein were radiolabeled with indirect iodination with the [(125)I]-Bolton-Hunter reagent and with direct iodination with Iodogen/[(125)I]-idodine. IDS and the HIRMAb-IDS fusion protein have comparable plasma pharmacokinetics and uptake by peripheral organs. IDS does not cross the BBB. The HIRMAb-IDS fusion protein crosses the BBB and the brain uptake is 1% of injected dose/brain. Brain imaging shows HIRMAb-IDS penetration to all parts of brain, and immunoprecipitation of brain radioactivity shows intact fusion protein in brain. The use of BBB molecular Trojan horses enables brain imaging of recombinant proteins that are re-engineered for BBB transport.

  13. Increased flux of the plant sterols campesterol and sitosterol across a disrupted blood brain barrier.

    Science.gov (United States)

    Saeed, Ahmed A; Genové, Guillem; Li, Tian; Hülshorst, Frank; Betsholtz, Christer; Björkhem, Ingemar; Lütjohann, Dieter

    2015-07-01

    The intact blood-brain barrier in mammalians prevents exchange of cholesterol loaden particles between periphery and brain and thus nearly all cholesterol in this organ originates from de novo synthesis. Dietary cholesterol homologues from plants, campesterol and sitosterol, are known to get enriched to some extent in the mammalian brain. We recently showed that Pdgfb(ret)(/)(ret) mice, with a pericyte deficiency and a leaking blood-brain barrier phenotype, have significantly higher levels of plant sterols in the brain compared to their heterozygous Pdgfb(ret)(/)(+) controls keeping the integrity of the blood-brain barrier (BBB). In order to further study the protective functionality of the BBB we synthesized a mixture of [(2)H6]campesterol/sitosterol and fed it for 10-40days to genetically different types of animals. There was a significant enrichment of both deuterium stable isotope labeled plant sterols in the brain of both strains of mice, however, with a lower enrichment in the controls. As expected, the percentage and absolute enrichment was higher for [(2)H6]campesterol than for the more lipophilic [(2)H6]sitosterol. The results confirm that a leaking BBB causes increased flux of plant sterols into the brain. The significant flux of the labeled plant sterols into the brain of the control mice illustrates that the presence of an alkyl group in the 24-position of the steroid side chain markedly increases the ability of cholesterol to pass an intact BBB. We discuss the possibility that there is a specific transport mechanism involved in the flux of alkylated cholesterol species across the BBB. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. /GD-Tracker/ A software for blood-brain barrier permeability assessment\

    Czech Academy of Sciences Publication Activity Database

    Kala, David; Svoboda, Jan; Litvinec, Andrej; Pošusta, Antonín; Lisý, J.; Šulc, V.; Tomek, A.; Marusič, P.; Jiruška, Přemysl; Otáhal, Jakub

    2017-01-01

    Roč. 47, č. 2 (2017), s. 43-48 ISSN 0301-5491 R&D Projects: GA MZd(CZ) NV15-33115A; GA MŠk(CZ) LM2015062 Institutional support: RVO:67985823 Keywords : blood-brain barrier * MRI * Gd-DTPA * permeability * stroke * epileptogenesis * MATLAB * freeware * Gd-Tracker Subject RIV: FH - Neurology

  15. Does sumatriptan cross the blood-brain barrier in animals and man?

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Peer

    2010-01-01

    Sumatriptan, a relatively hydrophilic triptan, based on several animal studies has been regarded to be unable to cross the blood-brain barrier (BBB). In more recent animal studies there are strong indications that sumatriptan to some extent can cross the BBB. The CNS adverse events of sumatriptan...

  16. Protective effects of monomethyl fumarate at the inflamed blood-brain barrier

    NARCIS (Netherlands)

    Lim, J.L.; van der Pol, S.M.A.; Di Dio, F.; van het Hof, B.; Kooij, G.; de Vries, H.E.; van Horssen, J.

    2015-01-01

    Background: Reactive oxygen species play a key role in the pathogenesis of multiple sclerosis as they induce blood-brain barrier disruption and enhance transendothelial leukocyte migration. Thus, therapeutic compounds with antioxidant and anti-inflammatory potential could have clinical value in

  17. Microfluidic organ-on-chip technology for blood-brain barrier research

    NARCIS (Netherlands)

    van der Helm, Marieke Willemijn; van der Meer, Andries Dirk; Eijkel, Jan C.T.; van den Berg, Albert; Segerink, Loes Irene

    Organs-on-chips are a new class of microengineered laboratory models that combine several of the advantages of current in vivo and in vitro models. In this review, we summarize the advances that have been made in the development of organ-on-chip models of the blood-brain barrier (BBBs-on-chips) and

  18. Microfluidic organ-on-chip technology for blood-brain barrier research

    NARCIS (Netherlands)

    van der Helm, Marieke Willemijn; van der Meer, Andries Dirk; Eijkel, Jan C.T.; van den Berg, Albert; Segerink, Loes Irene

    2016-01-01

    Organs-on-chips are a new class of microengineered laboratory models that combine several of the advantages of current in vivo and in vitro models. In this review, we summarize the advances that have been made in the development of organ-on-chip models of the blood-brain barrier (BBBs-on-chips) and

  19. Blood-brain barrier leakage after status epilepticus in rapamycin-treated rats II : Potential mechanisms

    NARCIS (Netherlands)

    van Vliet, Erwin A; Otte, Wim M; Wadman, Wytse J; Aronica, Eleonora; Kooij, Gijs; de Vries, Helga E; Dijkhuizen, Rick M; Gorter, Jan A

    OBJECTIVE: Blood-brain barrier (BBB) leakage may play a pro-epileptogenic role after status epilepticus. In the accompanying contrast-enhanced magnetic resonance imaging (CE-MRI) study we showed that the mammalian target of rapamycin (mTOR) inhibitor rapamycin reduced BBB leakage and seizure

  20. Theranastic USPIO-loaded microbubbles for mediating and monitoring blood-brain barrier permeation

    NARCIS (Netherlands)

    Lammers, Twan Gerardus Gertudis Maria; Koczera, Patrick; Fokong, Stanley; Gremse, Felix; Ehling, Josef; Vogt, Michael; Pich, Andrij; Storm, Gerrit; van Zandvoort, Marc; Kiessling, Fabian

    2015-01-01

    Efficient and safe drug delivery across the blood-brain barrier (BBB) remains one of the major challenges of biomedical and (nano-) pharmaceutical research. Here, it is demonstrated that poly(butyl cyanoacrylate)-based microbubbles (MB), carrying ultrasmall superparamagnetic iron oxide (USPIO)

  1. Theranostic USPIO-loaded microbubbles for mediating and monitoring blood-brain barrier permeation

    NARCIS (Netherlands)

    Lammers, Twan|info:eu-repo/dai/nl/304824577; Koczera, Patrick; Fokong, Stanley; Gremse, Felix; Ehling, Josef; Vogt, Michael; Pich, Andrij; Storm, G|info:eu-repo/dai/nl/073356328; Van Zandvoort, Marc; Kiessling, Fabian

    2015-01-01

    Efficient and safe drug delivery across the blood-brain barrier (BBB) remains one of the major challenges of biomedical and (nano-) pharmaceutical research. Here, it is demonstrated that poly(butyl cyanoacrylate)-based microbubbles (MB), carrying ultrasmall superparamagnetic iron oxide (USPIO)

  2. P-Glycoprotein Function at the Blood-Brain Barrier: Effects of Age and Gender

    NARCIS (Netherlands)

    van Assema, D.M.E.; Lubberink, J.M.; Boellaard, R.; Schuit, R.C.; Windhorst, A.D.; Scheltens, P.; Lammertsma, A.A.; van Berckel, B.N.M.

    2012-01-01

    Purpose: P-glycoprotein (Pgp) is an efflux transporter involved in transport of several compounds across the blood-brain barrier (BBB). Loss of Pgp function with increasing age may be involved in the development of age-related disorders, but this may differ between males and females. Pgp function

  3. The rights and wrongs of blood-brain barrier permeability studies

    DEFF Research Database (Denmark)

    Saunders, Norman R; Dreifuss, Jean-Jacques; Dziegielewska, Katarzyna M

    2014-01-01

    important for clinicians to have proper evidence on which to advise pregnant women who may need to take medications for serious medical conditions. Beliefs in immaturity of the blood-brain barrier have held the field back for decades. Their history illustrates the importance of taking account of all...

  4. Lack of IL-6 increases blood–brain barrier permeability in fungal ...

    Indian Academy of Sciences (India)

    − mice ... Interleukin (IL-6) is a multifunctional cytokine, and numerous studies have shown that IL‐6 influences the integrity of the blood–brain barrier. In this study we ... Dates. Manuscript received: 16 June 2014; Accepted: 10 November 2014 ...

  5. Blood-brain barrier transport kinetics of the cyclic depsipeptide mycotoxins beauvericin and enniatins.

    Science.gov (United States)

    Taevernier, Lien; Bracke, Nathalie; Veryser, Lieselotte; Wynendaele, Evelien; Gevaert, Bert; Peremans, Kathelijne; De Spiegeleer, Bart

    2016-09-06

    The cyclic depsipeptide mycotoxins beauvericin and enniatins are capable of reaching the systemic circulation through various routes of exposure and are hence capable of exerting central nervous system (CNS) effects, if they are able to pass the blood-brain barrier (BBB), which was the main objective of this study. Quantification of the mycotoxins was performed using an in-house developed and validated bio-analytical UHPLC-MS/MS method. Prior to the BBB experiments, the metabolic stability of the mycotoxins was evaluated in vitro in mouse serum and brain homogenate. The BBB permeation kinetics of beauvericin and enniatins were studied using an in vivo mice model, applying multiple time regression for studying the blood-to-brain influx. Additionally, capillary depletion was applied to obtain the fraction of the peptides really entering the brain parenchyma and the fraction loosely adhered to the brain capillary wall. Finally, also the brain-to-blood efflux transport kinetics was studied. Metabolic stability data indicated that the investigated mycotoxins were stable during the duration of the in vivo study. The brain influx study showed that beauvericin and enniatins are able to cross the blood-brain barrier in mice: using the Gjedde-Patlak biphasic model, it was shown that all investigated mycotoxins exert a high initial influx rate into the brain (K1 ranging from 11 to 53μL/(g×min)), rapidly reaching a plateau. After penetration, the mycotoxins reached the brain parenchyma (95%) with only a limited amount residing in the capillaries (5%). Negligible efflux (<0.005min(-1)) from the brain was observed in the 15min post-intracerebroventricular injection. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Intra-Arterial Delivery of AAV Vectors to the Mouse Brain After Mannitol Mediated Blood Brain Barrier Disruption

    Science.gov (United States)

    Santillan, Alejandro; Sondhi, Dolan; Dyke, Jonathan P.; Crystal, Ronald G.; Gobin, Y. Pierre; Ballon, Douglas J.

    2014-01-01

    The delivery of therapeutics to neural tissue is greatly hindered by the blood brain barrier (BBB). Direct local delivery via diffusive release from degradable implants or direct intra-cerebral injection can bypass the BBB and obtain high concentrations of the therapeutic in the targeted tissue, however the total volume of tissue that can be treated using these techniques is limited. One treatment modality that can potentially access large volumes of neural tissue in a single treatment is intra-arterial (IA) injection after osmotic blood brain barrier disruption. In this technique, the therapeutic of interest is injected directly into the arteries that feed the target tissue after the blood brain barrier has been disrupted by exposure to a hyperosmolar mannitol solution, permitting the transluminal transport of the therapy. In this work we used contrast enhanced magnetic resonance imaging (MRI) studies of IA injections in mice to establish parameters that allow for extensive and reproducible BBB disruption. We found that the volume but not the flow rate of the mannitol injection has a significant effect on the degree of disruption. To determine whether the degree of disruption we observed with this method was sufficient for delivery of nanoscale therapeutics, we performed IA injections of an adeno-associated viral vector containing the CLN2 gene (AAVrh.10CLN2), which is mutated in the lysosomal storage disorder Late Infantile Neuronal Ceroid Lipofuscinosis (LINCL). We demonstrated that IA injection of AAVrh.10CLN2 after BBB disruption can achieve widespread transgene production in the mouse brain after a single administration. Further, we showed that there exists a minimum threshold of BBB disruption necessary to permit the AAV.rh10 vector to pass into the brain parenchyma from the vascular system. These results suggest that IA administration may be used to obtain widespread delivery of nanoscale therapeutics throughout the murine brain after a single

  7. Effects of propranolol and clonidine on brain edema, blood-brain barrier permeability, and endothelial glycocalyx disruption after fluid percussion brain injury in the rat

    DEFF Research Database (Denmark)

    Genét, Gustav Folmer; Bentzer, Peter; Hansen, Morten Bagge

    2018-01-01

    ), vehicle (n = 16), or sham (n = 5) for 24 hours. Primary outcome was brain water content at 24 hours. Secondary outcomes were blood-brain barrier permeability and plasma levels of syndecan-1 (glycocalyx disruption), cell damage (histone-complexed DNA fragments), epinephrine, norepinephrine, and animal.......555). We found no effect of propranolol and propranolol/clonidine on blood-brain barrier permeability and animal motor scores. Unexpectedly, propranolol and propranolol/clonidine caused an increase in epinephrine and syndecan-1 levels. CONCLUSION: This study does not provide any support for unselective......BACKGROUND: Traumatic brain injury causes a disruption of the vascular endothelial glycocalyx layer that is associated with an overactivation of the sympathoadrenal system. We hypothesized that early and unselective beta-blockade with propranolol alone or in combination with the alfa2-agonist...

  8. Multiple blood-brain barrier transport mechanisms limit bumetanide accumulation, and therapeutic potential, in the mammalian brain.

    Science.gov (United States)

    Römermann, Kerstin; Fedrowitz, Maren; Hampel, Philip; Kaczmarek, Edith; Töllner, Kathrin; Erker, Thomas; Sweet, Douglas H; Löscher, Wolfgang

    2017-05-01

    There is accumulating evidence that bumetanide, which has been used over decades as a potent loop diuretic, also exerts effects on brain disorders, including autism, neonatal seizures, and epilepsy, which are not related to its effects on the kidney but rather mediated by inhibition of the neuronal Na-K-Cl cotransporter isoform NKCC1. However, following systemic administration, brain levels of bumetanide are typically below those needed to inhibit NKCC1, which critically limits its clinical use for treating brain disorders. Recently, active efflux transport at the blood-brain barrier (BBB) has been suggested as a process involved in the low brain:plasma ratio of bumetanide, but it is presently not clear which transporters are involved. Understanding the processes explaining the poor brain penetration of bumetanide is needed for developing strategies to improve the brain delivery of this drug. In the present study, we administered probenecid and more selective inhibitors of active transport carriers at the BBB directly into the brain of mice to minimize the contribution of peripheral effects on the brain penetration of bumetanide. Furthermore, in vitro experiments with mouse organic anion transporter 3 (Oat3)-overexpressing Chinese hamster ovary cells were performed to study the interaction of bumetanide, bumetanide derivatives, and several known inhibitors of Oats on Oat3-mediated transport. The in vivo experiments demonstrated that the uptake and efflux of bumetanide at the BBB is much more complex than previously thought. It seems that both restricted passive diffusion and active efflux transport, mediated by Oat3 but also organic anion-transporting polypeptide (Oatp) Oatp1a4 and multidrug resistance protein 4 explain the extremely low brain concentrations that are achieved after systemic administration of bumetanide, limiting the use of this drug for targeting abnormal expression of neuronal NKCC1 in brain diseases. Copyright © 2017 Elsevier Ltd. All rights

  9. Breaking down brain barrier breaches in cerebral malaria

    DEFF Research Database (Denmark)

    Petersen, Jens E V; Lavstsen, Thomas; Craig, Alister

    2016-01-01

    Recent findings have linked brain swelling to death in cerebral malaria (CM). These observations have prompted a number of investigations into the mechanisms of this pathology with the goal of identifying potential therapeutic targets. In this issue of the JCI, Gallego-Delgado and colleagues...... present evidence that implicates angiotensin receptors and the relocation of β-catenin to the endothelial cell nucleus in CM. This study provides a renewed focus on infected erythrocyte debris as the cause of endothelial damage and challenges previous work implicating direct effects of infected...

  10. The Trojan Horse Liposome Technology for Nonviral Gene Transfer across the Blood-Brain Barrier

    Directory of Open Access Journals (Sweden)

    Ruben J. Boado

    2011-01-01

    Full Text Available The application of blood-borne gene therapy protocols to the brain is limited by the presence of the blood-brain barrier (BBB. Viruses have been extensively used as gene delivery systems. However, their efficacy in brain is limited by the lack of transport across the BBB following intravenous (IV administration. Recent progress in the “Trojan Horse Liposome” (THL technology applied to transvascular non-viral gene therapy of the brain presents a promising solution to the trans-vascular brain gene delivery problem. THLs are comprised of immunoliposomes carrying nonviral gene expression plasmids. The tissue target specificity of the THL is provided by peptidomimetic monoclonal antibody (MAb component of the THL, which binds to specific endogenous receptors located on both the BBB and on brain cellular membranes, for example, insulin receptor and transferrin receptor. These MAbs mediate (a receptor-mediated transcytosis of the THL complex through the BBB, (b endocytosis into brain cells and (c transport to the brain cell nuclear compartment. The expression of the transgene in brain may be restricted using tissue/cell specific gene promoters. This manuscript presents an overview on the THL transport technology applied to brain disorders, including lysosomal storage disorders and Parkinson's disease.

  11. The Trojan Horse Liposome Technology for Nonviral Gene Transfer across the Blood-Brain Barrier.

    Science.gov (United States)

    Boado, Ruben J; Pardridge, William M

    2011-01-01

    The application of blood-borne gene therapy protocols to the brain is limited by the presence of the blood-brain barrier (BBB). Viruses have been extensively used as gene delivery systems. However, their efficacy in brain is limited by the lack of transport across the BBB following intravenous (IV) administration. Recent progress in the "Trojan Horse Liposome" (THL) technology applied to transvascular non-viral gene therapy of the brain presents a promising solution to the trans-vascular brain gene delivery problem. THLs are comprised of immunoliposomes carrying nonviral gene expression plasmids. The tissue target specificity of the THL is provided by peptidomimetic monoclonal antibody (MAb) component of the THL, which binds to specific endogenous receptors located on both the BBB and on brain cellular membranes, for example, insulin receptor and transferrin receptor. These MAbs mediate (a) receptor-mediated transcytosis of the THL complex through the BBB, (b) endocytosis into brain cells and (c) transport to the brain cell nuclear compartment. The expression of the transgene in brain may be restricted using tissue/cell specific gene promoters. This manuscript presents an overview on the THL transport technology applied to brain disorders, including lysosomal storage disorders and Parkinson's disease.

  12. Effects of propranolol and clonidine on brain edema, blood-brain barrier permeability, and endothelial glycocalyx disruption after fluid percussion brain injury in the rat.

    Science.gov (United States)

    Genét, Gustav Folmer; Bentzer, Peter; Hansen, Morten Bagge; Ostrowski, Sisse Rye; Johansson, Pär Ingemar

    2018-01-01

    Traumatic brain injury causes a disruption of the vascular endothelial glycocalyx layer that is associated with an overactivation of the sympathoadrenal system. We hypothesized that early and unselective beta-blockade with propranolol alone or in combination with the alfa2-agonist clonidine would decrease brain edema, blood-brain barrier permeability, and glycocalyx disruption at 24 hours after trauma. We subjected 53 adult male Sprague-Dawley rats to lateral fluid percussion brain injury and randomized infusion with propranolol (n = 16), propranolol + clonidine (n = 16), vehicle (n = 16), or sham (n = 5) for 24 hours. Primary outcome was brain water content at 24 hours. Secondary outcomes were blood-brain barrier permeability and plasma levels of syndecan-1 (glycocalyx disruption), cell damage (histone-complexed DNA fragments), epinephrine, norepinephrine, and animal motor function. We found no difference in brain water content (mean ± SD) between propranolol (80.8 ± 0.3%; 95% confidence interval [CI], 80.7-81.0) and vehicle (81.1 ± 0.6%; 95% CI, 80.8-81.4) (p = 0.668) or between propranolol/clonidine (80.8 ± 0.3%; 95% CI, 80.7-81.0) and vehicle (p = 0.555). We found no effect of propranolol and propranolol/clonidine on blood-brain barrier permeability and animal motor scores. Unexpectedly, propranolol and propranolol/clonidine caused an increase in epinephrine and syndecan-1 levels. This study does not provide any support for unselective beta-blockade with propranolol or the combination of propranolol and the alfa2-agonist clonidine on brain water content. The novel finding of an increase in plasma concentrations of epinephrine and syndecan-1 after propranolol treatment in traumatic brain injury is of unclear significance and should be investigated further.

  13. Modulation of p-glycoprotein transport function at the blood-brain barrier.

    Science.gov (United States)

    Bauer, Björn; Hartz, Anika M S; Fricker, Gert; Miller, David S

    2005-02-01

    The central nervous system (CNS) effects of many therapeutic drugs are blunted because of restricted entry into the brain. The basis for this poor permeability is the brain capillary endothelium, which comprises the blood-brain barrier. This tissue exhibits very low paracellular (tight-junctional) permeability and expresses potent, multispecific, drug export pumps. Together, these combine to limit use of pharmacotherapy to treat CNS disorders such as brain cancer and bacterial or viral infections. Of all the xenobiotic efflux pumps highly expressed in brain capillary endothelial cells, p-glycoprotein handles the largest fraction of commonly prescribed drugs and thus is an obvious target for manipulation. Here we review recent studies focused on understanding the mechanisms by which p-glycoprotein activity in the blood-brain barrier can be modulated. These include (i) direct inhibition by specific competitors, (ii) functional modulation, and (iii) transcriptional modulation. Each has the potential to specifically reduce p-glycoprotein function and thus selectively increase brain permeability of p-glycoprotein substrates.

  14. GLP-1 analog raises glucose transport capacity of blood-brain barrier in Alzheimer's disease

    DEFF Research Database (Denmark)

    Gejl, M.; Brock, B.; Egefjord, L.

    2017-01-01

    claim that the GLP-1 analog liraglutide may prevent the decline of blood-brain glucose transfer in AD. Methods: In this 26-week test of the hypothesis, we randomized 38 patients with AD to treatment with the GLP-1 analog liraglutide (n = 18) or placebo (n = 20). We determined blood-brain glucose......Objectives: Glucose enters the brain tissue from plasma by facilitated diffusion across the two membranes of the endothelium of the blood-brain barrier (BBB), mediated by the glucose transporter 1 (GLUT1). There is evidence in Alzheimer's disease (AD) of reduction of glucose transport across...... and degeneration. Hypothesis: The incretin hormone GLP-1 prevents the decline of the cerebral metabolic rate of glucose that signifies cognitive impairment, synaptic dysfunction, and disease evolution in AD, and GLP-1 may directly activate GLUT1 transport in brain capillary endothelium. For this reason, we here...

  15. The in vitro blood-brain barrier model under OGD condition

    DEFF Research Database (Denmark)

    Tornabene, Erica; Helms, Hans Christian Cederberg; Berndt, Philipp

    Introduction - The blood-brain barrier (BBB) is a physical, transport and metabolic barrier which plays a key role in preventing uncontrolled exchanges between blood and brain, ensuring an optimal environment for neurons activity. This extent interface is created by the endothelial cells forming...... of therapies to treat this devastating disease. Materials and Methods - Primary cultures of endothelial cells from bovine brain microvessels were cocultured with rat astrocytes in transwell inserts. At day 11, cells were treated with 4h of OGD by changing the culture medium with glucose-free medium...... of this regulation, further experiments will be performed. Conclusions – We have established an in vitro model of BBB in OGD condition and its characterization showed the disassembly of tight junctions at cell-cell contact with subsequent recovery during reperfusion....

  16. A2A Adenosine Receptor Antagonism Reverts the Blood-Brain Barrier Dysfunction Induced by Sleep Restriction.

    Directory of Open Access Journals (Sweden)

    Gabriela Hurtado-Alvarado

    Full Text Available Chronic sleep restriction induces blood-brain barrier disruption and increases pro-inflammatory mediators in rodents. Those inflammatory mediators may modulate the blood-brain barrier and constitute a link between sleep loss and blood-brain barrier physiology. We propose that adenosine action on its A2A receptor may be modulating the blood-brain barrier dynamics in sleep-restricted rats. We administrated a selective A2A adenosine receptor antagonist (SCH58261 in sleep-restricted rats at the 10th day of sleep restriction and evaluated the blood-brain barrier permeability to dextrans coupled to fluorescein (FITC-dextrans and Evans blue. In addition, we evaluated by western blot the expression of tight junction proteins (claudin-5, occludin, ZO-1, adherens junction protein (E-cadherin, A2A adenosine receptor, adenosine-synthesizing enzyme (CD73, and neuroinflammatory markers (Iba-1 and GFAP in the cerebral cortex, hippocampus, basal nuclei and cerebellar vermis. Sleep restriction increased blood-brain barrier permeability to FITC-dextrans and Evans blue, and the effect was reverted by the administration of SCH58261 in almost all brain regions, excluding the cerebellum. Sleep restriction increased the expression of A2A adenosine receptor only in the hippocampus and basal nuclei without changing the expression of CD73 in all brain regions. Sleep restriction reduced the expression of tight junction proteins in all brain regions, except in the cerebellum; and SCH58261 restored the levels of tight junction proteins in the cortex, hippocampus and basal nuclei. Finally, sleep restriction induced GFAP and Iba-1 overexpression that was attenuated with the administration of SCH58261. These data suggest that the action of adenosine on its A2A receptor may have a crucial role in blood-brain barrier dysfunction during sleep loss probably by direct modulation of brain endothelial cell permeability or through a mechanism that involves gliosis with subsequent

  17. A2A Adenosine Receptor Antagonism Reverts the Blood-Brain Barrier Dysfunction Induced by Sleep Restriction.

    Science.gov (United States)

    Hurtado-Alvarado, Gabriela; Domínguez-Salazar, Emilio; Velázquez-Moctezuma, Javier; Gómez-González, Beatriz

    2016-01-01

    Chronic sleep restriction induces blood-brain barrier disruption and increases pro-inflammatory mediators in rodents. Those inflammatory mediators may modulate the blood-brain barrier and constitute a link between sleep loss and blood-brain barrier physiology. We propose that adenosine action on its A2A receptor may be modulating the blood-brain barrier dynamics in sleep-restricted rats. We administrated a selective A2A adenosine receptor antagonist (SCH58261) in sleep-restricted rats at the 10th day of sleep restriction and evaluated the blood-brain barrier permeability to dextrans coupled to fluorescein (FITC-dextrans) and Evans blue. In addition, we evaluated by western blot the expression of tight junction proteins (claudin-5, occludin, ZO-1), adherens junction protein (E-cadherin), A2A adenosine receptor, adenosine-synthesizing enzyme (CD73), and neuroinflammatory markers (Iba-1 and GFAP) in the cerebral cortex, hippocampus, basal nuclei and cerebellar vermis. Sleep restriction increased blood-brain barrier permeability to FITC-dextrans and Evans blue, and the effect was reverted by the administration of SCH58261 in almost all brain regions, excluding the cerebellum. Sleep restriction increased the expression of A2A adenosine receptor only in the hippocampus and basal nuclei without changing the expression of CD73 in all brain regions. Sleep restriction reduced the expression of tight junction proteins in all brain regions, except in the cerebellum; and SCH58261 restored the levels of tight junction proteins in the cortex, hippocampus and basal nuclei. Finally, sleep restriction induced GFAP and Iba-1 overexpression that was attenuated with the administration of SCH58261. These data suggest that the action of adenosine on its A2A receptor may have a crucial role in blood-brain barrier dysfunction during sleep loss probably by direct modulation of brain endothelial cell permeability or through a mechanism that involves gliosis with subsequent inflammation and

  18. A2A Adenosine Receptor Antagonism Reverts the Blood-Brain Barrier Dysfunction Induced by Sleep Restriction

    Science.gov (United States)

    Hurtado-Alvarado, Gabriela; Domínguez-Salazar, Emilio; Velázquez-Moctezuma, Javier

    2016-01-01

    Chronic sleep restriction induces blood-brain barrier disruption and increases pro-inflammatory mediators in rodents. Those inflammatory mediators may modulate the blood-brain barrier and constitute a link between sleep loss and blood-brain barrier physiology. We propose that adenosine action on its A2A receptor may be modulating the blood-brain barrier dynamics in sleep-restricted rats. We administrated a selective A2A adenosine receptor antagonist (SCH58261) in sleep-restricted rats at the 10th day of sleep restriction and evaluated the blood-brain barrier permeability to dextrans coupled to fluorescein (FITC-dextrans) and Evans blue. In addition, we evaluated by western blot the expression of tight junction proteins (claudin-5, occludin, ZO-1), adherens junction protein (E-cadherin), A2A adenosine receptor, adenosine-synthesizing enzyme (CD73), and neuroinflammatory markers (Iba-1 and GFAP) in the cerebral cortex, hippocampus, basal nuclei and cerebellar vermis. Sleep restriction increased blood-brain barrier permeability to FITC-dextrans and Evans blue, and the effect was reverted by the administration of SCH58261 in almost all brain regions, excluding the cerebellum. Sleep restriction increased the expression of A2A adenosine receptor only in the hippocampus and basal nuclei without changing the expression of CD73 in all brain regions. Sleep restriction reduced the expression of tight junction proteins in all brain regions, except in the cerebellum; and SCH58261 restored the levels of tight junction proteins in the cortex, hippocampus and basal nuclei. Finally, sleep restriction induced GFAP and Iba-1 overexpression that was attenuated with the administration of SCH58261. These data suggest that the action of adenosine on its A2A receptor may have a crucial role in blood-brain barrier dysfunction during sleep loss probably by direct modulation of brain endothelial cell permeability or through a mechanism that involves gliosis with subsequent inflammation and

  19. The Role of P-Glycoprotein in Transport of Danshensu across the Blood-Brain Barrier

    Directory of Open Access Journals (Sweden)

    Peng-Fei Yu

    2011-01-01

    Full Text Available Danshensu (3-(3, 4-dihydroxyphenyl lactic acid, a water-soluble active component isolated from the root of Salvia miltiorrhiza Bunge, is widely used for the treatment of cerebrovascular diseases. The present study aims to investigate the role of P-glycoprotein in transport of Danshensu across the blood-brain barrier. Sprague-Dawley rats were pretreated with verapamil at a dose of 20 mg kg−1 (verapamil group or the same volume of normal saline (control group. Ninety minutes later, the animals were administrated with Danshensu (15 mg kg−1 by intravenous injection. At 15 min, 30 min, and 60 min after Danshensu administration, the levels of Danshensu in the blood and brain were detected by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS. The results showed that Danshensu concentrations in the brain of the rats pretreated with verapamil were significantly increased. In addition, the brain-plasma ratios of the group pretreated with verapamil were much higher than that of the control group. There was no difference in Danshensu level in plasma between the verapamil group and control group. The findings indicated that Danshensu can pass the blood-brain barrier, and P-glycoprotein plays an important role in Danshensu transportation in brain.

  20. Rapid and reversible enhancement of blood–brain barrier permeability using lysophosphatidic acid

    Science.gov (United States)

    On, Ngoc H; Savant, Sanjot; Toews, Myron; Miller, Donald W

    2013-01-01

    The present study characterizes the effects of lysophosphatidic acid (LPA) on blood–brain barrier (BBB) permeability focusing specifically on the time of onset, duration, and magnitude of LPA-induced changes in cerebrovascular permeability in the mouse using both magnetic resonance imaging (MRI) and near infrared fluorescence imaging (NIFR). Furthermore, potential application of LPA for enhanced drug delivery to the brain was also examined by measuring the brain accumulation of radiolabeled methotrexate. Exposure of primary cultured brain microvessel endothelial cells (BMECs) to LPA produced concentration-dependent increases in permeability that were completely abolished by clostridium toxin B. Administration of LPA disrupted BBB integrity and enhanced the permeability of small molecular weight marker gadolinium diethylenetriaminepentaacetate (Gd-DTPA) contrast agent, the large molecular weight permeability marker, IRdye800cwPEG, and the P-glycoprotein efflux transporter probe, Rhodamine 800 (R800). The increase in BBB permeability occurred within 3 minutes after LPA injection and barrier integrity was restored within 20 minutes. A decreased response to LPA on large macromolecule BBB permeability was observed after repeated administration. The administration of LPA also resulted in 20-fold enhancement of radiolabeled methotrexate in the brain. These studies indicate that administration of LPA in combination with therapeutic agents may increase drug delivery to the brain. PMID:24045401

  1. In vitro models of the blood–brain barrier: An overview of commonly used brain endothelial cell culture models and guidelines for their use

    Science.gov (United States)

    Helms, Hans C; Abbott, N Joan; Burek, Malgorzata; Cecchelli, Romeo; Couraud, Pierre-Olivier; Deli, Maria A; Förster, Carola; Galla, Hans J; Romero, Ignacio A; Shusta, Eric V; Stebbins, Matthew J; Vandenhaute, Elodie; Weksler, Babette

    2016-01-01

    The endothelial cells lining the brain capillaries separate the blood from the brain parenchyma. The endothelial monolayer of the brain capillaries serves both as a crucial interface for exchange of nutrients, gases, and metabolites between blood and brain, and as a barrier for neurotoxic components of plasma and xenobiotics. This “blood-brain barrier” function is a major hindrance for drug uptake into the brain parenchyma. Cell culture models, based on either primary cells or immortalized brain endothelial cell lines, have been developed, in order to facilitate in vitro studies of drug transport to the brain and studies of endothelial cell biology and pathophysiology. In this review, we aim to give an overview of established in vitro blood–brain barrier models with a focus on their validation regarding a set of well-established blood–brain barrier characteristics. As an ideal cell culture model of the blood–brain barrier is yet to be developed, we also aim to give an overview of the advantages and drawbacks of the different models described. PMID:26868179

  2. Drug transport into the central nervous system: using newer findings about the blood-brain barriers.

    Science.gov (United States)

    Banks, William A

    2012-06-01

    The blood-brain barriers (BBBs) represent one of the biggest challenges for the effective delivery of drugs today. Discoveries made in the last 30 years offer new strategies for central nervous system (CNS) drug development, but have yet to be fully incorporated into the field. Here, we examine seven recently discovered aspects of the BBB and how they have been or could be developed for drug delivery. These areas are brain-to-blood (efflux) transporters, immune cell trafficking into the brain under physiologic conditions, mechanisms by which antibodies can access the CNS, Trojan horse delivery systems, blood-to-brain transport systems for biologicals, lectin interactions and ligand modifications that enhance BBB penetration, and secretory capacities of cells comprising the BBBs.

  3. GLUT-1 GLUCOSE TRANSPORTERS IN THE BLOOD-BRAIN BARRIER: DIFFERENTIAL PHOSPHORYLATION

    Science.gov (United States)

    Devraj, Kavi; Klinger, Marianne E.; Myers, Roland L.; Mokashi, Ashwini; Hawkins, Richard A.; Simpson, Ian A.

    2013-01-01

    Glucose is the primary metabolic fuel for the mammalian brain and a continuous supply is required to maintain normal CNS function. The transport of glucose across the blood-brain barrier (BBB) into the brain is mediated by the facilitative glucose transporter GLUT-1. Prior studies (Simpson et al. 2001) had revealed that the conformations of the GLUT-1 transporter were different in luminal (blood facing) and abluminal (brain facing) membranes of bovine cerebral endothelial cells, based on differential antibody recognition. In this study we have extended these observations and using a combination of 2D-PAGE/Western blotting and immunogold electron microscopy we determined that these different conformations are exhibited in vivo and arise from differential phosphorylation of GLUT-1 and not from alternative splicing or altered O- or N-linked glycosylation. PMID:21910135

  4. How hormones influence composition and physiological function of the brain-blood barrier.

    Science.gov (United States)

    Hampl, R; Bičíková, M; Sosvorová, L

    2015-01-01

    Hormones exert many actions in the brain. Their access and effects in the brain are regulated by the blood-brain barrier (BBB). Hormones as other substances may enter the brain and vice versa either by paracellular way requiring breaching tight junctions stitching the endothelial cells composing the BBB, or by passage through the cells (transcellular way). Hormones influence both ways through their receptors, both membrane and intracellular, present on/in the BBB. In the review the main examples are outlined how hormones influence the expression and function of proteins forming the tight junctions, as well as how they regulate expression and function of major protein transporters mediating transport of various substances including hormone themselves.

  5. Elucidation of mechanism of blood-brain barrier damage for prevention and treatment of vascular dementia.

    Science.gov (United States)

    Ueno, Masaki

    2017-03-28

    It is well-known that the blood-brain barrier (BBB) plays significant roles in transporting intravascular substances into the brain. The BBB in cerebral capillaries essentially impedes the influx of intravascular compounds from the blood to the brain, while nutritive substances, such as glucose, can be selectively transported through several types of influx transporters in endothelial cells. In the choroid plexus, intravascular substances can invade the parenchyma as fenestrations exist in endothelial cells of capillaries. However, the substances cannot invade the ventricles easily as there are tight junctions between epithelial cells in the choroid plexus. This restricted movement of the substances across the cytoplasm of the epithelial cells constitutes a blood-cerebrospinal fluid barrier (BCSFB). In the brain, there are circumventricular organs, in which the barrier function is imperfect in capillaries. Accordingly, it is reasonable to consider that intravascular substances can move in and around the parenchyma of the organs. Actually, it was reported in mice that intravascular substances moved in the corpus callosum, medial portions of the hippocampus, and periventricular areas via the subfornical organs or the choroid plexus. Regarding pathways of intracerebral interstitial and cerebrospinal fluids to the outside of the brain, two representative drainage pathways, or perivascular drainage and glymphatic pathways, are being established. The first is the pathway in a retrograde direction to the blood flow through the basement membrane in walls of cerebral capillaries, the tunica media of arteries, and the vessels walls of the internal carotid artery. The second is in an anterograde direction to blood flow through the para-arterial routes, aquaporin 4-dependent transport through the astroglial cytoplasm, and para-venous routes, and then the fluids drain into the subarachnoid CSF. These fluids are finally considered to drain into the cervical lymph nodes or veins

  6. The Transferrin Receptor at the Blood-Brain Barrier - exploring the possibilities for brain drug delivery

    NARCIS (Netherlands)

    Visser, Corine

    2005-01-01

    There are many diseases of the central nervous system (CNS), like Parkinson's disease, Alzheimer's disease, depression, schizophrenia, epilepsy, migraine headache, and HIV infection in the brain. However, treatment is difficult since many drugs cannot reach the brain in sufficient quantities due to

  7. Transfer of opiorphin through a blood-brain barrier culture model.

    Science.gov (United States)

    Bocsik, Alexandra; Darula, Zsuzsanna; Tóth, Géza; Deli, Mária A; Wollemann, Mária

    2015-08-01

    Opioid peptides are potent analgesics with therapeutic potential in the treatment of acute and chronic pain. Their efficacy is limited by peptidases (enkephalinases). Opiorphin pentapeptide (QRFSR) is the first characterized human endogenous inhibitor of enkephalinases. The peptide is able to increase the binding and affinity of endogenous opiates to mu opioid receptors; thus, the mechanism of opiorphin may provide a new therapeutic approach in pain management. The analgesic effect of opiorphin was proven in several earlier published in vitro and in vivo studies. Our aim was to test the transfer of opiorphin through a blood-brain barrier model for the first time. The flux of opiorphin was tested on a blood-brain barrier culture model consisting of rat brain endothelial, glial and pericyte cells. Brain endothelial cells in this triple co-culture model form tight monolayers characterized by transendothelial electrical resistance measurement. Relative quantity of the peptide was estimated by mass spectrometry. The transfer of opiorphin through the blood-brain barrier model was estimated to be ∼3%, whereas the permeability coefficient was 0.53 ± 1.36 × 10(-6) cm/s (n = 4). We also observed rapid conversion of N-terminal glutamine into pyroglutamic acid during the transfer experiments. Our results indicate that opiorphin crosses cultured brain endothelial cells in the absence of serum factors in a significant amount. This is in agreement with previous in vivo data showing potentiation of enkephalin-mediated antinociception. We suggest that opiorphin may have a potential as a centrally acting novel drug to treat pain. Copyright © 2015 IMSS. Published by Elsevier Inc. All rights reserved.

  8. Neurovascular Unit Dysfunction and Blood–Brain Barrier Hyperpermeability Contribute to Schizophrenia Neurobiology: A Theoretical Integration of Clinical and Experimental Evidence

    Directory of Open Access Journals (Sweden)

    Souhel Najjar

    2017-05-01

    Full Text Available Schizophrenia is a psychotic disorder characterized by delusions, hallucinations, negative symptoms, as well as behavioral and cognitive dysfunction. It is a pathoetiologically heterogeneous disorder involving complex interrelated mechanisms that include oxidative stress and neuroinflammation. Neurovascular endothelial dysfunction and blood–brain barrier (BBB hyperpermeability are established mechanisms in neurological disorders with comorbid psychiatric symptoms such as epilepsy, traumatic brain injury, and Alzheimer’s disease. Schizophrenia is frequently comorbid with medical conditions associated with peripheral vascular endothelial dysfunction, such as metabolic syndrome, cardiovascular disease, and diabetes mellitus. However, the existence and etiological relevance of neurovascular endothelial dysfunction and BBB hyperpermeability in schizophrenia are still not well recognized. Here, we review the growing clinical and experimental evidence, indicating that neurovascular endotheliopathy and BBB hyperpermeability occur in schizophrenia patients. We present a theoretical integration of human and animal data linking oxidative stress and neuroinflammation to neurovascular endotheliopathy and BBB breakdown in schizophrenia. These abnormalities may contribute to the cognitive and behavioral symptoms of schizophrenia via several mechanisms involving reduced cerebral perfusion and impaired homeostatic processes of cerebral microenvironment. Furthermore, BBB disruption can facilitate interactions between brain innate and peripheral adaptive immunity, thereby perpetuating harmful neuroimmune signals and toxic neuroinflammatory responses, which can also contribute to the symptoms of schizophrenia. Taken together, these findings support the “mild encephalitis” hypothesis of schizophrenia. If neurovascular abnormalities prove to be etiologically relevant to the neurobiology of schizophrenia, then targeting these abnormalities may represent a

  9. Developmental changes of l-arginine transport at the blood-brain barrier in rats.

    Science.gov (United States)

    Tachikawa, Masanori; Hirose, Shirou; Akanuma, Shin-Ichi; Matsuyama, Ryo; Hosoya, Ken-Ichi

    2017-12-14

    l-Arginine is required for regulating synapse formation/patterning and angiogenesis in the developing brain. We hypothesized that this requirement would be met by increased transporter-mediated supply across the blood-brain barrier (BBB). Thus, the purpose of this work was to test the idea that elevation of blood-to-brain l-arginine transport across the BBB in the postnatal period coincides with up-regulation of cationic acid transporter 1 (CAT1) expression in developing brain capillaries. We found that the apparent brain-to-plasma concentration ratio (Kp, app) of l-arginine after intravenous administration during the first and second postnatal weeks was 2-fold greater than that at the adult stage. Kp, app of l-serine was also increased at the first postnatal week. In contrast, Kp, app of d-mannitol, a passively BBB-permeable molecule, did not change, indicating that increased transport of l-arginine and l-serine is not due to BBB immaturity. Double immunohistochemical staining of CAT1 and a marker protein, glucose transporter 1, revealed that CAT1 was localized on both luminal and abluminal membranes of brain capillary endothelial cells during the developmental and adult stages. A dramatic increase in CAT1 expression in the brain was seen at postnatal day 7 (P7) and day 14 (P14) and the expression subsequently decreased as the brain matured. In accordance with this, intense immunostaining of CAT1 was observed in brain capillaries at P7 and P14. These findings strongly support our hypothesis and suggest that the supply of blood-born l-arginine to the brain via CAT1 at the BBB plays a key role in meeting the elevated demand for l-arginine in postnatal brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Arginine-Vasopressin Receptor Blocker Conivaptan Reduces Brain Edema and Blood-Brain Barrier Disruption after Experimental Stroke in Mice.

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    Emil Zeynalov

    Full Text Available Stroke is a major cause of morbidity and mortality. Stroke is complicated by brain edema and blood-brain barrier (BBB disruption, and is often accompanied by increased release of arginine-vasopressin (AVP. AVP acts through V1a and V2 receptors to trigger hyponatremia, vasospasm, and platelet aggregation which can exacerbate brain edema. The AVP receptor blockers conivaptan (V1a and V2 and tolvaptan (V2 are used to correct hyponatremia, but their effect on post-ischemic brain edema and BBB disruption remains to be elucidated. Therefore, we conducted this study to investigate if these drugs can prevent brain edema and BBB disruption in mice after stroke.Experimental mice underwent the filament model of middle cerebral artery occlusion (MCAO with reperfusion. Mice were treated with conivaptan, tolvaptan, or vehicle. Treatments were initiated immediately at reperfusion and administered IV (conivaptan or orally (tolvaptan for 48 hours. Physiological variables, neurological deficit scores (NDS, plasma and urine sodium and osmolality were recorded. Brain water content (BWC and Evans Blue (EB extravasation index were evaluated at the end point.Both conivaptan and tolvaptan produced aquaresis as indicated by changes in plasma and urine sodium levels. However plasma and urine osmolality was changed only by conivaptan. Unlike tolvaptan, conivaptan improved NDS and reduced BWC in the ipsilateral hemisphere: from 81.66 ± 0.43% (vehicle to 78.28 ± 0.48% (conivaptan, 0.2 mg, p < 0.05 vs vehicle. Conivaptan also attenuated the EB extravasation from 1.22 ± 0.08 (vehicle to 1.01 ± 0.02 (conivaptan, 0.2 mg, p < 0.05.Continuous IV infusion with conivaptan for 48 hours after experimental stroke reduces brain edema, and BBB disruption. Conivaptan but not tolvaptan may potentially be used in patients to prevent brain edema after stroke.

  11. Process and barriers to organ donation and causes of brain death in northeast of Iran.

    Science.gov (United States)

    Bahrami, Abdollah; Khaleghi, Ebrahim; Vakilzadeh, Ali Khorsand; Afzalaghaee, Monavar

    2017-02-01

    Organ transplantation is the treatment of choice for some diseases. However, the need for cadaveric organ donation has either plateaued or is on a decreasing trend in some countries, especially in developed ones. In this study, we aimed to identify the barriers to organ donation in brain dead patients, who were referred to the organ procurement organizations (OPO) in northeast Iran. In this cross-sectional study during 2006 to 2013, data were collected from medical records of brain dead patients. Demographic information, cause of brain death, the process of obtaining informed consent, and the reasons for declining organ donation were obtained from the OPO records. The data were analyzed using chi-square test by SPSS 13 software. Of 1034 brain dead patients, 751 cases (72.6%) were eligible for organ donation, and, ultimately, 344 cases underwent organ donation. The rate of organ donation increased during the course of the study; medical and legal reasons as well as family refusal to authorize donation were the main barriers to the process. Based on the pattern of mortality, the need for living donors in developing countries, such as Iran and other countries in the Mediterranean region, can be reduced by improving the quality of healthcare, efficient identification of brain death, and obtaining consent with appropriate strategies.

  12. Chromatographic Behaviour Predicts the Ability of Potential Nootropics to Permeate the Blood-Brain Barrier

    OpenAIRE

    FARSA, Oldřich

    2012-01-01

    The log BB parameter is the logarithm of the ratio of a compound?s equilibrium concentrations in the brain tissue versus the blood plasma. This parameter is a useful descriptor in assessing the ability of a compound to permeate the blood-brain barrier. The aim of this study was to develop a Hansch-type linear regression QSAR model that correlates the parameter log BB and the retention time of drugs and other organic compounds on a reversed-phase HPLC containing an embedded amide moiety. The r...

  13. Interleukin-34 restores blood-brain barrier integrity by upregulating tight junction proteins in endothelial cells.

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    Shijie Jin

    Full Text Available Interleukin-34 (IL-34 is a newly discovered cytokine as an additional ligand for colony stimulating factor-1 receptor (CSF1R, and its functions are expected to overlap with colony stimulating factor-1/macrophage-colony stimulating factor. We have previously shown that the IL-34 is primarily produced by neurons in the central nervous system (CNS and induces proliferation and neuroprotective properties of microglia which express CSF1R. However, the functions of IL-34 in the CNS are still elucidative. Here we show that CNS capillary endothelial cells also express CSF1R. IL-34 protected blood-brain barrier integrity by restored expression levels of tight junction proteins, which were downregulated by pro-inflammatory cytokines. The novel function of IL-34 on the blood-brain barrier may give us a clue for new therapeutic strategies in neuroinflammatory and neurodegenerative diseases such as multiple sclerosis and Alzheimer's disease.

  14. A novel transgenic zebrafish model for blood-brain and blood-retinal barrier development

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    Sugimoto Masahiko

    2010-07-01

    Full Text Available Abstract Background Development and maintenance of the blood-brain and blood-retinal barrier is critical for the homeostasis of brain and retinal tissue. Despite decades of research our knowledge of the formation and maintenance of the blood-brain (BBB and blood-retinal (BRB barrier is very limited. We have established an in vivo model to study the development and maintenance of these barriers by generating a transgenic zebrafish line that expresses a vitamin D-binding protein fused with enhanced green fluorescent protein (DBP-EGFP in blood plasma, as an endogenous tracer. Results The temporal establishment of the BBB and BRB was examined using this transgenic line and the results were compared with that obtained by injection of fluorescent dyes into the sinus venosus of embryos at various stages of development. We also examined the expression of claudin-5, a component of tight junctions during the first 4 days of development. We observed that the BBB of zebrafish starts to develop by 3 dpf, with expression of claudin-5 in the central arteries preceding it at 2 dpf. The hyaloid vasculature in the zebrafish retina develops a barrier function at 3 dpf, which endows the zebrafish with unique advantages for studying the BRB. Conclusion Zebrafish embryos develop BBB and BRB function simultaneously by 3 dpf, which is regulated by tight junction proteins. The Tg(l-fabp:DBP-EGFP zebrafish will have great advantages in studying development and maintenance of the blood-neural barrier, which is a new application for the widely used vertebrate model.

  15. Tailored delivery of analgesic ziconotide across a blood brain barrier model using viral nanocontainers

    OpenAIRE

    Prachi Anand; Alison O’Neil; Emily Lin; Trevor Douglas; Mandë Holford

    2015-01-01

    The blood brain barrier (BBB) is often an insurmountable obstacle for a large number of candidate drugs, including peptides, antibiotics, and chemotherapeutic agents. Devising an adroit delivery method to cross the BBB is essential to unlocking widespread application of peptide therapeutics. Presented here is an engineered nanocontainer for delivering peptidic drugs across the BBB encapsulating the analgesic marine snail peptide ziconotide (Prialt?). We developed a bi-functional viral nanocon...

  16. Chromatographic Behaviour Predicts the Ability of Potential Nootropics to Permeate the Blood-Brain Barrier

    Science.gov (United States)

    Farsa, Oldřich

    2013-01-01

    The log BB parameter is the logarithm of the ratio of a compound’s equilibrium concentrations in the brain tissue versus the blood plasma. This parameter is a useful descriptor in assessing the ability of a compound to permeate the blood-brain barrier. The aim of this study was to develop a Hansch-type linear regression QSAR model that correlates the parameter log BB and the retention time of drugs and other organic compounds on a reversed-phase HPLC containing an embedded amide moiety. The retention time was expressed by the capacity factor log k′. The second aim was to estimate the brain’s absorption of 2-(azacycloalkyl)acetamidophenoxyacetic acids, which are analogues of piracetam, nefiracetam, and meclofenoxate. Notably, these acids may be novel nootropics. Two simple regression models that relate log BB and log k′ were developed from an assay performed using a reversed-phase HPLC that contained an embedded amide moiety. Both the quadratic and linear models yielded statistical parameters comparable to previously published models of log BB dependence on various structural characteristics. The models predict that four members of the substituted phenoxyacetic acid series have a strong chance of permeating the barrier and being absorbed in the brain. The results of this study show that a reversed-phase HPLC system containing an embedded amide moiety is a functional in vitro surrogate of the blood-brain barrier. These results suggest that racetam-type nootropic drugs containing a carboxylic moiety could be more poorly absorbed than analogues devoid of the carboxyl group, especially if the compounds penetrate the barrier by a simple diffusion mechanism. PMID:23641330

  17. Blood–brain barrier and laser technology for drug brain delivery

    Directory of Open Access Journals (Sweden)

    Oxana V. Semyachkina-Glushkovskaya

    2017-09-01

    Photodynamic therapy (PDT is usual clinical method of surgical navigation for the resection of brain tumor and anti-cancer therapy. Nowadays, the application of PDT is considered as a potential promising tool for brain drug delivery via opening of BBB. Here, we show the first successful experimental results in this field discussing the adventures and disadvantages of PDT-related BBB disruption as well as alternatives to overcome these limitations and possible mechanisms with new pathways for brain clearance via glymphatic and lymphatic systems.

  18. Current research into brain barriers and the delivery of therapeutics for neurological diseases

    DEFF Research Database (Denmark)

    Greenwood, John; Hammarlund-Udenaes, Margareta; Jones, Hazel C

    2017-01-01

    This is a report on the CNS barrier congress held in London, UK, March 22-23rd 2017 and sponsored by Kisaco Research Ltd. The two 1-day sessions were chaired by John Greenwood and Margareta Hammarlund-Udenaes, respectively, and each session ended with a discussion led by the chair. Speakers consi...... consisted of invited academic researchers studying the brain barriers in relation to neurological diseases and industry researchers studying new methods to deliver therapeutics to treat neurological diseases. We include here brief reports from the speakers.......This is a report on the CNS barrier congress held in London, UK, March 22-23rd 2017 and sponsored by Kisaco Research Ltd. The two 1-day sessions were chaired by John Greenwood and Margareta Hammarlund-Udenaes, respectively, and each session ended with a discussion led by the chair. Speakers...

  19. Astrocytic modulation of blood brain barrier: perspectives on Parkinson’s disease

    Science.gov (United States)

    Cabezas, Ricardo; Ávila, Marcos; Gonzalez, Janneth; El-Bachá, Ramon Santos; Báez, Eliana; García-Segura, Luis Miguel; Jurado Coronel, Juan Camilo; Capani, Francisco; Cardona-Gomez, Gloria Patricia; Barreto, George E.

    2014-01-01

    The blood–brain barrier (BBB) is a tightly regulated interface in the Central Nervous System (CNS) that regulates the exchange of molecules in and out from the brain thus maintaining the CNS homeostasis. It is mainly composed of endothelial cells (ECs), pericytes and astrocytes that create a neurovascular unit (NVU) with the adjacent neurons. Astrocytes are essential for the formation and maintenance of the BBB by providing secreted factors that lead to the adequate association between the cells of the BBB and the formation of strong tight junctions. Under neurological disorders, such as chronic cerebral ischemia, brain trauma, Epilepsy, Alzheimer and Parkinson’s Diseases, a disruption of the BBB takes place, involving a lost in the permeability of the barrier and phenotypical changes in both the ECs and astrocytes. In this aspect, it has been established that the process of reactive gliosis is a common feature of astrocytes during BBB disruption, which has a detrimental effect on the barrier function and a subsequent damage in neuronal survival. In this review we discuss the implications of astrocyte functions in the protection of the BBB, and in the development of Parkinson’s disease (PD) and related disorders. Additionally, we highlight the current and future strategies in astrocyte protection aimed at the development of restorative therapies for the BBB in pathological conditions. PMID:25136294

  20. Astrocytic modulation of Blood Brain Barrier: Perspectives on Parkinson´s Disease

    Directory of Open Access Journals (Sweden)

    Ricardo eCabezas

    2014-08-01

    Full Text Available TThe blood–brain barrier (BBB is a tightly regulated interface in the Central Nervous System that regulates the exchange of molecules in and out from the brain thus maintaining the CNS homeostasis. It is mainly composed of endothelial cells, pericytes and astrocytes that create a neurovascular unit with the adjacent neurons. Astrocytes are essential for the formation and maintenance of the BBB by providing secreted factors that lead to the adequate association between the cells of the BBB and the formation of strong tight junctions. Under neurological disorders, such as chronic cerebral ischemia, brain trauma, Epilepsy, Alzheimer and Parkinson´s Diseases, a disruption of the BBB takes place, involving a lost in the permeability of the barrier and phenotypical changes in both the endothelial cells and astrocytes. In this aspect, it has been established that the process of reactive gliosis is a common feature of astrocytes during BBB disruption, which has a detrimental effect on the barrier function and a subsequent damage in neuronal survival. In this review we discuss the implications of astrocyte functions in the protection of the BBB, and in the development of Parkinson´s disease and related disorders. Additionally, we highlight the current and future strategies in astrocyte protection aimed at the development of restorative therapies for the BBB in pathological conditions.

  1. Candesartan improves ischemia-induced impairment of the blood-brain barrier in vitro.

    Science.gov (United States)

    So, Gohei; Nakagawa, Shinsuke; Morofuji, Yoichi; Hiu, Takeshi; Hayashi, Kentaro; Tanaka, Kunihiko; Suyama, Kazuhiko; Deli, Maria A; Nagata, Izumi; Matsuo, Takayuki; Niwa, Masami

    2015-05-01

    Candesartan has been reported to have a protective effect on cerebral ischemia in vivo and in human ischemic stroke. We studied the direct effects of candesartan on blood-brain barrier (BBB) function with our in vitro monolayer model generated using rat brain capillary endothelial cells (RBECs). The in vitro BBB model was subjected to normoxia or 6-h oxygen glucose deprivation (OGD)/24-h reoxygenation, with or without candesartan. 6-h OGD/24-h reoxygenation decreased transendothelial electrical resistance and increased the endothelial permeability for sodium fluorescein in RBEC monolayers. Candesartan (10 nM) improved RBEC barrier dysfunction induced by 6-h OGD/24-h reoxygenation. Immunostaining and immunoblotting analysis indicated that the effect of candesartan on barrier function under 6-h OGD/24-h reoxygenation was not related to the expression levels of tight junction proteins. However, candesartan affected RBEC morphological changes induced by 6-h OGD/24-h reoxygenation. We analyzed oxidative stress and cell viability using chemical reagents. Candesartan improved cell viability following 6-h OGD/24-h reoxygenation, whereas candesartan had no effect on oxidative stress. These results show that candesartan directly improves cell function and viability of brain capillary endothelial cells under OGD/reoxygenation, suggesting that the protective effects of candesartan on ischemic stroke are related to protection of the BBB.

  2. Blood Brain Barrier Dysfunction and Delayed Neurological Deficits in Mild Traumatic Brain Injury Induced by Blast Shock Waves

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    Ashok K Shetty

    2014-08-01

    Full Text Available Mild traumatic brain injury (mTBI resulting from exposure to blast shock waves (BSWs is one of the most predominant causes of illnesses among veterans who served in the recent Iraq and Afghanistan wars. Such mTBI can also happen to civilians if exposed to shock waves of bomb attacks by terrorists. While cognitive problems, memory dysfunction, depression, anxiety and diffuse white matter injury have been observed at both early and/or delayed time-points, an initial brain pathology resulting from exposure to BSWs appears to be the dysfunction or disruption of the blood-brain barrier (BBB. Studies in animal models suggest that exposure to relatively milder BSWs (123 kPa initially induces free radical generating enzymes in and around brain capillaries, which enhances oxidative stress resulting in loss of tight junction proteins, edema formation, and leakiness of BBB with disruption or loss of its components pericytes and astrocyte end-feet. On the other hand, exposure to more intense BSWs (145-323 kPa causes acute disruption of the BBB with vascular lesions in the brain. Both of these scenarios lead to apoptosis of endothelial and neural cells and neuroinflammation in and around capillaries, which may progress into chronic traumatic encephalopathy and/or a variety of neurological impairments, depending on brain regions that are afflicted with such lesions. This review discusses studies that examined alterations in the brain milieu causing dysfunction or disruption of the BBB and neuroinflammation following exposure to different intensities of BSWs. Furthermore, potential of early intervention strategies capable of easing oxidative stress, repairing the BBB or blocking inflammation for minimizing delayed neurological deficits resulting from exposure to BSWs is conferred.

  3. Overcoming the blood-brain barrier for delivering drugs into the brain by using adenosine receptor nanoagonist.

    Science.gov (United States)

    Gao, Xihui; Qian, Jun; Zheng, Shuyan; Changyi, Yinzhi; Zhang, Jianping; Ju, Shenghong; Zhu, Jianhua; Li, Cong

    2014-04-22

    The extremely low permeability of the blood-brain barrier (BBB) poses the greatest impediment in the treatment of central nervous system (CNS) diseases. Recent work indicated that BBB permeability can be up-regulated by activating A2A adenosine receptor (AR), which temporarily increases intercellular spaces between the brain capillary endothelial cells. However, due to transient circulation lifetime of adenosine-based agonists, their capability to enhance brain delivery of drugs, especially macromolecular drugs, is limited. In this work, a series of nanoagonists (NAs) were developed by labeling different copies of A2A AR activating ligands on dendrimers. In vitro transendothelial electrical resistance measurements demonstrated that the NAs increased permeability of the endothelial cell monolayer by compromising the tightness of tight junctions, the key structure that restricts the entry of blood-borne molecules into the brain. In vivo imaging studies indicated the remarkably up-regulated brain uptake of a macromolecular model drug (45 kDa) after intravenous injection of NAs. Autoradiographic imaging showed that the BBB opening time-window can be tuned in a range of 0.5-2.0 h by the NAs labeled with different numbers of AR-activating ligands. By choosing a suitable NA, it is possible to maximize brain drug delivery and minimize the uncontrollable BBB leakage by matching the BBB opening time-window with the pharmacokinetics of a therapeutic agent. The NA-mediated brain drug delivery strategy holds promise for the treatment of CNS diseases with improved therapeutic efficiency and reduced side-effects.

  4. Blood brain barrier dysfunction and delayed neurological deficits in mild traumatic brain injury induced by blast shock waves.

    Science.gov (United States)

    Shetty, Ashok K; Mishra, Vikas; Kodali, Maheedhar; Hattiangady, Bharathi

    2014-01-01

    Mild traumatic brain injury (mTBI) resulting from exposure to blast shock waves (BSWs) is one of the most predominant causes of illnesses among veterans who served in the recent Iraq and Afghanistan wars. Such mTBI can also happen to civilians if exposed to shock waves of bomb attacks by terrorists. While cognitive problems, memory dysfunction, depression, anxiety and diffuse white matter injury have been observed at both early and/or delayed time-points, an initial brain pathology resulting from exposure to BSWs appears to be the dysfunction or disruption of the blood-brain barrier (BBB). Studies in animal models suggest that exposure to relatively milder BSWs (123 kPa) initially induces free radical generating enzymes in and around brain capillaries, which enhances oxidative stress resulting in loss of tight junction (TJ) proteins, edema formation, and leakiness of BBB with disruption or loss of its components pericytes and astrocyte end-feet. On the other hand, exposure to more intense BSWs (145-323 kPa) causes acute disruption of the BBB with vascular lesions in the brain. Both of these scenarios lead to apoptosis of endothelial and neural cells and neuroinflammation in and around capillaries, which may progress into chronic traumatic encephalopathy (CTE) and/or a variety of neurological impairments, depending on brain regions that are afflicted with such lesions. This review discusses studies that examined alterations in the brain milieu causing dysfunction or disruption of the BBB and neuroinflammation following exposure to different intensities of BSWs. Furthermore, potential of early intervention strategies capable of easing oxidative stress, repairing the BBB or blocking inflammation for minimizing delayed neurological deficits resulting from exposure to BSWs is conferred.

  5. The Drosophila surface glia transcriptome: evolutionary conserved blood-brain barrier processes.

    Directory of Open Access Journals (Sweden)

    Michael K DeSalvo

    2014-11-01

    Full Text Available AbstractCentral nervous system (CNS function is dependent on the stringent regulation of metabolites, drugs, cells, and pathogens exposed to the CNS space. Cellular blood-brain barrier (BBB structures are highly specific checkpoints governing entry and exit of all small molecules to and from the brain interstitial space, but the precise mechanisms that regulate the BBB are not well understood. In addition, the BBB has long been a challenging obstacle to the pharmacologic treatment of CNS diseases; thus model systems that can parse the functions of the BBB are highly desirable. In this study, we sought to define the transcriptome of the adult Drosophila melanogaster BBB by isolating the BBB surface glia with FACS and profiling their gene expression with microarrays. By comparing the transcriptome of these surface glia to that of all brain glia, brain neurons, and whole brains, we present a catalog of transcripts that are selectively enriched at the Drosophila BBB. We found that the fly surface glia show high expression of many ABC and SLC transporters, cell adhesion molecules, metabolic enzymes, signaling molecules, and components of xenobiotic metabolism pathways. Using gene sequence-based alignments, we compare the Drosophila and Murine BBB transcriptomes and discover many shared chemoprotective and small molecule control pathways, thus affirming the relevance of invertebrate models for studying evolutionary conserved BBB properties. The Drosophila BBB transcriptome is valuable to vertebrate and insect biologists alike as a resource for studying proteins underlying diffusion barrier development and maintenance, glial biology, and regulation of drug transport at tissue barriers.

  6. The Drosophila surface glia transcriptome: evolutionary conserved blood-brain barrier processes.

    Science.gov (United States)

    DeSalvo, Michael K; Hindle, Samantha J; Rusan, Zeid M; Orng, Souvinh; Eddison, Mark; Halliwill, Kyle; Bainton, Roland J

    2014-01-01

    Central nervous system (CNS) function is dependent on the stringent regulation of metabolites, drugs, cells, and pathogens exposed to the CNS space. Cellular blood-brain barrier (BBB) structures are highly specific checkpoints governing entry and exit of all small molecules to and from the brain interstitial space, but the precise mechanisms that regulate the BBB are not well understood. In addition, the BBB has long been a challenging obstacle to the pharmacologic treatment of CNS diseases; thus model systems that can parse the functions of the BBB are highly desirable. In this study, we sought to define the transcriptome of the adult Drosophila melanogaster BBB by isolating the BBB surface glia with fluorescence activated cell sorting (FACS) and profiling their gene expression with microarrays. By comparing the transcriptome of these surface glia to that of all brain glia, brain neurons, and whole brains, we present a catalog of transcripts that are selectively enriched at the Drosophila BBB. We found that the fly surface glia show high expression of many ATP-binding cassette (ABC) and solute carrier (SLC) transporters, cell adhesion molecules, metabolic enzymes, signaling molecules, and components of xenobiotic metabolism pathways. Using gene sequence-based alignments, we compare the Drosophila and Murine BBB transcriptomes and discover many shared chemoprotective and small molecule control pathways, thus affirming the relevance of invertebrate models for studying evolutionary conserved BBB properties. The Drosophila BBB transcriptome is valuable to vertebrate and insect biologists alike as a resource for studying proteins underlying diffusion barrier development and maintenance, glial biology, and regulation of drug transport at tissue barriers.

  7. Improvement of Blood-Brain Barrier Integrity in Traumatic Brain Injury and Hemorrhagic Shock Following Treatment With Valproic Acid and Fresh Frozen Plasma.

    Science.gov (United States)

    Nikolian, Vahagn C; Dekker, Simone E; Bambakidis, Ted; Higgins, Gerald A; Dennahy, Isabel S; Georgoff, Patrick E; Williams, Aaron M; Andjelkovic, Anuska V; Alam, Hasan B

    2018-01-01

    Combined traumatic brain injury and hemorrhagic shock are highly lethal. Following injuries, the integrity of the blood-brain barrier can be impaired, contributing to secondary brain insults. The status of the blood-brain barrier represents a potential factor impacting long-term neurologic outcomes in combined injuries. Treatment strategies involving plasma-based resuscitation and valproic acid therapy have shown efficacy in this setting. We hypothesize that a component of this beneficial effect is related to blood-brain barrier preservation. Following controlled traumatic brain injury, hemorrhagic shock, various resuscitation and treatment strategies were evaluated for their association with blood-brain barrier integrity. Analysis of gene expression profiles was performed using Porcine Gene ST 1.1 microarray. Pathway analysis was completed using network analysis tools (Gene Ontology, Ingenuity Pathway Analysis, and Parametric Gene Set Enrichment Analysis). Female Yorkshire swine were subjected to controlled traumatic brain injury and 2 hours of hemorrhagic shock (40% blood volume, mean arterial pressure 30-35 mmHg). Subjects were resuscitated with 1) normal saline, 2) fresh frozen plasma, 3) hetastarch, 4) fresh frozen plasma + valproic acid, or 5) hetastarch + valproic acid (n = 5 per group). After 6 hours of observation, brains were harvested for evaluation. Immunofluoroscopic evaluation of the traumatic brain injury site revealed significantly increased expression of tight-junction associated proteins (zona occludin-1, claudin-5) following combination therapy (fresh frozen plasma + valproic acid and hetastarch + valproic acid). The extracellular matrix protein laminin was found to have significantly improved expression with combination therapies. Pathway analysis indicated that valproic acid significantly modulated pathways involved in endothelial barrier function and cell signaling. Resuscitation with fresh frozen plasma results in improved expression of

  8. Increased Stability and Breakdown of Brain Effective Connectivity During Slow-Wave Sleep: Mechanistic Insights from Whole-Brain Computational Modelling

    OpenAIRE

    Jobst, Beatrice M; Hindriks, Rikkert; Laufs, Helmut; Tagliazucchi, E; Hahn, Gerald; Ponce-Alvarez, Adrián; Stevner, Angus B. A.; Kringelbach, Morten L.; Deco, Gustavo

    2017-01-01

    Recent research has found that the human sleep cycle is characterised by changes in spatiotemporal patterns of brain activity. Yet, we are still missing a mechanistic explanation of the local neuronal dynamics underlying these changes. We used whole-brain computational modelling to study the differences in global brain functional connectivity and synchrony of fMRI activity in healthy humans during wakefulness and slow-wave sleep. We applied a whole-brain model based on the normal form of a su...

  9. Expression of Astrocytic Type 2 Angiotensin Receptor in Central Nervous System Inflammation Correlates With Blood-Brain Barrier Breakdown

    DEFF Research Database (Denmark)

    Füchtbauer, Laila; Toft-Hansen, Henrik; Khorooshi, Reza

    2010-01-01

    in the hippocampus dentate gyrus after transection of axonal afferents, despite that leukocytes infiltrate to this site. Immunoreactivity for AT(2) was increased on glia limitans astrocytes in PTx-treated CCL2 transgenics, whereas AT(2) immunostaining was not induced in the lesion-reactive dentate gyrus. Our results...

  10. THE ROLE OF MULTIDRUG RESISTANCE ASSOCIATED PROTEIN (MRP) IN THE BLOOD-BRAIN BARRIER AND OPIOID ANALGESIA

    Science.gov (United States)

    Su, Wendy; Pasternak, Gavril W.

    2013-01-01

    The blood brain barrier protects the brain from circulating compounds and drugs. The ATP-binding cassette (ABC) transporter P-glycoprotein (Pgp) is involved with the barrier, both preventing the influx of agent from the blood into the brain and facilitating the efflux of compounds from the brain into the blood, raising the possibility of a similar role for other transporters. Multidrug resistance associated protein (MRP), a 190 kDa protein similar to Pgp is also ABC transport that has been implicated in the blood brain barrier. The current study explores its role in opioid action. Immunohistochemically, it is localized in the choroid plexus in ratsand can be selectively downregulated by antisense treatment at both the level of mRNA, as shown by RT-PCR, and protein, as demonstrated immunohistochemically. Behaviorally, downregulation of MRP significantly enhances the analgesic potency of systemic morphine in MRP knockout mice and in antisense-treated rats by lowering the blood brain barrier. Following intracerebroventricular administration, a number of compounds, including some opioids, are rapidly secreted from the brain into the blood where they contribute to the overall analgesic effects by activating peripheral systems. MRP plays a role in this efflux. Downregulating MRP expression leads to a corresponding decrease in the transport and a diminished analgesic response from opioids administered intracerebroventricularly. Thus, the transporter protein MRP plays a role in maintaining the blood-brain barrier and modulates the activity of opioids. PMID:23508590

  11. Aging alters mRNA expression of amyloid transporter genes at the blood-brain barrier.

    Science.gov (United States)

    Osgood, Doreen; Miller, Miles C; Messier, Arthur A; Gonzalez, Liliana; Silverberg, Gerald D

    2017-09-01

    Decreased clearance of potentially toxic metabolites, due to aging changes, likely plays a significant role in the accumulation of amyloid-beta (Aβ) peptides and other macromolecules in the brain of the elderly and in the patients with Alzheimer's disease (AD). Aging is the single most important risk factor for AD development. Aβ transport receptor proteins expressed at the blood-brain barrier are significantly altered with age: the efflux transporters lipoprotein receptor-related protein 1 and P-glycoprotein are reduced, whereas the influx transporter receptor for advanced glycation end products is increased. These receptors play an important role in maintaining brain biochemical homeostasis. We now report that, in a rat model of aging, gene transcription is altered in aging, as measured by Aβ receptor gene messenger RNA (mRNA) at 3, 6, 9, 12, 15, 20, 30, and 36 months. Gene mRNA expression from isolated cerebral microvessels was measured by quantitative polymerase chain reaction. Lipoprotein receptor-related protein 1 and P-glycoprotein mRNA were significantly reduced in aging, and receptor for advanced glycation end products was increased, in parallel with the changes seen in receptor protein expression. Transcriptional changes appear to play a role in aging alterations in blood-brain barrier receptor expression and Aβ accumulation. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. A stable and reproducible human blood-brain barrier model derived from hematopoietic stem cells.

    Directory of Open Access Journals (Sweden)

    Romeo Cecchelli

    Full Text Available The human blood brain barrier (BBB is a selective barrier formed by human brain endothelial cells (hBECs, which is important to ensure adequate neuronal function and protect the central nervous system (CNS from disease. The development of human in vitro BBB models is thus of utmost importance for drug discovery programs related to CNS diseases. Here, we describe a method to generate a human BBB model using cord blood-derived hematopoietic stem cells. The cells were initially differentiated into ECs followed by the induction of BBB properties by co-culture with pericytes. The brain-like endothelial cells (BLECs express tight junctions and transporters typically observed in brain endothelium and maintain expression of most in vivo BBB properties for at least 20 days. The model is very reproducible since it can be generated from stem cells isolated from different donors and in different laboratories, and could be used to predict CNS distribution of compounds in human. Finally, we provide evidence that Wnt/β-catenin signaling pathway mediates in part the BBB inductive properties of pericytes.

  13. Effect of losartan on the blood-brain barrier permeability in diabetic hypertensive rats.

    Science.gov (United States)

    Kaya, M; Kalayci, R; Küçük, M; Arican, N; Elmas, I; Kudat, H; Korkut, F

    2003-11-07

    Our previous publication has stressed the benefits of losartan, an angiotensin II receptor blocker, on the permeability of blood-brain barrier (BBB) and blood pressure during L-NAME-induced hypertension. This study reports the impacts of anti-hypertensive treatment by losartan on the brain endothelial barrier function and the arterial blood pressure, during acute hypertension episode, in experimentally diabetic hypertensive rats. Systolic blood pressure measurements were taken with tail cuff method before and during administration of L-NAME (0.5 mg/ml). We induced diabetes by using alloxan (50 mg/kg, i.p). Losartan (3 mg/kg, i.v) was given to rats following the L-NAME treatment. Acute hypertensive vascular injury was induced by epinephrine (40 microg/kg). The BBB disruption was quantified according to the extravasation of the Evans blue (EB) dye. L-NAME induced a significant increase in arterial blood pressure on day 14 in normoglycemic and hyperglycemic rats (p hypertensive and diabetic hypertensive rats (p hypertension in diabetic hypertensive rats increased the content of EB dye dramatically in cerebellum and diencephalon (p cerebral cortex (p hypertensive rats treated with epinephrine (p hypertensive rats, epinephrine administration leads to an increase in microvascular-EB-albumin efflux to brain, however losartan treatment significantly attenuates this protein's transport to brain tissue.

  14. Cytokine-mediated blood brain barrier disruption as a conduit for cancer/chemotherapy-associated neurotoxicity and cognitive dysfunction.

    Science.gov (United States)

    Wardill, Hannah R; Mander, Kimberley A; Van Sebille, Ysabella Z A; Gibson, Rachel J; Logan, Richard M; Bowen, Joanne M; Sonis, Stephen T

    2016-12-15

    Neurotoxicity is a common side effect of chemotherapy treatment, with unclear molecular mechanisms. Clinical studies suggest that the most frequent neurotoxic adverse events affect memory and learning, attention, concentration, processing speeds and executive function. Emerging preclinical research points toward direct cellular toxicity and induction of neuroinflammation as key drivers of neurotoxicity and subsequent cognitive impairment. Emerging data now show detectable levels of some chemotherapeutic agents within the CNS, indicating potential disruption of blood brain barrier integrity or transport mechanisms. Blood brain barrier disruption is a key aspect of many neurocognitive disorders, particularly those characterized by a proinflammatory state. Importantly, many proinflammatory mediators able to modulate the blood brain barrier are generated by tissues and organs that are targets for chemotherapy-associated toxicities. This review therefore aims to explore the hypothesis that peripherally derived inflammatory cytokines disrupt blood brain barrier permeability, thereby increasing direct access of chemotherapeutic agents into the CNS to facilitate neuroinflammation and central neurotoxicity. © 2016 UICC.

  15. Endothelial calcium dynamics, connexin channels and blood-brain barrier function.

    Science.gov (United States)

    De Bock, Marijke; Wang, Nan; Decrock, Elke; Bol, Mélissa; Gadicherla, Ashish K; Culot, Maxime; Cecchelli, Romeo; Bultynck, Geert; Leybaert, Luc

    2013-09-01

    Situated between the circulation and the brain, the blood-brain barrier (BBB) protects the brain from circulating toxins while securing a specialized environment for neuro-glial signaling. BBB capillary endothelial cells exhibit low transcytotic activity and a tight, junctional network that, aided by the cytoskeleton, restricts paracellular permeability. The latter is subject of extensive research as it relates to neuropathology, edema and inflammation. A key determinant in regulating paracellular permeability is the endothelial cytoplasmic Ca(2+) concentration ([Ca(2+)]i) that affects junctional and cytoskeletal proteins. Ca(2+) signals are not one-time events restricted to a single cell but often appear as oscillatory [Ca(2+)]i changes that may propagate between cells as intercellular Ca(2+) waves. The effect of Ca(2+) oscillations/waves on BBB function is largely unknown and we here review current evidence on how [Ca(2+)]i dynamics influence BBB permeability. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. PROGRESS AND PROBLEMS IN THE APPLICATION OF FOCUSED ULTRASOUND FOR BLOOD-BRAIN BARRIER DISRUPTION

    Science.gov (United States)

    Vykhodtseva, Natalia; McDannold, Nathan; Hynynen, Kullervo

    2008-01-01

    Advances in neuroscience have resulted in the development of new diagnostic and therapeutic agents for potential use in the central nervous system (CNS). However, the ability to deliver the majority of these agents to the brain is limited by the blood–brain barrier (BBB), a specialized structure of the blood vessel wall that hampers transport and diffusion from the blood to the brain. Many CNS disorders could be treated with drugs, enzymes, genes, or large-molecule biotechnological products such as recombinant proteins, if they could cross the BBB. This article reviews the problems of the BBB presence in treating the vast majority of CNS diseases and the efforts to circumvent the BBB through the design of new drugs and the development of more sophisticated delivery methods. Recent advances in the development of noninvasive, targeted drug delivery by MRI-guided ultrasound-induced BBB disruption are also summarized. PMID:18511095

  17. Ultrasound effects on brain-targeting mannosylated liposomes: in vitro and blood–brain barrier transport investigations

    Directory of Open Access Journals (Sweden)

    Zidan AS

    2015-07-01

    Full Text Available Ahmed S Zidan,1,2 Hibah Aldawsari1 1Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; 2Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt Abstract: Delivering drugs to intracerebral regions can be accomplished by improving the capacity of transport through blood–brain barrier. Using sertraline as model drug for brain targeting, the current study aimed at modifying its liposomal vesicles with mannopyranoside. Box-Behnken design was employed to statistically optimize the ultrasound parameters, namely ultrasound amplitude, time, and temperature, for maximum mannosylation capacity, sertraline entrapment, and surface charge while minimizing vesicular size. Moreover, in vitro blood–brain barrier transport model was established to assess the transendothelial capacity of the optimized mannosylated vesicles. Results showed a dependence of vesicular size, mannosylation capacity, and sertraline entrapment on cavitation and bubble implosion events that were related to ultrasound power amplitude, temperature. However, short ultrasound duration was required to achieve >90% mannosylation with nanosized vesicles (<200 nm of narrow size distribution. Optimized ultrasound parameters of 65°C, 27%, and 59 seconds for ultrasound temperature, amplitude, and time were elucidated to produce 81.1%, 46.6 nm, and 77.6% sertraline entrapment, vesicular size, and mannosylation capacity, respectively. Moreover, the transendothelial ability was significantly increased by 2.5-fold by mannosylation through binding with glucose transporters. Hence, mannosylated liposomes processed by ultrasound could be a promising approach for manufacturing and scale-up of brain-targeting liposomes. Keywords: CNS delivery, sizing, lipid based formulations, quality by design, sertraline hydrochloride

  18. The blood-brain barrier: structure, function and therapeutic approaches to cross it.

    Science.gov (United States)

    Tajes, Marta; Ramos-Fernández, Eva; Weng-Jiang, Xian; Bosch-Morató, Mònica; Guivernau, Biuse; Eraso-Pichot, Abel; Salvador, Bertrán; Fernàndez-Busquets, Xavier; Roquer, Jaume; Muñoz, Francisco J

    2014-08-01

    The blood-brain barrier (BBB) is constituted by a specialized vascular endothelium that interacts directly with astrocytes, neurons and pericytes. It protects the brain from the molecules of the systemic circulation but it has to be overcome for the proper treatment of brain cancer, psychiatric disorders or neurodegenerative diseases, which are dramatically increasing as the population ages. In the present work we have revised the current knowledge on the cellular structure of the BBB and the different procedures utilized currently and those proposed to cross it. Chemical modifications of the drugs, such as increasing their lipophilicity, turn them more prone to be internalized in the brain. Other mechanisms are the use of molecular tools to bind the drugs such as small immunoglobulins, liposomes or nanoparticles that will act as Trojan Horses favoring the drug delivery in brain. This fusion of the classical pharmacology with nanotechnology has opened a wide field to many different approaches with promising results to hypothesize that BBB will not be a major problem for the new generation of neuroactive drugs. The present review provides an overview of all state-of-the-art of the BBB structure and function, as well as of the classic strategies and these appeared in recent years to deliver drugs into the brain for the treatment of Central Nervous System (CNS) diseases.

  19. CB2 Receptor Activation Inhibits Melanoma Cell Transmigration through the Blood-Brain Barrier

    Directory of Open Access Journals (Sweden)

    János Haskó

    2014-05-01

    Full Text Available During parenchymal brain metastasis formation tumor cells need to migrate through cerebral endothelial cells, which form the morphological basis of the blood-brain barrier (BBB. The mechanisms of extravasation of tumor cells are highly uncharacterized, but in some aspects recapitulate the diapedesis of leukocytes. Extravasation of leukocytes through the BBB is decreased by the activation of type 2 cannabinoid receptors (CB2; therefore, in the present study we sought to investigate the role of CB2 receptors in the interaction of melanoma cells with the brain endothelium. First, we identified the presence of CB1, CB2(A, GPR18 (transcriptional variant 1 and GPR55 receptors in brain endothelial cells, while melanoma cells expressed CB1, CB2(A, GPR18 (transcriptional variants 1 and 2, GPR55 and GPR119. We observed that activation of CB2 receptors with JWH-133 reduced the adhesion of melanoma cells to the layer of brain endothelial cells. JWH-133 decreased the transendothelial migration rate of melanoma cells as well. Our results suggest that changes induced in endothelial cells are critical in the mediation of the effect of CB2 agonists. Our data identify CB2 as a potential target in reducing the number of brain metastastes originating from melanoma.

  20. Evaluation of blood-brain barrier-stealth nanocomposites for in situ glioblastoma theranostics applications

    Science.gov (United States)

    Su, Chia-Hao; Tsai, Ching-Yi; Tomanek, Boguslaw; Chen, Wei-Yu; Cheng, Fong-Yu

    2016-04-01

    The blood-brain barrier (BBB) is a physiological structure of the blood vessels in the brain. The BBB efficiently traps most therapeutic drugs in the blood vessels and stops them from entering the brain tissue, resulting in a decreased therapeutic efficiency. In this study, we developed BBB-stealth nanocomposites composed of iron oxide (Fe3O4) nanoparticles (NPs) as a safe nanocarrier for glioblastoma therapy. We showed the antitumor activity of Dox/alg-Fe3O4 NPs using in vitro and in vivo tests. We demonstrated that G23-alg-Fe3O4 NPs crossed the BBB and entered the brain. In situ glioblastoma tumor-bearing mice were used to successfully evaluate the antitumor activity of G23-Dox/alg-Fe3O4 NPs. Magnetic resonance imaging (MRI) and bioluminescence imaging (BLI) confirmed the BBB crossing. The BBB-stealth nanocomposites show great potential for a proof-of-concept clinical trial as a theranostics platform for human brain tumor therapy.The blood-brain barrier (BBB) is a physiological structure of the blood vessels in the brain. The BBB efficiently traps most therapeutic drugs in the blood vessels and stops them from entering the brain tissue, resulting in a decreased therapeutic efficiency. In this study, we developed BBB-stealth nanocomposites composed of iron oxide (Fe3O4) nanoparticles (NPs) as a safe nanocarrier for glioblastoma therapy. We showed the antitumor activity of Dox/alg-Fe3O4 NPs using in vitro and in vivo tests. We demonstrated that G23-alg-Fe3O4 NPs crossed the BBB and entered the brain. In situ glioblastoma tumor-bearing mice were used to successfully evaluate the antitumor activity of G23-Dox/alg-Fe3O4 NPs. Magnetic resonance imaging (MRI) and bioluminescence imaging (BLI) confirmed the BBB crossing. The BBB-stealth nanocomposites show great potential for a proof-of-concept clinical trial as a theranostics platform for human brain tumor therapy. Electronic supplementary information (ESI) available: Experimental details. See DOI: 10.1039/c6nr00280c

  1. Abnormal blood-brain barrier permeability in normal appearing white matter in multiple sclerosis investigated by MRI

    DEFF Research Database (Denmark)

    Cramer, Stig Præstekær; Simonsen, Helle Juhl; Frederiksen, Jette Lautrup Battistini

    2013-01-01

    To investigate whether blood-brain barrier (BBB) permeability is disrupted in normal appearing white matter in MS patients, when compared to healthy controls and whether it is correlated with MS clinical characteristics.......To investigate whether blood-brain barrier (BBB) permeability is disrupted in normal appearing white matter in MS patients, when compared to healthy controls and whether it is correlated with MS clinical characteristics....

  2. Preparation of Silica Nanoparticles Loaded with Nootropics and Their In Vivo Permeation through Blood-Brain Barrier

    OpenAIRE

    Jampilek, Josef; Zaruba, Kamil; Oravec, Michal; Kunes, Martin; Babula, Petr; Ulbrich, Pavel; Brezaniova, Ingrid; Opatrilova, Radka; Triska, Jan; Suchy, Pavel

    2015-01-01

    The blood-brain barrier prevents the passage of many drugs that target the central nervous system. This paper presents the preparation and characterization of silica-based nanocarriers loaded with piracetam, pentoxifylline, and pyridoxine (drugs from the class of nootropics), which are designed to enhance the permeation of the drugs from the circulatory system through the blood-brain barrier. Their permeation was compared with non-nanoparticle drug substances (bulk materials) by means of an i...

  3. Disruption in the Blood-Brain Barrier: The Missing Link between Brain and Body Inflammation in Bipolar Disorder?

    Directory of Open Access Journals (Sweden)

    Jay P. Patel

    2015-01-01

    Full Text Available The blood-brain barrier (BBB regulates the transport of micro- and macromolecules between the peripheral blood and the central nervous system (CNS in order to maintain optimal levels of essential nutrients and neurotransmitters in the brain. In addition, the BBB plays a critical role protecting the CNS against neurotoxins. There has been growing evidence that BBB disruption is associated with brain inflammatory conditions such as Alzheimer’s disease and multiple sclerosis. Considering the increasing role of inflammation and oxidative stress in the pathophysiology of bipolar disorder (BD, here we propose a novel model wherein transient or persistent disruption of BBB integrity is associated with decreased CNS protection and increased permeability of proinflammatory (e.g., cytokines, reactive oxygen species substances from the peripheral blood into the brain. These events would trigger the activation of microglial cells and promote localized damage to oligodendrocytes and the myelin sheath, ultimately compromising myelination and the integrity of neural circuits. The potential implications for research in this area and directions for future studies are discussed.

  4. Theoretical Compartment Modeling of DCE-MRI Data Based on the Transport across Physiological Barriers in the Brain

    Directory of Open Access Journals (Sweden)

    Laura Fanea

    2012-01-01

    Full Text Available Neurological disorders represent major causes of lost years of healthy life and mortality worldwide. Development of their quantitative interdisciplinary in vivo evaluation is required. Compartment modeling (CM of brain data acquired in vivo using magnetic resonance imaging techniques with clinically available contrast agents can be performed to quantitatively assess brain perfusion. Transport of 1H spins in water molecules across physiological compartmental brain barriers in three different pools was mathematically modeled and theoretically evaluated in this paper and the corresponding theoretical compartment modeling of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI data was analyzed. The pools considered were blood, tissue, and cerebrospinal fluid (CSF. The blood and CSF data were mathematically modeled assuming continuous flow of the 1H spins in these pools. Tissue data was modeled using three CMs. Results in this paper show that transport across physiological brain barriers such as the blood to brain barrier, the extracellular space to the intracellular space barrier, or the blood to CSF barrier can be evaluated quantitatively. Statistical evaluations of this quantitative information may be performed to assess tissue perfusion, barriers' integrity, and CSF flow in vivo in the normal or disease-affected brain or to assess response to therapy.

  5. Neuropathology of White Matter Lesions, Blood-Brain Barrier Dysfunction, and Dementia.

    Science.gov (United States)

    Hainsworth, Atticus H; Minett, Thais; Andoh, Joycelyn; Forster, Gillian; Bhide, Ishaan; Barrick, Thomas R; Elderfield, Kay; Jeevahan, Jamuna; Markus, Hugh S; Bridges, Leslie R

    2017-10-01

    We tested whether blood-brain barrier dysfunction in subcortical white matter is associated with white matter abnormalities or risk of clinical dementia in older people (n=126; mean age 86.4, SD: 7.7 years) in the MRC CFAS (Medical Research Council Cognitive Function and Ageing Study). Using digital pathology, we quantified blood-brain barrier dysfunction (defined by immunohistochemical labeling for the plasma marker fibrinogen). This was assessed within subcortical white matter tissue samples harvested from postmortem T2 magnetic resonance imaging (MRI)-detected white matter hyperintensities, from normal-appearing white matter (distant from coexistent MRI-defined hyperintensities), and from equivalent areas in MRI normal brains. Histopathologic lesions were defined using a marker for phagocytic microglia (CD68, clone PGM1). Extent of fibrinogen labeling was not significantly associated with white matter abnormalities defined either by MRI (odds ratio, 0.90; 95% confidence interval, 0.79-1.03; P=0.130) or by histopathology (odds ratio, 0.93; 95% confidence interval, 0.77-1.12; P=0.452). Among participants with normal MRI (no detectable white matter hyperintensities), increased fibrinogen was significantly related to decreased risk of clinical dementia (odds ratio, 0.74; 95% confidence interval, 0.58-0.94; P=0.013). Among participants with histological lesions, increased fibrinogen was related to increased risk of dementia (odds ratio, 2.26; 95% confidence interval, 1.25-4.08; P=0.007). Our data suggest that some degree of blood-brain barrier dysfunction is common in older people and that this may be related to clinical dementia risk, additional to standard MRI biomarkers. © 2017 American Heart Association, Inc.

  6. Pathogenesis and Blood-Brain Barrier Heterogeneity of Breast Cancer Brain Metastasis

    Science.gov (United States)

    2005-07-01

    fluorescence microscope . Serendipitous observations indicate that our current concepts about pathogenesis and BBB function of brain metastasis (Fenner and...GFP expression under a fluorescence microscope . Those colonies with robust GFP expression were picked, pooled, and expanded for further experiments...days. In our system, both vasculature and tumor cells were clearly visible under fluorescence microscope . The results suggest that the intravascular

  7. Characterization of the L-glutamate clearance pathways across the blood-brain barrier and the effect of astrocytes in an in vitro blood-brain barrier model

    DEFF Research Database (Denmark)

    Helms, Hans Cc; Aldana, Blanca I; Groth, Simon

    2017-01-01

    The aim was to characterize the clearance pathways for L-glutamate from the brain interstitial fluid across the blood-brain barrier using a primary in vitro bovine endothelial/rat astrocyte co-culture. Transporter profiling was performed using uptake studies of radiolabeled L-glutamate with co...

  8. Barriers, Benefits, and Beliefs of Brain Training Smartphone Apps: An Internet Survey of Younger US Consumers.

    Science.gov (United States)

    Torous, John; Staples, Patrick; Fenstermacher, Elizabeth; Dean, Jason; Keshavan, Matcheri

    2016-01-01

    While clinical evidence for the efficacy of brain training remains in question, numerous smartphone applications (apps) already offer brain training directly to consumers. Little is known about why consumers choose to download these apps, how they use them, and what benefits they perceive. Given the high rates of smartphone ownership in those with internet access and the younger demographics, we chose to approach this question first with a general population survey that would capture primarily this demographic. We conducted an online internet-based survey of the US population via mTurk regarding their use, experience, and perceptions of brain training apps. There were no exclusion criteria to partake although internet access was required. Respondents were paid 20 cents for completing each survey. The survey was offered for a 2-week period in September 2015. 3125 individuals completed the survey and over half of these were under age 30. Responses did not significantly vary by gender. The brain training app most frequently used was Lumosity. Belief that a brain-training app could help with thinking was strongly correlated with belief it could also help with attention, memory, and even mood. Beliefs of those who had never used brain-training apps were similar to those who had used them. Respondents felt that data security and lack of endorsement from a clinician were the two least important barriers to use. RESULTS suggest a high level of interest in brain training apps among the US public, especially those in younger demographics. The stability of positive perception of these apps among app-naïve and app-exposed participants suggests an important role of user expectations in influencing use and experience of these apps. The low concern about data security and lack of clinician endorsement suggest apps are not being utilized in clinical settings. However, the public's interest in the effectiveness of apps suggests a common theme with the scientific community

  9. Role of blood-brain barrier P-glycoprotein in limiting brain accumulation and sedative side-effects of asimadoline, a peripherally acting analgaesic drug

    NARCIS (Netherlands)

    Jonker, JW; Wagenaar, E; van Deemter, L; Gottschlich, R; Bender, HM; Dasenbrock, J; Schinkel, AH

    1 Studies with knockout mice lacking mdrla P-glycoprotein (P-gp) have previously shown that blood-brain barrier P-gp is important in preventing the accumulation of several drugs in the brain. 2 Asimadoline (EMD 61753) is a peripherally selective kappa-opioid receptor agonist which is under

  10. Hello from the Other Side: How Autoantibodies Circumvent the Blood–Brain Barrier in Autoimmune Encephalitis

    Directory of Open Access Journals (Sweden)

    Tyler Cutforth

    2017-04-01

    Full Text Available Antibodies against neuronal receptors and synaptic proteins are associated with autoimmune encephalitides (AE that produce movement and psychiatric disorders. In order to exert their pathological effects on neural circuits, autoantibodies against central nervous system (CNS targets must gain access to the brain and spinal cord by crossing the blood–brain barrier (BBB, a tightly regulated gateway formed by endothelial cells lining CNS blood vessels. To date, the pathogenic mechanisms that underlie autoantibody-triggered encephalitic syndromes are poorly understood, and how autoantibodies breach the barrier remains obscure for almost all AE syndromes. The relative importance of cellular versus humoral immune mechanisms for disease pathogenesis also remains largely unexplored. Here, we review the proposed triggers for various autoimmune encephalopathies and their animal models, as well as basic structural features of the BBB and how they differ among various CNS regions, a feature that likely underlies some regional aspects of autoimmune encephalitis pathogenesis. We then discuss the routes that antibodies and immune cells employ to enter the CNS and their implications for AE. Finally, we explore future therapeutic strategies that may either preserve or restore barrier function and thereby limit immune cell and autoantibody infiltration into the CNS. Recent mechanistic insights into CNS autoantibody entry indicate promising future directions for therapeutic intervention beyond current, short-lived therapies that eliminate circulating autoantibodies.

  11. Hello from the Other Side: How Autoantibodies Circumvent the Blood-Brain Barrier in Autoimmune Encephalitis.

    Science.gov (United States)

    Platt, Maryann P; Agalliu, Dritan; Cutforth, Tyler

    2017-01-01

    Antibodies against neuronal receptors and synaptic proteins are associated with autoimmune encephalitides (AE) that produce movement and psychiatric disorders. In order to exert their pathological effects on neural circuits, autoantibodies against central nervous system (CNS) targets must gain access to the brain and spinal cord by crossing the blood-brain barrier (BBB), a tightly regulated gateway formed by endothelial cells lining CNS blood vessels. To date, the pathogenic mechanisms that underlie autoantibody-triggered encephalitic syndromes are poorly understood, and how autoantibodies breach the barrier remains obscure for almost all AE syndromes. The relative importance of cellular versus humoral immune mechanisms for disease pathogenesis also remains largely unexplored. Here, we review the proposed triggers for various autoimmune encephalopathies and their animal models, as well as basic structural features of the BBB and how they differ among various CNS regions, a feature that likely underlies some regional aspects of autoimmune encephalitis pathogenesis. We then discuss the routes that antibodies and immune cells employ to enter the CNS and their implications for AE. Finally, we explore future therapeutic strategies that may either preserve or restore barrier function and thereby limit immune cell and autoantibody infiltration into the CNS. Recent mechanistic insights into CNS autoantibody entry indicate promising future directions for therapeutic intervention beyond current, short-lived therapies that eliminate circulating autoantibodies.

  12. Effects of ionizing radiation on the blood brain barrier permeability to pharmacologically active substances

    Energy Technology Data Exchange (ETDEWEB)

    Trnovec, T.; Kallay, Z.; Bezek, S. (Institute of Experimental Pharmacology, Bratislava (Yugoslavia))

    1990-12-01

    Ionizing radiation can impair the integrity of the blood brain barrier (BBB). Data on early and late damage after brain irradiation are usually reported separately, yet a gradual transition between these two types has become evident. Signs appearing within 3 weeks after irradiation are considered to be early manifestations. The mechanism of radiation-effected integrity impairment of the BBB is discussed in relation to changes in morphological structures forming the BBB, the endothelium of intracerebral vessels, and in the surrounding astrocytes. Alterations in the function of the BBB are manifested in the endothelium by changes in the ultrastructural location of the activity of phosphatases and by the activation of pinocytotic vesicular transport, and in astrocyte cytoplasm by glycogen deposition. The changes in ultrastructure were critically surveyed with regard to increasing doses of radiation to the brain in the range of 5 Gy to 960 Gy. The qualitative as well as the semiquantitative and quantitative observations on the passage of substances across the damaged BBB were treated separately. Qualitative changes are based mainly on findings of extravasation of vital stains and of labelled proteins. The quantitative studies established differences in radiation-induced changes in the permeability of the BBB depending on the structure and physico-chemical properties of the barrier penetrating tracers. Indirect evaluation of radiation-induced BBB changes is based on studies of pharmacological effects of substances acting on the CNS. In conclusion, radiation impairs significantly the integrity of the BBB following single irradiation of the brain with a dose exceeding 10-15 Gy. The response of the BBB to ionizing radiation is dependent both on the dose to which the brain is exposed and on specific properties of the tracer. 68 references.

  13. Unilateral Opening of Rat Blood-Brain Barrier Assisted by Diagnostic Ultrasound Targeted Microbubbles Destruction

    Directory of Open Access Journals (Sweden)

    Yali Xu

    2016-01-01

    Full Text Available Objective. Blood-brain barrier (BBB is a key obstacle that prevents the medication from blood to the brain. Microbubble-enhanced cavitation by focused ultrasound can open the BBB and proves to be valuable in the brain drug delivery. The study aimed to explore the feasibility, efficacy, and safety of unilateral opening of BBB using diagnostic ultrasound targeted microbubbles destruction in rats. Methods. A transtemporal bone irradiation of diagnostic ultrasound and intravenous injection of lipid-coated microbubbles were performed at unilateral hemisphere. Pathological changes were monitored. Evans Blue extravasation grades, extraction from brain tissue, and fluorescence optical density were quantified. Lanthanum nitrate was traced by transmission electron microscopy. Results. After diagnostic ultrasound mediated microbubbles destruction, Evans Blue extravasation and fluorescence integrated optical density were significantly higher in the irradiated hemisphere than the contralateral side (all p<0.01. Erythrocytes extravasations were demonstrated in the ultrasound-exposed hemisphere (4±1, grade 2 while being invisible in the control side. Lanthanum nitrate tracers leaked through interendothelial cleft and spread to the nerve fiber existed in the irradiation side. Conclusions. Transtemporal bone irradiation under DUS mediated microbubble destruction provides us with a more accessible, safer, and higher selective BBB opening approach in rats, which is advantageous in brain targeted drugs delivery.

  14. Unilateral Opening of Rat Blood-Brain Barrier Assisted by Diagnostic Ultrasound Targeted Microbubbles Destruction.

    Science.gov (United States)

    Xu, Yali; Cui, Hai; Zhu, Qiong; Hua, Xing; Xia, Hongmei; Tan, Kaibin; Gao, Yunhua; Zhao, Jing; Liu, Zheng

    2016-01-01

    Objective. Blood-brain barrier (BBB) is a key obstacle that prevents the medication from blood to the brain. Microbubble-enhanced cavitation by focused ultrasound can open the BBB and proves to be valuable in the brain drug delivery. The study aimed to explore the feasibility, efficacy, and safety of unilateral opening of BBB using diagnostic ultrasound targeted microbubbles destruction in rats. Methods. A transtemporal bone irradiation of diagnostic ultrasound and intravenous injection of lipid-coated microbubbles were performed at unilateral hemisphere. Pathological changes were monitored. Evans Blue extravasation grades, extraction from brain tissue, and fluorescence optical density were quantified. Lanthanum nitrate was traced by transmission electron microscopy. Results. After diagnostic ultrasound mediated microbubbles destruction, Evans Blue extravasation and fluorescence integrated optical density were significantly higher in the irradiated hemisphere than the contralateral side (all p ultrasound-exposed hemisphere (4 ± 1, grade 2) while being invisible in the control side. Lanthanum nitrate tracers leaked through interendothelial cleft and spread to the nerve fiber existed in the irradiation side. Conclusions. Transtemporal bone irradiation under DUS mediated microbubble destruction provides us with a more accessible, safer, and higher selective BBB opening approach in rats, which is advantageous in brain targeted drugs delivery.

  15. Vascular endothelial growth factors enhance the permeability of the mouse blood-brain barrier.

    Directory of Open Access Journals (Sweden)

    Shize Jiang

    Full Text Available The blood-brain barrier (BBB impedes entry of many drugs into the brain, limiting clinical efficacy. A safe and efficient method for reversibly increasing BBB permeability would greatly facilitate central nervous system (CNS drug delivery and expand the range of possible therapeutics to include water soluble compounds, proteins, nucleotides, and other large molecules. We examined the effect of vascular endothelial growth factor (VEGF on BBB permeability in Kunming (KM mice. Human VEGF165 was administered to treatment groups at two concentrations (1.6 or 3.0 µg/mouse, while controls received equal-volume saline. Changes in BBB permeability were measured by parenchymal accumulation of the contrast agent Gd-DTPA as assessed by 7 T magnetic resonance imaging (MRI. Mice were then injected with Evans blue, sacrificed 0.5 h later, and perfused transcardially. Brains were removed, fixed, and sectioned for histological study. Both VEGF groups exhibited a significantly greater signal intensity from the cerebral cortex and basal ganglia than controls (P<0.001. Evans blue fluorescence intensity was higher in the parenchyma and lower in the cerebrovasculature of VEGF-treated animals compared to controls. No significant brain edema was observed by diffusion weighted MRI (DWI or histological staining. Exogenous application of VEGF can increase the permeability of the BBB without causing brain edema. Pretreatment with VEGF may be a feasible method to facilitate drug delivery into the CNS.

  16. Evolutionarily Conserved Roles for Blood-Brain Barrier Xenobiotic Transporters in Endogenous Steroid Partitioning and Behavior.

    Science.gov (United States)

    Hindle, Samantha J; Munji, Roeben N; Dolghih, Elena; Gaskins, Garrett; Orng, Souvinh; Ishimoto, Hiroshi; Soung, Allison; DeSalvo, Michael; Kitamoto, Toshihiro; Keiser, Michael J; Jacobson, Matthew P; Daneman, Richard; Bainton, Roland J

    2017-10-31

    Central nervous system (CNS) chemical protection depends upon discrete control of small-molecule access by the blood-brain barrier (BBB). Curiously, some drugs cause CNS side-effects despite negligible transit past the BBB. To investigate this phenomenon, we asked whether the highly BBB-enriched drug efflux transporter MDR1 has dual functions in controlling drug and endogenous molecule CNS homeostasis. If this is true, then brain-impermeable drugs could induce behavioral changes by affecting brain levels of endogenous molecules. Using computational, genetic, and pharmacologic approaches across diverse organisms, we demonstrate that BBB-localized efflux transporters are critical for regulating brain levels of endogenous steroids and steroid-regulated behaviors (sleep in Drosophila and anxiety in mice). Furthermore, we show that MDR1-interacting drugs are associated with anxiety-related behaviors in humans. We propose a general mechanism for common behavioral side effects of prescription drugs: pharmacologically challenging BBB efflux transporters disrupts brain levels of endogenous substrates and implicates the BBB in behavioral regulation. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Delivery of Biologics Across the Blood-Brain Barrier with Molecular Trojan Horse Technology.

    Science.gov (United States)

    Pardridge, William M

    2017-12-01

    Biologics are potential new therapeutics for many diseases of the central nervous system. Biologics include recombinant lysosomal enzymes, neurotrophins, decoy receptors, and therapeutic antibodies. These are large molecule drugs that do not cross the blood-brain barrier (BBB). All classes of biologics have been tested, without success, in clinical trials of brain disease over the last 25 years. In none of these past clinical trials was the biologic re-engineered to enable transport across the BBB. If the biologic does not cross the BBB, the drug cannot reach the target site in brain, and success in a clinical trial is not expected. Biologics can be re-engineered for BBB transport with the use of molecular Trojan horse technology. A BBB molecular Trojan horse is a monoclonal antibody (MAb) against an endogenous BBB receptor transporter, such as the insulin receptor or transferrin receptor. The receptor-specific MAb penetrates the brain via transport on the endogenous BBB receptor. The MAb acts as a molecular Trojan horse to deliver across the BBB the biologic pharmaceutical that is genetically fused to the MAb. The lead Trojan horse is a MAb against the human insulin receptor (HIR), and HIRMAb-derived fusion proteins have entered clinical trials for the treatment of brain disease.

  18. Erythropoietin protects the in vitro blood-brain barrier against VEGF-induced permeability.

    Science.gov (United States)

    Martínez-Estrada, Ofelia María; Rodríguez-Millán, Elisabeth; González-De Vicente, Esther; Reina, Manuel; Vilaró, Senén; Fabre, Myriam

    2003-11-01

    The blood-brain barrier (BBB) ensures the homeostasis of the brain microenvironment, mostly through complex tight junctions between brain endothelial cells that prevent the passage of hydrophilic molecules from blood to brain and vice versa. A recent study has shown in vivo that systemic administration of erythropoietin (Epo) protects against brain injury. Using an in vitro model of the bovine BBB, we observed that the expression of the Epo receptor is modulated by its ligand and hypoxic stimuli such as vascular endothelial growth factor (VEGF) treatment. In addition, Epo protects against the VEGF-induced permeability of the BBB, decreases the levels of endothelial nitric oxide synthase and restores junction proteins. The kinetic transport experiments revealed the capacity of Epo to cross the in vitro BBB in a saturable and specific way. Our results suggest a new mechanism for Epo-induced neuroprotection, in which circulating Epo controls and maintains the BBB through an Epo receptor signalling pathway and the re-establishment of cell junctions.

  19. Effects of deferoxamine on blood-brain barrier disruption after subarachnoid hemorrhage.

    Directory of Open Access Journals (Sweden)

    Yanjiang Li

    Full Text Available Blood brain barrier (BBB disruption is a key mechanism of subarachnoid hemorrhage (SAH-induced brain injury. This study examined the mechanism of iron-induced BBB disruption after SAH and investigated the potential therapeutic effect of iron chelation on SAH. Male adult Sprague-Dawley rats had an endovascular perforation of left internal carotid artery bifurcation or sham operation. The rats were treated with deferoxamine (DFX or vehicle (100mg/kg for a maximum of 7 days. Brain edema, BBB leakage, behavioral and cognitive impairment were examined. In SAH rat, the peak time of brain edema and BBB impairment in the cortex was at day 3 after SAH. SAH resulted in a significant increase in ferritin expression in the cortex. The ferritin positive cells were colocalized with endothelial cells, pericytes, astrocytes, microglia and neurons. Compared with vehicle, DFX caused less ferritin upregulation, brain water content, BBB impairment, behavioral and cognitive deficits in SAH rats. The results suggest iron overload could be a therapeutic target for SAH induced BBB damage.

  20. Increased Stability and Breakdown of Brain Effective Connectivity During Slow-Wave Sleep : Mechanistic Insights from Whole-Brain Computational Modelling

    NARCIS (Netherlands)

    Jobst, Beatrice M; Hindriks, Rikkert; Laufs, Helmut; Tagliazucchi, E.; Hahn, Gerald; Ponce-Alvarez, Adrián; Stevner, Angus B A; Kringelbach, Morten L; Deco, Gustavo

    2017-01-01

    Recent research has found that the human sleep cycle is characterised by changes in spatiotemporal patterns of brain activity. Yet, we are still missing a mechanistic explanation of the local neuronal dynamics underlying these changes. We used whole-brain computational modelling to study the

  1. Tight junctions at the blood brain barrier: physiological architecture and disease-associated dysregulation

    Directory of Open Access Journals (Sweden)

    Luissint Anny-Claude

    2012-11-01

    Full Text Available Abstract The Blood–brain barrier (BBB, present at the level of the endothelium of cerebral blood vessels, selectively restricts the blood-to-brain paracellular diffusion of compounds; it is mandatory for cerebral homeostasis and proper neuronal function. The barrier properties of these specialized endothelial cells notably depend on tight junctions (TJs between adjacent cells: TJs are dynamic structures consisting of a number of transmembrane and membrane-associated cytoplasmic proteins, which are assembled in a multimolecular complex and acting as a platform for intracellular signaling. Although the structural composition of these complexes has been well described in the recent years, our knowledge about their functional regulation still remains fragmentary. Importantly, pericytes, embedded in the vascular basement membrane, and perivascular microglial cells, astrocytes and neurons contribute to the regulation of endothelial TJs and BBB function, altogether constituting the so-called neurovascular unit. The present review summarizes our current understanding of the structure and functional regulation of endothelial TJs at the BBB. Accumulating evidence points to a correlation between BBB dysfunction, alteration of TJ complexes and progression of a variety of CNS diseases, such as stroke, multiple sclerosis and brain tumors, as well as neurodegenerative diseases like Parkinson’s and Alzheimer’s diseases. Understanding how TJ integrity is controlled may thus help improve drug delivery across the BBB and the design of therapeutic strategies for neurological disorders.

  2. GM-CSF promotes migration of human monocytes across the blood brain barrier.

    Science.gov (United States)

    Vogel, Daphne Y S; Kooij, Gijs; Heijnen, Priscilla D A M; Breur, Marjolein; Peferoen, Laura A N; van der Valk, Paul; de Vries, Helga E; Amor, Sandra; Dijkstra, Christine D

    2015-06-01

    Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). Infiltration of monocytes into the CNS is crucial for disease onset and progression. Animal studies indicate that granulocyte-macrophages colony-stimulating factor (GM-CSF) may play an essential role in this process, possibly by acting on the migratory capacities of myeloid cells across the blood-brain barrier. This study describes the effect of GM-CSF on human monocytes, macrophages, and microglia. Furthermore, the expression of GM-CSF and its receptor was investigated in the CNS under healthy and pathological conditions. We show that GM-CSF enhances monocyte migration across human blood-brain barrier endothelial cells in vitro. Next, immunohistochemical analysis on human brain tissues revealed that GM-CSF is highly expressed by microglia and macrophages in MS lesions. The GM-CSF receptor is expressed by neurons in the rim of combined gray/white matter lesions and astrocytes. Finally, the effect of GM-CSF on human macrophages was determined, revealing an intermediate activation status, with a phenotype similar to that observed in active MS lesions. Together our data indicate that GM-CSF is a powerful stimulator of monocyte migration, and is abundantly present in the inflamed CNS where it may act as an activator of macrophages and microglia. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Optically enhanced blood-brain-barrier crossing of plasmonic-active nanoparticles in preclinical brain tumor animal models

    Science.gov (United States)

    Yuan, Hsiangkuo; Wilson, Christy M.; Li, Shuqin; Fales, Andrew M.; Liu, Yang; Grant, Gerald; Vo-Dinh, Tuan

    2014-02-01

    Nanotechnology provides tremendous biomedical opportunities for cancer diagnosis, imaging, and therapy. In contrast to conventional chemotherapeutic agents where their actual target delivery cannot be easily imaged, integrating imaging and therapeutic properties into one platform facilitates the understanding of pharmacokinetic profiles, and enables monitoring of the therapeutic process in each individual. Such a concept dubbed "theranostics" potentiates translational research and improves precision medicine. One particular challenging application of theranostics involves imaging and controlled delivery of nanoplatforms across blood-brain-barrier (BBB) into brain tissues. Typically, the BBB hinders paracellular flux of drug molecules into brain parenchyma. BBB disrupting agents (e.g. mannitol, focused ultrasound), however, suffer from poor spatial confinement. It has been a challenge to design a nanoplatform not only acts as a contrast agent but also improves the BBB permeation. In this study, we demonstrated the feasibility of plasmonic gold nanoparticles as both high-resolution optical contrast agent and focalized tumor BBB permeation-inducing agent. We specifically examined the microscopic distribution of nanoparticles in tumor brain animal models. We observed that most nanoparticles accumulated at the tumor periphery or perivascular spaces. Nanoparticles were present in both endothelial cells and interstitial matrices. This study also demonstrated a novel photothermal-induced BBB permeation. Fine-tuning the irradiating energy induced gentle disruption of the vascular integrity, causing short-term extravasation of nanomaterials but without hemorrhage. We conclude that our gold nanoparticles are a powerful biocompatible contrast agent capable of inducing focal BBB permeation, and therefore envision a strong potential of plasmonic gold nanoparticle in future brain tumor imaging and therapy.

  4. Upregulation of the low density lipoprotein receptor at the blood-brain barrier: intercommunications between brain capillary endothelial cells and astrocytes

    OpenAIRE

    1994-01-01

    In contrast to the endothelial cells in large vessels where LDL receptors are downregulated, brain capillary endothelial cells in vivo express an LDL receptor. Using a cell culture model of the blood-brain barrier consisting of a coculture of brain capillary endothelial cells and astrocytes, we observed that the capacity of endothelial cells to bind LDL is enhanced threefold when cocultured with astrocytes. We next investigated the ability of astrocytes to modulate endothelial cell LDL recept...

  5. Implications of MMP9 for Blood Brain Barrier Disruption And Hemorrhagic Transformation Following Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    Renee Jade Turner

    2016-03-01

    Full Text Available Numerous studies have documented increases in matrix metalloproteinases (MMPs, specifically MMP-9 levels following stroke, with such perturbations associated with disruption of the blood brain barrier (BBB, increased risk of hemorrhagic complications and worsened outcome. Despite this, controversy remains as to which cells release MMP-9 at the normal and pathological BBB, with even less clarity in the context of stroke. This may be further complicated by the influence of tissue plasminogen activator (tPA treatment. The aim of the present review is to examine the relationship between neutrophils, MMP-9 and tPA following ischemic stroke to elucidate which cells are responsible for the increases in MMP-9 and resultant barrier changes and hemorrhage observed following stroke.

  6. S-oxiracetam protect against ischemic stroke via alleviating blood brain barrier dysfunction in rats.

    Science.gov (United States)

    Huang, Liangliang; Shang, Erxin; Fan, Wenxiang; Li, Xiang; Li, Binbin; He, Shucheng; Fu, Yuxin; Zhang, Yizhi; Li, Yunman; Fang, Weirong

    2017-11-15

    The blood brain barrier (BBB) maintains the basic stability of the brain tissue under physiological conditions, while destroys and exaggerates brain edema and inflammatory response after ischemic stroke. In this study, we researched S-oxiracetam (S-ORC), a nootropic drug, alleviates BBB dysfunction and protects against ischemic stroke in rats. Middle cerebral artery occlusion(MCAO)/reperfusion in rats is applied to mimic ischemic stroke. One hour after reperfusion, rats are administered intravenously with different dose (0.12, 0.24, or 0.48g/kg) of S-ORC for continuative three days. Seventy-two hours after MCAO, TTC staining, hematoxylin and eosin (H&E) staining, brain water content, immunohistochemical staining, EB extravasation, western blot are provided to evaluate the protective effect and possible mechanism of S-ORC on BBB dysfunction. Furthermore, brain concentration of verapamil (P-glycoprotein substrate) and atenolol (paracellular transport marker) were assayed by UPLC-MS/MS co administration with or without S-ORC. The results show that post-treatment of S-ORC decreases cerebral infarct size, lessens brain edema, inhibits neutrophil infiltration and cytokines releasing. Furthermore, S-ORC treatment decreases EB leakage, downregulates MMP-9, upregulates occludin and claudin-5, and decreases brain concentration of verapamil and atenolol after MCAO surgery. In conclusion, the present study demonstrates that post-treatment of S-ORC alleviates BBB dysfunction by regulating tight junction proteins (TJPs), upregulating P-glycoprotein function, and protects against ischemic stroke as result. Copyright © 2017. Published by Elsevier B.V.

  7. Sulforaphane preconditioning of the Nrf2/HO-1 defense pathway protects the cerebral vasculature against blood-brain barrier disruption and neurological deficits in stroke.

    Science.gov (United States)

    Alfieri, Alessio; Srivastava, Salil; Siow, Richard C M; Cash, Diana; Modo, Michel; Duchen, Michael R; Fraser, Paul A; Williams, Steven C R; Mann, Giovanni E

    2013-12-01

    Disruption of the blood-brain barrier (BBB) and cerebral edema are the major pathogenic mechanisms leading to neurological dysfunction and death after ischemic stroke. The brain protects itself against infarction via activation of endogenous antioxidant defense mechanisms, and we here report the first evidence that sulforaphane-mediated preactivation of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream target heme oxygenase-1 (HO-1) in the cerebral vasculature protects the brain against stroke. To induce ischemic stroke, Sprague-Dawley rats were subjected to 70 min middle cerebral artery occlusion (MCAo) followed by 4, 24, or 72 h reperfusion. Nrf2 and HO-1 protein expression was upregulated in cerebral microvessels of peri-infarct regions after 4-72 h, with HO-1 preferentially associated with perivascular astrocytes rather than the cerebrovascular endothelium. In naïve rats, treatment with sulforaphane increased Nrf2 expression in cerebral microvessels after 24h. Upregulation of Nrf2 by sulforaphane treatment prior to transient MCAo (1h) was associated with increased HO-1 expression in perivascular astrocytes in peri-infarct regions and cerebral endothelium in the infarct core. BBB disruption, lesion progression, as analyzed by MRI, and neurological deficits were reduced by sulforaphane pretreatment. As sulforaphane pretreatment led to a moderate increase in peroxynitrite generation, we suggest that hormetic preconditioning underlies sulforaphane-mediated protection against stroke. In conclusion, we propose that pharmacological or dietary interventions aimed to precondition the brain via activation of the Nrf2 defense pathway in the cerebral microvasculature provide a novel therapeutic approach for preventing BBB breakdown and neurological dysfunction in stroke. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  8. Focused ultrasound delivery of Raman nanoparticles across the blood-brain barrier: Potential for targeting experimental brain tumors

    Science.gov (United States)

    Diaz, Roberto Jose; McVeigh, Patrick Z.; O’Reilly, Meaghan A.; Burrell, Kelly; Bebenek, Matthew; Smith, Christian; Etame, Arnold; Zadeh, Gelareh; Hynynen, Kullervo; Wilson, Brian C.; Rutka, James T.

    2014-01-01

    Spectral mapping of nanoparticles with surface enhanced Raman scattering (SERS) capability in the near-infrared range is an emerging molecular imaging technique. We used magnetic resonance image-guided transcranial focused ultrasound (TcMRgFUS) to reversibly disrupt the blood-brain barrier (BBB) adjacent to brain tumor margins in rats. Glioma cells were found to internalize SERS capable nanoparticles of 50 nm or 120 nm physical diameter. Surface coating with anti-epidermal growth factor receptor antibody or non-specific human immunoglobulin G, resulted in enhanced cell uptake of nanoparticles in-vitro compared to nanoparticles with methyl terminated 12-unit polyethylene glycol surface. BBB disruption permitted the delivery of SERS capable spherical 50 or 120 nm gold nanoparticles to the tumor margins. Thus, nanoparticles with SERS imaging capability can be delivered across the BBB non-invasively using TcMRgFUS and have the potential to be used as optical tracking agents at the invasive front of malignant brain tumors. PMID:24374363

  9. Breaking the Blood-Brain Barrier With Mannitol to Aid Stem Cell Therapeutics in the Chronic Stroke Brain.

    Science.gov (United States)

    Tajiri, Naoki; Lee, Jea Young; Acosta, Sandra; Sanberg, Paul R; Borlongan, Cesar V

    2016-01-01

    Blood-brain barrier (BBB) permeabilizers, such as mannitol, can facilitate peripherally delivered stem cells to exert therapeutic benefits on the stroke brain. Although this BBB permeation-aided stem cell therapy has been demonstrated in the acute stage of stroke, such BBB permeation in the chronic stage of the disease remains to be examined. Adult Sprague-Dawley rats initially received sham surgery or experimental stroke via the 1-h middle cerebral artery occlusion (MCAo) model. At 1 month after the MCAo surgery, stroke animals were randomly assigned to receive human umbilical cord stem cells only (2 million viable cells), mannitol only (1.1 mol/L mannitol at 4°C), combined human umbilical cord stem cells (200,000 viable cells) and mannitol (1.1 mol/L mannitol at 4°C), and vehicle (phosphate-buffered saline) only. Stroke animals that received human umbilical cord blood cells alone or combined human umbilical cord stem cells and mannitol exhibited significantly improved motor performance and significantly better brain cell survival in the peri-infarct area compared to stroke animals that received vehicle or mannitol alone, with mannitol treatment reducing the stem cell dose necessary to afford functional outcomes. Enhanced neurogenesis in the subventricular zone accompanied the combined treatment of human umbilical cord stem cells and mannitol. We showed that BBB permeation facilitates the therapeutic effects of a low dose of peripherally transplanted stem cells to effectively cause functional improvement and increase neurogenesis in chronic stroke.

  10. Candesartan attenuates ischemic brain edema and protects the blood-brain barrier integrity from ischemia/reperfusion injury in rats.

    Science.gov (United States)

    Panahpour, Hamdollah; Nekooeian, Ali Akbar; Dehghani, Gholam Abbas

    2014-01-01

    Angiotensin II (Ang II) has an important role on cerebral microcirculation; however, its direct roles in terms of ischemic brain edema need to be clarified. This study evaluated the role of central Ang II by using candesartan, as an AT1 receptor blocker, in the brain edema formation and blood-brain barrier (BBB) disruption caused by ischemia/reperfusion (I/R) injuries in rat. Rats were exposed to 60-min middle cerebral artery (MCA) occlusion. Vehicle and non-hypotensive doses of candesartan (0.1 mg/kg) were administered one hour before ischemia. Neurological dysfunction scoring was evaluated following 24 h of reperfusion. Animals were then decapitated under deep anesthesia for the assessments of cerebral infarct size, edema formation, and BBB permeability. The outcomes of 24 h reperfusion after 60-min MCA occlusion were severe neurological disability, massive BBB disruption (Evans blue extravasation = 12.5 ± 1.94 µg/g tissue), 4.02% edema, and cerebral infarction (317 ± 21 mm3). Candesartan at a dose of 0.1 mg/kg, without changing arterial blood pressure, improved neurological dysfunction scoring together with significant reductions in BBB disruption (54.9%), edema (59.2%), and cerebral infarction (54.9%). Inactivation of central AT1 receptors, if not accompanied with arterial hypotension, protected cerebral micro-vasculatures from damaging effects of acute stroke.

  11. Candesartan Attenuates Ischemic Brain Edema and Protects the Blood–Brain Barrier Integrity from Ischemia/Reperfusion Injury in Rats

    Science.gov (United States)

    Panahpour, Hamdollah; Nekooeian, Ali Akbar; Dehghani, Gholam Abbas

    2014-01-01

    Background: Angiotensin II (Ang II) has an important role on cerebral microcirculation; however, its direct roles in terms of ischemic brain edema need to be clarified. This study evaluated the role of central Ang II by using candesartan, as an AT1 receptor blocker, in the brain edema formation and blood-brain barrier (BBB) disruption caused by ischemia/reperfusion (I/R) injuries in rat. Methods: Rats were exposed to 60-min middle cerebral artery (MCA) occlusion. Vehicle and non-hypotensive doses of candesartan (0.1 mg/kg) were administered one hour before ischemia. Neurological dysfunction scoring was evaluated following 24 h of reperfusion. Animals were then decapitated under deep anesthesia for the assessments of cerebral infarct size, edema formation, and BBB permeability. Results: The outcomes of 24 h reperfusion after 60-min MCA occlusion were severe neurological disability, massive BBB disruption (Evans blue extravasation = 12.5 ± 1.94 µg/g tissue), 4.02% edema, and cerebral infarction (317 ± 21 mm3). Candesartan at a dose of 0.1 mg/kg, without changing arterial blood pressure, improved neurological dysfunction scoring together with significant reductions in BBB disruption (54.9%), edema (59.2%), and cerebral infarction (54.9%). Conclusions: Inactivation of central AT1 receptors, if not accompanied with arterial hypotension, protected cerebral micro-vasculatures from damaging effects of acute stroke. PMID:25326022

  12. Dietary Virgin Olive Oil Reduces Blood Brain Barrier Permeability, Brain Edema, and Brain Injury in Rats Subjected to Ischemia-Reperfusion

    Directory of Open Access Journals (Sweden)

    Fatemeh Mohagheghi

    2010-01-01

    Full Text Available Recent studies suggest that dietary virgin olive oil (VOO reduces hypoxia-reoxygenation injury in rat brain slices. We sought to extend these observations in an in vivo study of rat cerebral ischemia-reperfusion injury. Four groups, each consisting of 18 Wistar rats, were studied. One group (control received saline, while three treatment groups received oral VOO (0.25, 0.5, and 0.75 mL/kg/day, respectively. After 30 days, blood lipid profiles were determined, before a 60-min period of middle cerebral artery occlusion (MCAO. After 24-h reperfusion, neurological deficit scores, infarct volume, brain edema, and blood brain barrier permeability were each assessed in subgroups of six animals drawn from each main group. VOO reduced the LDL/HDL ratio in doses of 0.25, 0.5, and 0.75 mL/kg/day in comparison to the control group (p < 0.05, and offered cerebroprotection from ischemia-reperfusion. For controls vs. doses of 0.25 vs. 0.5 vs. 0.75 mL/kg/day, attenuated corrected infarct volumes were 207.82 ± 34.29 vs. 206.41 ± 26.23 vs. 124.21 ± 14.73 vs. 108.46 ± 31.63 mm3; brain water content of the infarcted hemisphere was 82 ±± 0.25 vs. 81.5 ± 0.56 vs. 80.5 ± 0.22 vs. 80.5 ± 0.34%; and blood brain barrier permeability of the infarcted hemisphere was 11.31 ± 2.67 vs. 9.21 ± 2.28 vs. 5.83 ± 1.6 vs. 4.43 ± 0.93 µg/g tissue (p < 0.05 for measures in doses 0.5 and 0.75 mL/kg/day vs. controls. Oral administration of VOO reduces infarct volume, brain edema, blood brain barrier permeability, and improves neurologic deficit scores after transient MCAO in rats.

  13. Intact blood-brain barrier during spontaneous attacks of migraine without aura

    DEFF Research Database (Denmark)

    Amin, F M; Hougaard, A; Cramer, S P

    2017-01-01

    BACKGROUND AND PURPOSE: The integrity of the blood-brain barrier (BBB) has been questioned in migraine, but BBB permeability has never been investigated during spontaneous migraine attacks. In the present study, BBB permeability during spontaneous attacks of migraine without aura was investigated...... compared to an interictal state. METHODS: Seventy-four patients suffering from migraine without aura were recruited to participate in this cross-sectional dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) study. The patients were instructed to report at the hospital for DCE-MRI scan during...... that the BBB permeability during spontaneous migraine attacks without aura was unchanged....

  14. Adult human dental pulp stem cells promote blood-brain barrier permeability through vascular endothelial growth factor-a expression.

    Science.gov (United States)

    Winderlich, Joshua N; Kremer, Karlea L; Koblar, Simon A

    2016-06-01

    Stem cell therapy is a promising new treatment option for stroke. Intravascular administration of stem cells is a valid approach as stem cells have been shown to transmigrate the blood-brain barrier. The mechanism that causes this effect has not yet been elucidated. We hypothesized that stem cells would mediate localized discontinuities in the blood-brain barrier, which would allow passage into the brain parenchyma. Here, we demonstrate that adult human dental pulp stem cells express a soluble factor that increases permeability across an in vitro model of the blood-brain barrier. This effect was shown to be the result of vascular endothelial growth factor-a. The effect could be amplified by exposing dental pulp stem cell to stromal-derived factor 1, which stimulates vascular endothelial growth factor-a expression. These findings support the use of dental pulp stem cell in therapy for stroke. © The Author(s) 2015.

  15. Delayed blood-brain barrier disruption after shallow-water diving demonstrated by magnetic resonance imaging.

    Science.gov (United States)

    Hadanny, Amir; Tal, Sigal; Fishlev, Gregori; Bechor, Yair; Efrati, Shai

    2015-06-01

    A 22-year-old diver presented to our emergency room complaining of headaches and left side numbness three days after diving to a depth of 6 metres for 25 minutes. On examination, he had left-sided hypaesthesia, and a post-contrast FLAIR brain MRI sequence revealed significant diffuse meningeal enhancement, indicating blood-brain-barrier (BBB) disruption. The patient was treated with hyperbaric oxygen; the initial four sessions resulted in only partial symptom improvement correlating with partial improvement in the MRI findings. Ten additional hyperbaric treatments resulted in complete resolution of the symptoms and normalization of MRI findings. The main aim of this case report is to present a probable, atypical, delayed-onset case of shallow-water decompression sickness culminating in significant BBB damage, which was demonstrated by special MRI techniques.

  16. Increased brainstem perfusion, but no blood-brain barrier disruption, during attacks of migraine with aura

    DEFF Research Database (Denmark)

    Hougaard, Anders; Amin, Faisal M; Christensen, Casper E

    2017-01-01

    See Moskowitz (doi:10.1093/brain/awx099) for a scientific commentary on this article.The migraine aura is characterized by transient focal cortical disturbances causing dramatic neurological symptoms that are usually followed by migraine headache. It is currently not understood how the aura...... symptoms are related to the headache phase of migraine. Animal studies suggest that cortical spreading depression, the likely mechanism of migraine aura, causes disruption of the blood-brain barrier and noxious stimulation of trigeminal afferents leading to activation of brainstem nuclei and triggering...... of the anterior, middle and posterior circulation during spontaneous attacks of migraine with aura. Patients reported to our institution to undergo magnetic resonance imaging during the headache phase after presenting with typical visual aura. Nineteen patients were scanned during attacks and on an attack...

  17. Tailored delivery of analgesic ziconotide across a blood brain barrier model using viral nanocontainers

    Science.gov (United States)

    Anand, Prachi; O'Neil, Alison; Lin, Emily; Douglas, Trevor; Holford, Mandë

    2015-08-01

    The blood brain barrier (BBB) is often an insurmountable obstacle for a large number of candidate drugs, including peptides, antibiotics, and chemotherapeutic agents. Devising an adroit delivery method to cross the BBB is essential to unlocking widespread application of peptide therapeutics. Presented here is an engineered nanocontainer for delivering peptidic drugs across the BBB encapsulating the analgesic marine snail peptide ziconotide (Prialt®). We developed a bi-functional viral nanocontainer based on the Salmonella typhimurium bacteriophage P22 capsid, genetically incorporating ziconotide in the interior cavity, and chemically attaching cell penetrating HIV-Tat peptide on the exterior of the capsid. Virus like particles (VLPs) of P22 containing ziconotide were successfully transported in several BBB models of rat and human brain microvascular endothelial cells (BMVEC) using a recyclable noncytotoxic endocytic pathway. This work demonstrates proof in principle for developing a possible alternative to intrathecal injection of ziconotide using a tunable VLP drug delivery nanocontainer to cross the BBB.

  18. Blood-brain barrier disruption: mechanistic links between Western diet consumption and dementia

    Directory of Open Access Journals (Sweden)

    Ted Menghsiung Hsu

    2014-05-01

    Full Text Available Both obesity and Alzheimer’s disease are major health burdens in Western societies. While commonly viewed as having separate etiologies, this review highlights data suggesting that intake of Western diets, diets high in saturated fatty acids and simple carbohydrates, may pose a common environmental risk factor contributing to the development of both of these adverse pathologies. We discuss the effects of Western Diet intake on learning and memory processes that are dependent on the hippocampus, as well as the importance of this brain region in both obesity development and the onset of Alzheimer’s and other dementias. A putative mechanism is discussed that mechanistically links Western diet consumption, blood brain barrier degradation, and subsequent hippocampal damage and dementia pathology.

  19. The rights and wrongs of blood-brain barrier permeability studies: a walk through 100 years of history

    Directory of Open Access Journals (Sweden)

    Norman Ruthven Saunders

    2014-12-01

    Full Text Available Careful examination of relevant literature shows that many of the most cherished concepts of the blood-brain barrier are incorrect. These include an almost mythological belief in its immaturity that is unfortunately often equated with absence or at least leakiness in the embryo and fetus. The original concept of a blood-brain barrier is often attributed to Ehrlich; however, he did not accept that permeability of cerebral vessels was different from other organs. Goldmann is often credited with the first experiments showing dye (trypan blue exclusion from the brain when injected systemically, but not when injected directly into it. Rarely cited are earlier experiments of Bouffard and of Franke who showed methylene blue and trypan red stained all tissues except the brain. The term blood-brain barrier Blut-Hirnschranke is often attributed to Lewandowsky, but it does not appear in his papers. The first person to use this term seems to be Stern in the early 1920s. Studies in embryos by Stern & colleagues, Weed and Wislocki showed results similar to those in adult animals. These were well-conducted experiments made a century ago, thus the persistence of a belief in barrier immaturity is puzzling. As discussed in this review, evidence for this belief, is of poor experimental quality, often misinterpreted and often not properly cited. The functional state of blood-brain barrier mechanisms in the fetus is an important biological phenomenon with implications for normal brain development. It is also important for clinicians to have proper evidence on which to advise pregnant women who may need to take medications for serious medical conditions. Beliefs in immaturity of the blood-brain barrier have held the field back for decades. Their history illustrates the importance of taking account of all the evidence and assessing its quality, rather than selecting papers that supports a preconceived notion or intuitive belief. This review attempts to right the

  20. Cyclosporine-inhibitable Blood-Brain Barrier Drug Transport Influences Clinical Morphine Pharmacodynamics

    Science.gov (United States)

    Meissner, Konrad; Avram, Michael J.; Yermolenka, Viktar; Francis, Amber M.; Blood, Jane; Kharasch, Evan D.

    2013-01-01

    Background The blood-brain barrier is richly populated by active influx and efflux transporters influencing brain drug concentrations. Morphine, a drug with delayed clinical onset, is a substrate for the efflux transporter P-glycoprotein in vitro and in animals. This investigation tested whether morphine is a transporter substrate in humans. Methods Fourteen healthy volunteers received morphine (0.1 mg/kg, 1 h intravenous infusion) in a crossover study after nothing (control) or the validated P-glycoprotein inhibitor cyclosporine (5 mg/kg, 2 h infusion). Plasma and urine morphine and morphine glucuronide metabolite concentrations were measured by mass spectrometry. Morphine effects were measured by miosis and analgesia. Results Cyclosporine minimally altered morphine disposition, increasing the area under the plasma morphine concentration versus time curve to 100 ± 21 versus 85 ± 24 ng/ml•hr (p miosis, and increased the area under the miosis-time curve (18 ± 9 vs. 11 ± 5 mm-hr), plasma-effect site transfer rate constant (ke0, median 0.27 vs. 0.17 hr−1), and maximum calculated effect site morphine concentration (11.5 ± 3.7 vs. 7.6 ± 2.9 ng/ml) (all p < 0.05). Analgesia testing was confounded by cyclosporine-related pain. Conclusions Morphine is a transporter substrate at the human blood-brain barrier. Results suggest a role for P-glycoprotein or other efflux transporters in brain morphine access, although the magnitude of the effect is small, and unlikely to be a major determinant of morphine clinical effects. Efflux may explain some variability in clinical morphine effects. PMID:23851346

  1. Cyclosporine A kinetics in brain cell cultures and its potential of crossing the blood-brain barrier.

    Science.gov (United States)

    Bellwon, P; Culot, M; Wilmes, A; Schmidt, T; Zurich, M G; Schultz, L; Schmal, O; Gramowski-Voss, A; Weiss, D G; Jennings, P; Bal-Price, A; Testai, E; Dekant, W

    2015-12-25

    There is an increasing need to develop improved systems for predicting the safety of xenobiotics. However, to move beyond hazard identification the available concentration of the test compounds needs to be incorporated. In this study cyclosporine A (CsA) was used as a model compound to assess the kinetic profiles in two rodent brain cell cultures after single and repeated exposures. CsA induced-cyclophilin B (Cyp-B) secretion was also determined as CsA-specific pharmacodynamic endpoint. Since CsA is a potent p-glycoprotein substrate, the ability of this compound to cross the blood-brain barrier (BBB) was also investigated using an in vitro bovine model with repeated exposures up to 14 days. Finally, CsA uptake mechanisms were studied using a parallel artificial membrane assay (PAMPA) in combination with a Caco-2 model. Kinetic results indicate a low intracellular CsA uptake, with no marked bioaccumulation or biotransformation. In addition, only low CsA amounts crossed the BBB. PAMPA and Caco-2 experiments revealed that CsA is mostly trapped to lipophilic compartments and exits the cell apically via active transport. Thus, although CsA is unlikely to enter the brain at cytotoxic concentrations, it may cause alterations in electrical activity and is likely to increase the CNS concentration of other compounds by occupying the BBBs extrusion capacity. Such an integrated testing system, incorporating BBB, brain culture models and kinetics could be applied for assessing neurotoxicity potential of compounds. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Kinetics of Transferrin and Transferrin-Receptor during Iron Transport through Blood Brain Barrier

    Science.gov (United States)

    Khan, Aminul; Liu, Jin; Dutta, Prashanta

    2017-11-01

    Transferrin and its receptors play an important role during the uptake and transcytosis of iron by blood brain barrier (BBB) endothelial cells to maintain iron homeostasis in BBB endothelium and brain. In the blood side of BBB, ferric iron binds with the apo-transferrin to form holo-transferrin which enters the endothelial cell via transferrin receptor mediated endocytosis. Depending on the initial concentration of iron inside the cell endocytosed holo-transferrin can either be acidified in the endosome or exocytosed through the basolateral membrane. Acidification of holo-transferrin in the endosome releases ferrous irons which may either be stored and used by the cell or transported into brain side. Exocytosis of the holo-transferrin through basolateral membrane leads to transport of iron bound to transferrin into brain side. In this work, kinetics of internalization, recycling and exocytosis of transferrin and its receptors are modeled by laws of mass action during iron transport in BBB endothelial cell. Kinetic parameters for the model are determined by least square analysis. Our results suggest that the cell's initial iron content determines the extent of the two possible iron transport pathways, which will be presented in this talk Research reported in this publication was supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Number R01GM122081.

  3. Zika Virus Infects, Activates, and Crosses Brain Microvascular Endothelial Cells, without Barrier Disruption

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    Michelle P. Papa

    2017-12-01

    Full Text Available Zika virus (ZIKV has been associated to central nervous system (CNS harm, and virus was detected in the brain and cerebrospinal fluids of microcephaly and meningoencephalitis cases. However, the mechanism by which the virus reaches the CNS is unclear. Here, we addressed the effects of ZIKV replication in human brain microvascular endothelial cells (HBMECs, as an in vitro model of blood brain barrier (BBB, and evaluated virus extravasation and BBB integrity in an in vivo mouse experimental model. HBMECs were productively infected by African and Brazilian ZIKV strains (ZIKVMR766 and ZIKVPE243, which induce increased production of type I and type III IFN, inflammatory cytokines and chemokines. Infection with ZIKVMR766 promoted earlier cellular death, in comparison to ZIKVPE243, but infection with either strain did not result in enhanced endothelial permeability. Despite the maintenance of endothelial integrity, infectious virus particles crossed the monolayer by endocytosis/exocytosis-dependent replication pathway or by transcytosis. Remarkably, both viruses' strains infected IFNAR deficient mice, with high viral load being detected in the brains, without BBB disruption, which was only detected at later time points after infection. These data suggest that ZIKV infects and activates endothelial cells, and might reach the CNS through basolateral release, transcytosis or transinfection processes. These findings further improve the current knowledge regarding ZIKV dissemination pathways.

  4. Distribution of blood-brain barrier disruption in primary blast injury.

    Science.gov (United States)

    Yeoh, Stewart; Bell, E David; Monson, Kenneth L

    2013-10-01

    Traumatic brain injury (TBI) resulting from explosive-related blast overpressure is a topic at the forefront of neurotrauma research. Compromise of the blood-brain barrier (BBB) and other cerebral blood vessel dysfunction is commonly reported in both experimental and clinical studies on blast injury. This study used a rifle primer-driven shock tube to investigate cerebrovascular injury in rats exposed to low-impulse, pure primary blast at three levels of overpressure (145, 232, and 323 kPa) and with three survival times (acute, 24, and 48 h). BBB disruption was quantified immunohistochemically by measuring immunoglobulin G (IgG) extravasation with image analysis techniques. Pure primary blast generated small lesions scattered throughout the brain. The number and size of lesions increased with peak overpressure level, but no significant difference was seen between survival times. Despite laterally directed blast exposure, equal numbers of lesions were found in each hemisphere of the brain. These observations suggest that cerebrovascular injury due to primary blast is distinct from that associated with conventional TBI.

  5. Estrogen provides neuroprotection against brain edema and blood brain barrier disruption through both estrogen receptors α and β following traumatic brain injury

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    Vida Naderi

    2015-02-01

    Full Text Available Objective(s:Estrogen (E2 has neuroprotective effects on blood-brain-barrier (BBB after traumatic brain injury (TBI. In order to investigate the roles of estrogen receptors (ERs in these effects, ER-α antagonist (MPP and, ER-β antagonist (PHTPP, or non-selective estrogen receptors antagonist (ICI 182780 were administered. Materials and Methods: Ovariectomized rats were divided into 10 groups, as follows: Sham, TBI, E2, oil, MPP+E2, PHTPP+E2, MPP+PHTPP+E2, ICI+E2, MPP, and DMSO. E2 (33.3 µg/Kg or oil were administered 30 min after TBI. 1 dose (150 µg/Kg of each of MPP, PHTPP, and (4 mg/kg ICI182780 was injected two times, 24 hr apart, before TBI and estrogen treatment. BBB disruption (Evans blue content and brain edema (brain water content evaluated 5 hr and 24 hr after the TBI were evaluated, respectively. Results: The results showed that E2 reduced brain edema after TBI compared to vehicle (P

  6. Overcoming the blood-brain tumor barrier for effective glioblastoma treatment.

    Science.gov (United States)

    van Tellingen, O; Yetkin-Arik, B; de Gooijer, M C; Wesseling, P; Wurdinger, T; de Vries, H E

    2015-03-01

    Gliomas are the most common primary brain tumors. Particularly in adult patients, the vast majority of gliomas belongs to the heterogeneous group of diffuse gliomas, i.e. glial tumors characterized by diffuse infiltrative growth in the preexistent brain tissue. Unfortunately, glioblastoma, the most aggressive (WHO grade IV) diffuse glioma is also by far the most frequent one. After standard treatment, the 2-year overall survival of glioblastoma patients is approximately only 25%. Advanced knowledge in the molecular pathology underlying malignant transformation has offered new handles and better treatments for several cancer types. Unfortunately, glioblastoma multiforme (GBM) patients have not yet profited as although numerous experimental drugs have been tested in clinical trials, all failed miserably. This grim prognosis for GBM is at least partly due to the lack of successful drug delivery across the blood-brain tumor barrier (BBTB). The human brain comprises over 100 billion capillaries with a total length of 400 miles, a total surface area of 20 m(2) and a median inter-capillary distance of about 50 μm, making it the best perfused organ in the body. The BBTB encompasses existing and newly formed blood vessels that contribute to the delivery of nutrients and oxygen to the tumor and facilitate glioma cell migration to other parts of the brain. The high metabolic demands of high-grade glioma create hypoxic areas that trigger increased expression of VEGF and angiogenesis, leading to the formation of abnormal vessels and a dysfunctional BBTB. Even though the BBTB is considered 'leaky' in the core part of glioblastomas, in large parts of glioblastomas and, even more so, in lower grade diffuse gliomas the BBTB more closely resembles the intact blood-brain barrier (BBB) and prevents efficient passage of cancer therapeutics, including small molecules and antibodies. Thus, many drugs can still be blocked from reaching the many infiltrative glioblastoma cells that

  7. Overweight worsens apoptosis, neuroinflammation and blood-brain barrier damage after hypoxic ischemia in neonatal brain through JNK hyperactivation

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    Wu Hsin-Chieh

    2011-04-01

    Full Text Available Abstract Background Apoptosis, neuroinflammation and blood-brain barrier (BBB damage affect the susceptibility of the developing brain to hypoxic-ischemic (HI insults. c-Jun N-terminal kinase (JNK is an important mediator of insulin resistance in obesity. We hypothesized that neonatal overweight aggravates HI brain damage through JNK hyperactivation-mediated upregulation of neuronal apoptosis, neuroinflammation and BBB leakage in rat pups. Methods Overweight (OF pups were established by reducing the litter size to 6, and control (NF pups by keeping the litter size at 12 from postnatal (P day 1 before HI on P7. Immunohistochemistry and immunoblotting were used to determine the TUNEL-(+ cells and BBB damage, cleaved caspase-3 and poly (ADP-ribose polymerase (PARP, and phospho-JNK and phospho-BimEL levels. Immunofluorescence was performed to determine the cellular distribution of phospho-JNK. Results Compared with NF pups, OF pups had a significantly heavier body-weight and greater fat deposition on P7. Compared with the NF-HI group, the OF-HI group showed significant increases of TUNEL-(+ cells, cleaved levels of caspase-3 and PARP, and ED1-(+ activated microglia and BBB damage in the cortex 24 hours post-HI. Immunofluorescence of the OF-HI pups showed that activated-caspase 3 expression was found mainly in NeuN-(+ neurons and RECA1-(+ vascular endothelial cells 24 hours post-HI. The OF-HI group also had prolonged escape latency in the Morris water maze test and greater brain-volume loss compared with the NF-HI group when assessed at adulthood. Phospho-JNK and phospho-BimEL levels were higher in OF-HI pups than in NF-HI pups immediately post-HI. JNK activation in OF-HI pups was mainly expressed in neurons, microglia and vascular endothelial cells. Inhibiting JNK activity by AS601245 caused more attenuation of cleaved caspase-3 and PARP, a greater reduction of microglial activation and BBB damage post-HI, and significantly reduced brain damage in

  8. Japanese encephalitis virus disrupts blood-brain barrier and modulates apoptosis proteins in THBMEC cells.

    Science.gov (United States)

    Al-Obaidi, Mazen M Jamil; Bahadoran, Azadeh; Har, Lee Sau; Mui, Wang Seok; Rajarajeswaran, Jayakumar; Zandi, Keivan; Manikam, Rishya; Sekaran, Shamala Devi

    2017-04-02

    Japanese encephalitis (JE) is a neurotropic flavivirus that causes inflammation in central nervous system (CNS), neuronal death and also compromises the structural and functional integrity of the blood-brain barrier (BBB). The aim of this study was to evaluate the BBB disruption and apoptotic process in Japanese encephalitis virus (JEV)-infected transfected human brain microvascular endothelial cells (THBMECs). THBMECs were overlaid by JEV with different MOIs (0.5, 1.0, 5.0 and 10.0) and monitored by electrical cell-substrate impedance sensing (ECIS) in a real-time manner in order to observe the barrier function of THBMECs. Additionally, the level of 43 apoptotic proteins was quantified in the virally infected cells with different MOIs at 24h post infection. Infection of THBMEC with JEV induced an acute reduction in transendothelial electrical resistance (TEER) after viral infection. Also, significant up-regulation of Bax, BID, Fas and Fasl and down-regulation of IGFBP-2, BID, p27 and p53 were observed in JEV infected THBMECs with 0.5 and 10 MOIs compared to uninfected cells. Hence, the permeability of THBMECs is compromised during the JEV infection. In addition high viral load of the virus has the potential to subvert the host cell apoptosis to optimize the course of viral infection through deactivation of pro-apoptotic proteins. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Computational Prediction of Blood-Brain Barrier Permeability Using Decision Tree Induction

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    Jörg Huwyler

    2012-08-01

    Full Text Available Predicting blood-brain barrier (BBB permeability is essential to drug development, as a molecule cannot exhibit pharmacological activity within the brain parenchyma without first transiting this barrier. Understanding the process of permeation, however, is complicated by a combination of both limited passive diffusion and active transport. Our aim here was to establish predictive models for BBB drug permeation that include both active and passive transport. A database of 153 compounds was compiled using in vivo surface permeability product (logPS values in rats as a quantitative parameter for BBB permeability. The open source Chemical Development Kit (CDK was used to calculate physico-chemical properties and descriptors. Predictive computational models were implemented by machine learning paradigms (decision tree induction on both descriptor sets. Models with a corrected classification rate (CCR of 90% were established. Mechanistic insight into BBB transport was provided by an Ant Colony Optimization (ACO-based binary classifier analysis to identify the most predictive chemical substructures. Decision trees revealed descriptors of lipophilicity (aLogP and charge (polar surface area, which were also previously described in models of passive diffusion. However, measures of molecular geometry and connectivity were found to be related to an active drug transport component.

  10. Disruption of the blood–brain barrier in pigs naturally infected with Taenia solium, untreated and after anthelmintic treatment

    Science.gov (United States)

    Guerra-Giraldez, Cristina; Marzal, Miguel; Cangalaya, Carla; Balboa, Diana; Orrego, Miguel Ángel; Paredes, Adriana; Gonzales-Gustavson, Eloy; Arroyo, Gianfranco; García, Hector H.; González, Armando E.; Mahanty, Siddhartha; Nash, Theodore E.

    2014-01-01

    Neurocysticercosis is a widely prevalent disease in the tropics that causes seizures and a variety of neurological symptoms in most of the world. Experimental models are limited and do not allow assessment of the degree of inflammation around brain cysts. The vital dye Evans Blue (EB) was injected into 11 pigs naturally infected with Taenia solium cysts to visually identify the extent of disruption of the blood brain barrier. A total of 369 cysts were recovered from the 11 brains and classified according to the staining of their capsules as blue or unstained. The proportion of cysts with blue capsules was significantly higher in brains from pigs that had received anthelmintic treatment 48 and 120 h before the EB infusion, indicating a greater compromise of the blood brain barrier due to treatment. The model could be useful for understanding the pathology of treatment-induced inflammation in neurocysticercosis. PMID:23684909

  11. Targeting transferrin receptors at the blood-brain barrier improves the uptake of immunoliposomes and subsequent cargo transport into the brain parenchyma

    DEFF Research Database (Denmark)

    Johnsen, Kasper B.; Burkhart, Annette; Melander, Fredrik

    2017-01-01

    Drug delivery to the brain is hampered by the presence of the blood-brain barrier, which excludes most molecules from freely diffusing into the brain, and tightly regulates the active transport mechanisms that ensure sufficient delivery of nutrients to the brain parenchyma. Harnessing...... the possibility of delivering neuroactive drugs by way of receptors already present on the brain endothelium has been of interest for many years. The transferrin receptor is of special interest since its expression is limited to the endothelium of the brain as opposed to peripheral endothelium. Here, we...... investigate the possibility of delivering immunoliposomes and their encapsulated cargo to the brain via targeting of the transferrin receptor. We find that transferrin receptor-targeting increases the association between the immunoliposomes and primary endothelial cells in vitro, but that this does...

  12. A Novel Dynamic Neonatal Blood-Brain Barrier on a Chip.

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    Sudhir P Deosarkar

    Full Text Available Studies of neonatal neural pathologies and development of appropriate therapeutics are hampered by a lack of relevant in vitro models of neonatal blood-brain barrier (BBB. To establish such a model, we have developed a novel blood-brain barrier on a chip (B3C that comprises a tissue compartment and vascular channels placed side-by-side mimicking the three-dimensional morphology, size and flow characteristics of microvessels in vivo. Rat brain endothelial cells (RBEC isolated from neonatal rats were seeded in the vascular channels of B3C and maintained under shear flow conditions, while neonatal rat astrocytes were cultured under static conditions in the tissue compartment of the B3C. RBEC formed continuous endothelial lining with a central lumen along the length of the vascular channels of B3C and exhibited tight junction formation, as measured by the expression of zonula occludens-1 (ZO-1. ZO-1 expression significantly increased with shear flow in the vascular channels and with the presence of astrocyte conditioned medium (ACM or astrocytes cultured in the tissue compartment. Consistent with in vivo BBB, B3C allowed endfeet-like astrocyte-endothelial cell interactions through a porous interface that separates the tissue compartment containing cultured astrocytes from the cultured RBEC in the vascular channels. The permeability of fluorescent 40 kDa dextran from vascular channel to the tissue compartment significantly decreased when RBEC were cultured in the presence of astrocytes or ACM (from 41.0 ± 0.9 x 10-6 cm/s to 2.9 ± 1.0 x 10-6 cm/s or 1.1±0.4 x 10-6 cm/s, respectively. Measurement of electrical resistance in B3C further supports that the addition of ACM significantly improves the barrier function in neonatal RBEC. Moreover, B3C exhibits significantly improved barrier characteristics compared to the transwell model and B3C permeability was not significantly different from the in vivo BBB permeability in neonatal rats. In summary, we

  13. Quantitation of blood-brain barrier defect by magnetic resonance imaging and gadolinium-DTPA in patients with multiple sclerosis and brain tumors

    DEFF Research Database (Denmark)

    Larsson, H B; Stubgaard, M; Frederiksen, J L

    1990-01-01

    In this study quantitation of the degree of deficiency of the blood-brain barrier (BBB) in patients with multiple sclerosis or brain tumors, by using MRI, is shown to be possible. As a measure of permeability of the BBB to Gadolinium-DTPA (Gd-DTPA) the flux per unit of distribution volume per unit...... of brain mass was used. This quantity was found by introducing the longitudinal relaxation rate (R1) as a measure of concentration of Gd-DTPA in the brain tissue in the mathematical model for the transcapillary transport over the BBB. High accordance between the observed data points and the model was found...

  14. Probabilistic description of traffic breakdowns

    Science.gov (United States)

    Kühne, Reinhart; Mahnke, Reinhard; Lubashevsky, Ihor; Kaupužs, Jevgenijs

    2002-06-01

    We analyze the characteristic features of traffic breakdown. To describe this phenomenon we apply the probabilistic model regarding the jam emergence as the formation of a large car cluster on a highway. In these terms, the breakdown occurs through the formation of a certain critical nucleus in the metastable vehicle flow, which enables us to confine ourselves to one cluster model. We assume that, first, the growth of the car cluster is governed by attachment of cars to the cluster whose rate is mainly determined by the mean headway distance between the car in the vehicle flow and, maybe, also by the headway distance in the cluster. Second, the cluster dissolution is determined by the car escape from the cluster whose rate depends on the cluster size directly. The latter is justified using the available experimental data for the correlation properties of the synchronized mode. We write the appropriate master equation converted then into the Fokker-Planck equation for the cluster distribution function and analyze the formation of the critical car cluster due to the climb over a certain potential barrier. The further cluster growth irreversibly causes jam formation. Numerical estimates of the obtained characteristics and the experimental data of the traffic breakdown are compared. In particular, we draw a conclusion that the characteristic intrinsic time scale of the breakdown phenomenon should be about 1 min and explain the case why the traffic volume interval inside which traffic breakdown is observed is sufficiently wide.

  15. Transport characteristics of guanidino compounds at the blood-brain barrier and blood-cerebrospinal fluid barrier: relevance to neural disorders

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    Tachikawa Masanori

    2011-02-01

    Full Text Available Abstract Guanidino compounds (GCs, such as creatine, phosphocreatine, guanidinoacetic acid, creatinine, methylguanidine, guanidinosuccinic acid, γ-guanidinobutyric acid, β-guanidinopropionic acid, guanidinoethane sulfonic acid and α-guanidinoglutaric acid, are present in the mammalian brain. Although creatine and phosphocreatine play important roles in energy homeostasis in the brain, accumulation of GCs may induce epileptic discharges and convulsions. This review focuses on how physiologically important and/or neurotoxic GCs are distributed in the brain under physiological and pathological conditions. Transporters for GCs at the blood-brain barrier (BBB and the blood-cerebrospinal fluid (CSF barrier (BCSFB have emerged as substantial contributors to GCs distribution in the brain. Creatine transporter (CRT/solute carrier (SLC 6A8 expressed at the BBB regulates creatine concentration in the brain, and represents a major pathway for supply of creatine from the circulating blood to the brain. CRT may be a key factor facilitating blood-to-brain guanidinoacetate transport in patients deficient in S-adenosylmethionine:guanidinoacetate N-methyltransferase, the creatine biosynthetic enzyme, resulting in cerebral accumulation of guanidinoacetate. CRT, taurine transporter (TauT/SLC6A6 and organic cation transporter (OCT3/SLC22A3 expressed at the BCSFB are involved in guanidinoacetic acid or creatinine efflux transport from CSF. Interestingly, BBB efflux transport of GCs, including guanidinoacetate and creatinine, is negligible, though the BBB has a variety of efflux transport systems for synthetic precursors of GCs, such as amino acids and neurotransmitters. Instead, the BCSFB functions as a major cerebral clearance system for GCs. In conclusion, transport of GCs at the BBB and BCSFB appears to be the key determinant of the cerebral levels of GCs, and changes in the transport characteristics may cause the abnormal distribution of GCs in the brain seen

  16. Breakdown of Epithelial Barrier Integrity and Overdrive Activation of Alveolar Epithelial Cells in the Pathogenesis of Acute Respiratory Distress Syndrome and Lung Fibrosis

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    Shigehisa Yanagi

    2015-01-01

    Full Text Available Individual alveolar epithelial cells (AECs collaboratively form a tight barrier between atmosphere and fluid-filled tissue to enable normal gas exchange. The tight junctions of AECs provide intercellular sealing and are integral to the maintenance of the AEC barrier integrity. Disruption and failure of reconstitution of AEC barrier result in catastrophic consequences, leading to alveolar flooding and subsequent devastating fibrotic scarring. Recent evidences reveal that many of the fibrotic lung diseases involve AECs both as a frequent target of injury and as a driver of ongoing pathological processes. Aberrantly activated AECs express most of the growth factors and chemokines responsible for the proliferation, migration, and activation of fibroblasts. Current evidences suggest that AECs may acquire overdrive activation in the initial step of fibrosis by several mechanisms, including abnormal recapitulation of the developmental pathway, defects of the molecules essential for epithelial integrity, and acceleration of aging-related properties. Among these initial triggering events, epithelial Pten, a multiple phosphatase that negatively regulates the PI3K/Akt pathway and is crucial for lung development, is essential for the prevention of alveolar flooding and lung fibrosis through the regulation of AEC barrier integrity after injury. Reestablishment of AEC barrier integrity also involves the deployment of specialized stem/progenitor cells.

  17. Evaluation and Computational Characterization of the Faciliated Transport of Glc Carbon C-1 Oxime Reactivators Across a Blood Brain Barrier Model

    Science.gov (United States)

    2013-01-01

    5a. CONTRACT NUMBER oxime reactivators across a blood brain barrier model 5b. GRANT NUMBER 1.E005.08.WR 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...Reduction Agency (Grant number 1.E005.08.WR). 14. ABSTRACT See reprint. 15. SUBJECT TERMS Facilitated transport, Sugar- oximes , Sox, Blood brain barrier...transport of Glc carbon C-1 oxime reactivators across a blood brain barrier model Jayendra B. Bhonsle a, Robert Causey b, Benjamin L. Oyler c, Cecilia

  18. BACE-1 is expressed?in the blood?brain barrier endothelium and is upregulated in a murine model of Alzheimer?s disease

    OpenAIRE

    Devraj, Kavi; Poznanovic, Slobodan; Spahn, Christoph; Schwall, Gerhard; Harter, Patrick N.; Mittelbronn, Michel; Antoniello, Katia; Paganetti, Paolo; Muhs, Andreas; Heilemann, Mike; Hawkins, Richard A.; Schrattenholz, Andr?; Liebner, Stefan

    2015-01-01

    Endothelial cells of the blood?brain barrier form a structural and functional barrier maintaining brain homeostasis via paracellular tight junctions and specific transporters such as P-glycoprotein. The blood?brain barrier is responsible for negligible bioavailability of many neuroprotective drugs. In Alzheimer?s disease, current treatment approaches include inhibitors of BACE-1 (?-site of amyloid precursor protein cleaving enzyme), a proteinase generating neurotoxic ?-amyloid. It is known th...

  19. Voluntary exercise protects against methamphetamine-induced oxidative stress in brain microvasculature and disruption of the blood-brain barrier.

    Science.gov (United States)

    Toborek, Michal; Seelbach, Melissa J; Rashid, Cetewayo S; András, Ibolya E; Chen, Lei; Park, Minseon; Esser, Karyn A

    2013-06-24

    There is no effective therapeutic intervention developed targeting cerebrovascular toxicity of drugs of abuse, including methamphetamine (METH). We hypothesize that exercise protects against METH-induced disruption of the blood-brain barrier (BBB) by enhancing the antioxidant capacity of cerebral microvessels and modulating caveolae-associated signaling. Mice were subjected to voluntary wheel running for 5 weeks resembling the voluntary pattern of human exercise, followed by injection with METH (10 mg/kg). The frequency, duration, and intensity of each running session were monitored for each mouse via a direct data link to a computer and the running data are analyzed by Clock lab™ Analysis software. Controls included mice sedentary that did not have access to running wheels and/or injections with saline. METH induced oxidative stress in brain microvessels, resulting in up regulation of caveolae-associated NAD(P)H oxidase subunits, and phosphorylation of mitochondrial protein 66Shc. Treatment with METH disrupted also the expression and colocalization of tight junction proteins. Importantly, exercise markedly attenuated these effects and protected against METH-induced disruption of the BBB integrity. The obtained results indicate that exercise is an important modifiable behavioral factor that can protect against METH-induced cerebrovascular toxicity. These findings may provide new strategies in preventing the toxicity of drug of abuse.

  20. Biotin and biocytin uptake into cultured primary calf brain microvessel endothelial cells of the blood-brain barrier.

    Science.gov (United States)

    Baur, B; Baumgartner, E R

    2000-03-10

    The uptake of biotin and the closely related biocytin was characterized in primary cultures of calf brain microvessel endothelial (CBME) cells. Biotin uptake was found to be Na(+)-gradient dependent and independent of changes in the membrane potential. Concentration dependence revealed a single saturation mechanism with a K(m) of 47 microM and a V(max) of 101 pmol/min/mg. Inhibition studies demonstrated dependence on metabolic energy and the necessity for a free carboxyl group for transport activity. The anticonvulsants primidone and carbamazepine had no inhibitory effect. Biotin uptake into CBME cells is a secondary active, electroneutral, saturable and specific process. Biocytin which accumulates in biotinidase deficiency, a human congenital disorder, did not inhibit biotin uptake and was not transported into these cells. The presence of human serum with normal biotinidase activity significantly reduced biotin uptake by about 50%. Further, added biocytin was hydrolyzed to biotin, which accumulated intracellularly but to a lesser extent than added free biotin. Biotin uptake after addition of plasma of biotinidase-deficient patients was not different from that in the presence of normal serum. These results indicate that the absence of biotinidase activity in serum does not reduce blood-brain barrier transport of biotin.

  1. Barriers, Benefits, and Beliefs of Brain Training Smartphone Apps: An Internet Survey of Younger US Consumers

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    John eTorous

    2016-04-01

    Full Text Available Background: While clinical evidence for the efficacy of brain training remains in question, numerous smartphone applications (apps already offer brain training directly to consumers. Little is known about why consumers choose to download these apps, how they use them, and what benefits they perceive. Given the high rates of smartphone ownership in those with internet access and the younger demographics, we chose to approach this question first with a general population survey that would capture primarily this demographic.Method: We conducted an online internet-based survey of the US population via mTurk regarding their use, experience, and perceptions of brain training apps. There were no exclusion criteria to partake although internet access was required. Respondents were paid 20 cents for completing each survey. The survey was offered for a two-week period in September 2015.Results: 3125 individuals completed the survey and over half of these were under age 30. Responses did not significantly vary by gender. The brain training app most frequently used was Lumosity. Belief that a brain-training app could help with thinking was strongly correlated with belief it could also help with attention, memory, and even mood. Beliefs of those who had never used brain-training apps were similar to those who had used them. Respondents felt that data security and lack of endorsement from a clinician were the two least important barriers to use.Discussion: Results suggest a high level of interest in brain training apps among the U.S. public, especially those in younger demographics. The stability of positive perception of these apps among app-naïve and app-exposed participants suggests an important role of user expectations in influencing use and experience of these apps. The low concern about data security and lack of clinician endorsement suggest apps are not being utilized in clinical settings. However, the public’s interest in the effectiveness of apps

  2. Early CT perfusion changes and blood-brain barrier permeability after aneurysmal subarachnoid hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Amanda; Bharatha, Aditya [University of Toronto, Department of Medical Imaging, Toronto, ON (Canada); De Oliveira Manoel, Airton Leonardo; Kouzmina, Ekaterina [St. Michael' s Hospital, Toronto (Canada); Burgers, Kyle; Lee, Ting [Robarts Research Institute, London (Canada); Macdonald, R.L. [St. Michael' s Hospital, Department of Neurosurgery, Toronto (Canada)

    2015-08-15

    Early brain injury (EBI) can occur within 72 h of aneurysmal subarachnoid hemorrhage (aSAH). The objective of this study was to determine if there are differences in early CTP parameters (<72 h) with respect to delayed cerebral ischemia (DCI), cerebral infarction, and functional outcome. We performed a prospective cohort study of aSAH patients admitted to a single tertiary care center. MTT, CBF and blood-brain barrier permeability (PS) were quantified with CTP within 72 h of aneurysm rupture. Primary outcomes were functional outcome by the Modified Rankin Scale (mRS) at 3 months and cerebral infarction. Secondary outcome was the development of DCI. Differences between early CTP parameters were determined with respect to primary and secondary outcomes. Fifty aSAH patients were included in the final analysis. MTT was significantly higher in patients who developed DCI (6.7 ± 1.2 vs 5.9 ± 1.0; p = 0.03) and cerebral infarction (7.0 ± 1.2 vs 5.9 ± 0.9; p = 0.007); however, no difference in MTT was found between patients with and without a poor outcome (mRS > 2). Early CBF and PS did not differ with respect to functional outcome, DCI, and cerebral infarction. Elevated MTT within 72 h of aneurysm rupture is associated with DCI and cerebral infarction but not with long-term functional outcome. Blood-brain barrier permeability, as assessed by CT perfusion, was not associated with DCI or worse outcome in this cohort. (orig.)

  3. Sirt1-Sirt3 axis regulates human blood-brain barrier permeability in response to ischemia

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    Tao Chen

    2018-04-01

    Full Text Available Sirtuin1 (Sirt1 and Sirtuin3 (Sirt3 are two well-characterized members of the silent information regulator 2 (Sir2 family of proteins. Both Sirt1 and Sirt3 have been shown to play vital roles in resistance to cellular stress, but the interaction between these two sirtuins has not been fully determined. In this study, we investigated the role of Sirt1-Sirt3 axis in blood-brain barrier (BBB permeability after ischemia in vitro. Human brain microvascular endothelial cells and astrocytes were co-cultured to model the BBB in vitro and oxygen and glucose deprivation (OGD was performed to mimic ischemia. The results of transepithelial electrical resistance (TEER showed that suppression of Sirt1 via siRNA or salermide significantly decreased BBB permeability, whereas Sirt3 knockdown increased BBB permeability. In addition, Sirt1 was shown to regulate Sirt3 expression after OGD through inhibiting the AMPK-PGC1 pathway. Application of the AMPK inhibitor compound C partially prevented the effects of Sirt1-Sirt3 axis on BBB permeability after OGD. The results of flow cytometry and cytochrome c release demonstrated that Sirt1 and Sirt3 exert opposite effects on OGD-induced apoptosis. Furthermore, suppression of Sirt1 was shown to attenuate mitochondrial reactive oxygen species (ROS generation, which contribute to the Sirt1-Sirt3 axis-induced regulation of BBB permeability and cell damage. In summary, these findings demonstrate that the Sirt1-Sirt3 axis might act as an important modulator in BBB physiology, and could be a therapeutic target for ischemic stroke via regulating mitochondrial ROS generation. Keywords: Stroke, Blood-brain barrier, Sirt1, Sirt3, Mitochondrial ROS

  4. Alpha Adrenergic Induction of Transport of Lysosomal Enzyme across the Blood-Brain Barrier.

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    Akihiko Urayama

    Full Text Available The impermeability of the adult blood-brain barrier (BBB to lysosomal enzymes impedes the ability to treat the central nervous system manifestations of lysosomal storage diseases. Here, we found that simultaneous stimulation of the alpha1 and alpha2 adrenoreceptor restores in adult mice the high rate of transport for the lysosomal enzyme P-GUS that is seen in neonates but lost with development. Beta adrenergics, other monoamines, and acetylcholine did not restore this transport. A high dose (500 microg/mouse of clonidine, a strong alpha2 and weak alpha1 agonist, was able to act as monotherapy in the stimulation of P-GUS transport. Neither use of alpha1 plus alpha2 agonists nor the high dose clonidine disrupted the BBB to albumin. In situ brain perfusion and immunohistochemistry studies indicated that adrengerics act on transporters already at the luminal surface of brain endothelial cells. These results show that adrenergic stimulation, including monotherapy with clonidine, could be key for CNS enzyme replacement therapy.

  5. Blood-brain barrier dysfunction in mice induced by lipopolysaccharide is attenuated by dapsone.

    Science.gov (United States)

    Zhou, Ting; Zhao, Lei; Zhan, Rui; He, Qihua; Tong, Yawei; Tian, Xiaosheng; Wang, Hecheng; Zhang, Tao; Fu, Yaoyun; Sun, Yang; Xu, Feng; Guo, Xiangyang; Fan, Dongsheng; Han, Hongbin; Chui, Dehua

    2014-10-24

    Blood-brain barrier (BBB) dysfunction is a key event in the development of many central nervous system (CNS) diseases, such as septic encephalopathy and stroke. 4,4'-Diaminodiphenylsulfone (DDS, Dapsone) has displayed neuroprotective effect, but whether DDS has protective role on BBB integrity is not clear. This study was designed to examine the effect of DDS on lipopolysaccharide (LPS)-induced BBB disruption and oxidative stress in brain vessels. Using in vivo multiphoton imaging, we found that DDS administration significantly restored BBB integrity compromised by LPS. DDS also increased the expression of tight junction proteins occludin, zona occludens-1 (ZO-1) and claudin-5 in brain vessels. Level of reactive oxygen species (ROS) was reduced by DDS treatment, which may due to decreased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and NOX2 expression. Our results showed that LPS-induced BBB dysfunction could be attenuated by DDS, indicated that DDS has a therapeutic potential for treating CNS infection and other BBB related diseases. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Blood-Brain Barrier Dysfunction as a Hallmark Pathology in Chronic Traumatic Encephalopathy.

    Science.gov (United States)

    Doherty, Colin P; O'Keefe, Eoin; Wallace, Eugene; Loftus, Teresa; Keaney, James; Kealy, John; Humphries, Marian M; Molloy, Michael G; Meaney, James F; Farrell, Michael; Campbell, Matthew

    2016-07-01

    Chronic traumatic encephalopathy (CTE) is a neurodegenerative condition associated with repetitive mild traumatic brain injury. In recent years, attention has focused on emerging evidence linking the development of CTE to concussive injuries in athletes and military personnel; however, the underlying molecular pathobiology of CTE remains unclear. Here, we provide evidence that the blood-brain barrier (BBB) is disrupted in regions of dense perivascular p-Tau accumulation in a case of CTE. Immunoreactivity patterns of the BBB-associated tight junction components claudin-5 and zonula occludens-1 were markedly discontinuous or absent in regions of perivascular p-Tau deposition; there was also immunohistochemical evidence of a BBB in these foci. Because the patient was diagnosed premortem clinically as having progressive supranuclear palsy (PSP), we also compromised that the CTE alterations appear to be distinct from those in the brain of a patient with PSP. This report represents the first description of BBB dysfunction in a pathologically proven CTE case and suggests a vascular component in the postconcussion cascade of events that may ultimately lead to development of a progressive degenerative disorder. BBB dysfunction may represent a correlate of neural dysfunction in live subjects suspected of being at risk for development of CTE. © 2016 American Association of Neuropathologists, Inc. All rights reserved.

  7. Reversible Opening of the Blood-Brain Barrier by Anti-Bacterial Antibodies

    Science.gov (United States)

    Tuomanen, Elaine I.; Prasad, Sudha M.; George, Jonathan S.; Hoepelman, Andy I. M.; Ibsen, Per; Heron, Iver; Starzyk, Ruth M.

    1993-08-01

    The leukocyte adhesion molecule CR3 (CD11b/CD18, Mac-1) promotes leukocyte transmigration into tissues by engaging an unknown cognate ligand on the surface of vascular endothelial cells. Filamentous hemagglutinin (FHA), an adhesin of the bacterium Bordetella pertussis, binds to CR3. We hypothesized that FHA mimics the native ligand for the CR3 integrin on endothelial cells and predicted that anti-FHA antibodies should bind to endothelial cells, interfere with leukocyte recruitment, and induce endothelial permeability. Anti-FHA monoclonal antibodies bound to cerebral microvessels in sections from human brain and upon intravenous injection into rabbits. Antibody binding correlated with the ability to recognize two polypeptides in extracts of human cerebral vessels that were also bound by CD18. In vivo, antibody binding not only interfered with transmigration of leukocytes into cerebrospinal fluid but also induced a dose-dependent reversible increase in blood-brain barrier permeability sufficient to improve delivery of intravenously administered therapeutic agents to brain parenchyma.

  8. Numerical Study of a Simple Transcranial Focused Ultrasound System Applied to Blood-Brain Barrier Opening

    Science.gov (United States)

    Deffieux, Thomas; Konofagou, Elisa E.

    2014-01-01

    In this paper, we investigate the focalization properties of single-element transducers at low frequencies (300 to 1000 kHz) through primate and human skulls. The study addresses the transcranial targeting involved in ultrasound-induced blood-brain barrier (BBB) opening with clinically relevant targets such as the hippocampus and the basal ganglia, which are typically affected by early Alzheimer’s and Parkinson’s disease, respectively. A finite-difference, time-domain simulation platform is used to solve the 3-D linear acoustic wave equation with CT-based acoustic maps of the skulls. The targeted brain structures were extracted from 3-D brain atlases registered with the skulls and used to virtually position and orient the transducers. The effect of frequency is first investigated and the targeting of the different structures is then tested. The frequency of 500 kHz provided the best trade off between phase aberrations and standing wave effects in the human case, whereas the frequency of 800 kHz was most suitable in the case of the primate skull. A fast periodic linear chirp method was developed and found capable of reducing the standing wave effects. Such a simple, affordable, and convenient system is concluded to be feasible for BBB opening in primates and humans and could thus allow for its broader impact and applications. PMID:21156360

  9. Disruption of astrocyte-vascular coupling and the blood-brain barrier by invading glioma cells

    Science.gov (United States)

    Watkins, Stacey; Robel, Stefanie; Kimbrough, Ian F.; Robert, Stephanie M.; Ellis-Davies, Graham; Sontheimer, Harald

    2014-01-01

    Astrocytic endfeet cover the entire cerebral vasculature and serve as exchange sites for ions, metabolites, and energy substrates from the blood to the brain. They maintain endothelial tight junctions that form the blood-brain barrier (BBB) and release vasoactive molecules that regulate vascular tone. Malignant gliomas are highly invasive tumors that use the perivascular space for invasion and co-opt existing vessels as satellite tumors form. Here we use a clinically relevant mouse model of glioma and find that glioma cells, as they populate the perivascular space of pre-existing vessels, displace astrocytic endfeet from endothelial or vascular smooth muscle cells. This causes a focal breach in the BBB. Furthermore, astrocyte-mediated gliovascular coupling is lost, and glioma cells seize control over regulation of vascular tone through Ca2+-dependent release of K+. These findings have important clinical implications regarding blood flow in the tumor-associated brain and the ability to locally deliver chemotherapeutic drugs in disease. PMID:24943270

  10. Noninvasive localized delivery of Herceptin to the mouse brain by MRI-guided focused ultrasound-induced blood-brain barrier disruption

    Science.gov (United States)

    Kinoshita, Manabu; McDannold, Nathan; Jolesz, Ferenc A.; Hynynen, Kullervo

    2006-08-01

    Antibody-based anticancer agents are promising chemotherapeutic agents. Among these agents, Herceptin (trastuzumab), a humanized anti-human epidermal growth factor receptor 2 (HER2/c-erbB2) monoclonal antibody, has been used successfully in patients with breast cancer. However, in patients with brain metastasis, the blood-brain barrier limits its use, and a different delivery method is needed to treat these patients. Here, we report that Herceptin can be delivered locally and noninvasively into the mouse central nervous system through the blood-brain barrier under image guidance by using an MRI-guided focused ultrasound blood-brain barrier disruption technique. The amount of Herceptin delivered to the target tissue was correlated with the extent of the MRI-monitored barrier opening, making it possible to estimate indirectly the amount of Herceptin delivered. Histological changes attributable to this procedure were minimal. This method may represent a powerful technique for the delivery of macromolecular agents such as antibodies to treat patients with diseases of the central nervous system. brain tumor | microbubble

  11. Modelling the endothelial blood-CNS barriers: a method for the production of robust in vitro models of the rat blood-brain barrier and blood-spinal cord barrier.

    Science.gov (United States)

    Watson, P Marc D; Paterson, Judy C; Thom, George; Ginman, Ulrika; Lundquist, Stefan; Webster, Carl I

    2013-06-18

    Modelling the blood-CNS barriers of the brain and spinal cord in vitro continues to provide a considerable challenge for research studying the passage of large and small molecules in and out of the central nervous system, both within the context of basic biology and for pharmaceutical drug discovery. Although there has been considerable success over the previous two decades in establishing useful in vitro primary endothelial cell cultures from the blood-CNS barriers, no model fully mimics the high electrical resistance, low paracellular permeability and selective influx/efflux characteristics of the in vivo situation. Furthermore, such primary-derived cultures are typically labour-intensive and generate low yields of cells, limiting scope for experimental work. We thus aimed to establish protocols for the high yield isolation and culture of endothelial cells from both rat brain and spinal cord. Our aim was to optimise in vitro conditions for inducing phenotypic characteristics in these cells that were reminiscent of the in vivo situation, such that they developed into tight endothelial barriers suitable for performing investigative biology and permeability studies. Brain and spinal cord tissue was taken from the same rats and used to specifically isolate endothelial cells to reconstitute as in vitro blood-CNS barrier models. Isolated endothelial cells were cultured to expand the cellular yield and then passaged onto cell culture inserts for further investigation. Cell culture conditions were optimised using commercially available reagents and the resulting barrier-forming endothelial monolayers were characterised by functional permeability experiments and in vitro phenotyping by immunocytochemistry and western blotting. Using a combination of modified handling techniques and cell culture conditions, we have established and optimised a protocol for the in vitro culture of brain and, for the first time in rat, spinal cord endothelial cells. High yields of both CNS

  12. Preparation of Silica Nanoparticles Loaded with Nootropics and Their In Vivo Permeation through Blood-Brain Barrier

    Directory of Open Access Journals (Sweden)

    Josef Jampilek

    2015-01-01

    Full Text Available The blood-brain barrier prevents the passage of many drugs that target the central nervous system. This paper presents the preparation and characterization of silica-based nanocarriers loaded with piracetam, pentoxifylline, and pyridoxine (drugs from the class of nootropics, which are designed to enhance the permeation of the drugs from the circulatory system through the blood-brain barrier. Their permeation was compared with non-nanoparticle drug substances (bulk materials by means of an in vivo model of rat brain perfusion. The size and morphology of the nanoparticles were characterized by transmission electron microscopy. The content of the drug substances in silica-based nanocarriers was analysed by elemental analysis and UV spectrometry. Microscopic analysis of visualized silica nanocarriers in the perfused brain tissue was performed. The concentration of the drug substances in the tissue was determined by means of UHPLC-DAD/HRMS LTQ Orbitrap XL. It was found that the drug substances in silica-based nanocarriers permeated through the blood brain barrier to the brain tissue, whereas bulk materials were not detected in the brain.

  13. Preparation of silica nanoparticles loaded with nootropics and their in vivo permeation through blood-brain barrier.

    Science.gov (United States)

    Jampilek, Josef; Zaruba, Kamil; Oravec, Michal; Kunes, Martin; Babula, Petr; Ulbrich, Pavel; Brezaniova, Ingrid; Opatrilova, Radka; Triska, Jan; Suchy, Pavel

    2015-01-01

    The blood-brain barrier prevents the passage of many drugs that target the central nervous system. This paper presents the preparation and characterization of silica-based nanocarriers loaded with piracetam, pentoxifylline, and pyridoxine (drugs from the class of nootropics), which are designed to enhance the permeation of the drugs from the circulatory system through the blood-brain barrier. Their permeation was compared with non-nanoparticle drug substances (bulk materials) by means of an in vivo model of rat brain perfusion. The size and morphology of the nanoparticles were characterized by transmission electron microscopy. The content of the drug substances in silica-based nanocarriers was analysed by elemental analysis and UV spectrometry. Microscopic analysis of visualized silica nanocarriers in the perfused brain tissue was performed. The concentration of the drug substances in the tissue was determined by means of UHPLC-DAD/HRMS LTQ Orbitrap XL. It was found that the drug substances in silica-based nanocarriers permeated through the blood brain barrier to the brain tissue, whereas bulk materials were not detected in the brain.

  14. Glucose transporter 1, distribution in the brain and in neural disorders: its relationship with transport of neuroactive drugs through the blood-brain barrier.

    Science.gov (United States)

    Guo, Xiuli; Geng, Meiyu; Du, Guanhua

    2005-04-01

    Facilitative glucose transport is mediated by one or more of the members of the closely related glucose transporter (GLUT) family. Thirteen members of the GLUT family have been described thus far. GLUT1 is a widely expressed isoform that provides many cells with their basic glucose requirement. It is also the primary transporter across the blood-brain barrier. This review describes the distribution and expression of GLUT1 in brain in different pathophysiological conditions including Alzheimer's disease, epilepsy, ischemia, or traumatic brain injury. Recent investigations show that GLUT1 mediates the transport of some neuroactive drugs, such as glycosylated neuropeptides, low molecular weight heparin, and D-glucose derivatives, across the blood-brain barrier as a delivery system. By utilizing such highly specific transport mechanisms, it should be possible to establish strategies to regulate the entry of candidate drugs.

  15. MR-Guided Unfocused Ultrasound Disruption of the Rat Blood-Brain Barrier

    Science.gov (United States)

    Townsend, Kelly A.; King, Randy L.; Zaharchuk, Greg; Pauly, Kim Butts

    2011-09-01

    Therapeutic ultrasound with microbubbles can temporarily disrupt the blood-brain barrier (BBB) for drug delivery. Contrast-enhanced MRI (CE-MRI) can visualize gadolinium passage into the brain, indicating BBB opening. Previous studies used focused ultrasound, which is appropriate for the targeted delivery of drugs. The purpose of this study was to investigate unfocused ultrasound for BBB opening across the whole brain. In 10 rats, gadolinium-based MR contrast agent (Gd; 0.25 ml) was administered concurrent with ultrasound microbubbles (Optison, 0.25 ml) and circulated for 20 sec before sonication. A 753 kHz planar PZT transducer, diameter 1.8 cm, sonicated each rat brain with supplied voltage of 300, 400, or 500 mVpp for 10 sec in continuous wave mode, or at 500 mVpp at 20% duty cycle at 10 Hz for 30-300 sec. After sonication, coronal T1-weighted FSE CE-MRI images were acquired with a 3in surface coil. The imaging protocol was repeated 3-5 times after treatment. One control animal was given Gd and microbubbles, but not sonicated, and the other was given Gd and sonicated without microbubbles. Signal change in ROIs over the muscle, mesencephalon/ventricles, and the cortex/striatum were measured at 3-5 time points up to 36 min after sonication. Signal intensity was converted to % signal change compared to the initial image. In the controls, CE-MRI showed brightening of surrounding structures, but not the brain. In the continuous wave subjects, cortex/striatum signal did not increase, but ventricle/mesenchephalon signal did. Those that received pulsed sonications showed signal increases in both the cortex/striatum and ventricles/mesenchephalon. In conclusion, after pulsed unfocused ultrasound sonication, the BBB is disrupted across the whole brain, including cortex and deep grey matter, while continuous wave sonication affects only the ventricles and possibly deeper structures, without opening the cortex BBB. As time passes, the timeline of Gd passage into the brain

  16. Wnt Activation of Immortalized Brain Endothelial Cells as a Tool for Generating a Standardized Model of the Blood Brain Barrier In Vitro

    OpenAIRE

    Roberta Paolinelli; Monica Corada; Luca Ferrarini; Kavi Devraj; Cédric Artus; Czupalla, Cathrin J.; Noemi Rudini; Luigi Maddaluno; Eleanna Papa; Britta Engelhardt; Pierre Olivier Couraud; Stefan Liebner; Elisabetta Dejana

    2013-01-01

    Reproducing the characteristics and the functional responses of the blood-brain barrier (BBB) in vitro represents an important task for the research community, and would be a critical biotechnological breakthrough. Pharmaceutical and biotechnology industries provide strong demand for inexpensive and easy-to-handle in vitro BBB models to screen novel drug candidates. Recently, it was shown that canonical Wnt signaling is responsible for the induction of the BBB properties in the neonatal brain...

  17. Interrelations between blood-brain barrier permeability and matrix metalloproteinases are differently affected by tissue plasminogen activator and hyperoxia in a rat model of embolic stroke

    Directory of Open Access Journals (Sweden)

    Michalski Dominik

    2012-01-01

    Full Text Available Abstract Background In ischemic stroke, blood-brain barrier (BBB regulations, typically involving matrix metalloproteinases (MMPs and inhibitors (TIMPs as mediators, became interesting since tissue plasminogen activator (tPA-related BBB breakdown with risk of secondary hemorrhage was considered to involve these mediators too. Despite high clinical relevance, detailed interactions are purely understood. After a pilot study addressing hyperoxia as potential neuroprotective co-treatment to tPA, we analyzed interrelations between BBB permeability (BBB-P, MMPs and TIMPs. Findings Rats underwent embolic middle cerebral artery occlusion (eMCAO and treatment with normobaric (NBO or hyperbaric oxygen (HBO, tPA, tPA+HBO, or no treatment. BBB-P was assessed by intravenously applied FITC-albumin at 4 or 24 hours. MMP-2/-9 and TIMP-1/-2 serum levels were determined at 5 or 25 hours. Time point-corrected partial correlations were used to explore interrelations of BBB-P in ischemic regions (extra-/intravasal FITC-albumin ratio and related serum markers. BBB-P correlated positively with MMP-2 and MMP-9 in controls, whereas hyperoxia led to an inverse association, most pronounced for HBO/MMP-9 (r = -0.606; P Conclusions HBO was found to reverse the positively directed interrelation of BBB-P and MMPs after eMCAO, but this effect failed to sustain in the expected amount when HBO and tPA were given simultaneously.

  18. Studies on the potential neurotoxic and convulsant effects of increased blood levels of quinolinic acid in rats with altered blood-brain barrier permeability

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    Vezzani, A.; Stasi, M.A.; Wu, H.Q.; Castiglioni, M.; Weckermann, B.; Samanin, R. (Istituto di Ricerche Farmacologiche Mario Negri, Milano (Italy))

    1989-10-01

    Intravenous injection of 450 mg/kg quinolinic acid (Quin), an endogenous kynurenine metabolite with excitotoxic properties, induced only minor electroencephalographic (EEG) modifications and no neurotoxicity in rats with a mature blood-brain barrier (BBB). BBB permeability was altered in rats by focal unilateral irradiation of the cortex (7 mm in diameter and 5 mm in depth) with protons (60 Gy, 9 Gy/min). Three days after irradiation, Evans blue dye staining showed BBB breakdown in the dorsal hippocampus of the irradiated hemisphere. No neurotoxic or convulsant effects were observed as a consequence of the radiation itself. When BBB-lesioned rats were challenged with 225 mg/kg Quin iv, epileptiform activity was observed on EEG analysis. Tonic-clonic seizures were induced by 225-450 mg/kg Quin. Light microscopic analysis showed a dose-related excitotoxic type of lesion restricted to the hippocampus ipsilateral to the irradiated side. Neuro-degeneration was prevented by local injection of 120 nmol D(-)2-amino-7-phosphonoheptanoic acid, a selective N-methyl-D-aspartate receptor antagonist. No lesions or EEG or behavioral modifications occurred after 450 mg/kg nicotinic acid, an inactive analog of Quin. The potential neurotoxic and convulsant effects of increased blood levels of Quin under conditions of altered BBB permeability are discussed.

  19. Manganese distribution across the blood-brain barrier III. The divalent metal transporter-1 is not the major mechanism mediating brain manganese uptake.

    Science.gov (United States)

    Crossgrove, Janelle S; Yokel, Robert A

    2004-03-01

    Manganese (Mn) is essential for and toxic to the brain. Brain Mn uptake utilizes both diffusion and transporter-mediated pathways. The divalent metal transporter-1 (DMT-1) has been suggested to mediate brain Mn uptake. The b/b Belgrade rat does not express significant amounts of functional DMT-1. In the present work, brain influx transfer coefficients of (54) Mn ion and (54) Mn transferrin (Mn Tf) were determined in b/b and +/b Belgrade and Wistar rats using the in situ brain perfusion technique. Brain Mn uptake was not significantly different among the three rat strains for either Mn species. We hypothesized that Mn may enter brain endothelial cells by a DMT-1-independent process but not be able to distribute across those cells into brain tissue due to the absence of DMT-1 activity. To test this hypothesis the brain capillary endothelial cells were isolated from b/b and +/b Belgrade rats and Wistar rats after in situ brain perfusion. Some animals received cerebrovascular washout after in situ brain perfusion to ascertain any affect of genotype on (54) Mn adsorption to the endothelial cell luminal surface. Less than 30% of the brain (54) Mn after (54) Mn ion or (54) Mn Tf perfusion remained associated with endothelial cells, suggesting the majority had distributed into brain extracellular fluid (ECF) and/or brain cells. Mn appears to distribute across the rat blood-brain barrier (BBB) into the brain by one or more carrier-mediated processes other than the DMT-1.

  20. Blood-Brain Barrier Disruption Induced by Chronic Sleep Loss: Low-Grade Inflammation May Be the Link

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    G. Hurtado-Alvarado

    2016-01-01

    Full Text Available Sleep is a vital phenomenon related to immunomodulation at the central and peripheral level. Sleep deficient in duration and/or quality is a common problem in the modern society and is considered a risk factor to develop neurodegenerative diseases. Sleep loss in rodents induces blood-brain barrier disruption and the underlying mechanism is still unknown. Several reports indicate that sleep loss induces a systemic low-grade inflammation characterized by the release of several molecules, such as cytokines, chemokines, and acute-phase proteins; all of them may promote changes in cellular components of the blood-brain barrier, particularly on brain endothelial cells. In the present review we discuss the role of inflammatory mediators that increase during sleep loss and their association with general disturbances in peripheral endothelium and epithelium and how those inflammatory mediators may alter the blood-brain barrier. Finally, this manuscript proposes a hypothetical mechanism by which sleep loss may induce blood-brain barrier disruption, emphasizing the regulatory effect of inflammatory molecules on tight junction proteins.

  1. Blood-Brain Barrier Disruption Induced by Chronic Sleep Loss: Low-Grade Inflammation May Be the Link.

    Science.gov (United States)

    Hurtado-Alvarado, G; Domínguez-Salazar, E; Pavon, L; Velázquez-Moctezuma, J; Gómez-González, B

    2016-01-01

    Sleep is a vital phenomenon related to immunomodulation at the central and peripheral level. Sleep deficient in duration and/or quality is a common problem in the modern society and is considered a risk factor to develop neurodegenerative diseases. Sleep loss in rodents induces blood-brain barrier disruption and the underlying mechanism is still unknown. Several reports indicate that sleep loss induces a systemic low-grade inflammation characterized by the release of several molecules, such as cytokines, chemokines, and acute-phase proteins; all of them may promote changes in cellular components of the blood-brain barrier, particularly on brain endothelial cells. In the present review we discuss the role of inflammatory mediators that increase during sleep loss and their association with general disturbances in peripheral endothelium and epithelium and how those inflammatory mediators may alter the blood-brain barrier. Finally, this manuscript proposes a hypothetical mechanism by which sleep loss may induce blood-brain barrier disruption, emphasizing the regulatory effect of inflammatory molecules on tight junction proteins.

  2. Bexarotene reduces blood-brain barrier permeability in cerebral ischemia-reperfusion injured rats.

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    Lu Xu

    Full Text Available Matrix metalloproteinase-9 (MMP-9 over-expression disrupts the blood-brain barrier (BBB in the ischemic brain. The retinoid X receptor agonist bexarotene suppresses MMP-9 expression in endothelial cells and displays neuroprotective effects. Therefore, we hypothesized that bexarotene may have a beneficial effect on I/R-induced BBB dysfunction.A total of 180 rats were randomized into three groups (n = 60 each: (i a sham-operation group, (ii a cerebral ischemia-reperfusion (I/R group, and (iii an I/R+bexarotene group. Brain water content was measured by the dry wet weight method. BBB permeability was analyzed by Evans Blue staining and the magnetic resonance imaging contrast agent Omniscan. MMP-9 mRNA expression, protein expression, and activity were assessed by reverse transcription polymerase chain reaction, Western blotting, and gelatin zymography, respectively. Apolipoprotein E (apoE, claudin-5, and occludin expression were analyzed by Western blotting.After 24 h, 48 h, and 72 h post-I/R, several effects were observed with bexarotene administration: (i brain water content and BBB permeability were significantly reduced; (ii MMP-9 mRNA and protein expression as well as activity were significantly decreased; (iii claudin-5 and occludin expression were significantly increased; and (iv apoE expression was significantly increased.Bexarotene decreases BBB permeability in rats with cerebral I/R injury. This effect may be due in part to bexarotene's upregulation of apoE expression, which has been previously shown to reduce BBB permeability through suppressing MMP-9-mediated degradation of the tight junction proteins claudin-5 and occludin. This work offers insight to aid future development of therapeutic agents for cerebral I/R injury in human patients.

  3. Use of Ultrasound Pulses Combined with Definity for Targeted Blood-Brain Barrier Disruption

    Science.gov (United States)

    McDannold, Nathan; Vykhodtseva, Natalia; Hynynen, Kullervo

    2007-05-01

    We have developed a method to combine an ultrasound contrast agent (USCA) with low-intensity focused ultrasound pulses combined to produce temporary blood-brain barrier disruption (BBBD), a potential non-invasive means for targeted drug delivery in the brain. All of our previous work used the USCA Optison. The purpose of this work was to test the feasibility of using the USCA Definity for BBBD. Thirty-six non-overlapping locations were sonicated through a craniotomy in experiments in the brains of nine rabbits (4 locations per rabbit; US frequency: 0.69MHz, burst: 10ms, PRF: 1Hz, duration: 20s; pressure amplitude: 0.2-1.5 MPa). Eleven locations were sonicated using Optison at 0.5 MPa. For both agents, the probability for BBBD was estimated to be 50% at 0.4 MPa using probit regression. In histology, small isolated areas of extravasated erythrocytes were observed in some locations. At 0.8 MPa and above, this extravasation was sometimes accompanied by tiny (dimensions of 100 μm or less) regions of damaged brain parenchyma. The magnitude of the BBBD was larger with Optison than with Definity at 0.5 MPa (P=0.04), and more areas with extravasated erythrocytes were observed (P=0.03). We conclude that BBBD is possible using Definity for the dosage of USCA and the acoustic parameters tested in this study. While the probability for BBBD as a function of pressure amplitude and the type of acute tissue effects was similar to findings with Optison, under these experimental conditions, Optison produced a larger effect.

  4. Opening of brain blood barrier induced by red light and central analgesic improvement of cobra neurotoxin.

    Science.gov (United States)

    Ye, Yong; Li, Yue; Fang, Fei

    2014-05-05

    Cobra neurotoxin (NT) has central analgesic effects, but it is difficult to pass through brain blood barrier (BBB). A novel method of red light induction is designed to help NT across BBB, which is based on photosensitizer activation by red light to generate reactive oxygen species (ROS) to open BBB. The effects were evaluated on cell models and animals in vivo with illumination by semiconductor laser at 670nm on photosensitizer pheophorbide isolated from silkworm excrement. Brain microvascular endothelial cells and astrocytes were co-cultured to build up BBB cell model. The radioactivity of (125)I-NT was measured in cells and tissues for NT permeation. Three ways of cranial irradiation, nasal cavity and intravascular irradiation were tested with combined injection of (125)I-NT 20μg/kg and pheophorbide 100μg/kg to rats, and organs of rats were separated and determined the radioactivity. Paw pressure test in rats, hot plate and writhing test in mice were applied to appraise the analgesic effects. NT across BBB cell model increased with time of illumination, and reached stable level after 60min. So did ROS in cells. NT mainly distributed in liver and kidney of rats, significantly increased in brain after illumination, and improved analgesic effects. Excitation of pheophorbide at red light produces ROS to open BBB, help NT enter brain, and enhance its central action. This research provides a new method for drug across BBB to improve its central role. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Hyperthermic Laser Ablation of Recurrent Glioblastoma Leads to Temporary Disruption of the Peritumoral Blood Brain Barrier.

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    Eric C Leuthardt

    Full Text Available Poor central nervous system penetration of cytotoxic drugs due to the blood brain barrier (BBB is a major limiting factor in the treatment of brain tumors. Most recurrent glioblastomas (GBM occur within the peritumoral region. In this study, we describe a hyperthemic method to induce temporary disruption of the peritumoral BBB that can potentially be used to enhance drug delivery.Twenty patients with probable recurrent GBM were enrolled in this study. Fourteen patients were evaluable. MRI-guided laser interstitial thermal therapy was applied to achieve both tumor cytoreduction and disruption of the peritumoral BBB. To determine the degree and timing of peritumoral BBB disruption, dynamic contrast-enhancement brain MRI was used to calculate the vascular transfer constant (Ktrans in the peritumoral region as direct measures of BBB permeability before and after laser ablation. Serum levels of brain-specific enolase, also known as neuron-specific enolase, were also measured and used as an independent quantification of BBB disruption.In all 14 evaluable patients, Ktrans levels peaked immediately post laser ablation, followed by a gradual decline over the following 4 weeks. Serum BSE concentrations increased shortly after laser ablation and peaked in 1-3 weeks before decreasing to baseline by 6 weeks.The data from our pilot research support that disruption of the peritumoral BBB was induced by hyperthemia with the peak of high permeability occurring within 1-2 weeks after laser ablation and resolving by 4-6 weeks. This provides a therapeutic window of opportunity during which delivery of BBB-impermeant therapeutic agents may be enhanced.ClinicalTrials.gov NCT01851733.

  6. Hyperthermic Laser Ablation of Recurrent Glioblastoma Leads to Temporary Disruption of the Peritumoral Blood Brain Barrier.

    Science.gov (United States)

    Leuthardt, Eric C; Duan, Chong; Kim, Michael J; Campian, Jian L; Kim, Albert H; Miller-Thomas, Michelle M; Shimony, Joshua S; Tran, David D

    2016-01-01

    Poor central nervous system penetration of cytotoxic drugs due to the blood brain barrier (BBB) is a major limiting factor in the treatment of brain tumors. Most recurrent glioblastomas (GBM) occur within the peritumoral region. In this study, we describe a hyperthemic method to induce temporary disruption of the peritumoral BBB that can potentially be used to enhance drug delivery. Twenty patients with probable recurrent GBM were enrolled in this study. Fourteen patients were evaluable. MRI-guided laser interstitial thermal therapy was applied to achieve both tumor cytoreduction and disruption of the peritumoral BBB. To determine the degree and timing of peritumoral BBB disruption, dynamic contrast-enhancement brain MRI was used to calculate the vascular transfer constant (Ktrans) in the peritumoral region as direct measures of BBB permeability before and after laser ablation. Serum levels of brain-specific enolase, also known as neuron-specific enolase, were also measured and used as an independent quantification of BBB disruption. In all 14 evaluable patients, Ktrans levels peaked immediately post laser ablation, followed by a gradual decline over the following 4 weeks. Serum BSE concentrations increased shortly after laser ablation and peaked in 1-3 weeks before decreasing to baseline by 6 weeks. The data from our pilot research support that disruption of the peritumoral BBB was induced by hyperthemia with the peak of high permeability occurring within 1-2 weeks after laser ablation and resolving by 4-6 weeks. This provides a therapeutic window of opportunity during which delivery of BBB-impermeant therapeutic agents may be enhanced. ClinicalTrials.gov NCT01851733.

  7. Evaluation of the increase in permeability of the blood-brain barrier during tumor progression after pulsed focused ultrasound.

    Science.gov (United States)

    Yang, Feng-Yi; Wang, Hsin-Ell; Lin, Guan-Liang; Lin, Hui-Hsien; Wong, Tai-Tong

    2012-01-01

    The purpose of this study was to evaluate the permeability of the blood-brain barrier after sonication by pulsed high-intensity focused ultrasound and to determine if such an approach increases the tumor:ipsilateral brain permeability ratio. F98 glioma-bearing Fischer 344 rats were injected intravenously with Evans blue with or without blood-tumor barrier disruption induced by transcranial pulsed high-intensity focused ultrasound. Sonication was applied at a frequency of 1 MHz with a 5% duty cycle and a repetition frequency of 1 Hz. The permeability of the blood-brain barrier was assessed by the extravasation of Evans blue. Contrast-enhanced magnetic resonance images were used to monitor the gadolinium deposition path associated with transcranial pulsed high-intensity focused ultrasound, and the influencing size and location was also investigated. In addition, whole brain histological analysis was performed. The results were compared by two-tailed unpaired t-test. The accumulation of Evans blue in brains and the tumor:ipsilateral brain permeability ratio of Evans blue were significantly increased after pulsed high-intensity focused ultrasound exposure. Evans blue injection followed by sonication showed an increase in the tumor:ipsilateral brain ratio of the target tumors (9.14:1) of about 2.23-fold compared with the control tumors (x4.09) on day 6 after tumor implantation. Magnetic resonance images showed that pulsed high-intensity focused ultrasound locally enhances the permeability of the blood-tumor barrier in the glioma-bearing rats. This method could allow enhanced synergistic effects with respect to other brain tumor treatment regimens.

  8. Nanomedicine as a non-invasive strategy for drug delivery across the blood brain barrier.

    Science.gov (United States)

    Tam, Vivienne H; Sosa, Chris; Liu, Rui; Yao, Nan; Priestley, Rodney D

    2016-12-30

    The blood brain barrier (BBB) is a major obstacle to drug delivery for diseases of the central nervous system (CNS). This brief review highlights the current invasive and non-invasive technologies available to address this problem. In particular, nanomedicine has shown much promise as a non-invasive strategy due to its drug loading capabilities, ease of targeting to the BBB, and small size. The versatility of this technology in terms of type of drug and imaging agent, carrier material, and targeting mechanism is highlighted in this review. The recent inclusion of imaging agents in the nanocarriers has important consequences for the field of theranostics. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Developing drugs that can cross the blood-brain barrier: applications to Alzheimer's disease.

    Science.gov (United States)

    Banks, William A

    2008-12-10

    Development of therapeutics for the central nervous system is one of the most challenging areas in drug development. This is primarily because, in addition to all of the other complications one faces in developing new drugs targeting peripheral sites, one must also negotiate the blood-brain barrier (BBB). There are dozens of strategies to overcome the obstacle of the BBB, but many of these are bound to fail, barring extreme serendipity, because they are based on an inaccurate or incomplete picture of the BBB. This article therefore starts with a brief review of the BBB as it pertains to drug development. It then examines some examples of the delivery of drugs to the central nervous system that are relevant to Alzheimer's disease, placing emphasis on peptides, antibodies, and antisense oligonucleotides.

  10. Bicuculline methiodide in the blood-brain barrier-epileptogen model of epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Remler, M.P.; Marcussen, W.H.

    Focal epilepsy can be produced by a blood-brain barrier (BBB)-excluded systemic convulsant (penicillin, folic acid, etc.) in the presence of a focal BBB lesion. Bicuculline methiodide, a gamma-aminobutyric acid blocking epileptogen, crosses the normal BBB of rats poorly and produces no consistent abnormality behaviorally or on EEG at 36 mg/kg. When the BBB is opened in 0.25 ml of cortex by 6,000 rad of alpha particles, by a pin trauma lesion, or by a heat lesion, the rats are normal clinically and on EEG. When these lesioned rats are challenged with bicuculline methiodide, 36 mg/kg, an intense, highly localized epileptiform discharge results that begins approximately 20 min after injection and lasts 30-90 min. The plausibility and experimental utility of the BBB-epileptogen model of epilepsy are enhanced by these observations.

  11. Immunogold labeling reveals subcellular localisation of silica nanoparticles in a human blood-brain barrier model

    Science.gov (United States)

    Ye, Dong; Anguissola, Sergio; O'Neill, Tiina; Dawson, Kenneth A.

    2015-05-01

    Subcellular location of nanoparticles has been widely investigated with fluorescence microscopy, via fluorescently labeled antibodies to visualise target antigens in cells. However, fluorescence microscopy, such as confocal or live cell imaging, has generally limited 3D spatial resolution. Conventional electron microscopy can be useful in bridging resolution gap, but still not ideal in resolving subcellular organelle identities. Using the pre-embedding immunogold electron microscopic imaging, we performed accurate examination of the intracellular trafficking and gathered further evidence of transport mechanisms of silica nanoparticles across a human in vitro blood-brain barrier model. Our approach can effectively immunolocalise a variety of intracellular compartments and provide new insights into the uptake and subcellular transport of nanoparticles.Subcellular location of nanoparticles has been widely investigated with fluorescence microscopy, via fluorescently labeled antibodies to visualise target antigens in cells. However, fluorescence microscopy, such as confocal or live cell imaging, has generally limited 3D spatial resolution. Conventional electron microscopy can be useful in bridging resolution gap, but still not ideal in resolving subcellular organelle identities. Using the pre-embedding immunogold electron microscopic imaging, we performed accurate examination of the intracellular trafficking and gathered further evidence of transport mechanisms of silica nanoparticles across a human in vitro blood-brain barrier model. Our approach can effectively immunolocalise a variety of intracellular compartments and provide new insights into the uptake and subcellular transport of nanoparticles. Electronic supplementary information (ESI) available: Nanoparticle characterisation data, preservation of cellular structures, staining controls, optimisation of size amplification via the silver enhancement, and more imaging results from anti-clathrin and anti-caveolin 1

  12. Computing the blood brain barrier (BBB) diffusion coefficient: A molecular dynamics approach

    Energy Technology Data Exchange (ETDEWEB)

    Shamloo, Amir, E-mail: shamloo@sharif.edu; Pedram, Maysam Z.; Heidari, Hossein; Alasty, Aria, E-mail: aalasti@sharif.edu

    2016-07-15

    Various physical and biological aspects of the Blood Brain Barrier (BBB) structure still remain unfolded. Therefore, among the several mechanisms of drug delivery, only a few have succeeded in breaching this barrier, one of which is the use of Magnetic Nanoparticles (MNPs). However, a quantitative characterization of the BBB permeability is desirable to find an optimal magnetic force-field. In the present study, a molecular model of the BBB is introduced that precisely represents the interactions between MNPs and the membranes of Endothelial Cells (ECs) that form the BBB. Steered Molecular Dynamics (SMD) simulations of the BBB crossing phenomenon have been carried out. Mathematical modeling of the BBB as an input-output system has been considered from a system dynamics modeling viewpoint, enabling us to analyze the BBB behavior based on a robust model. From this model, the force profile required to overcome the barrier has been extracted for a single NP from the SMD simulations at a range of velocities. Using this data a transfer function model has been obtained and the diffusion coefficient is evaluated. This study is a novel approach to bridge the gap between nanoscale models and microscale models of the BBB. The characteristic diffusion coefficient has the nano-scale molecular effects inherent, furthermore reducing the computational costs of a nano-scale simulation model and enabling much more complex studies to be conducted. - Highlights: • Molecular dynamics simulation of crossing nano-particles through the BBB membrane at different velocities. • Recording the position of nano-particle and the membrane-NP interaction force profile. • Identification of a frequency domain model for the membrane. • Calculating the diffusion coefficient based on MD simulation and identified model. • Obtaining a relation between continuum medium and discrete medium.

  13. A New Noncanonical Anionic Peptide That Translocates a Cellular Blood–Brain Barrier Model

    Directory of Open Access Journals (Sweden)

    Sara Neves-Coelho

    2017-10-01

    Full Text Available The capacity to transport therapeutic molecules across the blood–brain barrier (BBB represents a breakthrough in the development of tools for the treatment of many central nervous system (CNS-associated diseases. The BBB, while being protective against infectious agents, hinders the brain uptake of many drugs. Hence, finding safe shuttles able to overcome the BBB is of utmost importance. Herein, we identify a new BBB-translocating peptide with unique properties. For years it was thought that cationic sequences were mandatory for a cell-penetrating peptide (CPP to achieve cellular internalization. Despite being anionic at physiological pH, PepNeg (sequence (SGTQEEY is an efficient BBB translocator that is able to carry a large cargo (27 kDa, while maintaining BBB integrity. In addition, PepNeg is able to use two distinct methods of translocation, energy-dependent and -independent, suggesting that direct penetration might occur when low concentrations of peptide are presented to cells. The discovery of this new anionic trans-BBB peptide allows the development of new delivery systems to the CNS and contributes to the need to rethink the role of electrostatic attraction in BBB-translocation.

  14. Blood-brain barrier: a definition of normal and altered function.

    Science.gov (United States)

    Pollay, M; Roberts, P A

    1980-06-01

    The anatomical component of the blood-brain barrier (BBB) has been shown to be the cerebral capillary. These capillary endothelial cells are connected by continuous tight intercellular junctions and under normal conditions do not demonstrate transendothelial channels or pinocytotic vesicles. The rate that substances penetrate the BBB is related to molecular size, lipid solubility, and the presence of a specific carrier-mediated transport system. This latter mechanism for transendothelial passage is utilized for the movement of a wide variety of biologically important compounds such as sugars, amino acids, and organic acids. In certain pathological conditions, the permeability of the BBB is altered so that normally excluded plasma proteins and fluid enter the brain extracellular space, with the subsequent development of cerebral edema. In other abnormal conditions, alterations in the specialized transport systems operating across the cerebral capillary result in adverse changes in cerebral and neurotransmitter metabolism. An understanding of the unique properties of the BBB and of the changes that occur in pathological conditions has allowed the development of rational therapeutic strategies for a wide variety of diseases of the central nervous system.

  15. Mapping the Structural Determinants Required for AAVrh.10 Transport across the Blood-Brain Barrier.

    Science.gov (United States)

    Albright, Blake H; Storey, Claire M; Murlidharan, Giridhar; Castellanos Rivera, Ruth M; Berry, Garrett E; Madigan, Victoria J; Asokan, Aravind

    2017-10-26

    Effective gene delivery to the CNS by intravenously administered adeno-associated virus (AAV) vectors requires crossing the blood-brain barrier (BBB). To achieve therapeutic CNS transgene expression, high systemic vector doses are often required, which poses challenges such as scale-up costs and dose-dependent hepatotoxicity. To improve the specificity and efficiency of CNS gene transfer, a better understanding of the structural features that enable AAV transit across the BBB is needed. We generated a combinatorial domain swap library using AAV1, a serotype that does not traverse the vasculature, and AAVrh.10, which crosses the BBB in mice. We then screened individual variants by phylogenetic and structural analyses and subsequently conducted systemic characterization in mice. Using this approach, we identified key clusters of residues on the AAVrh.10 capsid that enabled transport across the brain vasculature and widespread neuronal transduction in mice. Through rational design, we mapped a minimal footprint from AAVrh.10, which, when grafted onto AAV1, confers the aforementioned CNS phenotype while diminishing vascular and hepatic transduction through an unknown mechanism. Functional mapping of this capsid surface footprint provides a roadmap for engineering synthetic AAV capsids for efficient CNS gene transfer with an improved safety profile. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

  16. Transport rankings of non-steroidal antiinflammatory drugs across blood-brain barrier in vitro models.

    Directory of Open Access Journals (Sweden)

    Iveta Novakova

    Full Text Available The aim of this work was to conduct a comprehensive study about the transport properties of NSAIDs across the blood-brain barrier (BBB in vitro. Transport studies with celecoxib, diclofenac, ibuprofen, meloxicam, piroxicam and tenoxicam were accomplished across Transwell models based on cell line PBMEC/C1-2, ECV304 or primary rat brain endothelial cells. Single as well as group substance studies were carried out. In group studies substance group compositions, transport medium and serum content were varied, transport inhibitors verapamil and probenecid were added. Resulted permeability coefficients were compared and normalized to internal standards diazepam and carboxyfluorescein. Transport rankings of NSAIDs across each model were obtained. Single substance studies showed similar rankings as corresponding group studies across PBMEC/C1-2 or ECV304 cell layers. Serum content, glioma conditioned medium and inhibitors probenecid and verapamil influenced resulted permeability significantly. Basic differences of transport properties of the investigated NSAIDs were similar comparing all three in vitro BBB models. Different substance combinations in the group studies and addition of probenecid and verapamil suggested that transporter proteins are involved in the transport of every tested NSAID. Results especially underlined the importance of same experimental conditions (transport medium, serum content, species origin, cell line for proper data comparison.

  17. Targeted delivery of GDNF through the blood-brain barrier by MRI-guided focused ultrasound.

    Directory of Open Access Journals (Sweden)

    Feng Wang

    Full Text Available Neurotrophic factors, such as glial cell line-derived neurotrophic factor (GDNF, are promising therapeutic agents for neurodegenerative diseases. However, the application of GDNF to treat these diseases effectively is limited because the blood-brain barrier (BBB prevents the local delivery of macromolecular therapeutic agents from entering the central nervous system (CNS. Focused ultrasound combined with microbubbles (MBs using appropriate parameters has been previously demonstrated to be able to open the BBB locally and noninvasively. This study investigated the targeted delivery of GDNF MBs through the BBB by magnetic resonance imaging (MRI-guided focused ultrasound. Evans Blue extravasation and histological examination were used to determine the optimum focused ultrasound parameters. Enzyme-linked immunosorbent assay was performed to verify the effects of GDNF bound on MBs using a biotin-avidin bridging chemistry method to promote GDNF delivery into the brain. The results showed that GDNF can be delivered locally and noninvasively into the CNS through the BBB using MRI-guided focused ultrasound combined with MBs under optimum parameters. MBs that bind GDNF combined with MRI-guided focused ultrasound may be an effective way of delivering neurotrophic factors directly into the CNS. The method described herein provides a potential means of treating patients with CNS diseases.

  18. Magnetic Resonance Imaging to Assess Blood–Brain Barrier Damage in Murine Trypanosomiasis

    Science.gov (United States)

    Rodgers, Jean; McCabe, Christopher; Gettinby, George; Bradley, Barbara; Condon, Barrie; Kennedy, Peter G. E.

    2011-01-01

    The ability of trypanosomes to invade the brain and induce an inflammatory reaction is well-recognized. This study uses magnetic resonance imaging (MRI) in conjunction with a murine model of central nervous system (CNS) stage trypanosomiasis to investigate this phenomenon at the level of the blood–brain barrier (BBB). Mice were scanned before and after administration of the contrast agent. Signal enhancement maps were generated, and the percentage signal change was calculated. The severity of the neuroinflammation was also assessed. Statistical analysis of the signal change data revealed a significantly (P = 0.028) higher signal enhancement in mice at 28 days post-infection (least squares mean = 26.709) compared with uninfected animals (6.298), indicating the presence of BBB impairment. Leukocytes were found in the meninges and perivascular space of some blood vessels in the infected mice. This study shows that the integrity of the BBB is compromised during CNS stage trypanosomiasis and that the impairment does not correlate with inflammatory cell infiltration. PMID:21292912

  19. Enhanced cerebral uptake of receptor ligands by modulation of P-glycoprotein function in the blood-brain barrier

    NARCIS (Netherlands)

    Doze, P; Van Waarde, A; Elsinga, P H; Hendrikse, N H; Vaalburg, W

    Low cerebral uptake of some therapeutic drugs can be enhanced by modulation of P-glycoprotein (P-gp), an ATP-driven drug efflux pump at the blood-brain barrier (BBB). We investigated the possibility of increasing cerebral uptake of the beta-adrenergic ligands S-1'-[(18)F]-fluorocarazolol (FCAR) and

  20. Plasma from preeclamptic women increases blood-brain barrier permeability: role of vascular endothelial growth factor signaling.

    Science.gov (United States)

    Amburgey, Odül A; Chapman, Abbie C; May, Victor; Bernstein, Ira M; Cipolla, Marilyn J

    2010-11-01

    Circulating factors in preeclamptic women are thought to cause endothelial dysfunction and thereby contribute to the progression of this hypertensive condition. Despite the involvement of neurological complications in preeclampsia, there is a paucity of data regarding the effect of circulating factors on cerebrovascular function. Using a rat model of pregnancy, we investigated blood-brain barrier permeability, myogenic activity, and the influence of endothelial vasodilator mechanisms in cerebral vessels exposed intraluminally to plasma from normal pregnant or preeclamptic women. In addition, the role of vascular endothelial growth factor signaling in mediating changes in permeability in response to plasma was investigated. A 3-hour exposure to 20% normal pregnant or preeclamptic plasma increased blood-brain barrier permeability by ≈6.5- and 18.0-fold, respectively, compared with no plasma exposure (Pvascular endothelial growth factor receptor kinase activity prevented the increase in permeability in response to preeclamptic plasma but had no effect on changes in permeability of vessels exposed to normal pregnant plasma. Circulating factors in preeclamptic plasma did not affect myogenic activity or the influence of endothelium on vascular tone. These findings demonstrate that acute exposure to preeclamptic plasma has little effect on reactivity of cerebral arteries but significantly increases blood-brain barrier permeability. Prevention of increased permeability by inhibition of vascular endothelial growth factor signaling suggests that activation of this pathway may be responsible for increased blood-brain barrier permeability after exposure to preeclamptic plasma.

  1. Altered free radical metabolism in acute mountain sickness: implications for dynamic cerebral autoregulation and blood-brain barrier function

    DEFF Research Database (Denmark)

    Bailey, D M; Evans, K A; James, P E

    2008-01-01

    We tested the hypothesis that dynamic cerebral autoregulation (CA) and blood-brain barrier (BBB) function would be compromised in acute mountain sickness (AMS) subsequent to a hypoxia-mediated alteration in systemic free radical metabolism. Eighteen male lowlanders were examined in normoxia (21% O...

  2. Blood-brain barrier transport and protein binding of flumazenil and iomazenil in the rat: implications for neuroreceptor studies

    DEFF Research Database (Denmark)

    Videbaek, C; Ott, P; Paulson, O B

    1999-01-01

    of blood-brain barrier permeability for two benzodiazepine antagonists were performed in 44 rats by the double-indicator technique. Cerebral blood flow was measured by intracarotid Xe-injection. The apparent permeability-surface product (PSapp) was measured while CBF or bolus composition was changed...

  3. Dasatinib crosses the blood-brain barrier and is an efficient therapy for central nervous system philadelphia chromosome positive leukemia

    NARCIS (Netherlands)

    K. Porkka (Kimmo); P. Koskenvesa (Perttu); T. Lundan (Tuija); J. Rimpiläinen (Johanna); S. Mustjoki (Satu); R. Smykla (Richard); R. Wild (Robert); R. Luo (Roger); M. Arnan (Montserrat); B. Brethon (Benoit); L. Eccersley (Lydia); H. Hjorth-Hansen (Henrik); M. Höglund (Martin); H. Klamova (Hana); H. Knutsen (Håvar); S. Parikh (Suhag); E. Raffoux (Emmanuel); F. Gruber (Franz); F. Brito-Babapulle (Finella); H. Dombret (Hervé); R.F. Duarte (Rafael); E. Elonen (Erkki); R. Paquette (Ron); C.M. Zwaan (Christian Michel); F.Y.F. Lee (Francis)

    2008-01-01

    textabstractAlthough imatinib, a BCR-ABL tyrosine kinase inhibitor, is used to treat acute Philadelphia chromosome-positive (Ph+) leukemia, it does not prevent central nervous system (CNS) relapses resulting from poor drug penetration through the blood-brain barrier. Imatinib and dasatinib (a

  4. Non-invasive assessment of blood-brain barrier (BBB) permeability using a gamma camera to detect 99technetium-gluceptate extravasation in rat brain.

    Science.gov (United States)

    Esposito, P; Jacobson, S; Connolly, R; Gheorghe, D; Theoharides, T C

    2001-10-01

    The blood-brain barrier (BBB) is a complex structure of endothelial cells, astroglia, pericytes, and perivascular macrophages enclosed by basal lamina. The BBB regulates the entry of blood-borne molecules and cells into the brain, but it is disrupted in various inflammatory conditions of the central nervous system (CNS). We previously showed that 30 min of immobilization stress increased 99technetium-gluceptate (99Tc) extravasation, measured by a gamma counter, in brain regions containing mast cells, an effect blocked by the mast cell stabilizer disodium cromoglycate [Brain Res. 888 (2001) 117]. Here we report the use of a gamma camera to assess BBB permeability by assessing 99Tc extravasation in the rat brain, during and following acute stress, without having to sacrifice the experimental animals. This method also allows for repeated experimentation on the same animal, since the half-life of 99Tc is only 6 h, and permits testing of potential inhibitors of BBB permeability.

  5. Measurement of brain perfusion, blood volume, and blood-brain barrier permeability, using dynamic contrast-enhanced T(1)-weighted MRI at 3 tesla

    DEFF Research Database (Denmark)

    Larsson, Henrik B W; Courivaud, Frédéric; Rostrup, Egill

    2009-01-01

    Assessment of vascular properties is essential to diagnosis and follow-up and basic understanding of pathogenesis in brain tumors. In this study, a procedure is presented that allows concurrent estimation of cerebral perfusion, blood volume, and blood-brain permeability from dynamic T(1)-weighted...... imaging of a bolus of a paramagnetic contrast agent passing through the brain. The methods are applied in patients with brain tumors and in healthy subjects. Perfusion was estimated by model-free deconvolution using Tikhonov's method (gray matter/white matter/tumor: 72 +/- 16/30 +/- 8/56 +/- 45 mL/100 g...... on a pixel-by-pixel basis of cerebral perfusion, cerebral blood volume, and blood-brain barrier permeability....

  6. Assessment of blood–brain barrier disruption using dynamic contrast-enhanced MRI. A systematic review

    Directory of Open Access Journals (Sweden)

    Anna K. Heye

    2014-01-01

    Full Text Available There is increasing recognition of the importance of blood–brain barrier (BBB disruption in aging, dementia, stroke and multiple sclerosis in addition to more commonly-studied pathologies such as tumors. Dynamic contrast-enhanced MRI (DCE-MRI is a method for studying BBB disruption in vivo. We review pathologies studied, scanning protocols and data analysis procedures to determine the range of available methods and their suitability to different pathologies. We systematically review the existing literature up to February 2014, seeking studies that assessed BBB integrity using T1-weighted DCE-MRI techniques in animals and humans in normal or abnormal brain tissues. The literature search provided 70 studies that were eligible for inclusion, involving 417 animals and 1564 human subjects in total. The pathologies most studied are intracranial neoplasms and acute ischemic strokes. There are large variations in the type of DCE-MRI sequence, the imaging protocols and the contrast agents used. Moreover, studies use a variety of different methods for data analysis, mainly based on model-free measurements and on the Patlak and Tofts models. Consequently, estimated KTrans values varied widely. In conclusion, DCE-MRI is shown to provide valuable information in a large variety of applications, ranging from common applications, such as grading of primary brain tumors, to more recent applications, such as assessment of subtle BBB dysfunction in Alzheimer's disease. Further research is required in order to establish consensus-based recommendations for data acquisition and analysis and, hence, improve inter-study comparability and promote wider use of DCE-MRI.

  7. Resveratrol defends blood-brain barrier integrity in experimental autoimmune encephalomyelitis mice.

    Science.gov (United States)

    Wang, Dong; Li, Shi-Ping; Fu, Jin-Sheng; Zhang, Sheng; Bai, Lin; Guo, Li

    2016-11-01

    The mouse autoimmune encephalomyelitis (EAE), an experimental model of multiple sclerosis (MS), is primarily characterized as dysfunction of the blood-brain barrier (BBB). Resveratrol exhibits anti-inflammatory, antioxidative, and neuroprotective activities. We investigated the beneficial effects of resveratrol in protecting the integrity of the BBB in EAE mice and observed improved clinical outcome in the EAE mice after resveratrol treatment. Evans blue (EB) extravasation was used to detect the disruption of BBB. Western blot were used to detected the tight junction proteins and adhesion molecules zonula occludens-1 (ZO-1), occludin, ICAM-1, and VCAM-1. Inflammatory factors inducible nitric oxide synthase (iNOS), IL-1β, and arginase 1 were evaluated by quantitative RT-PCR (qPCR) and IL-10 by ELISA. NADPH oxidase (NOX) levels were evaluated by qPCR, and its activity was analyzed by lucigenin-derived chemiluminescence. Resveratrol at doses of 25 and 50 mg/kg produced a dose-dependent decrease in EAE paralysis and EB leakage, ameliorated EAE-induced loss of tight junction proteins ZO-1, occludin, and claudin-5, as well as repressed the EAE-induced increase in adhesion proteins ICAM-1 and VCAM-1. In addition, resveratrol suppressed the EAE-induced overexpression of proinflammatory transcripts iNOS and IL-1β and upregulated the expression of anti-inflammatory transcripts arginase 1 and IL-10 cytokine in the brain. Furthermore, resveratrol downregulated the overexpressed NOX2 and NOX4 in the brain and suppressed NADPH activity. Resveratrol ameliorates the clinical severity of MS through maintaining the BBB integrity in EAE mice. Copyright © 2016 the American Physiological Society.

  8. In vitro blood-brain barrier permeability predictions for GABAA receptor modulating piperine analogs.

    Science.gov (United States)

    Eigenmann, Daniela Elisabeth; Dürig, Carmen; Jähne, Evelyn Andrea; Smieško, Martin; Culot, Maxime; Gosselet, Fabien; Cecchelli, Romeo; Helms, Hans Christian Cederberg; Brodin, Birger; Wimmer, Laurin; Mihovilovic, Marko D; Hamburger, Matthias; Oufir, Mouhssin

    2016-06-01

    The alkaloid piperine from black pepper (Piper nigrum L.) and several synthetic piperine analogs were recently identified as positive allosteric modulators of γ-aminobutyric acid type A (GABAA) receptors. In order to reach their target sites of action, these compounds need to enter the brain by crossing the blood-brain barrier (BBB). We here evaluated piperine and five selected analogs (SCT-66, SCT-64, SCT-29, LAU397, and LAU399) regarding their BBB permeability. Data were obtained in three in vitro BBB models, namely a recently established human model with immortalized hBMEC cells, a human brain-like endothelial cells (BLEC) model, and a primary animal (bovine endothelial/rat astrocytes co-culture) model. For each compound, quantitative UHPLC-MS/MS methods in the range of 5.00-500ng/mL in the corresponding matrix were developed, and permeability coefficients in the three BBB models were determined. In vitro predictions from the two human BBB models were in good agreement, while permeability data from the animal model differed to some extent, possibly due to protein binding of the screened compounds. In all three BBB models, piperine and SCT-64 displayed the highest BBB permeation potential. This was corroborated by data from in silico prediction. For the other piperine analogs (SCT-66, SCT-29, LAU397, and LAU399), BBB permeability was low to moderate in the two human BBB models, and moderate to high in the animal BBB model. Efflux ratios (ER) calculated from bidirectional permeability experiments indicated that the compounds were likely not substrates of active efflux transporters. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Cellular Apoptosis and Blood Brain Barrier Permeability Changes in the Pre-Incubated Chicken Embryo’s Brain by Effect of Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    Sima Kalantari

    2015-02-01

    Full Text Available Background: Electromagnetic fields (EMF have teratogenic effects during the embryonic development. In current study, histopathological and physiological effects of sinusoidal EMF on the brain were investigated. We sought to determine the apoptosis level and changes in blood brain barrier permeability in brain tissue of pre-incubated white leghorn hen eggs in the field of EMF. Materials and Methods: In this experimental study, 300 healthy, fresh, and fertilized eggs (55-65 g were divided into experimental (3 groups, N=50, control (N=75 and sham (N=75 groups. Experimental eggs (inside the coil were exposed to 3 different intensities of 1.33, 2.66 and 7.32 mT and sham groups were also located inside the same coil but with no exposure, for 24 hrs before incubation. Control, sham and experimental groups were incubated in an incubator (38±0.5ºC, 60% humidity. Brains of 14 day old chicken embryos of all groups were removed, fixed in formalin (10%, stained with H & E and TUNEL, apoptotic cells were studied under light microscope. Brains of other embryos were prepared for scanning electron microscope. By injections of Evans blue, any possible changes in brain vessels were also investigated. Results: Our results showed electromagnetic fields have toxic effects on cell organelles and cell membranes. EMF would increase the level of cellular apoptosis in the brain. They also would tear up the blood vessels. Thereafter, they would affect the permeability of blood brain barrier of exposed chicken embryos. Conclusion: These findings suggest that electromagnetic fields induce different degrees of brain damages in chicken embryos brain tissue.

  10. Targeted delivery of neural stem cells to the brain using MRI-guided focused ultrasound to disrupt the blood-brain barrier.

    Directory of Open Access Journals (Sweden)

    Alison Burgess

    Full Text Available Stem cell therapy is a promising strategy to treat neurodegenerative diseases, traumatic brain injury, and stroke. For stem cells to progress towards clinical use, the risks associated with invasive intracranial surgery used to deliver the cells to the brain, needs to be reduced. Here, we show that MRI-guided focused ultrasound (MRIgFUS is a novel method for non-invasive delivery of stem cells from the blood to the brain by opening the blood brain barrier (BBB in specific brain regions. We used MRI guidance to target the ultrasound beam thereby delivering the iron-labeled, green fluorescent protein (GFP-expressing neural stem cells specifically to the striatum and the hippocampus of the rat brain. Detection of cellular iron using MRI established that the cells crossed the BBB to enter the brain. After sacrifice, 24 hours later, immunohistochemical analysis confirmed the presence of GFP-positive cells in the targeted brain regions. We determined that the neural stem cells expressed common stem cell markers (nestin and polysialic acid suggesting they survived after transplantation with MRIgFUS. Furthermore, delivered stem cells expressed doublecortin in vivo indicating the stem cells were capable of differentiating into neurons. Together, we demonstrate that transient opening of the BBB with MRIgFUS is sufficient for transplantation of stem cells from the blood to targeted brain structures. These results suggest that MRIgFUS may be an effective alternative to invasive intracranial surgery for stem cell transplantation.

  11. P-glycoprotein function at the blood-brain barrier imaged using 11C-N-desmethyl-loperamide in monkeys.

    Science.gov (United States)

    Liow, Jeih-San; Kreisl, William; Zoghbi, Sami S; Lazarova, Neva; Seneca, Nicholas; Gladding, Robert L; Taku, Andrew; Herscovitch, Peter; Pike, Victor W; Innis, Robert B

    2009-01-01

    11C-Loperamide is an avid substrate for P-glycoprotein (P-gp), but it is rapidly metabolized to 11C-N-desmethyl-loperamide (11C-dLop), which is also a substrate for P-gp and thereby contaminates the radioactive signal in the brain. Should further demethylation of 11C-dLop occur, radiometabolites with low entry into the brain are generated. Therefore, we evaluated the ability of 11C-dLop to quantify the function of P-gp at the blood-brain barrier in monkeys. Six monkeys underwent 12 PET scans of the brain, 5 at baseline and 7 after pharmacologic blockade of P-gp. A subset of monkeys also underwent PET scans with 15O-water to measure cerebral blood flow. To determine whether P-gp blockade affected peripheral distribution of 11C-dLop, we measured whole-body biodistribution in 4 monkeys at baseline and after P-gp blockade. The concentration of 11C-dLop in the brain was low under baseline conditions and increased 5-fold after P-gp blockade. This increase was primarily caused by an increased rate of entry into the brain rather than a decreased rate of removal from the brain. With P-gp blockade, uptake of radioactivity among brain regions correlated linearly with blood flow, suggesting a high single-pass extraction. After correction for cerebral blood flow, the uptake of 11C-dLop was fairly uniform among brain regions, suggesting that the function of P-gp is fairly uniformly distributed in the brain. On whole-body imaging, P-gp blockade significantly affected distribution of radioactivity only to the brain and not to other visually identified source organs. The effective dose estimated for humans was approximately 9 microSv/MBq. PET with 11C-dLop can quantify P-gp function at the blood-brain barrier in monkeys. The single-pass extraction of 11C-dLop is high and requires correction for blood flow to accurately measure the function of this efflux transporter. The low uptake at baseline and markedly increased uptake after P-gp blockade suggest that 11C-dLop will be useful to

  12. Brain-derived neurotrophic factor preserves intestinal mucosal barrier function and alters gut microbiota in mice

    Directory of Open Access Journals (Sweden)

    Chen Li

    2018-03-01

    Full Text Available The intestinal mucosal barrier (IMB enables the intestine to provide adequate containment of luminal microorganisms and molecules while preserving the ability to absorb nutrients. In this study, we explored the effect of brain-derived neurotrophic factor (BDNF on IMB function and gut microbiota in mice. BDNF gene knock-out mice (the BDNF+/− group and wild-type mice (the BDNF+/+ group were selected. The gut microbiota of these mice was analyzed by denaturing gradient gel electrophoresis (DGGE assay. The ultrastructure of the ileum and the colonic epithelium obtained from decapitated mice were observed by transmission electron microscopy. The protein expression of epithelial tight junction proteins, zonula occludens-1 (ZO-1 and occludin was detected by immunohistochemistry staining. The protein expression of claudin-1 and claudin-2 was determined by Western blotting. The DGGE band patterns of gut microbiota in the BDNF+/− group were significantly different from that in the BDNF+/+ group, which indicated that the BDNF expression alters the gut microbiota in mice. Compared with the BDNF+/+ group, the BDNF+/− group presented no significant difference in the ultrastructure of ileal epithelium; however, a significant difference was observed in the colonic epithelial barrier, manifested by decreased microvilli, widening intercellular space and bacterial invasion. Compared with the BDNF+/+ group, the expression of ZO-1 and occludin in the BDNF+/− group was significantly decreased. The expression of claudin-1 in the BDNF+/− group was significantly reduced, while the expression of claudin-2 was elevated. These findings indicate that BDNF preserves IMB function and modulates gut microbiota in mice.

  13. Remote Ischemia Preconditioning Attenuates Blood-Spinal Cord Barrier Breakdown in Rats Undergoing Spinal Cord Ischemia Reperfusion Injury: Associated with Activation and Upregulation of CB1 and CB2 Receptors.

    Science.gov (United States)

    Jing, Na; Fang, Bo; Wang, Zhi-Lin; Ma, Hong

    2017-10-31

    Remote ischemic preconditioning (RIPC) has protective effects on spinal cord ischemia reperfusion (I/R) injury, but the potential mechanisms remain unclear. In our study, the effects and underlying mechanisms of RIPC on blood-spinal cord barrier (BSCB) breakdown following I/R injury were investigated. animals underwent intraperitoneal administration with cannabinoid-1 (CB1) receptor antagonist AM251, cannabinoid-2 (CB2) receptor antagonist AM630 or vehicle 15 minutes before three 3-minute occlusion-reperfusion cycles on the right femoral artery or a sham operation. 30 minutes after the preconditioning, aortic arch was exposed with or without 14-minute occlusion. Neurological function was assessed with Tarlov scoring system. The disruption of BSCB was assessed by measuring Evans Blue (EB) extravasation. The expression of tight junction protein occludin was determined by western blot analyses. The expression and localization of CB1 and CB2 receptors were assessed by western blot and immunofluorescence. RIPC attenuated the motor dysfunction, BSCB disruption and downregulation of occludin after I/R injury, which were impaired by blocking CB1 and CB2 receptors. Moreover, RIPC upregulated the elevated perivascular expression of CB1 and CB2 receptors following I/R injury. These results indicated that RIPC, through activation and upregulation of CB1 and CB2 receptors, was involved in preserving the integrity of BSCB after spinal cord I/R injury. © 2017 The Author(s). Published by S. Karger AG, Basel.

  14. Remote Ischemia Preconditioning Attenuates Blood-Spinal Cord Barrier Breakdown in Rats Undergoing Spinal Cord Ischemia Reperfusion Injury: Associated with Activation and Upregulation of CB1 and CB2 Receptors

    Directory of Open Access Journals (Sweden)

    Na Jing

    2017-10-01

    Full Text Available Background/Aims: Remote ischemic preconditioning (RIPC has protective effects on spinal cord ischemia reperfusion (I/R injury, but the potential mechanisms remain unclear. In our study, the effects and underlying mechanisms of RIPC on blood-spinal cord barrier (BSCB breakdown following I/R injury were investigated. Methods: animals underwent intraperitoneal administration with cannabinoid-1 (CB1 receptor antagonist AM251, cannabinoid-2 (CB2 receptor antagonist AM630 or vehicle 15 minutes before three 3-minute occlusion-reperfusion cycles on the right femoral artery or a sham operation. 30 minutes after the preconditioning, aortic arch was exposed with or without 14-minute occlusion. Neurological function was assessed with Tarlov scoring system. The disruption of BSCB was assessed by measuring Evans Blue (EB extravasation. The expression of tight junction protein occludin was determined by western blot analyses. The expression and localization of CB1 and CB2 receptors were assessed by western blot and immunofluorescence. Results: RIPC attenuated the motor dysfunction, BSCB disruption and downregulation of occludin after I/R injury, which were impaired by blocking CB1 and CB2 receptors. Moreover, RIPC upregulated the elevated perivascular expression of CB1 and CB2 receptors following I/R injury. Conclusions: These results indicated that RIPC, through activation and upregulation of CB1 and CB2 receptors, was involved in preserving the integrity of BSCB after spinal cord I/R injury.

  15. Quantitation of blood-brain barrier defect by magnetic resonance imaging and gadolinium-DTPA in patients with multiple sclerosis and brain tumors

    DEFF Research Database (Denmark)

    Larsson, H B; Stubgaard, M; Frederiksen, Jette Lautrup Battistini

    1990-01-01

    In this study quantitation of the degree of deficiency of the blood-brain barrier (BBB) in patients with multiple sclerosis or brain tumors, by using MRI, is shown to be possible. As a measure of permeability of the BBB to Gadolinium-DTPA (Gd-DTPA) the flux per unit of distribution volume per unit......, and the results were comparable to results obtained from similar studies using positron emission tomography. The improved possibility of quantitating the defect of the BBB by MRI may give new information about pathogenesis or etiology, and leads to improved methods in monitoring the efficacy of treatments...... of brain mass was used. This quantity was found by introducing the longitudinal relaxation rate (R1) as a measure of concentration of Gd-DTPA in the brain tissue in the mathematical model for the transcapillary transport over the BBB. High accordance between the observed data points and the model was found...

  16. Blood-brain barrier to peptides: (/sup 3/H)gonadotropin-releasing hormone accumulation by eighteen regions of the rat brain and by anterior pituitary

    Energy Technology Data Exchange (ETDEWEB)

    Ermisch, A.; Ruehle, H.J. (Karl-Marx-Universitaet, Leipzig (German Democratic Republic). Sektion Biowissenschaften); Klauschenz, E.; Kretzschmar, R. (Akademie der Wissenschaften der DDR, Berlin. Inst. fuer Wirkstofforschung)

    1984-01-01

    After intracarotid injection of (/sup 3/H)gonadotropin-releasing hormone ((/sup 3/H)GnRH) the mean accumulation of radioactivity per unit wet weight of 18 brain samples investigated and the anterior pituitary was 0.38 +- 0.11% g/sup -1/ of the injected tracer dose. This indicates a low but measurable brain uptake of the peptide. The brain uptake of (/sup 3/H)GnRH in blood-brain barrier (BBB)-protected regions is 5% of that of separately investigated (/sup 3/H)OH. In BBB-free regions the accumulation of radioactivity was more than 25-fold higher than in BBB-protected regions. The accumulation of (/sup 3/H)GnRH among regions with BBB varies less than among regions with leaky endothelia. The data presented for (/sup 3/H)GnRH are similar to those for other peptides so far investigated.

  17. Walker 256 tumour cells increase substance P immunoreactivity locally and modify the properties of the blood-brain barrier during extravasation and brain invasion.

    Science.gov (United States)

    Lewis, Kate M; Harford-Wright, Elizabeth; Vink, Robert; Nimmo, Alan J; Ghabriel, Mounir N

    2013-01-01

    It is not yet known how tumour cells traverse the blood-brain barrier (BBB) to form brain metastases. Substance P (SP) release is a key component of neurogenic inflammation which has been recently shown to increase the permeability of the BBB following CNS insults, making it a possible candidate as a mediator of tumour cell extravasation into the brain. This study investigated the properties of the BBB in the early stages of tumour cell invasion into the brain, and the possible involvement of SP. Male Wistar rats were injected with Walker 256 breast carcinoma cells via the internal carotid artery and euthanised at 1, 3, 6 and 9 days post tumour inoculation. Culture medium-injected animals served as controls at 1 and 9 days. Evidence of tumour cell extravasation across the BBB was first observed at 3 days post-inoculation, which corresponded with significantly increased albumin (p tumoral area (p cerebral metastases may be a SP-mediated process.

  18. Fingolimod prevents blood-brain barrier disruption induced by the sera from patients with multiple sclerosis.

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    Hideaki Nishihara

    Full Text Available OBJECTIVE: Effect of fingolimod in multiple sclerosis (MS is thought to involve the prevention of lymphocyte egress from lymphoid tissues, thereby reducing autoaggressive lymphocyte infiltration into the central nervous system across blood-brain barrier (BBB. However, brain microvascular endothelial cells (BMECs represent a possible additional target for fingolimod in MS patients by directly repairing the function of BBB, as S1P receptors are also expressed by BMECs. In this study, we evaluated the effects of fingolimod on BMECs and clarified whether fingolimod-phosphate restores the BBB function after exposure to MS sera. METHODS: Changes in tight junction proteins, adhesion molecules and transendothelial electrical resistance (TEER in BMECs were evaluated following incubation in conditioned medium with or without fingolimod/fingolimod-phosphate. In addition, the effects of sera derived from MS patients, including those in the relapse phase of relapse-remitting (RR MS, stable phase of RRMS and secondary progressive MS (SPMS, on the function of BBB in the presence of fingolimod-phosphate were assessed. RESULTS: Incubation with fingolimod-phosphate increased the claudin-5 protein levels and TEER values in BMECs, although it did not change the amount of occludin, ICAM-1 or MelCAM proteins. Pretreatment with fingolimod-phosphate restored the changes in the claudin-5 and VCAM-1 protein/mRNA levels and TEER values in BMECs after exposure to MS sera. CONCLUSIONS: Pretreatment with fingolimod-phosphate prevents BBB disruption caused by both RRMS and SPMS sera via the upregulation of claudin-5 and downregulation of VCAM-1 in BMECs, suggesting that fingolimod-phosphate is capable of directly modifying the BBB. BMECs represent a possible therapeutic target for fingolimod in MS patients.

  19. Consequences of Repeated Blood-Brain Barrier Disruption in Football Players

    Science.gov (United States)

    Puvenna, Vikram; Janigro, Mattia; Ghosh, Chaitali; Zhong, Jianhui; Zhu, Tong; Blackman, Eric; Stewart, Desiree; Ellis, Jasmina; Butler, Robert; Janigro, Damir

    2013-01-01

    The acknowledgement of risks for traumatic brain injury in American football players has prompted studies for sideline concussion diagnosis and testing for neurological deficits. While concussions are recognized etiological factors for a spectrum of neurological sequelae, the consequences of sub-concussive events are unclear. We tested the hypothesis that blood-brain barrier disruption (BBBD) and the accompanying surge of the astrocytic protein S100B in blood may cause an immune response associated with production of auto-antibodies. We also wished to determine whether these events result in disrupted white matter on diffusion tensor imaging (DT) scans. Players from three college football teams were enrolled (total of 67 volunteers). None of the players experienced a concussion. Blood samples were collected before and after games (n = 57); the number of head hits in all players was monitored by movie review and post-game interviews. S100B serum levels and auto-antibodies against S100B were measured and correlated by direct and reverse immunoassays (n = 15 players; 5 games). A subset of players underwent DTI scans pre- and post-season and after a 6-month interval (n = 10). Cognitive and functional assessments were also performed. After a game, transient BBB damage measured by serum S100B was detected only in players experiencing the greatest number of sub-concussive head hits. Elevated levels of auto-antibodies against S100B were elevated only after repeated sub-concussive events characterized by BBBD. Serum levels of S100B auto-antibodies also predicted persistence of MRI-DTI abnormalities which in turn correlated with cognitive changes. Even in the absence of concussion, football players may experience repeated BBBD and serum surges of the potential auto-antigen S100B. The correlation of serum S100B, auto-antibodies and DTI changes support a link between repeated BBBD and future risk for cognitive changes. PMID:23483891

  20. Application of Texture Analysis to Study Small Vessel Disease and Blood–Brain Barrier Integrity

    Directory of Open Access Journals (Sweden)

    Maria del C. Valdés Hernández

    2017-07-01

    Full Text Available ObjectivesWe evaluate the alternative use of texture analysis for evaluating the role of blood–brain barrier (BBB in small vessel disease (SVD.MethodsWe used brain magnetic resonance imaging from 204 stroke patients, acquired before and 20 min after intravenous gadolinium administration. We segmented tissues, white matter hyperintensities (WMH and applied validated visual scores. We measured textural features in all tissues pre- and post-contrast and used ANCOVA to evaluate the effect of SVD indicators on the pre-/post-contrast change, Kruskal–Wallis for significance between patient groups and linear mixed models for pre-/post-contrast variations in cerebrospinal fluid (CSF with Fazekas scores.ResultsTextural “homogeneity” increase in normal tissues with higher presence of SVD indicators was consistently more overt than in abnormal tissues. Textural “homogeneity” increased with age, basal ganglia perivascular spaces scores (p < 0.01 and SVD scores (p < 0.05 and was significantly higher in hypertensive patients (p < 0.002 and lacunar stroke (p = 0.04. Hypertension (74% patients, WMH load (median = 1.5 ± 1.6% of intracranial volume, and age (mean = 65.6 years, SD = 11.3 predicted the pre/post-contrast change in normal white matter, WMH, and index stroke lesion. CSF signal increased with increasing SVD post-contrast.ConclusionA consistent general pattern of increasing textural “homogeneity” with increasing SVD and post-contrast change in CSF with increasing WMH suggest that texture analysis may be useful for the study of BBB integrity.

  1. Tailoring Particle Size of Mesoporous Silica Nanosystem To Antagonize Glioblastoma and Overcome Blood-Brain Barrier.

    Science.gov (United States)

    Mo, Jianbin; He, Lizhen; Ma, Bin; Chen, Tianfeng

    2016-03-23

    The blood-brain barrier (BBB) is the main bottleneck to prevent some macromolecular substance entering the cerebral circulation, resulting the failure of chemotherapy in the treatment of glioma. Cancer nanotechnology displays potent applications in glioma therapy owing to their penetration across BBB and accumulation into the tumor core. In this study, we have tailored the particle size of mesoporous silica nanoparticles (MSNs) through controlling the hydrolysis rate and polycondensation degree of reactants, and optimized the nanosystem that could effectively penetrate BBB and target the tumor tissue to achieve enhanced antiglioma efficacy. The nanoparticle was conjugated with cRGD peptide to enhance its cancer targeting effect, and then used to load antineoplastic doxorubicin. Therefore, the functionalized nanosystem (DOX@MSNs) selectively recognizes and binds to the U87 cells with higher expression level of ανβ3 integrin, sequentially enhancing the cellular uptake and inhibition to glioma cells, especially the particle size at 40 nm. This particle could rapidly enter cancer cells and was difficult to excrete outside the cells, thus leading to high drug accumulation. Furthermore, DOX@MSNs exhibited much higher selectivity and anticancer activity than free DOX and induced the glioma cells apoptosis through triggering ROS overproduction. Interestingly, DOX@MSNs at about 40 nm exhibited stronger permeability across the BBB, and could disrupt the VM-capability of glioma cells by regulating the expression of E-cadherin, FAK, and MMP-2, thus achieving satisfactory antiglioblastoma efficacy and avoiding the unwanted toxic side effects to normal brain tissue. Taken together, these results suggest that tailoring the particle size of MSNs nanosystem could be an effective strategy to antagonize glioblastoma and overcome BBB.

  2. Persistent Neuroinflammatory Effects of Serial Exposure to Stress and Methamphetamine on the Blood-Brain Barrier

    Science.gov (United States)

    Northrop, Nicole A.

    2013-01-01

    Studies of methamphetamine (Meth)-induced neurotoxicity have traditionally focused on monoaminergic terminal damage while more recent studies have found that stress exacerbates these damaging effects of Meth. Similarities that exist between the mechanisms that cause monoaminergic terminal damage in response to stress and Meth and those capable of producing a disruption of the blood-brain barrier (BBB) suggest that the well-known high comorbidity of stress and Meth could produce long-lasting structural and functional BBB disruption. The current studies examined the role of neuroinflammation in mediating the effects of exposure to chronic stress and/or Meth on BBB structure and function. Rats were pre-exposed to chronic unpredictable stress (CUS) and/or challenged with Meth. Twenty-four hours after the treatment of Meth in rats pre-exposed to CUS, occludin and claudin-5 immunoreactivity were decreased while truncation of β-dystroglycan, as well as FITC-dextran and water extravasation was increased. All changes other than β-dystroglycan and edema persisted 7 days later, occurred with increases in GFAP and COX-2, and were blocked by ketoprofen after Meth treatment. In addition, persistent increases in FITC-dextran extravasation were prevented by treatment with an EP1 receptor antagonist after Meth exposure. The results indicate that CUS and Meth synergize to produce long-lasting structural and functional BBB disruptions that are mediated by cyclooxygenase and protracted increases in inflammation. These results suggest that stress and Meth can synergize to produce a long-lasting vulnerability of the brain to subsequent environmental insults resulting from the persistent breach of the BBB. PMID:22833424

  3. Consequences of repeated blood-brain barrier disruption in football players.

    Directory of Open Access Journals (Sweden)

    Nicola Marchi

    Full Text Available The acknowledgement of risks for traumatic brain injury in American football players has prompted studies for sideline concussion diagnosis and testing for neurological deficits. While concussions are recognized etiological factors for a spectrum of neurological sequelae, the consequences of sub-concussive events are unclear. We tested the hypothesis that blood-brain barrier disruption (BBBD and the accompanying surge of the astrocytic protein S100B in blood may cause an immune response associated with production of auto-antibodies. We also wished to determine whether these events result in disrupted white matter on diffusion tensor imaging (DT scans. Players from three college football teams were enrolled (total of 67 volunteers. None of the players experienced a concussion. Blood samples were collected before and after games (n = 57; the number of head hits in all players was monitored by movie review and post-game interviews. S100B serum levels and auto-antibodies against S100B were measured and correlated by direct and reverse immunoassays (n = 15 players; 5 games. A subset of players underwent DTI scans pre- and post-season and after a 6-month interval (n = 10. Cognitive and functional assessments were also performed. After a game, transient BBB damage measured by serum S100B was detected only in players experiencing the greatest number of sub-concussive head hits. Elevated levels of auto-antibodies against S100B were elevated only after repeated sub-concussive events characterized by BBBD. Serum levels of S100B auto-antibodies also predicted persistence of MRI-DTI abnormalities which in turn correlated with cognitive changes. Even in the absence of concussion, football players may experience repeated BBBD and serum surges of the potential auto-antigen S100B. The correlation of serum S100B, auto-antibodies and DTI changes support a link between repeated BBBD and future risk for cognitive changes.

  4. Passage of amyloid beta protein antibody across the blood-brain barrier in a mouse model of Alzheimer's disease.

    Science.gov (United States)

    Banks, William A; Terrell, Brie; Farr, Susan A; Robinson, Sandra M; Nonaka, Naoko; Morley, John E

    2002-12-01

    Vaccinations against amyloid beta protein (A beta P) reduce amyloid deposition and reverse learning and memory deficits in mouse models of Alzheimer's disease. This has raised the question of whether circulating antibodies, normally restricted by the blood-brain barrier (BBB), can enter the brain [Nat. Med. 7 (2001) 369-372]. Here, we show that antibody directed against A beta P does cross the BBB at a very low rate. Entry is by way of the extracellular pathways with about 0.11% of an intravenous (i.v.) dose entering the brain by 1h. Clearance of antibody from brain increasingly dominates over time, but antibody is still detectable in brain 72 h after i.v. injection. Uptake and clearance is not altered in mice overexpressing A beta P. This ability to enter and exit the brain even in the presence of increased brain ligand supports the use of antibody in the treatment of Alzheimer's and other diseases of the brain.

  5. Acute Lesioning and Rapid Repair of Hypothalamic Neurons outside the Blood-Brain Barrier

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    Ernie Yulyaningsih

    2017-06-01

    Full Text Available Neurons expressing agouti-related protein (AgRP are essential for feeding. The majority of these neurons are located outside the blood-brain barrier (BBB, allowing them to directly sense circulating metabolic factors. Here, we show that, in adult mice, AgRP neurons outside the BBB (AgRPOBBB were rapidly ablated by peripheral administration of monosodium glutamate (MSG, whereas AgRP neurons inside the BBB and most proopiomelanocortin (POMC neurons were spared. MSG treatment induced proliferation of tanycytes, the putative hypothalamic neural progenitor cells, but the newly proliferated tanycytes did not become neurons. Intriguingly, AgRPOBBB neuronal number increased within a week after MSG treatment, and newly emerging AgRP neurons were derived from post-mitotic cells, including some from the Pomc-expressing cell lineage. Our study reveals that the lack of protection by the BBB renders AgRPOBBB vulnerable to lesioning by circulating toxins but that the rapid re-emergence of AgRPOBBB is part of a reparative process to maintain energy balance.

  6. Nanoparticulate Transport of Oximes over an In Vitro Blood-Brain Barrier Model

    Science.gov (United States)

    Wagner, Sylvia; Kufleitner, Jürgen; Zensi, Anja; Dadparvar, Miriam; Wien, Sascha; Bungert, Judith; Vogel, Tikva; Worek, Franz; Kreuter, Jörg; von Briesen, Hagen

    2010-01-01

    Background Due to the use of organophosphates (OP) as pesticides and the availability of OP-type nerve agents, an effective medical treatment for OP poisonings is still a challenging problem. The acute toxicity of an OP poisoning is mainly due to the inhibition of acetylcholinesterase (AChE) in the peripheral and central nervous systems (CNS). This results in an increase in the synaptic concentration of the neurotransmitter acetylcholine, overstimulation of cholinergic receptors and disorder of numerous body functions up to death. The standard treatment of OP poisoning includes a combination of a muscarinic antagonist and an AChE reactivator (oxime). However, these oximes can not cross the blood-brain barrier (BBB) sufficiently. Therefore, new strategies are needed to transport oximes over the BBB. Methodology/Principal Findings In this study, we combined different oximes (obidoxime dichloride and two different HI 6 salts, HI 6 dichloride monohydrate and HI 6 dimethanesulfonate) with human serum albumin nanoparticles and could show an oxime transport over an in vitro BBB model. In general, the nanoparticulate transported oximes achieved a better reactivation of OP-inhibited AChE than free oximes. Conclusions/Significance With these nanoparticles, for the first time, a tool exists that could enable a transport of oximes over the BBB. This is very important for survival after severe OP intoxication. Therefore, these nanoparticulate formulations are promising formulations for the treatment of the peripheral and the CNS after OP poisoning. PMID:21151975

  7. Endoplasmic Reticulum Stress Mediates Methamphetamine-Induced Blood-Brain Barrier Damage.

    Science.gov (United States)

    Qie, Xiaojuan; Wen, Di; Guo, Hongyan; Xu, Guanjie; Liu, Shuai; Shen, Qianchao; Liu, Yi; Zhang, Wenfang; Cong, Bin; Ma, Chunling

    2017-01-01

    Methamphetamine (METH) abuse causes serious health problems worldwide, and long-term use of METH disrupts the blood-brain barrier (BBB). Herein, we explored the potential mechanism of endoplasmic reticulum (ER) stress in METH-induced BBB endothelial cell damage in vitro and the therapeutic potential of endoplasmic reticulum stress inhibitors for METH-induced BBB disruption in C57BL/6J mice. Exposure of immortalized BMVEC (bEnd.3) cells to METH significantly decreased cell viability, induced apoptosis, and diminished the tightness of cell monolayers. METH activated ER stress sensor proteins, including PERK, ATF6, and IRE1, and upregulated the pro-apoptotic protein CHOP. The ER stress inhibitors significantly blocked the upregulation of CHOP. Knockdown of CHOP protected bEnd.3 cells from METH-induced cytotoxicity. Furthermore, METH elevated the production of reactive oxygen species (ROS) and induced the dysfunction of mitochondrial characterized by a Bcl2/Bax ratio decrease, mitochondrial membrane potential collapse, and cytochrome c. ER stress release was partially reversed by ROS inhibition, and cytochrome c release was partially blocked by knockdown of CHOP. Finally, PBA significantly attenuated METH-induced sodium fluorescein (NaFluo) and Evans Blue leakage, as well as tight junction protein loss, in C57BL/6J mice. These data suggest that BBB endothelial cell damage was caused by METH-induced endoplasmic reticulum stress, which further induced mitochondrial dysfunction, and that PBA was an effective treatment for METH-induced BBB disruption.

  8. MMP-Independent Role of TIMP-1 at the Blood Brain Barrier during Viral Encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Carine Savarin

    2013-10-01

    Full Text Available Infection of the CNS (central nervous system with a sublethal neurotropic coronavirus (JHMV induces a vigorous inflammatory response. CD4+ and CD8+ T cells are essential to control infectious virus but at the cost of tissue damage. An enigma in understanding the contribution of T cell subsets in pathogenesis resides in their distinct migration pattern across the BBB (blood brain barrier. CD4+ T cells transiently accumulate within the perivascular space, whereas CD8+ T cells migrate directly into the CNS parenchyma. As MMPs (matrix metalloproteinases facilitate migration across the glia limitans, specific expression of the TIMP (tissue inhibitor of MMPs-1 by CD4+ T cells present in the perivascular cuffs suggested that TIMP-1 is responsible for stalling CD4+ T cell migration into the CNS parenchyma. Using TIMP-1 deficient mice, the present data demonstrate an increase rather than a decrease in CD4+ T cell accumulation within the perivascular space during JHMV infection. Whereas virus control was not affected by perivascular retention of CD4+ T cells, disease severity was decreased and associated with reduced IFN γ (interferon γ production. Moreover, decreased CD4+ T cell recruitment into the CNS parenchyma of TIMP-1 deficient mice was not associated with impaired T cell recruiting chemokines or MMP expression, and no compensation by other TIMP molecules was identified. These data suggest an MMP-independent role of TIMP-1 in regulating CD4+ T cell access into the CNS parenchyma during acute JHMV encephalitis.

  9. Plasma from patients with HELLP syndrome increases blood-brain barrier permeability.

    Science.gov (United States)

    Wallace, Kedra; Tremble, Sarah M; Owens, Michelle Y; Morris, Rachael; Cipolla, Marilyn J

    2015-03-01

    Circulating inflammatory factors and endothelial dysfunction have been proposed to contribute to the pathophysiology of hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome. To date, the occurrence of neurological complications in these women has been reported, but few studies have examined whether impairment in blood-brain barrier (BBB) permeability or cerebrovascular reactivity is present in women having HELLP syndrome. We hypothesized that plasma from women with HELLP syndrome causes increased BBB permeability and cerebrovascular dysfunction. Posterior cerebral arteries from female nonpregnant rats were perfused with 20% serum from women with normal pregnancies (n = 5) or women with HELLP syndrome (n = 5), and BBB permeability and vascular reactivity were compared. Plasma from women with HELLP syndrome increased BBB permeability while not changing myogenic tone and reactivity to pressure. Addition of the nitric oxide (NO) synthase inhibitor N(ω)-nitro-L-arginine methyl ester caused constriction of arteries that was not different with the different plasmas nor was dilation to the NO donor sodium nitroprusside different between the 2 groups. However, dilation to the small- and intermediate-conductance, calcium-activated potassium channel activator NS309 was decreased in vessels exposed to HELLP plasma. Thus, increased BBB permeability in response to HELLP plasma was associated with selective endothelial dysfunction. © The Author(s) 2014.

  10. Interleukin-1β induces blood-brain barrier disruption by downregulating Sonic hedgehog in astrocytes.

    Directory of Open Access Journals (Sweden)

    Yue Wang

    Full Text Available The blood-brain barrier (BBB is composed of capillary endothelial cells, pericytes, and perivascular astrocytes, which regulate central nervous system homeostasis. Sonic hedgehog (SHH released from astrocytes plays an important role in the maintenance of BBB integrity. BBB disruption and microglial activation are common pathological features of various neurologic diseases such as multiple sclerosis, Parkinson's disease, amyotrophic lateral sclerosis, and Alzheimer's disease. Interleukin-1β (IL-1β, a major pro-inflammatory cytokine released from activated microglia, increases BBB permeability. Here we show that IL-1β abolishes the protective effect of astrocytes on BBB integrity by suppressing astrocytic SHH production. Astrocyte conditioned media, SHH, or SHH signal agonist strengthened BBB integrity by upregulating tight junction proteins, whereas SHH signal inhibitor abrogated these effects. Moreover, IL-1β increased astrocytic production of pro-inflammatory chemokines such as CCL2, CCL20, and CXCL2, which induce immune cell migration and exacerbate BBB disruption and neuroinflammation. Our findings suggest that astrocytic SHH is a potential therapeutic target that could be used to restore disrupted BBB in patients with neurologic diseases.

  11. Nanoparticulate transport of oximes over an in vitro blood-brain barrier model.

    Directory of Open Access Journals (Sweden)

    Sylvia Wagner

    Full Text Available BACKGROUND: Due to the use of organophosphates (OP as pesticides and the availability of OP-type nerve agents, an effective medical treatment for OP poisonings is still a challenging problem. The acute toxicity of an OP poisoning is mainly due to the inhibition of acetylcholinesterase (AChE in the peripheral and central nervous systems (CNS. This results in an increase in the synaptic concentration of the neurotransmitter acetylcholine, overstimulation of cholinergic receptors and disorder of numerous body functions up to death. The standard treatment of OP poisoning includes a combination of a muscarinic antagonist and an AChE reactivator (oxime. However, these oximes can not cross the blood-brain barrier (BBB sufficiently. Therefore, new strategies are needed to transport oximes over the BBB. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we combined different oximes (obidoxime dichloride and two different HI 6 salts, HI 6 dichloride monohydrate and HI 6 dimethanesulfonate with human serum albumin nanoparticles and could show an oxime transport over an in vitro BBB model. In general, the nanoparticulate transported oximes achieved a better reactivation of OP-inhibited AChE than free oximes. CONCLUSIONS/SIGNIFICANCE: With these nanoparticles, for the first time, a tool exists that could enable a transport of oximes over the BBB. This is very important for survival after severe OP intoxication. Therefore, these nanoparticulate formulations are promising formulations for the treatment of the peripheral and the CNS after OP poisoning.

  12. Characterization of Different Microbubbles in Assisting Focused Ultrasound-Induced Blood-Brain Barrier Opening

    Science.gov (United States)

    Wu, Sheng-Kai; Chu, Po-Chun; Chai, Wen-Yen; Kang, Shih-Tsung; Tsai, Chih-Hung; Fan, Ching-Hsiang; Yeh, Chih-Kuang; Liu, Hao-Li

    2017-04-01

    Microbubbles (MBs) serve as a critical catalyst to amplify local cavitation in CNS capillary lumen to facilitate focused ultrasound (FUS) to transiently open the blood-brain barrier (BBB). However, limited understanding is available regarding the effect of different microbubbles to induce BBB opening. The aim of this study is to characterize different MBs on their effect in FUS-induced BBB opening. Three MBs, SonoVue, Definity, and USphere, were tested, with 0.4-MHz FUS exposure at 0.62-1.38 of mechanical index (MI) on rats. Evans blue, dynamic contrast-enhanced (DCE) MRI and small-animal ultrasound imaging were used as surrogates to allow molecule-penetrated quantification, BBB-opened observation, and MBs circulation/persistence. Cavitation activity was measured via the passive cavitation detection (PCD) setup to correlate with the exposure level and the histological effect. Under given and identical MB concentrations, the three MBs induced similar and equivalent BBB-opening effects and persistence. In addition, a treatment paradigm by adapting exposure time is proposed to compensate MB decay to retain the persistence of BBB-opening efficiency in multiple FUS exposures. The results potentially improve understanding of the equivalence among MBs in focused ultrasound CNS drug delivery, and provide an effective strategy for securing persistence in this treatment modality.

  13. Opportunities and barriers for successful return to work after acquired brain injury: A patient perspective.

    Science.gov (United States)

    Matérne, Marie; Lundqvist, Lars-Olov; Strandberg, Thomas

    2017-01-01

    Many people who suffer an acquired brain injury (ABI) are of working age. There are benefits, for the patient, the workplace, and society, to finding factors that facilitate successful return to work (RTW). The aim was to increase knowledge of opportunities and barriers for a successful RTW in patients with ABI. Five men and five women with ABI participated. All had successfully returned to work at least 20 hours a week. Their experiences were gathered by semi-structured interviews, which were subsequently subjected to qualitative content analysis. Three themes that influenced RTW were identified: individually adapted rehabilitation; motivation for RTW; and cognitive and social abilities. An individually adapted rehabilitation was judged important because the patients were involved in their own rehabilitation and required individually adapted support from rehabilitation specialists, employers, and colleagues. A moderate level of motivation for RTW was needed. Awareness of the person's cognitive and social abilities is essential, in finding compensatory strategies and adaptations. It seems that the vocational rehabilitation process is a balancing act in individualized planning and support, as a partnership with the employer needs to be developed, motivation needs to be generated, and awareness built of abilities that facilitate or hinder RTW.

  14. Endoplasmic Reticulum Stress Mediates Methamphetamine-Induced Blood–Brain Barrier Damage

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    Xiaojuan Qie

    2017-09-01

    Full Text Available Methamphetamine (METH abuse causes serious health problems worldwide, and long-term use of METH disrupts the blood–brain barrier (BBB. Herein, we explored the potential mechanism of endoplasmic reticulum (ER stress in METH-induced BBB endothelial cell damage in vitro and the therapeutic potential of endoplasmic reticulum stress inhibitors for METH-induced BBB disruption in C57BL/6J mice. Exposure of immortalized BMVEC (bEnd.3 cells to METH significantly decreased cell viability, induced apoptosis, and diminished the tightness of cell monolayers. METH activated ER stress sensor proteins, including PERK, ATF6, and IRE1, and upregulated the pro-apoptotic protein CHOP. The ER stress inhibitors significantly blocked the upregulation of CHOP. Knockdown of CHOP protected bEnd.3 cells from METH-induced cytotoxicity. Furthermore, METH elevated the production of reactive oxygen species (ROS and induced the dysfunction of mitochondrial characterized by a Bcl2/Bax ratio decrease, mitochondrial membrane potential collapse, and cytochrome c. ER stress release was partially reversed by ROS inhibition, and cytochrome c release was partially blocked by knockdown of CHOP. Finally, PBA significantly attenuated METH-induced sodium fluorescein (NaFluo and Evans Blue leakage, as well as tight junction protein loss, in C57BL/6J mice. These data suggest that BBB endothelial cell damage was caused by METH-induced endoplasmic reticulum stress, which further induced mitochondrial dysfunction, and that PBA was an effective treatment for METH-induced BBB disruption.

  15. Molecular biology of the blood-brain and the blood-cerebrospinal fluid barriers: similarities and differences

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    Redzic Zoran

    2011-01-01

    Full Text Available Abstract Efficient processing of information by the central nervous system (CNS represents an important evolutionary advantage. Thus, homeostatic mechanisms have developed that provide appropriate circumstances for neuronal signaling, including a highly controlled and stable microenvironment. To provide such a milieu for neurons, extracellular fluids of the CNS are separated from the changeable environment of blood at three major interfaces: at the brain capillaries by the blood-brain barrier (BBB, which is localized at the level of the endothelial cells and separates brain interstitial fluid (ISF from blood; at the epithelial layer of four choroid plexuses, the blood-cerebrospinal fluid (CSF barrier (BCSFB, which separates CSF from the CP ISF, and at the arachnoid barrier. The two barriers that represent the largest interface between blood and brain extracellular fluids, the BBB and the BCSFB, prevent the free paracellular diffusion of polar molecules by complex morphological features, including tight junctions (TJs that interconnect the endothelial and epithelial cells, respectively. The first part of this review focuses on the molecular biology of TJs and adherens junctions in the brain capillary endothelial cells and in the CP epithelial cells. However, normal function of the CNS depends on a constant supply of essential molecules, like glucose and amino acids from the blood, exchange of electrolytes between brain extracellular fluids and blood, as well as on efficient removal of metabolic waste products and excess neurotransmitters from the brain ISF. Therefore, a number of specific transport proteins are expressed in brain capillary endothelial cells and CP epithelial cells that provide transport of nutrients and ions into the CNS and removal of waste products and ions from the CSF. The second part of this review concentrates on the molecular biology of various solute carrier (SLC transport proteins at those two barriers and underlines

  16. Acute Effects of Viral Exposure on P-Glycoprotein Function in the Mouse Fetal Blood-Brain Barrier

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    Enrrico Bloise

    2017-02-01

    Full Text Available Background/Aims: Viral infection during pregnancy is known to affect the fetal brain. The toll-like receptor (TLR-3 is a pattern recognition receptor activated by viruses known to elicit adverse fetal neurological outcomes. The P-glycoprotein (P-gp efflux transporter protects the developing fetus by limiting the transfer of substrates across both the placenta and the fetal blood-brain barrier (BBB. As such, inhibition of P-gp at these blood-barrier sites may result in increased exposure of the developing fetus to environmental toxins and xenobiotics present in the maternal circulation. We hypothesized that viral exposure during pregnancy would impair P-gp function in the placenta and in the developing BBB. Here we investigated whether the TLR-3 ligand, polyinosinic:polycytidylic acid (PolyI:C, increased accumulation of one P-gp substrate in the fetus and in the developing fetal brain. Methods: Pregnant C57BL/6 mice (GD15.5 were injected (i.p. with PolyI:C (5 mg/kg or 10 mg/kg or vehicle (saline. [3H]digoxin (P-gp substrate was injected (i.v. 3 or 23h post-treatment and animals were euthanized 1h later. Maternal plasma, ‘fetal-units’ (fetal membranes, amniotic fluid and whole fetus, and fetal brains were collected. Results: PolyI:C exposure (4h significantly elevated maternal plasma IL-6 (P<0.001 and increased [3H]digoxin accumulation in the fetal brain (P<0.05. In contrast, 24h after PolyI:C exposure, no effect on IL-6 or fetal brain accumulation of P-gp substrate was observed. Conclusion: Viral infection modeled by PolyI:C causes acute increases in fetal brain accumulation of P-gp substrates and by doing so, may increase fetal brain exposure to xenobiotics and environmental toxins present in the maternal circulation.

  17. The role of the cell surface LRP and soluble LRP in blood-brain barrier Abeta clearance in Alzheimer's disease.

    Science.gov (United States)

    Deane, R; Sagare, A; Zlokovic, B V

    2008-01-01

    Low-density lipoprotein receptor related protein-1 (LRP) is a member of the low-density lipoprotein (LDL) receptor family which has been linked to Alzheimer's disease (AD) by biochemical and genetic evidence. Levels of neurotoxic amyloid beta-peptide (Abeta) in the brain are elevated in AD contributing to the disease process and neuropathology. Faulty Abeta clearance from the brain appears to mediate focal Abeta accumulations in AD. Central and peripheral production of Abeta from Abeta-precursor protein (APP), transport of peripheral Abeta into the brain across the blood-brain barrier (BBB) via receptor for advanced glycation end products (RAGE), enzymatic Abeta degradation, Abeta oligomerization and aggregation, neuroinflammatory changes and microglia activation, and Abeta elimination from brain across the BBB by cell surface LRP; all may control brain Abeta levels. Recently, we have shown that a soluble form of LRP (sLRP) binds 70 to 90 % of plasma Abeta, preventing its access to the brain. In AD individuals, the levels of LRP at the BBB are reduced, as are levels of Abeta binding to sLRP in plasma. This, in turn, may increase Abeta brain levels through a decreased efflux of brain Abeta at the BBB and/or reduced sequestration of plasma Abeta associated with re-entry of free Abeta into the brain via RAGE. Thus, therapies which increase LRP expression at the BBB and/or enhance the peripheral Abeta "sink" activity of sLRP, hold potential to control brain Abeta accumulations, neuroinflammation and cerebral blood flow reductions in AD.

  18. The effect of regadenoson-induced transient disruption of the blood-brain barrier on temozolomide delivery to normal rat brain.

    Science.gov (United States)

    Jackson, Sadhana; Anders, Nicole M; Mangraviti, Antonella; Wanjiku, Teresia M; Sankey, Eric W; Liu, Ann; Brem, Henry; Tyler, Betty; Rudek, Michelle A; Grossman, Stuart A

    2016-02-01

    The blood-brain barrier (BBB) significantly reduces the delivery of many systemically administered agents to the central nervous system. Although temozolomide is the only chemotherapy to improve survival in patients with glioblastoma, its concentration in brain is only 20 % of that in blood. Regadenoson, an FDA approved adenosine receptor agonist used for cardiac stress testing, transiently disrupts rodent BBB allowing high molecular weight dextran (70 kD) to enter the brain. This study was conducted to determine if regadenoson could facilitate entry of temozolomide into normal rodent brain. Temozolomide (50 mg/kg) was administered by oral gavage to non-tumor bearing F344 rats. Two-thirds of the animals received a single dose of intravenous regadenoson 60-90 min later. All animals were sacrificed 120 or 360 min after temozolomide administration. Brain and plasma temozolomide concentrations were determined using HPLC/MS/MS. Brain temozolomide concentrations were significantly higher at 120 min when it was given with regadenoson versus alone (8.1 ± 2.7 and 5.1 ± 3.5 µg/g, P regadenoson. These results suggest co-administration of regadenoson with temozolomide results in 60% higher temozolomide levels in normal brain without affecting plasma concentrations. This novel approach to increasing intracranial concentrations of systemically administered agents has potential to improve the efficacy of chemotherapy in neuro-oncologic disorders.

  19. The effect of regadenoson-induced transient disruption of the blood–brain barrier on temozolomide delivery to normal rat brain

    Science.gov (United States)

    Jackson, Sadhana; Anders, Nicole M.; Mangraviti, Antonella; Wanjiku, Teresia M.; Sankey, Eric W.; Liu, Ann; Brem, Henry; Tyler, Betty; Rudek, Michelle A.

    2016-01-01

    The blood–brain barrier (BBB) significantly reduces the delivery of many systemically administered agents to the central nervous system. Although temozolomide is the only chemotherapy to improve survival in patients with glioblastoma, its concentration in brain is only 20 % of that in blood. Regadenoson, an FDA approved adenosine receptor agonist used for cardiac stress testing, transiently disrupts rodent BBB allowing high molecular weight dextran (70 kD) to enter the brain. This study was conducted to determine if regadenoson could facilitate entry of temozolomide into normal rodent brain. Temozolomide (50 mg/kg) was administered by oral gavage to non-tumor bearing F344 rats. Two-thirds of the animals received a single dose of intravenous regadenoson 60–90 min later. All animals were sacrificed 120 or 360 min after temozolomide administration. Brain and plasma temozolomide concentrations were determined using HPLC/MS/MS. Brain temozolomide concentrations were significantly higher at 120 min when it was given with regadenoson versus alone (8.1 ± 2.7 and 5.1 ± 3.5 μg/g, P regadenoson. These results suggest co-administration of regadenoson with temozolomide results in 60 % higher temozolomide levels in normal brain without affecting plasma concentrations. This novel approach to increasing intracranial concentrations of systemically administered agents has potential to improve the efficacy of chemotherapy in neuro-oncologic disorders. PMID:26626489

  20. Enhanced therapeutic agent delivery through magnetic resonance imaging-monitored focused ultrasound blood-brain barrier disruption for brain tumor treatment: an overview of the current preclinical status.

    Science.gov (United States)

    Liu, Hao-Li; Yang, Hung-Wei; Hua, Mu-Yi; Wei, Kuo-Chen

    2012-01-01

    Malignant glioma is a severe primary CNS cancer with a high recurrence and mortality rate. The current strategy of surgical debulking combined with radiation therapy or chemotherapy does not provide good prognosis, tumor progression control, or improved patient survival. The blood-brain barrier (BBB) acts as a major obstacle to chemotherapeutic treatment of brain tumors by severely restricting drug delivery into the brain. Because of their high toxicity, chemotherapeutic drugs cannot be administered at sufficient concentrations by conventional delivery methods to significantly improve long-term survival of patients with brain tumors. Temporal disruption of the BBB by microbubble-enhanced focused ultrasound (FUS) exposure can increase CNS-blood permeability, providing a promising new direction to increase the concentration of therapeutic agents in the brain tumor and improve disease control. Under the guidance and monitoring of MR imaging, a brain drug-delivery platform can be developed to control and monitor therapeutic agent distribution and kinetics. The success of FUS BBB disruption in delivering a variety of therapeutic molecules into brain tumors has recently been demonstrated in an animal model. In this paper the authors review a number of critical studies that have demonstrated successful outcomes, including enhancement of the delivery of traditional clinically used chemotherapeutic agents or application of novel nanocarrier designs for actively transporting drugs or extending drug half-lives to significantly improve treatment efficacy in preclinical animal models.

  1. Azo dyes and the blood-brain barrier: Robert Aird's novel concept in chronic neurological disease (1903-2000).

    Science.gov (United States)

    Bladin, Peter F

    2014-01-01

    The well-established medical involvement of derivatives of the azo dye industry lent credibility to the 1935 announcement by Stanley Cobb of the use of vital brilliant red dye as an anticonvulsant. Although in the fullness of time clinical experience would discard this concept, nevertheless it was to give rise to Robert Aird who posited that the mechanism of action of this dye was due to its ability to decrease the permeability of the blood-brain barrier. In a very prolonged exploration of this concept, Aird concluded that blood-brain barrier permeability underlay the causation of a long list of chronic neurological conditions--a concept that was eventually abandoned. This article examines the details and the effects of this concept and its impact upon neurology. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Transferrin-conjugated, fluorescein-loaded magnetic nanoparticles for targeted delivery across the blood-brain barrier.

    Science.gov (United States)

    Yan, Feng; Wang, Ying; He, Shenzhi; Ku, Shuting; Gu, Wei; Ye, Ling

    2013-10-01

    The blood-brain barrier (BBB) restricts the delivery of many potentially important therapeutic agents for the treatment of brain disorders. An efficient strategy for brain targeted delivery is the utilization of the targeting ligand conjugated nanoparticles to trigger the receptor-mediated transcytosis. In this study, transferrin (Tf) was employed as a brain targeting ligand to functionalize the fluorescein-loaded magnetic nanoparticles (FMNs). The Tf conjugated FMNs (Tf-FMNs) were characterized by transmission electron microscopy, thermal gravimetric analysis, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Using fluorescein as an optical probe, the potential of Tf-FMNs as brain targeting drug carriers was explored in vivo. It was demonstrated that Tf-FMNs were able to cross the intact BBB, diffuse into brain neurons, and distribute in the cytoplasm, dendrites, axons, and synapses of neurons. In contrast, magnetic nanoparticles without Tf conjugation cannot cross the BBB efficiently under the same conditions. Therefore, Tf-FMNs hold great potential in serving as an efficient multifunctional platform for the brain-targeted theranostics.

  3. In vivo assessment of the permeability of the blood-brain barrier and blood-retinal barrier to fluorescent indoline derivatives in zebrafish

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    Watanabe Kohei

    2012-08-01

    Full Text Available Abstract Background Successful delivery of compounds to the brain and retina is a challenge in the development of therapeutic drugs and imaging agents. This challenge arises because internalization of compounds into the brain and retina is restricted by the blood–brain barrier (BBB and blood-retinal barrier (BRB, respectively. Simple and reliable in vivo assays are necessary to identify compounds that can easily cross the BBB and BRB. Methods We developed six fluorescent indoline derivatives (IDs and examined their ability to cross the BBB and BRB in zebrafish by in vivo fluorescence imaging. These fluorescent IDs were administered to live zebrafish by immersing the zebrafish larvae at 7-8 days post fertilization in medium containing the ID, or by intracardiac injection. We also examined the effect of multidrug resistance proteins (MRPs on the permeability of the BBB and BRB to the ID using MK571, a selective inhibitor of MRPs. Results The permeability of these barriers to fluorescent IDs administered by simple immersion was comparable to when administered by intracardiac injection. Thus, this finding supports the validity of drug administration by simple immersion for the assessment of BBB and BRB permeability to fluorescent IDs. Using this zebrafish model, we demonstrated that the length of the methylene chain in these fluorescent IDs significantly affected their ability to cross the BBB and BRB via MRPs. Conclusions We demonstrated that in vivo assessment of the permeability of the BBB and BRB to fluorescent IDs could be simply and reliably performed using zebrafish. The structure of fluorescent IDs can be flexibly modified and, thus, the permeability of the BBB and BRB to a large number of IDs can be assessed using this zebrafish-based assay. The large amount of data acquired might be useful for in silico analysis to elucidate the precise mechanisms underlying the interactions between chemical structure and the efflux transporters at the

  4. Activation of RARα, RARγ, or RXRα Increases Barrier Tightness in Human Induced Pluripotent Stem Cell-Derived Brain Endothelial Cells.

    Science.gov (United States)

    Stebbins, Matthew J; Lippmann, Ethan S; Faubion, Madeline G; Daneman, Richard; Palecek, Sean P; Shusta, Eric V

    2017-09-28

    The blood-brain barrier (BBB) is critical to central nervous system (CNS) health. Brain microvascular endothelial cells (BMECs) are often used as in vitro BBB models for studying BBB dysfunction and therapeutic screening applications. Human pluripotent stem cells (hPSCs) can be differentiated to cells having key BMEC barrier and transporter properties, offering a renewable, scalable source of human BMECs. hPSC-derived BMECs have previously been shown to respond to all-trans retinoic acid (RA), and the goal of this study was to identify the stages at which differentiating human induced pluripotent stem cells (iPSCs) respond to activation of RA receptors (RARs) to impart BBB phenotypes. Here the authors identified that RA application to iPSC-derived BMECs at days 6-8 of differentiation led to a substantial elevation in transendothelial electrical resistance and induction of VE-cadherin expression. Specific RAR agonists identified RARα, RARγ, and RXRα as receptors capable of inducing barrier phenotypes. Moreover, RAR/RXRα costimulation elevated VE-cadherin expression and improved barrier fidelity to levels that recapitulated the effects of RA. This study elucidates the roles of RA signaling in iPSC-derived BMEC differentiation, and identifies directed agonist approaches that can improve BMEC fidelity for drug screening studies while also distinguishing potential nuclear receptor targets to explore in BBB dysfunction and therapy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Endomorphin-1 analogues (MELs) penetrate the blood-brain barrier and exhibit good analgesic effects with minimal side effects.

    Science.gov (United States)

    Wang, Yuan; Liu, Xin; Wang, Dan; Yang, Junxian; Zhao, Long; Yu, Jing; Wang, Rui

    2015-10-01

    Endomorphins are endogenous opioid peptides in mammals and display a strong antinociceptive effect after central administration. However, the clinical usage of these peptides is limited because of their diminished analgesic effect following systemic injection and their inability to cross the blood-brain barrier. In this study, we characterized the in vivo effects of four novel endomorphin-1 analogues (termed MELs), which previously showed potential as highly potent analgesics with a good pharmacological profile in vitro. The analogues were administered intravenously to several rodent pain models to examine their antinociception and blood-brain barrier permeability. The tested peptides, especially MEL1214, showed good analgesic activity and blood-brain barrier permeability. Behavioral studies showed dose-dependent analgesic effect after systematic administration of MEL1214 in the tested pain models. Pre-treatment of subcutaneous administration of naloxone methiodide did not affect the antinociception of these peptides. As compared to morphine, MEL1214 was less prone to induce tolerance after consecutive intravenous administration for 5 days. Gastrointestinal transit was evaluated by the isolated colon response and bead expulsion to determine the potential constipation effect. In contrast to morphine, MEL1214 produced no significant constipation effect at an equivalent dose. MEL1214 shows promise as a suitable compound to treat pain with reduced side effects, and exhibits good potential to be further developed as a novel opioid analgesic in pain treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. A Novel Algorithm for the Assessment of Blood-Brain Barrier Permeability Suggests That Brain Topical Application of Endothelin-1 Does Not Cause Early Opening of the Barrier in Rats

    Directory of Open Access Journals (Sweden)

    D. Jorks

    2011-01-01

    Full Text Available There are a number of different experimental methods for ex vivo assessment of blood-brain barrier (BBB opening based on Evans blue dye extravasation. However, these methods require many different steps to prepare the brain and need special equipment for quantification. We here report a novel, simple, and fast semiquantitative algorithm to assess BBB integrity ex vivo. The method is particularly suitable for cranial window experiments, since it keeps the spatial information about where the BBB opened. We validated the algorithm using sham controls and the established model of brain topical application of the bile salt dehydrocholate for early BBB disruption. We then studied spreading depolarizations in the presence and the absence of the vasoconstrictor endothelin-1 and found no evidence of early BBB opening (three-hour time window. The algorithm can be used, for example, to assess BBB permeability ex vivo in combination with dynamic in vivo studies of BBB opening.

  7. Not Just the Brain: Methamphetamine Disrupts Blood-Spinal Cord Barrier and Induces Acute Glial Activation and Structural Damage of Spinal Cord Cells

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    Eugene A Kiyatkin; Sharma, Hari S.

    2015-01-01

    Acute methamphetamine (METH) intoxication induces metabolic brain activation as well as multiple physiological and behavioral responses that could result in life-threatening health complications. Previously, we showed that METH (9 mg/kg) used in freely moving rats induces robust leakage of blood-brain barrier (BBB), acute glial activation, vasogenic edema, and structural abnormalities of brain cells. These changes tightly correlated with drug-induced brain hyperthermia and were greatly potent...

  8. The role of shear stress in Blood-Brain Barrier endothelial physiology

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    Puvenna Vikram

    2011-05-01

    Full Text Available Abstract Background One of the most important and often neglected physiological stimuli contributing to the differentiation of vascular endothelial cells (ECs into a blood-brain barrier (BBB phenotype is shear stress (SS. With the use of a well established humanized dynamic in vitro BBB model and cDNA microarrays, we have profiled the effect of SS in the induction/suppression of ECs genes and related functions. Results Specifically, we found a significant upregulation of tight and adherens junctions proteins and genes. Trans-endothelial electrical resistance (TEER and permeability measurements to know substances have shown that SS promoted the formation of a tight and highly selective BBB. SS also increased the RNA level of multidrug resistance transporters, ion channels, and several p450 enzymes. The RNA level of a number of specialized carrier-mediated transport systems (e.g., glucose, monocarboxylic acid, etc. was also upregulated. RNA levels of modulatory enzymes of the glycolytic pathway (e.g., lactate dehydrogenase were downregulated by SS while those involved in the Krebs cycle (e.g., lactate and other dehydrogenases were upregulated. Measurements of glucose consumption versus lactate production showed that SS negatively modulated the glycolytic bioenergetic pathways of glucose metabolism in favor of the more efficient aerobic respiration. BBB ECs are responsive to inflammatory stimuli. Our data showed that SS increased the RNA levels of integrins and vascular adhesion molecules. SS also inhibited endothelial cell cycle via regulation of BTG family proteins encoding genes. This was paralleled by significant increase in the cytoskeletal protein content while that of membrane, cytosol, and nuclear sub-cellular fractions decreased. Furthermore, analysis of 2D gel electrophoresis (which allows identifying a large number of proteins per sample of EC proteins extracted from membrane sub-cellular endothelial fractions showed that SS increased

  9. Experimental Cerebral Malaria Pathogenesis—Hemodynamics at the Blood Brain Barrier

    Science.gov (United States)

    Nacer, Adéla; Movila, Alexandru; Sohet, Fabien; Girgis, Natasha M.; Gundra, Uma Mahesh; Loke, P'ng; Daneman, Richard; Frevert, Ute

    2014-01-01

    Cerebral malaria claims the lives of over 600,000 African children every year. To better understand the pathogenesis of this devastating disease, we compared the cellular dynamics in the cortical microvasculature between two infection models, Plasmodium berghei ANKA (PbA) infected CBA/CaJ mice, which develop experimental cerebral malaria (ECM), and P. yoelii 17XL (PyXL) infected mice, which succumb to malarial hyperparasitemia without neurological impairment. Using a combination of intravital imaging and flow cytometry, we show that significantly more CD8+ T cells, neutrophils, and macrophages are recruited to postcapillary venules during ECM compared to hyperparasitemia. ECM correlated with ICAM-1 upregulation on macrophages, while vascular endothelia upregulated ICAM-1 during ECM and hyperparasitemia. The arrest of large numbers of leukocytes in postcapillary and larger venules caused microrheological alterations that significantly restricted the venous blood flow. Treatment with FTY720, which inhibits vascular leakage, neurological signs, and death from ECM, prevented the recruitment of a subpopulation of CD45hi CD8+ T cells, ICAM-1+ macrophages, and neutrophils to postcapillary venules. FTY720 had no effect on the ECM-associated expression of the pattern recognition receptor CD14 in postcapillary venules suggesting that endothelial activation is insufficient to cause vascular pathology. Expression of the endothelial tight junction proteins claudin-5, occludin, and ZO-1 in the cerebral cortex and cerebellum of PbA-infected mice with ECM was unaltered compared to FTY720-treated PbA-infected mice or PyXL-infected mice with hyperparasitemia. Thus, blood brain barrier opening does not involve endothelial injury and is likely reversible, consistent with the rapid recovery of many patients with CM. We conclude that the ECM-associated recruitment of large numbers of activated leukocytes, in particular CD8+ T cells and ICAM+ macrophages, causes a severe restriction in

  10. Expression and deposition of basement membrane proteins by brain capillary endothelial cells in a primary murine model of the blood-brain barrier

    DEFF Research Database (Denmark)

    Thomsen, Maj Schneider; Birkelund, Svend; Larsen, Annette Burkhart

    2016-01-01

    The blood-brain barrier (BBB) represents the interface between the blood and the brain parenchyma and consists of endothelial cells which are tightly sealed together by tight junction proteins. The endothelial cells are in addition supported by pericytes, which are embedded in the vascular basement...... membrane, and astrocyte endfeet. To study the interaction of the different cells of the BBB, construction of in vitro BBB models is valuable. However, the modulation and contribution of the cells of the BBB to the synthesis of basement membrane proteins in vitro is not fully elaborated. Thus, the aim...... of the present study was to create four different in vitro constructs of the murine BBB to characterise if the expression and secretion of basement membrane proteins by the murine brain capillary endothelial cells (mBCECs) was affected by co-culturing with pericytes, mixed glial cells, or both. Primary m...

  11. Anesthesia and Surgery Impair Blood–Brain Barrier and Cognitive Function in Mice

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    Siming Yang

    2017-08-01

    Full Text Available Blood–brain barrier (BBB dysfunction, e.g., increase in BBB permeability, has been reported to contribute to cognitive impairment. However, the effects of anesthesia and surgery on BBB permeability, the underlying mechanisms, and associated cognitive function remain largely to be determined. Here, we assessed the effects of surgery (laparotomy under 1.4% isoflurane anesthesia (anesthesia/surgery for 2 h on BBB permeability, levels of junction proteins and cognitive function in both 9- and 18-month-old wild-type mice and 9-month-old interleukin (IL-6 knockout mice. BBB permeability was determined by dextran tracer (immunohistochemistry imaging and spectrophotometric quantification, and protein levels were measured by Western blot and cognitive function was assessed by using both Morris water maze and Barnes maze. We found that the anesthesia/surgery increased mouse BBB permeability to 10-kDa dextran, but not to 70-kDa dextran, in an IL-6-dependent and age-associated manner. In addition, the anesthesia/surgery induced an age-associated increase in blood IL-6 level. Cognitive impairment was detected in 18-month-old, but not 9-month-old, mice after the anesthesia/surgery. Finally, the anesthesia/surgery decreased the levels of β-catenin and tight junction protein claudin, occludin and ZO-1, but not adherent junction protein VE-cadherin, E-cadherin, and p120-catenin. These data demonstrate that we have established a system to study the effects of perioperative factors, including anesthesia and surgery, on BBB and cognitive function. The results suggest that the anesthesia/surgery might induce an age-associated BBB dysfunction and cognitive impairment in mice. These findings would promote mechanistic studies of postoperative cognitive impairment, including postoperative delirium.

  12. Microbubble gas volume: A unifying dose parameter in blood-brain barrier opening by focused ultrasound.

    Science.gov (United States)

    Song, Kang-Ho; Fan, Alexander C; Hinkle, Joshua J; Newman, Joshua; Borden, Mark A; Harvey, Brandon K

    2017-01-01

    Focused ultrasound with microbubbles is being developed to transiently, locally and noninvasively open the blood-brain barrier (BBB) for improved pharmaceutical delivery. Prior work has demonstrated that, for a given concentration dose, microbubble size affects both the intravascular circulation persistence and extent of BBB opening. When matched to gas volume dose, however, the circulation half-life was found to be independent of microbubble size. In order to determine whether this holds true for BBB opening as well, we independently measured the effects of microbubble size (2 vs. 6 µm diameter) and concentration, covering a range of overlapping gas volume doses (1-40 µL/kg). We first demonstrated precise targeting and a linear dose-response of Evans Blue dye extravasation to the rat striatum for a set of constant microbubble and ultrasound parameters. We found that dye extravasation increased linearly with gas volume dose, with data points from both microbubble sizes collapsing to a single line. A linear trend was observed for both the initial sonication (R2=0.90) and a second sonication on the contralateral side (R2=0.68). Based on these results, we conclude that microbubble gas volume dose, not size, determines the extent of BBB opening by focused ultrasound (1 MHz, ~0.5 MPa at the focus). This result may simplify planning for focused ultrasound treatments by constraining the protocol to a single microbubble parameter - gas volume dose - which gives equivalent results for varying size distributions. Finally, using optimal parameters determined for Evan Blue, we demonstrated gene delivery and expression using a viral vector, dsAAV1-CMV-EGFP, one week after BBB disruption, which allowed us to qualitatively evaluate neuronal health.

  13. Anesthesia and Surgery Impair Blood–Brain Barrier and Cognitive Function in Mice

    Science.gov (United States)

    Yang, Siming; Gu, Changping; Mandeville, Emiri T.; Dong, Yuanlin; Esposito, Elga; Zhang, Yiying; Yang, Guang; Shen, Yuan; Fu, Xiaobing; Lo, Eng H.; Xie, Zhongcong

    2017-01-01

    Blood–brain barrier (BBB) dysfunction, e.g., increase in BBB permeability, has been reported to contribute to cognitive impairment. However, the effects of anesthesia and surgery on BBB permeability, the underlying mechanisms, and associated cognitive function remain largely to be determined. Here, we assessed the effects of surgery (laparotomy) under 1.4% isoflurane anesthesia (anesthesia/surgery) for 2 h on BBB permeability, levels of junction proteins and cognitive function in both 9- and 18-month-old wild-type mice and 9-month-old interleukin (IL)-6 knockout mice. BBB permeability was determined by dextran tracer (immunohistochemistry imaging and spectrophotometric quantification), and protein levels were measured by Western blot and cognitive function was assessed by using both Morris water maze and Barnes maze. We found that the anesthesia/surgery increased mouse BBB permeability to 10-kDa dextran, but not to 70-kDa dextran, in an IL-6-dependent and age-associated manner. In addition, the anesthesia/surgery induced an age-associated increase in blood IL-6 level. Cognitive impairment was detected in 18-month-old, but not 9-month-old, mice after the anesthesia/surgery. Finally, the anesthesia/surgery decreased the levels of β-catenin and tight junction protein claudin, occludin and ZO-1, but not adherent junction protein VE-cadherin, E-cadherin, and p120-catenin. These data demonstrate that we have established a system to study the effects of perioperative factors, including anesthesia and surgery, on BBB and cognitive function. The results suggest that the anesthesia/surgery might induce an age-associated BBB dysfunction and cognitive impairment in mice. These findings would promote mechanistic studies of postoperative cognitive impairment, including postoperative delirium. PMID:28848542

  14. Adrenaline increases blood-brain-barrier permeability after haemorrhagic cardiac arrest in immature pigs.

    Science.gov (United States)

    Semenas, E; Sharma, H S; Wiklund, L

    2014-05-01

    Adrenaline (ADR) and vasopressin (VAS) are used as vasopressors during cardiopulmonary resuscitation. Data regarding their effects on blood-brain barrier (BBB) integrity and neuronal damage are lacking. We hypothesised that VAS given during cardiopulmonary resuscitation (CPR) after haemorrhagic circulatory arrest will preserve BBB integrity better than ADR. Twenty-one anaesthetised sexually immature male piglets (with a weight of 24.3 ± 1.3 kg) were bled 35% via femoral artery to a mean arterial blood pressure of 25 mmHg in the period of 15 min. Afterwards, the piglets were subjected to 8 min of untreated ventricular fibrillation followed by 15 min of open-chest CPR. At 9 min of circulatory arrest, piglets received amiodarone 1.0 mg/kg and hypertonic-hyperoncotic solution 4 ml/kg infusions for 20 min. At the same time, VAS 0.4 U/kg was given intravenously to the VAS group (n = 9) while the ADR group received ADR 20 μg/kg (n = 12). Internal defibrillation was attempted from 11 min of cardiac arrest to achieve restoration of spontaneous circulation. The experiment was terminated 3 h after resuscitation. The intracranial pressure (ICP) in the post-resuscitation phase was significantly greater in ADR group than in VAS group. VAS group piglets exhibited a significantly smaller BBB disruption compared with ADR group. Cerebral pressure reactivity index showed that cerebral blood flow autoregulation was also better preserved in VAS group. Resuscitation with ADR as compared with VAS after haemorrhagic circulatory arrest increased the ICP and impaired cerebrovascular autoregulation more profoundly, as well as exerted an increased BBB disruption though no significant difference in neuronal injury was observed. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  15. Transcranial direct current stimulation transiently increases the blood-brain barrier solute permeability in vivo

    Science.gov (United States)

    Shin, Da Wi; Khadka, Niranjan; Fan, Jie; Bikson, Marom; Fu, Bingmei M.

    2016-03-01

    Transcranial Direct Current Stimulation (tDCS) is a non-invasive electrical stimulation technique investigated for a broad range of medical and performance indications. Whereas prior studies have focused exclusively on direct neuron polarization, our hypothesis is that tDCS directly modulates endothelial cells leading to transient changes in blood-brain-barrier (BBB) permeability (P) that are highly meaningful for neuronal activity. For this, we developed state-of-the-art imaging and animal models to quantify P to various sized solutes after tDCS treatment. tDCS was administered using a constant current stimulator to deliver a 1mA current to the right frontal cortex of rat (approximately 2 mm posterior to bregma and 2 mm right to sagittal suture) to obtain similar physiological outcome as that in the human tDCS application studies. Sodium fluorescein (MW=376), or FITC-dextrans (20K and 70K), in 1% BSA mammalian Ringer was injected into the rat (SD, 250-300g) cerebral circulation via the ipsilateral carotid artery by a syringe pump at a constant rate of ~3 ml/min. To determine P, multiphoton microscopy with 800-850 nm wavelength laser was applied to take the images from the region of interest (ROI) with proper microvessels, which are 100-200 micron below the pia mater. It shows that the relative increase in P is about 8-fold for small solute, sodium fluorescein, ~35-fold for both intermediate sized (Dex-20k) and large (Dex-70k) solutes, 10 min after 20 min tDCS pretreatment. All of the increased permeability returns to the control after 20 min post treatment. The results confirmed our hypothesis.

  16. Increase in blood-brain barrier permeability, oxidative stress, and activated microglia in a rat model of blast-induced traumatic brain injury.

    Science.gov (United States)

    Readnower, Ryan D; Chavko, Mikulas; Adeeb, Saleena; Conroy, Michael D; Pauly, James R; McCarron, Richard M; Sullivan, Patrick G

    2010-12-01

    Traumatic brain injury (TBI) as a consequence of exposure to blast is increasingly prevalent in military populations, with the underlying pathophysiological mechanisms mostly unknown. In the present study, we utilized an air-driven shock tube to investigate the effects of blast exposure (120 kPa) on rat brains. Immediately following exposure to blast, neurological function was reduced. BBB permeability was measured using IgG antibody and evaluating its immunoreactivity in the brain. At 3 and 24 hr postexposure, there was a transient significant increase in IgG staining in the cortex. At 3 days postexposure, IgG immunoreactivity returned to control levels. Quantitative immunostaining was employed to determine the temporal course of brain oxidative stress following exposure to blast. Levels of 4-hydroxynonenal (4-HNE) and 3-nitrotyrosine (3-NT) were significantly increased at 3 hr postexposure and returned to control levels at 24 hr postexposure. The response of microglia to blast exposure was determined by autoradiographic localization of (3) H-PK11195 binding. At 5 days postexposure, increased binding was observed in the contralateral and ipsilateral dentate gyrus. These regions also displayed increased binding at 10 days postexposure; in addition to these regions there was increased binding in the contralateral ventral hippocampus and substantia nigra at this time point. By using antibodies against CD11b/c, microglia morphology characteristic of activated microglia was observed in the hippocampus and substantia nigra of animals exposed to blast. These results indicate that BBB breakdown, oxidative stress, and microglia activation likely play a role in the neuropathology associated with TBI as a result of blast exposure. Copyright © 2010 Wiley-Liss, Inc.

  17. Money is Brain: Financial Barriers and Consequences for Canadian Stroke Patients.

    Science.gov (United States)

    Ganesh, Aravind; King-Shier, Kathryn; Manns, Braden J; Hill, Michael D; Campbell, David J T

    2017-03-01

    Stroke patients of lower socioeconomic status have worse outcomes. It remains poorly understood whether this is due to illness severity or personal or health system barriers. We explored the experiences of stroke patients with financial barriers in a qualitative descriptive pilot study, seeking to capture perceived challenges that interfere with their poststroke health and recovery. We interviewed six adults with a history of stroke and financial barriers in Alberta, Canada, inquiring about their: (1) experiences after stroke; (2) experience of financial barriers; (3) perceived reasons for financial barriers; (4) health consequences of financial barriers; and (5) mechanisms for coping with financial barriers. Two reviewers analyzed data using inductive thematic analysis. The participants developed new or worsened financial circumstances as a consequence of stroke-related disability. Poststroke impairments and financial barriers took a toll on their mental health. They struggled to access several aspects of long-term poststroke care, including allied health professional services, medications, and proper nutrition. They described opportunity costs and tradeoffs when accessing health services. In several cases, they were unaware of health resources available to them and were hesitant to disclose their struggles to their physicians and even their families. Some patients with financial barriers perceive challenges to accessing various aspects of poststroke care. They may have inadequate knowledge of resources available to them and may not disclose their concerns to their health care team. This suggests that providers themselves might consider asking stroke patients about financial barriers to optimize their long-term poststroke care.

  18. Structure-internalization relationship for adsorptive-mediated endocytosis of basic peptides at the blood-brain barrier.

    Science.gov (United States)

    Tamai, I; Sai, Y; Kobayashi, H; Kamata, M; Wakamiya, T; Tsuji, A

    1997-01-01

    For the purpose of the brain delivery of peptides, the structural specificity of adsorptive-mediated endocytosis at the blood-brain barrier was studied by measuring transport of a newly synthesized basic peptide 001-C8, H-MeTyr-Arg-MeArg-D-Leu-NH(CH2)aNH2, using primary cultured bovine brain capillary endothelial cells. The apparent uptake of [125I]001-C8 increased time-dependently and reached a steady-state at 60 min. The steady-state uptake of [125I]001-C8 was temperature and concentration dependent and was significantly decreased in the presence of dansylcadaverine, protamine or poly-L-lysine. Uptakes of peptides modified by 1,8-octanediamine, 1,5-pentanediamine, 1,2-ethanediamine or ethylamide and peptides with a free carboxyl terminal were significantly higher than, and similar to, that of [3H]PEG900, respectively. The half-saturation constants and the maximal uptake capacities of these peptides were in the ranges of 0.2 to 134 microM and 1.1 to 408 pmol/mg protein, respectively. These values were correlated with the basicity of the molecules. In conclusion, not the number of constituent amino acids of peptides, but rather the C-terminal structure and the basicity of the molecules are the most important determinants for the uptake by the adsorptive-mediated endocytosis system at the blood brain barrier.

  19. Induction of the Antimicrobial Peptide CRAMP in the Blood-Brain Barrier and Meninges after Meningococcal Infection▿

    Science.gov (United States)

    Bergman, Peter; Johansson, Linda; Wan, Hong; Jones, Allison; Gallo, Richard L.; Gudmundsson, Gudmundur H.; Hökfelt, Tomas; Jonsson, Ann-Beth; Agerberth, Birgitta

    2006-01-01

    Antimicrobial peptides are present in most living species and constitute important effector molecules of innate immunity. Recently, we and others have detected antimicrobial peptides in the brain. This is an organ that is rarely infected, which has mainly been ascribed to the protective functions of the blood-brain barrier (BBB) and meninges. Since the bactericidal properties of the BBB and meninges are not known, we hypothesized that antimicrobial peptides could play a role in these barriers. We addressed this hypothesis by infecting mice with the neuropathogenic bacterium Neisseria meningitidis. Brains were analyzed for expression of the antimicrobial peptide CRAMP by immunohistochemistry in combination with confocal microscopy. After infection, we observed induction of CRAMP in endothelial cells of the BBB and in cells of the meninges. To explore the functional role of CRAMP in meningococcal disease, we infected mice deficient of the CRAMP gene. Even though CRAMP did not appear to protect the brain from invasion of meningococci, CRAMP knockout mice were more susceptible to meningococcal infection than wild-type mice and exhibited increased meningococcal growth in blood, liver, and spleen. Moreover, we could demonstrate that carbonate, a compound that accumulates in the circulation during metabolic acidosis, makes meningococci more susceptible to CRAMP. PMID:17030578

  20. Neurovascular unit dysfunction with blood-brain barrier hyperpermeability contributes to major depressive disorder: a review of clinical and experimental evidence

    National Research Council Canada - National Science Library

    Najjar, Souhel; Pearlman, Daniel M; Devinsky, Orrin; Najjar, Amanda; Zagzag, David

    2013-01-01

    ... monoaminergic dysregulation that can contribute to the genesis and persistence of MDD. Oxidative stress and neuroinflammation are mechanistically linked to the presence of neurovascular dysfunction with blood-brain barrier (BBB...

  1. An isogenic blood-brain barrier model comprising brain endothelial cells, astrocytes, and neurons derived from human induced pluripotent stem cells.

    Science.gov (United States)

    Canfield, Scott G; Stebbins, Matthew J; Morales, Bethsymarie Soto; Asai, Shusaku W; Vatine, Gad D; Svendsen, Clive N; Palecek, Sean P; Shusta, Eric V

    2017-03-01

    The blood-brain barrier (BBB) is critical in maintaining a physical and metabolic barrier between the blood and the brain. The BBB consists of brain microvascular endothelial cells (BMECs) that line the brain vasculature and combine with astrocytes, neurons and pericytes to form the neurovascular unit. We hypothesized that astrocytes and neurons generated from human-induced pluripotent stem cells (iPSCs) could induce BBB phenotypes in iPSC-derived BMECs, creating a robust multicellular human BBB model. To this end, iPSCs were used to form neural progenitor-like EZ-spheres, which were in turn differentiated to neurons and astrocytes, enabling facile neural cell generation. The iPSC-derived astrocytes and neurons induced barrier tightening in primary rat BMECs indicating their BBB inductive capacity. When co-cultured with human iPSC-derived BMECs, the iPSC-derived neurons and astrocytes significantly elevated trans-endothelial electrical resistance, reduced passive permeability, and improved tight junction continuity in the BMEC cell population, while p-glycoprotein efflux transporter activity was unchanged. A physiologically relevant neural cell mixture of one neuron: three astrocytes yielded optimal BMEC induction properties. Finally, an isogenic multicellular BBB model was successfully demonstrated employing BMECs, astrocytes, and neurons from the same donor iPSC source. It is anticipated that such an isogenic facsimile of the human BBB could have applications in furthering understanding the cellular interplay of the neurovascular unit in both healthy and diseased humans. Read the Editorial Highlight for this article on page 843. © 2016 International Society for Neurochemistry.

  2. N-docosahexaenoyl, 3 hydroxytyramine: a dopaminergic compound that penetrates the blood-brain barrier and suppresses appetite.

    Science.gov (United States)

    Shashoua, V E; Hesse, G W

    1996-01-01

    Fatty acids with varying chain lengths (2-22 carbon atoms long) and degrees of unsaturation (0-6 double bonds) were used to synthesize dopaminergic compounds for a study of the carrier mediated transport of dopamine (DA) to the brain. The most active carrier was the all cis C22:6 fatty acid [docosahexaenoic acid, (DHA)]which increased DA uptake through the blood-brain barrier by greater than 7.5 fold. The DHA-DA compound, NMI 8739, depressed the general locomotor activity of mice in a dose dependent manner. It also suppressed the appetite of Balb c mice and Charles River rats by 50% and 95% respectively at a dose of 10 mg/kg. Daily administration of NMI-8739 for a three week period did not induce tolerance. These results demonstrate DHA's potential for the carrier mediated transport of small molecules to the brain.

  3. Nanoparticle- and liposome-carried drugs: new strategies for active targeting and drug delivery across blood-brain barrier.

    Science.gov (United States)

    Pinzón-Daza, Martha Leonor; Campia, Ivana; Kopecka, Joanna; Garzón, Ruth; Ghigo, Dario; Riganti, Chiara

    2013-07-01

    The blood-brain barrier (BBB), the unusual microvascular endothelial interface between the central nervous system (CNS) and the circulatory system, is a major hindrance to drug delivery in the brain parenchyma. Besides the absence of fenestrations and the abundance of tight junctions, ATP-binding cassette (ABC) transporters critically reduce drug entry within the CNS, as they carry many drugs back into the bloodstream. Nanoparticle- and liposome-carried drugs, because of their increased cellular uptake and reduced efflux through ABC transporters, have been developed in recent times to circumvent the low drug permeability of the BBB. This review discusses the role of ABC transporters in controlling drug penetration into the brain parenchyma, the rationale for using nanoparticle- and liposome-based strategies to increase drug delivery across the BBB and new therapeutic strategies for using nanoparticle- and liposome-carried drugs in different conditions, ranging from CNS tumors and neurodegenerative diseases to viral infections and epilepsy.

  4. Mannitol-Enhanced Delivery of Stem Cells and Their Growth Factors Across the Blood–Brain Barrier

    Science.gov (United States)

    Gonzales-Portillo, Gabriel S.; Sanberg, Paul R.; Franzblau, Max; Gonzales-Portillo, Chiara; Diamandis, Theo; Staples, Meaghan; Sanberg, Cyndy D.; Borlongan, Cesar V.

    2014-01-01

    Ischemic brain injury in adults and neonates is a significant clinical problem with limited therapeutic interventions. Currently, clinicians have only tPA available for stroke treatment and hypothermia for cerebral palsy. Owing to the lack of treatment options, there is a need for novel treatments such as stem cell therapy. Various stem cells including cells from embryo, fetus, perinatal, and adult tissues have proved effective in preclinical and small clinical trials. However, a limiting factor in the success of these treatments is the delivery of the cells and their by-products (neurotrophic factors) into the injured brain. We have demonstrated that mannitol, a drug with the potential to transiently open the blood–brain barrier and facilitate the entry of stem cells and trophic factors, as a solution to the delivery problem. The combination of stem cell therapy and mannitol may improve therapeutic outcomes in adult stroke and neonatal cerebral palsy. PMID:24480552

  5. Delivery of a peptide-drug conjugate targeting the blood brain barrier improved the efficacy of paclitaxel against glioma.

    Science.gov (United States)

    Li, Ying; Zheng, Xuemin; Gong, Min; Zhang, Jianning

    2016-11-29

    The challenge of effectively delivering therapeutic agents to the brain has created an entire field of active research devoted to overcoming the blood brain barrier (BBB) and efficiently delivering drugs to the brain. Angiopep-2 can trigger transcytosis and traverse the BBB by recognizing low-density lipoprotein related protein-1 (LRP-1) expressed on the brain capillary endothelial cells. Here, we designed a novel strategy for the delivery of drugs to the brain. The novel drug delivery system was a combination of a receptor-targeting ligand, such as low-density lipoprotein related protein 1, and a cell-penetrating peptide (CPP). It was hypothesized that this conjugate will enhance the delivery of associated therapeutic cargo across the BBB and increase the permeability of a solid tumor. Our findings indicate that the combination of these two agents in a delivery vehicle significantly improved translocation of small molecules (paclitaxel) into the brain compared to the vehicle treatment, which contained only receptor-targeting ligand. The application of this strategy could potentially expand the horizons for the treatment of central nervous system disorders.

  6. A mathematical approach for assessing the transport of large neutral amino acids across the blood-brain barrier in man.

    Science.gov (United States)

    Dahl, Rasmus Holmboe; Berg, Ronan M G

    2015-01-01

    Changes in the large neutral amino acid (LNAA) transport across the blood-brain barrier (BBB) is thought to contribute to brain dysfunction in a number of clinical conditions, including phenylketonuria, acute liver failure, and sepsis. Here, we present a novel approach for estimating BBB permeability and the LNAA concentrations in brain extracellular fluid, by demonstrating that they can be mathematically derived on the basis of kinetic constants of the BBB available from the literature, if cerebral blood flow and the arterial and jugular venous LNAA concentrations are known. While it is well known that the permeability surface area product of the BBB to a LNAA from blood to brain (PS1) can be calculated from the arterial LNAA concentrations and kinetic constants of the BBB, we demonstrate that the permeability surface area product from brain to blood (PS2) can be calculated by deriving the substrate activity of the saturable transporter from the kinetic constants and arterial and jugular venous LNAA concentrations, and that the concentration of the LNAA in brain extracellular fluid can then be determined. This approach is methodically simple, and may be useful for assessing the transcerebral exchange kinetics of LNAAs in future human-experimental and clinical studies.

  7. Focused ultrasound-induced blood-brain barrier opening to enhance temozolomide delivery for glioblastoma treatment: a preclinical study.

    Directory of Open Access Journals (Sweden)

    Kuo-Chen Wei

    Full Text Available The purpose of this study is to assess the preclinical therapeutic efficacy of magnetic resonance imaging (MRI-monitored focused ultrasound (FUS-induced blood-brain barrier (BBB disruption to enhance Temozolomide (TMZ delivery for improving Glioblastoma Multiforme (GBM treatment. MRI-monitored FUS with microbubbles was used to transcranially disrupt the BBB in brains of Fisher rats implanted with 9L glioma cells. FUS-BBB opening was spectrophotometrically determined by leakage of dyes into the brain, and TMZ was quantitated in cerebrospinal fluid (CSF and plasma by LC-MS\\MS. The effects of treatment on tumor progression (by MRI, animal survival and brain tissue histology were investigated. Results demonstrated that FUS-BBB opening increased the local accumulation of dyes in brain parenchyma by 3.8-/2.1-fold in normal/tumor tissues. Compared to TMZ alone, combined FUS treatment increased the TMZ CSF/plasma ratio from 22.7% to 38.6%, reduced the 7-day tumor progression ratio from 24.03 to 5.06, and extended the median survival from 20 to 23 days. In conclusion, this study provided preclinical evidence that FUS BBB-opening increased the local concentration of TMZ to improve the control of tumor progression and animal survival, suggesting its clinical potential for improving current brain tumor treatment.

  8. Uptake and metabolism of sulphated steroids by the blood-brain barrier in the adult male rat.

    Science.gov (United States)

    Qaiser, M Zeeshan; Dolman, Diana E M; Begley, David J; Abbott, N Joan; Cazacu-Davidescu, Mihaela; Corol, Delia I; Fry, Jonathan P

    2017-09-01

    Little is known about the origin of the neuroactive steroids dehydroepiandrosterone sulphate (DHEAS) and pregnenolone sulphate (PregS) in the brain or of their subsequent metabolism. Using rat brain perfusion in situ, we have found (3) H-PregS to enter more rapidly than (3) H-DHEAS and both to undergo extensive (> 50%) desulphation within 0.5 min of uptake. Enzyme activity for the steroid sulphatase catalysing this deconjugation was enriched in the capillary fraction of the blood-brain barrier and its mRNA expressed in cultures of rat brain endothelial cells and astrocytes. Although permeability measurements suggested a net efflux, addition of the efflux inhibitors GF120918 and/or MK571 to the perfusate reduced rather than enhanced the uptake of (3) H-DHEAS and (3) H-PregS; a further reduction was seen upon the addition of unlabelled steroid sulphate, suggesting a saturable uptake transporter. Analysis of brain fractions after 0.5 min perfusion with the (3) H-steroid sulphates showed no further metabolism of PregS beyond the liberation of free steroid pregnenolone. By contrast, DHEAS underwent 17-hydroxylation to form androstenediol in both the steroid sulphate and the free steroid fractions, with some additional formation of androstenedione in the latter. Our results indicate a gain of free steroid from circulating steroid sulphates as hormone precursors at the blood-brain barrier, with implications for ageing, neurogenesis, neuronal survival, learning and memory. © 2017 International Society for Neurochemistry.

  9. Lipopolysaccharide impairs amyloid beta efflux from brain: altered vascular sequestration, cerebrospinal fluid reabsorption, peripheral clearance and transporter function at the blood–brain barrier

    Directory of Open Access Journals (Sweden)

    Erickson Michelle A

    2012-06-01

    Full Text Available Abstract Background Defects in the low density lipoprotein receptor-related protein-1 (LRP-1 and p-glycoprotein (Pgp clearance of amyloid beta (Aβ from brain are thought to contribute to Alzheimer’s disease (AD. We have recently shown that induction of systemic inflammation by lipopolysaccharide (LPS results in impaired efflux of Aβ from the brain. The same treatment also impairs Pgp function. Here, our aim is to determine which physiological routes of Aβ clearance are affected following systemic inflammation, including those relying on LRP-1 and Pgp function at the blood–brain barrier. Methods CD-1 mice aged between 6 and 8 weeks were treated with 3 intraperitoneal injections of 3 mg/kg LPS at 0, 6, and 24 hours and studied at 28 hours. 125I-Aβ1-42 or 125I-alpha-2-macroglobulin injected into the lateral ventricle of the brain (intracerebroventricular (ICV or into the jugular vein (intravenous (IV was used to quantify LRP-1-dependent partitioning between the brain vasculature and parenchyma and peripheral clearance, respectively. Disappearance of ICV-injected 14 C-inulin from brain was measured to quantify bulk flow of cerebrospinal fluid (CSF. Brain microvascular protein expression of LRP-1 and Pgp was measured by immunoblotting. Endothelial cell localization of LRP-1 was measured by immunofluorescence microscopy. Oxidative modifications to LRP-1 at the brain microvasculature were measured by immunoprecipitation of LRP-1 followed by immunoblotting for 4-hydroxynonenal and 3-nitrotyrosine. Results We found that LPS: caused an LRP-1-dependent redistribution of ICV-injected Aβ from brain parenchyma to brain vasculature and decreased entry into blood; impaired peripheral clearance of IV-injected Aβ; inhibited reabsorption of CSF; did not significantly alter brain microvascular protein levels of LRP-1 or Pgp, or oxidative modifications to LRP-1; and downregulated LRP-1 protein levels and caused LRP-1 mislocalization in cultured brain

  10. Lipopolysaccharide impairs amyloid β efflux from brain: altered vascular sequestration, cerebrospinal fluid reabsorption, peripheral clearance and transporter function at the blood-brain barrier.

    Science.gov (United States)

    Erickson, Michelle A; Hartvigson, Pehr E; Morofuji, Yoichi; Owen, Joshua B; Butterfield, D Allan; Banks, William A

    2012-06-29

    Defects in the low density lipoprotein receptor-related protein-1 (LRP-1) and p-glycoprotein (Pgp) clearance of amyloid beta (Aβ) from brain are thought to contribute to Alzheimer's disease (AD). We have recently shown that induction of systemic inflammation by lipopolysaccharide (LPS) results in impaired efflux of Aβ from the brain. The same treatment also impairs Pgp function. Here, our aim is to determine which physiological routes of Aβ clearance are affected following systemic inflammation, including those relying on LRP-1 and Pgp function at the blood-brain barrier. CD-1 mice aged between 6 and 8 weeks were treated with 3 intraperitoneal injections of 3 mg/kg LPS at 0, 6, and 24 hours and studied at 28 hours. 125I-Aβ1-42 or 125I-alpha-2-macroglobulin injected into the lateral ventricle of the brain (intracerebroventricular (ICV)) or into the jugular vein (intravenous (IV)) was used to quantify LRP-1-dependent partitioning between the brain vasculature and parenchyma and peripheral clearance, respectively. Disappearance of ICV-injected 14 C-inulin from brain was measured to quantify bulk flow of cerebrospinal fluid (CSF). Brain microvascular protein expression of LRP-1 and Pgp was measured by immunoblotting. Endothelial cell localization of LRP-1 was measured by immunofluorescence microscopy. Oxidative modifications to LRP-1 at the brain microvasculature were measured by immunoprecipitation of LRP-1 followed by immunoblotting for 4-hydroxynonenal and 3-nitrotyrosine. We found that LPS: caused an LRP-1-dependent redistribution of ICV-injected Aβ from brain parenchyma to brain vasculature and decreased entry into blood; impaired peripheral clearance of IV-injected Aβ; inhibited reabsorption of CSF; did not significantly alter brain microvascular protein levels of LRP-1 or Pgp, or oxidative modifications to LRP-1; and downregulated LRP-1 protein levels and caused LRP-1 mislocalization in cultured brain endothelial cells. These results suggest that LRP-1

  11. Interaction mechanisms of encapsulated meningococci with eucaryotic cells: what does this tell us about the crossing of the blood-brain barrier by Neisseria meningitidis?

    Science.gov (United States)

    Nassif, X

    1999-02-01

    An important feature of Neisseria meningitidis is its ability to invade the meninges. This requires that bacteria cross the blood-brain barrier (BBB), which is one of the tightest barriers of the body. N. meningitidis has, therefore, evolved very sophisticated means by which it circumvents the physical properties of this cellular barrier. Recent advances have allowed the identification of several steps that might occur in the interaction of N. meningitidis with the BBB and the transit of the bacteria to the meninges.

  12. Transfection of rat brain endothelium in a primary culture model of the blood-brain barrier at different states of barrier maturity

    DEFF Research Database (Denmark)

    Larsen, Annette Burkhart; Thomsen, Louiza Bohn; Lichota, Jacek

    approaches have been developed. Gene therapy could be a promising and novel approach to overcome the restricting properties of the BBB to polypeptides and proteins. Gene therapy is based on the delivery of genetic material into brain capillary endothelial cells (BCECs), which, theoretically, will result...... in expression and secretion of the recombinant protein from the BCECs and into the brain, thus turning BCECs into small recombinant protein factories. In this study, the possibility of using BCECs as small factories for recombinant protein production was investigated. To mimic the in-vivo situation as closely...... transfection is positively correlated with cell division, with dividing cells being more sensitive to gene transfection. Therefore, by using this model, the transfection efficiency of the rat endothelium was investigated in an immature state and mature state of the BBB. During the transfection period...

  13. In silico predictive model to determine vector-mediated transport properties for the blood–brain barrier choline transporter

    Directory of Open Access Journals (Sweden)

    Shityakov S

    2014-09-01

    Full Text Available Sergey Shityakov, Carola Förster Department of Anaesthesia and Critical Care, University of Würzburg, Würzburg, Germany Abstract: The blood–brain barrier choline transporter (BBB-ChT may have utility as a drug delivery vector to the central nervous system (CNS. We therefore initiated molecular docking studies with the AutoDock and AutoDock Vina (ADVina algorithms to develop predictive models for compound screening and to identify structural features important for binding to this transporter. The binding energy predictions were highly correlated with r2=0.88, F=692.4, standard error of estimate =0.775, and P-value<0.0001 for selected BBB-ChT-active/inactive compounds (n=93. Both programs were able to cluster active (Gibbs free energy of binding <−6.0 kcal*mol-1 and inactive (Gibbs free energy of binding >−6.0 kcal*mol-1 molecules and dock them significantly better than at random with an area under the curve value of 0.86 and 0.84, respectively. In ranking smaller molecules with few torsional bonds, a size-related bias in scoring producing false-negative outcomes was detected. Finally, important blood–brain barrier parameters, such as the logBBpassive and logBBactive values, were assessed to predict compound transport to the CNS accurately. Knowledge gained from this study is useful to better understand the binding requirements in BBB-ChT, and until such time as its crystal structure becomes available, it may have significant utility in developing a highly predictive model for the rational design of drug-like compounds targeted to the brain. Keywords: blood–brain barrier choline transporter, central nervous system, drug delivery vector, molecular docking, virtual screening, Gibbs free energy of binding, diffusion

  14. Human Brain Microvascular Endothelial Cells Derived from the BC1 iPS Cell Line Exhibit a Blood-Brain Barrier Phenotype.

    Science.gov (United States)

    Katt, Moriah E; Xu, Zinnia S; Gerecht, Sharon; Searson, Peter C

    2016-01-01

    The endothelial cells that form capillaries in the brain are highly specialized, with tight junctions that minimize paracellular transport and an array of broad-spectrum efflux pumps that make drug delivery to the brain extremely challenging. One of the major limitations in blood-brain barrier research and the development of drugs to treat central nervous system diseases is the lack of appropriate cell lines. Recent reports indicate that the derivation of human brain microvascular endothelial cells (hBMECs) from human induced pluripotent stem cells (iPSCs) may provide a solution to this problem. Here we demonstrate the derivation of hBMECs extended to two new human iPSC lines: BC1 and GFP-labeled BC1. These hBMECs highly express adherens and tight junction proteins VE-cadherin, ZO-1, occludin, and claudin-5. The addition of retinoic acid upregulates VE-cadherin expression, and results in a significant increase in transendothelial electrical resistance to physiological values. The permeabilities of tacrine, rhodamine 123, and Lucifer yellow are similar to values obtained for MDCK cells. The efflux ratio for rhodamine 123 across hBMECs is in the range 2-4 indicating polarization of efflux transporters. Using the rod assay to assess cell organization in small vessels and capillaries, we show that hBMECs resist elongation with decreasing diameter but show progressive axial alignment. The derivation of hBMECs with a blood-brain barrier phenotype from the BC1 cell line highlights that the protocol is robust. The expression of GFP in hBMECs derived from the BC1-GFP cell line provides an important new resource for BBB research.

  15. YiQiFuMai powder injection ameliorates blood–brain barrier dysfunction and brain edema after focal cerebral ischemia–reperfusion injury in mice

    Directory of Open Access Journals (Sweden)

    Cao GS

    2016-01-01

    Full Text Available Guosheng Cao, Xinyi Ye, Yingqiong Xu, Mingzhu Yin, Honglin Chen, Junping Kou, Boyang Yu Jiangsu Key Laboratory of TCM Evaluation and Translational Research, Department of Complex Prescription of TCM, China Pharmaceutical University, Nanjing, People’s Republic of China Abstract: YiQiFuMai powder injection (YQFM is a modern preparation derived from the traditional Chinese medicine Sheng-Mai-San. YQFM is widely used in clinical practice in the People’s Republic of China, mainly for the treatment of microcirculatory disturbance-related diseases. However, little is known about its role in animals with ischemic stroke. The aim of this study was to examine the effect of YQFM on brain edema and blood–brain barrier (BBB dysfunction induced by cerebral ischemia–reperfusion (I/R injury. Male C57BL/6J mice underwent right middle cerebral artery occlusion for 1 hour with a subsequent 24-hour reperfusion to produce I/R injury. YQFM (three doses: 0.336, 0.671, and 1.342 g/kg was then given intraperitoneally (IP. The results demonstrated that YQFM significantly decreased infarct size, improved neurological deficits, reduced brain water content, and increased cerebral blood flow after I/R injury. 18F-fluorodeoxyglucose micro-positron emission tomography imaging and hematoxylin and eosin staining results indicated that YQFM is able to ameliorate brain metabolism and histopathological damage after I/R. Moreover, YQFM administration reduced BBB leakage and upregulated the expression of zona occludens-1 (ZO-1 and occludin, which was confirmed by Evans Blue extravasation, Western blotting, and immunofluorescence assay. Our findings suggest that YQFM provides protection against focal cerebral I/R injury in mice, possibly by improving BBB dysfunction via upregulation of the expression of tight junction proteins. Keywords: YiQiFuMai powder injection, YQFM, ischemic stroke, blood–brain barrier, microvascular permeability, tight junctions

  16. MicroRNA-210 Suppresses Junction Proteins and Disrupts Blood-Brain Barrier Integrity in Neonatal Rat Hypoxic-Ischemic Brain Injury.

    Science.gov (United States)

    Ma, Qingyi; Dasgupta, Chiranjib; Li, Yong; Huang, Lei; Zhang, Lubo

    2017-06-24

    Cerebral edema, primarily caused by disruption of the blood-brain barrier (BBB), is one of the serious complications associated with brain injury in neonatal hypoxic-ischemic encephalopathy (HIE). Our recent study demonstrated that the hypoxic-ischemic (HI) treatment significantly increased microRNA-210 (miR-210) in the neonatal rat brain and inhibition of miR-210 provided neuroprotection in neonatal HI brain injury. The present study aims to determine the role of miR-210 in the regulation of BBB integrity in the developing brain. miR-210 mimic was administered via intracerebroventricular injection (i.c.v.) into the brain of rat pups. Forty-eight hours after the injection, a modified Rice-Vannucci model was conducted to produce HI brain injury. Post-assays included cerebral edema analysis, western blotting, and immunofluorescence staining for serum immunoglobulin G (IgG) leakage. The results showed that miR-210 mimic exacerbated cerebral edema and IgG leakage into the brain parenchyma. In contrast, inhibition of miR-210 with its complementary locked nucleic acid oligonucleotides (miR-210-LNA) significantly reduced cerebral edema and IgG leakage. These findings suggest that miR-210 negatively regulates BBB integrity i n the neonatal brain. Mechanistically, the seed sequences of miR-210 were identified complementary to the 3' untranslated region (3' UTR) of the mRNA transcripts of tight junction protein occludin and adherens junction protein β-catenin, indicating downstream targets of miR-210. This was further validated by in vivo data showing that miR-210 mimic significantly reduced the expression of these junction proteins in rat pup brains. Of importance, miR-210-LNA preserved the expression of junction proteins occludin and β-catenin from neonatal HI insult. Altogether, the present study reveals a novel mechanism of miR-210 in impairing BBB integrity that contributes to cerebral edema formation after neonatal HI insult, and provides new insights in miR-210-LNA

  17. Transport of Poly(n-butylcyano-acrylate) nanoparticles across the blood-brain barrier in vitro and their influence on barrier integrity.

    Science.gov (United States)

    Rempe, Ralf; Cramer, Sandra; Hüwel, Sabine; Galla, Hans-Joachim

    2011-03-04

    In previous studies it was shown that polysorbate 80(PS80)-coated poly(n-butylcyano-acrylate) nanoparticles (PBCA-NP) are able to cross the blood-brain barrier (BBB) in vitro and in vivo. In order to explore and extend the potential applications of PBCA-NP as drug carriers, it is important to ascertain their effect on the BBB. The objective of the present study was to determine the effect of PS80-coated PBCA-NP on the BBB integrity of a porcine in vitro model. This has been investigated by monitoring the development of the transendothelial electrical resistance (TEER) after the addition of PBCA-NP employing impedance spectroscopy. Additionally, the integrity of the BBB in vitro was verified by measuring the passage of the reference substances (14)C-sucrose and FITC-BSA after addition of PBCA-NP. In this study we will show that the application of PS80-coated PBCA-NP leads to a reversible disruption of the barrier after 4h. The observed disruption of the barrier could also be confirmed by (14)C-sucrose and FITC-BSA permeability studies. Comparing the TEER and permeability studies the lowest resistances and maximal values for permeabilities were both observed after 4h. These results indicate that PS80-coated PBCA-NP might be suitable for the use as drug carriers. The reversible disruption also offers the possibility to use these particles as specific opener of the BBB. Instead of incorporating the therapeutic agents into the NP, the drugs may cross the BBB after being applied simultaneously with the PBCA-NP. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Transient blood-brain barrier permeability following profound temporary global ischemia: an experimental study using /sup 14/C-AIB

    Energy Technology Data Exchange (ETDEWEB)

    Dobbin, J.; Crockard, H.A.; Ross-Russell, R.

    1989-02-01

    The influence of reperfusion after profound incomplete forebrain ischemia on blood-brain barrier (BBB) permeability to a small protein tracer was studied in male Sprague-Dawley rats. The mean cortical blood to brain transfer constant (Ki) for /sup 14/C-amino isobutyric acid (AIB) was significantly greater at 3 and 6 h of reperfusion, 2.5 times the mean values of controls (p less than 0.05) (2.5 microliter g-1 min-1 and 1.0 microliters g-1 min-1 respectively), but had returned to control values after reperfusion for 24 h. Analysis of distribution of Ki values showed that following 15 min and 30 min of profound ischemia, there was a significant increase in transfer of AIB across the blood-brain barrier (BBB) after recirculation for up to 6 h, though there was no evidence of protein extravasation as assessed by Evans Blue (EB) dye. After 24 h of reperfusion, the BBB to AIB was restored, and Ki values had returned to control values. It is concluded that following transient global ischemia, the BBB may recover rapidly.

  19. Potential of biopartitioning micellar chromatography as an in vitro technique for predicting drug penetration across the blood-brain barrier.

    Science.gov (United States)

    Escuder-Gilabert, L; Molero-Monfort, M; Villanueva-Camañas, R M; Sagrado, S; Medina-Hernández, M J

    2004-08-05

    The blood-brain barrier (BBB) is considered to be the main barrier to drug transport into the central nervous system (CNS). The BBB restricts the passive diffusion of many drugs from blood to brain. The ease with which any particular drug diffuses across the BBB is determined largely by the molecular features of drugs, and it is therefore possible to predict the BBB permeability of a drug from its molecular structure. Biopartitioning micellar chromatography (BMC), a mode of micellar liquid chromatography that uses micellar mobile phases of Brij35 in adequate experimental conditions, can be useful in mimicking the drug partitioning process into biological systems. Retention in BMC depends on the hydrophobicity, electronic and steric properties of drugs. In this paper, the usefulness of BMC for predicting the BBB penetration ability of drugs expressed as the brain/blood distribution coefficient (BB) is demonstrated. A multiple linear regression (MLR) model that relates the BB distribution coefficients data with BMC retention data and total molar charge is proposed. The model is obtained using 44 heterogeneous drugs including, neutral, anionic, and cationic compounds. A comparison with other reported methodologies to predict the BBB permeability is also presented.

  20. PET studies on P-glycoprotein function in the blood-brain barrier : How it affects uptake and binding of drugs within the CNS

    NARCIS (Netherlands)

    Elsinga, PH; Hendrikse, Nelis; Bart, J; Vaalburg, W; van Waarde, A

    2004-01-01

    Permeability of the blood-brain barrier (BBB) is one of the factors determining the bioavailability of therapeutic drugs. The BBB only allows entry of lipophilic compounds with low molecular weights by passive diffusion. However, many lipophilic drugs show negligible brain uptake. They are

  1. Surface Characteristics of Nanoparticles Determine Their Intracellular Fate in and Processing by Human Blood-Brain Barrier Endothelial Cells In Vitro

    NARCIS (Netherlands)

    Georgieva, Julia V.; Kalicharan, Dharamdajal; Couraud, Pierre-Olivier; Romero, Ignacio A.; Weksler, Babette; Hoekstra, Dick; Zuhorn, Inge S.

    A polarized layer of endothelial cells that comprises the blood-brain barrier (BBB) precludes access of systemically administered medicines to brain tissue. Consequently, there is a need for drug delivery vehicles that mediate transendothelial transport of such medicines. Endothelial cells use a

  2. Generation of a High Resistance in vitro Blood-Brain-Barrier Model and Investigations of Brain-to-Blood Glutamate Efflux

    DEFF Research Database (Denmark)

    Helms, Hans Christian

    Blod-hjernebarrieren (blood-brain barrier, BBB) opretholder den generelle homeostase i hjernens væsker. BBB kan også spille en rolle i homeostasen for den eksitatoriske aminosyre, L-glutamat. In vitro modeller kan være effektive værktøjer til at få mekanistiske informationer om transcellulær...... transport. De fleste in vitro modeller mangler dog funktionelle tight junctions. Dette projekt indeholder to underprojekter med målene; etabler og karakteriser en BBB model bestående af endothelceller fra kalvehjerner dyrket i co-kultur med rotte astrocytter og undersøg, hvordan tight junction...

  3. Multimodal investigations of trans-endothelial cell trafficking under condition of disrupted blood-brain barrier integrity

    Directory of Open Access Journals (Sweden)

    Masaryk Thomas

    2010-03-01

    Full Text Available Abstract Background Stem cells or immune cells targeting the central nervous system (CNS bear significant promises for patients affected by CNS disorders. Brain or spinal cord delivery of therapeutic cells is limited by the blood-brain barrier (BBB which remains one of the recognized rate-limiting steps. Osmotic BBB disruption (BBBD has been shown to improve small molecule chemotherapy for brain tumors, but successful delivery of cells in conjunction with BBBD has never been reported. We have used a clinically relevant model (pig of BBBD to attempt brain delivery of TALL-104, a human leukemic T cell line. TALL-104 cells are potent tumor killers and have demonstrated potential for systemic tumor therapy. The pig model used is analogous to the clinical BBBD procedure. Cells were injected in the carotid artery after labeling with the MRI T1 contrast agent GdHPDO3A. Contrast CT scans were used to quantify BBBD and MRI was used to detect Gd++-loaded cells in the brain. Transcranial Doppler was used to monitor cerebral blood flow. EEG recordings were used to detect seizures. Immunocytochemical detection (Cresyl Violet, anti-human CD8 for TALL-104, Evans Blue for BBB damage, GFAP and NEUN was performed. Results At the concentration used TALL-104 cells were tolerated. Incomplete BBBD did not allow cell entry into the brain. MRI scans at 24 and 48 hours post-injection allowed visualization of topographically segregated cells in the hemisphere that underwent successful BBBD. Perivascular location of TALL-104 was confirmed in the BBBD hemisphere by Cresyl violet and CD8 immunocytochemistry. No significant alteration in CBF or EEG activity was recorded during cell injections. Conclusions Our data show that targeted CNS cell therapy requires blood-brain barrier disruption. MRI-detectable cytotoxic anti-neoplastic cells can be forced to transverse the BBB and accumulate in the perivascular space. The virtual absence of toxicity, the high anti-tumor activity

  4. Treatment with the NK1 antagonist emend reduces blood brain barrier dysfunction and edema formation in an experimental model of brain tumors.

    Directory of Open Access Journals (Sweden)

    Elizabeth Harford-Wright

    Full Text Available The neuropeptide substance P (SP has been implicated in the disruption of the blood-brain barrier (BBB and development of cerebral edema in acute brain injury. Cerebral edema accumulates rapidly around brain tumors and has been linked to several tumor-associated deficits. Currently, the standard treatment for peritumoral edema is the corticosteroid dexamethasone, prolonged use of which is associated with a number of deleterious side effects. As SP is reported to increase in many cancer types, this study examined whether SP plays a role in the genesis of brain peritumoral edema. A-375 human melanoma cells were injected into the right striatum of male Balb/c nude mice to induce brain tumor growth, with culture medium injected in animals serving as controls. At 2, 3 or 4 weeks following tumor cell inoculation, non-treated animals were perfusion fixed for immunohistochemical detection of Albumin, SP and NK1 receptor. A further subgroup of animals was treated with a daily injection of the NK1 antagonist Emend (3 mg/kg, dexamethasone (8 mg/kg or saline vehicle at 3 weeks post-inoculation. Animals were sacrificed a week later to determine BBB permeability using Evan's Blue and brain water content. Non-treated animals demonstrated a significant increase in albumin, SP and NK1 receptor immunoreactivity in the peritumoral area as well as increased perivascular staining in the surrounding brain tissue. Brain water content and BBB permeability was significantly increased in tumor-inoculated animals when compared to controls (p<0.05. Treatment with Emend and dexamethasone reduced BBB permeability and brain water content when compared to vehicle-treated tumor-inoculated mice. The increase in peritumoral staining for both SP and the NK1 receptor, coupled with the reduction in brain water content and BBB permeability seen following treatment with the NK1 antagonist Emend, suggests that SP plays a role in the genesis of peritumoral edema, and thus warrants

  5. Metformin induces up-regulation of blood-brain barrier functions by activating AMP-activated protein kinase in rat brain microvascular endothelial cells.

    Science.gov (United States)

    Takata, Fuyuko; Dohgu, Shinya; Matsumoto, Junichi; Machida, Takashi; Kaneshima, Shuji; Matsuo, Mai; Sakaguchi, Shinya; Takeshige, Yuki; Yamauchi, Atsushi; Kataoka, Yasufumi

    2013-04-19

    Blood-brain barrier (BBB) disruption occurs frequently in CNS diseases and injuries. Few drugs have been developed as therapeutic candidates for facilitating BBB functions. Here, we examined whether metformin up-regulates BBB functions using rat brain microvascular endothelial cells (RBECs). Metformin, concentration- and time-dependently increased transendothelial electrical resistance of RBEC monolayers, and decreased RBEC permeability to sodium fluorescein and Evans blue albumin. These effects of metformin were blocked by compound C, an inhibitor of AMP-activated protein kinase (AMPK). AMPK stimulation with an AMPK activator, AICAR, enhanced BBB functions. These findings indicate that metformin induces up-regulation of BBB functions via AMPK activation. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Impulse breakdown of small air gap in electric field Part I: Influence ...

    African Journals Online (AJOL)

    The influence of barrier position on breakdown voltage in air dielectric has been investigated. Needle and Cone positive point electrodes were used and the effects of electrode curvature on barrier position for maximum breakdown voltage were compared, with air gap for the point to plane electrode fixed at 10 cm for all the ...

  7. High and Low Molecular Weight Fluorescein Isothiocyanate (FITC)-Dextrans to Assess Blood-Brain Barrier Disruption: Technical Considerations.

    Science.gov (United States)

    Hoffmann, Angelika; Bredno, Jörg; Wendland, Michael; Derugin, Nikita; Ohara, Peter; Wintermark, Max

    2011-03-01

    This note is to report how histological preparation techniques influence the extravasation pattern of the different molecular sizes of fluorescein isothiocyanate (FITC)-dextrans, typically used as markers for blood-brain barrier leakage. By using appropriate preparation methods, false negative results can be minimized. Wistar rats underwent a 2-h middle cerebral artery occlusion and magnetic resonance imaging. After the last imaging scan, Evans blue and FITC-dextrans of 4, 40, and 70 kDa molecular weight were injected. Different histological preparation methods were used. Sites of blood-brain barrier leakage were analyzed by fluorescence microscopy. Extravasation of Evans blue and high molecular FITC-dextrans (40 and 70 kDa) in the infarcted region could be detected with all preparation methods used. If exposed directly to saline, the signal intensity of these FITC-dextrans decreased. Extravasation of the 4-kDa low molecular weight FITC-dextran could only be detected using freshly frozen tissue sections. Preparations involving paraformaldehyde and sucrose resulted in the 4-kDa FITC-dextran dissolving in these reactants and being washed out, giving the false negative result of no extravasation. FITC-dextrans represent a valuable tool to characterize altered blood-brain barrier permeability in animal models. Diffusion and washout of low molecular weight FITC-dextran can be avoided by direct immobilization through immediate freezing of the tissue. This pitfall needs to be known to avoid the false impression that there was no extravasation of low molecular weight FITC-dextrans.

  8. Characterization of the L-glutamate clearance pathways across the blood-brain barrier and the effect of astrocytes in an in vitro blood-brain barrier model.

    Science.gov (United States)

    Helms, Hans Cc; Aldana, Blanca I; Groth, Simon; Jensen, Morten M; Waagepetersen, Helle S; Nielsen, Carsten U; Brodin, Birger

    2017-12-01

    The aim was to characterize the clearance pathways for L-glutamate from the brain interstitial fluid across the blood-brain barrier using a primary in vitro bovine endothelial/rat astrocyte co-culture. Transporter profiling was performed using uptake studies of radiolabeled L-glutamate with co-application of transporter inhibitors and competing amino acids. Endothelial abluminal L-glutamate uptake was almost abolished by co-application of an EAAT-1 specific inhibitor, whereas luminal uptake was inhibited by L-glutamate and L-aspartate (1 mM). L-glutamate uptake followed Michaelis-Menten-like kinetics with high and low affinity at the abluminal and luminal membrane, respectively. This indicated that L-glutamate is taken up via EAAT-1 at the abluminal membrane and exits at the luminal membrane via a low affinity glutamate/aspartate transporter. Metabolism of L-glutamate and transport of metabolites was examined using [U- 13 C] L-glutamate. Intact L-glutamate and metabolites derived from oxidative metabolism were transported through the endothelial cells. High amounts of L-glutamate-derived lactate in the luminal medium indicated cataplerosis via malic enzyme. Thus, L-glutamate can be transported intact from brain to blood via the concerted action of abluminal and luminal transport proteins, but the total brain clearance is highly dependent on metabolism in astrocytes and endothelial cells followed by transport of metabolites.

  9. Neurons but not glial cells overexpress ubiquitin in the rat brain following focused ultrasound-induced opening of the blood-brain barrier.

    Science.gov (United States)

    Alonso, A; Reinz, E; Fatar, M; Jenne, J; Hennerici, M G; Meairs, S

    2010-08-11

    Focused ultrasound-induced opening of the blood-brain barrier (BBB) in the presence of ultrasound contrast agents is a promising strategy for a targeted drug delivery to the brain. The aim of our study was to identify whether brain molecular stress pathways are targeted by ultrasound treatment. Using an upper level of acoustic pressures in combination with microbubbles, which have been previously reported as reliable for BBB opening without causing tissue damage, we found that ultrasound leads to an increased ubiquitinylation of proteins in neuronal (11+/-3 ubiquitin-overexpressing cells per optical field) but not glial cells 6 h post-insonation, increasing to 16 (+/-4) labelled cells after 24 h. No changes in the expression of Hsp70 and Hsc70 were detected over 24 h. Ultrasound treatment was followed by limited apoptosis after 24 h (32+/-6 cleaved-caspase 3-positive cells per optical field) in the insonated areas. Only neurons were identified in the apoptotic population. Although these observations may not be applicable for all acoustic parameters useful for BBB opening, they demonstrate that insonation of the rat brain with the parameters used in our experiments is a useful tool for BBB opening and induces specific cellular stress response restricted to neuronal cells. Copyright (c) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

  10. A new PAMPA model using an in-house brain lipid extract for screening the blood-brain barrier permeability of drug candidates.

    Science.gov (United States)

    Bicker, Joana; Alves, Gilberto; Fortuna, Ana; Soares-da-Silva, Patrício; Falcão, Amílcar

    2016-03-30

    The determination of the permeability of drug candidates across the blood-brain barrier (BBB) is a fundamental step during drug discovery programs. The parallel artificial membrane permeability assay (PAMPA) is a high throughput screening tool applied to evaluate the passive permeability and adapted to predict BBB penetration. Herein, a new PAMPA model was developed using an in-house brain lipid extract capable of discriminating BBB permeable from non-permeable compounds. The apparent permeability (Papp) of 18 reference molecules and 10 test compounds was assessed and compared with phosphatidylcholine and commercial porcine polar brain lipid (PBL). The physicochemical selectivity of the in-house brain lipid extract was demonstrated by correlating Papp values with physicochemical properties and its predictive capacity estimated by establishing in vitro-in vivo correlations. The strong correlations achieved between 2% (w/v) in-house lipid extract and PBL for reference (r(2)=0.77) and test compounds (r(2)=0.94) support an equivalent discriminatory capacity and validate the presented model. Moreover, PAMPA studies performed with PBL and in-house lipid extract exhibited a higher correlation with the in vivo parameter logBB (r(2)=0.76 and r(2)=0.72, respectively) than phosphatidylcholine (r(2)=0.51). Overall, the applied lipid extraction process was reproducible, economical and provided lipid extracts that can be used to reliably assess BBB permeation. Copyright © 2016. Published by Elsevier B.V.

  11. Effects of GSM and UMTS mobile telephony signals on neuron degeneration and blood-brain barrier permeation in the rat brain.

    Science.gov (United States)

    Poulletier de Gannes, Florence; Masuda, Hiroshi; Billaudel, Bernard; Poque-Haro, Emmanuelle; Hurtier, Annabelle; Lévêque, Philippe; Ruffié, Gilles; Taxile, Murielle; Veyret, Bernard; Lagroye, Isabelle

    2017-11-14

    Blood-brain barrier (BBB) permeation and neuron degeneration were assessed in the rat brain following exposure to mobile communication radiofrequency (RF) signals (GSM-1800 and UMTS-1950). Two protocols were used: (i) single 2 h exposure, with rats sacrificed immediately, and 1 h, 1, 7, or 50 days later, and (ii) repeated exposures (2 h/day, 5 days/week, for 4 weeks) with the effects assessed immediately and 50 days after the end of exposure. The rats' heads were exposed at brain-averaged specific absorption rates (BASAR) of 0.026, 0.26, 2.6, and 13 W/kg. No adverse impact in terms of BBB leakage or neuron degeneration was observed after single exposures or immediately after the end of repeated exposure, with the exception of a transient BBB leakage (UMTS, 0.26 W/kg). Fifty days after repeated exposure, the occurrence of degenerating neurons was unchanged on average. However, a significant increased albumin leakage was detected with both RF signals at 13 W/kg. In this work, the strongest, delayed effect was induced by GSM-1800 at 13 W/kg. Considering that 13 W/kg BASAR in the rat head is equivalent to 4 times as much in the human head, deleterious effects may occur following repeated human brain exposure above 50 W/kg.

  12. Accurate determination of blood–brain barrier permeability using dynamic contrast-enhanced T1-weighted MRI

    DEFF Research Database (Denmark)

    Cramer, Stig P; Larsson, Henrik B W

    2014-01-01

    Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is increasingly used to estimate permeability in situations with subtle blood-brain barrier (BBB) leakage. However, the method's ability to differentiate such low values from zero is unknown, and no consensus exists on optimal selection.......25 seconds) greatly improved accuracy and precision for all three models, enabling us to differentiate values of permeability as low as 0.1 ml/100 g/min from zero. The Patlak model yielded highest accuracy and precision for permeability values

  13. Effects of radiofrequency field on the blood-brain barrier: A systematic review from 2005 to 2009

    Science.gov (United States)

    Perrin, Anne; Cretallaz, Celine; Collin, Alice; Amourette, Christine; Yardin, Catherine

    2010-11-01

    The published results available in 2005 were insufficient to draw firm conclusions concerning the possible non-thermal effects of radiofrequency fields on the blood-brain barrier (BBB). This critical review deals with 16 articles on this topic published since 2005. The methodological quality of these articles was not equivalent. We therefore analysed the underlying methodologies from both their biological and physical aspects. We conclude that recent studies provide no convincing proof of deleterious effects of RF on the integrity of the BBB, for specific absorption rates (SAR) up to 6 W/kg.

  14. Optimal Magnetic Field for Crossing Super-Para-Magnetic Nanoparticles through the Brain Blood Barrier: A Computational Approach

    Directory of Open Access Journals (Sweden)

    Maysam Z. Pedram

    2016-06-01

    Full Text Available This paper scrutinizes the magnetic field effect to deliver the superparamagnetic nanoparticles (SPMNs through the Blood Brain Barrier (BBB. Herein we study the interaction between the nanoparticle (NP and BBB membrane using Molecular Dynamic (MD techniques. The MD model is used to enhance our understanding of the dynamic behavior of SPMNs crossing the endothelial cells in the presence of a gradient magnetic field. Actuation of NPs under weak magnetic field offers the great advantage of a non-invasive drug delivery without the risk of causing injury to the brain. Furthermore, a weak magnetic portable stimulator can be developed using low complexity prototyping techniques. Based on MD simulation results in this paper, SPMNs can cross the cell membrane while experiencing very weak mechanical forces in the range of pN. This study also derives guidelines for the design of the SPMNs dedicated to crossing the BBB using external magnetic fields.

  15. Role of Transporters in Central Nervous System Drug Delivery and Blood-Brain Barrier Protection: Relevance to Treatment of Stroke

    Directory of Open Access Journals (Sweden)

    Hrvoje Brzica

    2017-03-01

    Full Text Available Ischemic stroke is a leading cause of morbidity and mortality in the United States. The only approved pharmacologic treatment for ischemic stroke is thrombolysis via recombinant tissue plasminogen activator (r-tPA. A short therapeutic window and serious adverse events (ie, hemorrhage, excitotoxicity greatly limit r-tPA therapy, which indicates an essential need to develop novel stroke treatment paradigms. Transporters expressed at the blood-brain barrier (BBB provide a significant opportunity to advance stroke therapy via central nervous system delivery of drugs that have neuroprotective properties. Examples of such transporters include organic anion–transporting polypeptides (Oatps and organic cation transporters (Octs. In addition, multidrug resistance proteins (Mrps are transporter targets in brain microvascular endothelial cells that can be exploited to preserve BBB integrity in the setting of stroke. Here, we review current knowledge on stroke pharmacotherapy and demonstrate how endogenous BBB transporters can be targeted for improvement of ischemic stroke treatment.

  16. [Permeability of blood-brain barrier oxygen-glucose deprivation induced by tetramethylpyrazine-puerarin in vitro].

    Science.gov (United States)

    Li, Jinhui; Che, Lingyan; Wang, Yu; Zhang, Yuyan; Wan, Haitong; Yang, Jiehong

    2010-10-01

    To explore permeability of artificial blood-brain barrier (aBBB) by oxygen-glucose deprivation combined (OGD)-induced using tetramethylpyrazine combined with puerarin in vitro. Rats were divided into normal control group, model group, tetramethylpyrazine group, puerarin group, tetramethylpyrazine-puerarin group and nimodipine group. Culture rat brain microvascular endothelial cells and astrocytes in vitro and build the OGD-induced aBBB damage model. Evaluate aBBB damage characteristics by TEER, gamma-GT, AKP and LDH. Determine contents of tetramethylpyrazine, puerarin, nimodipine and calculate drug permeating concentration of OGD-induced aBBB model by HPLC. Compared with the model, the level of TEER was lower than the control group with significant difference (P permeability of the OGD-induced aBBB.

  17. Communication from the periphery to the hypothalamus through the blood-brain barrier: An in vitro platform.

    Science.gov (United States)

    Martins, João Pedro; Alves, Cecília Juliana; Neto, Estrela; Lamghari, Meriem

    2016-02-29

    One of the major routes of communication from the peripheral systems to the hypothalamus, the core structure of body homeostasis, is the humoral transmission through the blood-brain barrier (BBB). The BBB cultures are the in vitro model of choice to depict the mechanisms behind blood-brain interplay. Still, this strategy excludes the integration of the brain tissue response and, therefore, the resulting output might be limited. In this study, two in vitro assays were established: BBB coculture model and hypothalamic organotypic cultures. The combination of these two assays was used as a platform to address the two critical steps in the humoral transmission through the BBB to the brain: blood-BBB/BBB-brain. The in vitro model of the BBB was performed according to a coculture system using a brain microvascular endothelial cell line (bEnd.3) and primary astrocytes. The expression of junctional molecules as claudin-5, ZO-1, occludin and VE-cadherin was observed in the bEnd.3 cell-cell contact, confirming the BBB phenotype of these endothelial cells. Moreover, the transendothelial electrical resistance (TEER) values (71.1±9.4Ω× cm(2)) and the permeability coefficients (Pe) obtained in the transendothelial flux test (3.3±0.11×10(-6)cm/sec) support high integrity of the established barrier. The hypothalamic organotypic cultures were prepared from 8-days-old C57Bl/6 mice brains, based on the air-medium interface culture method. High cell viability (82±9.6%) and a dense neuronal network were achieved. The stimulation with dexamethasone resulted in an increased neuropeptide (NPY) expression, confirming the responsiveness of the neuronal system of these organotypic cultures. After optimization and characterization of each assay, the functionality of the platform was validated through the evaluation of the hypothalamic response to deep wound encompassing skin and muscle in mice. Results allowed to identify increased NPY activity in hypothalamic slices in response to

  18. Trans-cranial opening of the blood-brain barrier in targeted regions using a stereotaxic brain atlas and focused ultrasound energy.

    Science.gov (United States)

    Bing, Chenchen; Ladouceur-Wodzak, Michelle; Wanner, Clinton R; Shelton, John M; Richardson, James A; Chopra, Rajiv

    2014-01-01

    The blood-brain barrier (BBB) protects the brain by preventing the entry of large molecules; this poses a major obstacle for the delivery of drugs to the brain. A novel technique using focused ultrasound (FUS) energy combined with microbubble contrast agents has been widely used for non-invasive trans-cranial BBB opening. Traditionally, FUS research is conducted with magnetic resonance imaging (MRI) guidance, which is expensive and poses physical limitations due to the magnetic field. A system that could allow researchers to test brain therapies without MR intervention could facilitate and accelerate translational research. In this study, we present a novel FUS system that uses a custom-built FUS generator mounted on a motorized stereotaxic apparatus with embedded brain atlas to locally open the BBB in rodents. The system was initially characterized using a tissue-mimicking phantom. Rodent studies were also performed to evaluate whether non-invasive, localized BBB opening could be achieved using brain atlas-based targeting. Brains were exposed to pulsed focused ultrasound energy at 1.06 MHz in rats and 3.23 MHz in mice, with the focal pressure estimated to be 0.5-0.6 MPa through the skull. BBB opening was confirmed in gross tissue sections by the presence of Evans blue leakage in the exposed region of the brain and by histological assessment. The targeting accuracy of the stereotaxic system was better than 0.5 mm in the tissue-mimicking phantom. Reproducible localized BBB opening was verified with Evans blue dye leakage in 32/33 rats and had a targeting accuracy of ±0.3 mm. The use of higher frequency exposures in mice enabled a similar precision of localized BBB opening as was observed with the low frequency in the rat model. With this dedicated small-animal motorized stereotaxic-FUS system, we achieved accurate targeting of focused ultrasound exposures in the brain for non-invasive opening of the BBB. This system can be used as an alternative to MR

  19. A novel IL-1RA-PEP fusion protein alleviates blood-brain barrier disruption after ischemia-reperfusion in male rats.

    Science.gov (United States)

    Zhang, Dong-Dong; Jin, Chen; Zhang, Ya-Tao; Gan, Xiang-Dong; Zou, Min-Ji; Wang, Yuan-Yuan; Fu, Wen-Liang; Xu, Tao; Xing, Wei-Wei; Xia, Wen-Ron; Xu, Dong-Gang

    2018-01-15

    Current options to treat clinical relapse in inflammatory central nervous system (CNS) conditions such as cerebral ischemia-reperfusion injury are limited, and agents that are more effective are required. Disruption of the blood-brain barrier is an early feature of lesion formation that correlates with clinical exacerbation and facilitates the entry of inflammatory medium and inflammatory cells. Interleukin-1 receptor antagonist (IL-1RA) is a naturally occurring anti-inflammatory antagonist of the interleukin-1 (IL-1) family. The broad-spectrum anti-inflammatory effects of IL-1RA have been investigated against various forms of neuroinflammation. However, the effect of IL-1RA on blood-brain barrier disruption following ischemia-reperfusion has not been reported. In this study, we investigated the effects of IL-1RA and a novel protein (IL-1RA-PEP) that was fused to IL-1RA with a cell penetrating peptide, on blood-brain barrier integrity, in male rats subjected to transient middle cerebral artery occlusion. After intravenous administration, IL-1RA-PEP (50 mg/kg) penetrated cerebral tissues more effectively than IL-1RA. Moreover, it preserved blood-brain barrier integrity, attenuated changes in expression and localization of tight junction proteins and matrix metalloproteinases, and enhanced angiogenesis in ischemic brain tissue. Further study suggested that the effects of IL-1RA-PEP on preserving blood-brain barrier integrity might be closely correlated with the p65/NF-κB pathway, as evidenced by the effects of the inhibitor JSH-23. Collectively, our results demonstrated that IL-1RA-PEP could effectively penetrate the brain of rats with middle cerebral artery occlusion and ameliorate blood-brain barrier disruption. This finding might represent its novel therapeutic potential in the treatment of the cerebral ischemia-reperfusion injury.

  20. Overcoming the blood-brain tumor barrier for effective glioblastoma treatment

    NARCIS (Netherlands)

    Tellingen, O. van; Yetkin-Arik, B.; Gooijer, M.C. de; Wesseling, P.; Wurdinger, T.; Vries, H.E. de

    2015-01-01

    Gliomas are the most common primary brain tumors. Particularly in adult patients, the vast majority of gliomas belongs to the heterogeneous group of diffuse gliomas, i.e. glial tumors characterized by diffuse infiltrative growth in the preexistent brain tissue. Unfortunately, glioblastoma, the most

  1. Perception of Barriers to the Diagnosis and Receipt of Treatment for Neuropsychiatric Disturbances After Traumatic Brain Injury.

    Science.gov (United States)

    Albrecht, Jennifer S; O'Hara, Lyndsay M; Moser, Kara A; Mullins, C Daniel; Rao, Vani

    2017-12-01

    To explore perceptions of barriers and facilitators to the diagnosis and receipt of treatment for neuropsychiatric disturbances (NPDs) after traumatic brain injury (TBI). Qualitative study using semistructured interviews and focus groups. A clinic specializing in the treatment of TBI NPDs, an urban trauma center, and a large urban academic hospital. A sample (N=33) of health care providers (n=10) who treat individuals with TBI, persons with TBI (n=18), and caregivers (n=5). Not applicable. Topic guides for the interviews and focus groups were guided by previous literature, clinical experience, and the goals of the project and focused on the 3 most common TBI NPDs: depression, anxiety, and posttraumatic stress disorder. The interviews and focus groups were audio-recorded and transcribed verbatim. We performed a conventional content analysis on the transcripts and grouped concepts into overall themes, incorporating feedback from stakeholders. Patient education, insurance, provider type, time since TBI, caregiver support, and recognition or screening for TBI NPDs were the most frequently mentioned barriers or facilitators to the diagnosis and treatment of TBI NPDs by both interview and focus group participants. We grouped these and other frequently mentioned concepts into 3 broad themes: education, access, and support. Each of these themes is explored in depth and supported with direct quotations. This study explored patient, caregiver, and health care provider and identified barriers and facilitators to the diagnosis and receipt of treatment for TBI NPDs. Barriers included poor provider education on TBI NPDs and limited access to care due to lack of insurance, transportation, and income. Facilitators included patient education on TBI NPDs and strong caregiver support. Future studies should develop and pilot interventions aimed at quality of care that address the identified barriers and facilitators. Copyright © 2017 American Congress of Rehabilitation Medicine

  2. Beta-Amyloid Downregulates MDR1-P-Glycoprotein (Abcb1 Expression at the Blood-Brain Barrier in Mice

    Directory of Open Access Journals (Sweden)

    Anja Brenn

    2011-01-01

    Full Text Available Neurovascular dysfunction is an important component of Alzheimer's disease, leading to reduced clearance across the blood-brain barrier and accumulation of neurotoxic β-amyloid (Aβ peptides in the brain. It has been shown that the ABC transport protein P-glycoprotein (P-gp, ABCB1 is involved in the export of Aβ from the brain into the blood. To determine whether Aβ influences the expression of key Aβ transporters, we studied the effects of 1-day subcutaneous Aβ1-40 and Aβ1-42 administration via Alzet mini-osmotic pumps on P-gp, BCRP, LRP1, and RAGE expression in the brain of 90-day-old male FVB mice. Our results demonstrate significantly reduced P-gp, LRP1, and RAGE mRNA expression in mice treated with Aβ1-42 compared to controls, while BCRP expression was not affected. The expression of the four proteins was unchanged in mice treated with Aβ1-40 or reverse-sequence peptides. These findings indicate that, in addition to the age-related decrease of P-gp expression, Aβ1-42 itself downregulates the expression of P-gp and other Aβ-transporters, which could exacerbate the intracerebral accumulation of Aβ and thereby accelerate neurodegeneration in Alzheimer's disease and cerebral β-amyloid angiopathy.

  3. Involvement of a proton-coupled organic cation antiporter in the blood-brain barrier transport of amantadine.

    Science.gov (United States)

    Suzuki, Toyofumi; Aoyama, Takahiko; Suzuki, Naoto; Kobayashi, Masaru; Fukami, Toshiro; Matsumoto, Yoshiaki; Tomono, Kazuo

    2016-09-01

    The blood-to-brain transport of amantadine, a weak N-methyl-d-aspartate (NMDA) antagonist, has been shown previously to participate in the cationic drug-sensitive transport system across the mouse blood-brain barrier (BBB). The purpose of the present study was to characterize the influx transport system by means of both an in situ mouse brain perfusion technique and in vitro studies using rat immortalized brain capillary endothelial cells (GPNT). The observed concentration-dependent initial uptake rate of [(3) H]amantadine suggested the involvement of a carrier-mediated transport mechanism. The normal uptake at physiological pH 7.4 was decreased by 72.9% in acidic perfusate, while it was increased by 35.3% in alkaline perfusate. These results suggest that pH-dependent transport is regulated by utilizing an oppositely directed proton gradient as a driving force. In addition, the [(3) H]amantadine uptake was moderately inhibited by the adamantane structural analogs (rimantadine and memantine) and other cationic drugs (pyrilamine, clonidine, nicotine, etc.), but not by substrates or inhibitors of the well-characterized organic cation transporters (tetraethylammonium, l-carnitine and choline). A similar inhibition pattern was observed between the in vivo studies and the in vitro experiments. These results indicate that the influx transport for amantadine across the BBB involves a proton-coupled organic cation antiporter. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  4. Feasibility study of a single-element transcranial focused ultrasound system for blood-brain barrier opening

    Science.gov (United States)

    Marquet, Fabrice; Tung, Yao-Sheng; Teichert, Tobias; Ferrera, Vincent P.; Konofagou, Elisa E.

    2012-10-01

    The blood-brain barrier (BBB) is a specialized vascular system that impedes entry of all large and the vast majority of small molecules including the most potent CNS disease therapeutic agents from entering from the lumen into the brain parenchyma. Microbubble-enhanced, focused ultrasound (ME-FUS) has been previously shown to disrupt noninvasively, selectively, and transiently the BBB in small animals in vivo. The study addresses the focusing properties of single-element transducers at intermediate frequencies (500 kHz) through primate and human skulls, targeting clinically relevant targets extracted from 3D brain atlases such as the hippocampus and the basal ganglia, which are typically affected by early Alzheimer's and Parkinson's disease, respectively. A preliminary in vivo study was performed to study the frequency dependence of BBB opening parameters in mice. Then, feasibility of transcranial ME-FUS BBB opening in non-human primates was demonstrated with subsequent BBB recovery. Sonications were combined with two different types of microbubbles (custom made 4-5 μm and Definity®). 3T MRI was used to confirm the BBB disruption and to assess brain damage.

  5. Na(+)/H(+) Exchanger 9 Regulates Iron Mobilization at the Blood-Brain Barrier in Response to Iron Starvation.

    Science.gov (United States)

    Beydoun, Rami; Hamood, Mohamed A; Gomez Zubieta, Daniela M; Kondapalli, Kalyan C

    2017-03-10

    Iron is essential for brain function, with loss of iron homeostasis in the brain linked to neurological diseases ranging from rare syndromes to more common disorders, such as Parkinson's and Alzheimer's diseases. Iron entry into the brain is regulated by the blood-brain barrier (BBB). Molecular mechanisms regulating this transport are poorly understood. Using an in vitro model of the BBB, we identify NHE9, an endosomal cation/proton exchanger, as a novel regulator of this system. Human brain microvascular endothelial cells (hBMVECs) that constitute the BBB receive brain iron status information via paracrine signals from ensheathing astrocytes. In hBMVECs, we show that NHE9 expression is up-regulated very early in a physiological response invoked by paracrine signals from iron-starved astrocytes. Ectopic expression of NHE9 in hBMVECs without external cues induced up-regulation of the transferrin receptor (TfR) and down-regulation of ferritin, leading to an increase in iron uptake. Mechanistically, we demonstrate that NHE9 localizes to recycling endosomes in hBMVECs where it raises the endosomal pH. The ensuing alkalization of the endosomal lumen increased translocation of TfRs to the hBMVEC membrane. TfRs on the membrane were previously shown to facilitate both recycling-dependent and -independent iron uptake. We propose that NHE9 regulates TfR-dependent, recycling-independent iron uptake in hBMVECs by fine-tuning the endosomal pH in response to paracrine signals and is therefore an important regulator in iron mobilization pathway at the BBB. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Model-based hypothesis of gut microbe populations and gut/brain barrier permeabilities in the development of regressive autism.

    Science.gov (United States)

    Downs, Ryan; Perna, Jonathon; Vitelli, Andrew; Cook, Daniel; Dhurjati, Prasad

    2014-12-01

    Regressive autism is a devastating disorder affecting children between the ages of 15-30 months. The disorder is characterized by the loss of social interaction and communication ability following otherwise healthy development. In spite of rising autism prevalence, current detection methods and treatment options for this disease are lacking. Therefore, this study introduces a systems-level model, which suggests that gut microbes and intestinal inflammation influence the onset of regressive autism through increasing gut permeability. This computational model provides a framework for quantitative understanding of how imbalances in populations of gut microbes alters the whole-body and brain distributions of neurotoxins produced by GI tract bacteria. Our results indicate that increased levels of the bacteria Bacteroides vulgatus lead to increased brain levels of propionic acid, a neurotoxin which has been known to cause symptoms characteristic of autism when injected into the brain of rats. Our results further indicate that immune response to virulence factors produced by bacteria in the gut leads to increased systemic levels of inflammatory cytokines, such as IL-1β, which significantly alter the permeability of the gut epithelial layer and the blood-brain barrier. Due to the large size of cytokines, however, we predict the time required for concentrations in the brain to stabilize to be on the order of years. This suggests that treatments preventing autism development could be administered after identifying microbial biomarkers of disease but before debilitating brain inflammation leads to regressive autism progression. Future research extending this work could provide new treatment options and diagnostic techniques to help combat regressive autism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. The effect of regadenoson on the integrity of the human blood-brain barrier, a pilot study.

    Science.gov (United States)

    Jackson, Sadhana; George, Richard T; Lodge, Martin A; Piotrowski, Anna; Wahl, Richard L; Gujar, Sachin K; Grossman, Stuart A

    2017-05-01

    Regadenoson is an FDA approved adenosine receptor agonist which increases blood-brain barrier (BBB) permeability in rodents. Regadenoson is used clinically for pharmacologic cardiac stress testing using SPECT or CT imaging agents that do not cross an intact BBB. This study was conducted to determine if standard doses of regadenoson transiently disrupt the human BBB allowing higher concentrations of systemically administered imaging agents to enter the brain. Patients without known intracranial disease undergoing clinically indicated pharmacologic cardiac stress tests were eligible for this study. They received regadenoson (0.4 mg) followed by brain imaging with either 99m Tc-sestamibi for SPECT or visipaque for CT imaging. Pre- and post-regadenoson penetration of imaging agents into brain were quantified [SPECT: radioactive counts, CT: Hounsfield units (HU)] and compared using a matched-pairs t-test. Twelve patients (33% male, median 60 yo) were accrued: 7 SPECT and 5 CT. No significant differences were noted in pre- and post-regadenoson values using mean radionuclide counts (726 vs. 757) or HU (29 vs. 30). While animal studies have demonstrated that regadenoson transiently increases the permeability of the BBB to dextran and temozolomide, we were unable to document changes in the penetration of contrast agents in humans with intact BBB using the FDA approved doses of regadenoson for cardiac evaluation. Further studies are needed exploring alternate regadenoson dosing, schedules, and studies in patients with brain tumors; as transiently disrupting the BBB to improve drug entry into the brain is critical to improving the care of patients with CNS malignancies.

  8. Possible involvement of cationic-drug sensitive transport systems in the blood-to-brain influx and brain-to-blood efflux of amantadine across the blood-brain barrier.

    Science.gov (United States)

    Suzuki, Toyofumi; Fukami, Toshiro; Tomono, Kazuo

    2015-03-01

    The purpose of this study was to characterize the brain-to-blood efflux transport of amantadine across the blood-brain barrier (BBB). The apparent in vivo efflux rate constant for [(3) H]amantadine from the rat brain (keff ) was found to be 1.53 × 10(-2) min(-1) after intracerebral microinjection using the brain efflux index method. The efflux of [(3) H]amantadine was inhibited by 1-methyl-4-phenylpyridinium (MPP(+) ), a cationic neurotoxin, suggesting that amantadine transport from the brain to the blood across the BBB potentially involves the rat plasma membrane monoamine transporter (rPMAT). On the other hand, other selected substrates for organic cation transporters (OCTs) and organic anion transporters (OATs), as well as inhibitors of P-glycoprotein (P-gp), did not affect the efflux transport of [(3) H]amantadine. In addition, in vitro studies using an immortalized rat brain endothelial cell line (GPNT) showed that the uptake and retention of [(3) H]amantadine by the cells was not changed by the addition of cyclosporin, which is an inhibitor of P-gp. However, cyclosporin affected the uptake and retention of rhodamine123. Finally, the initial brain uptake of [(3) H]amantadine was determined using an in situ mouse brain perfusion technique. Notably, the brain uptake clearance for [(3) H]amantadine was significantly decreased with the co-perfusion of quinidine or verapamil, which are cationic P-gp inhibitors, while MPP(+) did not have a significant effect. It is thus concluded that while P-gp is not involved, it is possible that rPMAT and the cationic drug-sensitive transport system participate in the brain-to-blood efflux and the blood-to-brain influx of amantadine across the BBB, respectively. Copyright © 2014 John Wiley & Sons, Ltd.

  9. In vivo measurements of blood-brain barrier permeability using micro-dialysis: radiobiological application; Etude in vivo des effets de l'irradiation gamma sur la permeabilite de la barriere hemato-encephalique

    Energy Technology Data Exchange (ETDEWEB)

    Agin, A.; Diserbo, M.; Mauris, J.; Martin, C

    1998-07-01

    The effects of total-body irradiation on the permeability of striatal blood-brain barrier (BBB) to [{sup 3}H] amino-isobutyric acid (AIBA) and [{sup 14}C] sucrose were investigated. Six weeks, three and five months after gamma exposure at the dose of 4.5 Gy, no modification of the transport of AIB or of the diffusion of sucrose from blood to brain was observed. (authors)

  10. Functional consequences of neuromyelitis optica-IgG astrocyte interactions on blood-brain barrier permeability and granulocyte recruitment.

    Science.gov (United States)

    Vincent, Thierry; Saikali, Philippe; Cayrol, Romain; Roth, Alejandro D; Bar-Or, Amit; Prat, Alexandre; Antel, Jack P

    2008-10-15

    Autoantibody neuromyelitis optica-IgG (NMO-IgG) recognizing aquaporin-4 (AQP4) is implicated as playing a central role in the physiopathology of NMO. The aim of this in vitro-based study was to characterize functional consequences of interaction between NMO-IgG and cells of the neurovascular unit (astrocytes and brain endothelium) that would provide insight into recognized features of NMO, namely altered blood-brain barrier (BBB) permeability and granulocyte recruitment. We used sera from NMO and longitudinally extensive transverse myelitis cases shown to bind in a characteristic perivascular pattern to primate cerebellar slices. Using flow cytometry, we found that sera from NMO-IgG-positive patients reacted with CNS-derived human fetal astrocytes, whereas sera from multiple sclerosis patients did not. We demonstrated that NMO-IgG binding to astrocytes alters aquaporin-4 polarized expression and increases permeability of a human BBB endothelium/astrocyte barrier. We further demonstrated that NMO-IgG binding to human fetal astrocytes can result in NK cell degranulation, astrocyte killing by Ab-dependent cellular cytotoxicity and complement-dependent granulocyte attraction through the BBB model. Our study highlights important functional roles for NMO-IgG that could account for pathological lesions and BBB dysfunction observed in NMO.

  11. Penetration of drugs through the blood-cerebrospinal fluid/blood-brain barrier for treatment of central nervous system infections.

    Science.gov (United States)

    Nau, Roland; Sörgel, Fritz; Eiffert, Helmut

    2010-10-01

    The entry of anti-infectives into the central nervous system (CNS) depends on the compartment studied, molecular size, electric charge, lipophilicity, plasma protein binding, affinity to active transport systems at the blood-brain/blood-cerebrospinal fluid (CSF) barrier, and host factors such as meningeal inflammation and CSF flow. Since concentrations in microdialysates and abscesses are not frequently available for humans, this review focuses on drug CSF concentrations. The ideal compound to treat CNS infections is of small molecular size, is moderately lipophilic, has a low level of plasma protein binding, has a volume of distribution of around 1 liter/kg, and is not a strong ligand of an efflux pump at the blood-brain or blood-CSF barrier. When several equally active compounds are available, a drug which comes close to these physicochemical and pharmacokinetic properties should be preferred. Several anti-infectives (e.g., isoniazid, pyrazinamide, linezolid, metronidazole, fluconazole, and some fluoroquinolones) reach a CSF-to-serum ratio of the areas under the curves close to 1.0 and, therefore, are extremely valuable for the treatment of CNS infections. In many cases, however, pharmacokinetics have to be balanced against in vitro activity. Direct injection of drugs, which do not readily penetrate into the CNS, into the ventricular or lumbar CSF is indicated when other effective therapeutic options are unavailable.

  12. Disruption of the blood–brain barrier after generalized tonic-clonic seizures correlates with cerebrospinal fluid MMP-9 levels

    Science.gov (United States)

    2013-01-01

    Background Increasing evidence suggests seizures cause blood–brain barrier (BBB) dysfunction including decreased seizure threshold and higher onset potential of future seizures. However, the mechanisms underlying BBB damage in seizures remains poorly understood. Evidence in human and animal models shows BBB disruption is associated with activation of matrix metalloproteinase-9 (MMP-9) after cerebral ischemia and inflammation. The objective of this study was to determine whether MMP-9 concentrations in cerebral spinal fluid (CSF) are associated with BBB disruption in patients after epileptic seizures. Methods Thirty-one patients with generalized tonic-clonic (GTC) seizures were included in the study: 20 had recurrent GTC seizures (RS), and 11 had a single GTC seizure (SS) episode. Twenty-five adult non-seizure patients were used as controls. CSF samples were collected by lumbar puncture within 24 h after seizure cessation (range: 3–15 h, mean 6.2 h). CSF MMP-9 levels were determined by an enzyme-linked immunosorbent assay (ELISA). MMP enzyme activity was measured by gelatin zymography. The CSF/serum albumin ratio (albumin quotient, QAlb) was used as a measure of blood–brain barrier permeability. Results We found significantly higher CSF MMP-9 concentrations in seizure patients compared with controls (P seizures. Gelatin zymography showed MMP-9 proteolytic activity only in GTC seizure patients. Conclusions Our results suggest MMP-9 plays a role in BBB dysfunction, characterized by invasion of leukocytes into the CSF during seizures. PMID:23829879

  13. Disruption of the blood-brain barrier after generalized tonic-clonic seizures correlates with cerebrospinal fluid MMP-9 levels.

    Science.gov (United States)

    Li, Ya-Jun; Wang, Zheng-Hai; Zhang, Bei; Zhe, Xiao; Wang, Ming-Jue; Shi, Shao-Ting; Bai, Jing; Lin, Tao; Guo, Chang-Jiang; Zhang, Shi-Jun; Kong, Xiang-Li; Zuo, Xing; Zhao, Hang

    2013-07-05

    Increasing evidence suggests seizures cause blood-brain barrier (BBB) dysfunction including decreased seizure threshold and higher onset potential of future seizures. However, the mechanisms underlying BBB damage in seizures remains poorly understood. Evidence in human and animal models shows BBB disruption is associated with activation of matrix metalloproteinase-9 (MMP-9) after cerebral ischemia and inflammation. The objective of this study was to determine whether MMP-9 concentrations in cerebral spinal fluid (CSF) are associated with BBB disruption in patients after epileptic seizures. Thirty-one patients with generalized tonic-clonic (GTC) seizures were included in the study: 20 had recurrent GTC seizures (RS), and 11 had a single GTC seizure (SS) episode. Twenty-five adult non-seizure patients were used as controls. CSF samples were collected by lumbar puncture within 24 h after seizure cessation (range: 3-15 h, mean 6.2 h). CSF MMP-9 levels were determined by an enzyme-linked immunosorbent assay (ELISA). MMP enzyme activity was measured by gelatin zymography. The CSF/serum albumin ratio (albumin quotient, QAlb) was used as a measure of blood-brain barrier permeability. We found significantly higher CSF MMP-9 concentrations in seizure patients compared with controls (P seizures. Gelatin zymography showed MMP-9 proteolytic activity only in GTC seizure patients. Our results suggest MMP-9 plays a role in BBB dysfunction, characterized by invasion of leukocytes into the CSF during seizures.

  14. Maternal Obesity in the Mouse Compromises the Blood-Brain Barrier in the Arcuate Nucleus of Offspring.

    Science.gov (United States)

    Kim, Dong Won; Glendining, Kelly A; Grattan, David R; Jasoni, Christine L

    2016-06-01

    The arcuate nucleus (ARC) regulates body weight in response to blood-borne signals of energy balance. Blood-brain barrier (BBB) permeability in the ARC is determined by capillary endothelial cells (ECs) and tanycytes. Tight junctions between ECs limit paracellular entry of blood-borne molecules into the brain, whereas EC transporters and fenestrations regulate transcellular entry. Tanycytes appear to form a barrier that prevents free diffusion of blood-borne molecules. Here we tested the hypothesis that gestation in an obese mother alters BBB permeability in the ARC of offspring. A maternal high-fat diet model was used to generate offspring from normal-weight (control) and obese dams (OffOb). Evans Blue diffusion into the ARC was higher in OffOb compared with controls, indicating that ARC BBB permeability was altered. Vessels investing the ARC in OffOb had more fenestrations than controls, although the total number of vessels was not changed. A reduced number of tanycytic processes in the ARC of OffOb was also observed. The putative transporters, Lrp1 and dysferlin, were up-regulated and tight junction components were differentially expressed in OffOb compared with controls. These data suggest that maternal obesity during pregnancy can compromise BBB formation in the fetus, leading to altered BBB function in the ARC after birth.

  15. An in vitro transport model for rapid screening and predicting the permeability of candidate compounds at blood-brain barrier.

    Science.gov (United States)

    Yang, Zhi-Hong; Sun, Xiao; Mei, Chao; Sun, Xiao-Bo; Liu, Xiao-Dong; Chang, Qi

    2011-12-01

    The aim of this study was to design and develop a simple in vitro blood-brain barrier (BBB) permeation model for elementarily and rapidly predicting the permeability of candidate compounds at BBB and further evaluating whether P-glycoprotein (P-gp) affects them across BBB. The model was mainly composed of cultured rat brain microvascular endothelial cells (rBMECs), glass contraption, and micropore membrane. First, we evaluated the model by morphological observation. Second, the restriction effects of paracellular transport were verified by measuring marker probes transport, and monitoring transendothelial electrical resistance (TEER) and leakage. Finally, protein expression and activity of P-gp were confirmed by carrying out Western blot analysis and polarized transport of rhodamine-123 (Rho123) in rBMECs. The rBMECs retained both endothelial cells and BBB features. The rBMECs model reproducibly attained approximately 130 Ω cm² on the steady-state TEER value, and displayed a barrier function to marker probes transport by decreasing the permeability. Protein band of 170 kDa manifested the existence of P-gp in the rBMECs, and the findings of cyclosporin A-sensitive decrease of Rho123 efflux confirmed the presence of P-gp activity. A simple, rapid, and convenient in vitro BBB permeation model was successfully established and applied to evaluate the BBB transport profiles of three natural flavonoids: quercetin, naringenin, and rutin.

  16. Permeability dependence study of the focused ultrasound-induced blood-brain barrier opening at distinct pressures and microbubble diameters using DCE-MRI.

    Science.gov (United States)

    Vlachos, Fotios; Tung, Yao-Sheng; Konofagou, Elisa

    2011-09-01

    Blood-brain barrier opening using focused ultrasound and microbubbles has been experimentally established as a noninvasive and localized brain drug delivery technique. In this study, the permeability of the opening is assessed in the murine hippocampus after the application of focused ultrasound at three different acoustic pressures and microbubble sizes. Using dynamic contrast-enhanced MRI, the transfer rates were estimated, yielding permeability maps and quantitative K(trans) values for a predefined region of interest. The volume of blood-brain barrier opening according to the K(trans) maps was proportional to both the pressure and the microbubble diameter. A K(trans) plateau of ∼0.05 min(-1) was reached at higher pressures (0.45 and 0.60 MPa) for the larger sized bubbles (4-5 and 6-8 μm), which was on the same order as the K(trans) of the epicranial muscle (no barrier). Smaller bubbles (1-2 μm) yielded significantly lower permeability values. A small percentage (7.5%) of mice showed signs of damage under histological examination, but no correlation with permeability was established. The assessment of the blood-brain barrier permeability properties and their dependence on both the pressure and the microbubble diameter suggests that K(trans) maps may constitute an in vivo tool for the quantification of the efficacy of the focused ultrasound-induced blood-brain barrier opening. Copyright © 2011 Wiley-Liss, Inc.

  17. Circulating Brain Microvascular Endothelial Cells (cBMECs) as Potential Biomarkers of the Blood–Brain Barrier Disorders Caused by Microbial and Non-Microbial Factors

    Science.gov (United States)

    Wu, Chun-Hua; Cao, Hong; Zhang, Aimin; Jong, Ambrose

    2013-01-01

    Despite aggressive research, central nervous system (CNS) disorders, including blood-brain barrier (BBB) injury caused by microbial infection, stroke, abused drugs [e.g., methamphetamine (METH) and nicotine], and other pathogenic insults, remain the world's leading cause of disabilities. In our previous work, we found that dysfunction of brain microvascular endothelial cells (BMECs), which are a major component of the BBB, could be caused by nicotine, meningitic pathogens and microbial factors, including HIV-1 virulence factors gp41 and gp120. One of the most challenging issues in this area is that there are no available cell-based biomarkers in peripheral blood for BBB disorders caused by microbial and non-microbial insults. To identify such cellular biomarkers for BBB injuries, our studies have shown that mice treated with nicotine, METH and gp120 resulted in increased blood levels of CD146+(endothelial marker)/S100B+ (brain marker) circulating BMECs (cBMECs) and CD133+[progenitor cell (PC) marker]/CD146+ endothelial PCs (EPCs), along with enhanced Evans blue and albumin extravasation into the brain. Nicotine and gp120 were able to significantly increase the serum levels of ubiquitin C-terminal hydrolase 1 (UCHL1) (a new BBB marker) as well as S100B in mice, which are correlated with the changes in cBMECs and EPCs. Nicotine- and meningitic E. coli K1-induced enhancement of cBMEC levels, leukocyte migration across the BBB and albumin extravasation into the brain were significantly reduced in alpha7 nAChR knockout mice, suggesting that this inflammatory regulator plays an important role in CNS inflammation and BBB disorders caused by microbial and non-microbial factors. These results demonstrated that cBMECs as well as EPCs may be used as potential cell-based biomarkers for indexing of BBB injury. PMID:23637989

  18. Circulating brain microvascular endothelial cells (cBMECs) as potential biomarkers of the blood-brain barrier disorders caused by microbial and non-microbial factors.

    Science.gov (United States)

    Huang, Sheng-He; Wang, Lin; Chi, Feng; Wu, Chun-Hua; Cao, Hong; Zhang, Aimin; Jong, Ambrose

    2013-01-01

    Despite aggressive research, central nervous system (CNS) disorders, including blood-brain barrier (BBB) injury caused by microbial infection, stroke, abused drugs [e.g., methamphetamine (METH) and nicotine], and other pathogenic insults, remain the world's leading cause of disabilities. In our previous work, we found that dysfunction of brain microvascular endothelial cells (BMECs), which are a major component of the BBB, could be caused by nicotine, meningitic pathogens and microbial factors, including HIV-1 virulence factors gp41 and gp120. One of the most challenging issues in this area is that there are no available cell-based biomarkers in peripheral blood for BBB disorders caused by microbial and non-microbial insults. To identify such cellular biomarkers for BBB injuries, our studies have shown that mice treated with nicotine, METH and gp120 resulted in increased blood levels of CD146+(endothelial marker)/S100B+ (brain marker) circulating BMECs (cBMECs) and CD133+[progenitor cell (PC) marker]/CD146+ endothelial PCs (EPCs), along with enhanced Evans blue and albumin extravasation into the brain. Nicotine and gp120 were able to significantly increase the serum levels of ubiquitin C-terminal hydrolase 1 (UCHL1) (a new BBB marker) as well as S100B in mice, which are correlated with the changes in cBMECs and EPCs. Nicotine- and meningitic E. coli K1-induced enhancement of cBMEC levels, leukocyte migration across the BBB and albumin extravasation into the brain were significantly reduced in alpha7 nAChR knockout mice, suggesting that this inflammatory regulator plays an important role in CNS inflammation and BBB disorders caused by microbial and non-microbial factors. These results demonstrated that cBMECs as well as EPCs may be used as potential cell-based biomarkers for indexing of BBB injury.

  19. Circulating brain microvascular endothelial cells (cBMECs as potential biomarkers of the blood-brain barrier disorders caused by microbial and non-microbial factors.

    Directory of Open Access Journals (Sweden)

    Sheng-He Huang

    Full Text Available Despite aggressive research, central nervous system (CNS disorders, including blood-brain barrier (BBB injury caused by microbial infection, stroke, abused drugs [e.g., methamphetamine (METH and nicotine], and other pathogenic insults, remain the world's leading cause of disabilities. In our previous work, we found that dysfunction of brain microvascular endothelial cells (BMECs, which are a major component of the BBB, could be caused by nicotine, meningitic pathogens and microbial factors, including HIV-1 virulence factors gp41 and gp120. One of the most challenging issues in this area is that there are no available cell-based biomarkers in peripheral blood for BBB disorders caused by microbial and non-microbial insults. To identify such cellular biomarkers for BBB injuries, our studies have shown that mice treated with nicotine, METH and gp120 resulted in increased blood levels of CD146+(endothelial marker/S100B+ (brain marker circulating BMECs (cBMECs and CD133+[progenitor cell (PC marker]/CD146+ endothelial PCs (EPCs, along with enhanced Evans blue and albumin extravasation into the brain. Nicotine and gp120 were able to significantly increase the serum levels of ubiquitin C-terminal hydrolase 1 (UCHL1 (a new BBB marker as well as S100B in mice, which are correlated with the changes in cBMECs and EPCs. Nicotine- and meningitic E. coli K1-induced enhancement of cBMEC levels, leukocyte migration across the BBB and albumin extravasation into the brain were significantly reduced in alpha7 nAChR knockout mice, suggesting that this inflammatory regulator plays an important role in CNS inflammation and BBB disorders caused by microbial and non-microbial factors. These results demonstrated that cBMECs as well as EPCs may be used as potential cell-based biomarkers for indexing of BBB injury.

  20. West Nile virus infection modulates human brain microvascular endothelial cells tight junction proteins and cell adhesion molecules: Transmigration across the in vitro blood-brain barrier.

    Science.gov (United States)

    Verma, Saguna; Lo, Yeung; Chapagain, Moti; Lum, Stephanie; Kumar, Mukesh; Gurjav, Ulziijargal; Luo, Haiyan; Nakatsuka, Austin; Nerurkar, Vivek R

    2009-03-15

    Neurological complications such as inflammation, failure of the blood-brain barrier (BBB), and neuronal death contribute to the mortality and morbidity associated with WNV-induced meningitis. Compromised BBB indicates the ability of the virus to gain entry into the CNS via the BBB, however, the underlying mechanisms, and the specific cell types associated with WNV-CNS trafficking are not well understood. Brain microvascular endothelial cells, the main component of the BBB, represent a barrier to virus dissemination into the CNS and could play key role in WNV spread via hematogenous route. To investigate WNV entry into the CNS, we infected primary human brain microvascular endothelial (HBMVE) cells with the neurovirulent strain of WNV (NY99) and examined WNV replication kinetics together with the changes in the expressions of key tight junction proteins (TJP) and cell adhesion molecules (CAM). WNV infection of HBMVE cells was productive as analyzed by plaque assay and qRT-PCR, and did not induce cytopathic effect. Increased mRNA and protein expressions of TJP (claudin-1) and CAM (vascular cell adhesion molecule and E-selectin) were observed at days 2 and 3 after infection, respectively, which coincided with the peak in WNV replication. Further, using an in vitro BBB model comprised of HBMVE cells, we demonstrate that cell-free WNV can cross the BBB, without compromising the BBB integrity. These data suggest that infection of HBMVE cells can facilitate entry of cell-free virus into the CNS without disturbing the BBB, and increased CAM may assist in the trafficking of WNV-infected immune cells into the CNS, via 'Trojan horse' mechanism, thereby contributing to WNV dissemination in the CNS and associated pathology.

  1. Dynamic analysis of the mesenchymal-epithelial transition of blood-brain barrier forming glia in Drosophila

    Science.gov (United States)

    Schwabe, Tina; Li, Xiaoling

    2017-01-01

    ABSTRACT During development, many epithelia are formed by a mesenchymal-epithelial transition (MET). Here, we examine the major stages and underlying mechanisms of MET during blood-brain barrier formation in Drosophila. We show that contact with the basal lamina is essential for the growth of the barrier-forming subperineurial glia (SPG). Septate junctions (SJs), which provide insulation of the paracellular space, are not required for MET, but are necessary for the establishment of polarized SPG membrane compartments. In vivo time-lapse imaging reveals that the Moody GPCR signaling pathway regulates SPG cell growth and shape, with different levels of signaling causing distinct phenotypes. Timely, well-coordinated SPG growth is essential for the uniform insertion of SJs and thus the insulating function of the barrier. To our knowledge, this is the first dynamic in vivo analysis of all stages in the formation of a secondary epithelium, and of the key role trimeric G protein signaling plays in this important morphogenetic process. PMID:28108476

  2. The role of the blood–brain barrier in the development and treatment of migraine and other pain disorders

    Science.gov (United States)

    DosSantos, Marcos F.; Holanda-Afonso, Rosenilde C.; Lima, Rodrigo L.; DaSilva, Alexandre F.; Moura-Neto, Vivaldo

    2014-01-01

    The function of the blood–brain barrier (BBB) related to chronic pain has been explored for its classical role in regulating the transcellular and paracellular transport, thus controlling the flow of drugs that act at the central nervous system, such as opioid analgesics (e.g., morphine) and non-steroidal anti-inflammatory drugs. Nonetheless, recent studies have raised the possibility that changes in the BBB permeability might be associated with chronic pain. For instance, changes in the relative amounts of occludin isoforms, resulting in significant increases in the BBB permeability, have been demonstrated after inflammatory hyperalgesia. Furthermore, inflammatory pain produces structural changes in the P-glycoprotein, the major efflux transporter at the BBB. One possible explanation for these findings is the action of substances typically released at the site of peripheral injuries that could lead to changes in the brain endothelial permeability, including substance P, calcitonin gene-related peptide, and interleukin-1 beta. Interestingly, inflammatory pain also results in microglial activation, which potentiates the BBB damage. In fact, astrocytes and microglia play a critical role in maintaining the BBB integrity and the activation of those cells is considered a key mechanism underlying chronic pain. Despite the recent advances in the understanding of BBB function in pain development