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Sample records for blood-brain barrier opening

  1. The Blood-Brain Barrier and Methamphetamine: Open Sesame?

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    Patric eTurowski

    2015-05-01

    Full Text Available The chemical and electrical microenvironment of neurons within the central nervous system is protected and segregated from the circulation by the vascular blood–brain barrier. This barrier operates on the level of endothelial cells and includes regulatory crosstalk with neighbouring pericytes, astrocytes and neurons. Within this neurovascular unit, the endothelial cells form a formidable, highly regulated barrier through the presence of inter-endothelial tight junctions, the absence of fenestrations, and the almost complete absence of fluid-phase transcytosis. The potent psychostimulant drug methamphetamine transiently opens the vascular blood–brain barrier through either or both the modulation of inter-endothelial junctions and the induction of fluid-phase transcytosis. Direct action of methamphetamine on the vascular endothelium induces acute opening of the blood-brain barrier. In addition, striatal effects of methamphetamine and resultant neuroinflammatory signalling can indirectly lead to chronic dysfunction of the blood-brain barrier. Breakdown of the blood-brain barrier may exacerbate the neuronal damage that occurs during methamphetamine abuse. However, this process also constitutes a rare example of agonist-induced breakdown of the blood-brain barrier and the adjunctive use of methamphetamine may present an opportunity to enhance delivery of chemotherapeutic agents to the underlying neural tissue.

  2. Ultrasound-induced blood-brain barrier opening.

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    Konofagou, Elisa E; Tung, Yao-Sheng; Choi, James; Deffieux, Thomas; Baseri, Babak; Vlachos, Fotios

    2012-06-01

    Over 4 million U.S. men and women suffer from Alzheimer's disease; 1 million from Parkinson's disease; 350,000 from multiple sclerosis (MS); and 20,000 from amyotrophic lateral sclerosis (ALS). Worldwide, these four diseases account for more than 20 million patients. In addition, aging greatly increases the risk of neurodegenerative disease. Although great progress has been made in recent years toward understanding of these diseases, few effective treatments and no cures are currently available. This is mainly due to the impermeability of the blood-brain barrier (BBB) that allows only 5% of the 7000 small-molecule drugs available to treat only a tiny fraction of these diseases. On the other hand, safe and localized opening of the BBB has been proven to present a significant challenge. Of the methods used for BBB disruption shown to be effective, Focused Ultrasound (FUS), in conjunction with microbubbles, is the only technique that can induce localized BBB opening noninvasively and regionally. FUS may thus have a huge impact in trans-BBB brain drug delivery. The primary objective in this paper is to elucidate the interactions between ultrasound, microbubbles and the local microenvironment during BBB opening with FUS, which are responsible for inducing the BBB disruption. The mechanism of the BBB opening in vivo is monitored through the MRI and passive cavitation detection (PCD), and the safety of BBB disruption is assessed using H&E histology at distinct pressures, pulse lengths and microbubble diameters. It is hereby shown that the BBB can be disrupted safely and transiently under specific acoustic pressures (under 0.45 MPa) and microbubble (diameter under 8 μm) conditions.

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

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    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.

  4. Numerical study of a simple transcranial focused ultrasound system applied to blood-brain barrier opening.

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    Deffieux, Thomas; Konofagou, Elisa E

    2010-12-01

    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, timedomain 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 tradeoff 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.

  5. Chirp- and random-based coded ultrasonic excitation for localized blood-brain barrier opening

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    Kamimura, HAS; Wang, S; Wu, S-Y; Karakatsani, ME; Acosta, C; Carneiro, AAO; Konofagou, EE

    2015-01-01

    Chirp- and random-based coded excitation methods have been proposed to reduce standing wave formation and improve focusing of transcranial ultrasound. However, no clear evidence has been shown to support the benefits of these ultrasonic excitation sequences in vivo. This study evaluates the chirp and periodic selection of random frequency (PSRF) coded-excitation methods for opening the blood-brain barrier (BBB) in mice. Three groups of mice (n=15) were injected with polydisperse microbubbles and sonicated in the caudate putamen using the chirp/PSRF coded (bandwidth: 1.5-1.9 MHz, peak negative pressure: 0.52 MPa, duration: 30 s) or standard ultrasound (frequency: 1.5 MHz, pressure: 0.52 MPa, burst duration: 20 ms, duration: 5 min) sequences. T1-weighted contrast-enhanced MRI scans were performed to quantitatively analyze focused ultrasound induced BBB opening. The mean opening volumes evaluated from the MRI were 9.38±5.71 mm3, 8.91±3.91 mm3 and 35.47 ± 5.10 mm3 for the chirp, random and regular sonications, respectively. The mean cavitation levels were 55.40±28.43 V.s, 63.87±29.97 V.s and 356.52±257.15 V.s for the chirp, random and regular sonications, respectively. The chirp and PSRF coded pulsing sequences improved the BBB opening localization by inducing lower cavitation levels and smaller opening volumes compared to results of the regular sonication technique. Larger bandwidths were associated with more focused targeting but were limited by the frequency response of the transducer, the skull attenuation and the microbubbles optimal frequency range. The coded methods could therefore facilitate highly localized drug delivery as well as benefit other transcranial ultrasound techniques that use higher pressure levels and higher precision to induce the necessary bioeffects in a brain region while avoiding damage to the surrounding healthy tissue. PMID:26394091

  6. Chirp- and random-based coded ultrasonic excitation for localized blood-brain barrier opening

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    Kamimura, H. A. S.; Wang, S.; Wu, S.-Y.; Karakatsani, M. E.; Acosta, C.; Carneiro, A. A. O.; Konofagou, E. E.

    2015-10-01

    Chirp- and random-based coded excitation methods have been proposed to reduce standing wave formation and improve focusing of transcranial ultrasound. However, no clear evidence has been shown to support the benefits of these ultrasonic excitation sequences in vivo. This study evaluates the chirp and periodic selection of random frequency (PSRF) coded-excitation methods for opening the blood-brain barrier (BBB) in mice. Three groups of mice (n  =  15) were injected with polydisperse microbubbles and sonicated in the caudate putamen using the chirp/PSRF coded (bandwidth: 1.5-1.9 MHz, peak negative pressure: 0.52 MPa, duration: 30 s) or standard ultrasound (frequency: 1.5 MHz, pressure: 0.52 MPa, burst duration: 20 ms, duration: 5 min) sequences. T1-weighted contrast-enhanced MRI scans were performed to quantitatively analyze focused ultrasound induced BBB opening. The mean opening volumes evaluated from the MRI were 9.38+/- 5.71 mm3, 8.91+/- 3.91 mm3and 35.47+/- 5.10 mm3 for the chirp, random and regular sonications, respectively. The mean cavitation levels were 55.40+/- 28.43 V.s, 63.87+/- 29.97 V.s and 356.52+/- 257.15 V.s for the chirp, random and regular sonications, respectively. The chirp and PSRF coded pulsing sequences improved the BBB opening localization by inducing lower cavitation levels and smaller opening volumes compared to results of the regular sonication technique. Larger bandwidths were associated with more focused targeting but were limited by the frequency response of the transducer, the skull attenuation and the microbubbles optimal frequency range. The coded methods could therefore facilitate highly localized drug delivery as well as benefit other transcranial ultrasound techniques that use higher pressure levels and higher precision to induce the necessary bioeffects in a brain region while avoiding damage to the surrounding healthy tissue.

  7. Real-time, transcranial monitoring of safe blood-brain barrier opening in non-human primates.

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    Fabrice Marquet

    Full Text Available The delivery of drugs to specific neural targets faces two fundamental problems: (1 most drugs do not cross the blood-brain barrier, and (2 those that do, spread to the entire brain. To date, there exists only one non-invasive methodology with the potential to solve these problems: selective blood-brain barrier (BBB opening using micro-bubble enhanced focused ultrasound. We have recently developed a single-element 500-kHz spherical transducer ultrasound setup for targeted BBB opening in the non-human primate that does not require simultaneous MRI monitoring. So far, however, the targeting accuracy that can be achieved with this system has not been quantified systematically. In this paper, the accuracy of this system was tested by targeting caudate nucleus and putamen of the basal ganglia in two macaque monkeys. The average lateral targeting error of the system was ∼2.5 mm while the axial targeting error, i.e., along the ultrasound path, was ∼1.5 mm. We have also developed a real-time treatment monitoring technique based on cavitation spectral analysis. This technique also allowed for delineation of a safe and reliable acoustic parameter window for BBB opening. In summary, the targeting accuracy of the system was deemed to be suitable to reliably open the BBB in specific sub-structures of the basal ganglia even in the absence of MRI-based verification of opening volume and position. This establishes the method and the system as a potentially highly useful tool for brain drug delivery.

  8. Permeability dependence study of the focused ultrasound-induced blood-brain barrier opening at distinct pressures and microbubble diameters using DCE-MRI.

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    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.

  9. Acoustic cavitation-based monitoring of the reversibility and permeability of ultrasound-induced blood-brain barrier opening

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    Sun, Tao; Samiotaki, Gesthimani; Wang, Shutao; Acosta, Camilo; Chen, Cherry C.; Konofagou, Elisa E.

    2015-12-01

    Cavitation events seeded by microbubbles have been previously reported to be associated with MR- or fluorescent-contrast enhancement after focused ultrasound (FUS)-induced blood-brain barrier (BBB) opening. However, it is still unknown whether bubble activity can be correlated with the reversibility (the duration of opening and the likelihood of safe reinstatement) and the permeability of opened BBB, which is critical for the clinical translation of using passive cavitation detection to monitor, predict and control the opening. In this study, the dependence of acoustic cavitation on the BBB opening duration, permeability coefficient and histological damage occurrence were thus investigated. Transcranial pulsed FUS at 1.5 MHz in the presence of systemically circulating microbubbles was applied in the mouse hippocampi (n  =  60). The stable and inertial cavitation activities were monitored during sonication. Contrast-enhanced MRI was performed immediately after sonication and every 24 h up to 6 d thereafter, to assess BBB opening, brain tissue permeability and potential edema. Histological evaluations were used to assess the occurrence of neurovascular damages. It was found that stable cavitation was well correlated with: (1) the duration of the BBB opening (r2  =  0.77) (2) the permeability of the opened BBB (r2  =  0.82) (3) the likelihood of safe opening (P  drug circulation time. In addition, avoiding adverse effects in the brain and assessing the pharmacokinetics of the compounds delivered can also be achieved by monitoring and controlling the stable cavitation emissions.

  10. Focused ultrasound-induced blood-brain barrier opening to enhance temozolomide delivery for glioblastoma treatment: a preclinical study.

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    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.

  11. Feasibility study of a single-element transcranial focused ultrasound system for blood-brain barrier opening

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    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.

  12. The Dependence of the Ultrasound-Induced Blood-Brain Barrier Opening Characteristics on Microbubble Size In Vivo

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    Choi, James J.; Feshitan, Jameel A.; Wang, Shougang; Tung, Yao-Sheng; Baseri, Babak; Borden, Mark A.; Konofagou, Elisa E.

    2009-04-01

    Recent neuropharmaceutical developments have led to potent disease-modifying drugs. In spite of these advancements, most agents cannot traverse the blood-brain barrier (BBB) and deposit in the brain. Focused ultrasound (FUS) with microbubbles has been shown to induce noninvasive, localized, and transient BBB opening. Although promising, safety and efficacy concerns still remain. Previously reported experiments used conventional imaging contrast agents that have a wide size distribution. In this study, we hypothesize that BBB opening characteristics are dependent on bubble diameter. A 25 μl bolus of in-house manufactured, lipid-shelled bubbles with either 1-2 or 4-5 μm diameter ranges was injected intravenously. Pulsed FUS (frequency: 1.5 MHz, peak-negative pressure: 146-607 kPa, duty cycle: 20%, duration: 1-min) was then applied to the left hippocampus of mice (n = 16) in vivo through the intact skin and skull. MRI or fluorescence microscopy was used to determine BBB opening. Contrast-enhanced (Omniscan™; 0.75 mL; molecular weight: 574 Da) MRI (9.4-T) was acquired on multiple days after sonication to determine BBB opening and closing. Fluorescence microscopy was also used to determine the feasibility of delivering large, 3 kDa dextran compounds through the BBB. The BBB opening acoustic pressure threshold for the 4-5μm bubbles was in the 146-304 kPa range while the threshold for the 1-2μm bubbles was higher. In conclusion, FUS-induced BBB opening and closing was shown to be dependent on the bubble diameter indicating the possibility of specifically designing bubbles to enhance this therapeutic application.

  13. Acoustic cavitation-based monitoring of the reversibility and permeability of ultrasound-induced blood-brain barrier opening.

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    Sun, Tao; Samiotaki, Gesthimani; Wang, Shutao; Acosta, Camilo; Chen, Cherry C; Konofagou, Elisa E

    2015-12-07

    Cavitation events seeded by microbubbles have been previously reported to be associated with MR- or fluorescent-contrast enhancement after focused ultrasound (FUS)-induced blood-brain barrier (BBB) opening. However, it is still unknown whether bubble activity can be correlated with the reversibility (the duration of opening and the likelihood of safe reinstatement) and the permeability of opened BBB, which is critical for the clinical translation of using passive cavitation detection to monitor, predict and control the opening. In this study, the dependence of acoustic cavitation on the BBB opening duration, permeability coefficient and histological damage occurrence were thus investigated. Transcranial pulsed FUS at 1.5 MHz in the presence of systemically circulating microbubbles was applied in the mouse hippocampi (n  =  60). The stable and inertial cavitation activities were monitored during sonication. Contrast-enhanced MRI was performed immediately after sonication and every 24 h up to 6 d thereafter, to assess BBB opening, brain tissue permeability and potential edema. Histological evaluations were used to assess the occurrence of neurovascular damages. It was found that stable cavitation was well correlated with: (1) the duration of the BBB opening (r(2)  =  0.77); (2) the permeability of the opened BBB (r(2)  =  0.82); (3) the likelihood of safe opening (P  cavitation dose was correlated with the resulting BBB permeability (r(2)  =  0.72). Stable cavitation was found to be more reliable than inertial cavitation at assessing the BBB opening within the pressure range used in this study. This study demonstrates that the stable cavitation response during BBB opening holds promise for predicting and controlling the restoration and pharmacokinetics of FUS-opened BBB. The stable cavitation response therefore showed great promise in predicting the BBB opening duration, enabling thus control of opening according to the drug

  14. Permeability dependence study of the focused ultrasound-induced blood-brain barrier opening at distinct pressures and microbubble diameters using DCE-MRI

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    Vlachos, Fotios; TUNG, YAO-SHENG; Konofagou, Elisa

    2011-01-01

    Blood-brain barrier (BBB) opening using focused ultrasound (FUS) and microbubbles has been experimentally established as a non-invasive and localized brain drug delivery technique. In this study, the permeability of the opening is assessed in the murine hippocampus after the application of FUS at three different acoustic pressures and microbubble sizes. Using DCE-MRI, the transfer rates were estimated, yielding permeability maps and quantitative Ktrans values for a predefined region of intere...

  15. In vivo transcranial cavitation threshold detection during ultrasound-induced blood-brain barrier opening in mice.

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    Tung, Yao-Sheng; Vlachos, Fotios; Choi, James J; Deffieux, Thomas; Selert, Kirsten; Konofagou, Elisa E

    2010-10-21

    The in vivo cavitation response associated with blood-brain barrier (BBB) opening as induced by transcranial focused ultrasound (FUS) in conjunction with microbubbles was studied in order to better identify the underlying mechanism in its noninvasive application. A cylindrically focused hydrophone, confocal with the FUS transducer, was used as a passive cavitation detector (PCD) to identify the threshold of inertial cavitation (IC) in the presence of Definity® microbubbles (mean diameter range: 1.1-3.3 µm, Lantheus Medical Imaging, MA, USA). A vessel phantom was first used to determine the reliability of the PCD prior to in vivo use. A cerebral blood vessel was simulated by generating a cylindrical channel of 610 µm in diameter inside a polyacrylamide gel and by saturating its volume with microbubbles. The microbubbles were sonicated through an excised mouse skull. Second, the same PCD setup was employed for in vivo noninvasive (i.e. transdermal and transcranial) cavitation detection during BBB opening. After the intravenous administration of Definity® microbubbles, pulsed FUS was applied (frequency: 1.525 or 1.5 MHz, peak-rarefactional pressure: 0.15-0.60 MPa, duty cycle: 20%, PRF: 10 Hz, duration: 1 min with a 30 s interval) to the right hippocampus of twenty-six (n = 26) mice in vivo through intact scalp and skull. T1 and T2-weighted MR images were used to verify the BBB opening. A spectrogram was generated at each pressure in order to detect the IC onset and duration. The threshold of BBB opening was found to be at a 0.30 MPa peak-rarefactional pressure in vivo. Both the phantom and in vivo studies indicated that the IC pressure threshold had a peak-rarefactional amplitude of 0.45 MPa. This indicated that BBB opening may not require IC at or near the threshold. Histological analysis showed that BBB opening could be induced without any cellular damage at 0.30 and 0.45 MPa. In conclusion, the cavitation response could be detected without craniotomy in mice

  16. In vivo transcranial cavitation threshold detection during ultrasound-induced blood-brain barrier opening in mice

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    Tung, Yao-Sheng; Vlachos, Fotios; Choi, James J; Deffieux, Thomas; Selert, Kirsten; Konofagou, Elisa E, E-mail: ek2191@columbia.ed [Department of Biomedical Engineering, Columbia University, New York, NY (United States)

    2010-10-21

    The in vivo cavitation response associated with blood-brain barrier (BBB) opening as induced by transcranial focused ultrasound (FUS) in conjunction with microbubbles was studied in order to better identify the underlying mechanism in its noninvasive application. A cylindrically focused hydrophone, confocal with the FUS transducer, was used as a passive cavitation detector (PCD) to identify the threshold of inertial cavitation (IC) in the presence of Definity (registered) microbubbles (mean diameter range: 1.1-3.3 {mu}m, Lantheus Medical Imaging, MA, USA). A vessel phantom was first used to determine the reliability of the PCD prior to in vivo use. A cerebral blood vessel was simulated by generating a cylindrical channel of 610 {mu}m in diameter inside a polyacrylamide gel and by saturating its volume with microbubbles. The microbubbles were sonicated through an excised mouse skull. Second, the same PCD setup was employed for in vivo noninvasive (i.e. transdermal and transcranial) cavitation detection during BBB opening. After the intravenous administration of Definity (registered) microbubbles, pulsed FUS was applied (frequency: 1.525 or 1.5 MHz, peak-rarefactional pressure: 0.15-0.60 MPa, duty cycle: 20%, PRF: 10 Hz, duration: 1 min with a 30 s interval) to the right hippocampus of twenty-six (n = 26) mice in vivo through intact scalp and skull. T1 and T2-weighted MR images were used to verify the BBB opening. A spectrogram was generated at each pressure in order to detect the IC onset and duration. The threshold of BBB opening was found to be at a 0.30 MPa peak-rarefactional pressure in vivo. Both the phantom and in vivo studies indicated that the IC pressure threshold had a peak-rarefactional amplitude of 0.45 MPa. This indicated that BBB opening may not require IC at or near the threshold. Histological analysis showed that BBB opening could be induced without any cellular damage at 0.30 and 0.45 MPa. In conclusion, the cavitation response could be detected

  17. Peripheral nerve injury and TRPV1-expressing primary afferent C-fibers cause opening of the blood-brain barrier

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    Salter Michael W

    2010-11-01

    Full Text Available Abstract Background The blood-brain barrier (BBB plays the crucial role of limiting exposure of the central nervous system (CNS to damaging molecules and cells. Dysfunction of the BBB is critical in a broad range of CNS disorders including neurodegeneration, inflammatory or traumatic injury to the CNS, and stroke. In peripheral tissues, the vascular-tissue permeability is normally greater than BBB permeability, but vascular leakage can be induced by efferent discharge activity in primary sensory neurons leading to plasma extravasation into the extravascular space. Whether discharge activity of sensory afferents entering the CNS may open the BBB or blood-spinal cord barrier (BSCB remains an open question. Results Here we show that peripheral nerve injury (PNI produced by either sciatic nerve constriction or transecting two of its main branches causes an increase in BSCB permeability, as assessed by using Evans Blue dye or horseradish peroxidase. The increase in BSCB permeability was not observed 6 hours after the PNI but was apparent 24 hours after the injury. The increase in BSCB permeability was transient, peaking about 24-48 hrs after PNI with BSCB integrity returning to normal levels by 7 days. The increase in BSCB permeability was prevented by administering the local anaesthetic lidocaine at the site of the nerve injury. BSCB permeability was also increased 24 hours after electrical stimulation of the sciatic nerve at intensity sufficient to activate C-fibers, but not when A-fibers only were activated. Likewise, BSCB permeability increased following application of capsaicin to the nerve. The increase in permeability caused by C-fiber stimulation or by PNI was not anatomically limited to the site of central termination of primary afferents from the sciatic nerve in the lumbar cord, but rather extended throughout the spinal cord and into the brain. Conclusions We have discovered that injury to a peripheral nerve and electrical stimulation of C

  18. Calcium-activated potassium channels mediated blood-brain tumor barrier opening in a rat metastatic brain tumor model

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    Ong John M

    2007-03-01

    Full Text Available Abstract Background The blood-brain tumor barrier (BTB impedes the delivery of therapeutic agents to brain tumors. While adequate delivery of drugs occurs in systemic tumors, the BTB limits delivery of anti-tumor agents into brain metastases. Results In this study, we examined the function and regulation of calcium-activated potassium (KCa channels in a rat metastatic brain tumor model. We showed that intravenous infusion of NS1619, a KCa channel agonist, and bradykinin selectively enhanced BTB permeability in brain tumors, but not in normal brain. Iberiotoxin, a KCa channel antagonist, significantly attenuated NS1619-induced BTB permeability increase. We found KCa channels and bradykinin type 2 receptors (B2R expressed in cultured human metastatic brain tumor cells (CRL-5904, non-small cell lung cancer, metastasized to brain, human brain microvessel endothelial cells (HBMEC and human lung cancer brain metastasis tissues. Potentiometric assays demonstrated the activity of KCa channels in metastatic brain tumor cells and HBMEC. Furthermore, we detected higher expression of KCa channels in the metastatic brain tumor tissue and tumor capillary endothelia as compared to normal brain tissue. Co-culture of metastatic brain tumor cells and brain microvessel endothelial cells showed an upregulation of KCa channels, which may contribute to the overexpression of KCa channels in tumor microvessels and selectivity of BTB opening. Conclusion These findings suggest that KCa channels in metastatic brain tumors may serve as an effective target for biochemical modulation of BTB permeability to enhance selective delivery of chemotherapeutic drugs to metastatic brain tumors.

  19. Barrier mechanisms in the Drosophila blood-brain barrier

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    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.

  20. Markers for blood-brain barrier integrity

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

    2015-01-01

    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...... 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...

  1. Barrier mechanisms in the Drosophila blood-brain barrier

    OpenAIRE

    Samantha Jane Hindle; Roland Jerome Bainton

    2014-01-01

    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 funct...

  2. AIDS and the blood-brain barrier

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    Ivey, Nathan S.; MacLean, Andrew G.; Lackner, Andrew A.

    2009-01-01

    The blood-brain barrier (BBB) plays a critical role in normal physiology of the central nervous system by regulating what reaches the brain from the periphery. The BBB also plays a major role in neurologic disease including neuropathologic sequelae associated with infection by human immunodeficiency virus (HIV) in humans and the closely related simian immunodeficiency virus (SIV) in macaques. In this review, we provide an overview of the function, structure and components of the BBB, followed...

  3. Enhanced delivery and bioactivity of the neurturin neurotrophic factor through focused ultrasound-mediated blood--brain barrier opening in vivo.

    Science.gov (United States)

    Samiotaki, Gesthimani; Acosta, Camilo; Wang, Shutao; Konofagou, Elisa E

    2015-03-31

    The blood-brain barrier (BBB) constitutes a major obstacle in brain drug delivery. Focused ultrasound (FUS) in conjunction with microbubbles has been shown to open the BBB noninvasively, locally, and transiently to allow large molecules diffusion. Neurturin (NTN), a member of the glial-derived neurotrophic factor (GDNF) family, has been demonstrated to have neuroprotective and regenerative effects on dopaminergic neurons in vivo using invasive drug delivery methods. The brain's ascending nigrostriatal pathway is severely damaged in Parkinson's disease (PD), and therefore the substantia nigra (SN) and striatal caudoputamen (CP) were selected as the target areas. The objective of the study was to investigate whether safe and efficient NTN delivery can be achieved through FUS-induced BBB opening via intravenous administration, and thus trigger the neuroregeneration cascade in the nigrostriatal pathway. After the optimization of FUS parameters and target locations in the murine brain, NTN bioavailability and downstream signaling were detected and characterized through immunostaining. FUS significantly enhanced the delivery of NTN compared with the direct injection technique, whereas triggering of the signaling cascade was detected downstream to the neuronal nuclei. These findings thus indicate the potential of the FUS method to mediate transport of proteins through the blood-brain barrier in a PD animal model.

  4. 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.

  5. 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.

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

    OpenAIRE

    Avsenik Jernej; Bisdas Sotirios; Popovic Katarina Surlan

    2015-01-01

    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 patholog...

  7. Focused Ultrasound-Induced Blood-Brain Barrier Opening: Association with Mechanical Index and Cavitation Index Analyzed by Dynamic Contrast-Enhanced Magnetic-Resonance Imaging

    Science.gov (United States)

    Chu, Po-Chun; Chai, Wen-Yen; Tsai, Chih-Hung; Kang, Shih-Tsung; Yeh, Chih-Kuang; Liu, Hao-Li

    2016-09-01

    Focused ultrasound (FUS) with microbubbles can temporally open the blood-brain barrier (BBB), and the cavitation activities of microbubbles play a key role in the BBB-opening process. Previous attempts used contrast-enhanced magnetic resonance imaging (CE-MRI) to correlate the mechanical index (MI) with the scale of BBB-opening, but MI only partially gauged acoustic activities, and CE-MRI did not fully explore correlations of pharmacodynamic/pharmacokinetic behaviors. Recently, the cavitation index (CI) has been derived to serve as an indicator of microbubble-ultrasound stable cavitation, and may also serve as a valid indicator to gauge the level of FUS-induced BBB opening. This study investigates the feasibility of gauging FUS-induced BBB opened level via the two indexes, MI and CI, through dynamic contrast-enhanced (DCE)-MRI analysis as well as passive cavitation detection (PCD) analysis. Pharmacodynamic/pharmacokinetic parameters derived from DCE-MRI were characterized to identify the scale of FUS-induced BBB opening. Our results demonstrated that DCE-MRI can successfully access pharmacodynamic/pharmacokinetic BBB-opened behavior, and was highly correlated both with MI and CI, implying the feasibility in using these two indices to gauge the scale of FUS-induced BBB opening. The proposed finding may facilitate the design toward using focused ultrasound as a safe and reliable noninvasive CNS drug delivery.

  8. Drug-loaded bubbles with matched focused ultrasound excitation for concurrent blood-brain barrier opening and brain-tumor drug delivery.

    Science.gov (United States)

    Fan, Ching-Hsiang; Ting, Chien-Yu; Chang, Yuan-Chih; Wei, Kuo-Chen; Liu, Hao-Li; Yeh, Chih-Kuang

    2015-03-01

    Focused ultrasound (FUS) with microbubbles has been used to achieve local blood-brain barrier opening (BBB opening) and increase the penetration of therapeutic drugs into brain tumors. However, inertial cavitation of microbubbles during FUS-induced BBB opening causes intracerebral hemorrhaging (ICH), leading to acute and chronic brain injury and limiting the efficiency of drug delivery. Here we investigated whether induction of drug (1,3-bis(2-chloroethyl)-1-nitrosourea, BCNU)-loaded bubbles (BCNU bubbles) to oscillate at their resonant frequency would reduce inertial cavitation during BBB opening, thereby eliminating ICH and enhancing drug delivery in a rat brain model. FUS was tested at 1 and 10 MHz, over a wide range of pressure (mechanical index ranging from 0.16 to 1.42) in the presence of BCNU bubbles. Excitation of BCNU bubbles by resonance frequency-matched FUS (10 MHz) resulted in predominantly stable cavitation and significantly reduced the occurrence of potential hazards of exposure to biological tissues during the BBB opening process. In addition, the drug release process could be monitored by acoustic emission obtained from ultrasound imaging. In tumor-bearing animals, BCNU bubbles with FUS showed significant control of tumor progression and improved maximum survival from 26 to 35 days. This study provides useful advancements toward the goal of successfully translating FUS theranostic bubble-enhanced brain drug delivery into clinical use.

  9. Low-Pressure Burst-Mode Focused Ultrasound Wave Reconstruction and Mapping for Blood-Brain Barrier Opening: A Preclinical Examination

    Science.gov (United States)

    Xia, Jingjing; Tsui, Po-Hsiang; Liu, Hao-Li

    2016-06-01

    Burst-mode focused ultrasound (FUS) exposure has been shown to induce transient blood-brain barrier (BBB) opening for potential CNS drug delivery. FUS-BBB opening requires imaging guidance during the intervention, yet current imaging technology only enables postoperative outcome confirmation. In this study, we propose an approach to visualize short-burst low-pressure focal beam distribution that allows to be applied in FUS-BBB opening intervention on small animals. A backscattered acoustic-wave reconstruction method based on synchronization among focused ultrasound emission, diagnostic ultrasound receiving and passively beamformed processing were developed. We observed that focal beam could be successfully visualized for in vitro FUS exposure with 0.5–2 MHz without involvement of microbubbles. The detectable level of FUS exposure was 0.467 MPa in pressure and 0.05 ms in burst length. The signal intensity (SI) of the reconstructions was linearly correlated with the FUS exposure level both in-vitro (r2 = 0.9878) and in-vivo (r2 = 0.9943), and SI level of the reconstructed focal beam also correlated with the success and level of BBB-opening. The proposed approach provides a feasible way to perform real-time and closed-loop control of FUS-based brain drug delivery.

  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. Pharmacodynamic and therapeutic investigation of focused ultrasound-induced blood-brain barrier opening for enhanced temozolomide delivery in glioma treatment.

    Directory of Open Access Journals (Sweden)

    Hao-Li Liu

    Full Text Available Focused ultrasound (FUS exposure with the presence of microbubbles has been shown to transiently open the blood-brain barrier (BBB, and thus has potential to enhance the delivery of various kinds of therapeutic agents into brain tumors. The purpose of this study was to assess the preclinical therapeutic efficacy of FUS-BBB opening for enhanced temozolomide (TMZ delivery in glioma treatment. FUS exposure with microbubbles was delivered to open the BBB of nude mice that were either normal or implanted with U87 human glioma cells. Different TMZ dose regimens were tested, ranging from 2.5 to 25 mg/kg. Plasma and brain samples were obtained at different time-points ranging from 0.5 to 4 hours, and the TMZ concentration within samples was quantitated via a developed LC-MS/MS procedure. Tumor progression was followed with T2-MRI, and animal survival and brain tissue histology were conducted. Results demonstrated that FUS-BBB opening caused the local TMZ accumulation in the brain to increase from 6.98 to 19 ng/mg. TMZ degradation time in the tumor core was found to increase from 1.02 to 1.56 hours. Improved tumor progression and animal survival were found at different TMZ doses (up to 15% and 30%, respectively. In conclusion, this study provides preclinical evidence that FUS-BBB opening increases the local concentration of TMZ to improve the control of tumor progression and animal survival, suggesting the potential for clinical application to improve current brain tumor treatment.

  12. Long-Term Safety of Repeated Blood-Brain Barrier Opening via Focused Ultrasound with Microbubbles in Non-Human Primates Performing a Cognitive Task.

    Directory of Open Access Journals (Sweden)

    Matthew E Downs

    Full Text Available Focused Ultrasound (FUS coupled with intravenous administration of microbubbles (MB is a non-invasive technique that has been shown to reliably open (increase the permeability of the blood-brain barrier (BBB in multiple in vivo models including non-human primates (NHP. This procedure has shown promise for clinical and basic science applications, yet the safety and potential neurological effects of long term application in NHP requires further investigation under parameters shown to be efficacious in that species (500 kHz, 200-400 kPa, 4-5 μm MB, 2 minute sonication. In this study, we repeatedly opened the BBB in the caudate and putamen regions of the basal ganglia of 4 NHP using FUS with systemically-administered MB over 4-20 months. We assessed the safety of the FUS with MB procedure using MRI to detect edema or hemorrhaging in the brain. Contrast enhanced T1-weighted MRI sequences showed a 98% success rate for openings in the targeted regions. T2-weighted and SWI sequences indicated a lack edema in the majority of the cases. We investigated potential neurological effects of the FUS with MB procedure through quantitative cognitive testing of' visual, cognitive, motivational, and motor function using a random dot motion task with reward magnitude bias presented on a touchpanel display. Reaction times during the task significantly increased on the day of the FUS with MB procedure. This increase returned to baseline within 4-5 days after the procedure. Visual motion discrimination thresholds were unaffected. Our results indicate FUS with MB can be a safe method for repeated opening of the BBB at the basal ganglia in NHP for up to 20 months without any long-term negative physiological or neurological effects with the parameters used.

  13. Real-time monitoring of focused ultrasound blood-brain barrier opening via subharmonic acoustic emission detection: implementation of confocal dual-frequency piezoelectric transducers.

    Science.gov (United States)

    Tsai, Chih-Hung; Zhang, Jia-Wei; Liao, Yi-Yi; Liu, Hao-Li

    2016-04-07

    Burst-tone focused ultrasound exposure in the presence of microbubbles has been demonstrated to be effective at inducing temporal and local opening of the blood-brain barrier (BBB), which promises significant clinical potential to deliver therapeutic molecules into the central nervous system (CNS). Traditional contrast-enhanced imaging confirmation after focused ultrasound (FUS) exposure serves as a post-operative indicator of the effectiveness of FUS-BBB opening, however, an indicator that can concurrently report the BBB status and BBB-opening effectiveness is required to provide effective feedback to implement this treatment clinically. In this study, we demonstrate the use of subharmonic acoustic emission detection with implementation on a confocal dual-frequency piezoelectric ceramic structure to perform real-time monitoring of FUS-BBB opening. A confocal dual-frequency (0.55 MHz/1.1 MHz) focused ultrasound transducer was designed. The 1.1 MHz spherically-curved ceramic was employed to deliver FUS exposure to induce BBB-opening, whereas the outer-ring 0.55 MHz ceramic was employed to detect the subharmonic acoustic emissions originating from the target position. In stage-1 experiments, we employed spectral analysis and performed an energy spectrum density (ESD) calculation. An optimized 0.55 MHz ESD level change was shown to effectively discriminate the occurrence of BBB-opening. Wideband acoustic emissions received from 0.55 MHz ceramics were also analyzed to evaluate its correlations with erythrocyte extravasations. In stage-2 real-time monitoring experiments, we applied the predetermined ESD change as a detection threshold in PC-controlled algorithm to predict the FUS exposure intra-operatively. In stage-1 experiment, we showed that subharmonic ESD presents distinguishable dynamics between intact BBB and opened BBB, and therefore a threshold ESD change level (5.5 dB) can be identified for BBB-opening prediction. Using this ESD change threshold detection as a

  14. Real-time monitoring of focused ultrasound blood-brain barrier opening via subharmonic acoustic emission detection: implementation of confocal dual-frequency piezoelectric transducers

    Science.gov (United States)

    Tsai, Chih-Hung; Zhang, Jia-Wei; Liao, Yi-Yi; Liu, Hao-Li

    2016-04-01

    Burst-tone focused ultrasound exposure in the presence of microbubbles has been demonstrated to be effective at inducing temporal and local opening of the blood-brain barrier (BBB), which promises significant clinical potential to deliver therapeutic molecules into the central nervous system (CNS). Traditional contrast-enhanced imaging confirmation after focused ultrasound (FUS) exposure serves as a post-operative indicator of the effectiveness of FUS-BBB opening, however, an indicator that can concurrently report the BBB status and BBB-opening effectiveness is required to provide effective feedback to implement this treatment clinically. In this study, we demonstrate the use of subharmonic acoustic emission detection with implementation on a confocal dual-frequency piezoelectric ceramic structure to perform real-time monitoring of FUS-BBB opening. A confocal dual-frequency (0.55 MHz/1.1 MHz) focused ultrasound transducer was designed. The 1.1 MHz spherically-curved ceramic was employed to deliver FUS exposure to induce BBB-opening, whereas the outer-ring 0.55 MHz ceramic was employed to detect the subharmonic acoustic emissions originating from the target position. In stage-1 experiments, we employed spectral analysis and performed an energy spectrum density (ESD) calculation. An optimized 0.55 MHz ESD level change was shown to effectively discriminate the occurrence of BBB-opening. Wideband acoustic emissions received from 0.55 MHz ceramics were also analyzed to evaluate its correlations with erythrocyte extravasations. In stage-2 real-time monitoring experiments, we applied the predetermined ESD change as a detection threshold in PC-controlled algorithm to predict the FUS exposure intra-operatively. In stage-1 experiment, we showed that subharmonic ESD presents distinguishable dynamics between intact BBB and opened BBB, and therefore a threshold ESD change level (5.5 dB) can be identified for BBB-opening prediction. Using this ESD change threshold detection as a

  15. 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.

  16. 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.

  17. Paramagnetic perfluorocarbon-filled albumin-(Gd-DTPA) microbubbles for the induction of focused-ultrasound-induced blood-brain barrier opening and concurrent MR and ultrasound imaging

    Science.gov (United States)

    Liao, Ai-Ho; Liu, Hao-Li; Su, Chia-Hao; Hua, Mu-Yi; Yang, Hung-Wei; Weng, Yu-Ting; Hsu, Po-Hung; Huang, Sheng-Min; Wu, Shih-Yen; Wang, Hsin-Ell; Yen, Tzu-Chen; Li, Pai-Chi

    2012-05-01

    This paper presents new albumin-shelled Gd-DTPA microbubbles (MBs) that can concurrently serve as a dual-modality contrast agent for ultrasound (US) imaging and magnetic resonance (MR) imaging to assist blood-brain barrier (BBB) opening and detect intracerebral hemorrhage (ICH) during focused ultrasound brain drug delivery. Perfluorocarbon-filled albumin-(Gd-DTPA) MBs were prepared with a mean diameter of 2320 nm and concentration of 2.903×109 MBs ml-1 using albumin-(Gd-DTPA) and by sonication with perfluorocarbon (C3F8) gas. The albumin-(Gd-DTPA) MBs were then centrifuged and the procedure was repeated until the free Gd3+ ions were eliminated (which were detected by the xylenol orange sodium salt solution). The albumin-(Gd-DTPA) MBs were also characterized and evaluated both in vitro and in vivo by US and MR imaging. Focused US was used with the albumin-(Gd-DTPA) MBs to induce disruption of the BBB in 18 rats. BBB disruption was confirmed with contrast-enhanced T1-weighted turbo-spin-echo sequence MR imaging. Heavy T2*-weighted 3D fast low-angle shot sequence MR imaging was used to detect ICH. In vitro US imaging experiments showed that albumin-(Gd-DTPA) MBs can significantly enhance the US contrast in T1-, T2- and T2*-weighted MR images. The r1 and r2 relaxivities for Gd-DTPA were 7.69 and 21.35 s-1mM-1, respectively, indicating that the MBs represent a positive contrast agent in T1-weighted images. In vivo MR imaging experiments on 18 rats showed that focused US combined with albumin-(Gd-DTPA) MBs can be used to both induce disruption of the BBB and detect ICH. To compare the signal intensity change between pure BBB opening and BBB opening accompanying ICH, albumin-(Gd-DTPA) MB imaging can provide a ratio of 5.14 with significant difference (p = 0.026), whereas Gd-DTPA imaging only provides a ratio of 2.13 and without significant difference (p = 0.108). The results indicate that albumin-(Gd-DTPA) MBs have potential as a US/MR dual-modality contrast agent for

  18. The bubble-dependent mechanism of FUS-induced blood-brain barrier opening in mice and in monkeys in vivo

    Science.gov (United States)

    Tung, Yao-Sheng; Marquet, Fabrice; Vlachos, Fotios; Feshitan, Jameel A.; Borden, Mark A.; Konofagou, Elisa E.

    2012-10-01

    The blood-brain barrier (BBB) prevents most neurological drugs from traversing from the cerebral microvasculature into the brain parenchyma. Previous studies have shown that the presence of bubbles in an acoustic field temporarily opens the BBB. The BBB opening pressure threshold was previously identified to lie between 0.30 and 0.46 MPa in the case of the smaller bubbles and between 0.15 and 0.30 MPa in the larger bubble case. However, the physical effects responsible for BBB opening remain unknown. In addition, the noninvasive in vivo cavitation detection with mono-dispersed microbubbles has not been studied as of yet. The purpose of this study is to unveil the physical mechanism of the FUS-induced BBB opening with monodispersed microbubbles. Lipid-shelled microbubbles with three different diameters (1-2, 4-5 and 6-8 μm) were manufactured in-house and size-isolated using differential centrifugation. Sixty-seven (n=67) mice were each injected intravenously with bubbles of either 1-2, 4-5 or 6-8 μm in diameter and the concentration of 107 numbers/mL. The right hippocampus of each mouse was then sonicated using focused ultrasound (1.5 MHz frequency; 100 cycles (67 μs) pulse length; 10 Hz pulse repetition frequency; 1 minute sonication duration) while the left hippocampus served as the control. A 10-MHz transducer was used as a passive cavitation detector (PCD) to determine the threshold of inertial cavitation (IC). Each mouse was sonicated at a specific acoustic peak-rarefactional pressure at 0.15, 0.30, 0.45 or 0.60 MPa in order to identify the threshold of BBB opening and IC. T1-weighted MRI was used to verify the BBB opening and spectrograms were generated in order to detect the IC onset and duration. Our results suggest that the BBB opens as a result of nonlinear (harmonic) bubble oscillation when the bubble diameter is similar to the capillary diameter and with inertial cavitation when it is not. The bubble may thus have to be in contact with the capillary

  19. Magnetic-resonance imaging for kinetic analysis of permeability changes during focused ultrasound-induced blood-brain barrier opening and brain drug delivery.

    Science.gov (United States)

    Chai, Wen-Yen; Chu, Po-Chun; Tsai, Meng-Yen; Lin, Yu-Chun; Wang, Jiun-Jie; Wei, Kuo-Chen; Wai, Yau-Yau; Liu, Hao-Li

    2014-10-28

    Focused ultrasound (FUS) with the presence of microbubbles has been shown to induce transient and local opening of the blood-brain barrier (BBB) for the delivery of therapeutic molecules which normally cannot penetrate into the brain. The success of FUS brain-drug delivery relies on its integration with in-vivo imaging to monitor kinetic change of therapeutic molecules into the brain. In this study, we developed a dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) technique for kinetic analysis of delivered molecules during FUS-BBB opening. Three kinetic parameters (Ktrans, Ve, Kep) were characterized dynamically to describe BBB-permeability at two FUS exposure conditions (0.4 or 0.8MPa) over 24h. Ktrans, defined as the influx volume transfer constant from plasma to EES, and Ve, the EES volume fraction, were both found to be pressure-dependent. Ktrans and Ve showed a peak increase of 0.0086-0.0131min(-1) (for 0.4-0.8MPa pressure), and 0.0431-0.0692, respectively, immediately after FUS exposure. Both parameters subsequently decreased exponentially as a function of time, with estimated half-lives of decay of 2.89-5.3 and 2.2-4.93h, respectively. The kinetics of Kep, defined as the efflux rate constant from the extracellular extravascular space (EES) to the plasma, were complementary to Ktrans, with an initial decrease from 0.2010 to 0.1901min(-1) followed by a significantly longer recovery time (half-life of 17.39-99.92h). Our observations strongly supported the existence of imbalanced and mismatched kinetics of influx (Ktrans) and efflux (Kep) between the plasma and EES, indicating the existence of directional permeability during FUS-BBB opening. We further showed that kinetic change determined by DCE-MRI correlated well with the concentration of Evans Blue (EB)-albumin (coefficient of 0.74-0.89). These findings suggest that MRI kinetic monitoring may serve as an alternative method for in-vivo monitoring of pharmacokinetics and pharmacodynamics (PK

  20. Non-invasive, neuron-specific gene therapy by focused ultrasound-induced blood-brain barrier opening in Parkinson's disease mouse model.

    Science.gov (United States)

    Lin, Chung-Yin; Hsieh, Han-Yi; Chen, Chiung-Mei; Wu, Shang-Rung; Tsai, Chih-Hung; Huang, Chiung-Yin; Hua, Mu-Yi; Wei, Kuo-Chen; Yeh, Chih-Kuang; Liu, Hao-Li

    2016-08-10

    Focused ultrasound (FUS)-induced with microbubbles (MBs) is a promising technique for noninvasive opening of the blood-brain barrier (BBB) to allow targeted delivery of therapeutic substances into the brain and thus the noninvasive delivery of gene vectors for CNS treatment. We have previously demonstrated that a separated gene-carrying liposome and MBs administration plus FUS exposure can deliver genes into the brain, with the successful expression of the reporter gene and glial cell line-derived neurotrophic factor (GDNF) gene. In this study, we further modify the delivery system by conjugating gene-carrying liposomes with MBs to improve the GDNF gene-delivery efficiency, and to verify the possibility of using this system to perform treatment in the 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced animal disease model. FUS-BBB opening was verified by contrast-enhanced MRI, and GFP gene expression was verified via in vivo imaging system (IVIS). Western blots as well as enzyme-linked immunosorbent assay (ELISA) were conducted to measure protein expression, and immunohistochemistry (IHC) was conducted to test the Tyrosine hydroxylase (TH)-neuron distribution. Dopamine (DA) and its metabolites as well as dopamine active transporter (DAT) were quantitatively analyzed to show dopaminergic neuronal dopamine secretion/activity/metabolism. Motor performance was evaluated by rotarod test weekly. Results demonstrated that the LpDNA-MBs (gene-liposome-MBs) complexes successfully serve as gene carrier and BBB-opening catalyst, and outperformed the separated LpDNA/MBs administration both in terms of gene delivery and expression. TH-positive IHC and measurement of DA and its metabolites DOPAC and HVA confirmed improved neuronal function, and the proposed system also provided the best neuroprotective effect to retard the progression of motor-related behavioral abnormalities. Immunoblotting and histological staining further confirmed the expression of reporter genes in

  1. Salicylic acid analogues as chemical exchange saturation transfer MRI contrast agents for the assessment of brain perfusion territory and blood-brain barrier opening after intra-arterial infusion.

    Science.gov (United States)

    Song, Xiaolei; Walczak, Piotr; He, Xiaowei; Yang, Xing; Pearl, Monica; Bulte, Jeff Wm; Pomper, Martin G; McMahon, Michael T; Janowski, Mirosław

    2016-07-01

    The blood-brain barrier (BBB) is a major obstacle for drug delivery to the brain. Predicted, focal opening of the BBB through intra-arterial infusion of hyperosmolar mannitol is feasible, but there is a need to facilitate imaging techniques (e.g. MRI) to guide interventional procedures and assess the outcomes. Here, we show that salicylic acid analogues (SAA) can depict the brain territory supplied by the catheter and detect the BBB opening, through chemical exchange saturation transfer (CEST) MRI. Hyperosmolar SAA solutions themselves are also capable of opening the BBB, and, when multiple SAA agents were co-injected, their locoregional perfusion could be differentiated.

  2. The Blood-Brain Barrier: An Engineering Perspective

    OpenAIRE

    Andrew eWong; Mao eYe; Amanda eLevy; Jeffrey eRothstein; Dwight eBergles; Peter Charles Searson

    2013-01-01

    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...

  3. Blood-brain barrier dysfunction in Parkinsonian midbrain in vivo

    NARCIS (Netherlands)

    Kortekaas, R; Leenders, KL; van Oostrom, JCH; Vaalburg, W; Bart, J; Willemsen, ATM; Hendrikse, NH

    2005-01-01

    Parkinson's disease (PD) is associated with a loss of neurons from the midbrain. The cause of PD is unknown, but it is established that certain neurotoxins can cause similar syndromes. The brain is normally protected from these noxious blood-borne chemicals by the blood-brain barrier which includes

  4. Increasing oxime efficacy by blood-brain barrier modulation

    NARCIS (Netherlands)

    Joosen, M.J.A.; Schans, M.J. van der; Dijk, C.G.M. van; Kuijpers, W.C.; Wortelboer, H.M.; Helden, H.P.M. van

    2011-01-01

    One of the shortcomings of current treatment of nerve agent poisoning is that oximes hardly penetrate the blood-brain barrier (BBB), whereas nerve agents easily do. Increasing the concentration of oximes in the brain, would therefore provide an attractive approach to improve medical countermeasures.

  5. Mathematical modelling of blood-brain barrier failure and edema

    Science.gov (United States)

    Waters, Sarah; Lang, Georgina; Vella, Dominic; Goriely, Alain

    2015-11-01

    Injuries such as traumatic brain injury and stroke can result in increased blood-brain barrier permeability. This increase may lead to water accumulation in the brain tissue resulting in vasogenic edema. Although the initial injury may be localised, the resulting edema causes mechanical damage and compression of the vasculature beyond the original injury site. We employ a biphasic mixture model to investigate the consequences of blood-brain barrier permeability changes within a region of brain tissue and the onset of vasogenic edema. We find that such localised changes can indeed result in brain tissue swelling and that the type of damage that results (stress damage or strain damage) depends on the ability of the brain to clear edema fluid.

  6. Focused Ultrasound-Induced Neurogenesis Requires an Increase in Blood-Brain Barrier Permeability

    Science.gov (United States)

    Mooney, Skyler J.; Shah, Kairavi; Yeung, Sharon; Burgess, Alison; Aubert, Isabelle; Hynynen, Kullervo

    2016-01-01

    Transcranial focused ultrasound technology used to transiently open the blood-brain barrier, is capable of stimulating hippocampal neurogenesis; however, it is not yet known what aspects of the treatment are necessary for enhanced neurogenesis to occur. The present study set out to determine whether the opening of blood-brain barrier, the specific pressure amplitudes of focused ultrasound, and/or the intravenous administration of microbubbles (phospholipid microspheres) are necessary for the enhancement of neurogenesis. Specifically, mice were exposed to burst (10ms, 1Hz burst repetition frequency) focused ultrasound at the frequency of 1.68MHz and with 0.39, 0.78, 1.56 and 3.0MPa pressure amplitudes. These treatments were also conducted with or without microbubbles, at 0.39 + 0.78MPa or 1.56 + 3.0MPa, respectively. Only focused ultrasound at the ~0.78 MPa pressure amplitude with microbubbles promoted hippocampal neurogenesis and was associated with an increase in blood-brain barrier permeability. These results suggest that focused ultrasound -mediated neurogenesis is dependent upon the opening of the blood-brain barrier. PMID:27459643

  7. The blood-brain barrier: an engineering perspective

    OpenAIRE

    Wong, Andrew D.; Ye, Mao; Levy, Amanda F.; Rothstein, Jeffrey D.; Bergles, Dwight E.; Searson, Peter C.

    2013-01-01

    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 this selective permeability 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...

  8. Alterations of Blood Brain Barrier Function in Hyperammonemia: An Overview

    OpenAIRE

    2011-01-01

    Ammonia is a neurotoxin involved in the pathogenesis of neurological conditions associated with hyperammonemia, including hepatic encephalopathy, a condition associated with acute—(ALF) or chronic liver failure. This article reviews evidence that apart from directly affecting the metabolism and function of the central nervous system cells, ammonia influences the passage of different molecules across the blood brain barrier (BBB). A brief description is provided of the tight junctions, which c...

  9. 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...

  10. 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.

  11. Epstein Barr Virus and Blood Brain Barrier in Multiple Sclerosis

    Science.gov (United States)

    2014-01-01

    Multiple sclerosis (MS) is a chronic, autoimmune neurodegenerative disease. Epstein-Barr virus (EBV) infection is associated with MS pathogenesis. However, mechanism for the EBV-MS connection is unclear. The blood brain barrier (BBB) is a separation of circulating blood and the brain extracellular fluid in the central nervous system. BBB contains both endothelial cells as well as astrocytes. Interestingly EBV is able to infect both kinds of cells. Because EBV is able to transfer infection from one cell type to another cell type, it is thus hypothesized that EBV uses

  12. Striatal blood-brain barrier permeability in Parkinson's disease.

    Science.gov (United States)

    Gray, Madison T; Woulfe, John M

    2015-05-01

    In vivo studies have shown that blood-brain barrier (BBB) dysfunction is involved in the course of Parkinson's disease (PD). However, these have lacked either anatomic definition or the ability to recognize minute changes in BBB integrity. Here, using histologic markers of serum protein, iron, and erythrocyte extravasation, we have shown significantly increased permeability of the BBB in the postcommissural putamen of PD patients. The dense innervation of the striatum by PD-affected regions allows for exploitation of this permeability for therapeutic goals. These results are also discussed in the context of the retrograde trans-synaptic hypothesis of PD spread.

  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. Impact of migraine attacks on the blood-brain barrier

    Institute of Scientific and Technical Information of China (English)

    GAO Hong-mei; LI Le; ZHANG Ke-ling; CHEN Xu-hui; TIAN Shu-qing; ZHANG Zhong-ling

    2010-01-01

    Background Cortical spreading depression can cause migraine attack, and up-regulate matrix metalloproteinase-9 (MMP-9) expression in animal. This study aimed to determine the impact on the structure and function of the blood-brain barrier by measuring plasma MMP-9 levels in patients at the acute and late stages of migraine attacks in order to elucidate the pathological mechanisms involved.Methods We recruited a case-control cohort of 38 adult migraine patients and 20 age- and gender-matched healthy control subjects. Five milliliter blood samples were collected at the acute and late stages of migraine (days 1-7), and also from the control subjects. Solid phase double antibody sandwich enzyme-linked immunosorbent assay was used to determine plasma MMP-9 levels. Statistical analysis was performed using the SAS version 9.1.Results Initial plasma MMP-9 levels of migraine patients were significantly higher than those of controls ((12.612±0.016)μg/L vs. (6.069±0.023) μg/L, respectively, P 0.05); in addition, levels were not correlated with degree of headache pain (P >0.05).Conclusions We hypothesize that migraine could lead to increased plasma MMP-9 levels resulting in blood-brain barrier damage. MMP-9 levels increase during days 1-6 of migraine attacks, peaking on day 3. Therefore, MMP-9 could be used as a biological marker to guide treatment of migraine attacks.

  15. A neurovascular blood-brain barrier in vitro model.

    Science.gov (United States)

    Zehendner, Christoph M; White, Robin; Hedrich, Jana; Luhmann, Heiko J

    2014-01-01

    The cerebral microvasculature possesses certain cellular features that constitute the blood-brain barrier (BBB) (Abbott et al., Neurobiol Dis 37:13-25, 2010). This dynamic barrier separates the brain parenchyma from peripheral blood flow and is of tremendous clinical importance: for example, BBB breakdown as in stroke is associated with the development of brain edema (Rosenberg and Yang, Neurosurg Focus 22:E4, 2007), inflammation (Kuhlmann et al., Neurosci Lett 449:168-172, 2009; Coisne and Engelhardt, Antioxid Redox Signal 15:1285-1303, 2011), and increased mortality. In vivo, the BBB consists of brain endothelial cells (BEC) that are embedded within a precisely regulated environment containing astrocytes, pericytes, smooth muscle cells, and glial cells. These cells experience modulation by various pathways of intercellular communication and by pathophysiological processes, e.g., through neurovascular coupling (Attwell et al., Nature 468:232-243, 2010), cortical spreading depression (Gursoy-Ozdemir et al., J Clin Invest 113:1447-1455, 2004), or formation of oxidative stress (Yemisci et al., Nat Med 15:1031-1037, 2009). Hence, this interdependent assembly of cells is referred to as the neurovascular unit (NVU) (Zlokovic, Nat Med 16:1370-1371, 2010; Zlokovic, Neuron 57:178-201, 2008). Experimental approaches to investigate the BBB in vitro are highly desirable to study the cerebral endothelium in health and disease. However, due to the complex interactions taking place within the NVU in vivo, it is difficult to mimic this interplay in vitro.Here, we describe a murine blood-brain barrier coculture model consisting of cortical organotypic slice cultures and brain endothelial cells that includes most of the cellular components of the NVU including neurons, astrocytes, and brain endothelial cells. This model allows the experimental analysis of several crucial BBB parameters such as transendothelial electrical resistance or tight junction protein localization by

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

    DEFF Research Database (Denmark)

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

    . 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......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...

  17. Astrocytic modulation of blood brain barrier: perspectives on Parkinson's disease.

    Science.gov (United States)

    Cabezas, Ricardo; Avila, 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.

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

    Science.gov (United States)

    Dubois, Luiz Gustavo; Campanati, Loraine; Righy, Cassia; D’Andrea-Meira, Isabella; Spohr, Tania Cristina Leite de Sampaio e; Porto-Carreiro, Isabel; Pereira, Claudia Maria; Balça-Silva, Joana; Kahn, Suzana Assad; DosSantos, Marcos F.; Oliveira, Marcela de Almeida Rabello; Ximenes-da-Silva, Adriana; Lopes, Maria Celeste; Faveret, Eduardo; Gasparetto, Emerson Leandro; Moura-Neto, Vivaldo

    2014-01-01

    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 BBB and the concerns that arise when this barrier is affected. PMID:25565956

  19. Cyclodextrins, blood-brain barrier, and treatment of neurological diseases.

    Science.gov (United States)

    Vecsernyés, Miklós; Fenyvesi, Ferenc; Bácskay, Ildikó; Deli, Mária A; Szente, Lajos; Fenyvesi, Éva

    2014-11-01

    Biological barriers are the main defense systems of the homeostasis of the organism and protected organs. The blood-brain barrier (BBB), formed by the endothelial cells of brain capillaries, not only provides nutrients and protection to the central nervous system but also restricts the entry of drugs, emphasizing its importance in the treatment of neurological diseases. Cyclodextrins are increasingly used in human pharmacotherapy. Due to their favorable profile to form hydrophilic inclusion complexes with poorly soluble active pharmaceutical ingredients, they are present as excipients in many marketed drugs. Application of cyclodextrins is widespread in formulations for oral, parenteral, nasal, pulmonary, and skin delivery of drugs. Experimental and clinical data suggest that cyclodextrins can be used not only as excipients for centrally acting marketed drugs like antiepileptics, but also as active pharmaceutical ingredients to treat neurological diseases. Hydroxypropyl-β-cyclodextrin received orphan drug designation for the treatment of Niemann-Pick type C disease. In addition to this rare lysosomal storage disease with neurological symptoms, experimental research revealed the potential therapeutic use of cyclodextrins and cyclodextrin nanoparticles in neurodegenerative diseases, stroke, neuroinfections and brain tumors. In this context, the biological effects of cyclodextrins, their interaction with plasma membranes and extraction of different lipids are highly relevant at the level of the BBB.

  20. Alterations of blood brain barrier function in hyperammonemia: an overview.

    Science.gov (United States)

    Skowrońska, Marta; Albrecht, Jan

    2012-02-01

    Ammonia is a neurotoxin involved in the pathogenesis of neurological conditions associated with hyperammonemia, including hepatic encephalopathy, a condition associated with acute--(ALF) or chronic liver failure. This article reviews evidence that apart from directly affecting the metabolism and function of the central nervous system cells, ammonia influences the passage of different molecules across the blood brain barrier (BBB). A brief description is provided of the tight junctions, which couple adjacent cerebral capillary endothelial cells to each other to form the barrier. Ammonia modulates the transcellular passage of low-to medium-size molecules, by affecting their carriers located at the BBB. Ammonia induces interrelated aberrations of the transport of the large neutral amino acids and aromatic amino acids (AAA), whose influx is augmented by exchange with glutamine produced in the course of ammonia detoxification, and maybe also modulated by the extracellularly acting gamma-glutamyl moiety transferring enzyme, gamma-glutamyl-transpeptidase. Impaired AAA transport affects neurotransmission by altering intracerebral synthesis of catecholamines (serotonin and dopamine), and producing "false neurotransmitters" (octopamine and phenylethylamine). Ammonia also modulates BBB transport of the cationic amino acids: the nitric oxide precursor, arginine, and ornithine, which is an ammonia trap, and affects the transport of energy metabolites glucose and creatine. Moreover, ammonia acting either directly or in synergy with liver injury-derived inflammatory cytokines also evokes subtle increases of the transcellular passage of molecules of different size (BBB "leakage"), which appears to be responsible for the vasogenic component of cerebral edema associated with ALF.

  1. [The blood-brain barrier and neurodegenerative lysosomal storage diseases].

    Science.gov (United States)

    Urayama, Akihiko

    2013-02-01

    Enzyme replacement therapy has been a very effective treatment for several lysosomal storage diseases. However, correcting central nervous system (CNS) storage has been challenging due to the presence of the blood-brain barrier (BBB), which hampers the entry of circulating lysosomal enzymes into the brain. In our previous studies, we discovered that luminally expressed cation-independent mannose 6-phosphate (M6P) receptor is a universal transporter for lysosomal enzymes that contain M6P moieties on the enzyme molecule. This receptor-mediated transport of lysosomal enzymes showed developmental down-regulation that resulted in a failure of delivery of lysosomal enzymes across the BBB in the adult brain. Conceptually, if one can re-induce M6P receptor-mediated transport of lysosomal enzymes in adult BBB, this could provide a novel brain targeting approach for treating abnormal storage in the CNS, regardless of the age of subjects. We found that systemic adrenergic stimuli restored functional transport of β-glucuronidase across the adult BBB. The concept of manipulating BBB transport activity by endogenous characteristics has also been demonstrated by another group who showed effective treatment in a Pompe disease model animal in vivo. It is intriguing that lysosomal enzymes utilize multiple mechanisms for their transport across the BBB. This review explores pharmacological manipulations for the delivery of lysosomal enzymes into the CNS, and the mechanisms of their transport across the BBB, based on existing evidence from studies of β-glucuronidase, sulfamidase, acid α-glucosidase, and arylsulfatase A.

  2. Transport characteristics of tramadol in the blood-brain barrier.

    Science.gov (United States)

    Kitamura, Atsushi; Higuchi, Kei; Okura, Takashi; Deguchi, Yoshiharu

    2014-10-01

    Tramadol is a centrally acting analgesic whose action is mediated by both agonistic activity at opioid receptors and inhibitory activity on neuronal reuptake of monoamines. The purpose of this study was to characterize the blood-brain barrier (BBB) transport of tramadol by means of microdialysis studies in rat brain and in vitro studies with human immortalized brain capillary endothelial cells (hCMEC/D3). The Kp,uu,brain value of tramadol determined by rat brain microdialysis was greater than unity, indicating that tramadol is actively taken up into the brain across the BBB. Tramadol was transported into hCMEC/D3 cells in a concentration-dependent manner. The uptake was inhibited by type II cations (pyrilamine, verapamil, etc.), but not by substrates of organic cation transporter OCTs or OCTN2. It was also inhibited by a metabolic inhibitor but was independent of extracellular sodium or membrane potential. The uptake was altered by changes of extracellular pH, and by ammonium chloride-induced intracellular acidification, suggesting that transport of tramadol is driven by an oppositely directed proton gradient. Thus, our in vitro and in vivo results suggest that tramadol is actively transported, at least in part, from blood to the brain across the BBB by proton-coupled organic cation antiporter.

  3. Blood-Brain Barrier Breakdown in the Aging Human Hippocampus

    Science.gov (United States)

    Montagne, Axel; Barnes, Samuel R.; Sweeney, Melanie D.; Halliday, Matthew R.; Sagare, Abhay P.; Zhao, Zhen; Toga, Arthur W.; Jacobs, Russell E.; Liu, Collin Y.; Amezcua, Lilyana; Harrington, Michael G.; Chui, Helena C.; Law, Meng; Zlokovic, Berislav V.

    2014-01-01

    Summary The blood-brain barrier (BBB) limits entry of blood-derived products, pathogens and cells into the brain that is essential for normal neuronal functioning and information processing. Post-mortem tissue analysis indicates BBB damage in Alzheimer’s disease (AD). The timing of BBB breakdown remains, however, elusive. Using an advanced dynamic contrast-enhanced magnetic resonance imaging protocol with high spatial and temporal resolutions to quantify regional BBB permeability in the living human brain, we show an age-dependent BBB breakdown in the hippocampus, a region critical for learning and memory that is affected early in AD. The BBB breakdown in the hippocampus and its CA1 and dentate gyrus subdivisions worsened with mild cognitive impairment that correlated with injury to BBB-associated pericytes, as shown by the cerebrospinal fluid analysis. Our data suggest that BBB breakdown is an early event in the aging human brain that begins in the hippocampus and may contribute to cognitive impairment. PMID:25611508

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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.

  6. Mechanisms of restriction of viral neuroinvasion at the blood-brain barrier.

    Science.gov (United States)

    Miner, Jonathan J; Diamond, Michael S

    2016-02-01

    The blood-brain barrier (BBB) consists of highly specialized cells including brain microvascular endothelial cells, astrocytes, microglia, pericytes, and neurons, which act in concert to restrict the entry of pathogens, immune cells, and soluble molecules into the central nervous system (CNS). If pathogens manage to cross the BBB and establish infection within the CNS, the BBB can open in a regulated manner to allow leukocyte transmigration into the CNS so that microbes, infected cells, and debris can be cleared. This review highlights how different inflammatory cytokines or signaling pathways disrupt or enhance BBB integrity in a way that regulates entry of neurotropic viruses into the CNS.

  7. Blood-Brain Barrier Changes in High Altitude.

    Science.gov (United States)

    Lafuente, José V; Bermudez, Garazi; Camargo-Arce, Lorena; Bulnes, Susana

    2016-01-01

    Cerebral syndromes related to high-altitude exposure are becoming more frequent as the number of trips to high altitudes has increased in the last decade. The commonest symptom is headache, followed by acute mountain sickness (AMS) and high-altitude cerebral edema (HACE), which can be fatal. The pathophysiology of these syndromes is not fully understood. The classical "tight-fit hypothesis" posits that there are some anatomical variations that would obstruct the sinovenous outflow and worsen vasogenic edema and intracranial hypertension reactive to hypoxia. This could explain microhemorrhages seen in autopsies. However, recent magnetic resonance imaging studies have demonstrated some components of cytotoxic edema in HACE absent in AMS, suggesting a dysfunction in water balance at the cellular level. Currently, the "red-ox theory" supports trigemino-vascular system activation by free radicals formed after hypoxia and the consequent oxidative stress cascades. Apart from trigemino-vascular system activation, free radicals can also provoke membrane destabilisation mediated by lipid peroxidation, inflammation, and local hypoxia inducible factor-1α and vascular endothelial growth factor activation, resulting in gross blood-brain barrier (BBB) dysfunction. Besides alterations in endothelial cells such as increased pinocytotic vesicles and disassembly of interendothelial tight junction proteins, capillary permeability may also increase with subsequent swelling of astrocyte end-feet. In conclusion, although the pathophysiology of AMS and HACE is not completely understood, recent evidence proposes a multifactorial entity, with brain swelling and compromise of the BBB considered to play an important role. A fuller comprehension of these processes is crucial to reduce and prevent BBB alterations during high-altitude exposure.

  8. Nanoscale drug delivery systems and the blood-brain barrier.

    Science.gov (United States)

    Alyautdin, Renad; Khalin, Igor; Nafeeza, Mohd Ismail; Haron, Muhammad Huzaimi; Kuznetsov, Dmitry

    2014-01-01

    The protective properties of the blood-brain barrier (BBB) are conferred by the intricate architecture of its endothelium coupled with multiple specific transport systems expressed on the surface of endothelial cells (ECs) in the brain's vasculature. When the stringent control of the BBB is disrupted, such as following EC damage, substances that are safe for peripheral tissues but toxic to neurons have easier access to the central nervous system (CNS). As a consequence, CNS disorders, including degenerative diseases, can occur independently of an individual's age. Although the BBB is crucial in regulating the biochemical environment that is essential for maintaining neuronal integrity, it limits drug delivery to the CNS. This makes it difficult to deliver beneficial drugs across the BBB while preventing the passage of potential neurotoxins. Available options include transport of drugs across the ECs through traversing occludins and claudins in the tight junctions or by attaching drugs to one of the existing transport systems. Either way, access must specifically allow only the passage of a particular drug. In general, the BBB allows small molecules to enter the CNS; however, most drugs with the potential to treat neurological disorders other than infections have large structures. Several mechanisms, such as modifications of the built-in pumping-out system of drugs and utilization of nanocarriers and liposomes, are among the drug-delivery systems that have been tested; however, each has its limitations and constraints. This review comprehensively discusses the functional morphology of the BBB and the challenges that must be overcome by drug-delivery systems and elaborates on the potential targets, mechanisms, and formulations to improve drug delivery to the CNS.

  9. Preventive administration of cromakalim reduces aquaporin-4 expression and blood-brain barrier permeability in a rat model of cerebral ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Shilei Wang; Yanting Wang; Yan Jiang; Qingxian Chang; Peng Wang; Shiduan Wang

    2011-01-01

    Cromakalim, an adenosine triphosphate-sensitive potassium channel opener, exhibits protective effects on cerebral ischemia/reperfusion injury. However, there is controversy as to whether this effect is associated with aquaporin-4 and blood-brain barrier permeability. Immunohistochemistry results show that preventive administration of cromakalim decreased aquaporin-4 and IgG protein expression in rats with ischemia/reperfusion injury; it also reduced blood-brain barrier permeability, and alleviated brain edema, ultimately providing neuroprotection.

  10. 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.

  11. Bypassing the blood-brain barrier: delivery of therapeutic agents by macrophages

    Science.gov (United States)

    Hirschberg, Henry; Baek, Seung-Kuk; Kwon, Young Jik; Sun, Chung-Ho; Madsen, Steen J.

    2010-02-01

    Introduction: Failure to eradicate infiltrating glioma cells using conventional treatment regimens results in tumor recurrence and is responsible for the dismal prognosis of patients with glioblastoma multiforme (GBM). This is due to the fact that these migratory cells are protected by the blood-brain barrier (BBB) and the blood brain tumor barrier (BBTB) which prevents the delivery of most anti-cancer agents. We have evaluated the ability of monocytes/macrophages (Mo/Ma) to cross the BBB in rats. This will permit access of anti-cancer agents such as nanoparticles to effectively target the infiltrating tumor cells, and potentially improve the treatment effectiveness for malignant gliomas. Materials and Methods: The infiltration of Mo/Ma into brain tumor spheroids in vitro was determined using fluorescent stained Mo/Ma. Tumors were also established in the brains of inbred rats and ALA-PDT was given 18 days following tumor induction. The degredation of the BBTB and quantification of the number of infiltrating Mo/Ma was examined on histological sections from removed brains. Results & Conclusion: PDT was highly effective in locally opening the BBTB and inducing macrophage migration into the irradiated portions of brain tumors.

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

    NARCIS (Netherlands)

    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 cros

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Review: Role of developmental inflammation and blood-brain barrier dysfunction in neurodevelopmental and neurodegenerative diseases.

    Science.gov (United States)

    Stolp, H B; Dziegielewska, K M

    2009-04-01

    The causes of most neurological disorders are not fully understood. Inflammation and blood-brain barrier dysfunction appear to play major roles in the pathology of these diseases. Inflammatory insults that occur during brain development may have widespread effects later in life for a spectrum of neurological disorders. In this review, a new hypothesis suggesting a mechanistic link between inflammation and blood-brain barrier function (integrity), which is universally important in both neurodevelopmental and neurodegenerative diseases, is proposed. The role of inflammation and the blood-brain barrier will be discussed in cerebral palsy, schizophrenia, Parkinson's disease, Alzheimer's disease and multiple sclerosis, conditions where both inflammation and blood-brain barrier dysfunction occur either during initiation and/or progression of the disease. We suggest that breakdown of normal blood-brain barrier function resulting in a short-lasting influx of blood-born molecules, in particular plasma proteins, may cause local damage, such as reduction of brain white matter observed in some newborn babies, but may also be the mechanism behind some neurodegenerative diseases related to underlying brain damage and long-term changes in barrier properties.

  15. Characterization of an in vitro Rhesus Macaque Blood-Brain Barrier

    Science.gov (United States)

    MacLean, Andrew G.; Orandle, Marlene S.; MacKey, John; Williams, Kenneth C.; Alvarez, Xavier; Lackner, Andrew A.

    2013-01-01

    The blood-brain barrier has been modeled in vitro in a number of species, including rat, cow and human. Coculture of multiple cell types is required for the correct expression of tight junction proteins by microvascular brain endothelial cells (MBEC). Markers of inflammation, especially MHC-II, and cell adhesion molecules, such as VCAM-1, are not expressed on the luminal surface of the barrier under resting conditions. The rhesus macaque model has been used to study early events of HIV-neuropathogenesis in vivo, but a suitable in vitro model has not been available for detailed mechanistic studies. Here we describe an in vitro rhesus macaque blood-brain barrier (BBB) that utilizes autologous MBEC and astrocytes. We believe that this model is highly relevant for examining immunological events at the blood-brain barrier and demonstrate its potential usefulness for examining early events in AIDS neuropathogenesis. PMID:12458041

  16. Aquaporin 4 expression and ultrastructure of the blood-brain barrier following cerebral contusion injury

    Institute of Scientific and Technical Information of China (English)

    Xinjun Li; Yangyun Han; Hong Xu; Zhongshu Sun; Zengjun Zhou; Xiaodong Long; Yumin Yang; Linbo Zou

    2013-01-01

    This study aimed to investigate aquaporin 4 expression and the ultrastructure of the blood-brain barrier at 2–72 hours following cerebral contusion injury, and correlate these changes to the formation of brain edema. Results revealed that at 2 hours after cerebral contusion and laceration injury, aquaporin 4 expression significantly increased, brain water content and blood-brain barrier permeability increased, and the number of pinocytotic vesicles in cerebral microvascular endothelial cells increased. In addition, the mitochondrial accumulation was observed. As contusion and laceration injury became aggravated, aquaporin 4 expression continued to increase, brain water content and blood-brain barrier permeability gradually increased, brain capillary endothelial cells and astrocytes swelled, and capillary basement membrane injury gradually increased. The above changes were most apparent at 12 hours after injury, after which they gradually attenuated. Aquaporin 4 expression positively correlated with brain water content and the blood-brain barrier index. Our experimental findings indicate that increasing aquaporin 4 expression and blood-brain barrier permeability after cerebral contusion and laceration injury in humans is involved in the formation of brain edema.

  17. Changes in blood-brain barrier function modify the neuroendocrine response to circulating substances.

    Science.gov (United States)

    Jezová, D; Johansson, B B; Oprsalová, Z; Vigas, M

    1989-04-01

    It is known that various experimental, pathological and even physiological situations may be accompanied by transient increases in blood-brain barrier (BBB) permeability. The hypothesis that under such conditions the blood-borne substances can reach the active sites in the brain in concentrations high enough to influence central control of hormone release was verified in these studies. A suitable experimental model of BBB opening by protamine sulfate administration in conscious rats was introduced. Using this model it was shown that the dopaminergic blocker domperidone inhibited apomorphine-induced ACTH release if permeability of the BBB was increased, but not under normal conditions. It is suggested that the changes in BBB function can modify the neuroendocrine response also to other circulating substances and this may be an important, until now unconsidered phenomenon in neuroendocrine research.

  18. 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.

  19. Focused ultrasound-mediated drug delivery through the blood-brain barrier.

    Science.gov (United States)

    Burgess, Alison; Shah, Kairavi; Hough, Olivia; Hynynen, Kullervo

    2015-05-01

    Despite recent advances in blood-brain barrier (BBB) research, it remains a significant hurdle for the pharmaceutical treatment of brain diseases. Focused ultrasound (FUS) is one method to transiently increase permeability of the BBB to promote drug delivery to specific brain regions. An introduction to the BBB and a brief overview of the methods, which can be used to circumvent the BBB to promote drug delivery, is provided. In particular, we discuss the advantages and limitations of FUS technology and the efficacy of FUS-mediated drug delivery in models of disease. MRI for targeting and evaluating FUS treatments, combined with administration of microbubbles, allows for transient, reproducible BBB opening. The integration of a real-time acoustic feedback controller has improved treatment safety. Successful clinical translation of FUS has the potential to transform the treatment of brain disease worldwide without requiring the development of new pharmaceutical agents.

  20. Effects of Yishendaluo decoction on blood-brain barrier integrity in mice with experimental autoimmune encephalomyelitis

    Institute of Scientific and Technical Information of China (English)

    Yanqing Wu; Ying Gao; Lingqun Zhu; Yonghong Gao; Dongmei Zhang; Lixia Lou; Yanfang Yan

    2011-01-01

    This study investigated the effects of Yishendaluo decoction on the loss of blood-brain barrier integrity in mice exhibiting experimental autoimmune encephalomyelitis.To this end,we used real-time fluorescent quantitative PCR to measure the levels of mRNAs specific to the T cell markers CD4 and CD8,and the monocyte marker CD11b.In addition,we used Evans blue dye extravasation in the spinal cord and brain tissues to assess blood-brain barrier permeability.The results indicated that an increase in blood-brain barrier permeability was associated with an increase in CD4,CD8 and CD11b mRNA expression in experimental autoimmune encephalomyelitis mice.Yishendaluo decoction administration significantly reversed inflammatory cell accumulation in cerebral tissues of experimental autoimmune encephalomyelitis mice.

  1. Is viscosity important in the production of blood-brain barrier disruption by intracarotid contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, J.; Sage, M.R.

    1984-11-01

    A canine model was used to investigate the effects of intracarotid methylglucamine iothalamate (280 mgI/ml) at different viscosities on the normal blood-brain barrier. To alter viscosity, without changing physicochemical parameters, injections were made at either 23/sup 0/C or 37/sup 0/C. The degree of blood-brain barrier damage was assessed using Evans' Blue dye as a visual marker and by contrast enhancement measured by a computed tomographic (CT) scanner. It was found that methylglucamine iothalamate caused more blood-brain barrier damage at 23/sup 0/C than at 37/sup 0/C (p<0.1). Control studies at each temperature using intracarotid injections of physiological saline showed no temperature effect (p>0.1). The implications of these findings are discussed.

  2. 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....

  3. Nanobiotechnology-based strategies for crossing the blood-brain barrier.

    Science.gov (United States)

    Jain, Kewal K

    2012-08-01

    The blood-brain barrier (BBB) is meant to protect the brain from noxious agents; however, it also significantly hinders the delivery of therapeutics to the brain. Several strategies have been employed to deliver drugs across this barrier and some of these may do structural damage to the BBB by forcibly opening it to allow the uncontrolled passage of drugs. The ideal method for transporting drugs across the BBB should be controlled and should not damage the barrier. Among the various approaches that are available, nanobiotechnology-based delivery methods provide the best prospects for achieving this ideal. This review describes various nanoparticle (NP)-based methods used for drug delivery to the brain and the known underlying mechanisms. Some strategies require multifunctional NPs combining controlled passage across the BBB with targeted delivery of the therapeutic cargo to the intended site of action in the brain. An important application of nanobiotechnology is to facilitate the delivery of drugs and biological therapeutics for brain tumors across the BBB. Although there are currently some limitations and concerns for the potential neurotoxicity of NPs, the future prospects for NP-based therapeutic delivery to the brain are excellent.

  4. Quorum Sensing Peptides Selectively Penetrate the Blood-Brain Barrier.

    Science.gov (United States)

    Wynendaele, Evelien; Verbeke, Frederick; Stalmans, Sofie; Gevaert, Bert; Janssens, Yorick; Van De Wiele, Christophe; Peremans, Kathelijne; Burvenich, Christian; De Spiegeleer, Bart

    2015-01-01

    Bacteria communicate with each other by the use of signaling molecules, a process called 'quorum sensing'. One group of quorum sensing molecules includes the oligopeptides, which are mainly produced by Gram-positive bacteria. Recently, these quorum sensing peptides were found to biologically influence mammalian cells, promoting i.a. metastasis of cancer cells. Moreover, it was found that bacteria can influence different central nervous system related disorders as well, e.g. anxiety, depression and autism. Research currently focuses on the role of bacterial metabolites in this bacteria-brain interaction, with the role of the quorum sensing peptides not yet known. Here, three chemically diverse quorum sensing peptides were investigated for their brain influx (multiple time regression technique) and efflux properties in an in vivo mouse model (ICR-CD-1) to determine blood-brain transfer properties: PhrCACET1 demonstrated comparatively a very high initial influx into the mouse brain (Kin = 20.87 μl/(g×min)), while brain penetrabilities of BIP-2 and PhrANTH2 were found to be low (Kin = 2.68 μl/(g×min)) and very low (Kin = 0.18 μl/(g×min)), respectively. All three quorum sensing peptides were metabolically stable in plasma (in vitro) during the experimental time frame and no significant brain efflux was observed. Initial tissue distribution data showed remarkably high liver accumulation of BIP-2 as well. Our results thus support the potential role of some quorum sensing peptides in different neurological disorders, thereby enlarging our knowledge about the microbiome-brain axis.

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

    NARCIS (Netherlands)

    Lammers, Twan; Koczera, Patrick; Fokong, Stanley; Gremse, Felix; Ehling, Josef; Vogt, Michael; Pich, Andrij; Storm, Gert; Zandvoort, van 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) nanop

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

    NARCIS (Netherlands)

    Lammers, Twan; Koczera, Patrick; Fokong, Stanley; Gremse, Felix; Ehling, Josef; Vogt, Michael; Pich, Andrij; Storm, G; 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) nanop

  7. Defense at the border : the blood-brain barrier versus bacterial foreigners

    NARCIS (Netherlands)

    van Sorge, Nina M.; Doran, Kelly S.

    2012-01-01

    Bacterial meningitis is among the top ten causes of infectious disease-related deaths worldwide, with up to half of the survivors left with permanent neurological sequelae. The blood-brain barrier (BBB), composed mainly of specialized brain microvascular endothelial cells, maintains biochemical home

  8. Dynamic Perfusion CT Assessment of the Blood-Brain Barrier Permeability : First Pass versus Delayed Acquisition

    NARCIS (Netherlands)

    Dankbaar, J. W.; Hom, J.; Schneider, T.; Cheng, S. -C.; Lau, B. C.; van der Schaaf, I.; Virmani, S.; Pohlman, S.; Dillon, W. P.; Wintermark, M.

    2008-01-01

    BACKGROUND AND PURPOSE: The Patlak model has been applied to first-pass perfusion CT (PCT) data to extract information on blood-brain barrier permeability (BBBP) to predict hemorrhagic transformation in patients with acute stroke. However, the Patlak model was originally described for the delayed st

  9. 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

  10. Systems pharmacology and blood-brain barrier functionality in Parkinson's disease

    NARCIS (Netherlands)

    Ravenstijn, Paulien Gerarda Maria

    2009-01-01

    Parkinson’s disease is a progressive neurodegenerative disease, which is composed of many components, each caused by interplay of a number of genetic and nongenetic causes. As the blood-brain barrier (BBB) is a key player in the relationship between plasma and brain pharmacokinetics, the influences

  11. Longitudinal assessment of blood-brain barrier leakage during epileptogenesis in rats. A quantitative MRI study.

    NARCIS (Netherlands)

    van Vliet, E.A.; Otte, W.M.; Gorter, J.A.; Dijkhuizen, R.M.; Wadman, W.J.

    2014-01-01

    The blood-brain barrier (BBB) plays an important role in the homeostasis of the brain. BBB dysfunction has been implicated in the pathophysiology of various neurological disorders, including epilepsy in which it may contribute to disease progression. Precise understanding of BBB dynamics during epil

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

    NARCIS (Netherlands)

    van Vliet, E.A.; Otte, W.M.; Wadman, W.J.; Aronica, E.; Kooij, G.; de Vries, H.E.; Dijkhuizen, R.M.; Gorter, J.A.

    2016-01-01

    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 activit

  13. 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

    2016-01-01

    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 activit

  14. In vitro models of the blood-brain barrier

    DEFF Research Database (Denmark)

    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...

  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. Matrix metalloproteinases in the brain and blood-brain barrier: Versatile breakers and makers.

    Science.gov (United States)

    Rempe, Ralf G; Hartz, Anika Ms; Bauer, Björn

    2016-09-01

    Matrix metalloproteinases are versatile endopeptidases with many different functions in the body in health and disease. In the brain, matrix metalloproteinases are critical for tissue formation, neuronal network remodeling, and blood-brain barrier integrity. Many reviews have been published on matrix metalloproteinases before, most of which focus on the two best studied matrix metalloproteinases, the gelatinases MMP-2 and MMP-9, and their role in one or two diseases. In this review, we provide a broad overview of the role various matrix metalloproteinases play in brain disorders. We summarize and review current knowledge and understanding of matrix metalloproteinases in the brain and at the blood-brain barrier in neuroinflammation, multiple sclerosis, cerebral aneurysms, stroke, epilepsy, Alzheimer's disease, Parkinson's disease, and brain cancer. We discuss the detrimental effects matrix metalloproteinases can have in these conditions, contributing to blood-brain barrier leakage, neuroinflammation, neurotoxicity, demyelination, tumor angiogenesis, and cancer metastasis. We also discuss the beneficial role matrix metalloproteinases can play in neuroprotection and anti-inflammation. Finally, we address matrix metalloproteinases as potential therapeutic targets. Together, in this comprehensive review, we summarize current understanding and knowledge of matrix metalloproteinases in the brain and at the blood-brain barrier in brain disorders.

  17. PET tracers for imaging of ABC transporters at the blood-brain barrier : Principles and Strategies

    NARCIS (Netherlands)

    Luurtsema, Gert; Elsinga, Philip; Dierckx, Rudi; Boellaard, Ronald; van Waarde, Aren

    2016-01-01

    ABC transporters at the human blood-brain barrier protect the brain against the entry of harmful compounds but may also limit (or prevent) the cerebral entry of therapeutic drugs (e.g. anti-epileptics, antidepressants and antipsychotics). The efflux function of these transporters may be impaired in

  18. St. John's Wort constituents modulate P-glycoprotein transport activity at the blood-brain barrier.

    NARCIS (Netherlands)

    Ott, M.; Huls, M.; Cornelius, M.G.; Fricker, G.

    2010-01-01

    PURPOSE: The purpose of this study was to investigate the short-term signaling effects of St. John's Wort (SJW) extract and selected SJW constituents on the blood-brain barrier transporter P-glycoprotein and to describe the role of PKC in the signaling. METHODS: Cultured porcine brain capillary endo

  19. BBB on chip: microfluidic platform to mechanically and biochemically modulate blood-brain barrier function

    NARCIS (Netherlands)

    Griep, L.M.; Wolbers, F.; Wagenaar, de B.; Braak, ter P.M.; Weksler, B.B.; Romero, A.; Couraud, P.O.; Vermes, I.; Meer, van der A.D.; Berg, van den A.

    2013-01-01

    The blood-brain barrier (BBB) is a unique feature of the human body, preserving brain homeostasis and preventing toxic substances to enter the brain. However, in various neurodegenerative diseases, the function of the BBB is disturbed. Mechanisms of the breakdown of the BBB are incompletely understo

  20. Blood-brain barrier P-glycoprotein function is not impaired in early Parkinson's disease

    NARCIS (Netherlands)

    Bartels, A. L.; van Berckel, B. N. M.; Lubberink, M.; Luurtsema, G.; Lammertsma, A. A.; Leenders, K. L.

    2008-01-01

    The cause of Parkinson's disease (PD) is unknown. Genetic susceptibility and exposure to environmental toxins contribute to specific neuronal loss in PD. Decreased blood-brain barrier (BBB) P-glycoprotein (P-gp) efflux function has been proposed as a possible causative link between toxin exposure an

  1. Blood-Brain Barrier P-Glycoprotein Function in Neurodegenerative Disease

    NARCIS (Netherlands)

    Bartels, A. L.

    2011-01-01

    Protection of the brain is strengthened by active transport and ABC transporters. P-glycoprotein (P-gp) at the blood-brain barrier (BBB) functions as an active efflux pump by extruding a substrate from the brain, which is important for maintaining loco-regional homeostasis in the brain and protectio

  2. The effect of blood brain barrier modulation on oxime efficacy in nerve agent poisoning (Abstract)

    NARCIS (Netherlands)

    Joosen, M.; Schans, M.J. van der; Dijk, C.G.M. van; Kuijpers, WC.; Wortelboer, H.M.; Helden, H.P.M. van

    2012-01-01

    One of the shortcomings of current treatment of nerve agent poisoning is that oximes hardly penetrate the blood brain barrier (BBB), whereas nerve agents easily do. Enhancing the efficacy of current oximes in the brain, would therefore provide an attractive approach to improve medical countermeasure

  3. Penetrating the Blood-Brain Barrier: Promise of Novel Nanoplatforms and Delivery Vehicles.

    Science.gov (United States)

    Ali, Iqbal Unnisa; Chen, Xiaoyuan

    2015-10-27

    Multifunctional nanoplatforms combining versatile therapeutic modalities with a variety of imaging options have the potential to diagnose, monitor, and treat brain diseases. The promise of nanotechnology can only be realized by the simultaneous development of innovative brain-targeting delivery vehicles capable of penetrating the blood-brain barrier without compromising its structural integrity.

  4. Protection of the blood-brain barrier by pentosan against amyloid-β-induced toxicity.

    Science.gov (United States)

    Deli, Mária A; Veszelka, Szilvia; Csiszár, Boglárka; Tóth, Andrea; Kittel, Agnes; Csete, Mária; Sipos, Aron; Szalai, Anikó; Fülöp, Lívia; Penke, Botond; Abrahám, Csongor S; Niwa, Masami

    2010-01-01

    Endothelial cells of brain capillaries forming the blood-brain barrier play an important role in the pathogenesis and therapy of Alzheimer's disease. Amyloid-β (Aβ) peptides are key pathological elements in the development of the disease. A blood-brain barrier model, based on primary rat brain endothelial cells was used in which the barrier properties were induced by glial cells. The effects of amyloid peptides have been tested on cell viability and barrier functions. Aβ showed toxic effects on primary rat brain endothelial cells measured by MTT dye conversion and the lactate dehydrogenase release. Morphologically cytoplasmic vacuolization, disruption of the structure of cytoplasmic organelles and tight junctions could be observed in brain endothelial cells. Treatment with Aβ1-42 decreased the electrical resistance, and increased the permeability of brain endothelial cell monolayers for both fluorescein and albumin. Serum amyloid P component which stabilizes Aβ fibrils in cortical amyloid plaques and cerebrovascular amyloid deposits significantly potentiated the barrier-weakening effect of Aβ1-42. Sulfated polysaccharide pentosan could decrease the toxic effects of Aβ peptides in brain endothelial cells. It could also significantly protect the barrier integrity of monolayers from damaging actions of peptides. Pentosan modified the size, and significantly decreased the number of amyloid aggregates demonstrated by atomic force microscopy. The present data further support the toxic effects of amyloid peptides on brain endothelial cells, and can contribute to the development of molecules protecting the blood-brain barrier in Alzheimer's disease.

  5. WR-2721 entry into the brain across a modified blood-brain barrier

    Energy Technology Data Exchange (ETDEWEB)

    Lamperti, A.; Conger, A.D.; Jenkins, O.; Cohen, G.; Rizzo, A.; Davis, M.E.; Sodicoff, M.

    1988-08-01

    Radioprotection of the CNS by WR-2721 has not been possible because of its inability to cross the blood-brain barrier (BBB) and so gain access to the neural tissue. Modification of the BBB using hypertonic arabinose (1.8 m), injected via the internal carotid artery (ica), permitted entry of ip-injected (/sup 14/C)WR-2721 into the ipsilateral cerebral hemisphere. The BBB-modified hemisphere had a 5.34-fold increased uptake compared to nonmodified controls. Delivery as a bolus via the ica further enhanced uptake after BBB opening; WR-2721 was 3.73 times greater than by ip injection. A 20-fold increase of WR-2721 brain uptake has been calculated for ica administration with the BBB opened as compared to the ip route without BBB modification. Toxicity of ip-administered WR-2721 with the BBB open was only 1.4 times greater than non-modified controls and 1.96 times more toxic when delivered via the ica. These data demonstrate significant uptake of WR-2721 into the CNS, a previously unprotected organ, and provide a model for future radioprotective studies.

  6. Peptide-Mediated Blood-Brain Barrier Transport of Polymersomes

    NARCIS (Netherlands)

    Georgieva, J.V.; Brinkhuis, R.P.; Stojanov, K.; Weijers, C.A.G.M.; Zuilhof, H.; Rutjes, F.P.J.T.; Hoekstra, D.; Hest, van J.C.M.; Zuhorn, I.S.

    2012-01-01

    A polymeric nanocarrier: Polymersomes tagged with a dodecamer peptide that recognizes gangliosides GM1 and GT1b are shown to cross the blood–brain barrier, both in an in vitro model and in vivo (see picture). The combination of polymeric vesicles with a small GM1-binding peptide and GM1/GT1b ganglio

  7. 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...... 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...

  8. 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...... 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....

  9. Derivation of blood-brain barrier endothelial cells from human pluripotent stem cells.

    Science.gov (United States)

    Lippmann, Ethan S; Azarin, Samira M; Kay, Jennifer E; Nessler, Randy A; Wilson, Hannah K; Al-Ahmad, Abraham; Palecek, Sean P; Shusta, Eric V

    2012-08-01

    The blood-brain barrier (BBB) is crucial to the health of the brain and is often compromised in neurological disease. Moreover, because of its barrier properties, this endothelial interface restricts uptake of neurotherapeutics. Thus, a renewable source of human BBB endothelium could spur brain research and pharmaceutical development. Here we show that endothelial cells derived from human pluripotent stem cells (hPSCs) acquire BBB properties when co-differentiated with neural cells that provide relevant cues, including those involved in Wnt/β-catenin signaling. The resulting endothelial cells have many BBB attributes, including well-organized tight junctions, appropriate expression of nutrient transporters and polarized efflux transporter activity. Notably, they respond to astrocytes, acquiring substantial barrier properties as measured by transendothelial electrical resistance (1,450 ± 140 Ω cm2), and they possess molecular permeability that correlates well with in vivo rodent blood-brain transfer coefficients.

  10. 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 first person to use this term seems to be Stern in the early 1920s. Studies in embryos by Stern and 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...

  11. 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

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

    Science.gov (United States)

    Cramer, Stig P; Modvig, Signe; Simonsen, Helle J; Frederiksen, Jette L; Larsson, Henrik B W

    2015-09-01

    Optic neuritis is an acute inflammatory condition that is highly associated with multiple sclerosis. Currently, the best predictor of future development of multiple sclerosis is the number of T2 lesions visualized by magnetic resonance imaging. Previous research has found abnormalities 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 as part of the diagnostic work-up at time of diagnosis. Eighteen healthy controls were included for comparison. Patients had magnetic resonance imaging and lumbar puncture performed within 4 weeks of onset of optic neuritis. Information on multiple sclerosis conversion was acquired from hospital records 2 years after optic neuritis onset. Logistic regression analysis showed that baseline permeability in normal-appearing white matter significantly improved prediction of multiple sclerosis conversion (according to the 2010 revised McDonald diagnostic criteria) within 2 years compared to T2 lesion count alone. There was no correlation between permeability and T2 lesion count. An increase in permeability in normal-appearing white matter of 0.1 ml/100 g/min increased the risk of multiple sclerosis 8.5 times whereas having more than nine T2 lesions increased the risk 52.6 times. Receiver operating characteristic curve analysis of permeability in normal-appearing white matter gave a cut-off of 0.13 ml/100 g/min, which predicted conversion to multiple sclerosis with a sensitivity of

  13. 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.

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

    DEFF Research Database (Denmark)

    Tornabene, Erica; Brodin, Birger

    2016-01-01

    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...... 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...... 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...

  15. 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

    Optic neuritis is an acute inflammatory condition that is highly associated with multiple sclerosis. Currently, the best predictor of future development of multiple sclerosis is the number of T2 lesions visualized by magnetic resonance imaging. Previous research has found abnormalities in the per......Optic neuritis is an acute inflammatory condition that is highly associated with multiple sclerosis. Currently, the best predictor of future development of multiple sclerosis is the number of T2 lesions visualized by magnetic resonance imaging. Previous research has found abnormalities...... 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...

  16. 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...... of blood pressure during electroconvulsive shocks attenuate electroconvulsive shock-induced amnestic changes; however, the evidence suggests that antihypertensive mechanisms may not necessarily be involved. Clinical studies involving pre-ECT administration of antihypertensive medications do not provide...... 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...

  17. Comparison of blood-brain barrier disruption by intracarotid iopamidol and methylglucamine iothalamate.

    Science.gov (United States)

    Sage, M R; Wilcox, J; Evill, C A; Benness, G T

    1983-01-01

    Using a canine model, the effect of intracarotid injections of the ionic contrast medium methylglucamine iothalamate was compared with that of the nonionic contrast medium iopamidol of similar iodine concentration (280 mg 1/ml). The degree and distribution of blood-brain barrier disruption was assessed using Evans blue stain as a visual marker and by contrast enhancement measured by a computed tomographic (CT) scanner. In all studies with methylglucamine iothalamate, Evans blue staining was demonstrated, and CT enhancement demonstrated a significant mean difference (p less than 0.01) between the control and injected hemispheres. The absence of blood-brain barrier disruption with iopamidol is probably related to its lower osmolality (570 mosmol/kg) compared with methylglucamine iothalamate (1,424 mosmol/kg) and the absence of any cation.

  18. Blood-brain barrier permeability of bioactive withanamides present in Withania somnifera fruit extract.

    Science.gov (United States)

    Vareed, Shaiju K; Bauer, Alison K; Nair, Kavitha M; Liu, Yunbao; Jayaprakasam, Bolleddula; Nair, Muraleedharan G

    2014-08-01

    The neuroprotective effect of Withania somnifera L. Dunal fruit extract, in rodent models, is known. Withanamides, the primary active constituents in W.somnifera fruit extract exhibited neuroprotective effects against β-amyloid-induced cytotoxicity in neuronal cell culture studies. Therefore, we investigated the blood-brain barrier permeability of withanamides in W.somnifera fruit extract in mice using HPLC coupled with high resolution quadrupole time of flight mass spectrometer (Q-TOF/MS) detection. Mice were administered with 250 mg/kg of W.somnifera extract by intraperitoneal injection, and the blood and brain samples analyzed by Q-TOF/MS detection. Four major withanamides were detected in brain and blood of mice administered with W.somnifera extract. The results suggested that the withanamides crossed the blood-brain barrier. These results may help to develop W.somnifera fruit extract as a preventive or therapeutic botanical drug for stress-induced neurological disorders.

  19. Surfactants, not size or zeta-potential influence blood-brain barrier passage of polymeric nanoparticles.

    Science.gov (United States)

    Voigt, Nadine; Henrich-Noack, Petra; Kockentiedt, Sarah; Hintz, Werner; Tomas, Jürgen; Sabel, Bernhard A

    2014-05-01

    Nanoparticles (NP) can deliver drugs across the blood-brain barrier (BBB), but little is known which of the factors surfactant, size and zeta-potential are essential for allowing BBB passage. To this end we designed purpose-built fluorescent polybutylcyanoacrylate (PBCA) NP and imaged the NP's passage over the blood-retina barrier - which is a model of the BBB - in live animals. Rats received intravenous injections of fluorescent PBCA-NP fabricated by mini-emulsion polymerisation to obtain various NP's compositions that varied in surfactants (non-ionic, anionic, cationic), size (67-464nm) and zeta-potential. Real-time imaging of retinal blood vessels and retinal tissue was carried out with in vivo confocal neuroimaging (ICON) before, during and after NP's injection. Successful BBB passage with subsequent cellular labelling was achieved if NP were fabricated with non-ionic surfactants or cationic stabilizers but not when anionic compounds were added. NP's size and charge had no influence on BBB passage and cell labelling. This transport was not caused by an unspecific opening of the BBB because control experiments with injections of unlabelled NP and fluorescent dye (to test a "door-opener" effect) did not lead to parenchymal labelling. Thus, neither NP's size nor chemo-electric charge, but particle surface is the key factor determining BBB passage. This result has important implications for NP engineering in medicine: depending on the surfactant, NP can serve one of two opposite functions: while non-ionic tensides enhance brain up-take, addition of anionic tensides prevents it. NP can now be designed to specifically enhance drug delivery to the brain or, alternatively, to prevent brain penetration so to reduce unwanted psychoactive effects of drugs or prevent environmental nanoparticles from entering tissue of the central nervous system.

  20. Radiation-induced blood-brain barrier changes: pathophysiological mechanisms and clinical implications.

    Science.gov (United States)

    d'Avella, D; Cicciarello, R; Angileri, F F; Lucerna, S; La Torre, D; Tomasello, F

    1998-01-01

    The pathophysiology of whole-brain radiation (WBR) toxicity remains incompletely understood. The possibility of a primary change in blood-brain barrier (BBB) associated with microvascular damage was investigated. Rats were exposed to conventional fractionation in radiation (200 +/- cGy/d, 5d/wk; total dose, 4,000 cGy). BBB changes were assessed by means of the quantitative 14C-alpha-aminoisobutyric acid (AIB) technique coupled with standard electron microscopy (EM) and morphometric techniques as well as studies of the transcapillary passage of horseradish peroxidase (HRP). At 15 days after WBR, AIB transport across BBB increased significantly in cerebral cortex. EM disclosed vesicular transport of HRP across the intact endothelium without opening of the tight junctions. Ninety days after WBR, well-defined alterations of the microvasculature were observed. The main feature of cortical microvessels was their collapsed aspect, associated with perivascular edema containing cell debris. Data suggest a possible association between damage of the microvascular/glial unit of tissue injury and development of radiation-induced brain cerebral dysfunction. We hypothesize the following sequence of pathophysiological events: WBR causes an early increase in BBB permeability, which produces perivascular edema and microvascular collapse. The interference with microcirculation affects blood flow and energy supply to the tissue, resulting in structural damage on an ischemic/dysmetabolic basis.

  1. Blood-brain barrier permeability after gamma whole-body irradiation: an in vivo microdialysis study

    Energy Technology Data Exchange (ETDEWEB)

    Diserbo, M.; Agin, A.; Lamproglou, I.; Mauris, J.; Staali, F.; Multon, E.; Amourette, C

    2002-07-01

    The effects of total-body irradiation on the permeability of rat striatal blood-brain barrier (BBB) to [{sup 3}H]{alpha}-aminoisobutyric acid (AIBA) and [{sup 14}C] sucrose were investigated using the microdialysis technique. Seven days, 3 and 6 weeks, and 3, 5, and 8 months after gamma exposure at a dose of 4.5 Gy, no modification of the permeability to both [{sup 3}H]AIBA and [{sup 14}C] sucrose was observed. But, in the course of the initial syndrome, we observed a significant but transient increase in the BBB permeability to the two markers between 3 and 17 h after exposure. A secondary transient 'opening' of the BBB to [{sup 14}C] sucrose was noticed about 28 h following irradiation without the corresponding increase in BBB permeability to [{sup 3}H]AIBA. On the contrary, the transport of [{sup 3}H]AIBA through the BBB was decreased between 33 and 47 h postradiation. In conclusion, our experiments showed early modifications of BBB permeability after a moderate-dose whole-body exposure. Confirmation of these results with other tracers, in another experimental model or in humans, would have clinical applications for designing appropriate pharmacotherapy in radiotherapy and treatment of accidental overexposure. (author)

  2. A fragment-based approach for the in silico prediction of blood-brain barrier permeation

    OpenAIRE

    Moda, Tiago L.; Carrara, Alexandre E.; Andricopulo, Adriano Defini

    2012-01-01

    Blood-brain barrier (BBB) permeation is an essential property for drugs that act in the central nervous system (CNS) for the treatment of human diseases, such as epilepsy, depression, Alzheimer's disease, Parkinson disease, schizophrenia, among others. In the present work, quantitative structure-property relationship (QSPR) studies were conducted for the development and validation of in silico models for the prediction of BBB permeation. The data set used has substantial chemical diversity an...

  3. Minocycline ameliorates prenatal valproic acid induced autistic behaviour, biochemistry and blood brain barrier impairments in rats.

    Science.gov (United States)

    Kumar, Hariom; Sharma, Bhupesh

    2016-01-01

    Autism is a neurodevelopment disorder. One percent worldwide population suffers with autism and males suffer more than females. Microglia plays an important role in neurodevelopment, neuropsychiatric and neurodegenerative disorders. The present study has been designed to investigate the role of minocycline in prenatal valproic acid induced autism in rats. Animals with prenatal valproic acid have reduced social interaction (three chamber social behaviour apparatus), spontaneous alteration (Y-Maze), exploratory activity (Hole board test), intestinal motility, serotonin levels (both in prefrontal cortex and ileum) and prefrontal cortex mitochondrial complex activity (complexes I, II, IV). Furthermore, prenatal valproic acid treated animals have shown an increase in locomotion (actophotometer), anxiety (elevated plus maze), brain oxidative stress (thiobarbituric acid reactive species, glutathione, catalase), nitrosative stress (nitrite/nitrate), inflammation (both in brain and ileum myeloperoxidase activity), calcium and blood brain barrier permeability. Treatment with minocycline significantly attenuated prenatal valproic acid induced reduction in social interaction, spontaneous alteration, exploratory activity intestinal motility, serotonin levels and prefrontal cortex mitochondrial complex activity. Furthermore, minocycline has also attenuated prenatal valproic acid induced increase in locomotion, anxiety, brain oxidative and nitrosative stress, inflammation, calcium and blood brain barrier permeability. Thus, it may be concluded that prenatal valproic acid has induced autistic behaviour, biochemistry and blood brain barrier impairment in animals, which were significantly attenuated by minocycline. Minocycline should be explored further for its therapeutic benefits in autism.

  4. Endothelial cells of the blood-brain barrier: a target for glucocorticoids and estrogens?

    Science.gov (United States)

    Dietrich, Jean-Bernard

    2004-01-01

    Adhesion molecules are involved in the leukocyte recruitment of leukocytes at the blood-brain barrier. For this reason, it is important to understand how the regulation of their gene expression controls lymphocyte adhesion to endothelial cells in microvessels. Indeed, due to their specificity and diversity, adhesion molecules involved in extravasation play an essential role in the recruitment of activated leukocytes and activation of inflammation. Multiple sclerosis results from a chronic inflammation of the CNS which is mediated by infiltration of inflammatory cells from the immune system. Administration of glucocorticoids is a routine method to control multiple sclerosis since naturally derived or synthetic glucocorticoids are potent immunosuppressive and anti-inflammatory agents. Glucocorticoids also have beneficial effects in stabilizing the blood-brain barrier, as steroid hormones regulate the expression of adhesion molecule genes in endothelial cells. Other hormones such as estrogens modulate many endothelial cell biological activities, among them adhesion to leukocytes. They regulate expression of adhesion molecules genes on endothelial cells and are useful for the treatment of experimental autoimmune encephalomyelitis, the animal model of multiple sclerosis. The effects of glucocorticoids and estrogens on the expression of adhesion molecules on endothelial cells, including microvascular endothelial cells of the blood-brain barrier, are reviewed in this paper, as well as the involvement of these hormones in the therapy of experimental autoimmune encephalomyelitis and multiple sclerosis.

  5. Disruption of the blood brain barrier following ALA mediated photodynamic therapy

    Science.gov (United States)

    Hirschberg, Henry; Peng, Qian; Uzal, Francisco A.; Chighvinadze, David; Zhang, Michelle J.; Madsen, Steen J.

    2008-02-01

    Introduction: Failure of treatment for high grade gliomas is usually due to local recurrence at the site of surgical resection indicating that a more aggressive form of local therapy, such as PDT, could be of benefit. PDT causes damage to tumor cells as well as degradation of the blood brain barrier (BBB). We have evaluated the ability of ALA mediated PDT to open the BBB in rats. This will permit access of chemotherapeutic agents to brain tumor cells remaining in the resection cavity wall, but limit their penetration into normal brain remote from the site of illumination. Materials and Methods: ALA-PDT was performed on non tumor bearing inbred Fisher rats at increasing fluence levels. T2 weighted MRI scans were used to evaluate edema formation and post-contrast T I MRI scans were used to monitor the degree BBB disruption which could be inferred from the intensity and volume of the contrast agent visualized. Results. PDT at increasing fluence levels between 9J and 26J demonstrated an increasing contrast flow rate. No effect on the BBB was observed if 26J of light were given in the absence of ALA. A similar increased contrast volume was observed with increasing fluence rates. The BBB was found to be disrupted 2hrs. following PDT and 80-100% restored 72hrs later. Conclusion: PDT was highly effective in opening the BBB in a limited region of the brain. The degradation of the BBB was temporary in nature, opening rapidly following treatment and significantly restored during the next 72 hrs.

  6. Characterization of an in vitro Rhesus Macaque Blood-Brain Barrier

    OpenAIRE

    2002-01-01

    The blood-brain barrier has been modeled in vitro in a number of species, including rat, cow and human. Coculture of multiple cell types is required for the correct expression of tight junction proteins by microvascular brain endothelial cells (MBEC). Markers of inflammation, especially MHC-II, and cell adhesion molecules, such as VCAM-1, are not expressed on the luminal surface of the barrier under resting conditions. The rhesus macaque model has been used to study early events of HIV-neurop...

  7. Selective disruption of the blood-brain barrier by photochemical internalization

    Science.gov (United States)

    Hirschberg, Henry; Zhang, Michelle J.; Gach, Michael H.; Uzal, Francisco A.; Chighvinadze, David; Madsen, Steen J.

    2009-02-01

    Introduction: Failure to eradicate infiltrating glioma cells using conventional treatment regimens results in tumor recurrence and is responsible for the dismal prognosis of patients with glioblastoma multiforme (GBM). This is due to the fact that these migratory cells are protected by the blood-brain barrier (BBB) which prevents the delivery of most anti-cancer agents. We have evaluated the ability of photochemical internalization (PCI) to selectively disrupt the BBB in rats. This will permit access of anti-cancer drugs to effectively target the infiltrating tumor cells, and potentially improve the treatment effectiveness for malignant gliomas. Materials and Methods: PCI treatment, coupling a macromolecule therapy of Clostridium perfringens (Cl p) epsilon prototoxin with AlPcS2a-PDT, was performed on non-tumor bearing inbred Fisher rats. T1-weighted post-contrast magnetic resonance imaging (MRI) scans were used to evaluate the extent of BBB disruption which can be inferred from the volume contrast enhancement. Results: The synergistic effect of PCI to disrupt the BBB was observed at a fluence level of 1 J with an intraperitoneal injection of Cl p prototoxin. At the fluence level of 2.5J, the extent of BBB opening induced by PCI was similar to the result of PDT suggesting no synergistic effect evoked under these conditions. Conclusion: PCI was found to be highly effective and efficient for inducing selective and localized disruption of the BBB. The extent of BBB opening peaked on day 3 and the BBB was completed restored by day 18 post treatment.

  8. Evidences of endocytosis via caveolae following blood-brain barrier breakdown by Phoneutria nigriventer spider venom.

    Science.gov (United States)

    Soares, Edilene Siqueira; Mendonça, Monique Culturato Padilha; Irazusta, Silvia Pierre; Coope, Andressa; Stávale, Leila Miguel; da Cruz-Höfling, Maria Alice

    2014-09-17

    Spider venoms contain neurotoxic peptides aimed at paralyzing prey or for defense against predators; that is why they represent valuable tools for studies in neuroscience field. The present study aimed at identifying the process of internalization that occurs during the increased trafficking of vesicles caused by Phoneutria nigriventer spider venom (PNV)-induced blood-brain barrier (BBB) breakdown. Herein, we found that caveolin-1α is up-regulated in the cerebellar capillaries and Purkinje neurons of PNV-administered P14 (neonate) and 8- to 10-week-old (adult) rats. The white matter and granular layers were regions where caveolin-1α showed major upregulation. The variable age played a role in this effect. Caveolin-1 is the central protein that controls caveolae formation. Caveolar-specialized cholesterol- and sphingolipid-rich membrane sub-domains are involved in endocytosis, transcytosis, mechano-sensing, synapse formation and stabilization, signal transduction, intercellular communication, apoptosis, and various signaling events, including those related to calcium handling. PNV is extremely rich in neurotoxic peptides that affect glutamate handling and interferes with ion channels physiology. We suggest that the PNV-induced BBB opening is associated with a high expression of caveolae frame-forming caveolin-1α, and therefore in the process of internalization and enhanced transcytosis. Caveolin-1α up-regulation in Purkinje neurons could be related to a way of neurons to preserve, restore, and enhance function following PNV-induced excitotoxicity. The findings disclose interesting perspectives for further molecular studies of the interaction between PNV and caveolar specialized membrane domains. It proves PNV to be excellent tool for studies of transcytosis, the most common form of BBB-enhanced permeability.

  9. 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.

  10. 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

  11. 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...

  12. Blood-brain barrier dysfunction-induced inflammatory signaling in brain pathology and epileptogenesis.

    Science.gov (United States)

    Kim, Soo Young; Buckwalter, Marion; Soreq, Hermona; Vezzani, Annamaria; Kaufer, Daniela

    2012-11-01

    The protection of the brain from blood-borne toxins, proteins, and cells is critical to the brain's normal function. Accordingly, a compromise in the blood-brain barrier (BBB) function accompanies many neurologic disorders, and is tightly associated with brain inflammatory processes initiated by both infiltrating leukocytes from the blood, and activation of glial cells. Those inflammatory processes contribute to determining the severity and prognosis of numerous neurologic disorders, and can both cause, and result from BBB dysfunction. In this review we examine the role of BBB and inflammatory responses, in particular activation of transforming grown factor β (TGFβ) signaling, in epilepsy, stroke, and Parkinson's disease.

  13. Role of histaminergic system in blood-brain barrier dysfunction associated with neurological disorders.

    Science.gov (United States)

    Bañuelos-Cabrera, Ivette; Valle-Dorado, María Guadalupe; Aldana, Blanca Irene; Orozco-Suárez, Sandra Adela; Rocha, Luisa

    2014-11-01

    Blood-brain barrier (BBB) disruption has been associated with several acute and chronic brain disorders such as Alzheimer's disease, Parkinson's disease and epilepsy. This represents a critical situation because damaged integrity of the BBB is related to the influx of immune mediators, plasma proteins and other outside elements from blood to the central nervous system (CNS) that may trigger a cascade of events that leads to neuroinflammation. In this review, evidence that mast cells and the release of factors such as histamine play an important role in the neuroinflammatory process associated with brain disorders such as Alzheimer's disease, Parkinson's disease and epilepsy is presented.

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

    OpenAIRE

    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 brai...

  15. Blood-brain barrier P-glycoprotein function in Alzheimer's disease.

    Science.gov (United States)

    van Assema, Daniëlle M E; Lubberink, Mark; Bauer, Martin; van der Flier, Wiesje M; Schuit, Robert C; Windhorst, Albert D; Comans, Emile F I; Hoetjes, Nikie J; Tolboom, Nelleke; Langer, Oliver; Müller, Markus; Scheltens, Philip; Lammertsma, Adriaan A; van Berckel, Bart N M

    2012-01-01

    A major pathological hallmark of Alzheimer's disease is accumulation of amyloid-β in senile plaques in the brain. Evidence is accumulating that decreased clearance of amyloid-β from the brain may lead to these elevated amyloid-β levels. One of the clearance pathways of amyloid-β is transport across the blood-brain barrier via efflux transporters. P-glycoprotein, an efflux pump highly expressed at the endothelial cells of the blood-brain barrier, has been shown to transport amyloid-β. P-glycoprotein function can be assessed in vivo using (R)-[(11)C]verapamil and positron emission tomography. The aim of this study was to assess blood-brain barrier P-glycoprotein function in patients with Alzheimer's disease compared with age-matched healthy controls using (R)-[(11)C]verapamil and positron emission tomography. In 13 patients with Alzheimer's disease (age 65 ± 7 years, Mini-Mental State Examination 23 ± 3), global (R)-[(11)C]verapamil binding potential values were increased significantly (P = 0.001) compared with 14 healthy controls (aged 62 ± 4 years, Mini-Mental State Examination 30 ± 1). Global (R)-[(11)C]verapamil binding potential values were 2.18 ± 0.25 for patients with Alzheimer's disease and 1.77 ± 0.41 for healthy controls. In patients with Alzheimer's disease, higher (R)-[(11)C]verapamil binding potential values were found for frontal, parietal, temporal and occipital cortices, and posterior and anterior cingulate. No significant differences between groups were found for medial temporal lobe and cerebellum. These data show altered kinetics of (R)-[(11)C]verapamil in Alzheimer's disease, similar to alterations seen in studies where P-glycoprotein is blocked by a pharmacological agent. As such, these data indicate that P-glycoprotein function is decreased in patients with Alzheimer's disease. This is the first direct evidence that the P-glycoprotein transporter at the blood-brain barrier is compromised in sporadic

  16. Polyploidization of glia in neural development links tissue growth to blood-brain barrier integrity.

    Science.gov (United States)

    Unhavaithaya, Yingdee; Orr-Weaver, Terry L

    2012-01-01

    Proper development requires coordination in growth of the cell types composing an organ. Many plant and animal cells are polyploid, but how these polyploid tissues contribute to organ growth is not well understood. We found the Drosophila melanogaster subperineurial glia (SPG) to be polyploid, and ploidy is coordinated with brain mass. Inhibition of SPG polyploidy caused rupture of the septate junctions necessary for the blood-brain barrier. Thus, the increased SPG cell size resulting from polyploidization is required to maintain the SPG envelope surrounding the growing brain. Polyploidization likely is a conserved strategy to coordinate tissue growth during organogenesis, with potential vertebrate examples.

  17. Novel models for studying the blood-brain and blood-eye barriers in Drosophila.

    Science.gov (United States)

    Pinsonneault, Robert L; Mayer, Nasima; Mayer, Fahima; Tegegn, Nebiyu; Bainton, Roland J

    2011-01-01

    In species as varied as humans and flies, humoral/central nervous system barrier structures are a major obstacle to the passive penetration of small molecules including endogenous compounds, environmental toxins, and drugs. In vivo measurement of blood-brain physiologic function in vertebrate animal models is difficult and current ex vivo models for more rapid experimentation using, for example, cultured brain endothelial cells, only partially reconstitute the anatomy and physiology of a fully intact blood-brain barrier (BBB). To address these problems, we and others continue to develop in vivo assays for studying the complex physiologic function of central nervous system (CNS) barriers using the fruit fly Drosophila melanogaster (Dm). These methods involve the introduction of small molecule reporters of BBB physiology into the fly humoral compartment by direct injection. Since these reporters must cross the Dm BBB in order to be visible in the eye, we can directly assess genetic or chemical modulators of BBB function by monitoring retinal fluorescence. This assay has the advantage of utilizing a physiologically intact BBB in a model organism that is economical and highly amenable to genetic manipulation. In combination with other approaches outlined here, such as brain dissection and behavioral assessment, one can produce a fuller picture of BBB biology and physiology. In this chapter, we provide detailed methods for examining BBB biology in the fly, including a Dm visual assay to screen for novel modulators of the BBB.

  18. MRI confirms loss of blood-brain barrier integrity in a mouse model of disseminated candidiasis.

    Science.gov (United States)

    Navarathna, Dhammika H M L P; Munasinghe, Jeeva; Lizak, Martin J; Nayak, Debasis; McGavern, Dorian B; Roberts, David D

    2013-09-01

    Disseminated candidiasis primarily targets the kidneys and brain in mice and humans. Damage to these critical organs leads to the high mortality associated with such infections, and invasion across the blood-brain barrier can result in fungal meningoencephalitis. Candida albicans can penetrate a brain endothelial cell barrier in vitro through transcellular migration, but this mechanism has not been confirmed in vivo. MRI using the extracellular vascular contrast agent gadolinium diethylenetriaminepentaacetic acid demonstrated that integrity of the blood-brain barrier is lost during C. albicans invasion. Intravital two-photon laser scanning microscopy was used to provide the first real-time demonstration of C. albicans colonizing the living brain, where both yeast and filamentous forms of the pathogen were found. Furthermore, we adapted a previously described method utilizing MRI to monitor inflammatory cell recruitment into infected tissues in mice. Macrophages and other phagocytes were visualized in kidney and brain by the administration of ultrasmall iron oxide particles. In addition to obtaining new insights into the passage of C. albicans across the brain microvasculature, these imaging methods provide useful tools to study further the pathogenesis of C. albicans infections, to define the roles of Candida virulence genes in kidney versus brain infection and to assess new therapeutic measures for drug development.

  19. Age-associated physiological and pathological changes at the blood-brain barrier: A review.

    Science.gov (United States)

    Erdő, Franciska; Denes, László; de Lange, Elizabeth

    2017-01-01

    The age-associated decline of the neurological and cognitive functions becomes more and more serious challenge for the developed countries with the increasing number of aged populations. The morphological and biochemical changes in the aging brain are the subjects of many extended research projects worldwide for a long time. However, the crucial role of the blood-brain barrier (BBB) impairment and disruption in the pathological processes in age-associated neurodegenerative disorders received special attention just for a few years. This article gives an overview on the major elements of the blood-brain barrier and its supporting mechanisms and also on their alterations during development, physiological aging process and age-associated neurodegenerative disorders (Alzheimer's disease, multiple sclerosis, Parkinson's disease, pharmacoresistant epilepsy). Besides the morphological alterations of the cellular elements (endothelial cells, astrocytes, pericytes, microglia, neuronal elements) of the BBB and neurovascular unit, the changes of the barrier at molecular level (tight junction proteins, adheres junction proteins, membrane transporters, basal lamina, extracellular matrix) are also summarized. The recognition of new players and initiators of the process of neurodegeneration at the level of the BBB may offer new avenues for novel therapeutic approaches for the treatment of numerous chronic neurodegenerative disorders currently without effective medication.

  20. Novel insights in the dysfunction of human blood-brain barrier after glycation.

    Science.gov (United States)

    Hussain, Maryam; Bork, Kaya; Gnanapragassam, Vinayaga S; Bennmann, Dorit; Jacobs, Kathleen; Navarette-Santos, Alexander; Hofmann, Britt; Simm, Andreas; Danker, Kerstin; Horstkorte, Rüdiger

    2016-04-01

    The blood-brain barrier (BBB) provides a dynamic and complex interface consisting of endothelial cells, pericytes and astrocytes, which are embedded in a collagen and fibronectin-rich basement membrane. This complex structure restricts the diffusion of small hydrophilic solutes and macromolecules as well as the transmigration of leukocytes into the brain. It has been shown that carbonyl stress followed by the formation of advanced glycation endproducts (AGE=glycation) interfere with the BBB integrity and function. Here, we present data that carbonyl stress induced by methylglyoxal leads to glycation of endothelial cells and the basement membrane, which interferes with the barrier-function and with the expression of RAGE, occludin and ZO-1. Furthermore, methylglyoxal induced carbonyl stress promotes the expression of the pro-inflammatory interleukins IL-6 and IL-8. In summary, this study provides new insights into the relationship between AGE formation by carbonyl stress and brain microvascular endothelial barrier dysfunction.

  1. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

  4. Nanoparticles and blood-brain barrier: the key to central nervous system diseases.

    Science.gov (United States)

    Domínguez, Alazne; Suárez-Merino, Blanca; Goñi-de-Cerio, Felipe

    2014-01-01

    Major central nervous system disorders represent a significant and worldwide public health problem. In fact, the therapeutic success of many pharmaceuticals developed to treat central nervous system diseases is still moderate, since the blood-brain barrier (BBB) limits the access of systemically administered compounds to the brain. Therefore, they require the application of a large total dose of a drug, and cause numerous toxic effects. The development of nanotechnological systems are useful tools to deliver therapeutics and/or diagnostic probes to the brain due to nanocarriers having the potential to improve the therapeutic effect of drugs and to reduce their side effects. This review provides a brief overview of the variety of carriers employed for central nervous system drug and diagnostic probes delivery. Further, this paper focuses on the novel nanocarriers developed to enhance brain delivery across the blood-brain barrier. Special attention is paid to liposomes, micelles, polymeric and lipid-based nanoparticles, dendrimers and carbon nanotubes. The recent developments in nanocarrier implementation through size/charge optimization and surface modifications (PEGylation, targeting delivery, and coating with surfactants) have been discussed. And a detailed description of the nanoscaled pharmaceutical delivery devices employed for the treatment of central nervous system disorders have also been defined. The aim of the review is to evaluate the nanotechnology-based drug delivery strategies to treat different central nervous system disorders.

  5. Exercise maintains blood-brain barrier integrity during early stages of brain metastasis formation.

    Science.gov (United States)

    Wolff, Gretchen; Davidson, Sarah J; Wrobel, Jagoda K; Toborek, Michal

    2015-08-07

    Tumor cell extravasation into the brain requires passage through the blood-brain barrier, which is a highly protected microvascular environment fortified with tight junction (TJ) proteins. TJ integrity can be regulated under physiological and pathophysiological conditions. There is evidence that exercise can modulate oxidation status within the brain microvasculature and protect against tumor cell extravasation and metastasis formation. In order to study these events, mature male mice were given access to voluntary exercise on a running wheel (exercise) or access to a locked wheel (sedentary) for five weeks. The average running distance was 9.0 ± 0.2 km/day. Highly metastatic tumor cells (murine Lewis lung carcinoma) were then infused into the brain microvasculature through the internal carotid artery. Analyses were performed at early stage (48 h) and late stage (3 weeks) post tumor cell infusion. Immunohistochemical analysis revealed fewer isolated tumor cells extravasating into the brain at both 48 h and 3 weeks post surgery in exercised mice. Occludin protein levels were reduced in the sedentary tumor group, but maintained in the exercised tumor group at 48 h post tumor cell infusion. These results indicate that voluntary exercise may participate in modulating blood-brain barrier integrity thereby protecting the brain during metastatic progression.

  6. Transport of carbamazepine and drug interactions at blood-brain barrier

    Institute of Scientific and Technical Information of China (English)

    Jing-jing SUN; Lin XIE; Xiao-dong LIU

    2006-01-01

    Aim: To investigate the characteristics of carbamazepine (CBZ) transport and drug interactions at the blood-brain barrier. Methods: Cultured rat brain microvascular endothelial cells (rBMEC) were used as an in vitro model of the blood-brain barrier (BBB). When cells became confluent, CBZ uptake over time was recorded by incubation of the cells in a medium containing 10 mg/L CBZ at 37 ℃. The steady-state uptake of CBZ by rBMEC was tested for different CBZ concentrations at 37 ℃. The effects of various agents on the steady-state uptake of CBZ and efflux of CBZ from rBMEC were also studied. Results: The uptake of CBZ by rBMEC was time- and concentration-dependent. The steady-state uptake occurred at 30 min for incubation. The steady-state uptake was significantly increased (P<0.01) by treatment with dinitrophenol. The co-administration of cyclosporine A significantly increased the steady-state uptake of CBZ by the rBMEC, whereas co-administration of olanzapine significantly decreased the uptake in a concentration- and temperature-dependent manner. The efflux of CBZ from rBMEC was inhibited by CsA. Conclusion: The transport of CBZ at the BBB is mediated by many transporters. Some specific ABC (ATP-binding cassette,ABC ) efflux transporters may be involved in the transport of CBZ. Drugs influence the transport of CBZ at the BBB in different ways.

  7. Blood-brain barrier changes with kainic acid-induced limbic seizures

    Energy Technology Data Exchange (ETDEWEB)

    Zucker, D.K.; Wooten, G.F.; Lothman, E.W.

    1983-02-01

    Rats were treated with kainic acid (KA) i.v. to produce increasingly severe limbic seizures that were monitored with a behavioral rating scale. At various times after the induction of seizures, the animals; blood-brain barriers (B-BB) were studied with alpha-(/sup 14/C)aminoisobutyric acid ((/sup 14/C)AIBA) autoradiography. Using optical density ratios, a coefficient was devised to assess the functional integrity of the B-BB in discrete anatomic regions and to quantitatively compare these measurements among different groups of experimental animals. In animals that exhibited only mild seizures, the B-BB was not different from controls. Animals with severe limbic seizures, however, showed alterations. For as long as 2 h after delivery of KA, the B-BB appeared normal; from 2 to 24 h, the permeability to (/sup 14/C)AIBA was markedly increased throughout the brain, especially in limbic regions; from 24 h to 7 days the B-BB returned to normal except for a small residual change in limbic structures. These findings were confirmed with Evans blue dye studies of the B-BB. A correlation between focal accentuation of B-BB alterations and neuropathologic changes was found. These experiments indicted that recurrent limbic seizures may lead to a breakdown in the B-BB independent of systemic metabolic derangements. Marked focal metabolic and electrical changes, however, occurred in several limbic structures several hours before the blood-brain barrier was altered.

  8. Non-viral liposome-mediated transfer of brain-derived neurotrophic factor across the blood-brain barrier

    Institute of Scientific and Technical Information of China (English)

    Ying Xing; Chun-yan Wen; Song-tao Li; Zong-xin Xia

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) plays an important role in the repair of central nervous system injury, but cannot directly tra-verse the blood-brain barrier. Liposomes are a new type of non-viral vector, able to carry macromolecules across the blood-brain barrier and into the brain. Here, we investigate whether BDNF could be transported across the blood-brain barrier by tail-vein injection of lipo-somes conjugated to transferrin (Tf) and polyethylene glycol (PEG), and carrying BDNF modiifed with cytomegalovirus promoter (pCMV) or glial ifbrillary acidic protein promoter (pGFAP) (Tf-pCMV-BDNF-PEG and Tf-pGFAP-BDNF-PEG, respectively). Both liposomes were able to traverse the blood-brain barrier, and BDNF was mainly expressed in the cerebral cortex. BDNF expression in the cerebral cortex was higher in the Tf-pGFAP-BDNF-PEG group than in the Tf-pCMV-BDNF-PEG group. This study demonstrates the successful construction of a non-virus targeted liposome, Tf-pGFAP-BDNF-PEG, which crosses the blood-brain barrier and is distributed in the cerebral cortex. Our work provides an experimental basis for BDNF-related targeted drug delivery in the brain.

  9. Non-viral liposome-mediated transfer of brain-derived neurotrophic factor across the blood-brain barrier

    Directory of Open Access Journals (Sweden)

    Ying Xing

    2016-01-01

    Full Text Available Brain-derived neurotrophic factor (BDNF plays an important role in the repair of central nervous system injury, but cannot directly traverse the blood-brain barrier. Liposomes are a new type of non-viral vector, able to carry macromolecules across the blood-brain barrier and into the brain. Here, we investigate whether BDNF could be transported across the blood-brain barrier by tail-vein injection of liposomes conjugated to transferrin (Tf and polyethylene glycol (PEG, and carrying BDNF modified with cytomegalovirus promoter (pCMV or glial fibrillary acidic protein promoter (pGFAP (Tf-pCMV-BDNF-PEG and Tf-pGFAP-BDNF-PEG, respectively. Both liposomes were able to traverse the blood-brain barrier, and BDNF was mainly expressed in the cerebral cortex. BDNF expression in the cerebral cortex was higher in the Tf-pGFAP-BDNF-PEG group than in the Tf-pCMV-BDNF-PEG group. This study demonstrates the successful construction of a non-virus targeted liposome, Tf-pGFAP-BDNF-PEG, which crosses the blood-brain barrier and is distributed in the cerebral cortex. Our work provides an experimental basis for BDNF-related targeted drug delivery in the brain.

  10. Altered blood-brain barrier permeability in rats with prehepatic portal hypertension turns to normal when portal pressure is lowered

    Institute of Scientific and Technical Information of China (English)

    Francisco Eizayaga; Camila Scorticati; Juan P Prestifilippo; Salvador Romay; Maria A Fernandez; José L Castro; Abraham Lemberg; Juan C Perazzo

    2006-01-01

    AIM: To study the blood-brain barrier integrity in prehepatic portal hypertensive rats induced by partial portal vein ligation, at 14 and 40 d after ligation when portal pressure is spontaneously normalized.METHODS: Adult male Wistar rats were divided into four groups: Group Ⅰ: Sham14d, sham operated; Group Ⅱ: PH14d, portal vein stenosis; (both groups were used 14 days after surgery); Group Ⅲ: Sham40d, Sham operated and Group Ⅳ: PH40d Portal vein stenosis (Groups Ⅱ and Ⅳ used 40 d after surgery). Plasma ammonia,plasma and cerebrospinal fluid protein and liver enzymes concentrations were determined. Trypan and Evans blue dyes, systemically injected, were investigated in hippocampus to study blood-brain barrier integrity. Portal pressure was periodically recorded.RESULTS: Forty days after stricture, portal pressure was normalized, plasma ammonia was moderately high,and both dyes were absent in central nervous system parenchyma. All other parameters were reestablished.When portal pressure was normalized and ammonia level was lowered, but not normal, the altered integrity of blood-brain barrier becomes reestablished.CONCLUSION: The impairment of blood-brain barrier and subsequent normalization could be a mechanism involved in hepatic encephalopathy reversibility. Hemodynamic changes and ammonia could trigger blood-brain barrier alterations and its reestablishment.

  11. Blood-brain barrier transport of drugs for the treatment of brain diseases.

    Science.gov (United States)

    Gabathuler, Reinhard

    2009-06-01

    The central nervous system is a sanctuary protected by barriers that regulate brain homeostasis and control the transport of endogenous compounds into the brain. The blood-brain barrier, formed by endothelial cells of the brain capillaries, restricts access to brain cells allowing entry only to amino acids, glucose and hormones needed for normal brain cell function and metabolism. This very tight regulation of brain cell access is essential for the survival of neurons which do not have a significant capacity to regenerate, but also prevents therapeutic compounds, small and large, from reaching the brain. As a result, various strategies are being developed to enhance access of drugs to the brain parenchyma at therapeutically meaningful concentrations to effectively manage disease.

  12. 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.

  13. Implications of MMP9 for Blood Brain Barrier Disruption and Hemorrhagic Transformation Following Ischemic Stroke

    Science.gov (United States)

    Turner, Renée J.; Sharp, Frank R.

    2016-01-01

    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. PMID:26973468

  14. 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 ...

  15. 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 in

  16. Gap junction proteins in the blood-brain barrier control nutrient-dependent reactivation of Drosophila neural stem cells.

    Science.gov (United States)

    Spéder, Pauline; Brand, Andrea H

    2014-08-11

    Neural stem cells in the adult brain exist primarily in a quiescent state but are reactivated in response to changing physiological conditions. How do stem cells sense and respond to metabolic changes? In the Drosophila CNS, quiescent neural stem cells are reactivated synchronously in response to a nutritional stimulus. Feeding triggers insulin production by blood-brain barrier glial cells, activating the insulin/insulin-like growth factor pathway in underlying neural stem cells and stimulating their growth and proliferation. Here we show that gap junctions in the blood-brain barrier glia mediate the influence of metabolic changes on stem cell behavior, enabling glia to respond to nutritional signals and reactivate quiescent stem cells. We propose that gap junctions in the blood-brain barrier are required to translate metabolic signals into synchronized calcium pulses and insulin secretion.

  17. Blood-brain barrier permeability mechanisms in view of quantitative structure-activity relationships (QSAR).

    Science.gov (United States)

    Bujak, Renata; Struck-Lewicka, Wiktoria; Kaliszan, Michał; Kaliszan, Roman; Markuszewski, Michał J

    2015-04-10

    The goal of the present paper was to develop a quantitative structure-activity relationship (QSAR) method using a simple statistical approach, such as multiple linear regression (MLR) for predicting the blood-brain barrier (BBB) permeability of chemical compounds. The "best" MLR models, comprised logP and either molecular mass (M) or isolated atomic energy (E(isol)), tested on a structurally diverse set of 66 compounds, is characterized the by correlation coefficients (R) around 0.8. The obtained models were validated using leave-one-out (LOO) cross-validation technique and the correlation coefficient of leave-one-out- R(LOO)(2) (Q(2)) was at least 0.6. Analysis of a case from legal medicine demonstrated informative value of our QSAR model. To best authors' knowledge the present study is a first application of the developed QSAR models of BBB permeability to case from the legal medicine. Our data indicate that molecular energy-related descriptors, in combination with the well-known descriptors of lipophilicity may have a supportive value in predicting blood-brain distribution, which is of utmost importance in drug development and toxicological studies.

  18. 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 (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.

  19. 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

  20. 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.

  1. Carbenoxolone does not cross the blood brain barrier: an HPLC study

    Directory of Open Access Journals (Sweden)

    Burnham William M

    2006-01-01

    Full Text Available Abstract Background Carbenoxolone (CBX is a widely used gap junctional blocker. Considering several reports indicating that transient gap junctional blockade could be a favourable intervention following injuries to central nervous tissue, and some current enthusiasm in studies using systemic injections of CBX, it is imperative to consider the penetration of CBX into central nervous tissue after systemic administrations. So far, only very indirect evidence suggests that CBX penetrates into the central nervous system after systemic administrations. We thus determined the amounts of CBX present in the blood and the cerebrospinal fluid of rats after intraperitoneal administration, using high performance liquid chromatography Results CBX was found in the blood of the animals, up to 90 minutes post-injection. However, the cerebrospinal fluid concentration of CBX was negligible. Conclusion Thus, we conclude that, most likely, CBX does not penetrate the blood brain barrier and therefore recommend careful consideration in the manner of administration, when a central effect is desired.

  2. 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.

  3. The Blood-Brain Barrier and Microvascular Water Exchange in Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Valerie C. Anderson

    2011-01-01

    Full Text Available Alzheimer's disease (AD is the most common form of dementia in the elderly. Although traditionally considered a disease of neurofibrillary tangles and amyloid plaques, structural and functional changes in the microvessels may contribute directly to the pathogenesis of the disease. Since vascular dysfunction often precedes cognitive impairment, understanding the role of the blood-brain barrier (BBB in AD may be key to rational treatment of the disease. We propose that water regulation, a critical function of the BBB, is disturbed in AD and results in abnormal permeability and rates of water exchange across the vessel walls. In this paper, we describe some of the pathological events that may disturb microvascular water exchange in AD and examine the potential of a relatively new imaging technique, dynamic contrast-enhanced MRI, to quantify water exchange on a cellular level and thus serve as a probe of BBB integrity in AD.

  4. Delivery of Biologics Across the Blood-Brain Barrier Through Nanoencapsulation

    DEFF Research Database (Denmark)

    Bruun, Jonas

    Drug delivery through nanoencapsulation is a promising approach that offers systemic protection of the pharmaceutical and targeted delivery to the diseased tissue. Especially cancer therapeutic and gene-based medicine may benefit from the advantages offered by encapsulation in nanocarriers, since...... the off-target effect of anti-cancer drug often is severe and gene-based medicine have low systemic stability on its own. This thesis presents four different nanocarrier system with specific focus on delivery of small interfering RNA (siRNA) and cancer therapeutics. The first nanocarrier presented...... is a polymeric micelle made from an anionic triblock copolymer and was intended for delivery of drugs to the central nervous system (CNS), which is protected by the largely impermeable blood-brain barrier (BBB). In order to target the nanocarrier to the brain endothelial cells and obtain receptor...

  5. Mini review on blood-brain barrier penetration of pyridinium aldoximes.

    Science.gov (United States)

    Kalász, H; Nurulain, S M; Veress, G; Antus, S; Darvas, F; Adeghate, E; Adem, A; Hashemi, F; Tekes, K

    2015-02-01

    This paper reviews the blood-brain barrier (BBB) penetration of newly developed pyridinium aldoximes. Pyridinium aldoximes are highly charged hydrophilic compounds used in the treatment of subjects exposed to organophosphonates because they are effective as acetylcholinesterase reactivators. Pyridinium aldoximes have antidotal effects against poisoning with cholinesterase inhibitors, a frequent problem affecting people working with organophosphate-based insecticides and pesticides. Toxic organophosphonate products such as sarin and tabun can be used by terrorists as chemical warfare agents. This poses a severe challenge to all innocent and peace-loving people worldwide. This review gives a brief summary of BBB transporters and description of the current in vitro and in vivo methods for the characterization of BBB penetration of established and novel pyridinium aldoximes. The authors provide a putative mechanism of penetration, outline some future ways of formulation and discuss the possible advantages and disadvantages of increasing BBB penetration.

  6. Blood-brain barrier-supported neurogenesis in healthy and diseased brain.

    Science.gov (United States)

    Pozhilenkova, Elena A; Lopatina, Olga L; Komleva, Yulia K; Salmin, Vladimir V; Salmina, Alla B

    2017-02-14

    Adult neurogenesis is one of the most important mechanisms contributing to brain development, learning, and memory. Alterations in neurogenesis underlie a wide spectrum of brain diseases. Neurogenesis takes place in highly specialized neurogenic niches. The concept of neurogenic niches is becoming widely accepted due to growing evidence of the important role of the microenvironment established in the close vicinity to stem cells in order to provide adequate control of cell proliferation, differentiation, and apoptosis. Neurogenic niches represent the platform for tight integration of neurogenesis and angiogenesis supported by specific properties of cerebral microvessel endothelial cells contributing to establishment of partially compromised blood-brain barrier (BBB) for the adjustment of local conditions to the current metabolic needs of stem and progenitor cells. Here, we review up-to-date data on microvascular dynamics in activity-dependent neurogenesis, specific properties of BBB in neurogenic niches, endothelial-driven mechanisms of clonogenic activity, and future perspectives for reconstructing the neurogenic niches in vitro.

  7. Analytical and Biological Methods for Probing the Blood-Brain Barrier

    Science.gov (United States)

    Kuhnline, Sloan; Courtney, D.; Nandi, Pradyot; Linz, Thomas H.; Aldrich, Jane V.; Audus, Kenneth L.; Lunte, Susan M.

    2012-07-01

    The blood-brain barrier (BBB) is an important interface between the peripheral and central nervous systems. It protects the brain against the infiltration of harmful substances and regulates the permeation of beneficial endogenous substances from the blood into the extracellular fluid of the brain. It can also present a major obstacle in the development of drugs that are targeted for the central nervous system. Several methods have been developed to investigate the transport and metabolism of drugs, peptides, and endogenous compounds at the BBB. In vivo methods include intravenous injection, brain perfusion, positron emission tomography, and microdialysis sampling. Researchers have also developed in vitro cell-culture models that can be employed to investigate transport and metabolism at the BBB without the complication of systemic involvement. All these methods require sensitive and selective analytical methods to monitor the transport and metabolism of the compounds of interest at the BBB.

  8. 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.

  9. Disruption of the blood-brain barrier in Parkinson's disease: curse or route to a cure?

    Science.gov (United States)

    Lee, Heyne; Pienaar, Ilse S

    2014-01-01

    The vertebrate blood-brain barrier (BBB) is critical for ensuring the maintenance of brain homeostasis, whilst protecting the brain against toxic insults. Various pathological events disrupt BBB integrity, holding several important clinical implications. In instances where the normal mechanisms controlling passage of substances into the brain are compromised, these could sensitize or even worsen endogenous pathological conditions. Recognition has grown recently that patients diagnosed with Parkinson's disease (PD) present with concurrent medical problems, including cerebrovascular lesions. However, cerebrovascular disturbances may also result from PD-related disease processes; the pathological mechanisms which could entail interaction between environment-derived and genetic factors. The current review addresses the accumulation of studies aimed at better understanding the series of processes affecting the neurovascular unit in human Parkinsonism, due in part to the BBB presenting as a formidable opponent in the effective delivery of therapeutics that have shown promise as therapeutic strategies for treating aspects of PD when tested in vitro.

  10. Blood-brain barrier P-glycoprotein function in neurodegenerative disease.

    Science.gov (United States)

    Bartels, A L

    2011-01-01

    Protection of the brain is strengthened by active transport and ABC transporters. P-glycoprotein (P-gp) at the blood-brain barrier (BBB) functions as an active efflux pump by extruding a substrate from the brain, which is important for maintaining loco-regional homeostasis in the brain and protection against toxic compounds. Importantly, dysfunctional BBB P-gp transport is postulated as an important factor contributing to accumulation of aggregated protein in neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD). Furthermore, P-gp is a major factor in mediating resistance to brain entry of numerous exogenous compounds, including toxins that can be involved in PD pathogenesis. This review highlights the role of altered P-gp function in the pathogenesis and progression of neurodegenerative disease. Also the implications of alterations in P-gp function for the treatment of these diseases are discussed.

  11. Targeting nanoparticles across the blood-brain barrier with monoclonal antibodies.

    Science.gov (United States)

    Loureiro, Joana A; Gomes, Bárbara; Coelho, Manuel A N; do Carmo Pereira, Maria; Rocha, Sandra

    2014-04-01

    Development of therapeutics for brain disorders is one of the more difficult challenges to be overcome by the scientific community due to the inability of most molecules to cross the blood-brain barrier (BBB). Antibody-conjugated nanoparticles are drug carriers that can be used to target encapsulated drugs to the brain endothelial cells and have proven to be very promising. They significantly improve the accumulation of the drug in pathological sites and decrease the undesirable side effect of drugs in healthy tissues. We review the systems that have demonstrated promising results in crossing the BBB through receptor-mediated endocytic mechanisms for the treatment of neurodegenerative disorders such as Alzheimer's and Parkinson's disease.

  12. Bioavailability of endomorphins and the blood-brain barrier--a review.

    Science.gov (United States)

    Perlikowska, Renata; Janecka, Anna

    2014-01-01

    Opioid peptides have the potential to be pharmaceutical agents for the treatment of pain because they modulate nociceptive pathways at supraspinal, spinal and peripheral levels. Unfortunately, peptides are generally hydrophilic compounds and therefore unable to cross the blood-brain barrier (BBB) by passive diffusion to reach the central nervous system (CNS) in an amount sufficient to activate appropriate receptors. Endomorphins (EMs) belong to the class of endogenous opioids eliciting the strongest analgesic effect, but only after direct administration to the CNS. Extensive research is in progress to better understand the relationships between EM structure and bioavailability. This article deals with the recent investigations that allow the design of stable and neuroactive EM analogs with enhanced brain passage and uptake.

  13. Changes in the permeability of blood brain barrier and endothelial cell damage after cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Ke Liu; Jiansheng Li

    2006-01-01

    OBJECTIVE: To investigate the effect of endothelial cells on the permeability of blood brain barrier (BBB) after brain injury and its effect mechanism.DATA SOURCES: We searched for the articles of permeability of BBB and endothelial cell injury after brain ischemia, which were published between January 1982 and December 2005, with the key words of "cerebral ischemia damage,blood brain barrier ( BBB),permeability,effect of endothelial cell (EC) and its variation mechanism"in English.STUDY SELECTION: The materials were primarily selected. The articles related to the changes in the permeability of BBB and the effect of endothelial cells as well as the change mechanism after cerebral ischemia damage were chosen. Repetitive studies or review articles were excluded.DATA EXTRACTION: Totally 55 related articles were collected, and 35 were excluded due to repetitive or review articles, finally 20 articles were involved.DATA SYNTHESIS: The content or viewpoints of involved literatures were analyzed. Cerebral ischemia had damage for endothelial cells, such as the inflow of a lot of Ca2+, the production of nitrogen monoxide and oxygen free radical, and aggravated destruction of BBB. After acceptors of inflammatory mediators on cerebrovascular endothelial cell membrane, such as histamine, bradykinin , 5-hydroxytryptamine and so on are activated, endothelial cells shrink and the permeability of BBB increases. Its mechanism involves in the inflow of extracellular Ca2+and the release of intracellular Ca2+ in the cells. Glycocalyx molecule on the surface of endothelial cell, having structural polytropy, is the determinative factor of the permeability of BBB. VEGF, intensively increasing the vasopermeability and mainly effecting on postcapillary vein and veinlet, is the strongest known blood vessel permeation reagent. Its chronic overexpression in the brain can lead the destruction of BBB.CONCLUSION: The injury of endothelial cell participants in the pathological mechanism of BBB

  14. 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.)

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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...

  18. Transactivating-transduction protein-polyethylene glycol modified liposomes traverse the blood-spinal cord and blood-brain barriers

    Institute of Scientific and Technical Information of China (English)

    Xianhu Zhou; Chunyuan Wang; Shiqing Feng; Jin Chang; Xiaohong Kong; Yang Liu; Shijie Gao

    2012-01-01

    Naive liposomes can cross the blood-brain barrier and blood-spinal cord barrier in small amounts. Liposomes modified by a transactivating-transduction protein can deliver antibiotics for the treatment of acute bacterial infection-induced brain inflammation. Liposomes conjugated with polyethylene glycol have the capability of long-term circulation. In this study we prepared transactivating-transduction protein-polyethylene glycol-modified liposomes labeled with fluorescein isothiocyanate. Thus, liposomes were characterized by transmembrane, long-term circulation and fluorescence tracing. Uptake, cytotoxicity, and the ability of traversing blood-spinal cord and blood-brain barriers were observed following coculture with human breast adenocarcinoma cells (MCF-7). Results demonstrated that the liposomes had good biocompatibility, and low cytotoxicity when cocultured with human breast adenocarcinoma cells. Liposomes could traverse cell membranes and entered the central nervous system and neurocytes through the blood-spinal cord and blood-brain barriers of rats via the systemic circulation. These results verified that fluorescein isothiocyanate-modified transactivating-transduction protein-polyethylene glycol liposomes have the ability to traverse the blood-spinal cord and blood-brain barriers.

  19. The role of multidrug resistance-associated protein in the blood-brain barrier and opioid analgesia.

    Science.gov (United States)

    Su, Wendy; Pasternak, Gavril W

    2013-09-01

    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 transporter 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 rats and 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.

  20. Disruption of the blood-brain barrier exacerbates spreading depression in the locust CNS.

    Science.gov (United States)

    Spong, Kristin E; Rochon-Terry, Geneviève; Money, Tomas G A; Robertson, R Meldrum

    2014-07-01

    In response to cellular stress in the nervous system of the locust (Locusta migratoria) neural function is interrupted in association with ionic disturbances propagating throughout nervous tissue (Spreading depression; SD). The insect blood-brain barrier (BBB) plays a critical role in the regulation of ion levels within the CNS. We investigated how a disruption in barrier function by transient exposure to 3M urea affects locusts' vulnerability to disturbances in ion levels. Repetitive SD was induced by bath application of ouabain and the extracellular potassium concentration ([K(+)]o) within the metathoracic ganglion (MTG) was monitored. Urea treatment increased the susceptibility to ouabain and caused a progressive impairment in the ability to maintain baseline [K(+)]o levels during episodes of repetitive SD. Additionally, using a within animal protocol we demonstrate that waves of SD, induced by high K(+), propagate throughout the MTG faster following disruption of the BBB. Lastly, we show that targeting the BBB of intact animals reduces their ability to sustain neural function during anoxic conditions. Our findings indicate that locust's ability to withstand stress is diminished following a reduction in barrier function likely due to an impairment of the ability of neural tissue to maintain ionic gradients.

  1. Polymeric nanoparticles assembled with microfluidics for drug delivery across the blood-brain barrier

    Science.gov (United States)

    Tavares, M. R.; de Menezes, L. R.; do Nascimento, D. F.; Souza, D. H. S.; Reynaud, F.; Marques, M. F. V.; Tavares, M. I. B.

    2016-07-01

    The blood-brain barrier (BBB) is a challenge in the treatment of some diseases, since it prevents many drugs from reaching therapeutic concentrations in the brain. In this context, there is a growing interest in nanoparticles for drug delivery, since they are able to cross this barrier and target the brain. The use of polymeric materials in the development of these nanoparticles has been extensively studied. It has already been demonstrated that these nanosystems have the ability to cross the BBB, which allows effective drug release into the brain. Biodegradable polymers provide a great advantage in the development of nanosystems, but modifications of the nanoparticles' surface is essential. The traditional batch methods lack precise control over the processes of nucleation and growth, resulting in poor control over final properties of the nanoparticles. Therefore, microfluidics could be used to achieve a better production environment for the fabrication of nano- structured drug delivery systems. This study provides a brief review of: the BBB, the polymeric nanoparticles with the ability to overcome the barrier, the properties of the most used polymeric matrices, and the nanostructured drug delivery systems assembled with microfluidics.

  2. Computing the blood brain barrier (BBB) diffusion coefficient: A molecular dynamics approach

    Science.gov (United States)

    Shamloo, Amir; Pedram, Maysam Z.; Heidari, Hossein; Alasty, Aria

    2016-07-01

    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.

  3. 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.

    2017-01-01

    ABSTRACT 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. PMID:28143979

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

    Directory of Open Access Journals (Sweden)

    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

  5. Optimal Duration of Acquisition for Dynamic Perfusion CT Assessment of Blood-Brain Barrier Permeability Using the Patlak Model

    NARCIS (Netherlands)

    Hom, J.; Dankbaar, J. W.; Schneider, T.; Cheng, S. -C.; Bredno, J.; Wintermark, M.

    2009-01-01

    BACKGROUND AND PURPOSE: A previous study demonstrated the need to use delayed acquisition rather than first-pass data for accurate blood-brain barrier permeability surface product (BBBP) calculation from perfusion CT (PCT) according to the Patlak model, but the optimal duration of the delayed acquis

  6. Eltrombopag, a thrombopoietin mimetic, crosses the blood-brain barrier and impairs iron-dependent hippocampal neuron dendrite development.

    Science.gov (United States)

    Bastian, T W; Duck, K A; Michalopoulos, G C; Chen, M J; Liu, Z-J; Connor, J R; Lanier, L M; Sola-Visner, M C; Georgieff, M K

    2017-03-01

    Essentials Potential neurodevelopmental side effects of thrombopoietin mimetics need to be considered. The effects of eltrombopag (ELT) on neuronal iron status and dendrite development were assessed. ELT crosses the blood-brain barrier and causes iron deficiency in developing neurons. ELT blunts dendrite maturation, indicating a need for more safety studies before neonatal use.

  7. 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

    The calculated fraction of receptor ligands available for blood-brain barrier passage in vivo (f(avail)) may differ from in vitro (f(eq)) measurements. This study evaluates the protein-ligand interaction for iomazenil and flumazenil in rats by comparing f(eq) and f(avail). Repeated measurements...

  8. Decreased blood-brain barrier P-glycoprotein function in the progression of Parkinson's disease, PSP and MSA

    NARCIS (Netherlands)

    Bartels, A. L.; Willemsen, A. T. M.; Kortekaas, R.; de Jong, B. M.; de Vries, R.; de Klerk, O.; van Oostrom, J. C. H.; Portman, A.; Leenders, K. L.

    2008-01-01

    Decreased blood-brain barrier (BBB) efflux function of the P-glycoprotein (P-gp) transport system could facilitate the accumulation of toxic compounds in the brain, increasing the risk of neurodegenerative pathology such as Parkinson's disease (PD). This study investigated in vivo BBB P-gp function

  9. Blood-brain barrier models and their relevance for a successful development of CNS drug delivery systems: a review.

    Science.gov (United States)

    Bicker, Joana; Alves, Gilberto; Fortuna, Ana; Falcão, Amílcar

    2014-08-01

    During the research and development of new drugs directed at the central nervous system, there is a considerable attrition rate caused by their hampered access to the brain by the blood-brain barrier. Throughout the years, several in vitro models have been developed in an attempt to mimic critical functionalities of the blood-brain barrier and reliably predict the permeability of drug candidates. However, the current challenge lies in developing a model that retains fundamental blood-brain barrier characteristics and simultaneously remains compatible with the high throughput demands of pharmaceutical industries. This review firstly describes the roles of all elements of the neurovascular unit and their influence on drug brain penetration. In vitro models, including non-cell based and cell-based models, and in vivo models are herein presented, with a particular emphasis on their methodological aspects. Lastly, their contribution to the improvement of brain drug delivery strategies and drug transport across the blood-brain barrier is also discussed.

  10. Review of "The blood-brain and other neural barriers reviews and protocols" by Sukriti Nag (Editor

    Directory of Open Access Journals (Sweden)

    Begley David J

    2011-05-01

    Full Text Available Abstract This is a review of the content and scope of a multi-author volume for readers with an interest in the structure and function of the blood-brain barrier and in drug delivery to the central nervous system.

  11. Review of "The blood-brain and other neural barriers reviews and protocols" by Sukriti Nag (Editor)

    OpenAIRE

    Begley David J

    2011-01-01

    Abstract This is a review of the content and scope of a multi-author volume for readers with an interest in the structure and function of the blood-brain barrier and in drug delivery to the central nervous system.

  12. Measurement of blood-brain barrier permeability using dynamic Gd-DTPA scanning--a comparison of methods

    DEFF Research Database (Denmark)

    Larsson, H B; Tofts, P S

    1992-01-01

    Two recently published methods of blood-brain barrier permeability measurement using Gd-DTPA scanning are compared by authors representing each group. The physiological models are reconciled. Results from both groups agree. These show that the transfer constant (the permeability surface area prod...

  13. Hyperammonemia,brain edema and blood-brain barrier alterations in prehepatic portal hypertensive rats and paravrtamol intoxication

    Institute of Scientific and Technical Information of China (English)

    Camila Scorticati; Juan P. Prestifilippo; Francisco X. Eizayaga; José L. Castro; Salvador Romay; Maria A. Fernández; Abraham Lemberg; Juan C. Perazzo

    2004-01-01

    AIM: To study the blood-brain barrier integrity, brain edema,animal behavior and ammonia plasma levels in prehepatic portal hypertensive rats with and without acute liver intoxication.METHODS: Adults male Wistar rats were divided into four groups. Group Ⅰ: sham operation; Ⅱ: Prehepatic portal hypertension, produced by partial portal vein ligation; Ⅲ:Acetaminophen intoxication and Ⅳ: Prehepatic portal hypertension plus acetaminophen. Acetaminophen was administered to produce acute hepatic injury. Portal pressure, liver serum enzymes and ammonia plasma levels were determined. Brain cortex water content was registered and trypan blue was utilized to study blood brain barrier integrity. Reflexes and behavioral tests were recorded.RESULTS: Portal hypertension was significantly elevated in groups Ⅱ and Ⅳ. Liver enzymes and ammonia plasma levels were increased in groups Ⅱ, Ⅳ and Ⅳ. Prehepatic portal hypertension (group Ⅱ), acetaminophen intoxication (group Ⅲ) and both (group Ⅳ) had changes in the blood brain-barrier integrity (trypan blue) and hyperammonemia. Cortical edema was present in rats with acute hepatic injury in groups Ⅲ and Ⅳ. Behavioral test (rota rod) was altered in group Ⅳ.CONCLUSION: These results suggest the possibility of another pathway for cortical edema production because blood brain barrier was altered (vasogenic) and hyperammonemia was registered (cytotoxic). Group Ⅳ, with behavioral altered test, can be considered as a model for study at an early stage of portal-systemic encephalopathy.

  14. Permeability of PEGylated Immunoarsonoliposomes Through In Vitro Blood Brain Barrier-Medulloblastoma Co-culture Models for Brain Tumor Therapy

    NARCIS (Netherlands)

    Al-Shehri, A.; Favretto, M.E.; Ioannou, P.V.; Romero, I.A.; Couraud, P.O.; Weksler, B.B.; Parker, T.L.; Kallinteri, P.

    2015-01-01

    PURPOSE: Owing to restricted access of pharmacological agents into the brain due to blood brain barrier (BBB) there is a need: 1. to develop a more representative 3-D-co-culture model of tumor-BBB interaction to investigate drug and nanoparticle transport into the brain for diagnostic and therapeuti

  15. Is peripheral immunity regulated by blood-brain barrier permeability changes?

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    Erin Bargerstock

    Full Text Available S100B is a reporter of blood-brain barrier (BBB integrity which appears in blood when the BBB is breached. Circulating S100B derives from either extracranial sources or release into circulation by normal fluctuations in BBB integrity or pathologic BBB disruption (BBBD. Elevated S100B matches the clinical presence of indices of BBBD (gadolinium enhancement or albumin coefficient. After repeated sub-concussive episodes, serum S100B triggers an antigen-driven production of anti-S100B autoantibodies. We tested the hypothesis that the presence of S100B in extracranial tissue is due to peripheral cellular uptake of serum S100B by antigen presenting cells, which may induce the production of auto antibodies against S100B. To test this hypothesis, we used animal models of seizures, enrolled patients undergoing repeated BBBD, and collected serum samples from epileptic patients. We employed a broad array of techniques, including immunohistochemistry, RNA analysis, tracer injection and serum analysis. mRNA for S100B was segregated to barrier organs (testis, kidney and brain but S100B protein was detected in immunocompetent cells in spleen, thymus and lymph nodes, in resident immune cells (Langerhans, satellite cells in heart muscle, etc. and BBB endothelium. Uptake of labeled S100B by rat spleen CD4+ or CD8+ and CD86+ dendritic cells was exacerbated by pilocarpine-induced status epilepticus which is accompanied by BBBD. Clinical seizures were preceded by a surge of serum S100B. In patients undergoing repeated therapeutic BBBD, an autoimmune response against S100B was measured. In addition to its role in the central nervous system and its diagnostic value as a BBBD reporter, S100B may integrate blood-brain barrier disruption to the control of systemic immunity by a mechanism involving the activation of immune cells. We propose a scenario where extravasated S100B may trigger a pathologic autoimmune reaction linking systemic and CNS immune responses.

  16. Cerebrolysin attenuates blood-brain barrier and brain pathology following whole body hyperthermia in the rat.

    Science.gov (United States)

    Sharma, Hari Shanker; Zimmermann-Meinzingen, Sibilla; Sharma, Aruna; Johanson, Conrad E

    2010-01-01

    The possibility that Cerebrolysin, a mixture of several neurotrophic factors, has some neuroprotective effects on whole body hyperthermia (WBH) induced breakdown of the blood-brain barrier (BBB), blood-CSF barrier (BCSFB), brain edema formation and neuropathology were examined in a rat model. Rats subjected to a 4 h heat stress at 38 degrees C in a biological oxygen demand (BOD) incubator exhibited profound increases in BBB and BCSFB permeability to Evans blue and radioiodine tracers compared to controls. Hippocampus, caudate nucleus, thalamus and hypothalamus exhibited pronounced increase in water content and brain pathology following 4 h heat stress. Pretreatment with Cerebrolysin (1, 2 or 5 mL/kg i.v.) 24 h before WBH significantly attenuated breakdown of the BBB or BCSFB and brain edema formation. This effect was dose dependent. Interestingly, the cell and tissue injury following WBH in cerebrolysin-treated groups were also considerably reduced. These novel observations suggest that cerebrolysin can attenuate WBH induced BBB and BCSFB damage resulting in neuroprotection.

  17. Tight junction modulation of the blood brain barrier: CNS delivery of small molecules.

    Science.gov (United States)

    Greene, Chris; Campbell, Matthew

    2016-01-01

    The blood brain barrier (BBB) represents a major obstacle for targeted drug delivery to the brain for the treatment of central nervous system (CNS) disorders. Significant advances in barrier research over the past decade has led to the discovery of an increasing number of structural and regulatory proteins in tight junctions (TJ) and adherens junctions (AJ). These discoveries are providing the framework for the development of novel TJ modulators which can act specifically and temporarily to alter BBB function and regulate paracellular uptake of molecules. TJ modulators that have shown therapeutic potential in preclinical models include claudin-5 and occludin siRNAs, peptides derived from zonula occludens toxin as well as synthetic peptides targeting the extracellular loops of TJs. Adding to the array of modulating agents are novel mechanisms of BBB regulation such as focused ultrasound (FUS). This review will give a succinct overview of BBB biology and TJ modulation in general. Novel insights into BBB regulation in health and disease will also be summarized.

  18. Blood-brain barrier pathology in Alzheimer's and Parkinson's disease: implications for drug therapy.

    Science.gov (United States)

    Desai, Brinda S; Monahan, Angela J; Carvey, Paul M; Hendey, Bill

    2007-01-01

    The blood-brain barrier (BBB) is a tightly regulated barrier in the central nervous system. Though the BBB is thought to be intact during neurodegenerative diseases such as Alzheimer's (AD) and Parkinson's disease (PD), recent evidence argues otherwise. Dysfunction of the BBB may be involved in disease progression, eliciting of peripheral immune response, and, most importantly, altered drug efficacy. In this review, we will give a brief overview of the BBB, its components, and their functions. We will critically evaluate the current literature in AD and PD BBB pathology resulting from insult, neuroinflammation, and neurodegeneration. Specifically, we will discuss alterations in tight junction, transport and endothelial cell surface proteins, and vascular density changes, all of which result in altered permeability. Finally, we will discuss the implications of BBB dysfunction in current and future therapeutics. Developing a better appreciation of BBB dysfunction in AD and PD may not only provide novel strategies in treatment, but will prove an interesting milestone in understanding neurodegenerative disease etiology and progression.

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Myeloperoxidase-derived oxidants induce blood-brain barrier dysfunction in vitro and in vivo.

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    Andreas Üllen

    Full Text Available Peripheral leukocytes can exacerbate brain damage by release of cytotoxic mediators that disrupt blood-brain barrier (BBB function. One of the oxidants released by activated leukocytes is hypochlorous acid (HOCl formed via the myeloperoxidase (MPO-H2O2-Cl(- system. In the present study we examined the role of leukocyte activation, leukocyte-derived MPO and MPO-generated oxidants on BBB function in vitro and in vivo. In a mouse model of lipopolysaccharide (LPS-induced systemic inflammation, neutrophils that had become adherent released MPO into the cerebrovasculature. In vivo, LPS-induced BBB dysfunction was significantly lower in MPO-deficient mice as compared to wild-type littermates. Both, fMLP-activated leukocytes and the MPO-H2O2-Cl(- system inflicted barrier dysfunction of primary brain microvascular endothelial cells (BMVEC that was partially rescued with the MPO inhibitor 4-aminobenzoic acid hydrazide. BMVEC treatment with the MPO-H2O2-Cl(- system or activated neutrophils resulted in the formation of plasmalogen-derived chlorinated fatty aldehydes. 2-chlorohexadecanal (2-ClHDA severely compromised BMVEC barrier function and induced morphological alterations in tight and adherens junctions. In situ perfusion of rat brain with 2-ClHDA increased BBB permeability in vivo. 2-ClHDA potently activated the MAPK cascade at physiological concentrations. An ERK1/2 and JNK antagonist (PD098059 and SP600125, respectively protected against 2-ClHDA-induced barrier dysfunction in vitro. The current data provide evidence that interference with the MPO pathway could protect against BBB dysfunction under (neuroinflammatory conditions.

  2. Stabilising cubosomes with Tween 80 as a step towards targeting lipid nanocarriers to the blood-brain barrier.

    Science.gov (United States)

    Azhari, Hanisah; Strauss, Mike; Hook, Sarah; Boyd, Ben J; Rizwan, Shakila B

    2016-07-01

    Coating nanoparticles with the surfactant Tween 80 have been previously shown to enhance drug delivery across the blood-brain barrier (BBB). The aim of this study was to investigate whether Tween 80 could be used to stabilise phytantriol-based cubosomes thereby enabling potential application in delivering macromolecular therapeutics to the brain. Cubosome particles with their large internal and external surface area by virtue of their nanostructure are ideal for delivery of macromolecules. Phase behaviour studies were conducted using a combination of optical microscopy and small-angle X-ray scattering (SAXS) and the addition of Tween 80 to mixtures of phytantriol and water resulted in a rich array of lyotropic mesophases. In particular, a large cubic phase region and a two-phase region of readily dispersed cubosomes is observed. Cubosomes with different concentrations of Tween 80 and phytantriol as the liquid crystal forming lipid were prepared using the solvent precursor method and their physical properties were investigated. A combination of dynamic light scattering, cryogenic electron tomography and SAXS shows formation of well-defined cubosomes with a narrow size distribution and the Im3m cubic structure. Collectively, the results confirm that Tween 80 can effectively stabilize phytantriol cubosomes, opening the possibility for future application in drug delivery across the BBB. Moreover, well-defined, homogenous cubosome formulations prepared using the mild solvent precursor dilution method has significant implications for large-scale production of cubosomes, which currently is a major barrier to the application of cubosomes in the clinic.

  3. 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

  4. Drugs developed to treat diabetes, liraglutide and lixisenatide, cross the blood brain barrier and enhance neurogenesis

    Directory of Open Access Journals (Sweden)

    Hunter Kerry

    2012-03-01

    Full Text Available Abstract Background Type 2 diabetes is a risk factor for Alzheimer's disease (AD, most likely linked to an impairment of insulin signalling in the brain. Therefore, drugs that enhance insulin signalling may have therapeutic potential for AD. Liraglutide (Victoza and exenatide (Byetta are novel long-lasting analogues of the GLP-1 incretin hormone and are currently available to treat diabetes. They facilitate insulin signalling via the GLP-1 receptor (GLP-1R. Numerous in vitro and in vivo studies have shown that GLP-1 analogues have a range of neuroprotective properties. GLP-1Rs are expressed in the hippocampal area of the brain an important site of adult neurogenesis and maintenance of cognition and memory formation. Therefore, if GLP-1 analogues can cross the blood brain barrier, diffuse through the brain to reach the receptors and most importantly activate them, their neuroprotective effects may be realized. Results In the present study we profiled the GLP-1 receptor agonists liraglutide (Victoza and lixisenatide (Lyxumia. We measured the kinetics of crossing the blood brain barrier (BBB, activation of the GLP-1R by measuring cAMP levels, and physiological effects in the brain on neuronal stem cell proliferation and neurogenesis. Both drugs were able to cross the BBB. Lixisenatide crossed the BBB at all doses tested (2.5, 25, or 250 nmol/kg bw ip. when measured 30 min post-injection and at 2.5-25 nmol/kg bw ip. 3 h post-injection. Lixisenatide also enhanced neurogenesis in the brain. Liraglutide crossed the BBB at 25 and 250 nmol/kg ip. but no increase was detectable at 2.5 nmol/kg ip. 30 min post-injection, and at 250 nmol/kg ip. at 3 h post-injection. Liraglutide and lixisenatide enhanced cAMP levels in the brain, with lixisenatide being more effective. Conclusions Our results suggest that these novel incretin analogues cross the BBB and show physiological activity and neurogenesis in the brain, which may be of use as a treatment of

  5. 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.

  6. 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.

  7. Current advances in delivery of biotherapeutics across the blood-brain barrier.

    Science.gov (United States)

    Rajadhyaksha, Manoj; Boyden, Tracey; Liras, Jennifer; El-Kattan, Ayman; Brodfuehrer, Joanne

    2011-06-01

    Significant efforts through genomic approaches have been dedicated toward the identification of novel protein-protein interactions as promising therapeutic targets for indications such as Alzheimer's disease, Parkinson's disease and neuropsychiatric disorders. Additionally, the number of biotherapeutic agents entering the Pharmaceutical sector continues to increase and according to EvaluatePharma's "World Preview 2014" report, "the compounded annual growth rate of biologics is expected to be 8.5 percent from 2008-2014, eight to 10 times greater than the growth rate of small molecules". However, there are limited examples of success in developing biotherapeutic modalities for central nervous system (CNS) diseases in the drug development pipeline. A primary reason for the lack of application of biotherapeutics to neuroscience targets, is that the blood-brain barrier (BBB) isolates and protects CNS structures creating a unique biochemically and immunologically privileged environment, therefore passage of macromolecules across this barrier has additional challenges. An understanding of the anatomical and physiological properties of this barrier with respect to penetration of biotherapeutics is presented in this review document. In this summary, recent advances in biotherapeutic delivery mechanisms across the BBB including transcranial brain drug delivery, focused ultrasound technology, nasal delivery, absorptive endocytosis, and receptor mediated endocytosis are evaluated using an industrial perspective. With acknowledgement that each approach has advantages and disadvantages, this review discusses the opportunities and challenges that are encountered during application of these methods across a variety of therapeutic areas such as, pain, obesity, neuroscience, and oncology. Utilizing an industrial perspective, including consideration of cost of goods and commercial feasibility for these approaches, this review highlights technology features which would enable industry

  8. Functional characterisation of the maturation of the blood-brain barrier in larval zebrafish.

    Directory of Open Access Journals (Sweden)

    Angeleen Fleming

    Full Text Available Zebrafish are becoming increasingly popular as an organism in which to model human disease and to study the effects of small molecules on complex physiological and pathological processes. Since larvae are no more than a few millimetres in length, and can live in volumes as small as 100 microliters, they are particularly amenable to high-throughput and high content compound screening in 96 well plate format. There is a growing literature providing evidence that many compounds show similar pharmacological effects in zebrafish as they do in mammals, and in particular humans. However, a major question regarding their utility for small molecule screening for neurological conditions is whether a molecule will reach its target site within the central nervous system. Studies have shown that Claudin-5 and ZO-1, tight-junction proteins which are essential for blood-brain barrier (BBB integrity in mammals, can be detected in some cerebral vessels in zebrafish from 3 days post-fertilisation (d.p.f. onwards and this timing coincides with the retention of dyes, immunoreactive tracers and fluorescent markers within some but not all cerebral vessels. Whilst these findings demonstrate that features of a BBB are first present at 3 d.p.f., it is not clear how quickly the zebrafish BBB matures or how closely the barrier resembles that of mammals. Here, we have combined anatomical analysis by transmission electron microscopy, functional investigation using fluorescent markers and compound uptake using liquid chromatography/tandem mass spectrometry to demonstrate that maturation of the zebrafish BBB occurs between 3 d.p.f. and 10 d.p.f. and that this barrier shares both structural and functional similarities with that of mammals.

  9. Submicron-bubble-enhanced focused ultrasound for blood-brain barrier disruption and improved CNS drug delivery.

    Directory of Open Access Journals (Sweden)

    Ching-Hsiang Fan

    Full Text Available The use of focused ultrasound (FUS with microbubbles has been proven to induce transient blood-brain barrier opening (BBB-opening. However, FUS-induced inertial cavitation of microbubbles can also result in erythrocyte extravasations. Here we investigated whether induction of submicron bubbles to oscillate at their resonant frequency would reduce inertial cavitation during BBB-opening and thereby eliminate erythrocyte extravasations in a rat brain model. FUS was delivered with acoustic pressures of 0.1-4.5 MPa using either in-house manufactured submicron bubbles or standard SonoVue microbubbles. Wideband and subharmonic emissions from bubbles were used to quantify inertial and stable cavitation, respectively. Erythrocyte extravasations were evaluated by in vivo post-treatment magnetic resonance susceptibility-weighted imaging, and finally by histological confirmation. We found that excitation of submicron bubbles with resonant frequency-matched FUS (10 MHz can greatly limit inertial cavitation while enhancing stable cavitation. The BBB-opening was mainly caused by stable cavitation, whereas the erythrocyte extravasation was closely correlated with inertial cavitation. Our technique allows extensive reduction of inertial cavitation to induce safe BBB-opening. Furthermore, the safety issue of BBB-opening was not compromised by prolonging FUS exposure time, and the local drug concentrations in the brain tissues were significantly improved to 60 times (BCNU; 18.6 µg versus 0.3 µg by using chemotherapeutic agent-loaded submicron bubbles with FUS. This study provides important information towards the goal of successfully translating FUS brain drug delivery into clinical use.

  10. The pivotal role of astrocytes in an in-vitro stroke model of the blood-brain barrier

    Directory of Open Access Journals (Sweden)

    Winfried eNeuhaus

    2014-10-01

    Full Text Available Stabilization of the blood-brain barrier during and after stroke can lead to less adverse outcome. For elucidation of underlying mechanisms and development of novel therapeutic strategies validated in-vitro disease models of the blood-brain barrier could be very helpful. To mimic in-vitro stroke conditions we have established a blood-brain barrier in-vitro model based on mouse cell line cerebEND and applied oxygen/glucose deprivation (OGD. The role of astrocytes in this disease model was investigated by using cell line C6. Transwell studies pointed out that addition of astrocytes during OGD increased the barrier damage significantly in comparison to the endothelial monoculture shown by changes of transendothelial electrical resistance as well as fluorescein permeability data. Analysis on mRNA and protein levels by qPCR, western blotting and immunofluorescence microscopy of tight junction molecules claudin-3,-5,-12, occludin and ZO-1 revealed that their regulation and localisation is associated with the functional barrier breakdown. Furthermore, soluble factors of astrocytes, OGD and their combination were able to induce changes of functionality and expression of ABC-transporters Abcb1a (P-gp, Abcg2 (bcrp and Abcc4 (mrp4. Moreover, the expression of proteases (matrixmetalloproteinases MMP-2, MMP-3 and MMP-9 and t-PA as well as of their endogenous inhibitors (TIMP-1, TIMP-3, PAI-1 was altered by astrocyte factors and OGD which resulted in significant changes of total MMP and t-PA activity. Morphological rearrangements induced by OGD and treatment with astrocyte factors were confirmed at a nanometer scale using atomic force microscopy. In conclusion, astrocytes play a major role in blood-brain barrier breakdown during OGD in vitro.

  11. Bacterial induction of Snail1 contributes to blood-brain barrier disruption

    Science.gov (United States)

    Kim, Brandon J.; Hancock, Bryan M.; Bermudez, Andres; Cid, Natasha Del; Reyes, Efren; van Sorge, Nina M.; Lauth, Xavier; Smurthwaite, Cameron A.; Hilton, Brett J.; Stotland, Aleksandr; Banerjee, Anirban; Buchanan, John; Wolkowicz, Roland; Traver, David; Doran, Kelly S.

    2015-01-01

    Bacterial meningitis is a serious infection of the CNS that results when blood-borne bacteria are able to cross the blood-brain barrier (BBB). Group B Streptococcus (GBS) is the leading cause of neonatal meningitis; however, the molecular mechanisms that regulate bacterial BBB disruption and penetration are not well understood. Here, we found that infection of human brain microvascular endothelial cells (hBMECs) with GBS and other meningeal pathogens results in the induction of host transcriptional repressor Snail1, which impedes expression of tight junction genes. Moreover, GBS infection also induced Snail1 expression in murine and zebrafish models. Tight junction components ZO-1, claudin 5, and occludin were decreased at both the transcript and protein levels in hBMECs following GBS infection, and this repression was dependent on Snail1 induction. Bacteria-independent Snail1 expression was sufficient to facilitate tight junction disruption, promoting BBB permeability to allow bacterial passage. GBS induction of Snail1 expression was dependent on the ERK1/2/MAPK signaling cascade and bacterial cell wall components. Finally, overexpression of a dominant-negative Snail1 homolog in zebrafish elevated transcription of tight junction protein–encoding genes and increased zebrafish survival in response to GBS challenge. Taken together, our data support a Snail1-dependent mechanism of BBB disruption and penetration by meningeal pathogens. PMID:25961453

  12. Collagen Micro-Flow Channels as an for In vitro Blood-Brain Barrier Model

    Science.gov (United States)

    Shibata, Katsuya; Terazono, Hideyuki; Hattori, Akihiro; Yasuda, Kenji

    2008-06-01

    An in vitro blood-brain barrier (BBB) model is useful for drug discovery and efficacy measurements because it is a simple and convenient model of the in vivo BBB. However, the conventional in vitro BBB model does not account for shear stress to endotherial cell (EC) layers although in vivo ECs are exposed by shear stress. To improve this deficiency, we applied a microfluidics technique to a conventional in vitro BBB model and constructed a new in vitro BBB model. First, we confirmed that ECs can survive and proliferate on a cross-linked collagen gel and on an agarose including microbeads decorated with collagen type IV (CIV). In addition, we found that the cross-linker 1-ethyl-3carbodiimide hydrochloride (EDC) with N-hydroxysuccinimide (NHS) is less effective for EC proliferation than glutaraldehyde (GA), ethyleneglycol diglycidyl ether (EGDE), and agarose with microbeads. Applying a focused infrared laser, we fabricated microtunnels within the collagen gel, and we successfully cultured ECs on the inner tunnel wall. The results indicate the potential of gel microstructures for a microfluidic in vitro BBB model.

  13. Transporter protein and drug-conjugated gold nanoparticles capable of bypassing the blood-brain barrier

    Science.gov (United States)

    Zhang, Yanhua; Walker, Janelle Buttry; Minic, Zeljka; Liu, Fangchao; Goshgarian, Harry; Mao, Guangzhao

    2016-05-01

    Drug delivery to the central nervous system (CNS) is challenging due to the inability of many drugs to cross the blood-brain barrier (BBB). Here, we show that wheat germ agglutinin horse radish peroxidase (WGA-HRP) chemically conjugated to gold nanoparticles (AuNPs) can be transported to the spinal cord and brainstem following intramuscular injection into the diaphragm of rats. We synthesized and determined the size and chemical composition of a three-part nanoconjugate consisting of WGA-HRP, AuNPs, and drugs for the treatment of diaphragm paralysis associated with high cervical spinal cord injury (SCI). Upon injection into the diaphragm muscle of rats, we show that the nanoconjugate is capable of delivering the drug at a much lower dose than the unconjugated drug injected systemically to effectively induce respiratory recovery in rats following SCI. This study not only demonstrates a promising strategy to deliver drugs to the CNS bypassing the BBB but also contributes a potential nanotherapy for the treatment of respiratory muscle paralysis resulted from cervical SCI.

  14. Blood-Brain Barrier Abnormalities Caused by HIV-1 gp120: Mechanistic and Therapeutic Implications

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    Jean-Pierre Louboutin

    2012-01-01

    Full Text Available The blood-brain barrier (BBB is compromised in many systemic and CNS diseases, including HIV-1 infection of the brain. We studied BBB disruption caused by HIV-1 envelope glycoprotein 120 (gp120 as a model. Exposure to gp120, whether acute [by direct intra-caudate-putamen (CP injection] or chronic [using SV(gp120, an experimental model of ongoing production of gp120] disrupted the BBB, and led to leakage of vascular contents. Gp120 was directly toxic to brain endothelial cells. Abnormalities of the BBB reflect the activity of matrix metalloproteinases (MMPs. These target laminin and attack the tight junctions between endothelial cells and BBB basal laminae. MMP-2 and MMP-9 were upregulated following gp120-injection. Gp120 reduced laminin and tight junction proteins. Reactive oxygen species (ROS activate MMPs. Injecting gp120 induced lipid peroxidation. Gene transfer of antioxidant enzymes protected against gp120-induced BBB abnormalities. NMDA upregulates the proform of MMP-9. Using the NMDA receptor (NMDAR-1 inhibitor, memantine, we observed partial protection from gp120-induced BBB injury. Thus, (1 HIV-envelope gp120 disrupts the BBB; (2 this occurs via lesions in brain microvessels, MMP activation and degradation of vascular basement membrane and vascular tight junctions; (3 NMDAR-1 activation plays a role in this BBB injury; and (4 antioxidant gene delivery as well as NMDAR-1 antagonists may protect the BBB.

  15. Nanoparticulate transport of oximes over an in vitro blood-brain barrier model.

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    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.

  16. Blood-brain barrier permeability and brain uptake mechanism of kainic acid and dihydrokainic acid.

    Science.gov (United States)

    Gynther, Mikko; Petsalo, Aleksanteri; Hansen, Steen H; Bunch, Lennart; Pickering, Darryl S

    2015-03-01

    The glutamatergic neurotransmitter system is involved in important neurophysiological processes and thus constitutes a promising target for the treatment of neurological diseases. The two ionotropic glutamate receptor agonists kainic acid (KA) and dihydrokainic acid (DHK) have been used as research 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 volume of distribution in brain is also low. Therefore, even though the total KA and DHK concentrations in the brain are low after systemic dosing, the concentrations in the vicinity of the glutamate receptors are sufficient for their activation and thus the observed efficacy.

  17. Caffeine blocks disruption of blood brain barrier in a rabbit model of Alzheimer's disease

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    Ghribi Othman

    2008-04-01

    Full Text Available Abstract High levels of serum cholesterol and disruptions of the blood brain barrier (BBB have all been implicated as underlying mechanisms in the pathogenesis of Alzheimer's disease. Results from studies conducted in animals and humans suggest that caffeine might be protective against Alzheimer's disease but by poorly understood mechanisms. Using rabbits fed a cholesterol-enriched diet, we tested our hypothesis that chronic ingestion of caffeine protects against high cholesterol diet-induced disruptions of the BBB. New Zealand rabbits were fed a 2% cholesterol-enriched diet, and 3 mg caffeine was administered daily in drinking water for 12 weeks. Total cholesterol and caffeine concentrations from blood were measured. Olfactory bulbs (and for some studies hippocampus and cerebral cortex as well were evaluated for BBB leakage, BBB tight junction protein expression levels, activation of astrocytes, and microglia density using histological, immunostaining and immunoblotting techniques. We found that caffeine blocked high cholesterol diet-induced increases in extravasation of IgG and fibrinogen, increases in leakage of Evan's blue dye, decreases in levels of the tight junction proteins occludin and ZO-1, increases in astrocytes activation and microglia density where IgG extravasation was present. Chronic ingestion of caffeine protects against high cholesterol diet-induced increases in disruptions of the BBB, and caffeine and drugs similar to caffeine might be useful in the treatment of Alzheimer's disease.

  18. 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.

  19. BLOOD-BRAIN BARRIER DYSFUNCTION IN DISORDERS OF THE DEVELOPING BRAIN

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    Raffaella eMoretti

    2015-02-01

    Full Text Available ABSTRACTDisorders of the developing brain represent a major health problem. The neurological manifestations of brain lesions can range from severe clinical deficits to more subtle neurological signs or behavioral problems and learning disabilities, which often become evident many years after the initial damage. These long-term sequelae are due at least in part to central nervous system immaturity at the time of the insult.The blood brain barrier (BBB protects the brain and maintains homeostasis. BBB alterations are observed during both acute and chronic brain insults. After an insult, excitatory amino acid neurotransmitters are released, causing reactive oxygen species (ROS-dependent changes in BBB permeability that allow immune cells to enter and stimulate an inflammatory response.The cytokines, chemokines and other molecules released as well as peripheral and local immune cells can activate an inflammatory cascade in the brain, leading to secondary neurodegeneration that can continue for months or even years and finally contribute to post-insult neuronal deficits. The role of the BBB in perinatal disorders is poorly understood. The inflammatory response, which can be either acute (e.g. perinatal stroke, traumatic brain injury or chronic (e.g. perinatal infectious diseases actively modulates the pathophysiological processes underlying brain injury. We present an overview of current knowledge about BBB dysfunction in the developing brain during acute and chronic insults, along with clinical and experimental data.

  20. The effect on the blood-brain barrier of intracarotid contrast media--iopamidol and diatrizoate.

    Science.gov (United States)

    Hayakawa, K; Nakamura, R; Ishii, Y

    1988-02-01

    The effect on the blood-brain barrier (BBB) was assessed following intracarotid injection of iopamidol (300 mgI/ml.), meglumine diatrizoate (305 mgI/ml.) and isotonic saline. Four ml/kg of 2% Evans blue solution and 0.1 mCi 99m Technetium-DTPA (Tc-DTPA) were used as tracers. No blue staining was observed in the saline group. Three out of 10 animals showed blue staining in the iopamidol group. All ten animals showed blue staining in the diatrizoate group. There were statistical differences between the diatrizoate and the other two groups. Tc-DTPA extravasation was 0.37 +/- 0.13 (mean +/- SD) in the saline group, 1.29 +/- 0.77 in the iopamidol group and 3.88 +/- 1.67 in the diatrizoate group. Statistical differences were observed among three groups. These observations suggest that Tc-DTPA is very sensitive in detecting a subtle BBB injury and that iopamidol had a significantly smaller effect on the BBB than did meglumine diatrizoate.

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

    Science.gov (United States)

    Haskó, János; Fazakas, Csilla; Molnár, Judit; Nyúl-Tóth, Ádám; Herman, Hildegard; Hermenean, Anca; Wilhelm, Imola; Persidsky, Yuri; Krizbai, István A.

    2014-01-01

    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. PMID:24815068

  2. Delivery of antihuman African trypanosomiasis drugs across the blood-brain and blood-CSF barriers.

    Science.gov (United States)

    Sekhar, Gayathri N; Watson, Christopher P; Fidanboylu, Mehmet; Sanderson, Lisa; Thomas, Sarah A

    2014-01-01

    Human African trypanosomiasis (HAT or sleeping sickness) is a potentially fatal disease caused by the parasite, Trypanosoma brucei sp. The parasites are transmitted by the bite of insect vectors belonging to the genus Glossina (tsetse flies) and display a life cycle strategy that is equally spread between human and insect hosts. T.b. gambiense is found in western and central Africa whereas, T.b. rhodesiense is found in eastern and southern Africa. The disease has two clinical stages: a blood stage after the bite of an infected tsetse fly, followed by a central nervous system (CNS) stage where the parasite penetrates the brain; causing death if left untreated. The blood-brain barrier (BBB) makes the CNS stage difficult to treat because it prevents 98% of all known compounds from entering the brain, including some anti-HAT drugs. Those that do enter the brain are toxic compounds in their own right and have serious side effects. There are only a few drugs available to treat HAT and those that do are stage specific. This review summarizes the incidence, diagnosis, and treatment of HAT and provides a close examination of the BBB transport of anti-HAT drugs and an overview of the latest drugs in development.

  3. Computational and in vitro studies of blast-induced blood-brain barrier disruption

    CERN Document Server

    Del Razo, Mauricio J; Meabon, James S; Huber, B Russell; Peskind, Elaine R; Banks, William A; Mourad, Pierre D; Leveque, Randall J; Cook, David G

    2015-01-01

    There is growing concern that blast-exposed individuals are at risk of developing neurological disorders later in life. Therefore, it is important to understand the dynamic properties of blast forces on brain cells, including the endothelial cells that maintain the blood-brain barrier (BBB), which regulates the passage of nutrients into the brain and protects it from toxins in the blood. To better understand the effect of shock waves on the BBB we have investigated an {\\em in vitro} model in which BBB endothelial cells are grown in transwell vessels and exposed in a shock tube, confirming that BBB integrity is directly related to shock wave intensity. It is difficult to directly measure the forces acting on these cells in the transwell container during the experiments, and so a computational tool has been developed and presented in this paper. Two-dimensional axisymmetric Euler equations with the Tammann equation of state were used to model the transwell materials, and a high-resolution finite volume method b...

  4. Predictive model of blood-brain barrier penetration of organic compounds

    Institute of Scientific and Technical Information of China (English)

    Xiao-lei MA; Cheng CHEN; Jie YANG

    2005-01-01

    Aim: To build up a theoretical model of organic compounds for the prediction of the activity of small molecules through the blood-brain barrier (BBB) in drug design. Methods: A training set of 37 structurally diverse compounds was used to construct quantitative structure-activity relationship (QSAR) models. Intermolecular and intramolecular solute descriptors were calculated using molecular mechanics, molecular dynamics simulations, quantum chemistry and so on. The QSAR models were optimized using multidimensional linear regression fitting and stepwise method. A test set of 8 compounds was evaluated using the models as part of a validation process. Results: Significant QSAR models (R=0.955, s=0.232) of the BBB penetration of organic compounds were constructed. BBB penetrationwas found to depend upon the polar surface area, the octanol/water partition coefficient, Balaban Index, the strength of a small molecule to combine with the membrane-water complex, and the changeability of the structure of a solute-membrane-water complex. Conclusion: The QSAR models indicate that the distribution of organic molecules through BBB is not only influenced by organic solutes themselves, but also relates to the properties of the solute-membrane-water complex, that is, interactions of the molecule with the phospholipid-rich regions of cellular membranes.

  5. Molecular anatomy of interendothelial junctions in human blood-brain barrier microvessels.

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    Andrzej W Vorbrodt

    2004-07-01

    Full Text Available Immunogold cytochemical procedure was used to study the localization at the ultrastructural level of interendothelial junction-associated protein molecules in the human brain blood microvessels, representing the anatomic site of the blood-brain barrier (BBB. Ultrathin sections of Lowicryl K4M-embedded biopsy specimens of human cerebral cortex obtained during surgical procedures were exposed to specific antibodies, followed by colloidal gold-labeled secondary antibodies. All tight junction-specific integral membrane (transmembrane proteins--occludin, junctional adhesion molecule (JAM-1, and claudin-5--as well as peripheral zonula occludens protein (ZO-1 were highly expressed. Immunoreactivity of the adherens junction-specific transmembrane protein VE-cadherin was of almost similar intensity. Immunolabeling of the adherens junction-associated peripheral proteins--alpha-catenin, beta-catenin, and p120 catenin--although positive, was evidently less intense. The expression of gamma-catenin (plakoglobin was considered questionable because solitary immunosignals (gold particles appeared in only a few microvascular profiles. Double labeling of some sections made possible to observe strict colocalization of the junctional molecules, such as occludin and ZO-1 or JAM-1 and VE-cadherin, in the interendothelial junctions. We found that in human brain microvessels, the interendothelial junctional complexes contain molecular components specific for both tight and adherens junctions. It is assumed that the data obtained can help us find the immunodetectable junctional molecules that can serve as sensitive markers of normal or abnormal function of the BBB.

  6. Effects of insulin on hexose transport across blood-brain barrier in normoglycemia

    Energy Technology Data Exchange (ETDEWEB)

    Namba, H.; Lucignani, G.; Nehlig, A.; Patlak, C.; Pettigrew, K.; Kennedy, C.; Sokoloff, L.

    1987-03-01

    The effects of insulin on 3-O-(/sup 14/C) methylglucose transport across the blood-brain barrier (BBB) were studied in conscious rats under steady-state normoglycemic conditions. The (/sup 14/C)methylglucose was infused intravenously at a constant rate, and animals were killed at various times between 5 and 30 min after the initiation of the infusion. The time course of the arterial plasma concentration of (/sup 14/C)methylglucose was determined in timed arterial blood samples taken during the infusion. Local cerebral tissue concentrations of (/sup 14/C)methylglucose at the time of killing were determined by quantitative autoradiography of brain sections. The rate constants for inward and outward transport of (/sup 14/C)methylglucose across the BBB, K/sub 1/, and k/sub 2/, respectively, were estimated by a least-squares, best-fit of a kinetic equation to the measured time courses of plasma and tissue concentrations. The equilibrium distribution ration, K/sub 1//k/sub 2/, for (/sup 14/C)methylglucose in brain increased by approx. 10-11% in the hyperinsulinemic animals. Because 3-O-(/sup 14/C)methylglucose shares the same carrier that transports glucose and other hexoses across the BBB, these results suggest that hyperinsulinemia decreases the rate constants for transport but increases the distribution space for hexoses in brain. These effects are, however, quite small and are probably minor or negligible when compared with the major effects of insulin in other tissues.

  7. Nanowired Drug Delivery Across the Blood-Brain Barrier in Central Nervous System Injury and Repair.

    Science.gov (United States)

    Sharma, Aruna; Menon, Preeti; Muresanu, Dafin F; Ozkizilcik, Asya; Tian, Z Ryan; Lafuente, José V; Sharma, Hari S

    2016-01-01

    The blood-brain barrier (BBB) is a physiological regulator of transport of essential items from blood to brain for the maintenance of homeostasis of the central nervous system (CNS) within narrow limits. The BBB is also responsible for export of harmful or metabolic products from brain to blood to keep the CNS fluid microenvironment healthy. However, noxious insults to the brain caused by trauma, ischemia or environmental/chemical toxins alter the BBB function to small as well as large molecules e.g., proteins. When proteins enter the CNS fluid microenvironment, development of brain edema occurs due to altered osmotic balance between blood and brain. On the other hand, almost all neurodegenerative diseases and traumatic insults to the CNS and subsequent BBB dysfunction lead to edema formation and cell injury. To treat these brain disorders suitable drug therapy reaching their brain targets is needed. However, due to edema formation or only a focal disruption of the BBB e.g., around brain tumors, many drugs are unable to reach their CNS targets in sufficient quantity. This results in poor therapeutic outcome. Thus, new technology such as nanodelivery is needed for drugs to reach their CNS targets and be effective. In this review, use of nanowires as a possible novel tool to enhance drug delivery into the CNS in various disease models is discussed based on our investigations. These data show that nanowired delivery of drugs may have superior neuroprotective ability to treat several CNS diseases effectively indicating their role in future therapeutic strategies.

  8. Extraction of [99mTc]-d,l-HM-PAO across the blood-brain barrier

    DEFF Research Database (Denmark)

    Andersen, A R; Friberg, H; Knudsen, K B

    1988-01-01

    The initial extraction (E) across the blood-brain barrier (BBB) of [99mTc]-d,l-HM-PAO after intracarotid injection was measured in 14 Wistar rats and 6 patients using the double indicator, single injection method with Na-24 as the cotracer. In both series, cerebral blood flow (CBF) was measured...... using the initial slope of the xenon-133 washout curve after intracarotid bolus injection. In rats, bolus size (20 or 120 microliters), bolus type (saline or 10% albumin), or CBF were changed. First-pass extraction was dependent on CBF (p less than 0.001): With a small bolus of saline and at resting CBF...... the apparent extraction across brain capillaries. In patients using a bolus of 1 ml saline, E decreased linearly with increasing CBF (r = -0.81, p less than 0.001). For a CBF of 0.59 ml/g/min and an average apparent E of 0.72, an apparent PS product of 0.76 ml/g/min was calculated.(ABSTRACT TRUNCATED AT 250...

  9. 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.

  10. Blood-brain barrier dysfunction in disorders of the developing brain

    Science.gov (United States)

    Moretti, Raffaella; Pansiot, Julien; Bettati, Donatella; Strazielle, Nathalie; Ghersi-Egea, Jean-François; Damante, Giuseppe; Fleiss, Bobbi; Titomanlio, Luigi; Gressens, Pierre

    2015-01-01

    Disorders of the developing brain represent a major health problem. The neurological manifestations of brain lesions can range from severe clinical deficits to more subtle neurological signs or behavioral problems and learning disabilities, which often become evident many years after the initial damage. These long-term sequelae are due at least in part to central nervous system immaturity at the time of the insult. The blood-brain barrier (BBB) protects the brain and maintains homeostasis. BBB alterations are observed during both acute and chronic brain insults. After an insult, excitatory amino acid neurotransmitters are released, causing reactive oxygen species (ROS)-dependent changes in BBB permeability that allow immune cells to enter and stimulate an inflammatory response. The cytokines, chemokines and other molecules released as well as peripheral and local immune cells can activate an inflammatory cascade in the brain, leading to secondary neurodegeneration that can continue for months or even years and finally contribute to post-insult neuronal deficits. The role of the BBB in perinatal disorders is poorly understood. The inflammatory response, which can be either acute (e.g., perinatal stroke, traumatic brain injury) or chronic (e.g., perinatal infectious diseases) actively modulates the pathophysiological processes underlying brain injury. We present an overview of current knowledge about BBB dysfunction in the developing brain during acute and chronic insults, along with clinical and experimental data. PMID:25741233

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Anti-miR delivery strategies to bypass the blood-brain barrier in glioblastoma therapy

    Science.gov (United States)

    Kim, Dong Geon; Kim, Kang Ho; Seo, Yun Jee; Yang, Heekyoung; Marcusson, Eric G.; Son, Eunju; Lee, Kyoungmin; Sa, Jason K.; Lee, Hye Won; Nam, Do-Hyun

    2016-01-01

    Small non-coding RNAs called miRNAs are key regulators in various biological processes, including tumor initiation, propagation, and metastasis in glioblastoma as well as other cancers. Recent studies have shown the potential for oncogenic miRNAs as therapeutic targets in glioblastoma. However, the application of antisense oligomers, or anti-miRs, to the brain is limited due to the blood-brain barrier (BBB), when administered in the traditional systemic manner. To induce a therapeutic effect in glioblastoma, anti-miR therapy requires a robust and effective delivery system to overcome this obstacle. To bypass the BBB, different delivery administration methods for anti-miRs were evaluated. Stereotaxic surgery was performed to administer anti-Let-7 through intratumoral (ITu), intrathecal (ITh), and intraventricular (ICV) routes, and each method's efficacy was determined by changes in the expression of anti-Let-7 target genes as well as by immunohistochemical analysis. ITu administration of anti-miRs led to a high rate of anti-miR delivery to tumors in the brain by both bolus and continuous administration. In addition, ICV administration, compared with ITu administration, showed a greater distribution of the miR across entire brain tissues. This study suggests that local administration methods are a promising strategy for anti-miR treatment and may overcome current limitations in the treatment of glioblastoma in preclinical animal models. PMID:27102443

  13. 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.

  14. Brain injury associated with widely abused amphetamines: neuroinflammation, neurogenesis and blood-brain barrier.

    Science.gov (United States)

    Silva, Ana P; Martins, Tânia; Baptista, Sofia; Gonçalves, Joana; Agasse, Fabienne; Malva, João O

    2010-12-01

    Over the course of the 20(th) century, it became increasingly clear that amphetamine-like psychostimulants carried serious abuse liability that has resulted in sociological use patterns that have been described as epidemics. In fact, drug addiction is a brain disease with a high worldwide prevalence, and is considered the most expensive of the neuropsychiatric disorders. This review goes beyond the previously well-documented evidence demonstrating that amphetamines cause neuronal injury. Cellular and molecular mechanisms involved in the neurotoxicity of psychostimulants drugs have been extensively described giving particular attention to the role of oxidative stress and metabolic compromise. Recently, it was shown that the amphetamine class of drugs of abuse triggers an inflammatory process, emerging as a critical concept to understand the toxic effects of these drugs. Moreover, it has been suggested that psychostimulants compromise the capacity of the brain to generate new neurons (neurogenesis), and can also lead to blood-brain barrier (BBB) dysfunction. Together, these effects may contribute to brain damage, allowing the entry of pathogens into the brain parenchyma and thus decreasing the endogenous brain repair resources. The overall objective of this review is to highlight experimental evidence in an attempt to clarify the role of neuroinflammation in amphetamines-induced brain dysfunction and the effect of these drugs on both neurogenesis and BBB integrity.

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

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    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. 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.

  17. Crossing the blood-brain-barrier with transferrin conjugated carbon dots: A zebrafish model study.

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    Li, Shanghao; Peng, Zhili; Dallman, Julia; Baker, James; Othman, Abdelhameed M; Blackwelder, Patrica L; Leblanc, Roger M

    2016-09-01

    Drug delivery to the central nervous system (CNS) in biological systems remains a major medical challenge due to the tight junctions between endothelial cells known as the blood-brain-barrier (BBB). Here we use a zebrafish model to explore the possibility of using transferrin-conjugated carbon dots (C-Dots) to ferry compounds across the BBB. C-Dots have previously been reported to inhibit protein fibrillation, and they are also used to deliver drugs for disease treatment. In terms of the potential medical application of C-Dots for the treatment of CNS diseases, one of the most formidable challenges is how to deliver them inside the CNS. To achieve this in this study, human transferrin was covalently conjugated to C-Dots. The conjugates were then injected into the vasculature of zebrafish to examine the possibility of crossing the BBB in vivo via transferrin receptor-mediated endocytosis. The experimental observations suggest that the transferrin-C-Dots can enter the CNS while C-Dots alone cannot.

  18. Transport rankings of non-steroidal antiinflammatory drugs across blood-brain barrier in vitro models.

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    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.

  19. Crossing the Blood-Brain Barrier: Recent Advances in Drug Delivery to the Brain.

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    Patel, Mayur M; Patel, Bhoomika M

    2017-02-01

    CNS disorders are on the rise despite advancements in our understanding of their pathophysiological mechanisms. A major hurdle to the treatment of these disorders is the blood-brain barrier (BBB), which serves as an arduous janitor to protect the brain. Many drugs are being discovered for CNS disorders, which, however fail to enter the market because of their inability to cross the BBB. This is a pronounced challenge for the pharmaceutical fraternity. Hence, in addition to the discovery of novel entities and drug candidates, scientists are also developing new formulations of existing drugs for brain targeting. Several approaches have been investigated to allow therapeutics to cross the BBB. As the molecular structure of the BBB is better elucidated, several key approaches for brain targeting include physiological transport mechanisms such as adsorptive-mediated transcytosis, inhibition of active efflux pumps, receptor-mediated transport, cell-mediated endocytosis, and the use of peptide vectors. Drug-delivery approaches comprise delivery from microspheres, biodegradable wafers, and colloidal drug-carrier systems (e.g., liposomes, nanoparticles, nanogels, dendrimers, micelles, nanoemulsions, polymersomes, exosomes, and quantum dots). The current review discusses the latest advancements in these approaches, with a major focus on articles published in 2015 and 2016. In addition, we also cover the alternative delivery routes, such as intranasal and convection-enhanced diffusion methods, and disruption of the BBB for brain targeting.

  20. Alpha synuclein is transported into and out of the brain by the blood-brain barrier.

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    Sui, Yu-Ting; Bullock, Kristin M; Erickson, Michelle A; Zhang, Jing; Banks, W A

    2014-12-01

    Alpha-synuclein (α-Syn), a small protein with multiple physiological and pathological functions, is one of the dominant proteins found in Lewy Bodies, a pathological hallmark of Lewy body disorders, including Parkinson's disease (PD). More recently, α-Syn has been found in body fluids, including blood and cerebrospinal fluid, and is likely produced by both peripheral tissues and the central nervous system. Exchange of α-Syn between the brain and peripheral tissues could have important pathophysiologic and therapeutic implications. However, little is known about the ability of α-Syn to cross the blood-brain barrier (BBB). Here, we found that radioactively labeled α-Syn crossed the BBB in both the brain-to-blood and the blood-to-brain directions at rates consistent with saturable mechanisms. Low-density lipoprotein receptor-related protein-1 (LRP-1), but not p-glycoprotein, may be involved in α-Syn efflux and lipopolysaccharide (LPS)-induced inflammation could increase α-Syn uptake by the brain by disrupting the BBB.

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

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    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.

  2. Advances in PET imaging of P-glycoprotein function at the blood-brain barrier.

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    Syvänen, Stina; Eriksson, Jonas

    2013-02-20

    Efflux transporter P-glycoprotein (P-gp) at the blood-brain barrier (BBB) restricts substrate compounds from entering the brain and may thus contribute to pharmacoresistance observed in patient groups with refractory epilepsy and HIV. Altered P-gp function has also been implicated in neurodegenerative diseases such as Alzheimer's and Parkinson's disease. Positron emission tomography (PET), a molecular imaging modality, has become a promising method to study the role of P-gp at the BBB. The first PET study of P-gp function was conducted in 1998, and during the past 15 years two main categories of P-gp PET tracers have been investigated: tracers that are substrates of P-gp efflux and tracers that are inhibitors of P-gp function. PET, as a noninvasive imaging technique, allows translational research. Examples of this are preclinical investigations of P-gp function before and after administering P-gp modulating drugs, investigations in various animal and disease models, and clinical investigations regarding disease and aging. The objective of the present review is to give an overview of available PET radiotracers for studies of P-gp and to discuss how such studies can be designed. Further, the review summarizes results from PET studies of P-gp function in different central nervous system disorders.

  3. Flavonoid transport across RBE4 cells: A blood-brain barrier model.

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    Faria, Ana; Pestana, Diogo; Teixeira, Diana; Azevedo, Joana; De Freitas, Victor; Mateus, Nuno; Calhau, Conceição

    2010-06-01

    There is a growing interest in dietary therapeutic strategies to combat oxidative stress-induced damage to the Central Nervous System (CNS), which is associated with a number of pathophysiological processes, including Alzheimer's and Parkinson's diseases and cerebrovascular diseases. Identifying the mechanisms associated with phenolic neuroprotection has been delayed by the lack of information concerning the ability of these compounds to enter the CNS. The aim of this study was to evaluate the transmembrane transport of flavonoids across RBE-4 cells (an immortalized cell line of rat cerebral capillary endothelial cells) and the effect of ethanol on this transport. The detection and quantification of all of the phenolic compounds in the studied samples (basolateral media) was performed using a HPLC-DAD (Diode Array Detector). All of the tested flavonoids (catechin, quercetin and cyanidin-3-glucoside) passed across the RBE-4 cells in a time-dependent manner. This transport was not influenced by the presence of 0.1% ethanol. In conclusion, the tested flavonoids were capable of crossing this blood-brain barrier model.

  4. Transport of nanoparticles through the blood-brain barrier for imaging and therapeutic applications

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    Shilo, Malka; Motiei, Menachem; Hana, Panet; Popovtzer, Rachela

    2014-01-01

    A critical problem in the treatment of neurodegenerative disorders and diseases, such as Alzheimer's and Parkinson's, is the incapability to overcome the restrictive mechanism of the blood-brain barrier (BBB) and to deliver important therapeutic agents to the brain. During the last decade, nanoparticles have gained attention as promising drug delivery agents that can transport across the BBB and increase the uptake of appropriate drugs in the brain. In this study we have developed insulin-targeted gold nanoparticles (INS-GNPs) and investigated quantitatively the amount of INS-GNPs that cross the BBB by the receptor-mediated endocytosis process. For this purpose, INS-GNPs and control GNPs were injected into the tail vein of male BALB/c mice. Major organs were then extracted and a blood sample was taken from the mice, and thereafter analyzed for gold content by flame atomic absorption spectroscopy. Results show that two hours post-intravenous injection, the amount of INS-GNPs found in mouse brains is over 5 times greater than that of the control, untargeted GNPs. Results of further experimentation on a rat model show that INS-GNPs can also serve as CT contrast agents to highlight specific brain regions in which they accumulate. Due to the fact that they can overcome the restrictive mechanism of the BBB, this approach could be a potentially valuable tool, helping to confront the great challenge of delivering important imaging and therapeutic agents to the brain for detection and treatment of neurodegenerative disorders and diseases.

  5. Interleukin-1β induces blood-brain barrier disruption by downregulating Sonic hedgehog in astrocytes.

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    Wang, Yue; Jin, Shijie; Sonobe, Yoshifumi; Cheng, Yi; Horiuchi, Hiroshi; Parajuli, Bijay; Kawanokuchi, Jun; Mizuno, Tetsuya; Takeuchi, Hideyuki; Suzumura, Akio

    2014-01-01

    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.

  6. Nanoparticle-mediated brain drug delivery: Overcoming blood-brain barrier to treat neurodegenerative diseases.

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    Saraiva, Cláudia; Praça, Catarina; Ferreira, Raquel; Santos, Tiago; Ferreira, Lino; Bernardino, Liliana

    2016-08-10

    The blood-brain barrier (BBB) is a vital boundary between neural tissue and circulating blood. The BBB's unique and protective features control brain homeostasis as well as ion and molecule movement. Failure in maintaining any of these components results in the breakdown of this specialized multicellular structure and consequently promotes neuroinflammation and neurodegeneration. In several high incidence pathologies such as stroke, Alzheimer's (AD) and Parkinson's disease (PD) the BBB is impaired. However, even a damaged and more permeable BBB can pose serious challenges to drug delivery into the brain. The use of nanoparticle (NP) formulations able to encapsulate molecules with therapeutic value, while targeting specific transport processes in the brain vasculature, may enhance drug transport through the BBB in neurodegenerative/ischemic disorders and target relevant regions in the brain for regenerative processes. In this review, we will discuss BBB composition and characteristics and how these features are altered in pathology, namely in stroke, AD and PD. Additionally, factors influencing an efficient intravenous delivery of polymeric and inorganic NPs into the brain as well as NP-related delivery systems with the most promising functional outcomes will also be discussed.

  7. Blood-brain barrier P-glycoprotein function is not impaired in early Parkinson's disease.

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    Bartels, A L; van Berckel, B N M; Lubberink, M; Luurtsema, G; Lammertsma, A A; Leenders, K L

    2008-08-01

    The cause of Parkinson's disease (PD) is unknown. Genetic susceptibility and exposure to environmental toxins contribute to specific neuronal loss in PD. Decreased blood-brain barrier (BBB) P-glycoprotein (P-gp) efflux function has been proposed as a possible causative link between toxin exposure and PD neurodegeneration. In the present study BBB P-gp function was investigated in vivo in 10 early stage PD patients and 8 healthy control subjects using (R)-[(11)C]-verapamil and PET. Cerebral volume of distribution (V(d)) of verapamil was used as measure of P-gp function. Both region of interest (ROI) analysis and voxel analysis using statistical parametric mapping (SPM) were performed to assess regional brain P-gp function. In addition, MDR1 genetic polymorphism was assessed. In the present study, a larger variation in V(d) of (R)-[(11)C]-verapamil was seen in the PD group as compared to the control group. However, decreased BBB P-gp function in early stage PD patients could not be confirmed.

  8. Influence of silver and titanium dioxide nanoparticles on in vitro blood-brain barrier permeability.

    Science.gov (United States)

    Chen, I-Chieh; Hsiao, I-Lun; Lin, Ho-Chen; Wu, Chien-Hou; Chuang, Chun-Yu; Huang, Yuh-Jeen

    2016-10-01

    An in vitro blood-brain barrier (BBB) model being composed of co-culture with endothelial (bEnd.3) and astrocyte-like (ALT) cells was established to evaluate the toxicity and permeability of Ag nanoparticles (AgNPs; 8nm) and TiO2 nanoparticles (TiO2NPs; 6nm and 35nm) in normal and inflammatory central nervous system. Lipopolysaccharide (LPS) was pre-treated to simulate the inflammatory responses. Both AgNPs and Ag ions can decrease transendothelial electrical resistance (TEER) value, and cause discontinuous tight junction proteins (claudin-5 and zonula occludens-1) of BBB. However, only the Ag ions induced inflammatory cytokines to release, and had less cell-to-cell permeability than AgNPs, which indicated that the toxicity of AgNPs was distinct from Ag ions. LPS itself disrupted BBB, while co-treatment with AgNPs and LPS dramatically enhanced the disruption and permeability coefficient. On the other hand, TiO2NPs exposure increased BBB penetration by size, and disrupted tight junction proteins without size dependence, and many of TiO2NPs accumulated in the endothelial cells were observed. This study provided the new insight of toxic potency of AgNPs and TiO2NPs in BBB.

  9. Biomarkers Indicative of Blood-Brain Barrier Disruption in Multiple Sclerosis

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    Emmanuelle Waubant

    2006-01-01

    Full Text Available Blood-brain barrier (BBB disruption is one of the hallmarks of multiple sclerosis (MS. It is incompletely understood whether BBB disruption is the initial MS event leading to MS lesion formation or whether it is merely a consequence of cellular infiltration in the central nervous system (CNS. The presence of gadolinium enhancing (Gd+ lesions on serial brain MRI scans is frequently used to evaluate BBB disruption. The presence of Gd enhancement has therefore been used as a reference for most works evaluating promising biomarkers of BBB disruption that are reviewed here. These promising biomarkers include cytokines and chemokines, and their receptors, cell surface markers, and matrix metalloproteinases and their natural inhibitors. At this time, none of these markers have been shown as sensitive as the presence of Gd enhancement to reflect BBB disruption. However, MRI scanning is not only unpractical and expensive; it may also under represent the overall extent of BBB disruption. Developing new MS biomarkers that are sensitive and specific for BBB disruption could 1 improve the monitoring of disease activity; 2 improve the monitoring of response to MS therapies which target BBB disruption; and 3 advance our understanding of dynamic MS processes participating in BBB disruption.

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

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    Kobus, Thiele; Vykhodtseva, Natalia; Pilatou, Magdalini; Zhang, Yongzhi; McDannold, Nathan

    2016-02-01

    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 0.66 and 0.80 MPa, were performed under magnetic resonance guidance. The success and degree of BBB disruption was estimated by signal enhancement of post-contrast T1-weighted imaging of the treated area. Histopathological analysis was performed after the last treatment. The consequences of repeated BBB disruption varied from no indications of vascular damage to signs of micro-hemorrhages, macrophage infiltration, micro-scar formations and cystic cavities. The signal enhancement on the contrast-enhanced T1-weighted imaging had limited value for predicting small-vessel damage. T2-weighted imaging corresponded well with the effects on histopathology and could be used to study treatment effects over time. This study demonstrates that repeated BBB disruption by FUS can be performed with no or limited damage to the brain tissue.

  11. Blood-Brain Barrier Alterations Provide Evidence of Subacute Diaschisis in an Ischemic Stroke Rat Model

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    Garbuzova-Davis, Svitlana; Rodrigues, Maria C. O.; Hernandez-Ontiveros, Diana G.; Tajiri, Naoki; Frisina-Deyo, Aric; Boffeli, Sean M.; Abraham, Jerry V.; Pabon, Mibel; Wagner, Andrew; Ishikawa, Hiroto; Shinozuka, Kazutaka; Haller, Edward; Sanberg, Paul R.; Kaneko, Yuji; Borlongan, Cesario V.

    2013-01-01

    Background Comprehensive stroke studies reveal diaschisis, a loss of function due to pathological deficits in brain areas remote from initial ischemic lesion. However, blood-brain barrier (BBB) competence in subacute diaschisis is uncertain. The present study investigated subacute diaschisis in a focal ischemic stroke rat model. Specific focuses were BBB integrity and related pathogenic processes in contralateral brain areas. Methodology/Principal Findings In ipsilateral hemisphere 7 days after transient middle cerebral artery occlusion (tMCAO), significant BBB alterations characterized by large Evans Blue (EB) parenchymal extravasation, autophagosome accumulation, increased reactive astrocytes and activated microglia, demyelinization, and neuronal damage were detected in the striatum, motor and somatosensory cortices. Vascular damage identified by ultrastuctural and immunohistochemical analyses also occurred in the contralateral hemisphere. In contralateral striatum and motor cortex, major ultrastructural BBB changes included: swollen and vacuolated endothelial cells containing numerous autophagosomes, pericyte degeneration, and perivascular edema. Additionally, prominent EB extravasation, increased endothelial autophagosome formation, rampant astrogliosis, activated microglia, widespread neuronal pyknosis and decreased myelin were observed in contralateral striatum, and motor and somatosensory cortices. Conclusions/Significance These results demonstrate focal ischemic stroke-induced pathological disturbances in ipsilateral, as well as in contralateral brain areas, which were shown to be closely associated with BBB breakdown in remote brain microvessels and endothelial autophagosome accumulation. This microvascular damage in subacute phase likely revealed ischemic diaschisis and should be considered in development of treatment strategies for stroke. PMID:23675488

  12. Blood-brain barrier alterations provide evidence of subacute diaschisis in an ischemic stroke rat model.

    Directory of Open Access Journals (Sweden)

    Svitlana Garbuzova-Davis

    Full Text Available BACKGROUND: Comprehensive stroke studies reveal diaschisis, a loss of function due to pathological deficits in brain areas remote from initial ischemic lesion. However, blood-brain barrier (BBB competence in subacute diaschisis is uncertain. The present study investigated subacute diaschisis in a focal ischemic stroke rat model. Specific focuses were BBB integrity and related pathogenic processes in contralateral brain areas. METHODOLOGY/PRINCIPAL FINDINGS: In ipsilateral hemisphere 7 days after transient middle cerebral artery occlusion (tMCAO, significant BBB alterations characterized by large Evans Blue (EB parenchymal extravasation, autophagosome accumulation, increased reactive astrocytes and activated microglia, demyelinization, and neuronal damage were detected in the striatum, motor and somatosensory cortices. Vascular damage identified by ultrastuctural and immunohistochemical analyses also occurred in the contralateral hemisphere. In contralateral striatum and motor cortex, major ultrastructural BBB changes included: swollen and vacuolated endothelial cells containing numerous autophagosomes, pericyte degeneration, and perivascular edema. Additionally, prominent EB extravasation, increased endothelial autophagosome formation, rampant astrogliosis, activated microglia, widespread neuronal pyknosis and decreased myelin were observed in contralateral striatum, and motor and somatosensory cortices. CONCLUSIONS/SIGNIFICANCE: These results demonstrate focal ischemic stroke-induced pathological disturbances in ipsilateral, as well as in contralateral brain areas, which were shown to be closely associated with BBB breakdown in remote brain microvessels and endothelial autophagosome accumulation. This microvascular damage in subacute phase likely revealed ischemic diaschisis and should be considered in development of treatment strategies for stroke.

  13. Neuropsychiatric lupus, the blood brain barrier, and the TWEAK/Fn14 pathway

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    Chaim ePutterman

    2013-12-01

    Full Text Available Patients with systemic lupus erythematosus (SLE can experience acute neurological events such as seizures, cerebrovascular accidents, and delirium, psychiatric conditions including depression, anxiety and psychosis, as well as memory loss and general cognitive decline. Neuropsychiatric SLE (NPSLE occurs in up to 70% of SLE patients, can constitute the initial patient presentation, and may occur outside the greater context of an SLE flare. Current efforts to elucidate the mechanistic underpinnings of NPSLE are focused on several different and potentially complementary pathways, including thrombosis, brain autoreactive antibodies, and complement deposition. Furthermore, significant effort is dedicated to understanding the contribution of neuroinflammation induced by TNF, IL-1, IL-6 and IFN-γ. More recent studies have pointed to a possible role for the TNF family ligand TWEAK in the pathogenesis of neuropsychiatric disease in human lupus patients, and in a murine model of this disease. The blood brain barrier (BBB consists of tight junctions between endothelial cells and astrocytic projections which regulate paracellular and transcellular flow into the central nervous system (CNS, respectively. Given the privileged environment of the CNS, an important question is whether and how the integrity of the BBB is compromised in NPSLE, and its potential pathogenic role. Evidence of BBB violation in NPSLE includes changes in the albumin quotient (Q¬alb between plasma and CSF, activation of brain endothelial cells, and magnetic resonance imaging. This review summarizes the evidence implicating BBB damage as an important component in NPSLE development, occurring via damage to barrier integrity by environmental triggers such as infection and stress; cerebrovascular ischemia as result of a generally prothrombotic state; and immune mediated endothelial cell activation, mediated by antibodies and/or inflammatory cytokines. Additionally, new evidence supporting

  14. Blood-brain barrier permeability during dopamine-induced hypertension in fetal sheep.

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    Harris, A P; Robinson, R; Koehler, R C; Traystman, R J; Gleason, C A

    2001-07-01

    Dopamine is often used as a pressor agent in sick newborn infants, but an increase in arterial blood pressure could disrupt the blood-brain barrier (BBB), especially in the preterm newborn. Using time-dated pregnant sheep, we tested the hypothesis that dopamine-induced hypertension increases fetal BBB permeability and cerebral water content. Barrier permeability was assessed in nine brain regions, including cerebral cortex, caudate, thalamus, brain stem, cerebellum, and spinal cord, by intravenous injection of the small tracer molecule [(14)C]aminoisobutyric acid at 10 min after the start of dopamine or saline infusion. We studied 23 chronically catheterized fetal sheep at 0.6 (93 days, n = 10) and 0.9 (132 days, n = 13) gestation. Intravenous infusion of dopamine increased mean arterial pressure from 38 +/- 3 to 53 +/- 5 mmHg in 93-day fetuses and from 55 +/- 5 to 77 +/- 8 mmHg in 132-day fetuses without a decrease in arterial O(2) content. These 40% increases in arterial pressure are close to the maximum hypertension reported for physiological stresses at these ages in fetal sheep. No significant increases in the brain transfer coefficient of aminoisobutyric acid were detected in any brain region in dopamine-treated fetuses compared with saline controls at 0.6 or 0.9 gestation. There was also no significant increase in cortical water content with dopamine infusion at either age. We conclude that a 40% increase in mean arterial pressure during dopamine infusion in normoxic fetal sheep does not produce substantial BBB disruption or cerebral edema even as early as 0.6 gestation.

  15. Mfsd2a is critical for the formation and function of the blood-brain barrier.

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    Ben-Zvi, Ayal; Lacoste, Baptiste; Kur, Esther; Andreone, Benjamin J; Mayshar, Yoav; Yan, Han; Gu, Chenghua

    2014-05-22

    The central nervous system (CNS) requires a tightly controlled environment free of toxins and pathogens to provide the proper chemical composition for neural function. This environment is maintained by the 'blood-brain barrier' (BBB), which is composed of blood vessels whose endothelial cells display specialized tight junctions and extremely low rates of transcellular vesicular transport (transcytosis). In concert with pericytes and astrocytes, this unique brain endothelial physiological barrier seals the CNS and controls substance influx and efflux. Although BBB breakdown has recently been associated with initiation and perpetuation of various neurological disorders, an intact BBB is a major obstacle for drug delivery to the CNS. A limited understanding of the molecular mechanisms that control BBB formation has hindered our ability to manipulate the BBB in disease and therapy. Here we identify mechanisms governing the establishment of a functional BBB. First, using a novel tracer-injection method for embryos, we demonstrate spatiotemporal developmental profiles of BBB functionality and find that the mouse BBB becomes functional at embryonic day 15.5 (E15.5). We then screen for BBB-specific genes expressed during BBB formation, and find that major facilitator super family domain containing 2a (Mfsd2a) is selectively expressed in BBB-containing blood vessels in the CNS. Genetic ablation of Mfsd2a results in a leaky BBB from embryonic stages through to adulthood, but the normal patterning of vascular networks is maintained. Electron microscopy examination reveals a dramatic increase in CNS-endothelial-cell vesicular transcytosis in Mfsd2a(-/-) mice, without obvious tight-junction defects. Finally we show that Mfsd2a endothelial expression is regulated by pericytes to facilitate BBB integrity. These findings identify Mfsd2a as a key regulator of BBB function that may act by suppressing transcytosis in CNS endothelial cells. Furthermore, our findings may aid in efforts

  16. The effects of hyperbaric air and hyperbaric oxygen on blood-brain barrier integrity in rats.

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    Cevik, Nihal Gunes; Orhan, Nurcan; Yilmaz, Canan Ugur; Arican, Nadir; Ahishali, Bulent; Kucuk, Mutlu; Kaya, Mehmet; Toklu, Akin Savas

    2013-09-19

    Hyperbaric oxygen (HBO) treatment yields conflicting results on blood-brain barrier (BBB) integrity under various pathological conditions and the effects of HBO on healthy brain is poorly understood. In this experimental study, the effects of HBO on BBB integrity were investigated in comparison with hyperbaric air (HBA) in intact rats. Four sessions of HBA or HBO were applied to intact rats in 24h. BBB integrity was functionally and structurally evaluated by determining extravasation of Evans blue (EB) dye and horseradish peroxidase (HRP) tracers. In immunohistochemical evaluation, relative staining intensity for occludin, a tight junction (TJ) protein, and aquaporin 4 (AQP4), a water-channel protein, was detected in the barrier type of microvessels of brain by image analysis. BBB permeability to EB dye significantly increased in animals in HBO treatment group compared to those in HBA and control groups (p<0.05). The immunoreactivity of occludin, a tight junction protein, remained essentially unaltered in capillaries of hippocampus in all groups. In animals exposed to HBO, AQP4 immunoreactivity significantly increased in parietal cortex compared to those in HBA and control groups (p<0.01). Ultrastructurally, frequent vesicles containing HRP reaction products were observed in capillary endothelial cells in cerebral cortex and hippocampus of rats subjected to both HBA and HBO. Our results indicate that the HBO administration to intact rats increased BBB permeability to both EB and HRP while HBA increased only HRP extravasation in these animals. The results of this study suggest that HBA also impairs the BBB integrity in intact rats as well as HBO.

  17. Enhanced blood-brain barrier transmigration using a novel transferrin embedded fluorescent magneto-liposome nanoformulation

    Science.gov (United States)

    Ding, Hong; Sagar, Vidya; Agudelo, Marisela; Pilakka-Kanthikeel, Sudheesh; Subba Rao Atluri, Venkata; Raymond, Andrea; Samikkannu, Thangavel; Nair, Madhavan P.

    2014-02-01

    The blood-brain barrier (BBB) is considered as the primary impediment barrier for most drugs. Delivering therapeutic agents to the brain is still a big challenge to date. In our study, a dual mechanism, receptor mediation combined with external non-invasive magnetic force, was incorporated into ferrous magnet-based liposomes for BBB transmigration enhancement. The homogenous magnetic nanoparticles (MNPs), with a size of ˜10 nm, were synthesized and confirmed by TEM and XRD respectively. The classical magnetism assay showed the presence of the characteristic superparamagnetic property. These MNPs encapsulated in PEGylated fluorescent liposomes as magneto-liposomes (MLs) showed mono-dispersion, ˜130 ± 10 nm diameter, by dynamic laser scattering (DLS) using the lipid-extrusion technique. Remarkably, a magnetite encapsulation efficiency of nearly 60% was achieved. Moreover, the luminescence and hydrodynamic size of the MLs was stable for over two months at 4 ° C. Additionally, the integrity of the ML structure remained unaffected through 120 rounds of circulation mimicking human blood fluid. After biocompatibility confirmation by cytotoxicity evaluation, these fluorescent MLs were further embedded with transferrin and applied to an in vitro BBB transmigration study in the presence or absence of external magnetic force. Comparing with magnetic force- or transferrin receptor-mediated transportation alone, their synergy resulted in 50-100% increased transmigration without affecting the BBB integrity. Consequently, confocal microscopy and iron concentration in BBB-composed cells further confirmed the higher cellular uptake of ML particles due to the synergic effect. Thus, our multifunctional liposomal magnetic nanocarriers possess great potential in particle transmigration across the BBB and may have a bright future in drug delivery to the brain.

  18. ST6GALNAC5 Expression Decreases the Interactions between Breast Cancer Cells and the Human Blood-Brain Barrier

    Science.gov (United States)

    Drolez, Aurore; Vandenhaute, Elodie; Delannoy, Clément Philippe; Dewald, Justine Hélène; Gosselet, Fabien; Cecchelli, Romeo; Julien, Sylvain; Dehouck, Marie-Pierre; Delannoy, Philippe; Mysiorek, Caroline

    2016-01-01

    The ST6GALNAC5 gene that encodes an α2,6-sialyltransferase involved in the biosynthesis of α-series gangliosides, was previously identified as one of the genes that mediate breast cancer metastasis to the brain. We have shown that the expression of ST6GALNAC5 in MDA-MB-231 breast cancer cells resulted in the expression of GD1α ganglioside at the cell surface. By using a human blood-brain barrier in vitro model recently developed, consisting in CD34+ derived endothelial cells co-cultivated with pericytes, we show that ST6GALNAC5 expression decreased the interactions between the breast cancer cells and the human blood-brain barrier. PMID:27529215

  19. Volatile Anesthetics Influence Blood-Brain Barrier Integrity by Modulation of Tight Junction Protein Expression in Traumatic Brain Injury

    OpenAIRE

    Thal, Serge C.; Clara Luh; Eva-Verena Schaible; Ralph Timaru-Kast; Jana Hedrich; Luhmann, Heiko J.; Kristin Engelhard; Zehendner, Christoph M.

    2012-01-01

    Disruption of the blood-brain barrier (BBB) results in cerebral edema formation, which is a major cause for high mortalityrnafter traumatic brain injury (TBI). As anesthetic care is mandatory in patients suffering from severe TBI it may be importantrnto elucidate the effect of different anesthetics on cerebral edema formation. Tight junction proteins (TJ) such as zonularnoccludens-1 (ZO-1) and claudin-5 (cl5) play a central role for BBB stability. First, the influence of the volatile anesthet...

  20. Inhibitory Effect of Matrine on Blood-Brain Barrier Disruption for the Treatment of Experimental Autoimmune Encephalomyelitis

    OpenAIRE

    Su Zhang; Quan-Cheng Kan; Yuming Xu; Guang-Xian Zhang; Lin Zhu

    2013-01-01

    Dysfunction of the blood-brain barrier (BBB) is a primary characteristic of experimental autoimmune encephalomyelitis (EAE), an experimental model of multiple sclerosis (MS). Matrine (MAT), a quinolizidine alkaloid derived from the herb Radix Sophorae Flave, has been recently found to suppress clinical EAE and CNS inflammation. However, whether this effect of MAT is through protecting the integrity and function of the BBB is not known. In the present study, we show that MAT treatment had a th...

  1. Benefits of agomelatine in behavioral, neurochemical and blood brain barrier alterations in prenatal valproic acid induced autism spectrum disorder.

    Science.gov (United States)

    Kumar, Hariom; Sharma, B M; Sharma, Bhupesh

    2015-12-01

    Valproic acid administration during gestational period causes behavior and biochemical deficits similar to those observed in humans with autism spectrum disorder. Although worldwide prevalence of autism spectrum disorder has been increased continuously, therapeutic agents to ameliorate the social impairment are very limited. The present study has been structured to investigate the therapeutic potential of melatonin receptor agonist, agomelatine in prenatal valproic acid (Pre-VPA) induced autism spectrum disorder in animals. Pre-VPA has produced reduction in social interaction (three chamber social behavior apparatus), spontaneous alteration (Y-Maze), exploratory activity (Hole board test), intestinal motility, serotonin levels (prefrontal cortex and ileum) and prefrontal cortex mitochondrial complex activity (complex I, II, IV). Furthermore, Pre-VPA has increased locomotor activity (actophotometer), anxiety, brain oxidative stress (thiobarbituric acid reactive species, glutathione, and catalase), nitrosative stress (nitrite/nitrate), inflammation (brain and ileum myeloperoxidase activity), calcium levels and blood brain barrier leakage in animals. Treatment with agomelatine has significantly attenuated Pre-VPA induced reduction in social interaction, spontaneous alteration, exploratory activity intestinal motility, serotonin levels and prefrontal cortex mitochondrial complex activity. Furthermore, agomelatine also attenuated Pre-VPA induced increase in locomotion, anxiety, brain oxidative stress, nitrosative stress, inflammation, calcium levels and blood brain barrier leakage. It is concluded that, Pre-VPA has induced autism spectrum disorder, which was attenuated by agomelatine. Agomelatine has shown ameliorative effect on behavioral, neurochemical and blood brain barrier alteration in Pre-VPA exposed animals. Thus melatonin receptor agonists may provide beneficial therapeutic strategy for managing autism spectrum disorder.

  2. 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.

  3. In vivo bioluminescence imaging of neurogenesis - the role of the blood brain barrier in an experimental model of Parkinson's disease.

    Science.gov (United States)

    Fricke, Inga B; Schelhaas, Sonja; Zinnhardt, Bastian; Viel, Thomas; Hermann, Sven; Couillard-Després, Sébastien; Jacobs, Andreas H

    2017-02-13

    Bioluminescence imaging in transgenic mice expressing firefly luciferase in Doublecortin(+) (Dcx) neuroblasts might serve as a powerful tool to study the role of neurogenesis in models of brain injury and neurodegeneration using non-invasive, longitudinal in vivo imaging. Therefore, we aimed to use BLI in B6(Cg)-Tyrc-2J/J Dcx-Luc (Doublecortin-Luciferase, Dcx-Luc) mice to investigate its suitability to assess neurogenesis in a unilateral injection model of Parkinson's disease. We further aimed to assess the blood brain barrier leakage associated with the intranigral 6-OHDA injection to evaluate its impact on substrate delivery and bioluminescence signal intensity. Two weeks after lesion, we observed an increase in bioluminescence signal in the ipsilateral hippocampal region in both, 6-OHDA and vehicle injected Dcx-Luc mice. At the same time, no corresponding increase in Dcx(+) neuroblast numbers could be observed in the dentate gyrus of C57Bl6 mice. Blood brain barrier leakage was observed in the hippocampal region and in the degenerating substantia nigra of C57Bl6 mice in vivo using T1 weighted Magnetic Resonance Imaging with Gadovist(®) and ex vivo using Evans Blue Fluorescence Reflectance Imaging and mouse Immunoglobulin G staining. Our data suggests a BLI signal dependency on blood brain barrier permeability, underlining a major pitfall of substrate/tracer dependent imaging in invasive disease models.

  4. Consequences of repeated blood-brain barrier disruption in football players.

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    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.

  5. Nano carriers for drug transport across the blood-brain barrier.

    Science.gov (United States)

    Li, Xinming; Tsibouklis, John; Weng, Tingting; Zhang, Buning; Yin, Guoqiang; Feng, Guangzhu; Cui, Yingde; Savina, Irina N; Mikhalovska, Lyuba I; Sandeman, Susan R; Howel, Carol A; Mikhalovsky, Sergey V

    2017-01-01

    Effective therapy lies in achieving a therapeutic amount of drug to the proper site in the body and then maintaining the desired drug concentration for a sufficient time interval to be clinically effective for treatment. The blood-brain barrier (BBB) hinders most drugs from entering the central nervous system (CNS) from the blood stream, leading to the difficulty of delivering drugs to the brain via the circulatory system for the treatment, diagnosis and prevention of brain diseases. Several brain drug delivery approaches have been developed, such as intracerebral and intracerebroventricular administration, intranasal delivery and blood-to-brain delivery, as a result of transient BBB disruption induced by biological, chemical or physical stimuli such as zonula occludens toxin, mannitol, magnetic heating and ultrasound, but these approaches showed disadvantages of being dangerous, high cost and unsuitability for most brain diseases and drugs. The strategy of vector-mediated blood-to-brain delivery, which involves improving BBB permeability of the drug-carrier conjugate, can minimize side effects, such as being submicrometre objects that behave as a whole unit in terms of their transport and properties, nanomaterials, are promising carrier vehicles for direct drug transport across the intact BBB as a result of their potential to enter the brain capillary endothelial cells by means of normal endocytosis and transcytosis due to their small size, as well as their possibility of being functionalized with multiple copies of the drug molecule of interest. This review provids a concise discussion of nano carriers for drug transport across the intact BBB, various forms of nanomaterials including inorganic/solid lipid/polymeric nanoparticles, nanoemulsions, quantum dots, nanogels, liposomes, micelles, dendrimers, polymersomes and exosomes are critically evaluated, their mechanisms for drug transport across the BBB are reviewed, and the future directions of this area are fully

  6. Administration of sesamol improved blood-brain barrier function in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    VanGilder, R L; Kelly, K A; Chua, M D; Ptachcinski, R L; Huber, Jason D

    2009-07-01

    Uncontrolled or poorly controlled blood glucose during diabetes is an important factor in worsened vascular function. While evidence suggests that hyperglycemia-induced oxidative stress plays a prominent role in development of microangiopathy of the retina, kidney, and nerves, the role oxidative stress plays on blood-brain barrier (BBB) function and structure has lagged behind. In this study, a natural antioxidant, sesamol, was administered to streptozotocin (STZ)-induced diabetic rats to examine the role that oxidative stress plays on BBB structure and function. Experiments were conducted at 56 days after STZ injection. Male Sprague-Dawley rats randomly were divided into four treatment groups CON--control; STZ--STZ-induced diabetes; CON + S--control + sesamol; STZ + S--STZ-induced diabetes + sesamol. Functional and structural changes to the BBB were measured by in situ brain perfusion and western blot analysis of changes in tight junction protein expression. Oxidative stress markers were visualized by fluorescent confocal microscopy and assayed by spectrophotometric analysis. Results demonstrated that the increased BBB permeability observed in STZ-induced diabetic rats was attenuated in STZ + S rats to levels observed in CON. Sesamol treatment reduced the negative impact of STZ-induced diabetes on tight junction protein expression in isolated cerebral microvessels. Oxidative stress markers were elevated in STZ as compared to CON. STZ + S displayed an improved antioxidant capacity which led to a reduced expression of superoxide and peroxynitrite and reduced lipid peroxidation. In conclusion, this study showed that sesamol treatment enhanced antioxidant capacity of the diabetic brain and led to decreased perturbation of hyperglycemia-induced changes in BBB structure and function.

  7. Sera from remitting and secondary progressive multiple sclerosis patients disrupt the blood-brain barrier.

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    Fumitaka Shimizu

    Full Text Available BACKGROUND: Pathological destruction of blood-brain barrier (BBB has been thought to be the initial key event in the process of developing multiple sclerosis (MS. The purpose of the present study was to clarify the possible molecular mechanisms responsible for the malfunction of BBB by sera from relapse-remitting MS (RRMS and secondary progressive MS (SPMS patients. METHODS: We evaluated the effects of sera from the patients in the relapse phase of RRMS (RRMS-R, stable phase of RRMS (RRMS-S and SPMS on the expression of tight junction proteins and vascular cell adhesion protein-1 (VCAM-1, and on the transendothelial electrical resistance (TEER in human brain microvascular endothelial cells (BMECs. RESULTS: Sera from the RRMS-R or SPMS patients decreased the claudin-5 protein expression and the TEER in BMECs. In RRMS-R, this effect was restored after adding an MMP inhibitor, and the MMP-2/9 secretion by BMECs was significantly increased after the application of patients' sera. In SPMS, the immunoglobulin G (IgG purified from patients' sera also decreased the claudin-5 protein expression and the TEER in BMECs. The sera and purified IgG from all MS patients increased the VCAM-1 protein expression in BMECs. CONCLUSIONS: The up-regulation of autocrine MMP-2/9 by BMECs after exposure to sera from RRMS-R patients or the autoantibodies against BMECs from SPMS patients can compromise the BBB. Both RRMS-S and SPMS sera increased the VCAM-1 expression in the BBB, thus indicating that targeting the VCAM-1 in the BBB could represent a possible therapeutic strategy for even the stable phase of MS and SPMS.

  8. Cell-Penetrating Peptides Selectively Cross the Blood-Brain Barrier In Vivo.

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    Sofie Stalmans

    Full Text Available Cell-penetrating peptides (CPPs are a group of peptides, which have the ability to cross cell membrane bilayers. CPPs themselves can exert biological activity and can be formed endogenously. Fragmentary studies demonstrate their ability to enhance transport of different cargoes across the blood-brain barrier (BBB. However, comparative, quantitative data on the BBB permeability of different CPPs are currently lacking. Therefore, the in vivo BBB transport characteristics of five chemically diverse CPPs, i.e. pVEC, SynB3, Tat 47-57, transportan 10 (TP10 and TP10-2, were determined. The results of the multiple time regression (MTR analysis revealed that CPPs show divergent BBB influx properties: Tat 47-57, SynB3, and especially pVEC showed very high unidirectional influx rates of 4.73 μl/(g × min, 5.63 μl/(g × min and 6.02 μl/(g × min, respectively, while the transportan analogs showed a negligible to low brain influx. Using capillary depletion, it was found that 80% of the influxed peptides effectively reached the brain parenchyma. Except for pVEC, all peptides showed a significant efflux out of the brain. Co-injection of pVEC with radioiodinated bovine serum albumin (BSA did not enhance the brain influx of radiodionated BSA, indicating that pVEC does not itself significantly alter the BBB properties. A saturable mechanism could not be demonstrated by co-injecting an excess dose of non-radiolabeled CPP. No significant regional differences in brain influx were observed, with the exception for pVEC, for which the regional variations were only marginal. The observed BBB influx transport properties cannot be correlated with their cell-penetrating ability, and therefore, good CPP properties do not imply efficient brain influx.

  9. Blood-brain barrier transport of non-viral gene and RNAi therapeutics.

    Science.gov (United States)

    Boado, Ruben J

    2007-09-01

    The development of gene- and RNA interference (RNAi)-based therapeutics represents a challenge for the drug delivery field. The global brain distribution of DNA genes, as well as the targeting of specific regions of the brain, is even more complicated because conventional delivery systems, i.e. viruses, have poor diffusion in brain when injected in situ and do not cross the blood-brain barrier (BBB), which is only permeable to lipophilic molecules of less than 400 Da. Recent advances in the "Trojan Horse Liposome" (THL) technology applied to the transvascular non-viral gene therapy of brain disorders presents a promising solution to the DNA/RNAi delivery obstacle. The THL is comprised of immunoliposomes carrying either a gene for protein replacement or small hairpin RNA (shRNA) expression plasmids for RNAi effect, respectively. The THL is engineered with known lipids containing polyethyleneglycol (PEG), which stabilizes its structure in vivo in circulation. The tissue target specificity of THL is given by conjugation of approximately 1% of the PEG residues to peptidomimetic monoclonal antibodies (MAb) that bind to specific endogenous receptors (i.e. insulin and transferrin receptors) located on both the BBB and the brain cellular membranes, respectively. 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 present review presents an overview of the THL technology and its current application to gene therapy and RNAi, including experimental models of Parkinson's disease and brain tumors.

  10. 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.

  11. MSFD2A is critical for the formation and function of the blood brain barrier

    Science.gov (United States)

    Ben-Zvi, Ayal; Lacoste, Baptiste; Kur, Esther; Andreone, Benjamin J.; Mayshar, Yoav; Yan, Han; Gu, Chenghua

    2014-01-01

    The central nervous system (CNS) requires a tightly controlled environment free of toxins and pathogens to provide the proper chemical composition for neural function. This environment is maintained by the ‘blood brain barrier’ (BBB), which is composed of blood vessels whose endothelial cells display specialized tight junctions and extremely low rates of transcellular vesicular transport (transcytosis)1–3. In concert with pericytes and astrocytes, this unique brain endothelial physiological barrier seals the CNS and controls substance influx and efflux4–6. While BBB breakdown has recently been associated with initiation and perpetuation of various neurological disorders, an intact BBB is a major obstacle for drug delivery to the CNS7–10. A limited understanding of the molecular mechanisms that control BBB formation has hindered our ability to manipulate the BBB in disease and therapy. Here, we identify mechanisms governing the establishment of a functional BBB. First, using a novel embryonic tracer injection method, we demonstrate spatiotemporal developmental profiles of BBB functionality and find that the mouse BBB becomes functional at embryonic day 15.5 (E15.5). We then screen for BBB-specific genes expressed during BBB formation, and find that major facilitator super family domain containing 2a (Mfsd2a) is selectively expressed in BBB-containing blood vessels in the CNS. Genetic ablation of Mfsd2a results in a leaky BBB from embryonic periods through adulthood, while maintaining the normal patterning of vascular networks. Electron microscopy examination reveals a dramatic increase in CNS endothelial cell vesicular transcytosis in Mfsd2a−/− mice, without obvious tight junction defects. Finally we show that MFSD2A endothelial expression is regulated by pericytes to facilitate BBB integrity. These findings identify MFSD2A as a key regulator of BBB function that may act by suppressing transcytosis in CNS endothelial cells. Further our findings may aid

  12. Permeability analysis of neuroactive drugs through a dynamic microfluidic in vitro blood-brain barrier model.

    Science.gov (United States)

    Booth, R; Kim, H

    2014-12-01

    This paper presents the permeability analysis of neuroactive drugs and correlation with in vivo brain/plasma ratios in a dynamic microfluidic blood-brain barrier (BBB) model. Permeability of seven neuroactive drugs (Ethosuximide, Gabapentin, Sertraline, Sunitinib, Traxoprodil, Varenicline, PF-304014) and trans-endothelial electrical resistance (TEER) were quantified in both dynamic (microfluidic) and static (transwell) BBB models, either with brain endothelial cells (bEnd.3) in monoculture, or in co-culture with glial cells (C6). Dynamic cultures were exposed to 15 dyn/cm(2) shear stress to mimic the in vivo environment. Dynamic models resulted in significantly higher average TEER (respective 5.9-fold and 8.9-fold increase for co-culture and monoculture models) and lower drug permeabilities (average respective decrease of 0.050 and 0.052 log(cm/s) for co-culture and monoculture) than static models; and co-culture models demonstrated higher average TEER (respective 90 and 25% increase for static and dynamic models) and lower drug permeability (average respective decrease of 0.063 and 0.061 log(cm/s) for static and dynamic models) than monoculture models. Correlation of the resultant logP e values [ranging from -4.06 to -3.63 log(cm/s)] with in vivo brain/plasma ratios (ranging from 0.42 to 26.8) showed highly linear correlation (R (2) > 0.85) for all model conditions, indicating the feasibility of the dynamic microfluidic BBB model for prediction of BBB clearance of pharmaceuticals.

  13. Effects of a disrupted blood-brain barrier on cholesterol homeostasis in the brain.

    Science.gov (United States)

    Saeed, Ahmed A; Genové, Guillem; Li, Tian; Lütjohann, Dieter; Olin, Maria; Mast, Natalia; Pikuleva, Irina A; Crick, Peter; Wang, Yuqin; Griffiths, William; Betsholtz, Christer; Björkhem, Ingemar

    2014-08-22

    The presence of the blood-brain barrier (BBB) is critical for cholesterol metabolism in the brain, preventing uptake of lipoprotein-bound cholesterol from the circulation. The metabolic consequences of a leaking BBB for cholesterol metabolism have not been studied previously. Here we used a pericyte-deficient mouse model, Pdgfb(ret/ret), shown to have increased permeability of the BBB to a range of low-molecular mass and high-molecular mass tracers. There was a significant accumulation of plant sterols in the brains of the Pdgfb(ret/ret) mice. By dietary treatment with 0.3% deuterium-labeled cholesterol, we could demonstrate a significant flux of cholesterol from the circulation into the brains of the mutant mice roughly corresponding to about half of the measured turnover of cholesterol in the brain. We expected the cholesterol flux into the brain to cause a down-regulation of cholesterol synthesis. Instead, cholesterol synthesis was increased by about 60%. The levels of 24(S)-hydroxycholesterol (24S-OHC) were significantly reduced in the brains of the pericyte-deficient mice but increased in the circulation. After treatment with 1% cholesterol in diet, the difference in cholesterol synthesis between mutants and controls disappeared. The findings are consistent with increased leakage of 24S-OHC from the brain into the circulation in the pericyte-deficient mice. This oxysterol is an efficient suppressor of cholesterol synthesis, and the results are consistent with a regulatory role of 24S-OHC in the brain. To our knowledge, this is the first demonstration that a defective BBB may lead to increased flux of a lipophilic compound out from the brain. The relevance of the findings for the human situation is discussed.

  14. Preparation of Trojan horse liposomes (THLs) for gene transfer across the blood-brain barrier.

    Science.gov (United States)

    Pardridge, William M

    2010-04-01

    Nonviral plasmid DNA is delivered to the brain via a transvascular route across the blood-brain barrier (BBB) following intravenous administration of DNA encapsulated within Trojan horse liposomes (THLs), also called PEGylated immunoliposomes (PILs). The liposome surface is covered with several thousand strands of polymer (e.g., polyethylene glycol [PEG]), and the tips of 1%-2% of the polymer strands are conjugated with a targeting monoclonal antibody that acts as a molecular Trojan horse (MTH). The MTH binds to a receptor (e.g., for transferrin or insulin) on the BBB and brain cell membrane, triggering receptor-mediated transcytosis of the THL across the BBB in vivo, and receptor-mediated endocytosis into brain cells beyond the BBB. The persistence of transgene expression in the brain is inversely related to the rate of degradation of the episomal plasmid DNA. THL technology enables an exogenous gene to be widely expressed in the majority of cells in adult brain (or other organs) within 1 d of a single intravenous administration. Applications of the THLs include tissue-specific gene expression with tissue-specific promoters, complete normalization of striatal tyrosine hydroxylase in experimental Parkinson's disease following intravenous tyrosine hydroxylase gene therapy, a 100% increase in survival time of mice with brain tumors following weekly intravenous antisense gene therapy using THLs, and a 90% increase in survival time with weekly intravenous RNA interference (RNAi) gene therapy in mice with intracranial brain tumors. This protocol describes the preparation of THLs for use in gene transfer in vitro or in vivo.

  15. Adenosine receptor signaling modulates permeability of the blood-brain barrier.

    Science.gov (United States)

    Carman, Aaron J; Mills, Jeffrey H; Krenz, Antje; Kim, Do-Geun; Bynoe, Margaret S

    2011-09-14

    The blood-brain barrier (BBB) is comprised of specialized endothelial cells that form the capillary microvasculature of the CNS and is essential for brain function. It also poses the greatest impediment in the treatment of many CNS diseases because it commonly blocks entry of therapeutic compounds. Here we report that adenosine receptor (AR) signaling modulates BBB permeability in vivo. A(1) and A(2A) AR activation facilitated the entry of intravenously administered macromolecules, including large dextrans and antibodies to β-amyloid, into murine brains. Additionally, treatment with an FDA-approved selective A(2A) agonist, Lexiscan, also increased BBB permeability in murine models. These changes in BBB permeability are dose-dependent and temporally discrete. Transgenic mice lacking A(1) or A(2A) ARs showed diminished dextran entry into the brain after AR agonism. Following treatment with a broad-spectrum AR agonist, intravenously administered anti-β-amyloid antibody was observed to enter the CNS and bind β-amyloid plaques in a transgenic mouse model of Alzheimer's disease (AD). Selective AR activation resulted in cellular changes in vitro including decreased transendothelial electrical resistance, increased actinomyosin stress fiber formation, and alterations in tight junction molecules. These results suggest that AR signaling can be used to modulate BBB permeability in vivo to facilitate the entry of potentially therapeutic compounds into the CNS. AR signaling at brain endothelial cells represents a novel endogenous mechanism of modulating BBB permeability. We anticipate these results will aid in drug design, drug delivery and treatment options for neurological diseases such as AD, Parkinson's disease, multiple sclerosis and cancers of the CNS.

  16. Separation methods that are capable of revealing blood-brain barrier permeability.

    Science.gov (United States)

    Dash, Alekha K; Elmquist, William F

    2003-11-25

    The objective of this review is to emphasize the application of separation science in evaluating the blood-brain barrier (BBB) permeability to drugs and bioactive agents. Several techniques have been utilized to quantitate the BBB permeability. These methods can be classified into two major categories: in vitro or in vivo. The in vivo methods used include brain homogenization, cerebrospinal fluid (CSF) sampling, voltametry, autoradiography, nuclear magnetic resonance (NMR) spectroscopy, positron emission tomography (PET), intracerebral microdialysis, and brain uptake index (BUI) determination. The in vitro methods include tissue culture and immobilized artificial membrane (IAM) technology. Separation methods have always played an important role as adjunct methods to the methods outlined above for the quantitation of BBB permeability and have been utilized the most with brain homogenization, in situ brain perfusion, CSF sampling, intracerebral microdialysis, in vitro tissue culture and IAM chromatography. However, the literature published to date indicates that the separation method has been used the most in conjunction with intracerebral microdialysis and CSF sampling methods. The major advantages of microdialysis sampling in BBB permeability studies is the possibility of online separation and quantitation as well as the need for only a small sample volume for such an analysis. Separation methods are preferred over non-separation methods in BBB permeability evaluation for two main reasons. First, when the selectivity of a determination method is insufficient, interfering substances must be separated from the analyte of interest prior to determination. Secondly, when large number of analytes is to be detected and quantitated by a single analytical procedure, the mixture must be separated to each individual component prior to determination. Chiral separation in particular can be essential to evaluate the stereo-selective permeation and distribution of agents into the

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

    Science.gov (United States)

    Behrens, Matthias; Hüwel, Sabine; Galla, Hans-Joachim; Humpf, Hans-Ulrich

    2015-01-01

    Background 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. Methods 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. Results 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. PMID:26600019

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

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    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 im...

  20. Effects of poly (ADP-ribose) polymerase inhibitor 3-aminobenzamide on blood-brain barrier and dopaminergic neurons of rats with lipopolysaccharide-induced Parkinson's disease.

    Science.gov (United States)

    Wu, Xiao-li; Wang, Ping; Liu, Yun-hui; Xue, Yi-xue

    2014-05-01

    Neuro-inflammation and dysfunction of blood-brain barrier play an important role in the occurrence, development, and neuronal degeneration of Parkinson's disease (PD). Studies have demonstrated that a variety of cytokines such as TNF-α and IL-1β destroy the structure and function of blood-brain barrier. The damage to blood-brain barrier results in death of dopaminergic neurons, while protection of blood-brain barrier slows down the progression of PD. Also, it has been shown that activation of poly (ADP-ribose) polymerase (PARP) plays an important role in causing damage to blood-brain barrier. In addition, the PARP inhibitor 3-AB has been shown to protect blood-brain barrier from damage and has neuroprotective effects. In this study, using a lipopolysaccharide (LPS)-induced PD rat model, we investigated whether 3-AB protects blood-brain barrier and dopaminergic neurons from functional damage. LPS significantly increased Evans blue content in the substantia nigra which peaked at 12 h, while administration of 3-AB significantly inhibited the LPS-induced increase in Evans blue content and also significantly increased the expression of the tight junction-associated proteins claudin-5, occludin and ZO-1. 3-AB also increased the number of tyrosine hydroxylase positive cells and reduced the IL-1β and TNF-α content significantly. According to western blot analysis, 3-AB significantly reduced the p-ERK1/2 expression, while the expression of p-p38MAPK increased. These results suggest that 3-AB protects the blood-brain barrier from functional damage in an LPS-induced PD rat model and dopaminergic neurons are protected from degeneration by upregulation of tight junction-associated proteins. These protective effects of 3-AB may be related to modulation of the ERK1/2 pathway.

  1. Importance of dose intensity in neuro-oncology clinical trials: summary report of the Sixth Annual Meeting of the Blood-Brain Barrier Disruption Consortium.

    OpenAIRE

    2001-01-01

    Therapeutic options for the treatment of malignant brain tumors have been limited, in part, because of the presence of the blood-brain barrier. For this reason, the Sixth Annual Meeting of the Blood-Brain Barrier Disruption Consortium, the focus of which was the "Importance of Dose Intensity in Neuro-Oncology Clinical Trials," was convened in April 2000, at Government Camp, Mount Hood, Oregon. This meeting, which was supported by the National Cancer Institute, the National Institute of Neurol...

  2. Pro-inflammatory cytokine regulation of P-glycoprotein in the developing blood-brain barrier.

    Directory of Open Access Journals (Sweden)

    Majid Iqbal

    Full Text Available Placental P-glycoprotein (P-gp acts to protect the developing fetus from exogenous compounds. This protection declines with advancing gestation leaving the fetus and fetal brain vulnerable to these compounds and potential teratogens in maternal circulation. This vulnerability may be more pronounced in pregnancies complicated by infection, which is common during pregnancy. Pro-inflammatory cytokines (released during infection have been shown to be potent inhibitors of P-gp, but nothing is known regarding their effects at the developing blood-brain barrier (BBB. We hypothesized that P-gp function and expression in endothelial cells of the developing BBB will be inhibited by pro-inflammatory cytokines. We have derived brain endothelial cell (BEC cultures from various stages of development of the guinea pig: gestational day (GD 50, 65 (term ~68 days and postnatal day (PND 14. Once these cultures reached confluence, BECs were treated with various doses (10(0-10(4 pg/mL of pro-inflammatory cytokines: interleukin-1β (IL-1β, interleukin-6 (IL-6 or tumor necrosis factor- α (TNF-α. P-gp function or abcb1 mRNA (encodes P-gp expression was assessed following treatment. Incubation of GD50 BECs with IL-1β, IL-6 or TNF-α resulted in no change in P-gp function. GD65 BECs displayed a dose-dependent decrease in function with all cytokines tested; maximal effects at 42%, 65% and 34% with IL-1β, IL-6 and TNF-α treatment, respectively (P<0.01. Inhibition of P-gp function by IL-1β, IL-6 and TNF-α was even greater in PND14 BECs; maximal effects at 36% (P<0.01, 84% (P<0.05 and 55% (P<0.01, respectively. Cytokine-induced reductions in P-gp function were associated with decreased abcb1 mRNA expression. These data suggest that BBB P-gp function is increasingly responsive to the inhibitory effects of pro-inflammatory cytokines, with increasing developmental age. Thus, women who experience infection and take prescription medication during pregnancy may expose the

  3. Melatonin Preserves Blood-Brain Barrier Integrity and Permeability via Matrix Metalloproteinase-9 Inhibition.

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    Himakarnika Alluri

    Full Text Available Microvascular hyperpermeability that occurs at the level of the blood-brain barrier (BBB often leads to vasogenic brain edema and elevated intracranial pressure following traumatic brain injury (TBI. At a cellular level, tight junction proteins (TJPs between neighboring endothelial cells maintain the integrity of the BBB via TJ associated proteins particularly, zonula occludens-1 (ZO-1 that binds to the transmembrane TJPs and actin cytoskeleton intracellularly. The pro-inflammatory cytokine, interleukin-1β (IL-1β as well as the proteolytic enzymes, matrix metalloproteinase-9 (MMP-9 are key mediators of trauma-associated brain edema. Recent studies indicate that melatonin a pineal hormone directly binds to MMP-9 and also might act as its endogenous inhibitor. We hypothesized that melatonin treatment will provide protection against TBI-induced BBB hyperpermeability via MMP-9 inhibition. Rat brain microvascular endothelial cells grown as monolayers were used as an in vitro model of the BBB and a mouse model of TBI using a controlled cortical impactor was used for all in vivo studies. IL-1β (10 ng/mL; 2 hours-induced endothelial monolayer hyperpermeability was significantly attenuated by melatonin (10 μg/mL; 1 hour, GM6001 (broad spectrum MMP inhibitor; 10 μM; 1 hour, MMP-9 inhibitor-1 (MMP-9 specific inhibitor; 5 nM; 1 hour or MMP-9 siRNA transfection (48 hours in vitro. Melatonin and MMP-9 inhibitor-1 pretreatment attenuated IL-1β-induced MMP-9 activity, loss of ZO-1 junctional integrity and f-actin stress fiber formation. IL-1β treatment neither affected ZO-1 protein or mRNA expression or cell viability. Acute melatonin treatment attenuated BBB hyperpermeability in a mouse controlled cortical impact model of TBI in vivo. In conclusion, one of the protective effects of melatonin against BBB hyperpermeability occurs due to enhanced BBB integrity via MMP-9 inhibition. In addition, acute melatonin treatment provides protection against BBB

  4. 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

  5. A unique carrier for delivery of therapeutic compounds beyond the blood-brain barrier.

    Directory of Open Access Journals (Sweden)

    Delara Karkan

    Full Text Available BACKGROUND: Therapeutic intervention in many neurological diseases is thwarted by the physical obstacle formed by the blood-brain barrier (BBB that excludes most drugs from entering the brain from the blood. Thus, identifying efficacious modes of drug delivery to the brain remains a "holy grail" in molecular medicine and nanobiotechnology. Brain capillaries, that comprise the BBB, possess an endogenous receptor that ferries an iron-transport protein, termed p97 (melanotransferrin, across the BBB. Here, we explored the hypothesis that therapeutic drugs "piggybacked" as conjugates of p97 can be shuttled across the BBB for treatment of otherwise inoperable brain tumors. APPROACH: Human p97 was covalently linked with the chemotherapeutic agents paclitaxel (PTAX or adriamycin (ADR and following intravenous injection, measured their penetration into brain tissue and other organs using radiolabeled and fluorescent derivatives of the drugs. In order to establish efficacy of the conjugates, we used nude mouse models to assess p97-drug conjugate activity towards glioma and mammary tumors growing subcutaneously compared to those growing intracranially. PRINCIPAL FINDINGS: Bolus-injected p97-drug conjugates and unconjugated p97 traversed brain capillary endothelium within a few minutes and accumulated to 1-2% of the injected by 24 hours. Brain delivery with p97-drug conjugates was quantitatively 10 fold higher than with free drug controls. Furthermore, both free-ADR and p97-ADR conjugates equally inhibited the subcutaneous growth of gliomas growing outside the brain. Evocatively, only p97-ADR conjugates significantly prolonged the survival of animals bearing intracranial gliomas or mammary tumors when compared to similar cumulated doses of free-ADR. SIGNIFICANCE: This study provides the initial proof of concept for p97 as a carrier capable of shuttling therapeutic levels of drugs from the blood to the brain for the treatment of neurological disorders

  6. The role of shear stress in Blood-Brain Barrier endothelial physiology

    Directory of Open Access Journals (Sweden)

    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

  7. MRI study on reversible and irreversible electroporation induced blood brain barrier disruption.

    Directory of Open Access Journals (Sweden)

    Mohammad Hjouj

    Full Text Available Electroporation, is known to induce cell membrane permeabilization in the reversible (RE mode and cell death in the irreversible (IRE mode. Using an experimental system designed to produce a continuum of IRE followed by RE around a single electrode we used MRI to study the effects of electroporation on the brain. Fifty-four rats were injected with Gd-DOTA and treated with a G25 electrode implanted 5.5 mm deep into the striata. MRI was acquired immediately after treatment, 10 min, 20 min, 30 min, and up to three weeks following the treatment using: T1W, T2W, Gradient echo (GE, serial SPGR (DCE-MRI with flip angles ranging over 5-25°, and diffusion-weighted MRI (DWMRI. Blood brain barrier (BBB disruption was depicted as clear enhancement on T1W images. The average signal intensity in the regions of T1-enhancement, representing BBB disruption, increased from 1887±83 (arbitrary units immediately post treatment to 2246±94 20 min post treatment, then reached a plateau towards the 30 min scan where it reached 2289±87. DWMRI at 30 min showed no significant effects. Early treatment effects and late irreversible damage were clearly depicted on T2W. The enhancing volume on T2W has increased by an average of 2.27±0.27 in the first 24-48 hours post treatment, suggesting an inflammatory tissue response. The permanent tissue damage, depicted as an enhancing region on T2W, 3 weeks post treatment, decreased to an average of 50±10% of the T2W enhancing volumes on the day of the treatment which was 33±5% of the BBB disruption volume. Permanent tissue damage was significantly smaller than the volume of BBB disruption, suggesting, that BBB disruption is associated with RE while tissue damage with IRE. These results demonstrate the feasibility of applying reversible and irreversible electroporation for transient BBB disruption or permanent damage, respectively, and applying MRI for planning/monitoring disruption volume/shape by optimizing electrode positions

  8. Pathophysiology of Blood-Brain Barrier in Brain Injury in Cold and Hot Environments: Novel Drug Targets for Neuroprotection.

    Science.gov (United States)

    Sharma, Hari Shanker; Muresanu, Dafin F; Lafuente, José V; Nozari, Ala; Patnaik, Ranjana; Skaper, Stephen D; Sharma, Aruna

    2016-01-01

    The blood-brain barrier (BBB) plays a pivotal role in the maintenance of central nervous system function in health and disease. Thus, in almost all neurodegenerative, traumatic or metabolic insults BBB breakdown occurs, allowing entry of serum proteins into the brain fluid microenvironment with subsequent edema formation and cellular injury. Accordingly, pharmacological restoration of BBB function will lead to neurorepair. However, brain injury which occurs following blast, bullet wounds, or knife injury appears to initiate different sets of pathophysiological responses. Moreover, other local factors at the time of injury such as cold or elevated ambient temperatures could also impact the final outcome. Obviously, drug therapy applied to different kinds of brain trauma occurring at either cold or hot environments may respond differently. This is largely due to the fact that internal defense mechanisms of the brain, gene expression, release of neurochemicals and binding of drugs to specific receptors are affected by external ambient temperature changes. These factors may also affect BBB function and development of edema formation after brain injury. In this review, the effects of seasonal exposure to heat and cold on traumatic brain injury using different models i.e., concussive brain injury and cerebral cortical lesion, on BBB dysfunction in relation to drug therapy are discussed. Our observations clearly suggest that closed head injury and open brain injury are two different entities and the external hot or cold environments affect both of them remarkably. Thus, effective pharmacological therapeutic strategies should be designed with these views in mind, as military personnel often experience blunt or penetrating head injuries in either cold or hot environments.

  9. Stimulation of the sphenopalatine ganglion induces reperfusion and blood-brain barrier protection in the photothrombotic stroke model.

    Directory of Open Access Journals (Sweden)

    Haviv Levi

    Full Text Available PURPOSE: The treatment of stroke remains a challenge. Animal studies showing that electrical stimulation of the sphenopalatine ganglion (SPG exerts beneficial effects in the treatment of stroke have led to the initiation of clinical studies. However, the detailed effects of SPG stimulation on the injured brain are not known. METHODS: The effect of acute SPG stimulation was studied by direct vascular imaging, fluorescent angiography and laser Doppler flowmetry in the sensory motor cortex of the anaesthetized rat. Focal cerebral ischemia was induced by the rose bengal (RB photothrombosis method. In chronic experiments, SPG stimulation, starting 15 min or 24 h after photothrombosis, was given for 3 h per day on four consecutive days. Structural damage was assessed using histological and immunohistochemical methods. Cortical functions were assessed by quantitative analysis of epidural electro-corticographic (ECoG activity continuously recorded in behaving animals. RESULTS: Stimulation induced intensity- and duration-dependent vasodilation and increased cerebral blood flow in both healthy and photothrombotic brains. In SPG-stimulated rats both blood brain-barrier (BBB opening, pathological brain activity and lesion volume were attenuated compared to untreated stroke animals, with no apparent difference in the glial response surrounding the necrotic lesion. CONCLUSION: SPG-stimulation in rats induces vasodilation of cortical arterioles, partial reperfusion of the ischemic lesion, and normalization of brain functions with reduced BBB dysfunction and stroke volume. These findings support the potential therapeutic effect of SPG stimulation in focal cerebral ischemia even when applied 24 h after stroke onset and thus may extend the therapeutic window of currently administered stroke medications.

  10. 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

    (2)) and following 6 h passive exposure to hypoxia (12% O(2)). Blood flow velocity in the middle cerebral artery (MCAv) and mean arterial blood pressure (MAP) were measured for determination of CA following calculation of transfer function analysis and rate of regulation (RoR). Nine subjects......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...

  11. Ultrasound-mediated blood-brain barrier disruption for targeted drug delivery in the central nervous system

    Science.gov (United States)

    McDannold, Nathan; Zhang, Yongzhi; Power, Chanikarn; Arvanitis, Costas D.; Vykhodtseva, Natalia; Livingstone, Margaret

    2015-05-01

    The physiology of the vasculature in the central nervous system (CNS), which includes the blood-brain barrier (BBB) and other factors, complicates the delivery of most drugs to the brain. Different methods have been used to bypass the BBB, but they have limitations such as being invasive, non-targeted or requiring the formulation of new drugs. Focused ultrasound (FUS), when combined with circulating microbubbles, is a noninvasive method to locally and transiently disrupt the BBB at discrete targets. The method presents new opportunities for the use of drugs and for the study of the brain.

  12. Local blood-brain barrier penetration following systemic contrast medium administration. A case report and an experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Utz, R.; Ekholm, S.E.; Isaac, L.; Sands, M.; Fonte, D.

    The present study was initiated by a severe complication in a patient with renal dysfunction who developed cortical blindness and weakness of her left extremities 30 hours following renal and abdominal angiography. To evaluate the impact of prolonged high serum concentrations of contrast medium (CM) this clinical situation was simulated in a laboratory model using sheep with elevated serum levels of contrast medium maintained for 48 hours. The experimental data did not support the theory that the prolonged exposure to high circulating levels of contrast medium (4 ml/kg body weight of meglumine diatrizoate 60%) is sufficient alone to cause penetration of the blood-brain barrier.

  13. The UDP-glucuronosyltransferases of the blood-brain barrier: their role in drug metabolism and detoxication

    Directory of Open Access Journals (Sweden)

    Mohamed eOuzzine

    2014-10-01

    Full Text Available UDP-glucuronosyltransferases (UGTs form a multigenic family of membrane-bound enzymes expressed in various tissues, including brain. They catalyze the formation of β-Dglucuronides from structurally unrelated substances (drugs, other xenobiotics, as well as endogenous compounds by the linkage of glucuronic acid from the high energy donor, UDP-αD-glucuronic acid. In brain, UGTs actively participate to the overall protection of the tissue against the intrusion of potentially harmful lipophilic substances that are metabolized as hydrophilic glucuronides. These metabolites are generally inactive, except for important pharmacologically glucuronides such as morphine-6-glucuronide. UGTs are mainly expressed in endothelial cells and astrocytes of the blood brain barrier. They are also associated to brain interfaces devoid of blood-brain barrier, such as circumventricular organ, pineal gland, pituitary gland and neuro-olfactory tissues. Beside their key-role as a detoxication barrier, UGTs play a role in the steady-state of endogenous compounds, like steroids or dopamine that participate to the function of the brain. UGT isoforms of family 1A, 2A, 2B and 3A are expressed in brain tissues to various levels and are known to present distinct but overlapping substrate specificity. The importance of these enzyme species with regard to the formation of toxic, pharmacologically or physiologically relevant glucuronides in the brain will be discussed.

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

    Directory of Open Access Journals (Sweden)

    Sylvia Wagner

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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.

  15. Development of a solvent-free analytical method for paracetamol quantitative determination in Blood Brain Barrier in vitro model.

    Science.gov (United States)

    Langlois, Marie-Hélène; Vekris, Antonios; Bousses, Christine; Mordelet, Elodie; Buhannic, Nathalie; Séguard, Céline; Couraud, Pierre-Olivier; Weksler, Babette B; Petry, Klaus G; Gaudin, Karen

    2015-04-15

    A Reversed Phase-High Performance Liquid Chromatography/Diode Array Detection method was developed and validated for paracetamol quantification in cell culture fluid from an in vitro Blood Brain Barrier model. The chromatographic method and sample preparation were developed using only aqueous solvents. The column was a XTerra RP18 150 × 4.6mm, 3.5 μm with a guard column XTerra RP18 20 × 4.6 mm, 3.5 μm at 35 °C and the mobile phase was composed by 100% formate buffer 20 mM at pH 4 and flow rate was set at 1 mL/min. The detection was at 242 nm. The sample was injected at 10 μL. Validation was performed using the accuracy profile approach. The analytical procedure was validated with the acceptance limits at ± 10% over a range of concentration from 1 to 58 mg L(-1). The procedure was then used in routine to determine paracetamol concentration in a brain blood barrier in vitro model. Application of the Unither paracetamol formulation in Blood Brain Barrier model allowed the determination and comparison of the transcellular passage of paracetamol at 37 °C and 4 °C, that excludes paracellular or non specific leakage.

  16. 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.

  17. 胶质瘤模型单剂量全脑放疗后血脑屏障开放的时间阈及紧密连接变化的研究%Study of Time-Domain of Blood-brain Barrier Opened and Tight Junction Changed in Glioma Models after Whole-brain Irradiated with Single Dose

    Institute of Scientific and Technical Information of China (English)

    李蓉; 刘国龙; 关明媚; 牛道立; 易炜; 孙健聪

    2012-01-01

    目的 观察C6脑胶质瘤15 Gy单次全脑放射线照射后血-脑屏障(blood-brain barrier,BBB)通透性的动态变化及紧密连接蛋白claudin-5的表达变化,观察大鼠血-脑屏障(BBB)开放的时间阈.方法 荷瘤鼠(建模后17天)60只,行15 Gy全脑放射线单次照射,并于照射后24h、3d、7d、14d、21d、28d各处死10只,各5只分别行硝酸镧(La+)透射电子显微镜示踪法观察肿瘤邻近处(brain adjacent to tumor,BAT)即距肿瘤边界2mm以内BBB通透性及免疫组织化学法测定紧密连接蛋白claudin-5的变化研究.结果 (1)照射后24h、3d硝酸镧渗出广泛,基底膜、血管腔外、脑组织间隙内及细胞内均可见;第7d为La3渗出减弱,基底膜及脑组织间隙内见细小的镧颗粒;第14d为La3+渗出至局部基底膜,较前减少;第21d、28d均为La3+无渗出.统计学分析硝酸镧渗出程度显示:24h和3d>7d>14d>21d和28d(P<0.05).(2)照射后24h、3d紧密连接蛋白claudin-5呈轻度表达,呈碎片状表达;照射后第7d为轻中度表达,血管扭曲、变形:照射后第14d为中度表达,血管扭曲、变形,但仍呈连续状态;照射后第21d、28d为中强度表达,出现连续与碎片表达并存.统计学分析claudin-5表达程度显示:24h和3d<7d<14d<21d和28d(P<0.05).结论 荷瘤鼠单次15 Gy照射后BBB开放,且2周后BBB通透性逐渐消失,表现出时间依赖性.%Objective To investigate the change in blood-brain barrier (BBB) permeability and ultrastruc-ture of microvessle in C6 glioma and the tight junction protein expression of claudin-5.which were whole-brain irradiated with 15 Gy,and to explore the time-domain of BBB opened. Methods Sixty tumor-bearing rats (17thday after inoculation) were whole-brain irradiated with 15 Gy,and 10 rats were severally sacrificed at 24 h,3 d,7 d,14 d,21 d and 28 d after irradiation,5 rats were using transmission electron microscopy of exogenous lanthanum nitrate (La3+ )-tracing to observe the

  18. Acanthamoeba produces disseminated infection in locusts and traverses the locust blood-brain barrier to invade the central nervous system

    Directory of Open Access Journals (Sweden)

    Kirk Ruth

    2010-07-01

    Full Text Available Abstract Background Many aspects of Acanthamoeba granulomatous encephalitis remain poorly understood, including host susceptibility and chronic colonization which represent important features of the spectrum of host-pathogen interactions. Previous studies have suggested locusts as a tractable model in which to study Acanthamoeba pathogenesis. Here we determined the mode of parasite invasion of the central nervous system (CNS. Results Using Acanthamoeba isolates belonging to the T1 and T4 genotypes, the findings revealed that amoebae induced sickness behaviour in locusts, as evidenced by reduced faecal output and weight loss and, eventually, leading to 100% mortality. Significant degenerative changes of various tissues were observed by histological sectioning. Both isolates produced disseminated infection, with viable amoebae being recovered from various tissues. Histological examination of the CNS showed that Acanthamoeba invaded the locust CNS, and this is associated with disruption of the perineurium cell/glial cell complex, which constitutes the locust blood-brain barrier. Conclusions This is the first study to demonstrate that Acanthamoeba invades locust brain by modulating the integrity of the insect's blood-brain barrier, a finding that is consistent with the human infection. These observations support the idea that locusts provide a tractable model to study Acanthamoeba encephalitis in vivo. In this way the locust model may generate potentially useful leads that can be tested subsequently in mammalian systems, thus replacing the use of vertebrates at an early stage, and reducing the numbers of mammals required overall.

  19. The age-related deficit in LTP is associated with changes in perfusion and blood-brain barrier permeability.

    Science.gov (United States)

    Blau, Christoph W; Cowley, Thelma R; O'Sullivan, Joan; Grehan, Belinda; Browne, Tara C; Kelly, Laura; Birch, Amy; Murphy, Niamh; Kelly, Aine M; Kerskens, Christian M; Lynch, Marina A

    2012-05-01

    In view of the increase in the aging population and the unavoidable parallel increase in the incidence of age-related neurodegenerative diseases, a key challenge in neuroscience is the identification of clinical signatures which change with age and impact on neuronal and cognitive function. Early diagnosis offers the possibility of early therapeutic intervention, thus magnetic resonance imaging (MRI) is potentially a powerful diagnostic tool. We evaluated age-related changes in relaxometry, blood flow, and blood-brain barrier (BBB) permeability in the rat by magnetic resonance imaging and assessed these changes in the context of the age-related decrease in synaptic plasticity. We report that T2 relaxation time was decreased with age; this was coupled with a decrease in gray matter perfusion, suggesting that the observed microglial activation, as identified by increased expression of CD11b, MHCII, and CD68 by immunohistochemistry, flow cytometry, or polymerase chain reaction (PCR), might be a downstream consequence of these changes. Increased permeability of the blood-brain barrier was observed in the perivascular area and the hippocampus of aged, compared with young, rats. Similarly there was an age-related increase in CD45-positive cells by flow cytometry, which are most likely infiltrating macrophages, with a parallel increase in the messenger mRNA expression of chemokines IP-10 and MCP-1. These combined changes may contribute to the deficit in long-term potentiation (LTP) in perforant path-granule cell synapses of aged animals.

  20. Intranasal nerve growth factor bypasses the blood-brain barrier and affects spinal cord neurons in spinal cord injur y

    Institute of Scientific and Technical Information of China (English)

    Luigi Aloe; Patrizia Bianchi; Alberto De Bellis; Marzia Soligo; Maria Luisa Rocco

    2014-01-01

    The purpose of this work was to investigate whether, by intranasal administration, the nerve growth factor bypasses the blood-brain barrier and turns over the spinal cord neurons and if such therapeutic approach could be of value in the treatment of spinal cord injury. Adult Sprague-Dawley rats with intact and injured spinal cord received daily intranasal nerve growth factor administration in both nostrils for 1 day or for 3 consecutive weeks. We found an in-creased content of nerve growth factor and enhanced expression of nerve growth factor receptor in the spinal cord 24 hours after a single intranasal administration of nerve growth factor in healthy rats, while daily treatment for 3 weeks in a model of spinal cord injury improved the deifcits in locomotor behaviour and increased spinal content of both nerve growth factor and nerve growth factor receptors. These outcomes suggest that the intranasal nerve growth factor bypasses blood-brain barrier and affects spinal cord neurons in spinal cord injury. They also suggest exploiting the possible therapeutic role of intranasally delivered nerve growth factor for the neuroprotection of damaged spinal nerve cells.

  1. Breakdown of the normal optic nerve head blood-brain barrier following acute elevation of intraocular pressure in experimental animals.

    Science.gov (United States)

    Radius, R L; Anderson, D R

    1980-03-01

    Five hours of elevated intraocular pressure produced evidence of an altered blood-brain barrier at the optic nerve head in 27 of 29 monkey eyes. The change in vascular permeability was documented by fluorescein angiography (18 of 21 eyes), by Evans blue fluorescence microscopy (21 of 23 eyes), or by both methods. Leakage occurred from major blood vessels as well as from microvasculature of the nerve head. In 22 eyes, rapid axonal transport was studied after intravitreal injection of tritiated leucine. In 18 of these 22 eyes, autoradiography demonstrated a local interruption of axonal transport. In 15 eyes examined by all three methods, leakage from microvasculature (as opposed to leakage from the major vessels) was loosely associated with severe and widespread blockade of axonal transport at the lamina cribrosa. Although cause-and-effect relationships are not proved, ischemia may be responsible both for the focal endothelial damage with breakdown of the normal blood-brain barrier and for the local abnormalities of axonal transport.

  2. Liposomes Coloaded with Elacridar and Tariquidar To Modulate the P-Glycoprotein at the Blood-Brain Barrier.

    Science.gov (United States)

    Nieto Montesinos, Rita; Béduneau, Arnaud; Lamprecht, Alf; Pellequer, Yann

    2015-11-01

    This study prepared three liposomal formulations coloaded with elacridar and tariquidar to overcome the P-glycoprotein-mediated efflux at the blood-brain barrier. Their pharmacokinetics, brain distribution, and impact on the model P-glycoprotein substrate, loperamide, were compared to those for the coadministration of free elacridar plus free tariquidar. After intravenous administration in rats, elacridar and tariquidar in conventional liposomes were rapidly cleared from the bloodstream. Their low levels in the brain did not improve the loperamide brain distribution. Although elacridar and tariquidar in PEGylated liposomes exhibited 2.6 and 1.9 longer half-lives than free elacridar and free tariquidar, respectively, neither their Kp for the brain nor the loperamide brain distribution was improved. However, the conjugation of OX26 F(ab')2 fragments to PEGylated liposomes increased the Kps for the brain of elacridar and tariquidar by 1.4- and 2.1-fold, respectively, in comparison to both free P-gp modulators. Consequently, the Kp for the brain of loperamide increased by 2.7-fold. Moreover, the plasma pharmacokinetic parameters and liver distribution of loperamide were not modified by the PEGylated OX26 F(ab')2 immunoliposomes. Thus, this formulation represents a promising tool for modulating the P-glycoprotein-mediated efflux at the blood-brain barrier and could improve the brain uptake of any P-glycoprotein substrate that is intended to treat central nervous system diseases.

  3. Predicting drug penetration across the blood-brain barrier: comparison of micellar liquid chromatography and immobilized artificial membrane liquid chromatography.

    Science.gov (United States)

    De Vrieze, Mike; Lynen, Frédéric; Chen, Kai; Szucs, Roman; Sandra, Pat

    2013-07-01

    Several in vitro methods have been tested for their ability to predict drug penetration across the blood-brain barrier (BBB) into the central nervous system (CNS). In this article, the performance of a variety of micellar liquid chromatographic (MLC) methods and immobilized artificial membrane (IAM) liquid chromatographic approaches were compared for a set of 45 solutes. MLC measurements were performed on a C18 column with sodium dodecyl sulfate (SDS), polyoxyethylene (23) lauryl ether (Brij35), or sodium deoxycholate (SDC) as surfactant in the micellar mobile phase. IAM liquid chromatography measurements were performed with Dulbecco's phosphate-buffered saline (DPBS) and methanol as organic modifier in the mobile phase. The corresponding retention and computed descriptor data for each solute were used for construction of models to predict transport across the blood-brain barrier (log BB). All data were correlated with experimental log BB values and the relative performance of the models was studied. SDS-based models proved most suitable for prediction of log BB values, followed closely by a simplified IAM method, in which it could be observed that extrapolation of retention data to 0% modifier in the mobile phase was unnecessary.

  4. Getting into the brain: liposome-based strategies for effective drug delivery across the blood-brain barrier.

    Science.gov (United States)

    Vieira, Débora B; Gamarra, Lionel F

    This review summarizes articles that have been reported in literature on liposome-based strategies for effective drug delivery across the blood-brain barrier. Due to their unique physicochemical characteristics, liposomes have been widely investigated for their application in drug delivery and in vivo bioimaging for the treatment and/or diagnosis of neurological diseases, such as Alzheimer's, Parkinson's, stroke, and glioma. Several strategies have been used to deliver drug and/or imaging agents to the brain. Covalent ligation of such macromolecules as peptides, antibodies, and RNA aptamers is an effective method for receptor-targeting liposomes, which allows their blood-brain barrier penetration and/or the delivery of their therapeutic molecule specifically to the disease site. Additionally, methods have been employed for the development of liposomes that can respond to external stimuli. It can be concluded that the development of liposomes for brain delivery is still in its infancy, although these systems have the potential to revolutionize the ways in which medicine is administered.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. The effect of micro-particles of linoleic acid emulsion on the blood-brain barrier in cats

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hak Jin; Lee, Chang Hun; Lee, Tae Hong [College of Medicine, Pusan National Univ., Pusan (Korea, Republic of); Pyun, Yong Seon [Daedong Hospital, Pusan (Korea, Republic of)

    2004-11-01

    The purpose of this study was to investigate the permeability change of the blood-brain barrier and the reversibility of the embolized lesions induced with a fat-emulsion technique by using magnetic resonance imaging (MRI), and we also wished to evaluate the resultant histologic findings in cat brains. MR imaging was scheduled serially at 1 hour, day 1, day 4 and day 7 after infusion of linoleic acid-emulsion (0.05 ml linoleic acid + 20 ml saline) to the internal carotid artery in 12 cats. Abnormal signal intensity or contrast enhancement was evaluated on diffusion-weighted images (DWIs), the apparent diffusion coefficient (ADC) maps, and gadolinium-enhanced T1-weighted images (Gd-T1WIs) at the stated times. MR imaging was stopped if the lesion shows isointensity and no contrast enhancement was observed at the acquisition time, and then brain tissue was harvested and examined. Light microscopic (LM) and electron microscopic (EM) examinations were performed. The embolized lesions appeared as isointensities (n = 7) or mild hyperintensities (n = 5) on DWIs, as isointensities (n = 12) on the ADC maps, and as contrast enhancements (n = 12) on Gd-T1WIs at 1 hour. The lesions showed isointensity on DWIs and the ADC maps, and as no contrast enhancement for all cats at day 1. The LM findings revealed small (< 1 cm) focal necrosis and demyelination in three cats. EM examinations showed minimal findings of small (< 3 {mu}m) fat globules within the endothelial wall (n = 10) and mild swelling of the neuropils (< 5 {mu}m). Widening of the interstitium or morphologic disruption of the endothelial wall was not seen. Cerebral fat embolism induced by linoleic acid emulsion revealed vasogenic edema and reversible changes as depicted on the MR images. These results might help us to understand the mechanisms of fat on the blood-brain barrier, and this technique could be used as a basic model for research of the effects of drugs on the disrupted blood-brain barrier, and also as a

  7. Development of Blood-Brain Barrier Permeable Nitrocatechol-Based Catechol O-Methyltransferase Inhibitors with Reduced Potential for Hepatotoxicity.

    Science.gov (United States)

    Silva, Tiago; Mohamed, Tarek; Shakeri, Arash; Rao, Praveen P N; Martínez-González, Loreto; Pérez, Daniel I; Martínez, Ana; Valente, Maria João; Garrido, Jorge; Uriarte, Eugenio; Serrão, Paula; Soares-da-Silva, Patrício; Remião, Fernando; Borges, Fernanda

    2016-08-25

    Recent efforts have been focused on the development of centrally active COMT inhibitors, which can be valuable assets for neurological disorders such as Parkinson's disease, due to the severe hepatotoxicity risk associated with tolcapone. New nitrocatechol COMT inhibitors based on naturally occurring caffeic acid and caffeic acid phenethyl ester were developed. All nitrocatechol derivatives displayed potent inhibition of peripheral and cerebral COMT within the nanomolar range. Druglike derivatives 13, 15, and 16 were predicted to cross the blood-brain barrier in vitro and were significantly less toxic than tolcapone and entacapone when incubated at 50 μM with rat primary hepatocytes. Moreover, their unique acidity and electrochemical properties decreased the chances of formation of reactive quinone-imines and, as such, the potential for hepatotoxicity. The binding mode of 16 confirmed that the major interactions with COMT were established via the nitrocatechol ring, allowing derivatization of the side chain for future lead optimization efforts.

  8. A human blood-brain barrier transcytosis assay reveals antibody transcytosis influenced by pH-dependent receptor binding.

    Directory of Open Access Journals (Sweden)

    Hadassah Sade

    Full Text Available We have adapted an in vitro model of the human blood-brain barrier, the immortalized human cerebral microvascular endothelial cells (hCMEC/D3, to quantitatively measure protein transcytosis. After validating the receptor-mediated transport using transferrin, the system was used to measure transcytosis rates of antibodies directed against potential brain shuttle receptors. While an antibody to the insulin-like growth factor 1 receptor (IGF1R was exclusively recycled to the apical compartment, the fate of antibodies to the transferrin receptor (TfR was determined by their relative affinities at extracellular and endosomal pH. An antibody with reduced affinity at pH5.5 showed significant transcytosis, while pH-independent antibodies of comparable affinities at pH 7.4 remained associated with intracellular vesicular compartments and were finally targeted for degradation.

  9. Correlation of aquaporin-4 expression to blood-brain barrier permeability in rats with focal cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Pengcheng Xu; Haorong Feng; Jinbu Xu; Yongping Wu

    2008-01-01

    BACKGROUND: Ischemic cerebrovascular disease causes injury to the blood-brain barrier. The occurrence of brain edema is associated with aquaporin expression following cerebral ischemia/reperfusion. OBJECTIVE: To analyze the correlation of aquaporin-4 expression to brain edema and blood-brain barrier permeability in brain tissues of rat models of ischemia/reperfusion. DESIGN, TIME AND SETTING: The randomized control experiment was performed at the Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College, China from December 2006 to October 2007. MATERIALS: A total of 112 adult, male, Sprague-Dawley rats, weighing 220-250 g, were used to establish rat models of middle cerebral artery occlusion and reperfusion by the suture method. Rabbit anti-aquaporin-4 (Santa Cruz, USA) and Evans blue (Sigma, USA) were used to analyze the tissue. METHODS: The rats were randomized into sham-operated (n = 16) and ischemia/reperfusion (n = 96) groups. There were 6 time points in the ischemia/reperfusion group, comprising 4, 6, 12, 24, 48, and 72 hours after reperfusion, with 16 rats for each time point. Rat models in the sham-operated group at 4 hours after surgery and rat models in the ischemia/reperfusion group at different time points were equally and randomly assigned into 4 different subgroups. MAIN OUTCOME MEASURES: Brain water content on the ischemic side and the control side was measured using the dry-wet weight method. Blood-brain barrier function was determined by Evans Blue. Aquaporin-4 expression surrounding the ischemic focus, as well as the correlation of aquaporin-4 expression with brain water content and Evans blue staining, were measured using immunohistochemistry and Western blot analysis. RESULTS: Brain water content on the ischemic side significantly increased at 12 hours after reperfusion, reached a peak at 48 hours, and was still high at 72 hours. Brain water content was greater on the ischemic hemispheres, compared with the control hemispheres

  10. Magnetic resonance imaging of post-ischemic blood-brain barrier damage with PEGylated iron oxide nanoparticles

    Science.gov (United States)

    Liu, Dong-Fang; Qian, Cheng; An, Yan-Li; Chang, Di; Ju, Sheng-Hong; Teng, Gao-Jun

    2014-11-01

    Blood-brain barrier (BBB) damage during ischemia may induce devastating consequences like cerebral edema and hemorrhagic transformation. This study presents a novel strategy for dynamically imaging of BBB damage with PEGylated supermagnetic iron oxide nanoparticles (SPIONs) as contrast agents. The employment of SPIONs as contrast agents made it possible to dynamically image the BBB permeability alterations and ischemic lesions simultaneously with T2-weighted MRI, and the monitoring could last up to 24 h with a single administration of PEGylated SPIONs in vivo. The ability of the PEGylated SPIONs to highlight BBB damage by MRI was demonstrated by the colocalization of PEGylated SPIONs with Gd-DTPA after intravenous injection of SPION-PEG/Gd-DTPA into a mouse. The immunohistochemical staining also confirmed the leakage of SPION-PEG from cerebral vessels into parenchyma. This study provides a novel and convenient route for imaging BBB alteration in the experimental ischemic stroke model.

  11. In Vitro Blood-Brain Barrier Models-An Overview of Established Models and New Microfluidic Approaches

    DEFF Research Database (Denmark)

    Wolff, Anette; Antfolk, Maria; Brodin, Birger;

    2015-01-01

    The societal need for new central nervous system (CNS) medicines is substantial, because of the global increase in life expectancy and the accompanying increase in age-related CNS diseases. Low blood-brain barrier (BBB) permeability has been one of the major causes of failure for new CNS drug...... candidates. There has therefore been a great interest in cell models, which mimic BBB permeation properties. In this review, we present an overview of the performance of monocultured, cocultured, and triple-cultured primary cells and immortalized cell lines, including key parameters such as transendothelial......-of-the-art models and it was noted that, although they show great promise, these systems have not yet reached beyond the proof-of-concept stage. In general, it was found that there were large variations in experimental protocols, BBB phenotype markers, and paracellular flux markers used. It is the author's opinion...

  12. Genetic analysis of coding SNPs in blood-brain barrier transporter MDR1 in European Parkinson's disease patients.

    Science.gov (United States)

    Funke, Claudia; Soehn, Anne S; Tomiuk, Juergen; Riess, Olaf; Berg, Daniela

    2009-04-01

    Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons and the presence of intracytoplasmic inclusions (Lewy bodies). Iron, which is elevated in the substantia nigra of PD patients, seems to be of pivotal importance, because of its capacity to enhance the amplification of reactive oxygen species. As iron enters and exits the brain via transport proteins in the blood-brain barrier (BBB), these proteins may represent candidates for a genetic susceptibility to PD. P-glycoprotein (P-gp) is one important efflux pump in the BBB. There is evidence that the function of P-gp is impaired in PD patients. In the current study we examined ten coding single nucleotide polymorphisms in the multidrug resistance gene 1 (MDR1) encoding P-gp to assess whether certain genotypes are associated with PD. However, genotyping of 300 PD patients and 302 healthy controls did not reveal a significant association between coding MDR1 gene polymorphisms and PD.

  13. Caffeine protects against disruptions of the blood-brain barrier in animal models of Alzheimer's and Parkinson's diseases.

    Science.gov (United States)

    Chen, Xuesong; Ghribi, Othman; Geiger, Jonathan D

    2010-01-01

    Sporadic Alzheimer's disease (AD) and Parkinson's disease (PD) are two of the most common neurodegenerative diseases and as such they represent major public health problems. Finding effective treatments for AD and PD represents an unmet and elusive goal largely because these diseases are chronic and progressive, and have a complicated and ill-understood pathogenesis. Although the underlying mechanisms are not fully understood, caffeine, the most commonly ingested psychoactive drug in the world, has been shown in human and animal studies to be protective against AD and PD. One mechanism implicated in the pathogenesis of AD and PD is blood-brain barrier (BBB) dysfunction and we reported recently that caffeine exerts protective effects against AD and PD at least in part by keeping the BBB intact. The present review focuses on the role of BBB dysfunction in the pathogenesis of AD and PD, caffeine's protective effects against AD and PD, and potential mechanisms whereby caffeine protects against BBB leakage.

  14. EMP-induced alterations of tight junction protein expression and disruption of the blood-brain barrier.

    Science.gov (United States)

    Ding, Gui-Rong; Qiu, Lian-Bo; Wang, Xiao-Wu; Li, Kang-Chu; Zhou, Yong-Chun; Zhou, Yan; Zhang, Jie; Zhou, Jia-Xing; Li, Yu-Rong; Guo, Guo-Zhen

    2010-07-15

    The blood-brain barrier (BBB) is critical to maintain cerebral homeostasis. In this study, we examined the effects of exposure to electromagnetic pulse (EMP) on the functional integrity of BBB and, on the localization and expression of tight junction (TJ) proteins (occludin and ZO-1) in rats. Animals were sham or whole-body exposed to EMP at 200 kV/m for 400 pulses. The permeability of BBB in rat cerebral cortex was examined by using Evans Blue (EB) and lanthanum nitrate as vascular tracers. The localization and expression of TJ proteins were assessed by western blot and immunofluorescence analysis, respectively. The data indicated that EMP exposure caused: (i) increased permeability of BBB, and (ii) altered localization as well as decreased levels of TJ protein ZO-1. These results suggested that the alteration of ZO-1 may play an important role in the disruption of tight junctions, which may lead to dysfunction of BBB after EMP exposure.

  15. Blood-brain barrier transport studies, aggregation, and molecular dynamics simulation of multiwalled carbon nanotube functionalized with fluorescein isothiocyanate.

    Science.gov (United States)

    Shityakov, Sergey; Salvador, Ellaine; Pastorin, Giorgia; Förster, Carola

    2015-01-01

    In this study, the ability of a multiwalled carbon nanotube functionalized with fluorescein isothiocyanate (MWCNT-FITC) was assessed as a prospective central nervous system-targeting drug delivery system to permeate the blood-brain barrier. The results indicated that the MWCNT-FITC conjugate is able to penetrate microvascular cerebral endothelial monolayers; its concentrations in the Transwell(®) system were fully equilibrated after 48 hours. Cell viability test, together with phase-contrast and fluorescence microscopies, did not detect any signs of MWCNT-FITC toxicity on the cerebral endothelial cells. These microscopic techniques also revealed presumably the intracellular localization of fluorescent MWCNT-FITCs apart from their massive nonfluorescent accumulation on the cellular surface due to nanotube lipophilic properties. In addition, the 1,000 ps molecular dynamics simulation in vacuo discovered the phenomenon of carbon nanotube aggregation driven by van der Waals forces via MWCNT-FITC rapid dissociation as an intermediate phase.

  16. Magnetic resonance imaging of blood brain/nerve barrier dysfunction and leukocyte infiltration: closely related or discordant?

    Science.gov (United States)

    Weise, Gesa; Stoll, Guido

    2012-01-01

    Unlike other organs the nervous system is secluded from the rest of the organism by the blood brain barrier (BBB) or blood nerve barrier (BNB) preventing passive influx of fluids from the circulation. Similarly, leukocyte entry to the nervous system is tightly controlled. Breakdown of these barriers and cellular inflammation are hallmarks of inflammatory as well as ischemic neurological diseases and thus represent potential therapeutic targets. The spatiotemporal relationship between BBB/BNB disruption and leukocyte infiltration has been a matter of debate. We here review contrast-enhanced magnetic resonance imaging (MRI) as a non-invasive tool to depict barrier dysfunction and its relation to macrophage infiltration in the central and peripheral nervous system under pathological conditions. Novel experimental contrast agents like Gadofluorine M (Gf) allow more sensitive assessment of BBB dysfunction than conventional Gadolinium (Gd)-DTPA enhanced MRI. In addition, Gf facilitates visualization of functional and transient alterations of the BBB remote from lesions. Cellular contrast agents such as superparamagnetic iron oxide particles (SPIO) and perfluorocarbons enable assessment of leukocyte (mainly macrophage) infiltration by MR technology. Combined use of these MR contrast agents disclosed that leukocytes can enter the nervous system independent from a disturbance of the BBB, and vice versa, a dysfunctional BBB/BNB by itself is not sufficient to attract inflammatory cells from the circulation. We will illustrate these basic imaging findings in animal models of multiple sclerosis, cerebral ischemia, and traumatic nerve injury and review corresponding findings in patients.

  17. Blood-brain barrier flux of aluminum, manganese, iron and other metals suspected to contribute to metal-induced neurodegeneration.

    Science.gov (United States)

    Yokel, Robert A

    2006-11-01

    The etiology of many neurodegenerative diseases has been only partly attributed to acquired traits, suggesting environmental factors may also contribute. Metal dyshomeostasis causes or has been implicated in many neurodegenerative diseases. Metal flux across the blood-brain barrier (the primary route of brain metal uptake) and the choroid plexuses as well as sensory nerve metal uptake from the nasal cavity are reviewed. Transporters that have been described at the blood-brain barrier are listed to illustrate the extensive possibilities for moving substances into and out of the brain. The controversial role of aluminum in Alzheimer's disease, evidence suggesting brain aluminum uptake by transferrin-receptor mediated endocytosis and of aluminum citrate by system Xc;{-} and an organic anion transporter, and results suggesting transporter-mediated aluminum brain efflux are reviewed. The ability of manganese to produce a parkinsonism-like syndrome, evidence suggesting manganese uptake by transferrin- and non-transferrin-dependent mechanisms which may include store-operated calcium channels, and the lack of transporter-mediated manganese brain efflux, are discussed. The evidence for transferrin-dependent and independent mechanisms of brain iron uptake is presented. The copper transporters, ATP7A and ATP7B, and their roles in Menkes and Wilson's diseases, are summarized. Brain zinc uptake is facilitated by L- and D-histidine, but a transporter, if involved, has not been identified. Brain lead uptake may involve a non-energy-dependent process, store-operated calcium channels, and/or an ATP-dependent calcium pump. Methyl mercury can form a complex with L-cysteine that mimics methionine, enabling its transport by the L system. The putative roles of zinc transporters, ZnT and Zip, in regulating brain zinc are discussed. Although brain uptake mechanisms for some metals have been identified, metal efflux from the brain has received little attention, preventing integration of

  18. P-glycoprotein activity in the blood-brain barrier is affected by virus-induced neuroinflammation and antipsychotic treatment.

    Science.gov (United States)

    Doorduin, Janine; de Vries, Erik F J; Dierckx, Rudi A; Klein, Hans C

    2014-10-01

    A large percentage of schizophrenic patients respond poorly to antipsychotic treatment. This could be explained by inefficient drug transport across the blood-brain barrier due to P-glycoprotein mediated efflux. P-glycoprotein activity and expression in the blood-brain barrier can be affected by inflammation and pharmacotherapy. We therefore investigated the effect of herpes simplex virus type-1 (HSV-1) induced neuroinflammation and antipsychotic treatment on P-glycoprotein activity. Rats were inoculated with HSV-1 or PBS (control) on day 0 and treated with saline, clozapine or risperidone from day 0 up until day 4 post-inoculation. Positron emission tomography with the P-glycoprotein substrate [11C]verapamil was used to assess P-glycoprotein activity at day 6 post-inoculation. Disease symptoms in HSV-1 inoculated rats increased over time and were not significantly affected by treatment. The volume of distribution (VT) of [11C]verapamil was significantly lower (10-22%) in HSV-1 inoculated rats than in control rats. In addition, antipsychotic treatment significantly affected the VT of [11C]verapamil in all brain regions, although this effect was drug dependent. In fact, VT of [11C]verapamil was significantly increased (22-39%) in risperidone treated rats in most brain regions when compared to clozapine treated rats and in midbrain when compared to saline treated rats. No interaction between HSV-1 inoculation and antipsychotic treatment on VT of [11C]verapamil was found. In this study we demonstrated that HSV-1 induced neuroinflammation increased and risperidone treatment decreased P-glycoprotein activity. This finding is of importance for the understanding of treatment resistance in schizophrenia, and warrants further investigation of the underlying mechanism and the importance in clinical practice.

  19. Blood-Brain Barrier Disruption and Oxidative Stress in Guinea Pig after Systemic Exposure to Modified Cell-Free Hemoglobin

    Science.gov (United States)

    Butt, Omer I.; Buehler, Paul W.; D'Agnillo, Felice

    2011-01-01

    Systemic exposure to cell-free hemoglobin (Hb) or its breakdown products after hemolysis or with the use of Hb-based oxygen therapeutics may alter the function and integrity of the blood-brain barrier. Using a guinea pig exchange transfusion model, we investigated the effect of a polymerized cell-free Hb (HbG) on the expression of endothelial tight junction proteins (zonula occludens 1, claudin-5, and occludin), astrocyte activation, IgG extravasation, heme oxygenase (HO), iron deposition, oxidative end products (4-hydroxynonenal adducts and 8-hydroxydeoxyguanosine), and apoptosis (cleaved caspase 3). Reduced zonula occludens 1 expression was observed after HbG transfusion as evidenced by Western blot and confocal microscopy. Claudin-5 distribution was altered in small- to medium-sized vessels. However, total expression of claudin-5 and occludin remained unchanged except for a notable increase in occludin 72 hours after HbG transfusion. HbG-transfused animals also showed increased astrocytic glial fibrillary acidic protein expression and IgG extravasation after 72 hours. Increased HO activity and HO-1 expression with prominent enhancement of HO-1 immunoreactivity in CD163-expressing perivascular cells and infiltrating monocytes/macrophages were also observed. Consistent with oxidative stress, HbG increased iron deposition, 4-hydroxynonenal and 8-hydroxydeoxyguanosine immunoreactivity, and cleaved caspase-3 expression. Systemic exposure to an extracellular Hb triggers blood-brain barrier disruption and oxidative stress, which may have important implications for the use of Hb-based therapeutics and may provide indirect insight on the central nervous system vasculopathies associated with excessive hemolysis. PMID:21356382

  20. Application of a blood-brain-barrier-penetrating form of GDNF in a mouse model for Parkinson's disease.

    Science.gov (United States)

    Dietz, Gunnar P H; Valbuena, Paoloa C; Dietz, Birgit; Meuer, Katrin; Müeller, Patrick; Weishaupt, Jachen H; Bähr, Mathias

    2006-04-12

    Glial-cell-line-derived neurotrophic factor (GDNF) promotes mesencephalic dopaminergic neuronal survival in several in vitro and in vivo models. As the demise of dopaminergic neurons is the cause for Parkinson's disease (PD) symptoms, GDNF is a promising agent for its treatment. However, this neurotrophin is unable to cross the blood-brain barrier, which has complicated its clinical use. Therefore, ways to deliver GDNF into the central nervous system in an effective manner are needed. The HIV-1-Tat-derived cell-penetrating peptide (CPP) provides a means to deliver fusion proteins into the brain. We generated a fusion protein between the 11 amino acid CPP of Tat and the rat GDNF mature protein to deliver GDNF across the blood-brain barrier. We showed previously that Tat-GDNF enhances the neuroprotective effect of GDNF in in vivo models for nerve trauma and ischemia. Here, we tested its effect in a subchronic scheme of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) application into the mouse as a model for PD to evaluate the effect of Tat-GDNF fusion protein in dopaminergic neuron survival. We showed that the fusion protein did indeed reach the dopaminergic neurons. However, the in vivo application of Tat-GDNF did not provide neuroprotection of dopaminergic neurons, as revealed by immunohistochemistry and counting of the number of tyrosine-hydroxylase-immunoreactive neurons in the substantia nigra pars compacta. Possibly, GDNF does protect nigro-striatal projections of those neurons that survive MPTP treatment but does not increase the number of surviving dopaminergic neurons. A concomitant treatment of Tat-GDNF with an anti-apoptotic Tat-fusion protein might be beneficial.

  1. Magnetic resonance imaging of blood brain/nerve barrier dysfunction and leukocyte infiltration: closely related or discordant?

    Directory of Open Access Journals (Sweden)

    Gesa eWeise

    2012-12-01

    Full Text Available Unlike other organs the nervous system is secluded from the rest of the organism by the blood brain (BBB or blood nerve barrier (BNB preventing passive influx of fluids from the circulation. Similarly, leukocyte entry to the nervous system is tightly controlled. Breakdown of these barriers and cellular inflammation are hallmarks of inflammatory as well as ischemic neurological diseases and thus represent potential therapeutic targets. The spatiotemporal relationship between BBB/BNB disruption and leukocyte infiltration has been a matter of debate. We here review contrast-enhanced magnetic resonance imaging (MRI as a non-invasive tool to depict barrier dysfunction and its relation to macrophage infiltration in the central and peripheral nervous system under pathological conditions. Novel experimental contrast agents like Gadofluorine M (Gf allow more sensitive assessment of BBB dysfunction than conventional Gadolinium (Gd-DTPA-enhanced MRI. In addition, Gf facilitates visualization of functional and transient alterations of the BBB remote from lesions. Cellular contrast agents such as superparamagnetic iron oxide particles (SPIO and perfluorocarbons (PFC enable assessment of leukocyte (mainly macrophage infiltration by MR technology. Combined use of these MR contrast agents disclosed that leukocytes can enter the nervous system independent from a disturbance of the BBB, and vice versa, a dysfunctional BBB/BNB by itself is not sufficient to attract inflammatory cells from the circulation. We will illustrate these basic imaging findings in animal models of multiple sclerosis (MS, cerebral ischemia and traumatic nerve injury and review corresponding findings in patients.

  2. 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 substrate

  3. Tailoring Lipid and Polymeric Nanoparticles as siRNA Carriers towards the Blood-Brain Barrier – from Targeting to Safe Administration

    DEFF Research Database (Denmark)

    Gomes, Maria João; Fernandes, Carlos; Martins, Susana

    2017-01-01

    Blood-brain barrier is a tightly packed layer of endothelial cells surrounding the brain that acts as the main obstacle for drugs enter the central nervous system (CNS), due to its unique features, as tight junctions and drug efflux systems. Therefore, since the incidence of CNS disorders is incr...

  4. Relationship of gelatinases-tight junction proteins and blood-brain barrier permeability in the early stage of cerebral ischemia and reperfusion

    Institute of Scientific and Technical Information of China (English)

    Haolin Xin; Wenzhao Liang; Jing Mang; Lina Lin; Na Guo; Feng Zhang; Zhongxin Xu

    2012-01-01

    Gelatinases matrix metalloproteinase-2 and matrix metalloproteinase-9 have been shown to mediate claudin-5 and occludin degradation, and play an important regulatory role in blood-brain barrier permeability. This study established a rat model of 1.5-hour middle cerebral artery occlusion with reperfusion. Protein expression levels of claudin-5 and occludin gradually decreased in the early stage of reperfusion, which corresponded to the increase of the gelatinolytic activity of matrix metalloproteinase-2 and matrix metalloproteinase-9. In addition, rats that received treatment with matrix metalloproteinase inhibitor N-[(2R)-2-(hydroxamidocarbonylmethyl)-4-methylpenthanoyl]-L- tryptophan methylamide (GM6001) showed a significant reduction in Evans blue leakage and an inhibition of claudin-5 and occludin protein degradation in striatal tissue. These data indicate that matrix metalloproteinase-2 and matrix metalloproteinase-9-mediated claudin-5 and occludin degradation is an important reason for blood-brain barrier leakage in the early stage of reperfusion. The leakage of the blood-brain barrier was present due to gelatinases-mediated degradation of claudin-5 and occludin proteins. We hypothesized that the timely closure of the structural component of the blood-brain barrier (tight junction proteins) is of importance.

  5. 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...

  6. Blood-brain barrier P-glycoprotein function decreases in specific brain regions with aging : A possible role in progressive neurodegeneration

    NARCIS (Netherlands)

    Bartels, Anna L.; Kortekaas, Rudie; Bart, Joost; Willemsen, Antoon T. M.; de Klerk, Onno L.; de Vries, Jeroen J.; van Oostrom, Joost C. H.; Leenders, Klaus L.

    2009-01-01

    Cerebrovascular P-glycoprotein (P-gp) acts at the blood-brain barrier (BBB) as an active cell membrane efflux pump for several endogenous and exogenous compounds. Age-associated decline in P-gp function could facilitate the accumulation of toxic substances in the brain, thus increasing the risk of n

  7. Blood-brain barrier P-glycoprotein function in healthy subjects and Alzheimer's disease patients : Effect of polymorphisms in the ABCB1 gene

    NARCIS (Netherlands)

    D.M.E. van Assema (Daniëlle); M. Lubberink (Mark); P. Rizzu (Patrizia); J.C. van Swieten (John); R.C. Schuit (Robert); J. Eriksson (Joel); P. Scheltens (Philip); M. Koepp (Matthias); A.A. Lammertsma (Adriaan); B.N.M. van Berckel (Bart )

    2012-01-01

    textabstractBackground: P-glycoprotein is a blood-brain barrier efflux transporter involved in the clearance of amyloid-beta from the brain and, as such, might be involved in the pathogenesis of Alzheimer's disease. P-glycoprotein is encoded by the highly polymorphic ABCB1 gene. Single-nucleotide po

  8. Development of Blood-Brain Barrier Permeable Nanoparticles as Potential Carriers for Salvianolic Acid B to CNS.

    Science.gov (United States)

    Grossi, Cristina; Guccione, Clizia; Isacchi, Benedetta; Bergonzi, Maria Camilla; Luccarini, Ilaria; Casamenti, Fiorella; Bilia, Anna Rita

    2017-03-01

    The blood-brain barrier hinders the passage of systemically delivered therapeutics and the brain extracellular matrix limits the distribution and durability of locally delivered agents. Drug-loaded nanocarriers represent a promising strategy to overcome these barriers and address specific drug delivery challenges due to their small size and versatile design. We synthetized [fluorescent poly(ethyl-cyanoacrylate) nanoparticles coated with Tween 80 by an emulsion polymerization method to target and reach the brain after intravenous and intraperitoneal administration. Nanoparticles were characterized in terms of dimensional analysis, polydispersity and zeta potential (ζ-potential), morphology, encapsulation efficacy, and loading capacity. After intracerebral injection in healthy rats, nanoparticles were distributed within the injected hemisphere and mainly interacted with microglial cells, presumably involved in their clearance by phagocytosis. Furthermore, nanoparticles were able to pass the blood-brain barrier after systemic administration in rats, and the lack of toxicity in C57/B6 mice chronically administered was highlighted. The data obtained helped to clarify the nanoparticles distribution, accumulation, fate, and toxicity into the brain. The selected nanoparticles may represent a biocompatible promising carrier to be further investigated as brain delivery systems. Salvianolic acid B from Salvia miltiorrhiza is a promising molecule in the protection of degeneration in several animal models by various biological mechanisms, but its poor chemical stability and low bioavailability limits its clinical application for central nervous system neuronal injury and degeneration. Nanoparticles were loaded with salvianolic acid B obtaining an encapsulation efficacy and loading capacities of 98.70 % ± 0.45 and 53.3 % ± 0.24, respectively. They were suitable for parental administration because their mean diameter was smaller than 300 nm, with a polydispersity of

  9. 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

    2006-12-01

    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.

  10. Increased blood-brain barrier permeability is associated with dementia and diabetes but not amyloid pathology or APOE genotype.

    Science.gov (United States)

    Janelidze, Shorena; Hertze, Joakim; Nägga, Katarina; Nilsson, Karin; Nilsson, Christer; Wennström, Malin; van Westen, Danielle; Blennow, Kaj; Zetterberg, Henrik; Hansson, Oskar

    2017-03-01

    Blood-brain barrier (BBB) dysfunction might be an important component of many neurodegenerative disorders. In this study, we investigated its role in dementia using large clinical cohorts. The cerebrospinal fluid (CSF)/plasma albumin ratio (Qalb), an indicator of BBB (and blood-CSF barrier) permeability, was measured in a total of 1015 individuals. The ratio was increased in patients with Alzheimer's disease, dementia with Lewy bodies or Parkinson's disease dementia, subcortical vascular dementia, and frontotemporal dementia compared with controls. However, this measure was not changed during preclinical or prodromal Alzheimer's disease and was not associated with amyloid positron emission tomography or APOE genotype. The Qalb was increased in diabetes mellitus and correlated positively with CSF biomarkers of angiogenesis and endothelial dysfunction (vascular endothelial growth factor, intracellular adhesion molecule 1, and vascular cell adhesion molecule 1). In healthy elderly, high body mass index and waist-hip ratio predicted increased Qalb 20 years later. In summary, BBB permeability is increased in major dementia disorders but does not relate to amyloid pathology or APOE genotype. Instead, BBB impairment may be associated with diabetes and brain microvascular damage.

  11. Postulated Role of Vasoactive Neuropeptide-Related Immunopathology of the Blood Brain Barrier and Virchow-Robin Spaces in the Aetiology of Neurological-Related Conditions

    OpenAIRE

    Staines, D. R.; E. W. Brenu; Marshall-Gradisnik, S.

    2008-01-01

    Vasoactive neuropeptides (VNs) such as pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) have critical roles as neurotransmitters, vasodilators including perfusion and hypoxia regulators, as well as immune and nociception modulators. They have key roles in blood vessels in the central nervous system (CNS) including maintaining functional integrity of the blood brain barrier (BBB) and blood spinal barrier (BSB). VNs are potent activators of aden...

  12. Improved survival in rats with glioma using MRI-guided focused ultrasound and microbubbles to disrupt the blood-brain barrier and deliver Doxil

    Science.gov (United States)

    Aryal, Muna; Zhi Zhang, Yong; Vykhodtseva, Natalia; Park, Juyoung; Power, Chanikarn; McDannold, Nathan

    2012-02-01

    Blood-brain-barrier (BBB) limits the transportation of most neuropeptides, proteins (enzymes, antibodies), chemotherapeutic agents, and genes that have therapeutic potential for the treatment of brain diseases. Different methods have been used to overcome this limitation, but they are invasive, non-targeted, or require the development of new drugs. We have developed a method that uses MRI-guided focused ultrasound (FUS) combined with circulating microbubbles to temporarily open BBB in and around brain tumors to deliver chemotherapy agents. Here, we tested whether this noninvasive technique could enhance the effectiveness of a chemotherapy agent (Doxil). Using 690 kHz FUS transducer and microbubble (Definity), we induced BBB disruption in intracranially-implanted 9L glioma tumors in rat's brain in three weekly sessions. Animals who received BBB disruption and Doxil had a median survival time of 34.5 days, which was significantly longer than that found in control animals which is 16, 18.5, 21 days who received no treatment, BBB disruption only and Doxil only respectively This work demonstrates that FUS technique has promise in overcoming barriers to drug delivery, which are particularly stark in the brain due to the BBB.

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

    OpenAIRE

    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 ce...

  14. 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

    2017-01-01

    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-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.

  15. 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.

  16. Molecular biology of the blood-brain and the blood-cerebrospinal fluid barriers: similarities and differences

    Directory of Open Access Journals (Sweden)

    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

  17. 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.

  18. Inhibitory Effect of Matrine on Blood-Brain Barrier Disruption for the Treatment of Experimental Autoimmune Encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Su Zhang

    2013-01-01

    Full Text Available Dysfunction of the blood-brain barrier (BBB is a primary characteristic of experimental autoimmune encephalomyelitis (EAE, an experimental model of multiple sclerosis (MS. Matrine (MAT, a quinolizidine alkaloid derived from the herb Radix Sophorae Flave, has been recently found to suppress clinical EAE and CNS inflammation. However, whether this effect of MAT is through protecting the integrity and function of the BBB is not known. In the present study, we show that MAT treatment had a therapeutic effect comparable to dexamethasone (DEX in EAE rats, with reduced Evans Blue extravasation, increased expression of collagen IV, the major component of the basement membrane, and the structure of tight junction (TJ adaptor protein Zonula occludens-1 (ZO-1. Furthermore, MAT treatment attenuated expression of matrix metalloproteinase-9 and -2 (MMP-9/-2, while it increased the expression of tissue inhibitors of metalloproteinase-1 and -2 (TIMP-1/-2. Our findings demonstrate that MAT reduces BBB leakage by strengthening basement membrane, inhibiting activities of MMP-2 and -9, and upregulating their inhibitors. Taken together, our results identify a novel mechanism underlying the effect of MAT, a natural compound that could be a novel therapy for MS.

  19. Radiation induces progenitor cell death, microglia activation, and blood-brain barrier damage in the juvenile rat cerebellum

    Science.gov (United States)

    Zhou, Kai; Boström, Martina; Ek, C. Joakim; Li, Tao; Xie, Cuicui; Xu, Yiran; Sun, Yanyan; Blomgren, Klas; Zhu, Changlian

    2017-01-01

    Posterior fossa tumors are the most common childhood intracranial tumors, and radiotherapy is one of the most effective treatments. However, irradiation induces long-term adverse effects that can have significant negative impacts on the patient’s quality of life. The purpose of this study was to characterize irradiation-induced cellular and molecular changes in the cerebellum. We found that irradiation-induced cell death occurred mainly in the external germinal layer (EGL) of the juvenile rat cerebellum. The number of proliferating cells in the EGL decreased, and 82.9% of them died within 24 h after irradiation. Furthermore, irradiation induced oxidative stress, microglia accumulation, and inflammation in the cerebellum. Interestingly, blood-brain barrier damage and blood flow reduction was considerably more pronounced in the cerebellum compared to other brain regions. The cerebellar volume decreased by 39% and the migration of proliferating cells to the internal granule layer decreased by 87.5% at 16 weeks after irradiation. In the light of recent studies demonstrating that the cerebellum is important not only for motor functions, but also for cognition, and since treatment of posterior fossa tumors in children typically results in debilitating cognitive deficits, this differential susceptibility of the cerebellum to irradiation should be taken into consideration for future protective strategies. PMID:28382975

  20. A dual functional fluorescent probe for glioma imaging mediated by blood-brain barrier penetration and glioma cell targeting.

    Science.gov (United States)

    Ma, Hongwei; Gao, Zhiyong; Yu, Panfeng; Shen, Shun; Liu, Yongmei; Xu, Bainan

    2014-06-20

    Glioma is a huge threat for human being because it was hard to be completely removed owing to both the infiltrating growth of glioma cells and integrity of blood brain barrier. Thus effectively imaging the glioma cells may pave a way for surgical removing of glioma. In this study, a fluorescent probe, Cy3, was anchored onto the terminal of AS1411, a glioma cell targeting aptamer, and then TGN, a BBB targeting peptide, was conjugated with Cy3-AS1411 through a PEG linker. The production, named AsT, was characterized by gel electrophoresis, (1)H NMR and FTIR. In vitro cellular uptake and glioma spheroid uptake demonstrated the AsT could not only be uptaken by both glioma and endothelial cells, but also penetrate through endothelial cell monolayer and uptake by glioma spheroids. In vivo, AsT could effectively target to glioma with high intensity. In conclusion, AsT could be used as an effective glioma imaging probe.

  1. 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.

  2. 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.

  3. Modulation of intercellular junctions by cyclic-ADT peptides as a method to reversibly increase blood-brain barrier permeability.

    Science.gov (United States)

    Laksitorini, Marlyn D; Kiptoo, Paul K; On, Ngoc H; Thliveris, James A; Miller, Donald W; Siahaan, Teruna J

    2015-03-01

    It is challenging to deliver molecules to the brain for diagnosis and treatment of brain diseases. This is primarily because of the presence of the blood-brain barrier (BBB), which restricts the entry of many molecules into the brain. In this study, cyclic-ADT peptides (ADTC1, ADTC5, and ADTC6) have been shown to modify the BBB to enhance the delivery of marker molecules [e.g., (14) C-mannitol, gadolinium-diethylenetriaminepentacetate (Gd-DTPA)] to the brain via the paracellular pathways of the BBB. The hypothesis is that these peptides modulate cadherin interactions in the adherens junctions of the vascular endothelial cells forming the BBB to increase paracellular drug permeation. In vitro studies indicated that ADTC5 had the best profile to inhibit adherens junction resealing in Madin-Darby canine kidney cell monolayers in a concentration-dependent manner (IC50 = 0.3 mM) with a maximal response at 0.4 mM. Under the current experimental conditions, ADTC5 improved the delivery of (14) C-mannitol to the brain about twofold compared with the negative control in the in situ rat brain perfusion model. Furthermore, ADTC5 peptide increased in vivo delivery of Gd-DTPA to the brain of Balb/c mice when administered intravenously. In conclusion, ADTC5 has the potential to improve delivery of diagnostic and therapeutic agents to the brain.

  4. The extracellular matrix protein laminin α2 regulates the maturation and function of the blood-brain barrier.

    Science.gov (United States)

    Menezes, Michael J; McClenahan, Freyja K; Leiton, Cindy V; Aranmolate, Azeez; Shan, Xiwei; Colognato, Holly

    2014-11-12

    Laminins are major constituents of the gliovascular basal lamina of the blood-brain barrier (BBB); however, the role of laminins in BBB development remains unclear. Here we report that Lama2(-/-) mice, lacking expression of the laminin α2 subunit of the laminin-211 heterotrimer expressed by astrocytes and pericytes, have a defective BBB in which systemically circulated tracer leaks into the brain parenchyma. The Lama2(-/-) vascular endothelium had significant abnormalities, including altered integrity and composition of the endothelial basal lamina, inappropriate expression of embryonic vascular endothelial protein MECA32, substantially reduced pericyte coverage, and tight junction abnormalities. Additionally, astrocytic endfeet were hypertrophic and lacked appropriately polarized aquaporin4 channels. Laminin-211 appears to mediate these effects at least in part by dystroglycan receptor interactions, as preventing dystroglycan expression in neural cells led to a similar set of BBB abnormalities and gliovascular disturbances, which additionally included perturbed vascular endothelial glucose transporter-1 localization. These findings provide insight into the cell and molecular changes that occur in congenital muscular dystrophies caused by Lama2 mutations or inappropriate dystroglycan post-translational modifications, which have accompanying brain abnormalities, including seizures. Our results indicate a novel role for laminin-dystroglycan interactions in the cooperative integration of astrocytes, endothelial cells, and pericytes in regulating the BBB.

  5. Development of the blood-brain barrier within the paraventricular nucleus of the hypothalamus: influence of fetal glucocorticoid excess.

    Science.gov (United States)

    Frahm, Krystle A; Tobet, Stuart A

    2015-07-01

    The blood-brain barrier (BBB) is a critical contributor to brain function. To understand its development and potential function in different brain regions, the postnatal (P) BBB was investigated in the mouse cortex (CTX), lateral hypothalamus, and paraventricular nucleus of the hypothalamus (PVN). Brains were examined on postnatal days (P)12, P22 and P52 for BBB competency and for pericytes as key cellular components of the BBB demarcated by immunoreactive desmin. Glucocorticoid influences (excess dexamethasone; dex) during prenatal development were also assessed for their impact on the blood vessels within these regions postnatally. At P12, there was significantly more extravascular leakage of a low molecular weight dye (fluorescein isothiocyanate) in the CTX than within hypothalamic regions. For pericytes, there were low levels of desmin immunoreactivity at P12 that increased with age for all regions. There was more desmin immunoreactivity present in the PVN at each age examined. Fetal dex exposure resulted in decreased blood vessel density within the PVN at P20. In the CTX, dex exposure increased BBB competency, in contrast to the PVN where there was a decrease in BBB competency and increased pericyte presence. Overall, unique alterations in the functioning of the BBB within the PVN may provide a novel mechanism for fetal antecedent programming that may influence adult disorders.

  6. The role of multidrug resistance protein (MRP-1) as an active efflux transporter on blood-brain barrier (BBB) permeability.

    Science.gov (United States)

    Lingineni, Karthik; Belekar, Vilas; Tangadpalliwar, Sujit R; Garg, Prabha

    2017-01-03

    Drugs acting on central nervous system (CNS) may take longer duration to reach the market as these compounds have a higher attrition rate in clinical trials due to the complexity of the brain, side effects, and poor blood-brain barrier (BBB) permeability compared to non-CNS-acting compounds. The roles of active efflux transporters with BBB are still unclear. The aim of the present work was to develop a predictive model for BBB permeability that includes the MRP-1 transporter, which is considered as an active efflux transporter. A support vector machine model was developed for the classification of MRP-1 substrates and non-substrates, which was validated with an external data set and Y-randomization method. An artificial neural network model has been developed to evaluate the role of MRP-1 on BBB permeation. A total of nine descriptors were selected, which included molecular weight, topological polar surface area, ClogP, number of hydrogen bond donors, number of hydrogen bond acceptors, number of rotatable bonds, P-gp, BCRP, and MRP-1 substrate probabilities for model development. We identified 5 molecules that fulfilled all criteria required for passive permeation of BBB, but they all have a low logBB value, which suggested that the molecules were effluxed by the MRP-1 transporter.

  7. Beta-Amyloid Downregulates MDR1-P-Glycoprotein (Abcb1 Expression at the Blood-Brain Barrier in Mice

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    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.

  8. A retinoic acid-enhanced, multicellular human blood-brain barrier model derived from stem cell sources

    Science.gov (United States)

    Lippmann, Ethan S.; Al-Ahmad, Abraham; Azarin, Samira M.; Palecek, Sean P.; Shusta, Eric V.

    2014-02-01

    Blood-brain barrier (BBB) models are often used to investigate BBB function and screen brain-penetrating therapeutics, but it has been difficult to construct a human model that possesses an optimal BBB phenotype and is readily scalable. To address this challenge, we developed a human in vitro BBB model comprising brain microvascular endothelial cells (BMECs), pericytes, astrocytes and neurons derived from renewable cell sources. First, retinoic acid (RA) was used to substantially enhance BBB phenotypes in human pluripotent stem cell (hPSC)-derived BMECs, particularly through adherens junction, tight junction, and multidrug resistance protein regulation. RA-treated hPSC-derived BMECs were subsequently co-cultured with primary human brain pericytes and human astrocytes and neurons derived from human neural progenitor cells (NPCs) to yield a fully human BBB model that possessed significant tightness as measured by transendothelial electrical resistance (~5,000 Ωxcm2). Overall, this scalable human BBB model may enable a wide range of neuroscience studies.

  9. Serum-borne bioactivity caused by pulmonary multiwalled carbon nanotubes induces neuroinflammation via blood-brain barrier impairment.

    Science.gov (United States)

    Aragon, Mario J; Topper, Lauren; Tyler, Christina R; Sanchez, Bethany; Zychowski, Katherine; Young, Tamara; Herbert, Guy; Hall, Pamela; Erdely, Aaron; Eye, Tracy; Bishop, Lindsey; Saunders, Samantha A; Muldoon, Pretal P; Ottens, Andrew K; Campen, Matthew J

    2017-03-07

    Pulmonary exposure to multiwalled carbon nanotubes (MWCNTs) causes indirect systemic inflammation through unknown pathways. MWCNTs translocate only minimally from the lungs into the systemic circulation, suggesting that extrapulmonary toxicity may be caused indirectly by lung-derived factors entering the circulation. To assess a role for MWCNT-induced circulating factors in driving neuroinflammatory outcomes, mice were acutely exposed to MWCNTs (10 or 40 µg/mouse) via oropharyngeal aspiration. At 4 h after MWCNT exposure, broad disruption of the blood-brain barrier (BBB) was observed across the capillary bed with the small molecule fluorescein, concomitant with reactive astrocytosis. However, pronounced BBB permeation was noted, with frank albumin leakage around larger vessels (>10 µm), overlain by a dose-dependent astroglial scar-like formation and recruitment of phagocytic microglia. As affirmed by elevated inflammatory marker transcription, MWCNT-induced BBB disruption and neuroinflammation were abrogated by pretreatment with the rho kinase inhibitor fasudil. Serum from MWCNT-exposed mice induced expression of adhesion molecules in primary murine cerebrovascular endothelial cells and, in a wound-healing in vitro assay, impaired cell motility and cytokinesis. Serum thrombospondin-1 level was significantly increased after MWCNT exposure, and mice lacking the endogenous receptor CD36 were protected from the neuroinflammatory and BBB permeability effects of MWCNTs. In conclusion, acute pulmonary exposure to MWCNTs causes neuroinflammatory responses that are dependent on the disruption of BBB integrity.

  10. The Role of the Blood-Brain Barrier in the Pathogenesis of Senile Plaques in Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    J. Provias

    2014-01-01

    Full Text Available The accumulation of beta-amyloid [Aβ] within senile plaques [SP] is characteristic of these lesions in Alzheimer’s disease. The accumulation of Aβ42, in particular, in the superior temporal [ST] cortex may result from an inability of the blood brain barrier (BBB to regulate the trans-endothelial transport and clearance of the amyloid. Lipoprotein receptor-related protein [LRP] and P-glycoprotein [P-gp] facilitate the efflux of Aβ out of the brain, whereas receptor for advanced glycation end products [RAGE] facilitates Aβ influx. Additionally, vascular endothelial growth factor [VEGF] and endothelial nitric oxide synthase [eNOS] may influence the trans-BBB transport of Aβ. In this study we examined ST samples and compared SP burden of all types with the capillary expression of LRP, p-gp, RAGE, VEGF, and e-NOS in samples from 15 control and 15 Alzheimer brains. LRP, P-gp, RAGE, VEGF, and eNOS positive capillaries and Aβ42 plaques were quantified and statistical analysis of the nonparametric data was performed using the Mann-Whitney and Kruskal-Wallis tests. In the Alzheimer condition P-gp, VEGF, and eNOS positive capillaries were negatively correlated with SP burden, but LRP and RAGE were positively correlated with SP burden. These results indicate altered BBB function in the pathogenesis of SPs in Alzheimer brains.

  11. Modeling HIV-1 Induced Neuroinflammation in Mice: Role of Platelets in Mediating Blood-Brain Barrier Dysfunction.

    Science.gov (United States)

    Jones, Letitia D; Jackson, Joseph W; Maggirwar, Sanjay B

    2016-01-01

    The number of HIV-1 positive individuals developing some form of HIV-associated neurocognitive disorder (HAND) is increasing. In these individuals, the integrity of the blood-brain barrier (BBB) is compromised due to an increase in exposure to pro-inflammatory mediators, viral proteins, and virus released from infected cells. It has been shown that soluble CD40L (sCD40L) is released upon platelet activation and is an important mediator of the pathogenesis of HAND but the underlying mechanisms are unclear, emphasizing the need of an effective animal model. Here, we have utilized a novel animal model in which wild-type (WT) mice were infected with EcoHIV; a derivative of HIV-1 that contains a substitution of envelope protein gp120 with that of gp80 derived from murine leukemia virus-1 (MuLV-1). As early as two-weeks post-infection, EcoHIV led to increased permeability of the BBB associated with decreased expression of tight junction protein claudin-5, in CD40L and platelet activation-dependent manner. Treatment with an antiplatelet drug, eptifibatide, in EcoHIV-infected mice normalized BBB function, sCD40L release and platelet activity, thus implicating platelet activation and platelet-derived CD40L in virally induced BBB dysfunction. Our results also validate and underscore the importance of EcoHIV infection mouse model as a tool to explore therapeutic targets for HAND.

  12. Human apolipoprotein E ɛ4 expression impairs cerebral vascularization and blood-brain barrier function in mice.

    Science.gov (United States)

    Alata, Wael; Ye, Yue; St-Amour, Isabelle; Vandal, Milène; Calon, Frédéric

    2015-01-01

    Human apolipoprotein E (APOE) exists in three isoforms ɛ2, ɛ3, and ɛ4, of which APOE4 is the main genetic risk factor of Alzheimer's disease (AD). As cerebrovascular defects are associated with AD, we tested whether APOE genotype has an impact on the integrity and function of the blood-brain barrier (BBB) in human APOE-targeted replacement mice. Using the quantitative in situ brain perfusion technique, we first found lower (13.0% and 17.0%) brain transport coefficient (Clup) of [(3)H]-diazepam in APOE4 mice at 4 and 12 months, compared with APOE2 and APOE3 mice, reflecting a decrease in cerebral vascularization. Accordingly, results from immunohistofluorescence experiments revealed a structurally reduced cerebral vascularization (26% and 38%) and thinner basement membranes (30% and 35%) in 12-month-old APOE4 mice compared with APOE2 and APOE3 mice, suggesting vascular atrophy. In addition, APOE4 mice displayed a 29% reduction in [(3)H]-d-glucose transport through the BBB compared with APOE2 mice without significant changes in the expression of its transporter GLUT1 in brain capillaries. However, an increase of 41.3% of receptor for advanced glycation end products (RAGE) was found in brain capillaries of 12-month-old APOE4 mice. In conclusion, profound divergences were observed between APOE genotypes at the cerebrovascular interface, suggesting that APOE4-induced BBB anomalies may contribute to AD development.

  13. Solid lipid nanoparticles carrying chemotherapeutic drug across the blood-brain barrier through insulin receptor-mediated pathway.

    Science.gov (United States)

    Kuo, Yung-Chih; Shih-Huang, Chun-Yuan

    2013-09-01

    Carmustine (BCNU)-loaded solid lipid nanoparticles (SLNs) were grafted with 83-14 monoclonal antibody (MAb) (83-14 MAb/BCNU-SLNs) and applied to the brain-targeting delivery. Human brain-microvascular endothelial cells (HBMECs) incubated with 83-14 MAb/BCNU-SLNs were stained to demonstrate the interaction between the nanocarriers and expressed insulin receptors (IRs). The results revealed that the particle size of 83-14 MAb/BCNU-SLNs decreased with an increasing weight percentage of Dynasan 114 (DYN). Storage at 4 °C for 6 weeks slightly deformed the colloidal morphology. In addition, poloxamer 407 on 83-14 MAb/BCNU-SLNs induced cytotoxicity to RAW264.7 cells and inhibited phagocytosis by RAW264.7 cells. An increase in the weight percentage of DYN from 0% to 67% slightly reduced the viability of RAW264.7 cells and promoted phagocytosis. Moreover, the transport ability of 83-14 MAb/BCNU-SLNs across the blood-brain barrier (BBB) in vitro enhanced with an increasing weight percentage of Tween 80. 83-14 MAb on MAb/BCNU-SLNs stimulated endocytosis by HBMECs via IRs and enhanced the permeability of BCNU across the BBB. 83-14 MAb/BCNU-SLNs can be a promising antitumor drug delivery system for transporting BCNU to the brain.

  14. Functional Coupling of Human Microphysiology Systems: Intestine, Liver, Kidney Proximal Tubule, Blood-Brain Barrier and Skeletal Muscle

    Science.gov (United States)

    Vernetti, Lawrence; Gough, Albert; Baetz, Nicholas; Blutt, Sarah; Broughman, James R.; Brown, Jacquelyn A.; Foulke-Abel, Jennifer; Hasan, Nesrin; In, Julie; Kelly, Edward; Kovbasnjuk, Olga; Repper, Jonathan; Senutovitch, Nina; Stabb, Janet; Yeung, Catherine; Zachos, Nick C.; Donowitz, Mark; Estes, Mary; Himmelfarb, Jonathan; Truskey, George; Wikswo, John P.; Taylor, D. Lansing

    2017-01-01

    Organ interactions resulting from drug, metabolite or xenobiotic transport between organs are key components of human metabolism that impact therapeutic action and toxic side effects. Preclinical animal testing often fails to predict adverse outcomes arising from sequential, multi-organ metabolism of drugs and xenobiotics. Human microphysiological systems (MPS) can model these interactions and are predicted to dramatically improve the efficiency of the drug development process. In this study, five human MPS models were evaluated for functional coupling, defined as the determination of organ interactions via an in vivo-like sequential, organ-to-organ transfer of media. MPS models representing the major absorption, metabolism and clearance organs (the jejunum, liver and kidney) were evaluated, along with skeletal muscle and neurovascular models. Three compounds were evaluated for organ-specific processing: terfenadine for pharmacokinetics (PK) and toxicity; trimethylamine (TMA) as a potentially toxic microbiome metabolite; and vitamin D3. We show that the organ-specific processing of these compounds was consistent with clinical data, and discovered that trimethylamine-N-oxide (TMAO) crosses the blood-brain barrier. These studies demonstrate the potential of human MPS for multi-organ toxicity and absorption, distribution, metabolism and excretion (ADME), provide guidance for physically coupling MPS, and offer an approach to coupling MPS with distinct media and perfusion requirements. PMID:28176881

  15. Drug delivery strategies to enhance the permeability of the blood-brain barrier for treatment of glioma.

    Science.gov (United States)

    Zhang, Fang; Xu, Chun-Lei; Liu, Chun-Mei

    2015-01-01

    Gliomas are amongst the most insidious and destructive types of brain cancer and are associated with a poor prognosis, frequent recurrences, and extremely high lethality despite combination treatment of surgery, radiotherapy, and chemotherapy. The existence of the blood-brain barrier (BBB) restricts the delivery of therapeutic molecules into the brain and offers the clinical efficacy of many pharmaceuticals that have been demonstrated to be effective for other kinds of tumors. This challenge emphasizes the need to be able to deliver drugs effectively across the BBB to reach the brain parenchyma. Enhancement of the permeability of the BBB and being able to transport drugs across it has been shown to be a promising strategy to improve drug absorption and treatment efficacy. This review highlights the innovative technologies that have been introduced to enhance the permeability of the BBB and to obtain an optimal distribution and concentration of drugs in the brain to treat gliomas, such as nanotechniques, hyperthermia techniques, receptor-mediated transport, cell-penetrating peptides, and cell-mediated delivery.

  16. Modeling localized delivery of Doxorubicin to the brain following focused ultrasound enhanced blood-brain barrier permeability

    Science.gov (United States)

    Nhan, Tam; Burgess, Alison; Lilge, Lothar; Hynynen, Kullervo

    2014-10-01

    Doxorubicin (Dox) is a well-established chemotherapeutic agent, however it has limited efficacy in treating brain malignancies due to the presence of the blood-brain barrier (BBB). Recent preclinical studies have demonstrated that focused ultrasound induced BBB disruption (BBBD) enables efficient delivery of Dox to the brain. For future treatment planning of BBBD-based drug delivery, it is crucial to establish a mathematical framework to predict the effect of transient BBB permeability enhancement on the spatiotemporal distribution of Dox at the targeted area. The constructed model considers Dox concentrations within three compartments (plasma, extracellular, intracellular) that are governed by various transport processes (e.g. diffusion in interstitial space, exchange across vessel wall, clearance by cerebral spinal fluid, uptake by brain cells). By examining several clinical treatment aspects (e.g. sonication scheme, permeability enhancement, injection mode), our simulation results support the experimental findings of optimal interval delay between two consecutive sonications and therapeutically-sufficient intracellular concentration with respect to transfer constant Ktrans range of 0.01-0.03 min-1. Finally, the model suggests that infusion over a short duration (20-60 min) should be employed along with single-sonication or multiple-sonication at 10 min interval to ensure maximum delivery to the intracellular compartment while attaining minimal cardiotoxicity via suppressing peak plasma concentration.

  17. Expression polymorphism of the blood-brain barrier component P-glycoprotein (MDR1) in relation to Parkinson's disease.

    Science.gov (United States)

    Furuno, Taku; Landi, Maria-Teresa; Ceroni, Mauro; Caporaso, Neil; Bernucci, Ilaria; Nappi, Giuseppe; Martignoni, Emilia; Schaeffeler, Elke; Eichelbaum, Michel; Schwab, Matthias; Zanger, Ulrich M

    2002-10-01

    Because drug transporters such as P-glycoprotein, the product of the multidrug resistance (MDR1 ) gene, contribute to the function of the blood-brain barrier, we hypothesized that differences in their expression could affect the uptake of neurotoxic xenobiotics, thereby modulating interindividual susceptibility for neurological disorders such as Parkinson's disease. In a pilot case-control study comprising 95 Parkinson's disease patients (25 early-onset patients with onset age T in exon 26, 2677G > T,A in exon 21, and -129T > C in exon 1b. There were no statistically significant associations between any of these polymorphisms and Parkinson's disease. However, a distribution pattern consistent with our hypothesis was observed in that the frequency of the 3435T/T genotype, which had previously been associated with decreased P-glycoprotein expression and function, was highest in the early-onset Parkinson's disease group (36.0%), second-highest in the late-onset Parkinson's disease group (22.9%), and lowest in the control group (18.9%). Furthermore, we confirmed that the MDR1 exon 21 and exon 26 polymorphisms are in significant linkage disequilibrium since the [2677G, 3435C] and [2677T, 3435T] haplotypes were far more frequently observed than expected. In conclusion, MDR1 and other drug transporters represent plausible candidates as Parkinson's disease risk genes. Larger studies are required to confirm this role in the etiology of Parkinson's disease.

  18. Decreased blood-brain barrier P-glycoprotein function in the progression of Parkinson's disease, PSP and MSA.

    Science.gov (United States)

    Bartels, A L; Willemsen, A T M; Kortekaas, R; de Jong, B M; de Vries, R; de Klerk, O; van Oostrom, J C H; Portman, A; Leenders, K L

    2008-07-01

    Decreased blood-brain barrier (BBB) efflux function of the P-glycoprotein (P-gp) transport system could facilitate the accumulation of toxic compounds in the brain, increasing the risk of neurodegenerative pathology such as Parkinson's disease (PD). This study investigated in vivo BBB P-gp function in patients with parkinsonian neurodegenerative syndromes, using [11C]-verapamil PET in PD, PSP and MSA patients. Regional differences in distribution volume were studied using SPM with higher uptake interpreted as reduced P-gp function. Advanced PD patients and PSP patients had increased [11C]-verapamil uptake in frontal white matter regions compared to controls; while de novo PD patients showed lower uptake in midbrain and frontal regions. PSP and MSA patients had increased uptake in the basal ganglia. Decreased BBB P-gp function seems a late event in neurodegenerative disorders, and could enhance continuous neurodegeneration. Lower [11C]-verapamil uptake in midbrain and frontal regions of de novo PD patients could indicate a regional up-regulation of P-gp function.

  19. The epithelial membrane protein 1 is a novel tight junction protein of the blood-brain barrier.

    Science.gov (United States)

    Bangsow, Thorsten; Baumann, Ewa; Bangsow, Carmen; Jaeger, Martina H; Pelzer, Bernhard; Gruhn, Petra; Wolf, Sabine; von Melchner, Harald; Stanimirovic, Danica B

    2008-06-01

    In the central nervous system, a constant microenvironment required for neuronal cell activity is maintained by the blood-brain barrier (BBB). The BBB is formed by the brain microvascular endothelial cells (BMEC), which are sealed by tight junctions (TJ). To identify genes that are differentially expressed in BMEC compared with peripheral endothelial cells, we constructed a subtractive cDNA library from porcine BMEC (pBMEC) and aortic endothelial cells (AOEC). Screening the library for differentially expressed genes yielded 26 BMEC-specific transcripts, such as solute carrier family 35 member F2 (SLC35F2), ADP-ribosylation factor-like 5B (ARL5B), TSC22 domain family member 1 (TSC22D1), integral membrane protein 2A (ITM2A), and epithelial membrane protein 1 (EMP1). In this study, we show that EMP1 transcript is enriched in pBMEC compared with brain tissue and that EMP1 protein colocalizes with the TJ protein occludin in mouse BMEC by coimmunoprecipitation and in rat brain vessels by immunohistochemistry. Epithelial membrane protein 1 expression was transiently induced in laser-capture microdissected rat brain vessels after a 20-min global cerebral ischemia, in parallel with the loss of occludin immunoreactivity. The study identifies EMP1 as a novel TJ-associated protein of the BBB and suggests its potential role in the regulation of the BBB function in cerebral ischemia.

  20. Methylophiopogonanone A Protects against Cerebral Ischemia/Reperfusion Injury and Attenuates Blood-Brain Barrier Disruption In Vitro.

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    Mingbao Lin

    Full Text Available Methylophiopogonanone A (MO-A, an active homoisoflavonoid of the Chinese herb Ophiopogon japonicus which has been shown to have protective effects on cerebral ischemia/reperfusion (I/R injury, has been demonstrated to have anti-inflammatory and anti-oxidative properties. However, little is known about its role in cerebral I/R injury. Therefore, in this study, by using a middle cerebral artery occlusion (MCAO and reperfusion rat model, the effect of MO-A on cerebral I/R injury was examined. The results showed that MO-A treatment reduced infarct volume and brain edema, improved neurological deficit scores, reversed animal body weight decreases, and increased animal survival time in the stroke groups. Western blotting showed that MO-A suppressed MMP-9, but restored the expression of claudin-3 and claudin-5. Furthermore, transmission electron microscopy were monitored to determine the blood-brain barrier (BBB alterations in vitro. The results showed that MO-A markedly attenuated BBB damage in vitro. Additionally, MO-A inhibited ROS production in ECs and MMP-9 release in differentiated THP-1 cells in vitro, and suppressed ICAM-1 and VCAM-1 expression in ECs and leukocyte/EC adhesion. In conclusion, our data indicate that MO-A has therapeutic potential against cerebral I/R injury through its ability to attenuate BBB disruption by regulating the expression of MMP-9 and tight junction proteins.

  1. Detrimental role of the EP1 prostanoid receptor in blood-brain barrier damage following experimental ischemic stroke.

    Science.gov (United States)

    Frankowski, Jan C; DeMars, Kelly M; Ahmad, Abdullah S; Hawkins, Kimberly E; Yang, Changjun; Leclerc, Jenna L; Doré, Sylvain; Candelario-Jalil, Eduardo

    2015-12-09

    Cyclooxygenase-2 (COX-2) is activated in response to ischemia and significantly contributes to the neuroinflammatory process. Accumulation of COX-2-derived prostaglandin E2 (PGE2) parallels the substantial increase in stroke-mediated blood-brain barrier (BBB) breakdown. Disruption of the BBB is a serious consequence of ischemic stroke, and is mainly mediated by matrix metalloproteinases (MMPs). This study aimed to investigate the role of PGE2 EP1 receptor in neurovascular injury in stroke. We hypothesized that pharmacological blockade or genetic deletion of EP1 protects against BBB damage and hemorrhagic transformation by decreasing the levels and activity of MMP-3 and MMP-9. We found that post-ischemic treatment with the EP1 antagonist, SC-51089, or EP1 genetic deletion results in a significant reduction in BBB disruption and reduced hemorrhagic transformation in an experimental model of transient focal cerebral ischemia. These neurovascular protective effects of EP1 inactivation are associated with a significant reduction in MMP-9/-3, less peripheral neutrophil infiltration, and a preservation of tight junction proteins (ZO-1 and occludin) composing the BBB. Our study identifies the EP1 signaling pathway as an important link between neuroinflammation and MMP-mediated BBB breakdown in ischemic stroke. Targeting the EP1 receptor could represent a novel approach to diminish the devastating consequences of stroke-induced neurovascular damage.

  2. P-glycoprotein mediates brain-to-blood efflux transport of buprenorphine across the blood-brain barrier.

    Science.gov (United States)

    Suzuki, Toyofumi; Zaima, Chika; Moriki, Yoshiaki; Fukami, Toshiro; Tomono, Kazuo

    2007-01-01

    The involvement of P-glycoprotein (P-gp) in buprenorphine (BNP) transport at the blood-brain barrier (BBB) in rats was investigated in vivo by means of both the brain uptake index technique and the brain efflux index technique. P-gp inhibitors, such as cyclosporin A, quinidine and verapamil, enhanced the apparent brain uptake of [3H]BNP by 1.5-fold. The increment of the BNP uptake by the brain suggests the involvement of a P-gp efflux mechanism of BNP transport at the BBB. [3H]BNP was eliminated with an apparent elimination half-life of 27.5 min after microinjection into the parietal cortex area 2 regions of the rat brain. The apparent efflux clearance of [3H]BNP across the BBB was 0.154 ml/min/g brain, which was calculated from the elimination rate constant (2.52 x 10- 2 min- 1) and the distribution volume in the brain (6.11 ml/g brain). The efflux transport of [3H]BNP was inhibited by range from 32 to 64% in the presence of P-gp inhibitors. The present results suggest that BNP is transported from the brain across the BBB via a P-gp-mediated efflux transport system, at least in part.

  3. Modeling HIV-1 Induced Neuroinflammation in Mice: Role of Platelets in Mediating Blood-Brain Barrier Dysfunction.

    Directory of Open Access Journals (Sweden)

    Letitia D Jones

    Full Text Available The number of HIV-1 positive individuals developing some form of HIV-associated neurocognitive disorder (HAND is increasing. In these individuals, the integrity of the blood-brain barrier (BBB is compromised due to an increase in exposure to pro-inflammatory mediators, viral proteins, and virus released from infected cells. It has been shown that soluble CD40L (sCD40L is released upon platelet activation and is an important mediator of the pathogenesis of HAND but the underlying mechanisms are unclear, emphasizing the need of an effective animal model. Here, we have utilized a novel animal model in which wild-type (WT mice were infected with EcoHIV; a derivative of HIV-1 that contains a substitution of envelope protein gp120 with that of gp80 derived from murine leukemia virus-1 (MuLV-1. As early as two-weeks post-infection, EcoHIV led to increased permeability of the BBB associated with decreased expression of tight junction protein claudin-5, in CD40L and platelet activation-dependent manner. Treatment with an antiplatelet drug, eptifibatide, in EcoHIV-infected mice normalized BBB function, sCD40L release and platelet activity, thus implicating platelet activation and platelet-derived CD40L in virally induced BBB dysfunction. Our results also validate and underscore the importance of EcoHIV infection mouse model as a tool to explore therapeutic targets for HAND.

  4. 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.

  5. Chronic exposure to nicotine and saquinavir decreases endothelial Notch-4 expression and disrupts blood-brain barrier integrity.

    Science.gov (United States)

    Manda, Vamshi K; Mittapalli, Rajendar K; Geldenhuys, Werner J; Lockman, Paul R

    2010-10-01

    Since the advent of HAART, there have been substantial improvements in HIV patient survival; however, the prevalence of HIV associated dementia has increased. Importantly, HIV positive individuals who smoke progress to HIV associated neurological conditions faster than those who do not. Recent in vitro data have shown that pharmacological levels of saquinavir causes endothelial oxidative stress and significantly decreases Notch-4 expression, a primary protein involved in maintaining stability of blood-brain barrier (BBB) endothelium. This is concerning as nicotine can also generate reactive oxygen species in endothelium. It is largely unknown if pharmacological doses of these drugs can cause a similar in vivo down-regulation of Notch-4 and if there is a concurrent destabilization of the integrity of the BBB. The data herein show: (i) nicotine and protease inhibitors cause an additive oxidative stress burden in endothelium; (ii) that the integrity of the BBB is disrupted after concurrent chronic nicotine and protease inhibitor administration; and (iii) that BBB endothelial dysfunction is correlated with a decrease in Notch-4 and ZO-1 expression. Considering the high prevalence of smoking in the HIV infected population (3- to 4-fold higher than in the general population) this data must be followed up to determine if all protease inhibitors cause a similar BBB disruption or if there is a safer alternative. In addition, this data may suggest that the induced BBB disruption may allow foreign molecules to gain access to brain and be a contributing factor to the slow progression of HIV associated dementia.

  6. Compromised Blood-Brain Barrier Competence in Remote Brain Areas in Ischemic Stroke Rats at Chronic Stage

    Science.gov (United States)

    Garbuzova-Davis, Svitlana; Haller, Edward; Williams, Stephanie N.; Haim, Eithan D.; Tajiri, Naoki; Hernandez-Ontiveros, Diana G.; Frisina-Deyo, Aric; Boffeli, Sean M.; Sanberg, Paul R.; Borlongan, Cesario V.

    2014-01-01

    Stroke is a life threatening disease leading to long-term disability in stroke survivors. Cerebral functional insufficiency in chronic stroke might be due to pathological changes in brain areas remote from initial ischemic lesion, i.e. diaschisis. Previously, we showed that the damaged blood-brain barrier (BBB) was implicated in subacute diaschisis. The present study investigated BBB competence in chronic diaschisis using a transient middle cerebral artery occlusion (tMCAO) rat model. Our results demonstrated significant BBB damage mostly in the ipsilateral striatum and motor cortex in rats at 30 days after tMCAO. The BBB alterations were also determined in the contralateral hemisphere via ultrastructural and immunohistochemical analyses. Major BBB pathological changes in contralateral remote striatum and motor cortex areas included: (1) vacuolated endothelial cells containing large autophagosomes, (2) degenerated pericytes displaying mitochondria with cristae disruption, (3) degenerated astrocytes and perivascular edema, (4) Evans Blue extravasation, and (5) appearance of parenchymal astrogliosis. Importantly, discrete analyses of striatal and motor cortex areas revealed significantly higher autophagosome accumulation in capillaries of ventral striatum and astrogliosis in dorsal striatum in both cerebral hemispheres. These widespread microvascular alterations in ipsilateral and contralateral brain hemispheres suggest persistent and/or continued BBB damage in chronic ischemia. The pathological changes in remote brain areas likely indicate chronic ischemic diaschisis, which should be considered in the development of treatment strategies for stroke. PMID:24610730

  7. Nanotech revolution for the anti-cancer drug delivery through blood-brain barrier.

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    Caraglia, M; De Rosa, G; Salzano, G; Santini, D; Lamberti, M; Sperlongano, P; Lombardi, A; Abbruzzese, A; Addeo, R

    2012-03-01

    Nanotechnology-based drug delivery was born as a chance for pharmaceutical weapons to be delivered in the body sites where drug action is required. Specifically, the incorporation of anti-cancer agents in nanodevices of 100-300 nm allows their delivery in tissues that have a fenestrated vasculature and a reduced lymphatic drainage. These two features are typical of neoplastic tissues and, therefore, allow the accumulation of nanostructured devices in tumours. An important issue of anti-cancer pharmacological strategies is the overcoming of anatomical barriers such as the bloodbrain- barrier (BBB) that protects brain from toxicological injuries but, at the same time, makes impossible for most of the pharmacological agents with anti-cancer activity to reach tumour cells placed in the brain and derived from either primary tumours or metastases. In fact, only highly lipophilic molecules can passively diffuse through BBB to reach central nervous system (CNS). Another possibility is to use nanotechnological approaches as powerful tools to across BBB, by both prolonging the plasma half-life of the drugs and crossing fenestrations of BBB damaged by brain metastases. Moreover, modifications of nanocarrier surface with specific endogenous or exogenous ligands can promote the crossing of intact BBB as in the case of primary brain tumours. This aim can be achieved through the binding of the nanodevices to carriers or receptors expressed by the endothelial cells of BBB and that can favour the internalization of the nanostructured devices delivering anti-cancer drugs. This review summarizes the most meaningful advances in the field of nanotechnologies for brain delivery of drugs.

  8. Evaluation of the Antidepressant Activity, Hepatotoxicity and Blood Brain Barrier Permeability of Methyl Genipin

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    Xin Che

    2016-07-01

    Full Text Available Geniposide (GE is the main bioactive component of Gardeniae Fructus. The hepatotoxicity of geniposide limited clinical application. In order to get a new geniposide derivative that has less hepatotoxicity and still possesses the antidepressant activity, a new C-1 hydroxyl methylation derivative named methyl genipin (MG was synthesized from geniposide. In the present study, we demonstrated that MG did not increase the liver index, alanine aminotransferase (ALT and aspirate aminotransferase (AST. Histopathological examination suggested that no toxic damages were observed in rats treated orally with MG (0.72 mmol/kg. More importantly, a 7-day treatment with MG at 0.13, 0.26, and 0.52 mmol/kg/day could reduce the duration of immobility. It showed that the antidepressant-like effects of MG were similar to GE in the tail suspension test and the forced swim test. Furthermore, we found MG could be detected in the brain homogenate of mice treated orally with MG 0.52 mmol/kg/day for 1 day by HPLC. The area under the curve (AUC of MG in the brain homogenate was enhanced to 21.7 times that of GE. The brain amount and distribution speed of MG were improved significantly after oral administration. This study demonstrated that MG possessed the antidepressant effects and could cross the blood–brain barrier, but had less hepatotoxicity.

  9. Volatile anesthetics influence blood-brain barrier integrity by modulation of tight junction protein expression in traumatic brain injury.

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    Serge C Thal

    Full Text Available Disruption of the blood-brain barrier (BBB results in cerebral edema formation, which is a major cause for high mortality after traumatic brain injury (TBI. As anesthetic care is mandatory in patients suffering from severe TBI it may be important to elucidate the effect of different anesthetics on cerebral edema formation. Tight junction proteins (TJ such as zonula occludens-1 (ZO-1 and claudin-5 (cl5 play a central role for BBB stability. First, the influence of the volatile anesthetics sevoflurane and isoflurane on in-vitro BBB integrity was investigated by quantification of the electrical resistance (TEER in murine brain endothelial monolayers and neurovascular co-cultures of the BBB. Secondly brain edema and TJ expression of ZO-1 and cl5 were measured in-vivo after exposure towards volatile anesthetics in native mice and after controlled cortical impact (CCI. In in-vitro endothelial monocultures, both anesthetics significantly reduced TEER within 24 hours after exposure. In BBB co-cultures mimicking the neurovascular unit (NVU volatile anesthetics had no impact on TEER. In healthy mice, anesthesia did not influence brain water content and TJ expression, while 24 hours after CCI brain water content increased significantly stronger with isoflurane compared to sevoflurane. In line with the brain edema data, ZO-1 expression was significantly higher in sevoflurane compared to isoflurane exposed CCI animals. Immunohistochemical analyses revealed disruption of ZO-1 at the cerebrovascular level, while cl5 was less affected in the pericontusional area. The study demonstrates that anesthetics influence brain edema formation after experimental TBI. This effect may be attributed to modulation of BBB permeability by differential TJ protein expression. Therefore, selection of anesthetics may influence the barrier function and introduce a strong bias in experimental research on pathophysiology of BBB dysfunction. Future research is required to investigate

  10. 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.

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

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    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

  12. Evaluation of sphingomyelin, cholester, and phosphatidylcholine-based immobilized artificial membrane liquid chromatography to predict drug penetration across the blood-brain barrier.

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    De Vrieze, Mike; Verzele, Dieter; Szucs, Roman; Sandra, Pat; Lynen, Frédéric

    2014-10-01

    Over the past decades, several in vitro methods have been tested for their ability to predict drug penetration across the blood-brain barrier. So far, in high-performance liquid chromatography, most attention has been paid to micellar liquid chromatography and immobilized artificial membrane (IAM) LC. IAMLC has been described as a viable approach, since the stationary phase emulates the lipid environment of a cell membrane. However, research in IAMLC has almost exclusively been limited to phosphatidylcholine (PC)-based stationary phases, even though PC is only one of the lipids present in cell membranes. In this article, sphingomyelin and cholester stationary phases have been tested for the first time towards their ability to predict drug penetration across the blood-brain barrier. Upon comparison with the PC stationary phase, the sphingomyelin- and cholester-based columns depict similar predictive performance. Combining data from the different stationary phases did not lead to improvements of the models.

  13. Large germinoma in basal ganglia treated by intraarterial chemotherapy with ACNU following osmotic blood-brain barrier disruption and radiation therapy

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    Miyagami, Mitsusuke; Tsubokawa, Takashi; Kobayashi, Makio.

    1988-10-01

    A rare case of large germinoma in the basal ganglia is reported which was effectively treated by intracarotid chemotherapy with ACNU following osmotic blood-brain barrier disruption using 20 % mannitol and radiation therapy. A 19-year-old man displayed slowly progressive right hemiparesis, motor aphasia and predementia on admission. Plain CT demonstrated a tumor which had a slightly high density with intratumoral calcification and a small cyst, and slight to moderate enhancement was observed following intravenous injection of contrast medium, but there was no unilateral ventricular enlargement. Cerebral angiography revealed hypervascular tumor staining with early draining veins. After biopsy, and as a result of intracarotid chemotherapy with ACNU following osmotic blood-brain barrier disruption and radiation therapy, the tumor decreased rapidly to about 20 % of its original mass. After discharge, tumor progression was observed. However, the enlarged tumor mass almost disappeared (except for calcification) on CT with clinical improvement in response to intracarotid chemotherapy with ACNU following 20 % mannitol.

  14. Peptide gH625 enters into neuron and astrocyte cell lines and crosses the blood-brain barrier in rats.

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    Valiante, Salvatore; Falanga, Annarita; Cigliano, Luisa; Iachetta, Giuseppina; Busiello, Rosa Anna; La Marca, Valeria; Galdiero, Massimiliano; Lombardi, Assunta; Galdiero, Stefania

    2015-01-01

    Peptide gH625, derived from glycoprotein H of herpes simplex virus type 1, can enter cells efficiently and deliver a cargo. Nanoparticles armed with gH625 are able to cross an in vitro model of the blood-brain barrier (BBB). In the present study, in vitro experiments were performed to investigate whether gH625 can enter and accumulate in neuron and astrocyte cell lines. The ability of gH625 to cross the BBB in vivo was also evaluated. gH625 was administered in vivo to rats and its presence in the liver and in the brain was detected. Within 3.5 hours of intravenous administration, gH625 can be found beyond the BBB in proximity to cell neurites. gH625 has no toxic effects in vivo, since it does not affect the maximal oxidative capacity of the brain or the mitochondrial respiration rate. Our data suggest that gH625, with its ability to cross the BBB, represents a novel nanocarrier system for drug delivery to the central nervous system. These results open up new possibilities for direct delivery of drugs into patients in the field of theranostics and might address the treatment of several human diseases.

  15. Impairment of blood brain barrier is related with the neuroinflammation induced peripheral immune status in intracerebroventricular colchicine injected rats: An experimental study with mannitol.

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    Sil, Susmita; Ghosh, Arijit; Ghosh, Tusharkanti

    2016-09-01

    The neurodegeneration in AD patients may be associated with changes of peripheral immune responses. Some peripheral immune responses are altered due to neuroinflammation in colchicine induced AD (cAD) rats. The leaky blood brain barrier (BBB) in cAD-rats may be involved in inducing peripheral inflammation, though there is no report in this regard. Therefore, the present study was designed to investigate the role of BBB in cADrats by altering the BBB in a time dependent manner with injection (i.v.) of mannitol (BBB opener). The inflammatory markers in the brain and serum along with the peripheral immune responses were measured after 30 and 60min of mannitol injection in cAD rats. The results showed higher inflammatory markers in the hippocampus and serum along with alterations in peripheral immune parameters in cAD rats. Although the hippocampal inflammatory markers did not further change after mannitol injection in cAD rats, the serum inflammatory markers and peripheral immune responses were altered and these changes were greater after 60min than that of 30min of mannitol injection. The present study shows that the peripheral immune responses in cAD rats after 30 and 60min of mannitol injection are related to magnitude of impairment of BBB in these conditions. It can be concluded from this study that impairment of BBB in cAD rats is related to the changes of peripheral immune responses observed in that condition.

  16. Human Brain Microvascular Endothelial Cells Derived from the BC1 iPS Cell Line Exhibit a Blood-Brain Barrier Phenotype

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    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...

  17. The effect of butylphthalide on the brain edema, blood-brain barrier of rats after focal cerebral infarction and the expression of Rho A.

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    Hu, Jinyang; Wen, Qingping; Wu, Yue; Li, Baozhu; Gao, Peng

    2014-06-01

    The aim of this study was to explore the effect of butylphthalide on the brain edema, blood-brain barrier of rats of rats after focal cerebral infarction and the expression of Rho A. A total of 195 sprague-dawley male rats were randomly divided into control group, model group, and butylphthalide group (40 mg/kg, once a day, by gavage). The model was made by photochemical method. After surgery 3, 12, 24, 72, and 144 h, brain water content was done to see the effect of butylphthalide for the cerebral edema. Evans blue extravasation method was done to see the changes in blood-brain barrier immunohistochemistry, and Western blot was done to see the expression of Rho A around the infarction. Compared with the control group, the brain water content of model group and butylphthalide group rats was increased, the permeability of blood-brain barrier of model group and butylphthalide group rats was increased, and the Rho A protein of model group and butylphthalide group rats was increased. Compared with the model group, the brain water content of butylphthalide group rats was induced (73.67 ± 0.67 vs 74.14 ± 0.46; 74.89 ± 0.57 vs 75.61 ± 0.52; 77.49 ± 0.34 vs 79.33 ± 0.49; 76.31 ± 0.56 vs 78.01 ± 0.48; 72.36 ± 0.44 vs 73.12 ± 0.73; P edema, protect the blood-brain barrier, and decrease the expression of Rho A around the infarction.

  18. Immune challenge by intraperitoneal administration of lipopolysaccharide directs gene expression in distinct blood-brain barrier cells toward enhanced prostaglandin E(2) signaling.

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    Vasilache, Ana Maria; Qian, Hong; Blomqvist, Anders

    2015-08-01

    The cells constituting the blood-brain barrier are critical for the transduction of peripheral immune signals to the brain, but hitherto no comprehensive analysis of the signaling events that occur in these cells in response to a peripheral inflammatory stimulus has been performed. Here, we examined the inflammatory transcriptome in blood-brain barrier cells, including endothelial cells, pericytes, and perivascular macrophages, which were isolated by fluorescent-activated cell sorting, from non-immune-challenged mice and from mice stimulated by bacterial wall lipopolysaccharide. We show that endothelial cells and perivascular macrophages display distinct transcription profiles for inflammatory signaling and respond in distinct and often opposing ways to the immune stimulus. Thus, endothelial cells show induced PGE2 synthesis and transport with attenuation of PGE2 catabolism, increased expression of cytokine receptors and down-stream signaling molecules, and downregulation of adhesion molecules. In contrast, perivascular macrophages show downregulation of the synthesis of prostanoids other than PGE2 and of prostaglandin catabolism, but upregulation of interleukin-6 synthesis. Pericytes were largely unresponsive to the immune stimulation, with the exception of downregulation of proteins involved in pericyte-endothelial cell communication. While the endothelial cells account for most of the immune-induced gene expression changes in the blood-brain barrier, the response of the endothelial cells occurs in a concerted manner with that of the perivascular cells to elevate intracerebral levels of PGE2, hence emphasizing the critical role of PGE2 in immune-induced signal transduction across the blood-brain barrier.

  19. Nutri-epigenetics ameliorates blood-brain barrier damage and neurodegeneration in hyperhomocysteinemia: role of folic acid.

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    Kalani, Anuradha; Kamat, Pradip K; Givvimani, Srikanth; Brown, Kasey; Metreveli, Naira; Tyagi, Suresh C; Tyagi, Neetu

    2014-02-01

    Epigenetic mechanisms underlying nutrition (nutrition epigenetics) are important in understanding human health. Nutritional supplements, for example folic acid, a cofactor in one-carbon metabolism, regulate epigenetic alterations and may play an important role in the maintenance of neuronal integrity. Folic acid also ameliorates hyperhomocysteinemia, which is a consequence of elevated levels of homocysteine. Hyperhomocysteinemia induces oxidative stress that may epigenetically mediate cerebrovascular remodeling and leads to neurodegeneration; however, the mechanisms behind such alterations remain unclear. Therefore, the present study was designed to observe the protective effects of folic acid against hyperhomocysteinemia-induced epigenetic and molecular alterations leading to neurotoxic cascades. To test this hypothesis, we employed 8-weeks-old male wild-type (WT) cystathionine-beta-synthase heterozygote knockout methionine-fed (CBS+/− + Met), WT, and CBS+/− + Met mice supplemented with folic acid (FA) [WT + FA and CBS+/− + Met + FA, respectively, 0.0057-μg g−1 day−1 dose in drinking water/4 weeks]. Hyperhomocysteinemia in CBS+/− + Met mouse brain was accompanied by a decrease in methylenetetrahydrofolate reductase and an increase in S-adenosylhomocysteine hydrolase expression, symptoms of oxidative stress, upregulation of DNA methyltransferases, rise in matrix metalloproteinases, a drop in the tissue inhibitors of metalloproteinases, decreased expression of tight junction proteins, increased permeability of the blood-brain barrier, neurodegeneration, and synaptotoxicity. Supplementation of folic acid to CBS+/− + Met mouse brain led to a decrease in the homocysteine level and rescued pathogenic and epigenetic alterations, showing its protective efficacy against homocysteine-induced neurotoxicity.

  20. Deficiency of tenascin-C and attenuation of blood-brain barrier disruption following experimental subarachnoid hemorrhage in mice.

    Science.gov (United States)

    Fujimoto, Masashi; Shiba, Masato; Kawakita, Fumihiro; Liu, Lei; Shimojo, Naoshi; Imanaka-Yoshida, Kyoko; Yoshida, Toshimichi; Suzuki, Hidenori

    2016-06-01

    OBJECT Tenascin-C (TNC), a matricellular protein, is induced in the brain following subarachnoid hemorrhage (SAH). The authors investigated if TNC causes brain edema and blood-brain barrier (BBB) disruption following experimental SAH. METHODS C57BL/6 wild-type (WT) or TNC knockout (TNKO) mice were subjected to SAH by endovascular puncture. Ninety-seven mice were randomly allocated to WT sham-operated (n = 16), TNKO sham-operated (n = 16), WT SAH (n = 34), and TNKO SAH (n = 31) groups. Mice were examined by means of neuroscore and brain water content 24-48 hours post-SAH; and Evans blue dye extravasation and Western blotting of TNC, matrix metalloproteinase (MMP)-9, and zona occludens (ZO)-1 at 24 hours post-SAH. As a separate study, 16 mice were randomized to WT sham-operated, TNKO sham-operated, WT SAH, and TNKO SAH groups (n = 4 in each group), and activation of mitogen-activated protein kinases (MAPKs) was immunohistochemically evaluated at 24 hours post-SAH. Moreover, 40 TNKO mice randomly received an intracerebroventricular injection of TNC or phosphate-buffered saline, and effects of exogenous TNC on brain edema and BBB disruption following SAH were studied. RESULTS Deficiency of endogenous TNC prevented neurological impairments, brain edema formation, and BBB disruption following SAH; it was also associated with the inhibition of both MMP-9 induction and ZO-1 degradation. Endogenous TNC deficiency also inhibited post-SAH MAPK activation in brain capillary endothelial cells. Exogenous TNC treatment abolished the neuroprotective effects shown in TNKO mice with SAH. CONCLUSIONS Tenascin-C may be an important mediator in the development of brain edema and BBB disruption following SAH, mechanisms for which may involve MAPK-mediated MMP-9 induction and ZO-1 degradation. TNC could be a molecular target against which to develop new therapies for SAH-induced brain injuries.

  1. C5a alters blood-brain barrier integrity in a human in vitro model of systemic lupus erythematosus.

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    Mahajan, Supriya D; Parikh, Neil U; Woodruff, Trent M; Jarvis, James N; Lopez, Molly; Hennon, Teresa; Cunningham, Patrick; Quigg, Richard J; Schwartz, Stanley A; Alexander, Jessy J

    2015-09-01

    The blood-brain barrier (BBB) plays a crucial role in brain homeostasis, thereby maintaining the brain environment precise for optimal neuronal function. Its dysfunction is an intriguing complication of systemic lupus erythematosus (SLE). SLE is a systemic autoimmune disorder where neurological complications occur in 5-50% of cases and is associated with impaired BBB integrity. Complement activation occurs in SLE and is an important part of the clinical profile. Our earlier studies demonstrated that C5a generated by complement activation caused the loss of brain endothelial layer integrity in rodents. The goal of the current study was to determine the translational potential of these studies to a human system. To assess this, we used a two dimensional in vitro BBB model constructed using primary human brain microvascular endothelial cells and astroglial cells, which closely emulates the in vivo BBB allowing the assessment of BBB integrity. Increased permeability monitored by changes in transendothelial electrical resistance and cytoskeletal remodelling caused by actin fiber rearrangement were observed when the cells were exposed to lupus serum and C5a, similar to the observations in mice. In addition, our data show that C5a/C5aR1 signalling alters nuclear factor-κB translocation into nucleus and regulates the expression of the tight junction proteins, claudin-5 and zonula occludens 1 in this setting. Our results demonstrate for the first time that C5a regulates BBB integrity in a neuroinflammatory setting where it affects both endothelial and astroglial cells. In addition, we also demonstrate that our previous findings in a mouse model, were emulated in human cells in vitro, bringing the studies one step closer to understanding the translational potential of C5a/C5aR1 blockade as a promising therapeutic strategy in SLE and other neurodegenerative diseases.

  2. 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.

  3. Assessing the Impact of Lithium Chloride on the Expression of P-Glycoprotein at the Blood-Brain Barrier.

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    Newman, Stephanie A; Pan, Yijun; Short, Jennifer L; Nicolazzo, Joseph A

    2017-01-16

    In addition to extruding drugs from the brain, P-glycoprotein (P-gp) at the blood-brain barrier (BBB) facilitates the brain-to-blood clearance of beta-amyloid (Aβ) and is down-regulated in Alzheimer's disease. Studies suggest that the mood-stabilizing drug lithium exerts a protective effect against Alzheimer's disease. Although the mechanisms underlying this effect are not fully understood, evidence suggests that lithium chloride (LiCl) increases P-gp expression in vitro, albeit at concentrations substantially outside the therapeutic window. Therefore, we investigated the effects of pharmacologically-relevant concentrations of LiCl on P-gp expression using in vitro and in vivo approaches. Swiss outbred mice administered LiCl (300 mg/kg/day, 21 days) showed no change in brain microvascular P-gp protein expression. Furthermore, P-gp transcript and protein levels were unaltered by LiCl (1.25-5 mM, 24 h) in human immortalized brain endothelial cells, while both gene and protein expression were significantly enhanced by the P-gp up-regulator, SR12813 by 1.5-fold and 2.0-fold, respectively. P-gp efflux function was also unaffected by LiCl in vitro, by measuring accumulation of the fluorescent P-gp substrate rhodamine-123. This suggests therefore that LiCl is unlikely to affect the BBB efflux of Aβ or other P-gp substrates at pharmacologically-relevant concentrations, suggesting that the Aβ-lowering effects of LiCl are unrelated to elevated BBB P-gp expression.

  4. Ceramide 1-Phosphate Increases P-Glycoprotein Transport Activity at the Blood-Brain Barrier via Prostaglandin E2 Signaling.

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    Mesev, Emily V; Miller, David S; Cannon, Ronald E

    2017-04-01

    P-glycoprotein, an ATP-driven efflux pump, regulates permeability of the blood-brain barrier (BBB). Sphingolipids, endogenous to brain tissue, influence inflammatory responses and cell survival in vitro. Our laboratory has previously shown that sphingolipid signaling by sphingosine 1-phosphate decreases basal P-glycoprotein transport activity. Here, we investigated the potential for another sphingolipid, ceramide 1-phosphate (C1P), to modulate efflux pumps at the BBB. Using confocal microscopy and measuring luminal accumulation of fluorescent substrates, we assessed the transport activity of several efflux pumps in isolated rat brain capillaries. C1P treatment induced P-glycoprotein transport activity in brain capillaries rapidly and reversibly. In contrast, C1P did not affect transport activity of two other major efflux transporters, multidrug resistance protein 2 and breast cancer resistance protein. C1P induced P-glycoprotein transport activity without changing transporter protein expression. Inhibition of the key signaling components in the cyclooxygenase-2 (COX-2)/prostaglandin E2 signaling cascade (phospholipase A2, COX-2, multidrug resistance protein 4, and G-protein-coupled prostaglandin E2 receptors 1 and 2), abolished P-glycoprotein induction by C1P. We show that COX-2 and prostaglandin E2 are required for C1P-mediated increases in P-glycoprotein activity independent of transporter protein expression. This work describes how C1P activates a signaling cascade to dynamically regulate P-glycoprotein transport at the BBB and offers potential clinical targets to modulate neuroprotection and drug delivery to the CNS.

  5. Behavioral and neuropharmacological evidence that serotonin crosses the blood-brain barrier in Coturnix japonica (Galliformes; Aves

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    PA. Polo

    Full Text Available This study was carried out aiming to reach behavioral and neuropharmacological evidence of the permeability of the blood-brain barrier (BBB to serotonin systemically administered in quails. Serotonin injected by a parenteral route (250-1000 µg.kg-1, sc elicited a sequence of behavioral events concerned with a sleeping-like state. Sleeping-like behaviors began with feather bristling, rapid oral movements, blinking and finally crouching and closure of the eyes. Previous administration of 5-HT2C antagonist, LY53857 (3 mg.kg-1, sc reduced the episodes of feather bristling and rapid oral movements significantly but without altering the frequency of blinking and closure of the eyes. Treatment with the 5-HT2A/2C antagonist, ketanserin (3 mg.kg-1, sc did not affect any of the responses evoked by the serotonin. Quipazine (5 mg.kg-1, sc a 5-HT2A/2C/3 agonist induced intense hypomotility, long periods of yawning-like and sleeping-like states. Previous ketanserin suppressed gaping responses and reduced hypomotility, rapid oral movements and bristling but was ineffective for remaining responses induced by quipazine. Results showed that unlike mammals, serotonin permeates the BBB and activates hypnogenic mechanisms in quails. Studies using serotoninergic agonist and antagonists have disclosed that among the actions of the serotonin, feather bristling, rapid oral movements and yawning-like state originated from activation of 5-HT2 receptors while blinking and closure of the eyes possibly require other subtypes of receptors.

  6. Excess soluble CD40L contributes to blood brain barrier permeability in vivo: implications for HIV-associated neurocognitive disorders.

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    Donna C Davidson

    Full Text Available Despite the use of anti-retroviral therapies, a majority of HIV-infected individuals still develop HIV-Associated Neurocognitive Disorders (HAND, indicating that host inflammatory mediators, in addition to viral proteins, may be contributing to these disorders. Consistently, we have previously shown that levels of the inflammatory mediator soluble CD40L (sCD40L are elevated in the circulation of HIV-infected, cognitively impaired individuals as compared to their infected, non-impaired counterparts. Recent studies from our group suggest a role for the CD40/CD40L dyad in blood brain barrier (BBB permeability and interestingly, sCD40L is thought to regulate BBB permeability in other inflammatory disorders of the CNS. Using complementary multiphoton microscopy and quantitative analyses in wild-type and CD40L deficient mice, we now reveal that the HIV transactivator of transcription (Tat can induce BBB permeability in a CD40L-dependent manner. This permeability of the BBB was found to be the result of aberrant platelet activation induced by Tat, since depletion of platelets prior to treatment reversed Tat-induced BBB permeability. Furthermore, Tat treatment led to an increase in granulocyte antigen 1 (Gr1 positive monocytes, indicating an expansion of the inflammatory subset of cells in these mice, which were found to adhere more readily to the brain microvasculature in Tat treated animals. Exploring the mechanisms by which the BBB becomes compromised during HIV infection has the potential to reveal novel therapeutic targets, thereby aiding in the development of adjunct therapies for the management of HAND, which are currently lacking.

  7. Excess soluble CD40L contributes to blood brain barrier permeability in vivo: implications for HIV-associated neurocognitive disorders.

    Science.gov (United States)

    Davidson, Donna C; Hirschman, Michael P; Sun, Anita; Singh, Meera V; Kasischke, Karl; Maggirwar, Sanjay B

    2012-01-01

    Despite the use of anti-retroviral therapies, a majority of HIV-infected individuals still develop HIV-Associated Neurocognitive Disorders (HAND), indicating that host inflammatory mediators, in addition to viral proteins, may be contributing to these disorders. Consistently, we have previously shown that levels of the inflammatory mediator soluble CD40L (sCD40L) are elevated in the circulation of HIV-infected, cognitively impaired individuals as compared to their infected, non-impaired counterparts. Recent studies from our group suggest a role for the CD40/CD40L dyad in blood brain barrier (BBB) permeability and interestingly, sCD40L is thought to regulate BBB permeability in other inflammatory disorders of the CNS. Using complementary multiphoton microscopy and quantitative analyses in wild-type and CD40L deficient mice, we now reveal that the HIV transactivator of transcription (Tat) can induce BBB permeability in a CD40L-dependent manner. This permeability of the BBB was found to be the result of aberrant platelet activation induced by Tat, since depletion of platelets prior to treatment reversed Tat-induced BBB permeability. Furthermore, Tat treatment led to an increase in granulocyte antigen 1 (Gr1) positive monocytes, indicating an expansion of the inflammatory subset of cells in these mice, which were found to adhere more readily to the brain microvasculature in Tat treated animals. Exploring the mechanisms by which the BBB becomes compromised during HIV infection has the potential to reveal novel therapeutic targets, thereby aiding in the development of adjunct therapies for the management of HAND, which are currently lacking.

  8. The protective effect of HET0016 on brain edema and blood-brain barrier dysfunction after cerebral ischemia/reperfusion.

    Science.gov (United States)

    Liu, Yu; Wang, Di; Wang, Huan; Qu, Youyang; Xiao, Xingjun; Zhu, Yulan

    2014-01-28

    N-hydroxy-N-(4-butyl-2-methylphenyl) formamidine (HET0016) is a specific 20-hydroxyeicosatetraenoic acid (20-HETE) inhibitor which was first synthesized in 2001. It has been demonstrated that HET0016 reduces cerebral infarction volume in rat middle cerebral artery occlusion (MCAO) models. However, little is known about the role of HET0016 in the blood-brain barrier (BBB) dysfunction after cerebral ischemia/reperfusion (I/R) injury. The present study was designed to examine the effect of HET0016 in a MCAO and reperfusion rat model to determine whether it protects against brain edema and BBB disruption. Rats were subjected to 90 min MCAO, followed by 4, 24, 48, and 72 h reperfusion. Brain edema was measured according to the wet and dry weight method. BBB permeability based on the extravasation of Evans blue and sodium fluorescein was detected. BBB ultrastructure alterations were presented through transmission electron microscope. Superoxide production in ischemic tissue was also measured by dihydroethidium fluorescent probe. Western blot was used to analyze the expression of Claudin-5, ZO-1, MMP-9, and JNK pathway. At 24h after reperfusion, HET0016 reduced brain edema and BBB leakage. Ultrastructural damage of BBB and the increase of superoxide production were attenuated by HET0016 treatment. Western blot showed that HET0016 suppressed the activation of MMP-9 and JNK pathway but restored the expression of Claudin-5 and ZO-1. In conclusion, these results suggest that HET0016 protects BBB dysfunction after I/R by regulating the expression of MMP-9 and tight junction proteins. Furthermore, inhibition of oxidative stress and JNK pathway may be involved in this protecting effect.

  9. Transcriptional profiling of human brain endothelial cells reveals key properties crucial for predictive in vitro blood-brain barrier models.

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    Eduard Urich

    Full Text Available Brain microvascular endothelial cells (BEC constitute the blood-brain barrier (BBB which forms a dynamic interface between the blood and the central nervous system (CNS. This highly specialized interface restricts paracellular diffusion of fluids and solutes including chemicals, toxins and drugs from entering the brain. In this study we compared the transcriptome profiles of the human immortalized brain endothelial cell line hCMEC/D3 and human primary BEC. We identified transcriptional differences in immune response genes which are directly related to the immortalization procedure of the hCMEC/D3 cells. Interestingly, astrocytic co-culturing reduced cell adhesion and migration molecules in both BECs, which possibly could be related to regulation of immune surveillance of the CNS controlled by astrocytic cells within the neurovascular unit. By matching the transcriptome data from these two cell lines with published transcriptional data from freshly isolated mouse BECs, we discovered striking differences that could explain some of the limitations of using cultured BECs to study BBB properties. Key protein classes such as tight junction proteins, transporters and cell surface receptors show differing expression profiles. For example, the claudin-5, occludin and JAM2 expression is dramatically reduced in the two human BEC lines, which likely explains their low transcellular electric resistance and paracellular leakiness. In addition, the human BEC lines express low levels of unique brain endothelial transporters such as Glut1 and Pgp. Cell surface receptors such as LRP1, RAGE and the insulin receptor that are involved in receptor-mediated transport are also expressed at very low levels. Taken together, these data illustrate that BECs lose their unique protein expression pattern outside of their native environment and display a more generic endothelial cell phenotype. A collection of key genes that seems to be highly regulated by the local

  10. Early outcome and blood-brain barrier integrity after co-administered thrombolysis and hyperbaric oxygenation in experimental stroke

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    Michalski Dominik

    2011-06-01

    Full Text Available Abstract Background After promising results in experimental stroke, normobaric (NBO or hyperbaric oxygenation (HBO have recently been discussed as co-medication with tissue plasminogen activator (tPA for improving outcome. This study assessed the interactions of hyperoxia and tPA, focusing on survival, early functional outcome and blood-brain barrier (BBB integrity following experimental stroke. Methods Rats (n = 109 underwent embolic middle cerebral artery occlusion or sham surgery. Animals were assigned to: Control, NBO (60-minute pure oxygen, HBO (60-minute pure oxygen at 2.4 absolute atmospheres, tPA, or HBO+tPA. Functional impairment was assessed at 4 and 24 hours using Menzies score, followed by intravenous application of FITC-albumin as a BBB permeability marker, which was allowed to circulate for 1 hour. Further, blood sampling was performed at 5 and 25 hours for MMP-2, MMP-9, TIMP-1 and TIMP-2 concentration. Results Mortality rates did not differ significantly between groups, whereas functional improvement was found for NBO, tPA and HBO+tPA. NBO and HBO tended to stabilize BBB and to reduce MMP-2. tPA tended to increase BBB permeability with corresponding MMP and TIMP elevation. Co-administered HBO failed to attenuate these early deleterious effects, independent of functional improvement. Conclusions The long-term consequences of simultaneously applied tPA and both NBO and HBO need to be addressed by further studies to identify therapeutic potencies in acute stroke, and to avoid unfavorable courses following combined treatment.

  11. Permeabilization of the blood-brain barrier via mucosal engrafting: implications for drug delivery to the brain.

    Directory of Open Access Journals (Sweden)

    Benjamin S Bleier

    Full Text Available Utilization of neuropharmaceuticals for central nervous system(CNS disease is highly limited due to the blood-brain barrier(BBB which restricts molecules larger than 500Da from reaching the CNS. The development of a reliable method to bypass the BBB would represent an enormous advance in neuropharmacology enabling the use of many potential disease modifying therapies. Previous attempts such as transcranial catheter implantation have proven to be temporary and associated with multiple complications. Here we describe a novel method of creating a semipermeable window in the BBB using purely autologous tissues to allow for high molecular weight(HMW drug delivery to the CNS. This approach is inspired by recent advances in human endoscopic transnasal skull base surgical techniques and involves engrafting semipermeable nasal mucosa within a surgical defect in the BBB. The mucosal graft thereby creates a permanent transmucosal conduit for drugs to access the CNS. The main objective of this study was to develop a murine model of this technique and use it to evaluate transmucosal permeability for the purpose of direct drug delivery to the brain. Using this model we demonstrate that mucosal grafts allow for the transport of molecules up to 500 kDa directly to the brain in both a time and molecular weight dependent fashion. Markers up to 40 kDa were found within the striatum suggesting a potential role for this technique in the treatment of Parkinson's disease. This proof of principle study demonstrates that mucosal engrafting represents the first permanent and stable method of bypassing the BBB thereby providing a pathway for HMW therapeutics directly into the CNS.

  12. Monoclonal antibody-glial-derived neurotrophic factor fusion protein penetrates the blood-brain barrier in the mouse.

    Science.gov (United States)

    Zhou, Qing-Hui; Boado, Ruben J; Lu, Jeff Zhiqiang; Hui, Eric Ka-Wai; Pardridge, William M

    2010-04-01

    Glial-derived neurotrophic factor (GDNF) is a potent neuroprotective agent for multiple brain disorders, including Parkinson's disease. However, GDNF drug development is difficult because GDNF does not cross the blood-brain barrier (BBB). To enable future drug development of GDNF in mouse models, the neurotrophin was re-engineered as an IgG fusion protein to enable penetration through the BBB after intravenous administration. The 134-amino acid GDNF was fused to the heavy chain of a chimeric monoclonal antibody (MAb) against the mouse transferrin receptor (TfR) designated the cTfRMAb. This antibody undergoes receptor-mediated transport across the BBB and acts as a molecular Trojan horse to ferry the GDNF into mouse brain. The cTfRMAb-GDNF fusion protein was expressed by stably transfected Chinese hamster ovary cells, affinity-purified, and the biochemical identity was confirmed by mouse IgG and GDNF Western blotting. The cTfRMAb-GDNF fusion protein was bifunctional and bound with high affinity to both the GDNF receptor alpha1, ED(50) = 1.7 +/- 0.2 nM, and the mouse TfR, ED(50) = 3.2 +/- 0.3 nM. The cTfRMAb-GDNF fusion protein was rapidly taken up by brain, and the brain uptake was 3.1 +/- 0.2% injected dose/g brain at 60 min after intravenous injection of a 1-mg/kg dose of the fusion protein. Brain capillary depletion analysis showed the majority of the fusion protein was transcytosed across the BBB with penetration into brain parenchyma. The brain uptake results indicate it is possible to achieve therapeutic elevations of GDNF in mouse brain with intravenous administration of the cTfRMAb-GDNF fusion protein.

  13. 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 Zubeita, Daniela M; Kondapalli, Kalyan C

    2017-01-27

    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 upregulated very early in a physiological response invoked by paracrine signals from iron-starved astrocytes. Ectopic expression of NHE9 in hBMVECs without external cues induced upregulation of the transferrin receptor (TfR) and downregulation 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 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.

  14. Permeabilization of the blood-brain barrier via mucosal engrafting: implications for drug delivery to the brain.

    Science.gov (United States)

    Bleier, Benjamin S; Kohman, Richie E; Feldman, Rachel E; Ramanlal, Shreshtha; Han, Xue

    2013-01-01

    Utilization of neuropharmaceuticals for central nervous system(CNS) disease is highly limited due to the blood-brain barrier(BBB) which restricts molecules larger than 500Da from reaching the CNS. The development of a reliable method to bypass the BBB would represent an enormous advance in neuropharmacology enabling the use of many potential disease modifying therapies. Previous attempts such as transcranial catheter implantation have proven to be temporary and associated with multiple complications. Here we describe a novel method of creating a semipermeable window in the BBB using purely autologous tissues to allow for high molecular weight(HMW) drug delivery to the CNS. This approach is inspired by recent advances in human endoscopic transnasal skull base surgical techniques and involves engrafting semipermeable nasal mucosa within a surgical defect in the BBB. The mucosal graft thereby creates a permanent transmucosal conduit for drugs to access the CNS. The main objective of this study was to develop a murine model of this technique and use it to evaluate transmucosal permeability for the purpose of direct drug delivery to the brain. Using this model we demonstrate that mucosal grafts allow for the transport of molecules up to 500 kDa directly to the brain in both a time and molecular weight dependent fashion. Markers up to 40 kDa were found within the striatum suggesting a potential role for this technique in the treatment of Parkinson's disease. This proof of principle study demonstrates that mucosal engrafting represents the first permanent and stable method of bypassing the BBB thereby providing a pathway for HMW therapeutics directly into the CNS.

  15. 7.0-T magnetic resonance imaging characterization of acute blood-brain-barrier disruption achieved with intracranial irreversible electroporation.

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    Paulo A Garcia

    Full Text Available The blood-brain-barrier (BBB presents a significant obstacle to the delivery of systemically administered chemotherapeutics for the treatment of brain cancer. Irreversible electroporation (IRE is an emerging technology that uses pulsed electric fields for the non-thermal ablation of tumors. We hypothesized that there is a minimal electric field at which BBB disruption occurs surrounding an IRE-induced zone of ablation and that this transient response can be measured using gadolinium (Gd uptake as a surrogate marker for BBB disruption. The study was performed in a Good Laboratory Practices (GLP compliant facility and had Institutional Animal Care and Use Committee (IACUC approval. IRE ablations were performed in vivo in normal rat brain (n = 21 with 1-mm electrodes (0.45 mm diameter separated by an edge-to-edge distance of 4 mm. We used an ECM830 pulse generator to deliver ninety 50-μs pulse treatments (0, 200, 400, 600, 800, and 1000 V/cm at 1 Hz. The effects of applied electric fields and timing of Gd administration (-5, +5, +15, and +30 min was assessed by systematically characterizing IRE-induced regions of cell death and BBB disruption with 7.0-T magnetic resonance imaging (MRI and histopathologic evaluations. Statistical analysis on the effect of applied electric field and Gd timing was conducted via Fit of Least Squares with α = 0.05 and linear regression analysis. The focal nature of IRE treatment was confirmed with 3D MRI reconstructions with linear correlations between volume of ablation and electric field. Our results also demonstrated that IRE is an ablation technique that kills brain tissue in a focal manner depicted by MRI (n = 16 and transiently disrupts the BBB adjacent to the ablated area in a voltage-dependent manner as seen with Evan's Blue (n = 5 and Gd administration.

  16. 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.

  17. Lycium barbarum extracts protect the brain from blood-brain barrier disruption and cerebral edema in experimental stroke.

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    Di Yang

    Full Text Available BACKGROUND AND PURPOSE: Ischemic stroke is a destructive cerebrovascular disease and a leading cause of death. Yet, no ideal neuroprotective agents are available, leaving prevention an attractive alternative. The extracts from the fruits of Lycium barbarum (LBP, a Chinese anti-aging medicine and food supplement, showed neuroprotective function in the retina when given prophylactically. We aim to evaluate the protective effects of LBP pre-treatment in an experimental stroke model. METHODS: C57BL/6N male mice were first fed with either vehicle (PBS or LBP (1 or 10 mg/kg daily for 7 days. Mice were then subjected to 2-hour transient middle cerebral artery occlusion (MCAO by the intraluminal method followed by 22-hour reperfusion upon filament removal. Mice were evaluated for neurological deficits just before sacrifice. Brains were harvested for infarct size estimation, water content measurement, immunohistochemical analysis, and Western blot experiments. Evans blue (EB extravasation was determined to assess blood-brain barrier (BBB disruption after MCAO. RESULTS: LBP pre-treatment significantly improved neurological deficits as well as decreased infarct size, hemispheric swelling, and water content. Fewer apoptotic cells were identified in LBP-treated brains by TUNEL assay. Reduced EB extravasation, fewer IgG-leaky vessels, and up-regulation of occludin expression were also observed in LBP-treated brains. Moreover, immunoreactivity for aquaporin-4 and glial fibrillary acidic protein were significantly decreased in LBP-treated brains. CONCLUSIONS: Seven-day oral LBP pre-treatment effectively improved neurological deficits, decreased infarct size and cerebral edema as well as protected the brain from BBB disruption, aquaporin-4 up-regulation, and glial activation. The present study suggests that LBP may be used as a prophylactic neuroprotectant in patients at high risk for ischemic stroke.

  18. Role of nitric oxide synthases in early blood-brain barrier disruption following transient focal cerebral ischemia.

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    Zheng Jiang

    Full Text Available The role of nitric oxide synthases (NOSs in early blood-brain barrier (BBB disruption was determined using a new mouse model of transient focal cerebral ischemia. Ischemia was induced by ligating the middle cerebral artery (MCA at its M2 segment and reperfusion was induced by releasing the ligation. The diameter alteration of the MCA, arterial anastomoses and collateral arteries were imaged and measured in real time. BBB disruption was assessed by Evans Blue (EB and sodium fluorescein (Na-F extravasation at 3 hours of reperfusion. The reperfusion produced an extensive vasodilation and a sustained hyperemia. Although expression of NOSs was not altered at 3 hours of reperfusion, L-NAME (a non-specific NOS inhibitor abolished reperfusion-induced vasodilation/hyperemia and significantly reduced EB and Na-F extravasation. L-NIO (an endothelial NOS (eNOS inhibitor significantly attenuated cerebral vasodilation but not BBB disruption, whereas L-NPA and 7-NI (neuronal NOS (nNOS inhibitors significantly reduced BBB disruption but not cerebral vasodilation. In contrast, aminoguanidine (AG (an inducible NOS (iNOS inhibitor had less effect on either cerebral vasodilation or BBB disruption. On the other hand, papaverine (PV not only increased the vasodilation/hyperemia but also significantly reduced BBB disruption. Combined treatment with L-NAME and PV preserved the vasodilation/hyperemia and significantly reduced BBB disruption. Our findings suggest that nNOS may play a major role in early BBB disruption following transient focal cerebral ischemia via a hyperemia-independent mechanism.

  19. Methylmercury Causes Blood-Brain Barrier Damage in Rats via Upregulation of Vascular Endothelial Growth Factor Expression

    Science.gov (United States)

    Takahashi, Tetsuya; Fujimura, Masatake; Koyama, Misaki; Kanazawa, Masato; Usuki, Fusako; Nishizawa, Masatoyo; Shimohata, Takayoshi

    2017-01-01

    Clinical manifestations of methylmercury (MeHg) intoxication include cerebellar ataxia, concentric constriction of visual fields, and sensory and auditory disturbances. The symptoms depend on the site of MeHg damage, such as the cerebellum and occipital lobes. However, the underlying mechanism of MeHg-induced tissue vulnerability remains to be elucidated. In the present study, we used a rat model of subacute MeHg intoxication to investigate possible MeHg-induced blood-brain barrier (BBB) damage. The model was established by exposing the rats to 20-ppm MeHg for up to 4 weeks; the rats exhibited severe cerebellar pathological changes, although there were no significant differences in mercury content among the different brain regions. BBB damage in the cerebellum after MeHg exposure was confirmed based on extravasation of endogenous immunoglobulin G (IgG) and decreased expression of rat endothelial cell antigen-1. Furthermore, expression of vascular endothelial growth factor (VEGF), a potent angiogenic growth factor, increased markedly in the cerebellum and mildly in the occipital lobe following MeHg exposure. VEGF expression was detected mainly in astrocytes of the BBB. Intravenous administration of anti-VEGF neutralizing antibody mildly reduced the rate of hind-limb crossing signs observed in MeHg-exposed rats. In conclusion, we demonstrated for the first time that MeHg induces BBB damage via upregulation of VEGF expression at the BBB in vivo. Further studies are required in order to determine whether treatment targeted at VEGF can ameliorate MeHg-induced toxicity. PMID:28118383

  20. Partial least square and hierarchical clustering in ADMET modeling: prediction of blood-brain barrier permeation of α-adrenergic and imidazoline receptor ligands.

    Science.gov (United States)

    Nikolic, Katarina; Filipic, Slavica; Smoliński, Adam; Kaliszan, Roman; Agbaba, Danica

    2013-01-01

    PURPOSE. Rate of brain penetration (logPS), brain/plasma equilibration rate (logPS-brain), and extent of blood-brain barrier permeation (logBB) of 29 α-adrenergic and imidazoline-receptors ligands were examined in Quantitative-Structure-Property Relationship (QSPR) study. METHODS. Experimentally determined chromatographic retention data (logKw at pH 4.4, slope (S) at pH 4.4, logKw at pH 7.4, slope (S) at pH 7.4, logKw at pH 9.1, and slope (S) at pH 9.1) and capillary electrophoresis migration parameters (μeff at pH 4.4, μeff at pH 7.4, and μeff at pH 9.1), together with calculated molecular descriptors, were used as independent variables in the QSPR study by use of partial least square (PLS) methodology. RESULTS. Predictive potential of the formed QSPR models, QSPR(logPS), QSPR(logPS-brain), QSPR(logBB), was confirmed by cross- and external validation. Hydrophilicity (Hy) and H-indices (H7m) were selected as significant parameters negatively correlated with both logPS and logPS-brain, while topological polar surface area (TPSA(NO)) was chosen as molecular descriptor negatively correlated with both logPS and logBB. The principal component analysis (PCA) and hierarchical clustering analysis (HCA) were applied to cluster examined drugs based on their chromatographic, electrophoretic and molecular properties. Significant positive correlations were obtained between the slope (S) at pH 7.4 and logBB in A/B cluster and between the logKw at pH 9.1 and logPS in C/D cluster. CONCLUSIONS. Results of the QSPR, clustering and correlation studies could be used as novel tool for evaluation of blood-brain barrier permeation of related α-adrenergic/imidazoline receptor ligands.This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.PURPOSE. Rate of brain penetration (logPS), brain/plasma equilibration rate (logPS-brain), and extent of blood-brain barrier permeation (logBB) of 29

  1. 聚焦超声开放血脑屏障联合用药治疗脑胶质瘤的实验研究%Opening of the blood-brain barrier through focused ultrasound in combination of drugs to treat glioma

    Institute of Scientific and Technical Information of China (English)

    潘敏; 张天奉; 邹超; 万倩; 刘新; 郑海荣

    2014-01-01

    声开放脑胶质瘤大鼠血脑屏障(blood brain barrier ,BBB),通过比较单药与联合给药对荷瘤鼠生存期及肿瘤大小的影响,评估联合用药对治疗脑胶质瘤的有效性。方法使用脑立体定位仪和微量注射泵,将C6细胞株注入40只雄性SD大鼠颅内特定区域,建立荷C6细胞株大鼠脑胶质瘤活体模型。将荷瘤大鼠随机分为4组:对照组、Avastin组、阿霉素脂质体(liposomal doxorubicin ,DOX)组、DOX+Avastin组。于瘤细胞种植后第12 d从大鼠尾静脉分别注入SonoVue超声微泡、DOX和Avastin后,采用聚焦超声开放特定区域BBB ,于治疗后即刻、每隔1周行M RI扫描,测量各组胶质瘤大小,记录各组荷瘤鼠生存期。结果各组平均生存期分别为:对照组(17±4)d ,Avastin组(20±4)d ,DOX组(25±5)d ,DOX+ Avastin组(40±5)d。各组治疗后肿瘤大小分别为:对照组(57.0±43.0)mm ,Avastin组(43.0±25.0)mm ,DOX 组(41.2±31.0)mm ,DOX+ Avastin组(22.0±13.0)mm。DOX+Avastin组平均生存期和治疗后肿瘤大小与其他组相比差异具有统计学意义( P <0.01)。结论M RI引导下聚焦超声开放荷脑胶质瘤大鼠BBB ,微泡爆破增加局部组织通透性,促进大分子化疗药和抗肿瘤新生血管药局部释放,二药合用有协同增强效应,可明显延缓脑胶质瘤生长速度,延长荷瘤鼠生存期。

  2. Vitamin D prevents hypoxia/reoxygenation-induced blood-brain barrier disruption via vitamin D receptor-mediated NF-kB signaling pathways.

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    Soonmi Won

    Full Text Available Maintaining blood-brain barrier integrity and minimizing neuronal injury are critical components of any therapeutic intervention following ischemic stroke. However, a low level of vitamin D hormone is a risk factor for many vascular diseases including stroke. The neuroprotective effects of 1,25(OH2D3 (vitamin D after ischemic stroke have been studied, but it is not known whether it prevents ischemic injury to brain endothelial cells, a key component of the neurovascular unit. We analyzed the effect of 1,25(OH2D3 on brain endothelial cell barrier integrity and tight junction proteins after hypoxia/reoxygenation in a mouse brain endothelial cell culture model that closely mimics many of the features of the blood-brain barrier in vitro. Following hypoxic injury in bEnd.3 cells, 1,25(OH2D3 treatment prevented the decrease in barrier function as measured by transendothelial electrical resistance and permeability of FITC-dextran (40 kDa, the decrease in the expression of the tight junction proteins zonula occludin-1, claudin-5, and occludin, the activation of NF-kB, and the increase in matrix metalloproteinase-9 expression. These responses were blocked when the interaction of 1,25(OH 2D3 with the vitamin D receptor (VDR was inhibited by pyridoxal 5'-phosphate treatment. Our findings show a direct, VDR-mediated, protective effect of 1,25(OH 2D3 against ischemic injury-induced blood-brain barrier dysfunction in cerebral endothelial cells.

  3. Anesthesia-Induced Hypothermia Attenuates Early-Phase Blood-Brain Barrier Disruption but Not Infarct Volume following Cerebral Ischemia.

    Science.gov (United States)

    Liu, Yu-Cheng; Lee, Yu-Da; Wang, Hwai-Lee; Liao, Kate Hsiurong; Chen, Kuen-Bao; Poon, Kin-Shing; Pan, Yu-Ling; Lai, Ted Weita

    2017-01-01

    Blood-brain barrier (BBB) disruption is thought to facilitate the development of cerebral infarction after a stroke. In a typical stroke model (such as the one used in this study), the early phase of BBB disruption reaches a peak 6 h post-ischemia and largely recovers after 8-24 h, whereas the late phase of BBB disruption begins 48-58 h post-ischemia. Because cerebral infarct develops within 24 h after the onset of ischemia, and several therapeutic agents have been shown to reduce the infarct volume when administered at 6 h post-ischemia, we hypothesized that attenuating BBB disruption at its peak (6 h post-ischemia) can also decrease the infarct volume measured at 24 h. We used a mouse stroke model obtained by combining 120 min of distal middle cerebral arterial occlusion (dMCAo) with ipsilateral common carotid arterial occlusion (CCAo). This model produced the most reliable BBB disruption and cerebral infarction compared to other models characterized by a shorter duration of ischemia or obtained with dMCAO or CCAo alone. The BBB permeability was measured by quantifying Evans blue dye (EBD) extravasation, as this tracer has been shown to be more sensitive for the detection of early-phase BBB disruption compared to other intravascular tracers that are more appropriate for detecting late-phase BBB disruption. We showed that a 1 h-long treatment with isoflurane-anesthesia induced marked hypothermia and attenuated the peak of BBB disruption when administered 6 h after the onset of dMCAo/CCAo-induced ischemia. We also demonstrated that the inhibitory effect of isoflurane was hypothermia-dependent because the same treatment had no effect on ischemic BBB disruption when the mouse body temperature was maintained at 37°C. Importantly, inhibiting the peak of BBB disruption by hypothermia had no effect on the volume of brain infarct 24 h post-ischemia. In conclusion, inhibiting the peak of BBB disruption is not an effective neuroprotective strategy, especially in comparison

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

    Science.gov (United States)

    Kobus, Thiele; Zervantonakis, Ioannis K; Zhang, Yongzhi; McDannold, Nathan J

    2016-09-28

    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 brain. We investigated whether we could improve the response by temporary disruption of the BBB using focused ultrasound in combination with microbubbles. To study this, we inoculated 30 nude rats with HER2-positive cells derived from a brain metastasis of a breast cancer patient (MDA-MB-361). The animals were divided into three groups: a control-group that received no treatment; an antibody-only group that received six weekly treatments of trastuzumab and pertuzumab; and an ultrasound+antibody group that received trastuzumab and pertuzumab in combination with six weekly sessions of BBB disruption using focused ultrasound. In two animals, the leakiness of the tumors before disruption was evaluated using contrast-enhanced T1-weighted magnetic resonance imaging and found that the tumors were not leaky. The same technique was used to evaluate the effectiveness of BBB disruption, which was successful in all sessions. The tumor in the control animals grew exponentially with a growth constant of 0.042±0.011mm(3)/day. None of the antibody-only animals responded to the treatment and the growth constant was 0.033±0.009mm(3)/day during the treatment period. Four of the ten animals in the ultrasound+antibody-group showed a response to the treatment with an average growth constant of 0.010±0.007mm(3)/day, compared to a growth constant 0.043±0.013mm(3)/day for the six non-responders. After the treatment period, the tumors in all groups grew at similar rates. As the tumors were not leaky before BBB disruption and there were no responders in the antibody-only group, these results show that at least in some cases disruption of the BBB is necessary for a response to the antibodies in

  5. Differences in amyloid-β clearance across mouse and human blood-brain barrier models: kinetic analysis and mechanistic modeling.

    Science.gov (United States)

    Qosa, Hisham; Abuasal, Bilal S; Romero, Ignacio A; Weksler, Babette; Couraud, Pierre-Oliver; Keller, Jeffrey N; Kaddoumi, Amal

    2014-04-01

    Alzheimer's disease (AD) has a characteristic hallmark of amyloid-β (Aβ) accumulation in the brain. This accumulation of Aβ has been related to its faulty cerebral clearance. Indeed, preclinical studies that used mice to investigate Aβ clearance showed that efflux across blood-brain barrier (BBB) and brain degradation mediate efficient Aβ clearance. However, the contribution of each process to Aβ clearance remains unclear. Moreover, it is still uncertain how species differences between mouse and human could affect Aβ clearance. Here, a modified form of the brain efflux index method was used to estimate the contribution of BBB and brain degradation to Aβ clearance from the brain of wild type mice. We estimated that 62% of intracerebrally injected (125)I-Aβ40 is cleared across BBB while 38% is cleared by brain degradation. Furthermore, in vitro and in silico studies were performed to compare Aβ clearance between mouse and human BBB models. Kinetic studies for Aβ40 disposition in bEnd3 and hCMEC/D3 cells, representative in vitro mouse and human BBB models, respectively, demonstrated 30-fold higher rate of (125)I-Aβ40 uptake and 15-fold higher rate of degradation by bEnd3 compared to hCMEC/D3 cells. Expression studies showed both cells to express different levels of P-glycoprotein and RAGE, while LRP1 levels were comparable. Finally, we established a mechanistic model, which could successfully predict cellular levels of (125)I-Aβ40 and the rate of each process. Established mechanistic model suggested significantly higher rates of Aβ uptake and degradation in bEnd3 cells as rationale for the observed differences in (125)I-Aβ40 disposition between mouse and human BBB models. In conclusion, current study demonstrates the important role of BBB in the clearance of Aβ from the brain. Moreover, it provides insight into the differences between mouse and human BBB with regards to Aβ clearance and offer, for the first time, a mathematical model that describes

  6. Matrix metalloproteinase-9 expression and blood brain barrier permeability in the rat brain after cerebral ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Lifang Lei; Xiaohong Zi; Qiuyun Tu

    2008-01-01

    BACKGROUND: The integrity of the blood brain barrier (BBB) plays an important role in the patho-physiological process of cerebral ischemia/reperfusion injury. It has been recently observed that metalloproteinase-9 (MMP-9) is closely related to cerebral ischemia/reperfusion injuryOBJECTIVE: This study was designed to observe MMP-9 expression in the rat brain after cerebral ischemia/reperfusion injury and to investigate its correlation to BBB permeability.DESIGN, TIME AND SETTING: This study, a randomized controlled animal experiment, was performed at the Institute of Neurobiology, Central South University between September 2005 and March 2006.MATERIALS: Ninety healthy male SD rats, aged 3-4 months, weighing 200-280g, were used in the present study. Rabbit anti-rat MMP-9 polyclonal antibody (Boster, Wuhan, China) and Evans blue (Sigma, USA) were also used.METHODS: All rats were randomly divided into 9 groups with 10 rats in each group: normal control group, sham-operated group, and ischemia for 2 hours followed by reperfusion for 3,6,12 hours, 1,2,4 and 7 days groups. In the ischemia/reperfusion groups, rats were subjected to ischemia/reperfusion injury by suture occlusion of the right middle cerebral artery. In the sham-operated group, rats were merely subjected to vessel dissociation. In the normal control group, rats were not modeled.MAIN OUTCOME MEASURES: BBB permeability was assessed by determining the level of effusion of Evans blue. MMP-9 expression was detected by an immunohistochemical method.RESULTS: All 90 rats were included in the final analysis. BBB permeability alteration was closely correlated to ischemia/reperfusion time. BBB permeability began to increase at ischemia/reperfusion for 3 hours, then it gradually reached a peak level at ischemia/reperfusion for 1 day, and thereafter it gradually decreased. MMP-9 expression began to increase at ischemia/reperfusion for 3 hours, then gradually reached its peak level 2 days after perfusion, and thereafter

  7. Microbubbles coupled to methotrexate-loaded liposomes for ultrasound-mediated delivery of methotrexate across the blood-brain barrier.

    Science.gov (United States)

    Wang, Xiang; Liu, Ping; Yang, Weixiao; Li, Lu; Li, Peijing; Liu, Zheng; Zhuo, Zhongxiong; Gao, Yunhua

    2014-01-01

    Methotrexate (MTX) is the single most effective agent for the treatment of primary central nervous system lymphoma. Currently, the delivery of MTX to the brain is achieved by high systemic doses, which cause severe long-term neurotoxicity, or intrathecal administration, which is highly invasive and may lead to infections or hemorrhagic complications. Acoustically active microbubbles have been developed as drug carriers for the noninvasive and brain-targeted delivery of therapeutics. However, their application is limited by their low drug-loading capacity. To overcome this limitation, we prepared microbubbles coupled to MTX-loaded liposomes using ZHIFUXIAN, a novel type of microbubbles with a superior safety profile and long circulation time. MTX-liposome-coupled microbubbles had a high drug-loading capacity of 8.91%± 0.86%, and their size (2.64 ± 0.93 μm in diameter) was suitable for intravenous injection. When used with ultrasound, they showed more potent in vitro cytotoxicity against Walker-256 cancer cells than MTX alone or MTX-loaded liposomes. When Sprague-Dawley rats were exposed to sonication, administration of these MTX-liposome-coupled microbubbles via the tail vein led to targeted disruption of the blood-brain barrier without noticeable tissue or capillary damage. High-performance liquid chromatography analysis of the brain MTX concentration showed that MTX delivery to the brain followed the order of MTX-liposome-coupled microbubbles + ultrasound (25.3 ± 2.4 μg/g) > unmodified ZHIFUXIAN + MTX + ultrasound (18.6 ± 2.2 μg/g) > MTX alone (6.97 ± 0.75 μg/g) > MTX-liposome-coupled microbubbles (2.92 ± 0.39 μg/g). Therefore, treatment with MTX-liposome-coupled microbubbles and ultrasound resulted in a significantly higher brain MTX concentration than all other treatments (Pliposome-coupled microbubbles may hold great promise as new and effective therapies for primary central nervous system lymphoma and other central nervous system malignancies.

  8. Effect of Xingnaojing injection on cerebral edema and blood-brain barrier in rats following traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    XU Miao; SU Wei; XU Qiu-ping; HUANG Wei-dong

    2010-01-01

    Objective:To explore the effects of Xingnaojing injection on cerebral edema and blood-brain barrier (BBB) in rats following traumatic brain injury (TBI).Methods: A total of 108 adult male Sprague-Dawley rats were used as subjects and randomly assigned to three groups:sham-operation,TBI and Xingnaojing injection was set up by the improved device of Feeney's weightcontent and BBB permeability expressed as Evans blue content were measured at 1, 3, 5 and 7 days after surgery.Results: In sham-operation group, brain water content and Evans blue content in brain tissue were 78.97%±1.22%and 5.13μg±0.71μg. Following TBI, water content in brain tissue was increased significantly at 1, 3, 5 and 7 days (83.49%±0.54%, 82.74%±0.72%, 80.22%±0.68%, 79.21%±0.60%), being significantly higher than that in sham operation group (P<0.05). Evans blue content was increased in TBI group (16.54 μg±0.60 μg, 14.92μg±0.71μg, 12.44 μg ±0.92μg, 10.14μg±0.52 μg) as compared with sham-operation group(P<0.05). After treatment with Xingnaojing injection, brain water content decreased as compared with TBI group (81.91%±1.04%, 80.38%±0.72%, 79.54%±0.58%,78.60%±0.77%, P<0.05). Xingnaojing injection also reduced the leakage of BBB as compared with TBI group (15.11 μg± 0.63 μg, 13.62 μg±0.85μg, 10.06 μg±0.67 μg, 9.54 μg±0.41 μg,P<0.05).Conclusion: Xingnaojing injection could alleviate cerebral edema following TBI via reducing permeability ofBBB.

  9. Synaptic and blood-brain barrier structural changes in a rat epilepsy model induced by coriaria lacton

    Institute of Scientific and Technical Information of China (English)

    Jiyan Cheng; Jichun Huang; Yi Han; Guangyi Liu; Ling Yin; Furong Zheng

    2008-01-01

    BACKGROUND: Structural and functional synaptic changes, as well as blood-brain barrier (BBB) changes, affect the micro-environment of nervous tissue and excitation, both of which play an important role in epilepsy.OBJECTIVE: To observe synaptic and BBB ultrastructural changes in the motor cortex of a rat epilepsy model induced by coriaria lacton, and to investigate the synaptic and BBB effects on the mechanism of epilepsy.DESIGN: A randomized controlled animal experiment.SETTING: Department of Histology and Embryology, Luzhou Medical College; and Electron Microscopy Laboratory, Luzhou Medical College.MATERIALS: Twenty healthy male Sprague Dawley rats, aged 8 weeks, were chosen for this study. The rats weighed (280 ± 50) g and were supplied by the Experimental Animal Center of Luzhou Medical College. Experimentation was performed in accordance with the ethical guidelines for the use and care of animals. The animals were randomly divided into a control group and an epilepsy group, with 10 rats in each group. METHODS: This study was performed at the Department of Histology and Embryology, and Electron Microscopy Laboratory, Luzhou Medical College between February and December 2006. According to the protocol, the epilepsy group was injected with 10 μL/100 g coriaria lacton into the lateral ventricles to establish an epileptic model. The control group rats were not administered anything. Eight days after the model was established, all rats were anesthetized with ether. The motor cortex was removed and sectioned into ultrathin sections. Synaptic and BBB ultrastructural changes were observed by electron microscopy. MAIN OUTCOME MEASURES: ①Structural changes of three different parts of the synapses, synaptic cleft width, postsynaptic density thickness, proportion of perforation synapses, curvature of synaptic interface, and length of active zones. ②Capillary and BBB changes (endothelium, basement membrane, pericyte, and the astrocyte endfeet).RESULTS: ①Curvature of

  10. Effects of matrix metalloproteinase 9 inhibition on the blood brain barrier and inflammation in rats following cardiopulmonary resuscitation

    Institute of Scientific and Technical Information of China (English)

    HE Zhi-jie; HUANG Zi-tong; CHEN Xiao-tong; ZOU Zi-jun

    2009-01-01

    resuscitation control group (P<0.05). Conclusions Expression of MMP9 protein and mRNA, water content, Evans blue content, TNF-a, IL-1, and IL-6 increased in rat brain tissue after CPR, indicating disruption of the blood-brain barrier and excess inflammatory reaction. MMP9 expression was reduced with SB-3CT, resulting in reduced brain injury.

  11. Changes and significance of occludin expression in rats with blood-brain barrier injury induced by microwave radiation

    Directory of Open Access Journals (Sweden)

    Xiang LI

    2011-07-01

    Full Text Available Objective To observe the changes in occludin expression in hippocampus of rats injured by long-term microwave exposure at low dosage,and explore the mechanism of the effect of occludin on microwave-induced blood-brain barrier(BBB injury.Methods A total of 156 male Wistar rats were assigned into 4 groups(39 each according to the microwave dosage they received(0,2.5,5 and 10 mW/cm2.Irradiation was given 5 times/week and 6 minutes for each exposure for one month.Five rats of each group were sacrificed at each time point(6h and day 7,14,30 and 60 after irradiation,the structural changes in hippocampus tissues BBB were observed by light and electron microscopy.Another 3 rats of each group were sacrificed after an intravenous injection of 2% Evans blue(EB at the time points of 6h and day 7 and 30 after irradiation,and the change in BBB permeability was examined by laser scanning confocal microscopy.Western blotting,real-time PCR and image analysis were used to detect the gene and protein expression of occludin in hippocampus of rats.Results After microwave irradiation in doses of 2.5,5 and 10 mW/cm2,respectively,on day 7,14 and 30,the astrocytes were found to be swollen,the capillary gaps of hippocampus were broadened and tight junction(TJ structure was inconspicuous or widened.In sham-group(0 mW/cm2,the red fluorescence of EB was limited in lumens of blood vessels,while in 5 and 10 mW/cm2 groups,Evans blue was dispersed surrounding the blood vessels at 6h and day 7 till day 30 in an irradiation dose-dependent manner.In 5 and 10 mW/cm2 groups,the expression of occludin protein in hippocampus decreased at day 14(P 0.05.In the 2.5,5 and 10 mW/cm2 groups,mRNA expression of occludin began to significantly decrease at day 7 and 14 and it lowered to the nadir at day 30(P 0.05.Conclusions A long-term microwave irradiation with dosage of 2.5 to 10 mW/cm2 may destroy the structure of BBB of rats’ hippocampus and increase permeability in a radiation

  12. MRI blood-brain barrier permeability measurements to predict hemorrhagic transformation in a rat model of ischemic stroke.

    Science.gov (United States)

    Hoffmann, Angelika; Bredno, Jörg; Wendland, Michael F; Derugin, Nikita; Hom, Jason; Schuster, Tibor; Zimmer, Claus; Su, Hua; Ohara, Peter T; Young, William L; Wintermark, Max

    2012-12-01

    Permeability imaging might add valuable information in the risk assessment of hemorrhagic transformation. This study evaluates the predictive value of blood-brain barrier permeability (BBBP) measurements extracted from dynamic contrast-enhanced MRI for hemorrhagic transformation in ischemic stroke. Spontaneously hypertensive and Wistar rats with 2 h filament occlusion of the right MCA underwent MRI during occlusion, at 4 and 24 h post reperfusion. BBBP was imaged by DCE imaging and quantified by Patlak analysis. Cresyl-violet staining was used to characterize hemorrhage in sacrificed rats at 24 h, immediately following the last imaging study. BBBP changes were evaluated at baseline, 4 and 24 h after reperfusion. Receiver-operating characteristic (ROC) analysis was performed to determine the most accurate BBBP threshold to predict hemorrhagic transformation. In animals showing macroscopic hemorrhage at 24 h, 95th BBBP percentile values ipsilateral were 0.323 [0.260, 0.387], 0.685 [0.385, 0.985], and 0.412 [0.210, 0.613] ml/min·100 g (marginal mean [95%CI]) during occlusion, at 4 and 24 h post reperfusion, respectively. The BBBP values on the infarcted and contralateral side were significantly different at 4 (p = 0.034) and 24 h post reperfusion (p = 0.031). The predictive value of BBBP in terms of macroscopic hemorrhage was highest 4 h after reperfusion (ROC area under the curve = 84 %) with a high negative predictive value (98.3 %) and limited positive predictive value (14.9 %) for a threshold of 0.35 ml/min·100g. Altered BBBP is a necessary but not sufficient condition to cause hemorrhagic transformation in rats with an infarct. Further research is needed to identify those additional risk factors that are required for hemorrhagic transformation to develop in the setting of ischemic stroke.

  13. Opening of the blood-brain barrier through focused ultrasound in combination with drugs to treat glioma%聚焦超声开放血脑屏障治疗脑胶质瘤疗效的实验研究

    Institute of Scientific and Technical Information of China (English)

    潘敏; 张天奉; 王峰; 邹超; 万倩; 吴碧峰; 刘新; 郑海荣

    2015-01-01

    Objective To evaluate the effectiveness of treating glioma in combination with drugs multiply by comparing the size of tumor and the survival time of different groups in rat glioma after targeted blood-brain barrier (BBB ) disruption by MRI-guided focused ultrasound.Methods The stereotaxis instruments and the 10 μl gas-tight syringes were used to inject gliosarcoma cells into the targeted area of the brain in 50 male Sprague-Dawley rats.The glioma-bearing rat model was established.Each rat received either:(1 )no treatment (control;n =8);(2)single liposomal doxorubicin (DOX;n = 10);(3)multiple DOX (n =10);(4)single Avastin (AVS)and DOX (n =10);(5)multiple AVS and DOX (n =10).The SonoVue microbubble ultrasonic contrast agent and DOX or AVS were injected into the tail vein respectively on day 12 after implantation.The tumor size was measured by MRI on pre-treatment,immediacy and once a week of post-treatment after targeted BBB disruption by focused ultrasound,and the life span in rat glioma was recorded.Results The mediam survival of different groups in rat glioma(The range of the life span 13-90 d):no treatment (7 d);single DOX (12 d);multiple DOX (1 5 d);single AVS + DOX (22 d), multiple AVS+ DOX (30 d).There was significant difference of the groups on mediam survival comparison (P < 0.01 ).The tumor growth pattern after post-treatment of different groups in rat glioma except control:single DOX was noticeable fast and multiple AVS+DOX was visibly delayed comparable to other groups,and finally the tumor size of multiple AVS + DOX even became small.Conclusions The microbubble blasting enhances the local tissue permeability and promotes the drug delivery of chemotherapy and anti-angiogenesis locally in glioma-bearing rats by MRI-guided focused ultrasound.Especially,the combination with drugs multiply has a synergism efficacy that may enhance the effectiveness of chemotherapy,reduce tumor growth,and even become small of the tumor size,and increase survival time

  14. Identification of neuronal and angiogenic growth factors in an in vitro blood-brain barrier model system: Relevance in barrier integrity and tight junction formation and complexity.

    Science.gov (United States)

    Freese, Christian; Hanada, Sanshiro; Fallier-Becker, Petra; Kirkpatrick, C James; Unger, Ronald E

    2017-05-01

    We previously demonstrated that the co-cultivation of endothelial cells with neural cells resulted in an improved integrity of the in vitro blood-brain barrier (BBB), and that this model could be useful to evaluate the transport properties of potential central nervous system disease drugs through the microvascular brain endothelial. In this study we have used real-time PCR, fluorescent microscopy, protein arrays and enzyme-linked immunosorbent assays to determine which neural- and endothelial cell-derived factors are produced in the co-culture and improve the integrity of the BBB. In addition, a further improvement of the BBB integrity was achieved by adjusting serum concentrations and growth factors or by the addition of brain pericytes. Under specific conditions expression of angiogenic, angiostatic and neurotrophic factors such as endostatin, pigment epithelium derived factor (PEDF/serpins-F1), tissue inhibitor of metalloproteinases (TIMP-1), and vascular endothelial cell growth factor (VEGF) closely mimicked the in vivo situation. Freeze-fracture analysis of these cultures demonstrated the quality and organization of the endothelial tight junction structures and their association to the two different lipidic leaflets of the membrane. Finally, a multi-cell culture model of the BBB with a transendothelial electrical resistance up to 371 (±15) Ω×cm(2) was developed, which may be useful for preliminary screening of drug transport across the BBB and to evaluate cellular crosstalk of cells involved in the neurovascular unit.

  15. The cellular and behavioral consequences of interleukin-1 alpha penetration through the blood-brain barrier of neonatal rats: a critical period for efficacy.

    Science.gov (United States)

    Tohmi, M; Tsuda, N; Zheng, Y; Mizuno, M; Sotoyama, H; Shibuya, M; Kawamura, M; Kakita, A; Takahashi, H; Nawa, H

    2007-11-30

    Proinflammatory cytokines circulating in the periphery of early postnatal animals exert marked influences on their subsequent cognitive and behavioral traits and are therefore implicated in developmental psychiatric diseases such as schizophrenia. Here we examined the relationship between the permeability of the blood-brain barrier to interleukin-1 alpha (IL-1 alpha) in neonatal and juvenile rats and their later behavioral performance. Following s.c. injection of IL-1 alpha into rat neonates, IL-1 alpha immunoreactivity was first detected in the choroid plexus, brain microvessels, and olfactory cortex, and later diffused to many brain regions such as neocortex and hippocampus. In agreement, IL-1 alpha administration to the periphery resulted in a marked increase in brain IL-1 alpha content of neonates. Repeatedly injecting IL-1 alpha to neonates triggered astrocyte proliferation and microglial activation, followed by behavioral abnormalities in startle response and putative prepulse inhibition at the adult stage. Analysis of covariance with a covariate of startle amplitude suggested that IL-1 alpha administration may influence prepulse inhibition. However, adult rats treated with IL-1 alpha as neonates exhibited normal learning ability as measured by contextual fear conditioning, two-way passive shock avoidance, and a radial maze task and had no apparent sign of structural abnormality in the brain. In comparison, when IL-1 alpha was administered to juveniles, the blood-brain barrier permeation was limited. The increases in brain IL-1 alpha content and immunoreactivity were less pronounced following IL-1 alpha administration and behavioral abnormalities were not manifested at the adult stage. During early development, therefore, circulating IL-1 alpha efficiently crosses the blood-brain barrier to induce inflammatory reactions in the brain and influences later behavioral traits.

  16. Blood-brain barrier permeability is positively correlated with cerebral microvascular perfusion in the early fluid percussion-injured brain of the rat.

    Science.gov (United States)

    Lin, Yong; Pan, Yaohua; Wang, Mingliang; Huang, Xianjian; Yin, Yuhua; Wang, Yu; Jia, Feng; Xiong, Wenhao; Zhang, Nu; Jiang, Ji-yao

    2012-11-01

    The blood-brain barrier (BBB) opening following traumatic brain injury (TBI) provides a chance for therapeutic agents to cross the barrier, yet the reduction of the cerebral microvascular perfusion after TBI may limit the intervention. Meanwhile, optimizing the cerebral capillary perfusion by the strategies such as fluid administration may cause brain edema due to the BBB opening post trauma. To guide the TBI therapy, we characterized the relationship between the changes in the cerebral capillary perfusion and BBB permeability after TBI. First, we observed the changes of the cerebral capillary perfusion by the intracardiac perfusion of Evans Blue and the BBB disruption with magnetic resonance imaging (MRI) in the rat subjected to lateral fluid percussion (FP) brain injury. The correlation between two variables was next evaluated with the correlation analysis. Since related to BBB breakdown, matrix metalloproteinase-9 (MMP-9) activity was finally detected by gelatin zymography. We found that the ratios of the perfused microvessel numbers in the lesioned cortices were significantly reduced at 0 and 1 h post trauma compared with that in the normal cortex, which then dramatically recovered at 4 and 24 h after injury, and that the BBB permeability was greatly augmented in the ipsilateral parts at 4, 12, and 24 h, and in the contralateral area at 24 h after injury compared with that in the uninjured brain. The correlation analysis showed that the BBB permeability increase was related to the restoration of the cerebral capillary perfusion over a 24-h period post trauma. Moreover, the gelatin zymography analysis indicated that the MMP-9 activity in the injured brain increased at 4 h and significantly elevated at 12 and 24 h as compared to that at 0 or 1 h after TBI. Our findings demonstrate that the 4 h post trauma is a critical turning point during the development of TBI, and, importantly, the correlation analysis may guide us how to treat TBI.

  17. Highly stabilized curcumin nanoparticles tested in an in vitro blood-brain barrier model and in Alzheimer's disease Tg2576 mice.

    Science.gov (United States)

    Cheng, Kwok Kin; Yeung, Chin Fung; Ho, Shuk Wai; Chow, Shing Fung; Chow, Albert H L; Baum, Larry

    2013-04-01

    The therapeutic effects of curcumin in treating Alzheimer's disease (AD) depend on the ability to penetrate the blood-brain barrier. The latest nanoparticle technology can help to improve the bioavailability of curcumin, which is affected by the final particle size and stability. We developed a stable curcumin nanoparticle formulation to test in vitro and in AD model Tg2576 mice. Flash nanoprecipitation of curcumin, polyethylene glycol-polylactic acid co-block polymer, and polyvinylpyrrolidone in a multi-inlet vortex mixer, followed by freeze drying with β-cyclodextrin, produced dry nanocurcumin with mean particle size nanoparticles with positive treatment effects in Tg2576 mice.

  18. Endothelial Proliferation and Increased Blood - Brain Barrier Permeability in the Basal Ganglia in a Rat Model of 3,4-Dihydrozyphenyl-L-Alanine-Induced Dyskinesia

    DEFF Research Database (Denmark)

    Westin, Jenny E.; Lindgren, Hanna S.; Gardi, Jonathan Eyal

    2006-01-01

    3,4-Dihydroxyphenyl-L-alanine (L-DOPA)-induced dyskinesia is associated with molecular and synaptic plasticity in the basal ganglia, but the occurrence of structural remodeling through cell genesis has not been explored. In this study, rats with 6-hydroxydopamine lesions received injections of th...... of angiogenesis and blood-brain barrier dysfunction in an experimental model of L-DOPA-induced dyskinesia. These microvascular changes are likely to affect the kinetics of L-DOPA entry into the brain, favoring the occurrence of motor complications....

  19. 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......, 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...

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

    Directory of Open Access Journals (Sweden)

    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

  1. Assessing blood brain barrier dynamics or identifying or measuring selected substances, including ethanol or toxins, in a subject by analyzing Raman spectrum signals

    Science.gov (United States)

    Lambert, James L. (Inventor); Borchert, Mark S. (Inventor)

    2008-01-01

    A non-invasive method for analyzing the blood-brain barrier includes obtaining a Raman spectrum of a selected portion of the eye and monitoring the Raman spectrum to ascertain a change to the dynamics of the blood brain barrier.Also, non-invasive methods for determining the brain or blood level of an analyte of interest, such as glucose, drugs, alcohol, poisons, and the like, comprises: generating an excitation laser beam at a selected wavelength (e.g., at a wavelength of about 400 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor, vitreous humor, or one or more conjunctiva vessels in the eye is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated portion of the eye; and then determining the blood level or brain level (intracranial or cerebral spinal fluid level) of an analyte of interest for the subject from the Raman spectrum. In certain embodiments, the detecting step may be followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level and/or brain level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing methods are also disclosed.

  2. Effects of salidroside pretreatment on expression of tumor necrosis factor-alpha and permeability of blood brain barrier in rat model of focal cerebralischemia-reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Tian Han

    2013-01-01

    Objective:To observe changes in expression of tumor necrosis factor(TNF)-alpha and permeability of blood brain barrier after salidroside pretreatment in rats with injury induced by focal cerebralischemia-reperfusion.Methods:Forty-five maleSD rats were randomly divided into three groups(n=15): control group, ischemia-reperfusion(IR) model group, and salidroside pretreatment group.Before theIR model establishment, the rats in the salidroside pretreatment group were intraperitoneally administered with salidroside at a dose of24 mg/(kg•d) for7 d.After30 min post the last administration, theIR model was induced by occlusion of middle cerebral artery with a filament.After24 h post the operation, the water content andEvens blue content in the ischemia cerebral hemisphere were determined, and the level of TNF-alpha mRNA was detected by the semi-quantitativeRT-PCR.Results:Compared with theIR model group, the salidroside pretreatment group had significantly lower(P<0.05) water content andEvens blue content in the ischemia cerebral hemisphere and also had significantly lower(P<0.05) level of TNF-alpha in the ischemic cerebral cortex tissue.Conclusions:The salidroside pretreatment alleviated the focal cerebralischemia-reperfusion injury in the rat model, possibly by decreasing the permeability of blood brain barrier, attenuating brain edema and reducingTNF-alpha expression.

  3. Aryl hydrocarbon receptor-mediated up-regulation of ATP-driven xenobiotic efflux transporters at the blood-brain barrier.

    Science.gov (United States)

    Wang, Xueqian; Hawkins, Brian T; Miller, David S

    2011-02-01

    Many widespread and persistent organic pollutants, e.g., 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), activate the aryl hydrocarbon receptor (AhR), causing it to translocate to the cell nucleus, where it transactivates target genes. AhR's ability to target the blood-brain barrier is essentially unexplored. We show here that exposing isolated rat brain capillaries to 0.05-0.5 nM TCDD roughly doubled transport activity and protein expression of P-glycoprotein, an ATP-driven drug efflux pump and a critical determinant of drug entry into the CNS. These effects were abolished by actinomycin D or cycloheximide or by the AhR antagonists resveratrol and α-naphthoflavone. Brain capillaries from TCDD-dosed rats (1-5 μg/kg, i.p.) exhibited increased transport activity and protein expression of 3 xenobiotic efflux pumps, P-glycoprotein, multidrug resistance-associated protein 2, and breast cancer resistance polypeptide, as well as expression of Cyp1a1 and Cyp1b1, both AhR target genes. Consistent with increased P-glycoprotein expression in capillaries from TCDD-dosed rats, in situ brain perfusion indicated significantly reduced brain accumulation of verapamil, a P-glycoprotein substrate. These findings suggest a new paradigm for the field of environmental toxicology: toxicants acting through AhR to target xenobiotic efflux transporters at the blood-brain barrier and thus reduce brain accumulation of CNS-acting therapeutic drugs.

  4. Monitoring stroke progression: in vivo imaging of cortical perfusion, blood-brain barrier permeability and cellular damage in the rat photothrombosis model.

    Science.gov (United States)

    Schoknecht, Karl; Prager, Ofer; Vazana, Udi; Kamintsky, Lyn; Harhausen, Denise; Zille, Marietta; Figge, Lena; Chassidim, Yoash; Schellenberger, Eyk; Kovács, Richard; Heinemann, Uwe; Friedman, Alon

    2014-11-01

    Focal cerebral ischemia is among the main causes of death and disability worldwide. The ischemic core often progresses, invading the peri-ischemic brain; however, assessing the propensity of the peri-ischemic brain to undergo secondary damage, understanding the underlying mechanisms, and adjusting treatment accordingly remain clinically unmet challenges. A significant hallmark of the peri-ischemic brain is dysfunction of the blood-brain barrier (BBB), yet the role of disturbed vascular permeability in stroke progression is unclear. Here we describe a longitudinal in vivo fluorescence imaging approach for the evaluation of cortical perfusion, BBB dysfunction, free radical formation and cellular injury using the photothrombosis vascular occlusion model in male Sprague Dawley rats. Blood-brain barrier dysfunction propagated within the peri-ischemic brain in the first hours after photothrombosis and was associated with free radical formation and cellular injury. Inhibiting free radical signaling significantly reduced progressive cellular damage after photothrombosis, with no significant effect on blood flow and BBB permeability. Our approach allows a dynamic follow-up of cellular events and their response to therapeutics in the acutely injured cerebral cortex.

  5. Oxygen-glucose deprivation and reoxygenation as an in vitro ischemia-reperfusion injury model for studying blood-brain barrier dysfunction.

    Science.gov (United States)

    Alluri, Himakarnika; Anasooya Shaji, Chinchusha; Davis, Matthew L; Tharakan, Binu

    2015-05-07

    Ischemia-Reperfusion (IR) injury is known to contribute significantly to the morbidity and mortality associated with ischemic strokes. Ischemic cerebrovascular accidents account for 80% of all strokes. A common cause of IR injury is the rapid inflow of fluids following an acute/chronic occlusion of blood, nutrients, oxygen to the tissue triggering the formation of free radicals. Ischemic stroke is followed by blood-brain barrier (BBB) dysfunction and vasogenic brain edema. Structurally, tight junctions (TJs) between the endothelial cells play an important role in maintaining the integrity of the blood-brain barrier (BBB). IR injury is an early secondary injury leading to a non-specific, inflammatory response. Oxidative and metabolic stress following inflammation triggers secondary brain damage including BBB permeability and disruption of tight junction (TJ) integrity. Our protocol presents an in vitro example of oxygen-glucose deprivation and reoxygenation (OGD-R) on rat brain endothelial cell TJ integrity and stress fiber formation. Currently, several experimental in vivo models are used to study the effects of IR injury; however they have several limitations, such as the technical challenges in performing surgeries, gene dependent molecular influences and difficulty in studying mechanistic relationships. However, in vitro models may aid in overcoming many of those limitations. The presented protocol can be used to study the various molecular mechanisms and mechanistic relationships to provide potential therapeutic strategies. However, the results of in vitro studies may differ from standard in vivo studies and should be interpreted with caution.

  6. Chemical modification of paclitaxel (Taxol) reduces P-glycoprotein interactions and increases permeation across the blood-brain barrier in vitro and in situ.

    Science.gov (United States)

    Rice, Antonie; Liu, Yanbin; Michaelis, Mary Lou; Himes, Richard H; Georg, Gunda I; Audus, Kenneth L

    2005-02-10

    The purpose of this work was to introduce a chemical modification into the paclitaxel (Taxol) structure to reduce interactions with the product of the multidrug resistant type 1 (MDR1) gene, P-glycoprotein (Pgp), resulting in improved blood-brain barrier (BBB) permeability. Specifically, a taxane analogue, Tx-67, with a succinate group added at the C10 position of Taxol, was synthesized and identified as such a candidate. In comparison studies, Tx-67 had no apparent interactions with Pgp, as demonstrated by the lack of enhanced uptake of rhodamine 123 by brain microvessel endothelial cells (BMECs) in the presence of the agent. By contrast, Taxol exposure substantially enhanced rhodamine 123 uptake by BMECs through inhibition of Pgp. The transport across BMEC monolayers was polarized for both Tx-67 and Taxol with permeation in the apical to basolateral direction greater for Tx-67 and substantially reduced for Taxol relative to basolateral to apical permeation. Taxol and cyclosporin A treatments also did not enhance Tx-67 permeation across BMEC monolayers. In an in situ rat brain perfusion study, Tx-67 was demonstrated to permeate across the BBB at a greater rate than Taxol. These results demonstrate that the Taxol analogue Tx-67 had a reduced interaction with Pgp and, as a consequence, enhanced permeation across the blood-brain barrier in vitro and in situ.

  7. Blood-Brain Barrier Deterioration and Hippocampal Gene Expression in Polymicrobial Sepsis: An Evaluation of Endothelial MyD88 and the Vagus Nerve.

    Directory of Open Access Journals (Sweden)

    Gerard Honig

    Full Text Available Systemic infection can initiate or exacerbate central nervous system (CNS pathology, even in the absence of overt invasion of bacteria into the CNS. Recent epidemiological studies have demonstrated that human survivors of sepsis have an increased risk of long-term neurocognitive decline. There is thus a need for improved understanding of the physiological mechanisms whereby acute sepsis affects the CNS. In particular, MyD88-dependent activation of brain microvascular endothelial cells and a resulting loss of blood-brain barrier integrity have been proposed to play an important role in the effects of systemic inflammation on the CNS. Signaling through the vagus nerve has also been considered to be an important component of CNS responses to systemic infection. Here, we demonstrate that blood-brain barrier permeabilization and hippocampal transcriptional responses during polymicrobial sepsis occur even in the absence of MyD88-dependent signaling in cerebrovascular endothelial cells. We further demonstrate that these transcriptional responses can occur without vagus nerve input. These results suggest that redundant signals mediate CNS responses in sepsis. Either endothelial or vagus nerve activation may be individually sufficient to transmit systemic inflammation to the central nervous system. Transcriptional activation in the forebrain in sepsis may be mediated by MyD88-independent endothelial mechanisms or by non-vagal neuronal pathways.

  8. Permeability of blood-brain barrier in macaque model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson disease.

    Science.gov (United States)

    Thiollier, Thibaud; Wu, Caisheng; Contamin, Hugues; Li, Qin; Zhang, Jinlan; Bezard, Erwan

    2016-06-01

    Brain bioavailability of drugs developed to address central nervous system diseases is classically documented through cerebrospinal fluid collected in normal animals, i.e., through an approximation as there are fundamental differences between cerebrospinal fluid and tissue contents. The fact that disease might affect brain availability of drugs is almost never considered at this stage although several conditions are associated with blood-brain barrier damage. Building upon our expertise in Parkinson's disease translational research, the present study addressed this gap comparing plasma and cerebrospinal fluid bioavailability of l-3,4-dihydroxyphenylalanine, carbamazepine, quinidine, lovastatin, and simvastatin, in healthy and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated macaques, the gold standard model of Parkinson's disease. The drugs were selected based upon their differential transport across the blood-brain barrier. Interestingly, brain bioavailability of quinidine was decreased while others were unaffected. Pharmacokinetics and pharmacodynamics experiments of drugs addressing Parkinson's disease might thus be performed in healthy animals unless the drugs are known to interact with the organic cation transporter.

  9. Importance of dose intensity in neuro-oncology clinical trials: summary report of the Sixth Annual Meeting of the Blood-Brain Barrier Disruption Consortium.

    Science.gov (United States)

    Doolittle, N D; Anderson, C P; Bleyer, W A; Cairncross, J G; Cloughesy, T; Eck, S L; Guastadisegni, P; Hall, W A; Muldoon, L L; Patel, S J; Peereboom, D; Siegal, T; Neuwelt, E A

    2001-01-01

    Therapeutic options for the treatment of malignant brain tumors have been limited, in part, because of the presence of the blood-brain barrier. For this reason, the Sixth Annual Meeting of the Blood-Brain Barrier Disruption Consortium, the focus of which was the "Importance of Dose Intensity in Neuro-Oncology Clinical Trials," was convened in April 2000, at Government Camp, Mount Hood, Oregon. This meeting, which was supported by the National Cancer Institute, the National Institute of Neurological Disorders and Stroke, and the National Institute of Deafness and Other Communication Disorders, brought together clinicians and basic scientists from across the U.S. to discuss the role of dose intensity and enhanced chemotherapy delivery in the treatment of malignant brain tumors and to design multicenter clinical trials. Optimizing chemotherapy delivery to the CNS is crucial, particularly in view of recent progress identifying certain brain tumors as chemosensitive. The discovery that specific constellations of genetic alterations can predict which tumors are chemoresponsive, and can therefore more accurately predict prognosis, has important implications for delivery of intensive, effective chemotherapy regimens with acceptable toxicities. This report summarizes the discussions, future directions, and key questions regarding dose-intensive treatment of primary CNS lymphoma, CNS relapse of systemic non-Hodgkin's lymphoma, anaplastic oligodendroglioma, high-grade glioma, and metastatic cancer of the brain. The promising role of cytoenhancers and chemoprotectants as part of dose-intensive regimens for chemosensitive brain tumors and development of improved gene therapies for malignant gliomas are discussed.

  10. Nanoparticle mediated P-glycoprotein silencing for improved drug delivery across the blood-brain barrier: a siRNA-chitosan approach.

    Directory of Open Access Journals (Sweden)

    Jostein Malmo

    Full Text Available The blood-brain barrier (BBB, composed of tightly organized endothelial cells, limits the availability of drugs to therapeutic targets in the central nervous system. The barrier is maintained by membrane bound efflux pumps efficiently transporting specific xenobiotics back into the blood. The efflux pump P-glycoprotein (P-gp, expressed at high levels in brain endothelial cells, has several drug substrates. Consequently, siRNA mediated silencing of the P-gp gene is one possible strategy how to improve the delivery of drugs to the brain. Herein, we investigated the potential of siRNA-chitosan nanoparticles in silencing P-gp in a BBB model. We show that the transfection of rat brain endothelial cells mediated effective knockdown of P-gp with subsequent decrease in P-gp substrate efflux. This resulted in increased cellular delivery and efficacy of the model drug doxorubicin.

  11. 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)

  12. Dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) of photodynamic therapy (PDT) outcome and associated changes in the blood-brain barrier following Pc 4-PDT of glioma in an athymic nude rat model

    Science.gov (United States)

    Belle, Vaijayantee; Anka, Ali; Cross, Nathan; Thompson, Paul; Mott, Eric; Sharma, Rahul; Gray, Kayla; Zhang, Ruozhen; Xu, Yueshuo; Sun, Jiayang; Flask, Chris A.; Oleinick, Nancy L.; Dean, David

    2012-02-01

    Introduction: Dynamic Contrast-Enhanced-Magnetic Resonance Imaging (DCE-MRI) appears to provide an unambiguous means of tracking the outcome of photodynamic therapy (PDT) of brain tumors with the photosensitizer Pc 4. The increase in Gd enhancement observed after Pc 4-PDT may be due to a temporary opening of the blood-brain-barrier which, as noted by others, may offer a therapeutic window. Methods: We injected 2.5 x 105 U87 cells into the brains of 9 athymic nude rats. After 8-9 days peri-tumor DCE-MRI images were acquired on a 7.0 T microMRI scanner before and after the administration of 150 μL Gd. DCE-MRI scans were repeated three times following Pc 4-PDT. Results: The average, normalized peak enhancement in the tumor region, approximately 30-90 seconds after Gd administration, was 1.31 times greater than baseline (0.03 Standard Error [SE]) prior to PDT and was 1.44 (0.02 SE) times baseline in the first Post-PDT scans (Day 11), a statistically significant (p ~ 0.014, N=8) increase over the Pre- PDT scans, and was 1.38 (0.02 SE) times baseline in the second scans (Day 12), also a statistically significant (p ~ 0.008, N=7) increase. Observations were mixed in the third Post-PDT scans (Day 13), averaging 1.29 (0.03 SE) times baseline (p ~ 0.66, N=7). Overall a downward trend in enhancement was observed from the first to the third Post-PDT scans. Discussion: DCE-MRI may provide an unambiguous indication of brain tumor PDT outcome. The initial increase in DCE-MRI signal may correlate with a temporary, PDT-induced opening of the blood-brain-barrier, creating a potential therapeutic window.

  13. 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.

  14. 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.

  15. Transgenic over-expression of slit2 enhances disruption of blood-brain barrier and increases cell death after traumatic brain injury in mice.

    Science.gov (United States)

    Li, Shuai; Li, Hang; He, Xiao-Fei; Li, Ge; Zhang, Qun; Liang, Feng-Ying; Jia, Huan-Huan; Li, Jiang-Chao; Huang, Ren; Pei, Zhong; Wang, Li-Jing; Zhang, Yu

    2016-09-19

    Traumatic brain injury (TBI) is the leading cause of mortality and disability among male adolescents and young adults; and mild traumatic brain injury is the most common type of traumatic brain injury. The disruption of blood-brain barrier (BBB) plays an important role in brain trauma. Previously, we have found that slit2, a member of slit protein family, increases permeability of BBB. In the present study, we examined the role of slit2 in the pathogenesis of mild TBI in a mouse model of micro TBI. Rhodamine BandPI (PropidiumIodide) staining were used to detect the permeability of BBB and cell death, respectively. The leakage of Rhodamine B and cell death were significantly increased in Slit2-Tg mice than in C57 control mice after micro TBI. The present results suggest that over expression of slit2 plays a detrimental role in the pathophysiology of mild TBI.

  16. Dopamine D2-receptor imaging with [sup 123]I-iodobenzamide SPECT in migraine patients abusing ergotamine: does ergotamine cross the blood brain barrier

    Energy Technology Data Exchange (ETDEWEB)

    Verhoeff, N.P.; Visser, W.H.; Ferrari, M.D.; Saxena, P.R.; Royen, E.A. van (Erasmus Univ., Rotterdam (Netherlands))

    1993-10-01

    Two migraine patients were studied by in vivo SPECT using the dopamine D2-receptor specific radioligand [sup 123]I-3-iodo-6-methoxybenzamide ([sup 123]I-IBZM) during ergotamine abuse and after withdrawal. Results were compared with 15 healthy controls. Striatum/cerebellum and striatum/occipital cortex ratios of count rate density were calculated as a semiquantitative measurement for striatal dopamine D2-receptor binding potential. No differences were found in striatal uptake of [sup 123]I-IBZM between healthy controls and the patients when on or off ergotamine. Preliminary evidence suggests that ergotamine may not occupy striatal dopamine D2-receptors to a large extent and thus may not cross the blood brain barrier in large quantities. 23 refs., 3 figs.

  17. Mechanism of blood-brain barrier impairment after mild traumatic brain injury caused by blast shock waves and its relationship with delayed nerve dysfunction

    Directory of Open Access Journals (Sweden)

    Zhao-xi XU

    2016-06-01

    Full Text Available Mild traumatic brain injury (mTBI caused by blast shock waves (BSWs is one of the most common injuries among soldiers in the war. Such mTBI can also happen in civilians if exposed to shock waves of accidental explosion disasters, bomb attacks by terrorists and so on. This injury often results in cognitive problems, memory dysfunction and emotional disorder, and these neurological deficits are closely related to the dysfunction or disruption of the blood-brain barrier (BBB. The present paper discusses mainly the relationship between dysfunction or disruption of BBB and inflammatory reaction in mild brain injury associated with explosive shock wave and effects of early intervention of oxidative stress injury, repairing the BBB and blocking inflammation on relieving delayed neurological deficits. DOI: 10.11855/j.issn.0577-7402.2016.05.15

  18. The effects of Tanshinone IIA on blood-brain barrier and brain edema after transient middle cerebral artery occlusion in rats.

    Science.gov (United States)

    Tang, Chao; Xue, Hongli; Bai, Changlin; Fu, Rong; Wu, Anhua

    2010-12-01

    Disruption of blood-brain barrier (BBB) and edema formation play a key role in the development of neurological dysfunction after cerebral ischemia. In this study, the effects of Tanshinone IIA (Tan IIA), one of the active ingredients of Salvia miltiorrhiza root, on the BBB and brain edema after transient middle cerebral artery occlusion in rats were examined. Our study demonstrated that Tan IIA reduced brain infarct area, water content in the ischemic hemisphere. Furthermore, Tan IIA significantly decreased BBB permeability to Evans blue, suppressed the expression of intercellular adhesion molecule-1 (ICAM-1), matrix metalloproteinase-9 (MMP-9), inhibited the degradation of tight junction proteins zonula occludens-1 (ZO-1) and Occludin. These results demonstrated that Tan IIA was effective for attenuating the extent of brain edema formation in response to ischemia injury in rats, partly by Tan IIA's protective effect on the BBB. Our results may have implications in the treatment of brain edema in cerebral ischemia.

  19. Investigation of Functionalized Poly(N,N-dimethylacrylamide)-block-polystyrene Nanoparticles As Novel Drug Delivery System to Overcome the Blood-Brain Barrier In Vitro.

    Science.gov (United States)

    Gregori, Maria; Bertani, Daniela; Cazzaniga, Emanuela; Orlando, Antonina; Mauri, Michele; Bianchi, Alberto; Re, Francesca; Sesana, Silvia; Minniti, Stefania; Francolini, Maura; Cagnotto, Alfredo; Salmona, Mario; Nardo, Luca; Salerno, Domenico; Mantegazza, Francesco; Masserini, Massimo; Simonutti, Roberto

    2015-12-01

    In the search of new drug delivery carriers for the brain, self-assembled nanoparticles (NP) were prepared from poly(N,N-dimethylacrylamide)-block-polystyrene polymer. NP displayed biocompatibility on cultured endothelial cells, macrophages and differentiated SH-SY5Y neuronal-like cells. The surface-functionalization of NP with a modified fragment of human Apolipoprotein E (mApoE) enhanced the uptake of NP by cultured human brain capillary endothelial cells, as assessed by confocal microscopy, and their permeability through a Transwell Blood Brain Barrier model made with the same cells, as assessed by fluorescence. Finally, mApoE-NP embedding doxorubicin displayed an enhanced release of drug at low pH, suggesting the potential use of these NP for the treatment of brain tumors.

  20. The permeation of dynorphin A 1-6 across the blood brain barrier and its effect on bovine brain microvessel endothelial cell monolayer permeability.

    Science.gov (United States)

    Sloan, Courtney D Kuhnline; Audus, Kenneth L; Aldrich, Jane V; Lunte, Susan M

    2012-12-01

    Dynorphin A 1-17 (Dyn A 1-17) is an endogenous neuropeptide known to act at the kappa opioid receptor; it has been implicated in a number of neurological disorders, including neuropathic pain, stress, depression, and Alzheimer's and Parkinson's diseases. The investigation of Dyn A 1-17 metabolism at the blood-brain barrier (BBB) is important since the metabolites exhibit unique biological functions compared to the parent compound. In this work, Dyn A 1-6 is identified as a metabolite of Dyn A 1-17 in the presence of bovine brain microvessel endhothelial cells (BBMECs), using LC-MS/MS. The transport of Dyn A 1-6 at the BBB was examined using this in vitro cell culture model of the BBB. Furthermore, the permeation of the BBB by the low molecular weight permeability marker fluorescein was characterized in the presence and absences of Dyn A 1-6.

  1. Blood-brain Barrier Permeability of Antibacterial Drugs:Literature Review and Analysis%抗菌药物血脑屏障通透能力概述

    Institute of Scientific and Technical Information of China (English)

    黄佳; 白婕; 赵志刚

    2012-01-01

      本文通过对抗菌药物通过血脑屏障及其影响因素进行分析和总结,发现β-内酰胺及酶抑制剂、第三代头孢菌素和万古霉素等抗菌药物在脑膜炎时的血脑屏障通透率较为理想,抗菌效果显著,安全性较高,可广泛用于神经外科。%  Through analyzing and summarizing the blood-brain barrier permeability rate of different antimicrobials and factors, we found that β-Lactam andβ-Lactam enzyme inhibitors antibiotics, third-generation cephalosporins and vancomycin were widely used in neurosurgery because of the low toxicity and good penetration into cerebrospinal fluid in the presence of meningitis.

  2. Expression of Iron-Related Proteins at the Neurovascular Unit Supports Reduction and Reoxidation of Iron for Transport Through the Blood-Brain Barrier

    DEFF Research Database (Denmark)

    Burkhart, Annette; Skjørringe, Tina; Johnsen, Kasper Bendix;

    2015-01-01

    The mechanisms for iron transport through the blood-brain barrier (BBB) remain a controversy. We analyzed for expression of mRNA and proteins involved in oxidation and transport of iron in isolated brain capillaries from dietary normal, iron-deficient, and iron-reverted rats. The expression...... was also investigated in isolated rat brain endothelial cells (RBECs) and in immortalized rat brain endothelial (RBE4) cells grown as monoculture or in hanging culture inserts with defined BBB properties. Transferrin receptor 1, ferrireductases Steap 2 and 3, divalent metal transporter 1 (DMT1...... cells provide the machinery for receptor-mediated uptake of ferric iron-containing transferrin. Ferric iron can then undergo reduction to ferrous iron by ferrireductases inside endosomes followed by DMT1-mediated pumping into the cytosol and subsequently cellular export by ferroportin. The expression...

  3. In vitro blood-brain barrier models for drug research: state-of-the-art and new perspectives on reconstituting these models on artificial basement membrane platforms.

    Science.gov (United States)

    Banerjee, Jayati; Shi, Yejiao; Azevedo, Helena S

    2016-09-01

    In vitro blood-brain barrier (BBB) models are indispensable screening tools for obtaining early information about the brain-penetrating behaviour of promising drug candidates. Until now, in vitro BBB models have focused on investigating the interplay among cellular components of neurovascular units and the effect of fluidic sheer stress in sustaining normal BBB phenotype and functions. However, an area that has received less recognition is the role of the noncellular basement membrane (BM) in modulating BBB physiology. This review describes the state-of-the-art on in vitro BBB models relevant in drug discovery research and highlights their strengths, weaknesses and the utility potential of some of these models in testing the permeability of nanocarriers as vectors for delivering therapeutics to the brain. Importantly, our review also introduces a new concept of engineering artificial BM platforms for reconstituting BBB models in vitro.

  4. 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.

  5. Exposure to 900 MHz electromagnetic fields activates the mkp-1/ERK pathway and causes blood-brain barrier damage and cognitive impairment in rats.

    Science.gov (United States)

    Tang, Jun; Zhang, Yuan; Yang, Liming; Chen, Qianwei; Tan, Liang; Zuo, Shilun; Feng, Hua; Chen, Zhi; Zhu, Gang

    2015-03-19

    With the rapid increase in the number of mobile phone users, the potential adverse effects of the electromagnetic field radiation emitted by a mobile phone has become a serious concern. This study demonstrated, for the first time, the blood-brain barrier and cognitive changes in rats exposed to 900 MHz electromagnetic field (EMF) and aims to elucidate the potential molecular pathway underlying these changes. A total of 108 male Sprague-Dawley rats were exposed to a 900 MHz, 1 mW/cm(2) EMF or sham (unexposed) for 14 or 28 days (3h per day). The specific energy absorption rate (SAR) varied between 0.016 (whole body) and 2 W/kg (locally in the head). In addition, the Morris water maze test was used to examine spatial memory performance determination. Morphological changes were investigated by examining ultrastructural changes in the hippocampus and cortex, and the Evans Blue assay was used to assess blood brain barrier (BBB) damage. Immunostaining was performed to identify heme oxygenase-1 (HO-1)-positive neurons and albumin extravasation detection. Western blot was used to determine HO-1 expression, phosphorylated ERK expression and the upstream mediator, mkp-1 expression. We found that the frequency of crossing platforms and the percentage of time spent in the target quadrant were lower in rats exposed to EMF for 28 days than in rats exposed to EMF for 14 days and unexposed rats. Moreover, 28 days of EMF exposure induced cellular edema and neuronal cell organelle degeneration in the rat. In addition, damaged BBB permeability, which resulted in albumin and HO-1 extravasation were observed in the hippocampus and cortex. Thus, for the first time, we found that EMF exposure for 28 days induced the expression of mkp-1, resulting in ERK dephosphorylation. Taken together, these results demonstrated that exposure to 900 MHz EMF radiation for 28 days can significantly impair spatial memory and damage BBB permeability in rat by activating the mkp-1/ERK pathway.

  6. 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.

  7. Passage of Magnetic Tat-Conjugated Fe3O4@SiO2 Nanoparticles Across In Vitro Blood-Brain Barrier

    Science.gov (United States)

    Zhao, Xueqin; Shang, Ting; Zhang, Xiaodan; Ye, Ting; Wang, Dajin; Rei, Lei

    2016-10-01

    Delivery of diagnostic or therapeutic agents across the blood-brain barrier (BBB) remains a major challenge of brain disease treatment. Magnetic nanoparticles are actively being developed as drug carriers due to magnetic targeting and subsequently reduced off-target effects. In this paper, we developed a magnetic SiO2@Fe3O4 nanoparticle-based carrier bound to cell-penetrating peptide Tat (SiO2@Fe3O4 -Tat) and studied its fates in accessing BBB. SiO2@Fe3O4-Tat nanoparticles (NPs) exhibited suitable magnetism and good biocompatibility. NPs adding to the apical chamber of in vitro BBB model were found in the U251 glioma cells co-cultured at the bottom of the Transwell, indicating that particles passed through the barrier and taken up by glioma cells. Moreover, the synergistic effects of Tat and magnetic field could promote the efficient cellular internalization and the permeability across the barrier. Besides, functionalization with Tat peptide allowed particles to locate into the nucleus of U251 cells than the non-conjugated NPs. These results suggest that SiO2@Fe3O4-Tat NPs could penetrate the BBB through the transcytosis of brain endothelial cells and magnetically mediated dragging. Therefore, SiO2@Fe3O4-Tat NPs could be exploited as a potential drug delivery system for chemotherapy and gene therapy of brain disease.

  8. Localized Down-regulation of P-glycoprotein by Focused Ultrasound and Microbubbles induced Blood-Brain Barrier Disruption in Rat Brain

    Science.gov (United States)

    Cho, HongSeok; Lee, Hwa-Youn; Han, Mun; Choi, Jong-ryul; Ahn, Sanghyun; Lee, Taekwan; Chang, Yongmin; Park, Juyoung

    2016-01-01

    Multi-drug resistant efflux transporters found in Blood-Brain Barrier (BBB) acts as a functional barrier, by pumping out most of the drugs into the blood. Previous studies showed focused ultrasound (FUS) induced microbubble oscillation can disrupt the BBB by loosening the tight junctions in the brain endothelial cells; however, no study was performed to investigate its impact on the functional barrier of the BBB. In this study, the BBB in rat brains were disrupted using the MRI guided FUS and microbubbles. The immunofluorescence study evaluated the expression of the P-glycoprotein (P-gp), the most dominant multi-drug resistant protein found in the BBB. Intensity of the P-gp expression at the BBB disruption (BBBD) regions was significantly reduced (63.2 ± 18.4%) compared to the control area. The magnitude of the BBBD and the level of the P-gp down-regulation were significantly correlated. Both the immunofluorescence and histologic analysis at the BBBD regions revealed no apparent damage in the brain endothelial cells. The results demonstrate that the FUS and microbubbles can induce a localized down-regulation of P-gp expression in rat brain. The study suggests a clinically translation of this method to treat neural diseases through targeted delivery of the wide ranges of brain disorder related drugs. PMID:27510760

  9. Localized Down-regulation of P-glycoprotein by Focused Ultrasound and Microbubbles induced Blood-Brain Barrier Disruption in Rat Brain

    Science.gov (United States)

    Cho, Hongseok; Lee, Hwa-Youn; Han, Mun; Choi, Jong-Ryul; Ahn, Sanghyun; Lee, Taekwan; Chang, Yongmin; Park, Juyoung

    2016-08-01

    Multi-drug resistant efflux transporters found in Blood-Brain Barrier (BBB) acts as a functional barrier, by pumping out most of the drugs into the blood. Previous studies showed focused ultrasound (FUS) induced microbubble oscillation can disrupt the BBB by loosening the tight junctions in the brain endothelial cells; however, no study was performed to investigate its impact on the functional barrier of the BBB. In this study, the BBB in rat brains were disrupted using the MRI guided FUS and microbubbles. The immunofluorescence study evaluated the expression of the P-glycoprotein (P-gp), the most dominant multi-drug resistant protein found in the BBB. Intensity of the P-gp expression at the BBB disruption (BBBD) regions was significantly reduced (63.2 ± 18.4%) compared to the control area. The magnitude of the BBBD and the level of the P-gp down-regulation were significantly correlated. Both the immunofluorescence and histologic analysis at the BBBD regions revealed no apparent damage in the brain endothelial cells. The results demonstrate that the FUS and microbubbles can induce a localized down-regulation of P-gp expression in rat brain. The study suggests a clinically translation of this method to treat neural diseases through targeted delivery of the wide ranges of brain disorder related drugs.

  10. Confounding parameters in preclinical assessment of blood-brain barrier permeation: an overview with emphasis on species differences and effect of disease states.

    Science.gov (United States)

    Deo, Anand K; Theil, Frank-Peter; Nicolas, Jean-Marie

    2013-05-06

    Drug delivery across the brain-blood interfaces is a complex process involving physicochemical drug properties, transporters, enzymes, and barrier dysfunction in diseased conditions. Intact blood-brain barrier (BBB) limits the entry of potentially harmful compounds into the brain but may also reduce the CNS permeability of therapeutic agents. BBB permeability is typically assessed by measuring brain-to-plasma ratio in rodents (referred to as B/P ratio, BB, or Kp, often calculated as logBB), an approach that suffers significant limitations as discussed in the present review. Kp is not a permeability measurement but a partition coefficient mainly driven by the relative binding to plasma and brain tissue components including lipids, phospholipids, and proteins. Compounds with high Kp are often lipophilic with low free fraction available to mediate CNS activities. Efforts should be more concentrated on measuring pharmacologically relevant free drug concentrations at the target site. Using healthy rodents to predict brain penetration in patients might be biased due to species differences in BBB-related parameters such as transporter expression and functional activities. In addition, pathophysiological conditions such as aging, multiple sclerosis, and Alzheimer's and Parkinson's diseases have been described to affect BBB permeability, with barrier leakage and altered transporter activity. The impact of these species differences and disease states on drug delivery to the brain is largely overlooked. More data are needed to better understand their clinical implication in order to design more appropriate screening strategies and ultimately better mitigate the risk for failure in late stage development.

  11. Sphingosine 1 Phosphate at the Blood Brain Barrier: Can the Modulation of S1P Receptor 1 Influence the Response of Endothelial Cells and Astrocytes to Inflammatory Stimuli?

    Directory of Open Access Journals (Sweden)

    Simona F Spampinato

    Full Text Available The ability of the Blood Brain Barrier (BBB to maintain proper barrier functions, keeping an optimal environment for central nervous system (CNS activity and regulating leukocytes' access, can be affected in CNS diseases. Endothelial cells and astrocytes are the principal BBB cellular constituents and their interaction is essential to maintain its function. Both endothelial cells and astrocytes express the receptors for the bioactive sphingolipid S1P. Fingolimod, an immune modulatory drug whose structure is similar to S1P, has been approved for treatment in multiple sclerosis (MS: fingolimod reduces the rate of MS relapses by preventing leukocyte egress from the lymph nodes. Here, we examined the ability of S1P and fingolimod to act on the BBB, using an in vitro co-culture model that allowed us to investigate the effects of S1P on endothelial cells, astrocytes, and interactions between the two. Acting selectively on endothelial cells, S1P receptor signaling reduced cell death induced by inflammatory cytokines. When acting on astrocytes, fingolimod treatment induced the release of a factor, granulocyte macrophage colony-stimulating factor (GM-CSF that reduced the effects of cytokines on endothelium. In an in vitro BBB model incorporating shear stress, S1P receptor modulation reduced leukocyte migration across the endothelial barrier, indicating a novel mechanism that might contribute to fingolimod efficacy in MS treatment.

  12. PET-CT imaging with [18F]-gefitinib to measure Abcb1a/1b (P-gp) and Abcg2 (Bcrp1) mediated drug-drug interactions at the murine blood-brain barrier

    NARCIS (Netherlands)

    Vlaming, M.L.H.; Läppchen, T.; Jansen, H.T.; Kivits, S.; Driel, A. van; Steeg, E. van der; Hoorn, J.W. van der; Sio, C.F.; Steinbach, O.C.; Groot, J. de

    2015-01-01

    Introduction: The efflux transporters P-glycoprotein (P-gp, ABCB1) and breast cancer resistance protein (BCRP, ABCG2) are expressed at the blood-brain barrier (BBB), and can limit the access of a wide range of drugs to the brain. In this study we developed a PET-CT imaging method for non-invasive, q

  13. Evaluation of [18F]MC225 as a PET radiotracer for measuring P-glycoprotein function at the blood-brain barrier in rats: Kinetics, metabolism, and selectivity.

    NARCIS (Netherlands)

    Savolainen, Heli; Windhorst, Albert D.; Elsinga, Philip H.; Cantore, Mariangela; Colabufo, Nicola A.; Willemsen, Antoon T.M.; Luurtsema, Geert

    2016-01-01

    P-glycoprotein is a protective efflux transporter at the blood-brain barrier showing altered function in many neurological disorders. The purpose of this study was to validate [18F]MC225 as a radiotracer for measuring P-glycoprotein function with positron emission tomography. Three groups of Sprague

  14. The use of biopartitioning micellar chromatography and immobilized artificial membrane column for in silico and in vitro determination of blood-brain barrier penetration of phenols.

    Science.gov (United States)

    Stępnik, Katarzyna E; Malinowska, Irena

    2013-04-19

    Biopartitioning Micellar Chromatography (BMC) is a mode of micellar liquid chromatography that uses C18 stationary phases and micellar mobile phases of Brij35 under adequate experimental conditions and can be useful to mimic human drug absorption, blood-brain barrier distribution or partitioning processes in biological systems. BMC system can be useful in constructing good predictive models because the characteristics of the BMC system are similar to biological barriers and extracellular fluids. Immobilized Artificial Membrane (IAM) chromatography uses stationary phase which consists of a monolayer of phosphatidylcholine covalently immobilized on an inert silica support. IAM columns are thought to mimic very closely a membrane bilayer and are used in a HPLC system with a physiological buffer as eluent. In this paper the usefulness of BMC and IAM system for in silico and in vitro determination of blood-brain barrier (BBB) penetration of phenols has been demonstrated. The most important pharmacokinetic parameters of brain have been obtained for the determination of BBB penetration, i.e. BBB permeability - surface area product (PS), usually given as a logPS, brain/plasma equilibration rate (log(PS×fu,brain)) and fraction unbound in plasma (Fu). Moreover, the relationships between retention of eighteen phenols and different parameters of molecular size, lipophilicity and BBB penetration were studied. Extrapolated to pure water values of the logarithms of retention factors (logkw) have been compared with the corresponding octanol-water partition coefficient (logPo-w) values of the solutes. In addition, different physicochemical parameters from Foley's equation for BMC system have been collated with the chromatographic data. The Linear Solvation Energy Relationship (LSER) using Abraham model for the describing of phenols penetration across BBB has been used. Four equations were developed as a multiple linear regression using retention data from IAM and BMC system (QRAR

  15. Effects of Lead and Cadmium on Brain Endothelial Cell Survival, Monolayer Permeability, and Crucial Oxidative Stress Markers in an in Vitro Model of the Blood-Brain Barrier

    Directory of Open Access Journals (Sweden)

    Shakila Tobwala

    2014-06-01

    Full Text Available Oxidative stress, which is the loss of balance between antioxidant defense and oxidant production in the cells, is implicated in the molecular mechanism of heavy metal-induced neurotoxicity. Given the key role of lead (Pb and cadmium (Cd in inducing oxidative stress, we investigated their role in disrupting the integrity and function of immortalized human brain microvascular endothelial cells (hCMEC/D3. To study this, hCMEC/D3 cells were exposed to control media or to media containing different concentrations of Pb or Cd. Those exposed to Pb or Cd showed significantly higher oxidative stress than the untreated group, as indicated by cell viability, reactive oxygen species (ROS, glutathione (GSH levels, and catalase enzyme activity. Pb also induced oxidative stress-related disruption of the hCMEC/D3 cell monolayer, as measured by trans-endothelial electrical resistance (TEER, the dextran permeability assay, and the level of tight junction protein, zona occluden protein (ZO-2. However, no significant disruption in the integrity of the endothelial monolayer was seen with cadmium at the concentrations used. Taken together, these results show that Pb and Cd induce cell death and dysfunction in hCMEC/D3 cells and, in the case of Pb, barrier disruption. This suggests blood brain barrier (BBB dysfunction as a contributing mechanism in Pb and Cd neurotoxicities.

  16. Traffic jam at the blood-brain barrier promotes greater accumulation of Alzheimer's disease amyloid-β proteins in the cerebral vasculature.

    Science.gov (United States)

    Agyare, Edward K; Leonard, Sarah R; Curran, Geoffry L; Yu, Caroline C; Lowe, Val J; Paravastu, Anant K; Poduslo, Joseph F; Kandimalla, Karunya K

    2013-05-06

    Amyloid-β (Aβ) deposition in the brain vasculature results in cerebral amyloid angiopathy (CAA), which occurs in about 80% of Alzheimer's disease (AD) patients. While Aβ42 predominates parenchymal amyloid plaques in AD brain, Aβ40 is prevalent in the cerebrovascular amyloid. Dutch mutation of Aβ40 (E22Q) promotes aggressive cerebrovascular accumulation and leads to severe CAA in the mutation carriers; knowledge of how DutchAβ40 drives this process more efficiently than Aβ40 could reveal various pathophysiological events that promote CAA. In this study we have demonstrated that DutchAβ40 shows preferential accumulation in the blood-brain-barrier (BBB) endothelial cells due to its inefficient blood-to-brain transcytosis. Consequently, DutchAβ40 establishes a permeation barrier in the BBB endothelium, prevents its own clearance from the brain, and promotes the formation of amyloid deposits in the cerebral microvessels. The BBB endothelial accumulation of native Aβ40 is not robust enough to exercise such a significant impact on its brain clearance. Hence, the cerebrovascular accumulation of Aβ40 is slow and may require other copathologies to precipitate into CAA. In conclusion, the magnitude of Aβ accumulation in the BBB endothelial cells is a critical factor that promotes CAA; hence, clearing vascular endothelium of Aβ proteins may halt or even reverse CAA.

  17. Postulated Role of Vasoactive Neuropeptide-Related Immunopathology of the Blood Brain Barrier and Virchow-Robin Spaces in the Aetiology of Neurological-Related Conditions

    Directory of Open Access Journals (Sweden)

    D. R. Staines

    2008-01-01

    Full Text Available Vasoactive neuropeptides (VNs such as pituitary adenylate cyclase-activating polypeptide (PACAP and vasoactive intestinal peptide (VIP have critical roles as neurotransmitters, vasodilators including perfusion and hypoxia regulators, as well as immune and nociception modulators. They have key roles in blood vessels in the central nervous system (CNS including maintaining functional integrity of the blood brain barrier (BBB and blood spinal barrier (BSB. VNs are potent activators of adenylate cyclase and thus also have a key role in cyclic AMP production affecting regulatory T cell and other immune functions. Virchow-Robin spaces (VRSs are perivascular compartments surrounding small vessels within the CNS and contain VNs. Autoimmunity of VNs or VN receptors may affect BBB and VRS function and, therefore, may contribute to the aetiology of neurological-related conditions including multiple sclerosis, Parkinson's disease, and amyotrophic lateral sclerosis. VN autoimmunity will likely affect CNS and immunological homeostasis. Various pharmacological and immunological treatments including phosphodiesterase inhibitors and plasmapheresis may be indicated.

  18. New therapeutic strategies regarding endovascular treatment of glioblastoma, the role of the blood-brain barrier and new ways to bypass it.

    Science.gov (United States)

    Peschillo, S; Caporlingua, A; Diana, F; Caporlingua, F; Delfini, R

    2016-10-01

    The treatment protocols for glioblastoma multiforme (GBM) involve a combination of surgery, radiotherapy and adjuvant chemotherapy. Despite this multimodal approach, the prognosis of patients with GBM remains poor and there is an urgent need to develop novel strategies to improve quality of life and survival in this population. In an effort to improve outcomes, intra-arterial drug delivery has been used in many recent clinical trials; however, their results have been conflicting. The blood-brain barrier (BBB) is the major obstacle preventing adequate concentrations of chemotherapy agents being reached in tumor tissue, regardless of the method of delivering the drugs. Therapeutic failures have often been attributed to an inability of drugs to cross the BBB. However, during the last decade, a better understanding of BBB physiology along with the development of new technologies has led to innovative methods to circumvent this barrier. This paper focuses on strategies and techniques used to bypass the BBB already tested in clinical trials in humans and also those in their preclinical stage. We also discuss future therapeutic scenarios, including endovascular treatment combined with BBB disruption techniques, for patients with GBM.

  19. 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

    is involved during BBB breakdown. We studied the type 2 angiotensin receptor AT(2) because of its suggested neuroprotective role. Two models of brain inflammation were used to distinguish solute versus cellular barrier functions. Both leukocytes and horseradish peroxidase (HRP) accumulated in the perivascular...

  20. Efavirenz and Metabolites in Cerebrospinal Fluid: Relationship with CYP2B6 c.516G→T Genotype and Perturbed Blood-Brain Barrier Due to Tuberculous Meningitis

    Science.gov (United States)

    Chau, Tran Thi Hong; Fisher, Martin; Nelson, Mark; Winston, Alan; Else, Laura; Carr, Daniel F.; Taylor, Steven; Ustianowski, Andrew; Back, David; Pirmohamed, Munir; Solomon, Tom; Farrar, Jeremy; Törok, M. Estée; Khoo, Saye

    2016-01-01

    Efavirenz (EFZ) has been associated with neuropsychiatric side effects. Recently, the 8-hydroxy-EFZ (8OH-EFZ) metabolite has been shown to be a potent neurotoxin in vitro, inducing neuronal damage at concentrations of 3.3 ng/ml. EFZ induced similar neuronal damage at concentrations of 31.6 ng/ml. We investigated the effect of genotype and blood-brain barrier integrity on EFZ metabolite concentrations in cerebrospinal fluid (CSF). We measured CSF drug concentrations in subjects from two separate study populations: 47 subjects with tuberculous meningitis (TBM) coinfection in Vietnam receiving 800 mg EFZ with standard antituberculous treatment and 25 subjects from the PARTITION study in the United Kingdom without central nervous system infection receiving 600 mg EFZ. EFZ and metabolite concentrations in CSF and plasma were measured and compared with estimates of effectiveness and neurotoxicity from available published in vitro and in vivo data. The effect of the CYP2B6 c.516G→T genotype (GG genotype, fast EFV metabolizer status; GT genotype, intermediate EFV metabolizer status; TT genotype, slow EFV metabolizer status) was examined. The mean CSF concentrations of EFZ and 8OH-EFZ in the TBM group were 60.3 and 39.3 ng/ml, respectively, and those in the no-TBM group were 15.0 and 5.9 ng/ml, respectively. Plasma EFZ and 8OH-EFZ concentrations were similar between the two groups. CSF EFZ concentrations were above the in vitro toxic concentration in 76% of samples (GG genotype, 61%; GT genotype, 90%; TT genotype, 100%) in the TBM group and 13% of samples (GG genotype, 0%; GT genotype, 18%; TT genotype, 50%) in the no-TBM group. CSF 8OH-EFZ concentrations were above the in vitro toxic concentration in 98% of the TBM group and 87% of the no-TBM group; levels were independent of genotype but correlated with the CSF/plasma albumin ratio. Potentially neurotoxic concentrations of 8OH-EFZ are frequently observed in CSF independently of the CYP2B6 genotype, particularly in those

  1. Lipid-Core Nanocapsules Act as a Drug Shuttle Through the Blood Brain Barrier and Reduce Glioblastoma After Intravenous or Oral Administration.

    Science.gov (United States)

    Rodrigues, Stephen F; Fiel, Luana A; Shimada, Ana L; Pereira, Natalia R; Guterres, Silvia S; Pohlmann, Adriana R; Farsky, Sandra H

    2016-05-01

    Lipid-core nanocapsules (LNC) are formed by an organogel surrounded by poly(epsilon-caprolactone) and stabilized by polysorbate 80. LNCs increase the concentration of drugs in the brain after oral or intravenous administration. We proposed to determine whether the drug is released from the LNC to cross the blood brain barrier (BBB) or the drug-loaded LNCs can cross the BBB to release the drug. We synthesized a Rhodamine B-polymer conjugate to prepare a fluorescent-labeled LNC formulation, and intravital microscopy was used to determine the ability of the LNCs to cross the brain barrier using different administration routes in C57BI/6 mice. A glioblastoma model was used to determine the impact of the LNC as a shuttle for treatment. After pial vessel exposure, intense fluorescence was detected inside the vessels 10 min after intravenous or 20 min after intraperitoneal injections of fluorescent-labeled LNC. The fluorescence was observed in the perivascular tissue after 30 and 60 min, respectively. Increased tissue fluorescence was detected 240 min after oral administration. The integrity of the barrier was determined during the experiments. Normal leukocyte and platelet adhesion to the vessel wall indicated that Rhodamine B-labeled LNC did not cause pial vessel alterations. After intravenous or oral administration, Rhodamine B-labeled LNC-containing co-encapsulated indomethacin and indomethacin ethyl ester exhibited similar behavior in pial vessels, being more efficient in the treatment of mice with glioblastoma than indomethacin in solution. Therefore, we demonstrated that LNCs act as drug shuttles through the BBB, delivering drugs in brain tissue with high efficiency and reducing glioblastoma after intravenous or oral administration.

  2. Live cell imaging techniques to study T cell trafficking across the blood-brain barrier in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Coisne Caroline

    2013-01-01

    Full Text Available Abstract Background The central nervous system (CNS is an immunologically privileged site to which access for circulating immune cells is tightly controlled by the endothelial blood–brain barrier (BBB located in CNS microvessels. Under physiological conditions immune cell migration across the BBB is low. However, in neuroinflammatory diseases such as multiple sclerosis, many immune cells can cross the BBB and cause neurological symptoms. Extravasation of circulating immune cells is a multi-step process that is regulated by the sequential interaction of different adhesion and signaling molecules on the immune cells and on the endothelium. The specialized barrier characteristics of the BBB, therefore, imply the existence of unique mechanisms for immune cell migration across the BBB. Methods and design An in vitro mouse BBB model maintaining physiological barrier characteristics in a flow chamber and combined with high magnification live cell imaging, has been established. This model enables the molecular mechanisms involved in the multi-step extravasation of T cells across the in vitro BBB, to be defined with high-throughput analyses. Subsequently these mechanisms have been verified in vivo using a limited number of experimental animals and a spinal cord window surgical technique. The window enables live observation of the dynamic interaction between T cells and spinal cord microvessels under physiological and pathological conditions using real time epifluorescence intravital imaging. These in vitro and in vivo live cell imaging methods have shown that the BBB endothelium possesses unique and specialized mechanisms involved in the multi-step T cell migration across this endothelial barrier under physiological flow. The initial T cell interaction with the endothelium is either mediated by T cell capture or by T cell rolling. Arrest follows, and then T cells polarize and especially CD4+ T cells crawl over long distances against the direction of

  3. A novel hypothesis of blood-brain barrier (BBB development and in vitro BBB model: neural stem cell is the driver of BBB formation and maintenance

    Directory of Open Access Journals (Sweden)

    Jian Lu

    2012-02-01

    Full Text Available There is an ongoing effort to develop in vitro models for the blood-brain barrier (BBB research and the central nervous system (CNS drug screening. But the phenotypes of the existing in vitro models are still very remote from those found in vivo. The trouble in establishing in vitro BBB models comes from the unclear mechanism of the BBB formation and maintenance. The astrocytes have been found to be responsible for the maintenance of the BBB, but the studies of the CNS development have shown that the BBB formation starts largely before the gliogenesis. We hypothesize here that the neural stem cell is the real driver of the BBB formation, development and maintenance. The formation of the BBB is initiated by the neural stem cells during the earliest stage of CNS angiogenesis. The maintenance of the BBB is driven by the soluble signals produced by the neural stem cells which exist in the dentate gyrus of the hippocampus and the subventricular zone throughout the life. The brain microvascular endothelial cells (BMEC-pericyte complex is the anatomical basis of the BBB. Based on our hypothesis we suggest using the neural stem cells to induce the BMEC-pericyte complex to establish in vitro BBB models. The further research on the role of the neural stem cells in the BBB formation and maintenance may elucidate the mechanism of the BBB development. [J Exp Integr Med 2012; 2(1.000: 39-43

  4. Structural Elucidation of the Cell-Penetrating Penetratin Peptide in Model Membranes at the Atomic Level: Probing Hydrophobic Interactions in the Blood-Brain Barrier.

    Science.gov (United States)

    Bera, Swapna; Kar, Rajiv K; Mondal, Susanta; Pahan, Kalipada; Bhunia, Anirban

    2016-09-06

    Cell-penetrating peptides (CPPs) have shown promise in nonpermeable therapeutic drug delivery, because of their ability to transport a variety of cargo molecules across the cell membranes and their noncytotoxicity. Drosophila antennapedia homeodomain-derived CPP penetratin (RQIKIWFQNRRMKWKK), being rich in positively charged residues, has been increasingly used as a potential drug carrier for various purposes. Penetratin can breach the tight endothelial network known as the blood-brain barrier (BBB), permitting treatment of several neurodegenerative maladies, including Alzheimer's disease, Parkinson's disease, and Huntington's disease. However, a detailed structural understanding of penetratin and its mechanism of action is lacking. This study defines structural features of the penetratin-derived peptide, DK17 (DRQIKIWFQNRRMKWKK), in several model membranes and describes a membrane-induced conformational transition of the DK17 peptide in these environments. A series of biophysical experiments, including high-resolution nuclear magnetic resonance spectroscopy, provides the three-dimensional structure of DK17 in different membranes mimicking the BBB or total brain lipid extract. Molecular dynamics simulations support the experimental results showing preferential binding of DK17 to particular lipids at atomic resolution. The peptide conserves the structure of the subdomain spanning residues Ile6-Arg11, despite considerable conformational variation in different membrane models. In vivo data suggest that the wild type, not a mutated sequence, enters the central nervous system. Together, these data highlight important structural and functional attributes of DK17 that could be utilized in drug delivery for neurodegenerative disorders.

  5. DNA sequences within glioma-derived extracellular vesicles can cross the intact blood-brain barrier and be detected in peripheral blood of patients

    Science.gov (United States)

    Lázaro-Ibáñez, Elisa; Peris-Celda, María; Alonso, Marta M.; Guzmán-De-Villoria, Juan; Fernández-Carballal, Carlos; de Mendivil, Ana Ortiz; García-Duque, Sara; Escobedo-Lucea, Carmen; Prat-Acín, Ricardo; Belda-Iniesta, Cristóbal; Ayuso-Sacido, Angel

    2017-01-01

    Tumor-cell-secreted extracellular vesicles (EVs) can cross the disrupted blood-brain barrier (BBB) into the bloodstream. However, in certain gliomas, the BBB remains intact, which might limit EVs release. To evaluate the ability of tumor-derived EVs to cross the BBB, we used an orthotopic xenotransplant mouse model of human glioma-cancer stem cells featuring an intact BBB. We demonstrated that all types of tumor cells-derived EVs−apoptotic bodies, shedding microvesicles and exosomes−cross the intact BBB and can be detected in the peripheral blood, which provides a minimally invasive method for their detection compared to liquid biopsies obtained from cerebrospinal fluid (CSF). Furthermore, these EVs can be readily distinguished from total murine EVs, since they carry human-specific DNA sequences relevant for GBM biology. In a small cohort of glioma patients, we finally demonstrated that peripheral blood EVs cargo can be successfully used to detect the presence of IDH1G395A, an essential biomarker in the current management of human glioma PMID:27902458

  6. The ameliorative effects of exercise on cognitive impairment and white matter injury from blood-brain barrier disruption induced by chronic cerebral hypoperfusion in adolescent rats.

    Science.gov (United States)

    Lee, Jae-Min; Park, Jong-Min; Song, Min Kyung; Oh, Yoo Joung; Kim, Chang-Ju; Kim, Youn-Jung

    2017-01-18

    Vascular dementia is the progressive change in blood vessels that leads to neuronal injuries in vulnerable areas induced by chronic cerebral hypoperfusion (CCH). CCH induces disruption of blood-brain barrier (BBB), and this BBB disruption can initiate the cognitive impairment and white matter injury. In the present study, we evaluated the effect of treadmill exercise on the cognitive impairment, white matter injury, and BBB disruption induced by CCH. Vascular dementia was induced by permanent bilateral common carotid arteries occlusion (BCCAO) in rats. The rats in the exercise group were made to run on a treadmill for 30min once a day for 14 weeks, starting 4 weeks after birth. Our results revealed that treadmill exercise group was alleviated the cognitive impairment and myelin degradation induced by CCH. The disruption of BBB after CCH indicates degradation of occludin, zonula occluden-1 (ZO-1), and up-regulation of matrix metalloproteinases (MMPs). Treadmill exercise may provide protective effects on BBB disruption from degradation of occludin, ZO-1, and overexpression of MMP-9 after CCH. These findings suggest that treadmill exercise ameliorates cognitive impairment and white matter injury from BBB disruption induced by CCH in rats. The present study will be valuable for means of prophylactic and therapeutic intervention for patients with CCH.

  7. Anti-infective therapy of blood-brain barrier and antibacterials%血脑屏障与抗菌药物的抗感染治疗

    Institute of Scientific and Technical Information of China (English)

    熊星华; 雷招宝; 贾东岗

    2010-01-01

    @@ 1 血脑屏障及其临床意义 细菌、病毒和真菌等可引起中枢神经系统感染CNS.CNS感染的主要临床表现有发热(有时伴有寒战)、头痛、呕吐、神经系统体征等,严重者可发生昏迷,小儿可出现惊厥.CNS感染发生率虽然不高,但病死率高,远期神经系统后遗症多,属于一类严重的感染性疾病.CNS的重要特点之一是存在血脑屏障(blood-brain barrier,BBB).由于许多抗菌药物不能通过BBB或通过得不多,在脑脊液(Cerebro-spinsdl fluid,CSF)和脑组织中达不到有效治疗浓度,因此治疗困难,预后较差.

  8. Pathogenic Triad in Bacterial Meningitis: Pathogen Invasion, NF-κB Activation, and Leukocyte Transmigration that Occur at the Blood-Brain Barrier.

    Science.gov (United States)

    Wang, Shifu; Peng, Liang; Gai, Zhongtao; Zhang, Lehai; Jong, Ambrose; Cao, Hong; Huang, Sheng-He

    2016-01-01

    Bacterial meningitis remains the leading cause of disabilities worldwide. This life-threatening disease has a high mortality rate despite the availability of antibiotics and improved critical care. The interactions between bacterial surface components and host defense systems that initiate bacterial meningitis have been studied in molecular and cellular detail over the past several decades. Bacterial meningitis commonly exhibits triad hallmark features (THFs): pathogen penetration, nuclear factor-kappaB (NF-κB) activation in coordination with type 1 interferon (IFN) signaling and leukocyte transmigration that occur at the blood-brain barrier (BBB), which consists mainly of brain microvascular endothelial cells (BMEC). This review outlines the progression of these early inter-correlated events contributing to the central nervous system (CNS) inflammation and injury during the pathogenesis of bacterial meningitis. A better understanding of these issues is not only imperative to elucidating the pathogenic mechanism of bacterial meningitis, but may also provide the in-depth insight into the development of novel therapeutic interventions against this disease.

  9. Measurement of blood-brain barrier permeability with t1-weighted dynamic contrast-enhanced MRI in brain tumors: a comparative study with two different algorithms.

    Science.gov (United States)

    Bergamino, Maurizio; Saitta, Laura; Barletta, Laura; Bonzano, Laura; Mancardi, Giovanni Luigi; Castellan, Lucio; Ravetti, Jean Louis; Roccatagliata, Luca

    2013-01-01

    The purpose of this study was to assess the feasibility of measuring different permeability parameters with T1-weighted dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) in order to investigate the blood brain-barrier permeability associated with different brain tumors. The Patlak algorithm and the extended Tofts-Kety model were used to this aim. Twenty-five adult patients with tumors of different histological grades were enrolled in this study. MRI examinations were performed at 1.5 T. Multiflip angle, fast low-angle shot, and axial 3D T1-weighted images were acquired to calculate T1 maps, followed by a DCE acquisition. A region of interest was placed within the tumor of each patient to calculate the mean value of different permeability parameters. Differences in permeability measurements were found between different tumor grades, with higher histological grades characterized by higher permeability values. A significant difference in transfer constant (K (trans)) values was found between the two methods on high-grade tumors; however, both techniques revealed a significant correlation between the histological grade of tumors and their K (trans) values. Our results suggest that DCE acquisition is feasible in patients with brain tumors and that K (trans) maps can be easily obtained by these two algorithms, even if the theoretical model adopted could affect the final results.

  10. Pathogenic triad in bacterial meningitis: pathogen invasion, NF-κB activation and leukocyte transmigration that occur at the Blood-Brain Barrier

    Directory of Open Access Journals (Sweden)

    Sheng-He eHuang

    2016-02-01

    Full Text Available Bacterial meningitis remains the leading cause of disabilities worldwide. This life-threatening disease has a high