WorldWideScience

Sample records for blood-brain barrier experiments

  1. The blood-brain barrier.

    Science.gov (United States)

    Obermeier, Birgit; Verma, Ajay; Ransohoff, Richard M

    2016-01-01

    In autoimmune neurologic disorders, the blood-brain barrier (BBB) plays a central role in immunopathogenesis, since this vascular interface is an entry path for cells and effector molecules of the peripheral immune system to reach the target organ, the central nervous system (CNS). The BBB's unique anatomic structure and the tightly regulated interplay of its cellular and acellular components allow for maintenance of brain homeostasis, regulation of influx and efflux, and protection from harm; these ensure an optimal environment for the neuronal network to function properly. In both health and disease, the BBB acts as mediator between the periphery and the CNS. For example, immune cell trafficking through the cerebral vasculature is essential to clear microbes or cell debris from neural tissues, while poorly regulated cellular transmigration can underlie or worsen CNS pathology. In this chapter, we focus on the specialized multicellular structure and function of the BBB/neurovascular unit and discuss how BBB breakdown can precede or be a consequence of neuroinflammation. We introduce the blood-cerebrospinal fluid barrier and include a brief aside about evolutionary aspects of barrier formation and refinements. Lastly, since restoration of barrier function is considered key to ameliorate neurologic disease, we speculate about new therapeutic avenues to repair a damaged BBB. PMID:27112670

  2. 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.

  3. Markers for blood-brain barrier integrity

    DEFF Research Database (Denmark)

    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 of...

  4. Laser Unlocks Blood-Brain Barrier for Chemotherapy, Study Shows

    Science.gov (United States)

    ... nlm.nih.gov/medlineplus/news/fullstory_157444.html Laser Unlocks Blood-Brain Barrier for Chemotherapy, Study Shows ... 24, 2016 WEDNESDAY, Feb. 24, 2016 (HealthDay News) -- Laser surgery can open the protective blood-brain barrier, ...

  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. Medulloblastoma Genotype Dictates Blood Brain Barrier Phenotype.

    Science.gov (United States)

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

    2016-04-11

    The childhood brain tumor, medulloblastoma, includes four subtypes with very different prognoses. Here, we show that paracrine signals driven by mutant β-catenin in WNT-medulloblastoma, an essentially curable form of the disease, induce an aberrant fenestrated vasculature that permits the accumulation of high levels of intra-tumoral chemotherapy and a robust therapeutic response. In contrast, SHH-medulloblastoma, a less curable disease subtype, contains an intact blood brain barrier, rendering this tumor impermeable and resistant to chemotherapy. The medulloblastoma-endothelial cell paracrine axis can be manipulated in vivo, altering chemotherapy permeability and clinical response. Thus, medulloblastoma genotype dictates tumor vessel phenotype, explaining in part the disparate prognoses among medulloblastoma subtypes and suggesting an approach to enhance the chemoresponsiveness of other brain tumors. PMID:27050100

  7. Blood-Brain Barrier Genomics, Proteomics, and New Transporter Discovery

    OpenAIRE

    Shusta, Eric V.

    2005-01-01

    Summary: The blood-brain barrier (BBB) is an impermeable cellular interface that physically separates the blood from the interstices of the brain. The endothelial cells lining the brain blood vessels form the principle barrier, and their unique phenotype is a consequence of dynamic interactions with several perivascular cell types present in the brain parenchyma. In addition, BBB dysfunction has been observed in the large majority of neurological diseases, but the causes of aberrant vascular ...

  8. Cerebrospinal fluid aquaporin-4-immunoglobulin G disrupts blood brain barrier.

    Science.gov (United States)

    Asgari, Nasrin; Berg, Carsten Tue; Mørch, Marlene Thorsen; Khorooshi, Reza; Owens, Trevor

    2015-08-01

    To clarify the significance of immunoglobulin G autoantibody specific for the astrocyte water channel aquaporin-4 in cerebrospinal fluid, aquaporin-4-immunoglobulin G from a neuromyelitis optica patient was administered intrathecally to naïve mice, and the distribution and pathogenic impact was evaluated. A distinct distribution pattern of aquaporin-4-immunoglobulin G deposition was observed in the subarachnoid and subpial spaces where vessels penetrate the brain parenchyma, via a paravascular route with intraparenchymal perivascular deposition. Perivascular astrocyte-destructive lesions were associated with blood-borne horseradish peroxidase leakage indicating blood-brain barrier breakdown. The cerebrospinal fluid aquaporin-4-immunoglobulin G therefore distributes widely in brain to initiate astrocytopathy and blood-brain barrier breakdown. PMID:26339679

  9. 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.

  10. 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...... 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....

  11. Effects of intravascular contrast media on blood-brain barrier

    International Nuclear Information System (INIS)

    The effects upon the rabbit blood-brain barrier after intracarotid injection of two non-ionic contrast media, iopentol (a monomer) and iodixanol (a dimer) were compared. Iothalamate and iohexol were used as reference substances. 99Tcm-DTPA, 125I-HSA and Trypsin blue were used as tracers in order to demonstrate various degrees of damage to the barrier. Injection of iothalamate led to large extravasation of 99Tcm-DTPA, 125I-HSA and Trypan blue which means severe damage of the blood-brain barrier. Injection of iopentol and iohexol resulted in some extravasation of all three tracers used, whereas injection of iodixanol only led to extravasation of the small molecule tracer 99Tcm-DTPA demonstrating minor changes of the barrier. At computed tomography of the brain with intravascular contrast medium enhancement it is safer to use iodixanol than iothalamate. Iodixanol is expected to cause even less adverse effects to the brain after intraarterial injection than iopentol and iohexol. (orig.)

  12. 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.

  13. 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.

  14. Protection of the blood-brain barrier by hypercapnia during acute hypertension

    International Nuclear Information System (INIS)

    The purpose of this study was to examine effects of hypercapnia on susceptibility of the blood-brain barrier to disruption during acute hypertension. Two methods were used to test the hypothesis that cerebral vasodilation during hypercapnia increases disruption of the blood-brain barrier. First, permeability of the blood-brain barrier was measured in anesthetized cats with 125I-labeled serum albumin. Severe hypertension markedly increased permeability of the blood-brain barrier during normocapnia, but not during hypercapnia. The protective effect of hypercapnia was not dependent on sympathetic nerves. Second, in anesthetized rats, permeability of the barrier was quantitated by clearance of fluorescent dextran. Disruption of the blood-brain barrier during hypertension was decreased by hypercapnia. Because disruption of the blood-brain barrier occurred primarily in pial venules, the authors also measured pial venular diameter and pressure. Acute hypertension increased pial venular pressure and diameter in normocapnic rats. Hypercapnia alone increased pial venular pressure and pial venular diameter, and acute hypertension during hypercapnia further increased venular pressure. The magnitude of increase in pial venular pressure during acute hypertension was significantly less in hypercapnic than in normocapnic rats. They conclude that hypercapnia protects the blood-brain barrier. Possible mechanisms of this effect include attenuation of the incremental increase in pial venular pressure by hypercapnia or a direct effect on the blood-brain barrier not related to venous pressure

  15. 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

  16. Drug transport across the blood-brain barrier.

    Science.gov (United States)

    Pardridge, William M

    2012-11-01

    The blood-brain barrier (BBB) prevents the brain uptake of most pharmaceuticals. This property arises from the epithelial-like tight junctions within the brain capillary endothelium. The BBB is anatomically and functionally distinct from the blood-cerebrospinal fluid barrier at the choroid plexus. Certain small molecule drugs may cross the BBB via lipid-mediated free diffusion, providing the drug has a molecular weight hydrogen bonds. These chemical properties are lacking in the majority of small molecule drugs, and all large molecule drugs. Nevertheless, drugs can be reengineered for BBB transport, based on the knowledge of the endogenous transport systems within the BBB. Small molecule drugs can be synthesized that access carrier-mediated transport (CMT) systems within the BBB. Large molecule drugs can be reengineered with molecular Trojan horse delivery systems to access receptor-mediated transport (RMT) systems within the BBB. Peptide and antisense radiopharmaceuticals are made brain-penetrating with the combined use of RMT-based delivery systems and avidin-biotin technology. Knowledge on the endogenous CMT and RMT systems expressed at the BBB enable new solutions to the problem of BBB drug transport. PMID:22929442

  17. 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.

  18. Dyslipidemia and Blood-Brain Barrier Integrity in Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Gene L. Bowman

    2012-01-01

    Full Text Available Background. Blood-brain barrier (BBB dysfunction may have a significant role in the pathogenesis of Alzheimer's disease (AD. Modifiable factors associated with BBB function may have therapeutic implication. This study tested the hypothesis that dyslipidemia is associated with BBB impairment in mild-to-moderate AD. Methods. Thirty-six subjects with AD were followed for 1 year. Fasting CSF and plasma were collected with clinical assessments at baseline and 12 months. BBB impairment was defined as CSF albumin index ≥9. Independent t-tests and linear regression assessed the relationship between plasma lipoproteins and BBB integrity. Results. Dyslipidemia was prevalent in 47% of the population, and in 75% of those with BBB impairment. Subjects with BBB impairment had significantly higher mean plasma triglyceride and lower HDL cholesterol (TG, P=0.007; HDL, P=0.043. Plasma triglycerides explained 22% of the variance in BBB integrity and remained significant after controlling for age, gender, ApoE-4 genotype, blood pressure, and statin use. Conclusion. Dyslipidemia is more prevalent in AD subjects with BBB impairment. Plasma triglyceride and HDL cholesterol may have a role in maintaining BBB integrity in mild-to-moderate Alzheimer's disease.

  19. Estrogen and insulin transport through the blood-brain barrier.

    Science.gov (United States)

    May, Aaron A; Bedel, Nicholas D; Shen, Ling; Woods, Stephen C; Liu, Min

    2016-09-01

    Obesity is associated with insulin resistance and reduced transport of insulin through the blood-brain barrier (BBB). Reversal of high-fat diet-induced obesity (HFD-DIO) by dietary intervention improves the transport of insulin through the BBB and the sensitivity of insulin in the brain. Although both insulin and estrogen (E2), when given alone, reduce food intake and body weight via the brain, E2 actually renders the brain relatively insensitive to insulin's catabolic action. The objective of these studies was to determine if E2 influences the ability of insulin to be transported into the brain, since the receptors for both E2 and insulin are found in BBB endothelial cells. E2 (acute or chronic) was systemically administered to ovariectomized (OVX) female rats and male rats fed a chow or a high-fat diet. Food intake, body weight and other metabolic parameters were assessed along with insulin entry into the cerebrospinal fluid (CSF). Acute E2 treatment in OVX female and male rats reduced body weight and food intake, and chronic E2 treatment prevented or partially reversed high-fat diet-induced obesity. However, none of these conditions increased insulin transport into the CNS; rather, chronic E2 treatment was associated less-effective insulin transport into the CNS relative to weight-matched controls. Thus, the reduction of brain insulin sensitivity by E2 is unlikely to be mediated by increasing the amount of insulin entering the CNS. PMID:27182046

  20. Stress does not increase blood-brain barrier permeability in mice.

    Science.gov (United States)

    Roszkowski, Martin; Bohacek, Johannes

    2016-07-01

    Several studies have reported that exposure to acute psychophysiological stressors can lead to an increase in blood-brain barrier permeability, but these findings remain controversial and disputed. We thoroughly examined this issue by assessing the effect of several well-established paradigms of acute stress and chronic stress on blood-brain barrier permeability in several brain areas of adult mice. Using cerebral extraction ratio for the small molecule tracer sodium fluorescein (NaF, 376 Da) as a sensitive measure of blood-brain barrier permeability, we find that neither acute swim nor restraint stress lead to increased cerebral extraction ratio. Daily 6-h restraint stress for 21 days, a model for the severe detrimental impact of chronic stress on brain function, also does not alter cerebral extraction ratio. In contrast, we find that cold forced swim and cold restraint stress both lead to a transient, pronounced decrease of cerebral extraction ratio in hippocampus and cortex, suggesting that body temperature can be an important confounding factor in studies of blood-brain barrier permeability. To additionally assess if stress could change blood-brain barrier permeability for macromolecules, we measured cerebral extraction ratio for fluorescein isothiocyanate-dextran (70 kDa). We find that neither acute restraint nor cold swim stress affected blood-brain barrier permeability for macromolecules, thus corroborating our findings that various stressors do not increase blood-brain barrier permeability. PMID:27146513

  1. 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.

  2. Neurosurgical Techniques for Disruption of the Blood-Brain Barrier for Glioblastoma Treatment.

    Science.gov (United States)

    Rodriguez, Analiz; Tatter, Stephen B; Debinski, Waldemar

    2015-01-01

    The blood-brain barrier remains a main hurdle to drug delivery to the brain. The prognosis of glioblastoma remains grim despite current multimodal medical management. We review neurosurgical technologies that disrupt the blood-brain barrier (BBB). We will review superselective intra-arterial mannitol infusion, focused ultrasound, laser interstitial thermotherapy, and non-thermal irreversible electroporation (NTIRE). These technologies can lead to transient BBB and blood-brain tumor barrier disruption and allow for the potential of more effective local drug delivery. Animal studies and preliminary clinical trials show promise for achieving this goal. PMID:26247958

  3. Hydrophilic solute transport across the rat blood-brain barrier

    International Nuclear Information System (INIS)

    Brain capillary permeability-surface area products (PS) of hydrophilic solutes ranging in size from 180 to 5,500 Daltons were measured in rats according to the method of Ohno, Pettigrew and Rapoport. The distribution volume of 70 KD dextran at 10 minutes after i.v. injection was also measured to determine the residual volume of blood in brain tissue at the time of sacrifice. Small test solutes were injected in pairs in order to elucidate whether their transfer into the brain proceeds by diffusion through water- or lipid-filled channels or by vesicular transport. This issue was examined in rats whose blood-brain barrier (BBB) was presumed to be intact (untreated) and in rats that received intracarotid infusions to open the BBB (isosmotic salt (ISS) and hyperosmolar arabinose). Ohno PS values of 3H-inulin and 14C-L-glucose in untreated rats were found to decrease as the labelling time was lengthened. This was evidence that a rapidly equilibrating compartment exists between blood and brain that renders the Ohno two-compartment model inadequate for computing true transfer rate constants. When the data were reanalyzed using a multi-compartment graphical analysis, solutes with different molecular radii were found to enter the brain at approximately equal rates. Furthermore, unidirectional transport is likely to be initiated by solute adsorption to a glycocalyx coat on the luminal surface of brain capillary endothelium. Apparently, more inulin than L-glucose was adsorbed, which may account for its slightly faster transfer across the BBB. After rats were treated with intracarotid infusions of ISS or hyperosmolar arabinose, solute PS values were significantly increased, but the ratio of PS for each of the solute pairs approached that of their free-diffusion coefficients

  4. Demonstration of blood brain barrier injury by computed tomography

    International Nuclear Information System (INIS)

    Blood brain barrier (BBB) injury was evoked by the injection of hypertonic solution, 50% glucose or 80% sodium iothalamate, through the catheter placed in the common carotid artery of the adult mongrel dogs. Plain CT and then contrast CT were performed at 30 minutes intervals until 3 hours to determine the relationship between the degrees of contrast enhancement (CE) and the amount of injected hypertonic solution, and to examine the diminishing rates of CE according to time elapsed after the intravenous contrast injection. Another four groups of dogs received contrast CT immediately, at 1, 2 and 3 hours after the injection of hypertonic solution to examine the degree of repair of BBB injury. Contrast media, which was leaked through BBB injured by the injection of hypertonic solution, was recognized by CT, and the area of CE coincided exactly with the dyed area by Evans blue, injected intravenously after induction of BBB injury. Degrees of CE were found to correlate linearly to the amount of hypertonic solution within a certain range. These results indicate that CT can demonstrate BBB injury qualitatively and quantitatively. In sequential CT after the artificial injury of BBB, degree of CE diminished linearly with a half life of about 3 hours. Hydrocortisone accelerated this washout of leaked contrast media. Repair of BBB itself, determined by contrast CT which were performed at 1, 2 and 3 hours after the induction of BBB injury, has been accomplished until 3 hours, and not affected by the administration of hydrocortisone. These experimental results suggest that CT is the most promising method to detect quantitatively and non-invasively the degree and the extent of BBB injury in clinical cases. (J.P.N.)

  5. 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

    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...

  6. Restraint Stress-Induced Morphological Changes at the Blood-Brain Barrier in Adult Rats

    OpenAIRE

    Petra eSántha; Szilvia eVeszelka; Zsófia eHoyk; Mária eMészáros; Walter, Fruzsina R.; Andrea E Tóth; Lóránd eKiss; András eKincses; Zita eOláh; György eSeprényi; Gabor eRakhely; András eDér; Magdolna ePákáski; Janos eKalman; Ágnes eKittel

    2016-01-01

    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 recognized 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 th...

  7. Comparison study of ferrofluid and powder iron oxide nanoparticle permeability across the blood-brain barrier.

    Science.gov (United States)

    Hoff, Dan; Sheikh, Lubna; Bhattacharya, Soumya; Nayar, Suprabha; Webster, Thomas J

    2013-01-01

    In the present study, the permeability of 11 different iron oxide nanoparticle (IONP) samples (eight fluids and three powders) was determined using an in vitro blood-brain barrier model. Importantly, the results showed that the ferrofluid formulations were statistically more permeable than the IONP powder formulations at the blood-brain barrier, suggesting a role for the presently studied in situ synthesized ferrofluid formulations using poly(vinyl) alcohol, bovine serum albumin, collagen, glutamic acid, graphene, and their combinations as materials which can cross the blood-brain barrier to deliver drugs or have other neurological therapeutic efficacy. Conversely, the results showed the least permeability across the blood-brain barrier for the IONP with collagen formulation, suggesting a role as a magnetic resonance imaging contrast agent but limiting IONP passage across the blood-brain barrier. Further analysis of the data yielded several trends of note, with little correlation between permeability and fluid zeta potential, but a larger correlation between permeability and fluid particle size (with the smaller particle sizes having larger permeability). Such results lay the foundation for simple modification of iron oxide nanoparticle formulations to either promote or inhibit passage across the blood-brain barrier, and deserve further investigation for a wide range of applications. PMID:23426527

  8. What role does the blood brain barrier play in acute mountain sickness?

    Science.gov (United States)

    Baneke, Alex

    2010-07-01

    As high altitude travel increases, acute mountain sickness (AMS) and life threatening high altitude cerebral oedema (HACE) are becoming more prevalent. Acute mountain sickness occurs in 45% of lowlanders above 4250 m. Predisposing factors are still unknown and its development is more complex than the original "tight fit" hypothesis. This review examines evidence relating to a possible role of the blood brain barrier in AMS as suggested by MRI studies. Underlying mechanisms may involve vascular endothelial growth factor and free radicals in addition to increases in hydrostatic pressure. An increased understanding is important in advising patients planning high altitude adventures. Current studies have linked increased blood brain barrier permeability to high altitude cerebral oedema, but the role of the blood brain barrier in acute mountain sickness is less clear; varied symptoms include headache. MRI shows vasogenic oedema occurs in high altitude cerebral oedema, suggesting blood brain barrier permeability increases, and acute mountain sickness typically precedes high altitude cerebral oedema. Hypoxia leads to increased hydrostatic pressure, and blood brain barrier permeability has been shown to increase in stroke patients. Vascular endothelial growth factor is upregulated in hypoxia, and may increase blood brain barrier permeability. PMID:20952272

  9. An ex Vivo Model for Evaluating Blood-Brain Barrier Permeability, Efflux, and Drug Metabolism.

    Science.gov (United States)

    Hellman, Karin; Aadal Nielsen, Peter; Ek, Fredrik; Olsson, Roger

    2016-05-18

    The metabolism of drugs in the brain is difficult to study in most species because of enzymatic instability in vitro and interference from peripheral metabolism in vivo. A locust ex vivo model that combines brain barrier penetration, efflux, metabolism, and analysis of the unbound fraction in intact brains was evaluated using known drugs. Clozapine was analyzed, and its major metabolites, clozapine N-oxide (CNO) and N-desmethylclozapine (NDMC), were identified and quantified. The back-transformation of CNO into clozapine observed in humans was also observed in locusts. In addition, risperidone, citalopram, fluoxetine, and haloperidol were studied, and one preselected metabolite for each drug was analyzed, identified, and quantified. Metabolite identification studies of clozapine and midazolam showed that the locust brain was highly metabolically active, and 18 and 14 metabolites, respectively, were identified. The unbound drug fraction of clozapine, NDMC, carbamazepine, and risperidone was analyzed. In addition, coadministration of drugs with verapamil or fluvoxamine was performed to evaluate drug-drug interactions in all setups. All findings correlated well with the data in the literature for mammals except for the stated fact that CNO is a highly blood-brain barrier permeant compound. Overall, the experiments indicated that invertebrates might be useful for screening of blood-brain barrier permeation, efflux, metabolism, and analysis of the unbound fraction of drugs in the brain in early drug discovery. PMID:26930271

  10. 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.

  11. 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.

  12. Permeability of ergot alkaloids across the blood-brain barrier in vitro and influence on the barrier integrity

    OpenAIRE

    Mulac, Dennis; Hüwel, Sabine; Galla, Hans-Joachim; Humpf, Hans-Ulrich

    2011-01-01

    Scope Ergot alkaloids are secondary metabolites of Claviceps spp. and they have been in the focus of research for many years. Experiments focusing on ergotamine as a former migraine drug referring to the ability to reach the brain revealed controversial results. The question to which extent ergot alkaloids are able to cross the blood-brain barrier is still not answered. Methods and results In order to answer this question we have studied the ability of ergot alkaloids to penetrate the blood-b...

  13. Next generation of non-mammalian blood-brain barrier models to study parasitic infections of the central nervous system

    OpenAIRE

    Siddiqui, Ruqaiyyah; Edwards-Smallbone, James; Flynn, Robin; Khan, Naveed Ahmed

    2012-01-01

    Transmigration of neuropathogens across the blood-brain barrier is a key step in the development of central nervous system infections, making it a prime target for drug development. The ability of neuropathogens to traverse the blood-brain barrier continues to inspire researchers to understand the specific strategies and molecular mechanisms that allow them to enter the brain. The availability of models of the blood-brain barrier that closely mimic the situation in vivo offers unprecedented o...

  14. 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.

  15. In vivo interactions of magnetic nanoparticles with the blood-brain barrier

    International Nuclear Information System (INIS)

    Targeted drug delivery to the brain parenchyma, i.e., in brain tumor patients, by means of magnetically supported carrier delivery through the tight vascular endothelium of the blood-brain barrier is of critical biomedical importance. We were interested in delineating the first steps in successful brain drug delivery, which focuses on the interactions between magnetically guided yet freely blood circulating nanoparticles and the blood-brain barrier. We employed an in vivo model to quantitatively determine changes in cerebrovascular flow rate and volume during magnetically guided exposure of circulating nanoparticles.

  16. Study on permeability of β-NGF through blood brain barrier by 125I tracing

    International Nuclear Information System (INIS)

    β-NGF is extracted from fetus brain by centrifugation, dialysing and ion-exchange chromatography. The molecular weight of β-NGF is 13 kD detected by SDS-PAGE electrophoresis; the isoelectric point of β-NGF are 9.0, 9.2 and 9.3 respectively detected by isoelectric focusing electrophoresis; the β-NGF shows the effect of stimulating neurite growth by PC12 cells culture. Using the 125I tracing technique, the animal experiments indicate (2.41 +- 0.12)% of injected 125I-β-NGF could go through the blood brain barrier at 15 min, and increase to (4.20 +- 0.07)% at 30 min. The results provides scientific basis for research of β-NGF in clinical therapeutic application

  17. Establishment of rat model of opening blood-brain barrier with conventional whole-brain irradiation

    International Nuclear Information System (INIS)

    Objective: To establish a rat model of opening blood-brain barrier with conventional whole-brain irradiation. Methods: According to different dosage of irradiation, a hundred Sprague-Dowley rats were randomly assigned into five groups, the control group (no irradiation), and four irradiated groups at 10 grays, 20 grays, 30 grays and 40 grays. The rats were administered to conventional fraction irradiation (2 Gy/day and 5 days a week) with routine 60Co gamma-rays. The intake of feed and autonomic activities were observed every day. Changes in skin and hair in the irradiated field, body weight, and center nervous system symptoms and signs were examined and recorded every week during irradiation. The neurological status was ranked on a scale based on the Mickley's Scale. Ultrastructure changes of blood-brain barrier at 16 hours after the last irradiation were examined with electron microscope using lanthanum trace labeling. Results: Neither abnormal nervous sign, nor change of feed intake, skin and hair was observed in all the rats. No statistically significant difference of body weight was observed among the five groups (P>0.05). The effect that radiation can directly damage the function and structure of blood-brain barrier was proportional to irradiation doses. Conclusion: This rat model is a suitable for study on blood-brain barrier pathophysiology and molecular biology after conventional whole-brain irradiation. (authors)

  18. 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

  19. 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

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

    NARCIS (Netherlands)

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

    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

  1. 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

  2. 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

  3. Reproductive hormones regulate the selective permeability of the blood-brain barrier

    OpenAIRE

    Wilson, Andrea C.; Clemente, Luca; Liu, Tianbing; Bowen, Richard L.; Meethal, Sivan Vadakkadath; Atwood, Craig S.

    2008-01-01

    Reproductive hormones regulate the selective permeability of the blood-brain barrier : Current address: Department of Biochemistry, Colorado State University, CO, USA. (Clemente, Luca) correspondence: Corresponding author. University of Wisconsin-Madison Medical School, Wm S. Middleton Memorial VA (GRECC 11G), 2500 Overlook Terrace, Madison, WI 53705, USA. Tel.: +1 608 256 1901x11664; fax: +1 608 280 7291. (Atw...

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

    NARCIS (Netherlands)

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

    2014-01-01

    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 inf

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

    Science.gov (United States)

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

    2016-09-01

    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. PMID:27349679

  6. Enhanced blood-brain barrier transmigration using a novel Transferrin-embedded fluorescent magnetoliposome nanoformulation

    OpenAIRE

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

    2014-01-01

    Blood-brain barrier (BBB) is considered as the primary impediment barrier for most of drugs. Delivering therapeutic agents to brain is still a big challenge by now. In our study, a dual mechanism, receptor mediation combining with external non-invasive magnetic force, was incorporated together into ferrous magnet-based liposome for BBB transmigration enhancement. The homogenous magnetic nanoparticles (MNPs) with size of ~ 10 nm were synthesized and confirmed by TEM and XRD respectively. The c...

  7. Role of the Blood-Brain Barrier in the Formation of Brain Metastases

    OpenAIRE

    Krizbai, István A.; János Haskó; Csilla Fazakas; Judit Molnár; Imola Wilhelm

    2013-01-01

    The majority of brain metastases originate from lung cancer, breast cancer and malignant melanoma. In order to reach the brain, parenchyma metastatic cells have to transmigrate through the endothelial cell layer of brain capillaries, which forms the morphological basis of the blood-brain barrier (BBB). The BBB has a dual role in brain metastasis formation: it forms a tight barrier protecting the central nervous system from entering cancer cells, but it is also actively involved in protecting ...

  8. Understanding the rules of the road: proteomic approaches to interrogate the blood brain barrier

    OpenAIRE

    Torbett, Bruce E.; Baird, Andrew; Eliceiri, Brian P

    2015-01-01

    The blood brain barrier (BBB) is often regarded as a passive barrier that protects brain parenchyma from toxic substances, circulating leukocytes, while allowing the passage of selected molecules. Recently, a combination of molecular profiling techniques have characterized the constituents of the BBB based on in vitro models using isolated endothelial cells and ex vivo models analyzing isolated blood vessels. Characterization of gene expression profiles that are specific to the endothelium of...

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

    OpenAIRE

    Jörg Huwyler; Felix Hammann; Claudia Suenderhauf

    2012-01-01

    Predicting blood-brain barrier (BBB) permeability is essential to drug development, as a molecule cannot exhibit pharmacological activity within the brain parenchyma without first transiting this barrier. Understanding the process of permeation, however, is complicated by a combination of both limited passive diffusion and active transport. Our aim here was to establish predictive models for BBB drug permeation that include both active and passive transport. A database of 153 compounds was co...

  10. 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...... other 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....

  11. 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...... other 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...

  12. In vitro model of the blood-brain barrier established by co-culture of primary cerebral microvascular endothelial and astrocyte cells

    OpenAIRE

    Yan Wang; Ning Wang; Biao Cai; Guang-yun Wang; Jing Li; Xing-xing Piao

    2015-01-01

    Drugs for the treatment and prevention of nervous system diseases must permeate the blood-brain barrier to take effect. In vitro models of the blood-brain barrier are therefore important in the investigation of drug permeation mechanisms. However, to date, no unified method has been described for establishing a blood-brain barrier model. Here, we modified an in vitro model of the blood-brain barrier by seeding brain microvascular endothelial cells and astrocytes from newborn rats on a polyest...

  13. Next generation of non-mammalian blood-brain barrier models to study parasitic infections of the central nervous system

    Science.gov (United States)

    Siddiqui, Ruqaiyyah; Edwards-Smallbone, James; Flynn, Robin; Khan, Naveed Ahmed

    2012-01-01

    Transmigration of neuropathogens across the blood-brain barrier is a key step in the development of central nervous system infections, making it a prime target for drug development. The ability of neuropathogens to traverse the blood-brain barrier continues to inspire researchers to understand the specific strategies and molecular mechanisms that allow them to enter the brain. The availability of models of the blood-brain barrier that closely mimic the situation in vivo offers unprecedented opportunities for the development of novel therapeutics. PMID:21921682

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

    OpenAIRE

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

    2015-01-01

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

  15. Influence of BNCT radiations on the blood-brain barrier in terms of boron-10 uptake

    International Nuclear Information System (INIS)

    A key issue is to determine whether fractionated BNCT is a feasible proposition. This issue has been reviewed by Dorn et al, who call for further experimental investigation of BNCT induced changes in the blood brain barrier and investigated by Hatanaka et al. In order to investigate the effect on BNCT, the authors measured 10B concentration and water content in the normal brain which has been subjected to BNCT regimen

  16. Blood-brain barrier permeability in rats exposed to electromagnetic fields used in wireless communication

    OpenAIRE

    Persson, Bertil R.; Leif G Salford; Brun, Arne

    1997-01-01

    iological effects of radio frequency electromagnetic fields (EMF) on the blood-brain barrier (BBB) have been studied in Fischer 344 rats of both sexes. The rats were not anaesthetised during the exposure. All animals were sacrificed by perfusion–fixation of the brains under chloralhydrate anaesthesia after the exposure. The brains were perfused with saline for 3–4 minutes, and thereafter perfusion fixed with 4% formaldehyde for 5–6 minutes. Whole coronal sections of the brains were d...

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

    OpenAIRE

    Del Razo, Mauricio J.; MOROFUJI, Yoichi; 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 ...

  18. Matrix Metalloproteinases and Blood-Brain Barrier Disruption in Acute Ischemic Stroke

    OpenAIRE

    Lakhan, Shaheen E.; Kirchgessner, Annette; Tepper, Deborah; Leonard, Aidan

    2013-01-01

    Ischemic stroke continues to be one of the most challenging diseases in translational neurology. Tissue plasminogen activator (tPA) remains the only approved treatment for acute ischemic stroke, but its use is limited to the first hours after stroke onset due to an increased risk of hemorrhagic transformation over time resulting in enhanced brain injury. In this review we discuss the role of matrix metalloproteinases (MMPs) in blood-brain barrier (BBB) disruption as a consequence of ischemic ...

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

    OpenAIRE

    Renée J Turner; 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...

  20. Effect of monocrotaline on blood-brain barrier permeability in rats

    OpenAIRE

    Coll, Carlos; Fernández, María Alejandra; Coll, Sebastián; Coll, Tamara; Malliardi, Pablo; Perazzo, Juan; Filinger, Ester Julia; Lemberg, Abraham

    2011-01-01

    We studied if monocrotaline (MCT) portal hypertensive model modifies blood-brain barrier (BBB) condition. Male Wistar rats were used: Group MCT injected i.p. with MCT (60 mg/kg of body weight) and Group Sham (GS) with saline. Forty-four days after injection rats were sacrificed. Trypan blue and Evans blue tests were performed to evaluate BBB integrity in both groups. In cerebrospinal fluid (CF), protein and glucose were determined. Alanine aminotransferase (ALT), aspartate aminotransferase (A...

  1. The Effects of Psychostimulant Drugs on Blood Brain Barrier Function and Neuroinflammation

    OpenAIRE

    Kousik, Sharanya M.; T. Celeste eNapier; Carvey, Paul M.

    2012-01-01

    The blood brain barrier (BBB) is a highly dynamic interface between the central nervous system (CNS) and periphery. The BBB is comprised of a number of components and is part of the larger neuro(glio)vascular unit. Current literature suggests that psychostimulant drugs of abuse alter the function of the BBB which likely contributes to the neurotoxicities associated with these drugs. In both preclinical and clinical studies, psychostimulants including methamphetamine, MDMA, cocaine, and nicoti...

  2. Blood Brain Barrier: A Challenge for Effectual Therapy of Brain Tumors

    OpenAIRE

    Arijit Bhowmik; Rajni Khan; Mrinal Kanti Ghosh

    2015-01-01

    Brain tumors are one of the most formidable diseases of mankind. They have only a fair to poor prognosis and high relapse rate. One of the major causes of extreme difficulty in brain tumor treatment is the presence of blood brain barrier (BBB). BBB comprises different molecular components and transport systems, which in turn create efflux machinery or hindrance for the entry of several drugs in brain. Thus, along with the conventional techniques, successful modification of drug delivery and n...

  3. Blood-Brain Barrier Active Efflux Transporters: ATP-Binding Cassette Gene Family

    OpenAIRE

    Löscher, Wolfgang; Potschka, Heidrun

    2005-01-01

    Summary: The blood-brain barrier (BBB) contributes to brain homeostasis by protecting the brain from potentially harmful endogenous and exogenous substances. BBB active drug efflux transporters of the ATP-binding cassette (ABC) gene family are increasingly recognized as important determinants of drug distribution to, and elimination from, the CNS. The ABC efflux transporter P-glycoprotein (Pgp) has been demonstrated as a key element of the BBB that can actively transport a huge variety of lip...

  4. Biologic TNFα-inhibitors that cross the human blood-brain barrier

    OpenAIRE

    Pardridge, William M.

    2010-01-01

    Tumor necrosis factor (TNF)α inhibitors (TNFI) are a major class of biologic therapeutics, and include decoy receptor and monoclonal antibody (MAb) therapeutics that block TNFα action. TNFα is a pro-inflammatory cytokine in brain disease, such as stroke, brain or spinal cord injury, or Alzheimer disease. However, the biologic TNFIs cannot be developed for the brain, because these large molecules do not cross the blood-brain barrier (BBB). Brain penetrating forms of TNFα decoy receptors or ant...

  5. MicroRNA-155 negatively affects blood-brain barrier function during neuroinflammation.

    OpenAIRE

    Lopez-Ramirez, Miguel Alejandro; Wu, Dongsheng; Pryce, Gareth; Julie E Simpson; Reijerkerk, Arie; King-Robson, Josh; Kay, Oliver; de Vries, Helga E.; Hirst, Mark C; Sharrack, Basil; Baker, David; Male, David Kingsley; Michael, Gregory J.; Romero, Ignacio Andres

    2014-01-01

    Blood-brain barrier (BBB) dysfunction is a hallmark of neurological conditions such as multiple sclerosis (MS) and stroke. However, the molecular mechanisms underlying neurovascular dysfunction during BBB breakdown remain elusive. MicroRNAs (miRNAs) have recently emerged as key regulators of pathogenic responses, although their role in central nervous system (CNS) microvascular disorders is largely unknown. We have identified miR-155 as a critical miRNA in neuroinflammation at the BBB. miR-15...

  6. Blood-Brain Barrier Integrity and Breast Cancer Metastasis to the Brain

    OpenAIRE

    Hava Karsenty Avraham; Shalom Avraham; Christopher Sy; Lili Wang; Farheen Arshad

    2011-01-01

    Brain metastasis, an important cause of cancer morbidity and mortality, occurs in at least 30% of patients with breast cancer. A key event of brain metastasis is the migration of cancer cells through the blood-brain barrier (BBB). Although preventing brain metastasis is immensely important for survival, very little is known about the early stage of transmigration and the molecular mechanisms of breast tumor cells penetrating the BBB. The brain endothelium plays an important role in brain meta...

  7. Traversal of Candida albicans across Human Blood-Brain Barrier In Vitro

    OpenAIRE

    Jong, Ambrose Y.; Stins, Monique F.; Huang, Sheng-He; Chen, Steven H. M.; Kim, Kwang Sik

    2001-01-01

    Candida albicans is an opportunistic pathogen, which primarily affects neonates and immunocompromised individuals. The pathogen can invade the central nervous system, resulting in meningitis. At present, the pathogenesis of C. albicans meningitis is unclear. We used an in vitro model of the human blood-brain barrier to investigate the interaction(s) of C. albicans with human brain microvascular endothelial cells (BMEC). Binding of C. albicans to human BMEC was time and inoculum dependent. Inv...

  8. Selective permeabilization of the blood-brain barrier at sites of metastasis

    OpenAIRE

    Sibson, NR; Vallis, KA; Hamilton, A.; Seymour, L.; Anthony, DC; Connell, JJ; Chatain, G

    2013-01-01

    BACKGROUND: Effective chemotherapeutics for primary systemic tumors have limited access to brain metastases because of the blood-brain barrier (BBB). The aim of this study was to develop a strategy for specifically permeabilizing the BBB at sites of cerebral metastases. METHODS: BALB/c mice were injected intracardially to induce brain metastases. After metastasis induction, either tumor necrosis factor (TNF) or lymphotoxin (LT) was administered intravenously, and 2 to 24 hours later gadoliniu...

  9. A statistical model describing combined irreversible electroporation and electroporation-induced blood-brain barrier disruption

    Directory of Open Access Journals (Sweden)

    Sharabi Shirley

    2016-03-01

    Full Text Available Electroporation-based therapies such as electrochemotherapy (ECT and irreversible electroporation (IRE are emerging as promising tools for treatment of tumors. When applied to the brain, electroporation can also induce transient blood-brain-barrier (BBB disruption in volumes extending beyond IRE, thus enabling efficient drug penetration. The main objective of this study was to develop a statistical model predicting cell death and BBB disruption induced by electroporation. This model can be used for individual treatment planning.

  10. A statistical model describing combined irreversible electroporation and electroporation-induced blood-brain barrier disruption

    OpenAIRE

    Sharabi Shirley; Kos Bor; Last David; Guez David; Daniels Dianne; Harnof Sagi; Mardor Yael; Miklavcic Damijan

    2016-01-01

    Background Electroporation-based therapies such as electrochemotherapy (ECT) and irreversible electroporation (IRE) are emerging as promising tools for treatment of tumors. When applied to the brain, electroporation can also induce transient blood-brain-barrier (BBB) disruption in volumes extending beyond IRE, thus enabling efficient drug penetration. The main objective of this study was to develop a statistical model predicting cell death and BBB disruption induced by electroporation. This m...

  11. 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. PMID:26551768

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

    Science.gov (United States)

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

    2016-10-01

    The blood-brain barrier accounts for the high attrition rate of the treatments of most brain disorders, which therefore remain one of the greatest health-care challenges of the twenty first century. Against this background of hindrance to brain delivery, nanomedicine takes advantage of the assembly at the nanoscale of available biomaterials to provide a delivery platform with potential to raising brain levels of either imaging or therapeutic agents. Nevertheless, to prevent later failure due to ineffective drug levels at the target site, researchers have been endeavoring to develop a battery of in vitro screening procedures that can predict earlier in the drug discovery process the ability of these cutting-edge drug delivery platforms to cross the blood-brain barrier for biomedical purposes. This review provides an in-depth analysis of the currently available in vitro blood-brain barrier models (both cell-based and non-cell-based) with the focus on their suitability for understanding the biological brain distribution of forthcoming nanomedicines. The relationship between experimental factors and underlying physiological assumptions that would ultimately lead to a more predictive capacity of their in vivo performance, and those methods already assayed for the evaluation of the brain distribution of nanomedicines are comprehensively discussed. PMID:27392291

  13. Blood brain barrier and brain tissue injury by Gd-DTPA in uremia-induced rabbits

    International Nuclear Information System (INIS)

    An experimental study was carried out to evaluate the morphological changes in the blood brain barrier and neighbouring brain tissue caused by Gd-DTPA in uremia-induced rabbits. Bilateral renal arteries and veins of ten rabbits were ligated. Gd-DTPA(0.2mmol/kg) was intravenously injected into seven rabbits immediately after ligation. After MRI, they were sacrificed 2 or 3 days after ligation in order to observe light and electron microscopic changes in the blood brain barrier and brain tissue. MRI findings were normal, except for enhancement of the superior and inferior sagittal sinuses on T1 weighted images in uremia-induced rabbits injected with Gd-DTPA. On light microscopic examination, these rabbits showed perivascular edema and glial fibrillary acidic protein expression: electron microscopic examination showed separation of tight junctions of endothelial cells, duplication/rarefaction of basal lamina, increased lysosomes of neurons with neuronal death, demyelination of myelin, and extravasation of red blood cells. Uremia-induced rabbits injected with Gd-DTPA showed more severe changes than those without Gd-DTPA injection. Injuries to the blood brain barrier and neighbouring brain tissue were aggravated by Gd-DTPA administration in uremia-induced rabbits. These findings appear to be associated with the neurotoxicity of Gd-DTPA

  14. Effect of some drugs on ethanol-induced changes in blood brain barrier permeability for 14C-tyrosine

    International Nuclear Information System (INIS)

    This investigation seeks to compare the effects of membrane stabilizers chlorpromazine and alpha-tocopherol, and also the dopaminergic antagonist haloperidol, in changes in permeability of the blood-brain barrier for carbon 14-labelled tyrosine

  15. Blood-brain barrier and blood-cerebrospinal fluid barrier in normal and pathological conditions.

    Science.gov (United States)

    Ueno, Masaki; Chiba, Yoichi; Murakami, Ryuta; Matsumoto, Koichi; Kawauchi, Machi; Fujihara, Ryuji

    2016-04-01

    Blood-borne substances can invade into the extracellular spaces of the brain via endothelial cells in sites without the blood-brain barrier (BBB), and can travel through the interstitial fluid (ISF) of the brain parenchyma adjacent to non-BBB sites. It has been shown that cerebrospinal fluid (CSF) drains directly into the blood via the arachnoid villi and also into lymph nodes via the subarachnoid spaces of the brain, while ISF drains into the cervical lymph nodes through perivascular drainage pathways. In addition, the glymphatic pathway of fluids, characterized by para-arterial pathways, aquaporin4-dependent passage through astroglial cytoplasm, interstitial spaces, and paravenous routes, has been established. Meningeal lymphatic vessels along the superior sagittal sinus were very recently discovered. It is known that, in mice, blood-borne substances can be transferred to areas with intact BBB function, such as the medial regions of the hippocampus, presumably through leaky vessels in non-BBB sites. In the present paper, we review the clearance mechanisms of interstitial substances, such as amyloid-β peptides, as well as summarize models of BBB deterioration in response to different types of insults, including acute ischemia followed by reperfusion, hypertension, and chronic hypoperfusion. Lastly, we discuss the relationship between perivascular clearance and brain disorders. PMID:26920424

  16. Oligodendrocyte precursor cells support blood-brain barrier integrity via TGF-β signaling.

    Directory of Open Access Journals (Sweden)

    Ji Hae Seo

    Full Text Available Trophic coupling between cerebral endothelium and their neighboring cells is required for the development and maintenance of blood-brain barrier (BBB function. Here we report that oligodendrocyte precursor cells (OPCs secrete soluble factor TGF-β1 to support BBB integrity. Firstly, we prepared conditioned media from OPC cultures and added them to cerebral endothelial cultures. Our pharmacological experiments showed that OPC-conditioned media increased expressions of tight-junction proteins and decreased in vitro BBB permeability by activating TGB-β-receptor-MEK/ERK signaling pathway. Secondly, our immuno-electron microscopic observation revealed that in neonatal mouse brains, OPCs attach to cerebral endothelial cells via basal lamina. And finally, we developed a novel transgenic mouse line that TGF-β1 is knocked down specifically in OPCs. Neonates of these OPC-specific TGF-β1 deficient mice (OPC-specific TGF-β1 partial KO mice: PdgfraCre/Tgfb1flox/wt mice or OPC-specific TGF-β1 total KO mice: PdgfraCre/Tgfb1flox/flox mice exhibited cerebral hemorrhage and loss of BBB function. Taken together, our current study demonstrates that OPCs increase BBB tightness by upregulating tight junction proteins via TGF-β signaling. Although astrocytes and pericytes are well-known regulators of BBB maturation and maintenance, these findings indicate that OPCs also play a pivotal role in promoting BBB integrity.

  17. 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...

  18. 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...... 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...

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

    OpenAIRE

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

    2015-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  1. Non-thermal" Effects on the Blood-Brain Barrier in Fischer rats by exposure to microwaves

    OpenAIRE

    Persson, Bertil R; Malmgren, Lars; Brun, Arne; Eberhardt, Jacob; Nittby, Henrietta; Salford, Leif

    2012-01-01

    Effect of 915 MHz electromagnetic fields (EMF) on the blood brain-barrier (BBB) permeability has been studied in Fischer 344 rats of both sexes. Male and female Fischer 344 rats were exposed in a Transverse Electromagnetic Transmission line chamber to microwaves of 915 MHz as continuous wave (CW) and pulse-modulated with different pulse power and at various time intervals. The CW-pulse power varied from 0.001W to 10 W and the exposure time from 2 min. to 960 min. In each experi...

  2. Neuropsychiatric disease relevance of circulating anti-NMDA receptor autoantibodies depends on blood-brain barrier integrity.

    Science.gov (United States)

    Hammer, C; Stepniak, B; Schneider, A; Papiol, S; Tantra, M; Begemann, M; Sirén, A-L; Pardo, L A; Sperling, S; Mohd Jofrry, S; Gurvich, A; Jensen, N; Ostmeier, K; Lühder, F; Probst, C; Martens, H; Gillis, M; Saher, G; Assogna, F; Spalletta, G; Stöcker, W; Schulz, T F; Nave, K-A; Ehrenreich, H

    2014-10-01

    In 2007, a multifaceted syndrome, associated with anti-NMDA receptor autoantibodies (NMDAR-AB) of immunoglobulin-G isotype, has been described, which variably consists of psychosis, epilepsy, cognitive decline and extrapyramidal symptoms. Prevalence and significance of NMDAR-AB in complex neuropsychiatric disease versus health, however, have remained unclear. We tested sera of 2817 subjects (1325 healthy, 1081 schizophrenic, 263 Parkinson and 148 affective-disorder subjects) for presence of NMDAR-AB, conducted a genome-wide genetic association study, comparing AB carriers versus non-carriers, and assessed their influenza AB status. For mechanistic insight and documentation of AB functionality, in vivo experiments involving mice with deficient blood-brain barrier (ApoE(-/-)) and in vitro endocytosis assays in primary cortical neurons were performed. In 10.5% of subjects, NMDAR-AB (NR1 subunit) of any immunoglobulin isotype were detected, with no difference in seroprevalence, titer or in vitro functionality between patients and healthy controls. Administration of extracted human serum to mice influenced basal and MK-801-induced activity in the open field only in ApoE(-/-) mice injected with NMDAR-AB-positive serum but not in respective controls. Seropositive schizophrenic patients with a history of neurotrauma or birth complications, indicating an at least temporarily compromised blood-brain barrier, had more neurological abnormalities than seronegative patients with comparable history. A common genetic variant (rs524991, P=6.15E-08) as well as past influenza A (P=0.024) or B (P=0.006) infection were identified as predisposing factors for NMDAR-AB seropositivity. The >10% overall seroprevalence of NMDAR-AB of both healthy individuals and patients is unexpectedly high. Clinical significance, however, apparently depends on association with past or present perturbations of blood-brain barrier function. PMID:23999527

  3. 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

  4. A study of the blood brain barrier and an evaluation of demyelination in tuberculous meningitis

    International Nuclear Information System (INIS)

    The blood brain barrier (BBB) plays an important role in the regulation of homeostasis of the CNS. The effect of tuberculous meningitis (TBM) on the BBB was studied using a ratio of serum albumin-CSF albumin levels. During the acute stage of meningitis 80% of the patients had moderate to severe disturbances in the BBB that persisted 1 to 3 months post therapy. Neurological damage was assessed using Myelin Basic Protein (CBP) as marker. Over 62% of patients with TBM had a significantly high level of MBP. (author). 19 refs, 5 tabs

  5. Insulin Detemir is Not Transported Across the Blood-Brain Barrier

    OpenAIRE

    Banks, William A.; Morley, John E.; Lynch, Jessica L.; Lynch, Kristin M.; Mooradian, Arshag D.

    2010-01-01

    Insulin detemir has a different profile of action on the central nervous system (CNS) than human insulin. It has been hypothesized that this is caused by an altered ability of insulin detemir to cross the blood-brain barrier (BBB). Here, we measured the permeability of the BBB to insulin detemir. We labeled insulin detemir with radioactive iodine (I-Det) and examined its ability to cross the BBB of the mouse. Permeation was assessed after intravenous injection and by brain perfusion in the pr...

  6. Measurement of human blood brain barrier integrity using 11C-inulin and positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) using 11C-inulin was demonstrated to be applicable to the clinical measurement of blood brain barrier permeability and cerebral interstitial fluid volume. Kinetic data were analyzed by application of a two compartment model, in which blood plasma and interstitial fluid spaces constitute the compartments. The blood activity contribution was subtracted from the PET count with the aid of the 11CO inhalation technique. The values we estimated in a human brain were in agreement with the reported values obtained for animal brains by the use of 14C-inulin. (orig.)

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

    OpenAIRE

    Farsa, Oldřich

    2012-01-01

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

  8. In Situ Blood-Brain Barrier Permeability of a C-10 Paclitaxel Carbamate

    OpenAIRE

    Ballatore, Carlo; Zhang, Bin; Trojanowski, John Q.; Lee, Virginia M.-Y.; Smith, Amos B.

    2008-01-01

    We report the synthesis and blood-brain barrier (BBB) permeability of 14C-CNDR-29, a paclitaxel C-10 carbamate derivative shown to be devoid of P-glycoprotein (Pgp)-interactions, in an in situ mouse brain perfusion model, in comparison with 14C-paclitaxel. The results presented reveal a 3–4 fold higher BBB-permeability for the C-10 modified taxane compared to paclitaxel. These results support the notion that circumvention of Pgp-mediated efflux can lead to higher BBB-permeability. Further stu...

  9. 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...

  10. Blood-brain barrier shuttle peptides: an emerging paradigm for brain delivery.

    Science.gov (United States)

    Oller-Salvia, Benjamí; Sánchez-Navarro, Macarena; Giralt, Ernest; Teixidó, Meritxell

    2016-08-22

    Brain delivery is one of the major challenges in drug development because of the high number of patients suffering from neural diseases and the low efficiency of the treatments available. Although the blood-brain barrier (BBB) prevents most drugs from reaching their targets, molecular vectors - known as BBB shuttles - offer great promise to safely overcome this formidable obstacle. In recent years, peptide shuttles have received growing attention because of their lower cost, reduced immunogenicity, and higher chemical versatility than traditional Trojan horse antibodies and other proteins. PMID:27188322

  11. 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...... in migraine patients and normal volunteers also indicate a more general effect of sumatriptan on CNS indicating that the drug can cross the BBB in man. It has been discussed whether a defect in the BBB during migraine attacks could be responsible for a possible central effect of sumatriptan in migraine...

  12. Trafficking of Endogenous Immunoglobulins by Endothelial Cells at the Blood-Brain Barrier

    OpenAIRE

    Villaseñor, Roberto; Ozmen, Laurence; Messaddeq, Nadia; Grüninger, Fiona; Loetscher, Hansruedi; Keller, Annika; Betsholtz, Christer; Freskgård, Per-Ola; Collin, Ludovic

    2016-01-01

    The Blood-Brain Barrier (BBB) restricts access of large molecules to the brain. The low endocytic activity of brain endothelial cells (BECs) is believed to limit delivery of immunoglobulins (IgG) to the brain parenchyma. Here, we report that endogenous mouse IgG are localized within intracellular vesicles at steady state in BECs in vivo. Using high-resolution quantitative microscopy, we found a fraction of endocytosed IgG in lysosomes. We observed that loss of pericytes (key components of the...

  13. Identification of blood-brain barrier function following subarachnoid hemorrhage in rats at different stages

    Institute of Scientific and Technical Information of China (English)

    Zongyi Xie; Weiwei Shen; Ying Ma; Yuan Cheng

    2008-01-01

    BACKGROUND: Recent studies have indicated that blood-brain barrier (BBB) disruption following subarachnoid hemorrhage (SAH) significantly correlates with the development of brain injury and poor prognosis of patients subjected to SAH. OBJECTIVE: To investigate both functional and structural changes related to BBB in various phases after SAH in rats through quantitative and qualitative methods.DESIGN, TIME AND SETTING: This experiment, a completely randomized design and controlled experiment, was performed at the Department of Neurosurgery, the Second Affiliated Hospital of Chongqing University of Medical Sciences from June 2006 to March 2007.MATERIALS: A total of 128 female, healthy, Sprague-Dawley rats were selected for this study. Main reagents and instruments: Evans Blue dye (Sigma Company, USA), fluorescence spectrophotometer (Shimadzu Company, Japan), and transmission electron microscope (Olympus Company, Japan). MAIN OUTCOME MEASURES: Brain tissue water content was determined by the wet-dry method. BBB permeability in the cerebral cortex was determined by Evans Blue dye and fluorescent spectrophotometer. The ultrastructural changes in BBB were observed with transmission electron microscope.RESULTS: Compared with the sham-operated group, SAH induced a significant increase in brain water content between 24 and 60 hours (F = 888.32, P 0.05). Electron microscopy demonstrated only a mild perivascular edema at 24 hours after SAH. By 36 hours, a notable perivascular edema was associated with a collapse of the capillary. Astrocytic endfeet surrounding the capillary were prominently swollen in the edematous areas. The above-mentioned abnormal ultrastructural changes in the BBB were reversed by 72 hours after SAH. No obvious morphological changes in the BBB were detected in the sham-operated rats.CONCLUSION: These results directly suggest that SAH could induce rapid changes in BBB function and structure during the acute phases of BBB breakdown. Moreover, these dynamic

  14. 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

    The blood-brain barrier (BBB), a complex of endothelial and glial barriers, controls passage of cells and solutes between the blood and central nervous system (CNS). Blood-brain barrier breakdown refers to entry of cells and/or solutes. We were interested whether the renin-angiotensin system 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...

  15. Tempol modulates changes in xenobiotic permeability and occludin oligomeric assemblies at the blood-brain barrier during inflammatory pain

    OpenAIRE

    Lochhead, Jeffrey J; McCaffrey, Gwen; Sanchez-Covarrubias, Lucy; Finch, Jessica D.; DeMarco, Kristin M; Quigley, Colleen E.; Davis, Thomas P.; Ronaldson, Patrick T

    2011-01-01

    Our laboratory has shown that λ-carrageenan-induced peripheral inflammatory pain (CIP) can alter tight junction (TJ) protein expression and/or assembly leading to changes in blood-brain barrier xenobiotic permeability. However, the role of reactive oxygen species (ROS) and subsequent oxidative stress during CIP is unknown. ROS (i.e., superoxide) are known to cause cellular damage in response to pain/inflammation. Therefore, we examined oxidative stress-associated effects at the blood-brain ba...

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

    Science.gov (United States)

    Marchi, Nicola; Bazarian, Jeffrey J; Puvenna, Vikram; Janigro, Mattia; Ghosh, Chaitali; Zhong, Jianhui; Zhu, Tong; Blackman, Eric; Stewart, Desiree; Ellis, Jasmina; Butler, Robert; Janigro, Damir

    2013-01-01

    The acknowledgement of risks for traumatic brain injury in American football players has prompted studies for sideline concussion diagnosis and testing for neurological deficits. While concussions are recognized etiological factors for a spectrum of neurological sequelae, the consequences of sub-concussive events are unclear. We tested the hypothesis that blood-brain barrier disruption (BBBD) and the accompanying surge of the astrocytic protein S100B in blood may cause an immune response associated with production of auto-antibodies. We also wished to determine whether these events result in disrupted white matter on diffusion tensor imaging (DT) scans. Players from three college football teams were enrolled (total of 67 volunteers). None of the players experienced a concussion. Blood samples were collected before and after games (n = 57); the number of head hits in all players was monitored by movie review and post-game interviews. S100B serum levels and auto-antibodies against S100B were measured and correlated by direct and reverse immunoassays (n = 15 players; 5 games). A subset of players underwent DTI scans pre- and post-season and after a 6-month interval (n = 10). Cognitive and functional assessments were also performed. After a game, transient BBB damage measured by serum S100B was detected only in players experiencing the greatest number of sub-concussive head hits. Elevated levels of auto-antibodies against S100B were elevated only after repeated sub-concussive events characterized by BBBD. Serum levels of S100B auto-antibodies also predicted persistence of MRI-DTI abnormalities which in turn correlated with cognitive changes. Even in the absence of concussion, football players may experience repeated BBBD and serum surges of the potential auto-antigen S100B. The correlation of serum S100B, auto-antibodies and DTI changes support a link between repeated BBBD and future risk for cognitive changes. PMID:23483891

  17. In vitro blood-brain barrier permeability predictions for GABAA receptor modulating piperine analogs.

    Science.gov (United States)

    Eigenmann, Daniela Elisabeth; Dürig, Carmen; Jähne, Evelyn Andrea; Smieško, Martin; Culot, Maxime; Gosselet, Fabien; Cecchelli, Romeo; Helms, Hans Christian Cederberg; Brodin, Birger; Wimmer, Laurin; Mihovilovic, Marko D; Hamburger, Matthias; Oufir, Mouhssin

    2016-06-01

    The alkaloid piperine from black pepper (Piper nigrum L.) and several synthetic piperine analogs were recently identified as positive allosteric modulators of γ-aminobutyric acid type A (GABAA) receptors. In order to reach their target sites of action, these compounds need to enter the brain by crossing the blood-brain barrier (BBB). We here evaluated piperine and five selected analogs (SCT-66, SCT-64, SCT-29, LAU397, and LAU399) regarding their BBB permeability. Data were obtained in three in vitro BBB models, namely a recently established human model with immortalized hBMEC cells, a human brain-like endothelial cells (BLEC) model, and a primary animal (bovine endothelial/rat astrocytes co-culture) model. For each compound, quantitative UHPLC-MS/MS methods in the range of 5.00-500ng/mL in the corresponding matrix were developed, and permeability coefficients in the three BBB models were determined. In vitro predictions from the two human BBB models were in good agreement, while permeability data from the animal model differed to some extent, possibly due to protein binding of the screened compounds. In all three BBB models, piperine and SCT-64 displayed the highest BBB permeation potential. This was corroborated by data from in silico prediction. For the other piperine analogs (SCT-66, SCT-29, LAU397, and LAU399), BBB permeability was low to moderate in the two human BBB models, and moderate to high in the animal BBB model. Efflux ratios (ER) calculated from bidirectional permeability experiments indicated that the compounds were likely not substrates of active efflux transporters. PMID:27018328

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Agent based modeling of the effects of potential treatments over the blood-brain barrier in multiple sclerosis.

    Science.gov (United States)

    Pennisi, Marzio; Russo, Giulia; Motta, Santo; Pappalardo, Francesco

    2015-12-01

    Multiple sclerosis is a disease of the central nervous system that involves the destruction of the insulating sheath of axons, causing severe disabilities. Since the etiology of the disease is not yet fully understood, the use of novel techniques that may help to understand the disease, to suggest potential therapies and to test the effects of candidate treatments is highly advisable. To this end we developed an agent based model that demonstrated its ability to reproduce the typical oscillatory behavior observed in the most common form of multiple sclerosis, relapsing-remitting multiple sclerosis. The model has then been used to test the potential beneficial effects of vitamin D over the disease. Many scientific studies underlined the importance of the blood-brain barrier and of the mechanisms that influence its permeability on the development of the disease. In the present paper we further extend our previously developed model with a mechanism that mimics the blood-brain barrier behavior. The goal of our work is to suggest the best strategies to follow for developing new potential treatments that intervene in the blood-brain barrier. Results suggest that the best treatments should potentially prevent the opening of the blood-brain barrier, as treatments that help in recovering the blood-brain barrier functionality could be less effective. PMID:26343337

  3. 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.

  4. In vitro model of the blood-brain barrier established by co-culture of primary cerebral microvascular endothelial and astrocyte cells

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2015-01-01

    Full Text Available Drugs for the treatment and prevention of nervous system diseases must permeate the blood-brain barrier to take effect. In vitro models of the blood-brain barrier are therefore important in the investigation of drug permeation mechanisms. However, to date, no unified method has been described for establishing a blood-brain barrier model. Here, we modified an in vitro model of the blood-brain barrier by seeding brain microvascular endothelial cells and astrocytes from newborn rats on a polyester Transwell cell culture membrane with 0.4-µm pores, and conducted transepithelial electrical resistance measurements, leakage tests and assays for specific blood-brain barrier enzymes. We show that the permeability of our model is as low as that of the blood-brain barrier in vivo. Our model will be a valuable tool in the study of the mechanisms of action of neuroprotective drugs.

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

    Directory of Open Access Journals (Sweden)

    Renee Jade Turner

    2016-03-01

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

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

    DEFF Research Database (Denmark)

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

    Introduction - The blood-brain barrier (BBB) is a physical, transport and metabolic barrier which plays a key role in preventing uncontrolled exchanges between blood and brain, ensuring an optimal environment for neurons activity. This extent interface is created by the endothelial cells forming...... decreasing the oxygen level to 1% in a hypoxia workbench. To mimic the reperfusion phase, the aglycemic medium was replaced by glucose-supplemented medium and cells were further transferred in a normoxia incubator for 48h. TEER was monitored with an EVOHM and expression levels of relevant proteins were...... therapies to treat this devastating disease. Materials and Methods - Primary cultures of endothelial cells from bovine brain microvessels were cocultured with rat astrocytes in transwell inserts. At day 11, cells were treated with 4h of OGD by changing the culture medium with glucose-free medium and...

  7. 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

  8. Blood-brain barrier properties in vitro depend on composition and assembly of endogenous extracellular matrices.

    Science.gov (United States)

    Zobel, Kathrin; Hansen, Uwe; Galla, Hans-Joachim

    2016-08-01

    Brain capillary endothelial cells, which constitute the blood-brain barrier (BBB), are enveloped by the extracellular matrix (ECM) produced by endothelial cells, pericytes and astrocytes. The contribution of matrix components secreted by the various cell types at the neurovascular unit, however, remains unclear with respect to their effect on endothelial barrier function. In this study, a new in vitro model was established by growing endothelial cells on an ECM produced by pericytes, astrocytes or a serial combination of both. The last-mentioned was found to be more in vivo-like. We investigated the role of the composition and morphology of ECM supra-structures in maintaining BBB function. The composition was analysed by protein analysis (enzyme-linked immunosorbent assay) and the ultrastructure of generated matrices was analysed by transmission electron microscopy including immunogold labelling. We could show by electric cell-substrate impedance sensing measurements that pericytes and combined matrices significantly improved the barrier tightness of porcine brain capillary endothelial cells (PBCEC). The increase of the resistance was verified by enhanced expression of tight junction proteins. Thus, for the first time, we have shown that barrier integrity is strictly controlled by the ECM, which is a product of all cells involved in the secretion of ECM components and their modification by corresponding cells. Moreover, we have demonstrated that complex matrices by the various cells of the BBB induce barrier marker enzymes in PBCEC, such as alkaline phosphatase. PMID:27053246

  9. Molecular targets in radiation-induced blood-brain barrier disruption

    International Nuclear Information System (INIS)

    Disruption of the blood-brain barrier (BBB) is a key feature of radiation injury to the central nervous system. Studies suggest that endothelial cell apoptosis, gene expression changes, and alteration of the microenvironment are important in initiation and progression of injury. Although substantial effort has been directed at understanding the impact of radiation on endothelial cells and oligodendrocytes, growing evidence suggests that other cell types, including astrocytes, are important in responses that include induced gene expression and microenvironmental changes. Endothelial apoptosis is important in early BBB disruption. Hypoxia and oxidative stress in the later period that precedes tissue damage might lead to astrocytic responses that impact cell survival and cell interactions. Cell death, gene expression changes, and a toxic microenvironment can be viewed as interacting elements in a model of radiation-induced disruption of the BBB. These processes implicate particular genes and proteins as targets in potential strategies for neuroprotection

  10. 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.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    tools in various in vivo central nervous system disease models in rodents, as well as being templates in the design of novel ligands affecting the glutamatergic system. Both molecules are highly polar but yet capable of crossing the blood-brain barrier (BBB). We used an in situ rat brain perfusion...... 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...

  12. 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.

  13. 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. PMID:19811403

  14. 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.

  15. Autoradiographic evidence for passage of vincamine through the blood-brain barrier

    Energy Technology Data Exchange (ETDEWEB)

    Sprumont, P.; Lintermans, J.

    1982-01-01

    Autoradiographies of the brain and of the cerebellum were performed in 8-month old rats after intraperitoneal injection of /sup 3/H-labelled vincamine. Only those samples that were processed by freezedrying or by freezesubstitution gave interpretable results. Some specifically labelled cells were found in the molecular layer of the cerebellar cortex as well as in the internal granular and in the deeper layers of the cerebral cortex. They did not belong to the vascular system. It was concluded that vincamine or its metabolites crosses the blood-brain barrier. Any attempt to explain a possible action of the substance on the brain function should thus also consider the cellular components of the central nervous system and not only the haemodynamics of the cerebral circulation.

  16. Autoradiographic evidence for passage of vincamine through the blood-brain barrier

    International Nuclear Information System (INIS)

    Autoradiographies of the brain and of the cerebellum were performed in 8-month old rats after intraperitoneal injection of 3H-labelled vincamine. Only those samples that were processed by freezedrying or by freezesubstitution gave interpretable results. Some specifically labelled cells were found in the molecular layer of the cerebellar cortex as well as in the internal granular and in the deeper layers of the cerebral cortex. They did not belong to the vascular system. It was concluded that vincamine or its metabolites crosses the blood-brain barrier. Any attempt to explain a possible action of the substance on the brain function should thus also consider the cellular components of the central nervous system and not only the haemodynamics of the cerebral circulation. (orig.)

  17. Signaled drug delivery and transport across the blood-brain barrier.

    Science.gov (United States)

    Hinow, Peter; Radunskaya, Ami; Mackay, Sean M; Reynolds, John N J; Schroeder, Morgan; Tan, Eng Wui; Tucker, Ian G

    2016-09-01

    We use a mathematical model to describe the delivery of a drug to a specific region of the brain. The drug is carried by liposomes that can release their cargo by application of focused ultrasound (US). Thereupon, the drug is absorbed through the endothelial cells that line the brain capillaries and form the physiologically important blood-brain barrier (BBB). We present a compartmental model of a capillary that is able to capture the complex binding and transport processes the drug undergoes in the blood plasma and at the BBB. We apply this model to the delivery of levodopa (L-dopa, used to treat Parkinson's disease) and doxorubicin (an anticancer agent). The goal is to optimize the delivery of drug while at the same time minimizing possible side effects of the US. PMID:26572864

  18. 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. These...... changes may impair neuronal functioning and contribute to the mechanisms underlying ECT-induced cognitive deficits. Some but not all clinical data on the subject suggest that blood pressure changes during ECT correlate with indices of cognitive impairment. In animal models, pharmacological manipulations...... 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...

  19. Development of an in vitro blood-brain barrier model-cytotoxicity of mercury and aluminum.

    Science.gov (United States)

    Toimela, Tarja; Mäenpää, Hanna; Mannerström, Marika; Tähti, Hanna

    2004-02-15

    In this study, in vitro blood-brain barrier (BBB) models composed of two different cell types were compared. The aim of our study was to find an alternative human cell line that could be used in BBB models. Inorganic and organic mercury and aluminum were studied as model chemicals in the testing of the system. BBB models were composed of endothelial RBE4 cell line or retinal pigment epithelial (RPE) cell line ARPE-19 and neuronal SH-SY5Y cells as target cells. Glial U-373 MG cells were included in part of the tests to induce the formation of a tighter barrier. Millicell CM filter inserts were coated with rat-tail collagen, and RBE4 or ARPE-19 cells were placed on the filters at the density of 3.5-4 x 10(5) cells/filter. During culture, the state of confluency was microscopically observed and confirmed by the measurement of electrical resistance caused by the developing cell layer. The target cells, SH-SY5Y neuroblastoma cells, were plated on the bottom of cell culture wells at the density of 100000 cells/cm(2). In part of the studies, glial U-373 MG cells were placed on the under side of the membrane filter. When confluent filters with ARPE-19 or RBE4 cells were placed on top of the SH-SY5Y cells, different concentrations of mercuric chloride, methyl mercury chloride, and aluminum chloride were added into the filter cups along with a fluorescent tracer. Exposure time was 24 h, after which the cytotoxicity in the SH-SY5Y cell layer, as well as in the ARPE-19 or RBE4 cell layer, was evaluated by the luminescent measurement of total ATP. The leakage of the fluorescent tracer was also monitored. The results showed that both barrier cell types were induced by glial cells. Inorganic and organic mercury caused a leakage of the dye and cytotoxicity in SH-SY5Y cells. Especially, methyl mercury chloride could exert an effect on target cells before any profound cytotoxicity in barrier cells could be seen. Aluminum did not cause any leakage in the barrier cell layer, and even

  20. 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.

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

    International Nuclear Information System (INIS)

    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.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-15

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

  3. Correlation of Ultrastructural Changes of Endothelial Cells and Astrocytes Occurring during Blood Brain Barrier Damage after Traumatic Brain Injury with Biochemical Markers of Blood Brain Barrier Leakage and Inflammatory Response

    Czech Academy of Sciences Publication Activity Database

    Vajtr, D.; Benada, Oldřich; Kukačka, J.; Průša, R.; Houšťava, L.; Toupalík, P.; Kizek, R.

    2009-01-01

    Roč. 58, č. 2 (2009), s. 263-268. ISSN 0862-8408 Institutional research plan: CEZ:AV0Z50200510 Keywords : Blood brain barrier * Expansive contusion * Metalloproteinases Subject RIV: EE - Microbiology, Virology Impact factor: 1.430, year: 2009

  4. 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.

  5. Electroporation of Brain Endothelial Cells on Chip toward Permeabilizing the Blood-Brain Barrier.

    Science.gov (United States)

    Bonakdar, Mohammad; Wasson, Elisa M; Lee, Yong W; Davalos, Rafael V

    2016-01-19

    The blood-brain barrier, mainly composed of brain microvascular endothelial cells, poses an obstacle to drug delivery to the brain. Controlled permeabilization of the constituent brain endothelial cells can result in overcoming this barrier and increasing transcellular transport across it. Electroporation is a biophysical phenomenon that has shown potential in permeabilizing and overcoming this barrier. In this study we developed a microengineered in vitro model to characterize the permeabilization of adhered brain endothelial cells to large molecules in response to applied pulsed electric fields. We found the distribution of affected cells by reversible and irreversible electroporation, and quantified the uptaken amount of naturally impermeable molecules into the cells as a result of applied pulse magnitude and number of pulses. We achieved 81 ± 1.7% (N = 6) electroporated cells with 17 ± 8% (N = 5) cell death using an electric-field magnitude of ∼580 V/cm and 10 pulses. Our results provide the proper range for applied electric-field intensity and number of pulses for safe permeabilization without significantly compromising cell viability. Our results demonstrate that it is possible to permeabilize the endothelial cells of the BBB in a controlled manner, therefore lending to the feasibility of using pulsed electric fields to increase drug transport across the BBB through the transcellular pathway. PMID:26789772

  6. 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.

  7. 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.

  8. Drug and xenobiotic biotransformation in the blood-brain barrier: A neglected issue.

    Directory of Open Access Journals (Sweden)

    José A.G. Agúndez

    2014-10-01

    Full Text Available Drug biotransformation is a crucial mechanism for facilitating the elimination of chemicals from the organism and for decreasing their pharmacological activity. Published evidence suggests that brain drug metabolism may play a role in the development of adverse drug reactions and in the clinical response to drugs and xenobiotics. The blood-brain barrier (BBB has been regarded mainly as a physical barrier for drugs and xenobiotics, and little attention has been paid to BBB as a drug-metabolizing barrier. The presence of drug metabolizing enzymes in the BBB is likely to have functional implications because local metabolism may inactivate drugs or may modify the drug's ability to cross the BBB, thus modifying the drug response and the risk of developing adverse drug reactions. In this perspective paper, we discuss the expression of relevant xenobiotic metabolizing enzymes in the brain and in the BBB, and we cover current advances and future directions on the potential role of these BBB drug-metabolizing enzymes as modifiers of drug response.

  9. Blood-brain barrier proteomics: towards the understanding of neurodegenerative diseases.

    Science.gov (United States)

    Karamanos, Yannis; Gosselet, Fabien; Dehouck, Marie-Pierre; Cecchelli, Roméo

    2014-11-01

    The blood-brain barrier (BBB) regulates the passage of endogenous and exogenous compounds and thus contributes to the brain homeostasis with the help of well-known proteins such as tight junction proteins, plasma membrane transporters and metabolic barrier proteins. In the last decade, proteomics have emerged as supplementary tools for BBB research. The development of proteomic technologies has provided several means to extend knowledge on the BBB and to investigate additional routes for the bypass of this barrier. Proteomics approaches have been used in vivo and also using in vitro BBB models to decipher the physiological characteristics and, under stress conditions, to understand the molecular mechanisms of brain diseases. This work has demonstrated that both quantitative global and targeted proteomics approaches are powerful and provide significant information on the brain microvessel endothelium. However, current knowledge is only partial and it is necessary to increase the studies using proteomics tools that will provide additional information concerning brain pathologies or BBB metabolism. Highly sensitive, accurate and specific protein quantification by quantitative targeted proteomics appears as an essential methodology for human BBB studies. PMID:25446619

  10. 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

  11. The enzymatic degradation and transport of leucine-enkephalin and 4-imidazolidinone enkephalin prodrugs at the blood-brain barrier

    DEFF Research Database (Denmark)

    Lund, L.; Bak, A.; Friis, G.J.; Hovgaard, L.; Christrup, Lona Louring

    In this study, the stability in and transport across a cell culture model of the blood-brain barrier (BBB) is investigated for leucine-enkephalin (Leu-enkephalin) and four 4-imidazolidinone prodrugs of Leu-enkephalin. The results show that Leu-enkephalin is degraded in the cell culture model of t...

  12. Kinetic modeling of Fe-52/Mn-52m-citrate at the blood-brain barrier by positron emission tomography

    NARCIS (Netherlands)

    Calonder, C; Wurtenberger, PI; Maguire, RP; Pellikka, R; Leenders, KL

    1999-01-01

    The kinetics of iron at the blood-brain barrier of the monkey were studied in vivo using positron emission tomography (PET) and the tracer Fe-52/Mn-52m-citrate. Mn-52m is the beta(+)-emitting daughter nuclide of Fe-52 and therefore contributes to the observed signal and background in the PET images

  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. Localization of CGRP, CGRP receptor, PACAP and glutamate in trigeminal ganglion. Relation to the blood-brain barrier

    DEFF Research Database (Denmark)

    Eftekhari, Sajedeh; Salvatore, Christopher A; Johansson, Sara;

    2015-01-01

    ) and related this to the expression of CGRP and its receptor in rhesus trigeminal ganglion. Pituitary adenylate cyclase-activating polypeptide (PACAP) and glutamate were examined and related to the CGRP system. Furthermore, we examined if the trigeminal ganglion is protected by the blood-brain barrier...

  15. 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

  16. 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.

  17. MicroRNA-155 negatively affects blood-brain barrier function during neuroinflammation.

    Science.gov (United States)

    Lopez-Ramirez, Miguel Alejandro; Wu, Dongsheng; Pryce, Gareth; Simpson, Julie E; Reijerkerk, Arie; King-Robson, Josh; Kay, Oliver; de Vries, Helga E; Hirst, Mark C; Sharrack, Basil; Baker, David; Male, David Kingsley; Michael, Gregory J; Romero, Ignacio Andres

    2014-06-01

    Blood-brain barrier (BBB) dysfunction is a hallmark of neurological conditions such as multiple sclerosis (MS) and stroke. However, the molecular mechanisms underlying neurovascular dysfunction during BBB breakdown remain elusive. MicroRNAs (miRNAs) have recently emerged as key regulators of pathogenic responses, although their role in central nervous system (CNS) microvascular disorders is largely unknown. We have identified miR-155 as a critical miRNA in neuroinflammation at the BBB. miR-155 is expressed at the neurovascular unit of individuals with MS and of mice with experimental autoimmune encephalomyelitis (EAE). In mice, loss of miR-155 reduced CNS extravasation of systemic tracers, both in EAE and in an acute systemic inflammation model induced by lipopolysaccharide. In cultured human brain endothelium, miR-155 was strongly and rapidly upregulated by inflammatory cytokines. miR-155 up-regulation mimicked cytokine-induced alterations in junctional organization and permeability, whereas inhibition of endogenous miR-155 partially prevented a cytokine-induced increase in permeability. Furthermore, miR-155 modulated brain endothelial barrier function by targeting not only cell-cell complex molecules such as annexin-2 and claudin-1, but also focal adhesion components such as DOCK-1 and syntenin-1. We propose that brain endothelial miR-155 is a negative regulator of BBB function that may constitute a novel therapeutic target for CNS neuroinflammatory disorders. PMID:24604078

  18. Role of the Blood-Brain Barrier in the Formation of Brain Metastases

    Directory of Open Access Journals (Sweden)

    István A. Krizbai

    2013-01-01

    Full Text Available The majority of brain metastases originate from lung cancer, breast cancer and malignant melanoma. In order to reach the brain, parenchyma metastatic cells have to transmigrate through the endothelial cell layer of brain capillaries, which forms the morphological basis of the blood-brain barrier (BBB. The BBB has a dual role in brain metastasis formation: it forms a tight barrier protecting the central nervous system from entering cancer cells, but it is also actively involved in protecting metastatic cells during extravasation and proliferation in the brain. The mechanisms of interaction of cancer cells and cerebral endothelial cells are largely uncharacterized. Here, we provide a comprehensive review on our current knowledge about the role of junctional and adhesion molecules, soluble factors, proteolytic enzymes and signaling pathways mediating the attachment of tumor cells to brain endothelial cells and the transendothelial migration of metastatic cells. Since brain metastases represent a great therapeutic challenge, it is indispensable to understand the mechanisms of the interaction of tumor cells with the BBB in order to find targets of prevention of brain metastasis formation.

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

    Directory of Open Access Journals (Sweden)

    Jörg Huwyler

    2012-08-01

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

  20. Influence of age on the passage of paraquat through the blood-brain barrier in rats: a distribution and pathological examination

    International Nuclear Information System (INIS)

    Experiments were performed to determine the extent of paraquat entry into the brain of neonatal and elderly rats, as compared with adult rats, which may be dependent on the efficacy of the blood-brain barrier. A single, median lethal dose (20 mg/kg s.c.) of paraquat containing [14C]paraquat was administered to neonatal (10 day old), adult (3 month old) and elderly (18 month old) rats. In contrast to the adult and elderly rats where paraquat levels fell over the 24 h post-dosing period to negligible levels, paraquat concentrations in neonatal brains did not decrease with time between 0.5 and 24 h following dosing. The distribution of [14C]paraquat was measured in selective brain regions using quantitative autoradiography in all three age groups of rats, 30 min and 24 h following dosing. Autoradiography demonstrated that brain paraquat distributions were similar in the rat age groups. Most of the paraquat was confined to regions outside the blood-brain barrier and to brain regions that lack a complete blood-brain barrier e.g. dorsal hypothalamus, area postrema and the anterior olfactory bulb. Between 0.5 h and 24 h following dosing, paraquat concentrations in deeper brain structures, some distance away from the sites of entry, began to slowly increase in all the rat age groups. By 24 h following dosing, a majority of brain regions examined using quantitative autoradiography revealed significantly higher paraquat concentrations in neonatal brains as compared to brain regions of adult and elderly rats. Despite increased paraquat entry into neonatal brain, we could find no evidence for paraquat-induced neuronal cell damage following a detailed histopathological examination of perfused-fixed brains. In conclusion, impaired blood-brain barrier integrity in neonatal brain thus permitting more paraquat to enter than in adult brain, did not result in neuronal damage

  1. 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

  2. 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

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

    Directory of Open Access Journals (Sweden)

    Winfried Neuhaus

    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.

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

    Directory of Open Access Journals (Sweden)

    Sylvia Wagner

    Full Text Available BACKGROUND: Due to the use of organophosphates (OP as pesticides and the availability of OP-type nerve agents, an effective medical treatment for OP poisonings is still a challenging problem. The acute toxicity of an OP poisoning is mainly due to the inhibition of acetylcholinesterase (AChE in the peripheral and central nervous systems (CNS. This results in an increase in the synaptic concentration of the neurotransmitter acetylcholine, overstimulation of cholinergic receptors and disorder of numerous body functions up to death. The standard treatment of OP poisoning includes a combination of a muscarinic antagonist and an AChE reactivator (oxime. However, these oximes can not cross the blood-brain barrier (BBB sufficiently. Therefore, new strategies are needed to transport oximes over the BBB. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we combined different oximes (obidoxime dichloride and two different HI 6 salts, HI 6 dichloride monohydrate and HI 6 dimethanesulfonate with human serum albumin nanoparticles and could show an oxime transport over an in vitro BBB model. In general, the nanoparticulate transported oximes achieved a better reactivation of OP-inhibited AChE than free oximes. CONCLUSIONS/SIGNIFICANCE: With these nanoparticles, for the first time, a tool exists that could enable a transport of oximes over the BBB. This is very important for survival after severe OP intoxication. Therefore, these nanoparticulate formulations are promising formulations for the treatment of the peripheral and the CNS after OP poisoning.

  5. Recent advances in the brain-to-blood efflux transport across the blood-brain barrier.

    Science.gov (United States)

    Hosoya, Ken-ichi; Ohtsuki, Sumio; Terasaki, Tetsuya

    2002-11-01

    Elucidating the details of the blood-brain barrier (BBB) transport mechanism is a very important step towards successful drug targeting to the brain and understanding what happens in the brain. Although several brain uptake methods have been developed to characterize transport at the BBB, these are mainly useful for investigating influx transport across the BBB. In 1992, P-glycoprotein was found to act as an efflux pump for anti-cancer drugs at the BBB using primary cultured bovine brain endothelial cells. In order to determine the direct efflux transport from the brain to the circulating blood of exogenous compounds in vivo, the Brain Efflux Index method was developed to characterize several BBB efflux transport systems. Recently, we have established conditionally immortalized rat (TR-BBB) and mouse (TM-BBB) brain capillary endothelial cell lines from transgenic rats and mice harboring temperature-sensitive simian virus 40 large T-antigen gene to characterize the transport mechanisms at the BBB in vitro. TR-BBB and TM-BBB cells possess certain in vivo transport functions and express mRNAs for the BBB. Using a combination of newly developed in vivo and in vitro methods, we have elucidated the efflux transport mechanism at the BBB for neurosteroids, excitatory neurotransmitters, suppressive neurotransmitters, amino acids, and other organic anions to understand the physiological role played by the BBB as a detoxifying organ for the brain. PMID:12429456

  6. Blood-brain barrier dysfunction in white matter lesions of elderly patients with dementia

    International Nuclear Information System (INIS)

    We investigated blood-brain barrier (BBB) permeability in white matter lesions of Binswanger's and Alzheimer's disease with contrast-enhanced MRI. BBB permeability was quantified by calculation of T1 change defined as [(T1post-T1pre)/T1pre], where T1pre and T1post represent the T1 relaxation times before and after Gd-DTPA administration. T1 changes in periventricular hyperintensity (PVH) of Binswanger's disease (BD) and Alzheimer's disease (AD) patients significantly decreased in comparison with that in normal white matter of the control subjects, and PVH of BD patients showed significantly decreased T1 change compared to PVH of AD. The magnetization transfer ratio (MTR), reflecting the severity of tissue damage in the white matter, significantly decreased in PVH of BD and AD patients comfarmd with normal white matter of the controls, with a significant decrease in PVH of BD patients compared to PVH of AD patients. T1 change and MTR for area of PVH significantly correlated with the MMSE score in BD, but not in AD. These results suggest that BBB permeability increases in areas of PVH in BD and AD. Moreover, increased BBB permeability may be related to a decline in cognitive impairment in patients with BD. BBB dysfunction and tissue damage may be more severe in areas of PVH in BD patients than that in AD patients. (author)

  7. Opening of the blood-brain barrier by intravenous contrast media in euvolemic and dehydrated rabbits

    International Nuclear Information System (INIS)

    It has been suggested that intravenous injections of hypertonic contrast media when used in computed tomography and digital subtraction angiography might raise plasma osmolality sufficiently to open the blood-brain barrier (BBB). The current investigation establishes the threshold of plasma osmolality that causes the opening of the BBB in euvolemic and dehydrated rabbits. Euvolemic rabbits were allowed food and water ad libitum. Dehydrated rabbits received 4.0 mg/kg of furosemide intramuscularly and were deprived of water for 72 hours. Meglumine/sodium diatrizoate 76% (n=28) or mannitol 20% (n=12) was administrated intravenously, at a rate of 25 mmol/kg body weihgt/hour for 2, 3 or 4 hours. Plasma osmolality, blood iodine concentration, blood pressure, heart rate and hematocrit were assessed at regular intervals. Evans blue and 99Tcm-DTPA were used simultaneously as tracers for BBB opening. Rating of BBB opening with 99Tcm-DTPA correlated well with Evans blue staining (r=0.863, p<0.001; n=42). BBB opening was related to plasma osmolality and was similar for both contrast media and mannitol. Widespread BBB opening occurred above 400 mmol/kg while focal BBB opening occurred above 370 mmol/kg. Dehydration per se increased plasma osmolality but did not reduce the threshold for BBB opening. (orig.)

  8. Oxidative stress and blood-brain barrier dysfunction under particular consideration of matrix metalloproteinases.

    Science.gov (United States)

    Lehner, Christine; Gehwolf, Renate; Tempfer, Herbert; Krizbai, Istvan; Hennig, Bernhard; Bauer, Hans-Christian; Bauer, Hannelore

    2011-09-01

    A cell's "redox" (oxidation and reduction) state is determined by the sum of all redox processes yielding reactive oxygen species (ROS), reactive nitrogen species (RNS), and other reactive intermediates. Low amounts of ROS/RNS are generated by different mechanisms in every cell and are important regulatory mediators in many signaling processes (redox signaling). When the physiological balance between the generation and elimination of ROS/RNS is disrupted, oxidative/nitrosative stress with persistent oxidative damage of the organism occurs. Oxidative stress has been suggested to act as initiator and/or mediator of many human diseases. The cerebral vasculature is particularly susceptible to oxidative stress, which is critical since cerebral endothelial cells play a major role in the creation and maintenance of the blood-brain barrier (BBB). This article will only contain a focused introduction on the biochemical background of redox signaling, since this has been reported already in a series of excellent recent reviews. The goal of this work is to increase the understanding of basic mechanisms underlying ROS/RNS-induced BBB disruption, with a focus on the role of matrix metalloproteinases, which, after all, appear to be a key mediator in the initiation and progression of BBB damage elicited by oxidative stress. PMID:21294658

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

    Science.gov (United States)

    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. PMID:27187189

  10. Three-Dimensional Blood-Brain Barrier Model for in vitro Studies of Neurovascular Pathology

    Science.gov (United States)

    Cho, Hansang; Seo, Ji Hae; Wong, Keith H. K.; Terasaki, Yasukazu; Park, Joseph; Bong, Kiwan; Arai, Ken; Lo, Eng H.; Irimia, Daniel

    2015-10-01

    Blood-brain barrier (BBB) pathology leads to neurovascular disorders and is an important target for therapies. However, the study of BBB pathology is difficult in the absence of models that are simple and relevant. In vivo animal models are highly relevant, however they are hampered by complex, multi-cellular interactions that are difficult to decouple. In vitro models of BBB are simpler, however they have limited functionality and relevance to disease processes. To address these limitations, we developed a 3-dimensional (3D) model of BBB on a microfluidic platform. We verified the tightness of the BBB by showing its ability to reduce the leakage of dyes and to block the transmigration of immune cells towards chemoattractants. Moreover, we verified the localization at endothelial cell boundaries of ZO-1 and VE-Cadherin, two components of tight and adherens junctions. To validate the functionality of the BBB model, we probed its disruption by neuro-inflammation mediators and ischemic conditions and measured the protective function of antioxidant and ROCK-inhibitor treatments. Overall, our 3D BBB model provides a robust platform, adequate for detailed functional studies of BBB and for the screening of BBB-targeting drugs in neurological diseases.

  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. Blood brain barrier is impermeable to solutes and permeable to water after experimental pediatric cardiac arrest.

    Science.gov (United States)

    Tress, Erika E; Clark, Robert S B; Foley, Lesley M; Alexander, Henry; Hickey, Robert W; Drabek, Tomas; Kochanek, Patrick M; Manole, Mioara D

    2014-08-22

    Pediatric asphyxial cardiac arrest (CA) results in unfavorable neurological outcome in most survivors. Development of neuroprotective therapies is contingent upon understanding the permeability of intravenously delivered medications through the blood brain barrier (BBB). In a model of pediatric CA we sought to characterize BBB permeability to small and large molecular weight substances. Additionally, we measured the percent brain water after CA. Asphyxia of 9 min was induced in 16-18 day-old rats. The rats were resuscitated and the BBB permeability to small (sodium fluorescein and gadoteridol) and large (immunoglobulin G, IgG) molecules was assessed at 1, 4, and 24 h after asphyxial CA or sham surgery. Percent brain water was measured post-CA and in shams using wet-to-dry brain weight. Fluorescence, gadoteridol uptake, or IgG staining at 1, 4h and over the entire 24 h post-CA did not differ from shams, suggesting absence of BBB permeability to these solutes. Cerebral water content was increased at 3h post-CA vs. sham. In conclusion, after 9 min of asphyxial CA there is no BBB permeability over 24h to conventional small or large molecule tracers despite the fact that cerebral water content is increased early post-CA indicating the development of brain edema. Evaluation of novel therapies targeting neuronal death after pediatric CA should include their capacity to cross the BBB. PMID:24937271

  13. Role of Microfluidics in Blood-Brain Barrier Permeability Cell Culture Modeling: Relevance to CNS Disorders.

    Science.gov (United States)

    Rusanov, Alexander L; Luzgina, Natalia G; Barreto, George E; Aliev, Gjumrakch

    2016-01-01

    In vitro modeling of the human blood-brain barrier (BBB) is critical for pre-clinical evaluation and predicting the permeability of newly developed potentially neurotoxic and neurotrophic drugs. Here we summarize the specific structural and functional features of endothelial cells as a key component of the BBB and compare analysis of different cell culture models in reflecting these features. Particular attention is paid to cellular models of the BBB in microfluidic devices capable of circulating nutrient media to simulate the blood flow of the brain. In these conditions, it is possible to reproduce a number of factors affecting endothelial cells under physiological conditions, including shear stress. In comparison with static cell models, concentration gradients, which determine the velocity of transport of substances, reproduce more accurately conditions of nutrient medium flow, since they eliminate the accumulation of substances near the basal membrane of cells, not typical for the situation in vivo. Co-cultivation of different types of cells forming the BBB, in separate cell chambers connected by microchannels, allows to evaluate the mutual influences of cells under normal conditions and when exposed to the test substance. New experimental possibilities that can be achieved through modeling of BBB in microfluidic devices determine the feasibility of their use in the practice for pre-clinical studies of novel drugs against neurodegenerative diseases. PMID:26831260

  14. The effects of psychostimulant drugs on blood brain barrier function and neuroinflammation

    Directory of Open Access Journals (Sweden)

    Sharanya M Kousik

    2012-06-01

    Full Text Available The blood brain barrier (BBB is a highly dynamic interface between the central nervous system and periphery. The BBB is comprised of a number of components and is part of the larger neuro(gliovascular unit. Current literature suggests that psychostimulant drugs of abuse alter the function of the BBB which likely contributes to the neurotoxicities associated with these drugs. In both preclinical and clinical studies, psychostimulants including methamphetamine, MDMA, cocaine, and nicotine, produce BBB dysfunction through alterations in tight junction protein expression and conformation, increased glial activation, increased enzyme activation related to BBB cytoskeleton remodeling, and induction of neuroinflammatory pathways. These detrimental changes lead to increased permeability of the BBB and subsequent vulnerability of the brain to peripheral toxins. In fact, abuse of these psychostimulants, notably methamphetamine and cocaine, has been shown to increase the invasion of peripheral bacteria and viruses into the brain. Much work in this field has focused on the co-morbidity of psychostimulant abuse and human immunodeficiency virus (HIV infection. As psychostimulants alter BBB permeability, it is likely that this BBB dysfunction results in increased penetration of the HIV virus into the brain thus increasing the risk of and severity of neuroAIDS. This review will provide an overview of the specific changes in components within the BBB associated with psychostimulant abuse as well as the implications of these changes in exacerbating the neuropathology associated with psychostimulant drugs and HIV co-morbidity.

  15. MMP-independent role of TIMP-1 at the blood brain barrier during viral encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Carine Savarin

    2013-11-01

    Full Text Available Infection of the CNS (central nervous system with a sublethal neurotropic coronavirus (JHMV induces a vigorous inflammatory response. CD4+ and CD8+ T cells are essential to control infectious virus but at the cost of tissue damage. An enigma in understanding the contribution of T cell subsets in pathogenesis resides in their distinct migration pattern across the BBB (blood brain barrier. CD4+ T cells transiently accumulate within the perivascular space, whereas CD8+ T cells migrate directly into the CNS parenchyma. As MMPs (matrix metalloproteinases facilitate migration across the glia limitans, specific expression of the TIMP (tissue inhibitor of MMPs-1 by CD4+ T cells present in the perivascular cuffs suggested that TIMP-1 is responsible for stalling CD4+ T cell migration into the CNS parenchyma. Using TIMP-1 deficient mice, the present data demonstrate an increase rather than a decrease in CD4+ T cell accumulation within the perivascular space during JHMV infection. Whereas virus control was not affected by perivascular retention of CD4+ T cells, disease severity was decreased and associated with reduced IFNγ (interferon γ production. Moreover, decreased CD4+ T cell recruitment into the CNS parenchyma of TIMP-1 deficient mice was not associated with impaired T cell recruiting chemokines or MMP expression, and no compensation by other TIMP molecules was identified. These data suggest an MMP-independent role of TIMP-1 in regulating CD4+ T cell access into the CNS parenchyma during acute JHMV encephalitis.

  16. Clinical trial of blood-brain barrier disruption by pulsed ultrasound.

    Science.gov (United States)

    Carpentier, Alexandre; Canney, Michael; Vignot, Alexandre; Reina, Vincent; Beccaria, Kevin; Horodyckid, Catherine; Karachi, Carine; Leclercq, Delphine; Lafon, Cyril; Chapelon, Jean-Yves; Capelle, Laurent; Cornu, Philippe; Sanson, Marc; Hoang-Xuan, Khê; Delattre, Jean-Yves; Idbaih, Ahmed

    2016-06-15

    The blood-brain barrier (BBB) limits the delivery of systemically administered drugs to the brain. Methods to circumvent the BBB have been developed, but none are used in standard clinical practice. The lack of adoption of existing methods is due to procedural invasiveness, serious adverse effects, and the complications associated with performing such techniques coincident with repeated drug administration, which is customary in chemotherapeutic protocols. Pulsed ultrasound, a method for disrupting the BBB, was shown to effectively increase drug concentrations and to slow tumor growth in preclinical studies. We now report the interim results of an ultrasound dose-escalating phase 1/2a clinical trial using an implantable ultrasound device system, SonoCloud, before treatment with carboplatin in patients with recurrent glioblastoma (GBM). The BBB of each patient was disrupted monthly using pulsed ultrasound in combination with systemically injected microbubbles. Contrast-enhanced magnetic resonance imaging (MRI) indicated that the BBB was disrupted at acoustic pressure levels up to 1.1 megapascals without detectable adverse effects on radiologic (MRI) or clinical examination. Our preliminary findings indicate that repeated opening of the BBB using our pulsed ultrasound system, in combination with systemic microbubble injection, is safe and well tolerated in patients with recurrent GBM and has the potential to optimize chemotherapy delivery in the brain. PMID:27306666

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

    Directory of Open Access Journals (Sweden)

    Iveta Novakova

    Full Text Available The aim of this work was to conduct a comprehensive study about the transport properties of NSAIDs across the blood-brain barrier (BBB in vitro. Transport studies with celecoxib, diclofenac, ibuprofen, meloxicam, piroxicam and tenoxicam were accomplished across Transwell models based on cell line PBMEC/C1-2, ECV304 or primary rat brain endothelial cells. Single as well as group substance studies were carried out. In group studies substance group compositions, transport medium and serum content were varied, transport inhibitors verapamil and probenecid were added. Resulted permeability coefficients were compared and normalized to internal standards diazepam and carboxyfluorescein. Transport rankings of NSAIDs across each model were obtained. Single substance studies showed similar rankings as corresponding group studies across PBMEC/C1-2 or ECV304 cell layers. Serum content, glioma conditioned medium and inhibitors probenecid and verapamil influenced resulted permeability significantly. Basic differences of transport properties of the investigated NSAIDs were similar comparing all three in vitro BBB models. Different substance combinations in the group studies and addition of probenecid and verapamil suggested that transporter proteins are involved in the transport of every tested NSAID. Results especially underlined the importance of same experimental conditions (transport medium, serum content, species origin, cell line for proper data comparison.

  18. 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.

  19. Trafficking of Endogenous Immunoglobulins by Endothelial Cells at the Blood-Brain Barrier.

    Science.gov (United States)

    Villaseñor, Roberto; Ozmen, Laurence; Messaddeq, Nadia; Grüninger, Fiona; Loetscher, Hansruedi; Keller, Annika; Betsholtz, Christer; Freskgård, Per-Ola; Collin, Ludovic

    2016-01-01

    The Blood-Brain Barrier (BBB) restricts access of large molecules to the brain. The low endocytic activity of brain endothelial cells (BECs) is believed to limit delivery of immunoglobulins (IgG) to the brain parenchyma. Here, we report that endogenous mouse IgG are localized within intracellular vesicles at steady state in BECs in vivo. Using high-resolution quantitative microscopy, we found a fraction of endocytosed IgG in lysosomes. We observed that loss of pericytes (key components of the BBB) in pdgf-b(ret/ret) mice affects the intracellular distribution of endogenous mouse IgG in BECs. In these mice, endogenous IgG was not detected within lysosomes but instead accumulate at the basement membrane and brain parenchyma. Such IgG accumulation could be due to reduced lysosomal clearance and increased sorting to the abluminal membrane of BECs. Our results suggest that, in addition to low uptake from circulation, IgG lysosomal degradation may be a downstream mechanism by which BECs further restrict IgG access to the brain. PMID:27149947

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

    Science.gov (United States)

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

    2016-07-01

    Chronic traumatic encephalopathy (CTE) is a neurodegenerative condition associated with repetitive mild traumatic brain injury. In recent years, attention has focused on emerging evidence linking the development of CTE to concussive injuries in athletes and military personnel; however, the underlying molecular pathobiology of CTE remains unclear. Here, we provide evidence that the blood-brain barrier (BBB) is disrupted in regions of dense perivascular p-Tau accumulation in a case of CTE. Immunoreactivity patterns of the BBB-associated tight junction components claudin-5 and zonula occludens-1 were markedly discontinuous or absent in regions of perivascular p-Tau deposition; there was also immunohistochemical evidence of a BBB in these foci. Because the patient was diagnosed premortem clinically as having progressive supranuclear palsy (PSP), we also compromised that the CTE alterations appear to be distinct from those in the brain of a patient with PSP. This report represents the first description of BBB dysfunction in a pathologically proven CTE case and suggests a vascular component in the postconcussion cascade of events that may ultimately lead to development of a progressive degenerative disorder. BBB dysfunction may represent a correlate of neural dysfunction in live subjects suspected of being at risk for development of CTE. PMID:27245243

  1. Drug and gene delivery across the blood-brain barrier with focused ultrasound.

    Science.gov (United States)

    Timbie, Kelsie F; Mead, Brian P; Price, Richard J

    2015-12-10

    The blood-brain barrier (BBB) remains one of the most significant limitations to treatments of central nervous system (CNS) disorders including brain tumors, neurodegenerative diseases and psychiatric disorders. It is now well-established that focused ultrasound (FUS) in conjunction with contrast agent microbubbles may be used to non-invasively and temporarily disrupt the BBB, allowing localized delivery of systemically administered therapeutic agents as large as 100nm in size to the CNS. Importantly, recent technological advances now permit FUS application through the intact human skull, obviating the need for invasive and risky surgical procedures. When used in combination with magnetic resonance imaging, FUS may be applied precisely to pre-selected CNS targets. Indeed, FUS devices capable of sub-millimeter precision are currently in several clinical trials. FUS mediated BBB disruption has the potential to fundamentally change how CNS diseases are treated, unlocking potential for combinatorial treatments with nanotechnology, markedly increasing the efficacy of existing therapeutics that otherwise do not cross the BBB effectively, and permitting safe repeated treatments. This article comprehensively reviews recent studies on the targeted delivery of therapeutics into the CNS with FUS and offers perspectives on the future of this technology. PMID:26362698

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

    Directory of Open Access Journals (Sweden)

    Ruben J. Boado

    2011-01-01

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

  3. 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

    2016-01-01

    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. PMID:27180729

  4. Study on permeability of the recombinant β-NGF through blood-brain barrier

    International Nuclear Information System (INIS)

    Objective: Study on the permeability of rhβ-nerve growth factors (NGF) through blood brain barrier (BBB) to provide scientific basis for research of β-NGF in clinical therapeutic application. Methods: to transfect the COS-7 cell line with recombination expressive vector, PcDNA3-β-NGF, by lipofectamine. The proteins, produced in the supernatant by the transfected cells, was isolated and purified by ion exchange chromatography on carboxymethyl cellulose. The biological activity of the purified protein was analyzed by the prospection of processes grow out from PC12 cell line; and the protein was labelled with 125I and injected i.v into rats, and then the radioactivity of rat brain tissue was analyzed by γ scintillometer. Results: The purified protein could stimulate the process growth of PC12 cell line and the results of γ scintigraphy analysis showed that the radioactivity achieved high level in rat brain tissue 30 min after the protein injection. Conclusion: Purified rhβ-NGF has good biological activity and it could partially penetrate the BBB

  5. The blood-brain barrier induces differentiation of migrating monocytes into Th17-polarizing dendritic cells.

    Science.gov (United States)

    Ifergan, Igal; Kébir, Hania; Bernard, Monique; Wosik, Karolina; Dodelet-Devillers, Aurore; Cayrol, Romain; Arbour, Nathalie; Prat, Alexandre

    2008-03-01

    Trafficking of antigen-presenting cells into the CNS is essential for lymphocyte reactivation within the CNS compartment. Although perivascular dendritic cells found in inflammatory lesions are reported to polarize naive CD4+ T lymphocytes into interleukin-17-secreting-cells, the origin of those antigen-presenting cells remains controversial. We demonstrate that a subset of CD14+ monocytes migrate across the inflamed human blood-brain barrier (BBB) and differentiate into CD83+CD209+ dendritic cells under the influence of BBB-secreted transforming growth factor-beta and granulocyte-macrophage colony-stimulating factor. We also demonstrate that these dendritic cells secrete interleukin-12p70, transforming growth factor-beta and interleukin-6 and promote the proliferation and expansion of distinct populations of interferon-gamma-secreting Th1 and interleukin-17-secreting Th17 CD4+ T lymphocytes. We further confirmed the abundance of such dendritic cells in situ, closely associated with microvascular BBB-endothelial cells within acute multiple sclerosis lesions, as well as a significant number of CD4+ interleukin-17+ T lymphocytes in the perivascular infiltrate. Our data support the notion that functional perivascular myeloid CNS dendritic cells arise as a consequence of migration of CD14+ monocytes across the human BBB, through the concerted actions of BBB-secreted transforming growth factor-beta and granulocyte-macrophage colony-stimulating factor. PMID:18156156

  6. Addressing safety liabilities of TfR bispecific antibodies that cross the blood-brain barrier.

    Science.gov (United States)

    Couch, Jessica A; Yu, Y Joy; Zhang, Yin; Tarrant, Jacqueline M; Fuji, Reina N; Meilandt, William J; Solanoy, Hilda; Tong, Raymond K; Hoyte, Kwame; Luk, Wilman; Lu, Yanmei; Gadkar, Kapil; Prabhu, Saileta; Ordonia, Benjamin A; Nguyen, Quyen; Lin, Yuwen; Lin, Zhonghua; Balazs, Mercedesz; Scearce-Levie, Kimberly; Ernst, James A; Dennis, Mark S; Watts, Ryan J

    2013-05-01

    Bispecific antibodies using the transferrin receptor (TfR) have shown promise for boosting antibody uptake in brain. Nevertheless, there are limited data on the therapeutic properties including safety liabilities that will enable successful development of TfR-based therapeutics. We evaluate TfR/BACE1 bispecific antibody variants in mouse and show that reducing TfR binding affinity improves not only brain uptake but also peripheral exposure and the safety profile of these antibodies. We identify and seek to address liabilities of targeting TfR with antibodies, namely, acute clinical signs and decreased circulating reticulocytes observed after dosing. By eliminating Fc effector function, we ameliorated the acute clinical signs and partially rescued a reduction in reticulocytes. Furthermore, we show that complement mediates a residual decrease in reticulocytes observed after Fc effector function is eliminated. These data raise important safety concerns and potential mitigation strategies for the development of TfR-based therapies that are designed to cross the blood-brain barrier. PMID:23636093

  7. Microfluidic modeling of the effects of nanoparticles on the blood-brain barrier in flow

    Science.gov (United States)

    Schwait, Craig; Hartman, Ryan; Bao, Yuping; Xu, Yaolin

    2011-11-01

    The difficulty of diffusing drugs across the blood-brain barrier (BBB) has caused an impasse for many brain treatments. Nanoparticles (NPs), to which drugs can adsorb, attach, or be entrapped, have the potential to deliver drugs past the BBB. Before nanoparticles can be used, their effects on the BBB and brain must be ascertained. Previous steady-state studies fall short for closely modeling in vivo conditions . Convection of nanoparticles is ignored, and endothelial cells' (ECs) morphology differs based on loading conditions; in vitro loading with continuous flow exhibit ECs indicating a more similar in vivo phenotype. NPs interact with monocytes prior to the BBB, and their toxicity effects were measured in flow conditions using both Trypan Blue cell counting and cell proliferation assays. The microfluidic device designed to model the BBB contained a concentric PES hollow fiber porous membrane in PFA tubing. Full use of the device will include ECs adhered on the inner surface and astrocytes adhered to the outer surface of the PES membrane to model cerebrovascular capillaries. Funded by NSF REU Site 1062611.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Shize Jiang

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

  10. Blood-brain barrier permeability to morphine-6-glucuronide is markedly reduced compared with morphine.

    Science.gov (United States)

    Wu, D; Kang, Y S; Bickel, U; Pardridge, W M

    1997-06-01

    The blood-brain barrier (BBB) permeability to morphine and morphine-6-glucuronide (M6G) is measured under identical conditions using an intravenous injection method in the rat and HPLC separation of morphine from its metabolites. The brain uptake of M6G expressed as %ID/g was 32-fold lower than that of morphine, and the BBB permeability surface area product (PS) of M6G was 57-fold lower as compared with that of morphine. Consistent with these in vivo data, the 1-octanol/buffer partition study showed the liposolubility of M6G was 187-fold lower than that of morphine. The CNS origin of M6G analgesia after peripheral administration was confirmed because the analgesia was completely blocked by naloxone, which crosses BBB, but not by naloxone methiodide, which does not enter brain from blood. In conclusion, the BBB permeability to M6G is markedly reduced as compared with morphine, consistent with the much lower lipid solubility of M6G relative to morphine. PMID:9193881

  11. 'À la carte' peptide shuttles: tools to increase their passage across the blood-brain barrier.

    Science.gov (United States)

    Malakoutikhah, Morteza; Guixer, Bernat; Arranz-Gibert, Pol; Teixidó, Meritxell; Giralt, Ernest

    2014-07-01

    Noninvasive methods for efficient drug delivery to the brain is an unmet need. Molecular access to the brain is regulated by the blood-brain barrier (BBB) established by the endothelial cells of brain vessels. Passive diffusion is one of the main mechanisms that organic compounds use to travel through these endothelial cells. This passage across the BBB is determined mainly by certain physicochemical properties of the molecule such as lipophilicity, size, and the presence of hydrogen bond donors and acceptors. One emerging strategy to facilitate the passage of organic compounds across the BBB is the use of peptide shuttles.1 In using this approach the permeability in front the BBB is, clearly, determined by the combined physicochemical properties of both the cargo and the shuttle. Herein we report the synthesis of a series of variations of one of the more efficient peptide shuttles, (N-MePhe)n . These include diverse structural features such as various backbone stereochemistries or the presence of non-natural amino acids, including halogenated residues. In several cases, we assessed the BBB permeability of both the shuttles alone and linked to a few cargos. Our results show how factors such as stereochemistry or halogen content influences the passage across the BBB and, more importantly, opens the way to a strategy of peptide shuttles 'à la carte', in which a particular fine-tuned shuttle is used for each specific cargo. PMID:24665021

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

    Science.gov (United States)

    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. PMID:27208862

  13. The TAM receptor Mertk protects against neuroinvasive viral infection by maintaining blood-brain barrier integrity.

    Science.gov (United States)

    Miner, Jonathan J; Daniels, Brian P; Shrestha, Bimmi; Proenca-Modena, Jose L; Lew, Erin D; Lazear, Helen M; Gorman, Matthew J; Lemke, Greg; Klein, Robyn S; Diamond, Michael S

    2015-12-01

    The TAM receptors Tyro3, Axl and Mertk are receptor tyrosine kinases that dampen host innate immune responses following engagement with their ligands Gas6 and Protein S, which recognize phosphatidylserine on apoptotic cells. In a form of apoptotic mimicry, many enveloped viruses display phosphatidylserine on the outer leaflet of their membranes, enabling TAM receptor activation and downregulation of antiviral responses. Accordingly, we hypothesized that a deficiency of TAM receptors would enhance antiviral responses and protect against viral infection. Unexpectedly, mice lacking Mertk and/or Axl, but not Tyro3, exhibited greater vulnerability to infection with neuroinvasive West Nile and La Crosse encephalitis viruses. This phenotype was associated with increased blood-brain barrier permeability, which enhanced virus entry into and infection of the brain. Activation of Mertk synergized with interferon-β to tighten cell junctions and prevent virus transit across brain microvascular endothelial cells. Because TAM receptors restrict pathogenesis of neuroinvasive viruses, these findings have implications for TAM antagonists that are currently in clinical development. PMID:26523970

  14. 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 (pmale animals (pfemale groups; dye contents in the whole brains were 0.14±0.01mg% in the control, 0.24±0.03mg% in 900MHz exposed and 0.14±0.02mg% in 1800MHz exposed animals. No statistical variance found between the control and 1800MHz exposed animals (p>0.01). 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. PMID:26723545

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-12-01

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

  16. Control of the blood-brain barrier function in cancer cell metastasis.

    Science.gov (United States)

    Blecharz, Kinga G; Colla, Ruben; Rohde, Veit; Vajkoczy, Peter

    2015-10-01

    Cerebral metastases are the most common brain neoplasms seen clinically in the adults and comprise more than half of all brain tumours. Actual treatment options for brain metastases that include surgical resection, radiotherapy and chemotherapy are rarely curative, although palliative treatment improves survival and life quality of patients carrying brain-metastatic tumours. Chemotherapy in particular has also shown limited or no activity in brain metastasis of most tumour types. Many chemotherapeutic agents used systemically do not cross the blood-brain barrier (BBB), whereas others may transiently weaken the BBB and allow extravasation of tumour cells from the circulation into the brain parenchyma. Increasing evidence points out that the interaction between the BBB and tumour cells plays a key role for implantation and growth of brain metastases in the central nervous system. The BBB, as the tightest endothelial barrier, prevents both early detection and treatment by creating a privileged microenvironment. Therefore, as observed in several in vivo studies, precise targetting the BBB by a specific transient opening of the structure making it permeable for therapeutic compounds, might potentially help to overcome this difficult clinical problem. Moreover, a better understanding of the molecular features of the BBB, its interrelation with metastatic tumour cells and the elucidation of cellular mechanisms responsible for establishing cerebral metastasis must be clearly outlined in order to promote treatment modalities that particularly involve chemotherapy. This in turn would substantially expand the survival and quality of life of patients with brain metastasis, and potentially increase the remission rate. Therefore, the focus of this review is to summarise the current knowledge on the role and function of the BBB in cancer metastasis. PMID:26032862

  17. 7.0-T Magnetic Resonance Imaging Characterization of Acute Blood-Brain-Barrier Disruption Achieved with Intracranial Irreversible Electroporation

    OpenAIRE

    Garcia, Paulo A.; John H. Rossmeisl; Robertson, John L.; Olson, John D.; Johnson, Annette J.; Ellis, Thomas L; Davalos, Rafael V.

    2012-01-01

    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) up...

  18. P03.09PHARMACOLOGICAL MODULATION OF BLOOD-BRAIN BARRIER: FUTURE STRATEGY FOR TREATMENT OF BRAIN TUMORS

    OpenAIRE

    Sardi, I.; Cardellicchio, S.; Iorio, A.L.; da Ros, M.; la Marca, G.; Giunti, L.; Massimino, M.; L. Genitori

    2014-01-01

    A prerequisite for the efficacy of chemotherapy is that it reaches the tumor mass at a therapeutic concentration. In brain tumors this phenomenon is hampered by the presence of the blood brain barrier (BBB) which limits the spread of chemotherapeutic agents within the brain. It is lately emerged as this Multi Drug Resistance (MDR) phenomenon is explained through the cooperation of P-glycoprotein (P-gp, ABCB1) and breast cancer resistance protein (BCRP, ABCG2), two “gatekeeper" transporters th...

  19. Blood-brain barrier permeability is increased in normal appearing white matter in patients with lacunar stroke and leukoaraiosis

    OpenAIRE

    Topakian, R; Barrick, T R; Howe, F. A.; Markus, H. S.

    2010-01-01

    Abstract Background and purpose: The pathogenesis of cerebral small vessel disease (SVD) is incompletely understood. Endothelial dysfunction has been implicated and may result in increased blood-brain barrier (BBB) permeability with leakage of blood constituents into the vessel wall and white matter. We used contrast enhanced magnetic resonance imaging (MRI) to determine whether there was evidence for BBB permeability in the white matter of patients with SVD, and whether this was p...

  20. N-acetyl-L-aspartyl-L-glutamate changes functional and structural properties of rat blood-brain barrier

    Czech Academy of Sciences Publication Activity Database

    Pliss, Lioudmila; Ježová, D.; Mareš, Vladislav; Balcar, V. J.; Šťastný, František

    2002-01-01

    Roč. 317, č. 2 (2002), s. 85-88. ISSN 0304-3940 R&D Projects: GA ČR GA309/99/0211 Grant ostatní: Clive and Vera Ramaciotti Foundation(AU) - Institutional research plan: CEZ:AV0Z5011922 Keywords : N-Acetyl-L-aspartyl-L-glutamate * blood brain barrier Subject RIV: FF - HEENT, Dentistry Impact factor: 2.100, year: 2002

  1. Deoxycholic Acid as a Modifier of the Permeation of Gliclazide through the Blood Brain Barrier of a Rat

    OpenAIRE

    Mladena Lalić-Popović; Velibor Vasović; Boris Milijašević; Svetlana Goločorbin-Kon; Hani Al-Salami; Momir Mikov

    2013-01-01

    Major problem for diabetic patients represents damage of blood vessels and the oxidative stress of the brain cells due to increased concentration of free radicals and poor nutrition of brain cells. Gliclazide has antioxidative properties and poor blood brain barrier (BBB) penetration. Bile acids are known for their hypoglycemic effect and as promoters of drug penetration across biological membranes. Accordingly, the aim of this study is to investigate whether the bile acid (deoxycholic acid) ...

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

    OpenAIRE

    Aryal, Muna; Arvanitis, Costas D.; Alexander, Phillip M.; McDannold, Nathan

    2014-01-01

    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 t...

  3. Blood-brain barrier delivery of protein and non-viral gene therapeutics with molecular Trojan horses

    OpenAIRE

    Pardridge, William M

    2007-01-01

    The products of biotechnology, recombinant proteins, monoclonal antibodies, antisense, RNA interference, or non-viral gene transfer, cannot be developed as pharmaceuticals for the brain, unless these molecules are re-formulated to enable transport across the blood-brain barrier (BBB). Large molecule drugs, and plasmid DNA, can be delivered across the BBB with receptor-specific molecular Trojan horses. Trojan horse BBB delivery systems, coupled with one of 3 different technology platforms (fus...

  4. Multimodal investigations of trans-endothelial cell trafficking under condition of disrupted blood-brain barrier integrity

    OpenAIRE

    Masaryk Thomas; Desai Nirav K; Franic Linda; Nguyen Minh T; Teng Qingshan; Marchi Nicola; Rasmussen Peter; Trasciatti Silvia; Janigro Damir

    2010-01-01

    Abstract Background Stem cells or immune cells targeting the central nervous system (CNS) bear significant promises for patients affected by CNS disorders. Brain or spinal cord delivery of therapeutic cells is limited by the blood-brain barrier (BBB) which remains one of the recognized rate-limiting steps. Osmotic BBB disruption (BBBD) has been shown to improve small molecule chemotherapy for brain tumors, but successful delivery of cells in conjunction with BBBD has never been reported. We h...

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

    OpenAIRE

    2007-01-01

    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 perm...

  6. STAT1 signaling modulates HIV-1–induced inflammatory responses and leukocyte transmigration across the blood-brain barrier

    OpenAIRE

    Chaudhuri, Anathbandhu; Yang, Bo; Gendelman, Howard E; Persidsky, Yuri; Kanmogne, Georgette D.

    2008-01-01

    The relationship among neuroinflammation, blood-brain barrier (BBB) dysfunction, and progressive HIV-1 infection as they affect the onset and development of neuroAIDS is incompletely understood. One possible link is signal transducers and activators of transcription (STATs) pathways. These respond to proinflammatory and regulatory factors and could affect neuroinflammatory responses induced from infected cells and disease-affected brain tissue. Our previous works demonstrated that HIV-1 activ...

  7. Impact of standing wave effects on transcranial focused ultrasound disruption of the blood-brain barrier in a rat model

    OpenAIRE

    O’Reilly, Meaghan A.; Huang, Yuexi; Hynynen, Kullervo

    2010-01-01

    Microbubble mediated disruption of the blood brain barrier (BBB) for targeted drug delivery using focused ultrasound shows great potential as a therapy for a wide range of brain disorders. This technique is currently at the pre-clinical stage and important work is being conducted in animal models. Measurements of standing waves in ex vivo rat skulls were conducted using an optical hydrophone and a geometry dependence was identified. Standing waves could not be eliminated through the use of sw...

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

    Science.gov (United States)

    Zaruba, Kamil; Kunes, Martin; Ulbrich, Pavel; Brezaniova, Ingrid; Triska, Jan; Suchy, Pavel

    2015-01-01

    The blood-brain barrier prevents the passage of many drugs that target the central nervous system. This paper presents the preparation and characterization of silica-based nanocarriers loaded with piracetam, pentoxifylline, and pyridoxine (drugs from the class of nootropics), which are designed to enhance the permeation of the drugs from the circulatory system through the blood-brain barrier. Their permeation was compared with non-nanoparticle drug substances (bulk materials) by means of an in vivo model of rat brain perfusion. The size and morphology of the nanoparticles were characterized by transmission electron microscopy. The content of the drug substances in silica-based nanocarriers was analysed by elemental analysis and UV spectrometry. Microscopic analysis of visualized silica nanocarriers in the perfused brain tissue was performed. The concentration of the drug substances in the tissue was determined by means of UHPLC-DAD/HRMS LTQ Orbitrap XL. It was found that the drug substances in silica-based nanocarriers permeated through the blood brain barrier to the brain tissue, whereas bulk materials were not detected in the brain. PMID:26075264

  9. 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.

  10. Electrospun gelatin biopapers as substrate for in vitro bilayer models of blood-brain barrier tissue.

    Science.gov (United States)

    Bischel, Lauren L; Coneski, Peter N; Lundin, Jeffrey G; Wu, Peter K; Giller, Carl B; Wynne, James; Ringeisen, Brad R; Pirlo, Russell K

    2016-04-01

    Gaining a greater understanding of the blood-brain barrier (BBB) is critical for improvement in drug delivery, understanding pathologies that compromise the BBB, and developing therapies to protect the BBB. In vitro human tissue models are valuable tools for studying these issues. The standard in vitro BBB models use commercially available cell culture inserts to generate bilayer co-cultures of astrocytes and endothelial cells (EC). Electrospinning can be used to produce customized cell culture substrates with optimized material composition and mechanical properties with advantages over off-the-shelf materials. Electrospun gelatin is an ideal cell culture substrate because it is a natural polymer that can aid cell attachment and be modified and degraded by cells. Here, we have developed a method to produce cell culture inserts with electrospun gelatin "biopaper" membranes. The electrospun fiber diameter and cross-linking method were optimized for the growth of primary human endothelial cell and primary human astrocyte bilayer co-cultures to model human BBB tissue. BBB co-cultures on biopaper were characterized via cell morphology, trans-endothelial electrical resistance (TEER), and permeability to FITC-labeled dextran and compared to BBB co-cultures on standard cell culture inserts. Over longer culture periods (up to 21 days), cultures on the optimized electrospun gelatin biopapers were found to have improved TEER, decreased permeability, and permitted a smaller separation between co-cultured cells when compared to standard PET inserts. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 901-909, 2016. PMID:26650896

  11. Bryostatin-1 Restores Blood Brain Barrier Integrity following Blast-Induced Traumatic Brain Injury.

    Science.gov (United States)

    Lucke-Wold, Brandon P; Logsdon, Aric F; Smith, Kelly E; Turner, Ryan C; Alkon, Daniel L; Tan, Zhenjun; Naser, Zachary J; Knotts, Chelsea M; Huber, Jason D; Rosen, Charles L

    2015-12-01

    Recent wars in Iraq and Afghanistan have accounted for an estimated 270,000 blast exposures among military personnel. Blast traumatic brain injury (TBI) is the 'signature injury' of modern warfare. Blood brain barrier (BBB) disruption following blast TBI can lead to long-term and diffuse neuroinflammation. In this study, we investigate for the first time the role of bryostatin-1, a specific protein kinase C (PKC) modulator, in ameliorating BBB breakdown. Thirty seven Sprague-Dawley rats were used for this study. We utilized a clinically relevant and validated blast model to expose animals to moderate blast exposure. Groups included: control, single blast exposure, and single blast exposure + bryostatin-1. Bryostatin-1 was administered i.p. 2.5 mg/kg after blast exposure. Evan's blue, immunohistochemistry, and western blot analysis were performed to assess injury. Evan's blue binds to albumin and is a marker for BBB disruption. The single blast exposure caused an increase in permeability compared to control (t = 4.808, p < 0.05), and a reduction back toward control levels when bryostatin-1 was administered (t = 5.113, p < 0.01). Three important PKC isozymes, PKCα, PKCδ, and PKCε, were co-localized primarily with endothelial cells but not astrocytes. Bryostatin-1 administration reduced toxic PKCα levels back toward control levels (t = 4.559, p < 0.01) and increased the neuroprotective isozyme PKCε (t = 6.102, p < 0.01). Bryostatin-1 caused a significant increase in the tight junction proteins VE-cadherin, ZO-1, and occludin through modulation of PKC activity. Bryostatin-1 ultimately decreased BBB breakdown potentially due to modulation of PKC isozymes. Future work will examine the role of bryostatin-1 in preventing chronic neurodegeneration following repetitive neurotrauma. PMID:25301233

  12. 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.

  13. Human blood-brain barrier insulin-like growth factor receptor

    International Nuclear Information System (INIS)

    Insulin-like growth factor (IGF)-1 and IGF-2, may be important regulatory molecules in the CNS. Possible origins of IGFs in brain include either de novo synthesis or transport of circulating IGFs from blood into brain via receptor mediated transcytosis mechanisms at the brain capillary endothelial wall, ie, the blood-brain barrier (BBB). In the present studies, isolated human brain capillaries are used as an in vitro model system of the human BBB and the characteristics of IGF-1 or IGF-2 binding to this preparation were assessed. The total binding of IGF-2 at 37 degrees C exceeded 130% per mg protein and was threefold greater than the total binding for IGF-1. However, at 37 degrees C nonsaturable binding equaled total binding, suggesting that endocytosis is rate limiting at physiologic temperatures. Binding studies performed at 4 degrees C slowed endocytosis to a greater extent than membrane binding, and specific binding of either IGF-1 or IGF-2 was detectable. Scatchard plots for either peptide were linear and the molar dissociation constant of IGF-1 and IGF-2 binding was 2.1 +/- 0.4 and 1.1 +/- 0.1 nmol/L, respectively. Superphysiologic concentrations of porcine insulin inhibited the binding of both IGF-1 (ED50 = 2 micrograms/mL) and IGF-2 (ED50 = 0.5 microgram/mL). Affinity cross linking of 125I-IGF-1, 125I-IGF-2, and 125I-insulin to isolated human brain capillaries was performed using disuccinimidylsuberate (DSS). These studies revealed a 141 kd binding site for both IGF-1 and IGF-2, and a 133 kd binding site for insulin

  14. Into rather unexplored terrain-transcellular transport across the blood-brain barrier.

    Science.gov (United States)

    De Bock, Marijke; Van Haver, Valérie; Vandenbroucke, Roosmarijn E; Decrock, Elke; Wang, Nan; Leybaert, Luc

    2016-07-01

    Efficient neuronal signaling in the central nervous system strictly depends on a well-balanced microenvironment around glial cells, synapses, and axons. Unique features of the blood-brain barrier (BBB) endothelium largely determine the composition of this micro-milieu and are dependent on the tight interplay with surrounding astrocytes and pericytes. BBB endothelial cells are endowed with a highly restrictive junctional complex that occludes the intercellular cleft, thereby preventing paracellular diffusion. The paracellular pathway is subject to extensive research as integrity loss of the junctional complex is associated with many neuropathologies, inflammation, and edema. Another important feature of the BBB endothelium is the low prevalence of nonspecific, transcytotic events, including (macro)pinocytosis, clathrin-dependent and caveolin-dependent endocytosis and the subsequent trafficking of vesicles to the opposite membrane. Although less studied, evidence is accruing that this pathway importantly contributes to increased BBB permeability, often when the junctional complex remains intact. Here, we review current knowledge on the contribution of the transcellular pathway to the BBB leak observed in different pathologic conditions. In addition, we hypothesize that nonselective, large pore connexin and pannexin channels may contribute to transcellular transport, either by providing a direct diffusion pathway across the endothelial monolayer, or indirectly, by exerting control over intracellular levels of the signaling ion Ca(2+) that is involved in many steps of the vesicular pathway. We conclude that transcytotic events at the BBB, despite being less acknowledged, cannot be simply dismissed as done in the past, but actively contribute to BBB leakage in many different pathologies. GLIA 2016;64:1097-1123. PMID:26852907

  15. 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.

  16. Hyperthermic Laser Ablation of Recurrent Glioblastoma Leads to Temporary Disruption of the Peritumoral Blood Brain Barrier.

    Directory of Open Access Journals (Sweden)

    Eric C Leuthardt

    Full Text Available Poor central nervous system penetration of cytotoxic drugs due to the blood brain barrier (BBB is a major limiting factor in the treatment of brain tumors. Most recurrent glioblastomas (GBM occur within the peritumoral region. In this study, we describe a hyperthemic method to induce temporary disruption of the peritumoral BBB that can potentially be used to enhance drug delivery.Twenty patients with probable recurrent GBM were enrolled in this study. Fourteen patients were evaluable. MRI-guided laser interstitial thermal therapy was applied to achieve both tumor cytoreduction and disruption of the peritumoral BBB. To determine the degree and timing of peritumoral BBB disruption, dynamic contrast-enhancement brain MRI was used to calculate the vascular transfer constant (Ktrans in the peritumoral region as direct measures of BBB permeability before and after laser ablation. Serum levels of brain-specific enolase, also known as neuron-specific enolase, were also measured and used as an independent quantification of BBB disruption.In all 14 evaluable patients, Ktrans levels peaked immediately post laser ablation, followed by a gradual decline over the following 4 weeks. Serum BSE concentrations increased shortly after laser ablation and peaked in 1-3 weeks before decreasing to baseline by 6 weeks.The data from our pilot research support that disruption of the peritumoral BBB was induced by hyperthemia with the peak of high permeability occurring within 1-2 weeks after laser ablation and resolving by 4-6 weeks. This provides a therapeutic window of opportunity during which delivery of BBB-impermeant therapeutic agents may be enhanced.ClinicalTrials.gov NCT01851733.

  17. 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

  18. Transport of Arylsulfatase A across the Blood-Brain Barrier in Vitro*

    Science.gov (United States)

    Matthes, Frank; Wölte, Philipp; Böckenhoff, Annika; Hüwel, Sabine; Schulz, Mareike; Hyden, Pia; Fogh, Jens; Gieselmann, Volkmar; Galla, Hans-Joachim; Matzner, Ulrich

    2011-01-01

    Enzyme replacement therapy is an option to treat lysosomal storage diseases caused by functional deficiencies of lysosomal hydrolases as intravenous injection of therapeutic enzymes can correct the catabolic defect within many organ systems. However, beneficial effects on central nervous system manifestations are very limited because the blood-brain barrier (BBB) prevents the transfer of enzyme from the circulation to the brain parenchyma. Preclinical studies in mouse models of metachromatic leukodystrophy, however, showed that arylsulfatase A (ASA) is able to cross the BBB to some extent, thus reducing lysosomal storage in brain microglial cells. The present study aims to investigate the routing of ASA across the BBB and to improve the transfer in vitro using a well established cell culture model consisting of primary porcine brain capillary endothelial cells cultured on Transwell filter inserts. Passive apical-to-basolateral ASA transfer was observed, which was not saturable up to high ASA concentrations. No active transport could be determined. The passive transendothelial transfer was, however, charge-dependent as reduced concentrations of negatively charged monosaccharides in the N-glycans of ASA or the addition of polycations increased basolateral ASA levels. Adsorptive transcytosis is therefore considered to be the major transport pathway. Partial inhibition of the transcellular ASA transfer by mannose 6-phosphate indicated a second route depending on the insulin-like growth factor II/mannose 6-phosphate receptor, MPR300. We conclude that cationization of ASA and an increase of the mannose 6-phosphate content of the enzyme may promote blood-to-brain transfer of ASA, thus leading to an improved therapeutic efficacy of enzyme replacement therapy behind the BBB. PMID:21454621

  19. Transport of arylsulfatase A across the blood-brain barrier in vitro.

    Science.gov (United States)

    Matthes, Frank; Wölte, Philipp; Böckenhoff, Annika; Hüwel, Sabine; Schulz, Mareike; Hyden, Pia; Fogh, Jens; Gieselmann, Volkmar; Galla, Hans-Joachim; Matzner, Ulrich

    2011-05-20

    Enzyme replacement therapy is an option to treat lysosomal storage diseases caused by functional deficiencies of lysosomal hydrolases as intravenous injection of therapeutic enzymes can correct the catabolic defect within many organ systems. However, beneficial effects on central nervous system manifestations are very limited because the blood-brain barrier (BBB) prevents the transfer of enzyme from the circulation to the brain parenchyma. Preclinical studies in mouse models of metachromatic leukodystrophy, however, showed that arylsulfatase A (ASA) is able to cross the BBB to some extent, thus reducing lysosomal storage in brain microglial cells. The present study aims to investigate the routing of ASA across the BBB and to improve the transfer in vitro using a well established cell culture model consisting of primary porcine brain capillary endothelial cells cultured on Transwell filter inserts. Passive apical-to-basolateral ASA transfer was observed, which was not saturable up to high ASA concentrations. No active transport could be determined. The passive transendothelial transfer was, however, charge-dependent as reduced concentrations of negatively charged monosaccharides in the N-glycans of ASA or the addition of polycations increased basolateral ASA levels. Adsorptive transcytosis is therefore considered to be the major transport pathway. Partial inhibition of the transcellular ASA transfer by mannose 6-phosphate indicated a second route depending on the insulin-like growth factor II/mannose 6-phosphate receptor, MPR300. We conclude that cationization of ASA and an increase of the mannose 6-phosphate content of the enzyme may promote blood-to-brain transfer of ASA, thus leading to an improved therapeutic efficacy of enzyme replacement therapy behind the BBB. PMID:21454621

  20. Blood-brain barrier transport kinetics of the neuromedin peptides NMU, NMN, NMB and NT.

    Science.gov (United States)

    Gevaert, Bert; Wynendaele, Evelien; Stalmans, Sofie; Bracke, Nathalie; D'Hondt, Matthias; Smolders, Ilse; van Eeckhaut, Ann; De Spiegeleer, Bart

    2016-08-01

    The neuromedin peptides are peripherally and centrally produced, but until now, it is generally believed that they only function as locally acting compounds without any quantitative knowledge about their blood-brain barrier (BBB) passage. Here, we characterize the transport kinetics of four neuromedins (NMU, NMN, NMB and NT) across the BBB, as well as their metabolization profile, and evaluate if they can act as endocrine hormones. Using the in vivo mouse model, multiple time regression (MTR), capillary depletion (CD) and brain efflux studies were performed. Data was fitted using linear (NMU, NT and NMB) or biphasic modeling (NMU and NMN). Three of the four investigated peptides, i.e. NMU, NT and NMN, showed a significant influx into the brain with unidirectional influx rate constants of 1.31 and 0.75 μL/(g × min) for NMU and NT respectively and initial influx constants (K1) of 72.14 and 7.55 μL/(g × min) and net influx constants (K) of 1.28 and 1.36 × 10(-16) μL/(g×min) for NMU and NMN respectively. The influx of NMB was negligible. Only NMN and NT showed a significant efflux out of the brain with an efflux constant (kout) of 0.042 min(-1) and 0.053 min(-1) respectively. Our results indicate that locally produced neuromedin peptides and/or fragments can be transported through the whole body, including passing the BBB, and taken up by different organs/tissues, supporting the idea that the neuromedins could have a much bigger role in the regulation of biological processes than currently assumed. PMID:27040796

  1. A novel platform for engineering blood-brain barrier-crossing bispecific biologics.

    Science.gov (United States)

    Farrington, Graham K; Caram-Salas, Nadia; Haqqani, Arsalan S; Brunette, Eric; Eldredge, John; Pepinsky, Blake; Antognetti, Giovanna; Baumann, Ewa; Ding, Wen; Garber, Ellen; Jiang, Susan; Delaney, Christie; Boileau, Eve; Sisk, William P; Stanimirovic, Danica B

    2014-11-01

    The blood-brain barrier (BBB) prevents the access of therapeutic antibodies to central nervous system (CNS) targets. The engineering of bispecific antibodies in which a therapeutic "arm" is combined with a BBB-transcytosing arm can significantly enhance their brain delivery. The BBB-permeable single-domain antibody FC5 was previously isolated by phenotypic panning of a naive llama single-domain antibody phage display library. In this study, FC5 was engineered as a mono- and bivalent fusion with the human Fc domain to optimize it as a modular brain delivery platform. In vitro studies demonstrated that the bivalent fusion of FC5 with Fc increased the rate of transcytosis (Papp) across brain endothelial monolayer by 25% compared with monovalent fusion. Up to a 30-fold enhanced apparent brain exposure (derived from serum and cerebrospinal fluid pharmacokinetic profiles) of FC5- compared with control domain antibody-Fc fusions after systemic dosing in rats was observed. Systemic pharmacological potency was evaluated in the Hargreaves model of inflammatory pain using the BBB-impermeable neuropeptides dalargin and neuropeptide Y chemically conjugated with FC5-Fc fusion proteins. Improved serum pharmacokinetics of Fc-fused FC5 contributed to a 60-fold increase in pharmacological potency compared with the single-domain version of FC5; bivalent and monovalent FC5 fusions with Fc exhibited similar systemic pharmacological potency. The study demonstrates that modular incorporation of FC5 as the BBB-carrier arm in bispecific antibodies or antibody-drug conjugates offers an avenue to develop pharmacologically active biotherapeutics for CNS indications. PMID:25070367

  2. Spatio-temporal analysis of molecular delivery through the blood-brain barrier using focused ultrasound

    International Nuclear Information System (INIS)

    The deposition of gadolinium through ultrasound-induced blood-brain barrier (BBB) openings in the murine hippocampus was investigated. First, wave propagation simulations through the intact mouse skull revealed minimal beam distortion while thermal deposition simulations, at the same sonication parameters used to induce BBB opening in vivo, revealed temperature increases lower than 0.5 0C. The simulation results were validated experimentally in ex vivo skulls (m = 6) and in vitro tissue specimens. Then, in vivo mice (n = 9) were injected with microbubbles (Optison(TM); 25-50 μl) and sonicated (frequency: 1.525 MHz, pressure amplitudes: 0.5-1.1 MPa, burst duration: 20 ms, duty cycle: 20%, durations: 2-4 shots, 30 s per shot, 30 s interval) at the left hippocampus, through intact skin and skull. Sequential, high-resolution, T1-weighted MRI (9.4 Tesla, in-plane resolution: 75 μm, scan time: 45-180 min) with gadolinium (Omniscan(TM); 0.5 ml) injected intraperitoneally revealed a threshold of the BBB opening at 0.67 MPa and BBB closing within 28 h from opening. The contrast-enhancement area and gadolinium deposition path were monitored over time and the influence of vessel density, size and location was determined. Sonicated arteries, or their immediate surroundings, depicted greater contrast enhancement than sonicated homogeneous brain tissue regions. In conclusion, gadolinium was delivered through a transiently opened BBB and contained to a specific brain region (i.e., the hippocampus) using a single-element focused ultrasound transducer. It was also found that the amount of gadolinium deposited in the hippocampal region increased with the acoustic pressure and that the spatial distribution of the BBB opening was determined not only by the ultrasound beam, but also by the vasculature of the targeted brain region

  3. Iron supplement prevents lead-induced disruption of the blood-brain barrier during rat development

    International Nuclear Information System (INIS)

    Children are known to be venerable to lead (Pb) toxicity. The blood-brain barrier (BBB) in immature brain is particularly vulnerable to Pb insults. This study was designed to test the hypothesis that Pb exposure damaged the integrity of the BBB in young animals and iron (Fe) supplement may prevent against Pb-induced BBB disruption. Male weanling Sprague-Dawley rats were divided into four groups. Three groups of rats were exposed to Pb in drinking water containing 342 μg Pb/mL as Pb acetate, among which two groups were concurrently administered by oral gavage once every other day with 7 mg Fe/kg and 14 mg Fe/kg as FeSO4 solution as the low and high Fe treatment group, respectively, for 6 weeks. The control group received sodium acetate in drinking water. Pb exposure significantly increased Pb concentrations in blood by 6.6-folds (p < 0.05) and brain tissues by 1.5-2.0-folds (p < 0.05) as compared to controls. Under the electron microscope, Pb exposure in young animals caused an extensive extravascular staining of lanthanum nitrate in brain parenchyma, suggesting a leakage of cerebral vasculature. Western blot showed that Pb treatment led to 29-68% reduction (p < 0.05) in the expression of occludin as compared to the controls. Fe supplement among Pb-exposed rats maintained the normal ultra-structure of the BBB and restored the expression of occludin to normal levels. Moreover, the low dose Fe supplement significantly reduced Pb levels in blood and brain tissues. These data suggest that Pb exposure disrupts the structure of the BBB in young animals. The increased BBB permeability may facilitate the accumulation of Pb. Fe supplement appears to protect the integrity of the BBB against Pb insults, a beneficial effect that may have significant clinical implications

  4. Angiogenesis is associated with blood-brain barrier permeability in temporal lobe epilepsy.

    Science.gov (United States)

    Rigau, Valérie; Morin, Mélanie; Rousset, Marie-Claude; de Bock, Frédéric; Lebrun, Aurore; Coubes, Philippe; Picot, Marie-Christine; Baldy-Moulinier, Michel; Bockaert, Joël; Crespel, Arielle; Lerner-Natoli, Mireille

    2007-07-01

    Previous studies from our group, focusing on neuro-glial remodelling in human temporal lobe epilepsy (TLE), have shown the presence of immature vascular cells in various areas of the hippocampus. Here, we investigated angiogenic processes in hippocampi surgically removed from adult patients suffering from chronic intractable TLE, with various aetiologies. We compared hippocampi from TLE patients to hippocampi obtained after surgery or autopsy from non-epileptic patients (NE). We quantified the vascular density, checked for the expression of angiogenic factors and their receptors and looked for any blood-brain barrier (BBB) leakage. We used a relevant model of rat limbic epilepsy, induced by lithium-pilocarpine treatment, to understand the sequence of events. In humans, the vessel density was significantly higher in TLE than in NE patients. This was neither dependent on the aetiology nor on the degree of neuronal loss, but was positively correlated with seizure frequency. In the whole hippocampus, we observed many complex, tortuous microvessels. In the dentate gyrus, when the granular layer was dispersed, long microvessels appeared radially orientated. Vascular endothelial factor (VEGF) and tyrosine kinase receptors were detected in different types of cells. An impairment of the BBB was demonstrated by the loss of tight junctions and by Immunoglobulines G (IgG) leakage and accumulation in neurons. In the rat model of TLE, VEGF over-expression and BBB impairment occurred early after status epilepticus, followed by a progressive increase in vascularization. In humans and rodents, angiogenic processes and BBB disruption were still obvious in the chronic focus, probably activated by recurrent seizures. We suggest that the persistent leakage of serum IgG in the interstitial space and their uptake by neurons may participate in hypoperfusion and in neuronal dysfunction occurring in TLE. PMID:17533168

  5. Fingolimod prevents blood-brain barrier disruption induced by the sera from patients with multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Hideaki Nishihara

    Full Text Available OBJECTIVE: Effect of fingolimod in multiple sclerosis (MS is thought to involve the prevention of lymphocyte egress from lymphoid tissues, thereby reducing autoaggressive lymphocyte infiltration into the central nervous system across blood-brain barrier (BBB. However, brain microvascular endothelial cells (BMECs represent a possible additional target for fingolimod in MS patients by directly repairing the function of BBB, as S1P receptors are also expressed by BMECs. In this study, we evaluated the effects of fingolimod on BMECs and clarified whether fingolimod-phosphate restores the BBB function after exposure to MS sera. METHODS: Changes in tight junction proteins, adhesion molecules and transendothelial electrical resistance (TEER in BMECs were evaluated following incubation in conditioned medium with or without fingolimod/fingolimod-phosphate. In addition, the effects of sera derived from MS patients, including those in the relapse phase of relapse-remitting (RR MS, stable phase of RRMS and secondary progressive MS (SPMS, on the function of BBB in the presence of fingolimod-phosphate were assessed. RESULTS: Incubation with fingolimod-phosphate increased the claudin-5 protein levels and TEER values in BMECs, although it did not change the amount of occludin, ICAM-1 or MelCAM proteins. Pretreatment with fingolimod-phosphate restored the changes in the claudin-5 and VCAM-1 protein/mRNA levels and TEER values in BMECs after exposure to MS sera. CONCLUSIONS: Pretreatment with fingolimod-phosphate prevents BBB disruption caused by both RRMS and SPMS sera via the upregulation of claudin-5 and downregulation of VCAM-1 in BMECs, suggesting that fingolimod-phosphate is capable of directly modifying the BBB. BMECs represent a possible therapeutic target for fingolimod in MS patients.

  6. 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

  7. 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.

  8. Intercellular transfer of P-glycoprotein in human blood-brain barrier endothelial cells is increased by histone deacetylase inhibitors.

    Science.gov (United States)

    Noack, Andreas; Noack, Sandra; Buettner, Manuela; Naim, Hassan Y; Löscher, Wolfgang

    2016-01-01

    The blood-brain barrier (BBB) controls the entry of compounds into the brain, thereby regulating brain homeostasis. Efflux transporters such as P-glycoprotein (Pgp) significantly contribute to BBB function. Multiple signaling pathways modulate the expression and activity of Pgp in response to xenobiotics and disease. A non-genetic way of intercellular transfer of Pgp occurs in cancer cells, but whether this also occurs in non-cancer cells such as endothelial cells that form the BBB is not known. A human brain endothelial cell line (hCMEC/D3) was used to study whether cell-to-cell Pgp transfer occurs during co-culturing with Pgp-EGFP expressing hCMEC/D3 cells. The Pgp-EGFP fusion protein was transferred from donor to recipient cells by cell-to-cell contact and Pgp-EGFP enriched vesicles, which were exocytosed by donor cells and endocytosed by adherent recipient cells. Flow cytometry experiments with the Pgp substrate eFLUXX-ID Gold demonstrated that the transferred Pgp is functional in the recipient cells. Exposure of the donor cells with inhibitors of histone deacetylases (HDACs) resulted in an enhanced intercellular Pgp transfer. Non-genetic transfer of a resistance phenotype and its regulation by HDACs is a novel mechanism of altering BBB functionality. This mechanism may have important implications for understanding drug-induced alterations in Pgp expression and activity. PMID:27375084

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

    Science.gov (United States)

    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.

  11. 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

  12. The Application of MRI for Depiction of Subtle Blood Brain Barrier Disruption in Stroke

    Directory of Open Access Journals (Sweden)

    David Israeli, David Tanne, Dianne Daniels, David Last, Ran Shneor, David Guez, Efrat Landau, Yiftach Roth, Aharon Ocherashvilli, Mati Bakon, Chen Hoffman, Amit Weinberg, Talila Volk, Yael Mardor

    2011-01-01

    Full Text Available The development of imaging methodologies for detecting blood-brain-barrier (BBB disruption may help predict stroke patient's propensity to develop hemorrhagic complications following reperfusion. We have developed a delayed contrast extravasation MRI-based methodology enabling real-time depiction of subtle BBB abnormalities in humans with high sensitivity to BBB disruption and high spatial resolution. The increased sensitivity to subtle BBB disruption is obtained by acquiring T1-weighted MRI at relatively long delays (~15 minutes after contrast injection and subtracting from them images acquired immediately after contrast administration. In addition, the relatively long delays allow for acquisition of high resolution images resulting in high resolution BBB disruption maps. The sensitivity is further increased by image preprocessing with corrections for intensity variations and with whole body (rigid+elastic registration. Since only two separate time points are required, the time between the two acquisitions can be used for acquiring routine clinical data, keeping the total imaging time to a minimum.A proof of concept study was performed in 34 patients with ischemic stroke and 2 patients with brain metastases undergoing high resolution T1-weighted MRI acquired at 3 time points after contrast injection. The MR images were pre-processed and subtracted to produce BBB disruption maps. BBB maps of patients with brain metastases and ischemic stroke presented different patterns of BBB opening. The significant advantage of the long extravasation time was demonstrated by a dynamic-contrast-enhancement study performed continuously for 18 min. The high sensitivity of our methodology enabled depiction of clear BBB disruption in 27% of the stroke patients who did not have abnormalities on conventional contrast-enhanced MRI. In 36% of the patients, who had abnormalities detectable by conventional MRI, the BBB disruption volumes were significantly larger in the

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

    Science.gov (United States)

    Alluri, Himakarnika; Wilson, Rickesha L.; Anasooya Shaji, Chinchusha; Wiggins-Dohlvik, Katie; Patel, Savan; Liu, Yang; Peng, Xu; Beeram, Madhava R.; Davis, Matthew L.; Huang, Jason H.; Tharakan, Binu

    2016-01-01

    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

  14. 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

  15. The blood-brain barrier penetration and distribution of PEGylated fluorescein-doped magnetic silica nanoparticles in rat brain

    International Nuclear Information System (INIS)

    PEGylated PAMAM conjugated fluorescein-doped magnetic silica nanoparticles (PEGylated PFMSNs) have been synthesized for evaluating their ability across the blood-brain barrier (BBB) and distribution in rat brain. The obtained nanoparticles were characterized by transmission electron microscopy (TEM), thermal gravimetry analyses (TGA), zeta potential (ζ-potential) titration, and X-ray photoelectron spectroscopy (XPS). The BBB penetration and distribution of PEGylated PFMSNs and FMSNs in rat brain were investigated not only at the cellular level with Confocal laser scanning microscopy (CLSM), but also at the subcellular level with transmission electron microscopy (TEM). The results provide direct evidents that PEGylated PFMSNs could penetrate the BBB and spread into the brain parenchyma.

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

    DEFF Research Database (Denmark)

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

    1979-01-01

    mean arterial blood pressure in the fetuses by blood withdrawal or infusion in this state, CBF was measured at different perfusion pressures (mean arterial blood pressure (MABP) minus central venous pressure (CVP)). A passive flow/pressure relationship--loss of autoregulation--was found, with hyperemia...... reaching CBF values up to 6 times normal at normal MABP of about 60 to 70 mmHg, and severe ischemia reaching CBF values close to zero in large cortical areas at MABP of 30 mmHg. CVP remained essentially unchanged at 10--15 mmHg. The severe and prolonged asphyxia rendered the blood-brain barrier leaky to...

  17. Internal benchmarking of a human blood-brain barrier cell model for screening of nanoparticle uptake and transcytosis.

    Science.gov (United States)

    Ragnaill, Michelle Nic; Brown, Meredith; Ye, Dong; Bramini, Mattia; Callanan, Sean; Lynch, Iseult; Dawson, Kenneth A

    2011-04-01

    Transport of drugs across the blood-brain barrier, which protects the brain from harmful agents, is considered the holy grail of targeted delivery, due to the extreme effectiveness of this barrier at preventing passage of non-essential molecules through to the brain. This has caused severe limitations for therapeutics for many brain-associated diseases, such as HIV and neurodegenerative diseases. Nanomaterials, as a result of their small size (in the order of many protein-lipid clusters routinely transported by cells) and their large surface area (which acts as a scaffold for proteins thereby rendering nanoparticles as biological entities) offer great promise for neuro-therapeutics. However, in parallel with developing neuro-therapeutic applications based on nanotechnology, it is essential to ensure their safety and long-term consequences upon reaching the brain. One approach to determining safe application of nanomaterials in biology is to obtain a deep mechanistic understanding of the interactions between nanomaterials and living systems (bionanointeractions). To this end, we report here on the establishment and internal round robin validation of a human cell model of the blood-brain barrier for use as a tool for screening nanoparticles interactions, and assessing the critical nanoscale parameters that determine transcytosis. PMID:21236340

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

    Science.gov (United States)

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

    2014-01-01

    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 into the brain. This concept relies on the application of natural or genetically engineered proteins or small peptides, capable of specifically ferrying a drug-payload that is either directly coupled or encapsulated in an appropriate nanocarrier, across the blood-brain barrier via receptor-mediated transcytosis. Specifically, in this process the nanocarrier-drug system ("Trojan horse complex") is transported transcellularly across the brain endothelium, from the blood to the brain interface, essentially trailed by a native receptor. Naturally, only certain properties would favor a receptor to serve as a transporter for nanocarriers, coated with appropriate ligands. Here we briefly discuss brain microvascular endothelial receptors that have been explored until now, highlighting molecular features that govern the efficiency of nanocarrier-mediated drug delivery into the brain. PMID:25407801

  19. Radiofrequency field emitted by mobile phones and alteration of the blood-brain barrier: how strong is the experimental evidence?

    International Nuclear Information System (INIS)

    Full text of publication follows: It is known that high power, thermal radiofrequency radiation (RFR) can alter the blood-brain barrier (BBB) permeability with a brain averaged specific absorption rate (BASAR) threshold evaluated at around 100 W/kg (1). Mobile communication technologies are using RFR with exposure guidelines for public local exposure at 2 W/kg, far lower than the threshold previously mentioned. However, in a paper recently published (2) the occurrence of BBB leakage and brain damage (presence of dark neurons) has been reported 50 days after a single 2-hour exposure of rats to a GSM-900 signal. In that investigation however, bias could have occurred as, for instance, exposed animals were mixed in terms of age (12- to 26-week old) and gender, while those differences were not taken into account in the analysis. Moreover, other groups have published contradictory results (3). Our group undertook a confirmation study of the Salford experiments within an international collaborative programme including technical improvements. Our study includes the detection of dark neurons, alteration of the permeability of the BBB and apoptosis 14 or 50 days after GSM-900 exposure. The exposure setup was the loop antenna that allows for head-only exposure. Five groups of 16 Fisher 344 rats (14 -week old) were exposed to GSM-900 during 2 hours at various SAR levels (0, 0.14 and 2.0 W/kg), or were used as cage control or positive controls. Positive controls were treated with kainic acid (10 mg/kg) or by cold injury (dry ice during 5 minutes). After exposure, rats were kept alive during 14 or 50 days to study brain damages. Then, they were anesthetized with urethane (i.p. 1.5 mg/kg), perfused with PBS and fixed with paraformaldehyde 4% (PAF 4%). Brains were extracted and put in cold PAF 4% during the following night, then placed in cold sucrose 20% during 2-3 days, frozen with isopentane and placed at -80 deg. C. Coding was done on brains. Frozen brains were cut in 3

  20. 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.

  1. The prospective application of a hypoxic radiosensitizer, doranidazole to rat intracranial glioblastoma with blood brain barrier disruption

    International Nuclear Information System (INIS)

    Glioblastoma is one of the intractable cancers and is highly resistant to ionizing radiation. This radioresistance is partly due to the presence of a hypoxic region which is widely found in advanced malignant gliomas. In the present study, we evaluated the effectiveness of the hypoxic cell sensitizer doranidazole (PR-350) using the C6 rat glioblastoma model, focusing on the status of blood brain barrier (BBB). Reproductive cell death in the rat C6 glioma cell line was determined by means of clonogenic assay. An intracranial C6 glioma model was established for the in vivo experiments. To investigate the status of the BBB in C6 glioma bearing brain, we performed the Evans blue extravasation test. Autoradiography with [14C]-doranidazole was performed to examine the distribution of doranidazole in the glioma tumor. T2-weighted MRI was employed to examine the effects of X-irradiation and/or doranidazole on tumor growth. Doranidazole significantly enhanced radiation-induced reproductive cell death in vitro under hypoxia, but not under normoxia. The BBB in C6-bearing brain was completely disrupted and [14C]-doranidazole specifically penetrated the tumor regions. Combined treatment with X-irradiation and doranidazole significantly inhibited the growth of C6 gliomas. Our results revealed that BBB disruption in glioma enables BBB-impermeable radiosensitizers to penetrate and distribute in the target region. This study is the first to propose that in malignant glioma the administration of hydrophilic hypoxic radiosensitizers could be a potent strategy for improving the clinical outcome of radiotherapy without side effects

  2. 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.

  3. Effect of X-irradiation on the pharmacokinetics of methotrexate in rats: alteration of the blood-brain barrier

    International Nuclear Information System (INIS)

    A study was designed to evaluate the effects of brain irradiation on the permeability of the blood-brain barrier for methotrexate (MTX). Female WAG/Rij rats were cranially irradiated with a single dose of 20 gy of 300 kV X-rays. At different times (1-15 days) after the exposure the rats were injected intravenously with MTX (25 mg/kg body wt). Irradiation had hardly any effect on the MTX concentrations in the plasma, heart and kidneys as determined by high-performance liquid chromatography. However, irradiation resulted in a significant increase of MTX (determined by 125I-radioimmunoassay) in brain tissue per gram wet weight (187.6 +- 17.9 pmol/g vs 46.4 +- 29.3 pmol/g in unirradiated brain). This change in permeability of the blood-brain barrier lasted for about 9 days. The MTX elimination from the irradiated brain was the same as that from the non-irradiated brain. This indicates that only the MTX uptake and not the elimination by the brain was affected by the irradiation treatment. (author)

  4. The fibrinolytic system facilitates tumor cell migration across the blood-brain barrier in experimental melanoma brain metastasis

    International Nuclear Information System (INIS)

    Patients with metastatic tumors to the brain have a very poor prognosis. Increased metastatic potential has been associated with the fibrinolytic system. We investigated the role of the fibrinolytic enzyme plasmin in tumor cell migration across brain endothelial cells and growth of brain metastases in an experimental metastatic melanoma model. Metastatic tumors to the brain were established by direct injection into the striatum or by intracarotid injection of B16F10 mouse melanoma cells in C57Bl mice. The role of plasminogen in the ability of human melanoma cells to cross a human blood-brain barrier model was studied on a transwell system. Wild type mice treated with the plasmin inhibitor epsilon-aminocaproic acid (EACA) and plg-/- mice developed smaller tumors and survived longer than untreated wild type mice. Tumors metastasized to the brain of wild type mice treated with EACA and plg-/- less efficiently than in untreated wild type mice. No difference was observed in the tumor growth in any of the three groups of mice. Human melanoma cells were able to cross the human blood-brain barrier model in a plasmin dependent manner. Plasmin facilitates the development of tumor metastasis to the brain. Inhibition of the fibrinolytic system could be considered as means to prevent tumor metastasis to the brain

  5. Altered free radical metabolism in acute mountain sickness: implications for dynamic cerebral autoregulation and blood-brain barrier function

    DEFF Research Database (Denmark)

    Bailey, D M; Evans, K A; James, P E;

    2008-01-01

    We tested the hypothesis that dynamic cerebral autoregulation (CA) and blood-brain barrier (BBB) function would be compromised in acute mountain sickness (AMS) subsequent to a hypoxia-mediated alteration in systemic free radical metabolism. Eighteen male lowlanders were examined in normoxia (21% O......(2)) 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...... MCAv, S100beta and neuron-specific enolase. In conclusion, these findings suggest that AMS is associated with altered redox homeostasis and disordered CA independent of barrier disruption....

  6. Evaluation of blood-brain barrier permeability changes in rhesus monkeys and man using 82Rb and positron emission tomography

    International Nuclear Information System (INIS)

    Dynamic positron tomography of the brain with /sup 82/Rb, obtained from a portable generator [/sup 82/Sr (25 days) - /sup 82/Rb (76 sec)], provides a means of studying blood-brain barrier (BBB) permeability in physiological and clinical investigations. The BBB in rhesus monkeys was opened unilaterally be intracarotid infusion of 3 M urea. This osmotic barrier opening allowed entry into the brain of intravenously administered rubidium chloride. The BBB opening was demonstrated noninvasively using /sup 82/Rb and positron emission tomography and corroborated by the accumulation of /sup 86/Rb in tissue samples. Positron emission tomography studies can be repeated every 5 min and indicate that dynamic tomography or static imaging can be used to study BBB permeability changes induced by a wide variety of noxious stimuli. Brain tumors in human subjects are readily detected because of the usual BBB permeability disruption in and around the tumors

  7. Evaluation of blood--brain barrier permeability changes in rhesus monkeys and man using 82Rb and positron emission tomography

    International Nuclear Information System (INIS)

    Dynamic positron tomography of the brain with 82Rb, obtained from a portable generator [82Sr (25 days) -- 82Rb (76 sec)], provides a means of studying blood-brain barrier (BBB) permeability in physiological and clinical investigations. The BBB in rhesus monkeys was opened unilaterally by intracarotid infusion of 3 M urea. This osmotic barrier opening allowed entry into the brain of intravenously administered rubidium chloride. The BBB opening was demonstrated noninvasively using 82Rb and positron emission tomography and corroborated by the accumulation of 86Rb in tissue samples. Positron emission tomography studies can be repeated every 5 min and indicate that dynamic tomography or static imaging can be used to study BBB permeability changes induced by a wide variety of noxious stimuli. Brain tumors in human subjects are readily detected because of the usual BBB permeability disruption in and around the tumors

  8. Quantitative assessment of P-glycoprotein function in the rat blood-brain barrier by distribution volume of [C-11]verapamil measured with PET

    NARCIS (Netherlands)

    Bart, J; Willemsen, ATM; Groen, HJM; van der Graaf, WTA; Wegman, TD; Vaalburg, W; de Vries, EGE; Hendrikse, NH

    2003-01-01

    The blood-brain barrier (BBB) is a functional barrier that hampers the delivery of various drugs to the brain by its physicoanatomical properties and by the presence of ATP-driven drug efflux pumps, such as P-glycoprotein (P-gp). The aims of this study were (1) to study whether the distribution volu

  9. 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

    papers. 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...... account of all the evidence and assessing its quality, rather than selecting papers that supports a preconceived notion or intuitive belief. This review attempts to right the wrongs. Based on careful translation of original papers, some published a century ago, as well as providing discussion of studies...

  10. Ictal lack of binding to brain parenchyma suggests integrity of the blood-brain barrier for 11C-dihydroergotamine during glyceryl trinitrate-induced migraine.

    Science.gov (United States)

    Schankin, Christoph J; Maniyar, Farooq H; Seo, Youngho; Kori, Shashidar; Eller, Michael; Chou, Denise E; Blecha, Joseph; Murphy, Stephanie T; Hawkins, Randall A; Sprenger, Till; VanBrocklin, Henry F; Goadsby, Peter J

    2016-07-01

    SEE DREIER DOI 101093/AWW112 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: For many decades a breakdown of the blood-brain barrier has been postulated to occur in migraine. Hypothetically this would facilitate access of medications, such as dihydroergotamine or triptans, to the brain despite physical properties otherwise restricting their entry. We studied the permeability of the blood-brain barrier in six migraineurs and six control subjects at rest and during acute glyceryl trinitrate-induced migraine attacks using positron emission tomography with the novel radioligand (11)C-dihydroergotamine, which is chemically identical to pharmacologically active dihydroergotamine. The influx rate constant Ki, average dynamic image and time activity curve were assessed using arterial blood sampling and served as measures for receptor binding and thus blood-brain barrier penetration. At rest, there was binding of (11)C-dihydroergotamine in the choroid plexus, pituitary gland, and venous sinuses as expected from the pharmacology of dihydroergotamine. However, there was no binding to the brain parenchyma, including the hippocampus, the area with the highest density of the highest-affinity dihydroergotamine receptors, and the raphe nuclei, a postulated brainstem site of action during migraine, suggesting that dihydroergotamine is not able to cross the blood-brain barrier. This binding pattern was identical in migraineurs during glyceryl trinitrate-induced migraine attacks as well as in matched control subjects. We conclude that (11)C-dihydroergotamine is unable to cross the blood-brain barrier interictally or ictally demonstrating that the blood-brain barrier remains tight for dihydroergotamine during acute glyceryl trinitrate-induced migraine attacks. PMID:27234268

  11. Fusion Antibody for Alzheimer’s Disease with Bi-Directional Transport Across the Blood-Brain Barrier and Abeta Fibril Disaggregation

    OpenAIRE

    Boado, Ruben J.; Zhang, Yufeng; Zhang, Yun; Xia, Chun-Fang; Pardridge, William M.

    2007-01-01

    Delivery of monoclonal antibody therapeutics across the blood-brain barrier is an obstacle to the diagnosis or therapy of CNS disease with antibody drugs. The immune therapy of Alzheimer’s disease attempts to disaggregate the amyloid plaque of Alzheimer’s disease with an anti-Abeta monoclonal antibody. The present work is based on a 3-step model of immune therapy of Alzheimer’s disease: (1) influx of the anti-Abeta monoclonal antibody across the blood-brain barrier in the blood to brain direc...

  12. Acute whole-body irradiation, even at moderate dose, induces alterations in blood-brain-barrier permeability

    International Nuclear Information System (INIS)

    Full text: A radiation-induced blood-brain barrier (BBB) breakdown has been evoked, but clearly demonstrated only at high doses of ionizing radiations. By using two protocols, we have searched an impairment in BBB integrity induced by moderate doses. First, the effects of irradiation on the permeability of striatal BBB to [3H]AIBA and [14C]sucrose were investigated in rats by using brain microdialysis. 32 rats, irradiated at 4.5Gy were serially experimented from 0 to 24 hours, from 24 to 48 hours and at later delays after exposure. 32 sham-irradiated rats served as controls. Second, the entry of pyridostigmine (PYR would not be expected to cross the BBB) into the brain was investigated in mice subjected to (neutron-g) exposure at 0.7Gy or 4Gy. For each dose 120 animals were irradiated and 120 sham-irradiated mice were included. At different delays after exposure, 10 mice were injected with 0.9% NaCl (control) or PYR bromide (0.1 mg/kg). Mice were killed 10min after injection and striatum, cortex and hippocampus were quickly dissected. Penetration of the drug into the brain was examined by measurement of AChE activity. Concerning microdialysis protocol, no late modification of the permeability of BBB was observed. But, in the course of the initial syndrome, we observed a transient increase of the permeability to the two markers, between the third and the 17th hour after exposure. A secondary transient 'opening' of the BBB to [14C] sucrose was noticed about 28 hours following irradiation with no modification of the permeability to [3H]AIBA. Concerning the BBB permeability to PYR, by comparing irradiated-PYR mice to sham-PYR mice, a decrease of AChE activity in the three cerebral areas was noted 48 hours after exposure at 4 Gy ; at 0.7 Gy this decrease is noted in the striatum only. In conclusion, our experiments by using two animal models, two types of radiations, and different tracers show modifications of the BBB permeability after moderate doses whole

  13. In vivo two-photon imaging measuring the blood-brain barrier permeability during early postnatal brain development in rodent

    Science.gov (United States)

    Shi, Lingyan; Rodríguez-Contreras, Adrián.

    2016-03-01

    The blood-brain barrier (BBB) is a unique structure between the cerebral blood circulation and the delicate neural environment that is important in regulating the movement of molecules and ions involved in brain development and function. However, little is known about the physiological permeability of molecules and ions across the BBB during brain development. In this study we applied an innovative approach to examine the development of BBB properties quantitatively. Two-photon microscopy was employed to measure BBB permeability in real time in vivo. Vascular growth and specific interactions between astrocyte end feet and microvessels were studied by using a combination of IB4 histochemistry, immunohistochemistry, confocal microscopy and 3D analysis.

  14. Focal MMP-2 and MMP-9 Activity at the Blood-Brain Barrier Promotes Chemokine-Induced Leukocyte Migration

    Directory of Open Access Journals (Sweden)

    Jian Song

    2015-02-01

    Full Text Available Although chemokines are sufficient for chemotaxis of various cells, increasing evidence exists for their fine-tuning by selective proteolytic processing. Using a model of immune cell chemotaxis into the CNS (experimental autoimmune encephalomyelitis [EAE] that permits precise localization of immigrating leukocytes at the blood-brain barrier, we show that, whereas chemokines are required for leukocyte migration into the CNS, additional MMP-2/9 activities specifically at the border of the CNS parenchyma strongly enhance this transmigration process. Cytokines derived from infiltrating leukocytes regulate MMP-2/9 activity at the parenchymal border, which in turn promotes astrocyte secretion of chemokines and differentially modulates the activity of different chemokines at the CNS border, thereby promoting leukocyte migration out of the cuff. Hence, cytokines, chemokines, and cytokine-induced MMP-2/9 activity specifically at the inflammatory border collectively act to accelerate leukocyte chemotaxis across the parenchymal border.

  15. 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.

  16. In Vivo Bioluminescent Imaging of ATP-Binding Cassette Transporter-Mediated Efflux at the Blood-Brain Barrier.

    Science.gov (United States)

    Bakhsheshian, Joshua; Wei, Bih-Rong; Hall, Matthew D; Simpson, R Mark; Gottesman, Michael M

    2016-01-01

    We provide a detailed protocol for imaging ATP-binding cassette subfamily G member 2 (ABCG2) function at the blood-brain barrier (BBB) of transgenic mice. D-Luciferin is specifically transported by ABCG2 found on the apical side of endothelial cells at the BBB. The luciferase-luciferin enzymatic reaction produces bioluminescence, which allows a direct measurement of ABCG2 function at the BBB. Therefore bioluminescence imaging (BLI) correlates with ABCG2 function at the BBB and this can be measured by administering luciferin in a mouse model that expresses luciferase in the brain parenchyma. BLI allows for a relatively low-cost alternative for studying transporter function in vivo compared to other strategies such as positron emission tomography. This method for imaging ABCG2 function at the BBB can be used to investigate pharmacokinetic inhibition of the transporter. PMID:27424909

  17. The effect of high energy electron irradiation on blood-brain barrier permeability to haloperidol and stobadin in rats

    International Nuclear Information System (INIS)

    The heads of rats were irradiated by 4 MeV electrons in doses 90, 180, and 360 Gy. The observed times of deaths ranged 120-600, 60-420, and 150-370 min after 90, 180, and 360 Gy, respectively. A dose dependent decrease of the brain uptake index of haloperidol was observed 1 and 3 h post radiation. On the other hand an increased brain uptake index was found for stobadin after head irradiation with doses of 180 and 360 Gy. Regional cerebral blood flow, blood pressure, and heart rate were not significantly altered in the period following irradiation with 180 Gy. The observed changes in blood-brain barrier (BBB) permeability seem to be the result of the damaged function of morphological structures forming the BBB rather than altered regional blood flow. (orig.)

  18. Multidrug-resistance gene (P-glycoprotein) is expressed by endothelial cells at blood-brain barrier sites

    Energy Technology Data Exchange (ETDEWEB)

    Cordon-Cardo, C.; O' Brien, J.P.; Casals, D.; Biedler, J.L.; Melamed, M.R.; Bertino, J.R. (Memorial Sloan-Kettering Cancer Center, New York, NY (USA)); Rittman-Grauer, L. (Hybritech, Inc., San Diego, CA (USA))

    1989-01-01

    Endothelial cells of human capillary blood vessels at the blood-brain and other blood-tissue barrier sites express P-glycoprotein as detected by mouse monoclonal antibodies against the human multidrug-resistance gene product. This pattern of endothelial cell expression may indicate a physiological role for P-glycoprotein in regulating the entry of certain molecules into the central nervous system and other anatomic compartments, such as the testes. These tissues, which limit the access of systemic drugs, are known pharmacologic sanctuaries for metastatic cancer. P-glycoprotein expression in capillary endothelium of brain and testes and not other tissues (i.e., kidney and placenta) may in part explain this phenomenon and could have important implications in cancer chemotherapy.

  19. Mechanisms and regulation of iron trafficking across the capillary endothelial cells of the blood-brain barrier

    Directory of Open Access Journals (Sweden)

    Daniel J. Kosman

    2015-07-01

    Full Text Available The transcellular trafficking of iron from the blood into the brain interstitium depends on iron uptake proteins in the apical membrane of brain microvascular capillary endothelial cells and efflux proteins at the basolateral, abluminal membrane. In this review, we discuss the three mechanisms by which these cells take-up iron from the blood and the sole mechanism by which they efflux this iron into the abluminal space. We then focus on the regulation of this efflux pathway by exocrine factors that are released from neighboring astrocytes. Also discussed are the cytokines secreted by capillary cells that regulate the expression of these glial cell signals. Among the interstitial factors that regulate iron efflux into the brain is the amyloid precursor protein. The role of this amyliodogenic species in brain iron metabolism is discussed. Last, we speculate on the potential relationship between iron transport at the blood-brain barrier and neurological disorders associated with iron mismanagement.

  20. Mesenchymal Stem Cells Regulate Blood Brain Barrier Integrity in Traumatic Brain Injury Through Production of the Soluble Factor TIMP3

    Science.gov (United States)

    Menge, Tyler; Zhao, Yuhai; Zhao, Jing; Wataha, Kathryn; Geber, Michael; Zhang, Jianhu; Letourneau, Phillip; Redell, John; Shen, Li; Wang, Jing; Peng, Zhalong; Xue, Hasen; Kozar, Rosemary; Cox, Charles S.; Khakoo, Aarif Y.; Holcomb, John B.; Dash, Pramod K.; Pati, Shibani

    2013-01-01

    Mesenchymal stem cells (MCSs) have been shown to have therapeutic potential in multiple disease states associated with vascular instability including traumatic brain injury (TBI). In the present study, Tissue Inhibitor of Matrix Metalloproteinase-3 (TIMP3) is identified as the soluble factor produced by MSCs that can recapitulate the beneficial effects of MSCs on endothelial function and blood brain barrier (BBB) compromise in TBI. Attenuation of TIMP3 expression in MSCs completely abrogates the effect of MSCs on BBB permeability and stability, while intravenous administration of rTIMP3 alone can inhibit BBB permeability in TBI. Our results demonstrate that MSCs increase circulating levels of soluble TIMP3, which inhibits VEGF-A induced breakdown of endothelial AJs in vitro and in vivo. These findings elucidate a clear molecular mechanism for the effects of MSCs on the BBB in TBI, and directly demonstrate a role for TIMP3 in regulation of BBB integrity. PMID:23175708

  1. Blood-brain barrier permeation in the rat during exposure to low-power 1.7-GHz microwave radiation

    International Nuclear Information System (INIS)

    The permeability of the blood-brain barrier to high-and low-molecular-weight compounds has been measured as a function of continuous-wave (CW) and pulsed-microwave radiation. Adult rats, anesthetized with pentobarbital and injected intravenously with a mixture of [14C] sucrose and [3H] inulin, were exposed for 30 min at a specific absorption rate of 0.1 W/kg to 1.7-GHz CW and pulsed (0.5-microseconds pulse width, 1,000 pps) microwaves. After exposure, the brain was perfused and sectioned into nine regions, and the radioactivity in each region was counted. During identical exposure conditions, temperatures of rats were measured in eight of the brain regions by a thermistor probe that did not perturb the field. No change in uptake of either tracer was found in any of the eight regions as compared with those of sham-exposed animals

  2. AAnti-leakage mechanism and effect of sodium aescinate on the permeability of blood-brain barrier

    Directory of Open Access Journals (Sweden)

    Ping GUO

    2012-02-01

    Full Text Available Objective  To study the anti-leakage mechanism and protective effect of sodium aescinate on the blood-brain barrier of rats acutely exposed to hypoxia. Methods  Seventy-five healthy SD rats were randomly divided into 3 groups (25 each: normoxic control (NC, simple hypoxic (SH and drug treated (DT group. Acute hypoxia brain edema rat model was established by a simulation of acute high-altitude hypoxia for 5 days. The cerebral water content was determined by dry-wet method. The permeability of the blood-brain barrier (BBB was evaluated by Evans blue (EB method. The pathological change of the brain was detected by HE staining. The state of BBB tight junction (TJ and ultrastructures of the brain tissues were observed by lanthanum nitrate tracer method under transmission electron microscope (TEM. Protein and mRNA expression of Occludin, Zo-1 and Claudin-5 were investigated by immunohistochemistry, Western-blotting and real-time PCR respectively. Results  After exposure to acute hypoxia for 5 days, compared with NC group, the water content of brain in SH group increased obviously (PPPPPConclusion  Acute hypoxia exposure may lead to a remarkable decline of the expressions of rat's brain Occludin protein and the Occludin, Zo-1 and Claudin-5 mRNA, and an obvious increase of BBB permeability. Sodium aescinate can up-regulate the expression level of these molecules and decrease BBB permeability, thus playing a profitable role of anti-leakage and BBB protection.

  3. 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

  4. 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

  5. Cilostazol reduces blood brain barrier dysfunction, white matter lesion formation and motor deficits following chronic cerebral hypoperfusion.

    Science.gov (United States)

    Edrissi, Hamidreza; Schock, Sarah C; Cadonic, Robert; Hakim, Antoine M; Thompson, Charlie S

    2016-09-01

    Cerebral small vessel disease (CSVD) is a pathological process leading to lacunar infarcts, leukoaraiosis and cerebral microbleeds. Dysfunction of the blood brain barrier (BBB) has been proposed as a mechanism in the progression cerebral small vessel disease. A rodent model commonly used to study some aspects of CSVD is bilateral common carotid artery occlusion (BCCAO) in the rat. In the present study it was determined that gait impairment, as determined by a tapered beam test, and BBB permeability increased following BCCAO. Cilostazol, a type III phosphodiesterase inhibitor, has been shown to have anti-apoptotic effects and prevent white matter vacuolation and rarefaction induced by BCCAO in rats. In this study the protective effect of cilostazol administration on the increase BBB permeability following BCCAO was determined as well as the effect on plasma levels of circulating microparticles (MPs), cerebral white matter rarefaction, glial activation and gait disturbance. The effect of cilostazol on in vitro endothelial barriers was also evaluated. Cilostazol treatment improved BBB permeability and reduced gait disturbance, visual impairment and microglial activation in optic tract following BCCAO in vivo. It also reduced the degree of cell death and the reduction in trans-endothelial electrical resistance (TEER) in artificial endothelial barriers in vitro induced by MP treatment of in vitro barriers. PMID:27350079

  6. Prolonged Morphine Exposure Induces Increased Firm Adhesion in an in Vitro Model of the Blood-Brain Barrier.

    Science.gov (United States)

    Strazza, Marianne; Pirrone, Vanessa; Wigdahl, Brian; Dampier, Will; Lin, Wei; Feng, Rui; Maubert, Monique E; Weksler, Babette; Romero, Ignacio A; Couraud, Pierre-Olivier; Nonnemacher, Michael R

    2016-01-01

    The blood-brain barrier (BBB) has been defined as a critically important protective barrier that is involved in providing essential biologic, physiologic, and immunologic separation between the central nervous system (CNS) and the periphery. Insults to the BBB can cause overall barrier damage or deregulation of the careful homeostasis maintained between the periphery and the CNS. These insults can, therefore, yield numerous phenotypes including increased overall permeability, interendothelial gap formation, alterations in cytokine and chemokine secretion, and accelerated cellular passage. The current studies expose the human brain microvascular endothelial cell line, hCMEC/D3, to prolonged morphine exposure and aim to uncover the mechanisms underlying alterations in barrier function in vitro. These studies show alterations in the mRNA and protein levels of the cellular adhesion molecules (CAMs) intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and activated leukocyte cell adhesion molecule that correlate with an increased firm adhesion of the CD3⁺ subpopulation of peripheral blood mononuclear cells (PBMCs). Overall, these studies suggest that prolonged morphine exposure may result in increased cell migration into the CNS, which may accelerate pathological processes in many diseases that involve the BBB. PMID:27294916

  7. (18)F-FCWAY, a serotonin 1A receptor radioligand, is a substrate for efflux transport at the human blood-brain barrier.

    Science.gov (United States)

    Liow, Jeih-San; Zoghbi, Sami S; Hu, Shuo; Hall, Matthew D; Hines, Christina S; Shetty, H Umesha; Araneta, Maria D; Page, Emily M; Pike, Victor W; Kreisl, William C; Herscovitch, Peter; Gottesman, Michael M; Theodore, William H; Innis, Robert B

    2016-09-01

    Efflux transporters at the blood-brain barrier can decrease the entry of drugs and increase the removal of those molecules able to bypass the transporter. We previously hypothesized that (18)F-FCWAY, a radioligand for the serotonin 5-HT1A receptor, is a weak substrate for permeability glycoprotein (P-gp) based on its very early peak and rapid washout from human brain. To determine whether (18)F-FCWAY is a substrate for P-gp, breast cancer resistance protein (BCRP), and multidrug resistance protein (MRP1) - the three most prevalent efflux transporters at the blood-brain barrier - we performed three sets of experiments. In vitro, we conducted fluorescence-activated cell sorting (FACS) flow cytometry studies in cells over-expressing P-gp, BCRP, and MRP1 treated with inhibitors specific to each transporter and with FCWAY. Ex vivo, we measured (18)F-FCWAY concentration in plasma and brain homogenate of transporter knockout mice using γ-counter and radio-HPLC. In vivo, we conducted positron emission tomography (PET) studies to assess changes in humans who received (18)F-FCWAY during an infusion of tariquidar (2-4mg/kg iv), a potent and selective P-gp inhibitor. In vitro studies showed that FCWAY allowed fluorescent substrates to get into the cell by competitive inhibition of all three transporters at the cell membrane. Ex vivo measurements in knockout mice indicate that (18)F-FCWAY is a substrate only for P-gp and not BCRP. In vivo, tariquidar increased (18)F-FCWAY brain uptake in seven of eight subjects by 60-100% compared to each person's baseline. Tariquidar did not increase brain uptake via some peripheral mechanism, given that it did not significantly alter concentrations in plasma of the parent radioligand (18)F-FCWAY or its brain-penetrant radiometabolite (18)F-FC. These results show that (18)F-FCWAY is a weak substrate for efflux transport at the blood-brain barrier; some radioligand can enter brain, but its removal is hastened by P-gp. Although (18)F-FCWAY is

  8. Synthesis and Preclinical Evaluation of Three Novel Fluorine-18 Labeled Radiopharmaceuticals for P-Glycoprotein PET Imaging at the Blood-Brain Barrier

    NARCIS (Netherlands)

    Savolainen, Heli; Cantore, Mariangela; Colabufo, Nicola A.; Elsinga, Philip H.; Windhorst, Albert D.; Luurtsema, Gert

    2015-01-01

    P-Glycoprotein (P-gp), along with other transporter proteins at the blood brain barrier (BBB), limits the entry of many pharmaceuticals into the brain. Altered P-gp function has been found in several neurological diseases. To study the P-gp function, many positron emission tomography (PET) radiophar

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

    DEFF Research Database (Denmark)

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

    1991-01-01

    Intracerebral inoculation of lymphocytic choriomeningitis virus (LCMV) generally results in a fatal T cell-mediated meningitis. In a previous study we have demonstrated a compromised blood-brain barrier (BBB) under such conditions. Using semi-quantitative radiography and the low molecular tracer ...

  10. 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 uni...... treatments in intracranial diseases....

  11. Adverse effects of antipsychotics on micro-vascular endothelial cells of the human blood-brain barrier.

    Science.gov (United States)

    Elmorsy, Ekramy; Elzalabany, Laila M; Elsheikha, Hany M; Smith, Paul A

    2014-10-01

    Although the mechanisms of action of antipsychotics (APs) on neuronal function are well understood, very little is known about their effects on cells of the blood-brain barrier (BBB); one function of which is to limit the access of these amphiphilic compounds to the central nervous system. To address this question we have investigated the cytological and functional effects of four APs: chlorpromazine (CLP), haloperidol (HAL), risperidone (RIS) and clozapine (CLZ), at concentrations typical of high therapeutic dosage on a human brain microvascular endothelial cell (HBMEC) model of the BBB. At ~10 µM all four APs impaired the ability of HBMECs to reduce MTT which was followed by decreased Trypan blue exclusion and increased Lactate dehydrogenase release. These effects were associated with oxidative stress which was partly reversed by incubation in 10mM glutathione. At their EC50 concentrations for MTT reduction, all four APs disrupted cellular ultrastructure and morphology. HAL, CPZ and CLZ increased Caspase -3, -8 and -9 activity, chromatin condensation and fragmentation, data indicative of apoptosis. These events were associated with decreased transcytosis of Evans blue and increased transendothelial potential difference and electrical resistance of this BBB model. These findings suggest that at high therapeutic concentrations, CPZ and CLZ are likely to incur cytoxic effects and apoptosis of BBB endothelia with an impairment of barrier functionality. Such events may underlie the aetiology of neuroleptic associated cerebral oedema and neuroleptic malignant syndrome. PMID:25139421

  12. Maternal Obesity in the Mouse Compromises the Blood-Brain Barrier in the Arcuate Nucleus of Offspring.

    Science.gov (United States)

    Kim, Dong Won; Glendining, Kelly A; Grattan, David R; Jasoni, Christine L

    2016-06-01

    The arcuate nucleus (ARC) regulates body weight in response to blood-borne signals of energy balance. Blood-brain barrier (BBB) permeability in the ARC is determined by capillary endothelial cells (ECs) and tanycytes. Tight junctions between ECs limit paracellular entry of blood-borne molecules into the brain, whereas EC transporters and fenestrations regulate transcellular entry. Tanycytes appear to form a barrier that prevents free diffusion of blood-borne molecules. Here we tested the hypothesis that gestation in an obese mother alters BBB permeability in the ARC of offspring. A maternal high-fat diet model was used to generate offspring from normal-weight (control) and obese dams (OffOb). Evans Blue diffusion into the ARC was higher in OffOb compared with controls, indicating that ARC BBB permeability was altered. Vessels investing the ARC in OffOb had more fenestrations than controls, although the total number of vessels was not changed. A reduced number of tanycytic processes in the ARC of OffOb was also observed. The putative transporters, Lrp1 and dysferlin, were up-regulated and tight junction components were differentially expressed in OffOb compared with controls. These data suggest that maternal obesity during pregnancy can compromise BBB formation in the fetus, leading to altered BBB function in the ARC after birth. PMID:27054554

  13. PHYSIOLOGY AND PATHOPHYSIOLOGY OF THE BLOOD BRAIN BARRIER: P-glycoprotein and occludin trafficking as therapeutic targets to optimize CNS drug delivery

    OpenAIRE

    McCaffrey, Gwen; Davis, Thomas P.

    2012-01-01

    The blood-brain barrier (BBB) is a physical and metabolic barrier that separates the CNS from the peripheral circulation. CNS drug delivery across the BBB is challenging, primarily due to the physical restriction of paracellular diffusion between the endothelial cells that comprise the microvessels of the BBB and the activity of efflux transporters that quickly expel back into the capillary lumen a wide variety of xenobiotics. Therapeutic manipulation of protein trafficking is emerging as a n...

  14. Multimodal investigations of trans-endothelial cell trafficking under condition of disrupted blood-brain barrier integrity

    Directory of Open Access Journals (Sweden)

    Masaryk Thomas

    2010-03-01

    Full Text Available Abstract Background Stem cells or immune cells targeting the central nervous system (CNS bear significant promises for patients affected by CNS disorders. Brain or spinal cord delivery of therapeutic cells is limited by the blood-brain barrier (BBB which remains one of the recognized rate-limiting steps. Osmotic BBB disruption (BBBD has been shown to improve small molecule chemotherapy for brain tumors, but successful delivery of cells in conjunction with BBBD has never been reported. We have used a clinically relevant model (pig of BBBD to attempt brain delivery of TALL-104, a human leukemic T cell line. TALL-104 cells are potent tumor killers and have demonstrated potential for systemic tumor therapy. The pig model used is analogous to the clinical BBBD procedure. Cells were injected in the carotid artery after labeling with the MRI T1 contrast agent GdHPDO3A. Contrast CT scans were used to quantify BBBD and MRI was used to detect Gd++-loaded cells in the brain. Transcranial Doppler was used to monitor cerebral blood flow. EEG recordings were used to detect seizures. Immunocytochemical detection (Cresyl Violet, anti-human CD8 for TALL-104, Evans Blue for BBB damage, GFAP and NEUN was performed. Results At the concentration used TALL-104 cells were tolerated. Incomplete BBBD did not allow cell entry into the brain. MRI scans at 24 and 48 hours post-injection allowed visualization of topographically segregated cells in the hemisphere that underwent successful BBBD. Perivascular location of TALL-104 was confirmed in the BBBD hemisphere by Cresyl violet and CD8 immunocytochemistry. No significant alteration in CBF or EEG activity was recorded during cell injections. Conclusions Our data show that targeted CNS cell therapy requires blood-brain barrier disruption. MRI-detectable cytotoxic anti-neoplastic cells can be forced to transverse the BBB and accumulate in the perivascular space. The virtual absence of toxicity, the high anti-tumor activity

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

    OpenAIRE

    Vykhodtseva, Natalia; McDannold, Nathan; Hynynen, Kullervo

    2008-01-01

    Advances in neuroscience have resulted in the development of new diagnostic and therapeutic agents for potential use in the central nervous system (CNS). However, the ability to deliver the majority of these agents to the brain is limited by the blood–brain barrier (BBB), a specialized structure of the blood vessel wall that hampers transport and diffusion from the blood to the brain. Many CNS disorders could be treated with drugs, enzymes, genes, or large-molecule biotechnological products s...

  16. 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.

  17. 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

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    Anja Brenn

    2011-01-01

    Full Text Available Neurovascular dysfunction is an important component of Alzheimer's disease, leading to reduced clearance across the blood-brain barrier and accumulation of neurotoxic β-amyloid (Aβ peptides in the brain. It has been shown that the ABC transport protein P-glycoprotein (P-gp, ABCB1 is involved in the export of Aβ from the brain into the blood. To determine whether Aβ influences the expression of key Aβ transporters, we studied the effects of 1-day subcutaneous Aβ1-40 and Aβ1-42 administration via Alzet mini-osmotic pumps on P-gp, BCRP, LRP1, and RAGE expression in the brain of 90-day-old male FVB mice. Our results demonstrate significantly reduced P-gp, LRP1, and RAGE mRNA expression in mice treated with Aβ1-42 compared to controls, while BCRP expression was not affected. The expression of the four proteins was unchanged in mice treated with Aβ1-40 or reverse-sequence peptides. These findings indicate that, in addition to the age-related decrease of P-gp expression, Aβ1-42 itself downregulates the expression of P-gp and other Aβ-transporters, which could exacerbate the intracerebral accumulation of Aβ and thereby accelerate neurodegeneration in Alzheimer's disease and cerebral β-amyloid angiopathy.

  20. Blood-Brain Barrier and Breast Cancer Resistance Protein: A Limit to the Therapy of CNS Tumors and Neurodegenerative Diseases

    Science.gov (United States)

    Iorio, Anna Lisa; da Ros, Martina; Fantappiè, Ornella; Lucchesi, Maurizio; Facchini, Ludovica; Stival, Alessia; Becciani, Sabrina; Guidi, Milena; Favre, Claudio; de Martino, Maurizio; Genitori, Lorenzo; Sardi, Iacopo

    2016-01-01

    The treatment of brain tumors and neurodegenerative diseases, represents an ongoing challenge. In Central Nervous System (CNS) the achievement of therapeutic concentration of chemical agents is complicated by the presence of distinct set of efflux proteins, such as ATP-Binding Cassette (ABC) transporters localized on the Blood-Brain Barrier (BBB). The activity of ABC transporters seems to be a common mechanism that underlies the poor response of CNS diseases to therapies. The molecular characterization of Breast Cancer Resistance Protein (BCRP/ABCG2), as an ABC transporter conferring multidrug resistance (MDR), has stimulated many studies to investigate its activity on the BBB, its involvement in physiology and CNS diseases and its role in limiting the delivery of drugs in CNS. In this review, we highlight the activity and localization of BCRP on the BBB and the action that this efflux pump has on many conventional drugs or latest generation molecules used for the treatment of CNS tumors and other neurodegenerative diseases. PMID:26584727

  1. On ultrasound-induced microbubble oscillation in a capillary blood vessel and its implications for the blood-brain barrier

    Science.gov (United States)

    Wiedemair, W.; Tuković, Ž.; Jasak, H.; Poulikakos, D.; Kurtcuoglu, V.

    2012-02-01

    The complex interaction between an ultrasound-driven microbubble and an enclosing capillary microvessel is investigated by means of a coupled, multi-domain numerical model using the finite volume formulation. This system is of interest in the study of transient blood-brain barrier disruption (BBBD) for drug delivery applications. The compliant vessel structure is incorporated explicitly as a distinct domain described by a dedicated physical model. Red blood cells (RBCs) are taken into account as elastic solids in the blood plasma. We report the temporal and spatial development of transmural pressure (Ptm) and wall shear stress (WSS) at the luminal endothelial interface, both of which are candidates for the yet unknown mediator of BBBD. The explicit introduction of RBCs shapes the Ptm and WSS distributions and their derivatives markedly. While the peak values of these mechanical wall parameters are not affected considerably by the presence of RBCs, a pronounced increase in their spatial gradients is observed compared to a configuration with blood plasma alone. The novelty of our work lies in the explicit treatment of the vessel wall, and in the modelling of blood as a composite fluid, which we show to be relevant for the mechanical processes at the endothelium.

  2. Sevoflurane-Sulfobutylether-β-Cyclodextrin Complex: Preparation, Characterization, Cellular Toxicity, Molecular Modeling and Blood-Brain Barrier Transport Studies

    Directory of Open Access Journals (Sweden)

    Sergey Shityakov

    2015-06-01

    Full Text Available The objective of the present investigation was to study the ability of sulfobutylether-β-cyclodextrin (SBEβCD to form an inclusion complex with sevoflurane (SEV, a volatile anesthetic with poor water solubility. The inclusion complex was prepared, characterized and its cellular toxicity and blood-brain barrier (BBB permeation potential of the formulated SEV have also been examined for the purpose of controlled drug delivery. The SEV-SBEβCD complex was nontoxic to the primary brain microvascular endothelial (pEND cells at a clinically relevant concentration of sevoflurane. The inclusion complex exhibited significantly higher BBB permeation profiles as compared with the reference substance (propranolol concerning calculated apparent permeability values (Papp. In addition, SEV binding affinity to SBEβCD was confirmed by a minimal Gibbs free energy of binding (ΔGbind value of −1.727 ± 0.042 kcal·mol−1 and an average binding constant (Kb of 53.66 ± 9.24 mM indicating rapid drug liberation from the cyclodextrin amphiphilic cavity.

  3. Sevoflurane-Sulfobutylether-β-Cyclodextrin Complex: Preparation, Characterization, Cellular Toxicity, Molecular Modeling and Blood-Brain Barrier Transport Studies.

    Science.gov (United States)

    Shityakov, Sergey; Puskás, István; Pápai, Katalin; Salvador, Ellaine; Roewer, Norbert; Förster, Carola; Broscheit, Jens-Albert

    2015-01-01

    The objective of the present investigation was to study the ability of sulfobutylether-β-cyclodextrin (SBEβCD) to form an inclusion complex with sevoflurane (SEV), a volatile anesthetic with poor water solubility. The inclusion complex was prepared, characterized and its cellular toxicity and blood-brain barrier (BBB) permeation potential of the formulated SEV have also been examined for the purpose of controlled drug delivery. The SEV-SBEβCD complex was nontoxic to the primary brain microvascular endothelial (pEND) cells at a clinically relevant concentration of sevoflurane. The inclusion complex exhibited significantly higher BBB permeation profiles as compared with the reference substance (propranolol) concerning calculated apparent permeability values (Papp). In addition, SEV binding affinity to SBEβCD was confirmed by a minimal Gibbs free energy of binding (ΔGbind) value of -1.727 ± 0.042 kcal·mol-1 and an average binding constant (Kb) of 53.66 ± 9.24 mM indicating rapid drug liberation from the cyclodextrin amphiphilic cavity. PMID:26046323

  4. 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.

  5. Blood-brain barrier breakdown and repair following gliotoxic drug injection in the brainstem of streptozotocin-diabetic rats

    Directory of Open Access Journals (Sweden)

    Eduardo Fernandes Bondan

    2012-03-01

    Full Text Available Ethidium bromide (EB causes local astrocytic disappearance, with glia limitans disruption and blood-brain barrier (BBB breakdown. The aim of this study was to evaluate the BBB integrity after the injection of 0.1% EB or 0.9% saline solution into the cisterna pontis of Wistar rats submitted or not to the streptozotocin diabetogenic model. Brainstem sections were collected from 24 hours to 31 days post-injection for ultrastructural analysis and glial fibrillary acidic protein immunohistochemical staining. Some animals received colloidal carbon ink by intravenous route at the same periods. In rats injected with EB, results revealed astrocyte disappearance and leakage of carbon particles beginning at 48 hours and persisting for 7 days in non-diabetic rats and for 15 days in the diabetic ones, although, in both groups, several areas remained devoid of astrocytic processes up to 31 days. In rats injected with saline, there was no sign of astrocytic loss or carbon particles leakage.

  6. Current preclinical studies on neuroinflammation and changes in blood-brain barrier integrity by MDMA and methamphetamine.

    Science.gov (United States)

    O'Shea, Esther; Urrutia, Andrés; Green, A Richard; Colado, M Isabel

    2014-12-01

    The blood-brain barrier (BBB) is essential in the maintenance of brain homeostasis both by preserving normal brain functioning and also by protecting the brain from exposure to a range of potentially harmful substances. This review presents some of the evidence of BBB disruption following exposure to the substituted amphetamines 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') and methamphetamine (METH), two drugs of abuse which are widely consumed recreationally by younger sectors of the population. Both MDMA and METH have been shown to produce disruption of the BBB as reflected by IgG extravasation and Evans Blue leakage. In particular, METH decreases the expression of basal lamina proteins associated with an increase in matrix metalloproteinase activity. These changes in BBB integrity appear to be related to MDMA-induced activation of the mitogen-activated protein kinase (MAPK) JNK1/2. The consequences of the disruption in the BBB by these two drugs remain to be established, but there is evidence in the literature that, at least in the case of METH, increased matrix metalloproteinase (MMP) activity may be related to increased behavioural sensitization and reward perhaps because of the modification of the passage of the drug into the CNS. In addition, the high incidence of AIDS-related neurologic disease in METH users may also be related to increased entry into the brain of virally derived neurotoxic products. This article is part of the Special Issue entitled 'CNS Stimulants'. PMID:24594477

  7. 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.

  8. Protective actions of des-acylated ghrelin on brain injury and blood-brain barrier disruption after stroke in mice.

    Science.gov (United States)

    Ku, Jacqueline M; Taher, Mohammadali; Chin, Kai Yee; Barsby, Tom; Austin, Victoria; Wong, Connie H Y; Andrews, Zane B; Spencer, Sarah J; Miller, Alyson A

    2016-09-01

    The major ghrelin forms, acylated ghrelin and des-acylated ghrelin, are novel gastrointestinal hormones. Moreover, emerging evidence indicates that these peptides may have other functions including neuro- and vaso-protection. Here, we investigated whether post-stroke treatment with acylated ghrelin or des-acylated ghrelin could improve functional and histological endpoints of stroke outcome in mice after transient middle cerebral artery occlusion (tMCAo). We found that des-acylated ghrelin (1 mg/kg) improved neurological and functional performance, reduced infarct and swelling, and decreased apoptosis. In addition, it reduced blood-brain barrier (BBB) disruption in vivo and attenuated the hyper-permeability of mouse cerebral microvascular endothelial cells after oxygen glucose deprivation and reoxygenation (OGD + RO). By contrast, acylated ghrelin (1 mg/kg or 5 mg/kg) had no significant effect on these endpoints of stroke outcome. Next we found that des-acylated ghrelin's vasoprotective actions were associated with increased expression of tight junction proteins (occludin and claudin-5), and decreased cell death. Moreover, it attenuated superoxide production, Nox activity and expression of 3-nitrotyrosine. Collectively, these results demonstrate that post-stroke treatment with des-acylated ghrelin, but not acylated ghrelin, protects against ischaemia/reperfusion-induced brain injury and swelling, and BBB disruption, by reducing oxidative and/or nitrosative damage. PMID:27303049

  9. Blood-Brain Barrier Opening in Behaving Non-Human Primates via Focused Ultrasound with Systemically Administered Microbubbles

    Science.gov (United States)

    Downs, Matthew E.; Buch, Amanda; Karakatsani, Maria Eleni; Konofagou, Elisa E.; Ferrera, Vincent P.

    2015-10-01

    Over the past fifteen years, focused ultrasound coupled with intravenously administered microbubbles (FUS) has been proven an effective, non-invasive technique to open the blood-brain barrier (BBB) in vivo. Here we show that FUS can safely and effectively open the BBB at the basal ganglia and thalamus in alert non-human primates (NHP) while they perform a behavioral task. The BBB was successfully opened in 89% of cases at the targeted brain regions of alert NHP with an average volume of opening 28% larger than prior anesthetized FUS procedures. Safety (lack of edema or microhemorrhage) of FUS was also improved during alert compared to anesthetized procedures. No physiological effects (change in heart rate, motor evoked potentials) were observed during any of the procedures. Furthermore, the application of FUS did not disrupt reaching behavior, but in fact improved performance by decreasing reaction times by 23 ms, and significantly decreasing touch error by 0.76 mm on average.

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

    International Nuclear Information System (INIS)

    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. (paper)

  11. Blood-brain barrier transport of butanol and water relative to N-isopropyl-p-iodoamphetamine as the internal reference

    International Nuclear Information System (INIS)

    The literature regarding the blood--brain barrier (BBB) transport of butanol is conflicting as studies report both incomplete and complete extraction of butanol by the brain. In this work the BBB transport of both [14C]butanol and [3H]water was studied using the carotid injection technique in conscious and in ketamine- or pentobarbital-anesthetized rats employing N-isopropyl-p-[125I]iodoamphetamine ([125I]IMP) as the internal reference and as a fluid microsphere. The three isotopes (3H, 125I, 14C) were conveniently counted simultaneously in a liquid scintillation spectrometer. IMP is essentially completely sequestered by the brain for at least 1 min in conscious rats and for 2 min in anesthetized animals. Butanol extraction by rat forebrain is not flow limited but ranges between 77 +/- 1 and 87 +/- 1% for the three conditions. The permeability-surface area product/cerebral blood flow ratio of butanol and water in rat forebrain remains relatively constant, despite a twofold increase in cerebral blood flow in conscious relative to pentobarbital-anesthetized rats. The absence of an inverse relationship between flow and butanol or water extraction is consistent with capillary recruitment being the principal mechanism underlying changes in cerebral blood flow in anesthesia. The diffusion restriction of BBB transport of butanol in some regions, but not in others, necessitates a careful regional analysis of BBB permeability to butanol prior to usage of this compound as a cerebral blood flow marker

  12. 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.

  13. Peptide transport through the blood-brain barrier. Final report 1 Jul 87-31 Dec 90

    Energy Technology Data Exchange (ETDEWEB)

    Partridge, W.M.

    1991-01-15

    Most neuropeptides are incapable of entering the brain from blood owing to the presence of unique anatomical structures in the brain capillary wall, which makes up the blood-brain barrier (BBB). Such neuropeptides could be introduced into the bloodstream by intranasal insufflation and, thus, could have powerful medicinal properties (e.g., Beta-endorphin for the treatment of pain, vasopressin analogues for treatment of memory, ACTH analogues for treatment of post-traumatic epilepsy), should these peptides be capable of traversing the BBB. One such strategy for peptide delivery through the BBB is the development of chimeric peptides, which is the basis of the present contract. The production of chimeric peptides involves the covalent coupling of a nontransportable peptide (e.g., Beta-endorphin, vasopressin) to a transportable vector peptide (e.g., insulin, transferrin, cationized albumin, histone). The transportable peptide is capable of penetrating the BBB via receptor-mediated or absorptive-mediated transcytosis. Therefore, the introduction of chimeric peptides allows the nontransportable peptide to traverse the BBB via a physiologic piggy back mechanism.

  14. 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.

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

    Science.gov (United States)

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

    2015-09-01

    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 electrical resistance values, permeabilities of paracellular flux markers, and expression of BBB-specific marker proteins. Microfluidic systems are gaining ground as a new automated technical platform for cell culture and systematic analysis. The performance of these systems was compared with current state-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 that the field may benefit greatly from developing standardized methodologies and initiating collaborative efforts on optimizing culture protocols. PMID:25630899

  16. Inhibition of chemokine-like factor 1 improves blood-brain barrier dysfunction in rats following focal cerebral ischemia.

    Science.gov (United States)

    Kong, Ling-Lei; Wang, Zhi-Yuan; Hu, Jin-Feng; Yuan, Yu-He; Li, Hua; Chen, Nai-Hong

    2016-08-01

    Disruption of blood-brain barrier (BBB) and subsequent edema are major contributors to the pathogenesis of ischemic stroke, and the current clinical therapy remains unsatisfied. Chemokine-like factor 1 (CKLF1), as a novel C-C chemokine, plays important roles in immune response. The expression of CKLF1 increased after focal cerebral ischemia and inhibition of CKLF1 activity showed neuroprotective effect by alleviating infiltration of neutrophil and neuron apoptosis in cerebral ischemia. However, few studies have focused on the role of CKLF1 on BBB integrity. The objective of present study was to investigate the role of CKLF1 on BBB integrity by applying anti-CKLF1 antibodies in rat focal cerebral ischemia and reperfusion model. Brain water content, Evans blue leakage and the expression of aquaporin-4 (AQP-4), matrix metalloproteinase-9 (MMP-9), Zonula Occludens-1 (ZO-1) and Occludin were measured. After treatment with anti-CKLF1 antibody, brain water content and Evans blue leakage in ipsilateral hemisphere were decreased in a dose-dependent manner at 24h after reperfusion, but not changed in contralateral hemisphere. Anti-CKLF1 antibody reduced the expression of AQP-4 and MMP-9, and upregulated the expression of ZO-1 and Occludin. These results suggest that CKLF1 is involved in BBB disruption after reperfusion. Inhibition of CKLF1 protects against cerebral ischemia by maintaining BBB integrity, possibly via inhibiting the expression of AQP-4 and MMP-9, and increasing the expression of tight junction protein. PMID:27283776

  17. Enolase of Streptococcus Suis Serotype 2 Enhances Blood-Brain Barrier Permeability by Inducing IL-8 Release.

    Science.gov (United States)

    Sun, Yingying; Li, Na; Zhang, Jing; Liu, Hongtao; Liu, Jianfang; Xia, Xiaojing; Sun, Changjiang; Feng, Xin; Gu, Jingmin; Du, Chongtao; Han, Wenyu; Lei, Liancheng

    2016-04-01

    Streptococcus suis serotype 2 (SS2) is an emerging zoonosis, and meningitis is the most frequent clinical manifestation, but mechanism of its virulent factor, enolase (Eno), is unknown in meningitis. In this study, Eno was inducibly expressed and added to an in vitro Transwell co-culture model of the blood-brain barrier (BBB) consisted of porcine brain microvascular endothelial cells (PBMECs) and astrocytes (ACs), the results showed that Eno induces a significant increase in BBB permeability and promotes the release of IL-8 et al. cytokines. Furthermore, IL-8 could significantly destroy the integrity of the BBB model in vitro. In mice models administered Eno for 24 h, Eno could significantly promote Evans blue (EB) moving from the blood to the brain and significantly increased the serum and brain levels of IL-8, as detected by ELISA. While G31P (IL-8 receptor antagonist) significantly decreased the concentration of EB in the brains of mice injected with Eno. The present study demonstrated that SS2 Eno may play an important role in disrupting BBB integrity by prompting IL-8 release. PMID:26732390

  18. Spatiotemporal changes in blood-brain barrier permeability, cerebral blood flow, T2 and diffusion following mild traumatic brain injury.

    Science.gov (United States)

    Li, Wei; Watts, Lora; Long, Justin; Zhou, Wei; Shen, Qiang; Jiang, Zhao; Li, Yunxia; Duong, Timothy Q

    2016-09-01

    The blood-brain barrier (BBB) can be impaired following traumatic brain injury (TBI), however the spatiotemporal dynamics of BBB leakage remain incompletely understood. In this study, we evaluated the spatiotemporal evolution of BBB permeability using dynamic contrast-enhanced MRI and measured the volume transfer coefficient (K(trans)), a quantitative measure of contrast agent leakage across the blood and extravascular compartment. Measurements were made in a controlled cortical impact (CCI) model of mild TBI in rats from 1h to 7 days following TBI. The results were compared with cerebral blood flow, T2 and diffusion MRI from the same animal. Spatially, K(trans) changes were localized to superficial cortical layers within a 1mm thickness, which was dramatically different from the changes in cerebral blood flow, T2 and diffusion, which were localized to not only the superficial layers but also to brain regions up to 2.2mm from the cortical surface. Temporally, K(trans) changes peaked at day 3, similar to CBF and ADC changes, but differed from T2 and FA, whose changes peaked on day 2. The pattern of superficial cortical layer localization of K(trans) was consistent with patterns revealed by Evans Blue extravasation. Collectively, these results suggest that BBB disruption, edema formation, blood flow disturbance and diffusion changes are related to different components of the mechanical impact, and may play different roles in determining injury progression and tissue fate processes following TBI. PMID:27208495

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

    Science.gov (United States)

    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  brain and assessing the pharmacokinetics of the compounds delivered can also be achieved by monitoring and controlling the stable cavitation emissions.

  20. Sodium butyrate exerts neuroprotective effects by restoring the blood-brain barrier in traumatic brain injury mice.

    Science.gov (United States)

    Li, Haixiao; Sun, Jing; Wang, Fangyan; Ding, Guoqiang; Chen, Wenqian; Fang, Renchi; Yao, Ye; Pang, Mengqi; Lu, Zhong-Qiu; Liu, Jiaming

    2016-07-01

    Sodium butyrate (SB) has been widely used to treat cerebral diseases. The aim of the present study is to examine the neuroprotective effects of SB on early TBI in mice and to explore the underlying mechanisms of these effects. TBI was induced using a modified weight-drop method. Neurological deficits were evaluated according to the neurological severity score (NSS), brain oedema was measured by brain water content, and blood-brain barrier (BBB) permeability was evaluated by Evans blue (EB) dye extravasation. Neuronal injury was assessed by hematoxylin and eosin (H&E) staining and Fluoro-Jade C staining. The expression of tight junction-associated proteins, such as occludin and zonula occludens-1 (ZO-1), was analysed by western blotting and immunofluorescence. Our results showed that mice subjected to TBI exhibited worsened NSS, brain oedema, neuronal damage and BBB permeability. However, these were all attenuated by SB. Moreover, SB reversed the decrease in occludin and ZO-1 expression induced by TBI. These findings suggest that SB might attenuate neurological deficits, brain oedema, neuronal change and BBB damage, as well as increase occludin and ZO-1 expression in the brain to protect against TBI. The protective effect of SB may be correlated with restoring the BBB following its impairment. PMID:27017959

  1. Intra-Blood-Brain Barrier Synthesis of Human Immunodeficiency Virus Antigen and Antibody in Humans and Chimpanzees

    Science.gov (United States)

    Goudsmit, Jaap; Epstein, Leon G.; Paul, Deborah A.; van der Helm, Hayo J.; Dawson, George J.; Asher, David M.; Yanagihara, Richard; Wolff, Axel V.; Gibbs, Clarence J.; Carleton Gajdusek, D.

    1987-06-01

    The presence of human immunodeficiency virus (HIV) antigens in cerebrospinal fluid (CSF) was associated with progressive encephalopathy in adult and pediatric patients with acquired immunodeficiency syndrome (AIDS). HIV antigen was detected in CSF from 6 of 7 AIDS patients with progressive encephalopathy. By contrast, HIV antigen, whether free or complexed, was detected in CSF from only 1 of 18 HIV antibody seropositive patients without progressive encephalopathy and from 0 of 8 experimentally infected chimpanzees without clinical signs. Intra-blood-brain barrier synthesis of HIV-specific antibody was demonstrated in the majority of patients with AIDS (9/12) or at risk for AIDS (8/13) as well as in the experimentally infected chimpanzees, indicating HIV-specific B-cell reactivity in the brain without apparent neurological signs. In 6 of 11 patients with HIV infection, antibodies synthesized in the central nervous system were directed against HIV envelope proteins. Active viral expression appears to be necessary for both the immunodeficiency and progressive encephalopathy associated with HIV infection.

  2. Feasibility Study of the Permeability and Uptake of Mesoporous Silica Nanoparticles across the Blood-Brain Barrier

    Science.gov (United States)

    Baghirov, Habib; Karaman, Didem; Viitala, Tapani; Duchanoy, Alain; Lou, Yan-Ru; Mamaeva, Veronika; Pryazhnikov, Evgeny; Khiroug, Leonard; de Lange Davies, Catharina; Sahlgren, Cecilia; Rosenholm, Jessica M.

    2016-01-01

    Drug delivery into the brain is impeded by the blood-brain-barrier (BBB) that filters out the vast majority of drugs after systemic administration. In this work, we assessed the transport, uptake and cytotoxicity of promising drug nanocarriers, mesoporous silica nanoparticles (MSNs), in in vitro models of the BBB. RBE4 rat brain endothelial cells and Madin-Darby canine kidney epithelial cells, strain II, were used as BBB models. We studied spherical and rod-shaped MSNs with the following modifications: bare MSNs and MSNs coated with a poly(ethylene glycol)-poly(ethylene imine) (PEG-PEI) block copolymer. In transport studies, MSNs showed low permeability, whereas the results of the cellular uptake studies suggest robust uptake of PEG-PEI-coated MSNs. None of the MSNs showed significant toxic effects in the cell viability studies. While the shape effect was detectable but small, especially in the real-time surface plasmon resonance measurements, coating with PEG-PEI copolymers clearly facilitated the uptake of MSNs. Finally, we evaluated the in vivo detectability of one of the best candidates, i.e. the copolymer-coated rod-shaped MSNs, by two-photon in vivo imaging in the brain vasculature. The particles were clearly detectable after intravenous injection and caused no damage to the BBB. Thus, when properly designed, the uptake of MSNs could potentially be utilized for the delivery of drugs into the brain via transcellular transport. PMID:27547955

  3. Cellular response of the blood-brain barrier to injury: Potential biomarkers and therapeutic targets for brain regeneration.

    Science.gov (United States)

    Tenreiro, M M; Ferreira, R; Bernardino, L; Brito, M A

    2016-07-01

    Endothelial cells are the main component of the blood-brain barrier (BBB), a vital structure for maintaining brain homeostasis that is seriously disrupted in various neurological pathologies. Therefore, vascular-targeted therapies may bring advantages for the prevention and treatment of brain disorders. In this sense, novel methods to identify and evaluate endothelial damage have been developed and include the detection of circulating endothelial cells, endothelial progenitor cells, endothelial microparticles and exosomes. These cells and cellular structures have been documented in numerous diseases, and increasingly in neurodegenerative disorders, which have led many to assume that they can either be possible biomarkers or tools of repair. Therefore, the purpose of this review is to discuss available data on BBB endothelial damage occurring in two pathologies of the central nervous system, Alzheimer's disease and stroke, which exemplify conditions where chronic and acute vascular damage occur, respectively. The ultimate goal is to identify useful biomarkers and/or therapeutic tools in the healthy and diseased brain that can be used for the treatment of neurodegenerative diseases where BBB permeability and integrity are impaired. PMID:26996728

  4. Ibogaine labeling with 99mTc-tricarbonyl: synthesis and transport at the mouse blood-brain barrier.

    Science.gov (United States)

    Tournier, Nicolas; André, Pascal; Blondeel, Sandy; Rizzo-Padoin, Nathalie; du Moulinet d'Hardemarre, Amaury; Declèves, Xavier; Scherrmann, Jean-Michel; Cisternino, Salvatore

    2009-12-01

    The (99m)Tc-tricarbonyl core may be used as an ideal tool for gamma-labeling ligands in noninvasive SPECT imaging. However, most (99m)Tc-tricarbonyl-labeled agents have difficulty crossing the blood-brain barrier (BBB). We radiolabeled the neuroactive indole ibogaine with (99m)Tc-tricarbonyl and measured its transport into the mouse brain by in situ brain perfusion. We measured the interactions of [(99m)Tc(CO)(3)-ibogaine](+) and (99m)Tc-tricarbonyl with the main BBB efflux transporters P-gp and BCRP in vitro and in vivo. Ibogaine was radiolabeled (yield: over 95%). [(99m)Tc(CO)(3)-ibogaine](+) entered the brain (K(in)) poorly (0.18 microL/g/s), at about the same rate as (99m)Tc-tricarbonyl (0.16 microL/g/s) and [(99m)Tc-sestamibi](+) (0.10 microL/g/s). The CNS tracer [(99m)Tc-HMPAO](0) entered the brain approximately 70-times higher than [(99m)Tc(CO)(3)-ibogaine](+). In vitro studies revealed that neither [(99m)Tc(CO)(3)-ibogaine](+) nor (99m)Tc-tricarbonyl ion were substrates for P-gp or BCRP. But lowering the membrane dipole potential barrier with phloretin enhanced the brain transport of [(99m)Tc(OH(2))(3)(CO)(3)](+) approximately 3-fold. Thus, ibogaine directly labeled with (99m)Tc-tricarbonyl is not suitable for CNS imaging because of its poor uptake. Brain transport is not restricted by efflux transporters but is reduced by its lipophilicity and interaction with the membrane-positive dipole potential. PMID:19492342

  5. Localization of Cellular Retinol-Binding Protein and Retinol-Binding Protein in Cells Comprising the Blood-Brain Barrier of Rat and Human

    Science.gov (United States)

    MacDonald, Paul N.; Bok, Dean; Ong, David E.

    1990-06-01

    Brain is not generally recognized as an organ that requiries vitamin A, perhaps because no obvious histologic lesions have been observed in severely vitamin A-deficient animals. However, brain tissue does contain cellular vitamin A-binding proteins and a nuclear receptor protein for retinoic acid. In the present study, immunohistochemical techniques were used to determine the cell-specific location of cellular retinol-binding protein in human and rat brain tissue. Cellular retinol-binding protein was localized specifically within the endothelial cells of the brain microvasculature and within the cuboidal epithelial cells of the choroid plexus, two primary sites of the mammalian blood-brain barrier. In addition, autoradiographic procedures demonstrated binding sites for serum retinol-binding protein in the choroidal epithelium. These observations suggest that a significant movement of retinol across the blood-brain barrier may occur.

  6. Localization of cellular retinol-binding protein and retinol-binding protein in cells comprising the blood-brain barrier of rat and human

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, P.N.; Ong, D.E. (Vanderbilt Univ., Nashville, TN (USA)); Bok, D. (Univ. of California, Los Angeles (USA))

    1990-06-01

    Brain is not generally recognized as an organ that requires vitamin A, perhaps because no obvious histologic lesions have been observed in severely vitamin A-deficient animals. However, brain tissue does contain cellular vitamin A-binding proteins and a nuclear receptor protein for retinoic acid. In the present study, immunohistochemical techniques were used to determine the cell-specific location of cellular retinol-binding protein in human and rat brain tissue. Cellular retinol-binding protein was localized specifically within the cuboidal epithelial cells of the choroid plexus, two primary sites of the mammalian blood-brain barrier. In addition, autoradiographic procedures demonstrated binding sites for serum retinol-binding protein in the choroidal epithelium. These observations suggest that a significant movement of retinol across the blood-brain barrier may occur.

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

    International Nuclear Information System (INIS)

    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. (author)

  8. Experimental studies on local radiation injuries of the brain as a result of sup(99m)Tc penetration through the blood-brain barrier

    Energy Technology Data Exchange (ETDEWEB)

    Zolotov, V.A.; Lomanov, M.F.; Luk' yashin, V.E.; Shimchuk, G.G.; Minakova, E.I.; Lundkvist, Kh.; Rozander, Ch. (Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Moscow. Inst. Teoreticheskoj i Ehksperimental' noj Fiziki; Akademiya Meditsinskikh Nauk SSSR, Moscow. Inst. Nevrologii)

    1982-07-01

    Studies on the blood-brain barrier have shown that disturbance of its permeability with reference to some dyes and radioactive tracers precedes histological changes found in the brain tissues. The paper is concerned with the techniques of detection of early changes in the blood-brain barrier during life-time after local irradiation of the brain with the proton beam, 5-7 mm in diameter. The use of sup(99m)Tc-pertechnate makes it possible to give a qualitative evaluation of the time course of radiation reactions in animals and to gain quite rapidly experimental data on the development of radiation injuries without killing large groups of experimental animals.

  9. Blood-Brain Barrier Disruption Caused by Ultrasound Bursts Combined with Microbubbles Depends on Anesthesia

    Science.gov (United States)

    McDannold, Nathan; Zhang, Yongzhi; Vykhodtseva, Natalia

    2011-09-01

    Prior works on BBB disruption via inter-arterial infusions of osmotic agents have shown a strong dependence on anesthesia. Here, we investigated whether different anesthesia agents can affect ultrasound-induced BBB disruption. A piston transducer fired through a rubber aperture (frequency: 532 kHz, diameter: 4 cm, aperture diameter: 16 mm) was used to generate the ultrasound fields, and sonications combined with an ultrasound contrast agent were performed at 5 power levels. BBB disruption was quantified by measuring the MRI contrast enhancement in T1-weighted MRI, and erythrocyte extravasation characterized in light microscopy. For each exposure level tested, experiments performed with ketamine/xylazine resulted in significantly greater (Panesthesia agent, possibly due effects on the vasculature. These results suggest that care is needed in comparing experiments with different anesthesia agents and physiological factors need to be considered with ultrasound-induced BBB disruption.

  10. Effect of Synthetic Matrix Metalloproteinase Inhibitors on Lipopolysaccharide-Induced Blood-Brain Barrier Opening in Rodents: Differences in Response Based on Strains and Solvents

    OpenAIRE

    Rosenberg, Gary A; Estrada, Eduardo Y.; Mobashery, Shahriar

    2006-01-01

    Matrix metalloproteinase inhibitors (MMPIs) reduce blood-brain barrier (BBB) disruption and prevent cell death. Animal models of multiple sclerosis, cerebral ischemia and hemorrhage, and bacterial meningitis respond to treatment with MMPIs. We have used the intracerebral injection of lipopolysaccharide (LPS) in rat, which induces MMP production and results in a delayed opening of the BBB, to screen MMPIs to identify therapeutic agents. We hypothesized that the mouse would respond similarly to...

  11. The interaction of carbon nanotubes with an in vitro blood-brain barrier model and mouse brain in vivo

    OpenAIRE

    Kafa, Houmam; Wang, Julie Tzu-Wen; Rubio, Noelia; Venner, Kerrie; Anderson, Glenn; Pach, Elzbieta; Ballesteros, Belén; Preston, Jane E.; Abbott, N. Joan; Al-Jamal, Khuloud T.

    2015-01-01

    Carbon nanotubes (CNTs) are a novel nanocarriers with interesting physical and chemical properties. Here we investigate the ability of amino-functionalized multi-walled carbon nanotubes (MWNTs-NH3(+)) to cross the Blood-Brain Barrier (BBB) in vitro using a co-culture BBB model comprising primary porcine brain endothelial cells (PBEC) and primary rat astrocytes, and in vivo following a systemic administration of radiolabelled f-MWNTs. Transmission Electron microscopy (TEM) confirmed that MWNTs...

  12. Temporary disruption of the blood-brain barrier by use of ultrasound and microbubbles: safety and efficacy evaluation in rhesus macaques

    OpenAIRE

    McDannold, Nathan; Arvanitis, Costas D.; Vykhodtseva, Natalia; Livingstone, Margaret S

    2012-01-01

    The blood-brain barrier (BBB) prevents entry of most drugs into the brain and is a major hurdle to the use of drugs for brain tumors and other central nervous system disorders. Work in small animals has shown that ultrasound combined with an intravenously circulating microbubble agent can temporarily permeabilize the BBB. Here, we evaluated whether this targeted drug delivery method can be applied safely, reliably, and in a controlled manner on rhesus macaques using a focused ultrasound syste...

  13. Transport of Twelve Coumarins from Angelicae Pubescentis Radix across a MDCK-pHaMDR Cell Monolayer—An in Vitro Model for Blood-Brain Barrier Permeability

    OpenAIRE

    Yan-Fang Yang; Wei Xu; Wei Song; Min Ye; Xiu-Wei Yang

    2015-01-01

    Angelicae Pubescentis Radix (APR), a widely used traditional Chinese medicine, is reported to have central nervous system activities. The purpose of this study was to characterize the blood-brain barrier permeability of twelve coumarins from APR including umbelliferone (1), osthol (2), scopoletin (3), peucedanol (4), ulopterol (5), angepubebisin (6), psoralen (7), xanthotoxin (8), bergapten (9), isoimperatorin (10), columbianadin (11), and columbianetin acetate (12) with an in vitro model usi...

  14. Toward Eradicating HIV Reservoirs in the Brain: Inhibiting P-glycoprotein at the Blood-Brain Barrier with Prodrug Abacavir Dimers

    OpenAIRE

    Namanja, Hilda A.; Emmert, Dana; Davis, David A.; Campos, Christopher; Miller, David S.; Hrycyna, Christine A.; Chmielewski, Jean

    2011-01-01

    Eradication of HIV reservoirs in the brain necessitates penetration of antiviral agents across the blood-brain barrier (BBB), a process limited by drug efflux proteins such as P-glycoprotein (P-gp) at the membrane of brain capillary endothelial cells. We present an innovative chemical strategy toward the goal of therapeutic brain penetration of the P-gp substrate and anti-viral agent abacavir, in conjunction with a traceless tether. Dimeric prodrugs of abacavir were designed to have two funct...

  15. Treatment with Sodium Orthovanadate Reduces Blood-Brain Barrier Disruption via Phosphatase and Tensin Homolog Deleted on Chromosome 10 (PTEN) Phosphorylation in Experimental Subarachnoid Hemorrhage

    OpenAIRE

    Hasegawa, Yu; Suzuki, Hidenori; Altay, Orhan; Chen, Hank; Zhang, John H.

    2011-01-01

    Attenuation of blood-brain barrier (BBB) disruption is one of the therapeutic candidates for treatment of subarachnoid hemorrhage (SAH). In this study, the protective effect of sodium orthovanadate (SOV) on BBB disruption was investigated in SAH using the endovascular perforation model. Fifty-five rats were randomly assigned to sham-operated, SAH treated with saline (as a vehicle) or 10mg/kg SOV groups, and evaluated for neurofunction and Evans blue dye extravasation. The phosphorylation of p...

  16. Cellular Apoptosis and Blood Brain Barrier Permeability Changes in the Pre-Incubated Chicken Embryo’s Brain by Effect of Electromagnetic Fields

    OpenAIRE

    Sima Kalantari; Mohammad Reza Bigdeli; Maryam Shams-Lahijani

    2015-01-01

    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 ...

  17. Targeting accuracy and closing timeline of the microbubble-enhanced focused ultrasound blood-brain barrier opening in non-human primates

    Science.gov (United States)

    Marquet, Fabrice; Tung, Yao-Sheng; Teichert, Tobias; Wu, Shih-Ying; Wang, Shutao; Downs, Matthew; Ferrera, Vincent P.; Konofagou, Elisa E.

    2012-11-01

    The delivery of drugs to specific neural targets faces two fundamental problems: Most drugs do not cross the blood-brain barrier and those that do spread to all parts of the brain. To date there exists only one non-invasive methodology with the potential to solve these problems: selective blood-brain barrier disruption using micro-bubble enhanced focused ultrasound. We have recently developed a single-element 500 kHz spherical transducer ultrasound setup for use in the non-human primate. Using this system for selective blood-brain barrier disruption is technically no more challenging than positioning a TMS coil, and does not rely on MRI-guided targeting or expensive phased array ultrasound systems. So far, however, the targeting accuracy that can be achieved with this system has not been quantified systematically. Here we tested the accuracy of the system by targeting the caudate nucleus of the basal ganglia in two macaque monkeys. Our results show that average in-plane error of the system is on the order of 2 mm and targeting error in depth, i.e., along the ultrasound path, is even smaller and averaged 1.2 mm. In summary, targeting accuracy of our system is good enough to enable the selective delivery of drugs to specific sub-structures of the basal ganglia.

  18. Chronic type 2 diabetes reduces the integrity of the blood-brain barrier by reducing tight junction proteins in the hippocampus.

    Science.gov (United States)

    Yoo, Dae Young; Yim, Hee Sun; Jung, Hyo Young; Nam, Sung Min; Kim, Jong Whi; Choi, Jung Hoon; Seong, Je Kyung; Yoon, Yeo Sung; Kim, Dae Won; Hwang, In Koo

    2016-07-01

    In the present study, we investigated the effects of type 2 diabetes-induced hyperglycemia on the integrity of the blood-brain barrier and tight junction markers in the rat hippocampus. Forty-week-old diabetic (Zucker diabetic fatty, ZDF) rats and littermate control (Zucker lean control, ZLC) rats were used in this study. We evaluated the integrity of the blood-brain barrier by measuring sodium fluorescein extravasation and blood vessel ultrastructure. In addition, tight junction markers, such as zona occludens-1, occludin and claudin-5, were quantified by western blot analysis. ZDF rats showed significantly increased sodium fluorescein leakage in the hippocampus. Tight junction markers, such as occludin and claudin-5, were significantly decreased in the hippocampi of ZDF rats compared to those of ZLC rats. In addition, ZDF rats showed ultrastructural changes with phagocytic findings in the blood vessels. These results suggest that chronic untreated diabetes impairs the permeability of the hippocampal blood-brain barrier by down-regulating occludin and claudin-5, indicating that chronic untreated diabetes may cause hippocampus-dependent dysfunction. PMID:26876499

  19. Measurement of blood-brain barrier permeation in rats during exposure to 2450-MHz microwaves

    International Nuclear Information System (INIS)

    Adult rats anesthesized with pentobarbital and injected intravenously with a mixture of [14C] sucrose and [3H] inulin were exposed for 30 min to an environment at an ambient temperature of 22, 30, or 40 degrees C, or were exposed at 22 degrees C to 2450-MHz CW microwave radiation at power densities of 0, 10, 20, or 30 mW/cm2. Following exposure, the brain was perfused and sectioned into eight regions, and the radioactivity in each region was counted. The data were analyzed by two methods. First, the data for each of the eight regions and for each of the two radioactive tracers were analyzed by regression analysis for a total of 16 analyses and Bonferroni's Inequality was applied to prevent false positive results from numerous analyses. By this conservative test, no statistically significant increase in permeation was found for either tracer in any brain region of rats exposed to microwaves. Second, a profile analysis was used for a general change in tracer uptake across all brain regions. Using this statistical method, a significant increase in permeation was found for sucrose but not for inulin. A correction factor was then derived from the warm-air experiments to correct for the increase in permeation of the brain associated with change in body temperature. This correction factor was applied to the data for the irradiated animals. After correcting the data for thermal effects of the microwave radiation, no significant increase in permeation was found

  20. The brain response to peripheral insulin declines with age: a contribution of the blood-brain barrier?

    Directory of Open Access Journals (Sweden)

    Tina Sartorius

    Full Text Available It is a matter of debate whether impaired insulin action originates from a defect at the neural level or impaired transport of the hormone into the brain. In this study, we aimed to investigate the effect of aging on insulin concentrations in the periphery and the central nervous system as well as its impact on insulin-dependent brain activity.Insulin, glucose and albumin concentrations were determined in 160 paired human serum and cerebrospinal fluid (CSF samples. Additionally, insulin was applied in young and aged mice by subcutaneous injection or intracerebroventricularly to circumvent the blood-brain barrier. Insulin action and cortical activity were assessed by Western blotting and electrocorticography radiotelemetric measurements.In humans, CSF glucose and insulin concentrations were tightly correlated with the respective serum/plasma concentrations. The CSF/serum ratio for insulin was reduced in older subjects while the CSF/serum ratio for albumin increased with age like for most other proteins. Western blot analysis in murine whole brain lysates revealed impaired phosphorylation of AKT (P-AKT in aged mice following peripheral insulin stimulation whereas P-AKT was comparable to levels in young mice after intracerebroventricular insulin application. As readout for insulin action in the brain, insulin-mediated cortical brain activity instantly increased in young mice subcutaneously injected with insulin but was significantly reduced and delayed in aged mice during the treatment period. When insulin was applied intracerebroventricularly into aged animals, brain activity was readily improved.This study discloses age-dependent changes in insulin CSF/serum ratios in humans. In the elderly, cerebral insulin resistance might be partially attributed to an impaired transport of insulin into the central nervous system.

  1. Cerebrovascular and blood-brain barrier morphology in spontaneously hypertensive rats: effect of treatment with choline alphoscerate.

    Science.gov (United States)

    Tayebati, Seyed Khosrow; Amenta, Francesco; Tomassoni, Daniele

    2015-01-01

    Cholinergic precursors increasing choline availability and acetylcholine synthesis/release may represent a therapeutic approach for countering cognitive impairment occurring in adult-onset dementia disorders. Choline alphoscerate (alpha-gliceryl-phosphoryl-choline, GPC) is among cholinergic precursors the most effective in enhancing acetylcholine biosynthesis and release in animal models. This study was designed to assess if a long-term treatment with GPC modify cerebrovascular components [perivascular astrocytes, blood-brain barrier (BBB) and microvessels] and endothelial inflammatory markers expression in spontaneously hypertensive rats (SHR) used as a model of brain vascular injury. Male SHR aged 32 weeks and age-matched normotensive Wistar-Kyoto rats were treated for 4 weeks with GPC (150 mg/kg/day) or a vehicle. Intracerebral arteries of different brain areas, perivascular astrocytes, BBB and endothelial inflammatory markers were assessed by quantitative morphological and immunohistochemical techniques. No significant changes in the size of perivascular astrocytes were observed in SHR versus normotensive Wistar-Kyoto rats, whereas the expression of the BBB marker aquaporin-4 increased in SHR. This phenomenon was countered by GPC treatment. On the contrary, GPC has no vasodilator effect on brain micro-vessels. Endothelial markers and vascular adhesion molecules expression were not homogeneously affected by hypertension and GPC treatment in intracerebral vessels. The observation that treatment with GPC reversed BBB changes and countered to some extent micro-vessels changes occurring in SHR could explain data of clinical trials reporting an improvement of cognitive function in subjects suffering from cerebrovascular disorders and treated with GPC. These preclinical data suggest that the compound could have a cerebrovascular protective effect deserving a further characterization. PMID:25714975

  2. Melatonin promotes blood-brain barrier integrity in methamphetamine-induced inflammation in primary rat brain microvascular endothelial cells.

    Science.gov (United States)

    Jumnongprakhon, Pichaya; Govitrapong, Piyarat; Tocharus, Chainarong; Tocharus, Jiraporn

    2016-09-01

    Melatonin is a neurohormone and has high potent of antioxidant that is widely reported to be active against methamphetamine (METH)-induced toxicity to neuron, glial cells, and brain endothelial cells. However, the role of melatonin on the inflammatory responses which are mostly caused by blood-brain barrier (BBB) impairment by METH administration has not been investigated. This study used the primary rat brain microvascular endothelial cells (BMVECs) to determine the protective mechanism of melatonin on METH-induced inflammatory responses in the BBB via nuclear factor-ĸB (NF-κB) and nuclear factor erythroid 2-related factor-2 (Nrf2) signaling. Herein, we demonstrated that melatonin reduced the level of the inflammatory mediators, including intercellular adhesion molecules (ICAM)-1, vascular cell adhesion molecules (VCAM)-1, matrix metallopeptidase (MMP)-9, inducible nitric oxide synthase (iNOS), and nitric oxide (NO) caused by METH. These responses were related to the decrease of the expression and translocation of the NF-κB p65 subunit and the activity of NADPH oxidase (NOX)-2. In addition, melatonin promoted the antioxidant processes, modulated the expression and translocation of Nrf2, and also increased the level of heme oxygenase (HO)-1, NAD (P) H: quinone oxidoreductase (NQO)-1, γ-glutamylcysteine synthase (γ-GCLC), and the activity of superoxide dismutase (SOD) through NOX2 mechanism. In addition, we found that the protective role of melatonin in METH-induced inflammatory responses in the BBB was mediated through melatonin receptors (MT1/2). We concluded that the interaction of melatonin with its receptor prevented METH-induced inflammatory responses by suppressing the NF-κB signaling and promoting the Nrf2 signaling before BBB impairment. PMID:27268413

  3. Pentylentetrazole-induced loss of blood-brain barrier integrity involves excess nitric oxide generation by neuronal nitric oxide synthase.

    Science.gov (United States)

    Danjo, Sonoko; Ishihara, Yasuhiro; Watanabe, Masatomo; Nakamura, Yu; Itoh, Kouichi

    2013-09-12

    Dysfunction of the blood-brain barrier (BBB) is one of the major pathophysiological consequences of epilepsy. The increase in the permeability caused by BBB failure is thought to contribute to the development of epileptic outcomes. We developed a method by which the BBB permeability can be demonstrated by gadolinium-enhanced T1 weighted imaging (GdET1WI). The present study examined the changes in the BBB permeability in mice with generalized convulsive seizures (GCS) induced by acute pentylentetrazole (PTZ) injection. At 15min after PTZ-induced GCS, the BBB temporarily leaks BBB-impermeable contrast agent into the parenchyma of the diencephalon, hippocampus and cerebral cortex in mice, and the loss of BBB integrity was gradually recovered by 24h. The temporary BBB failure is a critical link to the glutamatergic activities that occur following the injection of PTZ. PTZ activates the glutamatergic pathway via the NMDA receptor, then nitric oxide (NO) is generated by NMDA receptor-coupled neuronal NO synthase (nNOS). To examine the influence of nNOS-derived NO induced by PTZ on the increases of the BBB permeability, GdET1WI was performed using conventional nNOS gene-deficient mice with or without PTZ injection. The failure of the BBB induced by PTZ was completely protected by nNOS deficiency in the brain. These results suggest that nNOS-derived excess NO in the glutamatergic pathway plays a key role in the failure of the BBB during PTZ-induced GCS. The levels of NO synthetized by nNOS in the brain may represent an important target for the future development of drugs to protect the BBB. PMID:23831997

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

    Directory of Open Access Journals (Sweden)

    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

  5. Radiation-Induced Astrogliosis and Blood-Brain Barrier Damage Can Be Abrogated Using Anti-TNF Treatment

    International Nuclear Information System (INIS)

    Purpose: In this article, we investigate the role of tumor necrosis factor-alpha (TNF) in the initiation of acute damage to the blood-brain barrier (BBB) and brain tissue following radiotherapy (RT) for CNS tumors. Methods and Materials: Intravital microscopy and a closed cranial window technique were used to measure quantitatively BBB permeability to FITC-dextran 4.4-kDa molecules, leukocyte adhesion (Rhodamine-6G) and vessel diameters before and after 20-Gy cranial radiation with and without treatment with anti-TNF. Immunohistochemistry was used to quantify astrogliosis post-RT and immunofluorescence was used to visualize protein expression of TNF and ICAM-1 post-RT. Recombinant TNF (rTNF) was used to elucidate the role of TNF in leukocyte adhesion and vessel diameter. Results: Mice treated with anti-TNF showed significantly lower permeability and leukocyte adhesion at 24 and 48 h post-RT vs. RT-only animals. We observed a significant decrease in arteriole diameters at 48 h post-RT that was inhibited in TNF-treated animals. We also saw a significant increase in activated astrocytes following RT that was significantly lower in the anti-TNF-treated group. In addition, immunofluorescence showed protein expression of TNF and ICAM-1 in the cerebral cortex that was inhibited with anti-TNF treatment. Finally, administration of rTNF induced a decrease in arteriole diameter and a significant increase in leukocyte adhesion in venules and arterioles. Conclusions: TNF plays a significant role in acute changes in BBB permeability, leukocyte adhesion, arteriole diameter, and astrocyte activation following cranial radiation. Treatment with anti-TNF protects the brain's microvascular network from the acute damage following RT.

  6. Early outcome and blood-brain barrier integrity after co-administered thrombolysis and hyperbaric oxygenation in experimental stroke

    Directory of Open Access Journals (Sweden)

    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.

  7. Comparison of in vitro and in vivo models of drug transcytosis through the blood-brain barrier

    International Nuclear Information System (INIS)

    Drug and solute transport through in vitro and in vivo models of the blood-brain barrier (BBB) were compared to provide a measure of how well the in vitro model predicted BBB permeability found in vivo. The in vitro model employed bovine brain capillary endothelial cells in either primary tissue culture or as a continuous line grown on Transwells and placed in side-by-side diffusion chambers. The in vivo model of BBB transport utilized an internal carotid artery perfusion/capillary depletion method in anesthetized rats. BBB permeability in vivo and in vitro was measured for 15 radiolabeled drugs and for L-[3H]dopa, D-[14C]glucose and [3H]albumin. [3H]- or [14C]sucrose was used in vivo as a blood volume reference. Lipid solubility of each drug was measured based on the 1-octanol/Ringer's partition coefficient. The morphology of the endothelial cell in primary tissue culture was spindle-shaped and the morphology of the endothelial cell in continuous culture was cuboid-shaped. The cuboidal morphology demonstrated a 2-fold greater resistance to solute transport and was used for the majority of the in vitro studies. Drug and solute permeability coefficients (Pe) ranged from 3.9 X 10(-3) to 2.5 X 10(-1) cm/min in vitro and from 1.0 X 10(-5) to 2.1 X 10(-2) cm/min in vivo. The In of the permeability.surface area product in vitro correlated with the In partition coefficient (r = 0.62, P less than .0125) and the In permeability.surface area product in vivo correlated with the In partition coefficient (r = 0.84, P less than .0005)

  8. Alterations in blood-brain barrier ICAM-1 expression and brain microglial activation after λ-carrageenan-induced inflammatory pain

    Science.gov (United States)

    Huber, J. D.; Campos, C. R.; Mark, K. S.; Davis, T. P.

    2014-01-01

    Previous studies showed that peripheral inflammatory pain increased blood-brain barrier (BBB) permeability and altered tight junction protein expression and the delivery of opioid analgesics to the brain. What remains unknown is which pathways and mediators during peripheral inflammation affect BBB function and structure. The current study investigated effects of λ-carrageenan-induced inflammatory pain (CIP) on BBB expression of ICAM-1. We also examined the systemic contribution of a number of proinflammatory cytokines and microglial activation in the brain to elucidate pathways involved in BBB disruption during CIP. We investigated ICAM-1 RNA and protein expression levels in isolated rat brain microvessels after CIP using RT-PCR and Western blot analyses, screened inflammatory cytokines during the time course of inflammation, assessed white blood cell counts, and probed for BBB and central nervous system stimulation and leukocyte transmigration using immunohistochemistry and flow cytometry. Results showed an early increase in ICAM-1 RNA and protein expression after CIP with no change in circulating levels of several proinflammatory cytokines. Changes in ICAM-1 protein expression were noted at 48 h. Immunohistochemistry showed that the induction of ICAM-1 was region specific with increased expression noted in the thalamus and frontal and parietal cortices, which directly correlated with increased expression of activated microglia. The findings of the present study were that CIP induces increased ICAM-1 mRNA and protein expression at the BBB and that systemic proinflammatory mediators play no apparent role in the early response (1–6 h); however, brain region-specific increases in micro-glial activation suggest a potential for a central-mediated response. PMID:16199477

  9. Trans-blood brain barrier delivery of dopamine-loaded nanoparticles reverses functional deficits in parkinsonian rats.

    Science.gov (United States)

    Pahuja, Richa; Seth, Kavita; Shukla, Anshi; Shukla, Rajendra Kumar; Bhatnagar, Priyanka; Chauhan, Lalit Kumar Singh; Saxena, Prem Narain; Arun, Jharna; Chaudhari, Bhushan Pradosh; Patel, Devendra Kumar; Singh, Sheelendra Pratap; Shukla, Rakesh; Khanna, Vinay Kumar; Kumar, Pradeep; Chaturvedi, Rajnish Kumar; Gupta, Kailash Chand

    2015-05-26

    Sustained and safe delivery of dopamine across the blood brain barrier (BBB) is a major hurdle for successful therapy in Parkinson's disease (PD), a neurodegenerative disorder. Therefore, in the present study we designed neurotransmitter dopamine-loaded PLGA nanoparticles (DA NPs) to deliver dopamine to the brain. These nanoparticles slowly and constantly released dopamine, showed reduced clearance of dopamine in plasma, reduced quinone adduct formation, and decreased dopamine autoxidation. DA NPs were internalized in dopaminergic SH-SY5Y cells and dopaminergic neurons in the substantia nigra and striatum, regions affected in PD. Treatment with DA NPs did not cause reduction in cell viability and morphological deterioration in SH-SY5Y, as compared to bulk dopamine-treated cells, which showed reduced viability. Herein, we report that these NPs were able to cross the BBB and capillary endothelium in the striatum and substantia nigra in a 6-hydroxydopamine (6-OHDA)-induced rat model of PD. Systemic intravenous administration of DA NPs caused significantly increased levels of dopamine and its metabolites and reduced dopamine-D2 receptor supersensitivity in the striatum of parkinsonian rats. Further, DA NPs significantly recovered neurobehavioral abnormalities in 6-OHDA-induced parkinsonian rats. Dopamine delivered through NPs did not cause additional generation of ROS, dopaminergic neuron degeneration, and ultrastructural changes in the striatum and substantia nigra as compared to 6-OHDA-lesioned rats. Interestingly, dopamine delivery through nanoformulation neither caused alterations in the heart rate and blood pressure nor showed any abrupt pathological change in the brain and other peripheral organs. These results suggest that NPs delivered dopamine into the brain, reduced dopamine autoxidation-mediated toxicity, and ultimately reversed neurochemical and neurobehavioral deficits in parkinsonian rats. PMID:25825926

  10. 7.0-T magnetic resonance imaging characterization of acute blood-brain-barrier disruption achieved with intracranial irreversible electroporation.

    Directory of Open Access Journals (Sweden)

    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.

  11. Role of nitric oxide synthases in early blood-brain barrier disruption following transient focal cerebral ischemia.

    Directory of Open Access Journals (Sweden)

    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.

  12. Omega-3 polyunsaturated fatty acids mitigate blood-brain barrier disruption after hypoxic-ischemic brain injury.

    Science.gov (United States)

    Zhang, Wenting; Zhang, Hui; Mu, Hongfeng; Zhu, Wen; Jiang, Xiaoyan; Hu, Xiaoming; Shi, Yejie; Leak, Rehana K; Dong, Qiang; Chen, Jun; Gao, Yanqin

    2016-07-01

    Omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been shown to protect the neonatal brain against hypoxic/ischemic (H/I) injury. However, the mechanism of n-3 PUFA-afforded neuroprotection is not well understood. One major determinant of H/I vulnerability is the permeability of the blood-brain barrier (BBB). Therefore, we examined the effects of n-3 PUFAs on BBB integrity after neonatal H/I. Female rats were fed a diet with or without n-3 PUFA enrichment from day 2 of pregnancy to 14days after parturition. H/I was introduced in 7day-old offspring. We observed relatively rapid BBB penetration of the small molecule cadaverine (640Da) at 4h post-H/I and a delayed penetration of larger dextrans (3kD-40kD) 24-48h after injury. Surprisingly, the neonatal BBB was impermeable to Evans Blue or 70kD dextran leakage for up to 48h post-H/I, despite evidence of IgG extravasation at this time. As expected, n-3 PUFAs ameliorated H/I-induced BBB damage, as shown by reductions in tracer efflux and IgG extravasation, preservation of BBB ultrastructure, and enhanced tight junction protein expression. Furthermore, n-3 PUFAs prevented the elevation in matrix metalloproteinase (MMP) activity in the brain and blood after H/I. Thus, n-3 PUFAs may protect neonates against BBB damage by blunting MMPs activation after H/I. PMID:26921472

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

    Science.gov (United States)

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

    2014-02-01

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

  14. Transport of Twelve Coumarins from Angelicae Pubescentis Radix across a MDCK-pHaMDR Cell Monolayer-An in Vitro Model for Blood-Brain Barrier Permeability.

    Science.gov (United States)

    Yang, Yan-Fang; Xu, Wei; Song, Wei; Ye, Min; Yang, Xiu-Wei

    2015-01-01

    Angelicae Pubescentis Radix (APR), a widely used traditional Chinese medicine, is reported to have central nervous system activities. The purpose of this study was to characterize the blood-brain barrier permeability of twelve coumarins from APR including umbelliferone (1), osthol (2), scopoletin (3), peucedanol (4), ulopterol (5), angepubebisin (6), psoralen (7), xanthotoxin (8), bergapten (9), isoimperatorin (10), columbianadin (11), and columbianetin acetate (12) with an in vitro model using a MDCK-pHaMDR cell monolayer. The cell monolayer was validated to be suitable for the permeation experiments. The samples' transports were analyzed by high performance liquid chromatography and their apparent permeability coefficients (Papp) were calculated. According to the Papp value, most coumarins could be characterized as well-absorbed compounds except for 4, 10 and 11 which were moderately absorbed ones, in concentration-dependent and time-dependent manners. The results of P-glycoprotein (P-gp) inhibitor (verapamil) experiments showed that the transport of coumarin 4 was affected by the transport protein P-gp. Sigmoid functions between permeability log(Papp AP-BL*MW0.5) and log D (at pH 7.4) were established to analyze the structure-activity relationship of coumarins. The results provide useful information for discovering the substance basis for the central nervous system activities of APR, and predicting the permeability of other coumarins through BBB. PMID:26121397

  15. Transport of Twelve Coumarins from Angelicae Pubescentis Radix across a MDCK-pHaMDR Cell Monolayer—An in Vitro Model for Blood-Brain Barrier Permeability

    Directory of Open Access Journals (Sweden)

    Yan-Fang Yang

    2015-06-01

    Full Text Available Angelicae Pubescentis Radix (APR, a widely used traditional Chinese medicine, is reported to have central nervous system activities. The purpose of this study was to characterize the blood-brain barrier permeability of twelve coumarins from APR including umbelliferone (1, osthol (2, scopoletin (3, peucedanol (4, ulopterol (5, angepubebisin (6, psoralen (7, xanthotoxin (8, bergapten (9, isoimperatorin (10, columbianadin (11, and columbianetin acetate (12 with an in vitro model using a MDCK-pHaMDR cell monolayer. The cell monolayer was validated to be suitable for the permeation experiments. The samples’ transports were analyzed by high performance liquid chromatography and their apparent permeability coefficients (Papp were calculated. According to the Papp value, most coumarins could be characterized as well-absorbed compounds except for 4, 10 and 11 which were moderately absorbed ones, in concentration-dependent and time-dependent manners. The results of P-glycoprotein (P-gp inhibitor (verapamil experiments showed that the transport of coumarin 4 was affected by the transport protein P-gp. Sigmoid functions between permeability log(Papp AP-BL*MW0.5 and log D (at pH 7.4 were established to analyze the structure-activity relationship of coumarins. The results provide useful information for discovering the substance basis for the central nervous system activities of APR, and predicting the permeability of other coumarins through BBB.

  16. Enhanced delivery of iodine for synchrotron stereotactic radiotherapy by means of intracarotid injection and blood-brain barrier disruption: Quantitative iodine biodistribution studies and associated dosimetry

    International Nuclear Information System (INIS)

    Purpose: Synchrotron stereotactic radiotherapy (SSR) is a binary cancer treatment modality that involves the selective accumulation of a high Z element, such as iodine, in tumors, followed by stereotactic irradiation with kilovoltage X-rays from a synchrotron source. The success of SSR is directly related to the absolute amount of iodine achievable in the tumor. The purposes of this preclinical study were to determine whether the delivery of iodine to brain tumor models in rats could be enhanced by the means of its intracarotid injection with or without a hyperosmotic solution and to evaluate corresponding absorbed X-ray doses. Methods and materials: Experiments were performed on four groups of F98 glioma-bearing rats, which received either intracarotid (IC) or intravenous (IV) infusions of a mixture (6 mL in 12 min) of an iodinated contrast agent associated or not with a transient blood-brain barrier opener (mannitol). The mixture volumetric proportions were 8/13 of Iomeron (C = 350 mg/mL) for 5/13 of mannitol or saline, respectively. Absolute iodine concentration kinetic was measured in vivo in the tumor, blood, contralateral and ipsilateral brain, and muscle by monochromatic computed tomography. Associated dosimetry was performed by computing the iodine dose enhancement factor (DEF) in each region and building dose distribution maps by analytical simulations. Results: Infusion of mannitol significantly enhanced iodine tumor uptake compared with the control values (p < 0.0001 and p = 0.0138, for IC and IV protocols, respectively). The mean iodine concentrations (C) reached 20.5 ± 0.98 mg/mL (DEF = 4.1) after administration of iodine and mannitol vs. 4.1 ± 1.2 mg/mL i.c. with serum (DEF = 1.6). The tumor iodine uptakes after jugular injection with mannitol (C = 4.4 ± 2.1 mg/mL, DEF = 1.7) were not significantly different from IC injection of iodine without mannitol (p = 0.8142). The IV injection of iodine with saline led to an iodine concentration in the tumor

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

    Directory of Open Access Journals (Sweden)

    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. Reduced permeation of 14C-sucrose, 3H-mannitol and 3H-inulin across blood-brain barrier in nephrectomized rats

    International Nuclear Information System (INIS)

    Experiments were carried out to determine if changes in the concentration-time profile of a blood-borne radiotracer such as 14C-sucrose would spuriously alter measurements of its permeation across the blood-brain barrier (permeability-area product, PA) based on a 2-compartment (plasma/brain) simple diffusion model. Anesthetized rats which were bilaterally nephrectomized and given a standard intravenous bolus injection of 14C-sucrose, 3H-mannitol or 3H-inulin exhibited an elevated plasma tracer concentration compared to control animals. However, tracer concentration measured in brain parenchyma after 30 min was not proportionally elevated, and PA calculated from the ratio, parenchymal tracer concentration: plasma concentration-time integral, was significantly reduced below control values. In control rats, distortion and elevation of the plasma 14C-sucrose profile by continuous intravenous infusion did not result in lowered PA values. This suggested that the lowering of PA by nephrectomy reflected reduced cerebrovascular permeability or area or other cerebral influence rather than a deficiency in the 2-compartment model for PA measurement

  19. 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.

  20. A method to predict different mechanisms for blood-brain barrier permeability of CNS activity compounds in Chinese herbs using support vector machine.

    Science.gov (United States)

    Jiang, Ludi; Chen, Jiahua; He, Yusu; Zhang, Yanling; Li, Gongyu

    2016-02-01

    The blood-brain barrier (BBB), a highly selective barrier between central nervous system (CNS) and the blood stream, restricts and regulates the penetration of compounds from the blood into the brain. Drugs that affect the CNS interact with the BBB prior to their target site, so the prediction research on BBB permeability is a fundamental and significant research direction in neuropharmacology. In this study, we combed through the available data and then with the help of support vector machine (SVM), we established an experiment process for discovering potential CNS compounds and investigating the mechanisms of BBB permeability of them to advance the research in this field four types of prediction models, referring to CNS activity, BBB permeability, passive diffusion and efflux transport, were obtained in the experiment process. The first two models were used to discover compounds which may have CNS activity and also cross the BBB at the same time; the latter two were used to elucidate the mechanism of BBB permeability of those compounds. Three optimization parameter methods, Grid Search, Genetic Algorithm (GA), and Particle Swarm Optimization (PSO), were used to optimize the SVM models. Then, four optimal models were selected with excellent evaluation indexes (the accuracy, sensitivity and specificity of each model were all above 85%). Furthermore, discrimination models were utilized to study the BBB properties of the known CNS activity compounds in Chinese herbs and this may guide the CNS drug development. With the relatively systematic and quick approach, the application rationality of traditional Chinese medicines for treating nervous system disease in the clinical practice will be improved. PMID:26632324

  1. Vitamin D prevents hypoxia/reoxygenation-induced blood-brain barrier disruption via vitamin D receptor-mediated NF-kB signaling pathways.

    Science.gov (United States)

    Won, Soonmi; Sayeed, Iqbal; Peterson, Bethany L; Wali, Bushra; Kahn, Jared S; Stein, Donald G

    2015-01-01

    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(OH)2D3 (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(OH)2D3 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(OH)2D3 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. PMID:25815722

  2. Inhibition of Leptin-ObR Interaction Does not Prevent Leptin Translocation Across a Human Blood-Brain Barrier Model.

    Science.gov (United States)

    Gonzalez-Carter, D; Goode, A E; Fiammengo, R; Dunlop, I E; Dexter, D T; Porter, A E

    2016-06-01

    The adipocyte-derived hormone leptin regulates appetite and energy homeostasis through the activation of leptin receptors (ObR) on hypothalamic neurones; hence, leptin must be transported through the blood-brain barrier (BBB) to reach its target sites in the central nervous system. During obesity, however, leptin BBB transport is decreased, in part precluding leptin as a viable clinical therapy against obesity. Although the short isoform of the ObR (ObRa) has been implicated in the transport of leptin across the BBB as a result of its elevated expression in cerebral microvessels, accumulating evidence indicates that leptin BBB transport is independent of ObRa. In the present study, we employed an ObR-neutralising antibody (9F8) to directly examine the involvement of endothelial ObR in leptin transport across an in vitro human BBB model composed of the human endothelial cell line hCMEC/D3. Our results indicate that, although leptin transport across the endothelial monolayer was nonparacellular, and energy- and endocytosis-dependent, it was not inhibited by pre-treatment with 9F8, despite the ability of the latter to recognise hCMEC/D3-expressed ObR, prevent leptin-ObR binding and inhibit leptin-induced signal transducer and activator of transcription 3 (STAT-3) phosphorylation in hCMEC/D3 cells. Furthermore, hCMEC/D3 cells expressed the transporter protein low-density lipoprotein receptor-related protein-2 (LRP-2), which is capable of binding and endocytosing leptin. In conclusion, our results demonstrate that leptin binding to and signalling through ObR is not required for efficient transport across human endothelial monolayers, indicating that ObR is not the primary leptin transporter at the human BBB, a role which may fall upon LRP-2. A deeper understanding of leptin BBB transport will help clarify the exact causes for leptin resistance seen in obesity and aid in the development of more efficient BBB-penetrating leptin analogues. PMID:27037668

  3. Study of cellular retention of HMPAO and ECD in a model simulating the blood-brain barrier

    International Nuclear Information System (INIS)

    The HMPAO and ECD are two technetium-labelled lipophilic agents clinically used in the imagery of cerebral perfusion. These molecules cross the membranes and are retained inside the cell after being converted to a hydrophilic form. The aim of this study is to establish the distribution of this retention at the level of blood-brain barrier (BBB) and nerve cells. The incorporation of HMPAO or ECD was studied on a model of co-culture simulating the BBB by means of a T84 single-cell layer of tight junction separated from another layer of U373 astrocyte cells. The cell quality and tight junction permeability were evaluated by the cellular retention of 111-indium chloride and by para-cellular diffusion of 14C mannitol,d-1. The values reported below were obtained at 180 minutes when the radiotracers were added near the 'T84 layer'. The cell quality is validated by the low cellular retention of the indium chloride(2.3±0.3 μg-1 for the T84 cells and 8.2±5.8 μg-1 for the U373 cells). The activity of 14C mannitol,d-1 diminishes by 23 ± 5 % in the added compartment. The retention of ECD by the U373 cells is significantly higher (20.7 ±4.5 g-1) than that of T84 cells (2.9 ± 0.2 μg-1). For HMPAO a non-significant tendency could be observed (49 ± 34 μg-1 for the U373 cells and 38 ± 25 μg-1 for the T84 cells)> The results of cellular retention of indium by HMPAO or ECD when added near 'U373 layer' are not significantly different.In conclusion, independently of the side exposed to the radiotracers, one observes an enhanced incorporation of the U373 cells. The ensemble of these results represent additional arguments in favour of a specific cellular incorporation of the radiotracers, independent of the BBB permittivity

  4. Protective Effect of Angiopoietin-1 on the Blood Brain Barrier after Focal Cerebral IschemiaReperfusion Injury in Rats

    Directory of Open Access Journals (Sweden)

    Xuan GAO

    2015-03-01

    Full Text Available Objective: To observe the protective effect of angiopoietin-1 (Ang-1 on the blood brain barrier (BBB after focal cerebral ischemia-reperfusion injury (CIRI in rats. Methods: Forty male healthy Wister rats were selected. The focal CIRI models were established using middle cerebral artery occlusion and 30 rats were divided into sham-operation group (n=10, normal saline group (NS group (n=10 and Ang-1 treatment group (n=10. The rats were killed 48 h after reperfusion, and brain water content, BBB permeability, cerebral infarction volume and neurological severity scores in rats were detected respectively. Results: 48 h after reperfusion, both the brain water content and Evans blue (EB content in Ang-1 treatment group were significantly lower than in NS control [(68.69±4.46 % vs. (79.08±4.12 %, P<0.001; (98.60±10.56 μg/g vs. (379.90±21.64 μg/g, P<0.001], and there was no statistical significance by comparison to those in sham-operation group [(65.37±3.28 %; (89.62±8.65 μg/g, P>0.05]. The cerebral infarction volume in Ang-1 treatment group was markedly smaller than in NS group [(0.119±0.022 cm3 vs. (0.407±0.036 cm3, P<0.001], and no significant difference was presented when compared with sham-operation group [(0.104±0.011 cm3, P>0.05]. Besides, the neurological severity scores in Ang-1 treatment group were notably lower than in NS group [(1.83±0.29 points vs. (2.87±0.34 points, P<0.001], but higher than in sham-operation group [(0.79±0.11 points, P<0.001]. Conclusion: Ang-1 can decrease BBB permeability after focal CIRI in rats, so it has a protective effect on CIRI.

  5. A hematopoietic contribution to microhemorrhage formation during antiviral CD8 T cell-initiated blood-brain barrier disruption

    Directory of Open Access Journals (Sweden)

    Johnson Holly L

    2012-03-01

    Full Text Available Abstract Background The extent to which susceptibility to brain hemorrhage is derived from blood-derived factors or stromal tissue remains largely unknown. We have developed an inducible model of CD8 T cell-initiated blood-brain barrier (BBB disruption using a variation of the Theiler's murine encephalomyelitis virus (TMEV model of multiple sclerosis. This peptide-induced fatal syndrome (PIFS model results in severe central nervous system (CNS vascular permeability and death in the C57BL/6 mouse strain, but not in the 129 SvIm mouse strain, despite the two strains' having indistinguishable CD8 T-cell responses. Therefore, we hypothesize that hematopoietic factors contribute to susceptibility to brain hemorrhage, CNS vascular permeability and death following induction of PIFS. Methods PIFS was induced by intravenous injection of VP2121-130 peptide at 7 days post-TMEV infection. We then investigated brain inflammation, astrocyte activation, vascular permeability, functional deficit and microhemorrhage formation using T2*-weighted magnetic resonance imaging (MRI in C57BL/6 and 129 SvIm mice. To investigate the contribution of hematopoietic cells in this model, hemorrhage-resistant 129 SvIm mice were reconstituted with C57BL/6 or autologous 129 SvIm bone marrow. Gadolinium-enhanced, T1-weighted MRI was used to visualize the extent of CNS vascular permeability after bone marrow transfer. Results C57BL/6 and 129 SvIm mice had similar inflammation in the CNS during acute infection. After administration of VP2121-130 peptide, however, C57BL/6 mice had increased astrocyte activation, CNS vascular permeability, microhemorrhage formation and functional deficits compared to 129 SvIm mice. The 129 SvIm mice reconstituted with C57BL/6 but not autologous bone marrow had increased microhemorrhage formation as measured by T2*-weighted MRI, exhibited a profound increase in CNS vascular permeability as measured by three-dimensional volumetric analysis of

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

    Directory of Open Access Journals (Sweden)

    Wu Hsin-Chieh

    2011-04-01

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

  7. Hydrogen Sulfide Ameliorates Homocysteine-Induced Alzheimer's Disease-Like Pathology, Blood-Brain Barrier Disruption, and Synaptic Disorder.

    Science.gov (United States)

    Kamat, Pradip K; Kyles, Philip; Kalani, Anuradha; Tyagi, Neetu

    2016-05-01

    Elevated plasma total homocysteine (Hcy) level is associated with an increased risk of Alzheimer's disease (AD). During transsulfuration pathways, Hcy is metabolized into hydrogen sulfide (H2S), which is a synaptic modulator, as well as a neuro-protective agent. However, the role of hydrogen sulfide, as well as N-methyl-D-aspartate receptor (NMDAR) activation, in hyperhomocysteinemia (HHcy) induced blood-brain barrier (BBB) disruption and synaptic dysfunction, leading to AD pathology is not clear. Therefore, we hypothesized that the inhibition of neuronal NMDA-R by H2S and MK801 mitigate the Hcy-induced BBB disruption and synapse dysfunction, in part by decreasing neuronal matrix degradation. Hcy intracerebral (IC) treatment significantly impaired cerebral blood flow (CBF), and cerebral circulation and memory function. Hcy treatment also decreases the expression of cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE) in the brain along with increased expression of NMDA-R (NR1) and synaptosomal Ca(2+) indicating excitotoxicity. Additionally, we found that Hcy treatment increased protein and mRNA expression of intracellular adhesion molecule 1 (ICAM-1), matrix metalloproteinase (MMP)-2, and MMP-9 and also increased MMP-2 and MMP-9 activity in the brain. The increased expression of ICAM-1, glial fibrillary acidic protein (GFAP), and the decreased expression of vascular endothelial (VE)-cadherin and claudin-5 indicates BBB disruption and vascular inflammation. Moreover, we also found decreased expression of microtubule-associated protein 2 (MAP-2), postsynaptic density protein 95 (PSD-95), synapse-associated protein 97 (SAP-97), synaptosomal-associated protein 25 (SNAP-25), synaptophysin, and brain-derived neurotrophic factor (BDNF) showing synapse dysfunction in the hippocampus. Furthermore, NaHS and MK801 treatment ameliorates BBB disruption, CBF, and synapse functions in the mice brain. These results demonstrate a neuro-protective effect of H2S over Hcy

  8. 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

  9. The safest parameters for FUS-induced blood-brain barrier opening without effects on the opening volume

    Science.gov (United States)

    Tung, Yao-Sheng; Olumolade, Yemi; Wang, Shutao; Wu, Shih-Ying; Konofagou, Elisa E.

    2012-11-01

    Acoustic cavitation has been identified as the main physical mechanism for the focused ultrasound (FUS) induced blood-brain barrier (BBB) opening. In this paper, the mechanism of stable cavitation (SC) and inertial cavitation (IC) responsible for BBB opening was investigated. Thirty-three (n=33) mice were intravenously injected with bubbles of 4-5 μm in diameter. The right hippocampus was then sonicated using focused 1.5-MHz ultrasound and three different studies were carried out. First, pulse lengths (PLs) of 0.1, 0.5, 2, and 5 ms at 0.18- MPa peak rarefactional pressure with 5-Hz pulse repetition frequency (PRF) and 5-minute duration were used to identify the threshold of PL using SC. Second, the effects of the duty cycle and exposure time were investigated. Third, the BBB opening size was compared between the SC and the IC. In the case of IC-induced BBB opening, a burst sequence (3-cycles PL; 5-Hz burst repetition frequency (BRF); 30 s duration) at 0.45 MPa was applied. Passive cavitation detection was performed with each sonication to detect whether a broadband response was obtained, i.e., if IC occurred, during BBB opening. The properties of BBB opening were measured through MRI. The threshold of PL for BBB opening was identified between 0.1 and 0.5 ms using SC, but the BBB can be opened in few cycles using IC. The BBB opening volume and normalized intensity increased with the PL, but reached saturation when the PL was above 2 ms. Once the PL threshold was reached, the same exposure time induced a similar BBB opening volume, but longer sonication duration induced higher MR intensity. The duty cycle was found not to play an important role on the BBB opening. Comparable BBB opening volume (20-25 mm3) could be reached between long PL (7500 cycles, i.e., 5 ms) at 0.18 MPa and 3 cycles at 0.45 MPa. 3-kDa fluorescently tagged dextran may be able to diffuse to the parenchyma after IC-induced BBB opening at 0.45 MPa but not after SC-induced BBB opening at 0.18 MPa.

  10. Apolipoprotein E Regulates the Integrity of Tight Junctions in an Isoform-dependent Manner in an in Vitro Blood-Brain Barrier Model*

    OpenAIRE

    Nishitsuji, Kazuchika; Hosono, Takashi; Nakamura, Toshiyuki; Bu, Guojun; Michikawa, Makoto

    2011-01-01

    Apolipoprotein E (apoE) is a major apolipoprotein in the brain. The ϵ4 allele of apoE is a major risk factor for Alzheimer disease, and apoE deficiency in mice leads to blood-brain barrier (BBB) leakage. However, the effect of apoE isoforms on BBB properties are as yet unknown. Here, using an in vitro BBB model consisting of brain endothelial cells and pericytes prepared from wild-type (WT) mice, and primary astrocytes prepared from human apoE3- and apoE4-knock-in mice, we show that the barri...

  11. Diesel exhaust particles induce oxidative stress, proinflammatory signaling, and P-glycoprotein up-regulation at the blood-brain barrier

    OpenAIRE

    Hartz, Anika M.S.; Bauer, Björn; Block, Michelle L.; Hong, Jau-Shyong; Miller, David S.

    2008-01-01

    Here, we report that diesel exhaust particles (DEPs), a major constituent of urban air pollution, affect blood-brain barrier function at the tissue, cellular, and molecular levels. Isolated rat brain capillaries exposed to DEPs showed increased expression and transport activity of the key drug efflux transporter, P-glycoprotein (6 h EC50 was ∼5 μg/ml). Up-regulation of P-glycoprotein was abolished by blocking transcription or protein synthesis. Inhibition of NADPH oxidase or pretreatment of c...

  12. Changes in blood-brain barrier permeability and expression of related factors in a rat model of intracerebral hemorrhage following minocycline treatment

    Institute of Scientific and Technical Information of China (English)

    Wei Shi; Zizhang Wang; Jingnan Pu; Ruizhi Wang; Zhenyu Guo; Chongxiao Liu; Jianjun Sun; Ligui Gao; Ren Zhou

    2010-01-01

    Inflammatory factor aggregation and blood-brain barrier(BBB)damage occur around hematoma foci following intracerebral hemorrhage.Minocycline is lipophilic,can pass through the BBB,and shows anti-inflammatory effects in models of central nervous system disease.We found that minocycline application at 6 hours after intracerebral hemorrhage reduced BBB permeability,decreased vascular endothelial growth factor expression,and increased nerve growth factor and heat shock protein 70 expression,primarily in neurons and microglia.Early intraperitoneal injection of minocycline attenuated BBB damage possibly by reducing vascular endothelial growth factor expression and enhancing nerve growth factor and heat shock protein 70 expression.

  13. 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...... endothelial 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...

  14. 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; Jensen, M; Henriksen, O; Paulson, O B

    1990-01-01

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

  15. Blood-brain barrier permeability to manganese and to Gd-DOTA in a rat model of transient cerebral ischaemia. : BBB permeability after transient cerebral ischemia

    OpenAIRE

    Grillon, Emmanuelle; Provent, Peggy; Montigon, Olivier; Segebarth, Christoph; Rémy, Chantal; Barbier, Emmanuel

    2008-01-01

    Loss of integrity of the blood-brain barrier (BBB) and brain swelling is a potentially lethal complication of reperfusion in human stroke. To assess the time course of BBB modifications, we performed angiography, diffusion-weighted imaging, T1-weighted (T1 W) imaging and T1 mapping, and monitored acute changes after middle cerebral artery occlusion and recanalization in rats (n = 27). The animals were grouped according to the duration of occlusion: 30 min (group A, n = 8), 1 h 30 min (group B...

  16. 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

  17. Development of a blood-brain barrier model in a membrane-based microchip for characterization of drug permeability and cytotoxicity for drug screening.

    Science.gov (United States)

    Shao, Xiaojian; Gao, Dan; Chen, Yongli; Jin, Feng; Hu, Guangnan; Jiang, Yuyang; Liu, Hongxia

    2016-08-31

    Since most of the central nervous system (CNS) drug candidates show poor permeability across the blood-brain barrier (BBB), development of a reliable platform for permeability assay will greatly accelerate drug discovery. Herein, we constructed a microfluidic BBB model to mimic drug delivery into the brain to induce cytotoxicity at target cells. To reconstitute the in vivo BBB properties, human cerebral microvessel endothelial cells (hCMEC/D3) were dynamically cultured in a membrane-based microchannel. Sunitinib, a model drug, was then delivered into the microchannel and forced to permeate through the BBB model. The permeated amount was directly quantified by an electrospray ionization quadrupole time-of-flight mass spectrometer (ESI-Q-TOF MS) after on-chip SPE (μSPE) pretreatment. Moreover, the permeated drug was incubated with glioma cells (U251) cultured inside agarose gel in the downstream to investigate drug-induced cytotoxicity. The resultant permeability of sunitinib was highly correlated with literature reported value, and it only required 30 min and 5 μL of sample solution for each permeation experiment. Moreover, after 48 h of treatment, the survival rate of U251 cells cultured in 3D scaffolds was nearly 6% higher than that in 2D, which was in accordance with the previously reported results. These results demonstrate that this platform provides a valid tool for drug permeability and cytotoxicity assays which have great value for the research and development of CNS drugs. PMID:27506359

  18. The Blood-Brain Barrier Permeability of Lignans and Malabaricones from the Seeds of Myristica fragrans in the MDCK-pHaMDR Cell Monolayer Model

    Directory of Open Access Journals (Sweden)

    Ni Wu

    2016-01-01

    Full Text Available The blood-brain barrier (BBB permeability of twelve lignans and three phenolic malabaricones from the seeds of Myristica fragrans (nutmeg were studied with the MDCK-pHaMDR cell monolayer model. The samples were measured by high-performance liquid chromatography and the apparent permeability coefficients (Papp were calculated. Among the fifteen test compounds, benzonfuran-type, dibenzylbutane-type and arylnaphthalene-type lignans showed poor to moderate permeabilities with Papp values at 10−8–10−6 cm/s; those of 8-O-4′-neolignan and tetrahydrofuran-lignan were at 10−6–10−5 cm/s, meaning that their permeabilities are moderate to high; the permeabilities of malabaricones were poor as their Papp values were at 10−8–10−7 cm/s. To 5-methoxy-dehydrodiisoeugenol (2, erythro-2-(4-allyl-2,6-dimethoxyphenoxy-1-(3,4-dimethoxyphenyl-propan-1-ol acetate (6, verrucosin (8, and nectandrin B (9, an efflux way was involved and the main transporter for 6, 8 and 9 was demonstrated to be P-glycoprotein. The time and concentration dependency experiments indicated the main transport mechanism for neolignans dehydrodiisoeugenol (1, myrislignan (7 and 8 was passive diffusion. This study summarized the relationship between the BBB permeability and structure parameters of the test compounds, which could be used to preliminarily predict the transport of a compound through BBB. The results provide a significant molecular basis for better understanding the potential central nervous system effects of nutmeg.

  19. 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.

  20. 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. PMID:25160672

  1. 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.

  2. Synthesis and deposition of basement membrane proteins by primary brain capillary endothelial cells in a murine model of the blood-brain barrier

    DEFF Research Database (Denmark)

    Thomsen, Maj Schneider; Birkelund, Svend; Burkhart, Annette;

    2016-01-01

    The brain vascular basement membrane is important for both blood-brain barrier (BBB) development, stability, and barrier integrity and the contribution hereto from brain capillary endothelial cells (BCECs), pericytes, and astrocytes of the BBB is probably significant. The aim of the present study......-culture, in co-culture with pericytes or mixed glial cells, or as a triple-culture with both pericytes and mixed glial cells. The integrity of the BBB models was validated by measures of transendothelial electrical resistance (TEER) and passive permeability to mannitol. The expression of basement membrane...... proteins was analysed using RT-qPCR, mass spectrometry, and immunocytochemistry. Co-culturing mBCECs with pericytes, mixed glial cells, or both significantly increased the TEER compared to the mono-culture, and a low passive permeability was correlated with high TEER. The mBCECs expressed all major...

  3. 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

  4. A three-dimensional model of the human blood-brain barrier to analyse the transport of nanoparticles and astrocyte/endothelial interactions [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Peddagangannagari Sreekanthreddy

    2016-01-01

    Full Text Available The aim of this study was to develop a three-dimensional (3D model of the human blood-brain barrier in vitro, which mimics the cellular architecture of the CNS and could be used to analyse the delivery of nanoparticles to cells of the CNS. The model includes human astrocytes set in a collagen gel, which is overlaid by a monolayer of human brain endothelium (hCMEC/D3 cell line. The model was characterised by transmission electron microscopy (TEM, immunofluorescence microscopy and flow cytometry. A collagenase digestion method could recover the two cell types separately at 92-96% purity.  Astrocytes grown in the gel matrix do not divide and they have reduced expression of aquaporin-4 and the endothelin receptor, type B compared to two-dimensional cultures, but maintain their expression of glial fibrillary acidic protein. The effects of conditioned media from these astrocytes on the barrier phenotype of the endothelium was compared with media from astrocytes grown conventionally on a two-dimensional (2D substratum. Both induce the expression of tight junction proteins zonula occludens-1 and claudin-5 in hCMEC/D3 cells, but there was no difference between the induced expression levels by the two media. The model has been used to assess the transport of glucose-coated 4nm gold nanoparticles and for leukocyte migration. TEM was used to trace and quantitate the movement of the nanoparticles across the endothelium and into the astrocytes. This blood-brain barrier model is very suitable for assessing delivery of nanoparticles and larger biomolecules to cells of the CNS, following transport across the endothelium.

  5. 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.

  6. 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.

  7. Generation of a High Resistance in vitro Blood-Brain-Barrier Model and Investigations of Brain-to-Blood Glutamate Efflux

    DEFF Research Database (Denmark)

    Helms, Hans Christian

    Blod-hjernebarrieren (blood-brain barrier, BBB) opretholder den generelle homeostase i hjernens væsker. BBB kan også spille en rolle i homeostasen for den eksitatoriske aminosyre, L-glutamat. In vitro modeller kan være effektive værktøjer til at få mekanistiske informationer om transcellulær...... af claudin-5 ved en direkte påvirkning eller som en afledt konsekvens. mRNA ekspression af en række vigtige BBB markører blev bekræftet, og breat cancer resistance protein- og P-glycoprotein-ekspression blev vist funktionelt. EAAT-substraterne, L-aspartat, L-glutamat, men ikke D-aspartat udviste...

  8. Computational approaches to the prediction of blood-brain barrier permeability: A comparative analysis of central nervous system drugs versus secretase inhibitors for Alzheimer's disease.

    Science.gov (United States)

    Rishton, Gilbert M; LaBonte, Kristen; Williams, Antony J; Kassam, Karim; Kolovanov, Eduard

    2006-05-01

    This review summarizes progress made in the development of fully computational approaches to the prediction of blood-brain barrier (BBB) permeability of small molecules, with a focus on rapid computational methods suitable for the analysis of large compound sets and virtual screening. A comparative analysis using the recently developed Advanced Chemistry Development (ACD/Labs) Inc BBB permeability algorithm for the calculation of logBB values for known Alzheimer's disease medicines, selected central nervous system drugs and new secretase inhibitors for Alzheimer's disease, is presented. The trends in logBB values and the associated physiochemical properties of these agents as they relate to the potential for BBB permeability are also discussed. PMID:16729726

  9. Dopamine D2-receptor imaging with 123I-iodobenzamide SPECT in migraine patients abusing ergotamine: does ergotamine cross the blood brain barrier?

    International Nuclear Information System (INIS)

    Two migraine patients were studied by in vivo SPECT using the dopamine D2-receptor specific radioligand 123I-3-iodo-6-methoxybenzamide (123I-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 123I-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

  10. Blood brain barrier and neuroinflammation are critical targets of IGF-1-mediated neuroprotection in stroke for middle-aged female rats.

    Directory of Open Access Journals (Sweden)

    Shameena Bake

    Full Text Available Ischemia-induced cerebral infarction is more severe in older animals as compared to younger animals, and is associated with reduced availability of insulin-like growth factor (IGF-1. This study determined the effect of post-stroke IGF-1 treatment, and used microRNA profiling to identify mechanisms underlying IGF-1's neuroprotective actions. Post-stroke ICV administration of IGF-1 to middle-aged female rats reduced infarct volume by 39% when measured 24h later. MicroRNA analyses of ischemic tissue collected at the early post-stroke phase (4h indicated that 8 out of 168 disease-related miRNA were significantly downregulated by IGF-1. KEGG pathway analysis implicated these miRNA in PI3K-Akt signaling, cell adhesion/ECM receptor pathways and T-and B-cell signaling. Specific components of these pathways were subsequently analyzed in vehicle and IGF-1 treated middle-aged females. Phospho-Akt was reduced by ischemia at 4h, but elevated by IGF-1 treatment at 24h. IGF-1 induced Akt activation was preceded by a reduction of blood brain barrier permeability at 4h post-stroke and global suppression of cytokines including IL-6, IL-10 and TNF-α. A subset of these cytokines including IL-6 was also suppressed by IGF-1 at 24h post-stroke. These data are the first to show that the temporal and mechanistic components of post-stroke IGF-1 treatment in older animals, and that cellular components of the blood brain barrier may serve as critical targets of IGF-1 in the aging brain.

  11. MicroRNA-150 regulates blood-brain barrier permeability via Tie-2 after permanent middle cerebral artery occlusion in rats.

    Science.gov (United States)

    Fang, Zhi; He, Quan-Wei; Li, Qian; Chen, Xiao-Lu; Baral, Suraj; Jin, Hui-Juan; Zhu, Yi-Yi; Li, Man; Xia, Yuan-Peng; Mao, Ling; Hu, Bo

    2016-06-01

    The mechanism of blood-brain barrier (BBB) disruption, involved in poststroke edema and hemorrhagic transformation, is important but elusive. We investigated microRNA-150 (miR-150)-mediated mechanism in the disruption of BBB after stroke in rats. We found that up-regulation of miR-150 increased permeability of BBB as detected by MRI after permanent middle cerebral artery occlusion in vivo as well as increased permeability of brain microvascular endothelial cells after oxygen-glucose deprivation in vitro. The expression of claudin-5, a key tight junction protein, was decreased in the ischemic boundary zone after up-regulation of miR-150. We found in brain microvascular endothelial cells that overexpression of miR-150 decreased not only cell survival rate but also the expression levels of claudin-5 after oxygen-glucose deprivation. With dual-luciferase assay, we confirmed that miR-150 could directly regulate the angiopoietin receptor Tie-2. Moreover, silencing Tie-2 with lentivirus-delivered small interfering RNA reversed the effect of miR-150 on endothelial permeability, cell survival, and claudin-5 expression. Furthermore, poststroke treatment with antagomir-150, a specific miR-150 antagonist, contributed to BBB protection, infarct volume reduction, and amelioration of neurologic deficits. Collectively, our findings suggested that miR-150 could regulate claudin-5 expression and endothelial cell survival by targeting Tie-2, thus affecting the permeability of BBB after permanent middle cerebral artery occlusion in rats, and that miR-150 might be a potential alternative target for the treatment of stroke.-Fang, Z., He, Q.-W., Li, Q., Chen, X.-L., Baral, S., Jin, H.-J., Zhu, Y.-Y., Li, M., Xia, Y.-P., Mao, L., Hu, B. MicroRNA-150 regulates blood-brain barrier permeability via Tie-2 after permanent middle cerebral artery occlusion in rats. PMID:26887441

  12. 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. PMID:27070801

  13. 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.

  14. Effects of fractionated radiation on the brain vasculature in a murine model: Blood-brain barrier permeability, astrocyte proliferation, and ultrastructural changes

    International Nuclear Information System (INIS)

    Purpose: Radiation therapy of CNS tumors damages the blood-brain barrier (BBB) and normal brain tissue. Our aims were to characterize the short- and long-term effects of fractionated radiotherapy (FRT) on cerebral microvasculature in mice and to investigate the mechanism of change in BBB permeability in mice. Methods and Materials: Intravital microscopy and a cranial window technique were used to measure BBB permeability to fluorescein isothiocyanate (FITC)-dextran and leukocyte endothelial interactions before and after cranial irradiation. Daily doses of 2 Gy were delivered 5 days/week (total, 40 Gy). We immunostained the molecules to detect the expression of glial fibrillary acidic protein and to demonstrate astrocyte activity in brain parenchyma. To relate the permeability changes to endothelial ultrastructural changes, we used electron microscopy. Results: Blood-brain barrier permeability did not increase significantly until 90 days after FRT, at which point it increased continuously until 180 days post-FRT. The number of adherent leukocytes did not increase during the study. The number of astrocytes in the cerebral cortex increased significantly; vesicular activity in endothelial cells increased beginning 90 days after irradiation, and most tight junctions stayed intact, although some were shorter and less dense at 120 and 180 days. Conclusions: The cellular and microvasculature response of the brain to FRT is mediated through astrogliosis and ultrastructural changes, accompanied by an increase in BBB permeability. The response to FRT is delayed as compared with single-dose irradiation treatment, and does not involve leukocyte adhesion. However, FRT induces an increase in the BBB permeability, as in the case of single-dose irradiation

  15. 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

  16. Influence of T-2 and HT-2 toxin on the blood-brain barrier in vitro: new experimental hints for neurotoxic effects.

    Science.gov (United States)

    Weidner, Maria; Hüwel, Sabine; Ebert, Franziska; Schwerdtle, Tanja; Galla, Hans-Joachim; Humpf, Hans-Ulrich

    2013-01-01

    The trichothecene mycotoxin T-2 toxin is a common contaminant of food and feed and is also present in processed cereal derived products. Cytotoxic effects of T-2 toxin and its main metabolite HT-2 toxin are already well described with apoptosis being a major mechanism of action. However, effects on the central nervous system were until now only reported rarely. In this study we investigated the effects of T-2 and HT-2 toxin on the blood-brain barrier (BBB) in vitro. Besides strong cytotoxic effects on the BBB as determined by the CCK-8 assay, impairment of the barrier function starting at low nanomolar concentrations were observed for T-2 toxin. HT-2 toxin, however, caused barrier disruption at higher concentrations compared to T-2 toxin. Further, the influence on the tight junction protein occludin was studied and permeability of both toxins across the BBB was detected when applied from the apical (blood) or the basolateral (brain) side respectively. These results clearly indicate the ability of both toxins to enter the brain via the BBB. PMID:23544145

  17. Synthesis and antiprotozoal activity of N-alkoxy analogues of the trypanocidal lead compound 4,4'-bis(imidazolinylamino)diphenylamine with improved human blood-brain barrier permeability.

    Science.gov (United States)

    Nieto, Lidia; Mascaraque, Ainhoa; Miller, Florence; Glacial, Fabienne; Ríos Martínez, Carlos; Kaiser, Marcel; Brun, Reto; Dardonville, Christophe

    2011-01-27

    To improve the blood-brain barrier permeability of the trypanocidal lead compound 4,4'-bis(imidazolinylamino)diphenylamine (1), five N-alkoxy analogues were synthesized from bis(4-isothiocyanatophenyl)amine and N-alkoxy-N-(2-aminoethyl)-2-nitrobenzenesulfonamides following successive chemical reactions in just one reactor ("one-pot procedure"). This involved: (a) formation of a thiourea intermediate, (b) removal of the amine protecting groups, and (c) intramolecular cyclization. The blood-brain barrier permeability of the compounds determined in vitro by transport assays through the hCMEC/D3 human cell line, a well-known and characterized human cellular blood-brain barrier model, showed that the N-hydroxy analogue 16 had enhanced blood-brain barrier permeability compared with the unsubstituted lead compound. Moreover, this compound displayed low micromolar IC(50) against Trypanosoma brucei rhodesiense and Plasmodium falciparum and moderate activity by intraperitoneal administration in the STIB900 murine model of acute sleeping sickness. PMID:21175162

  18. Increased efflux of amyloid-β peptides through the blood-brain barrier by muscarinic acetylcholine receptor inhibition reduces pathological phenotypes in mouse models of brain amyloidosis.

    Science.gov (United States)

    Paganetti, Paolo; Antoniello, Katia; Devraj, Kavi; Toni, Nicolas; Kieran, Dairin; Madani, Rime; Pihlgren, Maria; Adolfsson, Oskar; Froestl, Wolfgang; Schrattenholz, André; Liebner, Stefan; Havas, Daniel; Windisch, Manfred; Cirrito, John R; Pfeifer, Andrea; Muhs, Andreas

    2014-01-01

    The formation and accumulation of toxic amyloid-β peptides (Aβ) in the brain may drive the pathogenesis of Alzheimer's disease. Accordingly, disease-modifying therapies for Alzheimer's disease and related disorders could result from treatments regulating Aβ homeostasis. Examples are the inhibition of production, misfolding, and accumulation of Aβ or the enhancement of its clearance. Here we show that oral treatment with ACI-91 (Pirenzepine) dose-dependently reduced brain Aβ burden in AβPPPS1, hAβPPSL, and AβPP/PS1 transgenic mice. A possible mechanism of action of ACI-91 may occur through selective inhibition of muscarinic acetylcholine receptors (AChR) on endothelial cells of brain microvessels and enhanced Aβ peptide clearance across the blood-brain barrier. One month treatment with ACI-91 increased the clearance of intrathecally-injected Aβ in plaque-bearing mice. ACI-91 also accelerated the clearance of brain-injected Aβ in blood and peripheral tissues by favoring its urinal excretion. A single oral dose of ACI-91 reduced the half-life of interstitial Aβ peptide in pre-plaque mhAβPP/PS1d mice. By extending our studies to an in vitro model, we showed that muscarinic AChR inhibition by ACI-91 and Darifenacin augmented the capacity of differentiated endothelial monolayers for active transport of Aβ peptide. Finally, ACI-91 was found to consistently affect, in vitro and in vivo, the expression of endothelial cell genes involved in Aβ transport across the Blood Brain Brain (BBB). Thus increased Aβ clearance through the BBB may contribute to reduced Aβ burden and associated phenotypes. Inhibition of muscarinic AChR restricted to the periphery may present a therapeutic advantage as it avoids adverse central cholinergic effects. PMID:24072071

  19. 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

  20. In Vitro Permeation of FITC-loaded Ferritins Across a Rat Blood-brain Barrier: a Model to Study the Delivery of Nanoformulated Molecules.

    Science.gov (United States)

    Fiandra, Luisa; Mazzucchelli, Serena; Truffi, Marta; Bellini, Michela; Sorrentino, Luca; Corsi, Fabio

    2016-01-01

    Brain microvascular endothelial cells, supported by pericytes and astrocytes endfeet, are responsible for the low permeation of large hydrosoluble drugs through the blood-brain barrier (BBB), causing difficulties for effective pharmacological therapies. In recent years, different strategies for promoting brain targeting have aimed to improve drug delivery and activity at this site, including innovative nanosystems for drug delivery across the BBB. In this context, an in vitro approach based on a simplified cellular model of the BBB provides a useful tool to investigate the effect of nanoformulations on the trans-BBB permeation of molecules. This study describes the development of a double-layer BBB, consisting of co-cultured commercially available primary rat brain microvascular endothelial cells and astrocytes. A multiparametric approach for the validation of the model, based on the measurement of the transendothelial electrical resistance and the apparent permeability of a high molecular weight dextran, is also described. As proof of concept for the employment of this BBB model to study the effect of different nanoformulations on the translocation of fluorescent molecules across the barrier, we describe the use of fluorescein isothiocyanate (FITC), loaded into ferritin nanoparticles. The ability of ferritins to improve the trans-BBB permeation of FITC was demonstrated by flux measurements and confocal microscopy analyses. The results suggest this is a useful system for validating nanosystems for delivery of drugs across the BBB. PMID:27583454

  1. 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.

  2. 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.

  3. Neutron capture therapy of intracerebral melanoma: enhanced survival and cure after blood-brain barrier opening to improve delivery of boronophenylalanine

    International Nuclear Information System (INIS)

    Purpose: Multicentric cerebral metastases of melanoma represent an important clinical problem for which there currently is no satisfactory treatment. We previously developed a model for melanoma metastatic to the brain employing nude rats bearing intracerebral implants of the human MRA27 melanoma. The purpose of the present study was to determine if the efficacy of boron neutron capture therapy (BNCT) could be improved by either Cereport (RMP-7) mediated modulation of blood-brain barrier (BBB) permeability or hyperosmotic mannitol-induced BBB disruption using boronophenylalanine (BPA) as the capture agent. Methods and Materials: Biodistribution studies were carried out at 0.5, 2.5, and 4 h after intracarotid administration of Cereport (1.5 μg/kg) and intracarotid or i.v. administration of BPA (500 mg/kg). Peak tumor boron concentrations (65.4 μg/g) and the best composite tumor:brain (6.1:1) and tumor:blood (6.3:1) ratios were observed at 2.5 h after intracarotid administration. BNCT was initiated at the Brookhaven Medical Research Reactor 13-14 days after intracerebral implantation of 106 MRA27 cells. Results: Untreated control rats had a median survival time (MeST) of 22 days and for irradiated controls, it was 30 days. Rats that received i.v. or intracarotid BPA without Cereport followed by BNCT 2.5 h later had MeSTs of 41 days and 57 days, respectively, with 20% long-term survivors (>180 days) in the latter group. Rats that received intracarotid BPA with Cereport had an MeST of 86 days with 36% long-term survivors, which was very close to that of rats that had hyperosmotic mannitol-induced disruption of the BBB (85 days with 25% long-term survivors). When these two groups were combined, and survival times were compared, using the Wilcoxon rank sum test, to those of rats that received intracarotid BPA without blood-brain barrier disruption, these differences were significant at the level p=0.01. Conclusions: Our data show that optimizing the delivery of BPA by

  4. Promising approaches to circumvent the blood-brain barrier: progress, pitfalls and clinical prospects in brain cancer

    OpenAIRE

    Papademetriou, Iason T.; Porter, Tyrone

    2015-01-01

    Brain drug delivery is a major challenge for therapy of central nervous system (CNS) diseases. Biochemical modifications of drugs or drug nanocarriers, methods of local delivery, and blood–brain barrier (BBB) disruption with focused ultrasound and microbubbles are promising approaches which enhance transport or bypass the BBB. These approaches are discussed in the context of brain cancer as an example in CNS drug development. Targeting to receptors enabling transport across the BBB offers non...

  5. Intercellular transfer of P-glycoprotein in human blood-brain barrier endothelial cells is increased by histone deacetylase inhibitors

    OpenAIRE

    Andreas Noack; Sandra Noack; Manuela Buettner; Naim, Hassan Y.; Wolfgang Löscher

    2016-01-01

    The blood–brain barrier (BBB) controls the entry of compounds into the brain, thereby regulating brain homeostasis. Efflux transporters such as P-glycoprotein (Pgp) significantly contribute to BBB function. Multiple signaling pathways modulate the expression and activity of Pgp in response to xenobiotics and disease. A non-genetic way of intercellular transfer of Pgp occurs in cancer cells, but whether this also occurs in non-cancer cells such as endothelial cells that form the BBB is not kno...

  6. 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

  7. Validation of UHPLC-MS/MS methods for the determination of kaempferol and its metabolite 4-hydroxyphenyl acetic acid, and application to in vitro blood-brain barrier and intestinal drug permeability studies.

    Science.gov (United States)

    Moradi-Afrapoli, Fahimeh; Oufir, Mouhssin; Walter, Fruzsina R; Deli, Maria A; Smiesko, Martin; Zabela, Volha; Butterweck, Veronika; Hamburger, Matthias

    2016-09-01

    Sedative and anxiolytic-like properties of flavonoids such as kaempferol and quercetin, and of some of their intestinal metabolites, have been demonstrated in pharmacological studies. However, routes of administration were shown to be critical for observing in vivo activity. Therefore, the ability to cross intestinal and blood-brain barriers was assessed in cell-based models for kaempferol (KMF), and for the major intestinal metabolite of KMF, 4-hydroxyphenylacetic acid (4-HPAA). Intestinal transport studies were performed with Caco-2 cells, and blood-brain barrier transport studies with an immortalized monoculture human model and a primary triple-co-culture rat model. UHPLC-MS/MS methods for KMF and 4-HPAA in Ringer-HEPES buffer and in Hank's balanced salt solution were validated according to industry guidelines. For all methods, calibration curves were fitted by least-squares quadratic regression with 1/X(2) as weighing factor, and mean coefficients of determination (R(2)) were >0.99. Data obtained with all barrier models showed high intestinal and blood-brain barrier permeation of KMF, and no permeability of 4-HPAA, when compared to barrier integrity markers. PMID:27281582

  8. Activation of signaling pathways following localized delivery of systemically administered neurotrophic factors across the blood-brain barrier using focused ultrasound and microbubbles

    Science.gov (United States)

    Baseri, Babak; Choi, James J.; Deffieux, Thomas; Samiotaki, Gesthimani; Tung, Yao-Sheng; Olumolade, Oluyemi; Small, Scott A.; Morrison, Barclay, III; Konofagou, Elisa E.

    2012-04-01

    The brain-derived neurotrophic factor (BDNF) has been shown to have broad neuroprotective effects in addition to its therapeutic role in neurodegenerative disease. In this study, the efficacy of delivering exogenous BDNF to the left hippocampus is demonstrated in wild-type mice (n = 7) through the noninvasively disrupted blood-brain barrier (BBB) using focused ultrasound (FUS). The BDNF bioactivity was found to be preserved following delivery as assessed quantitatively by immunohistochemical detection of the pTrkB receptor and activated pAkt, pMAPK, and pCREB in the hippocampal neurons. It was therefore shown for the first time that systemically administered neurotrophic factors can cross the noninvasively disrupted BBB and trigger neuronal downstream signaling effects in a highly localized region in the brain. This is the first time that the administered molecule is tracked through the BBB and localized in the neuron triggering molecular effects. Additional preliminary findings are shown in wild-type mice with two additional neurotrophic factors such as the glia-derived neurotrophic factor (n = 12) and neurturin (n = 2). This further demonstrates the impact of FUS for the early treatment of CNS diseases at the cellular and molecular level and strengthens its premise for FUS-assisted drug delivery and efficacy.

  9. Pharmacokinetic analysis of 111 in-labeled liposomal Doxorubicin in murine glioblastoma after blood-brain barrier disruption by focused ultrasound.

    Directory of Open Access Journals (Sweden)

    Feng-Yi Yang

    Full Text Available The goal of this study was to evaluate the pharmacokinetics of targeted and untargeted (111In-doxorubicin liposomes after these have been intravenously administrated to tumor-bearing mice in the presence of blood-brain barrier disruption (BBB-D induced by focused ultrasound (FUS. An intracranial brain tumor model in NOD-scid mice using human brain glioblastoma multiforme (GBM 8401 cells was developed in this study. (111In-labeled human atherosclerotic plaque-specific peptide-1 (AP-1-conjugated liposomes containing doxorubicin (Lipo-Dox; AP-1 Lipo-Dox were used as a microSPECT probe for radioactivity measurements in the GBM-bearing mice. Compared to the control tumors treated with an injection of (111In-AP-1 Lipo-Dox or (111In-Lipo-Dox, the animals receiving the drugs followed by FUS exhibited enhanced accumulation of the drug in the brain tumors (p<0.05. Combining sonication with drugs significantly increased the tumor-to-normal brain doxorubicin ratio of the target tumors compared to the control tumors. The tumor-to-normal brain ratio was highest after the injection of (111In-AP-1 Lipo-Dox with sonication. The (111In-liposomes micro-SPECT/CT should be able to provide important information about the optimum therapeutic window for the chemotherapy of brain tumors using sonication.

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

    Directory of Open Access Journals (Sweden)

    Vida Naderi

    2015-02-01

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

  11. Enhanced delivery of etoposide across the blood-brain barrier to restrain brain tumor growth using melanotransferrin antibody- and tamoxifen-conjugated solid lipid nanoparticles.

    Science.gov (United States)

    Kuo, Yung-Chih; Wang, I-Hsin

    2016-08-01

    Melanotransferrin antibody (MA) and tamoxifen (TX) were conjugated on etoposide (ETP)-entrapped solid lipid nanoparticles (ETP-SLNs) to target the blood-brain barrier (BBB) and glioblastom multiforme (GBM). MA- and TX-conjugated ETP-SLNs (MA-TX-ETP-SLNs) were used to infiltrate the BBB comprising a monolayer of human astrocyte-regulated human brain-microvascular endothelial cells (HBMECs) and to restrain the proliferation of malignant U87MG cells. TX-grafted ETP-SLNs (TX-ETP-SLNs) significantly enhanced the BBB permeability coefficient for ETP and raised the fluorescent intensity of calcein-AM when compared with ETP-SLNs. In addition, surface MA could increase the BBB permeability coefficient for ETP about twofold. The viability of HBMECs was higher than 86%, suggesting a high biocompatibility of MA-TX-ETP-SLNs. Moreover, the efficiency in antiproliferation against U87MG cells was in the order of MA-TX-ETP-SLNs  >  TX-ETP-SLNs  >  ETP-SLNs  >  SLNs. The capability of MA-TX-ETP-SLNs to target HBMECs and U87MG cells during internalization was verified by immunochemical staining of expressed melanotransferrin. MA-TX-ETP-SLNs can be a potent pharmacotherapy to deliver ETP across the BBB to GBM. PMID:26768307

  12. 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.

  13. Cytotoxicity and apoptotic gene expression in an in vitro model of the blood-brain barrier following exposure to poly(butylcyanoacrylate) nanoparticles.

    Science.gov (United States)

    Hall, Andrew M; Hemmer, Ruth; Spaulding, Robert; Wetzel, Hanna N; Curcio, Joseph; Sabel, Bernhard A; Henrich-Noack, Petra; Pixley, Sarah; Hopkins, Tracy; Boyce, Richard L; Schultheis, Patrick J; Haik, Kristi L

    2016-08-01

    Background Poly(butylcyanoacrylate) (PBCA) nanoparticles (NPs) loaded with doxorubicin (DOX) and coated with polysorbate 80 (PS80) have shown efficacy in the treatment of rat glioblastoma. However, cytotoxicity of this treatment remains unclear. Purpose The purpose of this study was to investigate cytotoxicity and apoptotic gene expression using a proven in vitro co-culture model of the blood-brain barrier. Methods The co-cultures were exposed to uncoated PBCA NPs, PBCA-PS80 NPs or PBCA-PS80-DOX NPs at varying concentrations and evaluated using a resazurin-based cytotoxicity assay and an 84-gene apoptosis RT-PCR array. Results The cytotoxicity assays showed PBCA-PS80-DOX NPs exhibited a decrease in metabolic function at lower concentrations than uncoated PBCA NPs and PBCA-PS80 NPs. The apoptosis arrays showed differential expression of 18 genes in PBCA-PS80-DOX treated cells compared to the untreated control. Discussion As expected, the cytotoxicity assays demonstrated enhanced dose-dependent toxicity in the DOX loaded NPs. The differentially expressed apoptotic genes participate in both the tumor necrosis factor receptor-1 and mitochondria-associated apoptotic pathways implicated in current DOX chemotherapeutic toxicity. Conclusion The following data suggest that the cytotoxic effect may be attributed to DOX and not the NPs themselves, further supporting the use of PBCA-PS80 NPs as an effective drug delivery vehicle for treating central nervous system conditions. PMID:26707984

  14. A new PAMPA model using an in-house brain lipid extract for screening the blood-brain barrier permeability of drug candidates.

    Science.gov (United States)

    Bicker, Joana; Alves, Gilberto; Fortuna, Ana; Soares-da-Silva, Patrício; Falcão, Amílcar

    2016-03-30

    The determination of the permeability of drug candidates across the blood-brain barrier (BBB) is a fundamental step during drug discovery programs. The parallel artificial membrane permeability assay (PAMPA) is a high throughput screening tool applied to evaluate the passive permeability and adapted to predict BBB penetration. Herein, a new PAMPA model was developed using an in-house brain lipid extract capable of discriminating BBB permeable from non-permeable compounds. The apparent permeability (Papp) of 18 reference molecules and 10 test compounds was assessed and compared with phosphatidylcholine and commercial porcine polar brain lipid (PBL). The physicochemical selectivity of the in-house brain lipid extract was demonstrated by correlating Papp values with physicochemical properties and its predictive capacity estimated by establishing in vitro-in vivo correlations. The strong correlations achieved between 2% (w/v) in-house lipid extract and PBL for reference (r(2)=0.77) and test compounds (r(2)=0.94) support an equivalent discriminatory capacity and validate the presented model. Moreover, PAMPA studies performed with PBL and in-house lipid extract exhibited a higher correlation with the in vivo parameter logBB (r(2)=0.76 and r(2)=0.72, respectively) than phosphatidylcholine (r(2)=0.51). Overall, the applied lipid extraction process was reproducible, economical and provided lipid extracts that can be used to reliably assess BBB permeation. PMID:26836708

  15. Intracerebroventricular transplantation of ex vivo expanded endothelial colony-forming cells restores blood-brain barrier integrity and promotes angiogenesis of mice with traumatic brain injury.

    Science.gov (United States)

    Huang, Xin-Tao; Zhang, Yong-Qiang; Li, Sheng-Jie; Li, Sheng-Hui; Tang, Qing; Wang, Zhi-Tao; Dong, Jing-Fei; Zhang, Jian-Ning

    2013-12-15

    Endothelial progenitor cells (EPCs) play a key role in tissue repair and regeneration. Previous studies have shown a positive correlation between the number of circulating EPCs and clinical outcomes of patients with traumatic brain injury (TBI). A recent study has further shown that intravenous infusion of human umbilical cord blood-derived endothelial colony-forming cells (ECFCs) improves outcomes of mice subjected to experimental TBI. This follow-up study was designed to determine whether intracerebroventricular (i.c.v.) infusion of ECFCs, which may reduce systemic effects of these cells, could repair the blood-brain barrier (BBB) and promote angiogenesis of mice with TBI. Adult nude mice were exposed to fluid percussion injury and transplanted i.c.v. with ECFCs on day 1 post-TBI. These ECFCs were detected at the TBI zone 3 days after transplantation by SP-DiIC18(3) and fluorescence in situ hybridization. Mice with ECFCs transplant had reduced Evans blue extravasation and brain water content, increased expression of ZO-1 and claudin-5, and showed a higher expression of angiopoietin 1. Consistent with the previous report, mice with ECFCs transplant had also increased microvascular density. Modified neurological severity score and Morris water maze test indicated significant improvements in motor ability, spatial acquisition and reference memory in mice receiving ECFCs, compared to those receiving saline. These data demonstrate the beneficial effects of ECFC transplant on BBB integrity and angiogenesis in mice with TBI. PMID:23957220

  16. Hurdles with using in vitro models to predict human blood-brain barrier drug permeability: a special focus on transporters and metabolizing enzymes.

    Science.gov (United States)

    Shawahna, Ramzi; Decleves, Xavier; Scherrmann, Jean-Michel

    2013-01-01

    The penetration of drugs into the human brain through the blood-brain barrier (BBB) is a major obstacle limiting the development of successful neuropharmaceuticals. This restricted permeability is due to the delicate intercellular junctions, efflux transporters and metabolizing enzymes present at the BBB. The pharmaceutical industry and academic research relies heavily on permeability studies conducted in animals and in vitro models of the BBB. This text reviews the available animal and in vitro BBB models with special emphasis on the situation in freshly isolated human brain microvessels and the unique tightness between brain endothelial cells, drug transport pathways and metabolic capacity. We first outline the delicate structure of the intercellular junctions and the particular interaction between the brain endothelial cells and other components of the neurovascular unit. We then examine the differences in transporters and metabolizing enzymes between species and in vitro systems and those found in isolated brain microvessels. Finally, we review the possibilities of benchmarking in vitro models of the BBB in terms of gene and protein expression. PMID:23215812

  17. Method for evaluating the potential of 14C labeled plant polyphenols to cross the blood-brain barrier using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Bioactive compounds in botanicals may be beneficial in preventing age-related neurodegenerative diseases, but for many compounds conventional methods may be inadequate to detect if these compounds cross the blood-brain barrier or to track the pharmacokinetics in the brain. By combining a number of unique technologies it has been possible to utilize the power of AMS to study the pharmacokinetics of bioactive compounds in the brain at very low concentrations. 14C labeled compounds can be biosynthesized by plant cell suspension cultures co-incubated with radioisotopically-labeled sucrose and isolated and separated into a series of bioactive fractions. To study the pharmacokinetics and tissue distribution of 14C labeled plant polyphenols, rats were implanted with jugular catheters, subcutaneous ultrafiltration probes and brain microdialysis probes. Labeled fractions were dosed orally. Interstitial fluid (ISF) and brain microdialysate samples were taken in tandem with blood samples. It was often possible to determine 14C in blood and ISF with a β-counter. However, brain microdialysate samples 14C levels on the order of 107 atoms/sample required AMS technology. The Brain MicrodialysateAUC/SerumAUC ranged from .021- to .029, with the higher values for the glycoside fractions. By using AMS in combination with traditional methods, it is possible to study uptake by blood, distribution to ISF and determine the amount of a dose which can reach the brain and follow the pharmacokinetics in the brain.

  18. [3H]Methotrexate loss from the rat brain following enhanced uptake by osmotic opening of the blood-brain barrier

    International Nuclear Information System (INIS)

    Right brain regions of anesthetized rats were loaded with [3,5,7-3H]methotrexate ([3H]MTX) or with [14C]sucrose by infusing the tracers into the right carotid artery, after the blood-brain barrier had been opened by right carotid infusion of a hypertonic arabinose solution. During the 6 hr following the procedure, the [3H]MTX concentration in 7 right-sided brain regions, when normalized to the plasma concentration integral during tracer infusion, fell, with an average half-time of 4.8 hr as compared to less than 20 min for the initial rate of loss [14C]sucrose. Right-left brain concentration differences 3 hr after treatment were statistically significant (p less than 0.05) for [3H]MTX but not for [14C]sucrose. The results indicate that intracerebral [3H]MTX is lost more slowly than is intracerebral [14C]sucrose, possibly because [3H]MTX enters brain cells, whereas [14C]sucrose remains largely extracellular

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

    Directory of Open Access Journals (Sweden)

    Michalski Dominik

    2012-01-01

    Full Text Available Abstract Background In ischemic stroke, blood-brain barrier (BBB regulations, typically involving matrix metalloproteinases (MMPs and inhibitors (TIMPs as mediators, became interesting since tissue plasminogen activator (tPA-related BBB breakdown with risk of secondary hemorrhage was considered to involve these mediators too. Despite high clinical relevance, detailed interactions are purely understood. After a pilot study addressing hyperoxia as potential neuroprotective co-treatment to tPA, we analyzed interrelations between BBB permeability (BBB-P, MMPs and TIMPs. Findings Rats underwent embolic middle cerebral artery occlusion (eMCAO and treatment with normobaric (NBO or hyperbaric oxygen (HBO, tPA, tPA+HBO, or no treatment. BBB-P was assessed by intravenously applied FITC-albumin at 4 or 24 hours. MMP-2/-9 and TIMP-1/-2 serum levels were determined at 5 or 25 hours. Time point-corrected partial correlations were used to explore interrelations of BBB-P in ischemic regions (extra-/intravasal FITC-albumin ratio and related serum markers. BBB-P correlated positively with MMP-2 and MMP-9 in controls, whereas hyperoxia led to an inverse association, most pronounced for HBO/MMP-9 (r = -0.606; P Conclusions HBO was found to reverse the positively directed interrelation of BBB-P and MMPs after eMCAO, but this effect failed to sustain in the expected amount when HBO and tPA were given simultaneously.

  20. Method for evaluating the potential of {sup 14}C labeled plant polyphenols to cross the blood-brain barrier using accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Janle, Elsa M., E-mail: janle@purdue.ed [Purdue University, Department of Foods and Nutrition, 700 West State Street, West Lafayette, IN 47907-0259 (United States); Lila, Mary Ann [University of Illinois, Department of Natural Resources and Environmental Sciences Urbana IL (United States); Grannan, Michael; Wood, Lauren; Higgins, Aine [Purdue University, Department of Foods and Nutrition, 700 West State Street, West Lafayette, IN 47907-0259 (United States); Yousef, Gad G.; Rogers, Randy B. [University of Illinois, Department of Natural Resources and Environmental Sciences Urbana IL (United States); Kim, Helen [University of Alabama at Birmingham, Department of Pharmacology, Birmingham AB (United States); Jackson, George S. [Purdue University, Department of Physics, West Lafayette, IN (United States); Weaver, Connie M. [Purdue University, Department of Foods and Nutrition, 700 West State Street, West Lafayette, IN 47907-0259 (United States)

    2010-04-15

    Bioactive compounds in botanicals may be beneficial in preventing age-related neurodegenerative diseases, but for many compounds conventional methods may be inadequate to detect if these compounds cross the blood-brain barrier or to track the pharmacokinetics in the brain. By combining a number of unique technologies it has been possible to utilize the power of AMS to study the pharmacokinetics of bioactive compounds in the brain at very low concentrations. {sup 14}C labeled compounds can be biosynthesized by plant cell suspension cultures co-incubated with radioisotopically-labeled sucrose and isolated and separated into a series of bioactive fractions. To study the pharmacokinetics and tissue distribution of {sup 14}C labeled plant polyphenols, rats were implanted with jugular catheters, subcutaneous ultrafiltration probes and brain microdialysis probes. Labeled fractions were dosed orally. Interstitial fluid (ISF) and brain microdialysate samples were taken in tandem with blood samples. It was often possible to determine {sup 14}C in blood and ISF with a beta-counter. However, brain microdialysate samples {sup 14}C levels on the order of 10{sup 7} atoms/sample required AMS technology. The Brain Microdialysate{sub AUC}/Serum{sub AUC} ranged from .021- to .029, with the higher values for the glycoside fractions. By using AMS in combination with traditional methods, it is possible to study uptake by blood, distribution to ISF and determine the amount of a dose which can reach the brain and follow the pharmacokinetics in the brain.

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

    Science.gov (United States)

    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. PMID:27288705

  2. Early Exercise Protects the Blood-Brain Barrier from Ischemic Brain Injury via the Regulation of MMP-9 and Occludin in Rats

    Directory of Open Access Journals (Sweden)

    Yuling Zhang

    2013-05-01

    Full Text Available Early exercise within 24 h after stroke can reduce neurological deficits after ischemic brain injury. However, the mechanisms underlying this neuroprotection remain poorly understood. Ischemic brain injury disrupts the blood-brain barrier (BBB and then triggers a cascade of events, leading to secondary brain injury and poor long-term outcomes. This study verified the hypothesis that early exercise protected the BBB after ischemia. Adult rats were randomly assigned to sham, early exercise (EE or non-exercise (NE groups. The EE and NE groups were subjected to ischemia induced by middle cerebral artery occlusion (MCAO. The EE group ran on a treadmill beginning 24 h after ischemia, 30 min per day for three days. After three-days’ exercise, EB extravasation and electron microscopy were used to evaluate the integrity of the BBB. Neurological deficits, cerebral infarct volume and the expression of MMP-9, the tissue inhibitors of metalloproteinase-1 (TIMP-1, and occludin were determined. The data indicated that early exercise significantly inhibited the ischemia-induced reduction of occludin, and an increase in MMP-9 promoted TIMP-1 expression (p < 0.01, attenuated the BBB disruption (p < 0.05 and neurological deficits (p < 0.01 and diminished the infarct volume (p < 0.01. Our results suggest that the neuroprotection conferred by early exercise was likely achieved by improving the function of the BBB via the regulation of MMP-9 and occludin.

  3. Pilot PET Study to Assess the Functional Interplay Between ABCB1 and ABCG2 at the Human Blood-Brain Barrier.

    Science.gov (United States)

    Bauer, M; Römermann, K; Karch, R; Wulkersdorfer, B; Stanek, J; Philippe, C; Maier-Salamon, A; Haslacher, H; Jungbauer, C; Wadsak, W; Jäger, W; Löscher, W; Hacker, M; Zeitlinger, M; Langer, O

    2016-08-01

    ABCB1 and ABCG2 work together at the blood-brain barrier (BBB) to limit brain distribution of dual ABCB1/ABCG2 substrates. In this pilot study we used positron emission tomography (PET) to assess brain distribution of two model ABCB1/ABCG2 substrates ([(11) C]elacridar and [(11) C]tariquidar) in healthy subjects without (c.421CC) or with (c.421CA) the ABCG2 single-nucleotide polymorphism (SNP) c.421C>A. Subjects underwent PET scans under conditions when ABCB1 and ABCG2 were functional and during ABCB1 inhibition with high-dose tariquidar. In contrast to the ABCB1-selective substrate (R)-[(11) C]verapamil, [(11) C]elacridar and [(11) C]tariquidar showed only moderate increases in brain distribution during ABCB1 inhibition. This provides evidence for a functional interplay between ABCB1 and ABCG2 at the human BBB and suggests that both ABCB1 and ABCG2 need to be inhibited to achieve substantial increases in brain distribution of dual ABCB1/ABCG2 substrates. During ABCB1 inhibition c.421CA subjects had significantly higher increases in [(11) C]tariquidar brain distribution than c.421CC subjects, pointing to impaired cerebral ABCG2 function. PMID:26940368

  4. Phosphoinositide 3-kinase γ affects LPS-induced disturbance of blood-brain barrier via lipid kinase-independent control of cAMP in microglial cells.

    Science.gov (United States)

    Frister, Adrian; Schmidt, Caroline; Schneble, Nadine; Brodhun, Michael; Gonnert, Falk A; Bauer, Michael; Hirsch, Emilio; Müller, Jörg P; Wetzker, Reinhard; Bauer, Reinhard

    2014-12-01

    The breakdown of the blood-brain barrier (BBB) is a key event in the development of sepsis-induced brain damage. BBB opening allows blood-born immune cells to enter the CNS to provoke a neuroinflammatory response. Abnormal expression and activation of matrix metalloproteinases (MMP) was shown to contribute to BBB opening. Using different mouse genotypes in a model of LPS-induced systemic inflammation, our present report reveals phosphoinositide 3-kinase γ (PI3Kγ) as a mediator of BBB deterioration and concomitant generation of MMP by microglia. Unexpectedly, microglia expressing lipid kinase-deficient mutant PI3Kγ exhibited similar MMP regulation as wild-type cells. Our data suggest kinase-independent control of cAMP phosphodiesterase activity by PI3Kγ as a crucial mediator of microglial cell activation, MMP expression and subsequent BBB deterioration. The results identify the suppressive effect of PI3Kγ on cAMP as a critical mediator of immune cell functions. PMID:25033932

  5. The impact of standing wave effects on transcranial focused ultrasound disruption of the blood-brain barrier in a rat model

    International Nuclear Information System (INIS)

    Microbubble-mediated disruption of the blood-brain barrier (BBB) for targeted drug delivery using focused ultrasound shows great potential as a therapy for a wide range of brain disorders. This technique is currently at the pre-clinical stage and important work is being conducted in animal models. Measurements of standing waves in ex vivo rat skulls were conducted using an optical hydrophone and a geometry dependence was identified. Standing waves could not be eliminated through the use of swept frequencies, which have been suggested to eliminate standing waves. Definitive standing wave patterns were detected in over 25% of animals used in a single study. Standing waves were successfully eliminated using a wideband composite sharply focused transducer and a reduced duty cycle. The modified pulse parameters were used in vivo to disrupt the BBB in a rat indicating that, unlike some other bioeffects, BBB disruption is not dependent on standing wave conditions. Due to the high variability of standing waves and the inability to correctly estimate in situ pressures given standing wave conditions, attempts to minimize standing waves should be made in all future work in this field to ensure that results are clinically translatable.

  6. Borneol Depresses P-Glycoprotein Function by a NF-κB Signaling Mediated Mechanism in a Blood Brain Barrier in Vitro Model

    Directory of Open Access Journals (Sweden)

    Xiang Fan

    2015-11-01

    Full Text Available P-glycoprotein (P-gp on brain microvascular endothelial cells (BMECs that form the blood brain barrier (BBB, influences transportation of substances between blood and brain. The objective of this study was to characterize the effects of borneol on P-gp efflux function on BBB and explore the potential mechanisms. We established an in vitro BBB model comprised of rat BMECs and astrocytes to measure the effects of borneol on the known P-gp substrates transport across BBB, and examined the function and expression of P-gp in BMECs and the signaling pathways regulating P-gp expression. Borneol increased intracellular accumulation of Rhodamine 123, enhanced verapamil and digoxin across the BBB in vitro model, and depressed mdr1a mRNA and P-gp expression. Borneol could activate nuclear factor-κB (NF-κB and inhibition of NF-κB with MG132 (carbobenzoxy-Leu-Leu-leucinal and SN50 (an inhibitory peptide obscuring the P-gp decreases induced by borneol. These data suggested that borneol depresses P-gp function in BMECs by a NF-κB signaling medicated mechanism in a BBB in vitro model.

  7. Development in NMR spiral imaging and application to the assessment of the permeability of the blood-brain barrier on 2 models of brain tumors

    International Nuclear Information System (INIS)

    The results presented in this work were obtained as part of methodological developments in magnetic resonance imaging. First of all, the setting of the rapid imaging technique using a k-space sampling scheme along a variable density spiral is described. Numerical simulations were used to optimize the acquisitions parameters and to compare different reconstruction techniques. An original approach to calibrate the k-space trajectory was proposed. Then, spiral imaging was used to implement a method to measure the blood brain barrier permeability to Gd-DOTA. This protocol was combined to blood volume and vessel size index measurements using Sinerem. The results obtained highlighted differences between the microvascular parameters measured on C6 and RG2 tumor models. The presence of Sinerem induces a mean decrease of the transfer constant across the vascular wall (Ktrans), in the tumor, of 24 per cent. This study also showed extravasation of the Sinerem, during the first two hours after the product injection, only in the RG2 tumors. (author)

  8. Enhanced tumor cell killing following BNCT with hyperosmotic mannitol-induced blood-brain barrier disruption and intracarotid injection of boronophenylalanine

    International Nuclear Information System (INIS)

    The delivery of boronophenylalanine (BPA) by means of intracarotid injection combined with opening the blood-brain barrier (BBB) have been shown significantly enhanced the tumor boron concentration and the survival time of glioma-bearing rats. However, no direct evidence demonstrates whether this treatment protocol can enhance the cell killing of tumor cells or infiltrating tumor cells and the magnitude of enhanced cell killing. The purpose of the present study was to determine if the tumor cell killing of boron neutron capture therapy could be enhanced by hyperosmotic mannitol-induced BBB disruption using BPA-Fr as the capture agent. F98 glioma-bearing rats were injected intravenously or intracarotidly with BPA at doses of 500 mg/kg body weight (b.w.) and with or without mannitol-induced hyperosmotic BBB disruption. The rats were irradiated with an epithermal neutron beam at the reactor of National Tsing-Hua University (THOR). After neutron beam irradiation, the rats were euthanized and the ipsilateral brains containing intracerebral F98 glioma were removed to perform in vivo/in vitro soft agar clonogenic assay. The results demonstrate BNCT with optimizing the delivery of BPA by means of intracarotid injection combined with opening the BBB by infusing a hyperosmotic solution of mannitol significantly enhanced the cell killing of tumor cells and infiltrating tumor cells, the tumor boron concentration and the boron ratio of tumor to normal brain tissues. (author)

  9. Cellular immune surveillance of central nervous system bypasses blood-brain barrier and blood-cerebrospinal-fluid barrier: revealed with the New Marburg cerebrospinal-fluid model in healthy humans.

    Science.gov (United States)

    Kleine, Tilmann O

    2015-03-01

    In healthy human brain/spinal cord, blood capillaries and venules are locked differently with junctions and basement membrane (blood-brain barrier, blood-venule barrier). In choroid plexus, epithelial tight junctions and basement membrane lock blood-cerebrospinal-fluid (CSF) barrier. Lymphocytic cell data, quantified with multicolour flow-cytometry or immuno-cytochemical methods in sample pairs of lumbar CSF, ventrictricular CSF and peripheral venous blood, are taken from references; similarly, data of thoracic duct chyle and blood sample pairs. Through three circumventricular organs (median eminence, organum vasculosum lamina terminalis, area postrema), 15-30 μl blood are pressed by blood pressure through fenestrated capillaries, matrix/basement membrane spaces and ependyma cell lacks into ventricular/suboccipital CSF to generate CD3(+) , CD4(+) , CD8(+) , CD3(+) HLA-DR(+) , CD16(+) 56(+) 3(-) NK, CD19(+) 3(-) B subsets; some B, few NK cells adhere in circumventricular organs. Into lumbar CSF, 10-15 μl thoracic chyle with five lymphocyte subsets (without CD3(+) HLA-DR(+) cells) reflux, when CSF drains out with to-and-fro movements of chyle/CSF along nerve roots. Lymphocytes in lumbar CSF represent a mixture of blood and lymph lymphocytic cells with similar HLA-DR(+) CD3(+) cell counts in ventricular and lumbar CSF, higher CD3(+) , CD4(+) , CD8(+) subsets in lumbar CSF, and few NK and B cells due to absorption in circumventricular organs. The Marburg CSF Model reflects origin and turnover of lymphatic cells in CSF realistically; the model differs from ligand-multistep processes of activated lymphocytes through blood-brain-, blood-venule-, and blood-CSF-barriers; because transfer of inactivated native lymphocytes through the barriers is not found with healthy humans, although described so in literature. PMID:25641944

  10. Differential blood-brain barrier permeabilities to [14C]sucrose and [3H]inulin after osmotic opening in the rat

    International Nuclear Information System (INIS)

    The blood-brain barrier (B-BB) in 3-month-old rats was opened unilaterally by infusing 1.8 m L(+)arabinose in water into the internal carotid artery through a catheter in the external carotid. Two poorly penetrating uncharged test radiotracers of differing molecular weight and size, [14C]sucrose (340 daltons, radius 5 A) and [3H]inulin (5500 daltons, radius 15 A), were simultaneously injected i.v. in untreated rats, or rats at 1, 30, or 50 min after infusion of hypertonic arabinose solution. Evans-blue solution was injected 5 min prior to osmotic treatment as a visual indicator of barrier integrity. In regions of uninfused control brains, the [14C]sucrose permeability-surface area (PA) product approximated 10(-5) s-1, whereas PA was not measurable for [3H]inulin. In arabinose-infused animals, PA products on the ipsilateral hemisphere for both [14C]sucrose and [3H]inulin were markedly elevated 6 min after infusion, but decreased by 35 and 55 min. In nearly all regions, statistically significant differences were not found between 6-min [14C]sucrose- and [3H]inulin-PA values (P greater than 0.05). However, at 35 and 55 min in most regions, the PA for [3H]inulin was significantly lower (P less than 0.05) than PA for [14C]sucrose. The results indicated that the B-BB closed more rapidly to larger than to smaller molecules after osmotic treatment and were consistent with a pore model for osmotic B-BB opening

  11. Organization of Endothelial Cells, Pericytes, and Astrocytes into a 3D Microfluidic in Vitro Model of the Blood-Brain Barrier.

    Science.gov (United States)

    Wang, Jack D; Khafagy, El-Sayed; Khanafer, Khalil; Takayama, Shuichi; ElSayed, Mohamed E H

    2016-03-01

    The endothelial cells lining the capillaries supplying the brain with oxygen and nutrients form a formidable barrier known as the blood-brain barrier (BBB), which exhibits selective permeability to small drug molecules and virtually impermeable to macromolecular therapeutics. Current in vitro BBB models fail to replicate this restrictive behavior due to poor integration of the endothelial cells with supporting cells (pericytes and astrocytes) following the correct anatomical organization observed in vivo. We report the coculture of mouse brain microvascular endothelial cells (b.End3), pericytes, with/without C8-D1A astrocytes in layered microfluidic channels forming three-dimensional (3D) bi- and triculture models of the BBB. The live/dead assay indicated high viability of all cultured cells up to 21 days. Trans-endothelial electrical resistance (TEER) values confirmed the formation of intact monolayers after 3 days in culture and showed statistically higher values for the triculture model compared to the single and biculture models. Screening the permeability of [(14)C]-mannitol and [(14)C]-urea showed the ability of bi- and triculture models to discriminate between different markers based on their size. Further, permeability of [(14)C]-mannitol across the triculture model after 18 days in culture matched its reported permeability across the BBB in vivo. Mathematical calculations also showed that the radius of the tight junctions pores (R) in the triculture model is similar to the reported diameter of the BBB in vivo. Finally, both the bi- and triculture models exhibited functional expression of the P-glycoprotein efflux pump, which increased with the increase in the number of days in culture. These results collectively indicate that the triculture model is a robust in vitro model of the BBB. PMID:26751280

  12. EAAC1 Gene Deletion Increases Neuronal Death and Blood Brain Barrier Disruption after Transient Cerebral Ischemia in Female Mice

    Directory of Open Access Journals (Sweden)

    Bo Young Choi

    2014-10-01

    Full Text Available EAAC1 is important in modulating brain ischemic tolerance. Mice lacking EAAC1 exhibit increased susceptibility to neuronal oxidative stress in mice after transient cerebral ischemia. EAAC1 was first described as a glutamate transporter but later recognized to also function as a cysteine transporter in neurons. EAAC1-mediated transport of cysteine into neurons contributes to neuronal antioxidant function by providing cysteine substrates for glutathione synthesis. Here we evaluated the effects of EAAC1 gene deletion on hippocampal blood vessel disorganization after transient cerebral ischemia. EAAC1−/− female mice subjected to transient cerebral ischemia by common carotid artery occlusion for 30 min exhibited twice as much hippocampal neuronal death compared to wild-type female mice as well as increased reduction of neuronal glutathione, blood–brain barrier (BBB disruption and vessel disorganization. Pre-treatment of N-acetyl cysteine, a membrane-permeant cysteine prodrug, increased basal glutathione levels in the EAAC1−/− female mice and reduced ischemic neuronal death, BBB disruption and vessel disorganization. These findings suggest that cysteine uptake by EAAC1 is important for neuronal antioxidant function under ischemic conditions.

  13. Progress in Alteration of Blood-brain Barrier Function by HIV-1Tat Protein%HIV-1 Tat蛋白改变血脑屏障结构和功能的研究进展

    Institute of Scientific and Technical Information of China (English)

    胡霄; 王震; 李桢; 曾柏瑞; 曾晓锋

    2013-01-01

    HIV-Tat蛋白是人类免疫缺陷病毒-1型(HIV-1)基因编码的一种被称为反式转录激活因子,是HIV转录和复制所必须的一个很重要的调控蛋白.艾滋病痴呆以及艾滋病相关性脑炎的患者其血脑屏障(blood-brain barrier,BBB)都受到不同程度的损伤,其中HIV-1 Tat蛋白起到了非常重要的作用.然而HIV-Tat蛋白改变血脑屏障结构和功能并不清楚,本综述主要讨论HIV-1 Tat蛋白对血脑屏障结构和功能的影响.%HIV-Tat protein is the human immunodeficiency virus type-1 (HIV-1) , a gene encoding is called trans-activator of transcription, is a necessary regulatory protein for transcription and replication of HIV. The blood brain barrier (BBB) is damaged in the AIDS correlated dementia (ADC) and HIV-associated encephalitis (HIVE) , HIV-Tat protein is believed to play an important role in the process. The mechanism HIV-1 Tat protein in alteration of blood-brain barrier function is not entirely clear. The paper reviews the alteration of blood-brain barrier function by HIV-1 Tat protein to provide reference materials for related research and AIDS prevention and treatment.

  14. Prevention of Escherichia coli K1 Penetration of the Blood-Brain Barrier by Counteracting the Host Cell Receptor and Signaling Molecule Involved in E. coli Invasion of Human Brain Microvascular Endothelial Cells▿

    OpenAIRE

    Zhu, Longkun; Pearce, Donna; Kim, Kwang Sik

    2010-01-01

    Escherichia coli meningitis is an important cause of mortality and morbidity, and a key contributing factor is our incomplete understanding of the pathogenesis of E. coli meningitis. We have shown that E. coli penetration into the brain requires E. coli invasion of human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. E. coli invasion of HBMEC involves its interaction with HBMEC receptors, such as E. coli cytotoxic necrotizing factor 1 (CNF1) interacti...

  15. Selenoprotein P and apolipoprotein E receptor-2 interact at the blood-brain barrier and also within the brain to maintain an essential selenium pool that protects against neurodegeneration

    Science.gov (United States)

    Burk, Raymond F.; Hill, Kristina E.; Motley, Amy K.; Winfrey, Virginia P.; Kurokawa, Suguru; Mitchell, Stuart L.; Zhang, Wanqi

    2014-01-01

    Selenoprotein P (Sepp1) and its receptor, apolipoprotein E receptor 2 (apoER2), account for brain retaining selenium better than other tissues. The primary sources of Sepp1 in plasma and brain are hepatocytes and astrocytes, respectively. ApoER2 is expressed in varying amounts by tissues; within the brain it is expressed primarily by neurons. Knockout of Sepp1 or apoER2 lowers brain selenium from ∼120 to ∼50 ng/g and leads to severe neurodegeneration and death in mild selenium deficiency. Interactions of Sepp1 and apoER2 that protect against this injury have not been characterized. We studied Sepp1, apoER2, and brain selenium in knockout mice. Immunocytochemistry showed that apoER2 mediates Sepp1 uptake at the blood-brain barrier. When Sepp1−/− or apoER2−/− mice developed severe neurodegeneration caused by mild selenium deficiency, brain selenium was ∼35 ng/g. In extreme selenium deficiency, however, brain selenium of ∼12 ng/g was tolerated when both Sepp1 and apoER2 were intact in the brain. These findings indicate that tandem Sepp1-apoER2 interactions supply selenium for maintenance of brain neurons. One interaction is at the blood-brain barrier, and the other is within the brain. We postulate that Sepp1 inside the blood-brain barrier is taken up by neurons via apoER2, concentrating brain selenium in them.—Burk, R. F., Hill, K. E., Motley, A. K., Winfrey, V. P., Kurokawa, S., Mitchell, S. L., Zhang, W. Selenoprotein P and apolipoprotein E receptor-2 interact at the blood-brain barrier and also within the brain to maintain an essential selenium pool that protects against neurodegeneration. PMID:24760755

  16. T3 may be a better agent than T4 in the critically ill hypothyroid patient: evaluation of transport across the blood-brain barrier in a primate model

    International Nuclear Information System (INIS)

    Thyroid hormone transport across the blood brain barrier in hypothyroid patients is clinically important yet poorly understood. To study this question, 200 micrograms of thyroxine (T4), 100 micrograms of 3,5,3'-triiodothyronine (T3) and 100 micrograms of 3,3',5'-triiodothyronine (reverse T3) were administered separately to 3 baboons, first iv and at a later date intrathecally (IT). Six animals were used. Three received the iv injections and three received the IT injections. In each of the 18 experiments, cerebrospinal fluid (CSF) and serum specimens were collected serially for 6 h after injection. Mean maximal elevations from baseline in CSF iodothyronine levels were 100 +/- 10 ng/dl after iv T4, 3921 +/- 293 ng/dl after iv T3 and 31 +/- 17 ng/dl after iv reverse T3. When given IT in the same dosages, the mean maximal increases in serum iodothyronine concentrations were: 1670 +/- 600 ng/dl for T4, 806 +/- 405 ng/dl for T3, and 210 +/- 43 ng/dl for reverse T3. In every animal studied, rapid bidirectional transfer of T3 from serum to CSF and CSF to serum occurred, whereas iv T4 resulted in delayed minimal increments in CSF T4 concentration. Isotopic experiments were also performed and the results analyzed using a kinetic model. When 125I-T3 was given iv, the equilibrium point in CSF was observed within 90 min with 1.7% of the administered dose/L able to be counted in CSF at any moment in time. When labeled T4 was given iv, only 0.6% of the administered dose/L was counted in CSF and the equilibrium point was not reached until 360 min. These data suggest: T4, T3, and reverse T3 are all capable of bidirectional transfer across the blood brain barrier, T3 may be a better agent than T4 in treating patients with myxedema coma because T3 crosses more rapidly and more completely from serum to CSF

  17. Early intervention with human albumin to reduce the tissue plasminogen activator-mediated blood-brain barrier permeability damaged by delayed reperfusion: an experimental study in rats

    International Nuclear Information System (INIS)

    Objective: To clarify whether early use of high-dose human albumin can reduce the permeability of blood-brain barrier (BBB) damaged by delayed thrombolysis or not, and, in tun, reduce the vasogenic brain edema. Methods: A total of 138 male SD rats weighing 320-380 grams were randomly divided into 4 groups: sham operation group (n=3), control group (n=45), albumin group (n=45) and albumin+rt-PA group (n=45). According to the reperfusion time after the onset of middle cerebral artery occlusion (MCAO), each group, except sham operation group, was divided into three subgroups of 2 h, 3 h and 4 h with 15 rats in each subgroup. Rats in albumin group and albumin+rt-PA group received an intravenous infusion of 20% human albumin (2.5 g/kg) 2 hours after the onset of MCAO, and rats in albumin+rt-PA group received an intravenous infusion of rt-PA (10 mg/kg) at all points of reperfusion time via the rat's femoral vein immediately after the reperfusion. All rats were sacrificed 24 hours after MCAO, the infarct volume of the brain was determined with TTC dye method, the leakage extent of BBB was quantitatively estimated by using Evans blue method, and the matrix metalloproteinase-9 (MMP-9) expression was assessed with immunohistochemistry technique. Results: Early intervention with the use of high-dose human albumin could significantly improve the neurological score at 24 h. In MCAO 3 h albumin group, MCAO 4 h albumin group and MCAO 3 h albumin+rt-PA group, neurological score was significantly better than that in the control group (P0.05). The volume of the infarct tissue was also significantly smaller in all the treated groups with high-dose human albumin groups (P<0.05) when compared with the control group. The infarct volume of the MCAO 4 h in albumin group and albumin+rt-PA group was reduced by 23% and by 17.3%, respectively. Cerebral hemorrhage transformation occurred in two rats of MCAO 4 h control group, in one rat of MCAO 4 h albumin group and in one rat of MCAO 4 h

  18. Avaliação da Barreira Hemato-Encefálica no transplante de medula óssea Blood-Brain Barrier evaluation in bone marrow transplantation

    Directory of Open Access Journals (Sweden)

    Sérgio Monteiro de Almeida

    1997-01-01

    Full Text Available A barreira hemato-encefálica (BHE contribui para o isolamento imunológico do sistema nervoso central (SNC. Sua avaliação nunca foi realizada em pacientes submetidos a transplante de medula óssea (TMO. Neste estudo a integridade da BHE foi avaliada através das proteínas do LCR, de forma quantitativa, a fim de observar a incidência e entender a fisiopatologia da doença do enxerto contra o hospedeiro crônica (DECH-C no SNC. Foram estudadas amostras pareadas de LCR e soro de 33 pacientes com leucemia mielóide crônica submetidos a TMO alogênico, de doador aparentado, HLA idêntico. As amostras foram coletadas nos períodos pré TMO, pós TMO e concomitante à DECH-C. Não foi evidenciada quebra de BHE durante a DECH-C em nenhum dos casos estudados.The blood-brain barrier (BBB contributes to the central nervous system (CNS immunological isolation. BBB has never been studied in patients who developed chronic graft-versus-host disease (GVHD after allogeneic bone marrow transplants (BMT, from HLA identical related donors. BBB disruption was investigated through the cerebrospinal fluid (CSF proteins, quantitative and graphically, in order to detect the incidence and possible pathophysiology of the CNS involvement in chronic GVHD. Thirty three CSF and matched serum samples from chronic myeloid leukemia patients were collected pre BMT, pos BMT and during chronic GVHD. There was no evidence of BBB disruption in any patient studied.

  19. Wnt activation of immortalized brain endothelial cells as a tool for generating a standardized model of the blood brain barrier in vitro.

    Directory of Open Access Journals (Sweden)

    Roberta Paolinelli

    Full Text Available Reproducing the characteristics and the functional responses of the blood-brain barrier (BBB in vitro represents an important task for the research community, and would be a critical biotechnological breakthrough. Pharmaceutical and biotechnology industries provide strong demand for inexpensive and easy-to-handle in vitro BBB models to screen novel drug candidates. Recently, it was shown that canonical Wnt signaling is responsible for the induction of the BBB properties in the neonatal brain microvasculature in vivo. In the present study, following on from earlier observations, we have developed a novel model of the BBB in vitro that may be suitable for large scale screening assays. This model is based on immortalized endothelial cell lines derived from murine and human brain, with no need for co-culture with astrocytes. To maintain the BBB endothelial cell properties, the cell lines are cultured in the presence of Wnt3a or drugs that stabilize β-catenin, or they are infected with a transcriptionally active form of β-catenin. Upon these treatments, the cell lines maintain expression of BBB-specific markers, which results in elevated transendothelial electrical resistance and reduced cell permeability. Importantly, these properties are retained for several passages in culture, and they can be reproduced and maintained in different laboratories over time. We conclude that the brain-derived endothelial cell lines that we have investigated gain their specialized characteristics upon activation of the canonical Wnt pathway. This model may be thus suitable to test the BBB permeability to chemicals or large molecular weight proteins, transmigration of inflammatory cells, treatments with cytokines, and genetic manipulation.

  20. Angiopoietin-2-induced blood-brain barrier compromise and increased stroke size are rescued by VE-PTP-dependent restoration of Tie2 signaling.

    Science.gov (United States)

    Gurnik, Stefanie; Devraj, Kavi; Macas, Jadranka; Yamaji, Maiko; Starke, Julia; Scholz, Alexander; Sommer, Kathleen; Di Tacchio, Mariangela; Vutukuri, Rajkumar; Beck, Heike; Mittelbronn, Michel; Foerch, Christian; Pfeilschifter, Waltraud; Liebner, Stefan; Peters, Kevin G; Plate, Karl H; Reiss, Yvonne

    2016-05-01

    The homeostasis of the central nervous system is maintained by the blood-brain barrier (BBB). Angiopoietins (Ang-1/Ang-2) act as antagonizing molecules to regulate angiogenesis, vascular stability, vascular permeability and lymphatic integrity. However, the precise role of angiopoietin/Tie2 signaling at the BBB remains unclear. We investigated the influence of Ang-2 on BBB permeability in wild-type and gain-of-function (GOF) mice and demonstrated an increase in permeability by Ang-2, both in vitro and in vivo. Expression analysis of brain endothelial cells from Ang-2 GOF mice showed a downregulation of tight/adherens junction molecules and increased caveolin-1, a vesicular permeability-related molecule. Immunohistochemistry revealed reduced pericyte coverage in Ang-2 GOF mice that was supported by electron microscopy analyses, which demonstrated defective intra-endothelial junctions with increased vesicles and decreased/disrupted glycocalyx. These results demonstrate that Ang-2 mediates permeability via paracellular and transcellular routes. In patients suffering from stroke, a cerebrovascular disorder associated with BBB disruption, Ang-2 levels were upregulated. In mice, Ang-2 GOF resulted in increased infarct sizes and vessel permeability upon experimental stroke, implicating a role of Ang-2 in stroke pathophysiology. Increased permeability and stroke size were rescued by activation of Tie2 signaling using a vascular endothelial protein tyrosine phosphatase inhibitor and were independent of VE-cadherin phosphorylation. We thus identified Ang-2 as an endothelial cell-derived regulator of BBB permeability. We postulate that novel therapeutics targeting Tie2 signaling could be of potential use for opening the BBB for increased CNS drug delivery or tighten it in neurological disorders associated with cerebrovascular leakage and brain edema. PMID:26932603

  1. [11C]befloxatone brain kinetics is not influenced by Bcrp function at the blood-brain barrier: A PET study using Bcrp TGEM knockout rats

    International Nuclear Information System (INIS)

    Knockout (KO) animals are useful tools with which to assess the interplay between P-glycoprotein (P-gp; Abcb1) and the breast cancer resistance protein (Bcrp, Abcg2), two major ABC-transporters expressed at the blood-brain barrier (BBB). However, one major drawback of such deficient models is the possible involvement of compensation between transporters. In the present study, P-gp and Bcrp distribution in the brain as well as P-gp expression levels at the BBB were compared between the Bcrp TGEM KO rat model and the wild-type (WT) strain. Therefore, we used confocal microscopy of brain slices and western blot analysis of the isolated brain microvessels forming the BBB. This deficient rat model was used to assess the influence of Bcrp on the brain and peripheral kinetics of its substrate [11C]befloxatone using positron emission tomography (PET). The influence of additional P-gp inhibition was tested using elacridar (GF120918) 2 mg/kg in Bcrp KO rats. The distribution pattern of P-gp in the brain as well as P-gp expression levels at the BBB was similar in Bcrp-deficient and WT rats. Brain and peripheral kinetics of [11C]befloxatone were not influenced by the lack of Bcrp. Neither was the brain uptake of [11C]befloxatone in Bcrp-deficient rats influenced by the inhibition of P-gp. In conclusion, the Bcrp-deficient rat strain, in which we detected no compensatory mechanism or modification of P-gp expression as compared to WT rats, is a suitable model to study Bcrp function separately from that of P-gp at the BBB. However, although selectively transported by BCRP in vitro, our results suggest that [11C]befloxatone PET imaging might not be biased by impaired function of this transporter in vivo. (authors)

  2. 99mTc complex conjugated to insulin: CNS radio-pharmaceuticals design based on principles of blood-brain barrier transport vector

    Institute of Scientific and Technical Information of China (English)

    LIU Fei; FAN Caiyun; ZHANG Jinming; WANG Wushang; LIU Boli

    2005-01-01

    Hydrophilic 99mTc-EC and nonlipophilic 99mTc- MAMA′-BA complexes, owing to the existing of intact blood-brain barrier (BBB) in vivo, cannot cross from blood to brain. Previous studies showed that insulin is selectively transported by receptor-mediated transcytosis through the brain capillary endothelial wall that makes up the BBB. In this paper, based on the characteristic of the insulin receptor enriched in brain capillary, the complexes of hydrophilic 99mTc-EC and nonlipophilic 99mTc-MAMA′-BA are conjugated to insulin respectively. After purification, the radiochemical purity of 99mTc-EC-insulin and 99mTc-MAMA′- BA-insulin was > 90% and the stability in vitro was good. Expectation for the special formulation can be internalized and endocytosed into the capillary membrane by the vector-mediated brain delivery system, and transported 99mTc-labeled conjugate through the BBB in vivo, thus enhancing brain uptake in mice. The biodistribution results of 99mTc-EC-insulin and 99mTc-MAMA′-BA-insulin in mice indicated that the brain uptake was higher than 99mTc-EC and 99mTc-MAMA′-BA to some extent. The ratios of brain uptake of 99mTc-EC-insulin to 99mTc-EC, 99mTc-MAMA′-BA-insulin to 99mTc-MAMA′-BA were 4―6 at 2 and 3 h post-injection respectively. In conclusion, the given results have illustrated a new way of brain uptake enhancing for nonlipophilic like complexes that have BBB delivery problems. It has a potential value for the ongoing development of 99mTc-labeled radiopharmaceuticals for CNS receptors imaging.

  3. Assessment of blood-brain barrier penetration of miltefosine used to treat a fatal case of granulomatous amebic encephalitis possibly caused by an unusual Balamuthia mandrillaris strain.

    Science.gov (United States)

    Roy, Sharon L; Atkins, Jane T; Gennuso, Rosemaria; Kofos, Danny; Sriram, Rama R; Dorlo, Thomas P C; Hayes, Teresa; Qvarnstrom, Yvonne; Kucerova, Zuzana; Guglielmo, B Joseph; Visvesvara, Govinda S

    2015-12-01

    Balamuthia mandrillaris, a free-living ameba, causes rare but frequently fatal granulomatous amebic encephalitis (GAE). Few patients have survived after receiving experimental drug combinations, with or without brain lesion excisions. Some GAE survivors have been treated with a multi-drug regimen including miltefosine, an investigational anti-leishmanial agent with in vitro amebacidal activity. Miltefosine dosing for GAE has been based on leishmaniasis dosing because no data exist in humans concerning its pharmacologic distribution in the central nervous system. We describe results of limited cerebrospinal fluid (CSF) and serum drug level testing performed during clinical management of a child with fatal GAE who was treated with a multiple drug regimen including miltefosine. Brain biopsy specimens, CSF, and sera were tested for B. mandrillaris using multiple techniques, including culture, real-time polymerase chain reaction, immunohistochemical techniques, and serology. CSF and serum miltefosine levels were determined using a liquid chromatography method coupled to tandem mass spectrometry. The CSF miltefosine concentration on hospital admission day 12 was 0.4 μg/mL. The serum miltefosine concentration on day 37, about 80 h post-miltefosine treatment, was 15.3 μg/mL. These are the first results confirming some blood-brain barrier penetration by miltefosine in a human, although with low-level CSF accumulation. Further evaluation of brain parenchyma penetration is required to determine optimal miltefosine dosing for Balamuthia GAE, balanced with the drug's toxicity profile. Additionally, the Balamuthia isolate was evaluated by real-time polymerase chain reaction (PCR), demonstrating genetic variability in 18S ribosomal RNA (18S rRNA) sequences and possibly signaling the first identification of multiple Balamuthia strains with varying pathogenicities. PMID:26329128

  4. The interaction of carbon nanotubes with an in vitro blood-brain barrier model and mouse brain in vivo

    Science.gov (United States)

    Kafa, Houmam; Wang, Julie Tzu-Wen; Rubio, Noelia; Venner, Kerrie; Anderson, Glenn; Pach, Elzbieta; Ballesteros, Belén; Preston, Jane E.; Abbott, N. Joan; Al-Jamal, Khuloud T.

    2015-01-01

    Carbon nanotubes (CNTs) are a novel nanocarriers with interesting physical and chemical properties. Here we investigate the ability of amino-functionalized multi-walled carbon nanotubes (MWNTs-NH3+) to cross the Blood-Brain Barrier (BBB) in vitro using a co-culture BBB model comprising primary porcine brain endothelial cells (PBEC) and primary rat astrocytes, and in vivo following a systemic administration of radiolabelled f-MWNTs. Transmission Electron microscopy (TEM) confirmed that MWNTs-NH3+ crossed the PBEC monolayer via energy-dependent transcytosis. MWNTs-NH3+ were observed within endocytic vesicles and multi-vesicular bodies after 4 and 24 h. A complete crossing of the in vitro BBB model was observed after 48 h, which was further confirmed by the presence of MWNTs-NH3+ within the astrocytes. MWNT-NH3+ that crossed the PBEC layer was quantitatively assessed using radioactive tracers. A maximum transport of 13.0 ± 1.1% after 72 h was achieved using the co-culture model. f-MWNT exhibited significant brain uptake (1.1  ±  0.3% injected dose/g) at 5 min after intravenous injection in mice, after whole body perfusion with heparinized saline. Capillary depletion confirmed presence of f-MWNT in both brain capillaries and parenchyma fractions. These results could pave the way for use of CNTs as nanocarriers for delivery of drugs and biologics to the brain, after systemic administration. PMID:25890741

  5. Cultured bovine brain capillary endothelial cells (BBCEC) - a blood-brain barrier model for studying the binding and internalization of insulin and insulin-like growth factor 1

    Energy Technology Data Exchange (ETDEWEB)

    Keller, B.T.; Borchardt, R.T.

    1987-05-01

    Cultured bovine brain capillary endothelial cells (BBCEC) have previously been reported by their laboratory as a working model for studying nutrient and drug transport and metabolism at the blood-brain barrier. In the present study, they have utilized this culture system to investigate the binding and internalization of (/sup 125/I)-labelled insulin (INS) and insulin-like growth factor 1(IGF-1) by BBCEC. After 2 hrs at 23/sup 0/C, the specific binding of INS and IGF-1 was 1.6% and 13.6%, respectively. At 37/sup 0/C, the maximum specific binding was 0.9% for INS and 5.8% for IGF-1. Using an acid-wash technique to assess peptide internalization, it was observed that, at 37/sup 0/C, approximately 60% of the bound INS rapidly became resistant to acid treatment, a value which was constant over 2 hr. With IGF-1, a similar proportion of the bound material, 62%, became resistant by 30 min, but subsequently decreased to 45% by 2 hr. Scatchard analysis of competitive binding studies indicated the presence of two binding sites for each protein, having K/sub d/'s of 0.82 nM and 19.2 nM for INS and 0.39 nM and 3.66 nM for IGF-1. Little change in the amount of INS binding was observed over a four-day interval as the cultures became a confluent monolayer. The present report of binding and internalization of these proteins suggests that the BBCEC may utilize a receptor-mediated process to internalize and/or transport (transcytosis) INS and IGF-1 from the circulation.

  6. Meningitic Escherichia coli K1 penetration and neutrophil transmigration across the blood-brain barrier are modulated by alpha7 nicotinic receptor.

    Directory of Open Access Journals (Sweden)

    Feng Chi

    Full Text Available Alpha7 nicotinic acetylcholine receptor (nAChR, an essential regulator of inflammation, is abundantly expressed in hippocampal neurons, which are vulnerable to bacterial meningitis. However, it is unknown whether α7 nAChR contributes to the regulation of these events. In this report, an aggravating role of α7 nAChR in host defense against meningitic E. coli infection was demonstrated by using α7-deficient (α7(-/- mouse brain microvascular endothelial cells (BMEC and animal model systems. As shown in our in vitro and in vivo studies, E. coli K1 invasion and polymorphonuclear neutrophil (PMN transmigration across the blood-brain barrier (BBB were significantly reduced in α7(-/- BMEC and α7(-/- mice. Stimulation by nicotine was abolished in the α7(-/- cells and animals. The same blocking effect was achieved by methyllycaconitine (α7 antagonist. The tight junction molecules occludin and ZO-1 were significantly reduced in the brain cortex of wildtype mice infected with E. coli and treated with nicotine, compared to α7(-/- cells and animals. Decreased neuronal injury in the hippocampal dentate gyrus was observed in α7(-/- mice with meningitis. Proinflammatory cytokines (IL-1β, IL-6, TNFα, MCP-1, MIP-1alpha, and RANTES and adhesion molecules (CD44 and ICAM-1 were significantly reduced in the cerebrospinal fluids of the α7(-/- mice with E. coli meningitis. Furthermore, α7 nAChR is the major calcium channel for nicotine- and E. coli K1-increased intracellular calcium concentrations of mouse BMEC. Taken together, our data suggest that α7 nAChR plays a detrimental role in the host defense against meningitic infection by modulation of pathogen invasion, PMN recruitment, calcium signaling and neuronal inflammation.

  7. Antidiabetic drugs restore abnormal transport of amyloid-β across the blood-brain barrier and memory impairment in db/db mice.

    Science.gov (United States)

    Chen, Fang; Dong, Rong Rong; Zhong, Kai Long; Ghosh, Arijit; Tang, Su Su; Long, Yan; Hu, Mei; Miao, Ming Xing; Liao, Jian Min; Sun, Hong Bing; Kong, Ling Yi; Hong, Hao

    2016-02-01

    Previous studies have shown significant changes in amyloid-β (Aβ) transport across the blood-brain barrier (BBB) under diabetic conditions with hypoinsulinemia, which is involved in diabetes-associated cognitive impairment. Present study employed db/db mice with hyperinsulinemia to investigate changes in Aβ transport across the BBB, hippocampal synaptic plasticity, and restorative effects of antidiabetic drugs. Our results showed that db/db mice exhibited similar changes in Aβ transport across the BBB to that of insulin-deficient mice. Chronic treatment of db/db mice with antidiabetic drugs such as metformin, glibenclamide and insulin glargine significantly decreased Aβ influx across the BBB determined by intra-arterial infusion of (125)I-Aβ(1-40), and expression of the receptor for advanced glycation end products (RAGE) participating in Aβ influx. Insulin glargine, but not, metformin or glibenclamide increased Aβ efflux across the BBB determined by stereotaxic intra-cerebral infusion of (125)I-Aβ(1-40), and expression of the low-density lipoprotein receptor related protein 1 (LRP1) participating in Aβ efflux. Moreover, treatment with these drugs significantly decreased hippocampal Aβ(1-40) or Aβ(1-42) and inhibited neuronal apoptosis. The drugs also ameliorated memory impairment confirmed by improved performance on behavioral tasks. However, insulin glargine or glibenclamide, but not metformin, restored hippocampal synaptic plasticity characterized by enhancing in vivo long-term potentiation (LTP). Further study found that these three drugs significantly restrained NF-κB, but only insulin glargine enhanced peroxisome proliferator-activated receptor γ (PPARγ) activity at the BBB in db/db mice. Our data indicate that the antidiabetic drugs can partially restore abnormal Aβ transport across the BBB and memory impairment under diabetic context. PMID:26211973

  8. Opiates Upregulate Adhesion Molecule Expression in Brain MicroVascular Endothelial Cells (BMVEC: Implications for Altered Blood Brain Barrier (BBB Permeability

    Directory of Open Access Journals (Sweden)

    Madhavan P.N. Nair

    2006-01-01

    Full Text Available The blood-brain barrier (BBB is an intricate cellular system composed of vascular endothelial cells and perivascular astrocytes that restrict the passage of immunocompetent cells into the central nervous system (CNS. Expression of the adhesion molecules, intercellular adhesion molecule 1 (ICAM-1 and vascular cell adhesion molecule-1 (VCAM-1 on brain microvascular endothelial cells (BMVEC and their interaction with human immunodeficiency virus (HIV-1 viral proteins may help enhance viral adhesion and virus-cell fusion resulting in increased infectivity. Additionally, transmigration through the BBB is facilitated by both endothelial and monocyte/macrophage-derived nitric oxide (NO. Dysregulated production of NO by BMVEC due to opiates and HIV-1 viral protein interactions play a pivotal role in brain endothelial injury, resulting in the irreversible loss of BBB integrity, which may lead to enhanced infiltration of virus-carrying cells across the BBB. Opioids act as co-factors in the neuropathogenesis of HIV-1 by facilitating BBB dysfunction however, no studies have been done to investigate the role of opiates alone or in combination with HIV-1 viral proteins on adhesion molecule expression in BMVEC. We hypothesize that opiates such as heroin and morphine in conjunction with the HIV-1 viral protein gp120 increase the expression of adhesion molecules ICAM-1 and VCAM-1 and these effects are mediated via the modulation of NO. Results show that opiates alone and in synergy with gp120 increase both the genotypic and phenotypic expression of ICAM-1 and VCAM-1 by BMVEC, additionally, these opiate induced effects may be the result of increased NO production. These studies will provide a better understanding of how opiate abuse in conjunction with HIV-1 infection facilitates the breakdown of the BBB and exacerbates the neuropathogenesis of HIV-1. Elucidation of the mechanisms of BBB modulation will provide new therapeutic approaches to maintain BBB integrity

  9. Insulin Receptor Antibody-α-N-Acetylglucosaminidase Fusion Protein Penetrates the Primate Blood-Brain Barrier and Reduces Glycosoaminoglycans in Sanfilippo Type B Fibroblasts.

    Science.gov (United States)

    Boado, Ruben J; Lu, Jeff Zhiqiang; Hui, Eric Ka-Wai; Lin, Huilan; Pardridge, William M

    2016-04-01

    Mucopolysaccharidosis Type IIIB (MPSIIIB) is caused by mutations in the gene encoding the lysosomal enzyme, α-N-acetylglucosaminidase (NAGLU). MPSIIIB presents with severe disease of the central nervous system, but intravenous NAGLU enzyme replacement therapy has not been developed because the NAGLU enzyme does not cross the blood-brain barrier (BBB). A BBB-penetrating form of the enzyme was produced by re-engineering NAGLU as an IgG-enzyme fusion protein, where the IgG domain is a monoclonal antibody (mAb) against the human insulin receptor (HIR). The HIRMAb traverses the BBB via transport on the endogenous insulin receptor and acts as a molecular Trojan horse to ferry the fused NAGLU across the BBB from blood. The NAGLU was fused to the carboxyl terminus of each heavy chain of the HIRMAb via an extended 31-amino acid linker, and the fusion protein is designated HIRMAb-LL-NAGLU. The fusion protein retains high affinity binding to the HIR, and on a molar basis has an enzyme activity equal to that of recombinant human NAGLU. Treatment of MPSIIIB fibroblasts with the fusion protein normalizes intracellular NAGLU enzyme activity and reduces sulfate incorporation into intracellular glycosoaminoglycan. The fusion protein is targeted to the lysosomal compartment of the cells as shown by confocal microscopy. The fusion protein was radiolabeled with the [(125)I]-Bolton-Hunter reagent and injected intravenously in the adult Rhesus monkey. The fusion protein was rapidly cleared from plasma by all major peripheral organs. The high brain uptake of the fusion protein, 1% injected dose/brain, enables normalization of brain NAGLU enzyme activity with a therapeutic dose of 1 mg/kg. The HIRMAb-LL-NAGLU fusion protein is a new treatment of the brain in MPSIIIB, which can be administered by noninvasive intravenous infusion. PMID:26910785

  10. The proton permeability of self-assembled polymersomes and their neuroprotection by enhancing a neuroprotective peptide across the blood-brain barrier after modification with lactoferrin

    Science.gov (United States)

    Yu, Yuan; Jiang, Xinguo; Gong, Shuyu; Feng, Liang; Zhong, Yanqiang; Pang, Zhiqing

    2014-02-01

    Biotherapeutics such as peptides possess strong potential for the treatment of intractable neurological disorders. However, because of their low stability and the impermeability of the blood-brain barrier (BBB), biotherapeutics are difficult to transport into brain parenchyma via intravenous injection. Herein, we present a novel poly(ethylene glycol)-poly(d,l-lactic-co-glycolic acid) polymersome-based nanomedicine with self-assembled bilayers, which was functionalized with lactoferrin (Lf-POS) to facilitate the transport of a neuroprotective peptide into the brain. The apparent diffusion coefficient (D*) of H+ through the polymersome membrane was 5.659 × 10-26 cm2 s-1, while that of liposomes was 1.017 × 10-24 cm2 s-1. The stability of the polymersome membrane was much higher than that of liposomes. The uptake of polymersomes by mouse brain capillary endothelial cells proved that the optimal density of lactoferrin was 101 molecules per polymersome. Fluorescence imaging indicated that Lf101-POS was effectively transferred into the brain. In pharmacokinetics, compared with transferrin-modified polymersomes and cationic bovine serum albumin-modified polymersomes, Lf-POS obtained the greatest BBB permeability surface area and percentage of injected dose per gram (%ID per g). Furthermore, Lf-POS holding S14G-humanin protected against learning and memory impairment induced by amyloid-β25-35 in rats. Western blotting revealed that the nanomedicine provided neuroprotection against over-expression of apoptotic proteins exhibiting neurofibrillary tangle pathology in neurons. The results indicated that polymersomes can be exploited as a promising non-invasive nanomedicine capable of mediating peptide therapeutic delivery and controlling the release of drugs to the central nervous system.

  11. Blood-brain barrier penetration of novel pyridinealdoxime methiodide (PAM)-type oximes examined by brain microdialysis with LC-MS/MS

    International Nuclear Information System (INIS)

    To develop a new reactivator of inhibited acetylcholinesterase (AChE) that can easily penetrate the blood-brain barrier (BBB), BBB penetration of 6 known and novel pyridinealdoxime methiodide (PAM)-type oximes (alkylPAMs) with relatively high reactivation activities was examined by in vivo rat brain microdialysis with liquid chromatography-mass spectrometry (LC-MS/MS). The 50% lethal dose (LD50) of alkylPAMs was intravenously determined for Wistar rats, then the limit of detection, quantification range and linearity of the calibration curve of the alkylPAMs in dialysate and blood were determined by LC-MS/MS. Following 10% LD50 intravenous administration of the alkylPAMs, 4-[(hydroxyimino) methyl]-1-(2-phenylethyl) pyridinium bromide (4-PAPE) and 4-[(hydroxyimino) methyl]-1-octylpyridinium bromide (4-PAO) appeared in the dialysate. Striatal extracellular fluid/blood concentration ratios were 0.039 ± 0.018 and 0.301 ± 0.183 (mean ± SEM), respectively, 1 h after treatment. This is the first report of BBB penetration of 4-PAPE, and the concentration ratio was smaller than that of 2-PAM.The mean BBB penetration of 4-PAO was approximately 30%, indicating that intravenous administration of 4-PAO may be effective for the reactivation of blocked cholinesterase in the brain. However, the toxicity of 4-PAO (LD50; 8.89 mg/kg) was greater than that of 2-PAM. Further investigation is required to determine the effects of these alkylPAMs in organophosphate poisoning

  12. P-glycoprotein differentially affects escitalopram, levomilnacipran, vilazodone and vortioxetine transport at the mouse blood-brain barrier in vivo.

    Science.gov (United States)

    Bundgaard, Christoffer; Eneberg, Elin; Sánchez, Connie

    2016-04-01

    P-glycoprotein (P-gp)-mediated brain efflux of xenobiotics is a well-known process, which may result in suboptimal target engagement and consequently reduced efficacy of drugs exerting their therapeutic effects in the central nervous system. In the present study the role of P-gp in transport across the blood-brain barrier (BBB) was investigated with a series of newer antidepressants (levomilnacipran, vilazodone and vortioxetine) and a control substrate (escitalopram) using P-gp knock-out (KO) and P-gp competent wild-type (WT) mice. Brain and plasma exposure time-courses were measured after an acute subcutaneous dose and at steady-state obtained after subcutaneous drug infusion by osmotic minipumps. Following acute dosing, the brain-to-plasma KO/WT exposure enhancement ratios ((AUCbrain ko/AUCplasma ko)/(AUCbrain WT/AUCplasma WT)) were 5.8 (levomilnacipran), 5.4 (vilazodone), 3.1 (escitalopram) and 0.9 (vortioxetine), respectively. At steady-state, assessment of Kp,uu (unbound brain concentrations/unbound plasma concentrations) revealed a restriction in the brain distribution in WT mice for all compounds except vortioxetine. Levomilnacipran exhibited the most pronounced efflux with a Kp,uu-value of 0.038 in WT mice which was increased to 0.37 in KO mice. Based on both the acute and steady-state distribution data, the results suggest that levomilnacipran, vilazodone and escitalopram are susceptible to P-gp mediated efflux at the BBB in vivo in mice, whereas vortioxetine was practically devoid of being affected by P-gp in vivo. The functional impact of the drug transport-controlling role of P-gp at the BBB was demonstrated by in vivo cortical serotonin transporter occupancy of vilazodone, which exhibited a 20-fold higher plasma EC50 in WT mice compared to KOs. PMID:26700248

  13. A 2D-QSPR approach to predict blood-brain barrier penetration of drugs acting on the central nervous system

    Directory of Open Access Journals (Sweden)

    Matheus Malta de Sá

    2010-12-01

    Full Text Available Drugs acting on the central nervous system (CNS have to cross the blood-brain barrier (BBB in order to perform their pharmacological actions. Passive BBB diffusion can be partially expressed by the blood/brain partition coefficient (logBB. As the experimental evaluation of logBB is time and cost consuming, theoretical methods such as quantitative structure-property relationships (QSPR can be useful to predict logBB values. In this study, a 2D-QSPR approach was applied to a set of 28 drugs acting on the CNS, using the logBB property as biological data. The best QSPR model [n = 21, r = 0.94 (r² = 0.88, s = 0.28, and Q² = 0.82] presented three molecular descriptors: calculated n-octanol/water partition coefficient (ClogP, polar surface area (PSA, and polarizability (α. Six out of the seven compounds from the test set were well predicted, which corresponds to good external predictability (85.7%. These findings can be helpful to guide future approaches regarding those molecular descriptors which must be considered for estimating the logBB property, and also for predicting the BBB crossing ability for molecules structurally related to the investigated set.Fármacos que atuam no sistema nervoso central (SNC devem atravessar a barreira hematoencefálica (BHE para exercerem suas ações farmacológicas. A difusão passiva através da BHE pode ser parcialmente expressa pelo coeficiente de partição entre os compartimentos encefálico e sanguíneo (logBB, brain/blood partition coefficient. Considerando-se que a avaliação experimental de logBB é dispendiosa e demorada, métodos teóricos como estudos das relações entre estrutura química e propriedade (QSPR, Quantitative Structure-Property Relationships podem ser utilizados na previsão dos valores de logBB. Neste estudo, uma abordagem de QSPR-2D foi aplicada a um conjunto de 28 moléculas com ação central, usando logBB como propriedade biológica. O melhor modelo de QSPR [n = 21, r = 0,94 (r

  14. Endothelial cells derived from the blood-brain barrier and islets of Langerhans differ in their response to the effects of bilirubin on oxidative stress under hyperglycemic conditions

    Directory of Open Access Journals (Sweden)

    JaimeKapitulnik

    2012-07-01

    Full Text Available Unconjugated bilirubin (UCB is a neurotoxic degradation product of heme. Its toxic effects include induction of apoptosis, and ultimately neuronal cell death. However, at low concentrations, UCB is a potent antioxidant that may protect cells and tissues against oxidative stress by neutralizing toxic metabolites such as reactive oxygen species (ROS. High glucose levels (hyperglycemia generate reactive metabolites. Endothelial cell dysfunction, an early vascular complication in diabetes, has been associated with hyperglycemia-induced oxidative stress. Both glucose and UCB are substrates for transport proteins in microvascular endothelial cells of the blood-brain barrier (BBB. In the current study we show that UCB (1-40 M induces apoptosis and reduces survival of bEnd3 cells, a mouse brain endothelial cell line which serves as an in vitro model of the BBB. These deleterious effects of UCB were enhanced in the presence of high glucose (25 mM levels. Interestingly, the bEnd3 cells exhibited an increased sensitivity to the apoptotic effects of UCB when compared to the MS1 microcapillary endothelial cell line. MS1 cells originate from murine pancreatic islets of Langherans, and are devoid of the barrier characteristics of BBB-derived endothelial cells. ROS production was increased in both bEnd3 and MS1 cells exposed to high glucose, as compared with cells exposed to normal (5.5 mM glucose levels. While UCB (0.1-40 M did not alter ROS production in cells exposed to normal glucose, relatively low ('physiological' UCB concentrations (0.1-5 M attenuated ROS generation in both cell lines exposed to high glucose levels. Most strikingly, higher UCB concentrations (20-40 M increased ROS generation in bEnd3 cells exposed to high glucose, but not in similarly treated MS1 cells. These results may be of critical importance for understanding the vulnerability of the BBB endothelium upon exposure to increasing UCB levels under hyperglycemic conditions.

  15. Downregulation of blood-brain barrier phenotype by proinflammatory cytokines involves NADPH oxidase-dependent ROS generation: consequences for interendothelial adherens and tight junctions.

    Directory of Open Access Journals (Sweden)

    Keith D Rochfort

    Full Text Available Blood-brain barrier (BBB dysfunction is an integral feature of neurological disorders and involves the action of multiple proinflammatory cytokines on the microvascular endothelial cells lining cerebral capillaries. There is still however, considerable ambiguity throughout the scientific literature regarding the mechanistic role(s of cytokines in this context, thereby warranting a comprehensive in vitro investigation into how different cytokines may cause dysregulation of adherens and tight junctions leading to BBB permeabilization.The present study employs human brain microvascular endothelial cells (HBMvECs to compare/contrast the effects of TNF-α and IL-6 on BBB characteristics ranging from the expression of interendothelial junction proteins (VE-cadherin, occludin and claudin-5 to endothelial monolayer permeability. The contribution of cytokine-induced NADPH oxidase activation to altered barrier phenotype was also investigated.In response to treatment with either TNF-α or IL-6 (0-100 ng/ml, 0-24 hrs, our studies consistently demonstrated significant dose- and time-dependent decreases in the expression of all interendothelial junction proteins examined, in parallel with dose- and time-dependent increases in ROS generation and HBMvEC permeability. Increased expression and co-association of gp91 and p47, pivotal NADPH oxidase subunits, was also observed in response to either cytokine. Finally, cytokine-dependent effects on junctional protein expression, ROS generation and endothelial permeability could all be attenuated to a comparable extent using a range of antioxidant strategies, which included ROS depleting agents (superoxide dismutase, catalase, N-acetylcysteine, apocynin and targeted NADPH oxidase blockade (gp91 and p47 siRNA, NSC23766.A timely and wide-ranging investigation comparing the permeabilizing actions of TNF-α and IL-6 in HBMvECs is presented, in which we demonstrate how either cytokine can similarly downregulate the

  16. Measurement of brain perfusion, blood volume, and blood-brain barrier permeability, using dynamic contrast-enhanced T(1)-weighted MRI at 3 tesla

    DEFF Research Database (Denmark)

    Larsson, Henrik B W; Courivaud, Frédéric; Rostrup, Egill;

    2009-01-01

    Assessment of vascular properties is essential to diagnosis and follow-up and basic understanding of pathogenesis in brain tumors. In this study, a procedure is presented that allows concurrent estimation of cerebral perfusion, blood volume, and blood-brain permeability from dynamic T(1)-weighted...

  17. Brain pericytes among cells constituting the blood-brain barrier are highly sensitive to tumor necrosis factor-α, releasing matrix metalloproteinase-9 and migrating in vitro

    Directory of Open Access Journals (Sweden)

    Miyaji Haruki

    2011-08-01

    Full Text Available Abstract Background Increased matrix metalloproteinase (MMP-9 in the plasma and brain is associated with blood-brain barrier (BBB disruption through proteolytic activity in neuroinflammatory diseases. MMP-9 is present in the brain microvasculature and its vicinity, where brain microvascular endothelial cells (BMECs, pericytes and astrocytes constitute the BBB. Little is known about the cellular source and role of MMP-9 at the BBB. Here, we examined the ability of pericytes to release MMP-9 and migrate in response to inflammatory mediators in comparison with BMECs and astrocytes, using primary cultures isolated from rat brains. Methods The culture supernatants were collected from primary cultures of rat brain endothelial cells, pericytes, or astrocytes. MMP-9 activities and levels in the supernatants were measured by gelatin zymography and western blot, respectively. The involvement of signaling molecules including mitogen-activated protein kinases (MAPKs and phosphoinositide-3-kinase (PI3K/Akt in the mediation of tumor necrosis factor (TNF-α-induced MMP-9 release was examined using specific inhibitors. The functional activity of MMP-9 was evaluated by a cell migration assay. Results Zymographic and western blot analyses demonstrated that TNF-α stimulated pericytes to release MMP-9, and this release was much higher than from BMECs or astrocytes. Other inflammatory mediators [interleukin (IL-1β, interferon-γ, IL-6 and lipopolysaccharide] failed to induce MMP-9 release from pericytes. TNF-α-induced MMP-9 release from pericytes was found to be mediated by MAPKs and PI3K. Scratch wound healing assay showed that in contrast to BMECs and astrocytes the extent of pericyte migration was significantly increased by TNF-α. This pericyte migration was inhibited by anti-MMP-9 antibody. Conclusion These findings suggest that pericytes are most sensitive to TNF-α in terms of MMP-9 release, and are the major source of MMP-9 at the BBB. This pericyte

  18. Preclinical Metabolism, Pharmacokinetics and In Vivo Analysis of New Blood-Brain-Barrier Penetrant Fingolimod Analogues: FTY720-C2 and FTY720-Mitoxy.

    Science.gov (United States)

    Enoru, Julius O; Yang, Barbara; Krishnamachari, Sesha; Villanueva, Ernesto; DeMaio, William; Watanyar, Adiba; Chinnasamy, Ramesh; Arterburn, Jeffrey B; Perez, Ruth G

    2016-01-01

    Parkinson's disease (PD) is a neurodegenerative aging disorder in which postmortem PD brain exhibits neuroinflammation, as well as synucleinopathy-associated protein phosphatase 2A (PP2A) enzymatic activity loss. Based on our translational research, we began evaluating the PD-repurposing-potential of an anti-inflammatory, neuroprotective, and PP2A stimulatory oral drug that is FDA-approved for multiple sclerosis, FTY720 (fingolimod, Gilenya®). We also designed two new FTY720 analogues, FTY720-C2 and FTY720-Mitoxy, with modifications that affect drug potency and mitochondrial localization, respectively. Herein, we describe the metabolic stability and metabolic profiling of FTY720-C2 and FTY720-Mitoxy in liver microsomes and hepatocytes. Using mouse, rat, dog, monkey, and human liver microsomes the intrinsic clearance of FTY720-C2 was 22.5, 79.5, 6.0, 20.2 and 18.3 μL/min/mg; and for FTY720-Mitoxy was 1.8, 7.8, 1.4, 135.0 and 17.5 μL/min/mg, respectively. In hepatocytes, both FTY720-C2 and FTY720-Mitoxy were metabolized from the octyl side chain, generating a series of carboxylic acids similar to the parent FTY720, but without phosphorylated metabolites. To assess absorption and distribution, we gave equivalent single intravenous (IV) or oral doses of FTY720-C2 or FTY720-Mitoxy to C57BL/6 mice, with two mice per time point evaluated. After IV delivery, both FTY720-C2 and FTY720-Mitoxy were rapidly detected in plasma and brain; and reached peak concentrations at the first sampling time points. After oral dosing, FTY720-C2 was present in plasma and brain, although FTY720-Mitoxy was not orally bioavailable. Brain-to-plasma ratio of both compounds increased time-dependently, suggesting a preferential partitioning to the brain. PP2A activity in mouse adrenal gland increased ~2-fold after FTY720-C2 or FTY720-Mitoxy, as compared to untreated controls. In summary, FTY720-C2 and FTY720-Mitoxy both (i) crossed the blood-brain-barrier; (ii) produced metabolites similar to

  19. Relationship between AQP4 expression and structural damage to the blood-brain barrier at early stages of traumatic brain injury in rats

    Institute of Scientific and Technical Information of China (English)

    LU Hong; LEI Xiao-yan; HU Hui; HE Zhan-ping

    2013-01-01

    Background Although some studies have reported that aquaporin-4 (AQP4) plays an important role in the brain edema after traumatic brain injury (TBI),little is known about the AQP4 expression in the early stage of TBI,or about the correlation between the structural damage to the blood-brain barrier (BBB) and angioedema.The aim of this project was to investigate the relationship between AQP4 expression and damage to the BBB at early stages of TBI.Methods One hundred and twenty healthy adult Wistar rats were randomly divided into two greups:sham operation group (SO) and TBI group.The TBI group was divided into five sub-groups according to the different time intervals:1,3,6,12,and 24 hours.The brains of the animals were taken out at different time points after TBI to measure brain water content.The cerebral edema and BBB changes in structure were examined with an optical microscopy (OM) and transmission electron microscopy (TEM),and the IgG content and AQP4 protein expression in traumatic brain tissue were determined by means of immunohistochemistry and Western blotting.The data were analyzed with SPSS 13.0statistical software.Results In the SO greup,tissue was negative for IgG,and there were no abnormalities in brain water content or AQP4 expression.In the TBI group,brain water content significantly increased at 6 hours and peaked at 24 hours following injury.IgG expression significantly increased from 1 to 6 hours following injury,and remained at a high level at 24 hours.Pathological observation revealed BBB damage at 1 hour following injury.Angioedema appeared at 1 hour,was gradually aggravated,and became obvious at 6 hours.Intracellular edema occurred at 3 hours,with the presence of large glial cell bodies and mitochondrial swelling.These phenomena were aggravated with time and became obvious at 12 hours.In addition,microglial proliferation was visible at 24 hours.AQP4 protein expression were reduced at 1 hour,lowest at 6 hours,and began to increase at 12 hours

  20. NG2, a common denominator for neuroinflammation, blood-brain barrier alteration, and oligodendrocyte precursor response in EAE, plays a role in dendritic cell activation.

    Science.gov (United States)

    Ferrara, Giovanni; Errede, Mariella; Girolamo, Francesco; Morando, Sara; Ivaldi, Federico; Panini, Nicolò; Bendotti, Caterina; Perris, Roberto; Furlan, Roberto; Virgintino, Daniela; Kerlero de Rosbo, Nicole; Uccelli, Antonio

    2016-07-01

    In adult CNS, nerve/glial-antigen 2 (NG2) is expressed by oligodendrocyte progenitor cells (OPCs) and is an early marker of pericyte activation in pathological conditions. NG2 could, therefore, play a role in experimental autoimmune encephalomyelitis (EAE), a disease associated with increased blood-brain barrier (BBB) permeability, inflammatory infiltrates, and CNS damage. We induced EAE in NG2 knock-out (NG2KO) mice and used laser confocal microscopy immunofluorescence and morphometry to dissect the effect of NG2 KO on CNS pathology. NG2KO mice developed milder EAE than their wild-type (WT) counterparts, with less intense neuropathology associated with a significant improvement in BBB stability. In contrast to WT mice, OPC numbers did not change in NG2KO mice during EAE. Through FACS and confocal microscopy, we found that NG2 was also expressed by immune cells, including T cells, macrophages, and dendritic cells (DCs). Assessment of recall T cell responses to the encephalitogen by proliferation assays and ELISA showed that, while WT and NG2KO T cells proliferated equally to the encephalitogenic peptide MOG35-55, NG2KO T cells were skewed towards a Th2-type response. Because DCs could be responsible for this effect, we assessed their expression of IL-12 by PCR and intracellular FACS. IL-12-expressing CD11c+ cells were significantly decreased in MOG35-55-primed NG2KO lymph node cells. Importantly, in WT mice, the proportion of IL-12-expressing cells was significantly lower in CD11c+ NG2- cells than in CD11c+ NG2+ cells. To assess the relevance of NG2 at immune system and CNS levels, we induced EAE in bone-marrow chimeric mice, generated with WT recipients of NG2KO bone-marrow cells and vice versa. Regardless of their original phenotype, mice receiving NG2KO bone marrow developed milder EAE than those receiving WT bone marrow. Our data suggest that NG2 plays a role in EAE not only at CNS/BBB level, but also at immune response level, impacting on DC activation and

  1. 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

  2. Magnetic resonance imaging indicators of blood-brain barrier and brain water changes in young rats with kaolin-induced hydrocephalus

    Directory of Open Access Journals (Sweden)

    Del Bigio Marc R

    2011-08-01

    Full Text Available Abstract Background Hydrocephalus is associated with enlargement of cerebral ventricles. We hypothesized that magnetic resonance (MR imaging parameters known to be influenced by tissue water content would change in parallel with ventricle size in young rats and that changes in blood-brain barrier (BBB permeability would be detected. Methods Hydrocephalus was induced by injection of kaolin into the cisterna magna of 4-week-old rats, which were studied 1 or 3 weeks later. MR was used to measure longitudinal and transverse relaxation times (T1 and T2 and apparent diffusion coefficients in several regions. Brain tissue water content was measured by the wet-dry weight method, and tissue density was measured in Percoll gradient columns. BBB permeability was measured by quantitative imaging of changes on T1-weighted images following injection of gadolinium diethylenetriamine penta-acetate (Gd-DTPA tracer and microscopically by detection of fluorescent dextran conjugates. Results In nonhydrocephalic rats, water content decreased progressively from age 3 to 7 weeks. T1 and T2 and apparent diffusion coefficients did not exhibit parallel changes and there was no evidence of BBB permeability to tracers. The cerebral ventricles enlarged progressively in the weeks following kaolin injection. In hydrocephalic rats, the dorsal cortex was more dense and the white matter less so, indicating that the increased water content was largely confined to white matter. Hydrocephalus was associated with transient elevation of T1 in gray and white matter and persistent elevation of T2 in white matter. Changes in the apparent diffusion coefficients were significant only in white matter. Ventricle size correlated significantly with dorsal water content, T1, T2, and apparent diffusion coefficients. MR imaging showed evidence of Gd-DTPA leakage in periventricular tissue foci but not diffusely. These correlated with microscopic leak of larger dextran tracers. Conclusions MR

  3. Treatment with the NK1 antagonist emend reduces blood brain barrier dysfunction and edema formation in an experimental model of brain tumors.

    Directory of Open Access Journals (Sweden)

    Elizabeth Harford-Wright

    Full Text Available The neuropeptide substance P (SP has been implicated in the disruption of the blood-brain barrier (BBB and development of cerebral edema in acute brain injury. Cerebral edema accumulates rapidly around brain tumors and has been linked to several tumor-associated deficits. Currently, the standard treatment for peritumoral edema is the corticosteroid dexamethasone, prolonged use of which is associated with a number of deleterious side effects. As SP is reported to increase in many cancer types, this study examined whether SP plays a role in the genesis of brain peritumoral edema. A-375 human melanoma cells were injected into the right striatum of male Balb/c nude mice to induce brain tumor growth, with culture medium injected in animals serving as controls. At 2, 3 or 4 weeks following tumor cell inoculation, non-treated animals were perfusion fixed for immunohistochemical detection of Albumin, SP and NK1 receptor. A further subgroup of animals was treated with a daily injection of the NK1 antagonist Emend (3 mg/kg, dexamethasone (8 mg/kg or saline vehicle at 3 weeks post-inoculation. Animals were sacrificed a week later to determine BBB permeability using Evan's Blue and brain water content. Non-treated animals demonstrated a significant increase in albumin, SP and NK1 receptor immunoreactivity in the peritumoral area as well as increased perivascular staining in the surrounding brain tissue. Brain water content and BBB permeability was significantly increased in tumor-inoculated animals when compared to controls (p<0.05. Treatment with Emend and dexamethasone reduced BBB permeability and brain water content when compared to vehicle-treated tumor-inoculated mice. The increase in peritumoral staining for both SP and the NK1 receptor, coupled with the reduction in brain water content and BBB permeability seen following treatment with the NK1 antagonist Emend, suggests that SP plays a role in the genesis of peritumoral edema, and thus warrants

  4. Inflammation Modulates RLIP76/RALBP1 Electrophile-Glutathione Conjugate Transporter and Housekeeping Genes in Human Blood-Brain Barrier Endothelial Cells.

    Directory of Open Access Journals (Sweden)

    Barbara Bennani-Baiti

    Full Text Available Endothelial cells are often present at inflammation sites. This is the case of endothelial cells of the blood-brain barrier (BBB of patients afflicted with neurodegenerative disorders such as Alzheimer's, Parkinson's, or multiple sclerosis, as well as in cases of bacterial meningitis, trauma, or tumor-associated ischemia. Inflammation is a known modulator of gene expression through the activation of transcription factors, mostly NF-κB. RLIP76 (a.k.a. RALBP1, an ATP-dependent transporter of electrophile-glutathione conjugates, modulates BBB permeability through the regulation of tight junction function, cell adhesion, and exocytosis. Genes and pathways regulated by RLIP76 are transcriptional targets of tumor necrosis factor alpha (TNF-α pro-inflammatory molecule, suggesting that RLIP76 may also be an inflammation target. To assess the effects of TNF-α on RLIP76, we faced the problem of choosing reference genes impervious to TNF-α. Since such genes were not known in human BBB endothelial cells, we subjected these to TNF-α, and measured by quantitative RT-PCR the expression of housekeeping genes commonly used as reference genes. We find most to be modulated, and analysis of several inflammation datasets as well as a metaanalysis of more than 5000 human tissue samples encompassing more than 300 cell types and diseases show that no single housekeeping gene may be used as a reference gene. Using three different algorithms, however, we uncovered a reference geneset impervious to TNF-α, and show for the first time that RLIP76 expression is induced by TNF-α and follows the induction kinetics of inflammation markers, suggesting that inflammation can influence RLIP76 expression at the BBB. We also show that MRP1 (a.k.a. ABCC1, another electrophile-glutathione transporter, is not modulated in the same cells and conditions, indicating that RLIP76 regulation by TNF-α is not a general property of glutathione transporters. The reference geneset

  5. Beneficial Effect of HHI-Ⅰ(活血化瘀注射液Ⅰ号)on Cerebral Microcirculation,Blood-Brain Barrier in Rats and Anti-hypoxic Activity in Mice

    Institute of Scientific and Technical Information of China (English)

    赵连根; 吴咸中; 伍孝先

    2009-01-01

    Objective:To investigate the effect of HHI-Ⅰ(活血化瘀注射液Ⅰ号) on the cerebral microcirculation,the blood-brain barrier permeability in rats and anti-hypoxic activity in mice.Methods:(1) The blood microcirculation of the brain in rats was investigated by laser Doppler flowmetry with the probes laid on the cerebral pia mater or inserted into the brain parenchyma.(2) The protective action of HHI-Ⅰagainst the brain microcirculation disturbance induced by intravenous injection of high-molecular dextran(10%,9 mL/kg)...

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

    Science.gov (United States)

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

    2015-10-01

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

  7. Ultrastructural Investigations of Development of Blood - Brain Barrier in Mice%小鼠血脑屏障发育的超微结构观察

    Institute of Scientific and Technical Information of China (English)

    陈凤钦; 徐剑文; 周琳瑛

    2011-01-01

    Objective To investigate the developmental characteristics of mouse blood - brain barrier (BBB). Methods Kunming mouse brain tissue at one - day, 14 - day ,28 - day, and 42 - day newborn mice were removed after birth, and the transmission electron microscope was used to observe the growth and development characteristics of BBB in mice. The parietal lobes of each group were cut into 1 mm X 1 mm×l mm (n = 2) . The samples of brain tissues were fixed with 30 mL · L-1 glutaraldehyde and 15 g · L-1 paraformaldehyde, postfixed further in 10 mL · L-1 osmium tetroxide and 15 mL · L-1 potassium ferrocyanide, and then embedded in a standard fashion. Thin sections were stained with uranyl acetate - lead citrate and examined with a Hu - 12A transmission electron microscope. Results The BBB was formed in the endothelial cells, basal lamina, and astrocytic foot processes (glia limitans). The ultrastructure of the BBB at various stages of development showed significant differences. The BBB was not fully developed in 1 - day mice after birth, their brain microvascular endothelial cells were not surrounded by intact basal lamina and there were only discontinuous basement membrane - like materials with varied thickness. Throughout the growth and development, the capillary walls were thinner and the basal lamina was thicker in 14 - day and 28 -day mice after birth. In 42 - day mice after birth, the basal lamina was significantly thicker than other groups with high electron density,and the soma of neurons and glial cells were gradually away from BBB. Conclusion The underdevelopment of BBB in newborn mice is a key factor for susceptible brain damages.%目的 探讨小鼠血脑屏障(BBB)的发育特点.方法 取出生第1天、第14天、第28天、第42天各2只昆明小鼠脑组织顶叶,切成1 mm×1 mm×1 mm小块,30 mL·L-1戊二醛和15g· L-1多聚甲醛前固定,10mL·L-1锇酸和15 mL· L-1亚铁氰化钾后固定,乙醇、丙酮脱水,环氧树脂618包埋剂包埋;

  8. Elucidation of Transport Mechanism of Paeoniflorin and the Influence of Ligustilide, Senkyunolide I and Senkyunolide A on Paeoniflorin Transport through Mdck-Mdr1 Cells as Blood-Brain Barrier in Vitro Model.

    Science.gov (United States)

    Hu, Peng-Yi; Liu, Dan; Zheng, Qin; Wu, Qing; Tang, Yu; Yang, Ming

    2016-01-01

    The objectives of the present investigation were to: (1) elucidate the transport mechanism of paeoniflorin (PF) across MDCK-MDR1 monolayers; and (2) evaluate the effect of ligustilide (LIG), senkyunolide I (SENI) and senkyunolide A (SENA) on the transport of PF through blood-brain barrier so as to explore the enhancement mechanism. Transport studies of PF were performed in both directions, from apical to basolateral side (A→B) and from basolateral to apical sides (B→A). Drug concentrations were analyzed by LC-MS/MS. PF showed relatively poor absorption in MDCK-MDR1 cells, apparent permeability coefficients (Papp) ranging from 0.587 × 10(-6) to 0.705 × 10(-6) cm/s. In vitro experiments showed that the transport of PF in both directions was concentration dependent and not saturable. The B→A/A→B permeability ER of PF was more than 2 in the MDCK-MDR1 cells, which indicated that the transport mechanism of PF might be passive diffusion as the dominating process with the active transportation mediated mechanism involved. The increased Papp of PF in A→B direction by EDTA-Na₂ suggested that PF was absorbed via the paracellular route. The P-gp inhibitor verapamil could significantly increase the transport of PF in A→B direction, and ER decreased from 2.210 to 0.690, which indicated that PF was P-gp substance. The transport of PF in A→B direction significantly increased when co-administrated with increasing concentrations of LIG, SENI and SENA. An increased cellular accumulation of Rho 123 and Western blot analysis indicated that LIG, SENI and SENA had increased the transport of PF in the BBB models attribute to down-regulate P-gp expression. A decrease in transepithelial electrical resistance (TEER) during the permeation experiment can be explained by the modulation and opening of the tight junctions caused by the permeation enhancer LIG, SENI and SENA. PMID:26950101

  9. An Electrically Tight In Vitro Blood-Brain Barrier Model Displays Net Brain-to-Blood Efflux of Substrates for the ABC Transporters, P-gp, Bcrp and Mrp-1

    DEFF Research Database (Denmark)

    Helms, Hans Christian; Hersom, Maria; Kuhlmann, Louise Borella;

    2014-01-01

    Efflux transporters of the ATP-binding cassette superfamily including breast cancer resistance protein (Bcrp/Abcg2), P-glycoprotein (P-gp/Abcb1) and multidrug resistance-associated proteins (Mrp's/Abcc's) are expressed in the blood-brain barrier (BBB). The aim of this study was to investigate if a......143, zosuquidar, reversan and MK 571 alone or in combinations. Digoxin was mainly transported via P-gp, estrone-3-sulphate via Bcrp and Mrp's and etoposide via P-gp and Mrp's. The expression of P-gp, Bcrp and Mrp-1 was confirmed using immunocytochemistry. The findings indicate that P-gp, Bcrp and at...... least one isoform of Mrp are functionally expressed in our bovine/rat co-culture model and that the model is suitable for investigations of small molecule transport....

  10. 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.

  11. (R)-[11C]Verapamil PET studies to assess changes in P-glycoprotein expression and functionality in rat blood-brain barrier after exposure to kainate-induced status epilepticus

    International Nuclear Information System (INIS)

    Increased functionality of efflux transporters at the blood-brain barrier may contribute to decreased drug concentrations at the target site in CNS diseases like epilepsy. In the rat, pharmacoresistant epilepsy can be mimicked by inducing status epilepticus by intraperitoneal injection of kainate, which leads to development of spontaneous seizures after 3 weeks to 3 months. The aim of this study was to investigate potential changes in P-glycoprotein (P-gp) expression and functionality at an early stage after induction of status epilepticus by kainate. (R)-[11C]verapamil, which is currently the most frequently used positron emission tomography (PET) ligand for determining P-gp functionality at the blood-brain barrier, was used in kainate and saline (control) treated rats, at 7 days after treatment. To investigate the effect of P-gp on (R)-[11C]verapamil brain distribution, both groups were studied without or with co-administration of the P-gp inhibitor tariquidar. P-gp expression was determined using immunohistochemistry in post mortem brains. (R)-[11C]verapamil kinetics were analyzed with approaches common in PET research (Logan analysis, and compartmental modelling of individual profiles) as well as by population mixed effects modelling (NONMEM). All data analysis approaches indicated only modest differences in brain distribution of (R)-[11C]verapamil between saline and kainate treated rats, while tariquidar treatment in both groups resulted in a more than 10-fold increase. NONMEM provided most precise parameter estimates. P-gp expression was found to be similar for kainate and saline treated rats. P-gp expression and functionality does not seem to change at early stage after induction of anticipated pharmacoresistant epilepsy by kainate

  12. A large-scale electrophoresis- and chromatography-based determination of gene expression profiles in bovine brain capillary endothelial cells after the re-induction of blood-brain barrier properties

    Directory of Open Access Journals (Sweden)

    Duban-Deweer Sophie

    2010-11-01

    Full Text Available Abstract Background Brain capillary endothelial cells (BCECs form the physiological basis of the blood-brain barrier (BBB. The barrier function is (at least in part due to well-known proteins such as transporters, tight junctions and metabolic barrier proteins (e.g. monoamine oxidase, gamma glutamyltranspeptidase and P-glycoprotein. Our previous 2-dimensional gel proteome analysis had identified a large number of proteins and revealed the major role of dynamic cytoskeletal remodelling in the differentiation of bovine BCECs. The aim of the present study was to elaborate a reference proteome of Triton X-100-soluble species from bovine BCECs cultured in the well-established in vitro BBB model developed in our laboratory. Results A total of 215 protein spots (corresponding to 130 distinct proteins were identified by 2-dimensional gel electrophoresis, whereas over 350 proteins were identified by a shotgun approach. We classified around 430 distinct proteins expressed by bovine BCECs. Our large-scale gene expression analysis enabled the correction of mistakes referenced into protein databases (e.g. bovine vinculin and constitutes valuable evidence for predictions based on genome annotation. Conclusions Elaboration of a reference proteome constitutes the first step in creating a gene expression database dedicated to capillary endothelial cells displaying BBB characteristics. It improves of our knowledge of the BBB and the key proteins in cell structures, cytoskeleton organization, metabolism, detoxification and drug resistance. Moreover, our results emphasize the need for both appropriate experimental design and correct interpretation of proteome datasets.

  13. Study of cellular retention of HMPAO and ECD in a model simulating the blood-brain barrier; Etude de la retention cellulaire de l`HMPAO et de l`ECD dans un modele simulant la barriere hematoencephalique

    Energy Technology Data Exchange (ETDEWEB)

    Ponce, C.; Pittet, N.; Slosman, D.O. [HUG, 1211 Geneve 14, (Switzerland)

    1997-12-31

    The HMPAO and ECD are two technetium-labelled lipophilic agents clinically used in the imagery of cerebral perfusion. These molecules cross the membranes and are retained inside the cell after being converted to a hydrophilic form. The aim of this study is to establish the distribution of this retention at the level of blood-brain barrier (BBB) and nerve cells. The incorporation of HMPAO or ECD was studied on a model of co-culture simulating the BBB by means of a T84 single-cell layer of tight junction separated from another layer of U373 astrocyte cells. The cell quality and tight junction permeability were evaluated by the cellular retention of 111-indium chloride and by para-cellular diffusion of {sup 14}C mannitol,d-1. The values reported below were obtained at 180 minutes when the radiotracers were added near the `T84 layer`. The cell quality is validated by the low cellular retention of the indium chloride(2.3{+-}0.3 {mu}g{sup -1} for the T84 cells and 8.2{+-}5.8 {mu}g{sup -1} for the U373 cells). The activity of {sup 14}C mannitol,d-1 diminishes by 23 {+-} 5 % in the added compartment. The retention of ECD by the U373 cells is significantly higher (20.7 {+-}4.5 g{sup -1}) than that of T84 cells (2.9 {+-} 0.2 {mu}g{sup -1}). For HMPAO a non-significant tendency could be observed (49 {+-} 34 {mu}g{sup -1} for the U373 cells and 38 {+-} 25 {mu}g{sup -1} for the T84 cells)> The results of cellular retention of indium by HMPAO or ECD when added near `U373 layer` are not significantly different.In conclusion, independently of the side exposed to the radiotracers, one observes an enhanced incorporation of the U373 cells. The ensemble of these results represent additional arguments in favour of a specific cellular incorporation of the radiotracers, independent of the BBB permittivity

  14. β-asarone and levodopa co-administration increase striatal dopamine level in 6-hydroxydopamine induced rats by modulating P-glycoprotein and tight junction proteins at the blood-brain barrier and promoting levodopa into the brain.

    Science.gov (United States)

    Huang, Liping; Deng, Minzhen; He, Yuping; Lu, Shiyao; Ma, Ruanxin; Fang, Yongqi

    2016-06-01

    Levodopa (L-dopa) is widely considered as one of the most effective drug constituents in the treatment of Parkinson's disease (PD), but the blood-brain barrier (BBB) permeability of L-dopa is dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), S100β and neuron-specific enolase (NSE) levels were subsequently determined. The P-glycoprotein (P-gp), zonula occludens-1 (ZO-1), claudin-5, occludin and actin expression was also assessed in cortex. Changes in BBB ultrastructure were observed using transmission electron microscopy. Our results showed that the co-administered treatment increased levels of L-dopa, DA, DOPAC and HVA in striatum, and S100β in plasma, but down-regulated NSE, P-gp, ZO-1, occludin, actin and claudin-5 in cortex. Crevices were observed between capillary endothelial cells at intercellular tight junction of the striatum in co-administered-treated group, while the endothelial cells in untreated group were tightly jointing each other. In addition, the correlations of L-dopa or DA and P-gp or tight junction proteins respectively were significantly negative in co-administered- and β-asarone-treated groups. These findings suggest that co-administered treatment may enhance the L-dopa BBB permeability and attenuate brain injury, which may be beneficial to PD treatment. PMID:26991136

  15. Evaluation of drug penetration into the brain: a double study by in vivo imaging with positron emission tomography and using an in vitro model of the human blood-brain barrier

    International Nuclear Information System (INIS)

    The blood brain barrier (BBB) passage of a set of radiopharmaceuticals candidates was measured both in vitro using a newly developed co-culture based model of human BBB and in vivo by positron emission tomography (PET). MATERIAL and METHODS: As an in vitro BBB model, a co-culture of primary human brain endothelial cells and primary human astrocytes was used. Dynamic PET studies were performed simultaneously on 4 anesthetized rats with the EXACT HR+ camera. Volumes of interest (VOI) were manually defined on the tomographic images in order to determine the pharmacokinetics of the compounds in various organs, including brain. The in vivo input function was measured by radioactivity counting of arterial blood samples. A two-compartment model analysis was used to compute the exchanging rate constants between blood and brain and to calculate the in vivo permeability coefficient. RESULTS: There was an excellent correlation between the in vitro and in vivo permeability coefficients (r = 0.99; p < 0.001) as well as between the in vivo distribution volume and the in vitro efflux /influx permeability coefficients ratio (r = 0.76). CONCLUSION: This double study evidenced a close relationship between the in vitro and the in vivo approaches for the assessment of the BBB passage. Hence, small animal PET imaging appeared suitable to screen drugs or radiopharmaceuticals candidates aimed at cerebral targets directly in the real-life situation in vivo. (author)

  16. Pathophysiological Impact of Cigarette Smoke Exposure on the Cerebrovascular System with a Focus on the Blood-brain Barrier: Expanding the Awareness of Smoking Toxicity in an Underappreciated Area

    Directory of Open Access Journals (Sweden)

    Luca Cucullo

    2010-11-01

    Full Text Available Recent evidence has indicated that active and passive cigarette smoking are associated, in a dose-dependent manner, with dysfunction of normal endothelial physiology. Tobacco smoke (TS may predispose individuals to atherogenic and thrombotic problems, significantly increasing the risk for ischemic manifestations such as acute coronary syndrome and stroke. Despite the strong evidence for an association between smoking and vascular impairment, the impact of TS exposure on the blood-brain barrier (BBB has only been marginally addressed. This is a major problem given that the BBB is crucial in the maintenance of brain homeostasis. Recent data have also shown that chronic smokers have a higher incidence of small vessel ischemic disease (SVID, a pathological condition characterized by leaky brain microvessels and loss of BBB integrity. In the brain TS increases the risk of silent cerebral infarction (SCI and stroke owing to the pro-coagulant and atherogenic effects of smoking. In this article we provide a detailed review and analysis of current knowledge of the pathophysiology of tobacco smoke toxicity at the cerebrovascular levels. We also discuss the potential toxicity of recently marketed “potential-reduced exposure products”.

  17. Ischemic brain edema following occlusion of the middle cerebral artery in the rat. I: The time courses of the brain water, sodium and potassium contents and blood-brain barrier permeability to 125I-albumin

    International Nuclear Information System (INIS)

    The present study was undertaken to analyze the roles of brain cations and of the blood-brain barrier (BBB) to albumin in the development of ischemic brain edema. Using the rat middle cerebral artery (MCA) occlusion model, changes in the brain water, sodium, and potassium contents were followed for a period of seven days. The permeability of the BBB to proteins was also followed by 125I-albumin transfer from the blood into the brain. A significant edema developed as early as three hours after MCA occlusion. This progressed rapidly to reach a maximum on the third day, gradually regressing thereafter. The increase in the brain water contents showed a parallel time course to the increase in the sodium and decrease in the potassium contents. A significant increase in the BBB permeability to albumin occurred 72 hours after MCA occlusion. However, there was no correlation between the brain water content and BBB permeability to albumin in the hemispheres studied 72 hours after MCA occlusion. The correlation between the brain water and sodium contents was not clear during the first six hours, but became highly significant thereafter. The data suggest that an increase in the BBB permeability to sodium occurred 12-48 hours after MCA occlusion, which, together with an antecedent intracellular shift of sodium, resulted in a massive influx of water and sodium into the brain. The BBB permeability change to sodium, not to proteins, seems to play a predominant role in the pathogenesis underlying ischemic brain edema

  18. Evaluation of blood-brain barrier transport and CNS drug metabolism in diseased and control brain after intravenous L-DOPA in a unilateral rat model of Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Ravenstijn Paulien GM

    2012-02-01

    Full Text Available Abstract Background Changes in blood-brain barrier (BBB functionality have been implicated in Parkinson's disease. This study aimed to investigate BBB transport of L-DOPA transport in conjunction with its intra-brain conversion, in both control and diseased cerebral hemispheres in the unilateral rat rotenone model of Parkinson's disease. Methods In Lewis rats, at 14 days after unilateral infusion of rotenone into the medial forebrain bundle, L-DOPA was administered intravenously (10, 25 or 50 mg/kg. Serial blood samples and brain striatal microdialysates were analysed for L-DOPA, and the dopamine metabolites DOPAC and HVA. Ex-vivo brain tissue was analyzed for changes in tyrosine hydroxylase staining as a biomarker for Parkinson's disease severity. Data were analysed by population pharmacokinetic analysis (NONMEM to compare BBB transport of L-DOPA in conjunction with the conversion of L-DOPA into DOPAC and HVA, in control and diseased cerebral hemisphere. Results Plasma pharmacokinetics of L-DOPA could be described by a 3-compartmental model. In rotenone responders (71%, no difference in L-DOPA BBB transport was found between diseased and control cerebral hemisphere. However, in the diseased compared with the control side, basal microdialysate levels of DOPAC and HVA were substantially lower, whereas following L-DOPA administration their elimination rates were higher. Conclusions Parkinson's disease-like pathology, indicated by a huge reduction of tyrosine hydroxylase as well as by substantially reduced levels and higher elimination rates of DOPAC and HVA, does not result in changes in BBB transport of L-DOPA. Taking the results of this study and that of previous ones, it can be concluded that changes in BBB functionality are not a specific characteristic of Parkinson's disease, and cannot account for the decreased benefit of L-DOPA at later stages of Parkinson's disease.

  19. 陷窝蛋白在脑缺血后血脑屏障破坏中的作用%Role of caveolins in the blood-brain barrier disruption after cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    王昭君; 王刘敏; 林颖; 刘亚红

    2016-01-01

    陷窝蛋白是陷窝的主要组成蛋白,也是实现其生理功能的重要蛋白。陷窝蛋白表达于平滑肌细胞、内皮细胞和脂肪细胞。陷窝既参与了细胞的脂肪摄取、胞吞和胞饮等基本生理过程,也对细胞的信号转导以及大分子物质的转运和通透起着非常重要的作用。随着对陷窝蛋白的分子构成和生物化学功能研究的深入,越来越多的研究表明陷窝及其主要成分陷窝蛋白在脑血管病的病理生理学过程起着重要作用。文章就陷窝蛋白在脑缺血后血脑屏障破坏中的作用进行了综述。%Caveolins are the major component proteins of the caveolae, and they are also the essential proteins to carry out the physiological functions of caveolae. Caveolins are expressed in smooth muscle cels, endothelial cels, and adipocytes. Caveolae are not only involved in the basic physiological processes, such as celular fat intake, endocytosis, and pinocytosis, but also play a very important role in cel signal transduction and transport and permeability of macromolecular substance. With the in-depth research on the molecular structure and biochemical function of caveolins, increasing studies have shown that caveolae and their main component caveolins play an important role in the pathophysiological process of cerebrovascular diseases. This article reviews the roles of caveolins in the blood-brain barrier destruction after cerebral ischemia.

  20. Gene expression of fatty acid transport and binding proteins in the blood-brain barrier and the cerebral cortex of the rat: differences across development and with different DHA brain status.

    Science.gov (United States)

    Pélerin, Hélène; Jouin, Mélanie; Lallemand, Marie-Sylvie; Alessandri, Jean-Marc; Cunnane, Stephen C; Langelier, Bénédicte; Guesnet, Philippe

    2014-11-01

    Specific mechanisms for maintaining docosahexaenoic acid (DHA) concentration in brain cells but also transporting DHA from the blood across the blood-brain barrier (BBB) are not agreed upon. Our main objective was therefore to evaluate the level of gene expression of fatty acid transport and fatty acid binding proteins in the cerebral cortex and at the BBB level during the perinatal period of active brain DHA accretion, at weaning, and until the adult age. We measured by real time RT-PCR the mRNA expression of different isoforms of fatty acid transport proteins (FATPs), long-chain acyl-CoA synthetases (ACSLs), fatty acid binding proteins (FABPs) and the fatty acid transporter (FAT)/CD36 in cerebral cortex and isolated microvessels at embryonic day 18 (E18) and postnatal days 14, 21 and 60 (P14, P21 and P60, respectively) in rats receiving different n-3 PUFA dietary supplies (control, totally deficient or DHA-supplemented). In control rats, all the genes were expressed at the BBB level (P14 to P60), the mRNA levels of FABP5 and ACSL3 having the highest values. Age-dependent differences included a systematic decrease in the mRNA expressions between P14-P21 and P60 (2 to 3-fold), with FABP7 mRNA abundance being the most affected (10-fold). In the cerebral cortex, mRNA levels varied differently since FATP4, ACSL3 and ACSL6 and the three FABPs genes were highly expressed. There were no significant differences in the expression of the 10 genes studied in n-3 deficient or DHA-supplemented rats despite significant differences in their brain DHA content, suggesting that brain DHA uptake from the blood does not necessarily require specific transporters within cerebral endothelial cells and could, under these experimental conditions, be a simple passive diffusion process. PMID:25123062

  1. West Nile virus-induced cell adhesion molecules on human brain microvascular endothelial cells regulate leukocyte adhesion and modulate permeability of the in vitro blood-brain barrier model.

    Directory of Open Access Journals (Sweden)

    Kelsey Roe

    Full Text Available Characterizing the mechanisms by which West Nile virus (WNV causes blood-brain barrier (BBB disruption, leukocyte infiltration into the brain and neuroinflammation is important to understand the pathogenesis of WNV encephalitis. Here, we examined the role of endothelial cell adhesion molecules (CAMs in mediating the adhesion and transendothelial migration of leukocytes across human brain microvascular endothelial cells (HBMVE. Infection with WNV (NY99 strain significantly induced ICAM-1, VCAM-1, and E-selectin in human endothelial cells and infected mice brain, although the levels of their ligands on leukocytes (VLA-4, LFA-1and MAC-1 did not alter. The permeability of the in vitro BBB model increased dramatically following the transmigration of monocytes and lymphocytes across the models infected with WNV, which was reversed in the presence of a cocktail of blocking antibodies against ICAM-1, VCAM-1, and E-selectin. Further, WNV infection of HBMVE significantly increased leukocyte adhesion to the HBMVE monolayer and transmigration across the infected BBB model. The blockade of these CAMs reduced the adhesion and transmigration of leukocytes across the infected BBB model. Further, comparison of infection with highly neuroinvasive NY99 and non-lethal (Eg101 strain of WNV demonstrated similar level of virus replication and fold-increase of CAMs in HBMVE cells suggesting that the non-neuropathogenic response of Eg101 is not because of its inability to infect HBMVE cells. Collectively, these results suggest that increased expression of specific CAMs is a pathological event associated with WNV infection and may contribute to leukocyte infiltration and BBB disruption in vivo. Our data further implicate that strategies to block CAMs to reduce BBB disruption may limit neuroinflammation and virus-CNS entry via 'Trojan horse' route, and improve WNV disease outcome.

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

    Science.gov (United States)

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

    2016-08-01

    Maple syrup urine disease (MSUD) is a rare metabolic disorder associated with acute and chronic brain dysfunction. This condition has been shown to lead to macroscopic cerebral alterations that are visible on imaging studies. Cerebral oedema is widely considered to be detrimental for MSUD patients; however, the mechanisms involved are still poorly understood. Therefore, we investigated whether acute administration of branched-chain amino acids (BCAA) causes cerebral oedema, modifies the Na(+),K(+)-ATPase activity, affects the permeability of the blood-brain barrier (BBB) and alters the levels of cytokines in the hippocampus and cerebral cortex of 10-day-old rats. Additionally, we investigated the influence of concomitant administration of dexamethasone on the alterations caused by BCAA. Our results showed that the animals submitted to the model of MSUD exhibited an increase in the brain water content, both in the cerebral cortex and in the hippocampus. By investigating the mechanism of cerebral oedema, we discovered an association between H-BCAA and the Na(+),K(+)-ATPase activity and the permeability of the BBB to small molecules. Moreover, the H-BCAA administration increases Il-1β, IL-6 and TNF-α levels in the hippocampus and cerebral cortex, whereas IL-10 levels were decreased in the hippocampus. Interestingly, we showed that the administration of dexamethasone successfully reduced cerebral oedema, preventing the inhibition of Na(+),K(+)-ATPase activity, BBB breakdown and the increase in the cytokines levels. In conclusion, these findings suggest that dexamethasone can improve the acute cerebral oedema and brain injury associated with high levels of BCAA, either through a direct effect on brain capillary Na(+),K(+)-ATPase or through a generalized effect on the permeability of the BBB to all compounds. PMID:26133302

  3. Astrocytes drive upregulation of the multidrug resistance transporter ABCB1 (P-Glycoprotein) in endothelial cells of the blood-brain barrier in mutant superoxide dismutase 1-linked amyotrophic lateral sclerosis.

    Science.gov (United States)

    Qosa, Hisham; Lichter, Jessica; Sarlo, Mark; Markandaiah, Shashirekha S; McAvoy, Kevin; Richard, Jean-Philippe; Jablonski, Michael R; Maragakis, Nicholas J; Pasinelli, Piera; Trotti, Davide

    2016-08-01

    The efficacy of drugs targeting the CNS is influenced by their limited brain access, which can lead to complete pharmacoresistance. Recently a tissue-specific and selective upregulation of the multidrug efflux transporter ABCB1 or P-glycoprotein (P-gp) in the spinal cord of both patients and the mutant SOD1-G93A mouse model of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease that prevalently kills motor neurons has been reported. Here, we extended the analysis of P-gp expression in the SOD1-G93A ALS mouse model and found that P-gp upregulation was restricted to endothelial cells of the capillaries, while P-gp expression was not detected in other cells of the spinal cord parenchyma such as astrocytes, oligodendrocytes, and neurons. Using both in vitro human and mouse models of the blood-brain barrier (BBB), we found that mutant SOD1 astrocytes were driving P-gp upregulation in endothelial cells. In addition, a significant increase in reactive oxygen species production, Nrf2 and NFκB activation in endothelial cells exposed to mutant SOD1 astrocytes in both human and murine BBB models were observed. Most interestingly, astrocytes expressing FUS-H517Q, a different familial ALS-linked mutated gene, also drove NFκB-dependent upregulation of P-gp. However, the pathway was not dependent on oxidative stress but rather involved TNF-α release. Overall, these findings indicated that nuclear translocation of NFκB was a converging mechanism used by endothelial cells of the BBB to upregulate P-gp expression in mutant SOD1-linked ALS and possibly other forms of familial ALS. GLIA 2016 GLIA 2016;64:1298-1313. PMID:27158936

  4. Dose-response assessment of tariquidar and elacridar and regional quantification of P-glycoprotein inhibition at the rat blood-brain barrier using (R)-[11C]verapamil PET

    International Nuclear Information System (INIS)

    Overactivity of the multidrug efflux transporter P-glycoprotein (P-gp) at the blood-brain barrier (BBB) is believed to play an important role in resistance to central nervous system drug treatment. (R)-[11C]verapamil (VPM) PET can be used to measure the function of P-gp at the BBB, but low brain uptake of VPM hampers the mapping of regional differences in cerebral P-gp function and expression. The aim of this study was to evaluate the dose-response relationship of two potent P-gp inhibitors and to investigate if increased brain uptake of VPM mediated by P-gp inhibition can be used to assess regional differences in P-gp activity. Two groups of Sprague-Dawley rats (n = 12) underwent single VPM PET scans at 120 min after administration of different doses of the P-gp inhibitors tariquidar and elacridar. In an additional six rats, paired VPM PET scans were performed before and after administration of 3 mg/kg tariquidar. Inhibitor administration resulted in an up to 11-fold increase in VPM brain distribution volumes (DV) with half-maximum effective dose (ED50) values of 3.0 ± 0.2 and 1.2 ± 0.1 mg/kg for tariquidar and elacridar, respectively. In paired PET scans, 3 mg/kg tariquidar resulted in regionally different enhancement of brain activity distribution, with lowest DV in cerebellum and highest DV in thalamus. Our data show that tariquidar and elacridar are able to increase VPM brain distribution in rat brain up to 11-fold over baseline at maximum effective doses, with elacridar being about three times more potent than tariquidar. Regional differences in tariquidar-induced modulation of VPM brain uptake point to regional differences in cerebral P-gp function and expression in rat brain. (orig.)

  5. Re-exposure to the hypobaric hypoxic brain injury of high altitude: plasma S100B levels and the possible effect of acclimatisation on blood-brain barrier dysfunction.

    Science.gov (United States)

    Winter, C D; Whyte, T; Cardinal, J; Kenny, R; Ballard, E

    2016-04-01

    Hypobaric hypoxic brain injury results in elevated peripheral S100B levels which may relate to blood-brain barrier (BBB) dysfunction. A period of acclimatisation or dexamethasone prevents altitude-related illnesses and this may involve attenuation of BBB compromise. We hypothesised that both treatments would diminish the S100B response (a measure of BBB dysfunction) on re-ascent to the hypobaric hypoxia of high altitude, in comparison to an identical ascent completed 48 h earlier by the same group. Twelve healthy volunteers, six of which were prescribed dexamethasone, ascended Mt Fuji (summit 3700 m) and serial plasma S100B levels measured. The S100B values reduced from a baseline 0.183 µg/l (95 % CI 0.083-0.283) to 0.145 µg/l (95 % CI 0.088-0.202) at high altitude for the dexamethasone group (n = 6) and from 0.147 µg/l (95 % CI 0.022-0.272) to 0.133 µg/l (95 % CI 0.085-0.182) for the non-treated group (n = 6) [not statistically significant (p = 0.43 and p = 0.82) for the treated and non-treated groups respectively]. [These results contrasted with the statistically significant increase during the first ascent, S100B increasing from 0.108 µg/l (95 % CI 0.092-0.125) to 0.216 µg/l (95 % CI 0.165-0.267) at high altitude]. In conclusion, an increase in plasma S100B was not observed in the second ascent and this may relate to the effect of acclimatisation (or hypoxic pre-conditioning) on the BBB. An exercise stimulated elevation of plasma S100B levels was also not observed during the second ascent. The small sample size and wide confidence intervals, however, precludes any statistically significant conclusions and a larger study would be required to confirm these findings. PMID:26924650

  6. Blood-brain transfer of Pittsburgh compound B in humans

    DEFF Research Database (Denmark)

    Gjedde, Albert; Aanerud, Joel; Braendgaard, Hans;

    2013-01-01

    In the labeled form, the Pittsburgh compound B (2-(4'-{N-methyl-[(11)C]}methyl-aminophenyl)-6-hydroxy-benzothiazole, [(11)C]PiB), is used as a biomarker for positron emission tomography (PET) of brain β-amyloid deposition in Alzheimer's disease (AD). The permeability of [(11)C]PiB in the blood......-brain barrier is held to be high but the permeability-surface area product and extraction fractions in patients or healthy volunteers are not known. We used PET to determine the clearance associated with the unidrectional blood-brain transfer of [(11)C]PiB and the corresponding cerebral blood flow rates in......-brain clearances of [(11)C]PiB in the patients....

  7. 纳米氧化铝对小鼠血脑屏障通透性的影响%Effect of nano-alumina on the blood brain barrier in mice

    Institute of Scientific and Technical Information of China (English)

    吉俊伟; 唐仕川; 白茹; 葛翠翠; 王志武; 张斌; 牛侨; 张勤丽

    2012-01-01

    Objective To study the effect of nano-alumina (nano-Al) on the blood brain barrier (BBB) of mice. Methods Three-month old ICR mice were exposed to nano-alumina by nasal drip method. To compare the toxicity of nanoparticle and chemistry, the mice were divided into 5 groups, as control, micro-alumina (micro-Al), nano-carbon ( nano-C ) , nano-Al and aluminum (Al) ion. To compare the dose effect of nano-Al, the mice were divided into 4 groups, as control, low-dose group, mid-dose group and high-dose group. Each mouse was poisoned 3 times/day, 10 μl/time, the course lasted 30 days. Lanthanum nitrate dyeing was used to detect the permeability of BBB, immunofluorescent chemistry was used to determine protein levels of ZO-1 and Occludin, western blot was used to measure the protein levels of ZO-1 and Claudin-5. Results The results of Lanthanum nitrate dyeing demonstrated that the particles of lanthanum nitrate surrounded in the middle of capillaries, no permeability was observed; those of micro-Al and nano-C treated mice partly presented in the middle of capillaries, showing higher BBB permeability; while most of the lanthanum nitrate particles of nano-Al and Al ion treated mice located in the middle of capillaries, forming a dentist trip, displaying BBB injury and permeability rise. Protein levels of ZO-1, Claudin-S and Occludin were highest in the control group, lower in the micro-Al and nano-C groups (P <0.0001) , and lowest in the nano-Al group ( P < 0. 0001). Furthermore, there was a dose-dependent relationship between the expression of doses and BBB permeability ( P < 0.0001). Conclusion Nano-Al could decrease the permeability of BBB, it derived from the combined toxicity of nanoparticle and chemistry. The mechanism may concern with the decreased proteins expression of ZO-1 , Occludin and Claudin-5.%目的 探讨纳米氧化铝颗粒对小鼠血脑屏障通透性的影响.方法 3月龄ICR小鼠用滴鼻法染毒,为了比较纳米铝作用的颗粒毒性和化学

  8. Long-term Administration Induced P-glycoprotein-mediated Drug Resistance at Blood-Brain Barrier%长期用药在血脑屏障上诱导P-糖蛋白介导的耐药性

    Institute of Scientific and Technical Information of China (English)

    何玲; 张陆勇; 刘国卿

    2003-01-01

    目的:考察长期用药在血脑屏障上是否引起耐药性及P-糖蛋白(P-gp)表达增强.方法:原代牛脑微血管内皮细胞(BCEC)加入环孢素A(CsA),长春新碱(VCR),阿霉素(Dox),或粉防己碱(Tet),初始剂量分别为0.0083,0.091,0.34,或0.32 μmol/L,培养至传代剂量翻倍.连续作用21,37,51或69 d后,用罗丹明123(Rh123)检测P-gp功能.将各药物诱导69天的BCEC制膜,用酶联免疫吸附法(ELISA)测定P-gp表达.结果:Dox用药37 d使胞内Rh123浓度降低38%.连续给药51和69 d后,Dox分别使胞内Rh123浓度降低47%和57%,VCR组分别降低36%和40%.而CsA和Tet组一直未见明显变化.维拉帕米(10μmol/L)分别使CsA、Tet、Dox和VCR诱导组BCEC内Rh123的摄取增加92%、85%、143%和186%.Dox和VCR连续用药69 d使P-gp的表达增强45%和32%.结论:长期使用Dox或VCR可在血脑屏障上诱导P-gp介导的耐药性以及P-gp表达增强.%AIM: To study whether long-term administration could induce drug resistance and P-glycoprotein(P-gp) expression at blood-brain barrier(BBB). METHOD: Primary bovine brain capillary endothelial cells(BCECs) were cultured in the presence of cyclosporin A(CsA),vincrinstine(VCR),doxorubicin(Dox),or tetrandrine(Tet) at the original concentration of 0.0083,0.091,0.34,or 0.32 μmol/L,respectively. The drug was maintained until the BCECs approached confluence,at which point the subculture and doubling of drug would be repeated,and the whole process continued through 4-5 cycles. Using rhodamine 123(Rh123) to examine the functional activity of P-gp expressed in drug-treated BCECs after a period of 21,37,51,and 69 d respectively. The plasma membranes of BCECs pretreated with inducing drug for 69 d were isolated and prepared,and the P-gp expression in the plasma membranes was detected by enzyme-linked immunosorbent assay(ELISA). RESULT: No significant change in P-gp function was observed in comparison with the control on d21. Administration of Dox obviously decreased the

  9. Development in NMR spiral imaging and application to the assessment of the permeability of the blood-brain barrier on 2 models of brain tumors; Developpements en imagerie RMN spirale et application a la caracterisation de la permeabilite de la barriere hemato-encephalique sur deux modeles de tumeurs intracerebrales

    Energy Technology Data Exchange (ETDEWEB)

    Beaumont, M

    2007-12-15

    The results presented in this work were obtained as part of methodological developments in magnetic resonance imaging. First of all, the setting of the rapid imaging technique using a k-space sampling scheme along a variable density spiral is described. Numerical simulations were used to optimize the acquisitions parameters and to compare different reconstruction techniques. An original approach to calibrate the k-space trajectory was proposed. Then, spiral imaging was used to implement a method to measure the blood brain barrier permeability to Gd-DOTA. This protocol was combined to blood volume and vessel size index measurements using Sinerem. The results obtained highlighted differences between the microvascular parameters measured on C6 and RG2 tumor models. The presence of Sinerem induces a mean decrease of the transfer constant across the vascular wall (Ktrans), in the tumor, of 24 per cent. This study also showed extravasation of the Sinerem, during the first two hours after the product injection, only in the RG2 tumors. (author)

  10. Barrier experiment: Shock initiation under complex loading

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-12

    The barrier experiments are a variant of the gap test; a detonation wave in a donor HE impacts a barrier and drives a shock wave into an acceptor HE. The question we ask is: What is the trade-off between the barrier material and threshold barrier thickness to prevent the acceptor from detonating. This can be viewed from the perspective of shock initiation of the acceptor subject to a complex pressure drive condition. Here we consider key factors which affect whether or not the acceptor undergoes a shock-to-detonation transition. These include the following: shock impedance matches for the donor detonation wave into the barrier and then the barrier shock into the acceptor, the pressure gradient behind the donor detonation wave, and the curvature of detonation front in the donor. Numerical simulations are used to illustrate how these factors affect the reaction in the acceptor.

  11. 孕酮对大鼠脑挫裂伤后水通道蛋白-4与血脑屏障通透性的影响%The influence of progesteron on the changes of aquaporin-4 expression and blood-brain barrier permeability in rats after experimental contusion and laceration of brain

    Institute of Scientific and Technical Information of China (English)

    段永红; 谌南武; 汪丹; 杨咏梅; 廖勇仕; 梁日初; 舒毓高

    2009-01-01

    目的 探讨孕酮减轻创伤性脑水肿的机制.方法 建立雄性大鼠额叶脑挫裂伤模型并予孕酮干预治疗.免疫组织化学法检测脑组织星形胶质细胞AQP4表达的变化;伊文氏蓝法测定脑组织血脑屏障通透性的变化.结果 经孕酮干预治疗,脑组织含水量在各时相点均下降(P<0.05).脑挫裂伤后24、72、120 h时间段伤灶及其周边脑组织星形胶质细胞AQP4阳性细胞计数下降(P<0.05);伤后6 h和24 h EB含量明显下降(P<0.01).结论 孕酮减轻创伤性脑水肿的作用,可能与它降低外伤后脑组织AQP4表达水平和减轻伤后早期血脑屏障通透性有关.%Objective To discuss the mechanism of progesterone that soften brain water content in traumatic brain edema in rats. Methods The models of focal lobe contusion and laceration of brain were made on the male rats treated by the progesterone following injury. Immunohistochemical method was used to assess the expression of aquaporin-4 (AQP4). Evan's Blue method was used to detect the permeability of blood-brain barrier. Results Treated by the progesteron, the brain water content was significantly decreased, and the lower expression of AQP4 took place on astrocytes of the contusion and peri-contusion of the brain tissue after 24 h,72h ,and 120h . The content of EB was decreased at 6 h and 24 h post-injury. Conclusions Progesterone can soften the traumatic brain water content, which may be associated with the attenuation of AQP4 in frontal lobe contusion following traumatic brain injury ( TBI) and progesterone can protect the blood-brain barrier at early time after TBI.

  12. 外周手术创伤致中枢炎症中血脑屏障的改变与术后认知功能障碍的关系%The role of blood brain barrier in the causing of central inflammation after peripheral surgery and the relationship with postoperative cognitive dysfunction

    Institute of Scientific and Technical Information of China (English)

    张祥; 董洪权; 钱燕宁

    2015-01-01

    背景 中枢炎症是术后认知功能障碍(postoperative cognitive dysfunction,POCD)的主要病理机制之一.而血脑屏障(blood brain barrier,BBB)结构和功能完整性的破坏在外周手术创伤后发生中枢炎症中发挥着不可或缺的作用.外周创伤后通过各种途径破坏BBB的完整性,导致BBB通透性的改变,引起和扩大中枢炎症,从而影响学习记忆和认知能力. 目的 探讨BBB在外周致中枢炎症中发挥的作用及其与认知功能的关系. 内容 主要从3个方面进行论述:中枢炎症与POCD的关系、BBB在外周致中枢炎症中的作用、BBB通透性的改变及其参与者. 趋向 中枢炎症是POCD的主要病理机制之一.BBB是外周手术致中枢炎症中起关键作用,但外周手术后BBB的变化及其与中枢炎症和认知的具体关系尚不清楚.%Background The central inflammatory response plays an important role in postoperative cognitive dysfunction (POCD).The disruption of blood brain barrier (BBB) play a key role in central inflammation after the peripheral surgical trauma.The inflammatory cytokines disrupt the integrity of BBB through a variety of pathway,thus causing and expanding the central inflammatory,affecting learning and cognitive abilities.Objective To investigate the role of BBB in central inflammation after the peripheral surgical trauma and the relationship with cognitive function.Content Reviewed mainly from three aspects:the relationship of central inflammation with POCD,the role of BBB in central inflammation induced by peripheral inflammation,the participants that involved in the change of BBB permeability.Trend The central inflammatory response plays an important role in POCD.BBB play a key rule in central inflammation induced by peripheral operation But the pathological change of BBB,and its exactly relationship with central inflammation are still unclear.

  13. TCP-FA4: A DERIVATIVE OF TRANYLCYPROMINE SHOWING IMPROVED BLOOD-BRAIN PERMEABILITY

    OpenAIRE

    Desino, Kelly E.; Pignatello, Rosario; Guccione, Salvatore; Basile, Livia; Ansar, Sabah; Michaelis, Mary Lou; Ramsay, Rona R.; Audus, Kenneth L.

    2009-01-01

    Abstract A variety of approaches have been taken to improve the brain penetration of pharmaceutical agents. The amphipathic character of a compound can improve its interaction with the lipid bilayer within cell membranes, and as a result improve permeability. Fatty acid chains or lipoamino acids of various lengths were attached to tranylcypromine (TCP), in an attempt to improve the blood-brain barrier (BBB) permeability by increasing the lipophilicity as well as the amphiphatic cha...

  14. Study of Ravanolds Extracted from Onion on the Blood-Brain Barrier Permeation and Neuroprotective Effects%洋葱中黄酮类提取物对血脑屏障透过及神经保护作用研究

    Institute of Scientific and Technical Information of China (English)

    何丹; 杜文婷; 范雪娇; 杨鸣鸣; 所起凤; 刘戟

    2011-01-01

    Objective To study the flavanoids extracted from onion on the blood-brain barrier (BBB) permeation , and their effects on primary cultured neuron cell proliferation and apoptosis of SD rats using ethanol reflux method. Methods The brain microvascular endothelial cells (BMVECs) were first successfully primary cultured. Then rats BMVECs and astrocytes (Acs) were co-cultured to establish the in vitro BBB model. The flavanoids were extracted from onion using ethanol reflux method. The model was verified by transmission electron microscopy (TEM) and trans-epithelial electric resistance (TEER). The flavanoids permeability was tested using high performance liquid chromatography (HPLC). Meanwhile, rat neuron cells were cultured and exposed to H2O2 and flavanoids. Their effects on the cell proliferation and apoptosis were observed using MTT assay. The injury of neuron DNAwas analyzed using single-cell gel electrophoresis (SCGE) and immunofluorescent assay. Results The in vitro BBB model was successfully established by TEM and TEER. Results of HPLC proved flavanoids extracts could effectively permeate the BBB with the permeability of 60. 58%. The extractive at 10 -20 pg/mL showed obvious inhibition on the apoptosis of neuron cells induced by H2O2 and attenuated the injury of neuron DNA. Conclusions The flavanoids extracted from onion ethanol reflux method could effectively penetrate the BBB. They also showed obvious inhibition on the H2O2 induced neuron cell apoptosis and DNA injury.%目的 研究采用乙醇回流法从洋葱中提取的黄酮类物质对血脑屏障(blood-brain barrier,BBB)透过作用以及对原代培养的鼠神经元细胞增殖和凋亡的影响.方法 首先原代培养成功SD鼠脑微血管内皮细胞(brain microvascular endothelial cells,BMVECs);然后原代共培养鼠BMVECs和星形胶质细胞(astrocytes,ACs)以建立BBB体外模型.采用乙醇回流法从洋葱中提取黄酮类物质,通过透射电子显微镜观察和跨膜电阻值测

  15. 人脑挫裂伤早期周围组织AQP4表达及血脑屏障超微结构观察%The expression of aquaporin-4 and the ultramicrostructure change of blood-brain barrier in human contusion brain tissue early after injury

    Institute of Scientific and Technical Information of China (English)

    李新军; 韩杨云; 徐宏; 孙中书; 周增俊; 龙晓东; 杨与敏; 邹林波

    2012-01-01

    Objective To observe the expression of aquaporin 4(AQP4) and the ultramicrostructure change of blood-brain barrier in human contusion brain tissue at different time points and investigate the mechanism of brain edema formation. Methods 60 cases brain contusion tissue (observation group) and 10 cases normal non-functional brain tissues (control group) were collected. The expression of AQP4 at different time point was detected by immunity histochemistry and image analytical technique at 2 ~72 h after injury,brain water contents, BBB index and ultramicrostructure were observed at the same time point. Results Compared with the normal control group, AQP4 expression increased in observation group at 2 h (P<0.05), obviously increased at 6 h ,8 h J2 h (P<0.01), reached peak at 24-72 h(P <0.01). The change of AQP4 expression and brain water content had same tendency (r = 0. 912, P < 0.01) which also was displayed between BBB index and brain water content(r =0.877,P <0.01). The change of AQP4 expression and BBB index had significant positive correlation(r =0.908, P <0.01). Blood-brain barrier structure changed early after injury, and then destroyed, severely damaged at 24 h, 72 h. Conclusions The expression of AQP4 and the permeability of BBB significantly increased after brain contusion which suggesting AQP4 may play an important role in the brain edema formation after brain contusion.%目的 观察人脑挫裂伤后AQP4和血脑屏障超微结构在脑水肿形成中不同时间点的变化特征,探讨脑水肿的形成机制.方法 取脑挫裂伤区组织标本60例(观察组),10例非功能区正常脑组织标本(对照组).采用免疫组化和图像分析技术测定正常组及观察组伤后2~72 h相应时间点水肿区AQP4的表达水平,同时观察脑水肿含水量,血脑屏障指数,血脑屏障超微结构的变化.结果 与正常组相比较,脑挫裂伤组在伤后2h后AQP4表达开始增加(P<0.05),6h、8h、12h明显增加(P<0.01),24~72 h

  16. Effects of aromatic resuscitation drugs on blood brain barrier in cerebral ischemia-reperfusion injury model rats%芳香开窍药对脑缺血再灌注损伤大鼠血脑屏障影响的实验研究

    Institute of Scientific and Technical Information of China (English)

    倪彩霞; 曾南; 许福会; 苟玲; 刘金伟; 王建; 夏厚林

    2011-01-01

    Objective: To research the effects of moschus, boraeol, styrax and benzoinum on the structure and function of blood brain barrier in cerebral ischemia-reperfusion injury model rats. Method; Focal middle cerebral artery occlusion ( MCAO) was introduced as an in vivo ischemic model in rats. After 2 h MCAO, nylon suture was pulled up 1 cm to give blood reperfusion. After 22 h reperfusion, all animals were decapitated. The ultramicrostructure of blood brain barrier of ischemia hemisphere side in fronto-pa-rietal cortex region by transmission electron microscope, and the content of VEGF and MMP-9 in ischemia side brain tissue were measured by ELISA. Result: In model and solvent group rats, the capillary endothelium cells, astro-glial cells and nerve cells in ischemia hemisphere side in fronto-parietal region were emerged in different degree compared with sham-operated groups, which exhibited tight junction between endothelial cells being opened, basal lamina being dissolved, and permeability increasing, and cellularedema. In bor-neol(0.2 g · kg-1)group rats, the structure of three kinds of cells were nearly normal, which tight junction structure was clear, rough endoplasmic reticulum and polyribosome could be found in cytoplasm. In moschus(66. 6 mg· kg-1 )group rats, the structure of capillary endothelium cells and astrocytes were nearly normal as well as the basal lamina, but the electrons in neurons was maldistribution. In styrax(1. 332 g· kg-1)group rats, astrocytes were nearly normal, while capillary endothelial cells and neurons exhibited oedema in different degrees. And the basal lamina was discontinuous, augmentation of cell spaces in endothelial cells increased the permeability, some endoplasmic reticulum broadened and ribosome ablated. In benzoinum( 1.0 g· kg-1)group rats, oedema of capillary endothelial cells and astrocytes was significant, basal lamina broke. Meanwhile endoplasmic reticulum broadened as vacuole, the number of ribosome in rough endoplasmic

  17. Drug Delivery Systems, CNS Protection, and the Blood Brain Barrier

    Directory of Open Access Journals (Sweden)

    Ravi Kant Upadhyay

    2014-01-01

    Full Text Available Present review highlights various drug delivery systems used for delivery of pharmaceutical agents mainly antibiotics, antineoplastic agents, neuropeptides, and other therapeutic substances through the endothelial capillaries (BBB for CNS therapeutics. In addition, the use of ultrasound in delivery of therapeutic agents/biomolecules such as proline rich peptides, prodrugs, radiopharmaceuticals, proteins, immunoglobulins, and chimeric peptides to the target sites in deep tissue locations inside tumor sites of brain has been explained. In addition, therapeutic applications of various types of nanoparticles such as chitosan based nanomers, dendrimers, carbon nanotubes, niosomes, beta cyclodextrin carriers, cholesterol mediated cationic solid lipid nanoparticles, colloidal drug carriers, liposomes, and micelles have been discussed with their recent advancements. Emphasis has been given on the need of physiological and therapeutic optimization of existing drug delivery methods and their carriers to deliver therapeutic amount of drug into the brain for treatment of various neurological diseases and disorders. Further, strong recommendations are being made to develop nanosized drug carriers/vehicles and noninvasive therapeutic alternatives of conventional methods for better therapeutics of CNS related diseases. Hence, there is an urgent need to design nontoxic biocompatible drugs and develop noninvasive delivery methods to check posttreatment clinical fatalities in neuropatients which occur due to existing highly toxic invasive drugs and treatment methods.

  18. Drug Delivery Systems, CNS Protection, and the Blood Brain Barrier

    OpenAIRE

    Ravi Kant Upadhyay

    2014-01-01

    Present review highlights various drug delivery systems used for delivery of pharmaceutical agents mainly antibiotics, antineoplastic agents, neuropeptides, and other therapeutic substances through the endothelial capillaries (BBB) for CNS therapeutics. In addition, the use of ultrasound in delivery of therapeutic agents/biomolecules such as proline rich peptides, prodrugs, radiopharmaceuticals, proteins, immunoglobulins, and chimeric peptides to the target sites in deep tissue locations insi...

  19. Glutamate Efflux at the Blood-Brain Barrier

    DEFF Research Database (Denmark)

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

    2014-01-01

    L-Glutamate is considered the most important excitatory amino acid in the mammalian brain. Strict control of its concentration in the brain interstitial fluid is important to maintain neurotransmission and avoid excitotoxicity. The role of astrocytes in handling L-glutamate transport and metabolism...... is well known, however endothelial cells may also play an important role through mediating brain-to-blood L-glutamate efflux. Expression of excitatory amino acid transporters has been demonstrated in brain endothelial cells of bovine, human, murine, rat and porcine origin. These can account for high...... affinity concentrative uptake of L-glutamate from the brain interstitial fluid into the capillary endothelial cells. The mechanisms in between L-glutamate uptake in the endothelial cells and L-glutamate appearing in the blood are still unclear and may involve a luminal transporter for L...

  20. Cerebrospinal fluid aquaporin-4-immunoglobulin G disrupts blood brain barrier

    DEFF Research Database (Denmark)

    Asgari, Nasrin; Berg, Carsten Tue; Mørch, Marlene Thorsen;

    2015-01-01

    To clarify the significance of immunoglobulin G autoantibody specific for the astrocyte water channel aquaporin-4 in cerebrospinal fluid, aquaporin-4-immunoglobulin G from a neuromyelitis optica patient was administered intrathecally to naïve mice, and the distribution and pathogenic impact was...

  1. 补阳还五汤对脑出血大鼠脑组织水通道蛋白4表达及血-脑脊液屏障通透性的影响研究%Effects of Buyanghuanwu Decoction on Aquaporin 4 Expression and the Permeability of the Blood Brain Barrier in Cerebral Hemorrhage Rats

    Institute of Scientific and Technical Information of China (English)

    刘绍晨; 吴晓光; 杨岚; 李义学; 仇志富

    2016-01-01

    Objective To explore the effects of Buyanghuanwu decoction on aquaporin 4(AQP4)expression and the permeability of the blood brain barrier in cerebral hemorrhage rats. Methods From March 2014 to November 2015,SPF level adult male SD rats were randomly divided into sham operation group,model group,Buyanghuanwu decoction low,medium and high dose groups, 24 in each group. Model group and Buyanghuanwu decoction groups prepared models of cerebral hemorrhage. Since two days after modeling, Buyanghuanwu decoction low, medium, and high dose groups were given Buyanghuanwu decoction by gastric perfusion,the dose was 13. 2 g·kg - 1 ·d - 1 ,26. 5 g·kg - 1 ·d - 1 and 53. 0 g·kg - 1 ·d - 1 respectively,continuously for 14 days,and sham operation group and model group were given the equal volume of the corresponding 0. 9% sodium chloride solution. The expression of phosphatidylinositol 3 kinase( PI3K) and protein kinase B (AKT ) was detected by immunohistochemistry. The expression of AQP4 was detected by immunofluorescence labeling method. Content of water in brain was detected by wet and dry weight method,and formamide method was used to detect the blood- brain barrier permeability. Results Sham operation group,model group,Buyanghuanwu decoction low,medium and high dose groups were significantly different in the expression of PI3K and AKT(P ﹤ 0. 05);Buyanghuanwu decoction low,medium and high dose groups were higher than model group in the expression of PI3K;Buyanghuanwu decoction medium and high dose groups were higher than model group in the expression of AKT( P ﹤ 0. 05). The 5 groups were significantly different in the expression of AQP4(F = 95. 79,P ﹤ 0. 001);Buyanghuanwu decoction low,medium and high dose groups were higher than model group in the expression of AQP4 ( P ﹤ 0. 05) . The 5 groups were significantly different in brain water content( F= 16. 21,P ﹤ 0. 001);Buyanghuanwu decoction high dose group was lower than model group in brain water content( P

  2. Evaluation of noise barriers for soundscape perception through laboratory experiments

    OpenAIRE

    Hong, Joo Young; Jang, Hyung Suk; Jeon, Jin Yong

    2012-01-01

    In the present study, soundscape qualities have been investigated for the different types of urban noise barriers. Field measurements were performed: the sound pressure levels in front and back of the barriers were measured and the pictures were taken. Accordingly, laboratory experiments were conducted to evaluate the soundscape quality when each noise barrier existed. The experiments consisted of three parts; 1) audio-only condition, 2) visual-only condition, and 3) audio-visual condition. A...

  3. Effects of Nimodipine on Blood-brain Barrier of Rats with Diffuse Axonal Injury%尼莫地平对弥散性轴索损伤大鼠血脑屏障通透性的影响研究

    Institute of Scientific and Technical Information of China (English)

    阎维维

    2012-01-01

    OBJECTIVE: To study the effects of nimodipine on blood-brain barrier (BBB) of rats with diffuse axonal injury (DAI). METHODS: Rats were randomly divided into DAI group and nimodipine group with 40 rats in each group. After modeling, nimodipine group was intraperitoneally injected nimodipine 0.5 mg·kg-1·d-1. The brain water content and the EB content were determined before and 0.25, 1, 3, 7 d after modeling to investigate the changes of cerebral edema and permeability of BBB. RESULTS: After modeling, brain water content and EB content of 2 groups increased first and then decreased; the peak value of them appeared at 1 d and 3 d after modeling. Compared with DAI group, peak value of brain water content and the EB content were significantly lowered(P<0.05). CONCLUSION: Nimodipine decreases the permeability of BBB and has definitive effect on brain edema after DAI.%目的:研究尼莫地平对弥散性轴索损伤(DAI)大鼠血脑屏障(BBB)通透性的影响.方法:取大鼠随机分为DAI组和尼莫地平组,每组40只,2组大鼠建立DAI后,尼莫地平组腹腔注射给药0.5 mg·kg-1·d-1,分别于建模前和建模后0.25、1、3、7d检测脑组织含水量和伊文蓝(EB)含量以考察脑水肿情况和BBB通透性变化.结果:DAI后,2组大鼠脑组织含水量和EB含量均呈先升高后降低的趋势,峰值分别出现在建模后1d和3d;与DAI组比较,尼莫地平组脑组织含水量和EB含量的峰值均明显降低(P<0.05).结论:尼莫地平可以有效减轻DAI后脑水肿情况,降低BBB的通透性.

  4. JET internal transport barriers: experiment vs theory

    International Nuclear Information System (INIS)

    A large variety of JET discharges with internal transport barriers (ITBs) has been analysed in order to determine the main features which characterize turbulence stabilization at the barrier. It is found that the location of barriers is well correlated with regions where the ExB flow shearing rate exceeds the linear growth rate of the ion temperature gradient mode instability (γηi). A key point is the dependence of γηi on the magnetic shear: in the discharges of this database the reduction of γηi associated to very low or null magnetic shear favours the formation of an ITB. After the ITB formation a positive feedback occurs in which the ExB flow shear mechanism has the leading role and the position of the barrier may be no longer linked to the low shear region

  5. Effects of Gross Saponins of Tribulus terrestris L. on Inflammatory Reaction and Permeability of Blood-brain Barrier in Rats Following Cerebral Ischemic Injury%蒺藜皂苷对局灶性脑缺血大鼠炎症反应和血脑屏障通透性的影响∗

    Institute of Scientific and Technical Information of China (English)

    翟凤国; 周福波; 李厚忠; 郭素芬; 林峰; 关利新

    2015-01-01

    目的:探讨蒺藜皂苷对大鼠脑缺血-再灌注损伤炎症反应和血脑屏障通透性的作用及其机制。方法斯泼累格•多雷(SD)大鼠60只,随机分为假手术组、模型对照组、蒺藜皂苷小剂量组(10 mg•kg-1)、蒺藜皂苷大剂量组(30 mg•kg-1),每组15只,采用线栓法制备脑缺血-再灌注损伤模型。缺血2 h 再灌注24 h 后分别检测大鼠神经功能损伤评分、缺血脑组织髓过氧化物酶(MPO)的活性和伊文思蓝(EB)的含量;采用酶联免疫吸附测定(ELISA)法检测脑组织肿瘤坏死因子-α(TNF-α)的含量,免疫印记法检测基质金属蛋白酶-9(MMP-9)的表达变化。结果与模型对照组比较,蒺藜皂苷小、大剂量组大鼠神经功能损伤减轻(P<0.05),缺血脑组织 MPO 活性和 EB 含量均明显降低(P<0.05或 P<0.01),TNF-α含量明显降低[分别为(0.760±0.110),(0.670±0.073) mg•g-1,模型对照组为(0.920±0.128) mg•g-1,P<0.05或 P<0.01)],MMP-9的表达水平均明显降低[分别为(1.770±0.181)%,(1.480±0.146)%,模型对照组为(2.200±0.186)%,P<0.01]。结论蒺藜皂苷对大鼠脑缺血-再灌注损伤的脑组织具有神经保护作用,其机制可能与降低 TNF-α含量和下调 MMP-9表达,从而降低炎症反应和血脑屏障通透性有关。%Objective To explore the effects of gross saponins of Tribulus terrestris L.on inflammatory reaction and permeability of blood-brain barrier in rats following cerebral ischemia-reperfusion injury and their potential mechanisms. Methods Sixty SD rats were divided into sham operation group,model control group,gross saponins of Tribulus terrestris L.at low-dose (10 mg•kg-1 )and high-dose groups(30 mg•kg-1 ).Cerebral ischemia -reperfusion model was established with suture emboli method in middle cerebral artery of rats.Neural injury scores,the contents of Evans blue ( EB) and myeloperoxidase( MPO) activities in rat brain were measured 24 hours after the cerebral reperfusion

  6. 右美托咪定对全脑缺血再灌注大鼠血脑屏障通透性的影响%Effect of dexmedetomidine on permeability of blood-brain barrier in rats subjected to global cerbral ischemia-reperfusion

    Institute of Scientific and Technical Information of China (English)

    郭培培; 严虹; 陈璟莉; 吴会生; 袁世荧

    2013-01-01

    Objective To evaluate the effects of dexmedetomidine on the permeability of blood-brain barrier in rats subjected to global cerebral ischemia-reperfusion (I/R).Methods Thirty-six male Sprague-Dawley rats,weighing 250-300 g,were randomly divided into 3 groups (n =12 each):sham operation group (group S),global cerebral I/R group (group I/R) and dexmedetomidine group (group D).Global cerebral I/R was induced by occlusion of bilateral common carotid arteries combined with hypotension (MAP was maintained at 35-45 mm Hg) in anesthetized rats.In group D,dexmedetomidine was infused at a rate of 3μg· kg-1 · h-1 until 2 h of reperfusion after a loading dose of dexmedetomidine 3 μg/kg was injected intravenously immediately after onset of I/R.The rats were sacrificed at 24 h of reperfusion and their brains were immediately removed for microscopic examination of hippocampal CA1 region and for determination of the cell apoptosis,brain water content,Evans blue content and aquaporin 4 (AQP4) expression.Results The number of apoptotic cells was significantly larger,and brain water content,Evans blue content and AQP4 expression were higher in groups I/R and D than in group S (P < 0.05 or 0.01).The number of apoptotic cells was significantly smaller,and brain water content,and Evans blue content and AQP4 expression were lower in group D than in group I/R (P < 0.05 or 0.01).Global cerebral I/R-induced pathological changes were significantly attenuated in group D.Conclusion Dexmedetomidine can decrease the permeability of blood-brain barrier and attenuate global cerebral I/R injury in rats,and down-regulation of AQP4 expression may be involved in the mechanism.%目的 评价右美托咪定对全脑缺血再灌注大鼠血脑屏障通透性的影响.方法 成年雄性SD大鼠36只,体重250 ~ 300 g,采用随机数字表法,将其分为3组(n=12):假手术组(S组)、全脑缺血再灌注组(I/R组)和右美托咪定组(D组).采用夹闭双侧颈总动脉联合低血压法

  7. Differential uptake of MRI contrast agents indicates charge-selective blood-brain interface in the crayfish.

    Science.gov (United States)

    Otopalik, Adriane G; Shin, Jane; Beltz, Barbara S; Sandeman, David C; Kolodny, Nancy H

    2012-08-01

    This study provides a new perspective on the long-standing problem of the nature of the decapod crustacean blood-brain interface. Previous studies of crustacean blood-brain interface permeability have relied on invasive histological, immunohistochemical and electrophysiological techniques, indicating a leaky non-selective blood-brain barrier. The present investigation involves the use of magnetic resonance imaging (MRI), a method for non-invasive longitudinal tracking of tracers in real-time. Differential uptake rates of two molecularly distinct MRI contrast agents, namely manganese (Mn(II)) and Magnevist® (Gd-DTPA), were observed and quantified in the crayfish, Cherax destructor. Contrast agents were injected into the pericardium and uptake was observed with longitudinal MRI for approximately 14.5 h. Mn(II) was taken up quickly into neural tissue (within 6.5 min), whereas Gd-DTPA was not taken up into neural tissue and was instead restricted to the intracerebral vasculature or excreted into nearby sinuses. Our results provide evidence for a charge-selective intracerebral blood-brain interface in the crustacean nervous system, a structural characteristic once considered too complex for a lower-order arthropod. PMID:22526631

  8. Effect and mechanism of interleukin-1β in process of opening the blood-brain barrier by bradykinin%白介素-1β在缓激肽开放血脑屏障过程中的作用及其机制

    Institute of Scientific and Technical Information of China (English)

    秦丽娟; 薛一雪; 谷艳婷; 张志勇; 张田; 孙娜; 王东春; 宋鸿艳

    2012-01-01

    目的 探讨白介素-1β(IL-1β)在缓激肽(BK)开放血脑屏障(BBB)过程中的作用及其机制.方法 缓激肽处理C6细胞后,动态观察培养液中IL-1β含量(放射免疫法)、C6细胞内热休克因子1(HSF1)蛋白的表达(Western blot法)及IL-1β的mRNA水平(RT-PCR法).利用伊文思蓝检测C6恶性胶质瘤大鼠经颈内动脉给予IL-1β及缓激肽后血脑屏障的通透性.结果 缓激肽作用于C6细胞后,培养液中IL-1β的含量明显增加,于120 min含量最多,其后开始减少.C6细胞内HSF1的表达及IL-1β的mRNA水平也在给予缓激肽后明显增加,并分别于干预后的30 min和60 min达高峰后逐渐减少.缓激肽与IL-1β单独作用于C6动物后均可引起胶质瘤大鼠的血脑屏障通透性增加,且IL-1β对肿瘤模型动物血脑屏障通透性的影响与C6细胞培养液中IL-1β的含量相一致.结论 IL-1β可能介导了缓激肽开放血脑屏障的作用,此作用可能是由于缓激肽诱导C6细胞内HSF1的表达增加,增加的HSF1促进神经胶质瘤细胞释放IL-1β所致.%Aim To investigate the effects of interleu-kin-1 p ( IL-1 p ) in process of opening blood-brain bar-rier( BBB ) by bradykinin( BK ) and its mechanism. Methods Contents of IL-1 p in nutrient fluid ( radio-immunity method ), HSF1 protein expression ( by Western blot) and levels of IL-1 p the mRNA( by RT-PCR method ) for C6 cells were dynamically observed, after BK treatment. Using Evans blue was applied to detect permeability of BBB after intracarotid infusion of IL-1 p for C6 rats. Results For C6 cells, contents of IL-1 p in the nutrient fluid were obviously increased after BK treatment and achieved the peak at 120 min,also BK significantly increased expressions of HSF1 and levels of IL-1 p mRNA in C6 cells and reached the peak at 30 min and 60 min, separately. Permeability of BBB of C6 animals was in conformity with concentrations of IL-ip in nutrient fluid after BK treatment. Conclusion The IL-1 p may

  9. Study on the effect and mechanism of agmatine on blood brain barrier with cerebral ischemic reperfusion injury rats%胍丁胺对脑缺血再灌注损伤大鼠血脑屏障的作用机制研究

    Institute of Scientific and Technical Information of China (English)

    郑立霞; 徐鑫淼; 郎现波; 张秀丽; 杨美子

    2015-01-01

    目的:研究胍丁胺对血脑屏障( BBB )通透性的影响及其与水通道蛋白( AQP)的相关性。方法将大鼠随机分为假手术组、实验组和模型组。大脑中动脉栓塞2 h后,实验组和模型组分别腹腔注射胍丁胺(50 mg · kg-1)和等量0.9%NaCl。通过测定脑水含量、BBB通透性,考察BBB的损害程度,用2,3,5-氯化三苯基四氮唑(TTC)染色法比较梗死灶大小,苏木精-伊红(HE)染色和电镜观察神经元形态学变化,Western-blotting法检测AQP4、AQP9的表达。结果实验组BBB通透性显著下降,变性神经元数明显减少,同时, AQP4与AQP9的表达较模型组显著降低。结论胍丁胺通过降低AQP4、AQP9的表达来改善BBB通透性,从而减轻脑水肿引起的神经元损伤。%Objective To observe the effect of agmatine on brain ede-ma and examine the relation between blood brain barrier ( BBB) per-meability and aquaporin 4 ( AQP4 ) and aquaporin 9 ( AQP9 ) in rats with cerebral ischemic reperfusion.Methods Health male Sprague-Dawley rats were randomly divided into sham group , model group and test ( agmatine ) group.And 2 h after middle cerebral artery occlusion, giving agmatine ( 50 mg · kg -1 ) in test group or 0.9%NaCl in sham and model groups by intraperitoneal injection, respec-tively.Brain edema and the size of the brain infarct were assayed by brain water content and BBB permeability and 2,3,5 -triphenyltet-razoliumchloridstaining( TTC).The morphological changes of neurons were observed by hematoxylin and eosin staining and transmission electron microscopy.And the expression of AQP4 and AQP9 were assessed by Western -blotting.Results The BBB permeability de-creased significantly and the morphological changes of neurons were reduced significantly and the expression of AQP4 and AQP9 decreased significantly in rats with agmatine.Conclusion Agmatine reduce the injury of the BBB by decreasing the expression of AQP4 and

  10. TMX-U Tandem-Mirror thermal-barrier experiments

    International Nuclear Information System (INIS)

    Thermal-barrier experiments have been carried out in the Tandem Mirror Experiment-Upgrade (TMX-U). Measurements of nonambipolar and ambipolar radial transport show that these transport processes, as well as end losses, can be controlled at modest densities and durations. Central-cell heating methods using ion-cyclotron heating (ICH) and neutral-beam injection have been demonstrated. Potential measurements with recently developed methods indicate that deep thermal barriers can be established

  11. Transport and metabolism at blood-brain interfaces and in neural cells: relevance to bilirubin-induced encephalopathy

    Directory of Open Access Journals (Sweden)

    Silvia eGazzin

    2012-05-01

    Full Text Available Bilirubin, the end-product of heme catabolism, circulates in non pathological plasma mostly as a protein-bound species. When bilirubin concentration builds up, the free fraction of the molecule increases. Unbound bilirubin then diffuses across blood-brain interfaces into the brain, where it accumulates and exerts neurotoxic effects. In this classical view of bilirubin neurotoxicity, blood-brain interfaces act merely as structural barriers impeding the penetration of the pigment-bound carrier protein, and neural cells are considered as passive targets of its toxicity. Yet, the role of blood-brain interfaces in the occurrence of bilirubin encephalopathy appears more complex than being simple barriers to the diffusion of bilirubin, and neural cells such as astrocytes and neurons can play an active role in controlling the balance between the neuroprotective and neurotoxic effects of bilirubin. This article reviews the emerging in vivo and in vitro data showing that transport and metabolic detoxification mechanisms at the blood-brain and blood-CSF barriers may modulate bilirubin flux across both cellular interfaces, and that these protective functions can be affected in chronic hyperbilirubinemia. Then the in vivo and in vitro arguments in favor of the physiological antioxidant function of intracerebral bilirubin are presented, as well as with the potential role of transporters such as ABCC-1 and metabolizing enzymes such as cytochromes P-450 in setting the cerebral cell- and structure-specific toxicity of bilirubin following hyperbilirubinemia. The relevance of these data to the pathophysiology of bilirubin-induced neurological diseases is discussed.

  12. Nuclear Physics Experiments Below The Coulomb Barrier

    International Nuclear Information System (INIS)

    In 1932, Cockcroft and Walton showed that (p,α) reactions with lithium were possible at energies near 100 keV. We report an undergraduate laboratory experiment with 90 keV protons colliding with a thick lithium target. The experiment allows students to observe the products of two reactions, to determine the product masses, and to learn techniques for deconvolving experimental spectra profiles.

  13. An RF cavity for barrier bucket experiment in the AGS

    International Nuclear Information System (INIS)

    A barrier bucket experiment in the AGS is planed in 1998. An accumulation of the beam, which intensity of 1.0 x 1014ppp is, acceleration after the injection with a barrier bucket scheme and other RF gymnastics experiments will be studied. An isolated RF pulse of 40 kV per cavity is necessary for the experiment. The RF frequency is 2 MHz and the isolated pulse is generated at the repetition rate of the revolution frequency of 357 kHz. We have developed the barrier cavity for this experiment. The cavity is loaded with FINEMET core. It has low Q value but high shunt impedance. It makes the necessary power less than that of ferrite-loaded cavity for an isolated RF pulse. (author)

  14. Commentary on “Alzheimer’s disease drug development and the problem of the blood-brain barrier”

    Science.gov (United States)

    Simpkins, James W.

    2016-01-01

    The perspective by Dr. William Pardridge entitled “Alzheimer’s Disease Drug Discovery and the Problem of the Blood-Brain Barrier” makes a strong case for the imbalance in resource distribution to the drug-discovery and brain drug delivery processes, where the latter received less than 1% of the investment of the former. My own calculations are consistent with this striking imbalance. Dr. Pardridge predicts that current trials of passive immunity against β-amyloid peptide will likely fail, whereas past trials of active immunization exhibited trial-ending side effects, in part because of disruption of the integrity of the blood-brain barrier. To bring an assessment of the physiology of the blood-brain barrier and the brain delivery of drugs to the fore, several changes are needed in the way we perceive the problem, train our young scientists, organize research efforts, and incentivize reaching our common goals of effective drug therapy for Alzheimer’s disease. PMID:19751923

  15. Protective Effect effect of Flavonoids flavonoids from Polygala Polygala Hongkongensis on the Blood blood Brain brain Barrier barrier in Rats rats with Focal focal Cerebral cerebral Ischemia ischemia Reperfusion reperfusion%香港远志黄酮苷对局灶性脑缺血再灌注大鼠血脑屏障的保护及作用机制

    Institute of Scientific and Technical Information of China (English)

    詹海涛; 吴剑峰; 李海燕; 孟红旗; 曾煦欣

    2012-01-01

    Objective To investigate the influence of flavonoids from Polygala Hongkongensis( FPH) on the permeability of Blood blood Brain brain Barrierbarrier ( BBB) , brain water content and expression of matrix metalloproleinase-9 ( MMP-9) 、and aquaporin 4( AQP4) in rats with focal cerebral ischemia reperfusion(IR). Methods SD rats were randomly divided into sham operated group ", model group and treatment groups (the treatment groups were divided into Kaempferol-3-O-rutinoside( PHN-08 ) 、and kaempferol-3-0-glucoside( PHN-11) and combined formula group. Treatment groups received drug respectively according to grouping protocol, the sham operated and model groups received infusions of normal saline. The method of middle cerebral artery occlusion ( MCAO) by thread approach was used to establish the model of focal brain ischemia reperfusion(IR) IR. At the IR 24h and 48h,the mount of Evan' s blue( EB) exudation of the brain tissue、brain water content and expression of MMP-9 、and AQP4 were observed. Results At the IR 24h and 48h,compared with that of the sham operated group,the mount of EB exudationNbrain water content and expression of MMP-9 and、AQP4 were significantly increased in both of the model and treatment groups(P <0. 05). Compared with that of the model group,the mount of EB exudatioexudation, n, brain water content and expression of MMP-9 and 、 AQP4 were significantly decreased in the treatment groups( P <0. 05). Conclusion The FPH given prior to the rats with focal cerebral IR plays a protective role on the BBB,which may be achieved by decreasing the expression of MMP-9 and AQP4.%目的 探讨香港远志黄酮苷预处理,对局灶性脑缺血再灌注大鼠血脑屏障(BBB)通透性、脑含水量、基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)及水通道蛋白4(aquaporin 4,AQP4)表达的影响.方法 线栓法制备SD大鼠大脑中动脉闭塞(MCAO)局灶性脑缺血再灌注模型,随机分假手术组、模型组、山柰酚-3-O

  16. Engineered barrier experiment. Power control and data acquisition systems

    International Nuclear Information System (INIS)

    The engineered barrier concept for the storage of radioactive wastes is being tested at almost full scale at CIEMAT facilities. A data acquisition and control is an element of this experiment. This system would be operating for next three years. (Author)

  17. Glucagon-like peptide-1 inhibits blood-brain glucose transfer in humans

    DEFF Research Database (Denmark)

    Lerche, Susanne; Brock, Birgitte; Rungby, Jørgen;

    2008-01-01

    demonstrated that a hormone involved in postprandial glucose regulation also limits glucose delivery to brain tissue and hence provides a possible regulatory mechanism for the link between plasma glucose and brain glucose. Because GLP-1 reduces glucose uptake across the intact blood-brain barrier at normal...... glycemia, GLP-1 may also protect the brain by limiting intracerebral glucose fluctuation when plasma glucose is increased.......OBJECTIVE: Glucagon-like peptide-1 (GLP-1) has many effects on glucose homeostasis, and GLP-1 receptors are broadly represented in many tissues including the brain. Recent research in rodents suggests a protective effect of GLP-1 on brain tissue. The mechanism is unknown. We therefore tested...

  18. Prostaglandin E2 metabolism in rat brain: Role of the blood-brain interfaces

    Directory of Open Access Journals (Sweden)

    Strazielle Nathalie

    2008-03-01

    Full Text Available Abstract Background Prostaglandin E2 (PGE2 is involved in the regulation of synaptic activity and plasticity, and in brain maturation. It is also an important mediator of the central response to inflammatory challenges. The aim of this study was to evaluate the ability of the tissues forming the blood-brain interfaces to act as signal termination sites for PGE2 by metabolic inactivation. Methods The specific activity of 15-hydroxyprostaglandin dehydrogenase was measured in homogenates of microvessels, choroid plexuses and cerebral cortex isolated from postnatal and adult rat brain, and compared to the activity measured in peripheral organs which are established signal termination sites for prostaglandins. PGE2 metabolites produced ex vivo by choroid plexuses were identified and quantified by HPLC coupled to radiochemical detection. Results The data confirmed the absence of metabolic activity in brain parenchyma, and showed that no detectable activity was associated with brain microvessels forming the blood-brain barrier. By contrast, 15-hydroxyprostaglandin dehydrogenase activity was measured in both fourth and lateral ventricle choroid plexuses from 2-day-old rats, albeit at a lower level than in lung or kidney. The activity was barely detectable in adult choroidal tissue. Metabolic profiles indicated that isolated choroid plexus has the ability to metabolize PGE2, mainly into 13,14-dihydro-15-keto-PGE2. In short-term incubations, this metabolite distributed in the tissue rather than in the external medium, suggesting its release in the choroidal stroma. Conclusion The rat choroidal tissue has a significant ability to metabolize PGE2 during early postnatal life. This metabolic activity may participate in signal termination of centrally released PGE2 in the brain, or function as an enzymatic barrier acting to maintain PGE2 homeostasis in CSF during the critical early postnatal period of brain development.

  19. The first experiments on dielectric barrier discharge under atmospheric pressure

    International Nuclear Information System (INIS)

    In order to obtain uniform and stable discharge plasma in atmospheric pressure, dielectric barrier discharge experiments were carried out. Main purpose is to examine the applicability of dielectric barrier discharge to production processes of semi-conductors. LSIs and flat display panels. In the experiments, at first, quite stable and uniform discharge was obtained at atmospheric pressure. Effects of applied voltage and frequency on plasma uniformity were studied. Improvement of discharge uniformity by introducing gas flow of helium or nitrogen between the discharge gap was observed. Finally, surface cleaning effect of the present plasma was confirmed by observing contact angle of liquid droplet. At least for cleaning process, possibility of application as process plasma was suggested

  20. Disabled people and the Internet: experiences, barriers and opportunities

    OpenAIRE

    PILLING, D; Barrett, P; Floyd, M.

    2004-01-01

    The UK government aims to make all its information and transactions available electronically by 2005. General use of the Internet also continues to grow. This report investigates the Internet's barriers and benefits for disabled people, and considers whether it acts as a means to reduce their social exclusion. The study surveys the views and experiences of disabled people, both Internet users and non-users. Topics covered include: what the Internet is used for; use of and difficulties wit...

  1. Environmental Management System and SMEs: EU Experience, Barriers and Perspectives

    OpenAIRE

    Iraldo, Fabio; Testa, Francesco; Frey, Marco

    2010-01-01

    In the authors’ intention this paper represents the attempt to identify solutions, tools and incentives for SMEs to overcome constraints and difficulties they experience by implementing an EMS. Removing potential barriers and reinforcing economic incentives should be main targets in order to allow for a wide diffusion of EMS among SMEs. Some methods and possible instruments have been dealt with in this paper: working by group seemed to be a good way to diffuse information and to share imple...

  2. Increased blood-brain transfer in a rabbit model of acute liver failure

    International Nuclear Information System (INIS)

    The blood-to-brain transfer of [14C]alpha-aminoisobutyric acid was investigated by quantitative autoradiography in normal rabbits and rabbits with acute liver failure induced by the selective hepatotoxin galactosamine. The blood-to-brain transfer of alpha-aminoisobutyric acid was similar in control animals and animals 2 and 7 h after galactosamine injections, but was increased five- to tenfold in certain gray-matter areas of the brain in animals 11 and 18 h after galactosamine treatment. No detectable differences in white-matter uptake of [14C]alpha-aminoisobutyric acid were found between the control and treated groups. The increase in alpha-aminoisobutyric acid transfer within the gray-matter areas suggested that a general or nonspecific increase in brain capillary permeability occurred in these areas. No clinical signs of early hepatic encephalopathy were observed in the treated rabbits, except for 1 animal from the 18-h postgalactosamine group. Thus, enhanced blood-brain transfer of alpha-aminoisobutyric acid preceded the development of overt hepatic encephalopathy. The distribution of radioactivity after the intravenous administration of [14C]galactosamine showed that virtually none of the hepatotoxin localized in the brain, suggesting that the drug itself does not have a direct effect upon the blood-brain barrier or the brain. The increased uptake of alpha-aminoisobutyric acid at 11 and 18 h implies that the transfer of other solutes would also be enhanced, that central nervous system homeostasis would be compromised, and that the resulting changes in brain fluid composition could contribute to or cause hepatic encephalopathy

  3. Peripheral blood brain-derived neurotrophic factor in bipolar disorder

    DEFF Research Database (Denmark)

    Munkholm, K; Vinberg, M; Kessing, L V

    2016-01-01

    Peripheral blood brain-derived neurotrophic factor (BDNF) has been proposed as a potential biomarker related to disease activity and neuroprogression in bipolar disorder, speculated to mirror alterations in brain expression of BDNF. The research area is rapidly evolving; however, recent...... investigations have yielded conflicting results with substantial variation in outcomes, highlighting the need to critically assess the state of current evidence. The aims of the study were to investigate differences in peripheral blood BDNF concentrations between bipolar disorder patients and healthy control...... subjects and between affective states in bipolar disorder patients, including assessment of the effect of treatment of acute episodes on BDNF levels. A systematic review of English language studies without considering publication status was conducted in PubMed (January 1950-November 2014), Embase (1974...

  4. Investigating the effects of the cromakalim pretreatment on the expression of aquaporin -4 and the blood -brain barrier permeability in acute cerebral ischemia/reperfusion injury mice%克罗卡林预处理对脑缺血/再灌注大鼠水通道蛋白4表达及血脑屏障通透性的影响

    Institute of Scientific and Technical Information of China (English)

    王艳婷; 王士雷; 常庆显; 李瑜; 江岩; 王世端

    2010-01-01

    Objective To investigate the effects of ATP-sensitive potassium channel openers (Cromakalim) on the expression of aquaporin-4 and permeability of blood-brain barrer (BBB) after cerebral ischemic/repeffusion. Methods Thirty healthy male Wistar rats were randomized into three groups for different conditioning, the sham-operated group(A,n=10), the cerebral I/R group(B,n=10),and the cerebral I/R+Cromakalim group (C,n=10). Intraluminal suture methods were applied to establish the middle cerebral artery occlusion(MCAO) model with occlusion 2 h and reperfusion 24 h. The neurobehavioral function was evaluated with Bederson's test, and the pathological changes were observed with hematoxylin-eosin(HE) staining. The water content of brain was evaluated by wet-dry weight method, and the expressions of IgG and AQP-4 in brain were observed by immunohistochemistry staining. Results In comparison with group A's water content(78.2±1.3 )% and expressions of IgG and AQP-4 (0.0±0.0,13.6±1.5) ,the expressions of IgG and AQP-4(2.4±0.4,19.8±1.9) and the water content (81.3±1.2)% in group B both were significantly higher (P0.05),但IgG与AQP-4的表达(1.1±0.2,15.7±1.2)也明显升高(P<0.05);与B组相比,C组神经行为缺损评分明显减低(P<0.05),IgG、AQP-4(1.1±0.2,15.7±1.2)蛋白表达及脑组织含水量(79.5±0.6)%亦明显降低(P<0.05).结论 脑I/R损伤过程中,克罗卡林可能通过降低AQP-4的表达和BBB的通透性,减轻脑水肿,发挥脑保护作用.

  5. Blood-brain transfer and metabolism of 6-[18F]fluoro-L-dopa in rat

    International Nuclear Information System (INIS)

    In a study designed to reveal the rates of blood-brain transfer and decarboxylation of fluoro-L-3,4-dihydroxyphenylalanine (FDOPA), we discovered a major discrepancy between the DOPA decarboxylase activity reported in the literature and the rate of FDOPA decarboxylation measured in the study. Donor rats received intravenous injections of 6 mCi fluorine-18-labeled FDOPA. The donor rats synthesized methyl-FDOPA. Arterial plasma, containing both FDOPA and methyl-FDOPA, was sampled from the donor rats at different times and reinjected into recipient rats in which it circulated for 20 s. The blood-brain clearance of the mixture of labeled tracers in the plasma was determined by an integral method. The individual permeabilities were determined by linear regression analysis, according to which the average methyl-FDOPA permeability in the blood-brain barrier was twice that of FDOPA, which averaged 0.037 ml g-1 min-1. The permeability ratio was used to determine the fractional clearance from the brain of FDOPA (and hence of methyl-FDOPA), which averaged 0.081 min-1. In the striatum, the measured average FDOPA decarboxylation rate constant (kD3) was 0.010 min-1, or no more than 1% of the rate of striatal decarboxylation of DOPA measured in vitro and in vivo. We interpreted this finding as further evidence in favor of the hypothesis that striatum has two dopamine (DA) pools, of which only DA in the large pool is protected from metabolism. Hence, no more than 1% of the quantity of fluoro-DA theoretically synthesized was actually retained in striatum

  6. Career Barriers: How People Experience, Overcome, and Avoid Failure.

    Science.gov (United States)

    London, Manuel

    This book defines career barriers, considers how people react to them, and offers ways to overcome and prevent them. It is geared towards people experiencing career barriers; for students at the start of their careers; for seasoned employees wanting to avoid or be prepared to deal with career barriers; and for managers, human resource…

  7. Renewable Energy Permitting Barriers in Hawaii: Experience from the Field

    Energy Technology Data Exchange (ETDEWEB)

    Busche, S.; Donnelly, C.; Atkins, D.; Fields, R.; Black, C.

    2013-03-01

    This white paper presents a summary of the solicited input from permitting agencies and renewable energy developers on the permitting process in Hawaii to provide stakeholders in Hawaii, particularly those involved in permitting, with information on current permitting barriers that renewable energy developers are experiencing.

  8. DTR, Taut Wire System: An alarm barrier with experience

    International Nuclear Information System (INIS)

    The Taut Wire Fence Alarm System concept was developed and introduced more that fifteen years ago in Israel. A sudden expansion of the nations's border lines, the difficulty to monitor intrusions along those elongated lines and the need for timely as well as accurate armed response to an intrusion attempt dictated the need for an alarming barrier. Traditionally, protection of perimeters was accomplished by the installation of a fence or other type obstacles (man made or natural) and surveillance by manned patrols, fixed observation posts, and/or electronic devices. Defense planners recognized therefore the need for an alarming barrier. A concentrated effort by scientists solved the problem by developing the first Taut Wire Fence Alarm System in a configuration of an alarm barrier. The system was specified to have an extremely low false alarm rate (FAR/NAR), high probability of detection, the capability to follow various terrains, operability in a wide range of environmental conditions, a capability to delay an intruder, ease of installation by unskilled labor, and low maintenance requirements. The authors try here to explain the various constraints and considerations given during the design stages of the Taut Wire Alarm System so as to bring the present magnitude of users to a better understanding of the system's operation

  9. Design of protein nanoparticles for cell targeting and blood brain barrier crossing

    OpenAIRE

    Xu, Zhikun

    2015-01-01

    En estos últimos años, muchos nuevos materiales han sido involucrados en los campos de las nanotecnologías, y especialmente en nanomedicina. Las nanoparticulas formadas por proteínas son un ejemplo de bio-material que está atrayendo cada vez más la atención debido a sus características tanto biológicas como estructurales, como por ekjemplo su baja toxicidad, baja inmunogenicidad y su biodegradabilidad. Además, a través de la ingeniería genética, estas proteínas se pueden diseñar para que form...

  10. Behavioral alterations following blood-brain barrier disruption stimulated by focused ultrasound.

    Science.gov (United States)

    Yang, Feng-Yi; Huang, Sheng-Fang; Cheng, Irene Han-Juo

    2016-05-10

    The purpose of this study was to investigate the behavioral alterations and histological changes of the brain after FUS-induced BBB disruption (BBBD). Rats were behaviorally tested using the open field, hole-board, and grip strength tests from day 1 through day 32 after undergoing BBBD induced by FUS with either a mild or heavy parameter. In the open field test, we found an increase in center entries on day 1 and day 9 following heavy FUS treatment and a decrease in center entries at day 18 following mild FUS treatment. With regard to memory-related alterations, rats subjected to heavy FUS treatment exhibited longer latency to start exploring and to find the first baited hole. However, rats subjected to mild FUS treatment exhibited no significant differences in terms of memory performance or grip force. The obtained data suggest that heavy FUS treatment might induce hyperactivity, spatial memory impairment, and forelimb gripping deficits. Furthermore, while mild FUS treatment may have an impact on anxiety-related behaviors, the data suggested it had no impact on locomotor activity, memory, or grip force. Thus, the behavioral alterations following FUS-induced BBBD require further investigation before clinical application. PMID:27034007

  11. Mannitol in Amanita muscaria--an osmotic blood-brain barrier disruptor enhancing its hallucinogenic action?

    Science.gov (United States)

    Maciejczyk, E; Kafarski, P

    2013-11-01

    Hypothesis have been made that relatively high level of mannitol present in the tissues of fly agaric (Amanita muscaria) enables more efficient transportation of these active substances into the brain and thus enhance their total activity. It may have been supported by the fact that hallucinogenic effect after A. muscaria consumption is greater than after ingestion of an active substance quantity which the eaten fungi dose contain. PMID:23932733

  12. Effect of photon irradiation on blood--brain barrier permeability to methotrexate in mice

    International Nuclear Information System (INIS)

    Methotrexate was administered by intraperitoneal injection (100 mg/kg) to unirradiated mice, and to mice receiving varying doses of cranial irradiation. The animals were sacrificed 24 hours after injection, and methotrexate assays were performed on brain tissue. No methotrexate was detected in the brains of the unirradiated animals. Detectable levels of methotrexate were present after 2000 rad cranial irradiation, but not after 500 rad, 1000 rad, or 1500 rad. The implications of these findings are discussed

  13. AMYLOID BETA ACCUMULATION IN HIV-1-INFECTED BRAIN: THE ROLE OF THE BLOOD BRAIN BARRIER

    OpenAIRE

    András, Ibolya E.; Toborek, Michal

    2012-01-01

    In recent years we face an increase in the aging of the HIV-1-infected population, which is not only due to effective antiretroviral therapy but also to new infections among older people. Even with the use of the antiretroviral therapy, HIV-associated neurocognitive disorders represent an increasing problem as the HIV-1-infected population ages. Increased amyloid beta (Aβ) deposition is characteristic of HIV-1-infected brains, and it has been hypothesized that brain vascular dysfunction contr...

  14. Transport of paclitaxel (Taxol) across the blood-brain barrier in vitro and in vivo

    OpenAIRE

    Fellner, Stephan; Bauer, Björn; Miller, David S.; Schaffrick, Martina; Fankhänel, Martina; Spruß, Thilo; Bernhardt, Günther; Graeff, Claudia; Färber, Lothar; Gschaidmeier, Harald; Buschauer, Armin; Fricker, Gert

    2002-01-01

    Paclitaxel concentrations in the brain are very low after intravenous injection. Since paclitaxel is excluded from some tumors by p-glycoprotein (p-gp), the same mechanism may prevent entry into the brain. In vitro, paclitaxel transport was examined in capillaries from rat brains by confocal microscopy using BODIPY Fl-paclitaxel. Western blots and immunostaining demonstrated apical expression of p-gp in isolated endothelial cells, vessels, and tissue. Secretion of BODIPY Fl-paclitaxel into ca...

  15. Permeability of the blood-brain barrier in the rat after local proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lundqvist, H.; Rosander, K. (Uppsala Univ. (Sweden). Gustaf Werner Inst.); Lomanov, M.; Lukjashin, V.; Shimchuk, G.; Zolotov, V.; Minakova, E. (Institute of Theoretical and Experimental Physics, Moscow, USSR)

    1982-01-01

    Rats were irradiated laterally through the brain with 200 MeV protons. The beam was of circular cross-section with a diameter of 5 or 7 mm. The doses were 50, 70, 100 and 150 Gy. After irradiation the rats were examined several times by use of injected /sup 99/Tcsup(m) pertechnetate. The uptake of the substance increased to a maximum after 20 to 30 days and then decreased to a normal level. Differences in maximum uptake with respect to dose were significant only for the smaller beam diameter.

  16. Machine learning algorithms to predict blood-brain barrier permeability of drug molecules

    OpenAIRE

    Martins, Inês Filipa dos Santos, 1988-

    2011-01-01

    Tese de mestrado. Bioinformática e Biologia Computacional (Bioinformática). Universidade de Lisboa, Faculdade de Ciências, 2011 A incidência de doenças ligadas ao sistema nervoso central (SNC) aumenta exponencialmente depois dos 65 anos e o aumento da esperança média de vida vem aumentar a população mundial com mais de 65 anos. Depressões, dor crónica, epilépsia e enxaquecas são algumas condições clínicas (distúrbios do SNC) que apresentam tratamento no entanto, podem ser consideradas exce...

  17. Recruitment of neutrophils across the blood-brain barrier: the role of posttraumatic hepatic ischemia

    Directory of Open Access Journals (Sweden)

    Mantovani Mario

    2003-01-01

    Full Text Available PURPOSE: To study the effects of total hepatic ischemia, and reperfusion on the accumulation of neutrophils in the brain of rats submitted to normovolemic conditions as well as to controlled hemorrhagic shock state. METHODS: Thirty two adult male Wistar rats, were divided into four groups: the Control group, was submitted to the standard procedures for a period of 60 min of observation; Shock group, was submitted to controlled hemorrhagic shock (mean arterial blood pressure=40mmHg, 20min followed by volemic resuscitation (lactated Ringer's solution + blood, 3:1 and reperfusion for 60min; Pringle group, was submitted to total hepatic ischemia for 15min and reperfusion for 60min. The total group was submitted to controlled hemorrhagic shock for 20min followed by volemic resuscitation (lactated Ringer's solution + blood, 3:1, total hepatic ischemia for 15min and reperfusion for 60min. Measurements of serum lactate and base excess were used to characterize the hemorrhagic shock state with low tissue perfusion. The counting of neutrophils on the brain was performed after the euthanasia of animals. RESULTS: The values for the counting of neutrophils on the brain indicate that did not occur difference among studied groups (p=0.196 (Control 0.12± 0.11, Shock 0.12± 0.13, Pringle 0.02± 0.04, Total 0.14± 0.16. CONCLUSION: Hemorrhagic shock associated to total hepatic ischemia for 15 minutes, followed by 60 minutes of reperfusion, did not causes significant neutrophils accumulation in the brain of rats.

  18. IDS Crossing of the Blood-Brain Barrier Corrects CNS Defects in MPSII Mice

    OpenAIRE

    Polito, Vinicia Assunta; Cosma, Maria Pia

    2015-01-01

    Mucopolysaccharidosis type II (MPSII), or Hunter syndrome, arises from a deficiency in iduronate 2-sulfatase (IDS), and it is characterized by progressive somatic and neurological involvement. The MPSII mouse model reproduces the features of MPSII patients. Systemic administration of the AAV2/5CMV-hIDS vector in MPSII mouse pups results in the full correction of glycosaminoglycan (GAG) accumulation in visceral organs and in the rescue of the defects and GAG accumulation in the central nervous...

  19. 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...