scholarly journals Species-Dependent Blood-Brain Barrier Disruption of Lipopolysaccharide: Amelioration by ColistinIn VitroandIn Vivo

2013 ◽  
Vol 57 (9) ◽  
pp. 4336-4342 ◽  
Author(s):  
Liang Jin ◽  
Roger L. Nation ◽  
Jian Li ◽  
Joseph A. Nicolazzo

ABSTRACTThe aim of this study was to usein vitroandin vivomodels to assess the impact of lipopolysaccharide (LPS) from two different bacterial species on blood-brain barrier (BBB) integrity and brain uptake of colistin. Following repeated administration of LPS fromPseudomonas aeruginosa, the brain-to-plasma ratio of [14C]sucrose in Swiss outbred mice was not significantly increased. Furthermore, while the brain uptake of colistin in mice increased 3-fold following administration of LPS fromSalmonella enterica, LPS fromP. aeruginosahad no significant effect on colistin brain uptake. This apparent species-dependent effect did not appear to correlate with differences in plasma cytokine levels, as the concentrations of tumor necrosis factor alpha and interleukin-6 following administration of each LPS were not different (P> 0.05). To clarify whether this species-specific effect of LPS was due to direct effects on the BBB, human brain capillary endothelial (hCMEC/D3) cells were treated with LPS fromP. aeruginosaorS. entericaand claudin-5 expression was measured by Western blotting.S. entericaLPS significantly (P< 0.05) reduced claudin-5 expression at a concentration of 7.5 μg/ml. In contrast,P. aeruginosaLPS decreased (P< 0.05) claudin-5 expression only at the highest concentration tested (i.e., 30 μg/ml). Coadministration of therapeutic concentrations of colistin ameliorated theS. entericaLPS-induced reduction in claudin-5 expression in hCMEC/D3 cells and the perturbation in BBB function in mice. This study demonstrates that BBB disruption induced by LPS is species dependent, at least betweenP. aeruginosaandS. enterica, and can be ameliorated by colistin.

2014 ◽  
Vol 58 (8) ◽  
pp. 4464-4469 ◽  
Author(s):  
Ji-Qin Wu ◽  
Kun Shao ◽  
Xuan Wang ◽  
Rui-Ying Wang ◽  
Ya-Hui Cao ◽  
...  

ABSTRACTAmphotericin B (AMB) has been a mainstay therapy for fungal infections of the central nervous system, but its use has been limited by its poor penetration into the brain, the mechanism of which remains unclear. In this study, we aimed to investigate the role of P-glycoprotein (P-gp) in AMB crossing the blood-brain barrier (BBB). The uptake of AMB by primary brain capillary endothelial cellsin vitrowas significantly enhanced after inhibition of P-gp by verapamil. The impact of two model P-gp inhibitors, verapamil and itraconazole, on brain/plasma ratios of AMB was examined in both uninfected CD-1 mice and those intracerebrally infected withCryptococcus neoformans. In uninfected mice, the brain/plasma ratios of AMB were increased 15 min (3.5 versus 2.0;P< 0.05) and 30 min (5.2 versus 2.8;P< 0.05) after administration of verapamil or 45 min (6.0 versus 3.9;P< 0.05) and 60 min (5.4 versus 3.8;P< 0.05) after itraconazole administration. The increases in brain/plasma ratios were also observed in infected mice treated with AMB and P-gp inhibitors. The brain tissue fungal CFU in infected mice were significantly lower in AMB-plus-itraconazole or verapamil groups than in the untreated group (P< 0.005), but none of the treatments protected the mice from succumbing to the infection. In conclusion, we demonstrated that P-gp inhibitors can enhance the uptake of AMB through the BBB, suggesting that AMB is a P-gp substrate.


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

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


1995 ◽  
Vol 7 (4) ◽  
pp. 114-121 ◽  
Author(s):  
Y.D. Van Der Werf ◽  
M.J.L. De Jongste ◽  
G.J. Ter Horst

SummaryIn this investigation the effects of immune activation on the brain are characterized. In order to study this, we used a model for chronic immune activation, the myocardial infarction, and intravenous injections with the pro-inflammatory cytokine Tumour Necrosis Factor alpha (TNF-α). The incentive for this study is the observation that myocardial infarction is accompanied by behavioural and neuronal abnormalities. The effects of myocardial infarction on the brain and its functioning are widespread. In order to examine the mechanism through which this interaction occurs, a group of rats underwent an experimentally induced myocardial infarction whereafter immunohistochemistry was performed on slices of the brain. This experiment revealed regional serum protein extravasation, pointing to leakage of the blood-brain barrier. This process occurred in certain cortical, subcortical and hindbrain areas in discrete patches. The leakage was co-localized with the expression of the immune activation marker ICAM-1. A second group of rats was therefore injected with TNF-α, a major pro-inflammatory cytokine, to assess the involvement of the immune system in the effects shown. This procedure rendered the same results. It is concluded that myocardial infarction may interfere with the integrity of the blood-brain barrier and possibly with brain functioning through activation of the immune system. The relevance for pathophysiological processes is discussed.


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

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


1990 ◽  
Vol 122 (2) ◽  
pp. 156-162 ◽  
Author(s):  
Arshag D. Mooradian

Abstract The effect of hypothyroidism in the adult rat on blood-brain barrier and muscle transport of hexoses, neutral amino acids, basic amino acids, monocarboxylic acids, and ketone bodies was examined using single arterial injection-tissue sampling technique. The cerebral blood flow and brain extraction of 3H2O (internal reference substance) was not altered in 3-month-old hypothyroid rats maintained on methimazole, 0.025% in the drinking water, for 7 weeks. The brain uptake index of D-β-hydroxybutyrate was significantly reduced in hypothyroid rats (2.4 ± 0.3 vs 4.6 ± 0.6% p<0.001). Hypothyroid rats given thyroid hormone replacement therapy had normal brain uptake of D-β-hydroxybutyrate (4.4 ± 0.8%). The brain uptake index of butyrate was also significantly reduced in hypothyroid rats (39.3 ± 2.1 vs 47.2 ± 0.74%, p<0.001). The brain uptake index of other test substances and muscle uptake of nutrients examined were not altered in hypothyroid rats. These studies indicate that of the four transport systems examined in two tissues, the blood-brain barrier monocarboxylic acid transport system is most susceptible to the hypothyroidism-induced changes.


1982 ◽  
Vol 57 (3) ◽  
pp. 394-398 ◽  
Author(s):  
Kazuo Yamada ◽  
Yukitaka Ushio ◽  
Toru Hayakawa ◽  
Amami Kato ◽  
Noriko Yamada ◽  
...  

✓ Quantitative autoradiographic technique was applied in measuring blood-brain barrier (BBB) permeability of autochthonous gliomas in rats. In small tumors (less than 2 mm in diameter), no increase in BBB permeability was noted. As the tumor grew and neovascularization occurred, BBB permeability increased in the center of the tumor, and it was suggested that the BBB was partly disrupted in the neovascularized vessels. In the fully grown tumors, BBB permeability was markedly increased in the viable part of the tumor to levels similar to the choroid plexus. Yet, the BBB was partly preserved at the periphery of the tumor and in the brain adjacent to the tumor. The heterogeneity of the BBB phenomenon according to the stage of tumor growth may be a major obstacle for uptake of chemotherapeutic drugs that do not cross the BBB easily.


2010 ◽  
Vol 55 (2) ◽  
pp. 502-507 ◽  
Author(s):  
Liang Jin ◽  
Jian Li ◽  
Roger L. Nation ◽  
Joseph A. Nicolazzo

ABSTRACTThe aim of this study was to investigate the factors limiting the blood-brain barrier (BBB) transport of colistin in healthy mice and to assess the impact of systemic inflammation on the transport of this antibiotic across the BBB. Colistin sulfate (40 mg/kg) was administered subcutaneously to Swiss outbred mice as single and multiple doses to determine any relationship between brain uptake and plasma concentrations of colistin. To assess the effect of P-glycoprotein (P-gp) on BBB transport, colistin sulfate (5 mg/kg) was concomitantly administered intravenously with PSC833 or GF120918 (10 mg/kg). Systemic inflammation was induced by three intraperitoneal injections of lipopolysaccharide (LPS; 3 mg/kg), and BBB transport of colistin was subsequently measured following subcutaneous administration and by anin situbrain perfusion. The brain uptake of colistin was low following single and multiple subcutaneous doses, with brain-to-plasma concentration ratios ranging between 0.021 and 0.037, and this was not significantly enhanced by coadministration of GF120918 or PSC833 (P> 0.05). LPS significantly increased the brain uptake of subcutaneously administered colistin with area under the brain concentration time curve (AUCbrain) values of 11.7 ± 2.7 μg·h/g and 4.0 ± 0.3 μg·h/g for LPS- and saline-treated mice, respectively (mean ± standard deviation). Similarly,in situperfusion of colistin led to higher antibiotic brain concentrations in LPS-treated animals than in saline-treated animals, with colistin brain-to-perfusate concentration ratios of 0.019 ± 0.001 and 0.014 ± 0.001, respectively. This study demonstrates that the BBB transport of colistin is negligible in healthy mice; however, brain concentrations of colistin can be significantly enhanced during systemic inflammation, as might be observed in infected patients.


2021 ◽  
Author(s):  
Jingfan Chen ◽  
Muzhaozi Yuan ◽  
Caitlin Madison ◽  
Shoshana Eitan ◽  
Ya Wang

Due to the low permeability and high selectivity of the blood-brain barrier (BBB), existing brain therapeutic technologies are limited by the inefficient BBB crossing of conventional drugs. Magnetic nanoparticles (MNPs) have shown great potential as nano-carriers for efficient BBB crossing under the external static magnetic field (SMF). To quantify the impact of SMF on MNPs' in vivo dynamics towards BBB crossing, we developed a physiologically based pharmacokinetic (PBPK) model for intraperitoneal (IP) injected superparamagnetic iron oxide nanoparticles coated by gold and conjugated with poly(ethylene glycol) (PEG) (SPIO-Au-PEG NPs) in mice. Unlike most reported PBPK models that ignore brain permeability, we first obtained the brain permeabilities with and without SMF by determining the concentration of SPIO-Au-PEG NPs in the cerebral blood and brain tissue. This concentration in the brain was simulated by the advection-diffusion equations and was numerically solved in COMSOL Multiphysics. The results from the PBPK model after incorporating the brain permeability showed a good agreement (regression coefficient R2 = 0.825) with the in vivo results, verifying the capability of using the proposed PBPK model to predict the in vivo biodistribution of SPIO-Au-PEG NPs under the exposure to SMF. Furthermore, the in vivo results revealed that the brain bioavailability under the exposure to SMF (4.01%) is slightly better than the control group (3.68%). In addition, the modification of SPIO-Au-PEG NPs with insulin (SPIO-Au-PEG-insulin) showed an improvement of the brain bioavailability by 24.47 % in comparison to the non-insulin group. With the SMF stimulation, the brain bioavailability of SPIO-Au-PEG-insulin was further improved by 3.91 % compared to the group without SMF.


1983 ◽  
Vol 245 (3) ◽  
pp. E253-E260 ◽  
Author(s):  
A. R. Conn ◽  
D. I. Fell ◽  
R. D. Steele

The transport of keto acids, monocarboxylic acids, and ketone bodies was studied in barbiturate-anesthetized, adult male Sprague-Dawley rats. [1-14C]propionate and D-3-[3-14C]hydroxybutyrate were found to cross the blood-brain barrier with brain uptake indexes of 43.53 and 7.10%, respectively. Transport of both of these substrates was saturable, with the values of transport Km being 2.03 and 6.54 mM, respectively. A Ki of 0.68 mM was derived from competition data measuring the uptake of [1-14C]alpha-ketoisocaproate in the presence of unlabeled alpha-ketobutyrate. This finding and results from classical inhibition studies support competition for transport of keto acids for a common carrier. The brain uptake of [1-14C]propionate was significantly reduced by keto acids and ketone bodies and the transport of D-3-[3-14C]hydroxybutyrate was significantly inhibited by unlabeled monocarboxylic acids, keto acids, and acetoacetate. Evidence for competitive transport of alpha-keto acids, monocarboxylic acids, and ketone bodies is presented in the form of classical double-reciprocal inhibition plots and of labeled monocarboxylic acids and ketone bodies by an increasing concentration of unlabeled alpha-ketoisocaproate, the latter method yielding Ki values of 0.29 and 0.63 mM, respectively. The brain uptake of labeled propionate was inhibited by unlabeled D-3-hydroxybutyrate. A Ki of 6.43 mM, derived from this data, approximated the Km of transport of D-3-hydroxybutyrate, suggesting that ketone bodies and monocarboxylic acids compete for transport via the same carrier that is operative for keto acids.


mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Taylor E. Senay ◽  
Jessica L. Ferrell ◽  
Filip G. Garrett ◽  
Taylor M. Albrecht ◽  
Jooyoung Cho ◽  
...  

ABSTRACT Listeria monocytogenes is thought to colonize the brain using one of three mechanisms: direct invasion of the blood-brain barrier, transportation across the barrier by infected monocytes, and axonal migration to the brain stem. The first two pathways seem to occur following unrestricted bacterial growth in the blood and thus have been linked to immunocompromise. In contrast, cell-to-cell spread within nerves is thought to be mediated by a particular subset of neurotropic L. monocytogenes strains. In this study, we used a mouse model of foodborne transmission to evaluate the neurotropism of several L. monocytogenes isolates. Two strains preferentially colonized the brain stems of BALB/cByJ mice 5 days postinfection and were not detectable in blood at that time point. In contrast, infection with other strains resulted in robust systemic infection of the viscera but no dissemination to the brain. Both neurotropic strains (L2010-2198, a human rhombencephalitis isolate, and UKVDL9, a sheep brain isolate) typed as phylogenetic lineage III, the least characterized group of L. monocytogenes. Neither of these strains encodes InlF, an internalin-like protein that was recently shown to promote invasion of the blood-brain barrier. Acute neurologic deficits were observed in mice infected with the neurotropic strains, and milder symptoms persisted for up to 16 days in some animals. These results demonstrate that neurotropic L. monocytogenes strains are not restricted to any one particular lineage and suggest that the foodborne mouse model of listeriosis can be used to investigate the pathogenic mechanisms that allow L. monocytogenes to invade the brain stem. IMPORTANCE Progress in understanding the two naturally occurring central nervous system (CNS) manifestations of listeriosis (meningitis/meningoencephalitis and rhombencephalitis) has been limited by the lack of small animal models that can readily distinguish between these distinct infections. We report here that certain neurotropic strains of Listeria monocytogenes can spread to the brains of young otherwise healthy mice and cause neurological deficits without causing a fatal bacteremia. The novel strains described here fall within phylogenetic lineage III, a small collection of L. monocytogenes isolates that have not been well characterized to date. The animal model reported here mimics many features of human rhombencephalitis and will be useful for studying the mechanisms that allow L. monocytogenes to disseminate to the brain stem following natural foodborne transmission.


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