Blood Brain Barrier Group

Baton Rouge, LA, United States

Blood Brain Barrier Group

Baton Rouge, LA, United States
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Pan W.,Blood Brain Barrier Group | Wu X.,Blood Brain Barrier Group | Wu X.,Shanghai University of Traditional Chinese Medicine | He Y.,Blood Brain Barrier Group | And 5 more authors.
Neuroscience and Biobehavioral Reviews | Year: 2013

Interleukin (IL)-15 is a ubiquitously expressed cytokine existing in both intracellular and secretory forms. Here we review the expression, regulation, and functions of IL15 and its receptors in the brain. IL15 receptors show robust upregulation after neuroinflammation, suggesting a major role of IL15 signaling in cerebral function. Involvement of the IL15 system in neuropsychiatric behavior is reflected by the effects of IL15, IL15Rα, and IL2Rγ deletions on neurobehavior and neurotransmitters, the effects of IL15 treatment on neuronal activity, and the potential role of IL15 in neuroplasticity/neurogenesis. The results show that IL15 modulates GABA and serotonin transmission. This may underlie deficits in mood (depressive-like behavior and decreased normal anxiety) and memory, as well as activity level, sleep, and thermoregulation. Although IL15 has only a low level of permeation across the blood-brain barrier, peripheral IL15 is able to activate multiple signaling pathways in neurons widely distributed in CNS regions. The effects of IL15 in " preventing" neuropsychiatric symptoms in normal mice implicate a potential therapeutic role of this polypeptide cytokine. © 2012 Elsevier Ltd.


Pan W.,Biopotentials Sleep Center | Kastin A.J.,Blood Brain Barrier Group
Neuroscientist | Year: 2017

Sleep and its disorders are known to affect the functions of essential organs and systems in the body. However, very little is known about how the blood-brain barrier (BBB) is regulated. A few years ago, we launched a project to determine the impact of sleep fragmentation and chronic sleep restriction on BBB functions, including permeability to fluorescent tracers, tight junction protein expression and distribution, glucose and other solute transporter activities, and mediation of cellular mechanisms. Recent publications and relevant literature allow us to summarize here the sleep-BBB interactions in five sections: (1) the structural basis enabling the BBB to serve as a huge regulatory interface; (2) BBB transport and permeation of substances participating in sleep-wake regulation; (3) the circadian rhythm of BBB function; (4) the effect of experimental sleep disruption maneuvers on BBB activities, including regional heterogeneity, possible threshold effect, and reversibility; and (5) implications of sleep disruption-induced BBB dysfunction in neurodegeneration and CNS autoimmune diseases. After reading the review, the general audience should be convinced that the BBB is an important mediating interface for sleep-wake regulation and a crucial relay station of mind-body crosstalk. The pharmaceutical industry should take into consideration that sleep disruption alters the pharmacokinetics of BBB permeation and CNS drug delivery, being attentive to the chrono timing and activation of co-transporters in subjects with sleep disorders. © The Author(s) 2016.


Hsuchou H.,Blood Brain Barrier Group | Kastin A.J.,Blood Brain Barrier Group | Pan W.,Blood Brain Barrier Group
Journal of Molecular Neuroscience | Year: 2012

Reactive gliosis, a sign of neuroinflammation, has been observed in mice with adult-onset obesity as well as CNS injury. The hypothesis that obesity-derived metabolic factors exacerbate reactive gliosis in response to mechanical injury was tested here on cultured primary glial cells subjected to a well-established model of scratch wound injury. Cells treated with serum from mice with diet-induced obesity (DIO) showed higher immunoreactivity of CD11b (marker for microglia) and GFAP (marker for astrocytes), with morphological changes at both the injury border and areas away from the injury. The effect of DIO serum was greater than that of scratch injury alone. Leptin was almost as effective as DIO serum in inducing microgliosis and astrogliosis in a dose-response manner. By contrast, C-reactive protein (CRP) mainly induced microgliosis in noninjured cells; injury-induced factors appeared to attenuate this effect. The effect of CRP also differed from the effect of the antibiotic minocycline. Minocycline attenuated the microgliosis and to a lesser extent astrogliosis, particularly in CRP-treated cells, thus serving as a negative control. We conclude that blood-borne proinflammatory metabolic factors in obesity increase reactive gliosis and probably exacerbate CNS injury. © Springer Science+Business Media, LLC 2012.


Kastin A.J.,Blood Brain Barrier Group | Pan W.,Blood Brain Barrier Group
Current Pharmaceutical Design | Year: 2010

Here we review a unique aspect of CNS research on biologically active peptides that started against a background of prevalent dogmas but ended by exerting considerable influence on the field. During the course of refuting some doctrines, we introduced several concepts that were unconventional and paradigm-shifting at the time. We showed that (1) hypothalamic peptides can act 'up' on the brain as well as 'down' on the pituitary, (2) peripheral peptides can affect the brain, (3) peptides can cross the blood-brain barrier, (4) the actions of peptides can persist longer than their half-lives in blood, (5) perinatal administration of peptides can exert actions persisting into adulthood, (6) a single peptide can have more than one action, (7) dose-response relationships of peptides need not be linear, (8) the brain produces antiopiate as well as opiate peptides, (9) there is a selective high affinity endogenous peptide ligand for the mu-opiate receptor, (10) a peptide's name does not restrict its effects, and (11) astrocytes assume an active role in response to metabolic disturbance and hyperleptinemia. The evolving questions in our laboratories reflect the diligent effort of the neuropeptide community to identify the roles of peptides in the CNS. The next decade is expected to see greater progress in the following areas: (a) interactions of peptides with other molecules in the CNS; (b) peptide involvement in cell-cell interactions; and (c) peptides in neuropsychiatric, autoimmune, and neurodegenerative diseases. The development of peptidomics and gene silencing approaches will expedite the formation of many new concepts in a new era. © 2010 Bentham Science Publishers Ltd.


Hsuchou H.,Blood Brain Barrier Group | Pan W.,Blood Brain Barrier Group | Kastin A.J.,Blood Brain Barrier Group
Fluids and Barriers of the CNS | Year: 2013

Background: Fibroblast growth factor (FGF)-19, an endocrine FGF protein mainly produced by the ileum, stimulates metabolic activity and alleviates obesity. FGF19 modulates metabolism after either intravenous or intracerebroventricular injection, and its receptor FGFR4 is present in the hypothalamus. This led to the question whether blood-borne FGF19 crosses the blood-brain barrier (BBB) to exert its metabolic effects.Methods: We determined the pharmacokinetics of FGF19 permeation from blood to brain in comparison with its distribution in peripheral organs. Multiple-time regression analysis after intravenous bolus injection, in-situ brain perfusion, and HPLC assays were performed.Results: FGF19 was relatively stable in blood and in the brain compartment. Significant influx was seen in the presence of excess unlabeled FGF19 in blood. This coincided with a slower decline of 125I-FGF19 in blood which suggested there was decreased clearance or peripheral tissue uptake. In support of an altered pattern of peripheral processing of 125I-FGF19 by excess unlabeled FGF19, the high influx to liver was significantly attenuated, whereas the minimal renal uptake was linearly accelerated. In the present setting, we did not detect a saturable transport of FGF19 across the BBB, as the entry rate of 125I-FGF19 was not altered by excess unlabeled FGF19 or its mouse homologue FGF15 during in-situ brain perfusion.Conclusion: FGF19 remained stable in the blood and brain compartments for up to 10 min. Its influx to the brain was non-linear, non-saturable, and affected by its blood concentration and distribution in peripheral organs. Liver showed a robust and specific uptake of FGF19 that could be inhibited by the presence of excess unlabeled FGF19, whereas kidney clearance was dose-dependent. © 2013 Hsuchou et al.; licensee BioMed Central Ltd.


Pan W.,Blood Brain Barrier Group | Pan W.,Biopotentials L.L.C. | Kastin A.J.,Blood Brain Barrier Group
Neuroscience and Biobehavioral Reviews | Year: 2014

Both obstructive sleep apnea (OSA) and Alzheimer's disease (AD) are increasing health concerns. The objective of this study is to review systematically the effects of OSA on the development of AD. The search was conducted in PubMed and Cochrane CENTRAL, and followed by a manual search of references of published studies. Cross-sectional, cohorts, and randomized clinical trials were reviewed. Besides clinical studies, we also discuss neuroimaging data, experimental animal evidence, and molecular mechanisms. Although a causal relationship between OSA and AD is not yet established, OSA induces neurodegenerative changes as a result of two major contributing processes: sleep fragmentation and intermittent hypoxia. As such, inflammation and cellular stress are sufficient to impair cell-cell interactions, synaptic function, and neural circuitry, leading to a decline of cognitive behavior. Sustained OSA could promote cognitive dysfunction, overlapping with that in AD and other neurodegenerative diseases. Early treatment by positive airway pressure and other current standards of care should have a positive impact to alleviate structural and functional deterioration. With better understanding of the cellular and neurophysiological mechanisms by which OSA contributes to AD, we may identify novel molecular targets for intervention. © 2014 Elsevier Ltd.


Ouyang S.,Blood Brain Barrier Group | Hsuchou H.,Blood Brain Barrier Group | Kastin A.J.,Blood Brain Barrier Group | Wang Y.,Blood Brain Barrier Group | And 2 more authors.
Journal of Cerebral Blood Flow and Metabolism | Year: 2014

The blood-brain barrier (BBB) is a regulatory interface between the central nervous system and the rest of the body. However, BBB changes in obesity and metabolic syndrome have not been fully elucidated. We hypothesized that obesity reduces energy metabolism in the cerebral microvessels composing the BBB, reflected by downregulation of protein expression and function. We performed comparative proteomic analyses in enriched microvessels from the cerebral cortex of mice 2 months after ingestion of a high-fat diet or regular rodent chow. In mice with diet-induced obesity (DIO), there was downregulation of 47 proteins in the cerebral microvessels, including cytoskeletal proteins, chaperons, enzymes, transport-related proteins, and regulators for transcriptional and translational activities. Only two proteins, involved in messenger RNA (mRNA) transport and processing, were upregulated. The changes of these proteins were further validated by quantitative polymerase chain reaction (qPCR), western blotting, and immunofluorescent staining of freshly isolated microvessels, in samples obtained from different batches of mice. The predominant downregulation suggests that DIO suppresses metabolic activity of BBB microvessels. The finding of a hypometabolic state of the BBB in mice at the chronic stage of DIO is unexpected and unprecedented; it may provide novel mechanistic insight into how obesity influences CNS function via regulatory changes of the BBB. © 2014 ISCBFM. All rights reserved.


Hsuchou H.,Blood Brain Barrier Group | Kastin A.J.,Blood Brain Barrier Group | Mishra P.K.,Blood Brain Barrier Group | Pan W.,Blood Brain Barrier Group
Cellular Physiology and Biochemistry | Year: 2012

Background/Aims: Acute phase C-reactive protein (CRP), elevated in obesity and infammation, is a major binding protein for leptin. It is thought that CRP contributes to leptin resistance by preventing leptin from crossing the blood-brain barrier (BBB). Here we determined how CRP interacts with the BBB and whether it deters leptin from reaching CNS targets. Methods: BBB permeability, compartmental distribution, tracer stability, and expression of tight junction protein and infammatory marker were determined. Results: CRP was stable in blood, but did not permeate the BBB in trace amounts. However, it increased paracellular permeability at a higher dose. Agouti viable (Avy) mice with adult-onset obesity show higher CRP entry into the brain. CRP did not permeate hCMEC/D3 cells nor change zona occludin-1 or cyclooxygenase-2 expression. An intermediate dose of CRP had no effect on leptin transport across the BBB after co-treatment. Thus, acute interactions between CRP and leptin at the BBB level were negligible and did not explain the leptin resistance seen in obesity. Conclusions: The interactions of CRP and the BBB are a two-phase process, with increased paracellular permeability at a high dose that enables its entry into the CNS and serves to induce reactive gliosis and impair CNS function. Copyright © 2012 S. Karger AG, Basel.


He J.,Blood Brain Barrier Group | Hsuchou H.,Blood Brain Barrier Group | He Y.,Blood Brain Barrier Group | Kastin A.J.,Blood Brain Barrier Group | And 2 more authors.
Journal of Neuroscience | Year: 2014

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


Stone K.P.,Blood Brain Barrier Group | Kastin A.J.,Blood Brain Barrier Group | Pan W.,Blood Brain Barrier Group
Cellular Physiology and Biochemistry | Year: 2011

Interleukin (IL)-15 and its receptors are induced by tumor necrosis factor α (TNF) in the cerebral endothelial cells composing the blood-brain barrier, but it is not yet clear how IL-15 modulates endothelial function. Contrary to the known induction of JAK/STAT3 signaling, here we found that nuclear factor (NF)-κB is mainly responsible for IL-15 actions on primary brain microvessel endothelial cells and cerebral endothelial cell lines. IL-15-induced transactivation of an NFκB luciferase reporter resulted in phosphorylation and degradation of the inhibitory subunit IκB that was followed by phosphorylation and nuclear translocation of the p65 subunit of NFκB. An IκB kinase inhibitor Bay 11-7082 only partially inhibited IL-15-induced NFκB luciferase activity. The effect of IL-15 was mediated by its specific receptor IL-15Rα, since endothelia from IL-15Rα knockout mice showed delayed nuclear translocation of p65, whereas those from knockout mice lacking a co-receptor IL-2Rγ did not show such changes. At the mRNA level, IL-15 and TNF showed similar effects in decreasing the tight junction protein claudin-2 and increasing the p65 subunit of NFκB but exerted different regulation on caveolin-1 and vimentin. Taken together, NFκB is a major signal transducer by which IL-15 affects cellular permeability, endocytosis, and intracellular trafficking at the level of the blood-brain barrier. © 2011 S. Karger AG, Basel.

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