scholarly journals Transforming Growth Factor-β Signaling Alters Substrate Permeability and Tight Junction Protein Expression at the Blood-Brain Barrier during Inflammatory Pain

2009 ◽  
Vol 29 (6) ◽  
pp. 1084-1098 ◽  
Author(s):  
Patrick T Ronaldson ◽  
Kristin M DeMarco ◽  
Lucy Sanchez-Covarrubias ◽  
Christine M Solinsky ◽  
Thomas P Davis
Keyword(s):  
Growth Factor ◽  
Protein Expression ◽  
Tight Junction ◽  
Blood Brain Barrier ◽  
Inflammatory Pain ◽  
Transforming Growth Factor ◽  
Brain Barrier ◽  
Functional Integrity ◽  
Blood Brain ◽  
Bbb Permeability

Our laboratory has shown that peripheral inflammatory pain induced by λ-carrageenan (CIP) can increase blood-brain barrier (BBB) permeability and alter tight junction (TJ) protein expression leading to changes in BBB functional integrity. However, the intracellular signaling mechanisms involved in this pathophysiologic response have not been elucidated. Transforming growth factor (TGF)-β signaling pathways are known to regulate vascular integrity and permeability. Therefore, we examined the function of TGF-β signaling at the BBB in rats subjected to CIP. During CIP, serum TGF-β1 and protein expression of the TGF-β receptor activin receptor-like kinase-5 (ALK5) were reduced. Brain permeability to 14C-sucrose was increased and expression of TJ proteins (i.e., claudin-5, occludin, zonula occluden (ZO-1)) were also altered after 3 h CIP. Pharmacological inhibition of ALK5 with the selective inhibitor SB431542 further enhanced brain uptake of 14C-sucrose, increased TJ protein expression (i.e., claudin-3, claudin-5, occludin, ZO-1), and decreased nuclear expression of TGF-β/ALK5 signaling molecules (i.e., Smad2, Smad3), which suggests a role for TGF-β/ALK5 signaling in the regulation of BBB integrity. Interestingly, administration of exogenous TGF-β before CIP activated the TGF-β/ALK5 pathway and reduced BBB permeability to 14C-sucrose. Taken together, our data show that TGF-β/ALK5 signaling is, in part, involved in the regulation of BBB functional integrity.

scholarly journals Angiogenesis and Blood-Brain Barrier Permeability in Vascular Remodeling after Stroke

2020 ◽  
Vol 18 (12) ◽  
pp. 1250-1265 ◽  
Author(s):  
Yi Yang ◽  
Michel T. Torbey
Keyword(s):  
Tight Junction ◽  
Blood Brain Barrier ◽  
Defense Mechanism ◽  
Vascular Endothelial Cells ◽  
Brain Plasticity ◽  
Normal Function ◽  
Brain Barrier ◽  
Neurologic Recovery ◽  
Blood Brain ◽  
Bbb Permeability

Angiogenesis, the growth of new blood vessels, is a natural defense mechanism helping to restore oxygen and nutrient supply to the affected brain tissue following an ischemic stroke. By stimulating vessel growth, angiogenesis may stabilize brain perfusion, thereby promoting neuronal survival, brain plasticity, and neurologic recovery. However, therapeutic angiogenesis after stroke faces challenges: new angiogenesis-induced vessels have a higher than normal permeability, and treatment to promote angiogenesis may exacerbate outcomes in stroke patients. The development of therapies requires elucidation of the precise cellular and molecular basis of the disease. Microenvironment homeostasis of the central nervous system is essential for its normal function and is maintained by the blood-brain barrier (BBB). Tight junction proteins (TJP) form the tight junction (TJ) between vascular endothelial cells (ECs) and play a key role in regulating the BBB permeability. We demonstrated that after stroke, new angiogenesis-induced vessels in peri-infarct areas have abnormally high BBB permeability due to a lack of major TJPs in ECs. Therefore, promoting TJ formation and BBB integrity in the new vessels coupled with speedy angiogenesis will provide a promising and safer treatment strategy for improving recovery from stroke. Pericyte is a central neurovascular unite component in vascular barriergenesis and are vital to BBB integrity. We found that pericytes also play a key role in stroke-induced angiogenesis and TJ formation in the newly formed vessels. Based on these findings, in this article, we focus on regulation aspects of the BBB functions and describe cellular and molecular special features of TJ formation with an emphasis on role of pericytes in BBB integrity during angiogenesis after stroke.

scholarly journals Expression of Neuronal CXCL10 Induced by Rabies Virus Infection Initiates Infiltration of Inflammatory Cells, Production of Chemokines and Cytokines, and Enhancement of Blood-Brain Barrier Permeability

2014 ◽  
Vol 89 (1) ◽  
pp. 870-876 ◽  
Author(s):  
Qingqing Chai ◽  
Ruiping She ◽  
Ying Huang ◽  
Zhen F. Fu
Keyword(s):  
Protein Expression ◽  
Blood Brain Barrier ◽  
Rabies Virus ◽  
Inflammatory Cells ◽  
Brain Barrier ◽  
Blood Brain ◽  
Brain Barrier Permeability ◽  
Rabies Virus Infection ◽  
Ifn Γ ◽  
Bbb Permeability

It has been shown that enhancement of blood-brain barrier (BBB) permeability is modulated by the expression of chemokines/cytokines and reduction of tight junction (TJ) proteins in the brains of mice infected with rabies virus (RABV). Since CXCL10 was found to be the most highly expressed chemokine, its temporal and spatial expression were determined in the present study. The expression of the chemokine CXCL10 was initially detected in neurons as early as 3 days postinfection (p.i.) in the brains of RABV-infected mice, after which it was detected in microglia (6 days p.i.) and astrocytes (9 days p.i.). Neutralization of CXCL10 by treatment with anti-CXCL10 antibodies reduced gamma interferon (IFN-γ) production and Th17 cell infiltration, as well as restoring TJ protein expression and BBB integrity. Together, these data suggest that it is the neuronal CXCL10 that initiates the cascade that leads to the activation of microglia/astrocytes, infiltration of inflammatory cells, expression of chemokines/cytokines, reduction of TJ protein expression, and enhancement of the BBB permeability.

scholarly journals TRA2A-induced upregulation of LINC00662 regulates blood-brain barrier permeability by affecting ELK4 mRNA stability in Alzheimer's microenvironment

2019 ◽  
Author(s):  
Qianshuo Liu ◽  
Lu Zhu ◽  
Xiaobai Liu ◽  
Jian Zheng ◽  
Yunhui Liu ◽  
...  
Keyword(s):  
Tight Junction ◽  
Blood Brain Barrier ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Brain Barrier ◽  
Blood Brain ◽  
Bbb Permeability ◽  
Novel Target ◽  
Related Proteins

Abstract The blood-brain barrier (BBB) plays a pivotal role in maintenance and regulation of the neural microenvironment. The occurrence of BBB disruption is the pathological change of early Alzheimer’s disease (AD). RNA-binding proteins and long non-coding RNAs are involved in the regulation of BBB permeability. Our study was performed to demonstrate TRA2A/LINC00662/ELK4 axis in regulating BBB permeability in AD microenvironment. In Aβ1-42-incubated microvascular endothelial cells (ECs) of BBB model in vitro, TRA2A and LINC00662 were enriched. TRA2A increased the stability of LINC00662 by binding with it. The knockdown of either TRA2A or LINC00662 decreased the BBB permeability via upregulating the expressions of tight junction-related proteins. ELK4 was lower expressed in BBB model in vitro in AD microenvironment. LINC00662 mediated the degradation of ELK4 mRNA by SMD pathway. The downregulated ELK4 increased the permeability of BTB by increasing the tight junction-related proteins expressions. TRA2A/LINC00662/ELK4 axis plays a crucial role in the regulation of BBB permeability in AD microenvironment, which may provide a novel target for the therapy of AD.

scholarly journals Inflammatory pain alters blood-brain barrier permeability and tight junctional protein expression

2001 ◽  
Vol 280 (3) ◽  
pp. H1241-H1248 ◽  
Author(s):  
J. D. Huber ◽  
K. A. Witt ◽  
S. Hom ◽  
R. D. Egleton ◽  
K. S. Mark ◽  
...  
Keyword(s):  
Protein Expression ◽  
Western Blot ◽  
Blood Brain Barrier ◽  
Inflammatory Pain ◽  
Molecular Properties ◽  
Brain Barrier ◽  
Peripheral Inflammation ◽  
Blood Brain ◽  
Junctional Protein

Effects of inflammatory pain states on functional and molecular properties of the rat blood-brain barrier (BBB) were investigated. Inflammation was produced by subcutaneous injection of formalin, λ-carrageenan, or complete Freund's adjuvant (CFA) into the right hind paw. In situ perfusion and Western blot analyses were performed to assess BBB integrity after inflammatory insult. In situ brain perfusion determined that peripheral inflammation significantly increased the uptake of sucrose into the cerebral hemispheres. Capillary depletion and cerebral blood flow analyses indicated the perturbations were due to increased paracellular permeability rather than vascular volume changes. Western blot analyses showed altered tight junctional protein expression during peripheral inflammation. Occludin significantly decreased in the λ-carrageenan- and CFA-treated groups. Zonula occluden-1 expression was significantly increased in all pain models. Claudin-1 protein expression was present at the BBB and remained unchanged during inflammation. Actin expression was significantly increased in the λ-carrageenan- and CFA-treated groups. We have shown that inflammatory-mediated pain alters both the functional and molecular properties of the BBB. Inflammatory-induced changes may significantly alter delivery of therapeutic agents to the brain, thus affecting dosing regimens during chronic pain.

The role of hypoxia-inducible factor-1α, aquaporin-4, and matrix metalloproteinase-9 in blood-brain barrier disruption and brain edema after traumatic brain injury

2011 ◽  
Vol 114 (1) ◽  
pp. 92-101 ◽  
Author(s):  
Tetsuhiro Higashida ◽  
Christian W. Kreipke ◽  
José A. Rafols ◽  
Changya Peng ◽  
Steven Schafer ◽  
...  
Keyword(s):  
Tight Junction ◽  
Brain Edema ◽  
Blood Brain Barrier ◽  
Hypoxia Inducible Factor ◽  
Brain Barrier ◽  
Tight Junction Proteins ◽  
Edema Formation ◽  
Blood Brain ◽  
Bbb Permeability ◽  
Junction Proteins

Object The present study investigated the role of hypoxia-inducible factor-1α (HIF-1α), aquaporin-4 (AQP-4), and matrix metalloproteinase-9 (MMP-9) in blood-brain barrier (BBB) permeability alterations and brain edema formation in a rodent traumatic brain injury (TBI) model. Methods The brains of adult male Sprague-Dawley rats (400–425 g) were injured using the Marmarou closed-head force impact model. Anti–AQP-4 antibody, minocycline (an inhibitor of MMP-9), or 2-methoxyestradiol (2ME2, an inhibitor of HIF-1α), was administered intravenously 30 minutes after injury. The rats were killed 24 hours after injury and their brains were examined for protein expression, BBB permeability, and brain edema. Expression of HIF-1α, AQP-4, and MMP-9 as well as expression of the vascular basal lamina protein (laminin) and tight junction proteins (zona occludens-1 and occludin) was determined by Western blotting. Blood-brain barrier disruption was assessed by FITC-dextran extravasation, and brain edema was measured by the brain water content. Results Significant (p < 0.05) edema and BBB extravasations were observed following TBI induction. Compared with sham-operated controls, the injured animals were found to have significantly (p < 0.05) enhanced expression of HIF-1α, AQP-4, and MMP-9, in addition to reduced amounts (p < 0.05) of laminin and tight junction proteins. Edema was significantly (p < 0.01) decreased after inhibition of AQP-4, MMP-9, or HIF-1α. While BBB permeability was significantly (p < 0.01) ameliorated after inhibition of either HIF-1α or MMP-9, it was not affected following inhibition of AQP-4. Inhibition of MMP reversed the loss of laminin (p < 0.01). Finally, while inhibition of HIF-1α significantly (p < 0.05) suppressed the expression of AQP-4 and MMP-9, such inhibition significantly (p < 0.05) increased the expression of laminin and tight junction proteins. Conclusions The data support the notion that HIF-1α plays a role in brain edema formation and BBB disruption via a molecular pathway cascade involving AQP-4 and MMP-9. Pharmacological blockade of this pathway in patients with TBI may provide a novel therapeutic strategy.

scholarly journals Protein Kinase C Activation Modulates Reversible Increase in Cortical Blood–Brain Barrier Permeability and Tight Junction Protein Expression during Hypoxia and Posthypoxic Reoxygenation

2010 ◽  
Vol 30 (11) ◽  
pp. 1847-1859 ◽  
Author(s):  
Colin L Willis ◽  
Diana S Meske ◽  
Thomas P Davis
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Expression ◽  
Tight Junction ◽  
Vascular Permeability ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Kinase C ◽  
Blood Brain ◽  
Junction Protein

Hypoxia (Hx) is a component of many disease states including stroke. Ischemic stroke occurs when there is a restriction of cerebral blood flow and oxygen to part of the brain. During the ischemic, and subsequent reperfusion phase of stroke, blood–brain barrier (BBB) integrity is lost with tight junction (TJ) protein disruption. However, the mechanisms of Hx and reoxygenation (HR)-induced loss of BBB integrity are not fully understood. We examined the role of protein kinase C (PKC) isozymes in modifying TJ protein expression in a rat model of global Hx. The Hx (6% O2) induced increased hippocampal and cortical vascular permeability to 4 and 10 kDa dextran fluorescein isothiocyanate (FITC) and endogenous rat-IgG. Cortical microvessels revealed morphologic changes in nPKC-θ distribution, increased nPKC-θ and aPKC-ζ protein expression, and activation by phosphorylation of nPKC-θ (Thr538) and aPKC-ζ (Thr410) residues after Hx treatment. Claudin-5, occludin, and ZO-1 showed disrupted organization at endothelial cell margins, whereas Western blot analysis showed increased TJ protein expression after Hx. The PKC inhibition with chelerythrine chloride (5 mg/kg intraperitoneally) attenuated Hx-induced hippocampal vascular permeability and claudin-5, PKC (θ and ζ) expression, and phosphorylation. This study supports the hypothesis that nPKC-θ and aPKC-ζ signaling mediates TJ protein disruption resulting in increased BBB permeability.

scholarly journals Maternal glucocorticoid exposure alters tight junction protein expression in the brain of fetal sheep

2010 ◽  
Vol 298 (1) ◽  
pp. H179-H188 ◽  
Author(s):  
Grazyna B. Sadowska ◽  
Shadi N. Malaeb ◽  
Barbara S. Stonestreet
Keyword(s):  
Spinal Cord ◽  
Cerebral Cortex ◽  
Protein Expression ◽  
Tight Junction ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Barrier Permeability ◽  
Blood Brain Barrier Permeability ◽  
Blood Brain ◽  
Brain Barrier Permeability

We examined the expression of tight junction (TJ) proteins in the cerebral cortex, cerebellum, and spinal cord of fetuses after maternal treatment with single and multiple courses of dexamethasone. Ewes received either single courses of four 6-mg dexamethasone or placebo injections every 12 h for 48 h between 104 and 107 days or the same treatment once a week between 76–78 and 104–107 days of gestation. TJ protein expression was determined by Western immunoblot analysis on tissue harvested at 105–108 days of gestation. Blood-brain barrier permeability has been previously quantified with the blood-to-brain transfer constant ( Ki) with α-aminoisobutyric acid ( 39 ). After a single course of dexamethasone, claudin-5 increased ( P < 0.05) in the cerebral cortex, occludin and claudin-1 increased in the cerebellum, and occludin increased in the spinal cord. After multiple dexamethasone courses, occludin and zonula occludens (ZO)-1 increased in the cerebral cortex, and occludin and claudin-1 increased in the cerebellum. Junctional adhesion molecule-A and ZO-2 expressions did not change. Linear regression comparing Ki to TJ proteins showed inverse correlations with claudin-1 and claudin-5 in the cerebral cortex after a single course and ZO-2 in the spinal cord after multiple courses and direct correlations with ZO-1 in the cerebellum and spinal cord after multiple courses. We conclude that maternal glucocorticoid treatment increases the expression of specific TJ proteins in vivo, patterns of TJ protein expression vary after exposure to single and multiple glucocorticoid courses, and decreases in blood-brain barrier permeability are associated with increases in claudin-1, claudin-5, and ZO-2 expression and decreases in ZO-1 expression. In utero glucocorticoid exposure alters the molecular composition of the barrier and affects fetal blood-brain barrier function.

scholarly journals PDGFR-β restores blood-brain barrier functions in a mouse model of focal cerebral ischemia

2018 ◽  
Vol 39 (8) ◽  
pp. 1501-1515 ◽  
Author(s):  
Jie Shen ◽  
Guihua Xu ◽  
Runxiu Zhu ◽  
Jun Yuan ◽  
Yoko Ishii ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Growth Factor ◽  
Blood Brain Barrier ◽  
Transforming Growth Factor ◽  
Focal Cerebral Ischemia ◽  
Brain Barrier ◽  
Ischemic Lesion ◽  
Blood Brain ◽  
Tgf Β1

Although platelet-derived growth factor receptor beta (PDGFR-β) mediates the recruitment of vascular pericytes into ischemic lesion to restore the blood-brain barrier (BBB) dysfunction, its mechanisms still remain elusive . Compared with control PDGFR-βfloxed/floxed mice (Floxed), postnatally induced systemic PDGFR-β knockout mice (Esr-KO) not only showed severe brain edema, neurologic functional deficits, decreased expression of tight junction (TJ) proteins, abundant endothelial transcytosis, and deformed TJs in the BBB, but also showed reduced expression of transforming growth factor-β (TGF-β) protein after photothrombotic middle cerebral artery occlusion (MCAO). In endothelial-pericyte co-culture, an in vitro model of BBB, the increment in the barrier function of endothelial monolayer induced by pericyte co-culture was completely cancelled by silencing PDGFR-β gene expression in pericytes, and was additively improved by PDGFR-β and TGF-β receptor signals under hypoxia condition. Exogenous PDGF-BB increased the expression of p-Smad2/3, while anti-TGF-β1 antibody at least partially inhibited the phosphorylation of Smad2/3 after PDGF-BB treatment in vitro. Furthermore, pre-administration of TGF-β1 partially alleviated edema formation, neurologic dysfunction, and TJs reduction in Esr-KO mice after MCAO. Accordingly, PDGFR-β signalling, via TGF-β signalling, may be crucial for restoration of BBB integrity after cerebral ischemia and therefore represents a novel potential therapeutic target.

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