scholarly journals Transient selective brain cooling confers neurovascular and functional protection from acute to chronic stages of ischemia/reperfusion brain injury

2018 ◽  
Vol 39 (7) ◽  
pp. 1215-1231 ◽  
Author(s):  
Jingyan Zhao ◽  
Hongfeng Mu ◽  
Liqiang Liu ◽  
Xiaoyan Jiang ◽  
Di Wu ◽  
...  
Keyword(s):  
Brain Injury ◽  
Blood Brain Barrier ◽  
Ischemia Reperfusion ◽  
Neurovascular Unit ◽  
Brain Barrier ◽  
Acute Injury ◽  
Experimental Stroke ◽  
Post Injury ◽  
Chronic Injury ◽  
Blood Brain

Ischemic injury can be alleviated by the judicious use of hypothermia. However, the optimal regimens and the temporal kinetics of post-stroke neurovascular responses to hypothermic intervention have not been systematically studied. These gaps slow the clinical translation of hypothermia as an anti-stroke therapy. Here, we characterized the effects of transient selective brain hypothermia (TSBH) from the hyperacute to chronic stages of focal ischemia/reperfusion brain injury induced by transient middle cerebral artery occlusion in mice. A simple cooling device was used to induce TSBH during cerebral ischemia. This treatment reduced mortality from 31.8% to 0% and improved neurological outcomes for at least 35 days post-injury. TSBH mitigated blood–brain barrier leakage during the hyperacute and acute injury stages (1–23 h post-reperfusion). This early protection of the blood–brain barrier was associated with anti-inflammatory phenotypic polarization of microglia/macrophages, reduced production of pro-inflammatory cytokines, and less brain infiltration of neutrophils and macrophages during the subacute injury stage (three days post-reperfusion). TSBH elicited enduring protective effects on both grey and white matter for at least 35 days post-injury and preserved the long-term electrophysiological function of fiber tracts. In conclusion, TSBH ameliorates ischemia/reperfusion injury in the neurovascular unit from hyperacute to chronic injury stages after experimental stroke.

scholarly journals Time-dependent dual effect of NLRP3 inflammasome in brain ischemia

2020 ◽  
Author(s):  
Alejandra Palomino-Antolin ◽  
Paloma Narros-Fernández ◽  
Víctor Farré-Alins ◽  
Javier Sevilla-Montero ◽  
Celine Decouty-Pérez ◽  
...  
Keyword(s):  
Brain Injury ◽  
Blood Brain Barrier ◽  
Inflammatory Cytokines ◽  
Nlrp3 Inflammasome ◽  
Neurovascular Unit ◽  
Time Dependent ◽  
Brain Barrier ◽  
Dependent Manner ◽  
Dual Effect ◽  
Blood Brain

AbstractBackground and purposePost-ischemic inflammation contributes to worsening of ischemic brain injury and in this process, the inflammasomes play a key role. Inflammasomes are cytosolic multiprotein complexes which upon assembly activate the maturation and secretion of the inflammatory cytokines IL-1β and IL-18. However, participation of the NLRP3 inflammasome in ischemic stroke remains controversial. Our aims were to determine the role of NLRP3 in ischemia and to explore the mechanism involved in the potential protective effect of the neurovascular unit.MethodsWT and NLRP3 knock-out mice were subjected to ischemia by middle cerebral artery occlusion (60 minutes) with or without treatment with MCC950 at different time points post-stroke. Brain injury was measured histologically with 2,3,5-triphenyltetrazolium chloride (TTC) staining.ResultsWe identified a time-dependent dual effect of NLRP3. While neither the pre-treatment with MCC950 nor the genetic approach (NLRP3 KO) proved to be neuroprotective, post-reperfusion treatment with MCC950 significantly reduced the infarct volume in a dose-dependent manner. Importantly, MCC950 improved the neuro-motor function and reduced the expression of different pro-inflammatory cytokines (IL-1β, TNF-α), NLRP3 inflammasome components (NLRP3, pro-caspase-1), protease expression (MMP9) and endothelial adhesion molecules (ICAM, VCAM). We observed a marked protection of the blood-brain barrier (BBB), which was also reflected in the recovery of the tight junctions proteins (ZO-1, Claudin-5). Additionally, MCC950 produced a reduction of the CCL2 chemokine in blood serum and in brain tissue, which lead to a reduction in the immune cell infiltration.ConclusionsThese findings suggest that post-reperfusion NLRP3 inhibition may be an effective acute therapy for protecting the blood-brain barrier in cerebral ischemia with potential clinical translation.

scholarly journals Lipid Reshaping and Lipophagy Are Induced in a Modeled Ischemia-Reperfusion Injury of Blood Brain Barrier

2019 ◽  
Vol 20 (15) ◽  
pp. 3752 ◽  
Author(s):  
Elena Lonati ◽  
Paola Antonia Corsetto ◽  
Gigliola Montorfano ◽  
Stefania Zava ◽  
Tatiana Carrozzini ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Brain Barrier ◽  
Ischemia Reperfusion Injury ◽  
Neutral Lipids ◽  
Ischemia Reperfusion ◽  
Neurovascular Unit ◽  
Standard Condition ◽  
Brain Barrier ◽  
Inflammatory Status ◽  
Blood Brain

Ischemic-reperfusion (I/R) injury induced a remodeling of protein and lipid homeostasis, under oxidative stress and inflammatory status. Starvation occurring during I/R is a condition leading to autophagy activation, which allows abnormal material clearance or amino acid, or both, and fatty acid (FA) recycling essential for survival. This study investigated the lipid reshaping, peroxidation, and related-signaling pathways, in rat brain endothelial cells (RBE4) subjected to 3 h of oxygen and glucose deprivation (OGD) and restoration of standard condition (I/R in vitro model). Lipids and proteins were analyzed after 1 or 24 h of oxygen and nutrient restoration. Together with the oxidative stress and inflammatory status, I/R injury induced a reshaping of neutral lipids and biogenesis of lipid droplets (LD) with excessive lipid storage. The increase of LC3-II/LC3-I ratio, an autophagy marker, and LC3 co-localization with LD suggest the activation of lipophagy machinery to counteract the cell engulfment. Lipophagy leads to cholesterol ester (CE) hydrolysis, increasing free cholesterol (FC) secretion, which occurred by specific transporters or unconventional exocytosis pathways, or both. Here, we propose that an unconventional spreading of FC and other lipid metabolites may influence the neurovascular unit (NVU) cells, contributing to Blood brain barrier (BBB) alteration or adaptation, or both, to the cumulative effects of several transient ischemia.

scholarly journals Neurological Diseases in Relation to the Blood–Brain Barrier

2012 ◽  
Vol 32 (7) ◽  
pp. 1139-1151 ◽  
Author(s):  
Gary A Rosenberg
Keyword(s):  
Free Radicals ◽  
Blood Brain Barrier ◽  
Neurological Diseases ◽  
Neurovascular Unit ◽  
Brain Barrier ◽  
Cellular Damage ◽  
Brain Diseases ◽  
Acute Injury ◽  
Blood Brain ◽  
The Brain

Disruption of the blood–brain barrier (BBB) has an important part in cellular damage in neurological diseases, including acute and chronic cerebral ischemia, brain trauma, multiple sclerosis, brain tumors, and brain infections. The neurovascular unit (NVU) forms the interface between the blood and brain tissues. During an injury, the cascade of molecular events ends in the final common pathway for BBB disruption by free radicals and proteases, which attack membranes and degrade the tight junction proteins in endothelial cells. Free radicals of oxygen and nitrogen and the proteases, matrix metalloproteinases and cyclooxgyenases, are important in the early and delayed BBB disruption as the neuroinflammatory response progresses. Opening of the BBB occurs in neurodegenerative diseases and contributes to the cognitive changes. In addition to the importance of the NVU in acute injury, angiogenesis contributes to the recovery process. The challenges to treatment of the brain diseases involve not only facilitating drug entry into the brain, but also understanding the timing of the molecular cascades to block the early NVU injury without interfering with recovery. This review will describe the molecular and cellular events associated with NVU disruption and potential strategies directed toward restoring its integrity.

scholarly journals Time-dependent dual effect of NLRP3 inflammasome in brain ischemia

2020 ◽  
Author(s):  
Alejandra Palomino-Antolin ◽  
Paloma Narros-Fernández ◽  
Victor Farré-Alins ◽  
Javier Sevilla-Montero ◽  
Celine Decouty-Pérez ◽  
...  
Keyword(s):  
Brain Injury ◽  
Blood Brain Barrier ◽  
Inflammatory Cytokines ◽  
Nlrp3 Inflammasome ◽  
Neurovascular Unit ◽  
Time Dependent ◽  
Brain Barrier ◽  
Dependent Manner ◽  
Dual Effect ◽  
Blood Brain

Background: Post-ischemic inflammation contributes to worsening of ischemic brain injury and in this process, the inflammasomes play a key role. Inflammasomes are cytosolic multiprotein complexes which upon assembly activate the maturation and secretion of the inflammatory cytokines IL-1β and IL-18. However, participation of the NLRP3 inflammasome in ischemic stroke remains controversial. Our aims were to determine the role of NLRP3 in ischemia and to explore the mechanism involved in the potential protective effect of the neurovascular unit. Methods: WT and NLRP3 knock-out mice were subjected to ischemia by middle cerebral artery occlusion (60 minutes) with or without treatment with MCC950 at different time points post-stroke. Brain injury was measured histologically with 2,3,5-triphenyltetrazolium chloride (TTC) staining. Results: We identified a time-dependent dual effect of NLRP3. While neither the pre-treatment with MCC950 nor the genetic approach (NLRP3 KO) proved to be neuroprotective, post-reperfusion treatment with MCC950 significantly reduced the infarct volume in a dose-dependent manner. Importantly, MCC950 improved the neuro-motor function and reduced the expression of different pro-inflammatory cytokines (IL-1β, TNF-α), NLRP3 inflammasome components (NLRP3, pro-caspase-1), protease expression (MMP9) and endothelial adhesion molecules (ICAM, VCAM). We observed a marked protection of the blood-brain barrier (BBB), which was also reflected in the recovery of the tight junctions proteins (ZO-1, Claudin-5). Additionally, MCC950 produced a reduction of the CCL2 chemokine in blood serum and in brain tissue, which lead to a reduction in the immune cell infiltration. Conclusions: These findings suggest that post-reperfusion NLRP3 inhibition may be an effective acute therapy for protecting the blood-brain barrier in cerebral ischemia with potential clinical translation.

scholarly journals Selective Liposomal Transport Through Blood Brain Barrier Disruption in Ischaemic Stroke Reveals Two Distinct Therapeutic Opportunities

2019 ◽  
Author(s):  
Zahraa S. Al-Ahmady ◽  
Dhifaf Jasim ◽  
Sabahuddin Syed Ahmad ◽  
Raymond Wong ◽  
Michael Haley ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Inflammatory Responses ◽  
Neurovascular Unit ◽  
Artery Occlusion ◽  
Brain Barrier ◽  
Experimental Stroke ◽  
Blood Brain Barrier Disruption ◽  
Blood Brain ◽  
Ischaemic Brain

AbstractThe development of new therapies for stroke continues to face repeated translational failures. Brain endothelial cells form paracellular and transcellular barriers to many blood-borne therapies and the development of efficient delivery strategies is highly warranted. Here, in a mouse model of stroke, we show selective recruitment of clinically used liposomes into the ischaemic brain that correlates with biphasic blood brain barrier (BBB) breakdown. Intravenous administration of liposomes into mice exposed to transient middle cerebral artery occlusion took place at early (0.5h and 4h) and delayed (24h and 48h) timepoints, covering different phases of BBB disruption after stroke. Using a combination of in vivo real-time imaging and histological analysis we show that selective liposomal brain accumulation coincides with biphasic enhancement in transcellular transport followed by a delayed impairment to the paracellular barrier. This process precedes neurological damage in the acute phase and maintains long-term liposomal co-localisation within the neurovascular unit, which could have great potential for neuroprotection. Levels of liposomal uptake by glial cells are similarly selectively enhanced in the ischaemic region late after experimental stroke (2-3 days), highlighting their potential for blocking delayed inflammatory responses or shifting the polarization of microglia/macrophages towards brain repair.These findings demonstrate the capability of liposomes to maximise selective translocation into the brain after stroke and identify for the first time two windows for therapeutic manipulation. This emphasizes the benefits of selective drug delivery for efficient tailoring of new stroke treatments.

scholarly journals Interleukin-1β Transfer across the Blood–Brain Barrier in the Ovine Fetus

2015 ◽  
Vol 35 (9) ◽  
pp. 1388-1395 ◽  
Author(s):  
Grazyna B Sadowska ◽  
Xiaodi Chen ◽  
Jiyong Zhang ◽  
Yow-Pin Lim ◽  
Erin E Cummings ◽  
...  
Keyword(s):  
Brain Injury ◽  
Blood Brain Barrier ◽  
Ischemia Reperfusion ◽  
Brain Regions ◽  
Interleukin 1Β ◽  
Brain Barrier ◽  
Ischemic Brain Injury ◽  
Ischemic Brain ◽  
Blood Brain ◽  
Hypoxic Ischemic Brain Injury

Pro-inflammatory cytokines contribute to hypoxic–ischemic brain injury. Blood–brain barrier (BBB) dysfunction represents an important component of hypoxic–ischemic brain injury in the fetus. Hypoxic–ischemic injury could accentuate systemic cytokine transfer across the fetal BBB. There has been considerable conjecture suggesting that systemic cytokines could cross the BBB during the perinatal period. Nonetheless, evidence to support this contention is sparse. We hypothesized that ischemia–reperfusion increases the transfer of systemic interleukin-1β (IL-1β) across the BBB in the fetus. Ovine fetuses at 127 days of gestation were studied 4 hours after 30 minutes of bilateral carotid artery occlusion and compared with a nonischemic group. Recombinant ovine IL-1β protein was expressed from an IL-1β pGEX-2 T vector in E. coli BL-21 cells and purified. The BBB function was quantified in 12 brain regions using a blood-to-brain transfer constant with intravenous 125I-radiolabeled IL-1β (125I-IL-1β). Interleukin-1β crossed the intact BBB in nonischemic fetuses. Blood-to-brain transport of 125I-IL-1β was higher ( P < 0.05) across brain regions in fetuses exposed to ischemia–reperfusion than nonischemic fetuses. We conclude that systemic IL-1β crosses the intact fetal BBB, and that ischemia–reperfusion increases transfer of this cytokine across the fetal BBB. Therefore, altered BBB function after hypoxia–ischemia facilitates entry of systemic cytokines into the brain of the fetus.

scholarly journals Absence of MCP-induced Protein 1 Enhances Blood–Brain Barrier Breakdown after Experimental Stroke in Mice

2019 ◽  
Vol 20 (13) ◽  
pp. 3214
Author(s):  
Zhuqing Jin ◽  
Jian Liang ◽  
Jiaqi Li ◽  
Pappachan E. Kolattukudy
Keyword(s):  
Cerebral Ischemia ◽  
Blood Brain Barrier ◽  
Zinc Finger Protein ◽  
Ischemia Reperfusion ◽  
Brain Barrier ◽  
Experimental Stroke ◽  
Wild Type ◽  
Cerebral Ischemia Reperfusion ◽  
Blood Brain ◽  
The Impact

Focal cerebral ischemia can cause blood–brain barrier (BBB) breakdown, which is implicated in neuroinflammation and progression of brain damage. Monocyte chemotactic protein 1–induced protein 1 (MCPIP1) is a newly identified zinc-finger protein that negatively regulates inflammatory signaling pathways. We aimed to evaluate the impact of genetic MCPIP1 deletion on BBB breakdown and expression of BBB-related matrix metalloproteinases (MMPs) and tight junction proteins after cerebral ischemia/reperfusion (I/R) using MCPIP1-deficient (MCPIP1–/–) mice. Transient middle cerebral artery occlusion was induced in the MCPIP1–/– mice and their wild-type littermates for 2 h followed by reperfusion for 24 h. The degree of BBB breakdown was evaluated by injection of fluorescein isothiocyanate (FITC)-dextran. Quantitative real-time polymerase chain reaction, western blot, and immunohistochemistry were performed to compare the expression of MMPs and claudin-5 and zonula occludens-1 (ZO-1). MCPIP1 deficiency in mice resulted in enhanced leakage of FITC-dextran, increased expression of MMP-9/3, and reduced expression of claudin-5 and ZO-1 in the brain compared to that seen in their wild-type littermates subjected to cerebral I/R. These results demonstrate that absence of MCPIP1 exacerbates cerebral I/R-induced BBB disruption by enhancing the expression of MMP-9/3 and the degradation of claudin-5 and ZO-1, providing novel insights into the mechanisms underlying BBB breakdown after cerebral ischemia/reperfusion

scholarly journals DHA Attenuates Cerebral Edema Following Traumatic Brain Injury via the Reduction in Blood–Brain Barrier Permeability

2020 ◽  
Vol 21 (17) ◽  
pp. 6291
Author(s):  
Zhuo-Hao Liu ◽  
Nan-Yu Chen ◽  
Po-hsun Tu ◽  
Chen-Te Wu ◽  
Shao-Chieh Chiu ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Blood Brain Barrier ◽  
Temporal Analysis ◽  
Brain Barrier ◽  
Functional Improvement ◽  
Post Injury ◽  
Edema Formation ◽  
Mortality And Morbidity ◽  
Blood Brain

Traumatic brain injury (TBI) could result in edema and cause an increase in intracranial pressure of the brain resulting in mortality and morbidity. Although there is hyperosmolarity therapy available for this pathophysiological event, it remains controversial. Recently, several groups have shown docosahexaenoic acid (DHA) to improve functional and histological outcomes following brain injury based on reduction of neuroinflammation and apoptosis. However, the effect of DHA on blood–brain barrier (BBB) dysfunction after brain injury has not been fully studied. Here, a controlled cortical impact rat model was used to test the effect of a single dose of DHA administered 30 min post injury. Modified neurological severity score (mNSS) and forelimb asymmetry were used to determine the functional outcomes. Neuroimaging and histology were used to characterize the edema and BBB dysfunction. The study showed that DHA-treated TBI rats had better mNSS and forelimb asymmetry score than vehicle-treated TBI rats. Temporal analysis of edema using MRI revealed a significant reduction in edema level with DHA treatment compared to vehicle in TBI rats. Histological analysis using immunoglobulin G (IgG) extravasation showed that there was less extravasation, which corresponded with a reduction in aquaporin 4 and astrocytic metalloprotease 9 expression, and greater endothelial occludin expression in the peri-contusional site of the TBI rat brain treated with DHA in comparison to vehicle treatment. In conclusion, the study shows that DHA can exert its functional improvement by prevention of the edema formation via prevention of BBB dysfunction after TBI.

Sign in / Sign up

Export Citation Format

Share Document