scholarly journals Impaired meningeal lymphatic vessel development worsens stroke outcome

2019 ◽  
Vol 40 (2) ◽  
pp. 263-275 ◽  
Author(s):  
Pavel Yanev ◽  
Katherine Poinsatte ◽  
Devon Hominick ◽  
Noor Khurana ◽  
Kielen R Zuurbier ◽  
...  
Keyword(s):  
Lymphatic Vessels ◽  
Growth Factor Receptor ◽  
Young Male ◽  
Artery Occlusion ◽  
Stroke Outcomes ◽  
Post Stroke ◽  
Sagittal Sinus ◽  
The Central Nervous System ◽  
Vessel Development ◽  
The Impact

The discovery of meningeal lymphatic vessels (LVs) has sparked interest in identifying their role in diseases of the central nervous system. Similar to peripheral LVs, meningeal LVs depend on vascular endothelial growth factor receptor-3 (VEGFR3) signaling for development. Here we characterize the effect of stroke on meningeal LVs, and the impact of meningeal lymphatic hypoplasia on post-stroke outcomes. We show that photothrombosis (PT), but not transient middle cerebral artery occlusion (tMCAo), induces meningeal lymphangiogenesis in young male C57Bl/J6 mice. We also show that Vegfr3wt/mut mice develop significantly fewer meningeal LVs than Vegfr3wt/wt mice. Again, meningeal lymphangiogenesis occurs in the alymphatic zone lateral to the sagittal sinus only after PT-induced stroke in Vegfr3wt/wt mice. Interestingly, Vegfr3wt/mut mice develop larger stroke volumes than Vegfr3wt/wt mice after tMCAo, but not after PT. Our results reveal differences between PT and tMCAo models of stroke and underscore the need to consider method of stroke induction when investigating the role of meningeal lymphatics. Taken together, our data indicate that ischemic injury can induce the growth of meningeal LVs and that the absence of these LVs can impact post-stroke outcomes.

Abstract P746: Sex Differences in Cognitive and Psychological Outcomes of Stroke: Impact of Diabetes

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Victoria L Wolf ◽  
Aunay Miller ◽  
Raghavendar Chandran ◽  
Weiguo Li ◽  
Adviye Ergul
Keyword(s):  
Artery Occlusion ◽  
Psychological Outcomes ◽  
Experimental Stroke ◽  
Dark Light ◽  
Stroke Outcomes ◽  
Post Stroke ◽  
Stroke Research ◽  
Y Maze ◽  
Male Animal ◽  
The Impact

Diabetes increases risk and severity of post-stroke cognitive impairment (PSCI), a major cause of disability worldwide. While it is known that females suffer more from PSCI, psychological outcomes and underlying reasons are poorly understood. From a preclinical perspective, potential explanations include 1) use of otherwise healthy animals in experimental stroke research without integration of common comorbid diseases like diabetes into the study design, and 2) optimization of most behavioral tests for sensorimotor and cognitive functions using only male animal models. Our hypothesis is that post-stroke outcomes are sex and comorbid disease-dependent. To test this, we validated the Novel Object Recognition (NOR), Y-maze, and Passive Avoidance (PAT) behavioral paradigms in Ctrl and Diabetic (DM) male (M) and female (F) rats pre- and post-stroke (S) via 60 min. middle cerebral artery occlusion (MCAO). We tested the PAT paradigm with a multi-trial method where the animals were habituated to the dark/light chambers without foot shock and then trained in 3 trials where they received foot shock upon entering the dark. We then tested retention following MCAO for their memory of foot shock 2 weeks prior. Multitrial results suggested that there was no difference between groups in learning to associate the dark chamber with the shock, so we revised the multitrial method into a single-trial method for ongoing retention tests to compare the impact of stroke on shock memory recall. PAT revealed (Table 1) disease- and sex-dependent responses to aversive stimulus. NOR revealed that M-DM-S and F-DM-S rats have decreased exploration time, suggesting that they are unmotivated or depressed. Y-maze indicated that males displayed spatial memory recovery, while females remained impaired. In summary, we have observed numerous sex- and disease-dependent post-stroke outcomes with standard behavioral paradigms, causing us to carefully consider how we evaluate preclinical outcomes.

scholarly journals Impact of Key Nicotinic AChR Subunits on Post-Stroke Pneumococcal Pneumonia

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 253
Author(s):  
Sandra Jagdmann ◽  
Claudia Dames ◽  
Daniel Berchtold ◽  
Katarzyna Winek ◽  
Luis Weitbrecht ◽  
...  
Keyword(s):  
Artery Occlusion ◽  
Experimental Stroke ◽  
Medical Complication ◽  
Α7 Nicotinic Acetylcholine Receptor ◽  
Post Stroke ◽  
Cholinergic Signaling ◽  
Cerebral Artery Occlusion ◽  
Pathogen Clearance ◽  
The Impact ◽  
Alveolar Capillary

Pneumonia is the most frequent severe medical complication after stroke. An overactivation of the cholinergic signaling after stroke contributes to immunosuppression and the development of spontaneous pneumonia caused by Gram-negative pathogens. The α7 nicotinic acetylcholine receptor (α7nAChR) has already been identified as an important mediator of the anti-inflammatory pathway after stroke. However, whether the α2, α5 and α9/10 nAChR expressed in the lung also play a role in suppression of pulmonary innate immunity after stroke is unknown. In the present study, we investigate the impact of various nAChRs on aspiration-induced pneumonia after stroke. Therefore, α2, α5, α7 and α9/10 nAChR knockout (KO) mice and wild type (WT) littermates were infected with Streptococcus pneumoniae (S. pneumoniae) three days after middle cerebral artery occlusion (MCAo). One day after infection pathogen clearance, cellularity in lung and spleen, cytokine secretion in bronchoalveolar lavage (BAL) and alveolar-capillary barrier were investigated. Here, we found that deficiency of various nAChRs does not contribute to an enhanced clearance of a Gram-positive pathogen causing post-stroke pneumonia in mice. In conclusion, these findings suggest that a single nAChR is not sufficient to mediate the impaired pulmonary defense against S. pneumoniae after experimental stroke.

Angiopoietin-1 promotes lymphatic sprouting and hyperplasia

Blood ◽  
2005 ◽  
Vol 105 (12) ◽  
pp. 4642-4648 ◽  
Author(s):  
Tuomas Tammela ◽  
Anne Saaristo ◽  
Marja Lohela ◽  
Tohru Morisada ◽  
Jenny Tornberg ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Viral Vectors ◽  
Lymphatic Vessels ◽  
Growth Factor Receptor ◽  
Soluble Form ◽  
Tissue Edema ◽  
Mouse Tissues ◽  
Vessel Development ◽  
Endothelial Growth Factor ◽  
Angiopoietin 1

Abstract Angiopoietin 1 (Ang1), a ligand for the receptor tyrosine kinase Tie2, regulates the formation and stabilization of the blood vessel network during embryogenesis. In adults, Ang1 is associated with blood vessel stabilization and recruitment of perivascular cells, whereas Ang2 acts to counter these actions. Recent results from gene-targeted mice have shown that Ang2 is also essential for the proper patterning of lymphatic vessels and that Ang1 can be substituted for this function. In order to characterize the effects of the angiopoietins on lymphatic vessels, we employed viral vectors for overexpression of Ang1 in adult mouse tissues. We found that Ang1 activated lymphatic vessel endothelial proliferation, vessel enlargement, and generation of long endothelial cell filopodia that eventually fused, leading to new sprouts and vessel development. Cutaneous lymphatic hyperplasia was also detected in transgenic mice expressing Ang1 in the basal epidermal cells. Tie2 was expressed in the lymphatic endothelial cells and Ang1 stimulation of these cells resulted in up-regulation of vascular endothelial growth factor receptor 3 (VEGFR-3). Furthermore, a soluble form of VEGFR-3 inhibited the observed lymphatic sprouting. Our results reinforce the concept that Ang1 therapy may be useful in settings of tissue edema. (Blood. 2005;105:4642-4648)

scholarly journals The regulation of glycemia in the recovery phase after stroke counteracts the detrimental effect of obesity-induced type 2 diabetes on neurological recovery

2020 ◽  
Author(s):  
Ada Admin ◽  
Ingrid Lovise Augestad ◽  
Hiranya Pintana ◽  
Martin Larsson ◽  
Camilla Krizhanovskii ◽  
...  
Keyword(s):  
Chronic Phase ◽  
Clinical Situation ◽  
Recovery Phase ◽  
Artery Occlusion ◽  
Stroke Recovery ◽  
Neurological Recovery ◽  
Standard Diet ◽  
Dipeptidyl Peptidase 4 ◽  
Post Stroke ◽  
The Impact

The interplay between obesity and T2D in post-stroke recovery is unclear. Moreover, the impact of glucose control during the chronic phase after stroke is undetermined. <p>We investigated whether obesity-induced T2D impairs neurological recovery after stroke by using a clinically relevant experimental design. We also investigated the potential efficacy of two clinically-used T2D drugs: the dipeptidyl peptidase-4 inhibitor linagliptin and the sulfonylurea glimepiride.</p> <p>We induced transient middle cerebral artery occlusion (tMCAO) in T2D/obese mice (after 7 months of high-fat diet (HFD)) and age-matched controls. After stroke, we replaced HFD with standard diet for 8 weeks to mimic the post-stroke clinical situation. Linagliptin or glimepiride were administered daily from 3 days after tMCAO for 8 weeks.<b> </b>We assessed neurological recovery weekly by upper-limb grip strength. Brain damage, neuroinflammation, stroke-induced neurogenesis and atrophy of parvalbumin (PV)+ interneurons were quantified by immunohistochemistry.</p> <p>T2D/obesity impaired post-stroke neurological recovery in association with hyperglycemia, neuroinflammation and atrophy of PV+ interneurons. Both drugs counteracted these effects. In non-diabetic mice, only linagliptin accelerated recovery.</p> These findings shed light on the interplay between obesity and T2D in stroke recovery. Moreover, they promote the use of rehabilitative strategies based on efficacious glycemia regulation, even if initiated days after stroke.

scholarly journals Temporal and Spatial Dynamics of Inflammasome Activation After Ischemic Stroke

2021 ◽  
Vol 12 ◽  
Author(s):  
Danli Lu ◽  
Mengyan Hu ◽  
Bingjun Zhang ◽  
Yinyao Lin ◽  
Qiang Zhu ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Spatial Dynamics ◽  
Size Control ◽  
Inflammasome Activation ◽  
Therapeutic Effects ◽  
Ischemic Lesion ◽  
Stroke Outcomes ◽  
Post Stroke ◽  
Caspase 1 ◽  
The Impact

Background: The inflammasome represents a highly pro-inflammatory mechanism. It has been identified that inflammasome was activated after ischemic stroke. However, the impact of inflammasomes on stroke outcomes remains contradictory. The participating molecules and the functioning arena of post-stroke inflammasome activation are still elusive.Methods: In the present study, blood samples from stroke patients were collected and analyzed with flow cytometry to evaluate the correlation of inflammasome activation and stroke outcomes. A stroke model was established using male C57/Bl6 mice with transient middle cerebral artery occlusion (tMCAO, 1 h). The dynamics of inflammasome components, cell type, and location of inflammasome activation and the therapeutic effects of inhibiting post-stroke inflammasome executors were evaluated.Results: We found that a high level of inflammasome activation might indicate detrimental stroke outcomes in patients and mice models. Post-stroke inflammasome activation, especially NLRP3, cleaved Caspase-1, cleaved Caspase-11, IL-1β, IL-18, and GSDMD, peaked at 3–5 days and declined at 7 days with the participation of multiple components in mice. Macrophage that infiltrated into the ischemic lesion was the main arena for post-stroke inflammasome activation among myeloid cells according to the data of mice. Among all the members of the Caspase family, Caspase-1 and −11 served as the main executing enzymes. Inhibiting Caspase-1/−11 signaling efficiently suppressed DAMPs-induced macrophage inflammasome activation and displayed neuroprotection to stroke models including infarct size (Control: 48.05 ± 14.98; Cas1.i: 19.34 ± 12.21; Cas11.i: 21.43 ± 14.67, P &lt; 0.001) and neurological deficit score (0 d-Control: 2.20 ± 0.63; 0 d-Cas1.i: 2.20 ± 0.63; 0 d-Cas11.i: 2.20 ± 0.63; 1 d-Control: 2.50 ± 0.53; 1 d-Cas1.i: 1.50 ± 0.71; 1 d-Cas11.i: 2.00 ± 0.67; 2 d-Control: 2.30 ± 0.48; 2 d-Cas1.i: 1.30 ± 0.48; 2 d-Cas11.i: 1.50 ± 0.53; 3 d-Control: 2.00 ± 0.67; 3 d-Cas1.i: 1.20 ± 0.42; 3 d-Cas11.i: 1.30 ± 0.48, P &lt; 0.001).Conclusions: Taken together, inflammasome activation played a detrimental role in stroke pathology. Targeting post-stroke inflammasome executing enzymes fitting in the dynamics of macrophages might obtain potential and efficient therapeutic effects.

scholarly journals The regulation of glycemia in the recovery phase after stroke counteracts the detrimental effect of obesity-induced type 2 diabetes on neurological recovery

2020 ◽  
Author(s):  
Ada Admin ◽  
Ingrid Lovise Augestad ◽  
Hiranya Pintana ◽  
Martin Larsson ◽  
Camilla Krizhanovskii ◽  
...  
Keyword(s):  
Chronic Phase ◽  
Clinical Situation ◽  
Recovery Phase ◽  
Artery Occlusion ◽  
Stroke Recovery ◽  
Neurological Recovery ◽  
Standard Diet ◽  
Dipeptidyl Peptidase 4 ◽  
Post Stroke ◽  
The Impact

The interplay between obesity and T2D in post-stroke recovery is unclear. Moreover, the impact of glucose control during the chronic phase after stroke is undetermined. <p>We investigated whether obesity-induced T2D impairs neurological recovery after stroke by using a clinically relevant experimental design. We also investigated the potential efficacy of two clinically-used T2D drugs: the dipeptidyl peptidase-4 inhibitor linagliptin and the sulfonylurea glimepiride.</p> <p>We induced transient middle cerebral artery occlusion (tMCAO) in T2D/obese mice (after 7 months of high-fat diet (HFD)) and age-matched controls. After stroke, we replaced HFD with standard diet for 8 weeks to mimic the post-stroke clinical situation. Linagliptin or glimepiride were administered daily from 3 days after tMCAO for 8 weeks.<b> </b>We assessed neurological recovery weekly by upper-limb grip strength. Brain damage, neuroinflammation, stroke-induced neurogenesis and atrophy of parvalbumin (PV)+ interneurons were quantified by immunohistochemistry.</p> <p>T2D/obesity impaired post-stroke neurological recovery in association with hyperglycemia, neuroinflammation and atrophy of PV+ interneurons. Both drugs counteracted these effects. In non-diabetic mice, only linagliptin accelerated recovery.</p> These findings shed light on the interplay between obesity and T2D in stroke recovery. Moreover, they promote the use of rehabilitative strategies based on efficacious glycemia regulation, even if initiated days after stroke.

scholarly journals A New NF-κB Inhibitor, MEDS-23, Reduces the Severity of Adverse Post-Ischemic Stroke Outcomes in Rats

2021 ◽  
Vol 12 (1) ◽  
pp. 35
Author(s):  
Elina Rubin ◽  
Agnese C. Pippione ◽  
Matthew Boyko ◽  
Giacomo Einaudi ◽  
Stefano Sainas ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Artery Occlusion ◽  
Brain Inflammation ◽  
Neurological Deficits ◽  
Stroke Outcomes ◽  
Post Stroke ◽  
Factor Α ◽  
Cerebral Artery Occlusion ◽  
First Time

Aim: Nuclear factor kappa B (NF-κB) is known to play an important role in the inflammatory process which takes place after ischemic stroke. The major objective of the present study was to examine the effects of MEDS-23, a potent inhibitor of NF-κB, on clinical outcomes and brain inflammatory markers in post-ischemic stroke rats. Main methods: Initially, a Toxicity Experiment was performed to determine the appropriate dose of MEDS-23 for use in animals, as MEDS-23 was analyzed in vivo for the first time. We used the middle cerebral artery occlusion (MCAO) model for inducing ischemic stroke in rats. The effects of MEDS-23 (at 10 mg/kg, ip) on post-stroke outcomes (brain inflammation, fever, neurological deficits, mortality, and depression- and anxiety-like behaviours) was tested in several efficacy experiments. Key findings: MEDS-23 was found to be safe and significantly reduced the severity of some adverse post-stroke outcomes such as fever and neurological deficits. Moreover, MEDS-23 significantly decreased prostaglandin E2 levels in the hypothalamus and hippocampus of post-stroke rats, but did not prominently alter the levels of interleukin-6 and tumor necrosis factor-α. Significance: These results suggest that NF-κB inhibition is a potential therapeutic strategy for the treatment of ischemic stroke.

scholarly journals Delayed Administration of Angiotensin Receptor (AT2R) Agonist C21 Improves Survival and Preserves Sensorimotor Outcomes in Female Diabetic Rats Post-Stroke through Modulation of Microglial Activation

2021 ◽  
Vol 22 (3) ◽  
pp. 1356
Author(s):  
LaDonya Jackson-Cowan ◽  
Wael Eldahshan ◽  
Selin Dumanli ◽  
Guangkuo Dong ◽  
Sarah Jamil ◽  
...  
Keyword(s):  
Therapeutic Option ◽  
Young Female ◽  
Artery Occlusion ◽  
Diabetic Rats ◽  
Stroke Recovery ◽  
Fine Motor ◽  
Post Stroke ◽  
The Impact

About 70% of stroke victims present with comorbid diseases such as diabetes and hypertension. The integration of comorbidities in pre-clinical experimental design is important in understanding the mechanisms involved in the development of stroke injury and recovery. We recently showed that administration of compound C21, an angiotensin II type 2 receptor agonist, at day 3 post-stroke improved sensorimotor outcomes by lowering neuroinflammation in diabetic male animals. In the current study, we hypothesized that a delayed administration of C21 would also lower chronic inflammation post-stroke in diabetic female animals. Young female diabetic rats were subjected to 1 h of middle cerebral artery occlusion (MCAO). Three days post-stroke, rats were administered C21 or vehicle in drinking water at a dose of 0.12 mg/kg/day for 4 weeks. The impact of C21 on microglial polarization was analyzed by flow cytometry in vivo and in vitro. Compound 21 treatment improved fine motor skills after MCAO through modulation of the microglia/macrophage inflammatory properties. In addition, C21 increased M2 polarization and reduced the M1:M2 ratio in vitro. In conclusion, delayed administration of C21 downregulates post-stroke inflammation in female diabetic animals. C21 may be a useful therapeutic option to lower neuro-inflammation and improve the post-stroke recovery in diabetes.

Identification of lymphatic endothelium in cranial arachnoid granulation-like dural gap

Microscopy ◽  
2020 ◽  
Vol 69 (6) ◽  
pp. 391-400 ◽  
Author(s):  
Osamu Kutomi ◽  
Sen Takeda
Keyword(s):  
Lymphatic Vessels ◽  
Lymphatic Endothelial Cell ◽  
Dural Sinus ◽  
Transmission Electron Microscopy Analysis ◽  
Sagittal Sinus ◽  
Csf Drainage ◽  
Transmission Electron ◽  
Physiological Relevance ◽  
Electron Microscopy Analysis ◽  
The Central Nervous System

Abstract The dynamics of cerebrospinal fluid (CSF) are essential for maintaining homeostasis in the central nervous system. Despite insufficiently detailed descriptions of their structural and molecular properties for a century, cranial arachnoid granulations (CAGs) on meninges have been thought to participate in draining CSF from the subarachnoid space into the dural sinuses. However, recent studies have demonstrated the existence of other types of CSF drainage systems, such as lymphatic vessels adjacent to dural sinus and paravascular space in the brain so-called glymphatic system. Therefore, the role of CAGs in CSF drainage has become dubious. To better understand CAG function, we analyzed the ultrastructure and molecular identity of CAG-like structure on meninges adjacent to the superior sagittal sinus of pigs. Transmission electron microscopy analysis revealed that this structure has a reticular conglomerate consisting of endothelial cells that resembles lymphatic linings. Furthermore, immunohistochemistry and immunoelectron microscopy showed that they express molecules specific to lymphatic endothelial cell. We coined a name ‘CAG-like dural gap (CAG-LDG)’ to this structure and discussed the physiological relevance in terms of CSF drainage.

scholarly journals Radiomics Derived Brain Age Predicts Functional Outcome After Acute Ischemic Stroke

2021 ◽  
Author(s):  
Martin Bretzner ◽  
Anna Bonkhoff ◽  
Markus Schirmer ◽  
Sungmin Hong ◽  
Adrian Dalca ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Aging ◽  
Stroke Care ◽  
Smoking History ◽  
Stroke Patients ◽  
Prognostic Information ◽  
Stroke Outcomes ◽  
Post Stroke ◽  
The Impact ◽  
Brain Age

Abstract While chronological age is one of the most influential determinants of post-stroke outcomes, little is known of the impact of neuroimaging-derived biological brain age. We here first examine whether radiomics analysis of the texture of brain T2-FLAIR MRI images can be used to predict brain age in stroke patients. We then assess the clinical determinants of accelerated brain aging and, finally, its impact on post-stroke functional outcomes. Leveraging a multisite cohort of 4,163 ischemic stroke patients, we show that older-appearing patients have more hypertension, diabetes mellitus, prior strokes, and smoking history and are more likely to develop worse post-stroke outcomes than their younger-appearing counterparts. Our results strengthen the importance of preventive medicine for maintaining brain health in stroke patients as they age and suggest a novel methodology to capture previously undescribed prognostic information available on commonly acquired MRI sequences during routine stroke care.

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