scholarly journals Sustained Functional Improvement by Hepatocyte Growth Factor-Like Small Molecule BB3 after Focal Cerebral Ischemia in Rats and Mice

2015 ◽  
Vol 35 (6) ◽  
pp. 1044-1053 ◽  
Author(s):  
Rafael E Chaparro ◽  
Miwa Izutsu ◽  
Toshihiro Sasaki ◽  
Huaxin Sheng ◽  
Yi Zheng ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Growth Factor ◽  
Hepatocyte Growth Factor ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Small Molecule ◽  
Artery Occlusion ◽  
Neurologic Function ◽  
Cerebral Artery Occlusion ◽  
Hepatocyte Growth

Hepatocyte growth factor (HGF), efficacious in preclinical models of acute central nervous system injury, is burdened by administration of full-length proteins. A multiinstitutional consortium investigated the efficacy of BB3, a small molecule with HGF-like activity that crosses the blood-brain barrier in rodent focal ischemic stroke using Stroke Therapy Academic Industry Roundtable (STAIR) and Good Laboratory Practice guidelines. In rats, BB3, begun 6 hours after temporary middle cerebral artery occlusion (tMCAO) reperfusion, or permanent middle cerebral artery occlusion (pMCAO) onset, and continued for 14 days consistently improved long-term neurologic function independent of sex, age, or laboratory. BB3 had little effect on cerebral infarct size and no effect on blood pressure. BB3 increased HGF receptor c-Met phosphorylation and synaptophysin expression in penumbral tissue consistent with a neurorestorative mechanism from HGF-like activity. In mouse tMCAO, BB3 starting 10 minutes after reperfusion and continued for 14 days improved neurologic function that persisted for 8 weeks in some, but not all measures. Study in animals with comorbidities and those exposed to common stroke drugs are the next steps to complete preclinical assessment. These data, generated in independent, masked, and rigorously controlled settings, are the first to suggest that the HGF pathway can potentially be harnessed by BB3 for neurologic benefit after ischemic stroke.

Abstract 166: Endothelial Overexpression of LOX-1 Increases Stroke Size in vivo

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Alexander Akhmedov ◽  
Remo D Spescha ◽  
Francesco Paneni ◽  
Giovani G Camici ◽  
Thomas F Luescher
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Endothelial Dysfunction ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Oxidized Ldl ◽  
Artery Occlusion ◽  
Cerebral Artery Occlusion ◽  
The Brain

Background— Stroke is one of the most common causes of death and long term disability worldwide primarily affecting the elderly population. Lectin-like oxidized LDL receptor 1 (LOX-1) is the receptor for oxidized LDL identified in endothelial cells. Binding of OxLDL to LOX-1 induces several cellular events in endothelial cells, such as activation of transcription factor NF-kB, upregulation of MCP-1, and reduction in intracellular NO. Accumulating evidence suggests that LOX-1 is involved in endothelial dysfunction, inflammation, atherogenesis, myocardial infarction, and intimal thickening after balloon catheter injury. Interestingly, a recent study demonstrated that acetylsalicylic acid (aspirin), which could prevent ischemic stroke, inhibited Ox-LDL-mediated LOX-1 expression in human coronary endothelial cells. The expression of LOX-1 was increased at a transient ischemic core site in the rat middle cerebral artery occlusion model. These data suggest that LOX-1 expression induces atherosclerosis in the brain and is the precipitating cause of ischemic stroke. Therefore, the goal of the present study was to investigate the role of endothelial LOX-1 in stroke using experimental mouse model. Methods and Results— 12-week-old male LOX-1TG generated recently in our group and wild-type (WT) mice were applied for a transient middle cerebral artery occlusion (MCAO) model to induce ischemia/reperfusion (I/R) brain injury. LOX-1TG mice developed 24h post-MCAO significantly larger infarcts in the brain compared to WT (81.51±8.84 vs. 46.41±10.13, n=7, p < 0.05) as assessed morphologically using Triphenyltetrazolium chloride (TTC) staining. Moreover, LOX-1TG showed higher neurological deficit in RotaRod (35.57±8.92 vs. 66.14±10.63, n=7, p < 0.05) and Bederson tests (2.22±0.14 vs. 1.25±0.30, n=9-12, p < 0.05) - two experimental physiological tests for neurological function. Conclusions— Thus, our data suggest that LOX-1 plays a critical role in the ischemic stroke when expressed at unphysiological levels. Such LOX-1 -associated phenotype could be due to the endothelial dysfunction. Therefore, LOX-1 may represent novel therapeutic targets for preventing ischemic stroke.

scholarly journals A Novel Model for Encephalomyosynangiosis Surgery after Middle Cerebral Artery Occlusion-Induced Stroke in Mice

2021 ◽  
Author(s):  
Mitch Paro ◽  
Daylin Gamiotea Turro ◽  
Leslie Blumenfeld ◽  
Ketan R Bulsara ◽  
Rajkumar Verma
Keyword(s):  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Therapeutic Option ◽  
Treatment Options ◽  
Artery Occlusion ◽  
Novel Treatment ◽  
Graft Tissue ◽  
Cerebral Artery Occlusion

Background and Purpose: No effective treatment is available for most patients who suffer ischemic stroke. Development of novel treatment options is imperative. The brain attempts to self-heal after ischemic stroke via various mechanism mediated by restored blood circulation in affected region of brain but this process is limited by inadequate angiogenesis or neoangiogenesis. Encephalomyosynangiosis (EMS) is a neurosurgical procedure that achieves angiogenesis with low morbidity in patients with moyamoya disease, reducing risk of stroke. However, EMS, surgery has never been studied as an therapeutic option after ischemic stroke. Here we described a novel procedure and feasibility data for EMS after ischemic stroke in mice. Methods: A 60 mins of middle cerebral artery occlusion (MCAo) was used to induce ischemic stroke in mice. After 3-4 hours of MCAo onset/sham, EMS was performed. Mortality of EMS, MCAo and. MCAo+EMS mice was recorded up to 21 days after surgery. Graft tissue viability was measured using a nicotinamide adenine dinucleotide reduced tetrazolium reductase assay. Results: EMS surgery after ischemic stroke does not increase mortality compared to stroke alone. Graft muscle tissue remained viable 21 days after surgery. Conclusions: This novel protocol is effective and well-tolerated, may serve as novel platform for new angiogenesis and thus recovery after ischemic stroke. If successful in mice, EMS can a very feasible and novel treatment option for ischemic stroke in humans.

Blocking A1 astrocyte conversion with semaglutide attenuates blood-brain barrier disruption in mice after middle cerebral artery occlusion

2021 ◽  
Author(s):  
Qi Zhang ◽  
Chang Liu ◽  
Rubing Shi ◽  
Huimin Shan ◽  
Lidong Deng ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Signaling Pathways ◽  
Middle Cerebral Artery Occlusion ◽  
Blood Brain Barrier ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Rna Seq ◽  
Neurobehavioral Outcomes ◽  
Cerebral Artery Occlusion

Abstract Background Astrocytes play an essential role in the modulation of blood-brain barrier function. Neurological diseases induce astrocytes to transform into a neurotoxic A1 phenotype, thus exacerbating brain injury. However, the effect of A1 astrocyte on the function of BBB after stroke is unknown. Method: Adult male ICR mice (n = 78) were subjected to 90-minute transient middle cerebral artery occlusion. Immunohistochemical staining of A1 (C3d) and A2 (S100A10) was performed to characterize phenotypic changes of astrocytes overtime after stroke. Glucagon-like peptide-1 receptor agonist semaglutide was intraperitoneally injected into the mice to inhibit A1 astrocyte. Infarct volume, atrophy volume, neurobehavioral outcomes, and BBB permeability were examined. RNA-seq was adopted to explore the potential targets and signaling pathways of A1 astrocytes induced BBB dysfunction. Results Astrocytes assumed the A2 phenotype at the early stage of ischemic stroke but gradually transformed to the A1 phenotype. Semaglutide treatment reduced M1 microglia polarization and A1 astrocytes conversion after ischemic stroke (p < 0.05). Ischemia induced brain infarct volume, atrophy volume and neuroinflammation were reduced in the semaglutide treated mice. Neurobehavioral outcomes were improved compared to the control mice (p < 0.05). Further study demonstrated that semaglutide treatment reduced the gap formation of tight junction proteins ZO-1, claudin-5 and occludin, as well as IgG leakage following three days of ischemic stroke (p < 0.05). In vitro experiments revealed that A1 astrocyte-conditioned medium disrupted BBB integrity. RNA-seq further showed that A1 astrocytes were enriched in inflammatory factors and chemokines, as well as significantly modulating TNF and chemokine signaling pathways, which are closely related to barrier damage. Conclusion We concluded that astrocytes undergo a conversion from A2 phenotype to A1 phenotype overtime after ischemic stroke. A1 astrocytes aggravated BBB disruption, suggesting that block of A1 astrocytes conversion provides a novel strategy for the treatment of ischemic stroke.

Abstract TP106: Automated Assessment of Behavioral Function After Experimental Stroke

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Terrance Chiang ◽  
Sean Harvey ◽  
Arjun V Pendharkar ◽  
Michelle Y Cheng ◽  
Gary K Steinberg
Keyword(s):  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Artery Occlusion ◽  
Motor Deficit ◽  
Motor Deficits ◽  
Stroke Models ◽  
Cerebral Artery Occlusion ◽  
Significant Motor

Introduction: Manual scoring of behavior tests is commonly used for assessing motor deficits after stroke, however, it is labor intensive and subject to bias. These limitations lead to inconsistent assessment between research groups and non-reproducible data. In this study, we investigated the feasibility of an automated motor deficit assessment system, Erasmus ladder, in two ischemic stroke models. Methods: Distal middle cerebral artery occlusion (dMCAO n=10) or transient middle cerebral artery occlusion (tMCAO 30 minutes, n=15) were performed on male C57BL6J mice (11-13 weeks) to generate cortical ischemic stroke, with. Naïve mice (n=10) were used as controls. Immunohistochemistry was performed on brains collected at post-stroke day (PD) 30 to assess for infarct size (MAP2) and inflammation (CD68). Mice without infarct in both cortex and striatum were excluded from the study. Behavior was assessed using Erasmus ladder at pre-stroke baseline (4 unperturbed and 4 perturbed sessions) and on PD 7, 14, 21, and 28 (all perturbed sessions). Results: Erasmus ladder detected significant motor deficits in the tMCAO model, specifically in the pre- and post- perturbed times as well as several key step types (HH long). Analyses in the tMCAO model reveal changes in various step patterns and their capability to react to the perturbation (obstacle). These significant motor deficits after tMCAO were detectable until PD28. We also observed a sustained decline in the use of affected limb compared to unaffected limb until PD28. While this trend is also present in dMCAO model, motor deficits were detected in the dMCAO only at early timepoints (PD7) and the difference subsided by PD28. Conclusion: We have assessed the data collected by Erasmus ladder on mice that underwent two commonly used stroke models (tMCAO and dMCAO). Our data showed that Erasmus ladder can detect long term motor deficit including reduced use of affected limb, step pattern, and motor reaction to obstacle. This automated instrument is effective in detecting motor deficits in the tMCAO model and thus, can be used to evaluate treatments for enhancing recovery after stroke.

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