scholarly journals Top Priorities for Cerebroprotective Studies: A Paradigm Shift

Stroke ◽  
2021 ◽  
Author(s):  
Patrick Lyden ◽  
Alastair Buchan ◽  
Johannes Boltze ◽  
Marc Fisher ◽  
Keyword(s):  
Ischemic Stroke ◽  
Brain Tissue ◽  
Imaging Techniques ◽  
Neurovascular Unit ◽  
Clinical Trial Design ◽  
Clinical Work ◽  
Brain Regions ◽  
Tissue Imaging ◽  
Health Concern ◽  
Stroke Treatment

Despite years of basic research and pioneering clinical work, ischemic stroke remains a major public health concern. Prior STAIR (Stroke Treatment Academic Industry Roundtable) conferences identified both failures of clinical trial design and failures in preclinical assessment in developing putative ischemic stroke treatments. At STAIR XI, participants in workshop no. 1 Top Priorities for Neuroprotection sought to redefine the neuroprotection paradigm and given the paucity of evidence underlying preclinical assessment, offer consensus-based recommendations. STAIR proposes the term brain cytoprotection or cerebroprotection to replace the term neuroprotection when the intention of an investigation is to demonstrate that a new, candidate treatment benefits the entire brain. Although “time is still brain,” tissue imaging techniques have been developed to identify patients with both predicted core injury and penumbral, salvageable brain tissue, regardless of time after stroke symptom onset. STAIR XI workshop participants called this imaging approach a tissue window to select patients for recanalization. Elements of the neurovascular unit show differential vulnerability evolving over differing time scales in different brain regions. STAIR proposes the term target window to suggest therapies that target the different elements of the neurovascular unit at different times. Based on contemporary principles of rigor and transparency, the workshop updated, revised, and enhanced the STAIR preclinical recommendations for developing new treatments in 2 phases: an exploratory qualification phase and a definitive validation phase. For new, putative treatments, investigators should carefully characterize the mechanism of action, the pharmacokinetics/pharmacodynamics, demonstrate target engagement, and confirm penetration through the blood-brain barrier. Before clinical trials, testing of candidate molecules in stroke models could proceed in a comprehensive manner using animals of both sexes and to include significant variables such as age and comorbid conditions. Comprehensive preclinical assessment might include multicenter, collaborative testing, for example, network trials. In the absence of a proven cerebroprotective agent to use as a gold standard, however, it remains speculative whether such comprehensive preclinical assessment can effectively predict clinical outcome.

scholarly journals Mesenchymal Stem Cell Derived Extracellular Vesicles for Repairing the Neurovascular Unit after Ischemic Stroke

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 767
Author(s):  
Courtney Davis ◽  
Sean I. Savitz ◽  
Nikunj Satani
Keyword(s):  
Ischemic Stroke ◽  
Extracellular Vesicles ◽  
Neurovascular Unit ◽  
Culture Conditions ◽  
Therapeutic Effects ◽  
Stroke Treatment ◽  
Inflammatory Molecules ◽  
The Brain

Ischemic stroke is a debilitating disease and one of the leading causes of long-term disability. During the early phase after ischemic stroke, the blood-brain barrier (BBB) exhibits increased permeability and disruption, leading to an influx of immune cells and inflammatory molecules that exacerbate the damage to the brain tissue. Mesenchymal stem cells have been investigated as a promising therapy to improve the recovery after ischemic stroke. The therapeutic effects imparted by MSCs are mostly paracrine. Recently, the role of extracellular vesicles released by these MSCs have been studied as possible carriers of information to the brain. This review focuses on the potential of MSC derived EVs to repair the components of the neurovascular unit (NVU) controlling the BBB, in order to promote overall recovery from stroke. Here, we review the techniques for increasing the effectiveness of MSC-based therapeutics, such as improved homing capabilities, bioengineering protein expression, modified culture conditions, and customizing the contents of EVs. Combining multiple techniques targeting NVU repair may provide the basis for improved future stroke treatment paradigms.

Localized Brain Tissue Cooling for Use During Intracranial Thrombectomy

2012 ◽  
Author(s):  
Thomas L. Merrill ◽  
Denise R. Merrill ◽  
Jennifer E. Akers
Keyword(s):  
Ischemic Stroke ◽  
Reperfusion Injury ◽  
Brain Tissue ◽  
Ischemic Injury ◽  
Blood Perfusion ◽  
Neuroprotective Agents ◽  
Tissue Necrosis ◽  
Stroke Treatment ◽  
Neurological Outcomes

The primary goal of current ischemic stroke treatment is quickly restoring blood perfusion. Recanalization is linked to improved neurological outcomes [1]. Resulting tissue necrosis, however, following a stroke has two causes: 1) ischemic injury and 2) reperfusion injury. Therefore, development of neuroprotective agents specifically beneficial against reperfusion injury are required.

scholarly journals Leveraging Neural Networks in Preclinical Alcohol Research

2020 ◽  
Vol 10 (9) ◽  
pp. 578
Author(s):  
Lauren C. Smith ◽  
Adam Kimbrough
Keyword(s):  
Neural Networks ◽  
Alcohol Use ◽  
Alcohol Drinking ◽  
Imaging Techniques ◽  
Structural Connectivity ◽  
Three Dimensional ◽  
Brain Regions ◽  
Tissue Imaging ◽  
Imaging Data ◽  
Neural Imaging

Alcohol use disorder is a pervasive healthcare issue with significant socioeconomic consequences. There is a plethora of neural imaging techniques available at the clinical and preclinical level, including magnetic resonance imaging and three-dimensional (3D) tissue imaging techniques. Network-based approaches can be applied to imaging data to create neural networks that model the functional and structural connectivity of the brain. These networks can be used to changes to brain-wide neural signaling caused by brain states associated with alcohol use. Neural networks can be further used to identify key brain regions or neural “hubs” involved in alcohol drinking. Here, we briefly review the current imaging and neurocircuit manipulation methods. Then, we discuss clinical and preclinical studies using network-based approaches related to substance use disorders and alcohol drinking. Finally, we discuss how preclinical 3D imaging in combination with network approaches can be applied alone and in combination with other approaches to better understand alcohol drinking.

scholarly journals Lipids and Lipid Mediators Associated with the Risk and Pathology of Ischemic Stroke

2020 ◽  
Vol 21 (10) ◽  
pp. 3618 ◽  
Author(s):  
Anna Kloska ◽  
Marcelina Malinowska ◽  
Magdalena Gabig-Cimińska ◽  
Joanna Jakóbkiewicz-Banecka
Keyword(s):  
Fatty Acids ◽  
Ischemic Stroke ◽  
Brain Tissue ◽  
Lipid Mediators ◽  
Normal Brain ◽  
Stroke Treatment ◽  
Post Stroke ◽  
Increased Risk ◽  
Risk Biomarkers ◽  
And Function

Stroke is a severe neurological disorder in humans that results from an interruption of the blood supply to the brain. Worldwide, stoke affects over 100 million people each year and is the second largest contributor to disability. Dyslipidemia is a modifiable risk factor for stroke that is associated with an increased risk of the disease. Traditional and non-traditional lipid measures are proposed as biomarkers for the better detection of subclinical disease. In the central nervous system, lipids and lipid mediators are essential to sustain the normal brain tissue structure and function. Pathways leading to post-stroke brain deterioration include the metabolism of polyunsaturated fatty acids. A variety of lipid mediators are generated from fatty acids and these molecules may have either neuroprotective or neurodegenerative effects on the post-stroke brain tissue; therefore, they largely contribute to the outcome and recovery from stroke. In this review, we provide an overview of serum lipids associated with the risk of ischemic stroke. We also discuss the role of lipid mediators, with particular emphasis on eicosanoids, in the pathology of ischemic stroke. Finally, we summarize the latest research on potential targets in lipid metabolic pathways for ischemic stroke treatment and on the development of new stroke risk biomarkers for use in clinical practice.

Analyses of thrombi in acute ischemic stroke: A consensus statement on current knowledge and future directions

2017 ◽  
Vol 12 (6) ◽  
pp. 606-614 ◽  
Author(s):  
Simon F De Meyer ◽  
Tommy Andersson ◽  
Blaise Baxter ◽  
Martin Bendszus ◽  
Patrick Brouwer ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Consensus Statement ◽  
Current Knowledge ◽  
Imaging Techniques ◽  
Cerebral Arteries ◽  
Clinical Engineering ◽  
Vessel Occlusion ◽  
Stroke Treatment ◽  
Interdisciplinary Approaches

Limited data exist on clot composition and detailed characteristics of arterial thrombi associated with large vessel occlusion in acute ischemic stroke. Advances in endovascular thrombectomy and related imaging modalities have created a unique opportunity to analyze thrombi removed from cerebral arteries. Insights into thrombus composition, etiology, physical properties and neurovascular interactions may lead to future advancements in acute ischemic stroke treatment and improved clinical outcomes. Advances in imaging techniques may enhance clot characterization and inform therapeutic decision-making prior to treatment and reveal stroke etiology to guide secondary prevention. Current imaging techniques can provide some information about thrombi, but there remains much to evaluate about relationships that may exist among thrombus composition, occlusion characteristics and treatment outcomes. Improved pathophysiological characterization of clot types, their properties and how these properties change over time, together with clinical correlates from ongoing studies, may facilitate revascularization with thrombolysis and thrombectomy. Interdisciplinary approaches covering clinical, engineering and scientific aspects of thrombus research will be key to advancing the understanding of thrombi and improving acute ischemic stroke therapy. This consensus statement integrates recent research on clots and thrombi retrieved from cerebral arteries and provides a rationale for further analyses, including current opportunities and limitations.

Cerebroprotection for Acute Ischemic Stroke: Looking Ahead

Stroke ◽  
2021 ◽  
Author(s):  
Patrick D. Lyden
Keyword(s):  
Clinical Trials ◽  
Ischemic Stroke ◽  
Molecular Mechanisms ◽  
Neurovascular Unit ◽  
Activated Protein C ◽  
Functional Impairments ◽  
Stroke Treatment ◽  
Target Drug ◽  
Single Target ◽  
Novel Approaches

We search for ischemic stroke treatment knowing we have failed—intensely and often—to translate mechanistic knowledge into treatments that alleviate our patients’ functional impairments. Lessons can be derived from our shared failures that may point to new directions and new strategies. First, the principle criticisms of both preclinical and clinical assessments are summarized. Next, previous efforts to develop single-mechanism treatments are reviewed. Finally, new definitions, novel approaches, and different directions are presented. In previous development efforts, the basic science and preclinical assessment of candidate treatments often lacked rigor and sufficiency; the clinical trials may have lacked power, rigor, or rectitude; or most likely both preclinical and clinical investigations were flawed. Single-target agents directed against specific molecular mechanisms proved unsuccessful. The term neuroprotection should be replaced as it has become ambiguous: protection of the entire neurovascular unit may be called cerebral cytoprotection or cerebroprotection. Success in developing cerebroprotection—either as an adjunct to recanalization or as stand-alone treatment—will require new definitions that recognize the importance of differential vulnerability in the neurovascular unit. Recent focus on pleiotropic multi-target agents that act via multiple mechanisms of action to interrupt ischemia at multiple steps may be more fruitful. Examples of pleiotropic treatments include therapeutic hypothermia and 3K3A-APC (activated protein C). Alternatively, the single-target drug NA-1 triggers multiple downstream signaling events. Renewed commitment to scientific rigor is essential, and funding agencies and journals may enforce quality principles of rigor in preclinical science. Appropriate animal models should be selected that are suited to the purpose of the investigation. Before clinical trials, preclinical assessment could include subjects that are aged, of both sexes, and harbor comorbid conditions such as diabetes or hypertension. With these new definitions, novel approaches, and renewed attention to rigor, the prospect for successful cerebroprotective therapy should improve.

Dl-3-n-Butylphthalide (NBP): A Promising Therapeutic Agent for Ischemic Stroke

2018 ◽  
Vol 17 (5) ◽  
pp. 338-347 ◽  
Author(s):  
Shan Wang ◽  
Fei Ma ◽  
Longjian Huang ◽  
Yong Zhang ◽  
Yuchen Peng ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Complex Disease ◽  
Time Window ◽  
Recombinant Tissue Plasminogen Activator ◽  
Research Progress ◽  
Apium Graveolens ◽  
Synthetic Compound ◽  
Stroke Treatment ◽  
Single Target ◽  
Anti Oxidant

Background and Objective: Stroke is a leading cause of morbidity and mortality in both developed and developing countries all over the world. The only drug for ischemic stroke approved by FDA is recombinant tissue plasminogen activator (rtPA). However, only 2-5% stroke patients receive rtPAs treatment due to its strict therapeutic time window. As ischemic stroke is a complex disease involving multiple mechanisms, medications with multi-targets may be more powerful compared with single-target drugs. Dl-3-n-Butylphthalide (NBP) is a synthetic compound based on l-3-n- Butylphthalide that is isolated from seeds of Apium graveolens. The racemic 3-n-butylphthalide (dl- NBP) was approved by Food and Drug Administration of China for the treatment of ischemic stroke in 2002. A number of clinical studies indicated that NBP not only improved the symptoms of ischemic stroke, but also contributed to the long-term recovery. The potential mechanisms of NBP for ischemic stroke treatment may target different pathophysiological processes, including anti-oxidant, antiinflammation, anti-apoptosis, anti-thrombosis, and protection of mitochondria et al. Conclusion: In this review, we have summarized the research progress of NBP for the treatment of ischemic stroke during the past two decades.

scholarly journals Could Lipoxins Represent a New Standard in Ischemic Stroke Treatment?

2021 ◽  
Vol 22 (8) ◽  
pp. 4207
Author(s):  
Nikola Tułowiecka ◽  
Dariusz Kotlęga ◽  
Andrzej Bohatyrewicz ◽  
Małgorzata Szczuko
Keyword(s):  
Ischemic Stroke ◽  
Cardiovascular Diseases ◽  
Blood Brain Barrier ◽  
Inflammatory Cytokines ◽  
The Body ◽  
Brain Barrier ◽  
Lipoxin A4 ◽  
Stroke Treatment ◽  
Blood Brain ◽  
Anti Inflammatory

Introduction: Cardiovascular diseases including stroke are one of the most common causes of death. Their main cause is atherosclerosis and chronic inflammation in the body. An ischemic stroke may occur as a result of the rupture of unstable atherosclerotic plaque. Cardiovascular diseases are associated with uncontrolled inflammation. The inflammatory reaction produces chemical mediators that stimulate the resolution of inflammation. One of these mediators is lipoxins—pro-resolving mediators that are derived from the omega-6 fatty acid family, promoting inflammation relief and supporting tissue regeneration. Aim: The aim of the study was to review the available literature on the therapeutic potential of lipoxins in the context of ischemic stroke. Material and Methods: Articles published up to 31 January 2021 were included in the review. The literature was searched on the basis of PubMed and Embase in terms of the entries: ‘stroke and lipoxin’ and ‘stroke and atherosclerosis’, resulting in over 110 articles in total. Studies that were not in full-text English, letters to the editor, and conference abstracts were excluded. Results: In animal studies, the injection/administration of lipoxin A4 improved the integrity of the blood–brain barrier (BBB), decreased the volume of damage caused by ischemic stroke, and decreased brain edema. In addition, lipoxin A4 inhibited the infiltration of neutrophils and the production of cytokines and pro-inflammatory chemokines, such as interleukin (Il-1β, Il-6, Il-8) and tumor necrosis factor-α (TNF-α). The beneficial effects were also observed after introducing the administration of lipoxin A4 analog—BML-111. BML-111 significantly reduces the size of a stroke and protects the cerebral cortex, possibly by reducing the permeability of the blood–brain barrier. Moreover, more potent than lipoxin A4, it has an anti-inflammatory effect by inhibiting the production of pro-inflammatory cytokines and increasing the amount of anti-inflammatory cytokines. Conclusions: Lipoxins and their analogues may find application in reducing damage caused by stroke and improving the prognosis of patients after ischemic stroke.

Sign in / Sign up

Export Citation Format

Share Document