Preventive Effects of Neuroprotective Agents in a Neonatal Rat of Photothrombotic Stroke Model

Estimating the therapeutic potential of NSAIDs and linoleic acid-isomers supplementation against neuroinflammation

Nonsteroidal anti-inflammatory drugs (NSAIDs) regulate inflammation, which is associated with their role in preventing neurodegenerative diseases in epidemiological studies. It has sparked interest in their unconventional application for reducing neuroinflammation, opening up new avenues in biomedical research. However, given the pharmacological drawbacks of NSAIDs, the development of formulations with naturally antioxidant/anti-inflammatory dietary fatty acids has been demonstrated to be advantageous for the clinical translation of anti-inflammatory-based therapies. It includes improved blood-brain barrier (BBB) permeability and reduced toxicity. It permits us to speculate about the value of linoleic acid (LA)-isomers in preventing and treating neuroinflammatory diseases compared to NSAIDs. Our research delved into the impact of various factors, such as administration route, dosage, timing of intervention, and BBB permeability, on the efficacy of NSAIDs and LA-isomers in preclinical and clinical settings. We conducted a systematic comparison between NSAIDs and LA-isomers regarding their therapeutic effectiveness, BBB compatibility, and side effects. Additionally, we explored their underlying mechanisms in addressing neuroinflammation. Through our analysis, we've identified challenges and drawn conclusions that could propel advancements in treating neurodegenerative diseases and inform the development of future alternative therapeutic strategies.

A New Perspective in the Treatment of Ischemic Stroke: Ferroptosis

Ischemic stroke is a common neurological disease. Currently, there are no Food and Drug Administration-approved drugs that can maximize the improvement in ischemic stroke-induced nerve damage. Hence, treating ischemic stroke remains a clinical challenge. Ferroptosis has been increasingly studied in recent years, and it is closely related to the pathophysiological process of ischemic stroke. Iron overload, reactive oxygen species accumulation, lipid peroxidation, and glutamate accumulation associated with ferroptosis are all present in ischemic stroke. This article focuses on describing the relationship between ferroptosis and ischemic stroke and summarizes the relevant substances that ameliorate ischemic stroke-induced neurological damage by inhibiting ferroptosis. Finally, the problems in the treatment of ischemic stroke targeting ferroptosis are discussed, hoping to provide a new direction for its treatment.

Rejuvenating aged microglia by p16ink4a-siRNA-loaded nanoparticles increases amyloid-β clearance in animal models of Alzheimer's disease

Age-dependent accumulation of amyloid plaques in patients with sporadic Alzheimer's disease (AD) is associated with reduced amyloid clearance. Older microglia have a reduced ability to phagocytose amyloid, so phagocytosis of amyloid plaques by microglia could be regulated to prevent amyloid accumulation. Furthermore, considering the aging-related disruption of cell cycle machinery in old microglia, we hypothesize that regulating their cell cycle could rejuvenate them and enhance their ability to promote more efficient amyloid clearance. First, we used gene ontology analysis of microglia from young and old mice to identify differential expression of cyclin-dependent kinase inhibitor 2A (p16ink4a), a cell cycle factor related to aging. We found that p16ink4a expression was increased in microglia near amyloid plaques in brain tissue from patients with AD and 5XFAD mice, a model of AD. In BV2 microglia, small interfering RNA (siRNA)-mediated p16ink4a downregulation transformed microglia with enhanced amyloid phagocytic capacity through regulated the cell cycle and increased cell proliferation. To regulate microglial phagocytosis by gene transduction, we used poly (D,L-lactic-co-glycolic acid) (PLGA) nanoparticles, which predominantly target microglia, to deliver the siRNA and to control microglial reactivity. Nanoparticle-based delivery of p16ink4a siRNA reduced amyloid plaque formation and the number of aged microglia surrounding the plaque and reversed learning deterioration and spatial memory deficits. We propose that downregulation of p16ink4a in microglia is a promising strategy for the treatment of Alzheimer's disease.

Perampanel Reduces Brain Damage via Induction of M2 Microglia in a Neonatal Rat Stroke Model

Purpose

Ischemic stroke is a leading cause of death and disability worldwide. Additionally, neonatal ischemia is a common cause of neonatal brain injury, resulting in cerebral palsy with subsequent learning disabilities and epilepsy. However, there is currently a lack of effective treatments available for patients with perinatal ischemic stroke. In this study, we investigated the effect of perampanel (PER)-loaded poly lactic-co-glycolic acid (PLGA) by targeting microglia in perinatal stroke.

Methods

After formation of focal ischemic stroke by photothrombosis in P7 rats, PER-loaded PLGA was injected intrathecally. Proinflammatory markers (TNF-α, IL-1β, IL-6, COX2, and iNOS) and M2 polarization markers (Ym1 and Arg1) were evaluated. We investigated whether PER increased M2 microglial polarization in vitro.

Results

PER-loaded PLGA nanoparticles decreased the pro-inflammatory cytokines compared to the control group. Furthermore, they increased M2 polarization.

Conclusion

PER-loaded PLGA nanoparticles decreased the size of the infarct and increased motor function in a perinatal ischemic stroke rat model. Pro-inflammatory cytokines were also reduced compared to the control group. Finally, this development of a drug delivery system targeting microglia confirms the potential to develop new therapeutic agents for perinatal ischemic stroke.

Design and Fabrication of Polymeric Hydrogel Carrier for Nerve Repair

Nerve regeneration and repair still remain a huge challenge for both central nervous and peripheral nervous system. Although some therapeutic substances, including neuroprotective agents, clinical drugs and stem cells, as well as various growth factors, are found to be effective to promote nerve repair, a carrier system that possesses a sustainable release behavior, in order to ensure high on-site concentration during the whole repair and regeneration process, and high bioavailability is still highly desirable. Hydrogel, as an ideal delivery system, has an excellent loading capacity and sustainable release behavior, as well as tunable physical and chemical properties to adapt to various biomedical scenarios; thus, it is thought to be a suitable carrier system for nerve repair. This paper reviews the structure and classification of hydrogels and summarizes the fabrication and processing methods that can prepare a suitable hydrogel carrier with specific physical and chemical properties. Furthermore, the modulation of the physical and chemical properties of hydrogels is also discussed in detail in order to obtain a better therapeutic effect to promote nerve repair. Finally, the future perspectives of hydrogel microsphere carriers for stroke rehabilitation are highlighted.

Dodging blood brain barrier with "nano" warriors: Novel strategy against ischemic stroke

Ischemic stroke (IS) is one of the leading causes of death and disability resulting in inevitable burden globally. Ischemic injury initiates cascade of pathological events comprising energy dwindling, failure of ionic gradients, failure of blood brain barrier (BBB), vasogenic edema, calcium over accumulation, excitotoxicity, increased oxidative stress, mitochondrial dysfunction, inflammation and eventually cell death. In spite of such complexity of the disease, the only treatment approved by US Food and Drug Administration (FDA) is tissue plasminogen activator (t-PA). This therapy overcome blood deficiency in the brain along with side effects of reperfusion which are responsible for considerable tissue injury. Therefore, there is urgent need of novel therapeutic perspectives that can protect the integrity of BBB and salvageable brain tissue. Advancement in nanomedicine is empowering new approaches that are potent to improve the understanding and treatment of the IS. Herein, we focus nanomaterial mediated drug delivery systems (DDSs) and their role to bypass and cross BBB especially via intranasal drug delivery. The various nanocarriers used in DDSs are also discussed. In a nut shell, the objective is to provide an overview of use of nanomedicine in the diagnosis and treatment of IS to facilitate the research from benchtop to bedside.

Chronic treatment with coenzyme Q10 mitigates the behavioral dysfunction of global cerebral ischemia/reperfusion injury in rats

Objectives

The Ischemia/reperfusion (I/R) phenomenon has a critical role in brain injuries induced by some kinds of stroke. The current study investigates the effects of Coenzyme Q10 (Q10) on global cerebral I/R in rats.

Materials and Methods

Fifty male Wistar rats were used in this study. The global cerebral I/R was induced by obstructing both common carotid arteries for 20 min and the animals were treated with Q10 (200 mg/kg; PO.) for 6 weeks. Depressive and anxiety-like behaviors were assessed using the elevated plus-maze and forced swimming test, respectively. Working and spatial learning and memory were assessed by the Y-maze continuous alternation task and Morris water maze. The brain tissues were evaluated for brain edema, brain-derived neurotrophic factor (BDNF) levels, and superoxide dismutase (SOD) activities.

Results

Our results indicated that global cerebral I/R increased anxiety and depression-like behavior as well as reduced cognitive performance. Moreover, the levels of BDNF and activities of SOD are reduced in stroke animals. Chronic post-stroke treatment with Q10 decreased brain edema. Furthermore, Q10 administration reduced anxiety and depressive-like behavior as well as cognitive impairments in stroke animals. Q10 also increased the SOD activities and BDNF levels in the brain tissues of stroke animals.

Conclusion

Finally, we can conclude that using Q10 supplementation may be beneficial against the global cerebral I/R complications.

Pathophysiology and Therapeutic Potential of NADPH Oxidases in Ischemic Stroke-Induced Oxidative Stress

Stroke is a leading cause of death and disability in humans. The excessive production of reactive oxygen species (ROS) is an important contributor to oxidative stress and secondary brain damage after stroke. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, an enzyme complex consisting of membrane subunits and cytoplasmic subunits, regulates neuronal maturation and cerebrovascular homeostasis. However, NADPH oxidase overproduction contributes to neurotoxicity and cerebrovascular disease. NADPH oxidase has been implicated as the principal source of ROS in the brain, and numerous studies have shown that the knockout of NADPH exerts a protective effect in the model of ischemic stroke. In this review, we summarize the mechanism of activation of the NADPH oxidase family members, the pathophysiological effects of NADPH oxidase isoforms in ischemic stroke, and the studies of NADPH oxidase inhibitors to explore potential clinical applications.