Neuroprotective effects of minocycline on focal cerebral ischemia injury: a systematic review

New targets in spontaneous intracerebral hemorrhage

PURPOSE OF REVIEW

Intracerebral hemorrhage (ICH) is a devastating stroke with limited medical treatments; thus, timely exploration of emerging therapeutic targets is essential. This review focuses on the latest strategies to mitigate secondary brain injury post-ICH other than targeting surgery or hemostasis, addressing a significant gap in clinical practice and highlighting potential improvements in patient outcomes.

RECENT FINDINGS

Promising therapeutic targets to reduce secondary brain injury following ICH have recently been identified, including attenuation of iron toxicity and inhibition of ferroptosis, enhancement of endogenous resorption of hematoma, and modulation of perihematomal inflammatory responses and edema. Additionally, novel insights suggest the lymphatic system of the brain may potentially play a role in hematoma clearance and edema management. Various experimental and early-phase clinical trials have demonstrated these approaches may potentially offer clinical benefits, though most research remains in the preliminary stages.

SUMMARY

Continued research is essential to identify multifaceted treatment strategies for ICH. Clinical translation of these emerging targets could significantly enhance the efficacy of therapeutic interventions and potentially reduce secondary brain damage and improve neurological recovery. Future efforts should focus on large-scale clinical trials to validate these approaches, to pave the way for more effective treatment protocols for spontaneous ICH.

Minocycline reduces neurobehavioral deficits evoked by chronic unpredictable stress in adult zebrafish

Chronic stress-related brain disorders are widespread and debilitating, and often cause lasting neurobehavioral deficits. Minocycline, a common antibiotic and an established inhibitor of microglia, emerges as potential treatment of these disorders. The zebrafish (Danio rerio) is an important emerging model organism in translational neuroscience and stress research. Here, we evaluated the potential of minocycline to correct microglia-mediated behavioral, genomic and neuroimmune responses induced by chronic unpredictable stress (CUS) in adult zebrafish. We demonstrated that CUS evoked overt behavioral deficits in the novel tank, light-dark box and shoaling tests, paralleled by elevated stress hormones (CRH, ACTH and cortisol), and upregulated brain expression of the 'neurotoxic M1' microglia-specific biomarker gene (MHC-2) and pro-inflammatory cytokine genes (IL-1β, IL-6 and IFN-γ). CUS also elevated peripheral (whole-body) pro-inflammatory (IL-1β, IFN-γ) and lowered anti-inflammatory cytokines (IL-4 and IL-10), as well as reduced whole-brain serotonin, dopamine and norepinephrine levels, and increased brain dopamine and serotonin turnover. In contrast, minocycline attenuated most of these effects, also reducing CUS-elevated peripheral levels of IL-6 and IFN-γ. Collectively, this implicates microglia in zebrafish responses to chronic stress, and suggests glial pathways as potential evolutionarily conserved drug targets for treating stress-evoked neuropathogenesis. Our findings also support the growing translational value of zebrafish models for understanding complex molecular mechanisms of brain pathogenesis and its therapy.

The Therapeutic Effects of SP-8356, a Verbenone Derivative, with Multimodal Cytoprotective Mechanisms in an Ischemic Stroke Rat Model

An ischemic cerebral stroke results from the interruption of blood flow to the brain, triggering rapid and complex cascades of excitotoxicity, oxidative stress, and inflammation. Current reperfusion therapies, including intravenous thrombolysis and mechanical thrombectomy, cause further brain injury due to reperfusion-induced cytotoxicity. To date, novel cytoprotective therapies that could address these challenges have yet to be developed, likely due to the limitations of targeting a single pathologic mechanism. To address these unmet clinical needs, we investigated a synthetic verbenone derivative, SP-8356, as a potential multi-target cytoprotective agent for acute ischemic strokes. In transient middle cerebral artery occlusion (MCAO) rats, SP-8356 significantly reduced brain infarct and edema volumes while improving acute neurological deficits in a dose-dependent manner. Furthermore, SP-8356 improved long-term outcomes, particularly by reducing mortality. These potent cytoprotective effects of SP-8356 were achieved by suppressing the excessive production of free radicals and pro-inflammatory cytokines, reducing the infiltration of inflammatory cells, and mitigating increases in blood-brain barrier permeability. Additional research is needed to determine whether co-administration of SP-8356 can extend the therapeutic time window of reperfusion therapies by mitigating ischemia/reperfusion injury.

Minocycline alleviates microglia ferroptosis by inhibiting HO-1 during cerebral ischemia-reperfusion injury

OBJECTIVE

Ischemic stroke is a leading cause of death and disability in individuals worldwide. Cerebral ischemia-reperfusion injury (CIRI) typically results in severe secondary injury and complications following reperfusion therapy. Microglia play critical roles in the inflammatory reaction of CIRI. However, less attention has been given to microglial death in this process. Our study aims to explore microglial death in CIRI and the effects and mechanism of minocycline treatment on microglia.

METHODS

A middle cerebral artery occlusion (MCAO) model was applied to induce CIRI in rats. At 0 h, 24 h and 48 h post-operation, rats were intraperitoneally injected with 45 mg/kg minocycline. Neurological deficit scoring, 2,3,5-triphenyltetrazolium chloride (TTC) staining, assessment of activated microglia and examination of mitochondrial structure were conducted and checked at 72 h after reperfusion. Additionally, an in vitro model of oxygen-glucose deprivation/reperfusion (OGD/R) model was established. BV-2 cells were treated with various pharmacological inhibitors of cell death or minocycline. Cell viability, lipid peroxidation, mitochondrial structure and function, and labile Fe2+ and ferroptosis-associated gene/protein levels were measured. Hemin was used for further validation after transcriptome analysis.

RESULTS

In the MCAO and OGD/R models, ferroptosis was identified as a major form of microglial death. Minocycline inhibited microglia ferroptosis by reducing HO-1 expression. In addition, minocycline improved mitochondrial membrane potential, mitochondrial structures and microglial survival in vivo. Minocycline also decreased labile Fe2+ levels, lipid peroxidation, and expression of ferritin heavy chain (FTH) and it improved mitochondrial structure and function in vitro. Upregulation of HO-1 counteracted the protective effect of minocycline.

CONCLUSION

Ferroptosis is a major form of microglial death in CIRI. The protective mechanism of minocycline in CIRI partially hinges on its ability to effectively ameliorate microglia ferroptosis by downregulating HO-1 expression. Consequently, targeting microglia ferroptosis is a promising treatment for CIRI.

Minocycline Acts as a Neuroprotective Agent Against Tramadol-Induced Neurodegeneration: Behavioral and Molecular Evidence

Background

Previous evidence indicates that tramadol (TRA) can lead to neurodegenerative events and minocycline (MIN) has neuroprotective properties.

Aim of the Study

The current research evaluated the neuroprotective effects of MIN for TRA-promoted neurodegeneration.

Methods

Sixty adult male rats were placed into the following groups: 1 (received 0.7 ml/rat of normal saline, IP), 2 (received 50 mg/kg of TRA, i.p.), 3, 4, 5 (administered TRA as 50 mg/kg simultaneously with MIN at 20, 40, and 60 mg/kg, IP, respectively), and 6 (received MIN alone as 60 mg/kg, IP). The treatment procedure was 21 days. An open field test (OFT) was used to measure motor activity and anxiety-related behavior. Furthermore, oxidative stress; hippocampal inflammation; apoptotic parameters as well as activity of mitochondrial complexes I, II, III, and IV; ATP levels; and mitochondrial membrane potential (MMP) were evaluated. In addition, histomorphological alteration was assessed in two regions of the hippocampus: Cornu Ammonis (CA1) and dentate gyrus (DG).

Results

MIN treatment could inhibit TRA-induced anxiety and motor activity disturbances (P < 0.05). In addition, MIN could attenuate reactive oxygen species (ROS), H2O2, oxidized glutathione (GSSG), and malondialdehyde (MDA) level (P < 0.05), while there was increased reduced glutathione (GSH), total antioxidant capacity (TAC), ATP, MMP, and BCL2 levels (P < 0.05) and also elevation of SOD, GPX, GSR (P < 0.05), and mitochondrial complexes I, II, III, and IV activity (P < 0.05) in TRA-treated rats. In consistence with these findings, MIN could reduce TNF/TNF-α, IL1B/IL1-β, BAX, and CASP3 levels (P < 0.05) in TRA-treated rats. MIN also restored the quantitative (P < 0.05) and qualitative histomorphological sequels of TRA in both CA1 and DG areas of the hippocampus.

Conclusions

MIN probably has repositioning capability for inhibition of TRA-induced neurodegeneration via modulation of inflammation, oxidative stress, apoptosis, and mitochondrial disorders.

Maternal Minocycline as Fetal Therapy in a Rat Model of Myelomeningocele

INTRODUCTION

This study aimed to investigate whether the maternal administration of minocycline, a tetracycline antibiotic known to have anti-inflammatory and neuroprotective properties in models of neural injury, reduces inflammation and neural cell death in a fetal rat model of myelomeningocele (MMC).

METHODS

E10 pregnant rats were gavaged with olive oil or olive oil + retinoic acid to induce fetal MMC. At E12, the dams were exposed to regular drinking water or water containing minocycline (range, 40-140 mg/kg/day). At E21, fetal lumbosacral spinal cords were isolated for immunohistochemistry and quantitative gene expression studies focused on microglia activity, inflammation, and apoptosis (P < 0.05).

RESULTS

There was a trend toward decreased activated Iba1+ microglial cells within the dorsal spinal cord of MMC pups following minocycline exposure when compared to water (H2O) alone (P = 0.052). Prenatal minocycline exposure was correlated with significantly reduced expression of the proinflammatory cytokine, IL-6 (minocycline: 1.75 versus H2O: 3.52, P = 0.04) and apoptosis gene, Bax (minocycline: 0.71 versus H2O: 1.04, P < 0.001) among MMC pups.

CONCLUSIONS

This study found evidence that the maternal administration of minocycline reduces selected markers of inflammation and apoptosis within the exposed dorsal spinal cords of fetal MMC rats. Further study of minocycline as a novel prenatal treatment strategy to mitigate spinal cord damage in MMC is warranted.

Citrate-coated silver nanoparticles loaded with agomelatine provide neuronal therapy in acute cerebral ischemia/reperfusion of rats by inhibiting the oxidative stress, endoplasmic reticulum stress, and P2X7 receptor-mediated inflammasome

Cerebral ischemia and reperfusion are related to various situations like injuries after various traumas, oxidative stress, increased calcium ion, capillary hypoperfusion, microvascular hyperpermeability, leukocyte infiltration, and blood-brain barrier disruption. An antidepressant Agomelatine which is a melatonin receptor (MT1/MT2) agonist and serotonin receptor (5-HT2C) antagonist has been reported by studies to have antioxidant and anti-inflammatory effects. In our study, we aimed to detect the effects of citrate-coated silver nanoparticle-loaded agomelatine application on neurodegeneration, endoplasmic reticulum stress, autophagic and apoptotic cell death, inflammation, and P2X7R expression in the cerebral ischemia-reperfusion model to facilitate the passage of blood-brain barrier. Forty two Sprague-Dawley rats in total were divided into six equal groups (n:7) and applications were performed. Acute cerebral injury in the ischemia-reperfusion model was created 2 h after internal carotid artery ligation in rats and then at the 2nd hour of reperfusion citrate-coated silver nanoparticles loaded with Agomelatine were applied. Twenty four hours later, neurologic analysis on animals in experimental groups was performed, animals were decapitated and GSH, GPx, SOD, CAT, MDA, IL-1β, and TNF-α parameters were examined after taking blood and the cerebral tissue samples. As a result, it was determined that ischemia-reperfusion caused endoplasmic reticulum stress in the cerebral tissues and thus caused cellular injury.

Mechanisms associated with post-stroke depression and pharmacologic therapy

Stroke is one of the most common cerebrovascular diseases, which is the cause of long-term mental illness and physical disability, Post-stroke depression (PSD) is the most common neuropsychiatric complication after stroke, and its mechanisms are characterized by complexity, plurality, and diversity, which seriously affects the quality of survival and prognosis of patients. Studies have focused on and recognized neurotransmitter-based mechanisms and selective serotonin-reuptake inhibitors (SSRIs) can be used to treat PSD. Neuroinflammation, neuroendocrinology, neurotrophic factors, and the site of the stroke lesion may affect neurotransmitters. Thus the mechanisms of PSD have been increasingly studied. Pharmacological treatment mainly includes SSRIs, noradrenergic and specific serotonergic antidepressant (NaSSA), anti-inflammatory drugs, vitamin D, ect, which have been confirmed to have better efficacy by clinical studies. Currently, there is an increasing number of studies related to the mechanisms of PSD. However, the mechanisms and pharmacologic treatment of PSD is still unclear. In the future, in-depth research on the mechanisms and treatment of PSD is needed to provide a reference for the prevention and treatment of clinical PSD.

Treating Traumatic Brain Injury with Minocycline

Traumatic brain injury (TBI) results in both rapid and delayed brain damage. The speed, complexity, and persistence of TBI present large obstacles to drug development. Preclinical studies from multiple laboratories have tested the FDA-approved anti-microbial drug minocycline (MINO) to treat traumatic brain injury. At concentrations greater than needed for anti-microbial action, MINO readily inhibits microglial activation. MINO has additional pleotropic effects including anti-inflammatory, anti-oxidant, and anti-apoptotic activities. MINO inhibits multiple proteins that promote brain injury including metalloproteases, caspases, calpain, and polyADP-ribose-polymerase-1. At these elevated doses, MINO is well tolerated and enters the brain even when the blood-brain barrier is intact. Most preclinical studies with a first dose of MINO at less than 1 h after injury have shown improved multiple outcomes after TBI. Fewer studies with more delayed dosing have yielded similar results. A small number of clinical trials for TBI have established the safety of MINO and suggested some drug efficacy. Studies are also ongoing that either improve MINO pharmacology or combine MINO with other drugs to increase its therapeutic efficacy against TBI. This review builds upon a previous, recent review by some of the authors (Lawless and Bergold, Neural Regen Res 17:2589-92, 2022). The present review includes the additional preclinical studies examining the efficacy of minocycline in preclinical TBI models. This review also includes recommendations for a clinical trial to test MINO to treat TBI.

Downregulation of Preso protects against ischemic/reperfusion-mediated neuronal injury through regulating PSD95-nNOS/YAP pathways

Cerebral ischemic/reperfusion (I/R) injury has become a great challenge harming patients' life. This study aims to explore the regulatory role of Preso during cerebral I/R injury and to elucidate the potential mechanism. Here, we established a middle cerebral artery occlusion/reperfusion (MCAO/IR) rat model and an oxygen-glucose deprivation/reoxygenation (OGD/R)-mediated PC12 cell model to evaluate the expression and role of Preso following cerebral I/R injury. Histopathological injury and infarct size were assessed by hematoxylin and eosin (HE) and 2,3,5-Triphenyltertrazolium chloride (TTC) staining. Double immunofluorescence staining was performed to assess neuronal apoptosis in brain tissues. Cell counting kit-8 (CCK-8) and flow cytometry were performed to evaluate cell viability and apoptosis, respectively. The reactive oxygen species (ROS) and nitric oxide (NO) levels were detected using their respective detection kits, and the expression of corresponding proteins was examined adopting Western blot. The results showed that Preso was upregulated in OGD/R-induced PC12 cells and MCAO rats. Preso knockdown significantly reduced OGD/R-caused viability loss, apoptosis and oxidative stress in PC12 cells, and reduced infarct size, attenuated histological injury, and inhibited apoptosis and oxidative stress in the brain tissues from MCAO rats, as well as inhibiting the expression of postsynaptic density protein-95 (PSD95) and nitric oxide synthase (nNOS) and repressing YAP phosphorylation in vitro. In addition, the protective role of Preso knockdown against cerebral I/R injury was partly strengthened by IC87201, the nNOS/PSD95 interaction inhibitor, or weakened by Verteporfin (Vert), an inhibitor of YAP. In conclusion, Perso knockdown might exert a protective role against cerebral I/R injury via regulating PSD95-nNOS and YAP pathways, providing a potential therapeutic target for the treatment of ischemic stroke.

The mechanisms of minocycline in alleviating ischemic stroke damage and cerebral ischemia-reperfusion injury

Stroke is a group of diseases resulting from cerebral vascular rupture or obstruction and subsequent brain blood circulation disorder, leading to rapid neurological deficits. Ischemic stroke accounts for the majority of all stroke cases. The current treatments for ischemic stroke mainly include t-PA thrombolytic therapy and surgical thrombectomy. However, these interventions aimed at recanalizing cerebral vessels can paradoxically lead to ischemia-reperfusion injury, which exacerbates the severity of brain damage. Minocycline, a semi-synthetic tetracycline antibiotic, has been shown to possess a wide range of neuroprotective effects independent of its antibacterial activity. Here we summarize the mechanisms underlying the protective effects of minocycline against cerebral ischemia-reperfusion injury based on the pathogenesis of cerebral ischemia-reperfusion injury, including its modulation of oxidative stress, inflammatory response, excitotoxicity, programmed cell death and blood-brain barrier injury, and also introduce the role of minocycline in alleviating stroke-related complications, in order to provide a theoretical basis for the clinical application of minocycline in cerebral ischemia-reperfusion injury.

Minocycline as a Neuroprotective Agent in Arsenic-Induced Neurotoxicity in PC12 Cells

Arsenic is a naturally occurring metalloid that exists in water, soil, food, and air. Humans can be exposed to arsenic through occupational, medical, or nutritional routes. Both acute and chronic forms of toxicity with severe outcomes are likely following arsenic exposure. Neurotoxicity is one of the serious manifestations of arsenic toxicity. In our study, the effect of minocycline, a widely used antimicrobial agent with antioxidant aspects and the ability to cross the blood-brain barrier, was evaluated against arsenic-induced neurotoxicity. PC12 cell line was used as the cellular model of this study. Cells were pre-treated with minocycline (50 nM-1 µM) for 2 h, and then incubated for 24 h after adding sodium arsenite (10 µM). The MTT assay and fluorimetry were performed to study cytotoxicity and reactive oxygen species generation, respectively. Finally, Western blotting was done to determine the levels of caspase-8, Bax, Bcl-2, and caspase-3. Once exposed to arsenic, the cell viability was significantly reduced, the intracellular oxidative balance was significantly disrupted, and the levels of proteins caspase-8, Bax/Bcl-2, and caspase-3 were significantly increased. Minocycline not only attenuated arsenic-induced cytotoxicity and reduced oxidative stress, but also led to lower levels of caspase-8, Bax/Bcl-2, and caspase-3 proteins compared with the arsenic-treated cells. Minocycline can significantly protect cells against arsenic-induced neurotoxicity by antioxidant and anti-apoptosis properties via both intrinsic and extrinsic caspase-dependent apoptotic pathways; therefore, at this point, it's worth considering it as a promising agent for the treatment of arsenic toxicity.

Neuroprotective Strategies for Ischemic Stroke-Future Perspectives

Ischemic stroke is the main cause of death and the most common cause of acquired physical disability worldwide. Recent demographic changes increase the relevance of stroke and its sequelae. The acute treatment for stroke is restricted to causative recanalization and restoration of cerebral blood flow, including both intravenous thrombolysis and mechanical thrombectomy. Still, only a limited number of patients are eligible for these time-sensitive treatments. Hence, new neuroprotective approaches are urgently needed. Neuroprotection is thus defined as an intervention resulting in the preservation, recovery, and/or regeneration of the nervous system by interfering with the ischemic-triggered stroke cascade. Despite numerous preclinical studies generating promising data for several neuroprotective agents, successful bench-to-bedside translations are still lacking. The present study provides an overview of current approaches in the research field of neuroprotective stroke treatment. Aside from "traditional" neuroprotective drugs focusing on inflammation, cell death, and excitotoxicity, stem-cell-based treatment methods are also considered. Furthermore, an overview of a prospective neuroprotective method using extracellular vesicles that are secreted from various stem cell sources, including neural stem cells and bone marrow stem cells, is also given. The review concludes with a short discussion on the microbiota-gut-brain axis that may serve as a potential target for future neuroprotective therapies.

Albiflorin relieves cerebral ischemia-reperfusion injury by activating Nrf2/HO-1 pathway

Our work aims to investigate the functions of a natural compound, Albiflorin (AF) in cerebral ischemia-reperfusion (IR) injury. The cerebral IR models were established by OGD/R in PC12 cells and MCAO/IR in rats. The cells in a glucose-free medium were placed in an anaerobic chamber containing 95% N₂ and 5% CO₂ for 3h at 37°C, returned to a normal medium, and incubated for 24h to accomplish OGD/R. Focal cerebral ischemia was conducted by thread occlusion of the right middle cerebral artery for 2h followed by 24h reperfusion in rats. CCK-8 assay indicated that AF had no toxicity to PC12 cells. Flow cytometry, Western blot, or TUNEL showed that AF treatment reduced apoptosis of cells or rat brain tissues. qRT-PCR and ELISA showed that AF decreased IL-1β, IL-6, and TNF-α levels in vitro and in vivo. Elevated levels of MDA, SOD, and ROS induced by IR injury were mitigated by AF in vitro and in vivo. HE and TTC staining revealed that AF ameliorated pathological injury in MCAO/IR rats. Western blot showed that Nrf2, NQO1, and HO-1 expression was activated by AF, and ML385 treatment suppressed the inhibition effects of AF in cerebral IR injury models. Overall, AF alleviates cerebral IR injury via regulating the Nrf2/HO-1 pathway.

Cardioprotective effects of minocycline against doxorubicin-induced cardiotoxicity

BACKGROUND

Doxorubicin (Dox)-induced cardiotoxicity has limited its use. Inflammation, oxidative stress, and apoptosis have important roles in Dox-induced cardiotoxicity. Minocycline (Min) is an antibiotic with anti-inflammatory, anti-oxidant and anti-apoptotic properties. Here, the cardioprotective effects of Min against Dox-induced cardiotoxicity in adult male rats were evaluated.

METHODS

Forty-two adult male rats were divided into six groups including control group (normal saline), Dox group, Min groups (Min 45 mg/kg and Min 90 mg/kg), and treatment groups (Dox + Min 45 mg/kg and Dox + Min 90 mg/kg). Dox (2.5 mg/kg) was administered three times a week for two weeks, and Min once a day for three weeks via intraperitoneal route. Cardiac tissue sections were stained with hematoxylin and eosin for histological examination. The activities of lactate dehydrogenase (LDH) and creatine kinase MB (CK-MB) in serum as well as the activity of catalase and superoxide dismutase (SOD) in cardiac tissue were measured. Cardiac tissue levels of malondialdehyde (MDA), TNF-α, and IL-1β were also measured using ELISA.

RESULTS

Compared with the Dox group, treatment with Min significantly decreased the activity of LDH and CK-MB. Min also increased the activity of catalase and SOD in the tissue samples. The results showed that the levels of MDA, TNF-α, and IL-1β in cardiac tissue samples were significantly lower in the Min groups compared with the Dox group. In addition, histopathological results showed that Min reduced the tissue damage caused by Dox.

CONCLUSION

Min reduced Dox-induced cardiotoxicity. The anti-oxidant and anti-inflammatory properties of Min may contribute to its protective effects.

LncRNA Small Nucleolar RNA Host Gene 11 (SNHG11) Participates in Hypoxia/Reoxygenation-Induced Adrenal Phaeochromocytoma (PC12) Cell Damage in a ceRNA-Dependent Manner

How to prevent cerebral ischemia-reperfusion injury (CI/R) is critical for treating ischemic stroke. LncRNA SNHG11 can participate in several diseases by competing endogenous RNA (ceRNA), but its’ role in CI/R is unclear. Hypoxia/reoxygenation model (H/R group) cells were set and separated into control team; H/R team; H/R+SNHG11 team and H/R+si-SNHG11 team followed by analysis of LncRNA SNHG11 by real-time PCR, LncRNA SNHG11 subcellular distribution by FISH assay, MTT assay for cell proliferation, flow cytometry for apoptosis, ROS and LDH content and PTEN expression by Western blot. In H/R group, SNHG11 level significantly increased and cell proliferation significantly decreased, along with increased cell apoptosis, ROS activity, LDH content and PTEN expression in comparison of control group (P-value less than 0.05); The foregoing variation was promoted further by the H/R group after overexpression of SNHG11 (P-value below 0.05) and reversed after transfection of SNHG1 siRNA (P <0.05). LncRNA SNHG11 is mainly localized on the cell membrane. miR-16 is a SNHG11 targeted miRNA. Transfection of miR-16 mimics into PC12 cells in H/R group can significantly promote cell proliferation, inhibit apoptosis, reduce ROS activity, LDH content and PTEN expression versus the H/R group (P-value less than 0.05). SNHG11 level in H/R condition is increased and might target miR-16 to regulate PTEN expression and oxidative stress, leading to apoptosis and damage.

Zebrafish as a potential model for stroke: A comparative study with standardized models

Animal models of cerebral ischemia have improved our understanding of the pathophysiology and mechanisms involved in stroke, as well as the investigation of potential therapies. The potential of zebrafish to model human diseases has become increasingly evident. The availability of these models allows for an increased understanding of the role of chemical exposure in human conditions and provides essential tools for mechanistic studies of disease. To evaluate the potential neuroprotective properties of minocycline against ischemia and reperfusion injury in zebrafish and compare them with other standardized models. In vitro studies with BV-2 cells were performed, and mammalian transient middle cerebral artery occlusion (tMCAO) was used as a comparative standard with the zebrafish stroke model. Animals were subjected to ischemia and reperfusion injury protocols and treated with minocycline. Infarction size, cytokine levels, oxidative stress, glutamate toxicity, and immunofluorescence for microglial activation, and behavioral test results were determined and compared. Administration of minocycline provided significant protection in the three stroke models in different parameters analyzed. Both experimental models complement each other in their particularities. The proposal also strengthens the findings in the literature in rodent models and allows the validation of alternative models so that they can be used in further research involving diseases with ischemia and reperfusion injury.

Pathophysiology and Therapeutic Approaches for Spinal Cord Injury

Spinal cord injury (SCI) is a disabling condition that disrupts motor, sensory, and autonomic functions. Despite extensive research in the last decades, SCI continues to be a global health priority affecting thousands of individuals every year. The lack of effective therapeutic strategies for patients with SCI reflects its complex pathophysiology that leads to the point of no return in its function repair and regeneration capacity. Recently, however, several studies started to uncover the intricate network of mechanisms involved in SCI leading to the development of new therapeutic approaches. In this work, we present a detailed description of the physiology and anatomy of the spinal cord and the pathophysiology of SCI. Additionally, we provide an overview of different molecular strategies that demonstrate promising potential in the modulation of the secondary injury events that promote neuroprotection or neuroregeneration. We also briefly discuss other emerging therapies, including cell-based therapies, biomaterials, and epidural electric stimulation. A successful therapy might target different pathologic events to control the progression of secondary damage of SCI and promote regeneration leading to functional recovery.

Selenium Alleviates Cerebral Ischemia/Reperfusion Injury by Regulating Oxidative Stress, Mitochondrial Fusion and Ferroptosis

To clarify the potential role of selenium (Se) on cerebral ischemia/reperfusion (I/R) injury, we utilized mouse middle cerebral artery occlusion (MCAO) followed by reperfusion as an animal model and oxygen-glucose deprivation and reoxygenation (OGD/R) to treat N2a cells as a cell model, respectively. MCAO model was established in mice and then divided into different groups with or without Se treatment. TTC staining was used to observe whether the cerebral I/R modeling was successful, and the apoptosis level was determined by TUNEL staining. The expression of GPx-4 and p22phox was assessed by western blot. In vitro experiments, the OGD/R induced oxidative stress in N2a cells was assessed by levels of GSH/GSSG, malondialdehyde, superoxide dismutase and iron content, respectively. QRT-PCR was used to detect the mRNA levels of Cox-2, Fth1, Mfn1 and mtDNA in N2a cells. JC-1 staining and flow cytometry was performed to detect the mitochondrial membrane potential. Se treatment alleviated cerebral I/R injury and improved the survival rate of mice. Additionally, Se treatment apparently attenuated oxidative stress and inhibited iron accumulation in MCAO model mice and OGD/R model of N2a cells. In terms of its mechanism, Se could up-regulate Mfn1 expression to alleviate oxidative stress and ferroptosis by promoting mitochondrial fusion in vivo and vitro. These findings suggest that Se may have great potential in alleviating cerebral I/R injury.

Minocycline attenuates cholinergic dysfunction and neuro-inflammation-mediated cognitive impairment in scopolamine-induced Alzheimer's rat model

OBJECTIVE

Minocycline, a semisynthetic tetracycline-derived antibiotic, has various pharmacological effect such as anti-inflammatory, anti-oxidative stress, and anti-apoptotic effects. The current study investigated the involvement of neuro-inflammatory, oxidative stress, and cholinergic markers in neuroprotection by minocycline against scopolamine-induced brain damage.

METHODS

Minocycline was administered (oral, 10, 15, and 30 mg/kg, daily) to groups of amnesic rats for 21 days. Passive avoidance memory and spatial learning and memory were assessed. Following that, oxidative stress, cholinergic function, and neuro-inflammation markers were evaluated in the brain tissue.

RESULTS

According to our biochemical data, treatment of the scopolamine-injured rats with minocycline decreased the levels of malondialdehyde and acetylcholinesterase (AChE) as well as mRNA expression of AChE and neuro-inflammation markers (tumor necrosis factor-α, interleukin (IL)-1β, IL-6). It also increased the total thiol levels and superoxide dismutase activity as well as mRNA expression of cholinergic receptor M1 (ChRM1). Moreover, minocycline modified distance and latencies in Morris water maze, prolonged latency to enter the black zone and light time while decreasing time spent and frequency of entries to darkness.

CONCLUSION

Taken together, the data indicate that treatment with minocycline improved memory dysfunction mediated possibly through restoring AChE and ChRM1 levels, oxidant/antioxidant balance, as well as inhibiting inflammatory responses.

Hypothesized neuroprotective effect of minocycline against COVID-19-induced stroke and neurological dysfunction: possible role of matrix metalloprotease signaling pathway

Severe Acute Respiratory Syndrome Coronavirus-2 (COVID-19) is a respiratory disease that causes dysfunction in respiration. Since late 2019, this virus has infected and killed millions of people around the world and imposed many medical and therapeutic problems in the form of a pandemic. According to recent data, COVID-19 disease can increase the risk of stroke, which can be deadly or cause many neurological disorders after the disease. During the last two years, many efforts have been made to introduce new therapies for management of COVID-19-related complications, including stroke. To achieve this goal, several conventional drugs have been investigated for their possible therapeutic roles. Minocycline, a broad-spectrum, long-acting antibiotic with anti-inflammatory and antioxidant properties, is one such conventional drug that should be considered for treating COVID-19-related stroke, as indirect evidence indicates that it exerts neuroprotective effects, can modulate stroke occurrence, and can play an effective and strategic role in management of the molecular signals caused by stroke and its destructive consequences. The matrix metalloprotease (MMP) signaling pathway is one of the main signaling pathways involved in the occurrence and exacerbation of stroke; however, its role in COVID-19-induced stroke and the possible role of minocycline in the management of this signaling pathway in patients with COVID-19 is unclear and requires further investigation. Based on this concept, we hypothesize that minocycline might act via MMP signaling as a neuroprotective agent against COVID-19-induced neurological dysfunction, particularly stroke.

Network Pharmacology and Bioinformatics Methods Reveal the Mechanism of Berberine in the Treatment of Ischaemic Stroke

Aim

To elucidate the mechanism of action of berberine on ischaemic stroke based on network pharmacology, bioinformatics, and experimental verification.

Methods

Berberine-related long noncoding RNAs (lncRNAs) were screened from public databases. Differentially expressed lncRNAs in ischaemic stroke were retrieved from the Gene Expression Omnibus (GEO) database. GSE102541 was comprehensively analysed using GEO2R. The correlation between lncRNAs and ischaemic stroke was evaluated by the mammalian noncoding RNA-disease repository (MNDR) database. The component-target-disease network and protein-protein interaction (PPI) network of berberine in the treatment of ischaemic stroke were constructed by using network pharmacology. We then performed gene ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment analyses. Finally, according to the molecular docking analysis and the binding probability between the lncRNA and key proteins, the effectiveness of the results was further verified by in vitro experiments.

Results

After matching stroke-related lncRNAs with berberine-related lncRNAs, four genes were selected as potential targets of berberine in the treatment of ischaemic stroke. Subsequently, lncRNA H19 was identified as the potential crucial regulatory lncRNA of berberine. Here, 52 target proteins of berberine in the treatment of ischaemic stroke were identified through database mining. Through topological analysis, 20 key targets were identified which were enriched in inflammation, apoptosis, and immunity. Molecular docking results showed that MAPK8, JUN, and EGFR were central genes. Finally, in vitro experiments demonstrated that lncRNA H19, p-JNK1/JNK1, p-c-Jun/c-Jun, and EGFR expressions were significantly increased in hypoxia-treated SH-SY5Y cells and were restored by berberine treatment.

Conclusion

The potential targets and biological effects of berberine in the treatment of ischaemic stroke were predicted in this study. The lncRNA H19/EGFR/JNK1/c-Jun signalling pathway may be a key mechanism of berberine-induced neuroprotection in ischaemic stroke.

Treatment of pilocarpine-induced epileptic seizures in adult male mice

Epilepsy is one of the most common neurological disorders affecting most social, economic and biological aspects of human life. Most patients with epilepsy have uncontrolled seizures and drug side effects despite the medications. Patients with epilepsy often have problems with attention, memory, and information processing speed, which may be due to seizures, underlying causes, or anticonvulsants. Therefore, improving seizure control and reducing or changing the anti-epileptic drugs can solve these problems, but these problems will not be solved in most cases. In this work, we looked at the effects of pioglitazone, a Peroxisome Proliferator-Activated Receptor agonist used to treat type 2 diabetes, on pilocarpine-induced seizures in mice. The Racine scale was used to classify pilocarpine-induced convulsions. After that, all of the animals were beheaded, and the brain and hippocampus were dissected. Finally, biochemical techniques were used to determine the levels of Malondialdehyde and Catalase activity, as well as Superoxide Dismutase and Glutathione Reductase in the hippocampus. The results of this investigation suggest that pioglitazone's antioxidant action may play a key role in its neuroprotective properties against pilocarpine-induced seizure neuronal damage.

Minocycline as heart conditioning agent in experimental type 2 diabetes mellitus - an antibacterial drug in heart protection

Cardiovascular diseases, and among them certainly myocardial infarction, remain leading cause of death worldwide. Diabetes increases risk of occurrence as well as adverse outcome of myocardial infarction. Conditioning maneuvers are the most attractive method for alleviating both the consequences of ischemia and reperfusion. Minocycline is a tetracycline derivative which exerts antioxidant, anti-inflammatory, and anti-apoptotic effects. The aim of this study was to assess the protective ability of preconditioning and postconditioning of isolated hearts from healthy and rats with experimentally induced type 2 diabetes with minocycline on functional recovery and redox status after ischemia and reperfusion. The hearts from healthy and diabetic rats were excised and retrogradely perfused according to the Langendorff technique. Using sensor in the left ventricle, the cardiodynamic parameters were recorded and in the samples of the coronary venous effluent oxidative stress biomarkers were analyzed. Minocycline was injected directly into the coronary vessels, in preconditioning 5 min before global ischemia, and in postconditioning during the first 5 min of reperfusion. Results of this study clearly show beneficial effects of minocycline applied both before ischemia and in the first minutes of reperfusion fashion in both healthy and diabetic rat hearts. The most prominent protective effect regarding oxidative stress is related to the decreased production of superoxide anion radical due postconditioning with minocycline in diabetic hearts. Cardiodynamic parameters were significantly improved in minocycline conditioned groups. Superoxide anion radical stands out as the most susceptible to changes induced by minocycline.

Phosphorylation at Ser 727 Increases STAT3 Interaction with PKCε Regulating Neuron–Glia Crosstalk via IL-6-Mediated Hyperalgesia In Vivo and In Vitro

Methods

A rat hyperalgesia model was induced using an intraplantar injection of Freund's complete adjuvant (FCA) or an intrathecal injection of IL-6. Mechanical allodynia was evaluated using von Frey filament tests after intrathecal injections of T-5224 (c-Fos/AP-1 inhibitor), minocycline (Mino, a specific microglia inhibitor), L-2-aminoadipic acid (LAA, an astroglial toxin), PKCε inhibitor peptide, APTSTAT3-9R (STAT3 inhibitor), or anti-IL-6 antibody. The c-Fos, GFAP, Iba-1, PKCε, STAT3, pSTAT3^Tyr705 and pSTAT3^Ser727, and IL-6 expression at the spinal cord level was assessed by Western blot analysis. The interactive effects of PKCε and STAT3 were determined using immunofluorescence staining and immunoprecipitation in vivo and in vitro. Interleukin-6 promoter activity was examined using luciferase assays.

Results

T-5224, Mino, and LAA attenuated FCA- or IL-6-mediated inflammatory pain, with a decrease in c-Fos, GFAP, Iba-1, PKCε, and IL-6 expression. PKCε inhibitor peptide and APTSTAT3-9R reversed FCA-induced nociceptive behavior, while decreasing pSTAT3^Ser727, IL-6, c-Fos, GFAP, and Iba-1 expression and PKCε and STAT3 coexpression. Interleukin-6 promoter activity increased in the presence of PKCε and STAT3. The interaction with PKCε increased on phosphorylating STAT3 at Ser727 but not at Tyr705.

Conclusion

STAT3 phosphorylation at Ser 727 and the interaction with PKCε contribute to hyperalgesia via the IL-6-mediated signaling pathway, thus regulating neuron–glia crosstalk during inflammatory pain.

Mobile Single-Lead Electrocardiogram Technology for Atrial Fibrillation Detection in Acute Ischemic Stroke Patients

(1) Background: AliveCor KardiaMobile (KM) is a portable electrocardiography recorder for detection of atrial fibrillation (AF). The aim of the study was to define the group of acute ischemic stroke (AIS) patients who can use the KM device and assess the diagnostic test accuracy. (2) Methods: the AIS patients were recruited to the study. Thirty-second single-lead electrocardiogram (ECG) usages were recorded on demand for three days using KM portable device. Each KM ECG record was verified by a cardiologist. The feasibility was evaluated using operationalization criteria. (3) Results: the recruitment rate among AIS patients was 26.3%. The withdrawal rate before the start of the intervention was 26%. The withdrawal rate after the start of the intervention was 6%. KM device detected AF in 2.8% of AIS patients and in 2.2% of ECG records. Cardiologist confirmed the AF in 0.3% AIS patients. Sensitivity and specificity of KM for AF was 100% and 98.3%, respectively. (4) Conclusions: the results of this study suggest that it is feasible to use KM device to detect AF in the selected AIS patients (younger and in better neurological condition). KM detected AF in the selected AIS patients with high specificity and sensitivity.

Influence of Melatonin on Behavioral and Neurological Function of Rats with Focal Cerebral Ischemia-Reperfusion Injury via the JNK/FoxO3a/Bim Pathway

OBJECTIVE

To investigate the influence of melatonin on behavioral and neurological function of rats with focal cerebral ischemia-reperfusion injury via the JNK/FoxO3a/Bim pathway.

METHODS

One hundred and twenty healthy male SD rats were randomized into the model group (Model: the middle cerebral artery occlusion (MCAO) model was constructed and received an equal volume of normal saline containing 5% DMSO), sham operation group (Sham: received no treatment except normal feeding), and low, medium, and high dose of melatonin group (L-MT, M-MT, and H-MT intraperitoneally injected 10, 20, and 40 mg/kg melatonin 30 min after IR, respectively), with 24 rats in each group. Following 24 h of reperfusion, the rats in each of the above groups were tested for neurological deficit symptoms and behavioral changes to screen the rats included in the study. HE and TUNEL stainings were performed to observe pathological changes. Levels of oxidative stress-related indexes, inflammatory factor-related indexes, nuclear factor-κB p65 (NF-κB p65), and interferon-γ (IFN-γ) in the rat brain were measured by ELISA. The JNK/FoxO3a/Bim pathway-related proteins as well as Bcl-2, Caspase-3, and Bax were examined using Western blot.

RESULTS

Detection of behavioral indicators showed that the MACO model was successfully constructed in rats. L-MT, M-MT, and L-MT groups presented reduced malondialdehyde (MDA), reactive oxygen species (ROS), tumor necrosis factor- (TNF-) α, interleukin- (IL-) 6, IL-1β, IFN-γ, NF-κB p65, and apoptosis compared with the Model group (P < 0.05), and the improvement degree was better in the M-MT group versus the L-HT group. Bcl-2 protein expression in the brain tissue of L-MT, M-MT, and H-MT groups increased significantly, while Bax, Caspase-3, p-JNK, p-FoxO3a, and Bim protein expression declined markedly, versus the Model group (P < 0.05). The changes of indexes were greater in the M-MT group compared with that in the L-MT group. No significant difference was observed in all the above indexes between the M-MT group and the H-MT group (P > 0.05).

CONCLUSIONS

In the MACO rat model, melatonin can effectively reduce Bax and Caspase-3 levels by modulating the JNK/FoxO3a/Bim pathway, inhibit neuronal apoptosis, and alleviate neurological deficits by reducing the release of proinflammatory mediators, with anti-inflammatory and antioxidant effects. In addition, 20 mg/kg is the optimal melatonin concentration.

Protective Effect of Minocycline on Bax and Bcl-2 Gene Expression, Histological Damages and Oxidative Stress Induced by Ovarian Torsion in Adult Rats

BACKGROUND

Minocycline is a widely used bacteriostatic antibiotic with various functions. The aim of this study was to investigate impact of apoptotic genes in ovary of the torsion/detorsion treated rat model by minocycline.

MATERIALS AND METHODS

This experimental study was performed in 32 female Wistar rats classified in four groups, including: i. sham, ii. TD: torsion/detorsion group received normal saline, iii. TDM: torsion/detorsion group treated with 40 mg/kg Minocycline, and iv. MC: healthy group received 40 mg/kg Minocycline. After treatment period (7 days), histoplogical parameters, oxidative stress markers and hormone profile of serum as well as the expression of Bax and Bcl-2 genes were measured in the ovary of rats.

RESULTS

Levels of superoxide dismutase (SOD), glutathione peroxidase (GPX) and estrogen were decreased in the TD group and significantly increased in the treated groups (P=0.001). Levels of malondialdehyde (MDA) and testosterone were increased in the TD group and decreased in the treated groups (P=0.001). Expression level of Bax was elevated in the TD group, while it was attenuated in the treated groups (P=0.001). Expression level of Bcl-2 was significantly increased in treated groups (P=0.001).

CONCLUSION

Minocycline can repair oxidative damage in ovarian tissue and regulate apoptotic-related gene expressions.

Melatonin ameliorates methamphetamine-induced cognitive impairments by inhibiting neuroinflammation via suppression of the TLR4/MyD88/NFκB signaling pathway in the mouse hippocampus

Methamphetamine (METH) is a highly addictive psychostimulant that causes significant health issues due to high prevalence of its illegal use. Chronic use of METH is associated with cognitive impairments in both human and animal studies, but the underlying mechanism remains unclear. METH-induced neuroinflammation is, potentially, one of the factors that causes cognitive impairments. Therefore, the present study aimed to assess whether melatonin could provide protection against inflammation, in a manner comparable to the anti-inflammatory agent, minocycline, with consequent improvements of METH-induced cognitive impairments and associated abnormalities in the mouse hippocampus. Results from the Morris water maze (MWM) test and the novel object recognition test (NORT) showed that melatonin given after METH injections could ameliorate both METH-induced spatial and recognition memory impairments. These memory impairments are associated with changes in the neuroinflammatory profiles, including IL-6, IL-1β, and TNF-α, both in the blood serum and hippocampus of adult mice. METH-treated mice also exhibited reactive astrocytes and activated microglia in the hippocampus. METH-induced activation of glial cells is associated with the activation of the TLR4/MyD88/NFκB signaling pathway. Moreover, melatonin administration led to recovery of these METH-induced markers to control levels. Thus, we conclude that melatonin could potentially be used as a cognitive enhancer and anti-inflammatory agent in the treatment of METH use disorder in humans.

Neuroinflammation as a Key Driver of Secondary Neurodegeneration Following Stroke?

Ischaemic stroke involves the rapid onset of focal neurological dysfunction, most commonly due to an arterial blockage in a specific region of the brain. Stroke is a leading cause of death and common cause of disability, with over 17 million people worldwide suffering from a stroke each year. It is now well-documented that neuroinflammation and immune mediators play a key role in acute and long-term neuronal tissue damage and healing, not only in the infarct core but also in distal regions. Importantly, in these distal regions, termed sites of secondary neurodegeneration (SND), spikes in neuroinflammation may be seen sometime after the initial stroke onset, but prior to the presence of the neuronal tissue damage within these regions. However, it is key to acknowledge that, despite the mounting information describing neuroinflammation following ischaemic stroke, the exact mechanisms whereby inflammatory cells and their mediators drive stroke-induced neuroinflammation are still not fully understood. As a result, current anti-inflammatory treatments have failed to show efficacy in clinical trials. In this review we discuss the complexities of post-stroke neuroinflammation, specifically how it affects neuronal tissue and post-stroke outcome acutely, chronically, and in sites of SND. We then discuss current and previously assessed anti-inflammatory therapies, with a particular focus on how failed anti-inflammatories may be repurposed to target SND-associated neuroinflammation.

A preparation of Ginkgo biloba L. leaves extract inhibits the apoptosis of hippocampal neurons in post-stroke mice via regulating the expression of Bax/Bcl-2 and Caspase-3

ETHNOPHARMACOLOGICAL RELEVANCE

Shuxuening injection (SXNI) is a Chinese medicine of Ginkgo biloba L. leaves extract (GBE), which is widely used clinically for cardiovascular diseases such as stroke and myocardial infarction, but the pharmacological mechanism of its therapeutic effect is not fully understood.

AIM OF THE STUDY

Preclinical studies suggested that inhibition of neuronal apoptosis effectively improves brain damage after ischemic stroke. The purpose of this study was to investigate the inhibitory effect of SXNI on neuronal apoptosis in post-stroke mice and its underlying mechanism.

MATERIALS AND METHODS

A mouse cerebral ischemia-reperfusion injury (CIRI) model was constructed by middle cerebral artery occlusion (MCAO) and treated with 3 mL/kg SXNI. TUNEL and immunohistochemistry experiments were performed on brain slices on the 7th day after stroke. The protein was extracted from the hippocampus region of the brain for western-blot assay. To simulate the in vivo ischemia-reperfusion process, the hippocampal neuron cell line HT-22 was subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro, and 200 μg/mL SXNI was administered. The HT-22 cells were then studied by RT-PCR and immunocytochemistry.

RESULTS

In vivo, SXNI treatment significantly reduced hippocampal neuronal apoptosis. Immunohistochemistry showed that SXNI inhibited the activation of Caspase-3 protein in the hippocampus after ischemic stroke. Western blot analysis further confirmed that SXNI regulated the expression of the antagonizing protein pair Bax and Bcl-2 to exert anti-apoptotic effect in addition to reducing the expression of Cleaved-Caspase-3 in the hippocampus. In vitro, 200 μg/mL SXNI treatment significantly improved HT-22 apoptosis caused by OGD/R. Further RT-PCR and immunocytochemistry study showed that 200 μg/mL SXNI inhibited apoptosis of hippocampal neurons by regulating the mRNA and protein expressions of apoptotic molecules Bax, Bcl-2 and Caspase-3.

CONCLUSIONS

CIRI can induce hippocampal neuronal apoptosis, which is inhibited by SXNI via regulating Bax/Bcl-2 and blocking Caspase-3 activation. Therefore, SXNI may be a promising treatment strategy to improve the prognosis of ischemic stroke.

ATP2B1-AS1 Promotes Cerebral Ischemia/Reperfusion Injury Through Regulating the miR-330-5p/TLR4-MyD88-NF-κB Signaling Pathway

We aim to explore the expression and function of long non-coding RNA (lncRNA) ATP2B1-AS1 in a cerebral ischemia/reperfusion (I/R) injury. In this study, we established a middle cerebral artery occlusion/reperfusion (MCAO/IR) rat model and an OGD/R PC12 cell model to evaluate the expression and role of ATP2B1-AS1 in the cerebral I/R injury. We found that the expression of ATP2B1-AS1 was upregulated in both in vitro and in vivo cerebral I/R injury models. Knockdown of ATP2B1-AS1 increased the cell viability, inhibited apoptosis, and decreased the expressions of inflammation cytokines. The target of ATP2B1-AS1 was predicted and validated to be miR-330-5p. MiR-330-5p abrogated the regulatory effect of ATP2B1-AS1 on cell viability, apoptosis, and cytokines of OGD/R PC12 cells. Furthermore, the results showed that miR-330-5p targeted TLR4, which was also upregulated in the infarcted area of MCAO/IR rats and OGD/R PC12 cells. Overexpression of ATP2B1-AS1 increased the expressions of TLR4, MyD88, and NF-κB p65 of OGD/R PC12 cells, while the effect of ATP2B1-AS1 was abrogated by miR-330-5p. In addition, knockdown of ATP2B1-AS1 decreased the latency time, increased the time of passing the platform position, reduced the cerebral infarct volume, decreased neurological deficit scores, and reduced the number of damaged neurons of MCAO/IR rats that were subjected to the Morris water maze test. Taken together, our study indicates that ATP2B1-AS1 may be an attractive therapeutic target for the treatment of cerebral ischemic injuries.

Nanomedicines, an emerging therapeutic regimen for treatment of ischemic cerebral stroke: A review

Owing to its intricate pathophysiology, cerebral stroke is a serious medical condition caused by interruption or obstruction of blood supply (blockage of vasculature) to the brain tissues which results in diminished supply of essential nutrients and oxygen (hypoxia) and ultimate necrosis of neuronal tissues. A prompt risks assessment and immediate rational therapeutic plan with proficient neuroprotection play critically important role in the effective management of this neuronal emergency. Various conventional medications are being used for treatment of acute ischemic cerebral stroke but fibrinolytic agents, alone or in combination with other agents are considered the mainstay. These clot-busting agents effectively restore blood supply (reperfusion) to ischemic regions of the brain; however, their clinical significance is hampered due to various factors such as short plasma half-life, limited distribution to brain tissues due to the presence of highly efficient physiological barrier, blood brain barrier (BBB), and lacking of target-specific delivery to the ischemic brain regions. To alleviate these issues, various types of nanomedicines such as polymeric nanoparticles (NPs), liposomes, nanoemulsion, micelles and dendrimers have been designed and evaluated. The implication of these newer therapies (nanomedicines) have revolutionized the therapeutic outcomes by improving the plasma half-life, permeation across BBB, efficient distribution to ischemic cerebral tissues and neuroprotection. Furthermore, the adaptation of some diverse techniques including PEGylation, tethering of targeting ligands on the surfaces of nanomedicines, and pH responsive features have also been pondered. The implication of these emerging adaptations have shown remarkable potential in maximizing the targeting efficiency of drugs to ischemic brain tissues, simultaneous delivery of drugs and imaging agents (for early prognosis as well as monitoring of therapy), and therapeutic outcomes such as long-term neuroprotection.

Neuroprotective effects of minocycline and KML29, a potent inhibitor of monoacylglycerol lipase, in an experimental stroke model: a small-animal positron emission tomography study

Hypoxia caused by ischemia induces acidosis and neuroexcitotoxicity, resulting in neuronal death in the central nervous system (CNS). Monoacylglycerol lipase (MAGL) is a modulator of 2-arachidonoylglycerol (2-AG), which is involved in retrograde inhibition of glutamate release in the endocannabinoid system. In the present study, we used positron emission tomography (PET) to monitor MAGL-positive neurons and neuroinflammation in the brains of ischemic rats. Additionally, we performed PET imaging to evaluate the neuroprotective effects of an MAGL inhibitor in an ischemic injury model.

Methods: Ischemic-injury rat models were induced by intraluminal right middle cerebral artery occlusion (MCAO). PET studies of the brains of the ischemic rats were performed at several experimental time points (pre-occlusion, days 2, 4, and 7 after the MCAO surgery) using [¹¹C]SAR127303 for MAGL and [¹⁸F]FEBMP for 18 kDa translocator protein (TSPO, a hall-mark of neuroinflammation). Medication using minocycline (a well-known neuroprotective agent) or KML29 (a potent MAGL inhibitor) was given immediately after the MCAO surgery and then daily over the subsequent three days.

Results: PET imaging of the ischemic rats using [¹¹C]SAR127303 showed an acute decline of radioactive accumulation in the ipsilateral side at two days after MCAO surgery (ratio of the area under the curve between the ipsilateral and contralateral sides: 0.49 ± 0.04 in the cortex and 0.73 ± 0.02 in the striatum). PET imaging with [¹⁸F]FEBMP, however, showed a moderate increase in accumulation of radioactivity in the ipsilateral hemisphere on day 2 (1.36 ± 0.11), and further increases on day 4 (1.72 ± 0.15) and day 7 (1.99 ± 0.06). Treatment with minocycline or KML29 eased the decline in radioactive accumulation of [¹¹C]SAR127303 for MAGL (minocycline-treated group: 0.82 ± 0.06 in the cortex and 0.81 ± 0.05 in the striatum; KML29-treated group: 0.72 ± 0.07 in the cortex and 0.88 ± 0.04 in the striatum) and increased uptake of [¹⁸F]FEBMP for TSPO (minocycline-treated group: 1.52 ± 0.21 in the cortex and 1.56 ± 0.11 in the striatum; KML29-treated group: 1.63 ± 0.09 in the cortex and 1.50 ± 0.17 in the striatum). In MCAO rats, minocycline treatment showed a neuroprotective effect in the sensorimotor cortex suffering from severe hypoxic injury, whereas KML29 treatment saved neurons in the striatum, including bundles of myelinated axons.

Conclusions: PET imaging allowed visualization of the different neuroprotective effects of minocycline and KML29, and indicated that combination pharmacotherapy using these drugs may be an effective therapy in acute ischemia.

Exploring the Potential Mechanism of Shennao Fuyuan Tang for Ischemic Stroke Based on Network Pharmacology and Molecular Docking

METHODS

Screen the biologically active components and potential targets of SNFYT through Traditional Chinese Medicine Systems Pharmacology (TCMSP), Traditional Chinese Medicines Integrated Database (TCMID), and related literature. In addition, DrugBank, OMIM, DisGeNET, and the Therapeutic Target Database were searched to explore the therapeutic targets of IS. The cross-targets of SNFYT potential targets and IS treatment targets were taken as candidate gene targets, and GO and KEGG enrichment analyses were performed on the candidate targets. On this basis, the SNFYT-component-target network and protein-protein interaction (PPI) network were constructed using Cytoscape 3.7.2. Finally, AutoDock was used to verify the molecular docking of core components and core targets.

RESULTS

We screened out 95 potentially active components and 143 candidate targets. SNFYT-component-target network, PPI network, and Cytoscape analysis identified four core active ingredients and 14 core targets. GO enrichment analyzed 2333 biological processes, 79 cell components, and 149 molecular functions. There are 170 KEGG-related signal pathways (P < 0.05), including the IL-17 signal pathway, TNF signal pathway, and HIF-1 signal pathway. The molecular docking results of the core components and the core targets showed good binding power.

CONCLUSIONS

SNFYT may achieve the effect of treating ischemic stroke through its anti-inflammatory effect through a signal pathway with core targets as the core.

M, Siva Sankar Reddy L, Dastagiri Reddy Y, Somasekhar G, Sirisha N, Nagaraju K, Shouib M, Rizwaan A. A new cerebral ischemic injury model in rats, preventive effect of gallic acid and in silico approaches

Current study was designed multiple occlusions and reperfusion of bilateral carotid arteries induced cerebral injury model and evaluated the protective effect of gallic acid on it. In silico study was involved to study gallic acid binding affinity on cerebrotonic proteins compared with standard drugs using Autodoc vina tool. Cerebral ischemia was induced by occlusion of bilateral common carotid arteries for 10 mins followed by 10 reperfusions (1 cycle), cycle was continued to 3 cycles (MO/RCA), then pathological changes were observed by estimation of brain antioxidants as superoxide dismutase, glutathione, catalase, oxidants like malonaldehyde, cerebral infarction area, histopathology, and study gallic acid treatment against cerebral injury. Gallic acid exhibited a strong binding affinity on targeted cerebrotoxic proteins. MO/RCA rat brain antioxidant levels were significantly decreased and increased MDA levels (p < 0.0001), Infarction size compared to sham rats. Gallic acid treatment rat brain MDA levels significantly decreased (p < 0.4476) and increased SOD (p < 0.0001), CAT (p < 0.0001), GSH (p < 0.0001), cerebral infarction area when compared to MO/RCA group. Developed model showed significant cerebral ischemic injury in rats, injury was ameliorated by Gallic acid treatment and in silico approaches also inhibit the cerebrotoxic protein function by targeting on active sites.

Understanding Why Post-Stroke Depression May Be the Norm Rather Than the Exception: The Anatomical and Neuroinflammatory Correlates of Post-Stroke Depression

Ischemic Stroke precedes depression. Post-stroke depression (PSD) is a major driver for poor recovery, negative quality of life, poor rehabilitation outcomes and poor functional ability. In this systematic review, we analysed the inflammatory basis of post-stroke depression, which involves bioenergetic failure, deranged iron homeostasis (calcium influx, Na influx, potassium efflux etc), excitotoxicity, acidotoxicity, disruption of the blood brain barrier, cytokine-mediated cytotoxicity, reactive oxygen mediated toxicity, activation of cyclooxygenase pathway and generation of toxic products. This process subsequently results in cell death, maladapted, persistent neuro-inflammation and deranged neuronal networks in mood-related brain regions. Furthermore, an in-depth review likewise reveals that anatomic structures related to post-stroke depression may be localized to complex circuitries involving the cortical and subcortical regions.

Tetrandrine attenuates ischemia/reperfusion‑induced neuronal damage in the subacute phase

Ischemic stroke, the third leading cause of disability globally, imposes a notable economic burden. Tetrandrine (Tet), which has been widely used clinically, exhibits potential protective effects against stroke. However, there has been little pre‑clinical research to evaluate the therapeutic effects of Tet on stroke. The present study investigated the beneficial effect of Tet on ischemia‑reperfusion (I/R) injury and its underlying mechanism in rats. Rats were subjected to occlusion of the middle cerebral artery, then treated with Tet (30 mg/kg/day, intraperitoneal) in the subacute phase for 7 days. In order to detect the effects of Tet on the behavior of rats, modified neurological severity score and longa behavior, grasping capability and inclined plane tests were conducted on days 1, 3 and 7 following cerebral ischemia. In addition, neuronal apoptosis in the cortex and hippocampus following ischemia was assessed by Nissl staining and TUNEL assay. Finally, oxidative stress was evaluated by measurement of free radicals and immunofluorescence staining of LC3 was used to assess autophagy. Tet improved neurological function and decreased infarct volume in I/R injury rats. Tet also prevented neuronal apoptosis in the cortex and hippocampus region. In addition, Tet protected against oxidative damage following ischemia, which was reflected by decreased levels of nitric oxide and malondialdehyde and increased levels of glutathione (GSH) and GSH peroxidase. In addition, the expression levels of the autophagy marker LC3 decreased in the Tet treatment group. In conclusion, Tet attenuated I/R‑induced neuronal damage in the subacute phase by decreasing oxidative stress, apoptosis and autophagy.

Neuroprotective effect of minocycline against acute brain injury in clinical practice: A systematic review

Acute brain injury is a leading cause of morbidity and mortality worldwide. The term is inclusive of traumatic brain injury, cerebral ischemia, subarachnoid hemorrhage, and intracerebral hemorrhage. Current pharmacologic treatments have had minimal effect on improving neurological outcomes leading to a significant interest in the development neuroprotective agents. Minocycline is a second-generation tetracycline with high blood brain barrier penetrance due to its lipophilic properties. It functions across multiple molecular pathways involved in secondary-injury cascades following acute brain injury. Animal model studies suggest that minocycline might lead to improved neurologic outcomes, but few such trials exist in humans. Clinical investigations have been limited to small randomized trials in ischemic stroke patients which have not demonstrated a clear advantage in neurologic outcomes, but also have not been sufficiently powered to draw definitive conclusions. The potential neuroprotective effect of minocycline in the setting of traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage have all been limited to pilot studies with phase II/III investigations pending. The authors aim to synthesize what is currently known about minocycline as a neuroprotective agent against acute brain injury in humans.

An arylthiazyne derivative is a potent inhibitor of lipid peroxidation and ferroptosis providing neuroprotection in vitro and in vivo

Lipid peroxidation-initiated ferroptosis is an iron-dependent mechanism of programmed cell death taking place in neurological diseases. Here we show that a condensed benzo[b]thiazine derivative small molecule with an arylthiazine backbone (ADA-409-052) inhibits tert-Butyl hydroperoxide (TBHP)-induced lipid peroxidation (LP) and protects against ferroptotic cell death triggered by glutathione (GSH) depletion or glutathione peroxidase 4 (GPx4) inhibition in neuronal cell lines. In addition, ADA-409-052 suppresses pro-inflammatory activation of BV2 microglia and protects N2a neuronal cells from cell death induced by pro-inflammatory RAW 264.7 macrophages. Moreover, ADA-409-052 efficiently reduces infarct volume, edema and expression of pro-inflammatory genes in a mouse model of thromboembolic stroke. Targeting ferroptosis may be a promising therapeutic strategy in neurological diseases involving severe neuronal death and neuroinflammation.

Protective effects of polysaccharides on cerebral ischemia: A mini-review of the mechanisms

Cerebral ischemia, a common cerebrovascular disease, is one of the great threats to human health. Nowadays, many drugs used in the treatment of cerebral ischemia such as clot busting drugs, antiplatelet drugs, and neuroprotective drugs have limits. It is urgent finding new effective treatments for the patients. Researches have confirmed that many kinds of polysaccharides from natural resources possess therapeutic effects on cerebral ischemia, but are still lack of a comprehensively understanding. In this paper, based on the pathophysiology of cerebral ischemic injury, we summarize the latest discoveries and advancements of 29 kinds of polysaccharides, focusing on their ameliorating effects on cerebral ischemia and the underlying mechanisms. Several mechanisms are involved, mainly including antioxidant activities, anti-inflammatory activities, regulating neuron apoptosis, as well as resisting nitrosative stress injury. Besides, polysaccharides show protective effects through certain signaling pathways including PI3K/Akt, MAPK, and NF-κB, PARP-1/AIF, JNK3/c-Jun/Fas-L, and Nrf2/HO-1 signaling pathways. The main goal of this mini-review is to emphasize the important roles of polysaccharides in attenuating cerebral ischemic injury through the elucidation of mechanisms.

Excitotoxicity: Still Hammering the Ischemic Brain in 2020

Interest in excitotoxicity expanded following its implication in the pathogenesis of ischemic brain injury in the 1980s, but waned subsequent to the failure of N-methyl-D-aspartate (NMDA) antagonists in high profile clinical stroke trials. Nonetheless there has been steady progress in elucidating underlying mechanisms. This review will outline the historical path to current understandings of excitotoxicity in the ischemic brain, and suggest that this knowledge should be leveraged now to develop neuroprotective treatments for stroke.

Minocycline in Treating Glioblastoma Multiforme: Far beyond a Conventional Antibiotic

One of the most lethal forms of CNS pathologies is glioblastoma multiforme (GBM) that represents high invasiveness, uncontrolled proliferation, and angiogenic features. Its invasiveness is responsible for the high recurrence even after maximal surgical interventions. Minocycline is a semisynthetic analog of tetracyclines with potential anti-inflammatory and anticancer effects, distinct from its antimicrobial activity. In this review, we highlight the importance and the cytotoxic mechanisms of minocycline on GBM pathophysiology. Considering the role of certain enzymes in autophagy, apoptosis, tumor cell invasion, and metastatic ability, the possible use of tetracyclines for cancer therapy should be investigated, especially GBM. The present study is, therefore, going to cover the main topics in minocycline pharmacology to date, encouraging its consideration as a new treatment approach for cancer and GBM.

Layered biocompatible pH-responsive antibacterial composite film based on HNT/PLGA/chitosan for controlled release of minocycline as burn wound dressing

In the present study, a promising pH-responsive wound dressing was prepared. Halloysite nanotube (HNT) composites were modified with different concentration of both poly (lactic-co-glycolic acid) (PLGA) and chitosan (CS) through the Layer-by-Layer (LbL) strategy for targeted and controlled drug delivery of minocycline (MC). The resulting composites were characterized by FT-IR, XRD, zeta-potential, TGA, FE-SEM and TEM studies. Studying the biodegradability, water uptake, photostability, and water vapor transmission of resulting composites revealed that the composite film absorbed wound secretions, did not degrade, and penetrated properly to wound during the treatment. The results of protein adsorption showed that the optimized composite (C₄₀P₆₀MNT) was blood-compatible. Studying the release profile of the drug showed pH-responsive behavior that was fitted with Korsmeyer-Peppas kinetic model. In-vitro antibacterial testing showed that the C₄₀P₆₀MNT sample had an acceptable effect on the inhibition of gram-positive and gram-negative bacteria. In wound healing test (in-vivo studies), this MC loaded composite film showed faster healing of the burn wound in rat compare to the control sample. Due to the characteristics of the optimized sample, it can be considered as a promising candidate for pH-responsive drug delivery in the treatment of chronic burn wounds.

Structural and Functional Remodeling of the Brain Vasculature Following Stroke

Maintenance of cerebral blood vessel integrity and regulation of cerebral blood flow ensure proper brain function. The adult human brain represents only a small portion of the body mass, yet about a quarter of the cardiac output is dedicated to energy consumption by brain cells at rest. Due to a low capacity to store energy, brain health is heavily reliant on a steady supply of oxygen and nutrients from the bloodstream, and is thus particularly vulnerable to stroke. Stroke is a leading cause of disability and mortality worldwide. By transiently or permanently limiting tissue perfusion, stroke alters vascular integrity and function, compromising brain homeostasis and leading to widespread consequences from early-onset motor deficits to long-term cognitive decline. While numerous lines of investigation have been undertaken to develop new pharmacological therapies for stroke, only few advances have been made and most clinical trials have failed. Overall, our understanding of the acute and chronic vascular responses to stroke is insufficient, yet a better comprehension of cerebrovascular remodeling following stroke is an essential prerequisite for developing novel therapeutic options. In this review, we present a comprehensive update on post-stroke cerebrovascular remodeling, an important and growing field in neuroscience, by discussing cellular and molecular mechanisms involved, sex differences, limitations of preclinical research design and future directions.

A network pharmacology approach to investigate the mechanism of Shuxuening injection in the treatment of ischemic stroke

ETHNOPHARMACOLOGICAL RELEVANCE

Shuxuening injection (SXNI), a popular herbal medicine, is an extract of Ginkgo biloba leaves (GBE), and is used to treat ischemic stroke (IS) in China. However, its specific active ingredients and molecular mechanisms in IS remain unclear.

AIM OF THE STUDY

The purpose of the research is to identify the main active ingredients in GBE and explore its molecular mechanisms in the treatment of IS.

MATERIALS AND METHODS

The main active components of GBE were discerned through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis (TCMSP), Traditional Chinese Medicine Integrated Database (TCMID), Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicine (BATMAN-TCM) database, and absorption, distribution, metabolism and excretion (ADME) analysis. The targets related to IS were obtained using Genecards, Online Mendelian Inheritance in Man (OMIM), Therapeutic Target Database (TTD), and Disgenet. We discovered an intersection of genes. Subsequently, protein-protein interaction (PPI) networks were constructed with Cytoscape 3.7.1 and the String database. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to analyze the intersection of targets via the Database for Annotation, Visualization, and Integrated Discovery (DAVID) 6.8. Built on the above analysis, we made a Compound-Target-Pathway (C-T-P) network. Autodock Vina was used for molecular docking analysis. Maestro 11.9 was used to calculate the root-mean-square deviation (RMSD). Animal experiments were performed to verify the core targets. Triphenyl tetrazolium chloride (TTC) staining was used to calculate the infarct volume in rats. Hematoxylin-eosin (HE) staining was employed to observe the morphology of hippocampal neuron cells. RT-qPCR was applied to detect relative mRNA levels, and protein expression was determined using Western blotting.

RESULTS

Molecular docking showed that PTGS2, NOS3 and CASP3 docked with small molecule compounds. According to RT-qPCR and Western blotting, mRNA and protein expression of PTGS2 and CASP3 were up-regulated (P < 0.05), and mRNA and protein levels of NOS3 were down-regulated (P < 0.05).

CONCLUSIONS

SXNI can treat IS through multiple targets and routes, and reduce the apoptosis of neuron cells in brain tissue by inhibiting inflammation and regulating the level of oxidative stress, thereby protecting rats brain tissue.