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1.
Sci Transl Med ; 15(714): eadg8656, 2023 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-37729432

RESUMO

Human diseases may be modeled in animals to allow preclinical assessment of putative new clinical interventions. Recent, highly publicized failures of large clinical trials called into question the rigor, design, and value of preclinical assessment. We established the Stroke Preclinical Assessment Network (SPAN) to design and implement a randomized, controlled, blinded, multi-laboratory trial for the rigorous assessment of candidate stroke treatments combined with intravascular thrombectomy. Efficacy and futility boundaries in a multi-arm multi-stage statistical design aimed to exclude from further study highly effective or futile interventions after each of four sequential stages. Six independent research laboratories performed a standard focal cerebral ischemic insult in five animal models that included equal numbers of males and females: young mice, young rats, aging mice, mice with diet-induced obesity, and spontaneously hypertensive rats. The laboratories adhered to a common protocol and efficiently enrolled 2615 animals with full data completion and comprehensive animal tracking. SPAN successfully implemented treatment masking, randomization, prerandomization inclusion and exclusion criteria, and blinded assessment of outcomes. The SPAN design and infrastructure provide an effective approach that could be used in similar preclinical, multi-laboratory studies in other disease areas and should help improve reproducibility in translational science.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Feminino , Humanos , Masculino , Ratos , Animais , Camundongos , Roedores , Laboratórios , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/terapia
2.
Stroke ; 54(10): 2640-2651, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37610105

RESUMO

BACKGROUND: Spreading depolarizations (SDs) occur in all types of brain injury and may be associated with detrimental effects in ischemic stroke and subarachnoid hemorrhage. While rapid hematoma growth during intracerebral hemorrhage triggers SDs, their role in intracerebral hemorrhage is unknown. METHODS: We used intrinsic optical signal and laser speckle imaging, combined with electrocorticography, to investigate the effects of SD on hematoma growth during the hyperacute phase (0-4 hours) after intracortical collagenase injection in mice. Hematoma expansion, SDs, and cerebral blood flow were simultaneously monitored under normotensive and hypertensive conditions. RESULTS: Spontaneous SDs erupted from the vicinity of the hematoma during rapid hematoma growth. We found that hematoma growth slowed down by >60% immediately after an SD. This effect was even stronger in hypertensive animals with faster hematoma growth. To establish causation, we exogenously induced SDs (every 30 minutes) at a remote site by topical potassium chloride application and found reduced hematoma growth rate and final hemorrhage volume (18.2±5.8 versus 10.7±4.1 mm3). Analysis of cerebral blood flow using laser speckle flowmetry revealed that suppression of hematoma growth by spontaneous or induced SDs coincided and correlated with the characteristic oligemia in the wake of SD, implicating the vasoconstrictive effect of SD as one potential mechanism of action. CONCLUSIONS: Our findings reveal that SDs limit hematoma growth during the early hours of intracerebral hemorrhage and decrease final hematoma volume.


Assuntos
Depressão Alastrante da Atividade Elétrica Cortical , Hemorragia Subaracnóidea , Camundongos , Animais , Depressão Alastrante da Atividade Elétrica Cortical/fisiologia , Hemorragia Subaracnóidea/complicações , Eletrocorticografia , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/tratamento farmacológico , Hemorragia Cerebral/complicações , Hematoma/diagnóstico por imagem , Hematoma/complicações
3.
Stroke ; 54(2): 620-631, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36601951

RESUMO

The Stroke Preclinical Assessment Network (SPAN) is a multicenter preclinical trial platform using rodent models of transient focal cerebral ischemia to address translational failure in experimental stroke. In addition to centralized randomization and blinding and large samples, SPAN aimed to introduce heterogeneity to simulate the heterogeneity embodied in clinical trials for robust conclusions. Here, we report the heterogeneity introduced by allowing the 6 SPAN laboratories to vary most of the biological and experimental model variables and the impact of this heterogeneity on middle cerebral artery occlusion (MCAo) performance. We included the modified intention-to-treat population of the control mouse cohort of the first SPAN trial (n=421) and examined the biological and procedural independent variables and their covariance. We then determined their impact on the dependent variables cerebral blood flow drop during MCAo, time to achieve MCAo, and total anesthesia duration using multivariable analyses. We found heterogeneity in biological and procedural independent variables introduced mainly by the site. Consequently, all dependent variables also showed heterogeneity among the sites. Multivariable analyses with the site as a random effect variable revealed filament choice as an independent predictor of cerebral blood flow drop after MCAo. Comorbidity, sex, use of laser Doppler flow to monitor cerebral blood flow, days after trial onset, and maintaining anesthesia throughout the MCAo emerged as independent predictors of time to MCAo. Total anesthesia duration was predicted by most independent variables. We present with high granularity the heterogeneity introduced by the biological and model selections by the testing sites in the first trial of cerebroprotection in rodent transient filament MCAo by SPAN. Rather than trying to homogenize all variables across all sites, we embraced the heterogeneity to better approximate clinical trials. Awareness of the heterogeneity, its sources, and how it impacts the study performance may further improve the study design and statistical modeling for future multicenter preclinical trials.


Assuntos
Ataque Isquêmico Transitório , Acidente Vascular Cerebral , Camundongos , Animais , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média , Projetos de Pesquisa , Circulação Cerebrovascular/fisiologia , Estudos Multicêntricos como Assunto
4.
J Control Release ; 353: 216-228, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36410615

RESUMO

The production of reactive oxygen species (ROS) during and after the onset of an ischemic stroke induces neuronal cell death and severely damages brain function. Therefore, reducing ROS by administrating antioxidant compounds is a promising approach to improving ischemic symptoms. Alpha-mangostin (α-M) is an antioxidant compound extracted from the pericarp of the mangosteen fruit. Reportedly, α-M decreases neuronal toxicity in primary rat cerebral cortical neurons. In this study, we investigated the neuroprotective activity of α-M in both in vitro and in vivo assays. Pretreatment with α-M inhibited excessive cellular ROS production after oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro using an SH-SY5Y (human neuroblastoma) cell line. In addition, α-M maintained mitochondrial membrane potential and suppressed mitochondrial-specific ROS production induced by OGD/R. Meanwhile, the low bioavailability of α-M due to its poor water solubility has been an insuperable obstruction impeding extensive investigations of the biological functions of α-M and its medical applications. To overcome this problem, we synthesized a cyclodextrin-based nanoparticle (CDNP) that is known to increase the loading efficiency and binding constant of α-M, compared with cyclodextrins themselves. This nano-formulated α-M (α-M/CDNP) was optimized for an in vivo ischemic stroke model. Our results indicated that α-M/CDNP (25 mg/kg/injection) reduced infarct volume and improved neurological behavior (p = 0.036 and p = 0.046, respectively). These in vivo results suggest that α-M appears to cross the blood-brain barrier (BBB) with the help of a nano-formulation with CDNP. Combining an in vitro BBB model and a physicochemical binding assay between α-M and albumin, it is speculated that α-M released from CDNP would interact with albumin during its prolonged circulation in the blood, and the resultant α-M/albumin complex may cross the BBB through the absorptive-mediated transcytosis pathway. These findings suggest the potential clinical application of α-M in ischemic stroke treatment.


Assuntos
Isquemia Encefálica , Ciclodextrinas , AVC Isquêmico , Neuroblastoma , Fármacos Neuroprotetores , Traumatismo por Reperfusão , Ratos , Humanos , Animais , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes/farmacologia , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Oxigênio/uso terapêutico , Glucose/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Fármacos Neuroprotetores/farmacologia , Traumatismo por Reperfusão/metabolismo , Apoptose
5.
Stroke ; 53(5): 1802-1812, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35354299

RESUMO

Cerebral ischemia and reperfusion initiate cellular events in brain that lead to neurological disability. Investigating these cellular events provides ample targets for developing new treatments. Despite considerable work, no such therapy has translated into successful stroke treatment. Among other issues-such as incomplete mechanistic knowledge and faulty clinical trial design-a key contributor to prior translational failures may be insufficient scientific rigor during preclinical assessment: nonblinded outcome assessment; missing randomization; inappropriate sample sizes; and preclinical assessments in young male animals that ignore relevant biological variables, such as age, sex, and relevant comorbid diseases. Promising results are rarely replicated in multiple laboratories. We sought to address some of these issues with rigorous assessment of candidate treatments across 6 independent research laboratories. The Stroke Preclinical Assessment Network (SPAN) implements state-of-the-art experimental design to test the hypothesis that rigorous preclinical assessment can successfully reduce or eliminate common sources of bias in choosing treatments for evaluation in clinical studies. SPAN is a randomized, placebo-controlled, blinded, multilaboratory trial using a multi-arm multi-stage protocol to select one or more putative stroke treatments with an implied high likelihood of success in human clinical stroke trials. The first stage of SPAN implemented procedural standardization and experimental rigor. All participating research laboratories performed middle cerebral artery occlusion surgery adhering to a common protocol and rapidly enrolled 913 mice in the first of 4 planned stages with excellent protocol adherence, remarkable data completion and low rates of subject loss. SPAN stage 1 successfully implemented treatment masking, randomization, prerandomization inclusion/exclusion criteria, and blinded assessment to exclude bias. Our data suggest that a large, multilaboratory, preclinical assessment effort to reduce known sources of bias is feasible and practical. Subsequent SPAN stages will evaluate candidate treatments for potential success in future stroke clinical trials using aged animals and animals with comorbid conditions.


Assuntos
Isquemia Encefálica , Acidente Vascular Cerebral , Idoso , Animais , Encéfalo , Isquemia Encefálica/terapia , Estudos de Viabilidade , Humanos , Infarto da Artéria Cerebral Média/terapia , Masculino , Camundongos , Acidente Vascular Cerebral/terapia
6.
J Clin Invest ; 132(8)2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35202003

RESUMO

Cerebral autosomal dominant arteriopathy, subcortical infarcts, and leukoencephalopathy (CADASIL) is the most common monogenic form of small vessel disease characterized by migraine with aura, leukoaraiosis, strokes, and dementia. CADASIL mutations cause cerebrovascular dysfunction in both animal models and humans. Here, we showed that 2 different human CADASIL mutations (Notch3 R90C or R169C) worsen ischemic stroke outcomes in transgenic mice; this was explained by the higher blood flow threshold to maintain tissue viability compared with that in wild type (WT) mice. Both mutants developed larger infarcts and worse neurological deficits compared with WT mice, regardless of age or sex after filament middle cerebral artery occlusion. However, full-field laser speckle flowmetry during distal middle cerebral artery occlusion showed comparable perfusion deficits in mutants and their respective WT controls. Circle of Willis anatomy and pial collateralization also did not differ among the genotypes. In contrast, mutants had a higher cerebral blood flow threshold, below which infarction ensued, suggesting increased sensitivity of brain tissue to ischemia. Electrophysiological recordings revealed a 1.5- to 2-fold higher frequency of peri-infarct spreading depolarizations in CADASIL mutants. Higher extracellular K+ elevations during spreading depolarizations in the mutants implicated a defect in extracellular K+ clearance. Altogether, these data reveal a mechanism of enhanced vulnerability to ischemic injury linked to abnormal extracellular ion homeostasis and susceptibility to ischemic depolarizations in CADASIL.


Assuntos
CADASIL , Animais , Encéfalo , CADASIL/genética , Homeostase , Infarto da Artéria Cerebral Média , Camundongos , Mutação , Potássio , Receptores Notch/genética
8.
J Pharmacol Sci ; 148(1): 65-72, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34924132

RESUMO

This study aimed to evaluate the effects of nafamostat, a serin protease inhibitor, in the management of subarachnoid hemorrhage (SAH). SAH was induced by endovascular perforation in male mice. Nafamostat was administered intraperitoneally four times immediately after SAH induction. Cerebral blood flow, neurological behavior tests, SAH grade and protein expression were evaluated at 24 h after SAH induction. In the in vitro model, human brain microvascular endothelial cells (HBMVECs), HBVECs were exposed to thrombin and hypoxia for 24 h; nafamostat was administered and the protein expression was evaluated. Eighty-eight mice were included in the in vivo study. Fifteen mice (17%) were excluded because of death or procedure failure. Nafamostat exerted no significant effect on the SAH grade or cerebral blood flow; however, it improved the neurological behavior and suppressed the thrombin and MMP-9 expression. In addition, nafamostat suppressed the ICAM-1 expression and p38 phosphorylation in the in vitro study. Nafamostat has a protective effect against HBMVEC after exposure to thrombin and hypoxia, suggesting its role in improving the neurological outcomes after SAH. These findings indicate that nafamostat has the potential to be a novel therapeutic drug in the management of SAH.


Assuntos
Benzamidinas/administração & dosagem , Lesões Encefálicas/etiologia , Lesões Encefálicas/prevenção & controle , Guanidinas/administração & dosagem , Inibidores de Serina Proteinase/administração & dosagem , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/tratamento farmacológico , Animais , Benzamidinas/farmacologia , Encéfalo/citologia , Lesões Encefálicas/genética , Células Cultivadas , Circulação Cerebrovascular , Modelos Animais de Doenças , Células Endoteliais/metabolismo , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Guanidinas/farmacologia , Humanos , Infusões Parenterais , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/metabolismo , Masculino , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Camundongos Endogâmicos , Inibidores de Serina Proteinase/farmacologia , Hemorragia Subaracnóidea/genética , Trombina/genética , Trombina/metabolismo
9.
Sci Rep ; 11(1): 24254, 2021 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-34930932

RESUMO

Human induced pluripotent stem cells (hiPSCs) can differentiate into cells of the three germ layers and are promising cell sources for regenerative medicine therapies. However, current protocols generate hiPSCs with low efficiency, and the generated iPSCs have variable differentiation capacity among different clones. Our previous study reported that MYC proteins (c-MYC and MYCL) are essential for reprogramming and germline transmission but that MYCL can generate hiPSC colonies more efficiently than c-MYC. The molecular underpinnings for the different reprogramming efficiencies between c-MYC and MYCL, however, are unknown. In this study, we found that MYC Box 0 (MB0) and MB2, two functional domains conserved in the MYC protein family, contribute to the phenotypic differences and promote hiPSC generation in MYCL-induced reprogramming. Proteome analyses suggested that in MYCL-induced reprogramming, cell adhesion-related cytoskeletal proteins are regulated by the MB0 domain, while the MB2 domain regulates RNA processes. These findings provide a molecular explanation for why MYCL has higher reprogramming efficiency than c-MYC.


Assuntos
Células-Tronco Pluripotentes Induzidas/citologia , Proteínas Proto-Oncogênicas c-myc/fisiologia , Adesão Celular , Técnicas de Cultura de Células/métodos , Diferenciação Celular/genética , Células Cultivadas , Reprogramação Celular , Citometria de Fluxo , Deleção de Genes , Humanos , Mutação , Fenótipo , Domínios Proteicos , Proteoma , Proteômica , Proteínas Recombinantes/química
10.
J Stroke Cerebrovasc Dis ; 30(9): 105952, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34214963

RESUMO

OBJECTIVE: Cerebral Blood Flow (CBF) change after Subarachnoid Hemorrhage (SAH) is strongly associated with brain injuries such as early brain injury and delayed cerebral ischemia. We evaluated the correlation between CBF using Laser Speckle Flow Imaging (LSFI) after SAH and neurological findings in the sub-acute phase. METHOD: An SAH was induced by endovascular perforation in male mice. CBF was quantitatively measured by using LSFI at six time points, immediately to 14 days after SAH induction. Behavior tests and survival rate were evaluated. The mice were divided into recovery and hypo-perfusion groups according to their CBF at 1 day after the procedure. RESULT: Forty mice were included in this study. Five mice (20%) were included in the hypo-perfusion group, and the remaining 20 (80%) mice were classified as the recovery group. The decrease of CBF in the recovery group was observed until 1 day after the procedure. However, the decrease of CBF in the hypo-perfusion group was prolonged until 7 days after the procedure. Neurological findings and survival rates in the hypo-perfusion group were significantly worse than those in the recovery group. The low alternation cases (≤ 50%) in the Y-maze test in the recovery group (n = 5) had significantly lower CBF at 1 day after the procedure. CONCLUSION: Low blood flow at 1 day after SAH was associated with worse survival rate, neurological findings, and memory disturbance. Early improvement in CBF may be associated with an improved prognosis after SAH.


Assuntos
Comportamento Animal , Encéfalo/irrigação sanguínea , Circulação Cerebrovascular , Transtornos da Memória/fisiopatologia , Memória , Hemorragia Subaracnóidea/fisiopatologia , Animais , Velocidade do Fluxo Sanguíneo , Cognição , Modelos Animais de Doenças , Imagem de Contraste de Manchas a Laser , Masculino , Aprendizagem em Labirinto , Transtornos da Memória/etiologia , Transtornos da Memória/psicologia , Camundongos , Imagem de Perfusão , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/psicologia , Fatores de Tempo
11.
Curr Neurovasc Res ; 18(1): 85-92, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34011258

RESUMO

BACKGROUND: Neovascular age-related macular degeneration (AMD) with choroidal neovascularization (CNV) is a leading cause of blindness in elderly people. Anti-vascular endothelial growth factor (anti-VEGF)-drugs are used to treat AMD patients; however, some patients are resistant to these therapies. OBJECTIVE: The purpose of this study was to investigate the anti-angiogenic effects of α2-adrenergic agonists, including guanabenz and clonidine. METHODS: We evaluated the anti-angiogenic effects of α2-adrenergic agonists in human retinal microvascular endothelial cells (HRMECs). A proliferation assay was conducted, and the migration ratio was evaluated. In a laser-induced CNV model, guanabenz and clonidine were delivered via intraperitoneal injection or implantation of an osmotic pump device. Fourteen days following CNV induction, CNV lesion size and fundus fluorescein angiography (FFA) were evaluated. RESULTS: Guanabenz and clonidine inhibited VEGF-induced retinal endothelial cell growth and migration. In the CNV model mice, CNV lesion sizes were reduced by intraperitoneal administration of guanabenz or clonidine. Data, including body weight, systolic blood pressure, and heart rate showed that guanabenz (0.5 and 2.0 mg/kg/day) had little effect on these parameters; conversely, a high dose of clonidine (1.0 mg/kg/day) did affect these parameters. Additionally, clonidine did not affect CNV size, but continuous administration of guanabenz attenuated both CNV size and leakage from neovessels. CONCLUSION: Our study suggests a key role for α2-adrenergic receptors during CNV formation. Therefore, we suggest that α2-adrenergic receptor agonists may represent novel therapeutic drugs for patients with neovascular AMD.


Assuntos
Agonistas de Receptores Adrenérgicos alfa 2/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Neovascularização de Coroide/tratamento farmacológico , Clonidina/uso terapêutico , Guanabenzo/uso terapêutico , Agonistas de Receptores Adrenérgicos alfa 2/administração & dosagem , Animais , Movimento Celular/efeitos dos fármacos , Neovascularização de Coroide/patologia , Clonidina/administração & dosagem , Modelos Animais de Doenças , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Guanabenzo/administração & dosagem , Humanos , Masculino , Camundongos , Retina/efeitos dos fármacos , Retina/patologia , Resultado do Tratamento , Fator A de Crescimento do Endotélio Vascular/farmacologia
12.
J Cereb Blood Flow Metab ; 41(7): 1483-1500, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33444090

RESUMO

Intracranial hemorrhage (ICH) is a devastating disease which induces high mortality and poor outcomes including severe neurological dysfunctions. ICH pathology is divided into two types: primary brain injury (PBI) and secondary brain injury (SBI). Although there are numerous preclinical studies documenting neuroprotective agents in experimental ICH models, no effective drugs have been developed for clinical use due to complicated ICH pathology. Oxidative and inflammatory stresses play central roles in the onset and progression of brain injury after ICH, especially SBI. Nrf2 is a crucial transcription factor in the anti-oxidative stress defense system. Under normal conditions, Nrf2 is tightly regulated by the Keap1. Under ICH pathological conditions, such as overproduction of reactive oxygen species (ROS), Nrf2 is translocated into the nucleus where it up-regulates the expression of several anti-oxidative phase II enzymes such as heme oxygenase-1 (HO-1). Recently, many reports have suggested the therapeutic potential of Nrf2 activators (including natural or synthesized compounds) for treating neurodegenerative diseases. Moreover, several Nrf2 activators attenuate ischemic stroke-induced brain injury in several animal models. This review summarizes the efficacy of several Nrf2 activators in ICH animal models. In the future, Nrf2 activators might be approved for the treatment of ICH patients.


Assuntos
Hemorragias Intracranianas/tratamento farmacológico , Fator 2 Relacionado a NF-E2/agonistas , Fármacos Neuroprotetores/farmacologia , Animais , Humanos , Hemorragias Intracranianas/metabolismo , Hemorragias Intracranianas/patologia
13.
FASEB J ; 35(2): e21313, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33484194

RESUMO

Anti-vascular endothelial growth factor (VEGF) therapies are now the first-line treatment for many ocular diseases, but some patients are non-responders to these therapies. The purpose of this study was to determine whether the level of adiponectin increased the pathogenesis of retinal edema and neovascularization in the retina of progressive ocular vascular diseases. We examined the role played by adiponectin in two types of cells and animal models which are retinal vein occlusion (RVO) and oxygen-induced retinopathy (OIR) mice. Our results showed that an injection of anti-adiponectin antibody ameliorated the retinal edema and ischemia through the depression of the expression level of VEGF-related factors and tight junction-related proteins in the retina of RVO mice. The intravitreal injection of anti-adiponectin antibody also decreased the degree of retinal neovascularization in an OIR mice. In addition, exposure of human retinal microvascular endothelial cells and human brain microvascular pericytes in culture to adiponectin increased both the vascular permeability and neovascularization through the increase of inflammatory factor and the dropout of the pericytes. These findings indicate that adiponectin plays a critical role in retinal edema and neovascularization, and adiponectin is a potential therapeutic target for the treatment of diabetic macular edema, proliferative diabetic retinopathy, and RVO.


Assuntos
Adiponectina/metabolismo , Oftalmopatias/metabolismo , Oftalmopatias/patologia , Olho/metabolismo , Olho/patologia , Doenças Vasculares/metabolismo , Doenças Vasculares/patologia , Adiponectina/genética , Animais , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Sobrevivência Celular/fisiologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Humanos , Masculino , Camundongos , Papiledema/metabolismo , Papiledema/patologia , Reação em Cadeia da Polimerase em Tempo Real , Neovascularização Retiniana/metabolismo , Neovascularização Retiniana/patologia , Vasos Retinianos/metabolismo , Vasos Retinianos/patologia
14.
Naunyn Schmiedebergs Arch Pharmacol ; 394(1): 73-84, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32808069

RESUMO

PURPOSE: Intracranial hemorrhage (ICH) is a devastating disease with high mortality and morbidity. After ICH, iron released from the hematoma plays a crucial role in secondary brain injury. Deferasirox (DFR) is a trivalent iron chelator, which was approved to treat iron overload syndrome after transfusion. The aim of the present study was to investigate the protective effects of DFR in both in vitro and in vivo ICH models. METHODS: Using a hemin-induced SH-SY5Y cell damage model, we performed an intracellular bivalent iron (Fe2+) accumulation assay, cell death assay, oxidative stress assessments, and Western blotting analysis. Moreover, the effects of DFR intraventricular administration on hematoma, neurological deficits, and histological alteration were evaluated in an in vivo ICH mouse model by collagenase. RESULTS: DFR significantly suppressed the intracellular Fe2+ accumulation and cell death caused by hemin exposure. These effects were related to the suppression of both reactive oxygen species and lipid peroxidation over-production. In Western blotting analysis, hemin increased the expression of ferritin (an iron storage protein), LC3 and p62 (autophagy-related markers), phosphorylated p38 (a stress response protein), and cleaved-caspase3 and cleaved-poly (adenosine diphosphate ribose) polymerase (PARP) (apoptosis-related makers). However, DFR suppressed the increase of these proteins. In addition, DFR attenuated the neurological deficits until 7 days after ICH without affecting hematoma and injury area. Furthermore, DFR also suppressed microglia/macrophage activation in peri-hematoma area at 3 days after ICH. CONCLUSION: These findings indicate that DFR might be a useful therapeutic agent for the therapy of ICH.


Assuntos
Antioxidantes/uso terapêutico , Deferasirox/uso terapêutico , Acidente Vascular Cerebral Hemorrágico/tratamento farmacológico , Quelantes de Ferro/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Animais , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Deferasirox/farmacologia , Modelos Animais de Doenças , Acidente Vascular Cerebral Hemorrágico/patologia , Humanos , Ferro/metabolismo , Quelantes de Ferro/farmacologia , Masculino , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Espécies Reativas de Oxigênio/metabolismo
15.
J Stroke Cerebrovasc Dis ; 29(11): 105215, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33066911

RESUMO

OBJECTIVE: Intracranial hemorrhage (ICH) catastrophically damages the cerebral vasculature, and severely compromises blood-brain barrier (BBB) function. The prognosis of ICH is poor due to the drastic and rapid progression of its pathology, and the lack of effective treatments presents a significant unmet clinical need. The present paper provides several evidences about the relationship between ICH bleeding status and mortality and the potential therapeutic effects of an iron chelator for ICH. METHODS: Zebrafish are a highly transparent animal model, allowing live imaging of the complex cerebral vasculature. Thus, to further elucidate ATV-induced ICH, we investigated the concentration- and time-dependent phenotypes of ATV-induced ICH with zebrafish larvae. RESULTS: The effects of ATV on mortality and ICH incidence in zebrafish larvae were concentration-dependent. Further, ATV treatment decreased vascular density of the hindbrain in a concentration-dependent manner, and hematoma volume was inversely correlated with ATV concentration. The number of cranial TUNEL-positive apoptotic cells was markedly increased 3 days post-fertilization. Importantly, the iron chelator deferasirox (DFR) decreased the incidence of ATV-induced ICH in zebrafish larvae. CONCLUSION: These findings provided insight into the pathology and regulatory mechanism of ATV-induced ICH, and demonstrated the therapeutic effects of iron chelators.


Assuntos
Encéfalo/efeitos dos fármacos , Deferasirox/farmacologia , Hemorragias Intracranianas/prevenção & controle , Quelantes de Ferro/farmacologia , Animais , Animais Geneticamente Modificados , Apoptose/efeitos dos fármacos , Atorvastatina , Encéfalo/embriologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Hemorragias Intracranianas/induzido quimicamente , Hemorragias Intracranianas/embriologia , Larva , Fatores de Tempo , Peixe-Zebra/embriologia , Peixe-Zebra/genética
16.
J Stroke Cerebrovasc Dis ; 29(11): 105243, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33066951

RESUMO

OBJECTIVE: Concomitant cerebral infarction (CI) is could be a potential concern in experimental subarachnoid hemorrhage (SAH) induced by endovascular perforation. We propose a noninvasive method for excluding CI in a murine SAH model by using Laser speckle flow imaging (LSFI). METHODS: An SAH was induced with endovascular perforation (EVP) in male ddY mice. The cerebral blood flow (CBF) was quantitatively measured in the bilateral cerebral cortex was performed by using LSFI at five timepoints (preprocedure, immediately after, and 3 hours, 6 hours, and 24 hours after the procedure). The mice were then euthanized, and the SAH grade and volume of the CI were evaluated. The mice were divided into the SAH group and the SAH + CI group. Differences between the groups were assessed. RESULTS: Forty-eight mice were used in this study. Six were the sham control group. Five SAH mice died within 24 hours after the procedure. A large CI on the ipsilateral side occurred in 15 (40.5%) mice (i.e., SAH + CI group). The remaining 22 (59.5%) mice were classified as the SAH group. The SAH grading score was not significantly different between the groups. The neurological score and CBF of the ipsilateral hemisphere were significantly higher in the SAH group than in the SAH + CI group (neurological score: 12.3 vs. 8, p < 0.01; CBF: 343.1 vs. 205.5; p < 0.01). The cut-off modified neurological score for excluding CI was 8 (area under the curve [AUC]: 0.77) and CBF at 24 hours after the procedure was 279.2 (AUC:0.856). CONCLUSIONS: Using LSFI is less invasive and effectively excludes concomitant CI in experimental SAH. This methodological protocol may ad in improving the quality of the EVP-SAH model.


Assuntos
Infarto Cerebral/diagnóstico por imagem , Circulação Cerebrovascular , Procedimentos Endovasculares , Fluxometria por Laser-Doppler , Hemorragia Subaracnóidea/diagnóstico por imagem , Animais , Comportamento Animal , Velocidade do Fluxo Sanguíneo , Infarto Cerebral/etiologia , Infarto Cerebral/patologia , Infarto Cerebral/fisiopatologia , Modelos Animais de Doenças , Masculino , Camundongos , Atividade Motora , Valor Preditivo dos Testes , Hemorragia Subaracnóidea/etiologia , Hemorragia Subaracnóidea/patologia , Hemorragia Subaracnóidea/fisiopatologia , Fatores de Tempo
17.
Mar Drugs ; 18(9)2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32962073

RESUMO

Several antitumour drugs have been isolated from natural products and many clinical trials are underway to evaluate their potential. There have been numerous reports about the antitumour effects of astaxanthin against several tumours but no studies into its effects against glioblastoma. Astaxanthin is a red pigment found in crustaceans and fish and is also synthesized in Haematococcus pluvialis; adonixanthin is an intermediate product of astaxanthin. It is known that both astaxanthin and adonixanthin possess radical scavenging activity and can confer a protective effect on several damages. In this study, we clarified the antitumour effects of astaxanthin and adonixanthin using glioblastoma models. Specifically, astaxanthin and adonixanthin showed an ability to suppress cell proliferation and migration in three types of glioblastoma cells. Furthermore, these compounds were confirmed to transfer to the brain in a murine model. In the murine orthotopic glioblastoma model, glioblastoma progression was suppressed by the oral administration of astaxanthin and adonixanthin at 10 and 30 mg/kg, respectively, for 10 days. These results suggest that both astaxanthin and adonixanthin have potential as treatments for glioblastoma.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Carotenoides/farmacologia , Glioblastoma/tratamento farmacológico , Administração Oral , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Carotenoides/administração & dosagem , Linhagem Celular Tumoral , Progressão da Doença , Glioblastoma/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Xantofilas/administração & dosagem , Xantofilas/farmacologia
18.
Neuroscience ; 443: 110-119, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32738431

RESUMO

After ischemic stroke, oxygen and nutrition depletion induce mitochondrial dysfunction, which aggravates brain injury. Bendavia, a mitochondria-targeted tetra-peptide, has anti-oxidative and anti-inflammatory activities. We previously reported that bendavia protected human brain microvascular endothelial cells against oxygen/glucose deprivation (OGD)-induced damage via preserving mitochondrial function. The effects of bendavia on mitochondrial function include the inhibition of reactive oxygen species (ROS) production, inhibition of apoptosis, and restoration of adenosine tri-phosphate synthesis. However, the influence of bendavia on the blood-brain barrier (BBB) and neurons after brain ischemia/reperfusion damage is unclear. The aim of this study was to investigate whether bendavia has protective effects against ischemia/reperfusion damage using both in vivo and in vitro models. The in vivo experiments were conducted in mice, which were subjected to transient middle cerebral occlusion (t-MCAO) to induce brain ischemia/reperfusion damage. After t-MCAO, the cerebral blood flow (CBF), neurological deficits, infarct volume, BBB permeability, and microglia/macrophage activation were assessed. Compared to the vehicle group, bendavia administration (administered twice; immediately after reperfusion and 4 h later) attenuated the sensori-motor dysfunction and infarct formation independent of CBF variation. In addition, bendavia decreased BBB hyper-permeability and microglia/macrophage activation. The in vitro experiments were conducted utilizing two models: (1) OGD/re-oxygenation (OGD/R) or (2) hydrogen peroxide (H2O2)-induced neuron damage. In both models, bendavia inhibited neuronal cell death induced by OGD/R or H2O2. These findings indicated that bendavia attenuated brain ischemia/reperfusion damage and has direct neuroprotective effects against cell injury. Therefore, bendavia may be a novel therapeutic agent to improve ischemic stroke patient outcome.


Assuntos
Isquemia Encefálica , Fármacos Neuroprotetores , Traumatismo por Reperfusão , Acidente Vascular Cerebral , Animais , Isquemia Encefálica/tratamento farmacológico , Células Endoteliais , Peróxido de Hidrogênio , Isquemia , Camundongos , Mitocôndrias , Fármacos Neuroprotetores/farmacologia , Oligopeptídeos , Reperfusão , Traumatismo por Reperfusão/tratamento farmacológico
19.
Neuroscience ; 431: 25-33, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32058064

RESUMO

Intracranial hemorrhage (ICH) is a devastating disease that induces hematoma formation with poor neuronal outcome. Levetiracetam (LEV) has been approval for epilepsy seizures. In a previous study, LEV exerted protective effects on cerebral ischemia models; however, the detail effects and the influence of LEV on ICH are still unknown. The aim of this study was to investigate whether oral administration of LEV (50 or 150 mg/kg) has protective effects on ICH injury using both in vivo and in vitro experiments. In in vivo experiments, we utilized ICH models induced by autologous blood (bICH) or collagenase (cICH) injection. Moreover, we established a neuronal injury model using SYSH5Y human neuroblastoma cell lines. In the bICH model, frequently oral administration of LEV attenuated both cerebral edema and neurological deficits. In addition, the expression levels of phosphorylation-extracellular signal­related kinase (ERK) 1/2 and cleaved caspase-7 were increased after ICH, and LEV suppressed such alterations. In in vitro experiments, hematoma releasing factors, such as hemoglobin (Hb) and hemin, induced neuronal cell death, and LEV treatment attenuated neuronal injury in a dose-dependent manner. In the cICH model, neurological deficits induced by extensive hematoma formation were attenuated by LEV without affecting hematoma volume. Taken together, these findings suggested that LEV has protective effect on neurons after ICH injury. Therefore, LEV may not only be an efficacious therapeutic agent for seizures, but also for post-hemorrhagic stroke brain injury.


Assuntos
Fármacos Neuroprotetores , Animais , Anticonvulsivantes/farmacologia , Anticonvulsivantes/uso terapêutico , Hemorragia Cerebral/complicações , Hemorragia Cerebral/tratamento farmacológico , Modelos Animais de Doenças , Humanos , Hemorragias Intracranianas/tratamento farmacológico , Levetiracetam/uso terapêutico , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico
20.
J Pharmacol Sci ; 141(3): 119-126, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31679961

RESUMO

Reperfusion injury is a serious problem in ischemic stroke therapy, which leads to neuronal damage and intracranial hemorrhage (ICH). A novel free radical scavenger, NSP-116, has anti-oxidative effect and may ameliorate reperfusion injury. The purpose of this study was to investigate the effects of NSP-116 on both ischemic and hemorrhagic stroke models. First, we assessed whether NSP-116 has protective effects in vitro. Pre-treatment of NSP-116 decreased neuronal cell damage induced by H2O2 or LPS. Moreover, NSP-116 also suppressed mitochondria damage and apoptosis in H2O2-induced neuronal injury model. Based on these results, we used a middle cerebral artery occlusion (MCAO)-induced ischemic stroke model or a collagenase-induced ICH model. Using the MCAO model, we evaluated the cerebral blood flow (CBF), neurological deficit, and infarct volume. Hematoma volume was assessed at 3 days after ICH. In the MCAO model, oral administration of NSP-116 at 30 mg/kg attenuated the reduction of CBF, neurological deficits, and infarct formation. Interestingly, NSP-116 also ameliorated hematoma expansion and neurological deficits in the ICH model. Additionally, pre-treatment of NSP-116 suppressed the brain microvascular endothelial cell death induced by collagenase treatment. Collectively, our findings indicated that oral administration of NSP-116 attenuates both ischemic and hemorrhagic brain injuries after stroke.


Assuntos
Compostos de Anilina/farmacologia , Lesões Encefálicas/tratamento farmacológico , Imidazóis/farmacologia , Fármacos Neuroprotetores/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Acidente Vascular Cerebral/tratamento farmacológico , Animais , Encéfalo/efeitos dos fármacos , Circulação Cerebrovascular/efeitos dos fármacos , Modelos Animais de Doenças , Sequestradores de Radicais Livres/farmacologia , Humanos , Masculino , Camundongos
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