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1.
Brain Behav Immun ; 94: 437-457, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33588074

RESUMO

Hematoma size after intracerebral hemorrhage (ICH) significantly affects patient outcome. However, our knowledge of endogenous mechanisms that underlie hematoma clearance and the potential role of the anti-inflammatory cytokine interleukin-10 (IL-10) is limited. Using organotypic hippocampal slice cultures and a collagenase-induced ICH mouse model, we investigated the role of microglial IL-10 in phagocytosis ex vivo and hematoma clearance in vivo. In slice culture, exposure to hemoglobin induced IL-10 expression in microglia and enhanced phagocytosis that depended on IL-10-regulated expression of CD36. Following ICH, IL-10-deficient mice had more severe neuroinflammation, brain edema, iron deposition, and neurologic deficits associated with delayed hematoma clearance. Intranasal administration of recombinant IL-10 accelerated hematoma clearance and improved neurologic function. Additionally, IL-10-deficient mice had weakened in vivo phagocytic ability owing to decreased expression of microglial CD36. Moreover, loss of IL-10 significantly increased monocyte-derived macrophage infiltration and enhanced brain inflammation in vivo. These results indicate that IL-10 regulates microglial phagocytosis and monocyte-derived macrophage infiltration after ICH and that CD36 is a key phagocytosis effector regulated by IL-10. Leveraging the innate immune response to ICH by augmenting IL-10 signaling may provide a useful strategy for accelerating hematoma clearance and improving neurologic outcome in clinical translation studies.


Assuntos
Interleucina-10 , Microglia , Animais , Hemorragia Cerebral , Hematoma , Camundongos , Fagocitose
2.
Brain Behav Immun ; 69: 568-581, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29458197

RESUMO

Intracerebral hemorrhage (ICH) is a detrimental type of stroke. Mouse models of ICH, induced by collagenase or blood infusion, commonly target striatum, but not other brain sites such as ventricular system, cortex, and hippocampus. Few studies have systemically investigated brain damage and neurobehavioral deficits that develop in animal models of ICH in these areas of the right hemisphere. Therefore, we evaluated the brain damage and neurobehavioral dysfunction associated with right hemispheric ICH in ventricle, cortex, hippocampus, and striatum. The ICH model was induced by autologous whole blood or collagenase VII-S (0.075 units in 0.5 µl saline) injection. At different time points after ICH induction, mice were assessed for brain tissue damage and neurobehavioral deficits. Sham control mice were used for comparison. We found that ICH location influenced features of brain damage, microglia/macrophage activation, and behavioral deficits. Furthermore, the 24-point neurologic deficit scoring system was most sensitive for evaluating locomotor abnormalities in all four models, especially on days 1, 3, and 7 post-ICH. The wire-hanging test was useful for evaluating locomotor abnormalities in models of striatal, intraventricular, and cortical ICH. The cylinder test identified locomotor abnormalities only in the striatal ICH model. The novel object recognition test was effective for evaluating recognition memory dysfunction in all models except for striatal ICH. The tail suspension test, forced swim test, and sucrose preference test were effective for evaluating emotional abnormality in all four models but did not correlate with severity of brain damage. These results will help to inform future preclinical studies of ICH outcomes.


Assuntos
Comportamento Animal/fisiologia , Encéfalo/patologia , Hemorragia Cerebral/fisiopatologia , Cognição/fisiologia , Emoções/fisiologia , Destreza Motora/fisiologia , Animais , Hemorragia Cerebral/patologia , Hemorragia Cerebral/psicologia , Modelos Animais de Doenças , Camundongos
3.
Neurobiol Dis ; 103: 54-69, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28365213

RESUMO

Microglia/macrophages (MMΦ) are highly plastic phagocytes that can promote both injury and repair in diseased brain through the distinct function of classically activated and alternatively activated subsets. The role of MMΦ polarization in intracerebral hemorrhage (ICH) is unknown. Herein, we comprehensively characterized MMΦ dynamics after ICH in mice and evaluated the relevance of MMΦ polarity to hematoma resolution. MMΦ accumulated within the hematoma territory until at least 14days after ICH induction. Microglia rapidly reacted to the hemorrhagic insult as early as 1-1.5h after ICH and specifically presented a "protective" alternatively activated phenotype. Substantial numbers of activated microglia and newly recruited monocytes also assumed an early alternatively activated phenotype, but the phenotype gradually shifted to a mixed spectrum over time. Ultimately, markers of MMΦ classic activation dominated at the chronic stage of ICH. We enhanced MMΦ alternative activation by administering intraperitoneal injections of rosiglitazone, and subsequently observed elevations in CD206 expression on brain-isolated CD11b+ cells and increases in IL-10 levels in serum and perihematomal tissue. Enhancement of MMΦ alternative activation correlated with hematoma volume reduction and improvement in neurologic deficits. Intraventricular injection of alternative activation signature cytokine IL-10 accelerated hematoma resolution, whereas microglial phagocytic ability was abolished by IL-10 receptor neutralization. Our results suggest that MMΦ respond dynamically to brain hemorrhage by exhibiting diverse phenotypic changes at different stages of ICH. Alternative activation-skewed MMΦ aid in hematoma resolution, and IL-10 signaling might contribute to regulation of MMΦ phagocytosis and hematoma clearance in ICH.


Assuntos
Hemorragia Cerebral/metabolismo , Hematoma/metabolismo , Ativação de Macrófagos/fisiologia , Macrófagos/metabolismo , Microglia/metabolismo , Animais , Hemorragia Cerebral/patologia , Hematoma/patologia , Hipocampo/metabolismo , Hipocampo/patologia , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/patologia , Técnicas de Cultura de Órgãos , Distribuição Aleatória
4.
Brain Behav Immun ; 61: 326-339, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28007523

RESUMO

Neuroinflammation is a major contributor to intracerebral hemorrhage (ICH) progression, but no drug is currently available to reduce this response and protect against ICH-induced injury. Recently, the natural product pinocembrin has been shown to ameliorate neuroinflammation and is undergoing a phase II clinical trial for ischemic stroke treatment. In this study, we examined the efficacy of pinocembrin in an ICH model, and further examined its effect on microglial activation and polarization. In vivo, pinocembrin dose-dependently reduced lesion volume by ∼47.5% and reduced neurologic deficits of mice at 72h after collagenase-induced ICH. The optimal dose of pinocembrin (5mg/kg) suppressed microglial activation as evidenced by decreases in CD68-positive microglia and reduced proinflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6. Pinocembrin also reduced the number of classically activated M1-like microglia without affecting M2-like microglia in the perilesional region. Additionally, pinocembrin decreased the expression of toll-like receptor (TLR)4 and its downstream target proteins TRIF and MyD88. The protection by pinocembrin was lost in microglia-depleted mice and in TLR4lps-del mice, and pinocembrin failed to decrease the number of M1-like microglia in TLR4lps-del mice. In lipopolysaccharide-stimulated BV-2 cells or primary microglia, pinocembrin decreased M1-related cytokines and markers (IL-1ß, IL-6, TNF-α, and iNOS), NF-κB activation, and TLR4 expression, but it did not interfere with TLR4/MyD88 and TLR4/TRIF interactions or affect microglial phagocytosis of red blood cells. Inhibition of the TLR4 signaling pathway and reduction in M1-like microglial polarization might be the major mechanism by which pinocembrin protects hemorrhagic brain. With anti-inflammatory properties, pinocembrin could be a promising new drug candidate for treating ICH and other acute brain injuries.


Assuntos
Anti-Inflamatórios/farmacologia , Flavanonas/farmacologia , Hemorragias Intracranianas/tratamento farmacológico , Microglia/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Receptor 4 Toll-Like/antagonistas & inibidores , Animais , Anti-Inflamatórios/uso terapêutico , Citocinas/metabolismo , Flavanonas/uso terapêutico , Hemorragias Intracranianas/metabolismo , Masculino , Camundongos , Microglia/metabolismo , Fármacos Neuroprotetores/uso terapêutico
6.
Nanomaterials (Basel) ; 14(4)2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38392696

RESUMO

The functionalized graphene oxide (GO)-based composites as fillers added into organic coatings are desired for realizing the longstanding corrosion protection of carbon steel. Here, the pH-responsive two-dimensional/three-dimensional (2D/3D) GO-based composite (ZIF-90-AAP/GO) was developed by environmentally friendly corrosion inhibitor 4-aminoantipyrine (AAP) anchored on the in situ growth of zeolite imidazolate framework-90 (ZIF-90) on the GO surface (ZIF-90/GO) through the Schiff base reaction. The active filler (ZIF-90-AAP/GO) was incorporated into an epoxy coating (EP) to obtain a high-performance self-healing coating on the surface of carbon steel. ZIF-90-AAP can greatly improve dispersion and compatibility of GO in EP. The low-frequency impedance modulus of ZIF-90-AAP/GO-EP can still reach up to 1.35 × 1010 Ω⋅cm2 after 40 days, which is about three orders of magnitude higher than that of the EP containing GO (GO-EP) relying on its passive and active corrosion protection. Meanwhile, ZIF-90-AAP/GO-EP exhibits excellent self-healing performance. The self-healing rate of ZIF-90-AAP/GO changes from negative to positive after 24 h, which results from the effective corrosion inhibition activity of ZIF-90-AAP for carbon steel based on the pH-triggered controlled release of AAP. The developed pH-responsive 2D/3D GO-based composite coating is very attractive for the corrosion protection of carbon steel.

8.
J Colloid Interface Sci ; 669: 912-926, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38754144

RESUMO

Polyelectrolyte-encapsulated nanocontainers can effectively respond to changes of pH and thus control the on-demand release of corrosion inhibitors. A pH-responsive release system (Phen-Tpp@MTNs-PDDA) was developed based on the cationic polyelectrolyte poly dimethyl diallyl ammonium chloride (PDDA) encapsulated mesoporous TiO2 nanocontainers (MTNs) loaded with 1,10-phenanthroline (Phen) and tripolyphosphate ions (Tpp) corrosion inhibitors. The epoxy coating (EP) embedded with Phen-Tpp@MTNs-PDDA (Phen-Tpp@MTNs-PDDA/EP) demonstrates superior self-healing properties and confers long-term protection on the metal substrate through the cooperative effect of Phen and Tpp. Simultaneously, this hybrid coating is endowed with corrosion sensing capability based on the color development originating from the interaction of Phen and carbon steel. This self-healing and corrosion-sensing multifunctional coating provides an effective strategy for the corrosion protection of metals.

9.
bioRxiv ; 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-38826432

RESUMO

Pain after surgery causes significant suffering. Opioid analgesics cause severe side effects and accidental death. Therefore, there is an urgent need to develop non-opioid therapies for managing post-surgical pain. Local application of Clarix Flo (FLO), a human amniotic membrane (AM) product, attenuated established post-surgical pain hypersensitivity without exhibiting known side effects of opioid use in mice. This effect was achieved through direct inhibition of nociceptive dorsal root ganglion (DRG) neurons via CD44-dependent pathways. We further purified the major matrix component, the heavy chain-hyaluronic acid/pentraxin 3 (HC-HA/PTX3) from human AM that has greater purity and water solubility than FLO. HC-HA/PTX3 replicated FLO-induced neuronal and pain inhibition. Mechanistically, HC-HA/PTX3 induced cytoskeleton rearrangements to inhibit sodium current and high-voltage activated calcium current on nociceptive neurons, suggesting it is a key bioactive component mediating pain relief. Collectively, our findings highlight the potential of naturally derived biologics from human birth tissues as an effective non-opioid treatment for post-surgical pain. Moreover, we unravel the underlying mechanisms of pain inhibition induced by FLO and HC-HA/PTX3.

10.
Front Public Health ; 11: 1147838, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37124792

RESUMO

The response of the Bitcoin market to the novel coronavirus (COVID-19) pandemic is an example of how a global public health crisis can cause drastic market adjustments or even a market crash. Investor attention on the COVID-19 pandemic is likely to play an important role in this response. Focusing on the Bitcoin futures market, this paper aims to investigate whether pandemic attention can explain and forecast the returns and volatility of Bitcoin futures. Using the daily Google search volume index for the "coronavirus" keyword from January 2020 to February 2022 to represent pandemic attention, this paper implements the Granger causality test, Vector Autoregression (VAR) analysis, and several linear effects analyses. The findings suggest that pandemic attention is a granger cause of Bitcoin returns and volatility. It appears that an increase in pandemic attention results in lower returns and excessive volatility in the Bitcoin futures market, even after taking into account the interactive effects and the influence of controlling other financial markets. In addition, this paper carries out the out-of-sample forecasts and finds that the predictive models with pandemic attention do improve the out-of-sample forecast performance, which is enhanced in the prediction of Bitcoin returns while diminished in the prediction of Bitcoin volatility as the forecast horizon is extended. Finally, the predictive models including pandemic attention can generate significant economic benefits by constructing portfolios among Bitcoin futures and risk-free assets. All the results demonstrate that pandemic attention plays an important and non-negligible role in the Bitcoin futures market. This paper can provide enlightens for subsequent research on Bitcoin based on investor attention sparked by public emergencies.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , Pandemias , SARS-CoV-2 , Saúde Pública
11.
Exp Neurol ; 355: 114125, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35644427

RESUMO

The goal of this study was to determine whether deficiency of anti-inflammatory cytokine interleukin-10 (IL-10) affects traumatic brain injury (TBI) outcomes in a sex-dependent manner. Moderate TBI was induced by controlled cortical impact in 8-10 week-old wild-type and IL-10-deficient mice. In wild-type mice, serum IL-10 was significantly increased after TBI in males but not in females. At 4-5 weeks after TBI, sensorimotor function, cognitive function (Y-maze and novel object recognition tests), anxiety-related behavior (light-dark box and open field test), and depression-like behavior (forced swim test) were assessed. IL-10-deficient male mice had larger lesion volumes than did wild-type mice in the early recovery phase and worse performance on sensorimotor tasks, cognitive tests, and anxiety- and depression-related tests in the late recovery phase, whereas female IL-10-deficient mice had lesion volume equivalent to that of wild-type females and worse performance only on sensorimotor tasks. At 3 days after TBI, the number of GFAP- and Iba1-positive cells were augmented in areas in proximity to the injury (cerebral cortex and hippocampus) and in remote functional regions (striatum and amygdala) of IL-10-deficient male, but not female, mice. Moreover, on day 35, significantly fewer NeuN-positive cells were present in cortex, striatum, and amygdala of IL-10-deficient male mice than in wild-type males. This difference was not evident in females. We conclude that IL-10 deficiency aggravates cognitive and emotional recovery from TBI in association with enhanced gliosis and neuronal loss selectively in males, suggesting that recruitment of this cytokine limits damage in a sex-dependent manner.


Assuntos
Lesões Encefálicas Traumáticas , Interleucina-10 , Animais , Lesões Encefálicas Traumáticas/patologia , Córtex Cerebral/patologia , Modelos Animais de Doenças , Hipocampo/patologia , Interleucina-10/genética , Masculino , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL
12.
Neurotrauma Rep ; 3(1): 261-275, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35982981

RESUMO

After traumatic brain injury (TBI), early assessment of secondary injury severity is critically important for estimating prognosis and treatment stratification. Currently, secondary injury severity is difficult to estimate. The objective of this study was to investigate the capacity of non-invasive amide proton transfer-weighted (APTw) magnetic resonance imaging (MRI) techniques to assess TBI injury in different brain regions and predict long-term neurobehavior outcomes. Fifty-five male and female rats were subjected to a controlled cortical impact with one of three different impactor depths to produce different degrees of TBI. Multi-parameter MRI data were acquired on a 4.7-Tesla scanner at 1 h, 1 day, and 3 days. Immunofluorescence staining was used to detect activated microglia at 3 days, and neurobehavioral tests were performed to assess long-term outcomes after 28 days. The APTw signal in the injury core at 1 day correlated with deficits in sensorimotor function, the sucrose preference test (a test for anhedonia), and spatial memory function on the Barnes maze. The APTw signal in the perilesion ipsilateral cortex gradually increased after TBI, and the value at 3 days correlated with microglia density at 3 days and with spatial memory decline and anhedonia at 28 days. The correlation between APTw and activated microglia was also observed in the ipsilateral thalamus, and its correlation to memory deficit and depression was evident in other ipsilateral sites. These results suggest that APTw imaging can be used for detecting secondary injury and as a potential predictor of long-term outcomes from TBI.

13.
PLoS One ; 16(12): e0261640, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34910780

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0097423.].

14.
Front Neurol ; 12: 763419, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34867747

RESUMO

Intracerebral hemorrhage (ICH) is a highly fatal type of stroke that leads to various types of neuronal death. Recently, ferroptosis, a form of cell death resulting from iron-dependent lipid peroxide accumulation, was observed in a mouse ICH model. N-hydroxy-N'-(4-n-butyl-2-methylphenyl)-formamidine (HET0016), which inhibits synthesis of the arachidonic acid metabolite 20-hydroxyeicosatetraenoic acid (20-HETE), has shown a protective effect after ICH. However, the underlying mechanisms of the neuroprotective effect need further investigation. We explored whether 20-HETE participates in ICH-induced ferroptosis ex vivo by using hemoglobin-treated organotypic hippocampal slice cultures (OHSCs) and in vivo by using a collagenase-induced ICH mouse model. Ex vivo, we found that the 20-HETE synthesis inhibitor HET0016 and antagonist 20-6,15-HEDGE reduced hemoglobin-induced cell death, iron deposition, and lipid reactive oxygen species levels in OHSCs. Furthermore, 20-HETE inhibition in OHSCs increased the expression of glutathione peroxidase (GPX) 4, an antioxidant enzyme that serves as a main regulator of ferroptosis. In contrast, exposure of OHSCs to the 20-HETE stable mimetic 20-5,14-HEDGE induced cell death that was significantly inhibited by the ferroptosis inhibitor ferrostatin-1. In vivo, HET0016 treatment ameliorated focal deficits, reduced lesion volume, and decreased iron accumulation around the lesion at day 3 and 7 after ICH. In addition, lipid peroxidation was decreased and expression of GPX4 was increased in the HET0016-treated ICH group. The mitogen-activated protein kinase pathway also was inhibited by HET0016 in vivo. These results indicate that 20-HETE contributes to ICH-induced acute brain injury in part by activating ferroptosis pathways, thereby providing an upstream target for inhibiting ferroptosis.

15.
J Cereb Blood Flow Metab ; 40(9): 1752-1768, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32423330

RESUMO

Intracerebral hemorrhage (ICH) is a subtype of stroke with high mortality and disability but no specific or effective treatment. In the last two decades, much has been learned about the pathologic mechanisms of ICH. It is now known that after ICH onset, immune and inflammatory responses contribute to blood-brain barrier disruption, edema development, and cell death processes, jointly resulting in secondary brain injury. However, the translation of potential therapies from preclinical to clinical success has been disappointing. With the development of new laboratory technology, recent progress has been made in the understanding of ICH pathomechanisms, and promising therapeutic targets have been identified. This review provides an update of recent progress on ICH and describes the prospects for further preclinical studies in this field. Our goal is to discuss new therapeutic targets and directions for the treatment of ICH and promote the effective transformation from preclinical to clinical trials.


Assuntos
Hemorragia Cerebral/complicações , Hemorragia Cerebral/terapia , Encefalite/etiologia , Encefalite/terapia , Animais , Barreira Hematoencefálica/patologia , Ensaios Clínicos como Assunto , Humanos , Macrófagos
16.
Stroke Vasc Neurol ; 4(2): 93-95, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31338218

RESUMO

Intracerebral haemorrhage (ICH) is a devastating type of stroke with high mortality and morbidity. However, we have few options for ICH therapy and limited knowledge about post-ICH neuronal death and related mechanisms. In the aftermath of ICH, iron overload within the perihaematomal region can induce lethal reactive oxygen species (ROS) production and lipid peroxidation, which contribute to secondary brain injury. Indeed, iron chelation therapy has shown efficacy in preclinical ICH studies. Recently, an iron-dependent form of non-apoptotic cell death known as ferroptosis was identified. It is characterised by an accumulation of iron-induced lipid ROS, which leads to intracellular oxidative stress. The ROS cause damage to nucleic acids, proteins and lipid membranes, and eventually cell death. Recently, we and others discovered that ferroptosis does occur after haemorrhagic stroke in vitro and in vivo and contributes to neuronal death. Inhibition of ferroptosis is beneficial in several in vivo and in vitro ICH conditions. This minireview summarises current research on iron toxicity, lipid peroxidation and ferroptosis in the pathomechanisms of ICH, the underlying molecular mechanisms of ferroptosis and the potential for combined therapeutic strategies. Understanding the role of ferroptosis after ICH will provide a vital foundation for cell death-based ICH treatment and prevention.


Assuntos
Encéfalo/metabolismo , Hemorragia Cerebral/metabolismo , Ferroptose , Ferro/metabolismo , Peroxidação de Lipídeos , Estresse Oxidativo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Hemorragia Cerebral/tratamento farmacológico , Hemorragia Cerebral/patologia , Ferroptose/efeitos dos fármacos , Humanos , Ferro/sangue , Quelantes de Ferro/uso terapêutico , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
17.
J Cereb Blood Flow Metab ; 39(8): 1531-1543, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-29485354

RESUMO

20-HETE, an arachidonic acid metabolite synthesized by cytochrome P450 4A, plays an important role in acute brain damage from ischemic stroke or subarachnoid hemorrhage. We tested the hypothesis that 20-HETE inhibition has a protective effect after intracerebral hemorrhage (ICH) and then investigated its effect on angiogenesis. We exposed hippocampal slice cultures to hemoglobin and induced ICH in mouse brains by intrastriatal collagenase injection to investigate the protective effect of 20-HETE synthesis inhibitor N-hydroxy-N'-(4-n-butyl-2-methylphenyl)-formamidine (HET0016). Hemoglobin-induced neuronal death was assessed by propidium iodide after 18 h in vitro. Lesion volume, neurologic deficits, cell death, reactive oxygen species (ROS), neuroinflammation, and angiogenesis were evaluated at different time points after ICH. In cultured mouse hippocampal slices, HET0016 attenuated hemoglobin-induced neuronal death and decreased levels of proinflammatory cytokines and ROS. In vivo, HET0016 reduced brain lesion volume and neurologic deficits, and decreased neuronal death, ROS production, gelatinolytic activity, and the inflammatory response at three days after ICH. However, HET0016 did not inhibit angiogenesis, as levels of CD31, VEGF, and VEGFR2 were unchanged on day 28. We conclude that 20-HETE is involved in ICH-induced brain damage. Inhibition of 20-HETE synthesis may provide a viable means to mitigate ICH injury without inhibition of angiogenesis.


Assuntos
Hemorragia Cerebral/metabolismo , Ácidos Hidroxieicosatetraenoicos/metabolismo , Neovascularização Fisiológica/fisiologia , Animais , Hemorragia Cerebral/patologia , Inibidores Enzimáticos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Fisiológica/efeitos dos fármacos
18.
Free Radic Biol Med ; 124: 504-516, 2018 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-29966698

RESUMO

Salvianolic acid B (SalB), a natural polyphenolic compound extracted from the herb of Salvia miltiorrhiza, possesses antioxidant and neuroprotective properties and has been shown to be beneficial for diseases that affect vasculature and cognitive function. Here we investigated the protective effects of SalB against subarachnoid hemorrhage (SAH)-induced oxidative damage, and the involvement of underlying molecular mechanisms. In a rat model of SAH, SalB inhibited SAH-induced oxidative damage. The reduction in oxidative damage was associated with suppressed reactive oxygen species generation; decreased lipid peroxidation; and increased glutathione peroxidase, glutathione, and superoxide dismutase activities. Concomitant with the suppressed oxidative stress, SalB significantly reduced neurologic impairment, brain edema, and neural cell apoptosis after SAH. Moreover, SalB dramatically induced nuclear factor-erythroid 2-related factor 2 (Nrf2) nuclear translocation and increased expression of heme oxygenase-1 and NADPH: quinine oxidoreductase-1. In a mouse model of SAH, Nrf2 knockout significantly reversed the antioxidant effects of SalB against SAH. Additionally, SalB activated sirtuin 1 (SIRT1) expression, whereas SIRT1-specific inhibitor sirtinol pretreatment significantly suppressed SalB-induced SIRT1 activation and Nrf2 expression. Sirtinol pretreatment also reversed the antioxidant and neuroprotective effects of SalB. In primary cultured cortical neurons, SalB suppressed oxidative damage, alleviated neuronal degeneration, and improved cell viability. These beneficial effects were associated with activation of the SIRT1 and Nrf2 signaling pathway and were reversed by sirtinol treatment. Taken together, these in vivo and in vitro findings suggest that SalB provides protection against SAH-triggered oxidative damage by upregulating the Nrf2 antioxidant signaling pathway, which may be modulated by SIRT1 activation.


Assuntos
Benzofuranos/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Sirtuína 1/metabolismo , Hemorragia Subaracnóidea/metabolismo , Hemorragia Subaracnóidea/patologia , Animais , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
19.
Front Neurol ; 9: 581, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30065697

RESUMO

Although intracerebral hemorrhage (ICH) is a devastating disease worldwide, the pathologic changes in ultrastructure during the acute and chronic phases of ICH are poorly described. In this study, transmission electron microscopy was used to examine the ultrastructure of ICH-induced pathology. ICH was induced in mice by an intrastriatal injection of collagenase. Pathologic changes were observed in the acute (3 days), subacute (6 days), and chronic (28 days) phases. Compared with sham animals, we observed various types of cell death in the injured striatum during the acute phase of ICH, including necrosis, ferroptosis, and autophagy. Different degrees of axon degeneration in the striatum were seen in the acute phase, and axonal demyelination was observed in the ipsilateral striatum and corpus callosum at late time points. In addition, phagocytes, resident microglia, and infiltrating monocyte-macrophages were present around red blood cells and degenerating neurons and were observed to engulf red blood cells and other debris. Many synapses appeared abnormal or were lost. This systematic analysis of the pathologic changes in ultrastructure after ICH in mice provides information that will be valuable for future ICH pathology studies.

20.
J Cereb Blood Flow Metab ; 37(9): 3110-3123, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28534662

RESUMO

Iron overload plays a key role in the secondary brain damage that develops after intracerebral hemorrhage (ICH). The significant increase in iron deposition is associated with the generation of reactive oxygen species (ROS), which leads to oxidative brain damage. In this study, we examined the protective effects of VK-28, a brain-permeable iron chelator, against hemoglobin toxicity in an ex vivo organotypic hippocampal slice culture (OHSC) model and in middle-aged mice subjected to an in vivo, collagenase-induced ICH model. We found that the effects of VK-28 were similar to those of deferoxamine (DFX), a well-studied iron chelator. Both decreased cell death and ROS production in OHSCs and in vivo, decreased iron-deposition and microglial activation around hematoma in vivo, and improved neurologic function. Moreover, compared with DFX, VK-28 polarized microglia to an M2-like phenotype, reduced brain water content, deceased white matter injury, improved neurobehavioral performance, and reduced overall death rate after ICH. The protection of VK-28 was confirmed in a blood-injection ICH model and in aged-male and young female mice. Our findings indicate that VK-28 is protective against iron toxicity after ICH and that, at the dosage tested, it has better efficacy and less toxicity than DFX does.


Assuntos
Envelhecimento/metabolismo , Hemorragia Cerebral/tratamento farmacológico , Hipocampo/efeitos dos fármacos , Quelantes de Ferro/uso terapêutico , Ferro/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Piperazinas/uso terapêutico , Quinolinas/uso terapêutico , Envelhecimento/patologia , Animais , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/metabolismo , Modelos Animais de Doenças , Feminino , Hemoglobinas/metabolismo , Hipocampo/diagnóstico por imagem , Hipocampo/metabolismo , Hipocampo/patologia , Técnicas In Vitro , Quelantes de Ferro/administração & dosagem , Quelantes de Ferro/farmacocinética , Masculino , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/farmacocinética , Piperazinas/administração & dosagem , Piperazinas/farmacocinética , Quinolinas/administração & dosagem , Quinolinas/farmacocinética
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