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1.
J Neuroinflammation ; 21(1): 130, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38750510

RESUMO

Epidemiological studies have unveiled a robust link between exposure to repetitive mild traumatic brain injury (r-mTBI) and elevated susceptibility to develop neurodegenerative disorders, notably chronic traumatic encephalopathy (CTE). The pathogenic lesion in CTE cases is characterized by the accumulation of hyperphosphorylated tau in neurons around small cerebral blood vessels which can be accompanied by astrocytes that contain phosphorylated tau, the latter termed tau astrogliopathy. However, the contribution of tau astrogliopathy to the pathobiology and functional consequences of r-mTBI/CTE or whether it is merely a consequence of aging remains unclear. We addressed these pivotal questions by utilizing a mouse model harboring tau-bearing astrocytes, GFAPP301L mice, subjected to our r-mTBI paradigm. Despite the fact that r-mTBI did not exacerbate tau astrogliopathy or general tauopathy, it increased phosphorylated tau in the area underneath the impact site. Additionally, gene ontology analysis of tau-bearing astrocytes following r-mTBI revealed profound alterations in key biological processes including immunological and mitochondrial bioenergetics. Moreover, gene array analysis of microdissected astrocytes accrued from stage IV CTE human brains revealed an immunosuppressed astroglial phenotype similar to tau-bearing astrocytes in the GFAPP301L model. Additionally, hippocampal reduction of proteins involved in water transport (AQP4) and glutamate homeostasis (GLT1) was found in the mouse model of tau astrogliopathy. Collectively, these findings reveal the importance of understanding tau astrogliopathy and its role in astroglial pathobiology under normal circumstances and following r-mTBI. The identified mechanisms using this GFAPP301L model may suggest targets for therapeutic interventions in r-mTBI pathogenesis in the context of CTE.


Assuntos
Aquaporina 4 , Astrócitos , Transportador 2 de Aminoácido Excitatório , Camundongos Transgênicos , Tauopatias , Proteínas tau , Astrócitos/metabolismo , Astrócitos/patologia , Animais , Camundongos , Proteínas tau/metabolismo , Proteínas tau/genética , Aquaporina 4/metabolismo , Aquaporina 4/genética , Tauopatias/metabolismo , Tauopatias/patologia , Tauopatias/genética , Humanos , Transportador 2 de Aminoácido Excitatório/metabolismo , Transportador 2 de Aminoácido Excitatório/genética , Transportador 2 de Aminoácido Excitatório/biossíntese , Concussão Encefálica/metabolismo , Concussão Encefálica/patologia , Masculino , Fenótipo , Camundongos Endogâmicos C57BL
2.
Exp Neurol ; 374: 114702, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38301863

RESUMO

Repetitive mild traumatic brain injuries (r-mTBI) sustained in the military or contact sports have been associated with the accumulation of extracellular tau in the brain, which may contribute to the pathogenesis of neurodegenerative tauopathies. The expression of the apolipoprotein E4 (apoE4) isoform has been associated with higher levels of tau in the brain, and worse clinical outcomes after r-mTBI, though the influence of apoE genotype on extracellular tau dynamics in the brain is poorly understood. We recently demonstrated that extracellular tau can be eliminated across blood-brain barrier (BBB), which is progressively impaired following r-mTBI. The current studies investigated the influence of repetitive mild TBI (r-mTBI) and apoE genotype on the elimination of extracellular solutes from the brain. Following intracortical injection of biotin-labeled tau into humanized apoE-Tr mice, the levels of exogenous tau residing in the brain of apoE4 mice were elevated compared to other isoforms, indicating reduced tau elimination. Additionally, we found exposure to r-mTBI increased tau residence in apoE2 mice, similar to our observations in E2FAD animals. Each of these findings may be the result of diminished tau efflux via LRP1 at the BBB, as LRP1 inhibition significantly reduced tau uptake in endothelial cells and decreased tau transit across an in vitro model of the BBB (basolateral-to-apical). Notably, we showed that injury and apoE status, (particularly apoE4) resulted in chronic alterations in BBB integrity, pericyte coverage, and AQP4 polarization. These aberrations coincided with an atypical reactive astrocytic gene signature indicative of diminished CSF-ISF exchange. Our work found that CSF movement was reduced in the chronic phase following r-mTBI (>18 months post injury) across all apoE genotypes. In summary, we show that apoE genotype strongly influences cerebrovascular homeostasis, which can lead to age-dependent deficiencies in the elimination of toxic proteins from the brain, like tau, particularly in the aftermath of head trauma.


Assuntos
Apolipoproteína E4 , Concussão Encefálica , Camundongos , Animais , Apolipoproteína E4/genética , Apolipoproteína E4/metabolismo , Camundongos Transgênicos , Células Endoteliais/metabolismo , Encéfalo/metabolismo , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Concussão Encefálica/metabolismo
3.
Sci Rep ; 13(1): 9782, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37328630

RESUMO

This paper presents a QV-based approach called Critical Voltage-Reactive Power Ratio (CVQR) index to assess the voltage instability tendencies of power system buses with increase in renewable energy (RE) penetration within the power system. The buses are thus ranked according to the order in which they are impacted by increase in renewable energy penetration. Simulations were performed using DIgSILENT PowerFactory and result analyses were done with MATLAB. The developed CVQR index has been employed to assess the effect of increasing RE generation on grid voltage stability. This index provides information on the voltage instability tendencies of all non-slack buses of the RE-integrated grid and the buses are ranked from the weakest to the strongest. The rankings obtained from the developed CVQR has been compared with five commonly-used indices and the result of the comparison verifies the accuracy of the proposed index. IEEE 14-bus and IEEE 39-bus New England systems have been used to evaluate the proposed CVQR index and various scenarios of RE system combinations and placements have been considered. Voltage collapse condition is indicated whenever the CVQR index associated with any bus becomes positive (CVQR > 0). This index can as well be applied to other power system networks. The overall ranking of the buses based on the CVQR index can provide insights on the most appropriate location for large inductive loads or compensating devices, which can either absorb or inject reactive power into the power system, thereby influencing the system's voltage stability.


Assuntos
Veículos Automotores , Energia Renovável , New England
4.
Mol Cell Neurosci ; 125: 103855, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37084991

RESUMO

Traumatic brain injury is a leading cause of morbidity and mortality in adults and children in developed nations. Following the primary injury, microglia, the resident innate immune cells of the CNS, initiate several inflammatory signaling cascades and pathophysiological responses that may persist chronically; chronic neuroinflammation following TBI has been closely linked to the development of neurodegeneration and neurological dysfunction. Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases that have been shown to regulate several key mechanisms in the inflammatory response to TBI. Increasing evidence has shown that the modulation of the PI3K/AKT signaling pathway has the potential to influence the cellular response to inflammatory stimuli. However, directly targeting PI3K signaling poses several challenges due to its regulatory role in several cell survival pathways. We have previously identified that the phosphatase and tensin homolog deleted on chromosome 10 (PTEN), the major negative regulator of PI3K/AKT signaling, is dysregulated following exposure to repetitive mild traumatic brain injury (r-mTBI). Moreover, this dysregulated PI3K/AKT signaling was correlated with chronic microglial-mediated neuroinflammation. Therefore, we interrogated microglial-specific PTEN as a therapeutic target in TBI by generating a microglial-specific, Tamoxifen inducible conditional PTEN knockout model using a CX3CR1 Cre recombinase mouse line PTENfl/fl/CX3CR1+/CreERT2 (mcg-PTENcKO), and exposed them to our 20-hit r-mTBI paradigm. Animals were treated with tamoxifen at 76 days post-last injury, and the effects of microglia PTEN deletion on immune-inflammatory responses were assessed at 90-days post last injury. We observed that the deletion of microglial PTEN ameliorated the proinflammatory response to repetitive brain trauma, not only reducing chronic microglial activation and proinflammatory cytokine production but also rescuing TBI-induced reactive astrogliosis, demonstrating that these effects extended beyond microglia alone. Additionally, we observed that the pharmacological inhibition of PTEN with BpV(HOpic) ameliorated the LPS-induced activation of microglial NFκB signaling in vitro. Together, these data provide support for the role of PTEN as a regulator of chronic neuroinflammation following repetitive mild TBI.


Assuntos
Lesões Encefálicas Traumáticas , Microglia , Animais , Camundongos , Lesões Encefálicas Traumáticas/metabolismo , Modelos Animais de Doenças , Inflamação/metabolismo , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Doenças Neuroinflamatórias , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
5.
Acta Neuropathol Commun ; 10(1): 147, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36258255

RESUMO

Chemical and pharmaceutical exposures have been associated with the development of Gulf War Illness (GWI), but how these factors interact with the pathophysiology of traumatic brain injury (TBI) remains an area of study that has received little attention thus far. We studied the effects of pyridostigmine bromide (an anti-nerve agent) and permethrin (a pesticide) exposure in a mouse model of repetitive mild TBI (r-mTBI), with 5 impacts over a 9-day period, followed by Gulf War (GW) toxicant exposure for 10 days beginning 30 days after the last head injury. We then assessed the chronic behavioral and pathological sequelae 5 months after GW agent exposure. We observed that r-mTBI and GWI cumulatively affect the spatial memory of mice in the Barnes maze and result in a shift of search strategies employed by r-mTBI/GW exposed mice. GW exposure also produced anxiety-like behavior in sham animals, but r-mTBI produced disinhibition in both the vehicle and GW treated mice. Pathologically, GW exposure worsened r-mTBI dependent axonal degeneration and neuroinflammation, increased oligodendrocyte cell counts, and increased r-mTBI dependent phosphorylated tau, which was found to colocalize with oligodendrocytes in the corpus callosum. These results suggest that GW exposures may worsen TBI-related deficits. Veterans with a history of both GW chemical exposures as well as TBI may be at higher risk for worse symptoms and outcomes. Subsequent exposure to various toxic substances can influence the chronic nature of mTBI and should be considered as an etiological factor influencing mTBI recovery.


Assuntos
Concussão Encefálica , Lesões Encefálicas Traumáticas , Praguicidas , Camundongos , Animais , Guerra do Golfo , Concussão Encefálica/complicações , Brometo de Piridostigmina/toxicidade , Permetrina/toxicidade , Modelos Animais de Doenças , Preparações Farmacêuticas
6.
Heliyon ; 8(8): e09988, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35991969

RESUMO

The study of the relationship between the Received Signal Strengths (RSS) from Unity TV (786 MHz) located at Rayfield (9.84 o North 8.89 o East), Jos, Plateau State and some atmospheric parameters with noise temperature has been done using two years half-hourly data. The measurement was carried from 5 am and 9 pm daily. The analysis was carried out using the regression, co-integration and Granger causality models. The results show that the RSS is higher in the morning hours (5.00 am-9.00 am) late in the evening (6.30 pm-9.00 pm) but lower between 9.00 am and 6.30 pm. This might be due to the "dusty" atmosphere and low reflection of ionosphere in the day time which causes signal attenuation within the day time. The correlation coefficients from the coefficient of determination (R squared) of 0.88, 0.004, 0.838. 0.25, 0.867, and 0.112, are -0.94, -0.07, 0.92, -0.50, -0.93, -0.334 for atmospheric temperature, pressure, relative humidity, wind speed, noise temperature and rainfall respectively. It means all the independent variables except relative humidity are inversely proportional with the RSS. Also, the higher R2 values for atmospheric temperature, relative humidity and noise temperature respectively, indicates higher correlation between RSS and these parameters. It can be inferred that the models are suitable for predicting Unity TV (UTV) signal strength and that of other TV stations in Jos and environs, using T, RH and NT as inputs. The results also showed that there is a co-integration and Granger Causal relationship between the parameters and RSS. The result will find applications to the Nigeria Broadcasting Commission in the assigning of frequencies taking atmospheric parameters into considerations, Radio Engineers and Scientists, Satellite link designers, and mobile communication experts for the link budget design and appropriate equipment deployment based on the atmospheric condition on the geographical areas.

7.
Fluids Barriers CNS ; 18(1): 48, 2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34702292

RESUMO

Repetitive head trauma has been associated with the accumulation of tau species in the brain. Our prior work showed brain vascular mural cells contribute to tau processing in the brain, and that these cells progressively degenerate following repetitive mild traumatic brain injury (r-mTBI). The current studies investigated the role of the cerebrovasculature in the elimination of extracellular tau from the brain, and the influence of r-mTBI on these processes. Following intracranial injection of biotin-labeled tau, the levels of exogenous labeled tau residing in the brain were elevated in a mouse model of r-mTBI at 12 months post-injury compared to r-sham mice, indicating reduced tau elimination from the brain following head trauma. This may be the result of decreased caveolin-1 mediated tau efflux at the blood-brain barrier (BBB), as the caveolin inhibitor, methyl-ß-cyclodextrin, significantly reduced tau uptake in isolated cerebrovessels and significantly decreased the basolateral-to-apical transit of tau across an in vitro model of the BBB. Moreover, we found that the upstream regulator of endothelial caveolin-1, Mfsd2a, was elevated in r-mTBI cerebrovessels compared to r-sham, which coincided with a decreased expression of cerebrovascular caveolin-1 in the chronic phase following r-mTBI (> 3 months post-injury). Lastly, angiopoietin-1, a mural cell-derived protein governing endothelial Mfsd2a expression, was secreted from r-mTBI cerebrovessels to a greater extent than r-sham animals. Altogether, in the chronic phase post-injury, release of angiopoietin-1 from degenerating mural cells downregulates caveolin-1 expression in brain endothelia, resulting in decreased tau elimination across the BBB, which may describe the accumulation of tau species in the brain following head trauma.


Assuntos
Barreira Hematoencefálica/metabolismo , Lesões Encefálicas Traumáticas/metabolismo , Proteínas tau/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL
8.
Mol Brain ; 14(1): 110, 2021 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-34238312

RESUMO

Cerebrovascular dysfunction is a hallmark feature of Alzheimer's disease (AD). One of the greatest risk factors for AD is the apolipoprotein E4 (E4) allele. The APOE4 genotype has been shown to negatively impact vascular amyloid clearance, however, its direct influence on the molecular integrity of the cerebrovasculature compared to other APOE variants (APOE2 and APOE3) has been largely unexplored. To address this, we employed a 10-plex tandem isobaric mass tag approach in combination with an ultra-high pressure liquid chromatography MS/MS (Q-Exactive) method, to interrogate unbiased proteomic changes in cerebrovessels from AD and healthy control brains with different APOE genotypes. We first interrogated changes between healthy control cases to identify underlying genotype specific effects in cerebrovessels. EIF2 signaling, regulation of eIF4 and 70S6K signaling and mTOR signaling were the top significantly altered pathways in E4/E4 compared to E3/E3 cases. Oxidative phosphorylation, EIF2 signaling and mitochondrial dysfunction were the top significant pathways in E2E2 vs E3/E3cases. We also identified AD-dependent changes and their interactions with APOE genotype and found the highest number of significant proteins from this interaction was observed in the E3/E4 (192) and E4/E4 (189) cases. As above, EIF2, mTOR signaling and eIF4 and 70S6K signaling were the top three significantly altered pathways in E4 allele carriers (i.e. E3/E4 and E4/E4 genotypes). Of all the cerebrovascular cell-type specific markers identified in our proteomic analyses, endothelial cell, astrocyte, and smooth muscle cell specific protein markers were significantly altered in E3/E4 cases, while endothelial cells and astrocyte specific protein markers were altered in E4/E4 cases. These proteomic changes provide novel insights into the longstanding link between APOE4 and cerebrovascular dysfunction, implicating a role for impaired autophagy, ER stress, and mitochondrial bioenergetics. These APOE4 dependent changes we identified could provide novel cerebrovascular targets for developing disease modifying strategies to mitigate the effects of APOE4 genotype on AD pathogenesis.


Assuntos
Envelhecimento/patologia , Doença de Alzheimer/genética , Apolipoproteínas E/genética , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Demência/genética , Predisposição Genética para Doença , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Proteoma/metabolismo , Proteômica , Frações Subcelulares/metabolismo
9.
Front Aging Neurosci ; 13: 658605, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34079449

RESUMO

Cerebrovascular dysfunction and cerebral amyloid angiopathy (CAA) are hallmark features of Alzheimer's disease (AD). Molecular damage to cerebrovessels in AD may result in alterations in vascular clearance mechanisms leading to amyloid deposition around blood vessels and diminished neurovascular-coupling. The sequelae of molecular events leading to these early pathogenic changes remains elusive. To address this, we conducted a comprehensive in-depth molecular characterization of the proteomic changes in enriched cerebrovessel fractions isolated from the inferior frontal gyrus of autopsy AD cases with low (85.5 ± 2.9 yrs) vs. high (81 ± 4.4 yrs) CAA score, aged-matched control (87.4 ± 1.5 yrs) and young healthy control (47 ± 3.3 yrs) cases. We employed a 10-plex tandem isobaric mass tag approach in combination with our ultra-high pressure liquid chromatography MS/MS (Q-Exactive) method. Enriched cerebrovascular fractions showed very high expression levels of proteins specific to endothelial cells, mural cells (pericytes and smooth muscle cells), and astrocytes. We observed 150 significantly regulated proteins in young vs. aged control cerebrovessels. The top pathways significantly modulated with aging included chemokine, reelin, HIF1α and synaptogenesis signaling pathways. There were 213 proteins significantly regulated in aged-matched control vs. high CAA cerebrovessels. The top three pathways significantly altered from this comparison were oxidative phosphorylation, Sirtuin signaling pathway and TCA cycle II. Comparison between low vs. high CAA cerebrovessels identified 84 significantly regulated proteins. Top three pathways significantly altered between low vs. high CAA cerebrovessels included TCA Cycle II, Oxidative phosphorylation and mitochondrial dysfunction. Notably, high CAA cases included more advanced AD pathology thus cerebrovascular effects may be driven by the severity of amyloid and Tangle pathology. These descriptive proteomic changes provide novel insights to explain the age-related and AD-related cerebrovascular changes contributing to AD pathogenesis. Particularly, disturbances in energy bioenergetics and mitochondrial biology rank among the top AD pathways altered in cerebrovessels. Targeting these failed mechanisms in endothelia and mural cells may provide novel disease modifying targets for developing therapeutic strategies against cerebrovascular deterioration and promoting cerebral perfusion in AD. Our future work will focus on interrogating and validating these novel targets and pathways and their functional significance.

10.
Neurobiol Dis ; 150: 105237, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33383188

RESUMO

A pathological characteristic of repetitive traumatic brain injury (TBI) is the deposition of hyperphosphorylated and aggregated tau species in the brain and increased levels of extracellular monomeric tau are believed to play a role in the pathogenesis of neurodegenerative tauopathies. The pathways by which extracellular tau is eliminated from the brain, however, remains elusive. The purpose of this study was to examine tau uptake by cerebrovascular cells and the effect of TBI on these processes. We found monomeric tau interacts with brain vascular mural cells (pericytes and smooth muscle cells) to a greater extent than other cerebrovascular cells, indicating mural cells may contribute to the elimination of extracellular tau, as previously described for other solutes such as beta-amyloid. Consistent with other neurodegenerative disorders, we observed a progressive decline in cerebrovascular mural cell markers up to 12 months post-injury in a mouse model of repetitive mild TBI (r-mTBI) and human TBI brain specimens, when compared to control. These changes appear to reflect mural cell degeneration and not cellular loss as no difference in the mural cell population was observed between r-mTBI and r-sham animals as determined through flow cytometry. Moreover, freshly isolated r-mTBI cerebrovessels showed reduced tau uptake at 6 and 12 months post-injury compared to r-sham animals, which may be the result of diminished cerebrovascular endocytosis, as caveolin-1 levels were significantly decreased in mouse r-mTBI and human TBI cerebrovessels compared to their respective controls. Further emphasizing the interaction between mural cells and tau, similar reductions in mural cell markers, tau uptake, and caveolin-1 were observed in cerebrovessels from transgenic mural cell-depleted animals. In conclusion, our studies indicate repeated injuries to the brain causes chronic mural cell degeneration, reducing the caveolar-mediated uptake of tau by these cells. Alterations in tau uptake by vascular mural cells may contribute to tau deposition in the brain following head trauma and could represent a novel therapeutic target for TBI or other neurodegenerative disorders.


Assuntos
Doença de Alzheimer/metabolismo , Concussão Encefálica/metabolismo , Encéfalo/metabolismo , Células Endoteliais/metabolismo , Microglia/metabolismo , Miócitos de Músculo Liso/metabolismo , Pericitos/metabolismo , Proteínas tau/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Animais , Encéfalo/irrigação sanguínea , Caveolina 1/metabolismo , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Músculo Liso Vascular/citologia , Presenilina-1/genética , Recidiva
11.
Sci Rep ; 11(1): 24526, 2021 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-34972819

RESUMO

This paper investigates the application of large-scale solar photovoltaic (SPV) system for voltage stability improvement of weak national grids. Large-scale SPV integration has been investigated on the Nigerian power system to enhance voltage stability and as a viable alternative to the aged shunt reactors currently being used in the Nigerian national grid to mitigate overvoltage issues in Northern Nigeria. Two scenarios of increasing SPV penetration level (PL) are investigated in this work, namely, centralized large-scale SPV at the critical bus and dispersed large-scale SPV across the weak buses. The voltage stability of the system is evaluated using the active power margin (APM) also called megawatt margin (MWM) derived from Active Power-Voltage (P-V) analysis, the reactive power margin (RPM) and the associated critical voltage-reactive power ratio (CVQR) index obtained from Reactive Power-Voltage (Q-V) analysis. All simulations are carried out in DIgSILENT PowerFactory software and result analyses done with MATLAB. The results show that with centralized SPV generation for the case study system, the highest bus voltage is able to fall within acceptable limits at 26.29% (1000 MW), while the dispersed SPV achieves this at 21.44% (800 MW). Also, the dispersed SPV scenario provides better voltage stability improvement for the system as indicated by the MWM, RPM and the CVQR index of the system. Therefore, this work provides a baseline insight on the potential application of large-scale SPV in weak grids such as the Nigerian case to address the voltage stability problems in the power system while utilizing the abundant solar resource to meet the increasing energy demand.

12.
J Cereb Blood Flow Metab ; 41(6): 1362-1378, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33050825

RESUMO

Incidences of repetitive mild TBI (r-mTBI), like those sustained by contact sports athletes and military personnel, are thought to be a risk factor for development of neurodegenerative disorders. Those suffering from chronic TBI-related illness demonstrate deficits in cerebrovascular reactivity (CVR), the ability of the cerebral vasculature to respond to a vasoactive stimulus. CVR is thus an important measure of traumatic cerebral vascular injury (TCVI), and a possible in vivo endophenotype of TBI-related neuropathogenesis. We combined laser speckle imaging of CVR in response to hypercapnic challenge with neurobehavioral assessment of learning and memory, to investigate if decreased cerebrovascular responsiveness underlies impaired cognitive function in our mouse model of chronic r-mTBI. We demonstrate a profile of blunted hypercapnia-evoked CVR in the cortices of r-mTBI mice like that of human TBI, alongside sustained memory and learning impairment, without biochemical or immunohistopathological signs of cerebral vessel laminar or endothelium constituent loss. Transient decreased expression of alpha smooth muscle actin and platelet-derived growth factor receptor ß, indicative of TCVI, is obvious only at the time of the most pronounced CVR deficit. These findings implicate CVR as a valid preclinical measure of TCVI, perhaps useful for developing therapies targeting TCVI after recurrent mild head trauma.


Assuntos
Concussão Encefálica/fisiopatologia , Circulação Cerebrovascular/fisiologia , Hipercapnia/fisiopatologia , Animais , Modelos Animais de Doenças , Hipercapnia/complicações , Masculino , Camundongos , Camundongos Endogâmicos C57BL
13.
Artigo em Inglês | MEDLINE | ID: mdl-32682873

RESUMO

The lack of progress in the psychopharmacological treatment of stress-related disorders such as PTSD is an ongoing crisis due to its negative socioeconomic implications. Current PTSD pharmacotherapy relies on a few FDA approved medications used primarily for depression which offer only symptomatic relief and show limited efficacy. As the population of PTSD patients is growing, the identification of effective etiology-based treatments for the condition is a high priority. This requires an in-depth understanding of the neurobiological and behavioral outcomes of stress in translationally relevant animal models. In this study, we use neuroendocrine, biochemical and behavioral measures to assess the HPA axis function and fear-memory deficits in a mouse model of chronic stress. The chronic stress procedures involved exposure to 21 days of repeated unpredictable stress (RUS), including predator stress, restraint and foot shock, followed by chronic social isolation. We show that mice exposed to our stress paradigm demonstrate exaggerated fear memory recall and blunted HPA axis functionality at one month after RUS. Our neuroendocrinal testing suggests that the attenuated stress response in our model may be related to an alteration in the adrenal MC2 receptor reactivity. While there was no noticeable change in pituitary negative feedback regulation mechanisms, CRH and phosphorylated Glucocorticoid receptors levels were altered in the hypothalamus. We also show that chronic supplementation with a peripheral glucocorticoid receptor agonist (low-dose dexamethasone) after RUS partially restores a number of stress-related behavioral deficits in the RUS model. This suggests a direct relationship between HPA axis function and behavior in our model. Our findings emphasize the importance of the adrenal receptors as a target for HPA axis dysfunction in stress and fear-related disorders.


Assuntos
Medo/fisiologia , Sistema Hipotálamo-Hipofisário/metabolismo , Memória/fisiologia , Sistema Hipófise-Suprarrenal/metabolismo , Isolamento Social , Estresse Psicológico/sangue , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Corticosterona/sangue , Dexametasona/farmacologia , Dexametasona/uso terapêutico , Medo/efeitos dos fármacos , Medo/psicologia , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Masculino , Memória/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Isolamento Social/psicologia , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/psicologia
14.
BMC Neurol ; 20(1): 317, 2020 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-32854643

RESUMO

BACKGROUND: The ventricular system plays a vital role in blood-cerebrospinal fluid (CSF) exchange and interstitial fluid-CSF drainage pathways. CSF is formed in the specialized secretory tissue called the choroid plexus, which consists of epithelial cells, fenestrated capillaries and the highly vascularized stroma. Very little is currently known about the role played by the ventricles and the choroid plexus tissue in aging and Alzheimer's disease (AD). METHODS: In this study, we used our state-of-the-art proteomic platform, a liquid chromatography/mass spectrometry (LC-MS/MS) approach coupled with Tandem Mass Tag isobaric labeling to conduct a detailed unbiased proteomic analyses of autopsied tissue isolated from the walls of the inferior horn of the lateral ventricles in AD (77.2 ± 0.6 yrs), age-matched controls (77.0 ± 0.5 yrs), and nonagenarian cases (93.2 ± 1.1 yrs). RESULTS: Ingenuity pathway analyses identified phagosome maturation, impaired tight-junction signaling, and glucose/mannose metabolism as top significantly regulated pathways in controls vs nonagenarians. In matched-control vs AD cases we identified alterations in mitochondrial bioenergetics, oxidative stress, remodeling of epithelia adherens junction, macrophage recruitment and phagocytosis, and cytoskeletal dynamics. Nonagenarian vs AD cases demonstrated augmentation of oxidative stress, changes in gluconeogenesis-glycolysis pathways, and cellular effects of choroidal smooth muscle cell vasodilation. Amyloid plaque score uniquely correlated with remodeling of epithelial adherens junctions, Fc γ-receptor mediated phagocytosis, and alterations in RhoA signaling. Braak staging was uniquely correlated with altered iron homeostasis, superoxide radical degradation and phagosome maturation. CONCLUSIONS: These changes provide novel insights to explain the compromise to the physiological properties and function of the ventricles/choroid plexus system in nonagenarian aging and AD pathogenesis. The pathways identified could provide new targets for therapeutic strategies to mitigate the divergent path towards AD.


Assuntos
Doença de Alzheimer/fisiopatologia , Encéfalo/patologia , Ventrículos Laterais/patologia , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Doença de Alzheimer/líquido cefalorraquidiano , Ventrículos Cerebrais/patologia , Plexo Corióideo/patologia , Cromatografia Líquida , Feminino , Humanos , Masculino , Placa Amiloide/patologia , Proteômica , Espectrometria de Massas em Tandem
15.
Neurotoxicology ; 79: 84-94, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32343995

RESUMO

Gulf War Illness (GWI) affects 30% of veterans from the 1991 Gulf War (GW), who suffer from symptoms that reflect ongoing mitochondria dysfunction. Brain mitochondria bioenergetics dysfunction in GWI animal models corresponds with astroglia activation and neuroinflammation. In a pilot study of GW veterans (n = 43), we observed that blood nicotinamide adenine dinucleotide (NAD) and sirtuin 1 (Sirt1) protein levels were decreased in the blood of veterans with GWI compared to healthy GW veterans. Since nicotinamide riboside (NR)-mediated targeting of Sirt1 is shown to improve mitochondria function, we tested whether NR can restore brain bioenergetics and reduce neuroinflammation in a GWI mouse model. We administered a mouse diet supplemented with NR at 100µg/kg daily for 2-months to GWI and control mice (n = 27). During treatment, mice were assessed for fatigue-type behavior using the Forced Swim Test (FST), followed by euthanasia for biochemistry and immunohistochemistry analyses. Fatigue-type behavior was elevated in GWI mice compared to control mice and lower in GWI mice treated with NR compared to untreated GWI mice. Levels of plasma NAD and brain Sirt1 were low in untreated GWI mice, while GWI mice treated with NR had higher levels, similar to those of control mice. Deacetylation of the nuclear-factor κB (NFκB) p65 subunit and peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α) was an increase in the brains of NR-treated GWI mice. This corresponded with a decrease in pro-inflammatory cytokines and lipid peroxidation and an increase in markers of mitochondrial bioenergetics in the brains of GWI mice. These findings suggest that targeting NR mediated Sirt1 activation restores brain bioenergetics and reduces inflammation in GWI mice. Further evaluation of NR in GWI is warranted to determine its potential efficacy in treating GWI.


Assuntos
Anti-Inflamatórios/farmacologia , Encéfalo/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Niacinamida/análogos & derivados , Síndrome do Golfo Pérsico/tratamento farmacológico , Compostos de Piridínio/farmacologia , Sirtuína 1/metabolismo , Idoso , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Comportamento Animal/efeitos dos fármacos , Encéfalo/enzimologia , Encéfalo/fisiopatologia , Estudos de Casos e Controles , Modelos Animais de Doenças , Fadiga/tratamento farmacológico , Fadiga/enzimologia , Fadiga/fisiopatologia , Fadiga/psicologia , Feminino , Guerra do Golfo , Humanos , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , NAD/sangue , Niacinamida/farmacologia , Biogênese de Organelas , Estresse Oxidativo/efeitos dos fármacos , Síndrome do Golfo Pérsico/enzimologia , Síndrome do Golfo Pérsico/fisiopatologia , Síndrome do Golfo Pérsico/psicologia , Projetos Piloto , Sirtuína 1/sangue , Saúde dos Veteranos
17.
Neuromolecular Med ; 22(2): 331, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32078110

RESUMO

The original version of this article unfortunately contained a mistake. Gary S. Laco should not be listed as an author in the author group.

18.
J Appl Entomol ; 143(6): 683-692, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31423052

RESUMO

The flower bud thrips, Megalurothrips sjostedti Trybom (Thysanoptera: Thripidae), is an economically important pest of cowpea in sub-Saharan Africa. Varietal resistance is the most preferred, environmentally friendly, cost-effective and sustainable option for controlling this pest. The objective of this study was to identify sources of resistance to M. sjostedti among mini core accessions from the largest world cowpea germplasm collection maintained at the International Institute of Tropical Agriculture (IITA). The study was conducted during the 2015 and 2016 cropping seasons where 365 accessions were screened under field conditions. Each accession was rated visually for thrips damage score, flower abortion rate, number of pods per plant and number of thrips per flower. The resistance levels observed in genotypes TVu8631, TVu16368, TVu8671 and TVu7325 were similar to that of the resistant check "Sanzisabinli" (called Sanzi) during both seasons. In addition, 56 mini core genotypes showed moderate resistance to thrips damage. High heritability values were associated with thrips damage scores at 65 days after planting (0.60), percentage of effective peduncles (0.59), flower bud abortion rate (0.59), number of pods per plant (0.51) and number of peduncles with pods (0.5). The accessions identified with good levels of resistance to flower bud thrips will be used in cowpea breeding programs to develop improved resistant varieties.

19.
Sci Rep ; 9(1): 11011, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31337781

RESUMO

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

20.
Brain Behav Immun ; 81: 545-559, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31325531

RESUMO

Gulf War Illness (GWI), affecting 30% of veterans from the 1991 Gulf War (GW), is a multi-symptom illness with features similar to those of patients with autoimmune diseases. The objective of the current work is to determine if exposure to GW-related pesticides, such as permethrin (PER), activates peripheral and central nervous system (CNS) adaptive immune responses. In the current study, we focused on a PER metabolite, 3-phenoxybenzoic acid (3-PBA), as this is a common metabolite previously shown to form adducts with endogenous proteins. We observed the presence of 3-PBA and 3-PBA modified lysine of protein peptides in the brain, blood and liver of pyridostigmine bromide (PB) and  PER (PB+PER) exposed mice at acute and chronic post-exposure timepoints. We tested whether 3-PBA-haptenated albumin (3-PBA-albumin) can activate immune cells since it is known that chemically haptenated proteins can stimulate immune responses. We detected autoantibodies against 3-PBA-albumin in plasma from PB + PER exposed mice and veterans with GWI at chronic post-exposure timepoints. We also observed that in vitro treatment of blood with 3-PBA-albumin resulted in the activation of B- and T-helper lymphocytes and that these immune cells were also increased in blood of PB + PER exposed mice and veterans with GWI. These immune changes corresponded with elevated levels of infiltrating monocytes in the brain and blood of PB + PER exposed mice which coincided with alterations in the markers of blood-brain barrier disruption, brain macrophages and neuroinflammation. These studies suggest that pesticide exposure associated with GWI may have resulted in the activation of the peripheral and CNS adaptive immune responses, possibly contributing to an autoimmune-type phenotype in veterans with GWI.


Assuntos
Imunidade Adaptativa/efeitos dos fármacos , Permetrina/efeitos adversos , Síndrome do Golfo Pérsico/metabolismo , Adulto , Animais , Benzoatos/análise , Encéfalo/metabolismo , Sistema Nervoso Central/metabolismo , Modelos Animais de Doenças , Feminino , Guerra do Golfo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Permetrina/metabolismo , Síndrome do Golfo Pérsico/fisiopatologia , Brometo de Piridostigmina/efeitos adversos , Brometo de Piridostigmina/metabolismo , Veteranos
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