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1.
Artigo em Inglês | MEDLINE | ID: mdl-37941895

RESUMO

Viola L. is the largest genus of the Violaceae family with more than 500 species across the globe. The present extensive literature survey revealed Viola species to be a group of important nutritional and medicinal plants used for the ethnomedicinal treatment of noncommunicable diseases (NCDs) such as diabetes, asthma, lung diseases, and fatigue. Many plant species of this genus have also received scientific validation of their pharmacological activities including neuroprotective, immunomodulatory, anticancer, antihypertensive, antidyslipidemic, analgesic, antipyretic, diuretic, anti-inflammatory, anthelmintic, and antioxidant. Viola is highly rich in different natural products some of which have been isolated and identified in the past few decades; these include flavonoids terpenoids and phenylpropanoids of different pharmacological activities. The pharmacokinetics and clinical studies on this genus are lacking, and the present review is aimed at summarizing the current understanding of the ethnopharmacology, phytochemistry, nutritional composition, and pharmacological profile of medicinal plants from the Viola genus to reveal its therapeutic potentials, gaps, and subsequently open a new window for future pharmacological research.

2.
Cell Rep ; 42(11): 113333, 2023 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-37897724

RESUMO

Motor neuron (MN) development and nerve regeneration requires orchestrated action of a vast number of molecules. Here, we identify SorCS2 as a progranulin (PGRN) receptor that is required for MN diversification and axon outgrowth in zebrafish and mice. In zebrafish, SorCS2 knockdown also affects neuromuscular junction morphology and fish motility. In mice, SorCS2 and PGRN are co-expressed by newborn MNs from embryonic day 9.5 until adulthood. Using cell-fate tracing and nerve segmentation, we find that SorCS2 deficiency perturbs cell-fate decisions of brachial MNs accompanied by innervation deficits of posterior nerves. Additionally, adult SorCS2 knockout mice display slower motor nerve regeneration. Interestingly, primitive macrophages express high levels of PGRN, and their interaction with SorCS2-positive motor axon is required during axon pathfinding. We further show that SorCS2 binds PGRN to control its secretion, signaling, and conversion into granulins. We propose that PGRN-SorCS2 signaling controls MN development and regeneration in vertebrates.


Assuntos
Peptídeos e Proteínas de Sinalização Intercelular , Peixe-Zebra , Camundongos , Animais , Progranulinas , Peixe-Zebra/metabolismo , Neurônios Motores/metabolismo , Granulinas , Camundongos Knockout , Proteínas do Tecido Nervoso/metabolismo , Receptores de Superfície Celular/metabolismo
3.
Front Mol Neurosci ; 16: 1179209, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37456526

RESUMO

Classic experiments with peripheral sympathetic neurons established an absolute dependence upon NGF for survival. A forgotten problem is how these neurons become resistant to deprivation of trophic factors. The question is whether and how neurons can survive in the absence of trophic support. However, the mechanism is not understood how neurons switch their phenotype to lose their dependence on trophic factors, such as NGF and BDNF. Here, we approach the problem by considering the requirements for trophic support of peripheral sympathetic neurons and hippocampal neurons from the central nervous system. We developed cellular assays to assess trophic factor dependency for sympathetic and hippocampal neurons and identified factors that rescue neurons in the absence of trophic support. They include enhanced expression of a subunit of the NGF receptor (Neurotrophin Receptor Homolog, NRH) in sympathetic neurons and an increase of the expression of the glucocorticoid receptor in hippocampal neurons. The results are significant since levels and activity of trophic factors are responsible for many neuropsychiatric conditions. Resistance of neurons to trophic factor deprivation may be relevant to the underlying basis of longevity, as well as an important element in preventing neurodegeneration.

4.
iScience ; 26(4): 106545, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37128547

RESUMO

Alzheimer's disease (AD) is characterized by neurodegeneration, memory loss, and social withdrawal. Brain inflammation has emerged as a key pathogenic mechanism in AD. We hypothesized that oxytocin, a pro-social hypothalamic neuropeptide with anti-inflammatory properties, could have therapeutic actions in AD. Here, we investigated oxytocin expression in experimental models of AD, and evaluated the therapeutic potential of treatment with oxytocin. Amyloid-ß peptide oligomers (AßOs) reduced oxytocin expression in vitro and in vivo, and treatment with oxytocin prevented microglial activation induced by AßOs in purified microglial cultures. Treatment of aged APP/PS1 mice, a mouse model of AD, with intranasal oxytocin attenuated microglial activation and favored deposition of Aß in dense core plaques, a potentially neuroprotective mechanism. Remarkably, treatment with oxytocin alleviated social and non-social memory impairments in aged APP/PS1 mice. Our findings point to oxytocin as a potential therapeutic target to reduce brain inflammation and correct memory deficits in AD.

5.
bioRxiv ; 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37066303

RESUMO

Astrocytes are a highly abundant glial cell type that perform critical homeostatic functions in the central nervous system. Like neurons, astrocytes have many discrete heterogenous subtypes. The subtype identity and functions are, at least in part, associated with their anatomical location and can be highly restricted to strategically important anatomical domains. Here, we report that astrocytes forming the glia limitans superficialis, the outermost border of brain and spinal cord, are a highly specialized astrocyte subtype and can be identified by a single marker: Myocilin (Myoc). We show that Myoc+ astrocytes cover the entire brain and spinal cord surface, exhibit an atypical morphology, and are evolutionarily conserved from rodents to humans. Identification of this highly specialized astrocyte subtype will advance our understanding of CNS homeostasis and potentially be targeted for therapeutic intervention to combat peripheral inflammatory effects on the CNS.

6.
Res Sq ; 2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-37034806

RESUMO

Oxytocin is a neuropeptide critical for maternal physiology and social behavior, and is thought to be dysregulated in several neuropsychiatric disorders. Despite the biological and neurocognitive importance of oxytocin signaling, methods are lacking to activate oxytocin receptors with high spatiotemporal precision in the brain and peripheral mammalian tissues. Here we developed and validated caged analogs of oxytocin which are functionally inert until cage release is triggered by ultraviolet light. We examined how focal versus global oxytocin application affected oxytocin-driven Ca2+ wave propagation in mouse mammary tissue. We also validated the application of caged oxytocin in the hippocampus and auditory cortex with electrophysiological recordings in vitro, and demonstrated that oxytocin uncaging can accelerate the onset of mouse maternal behavior in vivo. Together, these results demonstrate that optopharmacological control of caged peptides is a robust tool with spatiotemporal precision for modulating neuropeptide signaling throughout the brain and body.

7.
Front Mol Neurosci ; 15: 891537, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35721318

RESUMO

Brain-derived Neurotrophic Factor (BDNF) binds to the TrkB tyrosine kinase receptor, which dictates the sensitivity of neurons to BDNF. A unique feature of TrkB is the ability to be activated by small molecules in a process called transactivation. Here we report that the brain neuropeptide oxytocin increases BDNF TrkB activity in primary cortical neurons and in the mammalian neocortex during postnatal development. Oxytocin produces its effects through a G protein-coupled receptor (GPCR), however, the receptor signaling events that account for its actions have not been fully defined. We find oxytocin rapidly transactivates TrkB receptors in bath application of acute brain slices of 2-week-old mice and in primary cortical culture by increasing TrkB receptor tyrosine phosphorylation. The effects of oxytocin signaling could be distinguished from the related vasopressin receptor. The transactivation of TrkB receptors by oxytocin enhances the clustering of gephyrin, a scaffold protein responsible to coordinate inhibitory responses. Because oxytocin displays pro-social functions in maternal care, cognition, and social attachment, it is currently a focus of therapeutic strategies in autism spectrum disorders. Interestingly, oxytocin and BDNF are both implicated in the pathophysiology of depression, schizophrenia, anxiety, and cognition. These results imply that oxytocin may rely upon crosstalk with BDNF signaling to facilitate its actions through receptor transactivation.

8.
J Neurosci ; 42(23): 4725-4736, 2022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35577554

RESUMO

Physical exercise improves motor performance in individuals with Parkinson's disease and elevates mood in those with depression. Although underlying factors have not been identified, clues arise from previous studies showing a link between cognitive benefits of exercise and increases in brain-derived neurotrophic factor (BDNF). Here, we investigated the influence of voluntary wheel-running exercise on BDNF levels in the striatum of young male wild-type (WT) mice, and on the striatal release of a key motor-system transmitter, dopamine (DA). Mice were allowed unlimited access to a freely rotating wheel (runners) or a locked wheel (controls) for 30 d. Electrically evoked DA release was quantified in ex vivo corticostriatal slices from these animals using fast-scan cyclic voltammetry. We found that exercise increased BDNF levels in dorsal striatum (dStr) and increased DA release in dStr and in nucleus accumbens core and shell. Increased DA release was independent of striatal acetylcholine (ACh), and persisted after a week of rest. We tested a role for BDNF in the influence of exercise on DA release using mice that were heterozygous for BDNF deletion (BDNF+/-). In contrast to WT mice, evoked DA release did not differ between BDNF+/- runners and controls. Complementary pharmacological studies using a tropomyosin receptor kinase B (TrkB) agonist in WT mouse slices showed that TrkB receptor activation also increased evoked DA release throughout striatum in an ACh-independent manner. Together, these data support a causal role for BDNF in exercise-enhanced striatal DA release and provide mechanistic insight into the beneficial effects of exercise in neuropsychiatric disorders, including Parkinson's, depression, and anxiety.SIGNIFICANCE STATEMENT Exercise has been shown to improve movement and cognition in humans and rodents. Here, we report that voluntary exercise for 30 d leads to an increase in evoked DA release throughout the striatum and an increase in BDNF in the dorsal (motor) striatum. The increase in DA release appears to require BDNF, indicated by the absence of DA release enhancement with running in BDNF+/- mice. Activation of BDNF receptors using a pharmacological agonist was also shown to boost DA release. Together, these data support a necessary and sufficient role for BDNF in exercise-enhanced DA release and provide mechanistic insight into the reported benefits of exercise in individuals with dopamine-linked neuropsychiatric disorders, including Parkinson's disease and depression.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Dopamina , Doença de Parkinson , Acetilcolina/farmacologia , Animais , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Corpo Estriado , Dopamina/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Núcleo Accumbens
9.
J Neurosci ; 42(19): 3919-3930, 2022 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-35361702

RESUMO

The molecular mechanisms underlying somatodendritic dopamine (DA) release remain unresolved, despite the passing of decades since its discovery. Our previous work showed robust release of somatodendritic DA in submillimolar extracellular Ca2+ concentration ([Ca2+]o). Here we tested the hypothesis that the high-affinity Ca2+ sensor synaptotagmin 7 (Syt7), is a key determinant of somatodendritic DA release and its Ca2+ dependence. Somatodendritic DA release from SNc DA neurons was assessed using whole-cell recording in midbrain slices from male and female mice to monitor evoked DA-dependent D2 receptor-mediated inhibitory currents (D2ICs). Single-cell application of an antibody to Syt7 (Syt7 Ab) decreased pulse train-evoked D2ICs, revealing a functional role for Syt7. The assessment of the Ca2+ dependence of pulse train-evoked D2ICs confirmed robust DA release in submillimolar [Ca2+]o in wild-type (WT) neurons, but loss of this sensitivity with intracellular Syt7 Ab or in Syt7 knock-out (KO) mice. In millimolar [Ca2+]o, pulse train-evoked D2ICs in Syt7 KOs showed a greater reduction in decreased [Ca2+]o than seen in WT mice; the effect on single pulse-evoked DA release, however, did not differ between genotypes. Single-cell application of a Syt1 Ab had no effect on train-evoked D2ICs in WT SNc DA neurons, but did cause a decrease in D2IC amplitude in Syt7 KOs, indicating a functional substitution of Syt1 for Syt7. In addition, Syt1 Ab decreased single pulse-evoked D2ICs in WT cells, indicating the involvement of Syt1 in tonic DA release. Thus, Syt7 and Syt1 play complementary roles in somatodendritic DA release from SNc DA neurons.SIGNIFICANCE STATEMENT The respective Ca2+ dependence of somatodendritic and axonal dopamine (DA) release differs, resulting in the persistence of somatodendritic DA release in submillimolar Ca2+ concentrations too low to support axonal release. We demonstrate that synaptotagmin7 (Syt7), a high-affinity Ca2+ sensor, underlies phasic somatodendritic DA release and its Ca2+ sensitivity in the substantia nigra pars compacta. In contrast, we found that synaptotagmin 1 (Syt1), the Ca2+ sensor underlying axonal DA release, plays a role in tonic, but not phasic, somatodendritic DA release in wild-type mice. However, Syt1 can facilitate phasic DA release after Syt7 deletion. Thus, we show that both Syt1 and Syt7 act as Ca2+ sensors subserving different aspects of somatodendritic DA release processes.


Assuntos
Dopamina , Substância Negra , Sinaptotagmina I , Sinaptotagminas , Animais , Dendritos , Dopamina/farmacologia , Neurônios Dopaminérgicos , Estimulação Elétrica , Feminino , Masculino , Camundongos , Sinaptotagmina I/genética , Sinaptotagminas/genética
10.
EMBO Rep ; 23(2): e53543, 2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-34842321

RESUMO

Single-cell RNA sequencing (scRNA-seq) is a powerful technique for dissecting the complexity of normal and diseased tissues, enabling characterization of cell diversity and heterogeneous phenotypic states in unprecedented detail. However, this technology has been underutilized for exploring the interactions between the host cell and viral pathogens in latently infected cells. Herein, we use scRNA-seq and single-molecule sensitivity fluorescent in situ hybridization (smFISH) technologies to investigate host single-cell transcriptome changes upon the reactivation of a human neurotropic virus, herpes simplex virus-1 (HSV-1). We identify the stress sensor growth arrest and DNA damage-inducible 45 beta (Gadd45b) as a critical antiviral host factor that regulates HSV-1 reactivation events in a subpopulation of latently infected primary neurons. We show that distinct subcellular localization of Gadd45b correlates with the viral late gene expression program, as well as the expression of the viral transcription factor, ICP4. We propose that a hallmark of a "successful" or "aborted" HSV-1 reactivation state in primary neurons is determined by a unique subcellular localization signature of the stress sensor Gadd45b.


Assuntos
Antígenos de Diferenciação/metabolismo , Herpesvirus Humano 1 , Neurônios/virologia , Ativação Viral , Latência Viral , Regulação da Expressão Gênica , Herpesvirus Humano 1/fisiologia , Humanos , Hibridização in Situ Fluorescente , Transcriptoma
11.
Am J Phys Med Rehabil ; 101(10): 937-946, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34864768

RESUMO

OBJECTIVE: This study's aims were to refine Music Upper Limb Therapy-Integrated (MULT-I) to create a feasible enriched environment for stroke rehabilitation and compare its biologic and behavioral effects with that of a home exercise program (HEP). DESIGN: This was a randomized mixed-methods study of 30 adults with post-stroke hemiparesis. Serum brain-derived neurotrophic factor and oxytocin levels measured biologic effects, and upper limb function, disability, quality of life, and emotional well-being were assessed as behavioral outcomes. Participant experiences were explored using semistructured interviews. RESULTS: MULT-I participants showed reduced depression from preintervention to postintervention as compared with HEP participants. Brain-derived neurotrophic factor levels significantly increased for MULT-I participants but decreased for HEP participants, with a significant difference between groups after excluding those with post-stroke depression. MULT-I participants additionally improved quality of life and self-perceived physical strength, mobility, activity, participation, and recovery from preintervention to postintervention. HEP participants improved upper limb function. Qualitatively, MULT-I provided psychosocial support and enjoyment, whereas HEP supported self-management of rehabilitation. CONCLUSIONS: Implementation of a music-enriched environment is feasible, reduces post-stroke depression, and may enhance the neural environment for recovery via increases in brain-derived neurotrophic factor levels. Self-management of rehabilitation through an HEP may further improve upper limb function.


Assuntos
Produtos Biológicos , Musicoterapia , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Adulto , Fator Neurotrófico Derivado do Encéfalo , Depressão/etiologia , Depressão/terapia , Terapia por Exercício/métodos , Humanos , Projetos Piloto , Qualidade de Vida , Recuperação de Função Fisiológica , Reabilitação do Acidente Vascular Cerebral/métodos , Resultado do Tratamento , Extremidade Superior
13.
Int J Biol Macromol ; 156: 851-857, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32278600

RESUMO

Alhydwan, has been used in bakery products for many years in South of Yemen. Alhydwan primary function in bakery products is to inhibit moisture content during storage, leading to improved shelf life. However, as a fresh strategy to bread staling, no extensive study has been conducted to evaluate its potential. The present study therefore examined the alhydwan as a comparison with Carboxymethylcellulose (CMC) at 0.5% (w/w) level in dough rheology improvement, microstructure, quality parameters and delayed wheat bread staling. The CMC or alhydwan for farinograph characteristics comprising the dough's portrayed showed greater water absorption, while growth and stability time was significantly decreased. Staling of bread, the findings showed that in both alhydwan and CMC minimized crumb hardening frequency and enhanced freshness, quality and retention ability for moisture, making the bread softer and postponed staling. The microstructure of CMC or alhydwan supplemented formulation showed the distinguishable characteristics and constituents that could explain, to some degree, that the CMC and alhydwan had antistaling effect. The incorporation of alhydwan such as CMC into the formulation of bread could thus play a sustainable role in improving the quality of bread by having an extended shelf life.


Assuntos
Pão/análise , Carboximetilcelulose Sódica/química , Farinha/análise , Análise de Alimentos , Qualidade dos Alimentos , Triticum/química , Manipulação de Alimentos , Microscopia , Reologia
14.
Dev Neurobiol ; 79(8): 794-804, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31509642

RESUMO

In adult songbirds, the telencephalic song nucleus HVC and its efferent target RA undergo pronounced seasonal changes in morphology. In breeding birds, there are increases in HVC volume and total neuron number, and RA neuronal soma area compared to nonbreeding birds. At the end of breeding, HVC neurons die through caspase-dependent apoptosis and thus, RA neuron size decreases. Changes in HVC and RA are driven by seasonal changes in circulating testosterone (T) levels. Infusing T, or its metabolites 5α-dihydrotestosterone (DHT) and 17 ß-estradiol (E2), intracerebrally into HVC (but not RA) protects HVC neurons from death, and RA neuron size, in nonbreeding birds. The phosphoinositide 3-kinase (PI3K)-Akt (a serine/threonine kinase)-mechanistic target of rapamycin (mTOR) signaling pathway is a point of convergence for neuroprotective effects of sex steroids and other trophic factors. We asked if mTOR activation is necessary for the protective effect of hormones in HVC and RA of adult male Gambel's white-crowned sparrows (Zonotrichia leucophrys gambelii). We transferred sparrows from breeding to nonbreeding hormonal and photoperiod conditions to induce regression of HVC neurons by cell death and decrease of RA neuron size. We infused either DHT + E2, DHT + E2 plus the mTOR inhibitor rapamycin, or vehicle alone in HVC. Infusion of DHT + E2 protected both HVC and RA neurons. Coinfusion of rapamycin with DHT + E2, however, blocked the protective effect of hormones on HVC volume and neuron number, and RA neuron size. These results suggest that activation of mTOR is an essential downstream step in the neuroprotective cascade initiated by sex steroid hormones in the forebrain.


Assuntos
Plasticidade Neuronal/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Sirolimo/farmacologia , Vocalização Animal/efeitos dos fármacos , Envelhecimento , Animais , Di-Hidrotestosterona/farmacologia , Estrogênios/farmacologia , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia , Pardais/fisiologia , Telencéfalo/efeitos dos fármacos , Testosterona/farmacologia , Vocalização Animal/fisiologia
15.
Proc Natl Acad Sci U S A ; 116(43): 21343-21345, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31527273
16.
Mol Cell Neurosci ; 99: 103395, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31422108

RESUMO

BACE1 is a transmembrane aspartic protease that cleaves various substrates and it is required for normal brain function. BACE1 expression is high during early development, but it is reduced in adulthood. Under conditions of stress and injury, BACE1 levels are increased; however, the underlying mechanisms that drive BACE1 elevation are not well understood. One mechanism associated with brain injury is the activation of injurious p75 neurotrophin receptor (p75), which can trigger pathological signals. Here we report that within 72 h after controlled cortical impact (CCI) or laser injury, BACE1 and p75 are increased and tightly co-expressed in cortical neurons of mouse brain. Additionally, BACE1 is not up-regulated in p75 null mice in response to focal cortical injury, while p75 over-expression results in BACE1 augmentation in HEK-293 and SY5Y cell lines. A luciferase assay conducted in SY5Y cell line revealed that BACE1 expression is regulated at the transcriptional level in response to p75 transfection. Interestingly, this effect does not appear to be dependent upon p75 ligands including mature and pro-neurotrophins. In addition, BACE1 activity on amyloid precursor protein (APP) is enhanced in SY5Y-APP cells transfected with a p75 construct. Lastly, we found that the activation of c-jun n-terminal kinase (JNK) by p75 contributes to BACE1 up-regulation. This study explores how two injury-induced molecules are intimately connected and suggests a potential link between p75 signaling and the expression of BACE1 after brain injury.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Lesões Encefálicas Traumáticas/metabolismo , Receptor de Fator de Crescimento Neural/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/genética , Linhagem Celular Tumoral , Células Cultivadas , Córtex Cerebral/metabolismo , Células HEK293 , Humanos , MAP Quinase Quinase 4/metabolismo , Masculino , Camundongos , Receptor de Fator de Crescimento Neural/genética , Transdução de Sinais , Regulação para Cima
17.
Neurobiol Dis ; 132: 104540, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31349032

RESUMO

INTRODUCTION: Downregulation of brain-derived neurotrophic factor (BDNF) and its cognate neurotrophin receptor, TrkB, were observed during the progression of dementia, but whether the Alzheimer's disease (AD) pathological lesions diffuse plaques, (DPs), neuritic plaques (NPs), and neurofibrillary tangles (NFTs) are related to this alteration remains to be clarified. METHODS: Negative binomial (NB) regressions were performed using gene expression data accrued from a single population of CA1 pyramidal neurons and regional hippocampal dissections obtained from participants in the Rush Religious Orders Study (RROS). RESULTS: Downregulation of Bdnf is independently associated with increased entorhinal cortex NPs. Downregulation of TrkB is independently associated with increased entorhinal cortex NFTs and CA1 NPs during the progression of AD. DISCUSSION: Results indicate that BDNF and TrkB dysregulation contribute to AD neuropathology, most notably hippocampal NPs and NFTs. These data suggest attenuating BDNF/TrkB signaling deficits either at the level of BDNF, TrkB, or downstream of TrkB signaling may abrogate NPs and/or NFTs.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/biossíntese , Hipocampo/metabolismo , Glicoproteínas de Membrana/biossíntese , Emaranhados Neurofibrilares/metabolismo , Placa Amiloide/metabolismo , Receptor trkB/biossíntese , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Fator Neurotrófico Derivado do Encéfalo/genética , Feminino , Expressão Gênica , Hipocampo/patologia , Humanos , Masculino , Glicoproteínas de Membrana/genética , Emaranhados Neurofibrilares/genética , Emaranhados Neurofibrilares/patologia , Placa Amiloide/genética , Placa Amiloide/patologia , Valor Preditivo dos Testes , Receptor trkB/genética
18.
Mol Cell ; 74(3): 466-480.e4, 2019 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-30930055

RESUMO

The mTOR pathway integrates both extracellular and intracellular signals and serves as a central regulator of cell metabolism, growth, survival, and stress responses. Neurotropic viruses, such as herpes simplex virus-1 (HSV-1), also rely on cellular AKT-mTORC1 signaling to achieve viral latency. Here, we define a novel genotoxic response whereby spatially separated signals initiated by extracellular neurotrophic factors and nuclear DNA damage are integrated by the AKT-mTORC1 pathway. We demonstrate that endogenous DNA double-strand breaks (DSBs) mediated by Topoisomerase 2ß-DNA cleavage complex (TOP2ßcc) intermediates are required to achieve AKT-mTORC1 signaling and maintain HSV-1 latency in neurons. Suppression of host DNA-repair pathways that remove TOP2ßcc trigger HSV-1 reactivation. Moreover, perturbation of AKT phosphorylation dynamics by downregulating the PHLPP1 phosphatase led to AKT mis-localization and disruption of DSB-induced HSV-1 reactivation. Thus, the cellular genome integrity and environmental inputs are consolidated and co-opted by a latent virus to balance lifelong infection with transmission.


Assuntos
DNA Topoisomerases Tipo II/genética , Herpesvirus Humano 1/genética , Proteínas Nucleares/genética , Proteínas Proto-Oncogênicas c-akt/genética , Latência Viral/genética , Animais , Quebras de DNA de Cadeia Dupla , Dano ao DNA/genética , Reparo do DNA por Junção de Extremidades/genética , Reparo do DNA/genética , Enzimas Reparadoras do DNA/genética , Proteínas de Ligação a DNA/genética , Herpesvirus Humano 1/patogenicidade , Humanos , Proteína Homóloga a MRE11/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Neurônios/metabolismo , Neurônios/virologia , Fosforilação , Ratos , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/genética
19.
Hippocampus ; 29(5): 422-439, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-28888073

RESUMO

Hippocampal CA1 pyramidal neurons, a major component of the medial temporal lobe memory circuit, are selectively vulnerable during the progression of Alzheimer's disease (AD). The cellular mechanism(s) underlying degeneration of these neurons and the relationship to cognitive performance remains largely undefined. Here, we profiled neurotrophin and neurotrophin receptor gene expression within microdissected CA1 neurons along with regional hippocampal dissections from subjects who died with a clinical diagnosis of no cognitive impairment (NCI), mild cognitive impairment (MCI), or AD using laser capture microdissection (LCM), custom-designed microarray analysis, and qPCR of CA1 subregional dissections. Gene expression levels were correlated with cognitive test scores and AD neuropathology criteria. We found a significant downregulation of several neurotrophin genes (e.g., Gdnf, Ngfb, and Ntf4) in CA1 pyramidal neurons in MCI compared to NCI and AD subjects. In addition, the neurotrophin receptor transcripts TrkB and TrkC were decreased in MCI and AD compared to NCI. Regional hippocampal dissections also revealed select neurotrophic gene dysfunction providing evidence for vulnerability within the hippocampus proper during the progression of dementia. Downregulation of several neurotrophins of the NGF family and cognate neurotrophin receptor (TrkA, TrkB, and TrkC) genes correlated with antemortem cognitive measures including the Mini-Mental State Exam (MMSE), a composite global cognitive score (GCS), and Episodic, Semantic, and Working Memory, Perceptual Speed, and Visuospatial domains. Significant correlations were found between select neurotrophic expression downregulation and neuritic plaques (NPs) and neurofibrillary tangles (NFTs), but not diffuse plaques (DPs). These data suggest that dysfunction of neurotrophin signaling complexes have profound negative sequelae within vulnerable hippocampal cell types, which play a role in mnemonic and executive dysfunction during the progression of AD.


Assuntos
Doença de Alzheimer/patologia , Disfunção Cognitiva/patologia , Hipocampo/patologia , Fatores de Crescimento Neural/metabolismo , Células Piramidais/patologia , Receptores de Fator de Crescimento Neural/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/metabolismo , Região CA1 Hipocampal/metabolismo , Região CA1 Hipocampal/patologia , Disfunção Cognitiva/metabolismo , Progressão da Doença , Feminino , Hipocampo/metabolismo , Humanos , Masculino , Células Piramidais/metabolismo
20.
Ethn Health ; 24(5): 560-574, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-28670980

RESUMO

OBJECTIVES: Despite the disproportionately high rates of heterosexually transmitted HIV infection among US Blacks and ongoing need for effective inexpensive behavioral interventions, the use of sermons as an HIV prevention tool in Black churches has received little research attention. The Black church plays an important role in Black communities and is a potential ally in development and delivery of sexual risk prevention messages. The objective of this study was to examine Black pastors' thoughts about whether sermons should address issues related to heterosexual relationships - and the barriers and facilitators to discussing these topics in a sermon setting. DESIGN: We conducted in-depth semi-structured, individual interviews among 39 pastors of Black churches in North Carolina and analyzed the interview data using thematic analysis strategies based on grounded theory. RESULTS: Pastors expressed widely ranging opinions, especially about discussion of condom use, but generally agreed that sermons should discuss marriage, abstinence, monogamy, dating, and infidelity - behaviors that impact sexual networks and HIV transmission. The major barriers to incorporation of these subjects into sermons include the extent to which a concept undermines their religious beliefs and uncertainty about how to incorporate it. However, scriptural support for a prevention message and the pastor's perception that the message is relevant to the congregation facilitate incorporation of related topics into sermons. CONCLUSIONS: These findings have implications for the potential utility of sermons as an HIV prevention tool and suggest that it is possible for public health professionals and pastors of Black churches to form partnerships to develop messages that are consonant with pastors' religious convictions as well as public health recommendations.


Assuntos
Negro ou Afro-Americano , Cristianismo , Clero , Infecções por HIV/prevenção & controle , Comportamento Sexual , Adolescente , Adulto , Bíblia , Preservativos , Feminino , Infecções por HIV/etnologia , Humanos , Entrevistas como Assunto , Masculino , Casamento , Pessoa de Meia-Idade , North Carolina , Abstinência Sexual , Adulto Jovem
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