Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
1.
Plant Cell Environ ; 44(6): 1788-1801, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33506954

RESUMO

Heat shock factor A1 (HsfA1) family proteins are the master regulators of the heat stress-responsive transcriptional cascade in Arabidopsis. Although 70 kDa heat shock proteins (HSP70s) are known to participate in repressing HsfA1 activity, the mechanisms by which they regulate HsfA1 activity have not been clarified. Here, we report the physiological functions of three cytosolic HSP70s, HSC70-1, HSC70-2 and HSC70-3, under normal and stress conditions. Expression of the HSC70 genes was observed in whole seedlings, and the HSC70 proteins were observed in the cytoplasm and nucleus under normal and stress conditions, as were the HsfA1s. hsc70-1/2 double and hsc70-1/2/3 triple mutants showed higher thermotolerance than the wild-type (WT) plants. Transcriptomic analysis revealed the upregulation of heat stress-responsive HsfA1-downstream genes in hsc70-1/2/3 mutants under normal growth conditions, demonstrating that these HSC70s redundantly function as repressors of HsfA1 activity. Furthermore, hsc70-1/2/3 plants showed a more severe growth delay during the germination stage than the WT plants under high-salt stress conditions, and many seed-specific cluster 2 genes that exhibited suppressed expression during germination were expressed in hsc70-1/2/3 plants, suggesting that these HSC70s also function in the developmental transition from seed to seedling under high-salt conditions by suppressing the expression of cluster 2 genes.


Assuntos
Proteínas de Arabidopsis/metabolismo , Germinação/fisiologia , Proteínas de Choque Térmico HSC70/metabolismo , Estresse Salino/fisiologia , Sementes/fisiologia , Arabidopsis/citologia , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Citosol/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Choque Térmico HSC70/genética , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Fatores de Transcrição de Choque Térmico/genética , Fatores de Transcrição de Choque Térmico/metabolismo , Mutação , Células Vegetais/metabolismo , Termotolerância/fisiologia
2.
Int J Mol Sci ; 22(15)2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34361100

RESUMO

The pathological aggregation of the presynaptic protein α-synuclein (α-syn) and propagation through synaptically coupled neuroanatomical tracts is increasingly thought to underlie the pathophysiological progression of Parkinson's disease (PD) and related synucleinopathies. Although the precise molecular mechanisms responsible for the spreading of pathological α-syn accumulation in the CNS are not fully understood, growing evidence suggests that de novo α-syn misfolding and/or neuronal internalization of aggregated α-syn facilitates conformational templating of endogenous α-syn monomers in a mechanism reminiscent of prions. A refined understanding of the biochemical and cellular factors mediating the pathological neuron-to-neuron propagation of misfolded α-syn will potentially elucidate the etiology of PD and unravel novel targets for therapeutic intervention. Here, we discuss recent developments on the hypothesis regarding trans-synaptic propagation of α-syn pathology in the context of neuronal vulnerability and highlight the potential utility of novel experimental models of synucleinopathies.


Assuntos
Doença de Parkinson/patologia , Príons/metabolismo , Agregação Patológica de Proteínas , alfa-Sinucleína/metabolismo , Animais , Humanos , Doença de Parkinson/metabolismo
3.
Plant Biotechnol J ; 18(8): 1711-1721, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31930666

RESUMO

Increasing drought resistance without sacrificing grain yield remains an ongoing challenge in crop improvement. In this study, we report that Oryza sativa CCCH-tandem zinc finger protein 5 (OsTZF5) can confer drought resistance and increase grain yield in transgenic rice plants. Expression of OsTZF5 was induced by abscisic acid, dehydration and cold stress. Upon stress, OsTZF5-GFP localized to the cytoplasm and cytoplasmic foci. Transgenic rice plants overexpressing OsTZF5 under the constitutive maize ubiquitin promoter exhibited improved survival under drought but also growth retardation. By introducing OsTZF5 behind the stress-responsive OsNAC6 promoter in two commercial upland cultivars, Curinga and NERICA4, we obtained transgenic plants that showed no growth retardation. Moreover, these plants exhibited significantly increased grain yield compared to non-transgenic cultivars in different confined field drought environments. Physiological analysis indicated that OsTZF5 promoted both drought tolerance and drought avoidance. Collectively, our results provide strong evidence that OsTZF5 is a useful biotechnological tool to minimize yield losses in rice grown under drought conditions.


Assuntos
Oryza , Secas , Grão Comestível/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Zinco , Dedos de Zinco/genética
4.
Arch Microbiol ; 202(6): 1449-1458, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32189018

RESUMO

Polymerases are enzymes that synthesize long chains or polymers of nucleic acids including DNA or RNA from nucleotides. They assemble nucleic acids by copying a DNA or RNA template strand using base-pairing interactions. One of the polymerase enzymes, Taq DNA polymerase, originally isolated from Thermus aquaticus (Taq) is a widely used enzyme in molecular biology so far. The thermostable properties of this enzyme have contributed majorly to the specificity, automation, and efficacy of the polymerase chain reaction (PCR), making it a powerful tool for today's molecular biology researches across the globe. The purification of Taq DNA polymerase from the native host results in low yield, more labor and time consumption. Therefore, many studies have been previously conducted to obtain this enzyme using alternative hosts. So far, all the existing methodologies are more laborious, time-consuming and require heavy expense. We used a novel approach to purify the enzyme with relatively high efficiency, yield and minimum time consumption using Escherichia coli (E. coli) as an alternative host. We cloned a 2500 base pair Taq DNA polymerase gene into pGEX-4T-1 vector, containing a GST-tag, downstream of tac promoter and overexpressed it using isopropyl ß-d-1-thiogalactopyranoside (IPTG) as an inducer. The enzyme was efficiently purified using novel chromatography approaches and was used in routine PCR assays in our laboratory. Our findings suggest a novel approach to facilitate the availability of polymerases for molecular and diagnostic studies. In the future, it may be used for the purification of other recombinant peptides or proteins used in structural biology and proteomics-based researches.


Assuntos
Clonagem Molecular/métodos , Escherichia coli/enzimologia , Taq Polimerase/genética , Taq Polimerase/metabolismo , Sequência de Bases , DNA Bacteriano/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica/genética , Nucleotídeos , Reação em Cadeia da Polimerase/métodos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Taq Polimerase/química
5.
Acta Neuropathol ; 137(4): 535-555, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30739199

RESUMO

Messenger RNA (mRNA) translation is the terminal step in protein synthesis, providing a crucial regulatory checkpoint for this process. Translational control allows specific cell types to respond to rapid changes in the microenvironment or to serve specific functions. For example, neurons use mRNA transport to achieve local protein synthesis at significant distances from the nucleus, the site of RNA transcription. Altered expression or functions of the various components of the translational machinery have been linked to several pathologies in the central nervous system. In this review, we provide a brief overview of the basic principles of mRNA translation, and discuss alterations of this process relevant to CNS disease conditions, with a focus on brain tumors and chronic neurological conditions. Finally, synthesizing this knowledge, we discuss the opportunities to exploit the biology of altered mRNA translation for novel therapies in brain disorders, as well as how studying these alterations can shed new light on disease mechanisms.


Assuntos
Neoplasias Encefálicas/patologia , Encéfalo/patologia , Doenças Neurodegenerativas/patologia , Biossíntese de Proteínas , Encéfalo/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Humanos , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
6.
Acta Neuropathol ; 133(1): 101-119, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27752775

RESUMO

Soluble oligomers of amyloid-ß (Aß) impair synaptic plasticity, perturb neuronal energy homeostasis, and are implicated in Alzheimer's disease (AD) pathogenesis. Therefore, significant efforts in AD drug discovery research aim to prevent the formation of Aß oligomers or block their neurotoxicity. The eukaryotic elongation factor-2 kinase (eEF2K) plays a critical role in synaptic plasticity, and couples neurotransmission to local dendritic mRNA translation. Recent evidence indicates that Aß oligomers activate neuronal eEF2K, suggesting a potential link to Aß induced synaptic dysfunction. However, a detailed understanding of the role of eEF2K in AD pathogenesis, and therapeutic potential of eEF2K inhibition in AD, remain to be determined. Here, we show that eEF2K activity is increased in postmortem AD patient cortex and hippocampus, and in the hippocampus of aged transgenic AD mice. Furthermore, eEF2K inhibition using pharmacological or genetic approaches prevented the toxic effects of Aß42 oligomers on neuronal viability and dendrite formation in vitro. We also report that eEF2K inhibition promotes the nuclear factor erythroid 2-related factor (NRF2) antioxidant response in neuronal cells, which was crucial for the beneficial effects of eEF2K inhibition in neurons exposed to Aß42 oligomers. Accordingly, NRF2 knockdown or overexpression of the NRF2 inhibitor, Kelch-Like ECH-Associated Protein-1 (Keap1), significantly attenuated the neuroprotection associated with eEF2K inhibition. Finally, genetic deletion of the eEF2K ortholog efk-1 reduced oxidative stress, and improved chemotaxis and serotonin sensitivity in C. elegans expressing human Aß42 in neurons. Taken together, these findings highlight the potential utility of eEF2K inhibition to reduce Aß-mediated oxidative stress in AD.


Assuntos
Doença de Alzheimer/terapia , Peptídeos beta-Amiloides/metabolismo , Quinase do Fator 2 de Elongação/deficiência , Fragmentos de Peptídeos/metabolismo , Doença de Alzheimer/enzimologia , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/toxicidade , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Quinase do Fator 2 de Elongação/antagonistas & inibidores , Quinase do Fator 2 de Elongação/genética , Quinase do Fator 2 de Elongação/metabolismo , Inibidores Enzimáticos/farmacologia , Feminino , Lobo Frontal/efeitos dos fármacos , Lobo Frontal/enzimologia , Hipocampo/efeitos dos fármacos , Hipocampo/enzimologia , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Masculino , Fator 2 Relacionado a NF-E2/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Neurônios/patologia , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/toxicidade , Espécies Reativas de Oxigênio
7.
Planta ; 239(1): 47-60, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24062085

RESUMO

Rice production is greatly affected by environmental stresses such as drought and high salinity. Transgenic rice plants tolerant to such stresses are expected to be produced. Stress-responsive promoters with low expression under normal growth conditions are needed to minimize the adverse effects of stress-tolerance genes on rice growth. We performed expression analyses of drought-responsive genes in rice plants using a microarray, and selected LIP9, OsNAC6, OsLEA14a, OsRAB16D, OsLEA3-1, and Oshox24 for promoter analysis. Transient assays using the promoters indicated that AREB/ABF (abscisic acid (ABA)-responsive element-binding protein/ABA-binding factor) transcription factors enhanced expressions of these genes. We generated transgenic rice plants containing each promoter and the ß-glucuronidase (GUS) reporter gene. GUS assays revealed that the LIP9 and OsNAC6 promoters were induced by drought, high salinity, and ABA treatment, and both promoters showed strong activity under normal growth conditions in the root. The other promoters were strongly induced by stresses and ABA, but showed low activity under normal growth conditions. In seeds, GUS staining showed that Oshox24 expression was low and expressions of the other genes were high. Transgenic rice plants overexpressing OsNAC6 under the control of the Oshox24 promoter showed increased tolerance to drought and high salinity, and no growth defects. These data suggest that the Oshox24 promoter is useful to overexpress stress-tolerance genes without adversely affecting growth.


Assuntos
Secas , Regulação da Expressão Gênica de Plantas , Oryza/fisiologia , Proteínas de Plantas/genética , Regiões Promotoras Genéticas , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Análise de Sequência com Séries de Oligonucleotídeos , Oryza/efeitos dos fármacos , Oryza/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Sementes/efeitos dos fármacos , Sementes/genética , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
8.
Plant Physiol ; 161(3): 1202-16, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23296688

RESUMO

OsTZF1 is a member of the CCCH-type zinc finger gene family in rice (Oryza sativa). Expression of OsTZF1 was induced by drought, high-salt stress, and hydrogen peroxide. OsTZF1 gene expression was also induced by abscisic acid, methyl jasmonate, and salicylic acid. Histochemical activity of ß-glucuronidase in transgenic rice plants containing the promoter of OsTZF1 fused with ß-glucuronidase was observed in callus, coleoptile, young leaf, and panicle tissues. Upon stress, OsTZF1-green fluorescent protein localization was observed in the cytoplasm and cytoplasmic foci. Transgenic rice plants overexpressing OsTZF1 driven by a maize (Zea mays) ubiquitin promoter (Ubi:OsTZF1-OX [for overexpression]) exhibited delayed seed germination, growth retardation at the seedling stage, and delayed leaf senescence. RNA interference (RNAi) knocked-down plants (OsTZF1-RNAi) showed early seed germination, enhanced seedling growth, and early leaf senescence compared with controls. Ubi:OsTZF1-OX plants showed improved tolerance to high-salt and drought stresses and vice versa for OsTZF1-RNAi plants. Microarray analysis revealed that genes related to stress, reactive oxygen species homeostasis, and metal homeostasis were regulated in the Ubi:OsTZF1-OX plants. RNA-binding assays indicated that OsTZF1 binds to U-rich regions in the 3' untranslated region of messenger RNAs, suggesting that OsTZF1 might be associated with RNA metabolism of stress-responsive genes. OsTZF1 may serve as a useful biotechnological tool for the improvement of stress tolerance in various plants through the control of RNA metabolism of stress-responsive genes.


Assuntos
Adaptação Fisiológica/genética , Regulação da Expressão Gênica de Plantas , Oryza/crescimento & desenvolvimento , Oryza/fisiologia , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Dedos de Zinco , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas/genética , Metais/metabolismo , Especificidade de Órgãos/efeitos dos fármacos , Especificidade de Órgãos/genética , Oryza/efeitos dos fármacos , Oryza/genética , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Peptídeos/metabolismo , Fenótipo , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/genética , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Transporte Proteico/efeitos dos fármacos , Interferência de RNA , RNA de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Cloreto de Sódio/farmacologia , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Transcriptoma/efeitos dos fármacos , Transcriptoma/genética , Dedos de Zinco/genética
9.
Rice (N Y) ; 17(1): 25, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38592643

RESUMO

BACKGROUND: Development of transgenic rice overexpressing transcription factors involved in drought response has been previously reported to confer drought tolerance and therefore represents a means of crop improvement. We transformed lowland rice IR64 with OsTZF5, encoding a CCCH-tandem zinc finger protein, under the control of the rice LIP9 stress-inducible promoter and compared the drought response of transgenic lines and nulls to IR64 in successive screenhouse paddy and field trials up to the T6 generation. RESULTS: Compared to the well-watered conditions, the level of drought stress across experiments varied from a minimum of - 25 to - 75 kPa at a soil depth of 30 cm which reduced biomass by 30-55% and grain yield by 1-92%, presenting a range of drought severities. OsTZF5 transgenic lines showed high yield advantage under drought over IR64 in early generations, which was related to shorter time to flowering, lower shoot biomass and higher harvest index. However, the increases in values for yield and related traits in the transgenics became smaller over successive generations despite continued detection of drought-induced transgene expression as conferred by the LIP9 promoter. The decreased advantage of the transgenics over generations tended to coincide with increased levels of homozygosity. Background cleaning of the transgenic lines as well as introgression of the transgene into an IR64 line containing major-effect drought yield QTLs, which were evaluated starting at the BC3F1 and BC2F3 generation, respectively, did not result in consistently increased yield under drought as compared to the respective checks. CONCLUSIONS: Although we cannot conclusively explain the genetic factors behind the loss of yield advantage of the transgenics under drought across generations, our results help in distinguishing among potential drought tolerance mechanisms related to effectiveness of the transgenics, since early flowering and harvest index most closely reflected the levels of yield advantage in the transgenics across generations while reduced biomass did not.

10.
J Biol Chem ; 287(41): 34786-800, 2012 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-22891248

RESUMO

Increasing evidence implicates Aß peptides self-assembly and fibril formation as crucial events in the pathogenesis of Alzheimer disease. Thus, inhibiting Aß aggregation, among others, has emerged as a potential therapeutic intervention for this disorder. Herein, we employed 3-aminopyrazole as a key fragment in our design of non-dye compounds capable of interacting with Aß42 via a donor-acceptor-donor hydrogen bond pattern complementary to that of the ß-sheet conformation of Aß42. The initial design of the compounds was based on connecting two 3-aminopyrazole moieties via a linker to identify suitable scaffold molecules. Additional aryl substitutions on the two 3-aminopyrazole moieties were also explored to enhance π-π stacking/hydrophobic interactions with amino acids of Aß42. The efficacy of these compounds on inhibiting Aß fibril formation and toxicity in vitro was assessed using a combination of biophysical techniques and viability assays. Using structure activity relationship data from the in vitro assays, we identified compounds capable of preventing pathological self-assembly of Aß42 leading to decreased cell toxicity.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/química , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/química , Pirazóis/química , Linhagem Celular Tumoral , Citotoxinas/antagonistas & inibidores , Citotoxinas/química , Humanos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Estrutura Secundária de Proteína , Relação Estrutura-Atividade
11.
Sci Data ; 10(1): 432, 2023 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-37414779

RESUMO

The discovery of surrogate biomarkers reflecting neuronal dysfunction in neurodegenerative diseases (NDDs) remains an active area of research. To boost these efforts, we demonstrate the utility of publicly available datasets for probing the pathogenic relevance of candidate markers in NDDs. As a starting point, we introduce the readers to several open access resources, which contain gene expression profiles and proteomics datasets from patient studies in common NDDs, including proteomics analyses of cerebrospinal fluid (CSF). Then, we illustrate the method for curated gene expression analyses across select brain regions from four cohorts of Parkinson disease patients (and from one study in common NDDs), probing glutathione biogenesis, calcium signaling and autophagy. These data are complemented by findings of select markers in CSF-based studies in NDDs. Additionally, we enclose several annotated microarray studies, and summarize reports on CSF proteomics across the NDDs, which the readers can utilize for translational purposes. We anticipate that this "beginner's guide" will benefit the research community in NDDs, and would serve as a useful educational tool.


Assuntos
Doenças Neurodegenerativas , Doença de Parkinson , Humanos , Acesso à Informação , Biomarcadores , Perfilação da Expressão Gênica , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Doença de Parkinson/genética , Conjuntos de Dados como Assunto
12.
J Biol Chem ; 286(10): 8585-8596, 2011 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-21156804

RESUMO

The identification of toxic Aß species and/or the process of their formation is crucial for understanding the mechanism(s) of Aß neurotoxicity in Alzheimer disease and also for the development of effective diagnostic and therapeutic interventions. To elucidate the structural basis of Aß toxicity, we developed different procedures to isolate Aß species of defined size and morphology distribution, and we investigated their toxicity in different cell lines and primary neurons. We observed that crude Aß42 preparations, containing a monomeric and heterogeneous mixture of Aß42 oligomers, were more toxic than purified monomeric, protofibrillar fractions, or fibrils. The toxicity of protofibrils was directly linked to their interactions with monomeric Aß42 and strongly dependent on their ability to convert into amyloid fibrils. Subfractionation of protofibrils diminished their fibrillization and toxicity, whereas reintroduction of monomeric Aß42 into purified protofibril fractions restored amyloid formation and enhanced their toxicity. Selective removal of monomeric Aß42 from these preparations, using insulin-degrading enzyme, reversed the toxicity of Aß42 protofibrils. Together, our findings demonstrate that Aß42 toxicity is not linked to specific prefibrillar aggregate(s) but rather to the ability of these species to grow and undergo fibril formation, which depends on the presence of monomeric Aß42. These findings contribute significantly to the understanding of amyloid formation and toxicity in Alzheimer disease, provide novel insight into mechanisms of Aß protofibril toxicity, and important implications for designing anti-amyloid therapies.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Amiloide/metabolismo , Neurônios/metabolismo , Fragmentos de Peptídeos/metabolismo , Multimerização Proteica , Doença de Alzheimer/genética , Amiloide/química , Amiloide/genética , Amiloide/farmacologia , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/farmacologia , Animais , Humanos , Células PC12 , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/farmacologia , Estrutura Quaternária de Proteína , Ratos , Ratos Sprague-Dawley
13.
Cells ; 11(13)2022 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-35805109

RESUMO

Defects in brain energy metabolism and proteopathic stress are implicated in age-related degenerative neuronopathies, exemplified by Alzheimer's disease (AD) and Parkinson's disease (PD). As the currently available drug regimens largely aim to mitigate cognitive decline and/or motor symptoms, there is a dire need for mechanism-based therapies that can be used to improve neuronal function and potentially slow down the underlying disease processes. In this context, a new class of pharmacological agents that achieve improved glycaemic control via the glucagon-like peptide 1 (GLP-1) receptor has attracted significant attention as putative neuroprotective agents. The experimental evidence supporting their potential therapeutic value, mainly derived from cellular and animal models of AD and PD, has been discussed in several research reports and review opinions recently. In this review article, we discuss the pathological relevance of derangements in the neurovascular unit and the significance of neuron-glia metabolic coupling in AD and PD. With this context, we also discuss some unresolved questions with regard to the potential benefits of GLP-1 agonists on the neurovascular unit (NVU), and provide examples of novel experimental paradigms that could be useful in improving our understanding regarding the neuroprotective mode of action associated with these agents.


Assuntos
Doença de Alzheimer , Fármacos Neuroprotetores , Doença de Parkinson , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Animais , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Doença de Parkinson/metabolismo
14.
STAR Protoc ; 3(1): 101181, 2022 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-35243373

RESUMO

This protocol outlines a minimally invasive and quickly performed approach for transgene delivery in the extracranial nervous system of adult mice using recombinant adeno-associated virus (AAV). The technique, named Sciatic Nerve Direct Immersion (SciNDi), relies on the direct bilateral immersion of the exposed sciatic nerve with AAV. We show that in comparison with intramuscular AAV delivery, SciNDi results in widespread transduction in connected neuroanatomical tracts both in the sciatic nerve trunk and the lumbar spinal cord. For complete details on the use and execution of this protocol, please refer to Jan et al. (2019) and Richner et al. (2011, 2017).


Assuntos
Dependovirus , Imersão , Animais , Dependovirus/genética , Vetores Genéticos/genética , Camundongos , Medula Espinal , Transdução Genética
15.
Plant Signal Behav ; 17(1): 2142725, 2022 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-36398733

RESUMO

Different abiotic stresses induce OsTZF1, a tandem CCCH-type zinc finger domain gene, in rice. Here, we report that transgenic rice plants overexpressing OsTZF1 under own promoter (POsTZF1:OsTZF1-OX [for overexpression]) transferred to soil showed normal growth similar to vector control plants. The POsTZF1:OsTZF1-OX produced normal leaves without any lesion mimic phenotype and exhibited normal seed setting. The POsTZF1:OsTZF1-OX plants showed significantly increased tolerance to salt and drought stresses and enhanced post stress recovery. Microarray analysis revealed a total of 846 genes up-regulated and 360 genes down-regulated in POsTZF1:OsTZF1-OX salt-treated plants. Microarray analysis of POsTZF1:OsTZF1-OX plants showed the regulation of many abiotic stress tolerance genes. These results suggest that OsTZF1-OX under own promoter show abiotic stress tolerance and produces no pleiotropic effect on phenotype of transgenic rice plant.


Assuntos
Oryza , Oryza/metabolismo , Secas , Regulação da Expressão Gênica de Plantas/genética , Cloreto de Sódio/farmacologia , Dedos de Zinco/genética , Plantas Geneticamente Modificadas/metabolismo
16.
Comput Biol Med ; 151(Pt A): 106311, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36410097

RESUMO

Antimicrobial peptides (AMPs) are gaining a lot of attention as cutting-edge treatments for many infectious disorders. The effectiveness of AMPs against bacteria, fungi, and viruses has persisted for a long period, making them the greatest option for addressing the growing problem of antibiotic resistance. Due to their wide-ranging actions, AMPs have become more prominent, particularly in therapeutic applications. The prediction of AMPs has become a difficult task for academics due to the explosive increase of AMPs documented in databases. Wet-lab investigations to find anti-microbial peptides are exceedingly costly, time-consuming, and even impossible for some species. Therefore, in order to choose the optimal AMPs candidate before to the in-vitro trials, an efficient computational method must be developed. In this study, an effort was made to develop a machine learning-based classification system that is effective, accurate, and can distinguish between anti-microbial peptides. The position-specific-scoring-matrix (PSSM), Pseudo Amino acid composition, di-peptide composition, and combination of these three were utilized in the suggested scheme to extract salient aspects from AMPs sequences. The classification techniques K-nearest neighbor (KNN), Random Forest (RF), and Support Vector Machine (SVM) were employed. On the independent dataset and training dataset, the accuracy levels achieved by the suggested predictor (Target-AMP) are 97.07% and 95.71%, respectively. The results show that, when compared to other techniques currently used in the literature, our Target-AMP had the best success rate.


Assuntos
Aminoácidos , Peptídeos Antimicrobianos , Análise por Conglomerados , Bases de Dados Factuais
18.
Acta Neuropathol Commun ; 9(1): 31, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33632316

RESUMO

Pain is a common non-motor symptom of Parkinson's disease (PD), with current limited knowledge of its pathophysiology. Here, we show that peripheral inoculation of mouse alpha-synuclein (α-Syn) pre-formed fibrils, in a transgenic mouse model of PD, elicited retrograde trans-synaptic spreading of α-Syn pathology (pSer129) across sensory neurons and dorsal nerve roots, reaching central pain processing regions, including the spinal dorsal horn and the projections of the anterolateral system in the central nervous system (CNS). Pathological peripheral to CNS propagation of α-Syn aggregates along interconnected neuronal populations within sensory afferents, was concomitant with impaired nociceptive response, reflected by mechanical allodynia, reduced nerve conduction velocities (sensory and motor) and degeneration of small- and medium-sized myelinated fibers. Our findings show a link between the transneuronal propagation of α-Syn pathology with sensory neuron dysfunction and neuropathic impairment, suggesting promising avenues of investigation into the mechanisms underlying pain in PD.


Assuntos
Neuralgia/etiologia , Neuralgia/fisiopatologia , Degeneração Retrógrada/patologia , Degeneração Retrógrada/fisiopatologia , Células Receptoras Sensoriais/patologia , Sinucleinopatias/patologia , Sinucleinopatias/fisiopatologia , Animais , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Transgênicos , Microscopia Eletrônica de Transmissão , Doença de Parkinson/fisiopatologia , Células Receptoras Sensoriais/metabolismo , Células Receptoras Sensoriais/ultraestrutura , Transmissão Sináptica , alfa-Sinucleína/metabolismo
19.
Brain Commun ; 3(2): fcab104, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34136810

RESUMO

Neuropathological observations in neurodegenerative synucleinopathies, including Parkinson disease, implicate a pathological role of α-synuclein accumulation in extranigral sites during the prodromal phase of the disease. In a transgenic mouse model of peripheral-to-central neuroinvasion and propagation of α-synuclein pathology (via hindlimb intramuscular inoculation with exogenous fibrillar α-synuclein: the M83 line, expressing the mutant human Ala53Thr α-synuclein), we studied the development and early-stage progression of α-synuclein pathology in the CNS of non-symptomatic (i.e. freely mobile) mice. By immunohistochemical analyses of phosphroylated α-synuclein on serine residue 129 (p-S129), our data indicate that the incipient stage of pathological α-synuclein propagation could be categorized in distinct phases: (i) initiation phase, whereby α-synuclein fibrillar inoculum induced pathological lesions in pools of premotor and motor neurons of the lumbar spinal cord, as early as 14 days post-inoculation; (ii) early central phase, whereby incipient α-synuclein pathology was predominantly detected in the reticular nuclei of the brainstem; and (iii) late central phase, characterized by additional sites of lesions in the brain including vestibular nuclei, deep cerebellar nuclei and primary motor cortex, with coincidental emergence of a sensorimotor deficit (mild degree of hindlimb clasping). Intriguingly, we also detected progressive α-synuclein pathology in premotor and motor neurons in the thoracic spinal cord, which does not directly innervate the hindlimb, as well as in the oligodendroglia within the white matter tracts of the CNS during this prodromal phase. Collectively, our data provide crucial insights into the spatiotemporal propagation of α-synuclein pathology in the nervous system of this rodent model of α-synucleinopathy following origin in periphery, and present a neuropathological context for the progression from pre-symptomatic stage to an early deficit in sensorimotor coordination. These findings also hint towards a therapeutic window for targeting the early stages of α-synuclein pathology progression in this model, and potentially facilitate the discovery of mechanisms relevant to α-synuclein proteinopathies. In a rodent model of synucleinopathy, Ferreira et al., delineate the spatiotemporal progression of incipient α-synuclein pathology (of peripheral origin) in the CNS. The authors show early affection of brainstem reticular nuclei in non-paralyzed mice, and pathological white matter lesions in relation to the neuronal pathology.

20.
Acta Neuropathol Commun ; 9(1): 105, 2021 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-34092244

RESUMO

Circumstantial evidence points to a pathological role of alpha-synuclein (aSyn; gene symbol SNCA), conferred by aSyn misfolding and aggregation, in Parkinson disease (PD) and related synucleinopathies. Several findings in experimental models implicate perturbations in the tissue homeostatic mechanisms triggered by pathological aSyn accumulation, including impaired redox homeostasis, as significant contributors in the pathogenesis of PD. The nuclear factor erythroid 2-related factor (NRF2/Nrf2) is recognized as 'the master regulator of cellular anti-oxidant response', both under physiological as well as in pathological conditions. Using immunohistochemical analyses, we show a robust nuclear NRF2 accumulation in post-mortem PD midbrain, detected by NRF2 phosphorylation on the serine residue 40 (nuclear active p-NRF2, S40). Curated gene expression analyses of four independent publicly available microarray datasets revealed considerable alterations in NRF2-responsive genes in the disease affected regions in PD, including substantia nigra, dorsal motor nucleus of vagus, locus coeruleus and globus pallidus. To further examine the putative role of pathological aSyn accumulation on nuclear NRF2 response, we employed a transgenic mouse model of synucleionopathy (M83 line, expressing the mutant human A53T aSyn), which manifests widespread aSyn pathology (phosphorylated aSyn; S129) in the nervous system following intramuscular inoculation of exogenous fibrillar aSyn. We observed strong immunodetection of nuclear NRF2 in neuronal populations harboring p-aSyn (S129), and found an aberrant anti-oxidant and inflammatory gene response in the affected neuraxis. Taken together, our data support the notion that pathological aSyn accumulation impairs the redox homeostasis in nervous system, and boosting neuronal anti-oxidant response is potentially a promising approach to mitigate neurodegeneration in PD and related diseases.


Assuntos
Encéfalo/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Doença de Parkinson/patologia , alfa-Sinucleína/metabolismo , Animais , Encéfalo/metabolismo , Homeostase/imunologia , Humanos , Camundongos , Camundongos Transgênicos , Doenças Neuroinflamatórias/etiologia , Doenças Neuroinflamatórias/metabolismo , Doenças Neuroinflamatórias/patologia , Oxirredução , Doença de Parkinson/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA