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1.
J Virol ; 98(3): e0139223, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38363111

RESUMEN

Although it is widely accepted that herpesviruses utilize host RNA polymerase II (RNAPII) to transcribe viral genes, the mechanism of utilization varies significantly among herpesviruses. With the exception of herpes simplex virus 1 (HSV-1) in alpha-herpesviruses, the mechanism by which RNAPII transcribes viral genes in the remaining alpha-herpesviruses has not been reported. In this study, we investigated the transcriptional mechanism of an avian alpha-herpesvirus, Anatid herpesvirus 1 (AnHV-1). We discovered for the first time that hexamethylene-bis-acetamide-inducing protein 1 (HEXIM1), a major inhibitor of positive elongation factor B (P-TEFb), was significantly upregulated during AnHV-1 infection, and its expression was dynamically regulated throughout the progression of the disease. However, the expression level of HEXIM1 remained stable before and after HSV-1 infection. Excessive HEXIM1 assists AnHV-1 in progeny virus production, gene expression, and RNA polymerase II recruitment by promoting the formation of more inactive P-TEFb and the loss of RNAPII S2 phosphorylation. Conversely, the expression of some host survival-related genes, such as SOX8, CDK1, MYC, and ID2, was suppressed by HEXIM1 overexpression. Further investigation revealed that the C-terminus of the AnHV-1 US1 gene is responsible for the upregulation of HEXIM1 by activating its promoter but not by interacting with P-TEFb, which is the mechanism adopted by its homologs, HSV-1 ICP22. Additionally, the virus proliferation deficiency caused by US1 deletion during the early infection stage could be partially rescued by HEXIM1 overexpression, suggesting that HEXIM1 is responsible for AnHV-1 gaining transcription advantages when competing with cells. Taken together, this study revealed a novel HEXIM1-dependent AnHV-1 transcription mechanism, which has not been previously reported in herpesvirus or even DNA virus studies.IMPORTANCEHexamethylene-bis-acetamide-inducing protein 1 (HEXIM1) has been identified as an inhibitor of positive transcriptional elongation factor b associated with cancer, AIDS, myocardial hypertrophy, and inflammation. Surprisingly, no previous reports have explored the role of HEXIM1 in herpesvirus transcription. This study reveals a mechanism distinct from the currently known herpesvirus utilization of RNA polymerase II, highlighting the dependence on high HEXIM1 expression, which may be a previously unrecognized facet of the host shutoff manifested by many DNA viruses. Moreover, this discovery expands the significance of HEXIM1 in pathogen infection. It raises intriguing questions about whether other herpesviruses employ similar mechanisms to manipulate HEXIM1 and if this molecular target can be exploited to limit productive replication. Thus, this discovery not only contributes to our understanding of herpesvirus infection regulation but also holds implications for broader research on other herpesviruses, even DNA viruses.


Asunto(s)
Anseriformes , Factor B de Elongación Transcripcional Positiva , Proteínas de Unión al ARN , Factores de Transcripción , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/metabolismo , Factor B de Elongación Transcripcional Positiva/genética , Factor B de Elongación Transcripcional Positiva/metabolismo , ARN Polimerasa II/genética , ARN Polimerasa II/metabolismo , Proteínas de Unión al ARN/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transcripción Genética , Transcripción Viral , Animales
2.
Bioorg Med Chem Lett ; 98: 129576, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38061401

RESUMEN

Alzheimer's disease (AD) is a common type of neurodegenerative disease, which can only be symptomatically relieved but does not yet have a cure. Among the different Aß species, amyloid-ß 42 (Aß42) aggregates are proposed to be more neurotoxic than that of Aß40, and oligomeric Aß42 is thought to play a harmful role in the pathophysiology of AD. Therefore, the detection of Aß42 aggregation is very meaningful in the AD field. We herein report a conformationally-locked p- hydroxybenzylidene imidazolinone derivative, BDI, which exhibits selectivity and specificity towards Aß42 aggregation and remarkable fluorescent enhancement with a large Stokes shift (more than 100 nm). In the fluorescent co-localization study, BDI can sensitively detect a large population of Aß42 aggregation over that of Aß40 in the brain tissues of AD transgenic mouse models. Therefore, this new probe could provide a useful tool for the rapid detection of important Aß species in AD.


Asunto(s)
Enfermedad de Alzheimer , Enfermedades Neurodegenerativas , Animales , Ratones , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/efectos de los fármacos , Colorantes , Fragmentos de Péptidos , Imidazoles/química , Imidazoles/farmacología
3.
BMC Genomics ; 23(1): 509, 2022 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-35836133

RESUMEN

BACKGROUND: Duck plague virus (DPV), belonging to herpesviruses, is a linear double-stranded DNA virus. There are many reports about the outbreak of the duck plague in a variety of countries, which caused huge economic losses. Recently, increasing reports revealed that multiple long non-coding RNAs (lncRNAs) can possess great potential in the regulation of host antiviral immune response. Furthermore, it remains to be determined which specific molecular mechanisms are responsible for the DPV-host interaction in host immunity. Here, lncRNAs and mRNAs in DPV infected duck embryonic fibroblast (DEF) cells were identified by high-throughput RNA-sequencing (RNA-seq). And we predicted target genes of differentially expressed genes (DEGs) and formed a complex regulatory network depending on in-silico analysis and prediction. RESULT: RNA-seq analysis results showed that 2921 lncRNAs were found at 30 h post-infection (hpi). In our study, 218 DE lncRNAs and 2840 DE mRNAs were obtained in DEF after DPV infection. Among these DEGs and target genes, some have been authenticated as immune-related molecules, such as a Macrophage mannose receptor (MR), Anas platyrhynchos toll-like receptor 2 (TLR2), leukocyte differentiation antigen, interleukin family, and their related regulatory factors. Furthermore, according to the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analysis, we found that the target genes may have important effects on biological development, biosynthesis, signal transduction, cell biological regulation, and cell process. Also, we obtained, the potential targeting relationship existing in DEF cells between host lncRNAs and DPV-encoded miRNAs by software. CONCLUSIONS: This study revealed not only expression changes, but also the possible biological regulatory relationship of lncRNAs and mRNAs in DPV infected DEF cells. Together, these data and analyses provide additional insight into the role of lncRNAs and mRNAs in the host's immune response to DPV infection.


Asunto(s)
Patos/embriología , Fibroblastos/virología , Enfermedad de Marek/virología , Enfermedades de las Aves de Corral/virología , ARN Largo no Codificante/metabolismo , ARN Mensajero/metabolismo , Animales , Brotes de Enfermedades/veterinaria , Patos/genética , Patos/virología , Fibroblastos/metabolismo , Perfilación de la Expresión Génica , Infecciones por Herpesviridae/metabolismo , Mardivirus , Enfermedad de Marek/epidemiología , Enfermedad de Marek/inmunología , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/inmunología , ARN Largo no Codificante/análisis , ARN Largo no Codificante/genética , ARN Mensajero/análisis , ARN Mensajero/genética
4.
Anal Chem ; 94(4): 1999-2006, 2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-35041386

RESUMEN

ß-Amyloid deposition is one of the main pathological features of Alzheimer's disease (AD). The development of fluorescent probes targeting specific ß-amyloid species has recently become an attractive strategy to achieve the early diagnosis of AD. In this work, a dual-channel fluorescent protein chromophore derivative C17 was rationally designed and synthesized for the detection and discrimination of Aß42 aggregates and oligomers. C17 exhibits a specific turn-on emission peak for Aß42 oligomers at ∼470 nm (peak A) and a peak at ∼600 nm (peak B) for both Aß42 oligomers and Aß42 aggregates. Taking advantage of the dual emission of the probe, the dynamic aggregation process of the Aß42 peptide was monitored in solution. Moreover, double staining of brain sections from transgenic AD mice revealed that peak A of C17 preferentially detected Aß42 oligomers, whereas peak B was more sensitive to Aß42 aggregates. The fact that probe C17 can be used for dissecting these two Aß42 species makes C17 a comprehensive tool for ß-amyloid aggregation studies in AD research.


Asunto(s)
Enfermedad de Alzheimer , Fragmentos de Péptidos , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Animales , Encéfalo/metabolismo , Ratones , Ratones Transgénicos , Fragmentos de Péptidos/metabolismo , Agregado de Proteínas
5.
Analyst ; 145(20): 6579-6585, 2020 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-32780031

RESUMEN

Aberrant accumulation of Amyloid-ß (Aß) peptide is closely related to Alzheimer's disease. Thus, it is important to develop featured probes for the specific detection of Aß species. Herein, we designed and synthesized a novel near-infrared fluorescent probe SDPY based on the D-π-A architecture for the detection of Aß aggregates. The probe SDPY displayed higher affinity for Aß40 aggregates over Aß42 aggregates in solution (Kd = 164 nM vs. 2.1 µM). In addition, SDPY showed excellent anti-interference against a wide range of other substances. Furthermore, SDPY was capable of labeling Aß40 aggregates better than Aß42 aggregates in the brain sections of AD transgenic mouse models.


Asunto(s)
Enfermedad de Alzheimer , Colorantes Fluorescentes , Enfermedad de Alzheimer/diagnóstico , Péptidos beta-Amiloides/metabolismo , Animales , Encéfalo/metabolismo , Ratones , Ratones Transgénicos , Fragmentos de Péptidos
6.
Stud Health Technol Inform ; 308: 155-167, 2023 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-38007737

RESUMEN

Gastric cancer is a malignant tumor with high incidence and death rate. Every year, Approximately 950,000 new cases of gastric cancer occur globally with nearly 700000 deaths,so gastric precancerous lesions(GPL) was crucial and important.At present, the effective diagnostic methods for gastric precancerous lesions are generally gastroscope and pathological changes of gastric mucosal, but those methods were invasive and would bring some pains to patients and not suitable for frequent and large-scale screening of gastric cancer or GPL.This study aimed to look for a sensitive,effective and non-invasive diagnostic method to improve the early diagnosis rate of GLP, and thereby reduce the incidence and death rate of gastric cancer.Tongue diagnosis is one of the classic diagnostic methods in traditional Chinese medicine(TCM).The tongue was closely related to the spleen and stomach.In the study, we collected 133 patients with chronic gastritis, including 53 cases in inflammatory group, 31 cases in atrophic group, and 49 cases in intestinal metaplasia group. and we analyzed the correlation between tongue,microbiota of tongue coating and clinical symptoms of GLP.The results showed that greasy coating was closely related to the intestinal metaphase of patients, indicating that greasy coating was closed link with intestinal metaphase phase of patients.Abundance of 209 genus were significant differences between greasy and non-greasy coating in intestinal metaphase phase of patients, Top10 were Streptococcus,norank_p__Saccharibacteria,Alloprevotella, Atopobium, Megasphaera, Gemella, Moraxella,unclassified_f__Prevotellaceae, Solobacterium and Stomatobaculum. Alloprevotella and Streptococcus were important genus markers and Alloprevotella was selected as a potential oral biomarker to diagnose intestinal metaphase phase of patients, the AUC value is 0.74.


Asunto(s)
Gastritis , Lesiones Precancerosas , Neoplasias Gástricas , Humanos , Gastritis/diagnóstico , Gastritis/microbiología , Gastritis/patología , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/patología , Metafase , Biomarcadores , Lesiones Precancerosas/microbiología
7.
Neuropharmacology ; 235: 109576, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37164226

RESUMEN

The cumulative evidence suggests that oxytocin is involved in the male sexual behaviors. However, no significant sexual impairments were observed in oxytocin gene knock-out (KO) mice, suggesting that oxytocin is not necessary for sexual behavior in male mice. To better understand the role of oxytocin in male erection, two types of oxytocin gene KO mice were created. In the first type, the oxytocin gene was deleted in the zygote, while in the second type, the oxytocin gene was mutated in adulthood by injecting the CRISPR/Cas9 AAVs. The results showed that disrupting the oxytocin gene at either the embryonic or adult stage did not affect erection, indicating that oxytocin is not necessary for penile erection. Pharmacologically, injecting oxytocin receptor agonist Carbetocin into the VTA of the oxytocin gene KO mice still evoked penile erection. By employing the Oxt-Ires-Cre mice, we found that specifically activating oxytocinergic neurons through chemogenetics strongly induced penile erection, while inhibiting these neurons blocked the erection responses. Furthermore, ablating PVN oxytocinergic neurons abolished the male erection response. In conclusion, although the neuropeptide oxytocin is not essential for male erection, the activity of oxytocinergic neurons is required. Our results might reflect the redundancy in the central nerve system in the sense that many signals contribute to the activation of oxytocinergic neurons to evoke penile erection during sexual behaviors.


Asunto(s)
Neuronas , Oxitocina , Erección Peniana , Animales , Masculino , Ratones , Neuronas/fisiología , Núcleo Hipotalámico Paraventricular , Erección Peniana/fisiología , Receptores de Oxitocina/genética , Oxitocina/metabolismo
8.
Nature ; 440(7083): 528-34, 2006 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-16554819

RESUMEN

Neuropathological hallmarks of Alzheimer's disease are neurofibrillary tangles composed of tau and neuritic plaques comprising amyloid-beta peptides (Abeta) derived from amyloid precursor protein (APP), but their exact relationship remains elusive. Phosphorylation of tau and APP on certain serine or threonine residues preceding proline affects tangle formation and Abeta production in vitro. Phosphorylated Ser/Thr-Pro motifs in peptides can exist in cis or trans conformations, the conversion of which is catalysed by the Pin1 prolyl isomerase. Pin1 has been proposed to regulate protein function by accelerating conformational changes, but such activity has never been visualized and the biological and pathological significance of Pin1 substrate conformations is unknown. Notably, Pin1 is downregulated and/or inhibited by oxidation in Alzheimer's disease neurons, Pin1 knockout causes tauopathy and neurodegeneration, and Pin1 promoter polymorphisms appear to associate with reduced Pin1 levels and increased risk for late-onset Alzheimer's disease. However, the role of Pin1 in APP processing and Abeta production is unknown. Here we show that Pin1 has profound effects on APP processing and Abeta production. We find that Pin1 binds to the phosphorylated Thr 668-Pro motif in APP and accelerates its isomerization by over 1,000-fold, regulating the APP intracellular domain between two conformations, as visualized by NMR. Whereas Pin1 overexpression reduces Abeta secretion from cell cultures, knockout of Pin1 increases its secretion. Pin1 knockout alone or in combination with overexpression of mutant APP in mice increases amyloidogenic APP processing and selectively elevates insoluble Abeta42 (a major toxic species) in brains in an age-dependent manner, with Abeta42 being prominently localized to multivesicular bodies of neurons, as shown in Alzheimer's disease before plaque pathology. Thus, Pin1-catalysed prolyl isomerization is a novel mechanism to regulate APP processing and Abeta production, and its deregulation may link both tangle and plaque pathologies. These findings provide new insight into the pathogenesis and treatment of Alzheimer's disease.


Asunto(s)
Péptidos beta-Amiloides/biosíntesis , Precursor de Proteína beta-Amiloide/metabolismo , Isomerasa de Peptidilprolil/metabolismo , Procesamiento Proteico-Postraduccional , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Animales , Células CHO , Catálisis , Línea Celular , Línea Celular Tumoral , Cricetinae , Cricetulus , Humanos , Ratones , Ratones Noqueados , Peptidilprolil Isomerasa de Interacción con NIMA , Isomerasa de Peptidilprolil/genética , Fosforilación , Unión Proteica , Estructura Terciaria de Proteína , Treonina/metabolismo , Transfección
9.
Eur J Neurosci ; 34(2): 177-89, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21749491

RESUMEN

Cocaine relapse can occur when cocaine-associated environmental cues induce craving. Conditioned place preference (CPP) is a behavioral paradigm modeling the association between cocaine exposure and environmental cues. The amygdala is involved in cocaine cue associations with the basolateral amygdala (BLA) and central amygdala (CeA) acting differentially in cue-induced relapse. Activation of metabotropic glutamate receptors induces synaptic plasticity, the mechanism of which is thought to underlie learning, memory and drug-cue associations. The goal of this study was to examine the neural alterations in responses to group I metabotropic glutamate receptor (mGluR) agonists in the BLA to lateral capsula of CeA (BLA-CeLc) pathway in slices from rats exposed to cocaine-CPP conditioning and withdrawn for 14 days. mGluR1, but not mGluR5, agonist-induced long-term potentiation (mGluR1-LTP) in the BLA-CeLc pathway was reduced in rats withdrawal from cocaine for 2 and 14 days, and exhibited an altered concentration response to picrotoxin. Cocaine withdrawal also reduced γ-aminobutyric acid (GABA)ergic synaptic inhibition in CeLc neurons. Blocking cannabinoid receptor 1 (CB(1) ) reduced mGluR1-LTP in the saline-treated but not cocaine-withdrawn group. Response to CB(1) but not CB(2) agonist was altered after cocaine. Additionally, increasing endocannabinoid (eCB) levels abolished mGluR1-LTP in the saline but not cocaine-withdrawn group. However, CB(1) and CB(2) protein levels were increased in the amygdala of cocaine-withdrawn rats while mGluR1 and mGluR5 remained unchanged. These data suggested that the mechanisms underlying the diminished mGluR1-LTP in cocaine-withdrawn rats involve an altered GABAergic synaptic inhibition mediated by modulation of downstream eCB signaling. These changes may ultimately result in potentiated responses to environmental cues that would bias behavior toward drug-seeking.


Asunto(s)
Amígdala del Cerebelo/fisiología , Cocaína/farmacología , Potenciación a Largo Plazo/efectos de los fármacos , Receptores de Glutamato Metabotrópico/metabolismo , Síndrome de Abstinencia a Sustancias/fisiopatología , Transmisión Sináptica/fisiología , Ácido gamma-Aminobutírico/metabolismo , Amígdala del Cerebelo/efectos de los fármacos , Animales , Conducta Animal/efectos de los fármacos , Condicionamiento Psicológico/efectos de los fármacos , Potenciales Postsinápticos Excitadores/efectos de los fármacos , Potenciales Postsinápticos Excitadores/fisiología , Antagonistas del GABA/metabolismo , Potenciación a Largo Plazo/fisiología , Masculino , Técnicas de Placa-Clamp , Picrotoxina/metabolismo , Ratas , Ratas Sprague-Dawley , Receptor Cannabinoide CB1/agonistas , Receptor Cannabinoide CB1/análisis , Receptor Cannabinoide CB1/metabolismo , Receptor Cannabinoide CB2/agonistas , Receptor Cannabinoide CB2/análisis , Receptor Cannabinoide CB2/metabolismo , Receptor del Glutamato Metabotropico 5 , Receptores de Glutamato Metabotrópico/agonistas , Receptores de N-Metil-D-Aspartato/metabolismo , Transmisión Sináptica/efectos de los fármacos
10.
J Clin Invest ; 118(5): 1877-89, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18431510

RESUMEN

Tau pathology is a hallmark of many neurodegenerative diseases including Alzheimer disease (AD) and frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17). Genetic tau mutations can cause FTDP-17, and mice overexpressing tau mutants such as P301L tau are used as AD models. However, since no tau mutations are found in AD, it remains unclear how appropriate tau mutant mice are as an AD model. The prolyl isomerase Pin1 binds and isomerizes tau and has been implicated in protecting against neurodegeneration, but whether such Pin1 regulation is affected by tau mutations is unknown. Consistent with earlier findings that Pin1 KO induces tauopathy, here we demonstrate that Pin1 knockdown or KO increased WT tau protein stability in vitro and in mice and that Pin1 overexpression suppressed the tauopathy phenotype in WT tau transgenic mice. Unexpectedly, Pin1 knockdown or KO decreased P301L tau protein stability and abolished its robust tauopathy phenotype in mice. In contrast, Pin1 overexpression exacerbated the tauopathy phenotype in P301L tau mice. Thus, Pin1 has opposite effects on the tauopathy phenotype depending on whether the tau is WT or a P301L mutant, indicating the need for disease-specific therapies for tauopathies.


Asunto(s)
Isomerasa de Peptidilprolil/metabolismo , Mutación Puntual , Tauopatías , Proteínas tau , Animales , Encéfalo/citología , Encéfalo/metabolismo , Células Cultivadas , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Peptidilprolil Isomerasa de Interacción con NIMA , Neuronas/citología , Neuronas/metabolismo , Isomerasa de Peptidilprolil/genética , Fenotipo , Nervio Ciático/citología , Nervio Ciático/metabolismo , Nervio Ciático/patología , Médula Espinal/citología , Médula Espinal/metabolismo , Médula Espinal/patología , Tauopatías/metabolismo , Tauopatías/patología , Proteínas tau/genética , Proteínas tau/metabolismo
11.
J Neurosci Res ; 88(1): 102-10, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19642195

RESUMEN

The microtubule-associated protein tau has been implicated in beta-amyloid- and glutamate-induced neurotoxicity. However, the potential role of tau in response to other insults to neurons remains unclear. In this study, we examined whether deletion of tau would change cell injury induced by heat shock in primary cultures of cortical neurons. After 30 min of a 45 degrees C heat shock, lactate dehydrogenase (LDH) release increased, reaching a peak at 6 hr in wild-type (WT) neurons. A significantly lower LDH release, with a peak delayed by 24 hr, was detected in tau knockout (TKO) neurons. After heat shock treatment, MAP-2 and tubulin staining of the processes of WT neurons revealed more dramatic abnormalities than in TKO neurons. Both WT and TKO neurons exhibited a similar elevation of HSP70 level but different time courses of Akt phosphorylation. In contrast to an early, brief response in WT neurons, TKO neurons displayed a late, but long-lasting increase in phosphorylation of Akt and its downstream target, glycogen synthase kinase 3beta. Additionally, inhibition of Akt activity aggravated the cell morbidity caused by heat shock exposure in both WT and TKO neurons, indicating a protective role of Akt against cell injury. In conclusion, our results demonstrate that deletion of tau attenuated heat shock-induced neuronal injury. Enhanced Akt response in the absence of endogenous tau is suggested to represent a compensatory mechanism for regulating cell reactions to stress stimuli.


Asunto(s)
Corteza Cerebral/metabolismo , Respuesta al Choque Térmico/genética , Neuronas/metabolismo , Proteínas tau/genética , Análisis de Varianza , Animales , Western Blotting , Supervivencia Celular , Células Cultivadas , Corteza Cerebral/citología , Técnica del Anticuerpo Fluorescente , Glucógeno Sintasa Quinasa 3/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Calor , Ratones , Ratones Noqueados , Neuronas/citología , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factores de Tiempo , Proteínas tau/metabolismo
12.
Nature ; 424(6948): 556-61, 2003 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-12891359

RESUMEN

The neuropathological hallmarks of Alzheimer's disease and other tauopathies include senile plaques and/or neurofibrillary tangles. Although mouse models have been created by overexpressing specific proteins including beta-amyloid precursor protein, presenilin and tau, no model has been generated by gene knockout. Phosphorylation of tau and other proteins on serine or threonine residues preceding proline seems to precede tangle formation and neurodegeneration in Alzheimer's disease. Notably, these phospho(Ser/Thr)-Pro motifs exist in two distinct conformations, whose conversion in some proteins is catalysed by the Pin1 prolyl isomerase. Pin1 activity can directly restore the conformation and function of phosphorylated tau or it can do so indirectly by promoting its dephosphorylation, which suggests that Pin1 is involved in neurodegeneration; however, genetic evidence is lacking. Here we show that Pin1 expression is inversely correlated with predicted neuronal vulnerability and actual neurofibrillary degeneration in Alzheimer's disease. Pin1 knockout in mice causes progressive age-dependent neuropathy characterized by motor and behavioural deficits, tau hyperphosphorylation, tau filament formation and neuronal degeneration. Thus, Pin1 is pivotal in protecting against age-dependent neurodegeneration, providing insight into the pathogenesis and treatment of Alzheimer's disease and other tauopathies.


Asunto(s)
Envejecimiento/fisiología , Isomerasa de Peptidilprolil/metabolismo , Tauopatías/enzimología , Tauopatías/prevención & control , Enfermedad de Alzheimer/enzimología , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/fisiopatología , Enfermedad de Alzheimer/prevención & control , Secuencias de Aminoácidos , Animales , Conducta Animal/fisiología , Eliminación de Gen , Expresión Génica , Humanos , Ratones , Ratones Noqueados , Microscopía Electrónica , Actividad Motora/fisiología , Peptidilprolil Isomerasa de Interacción con NIMA , Ovillos Neurofibrilares/metabolismo , Ovillos Neurofibrilares/patología , Neuronas/metabolismo , Neuronas/patología , Fármacos Neuroprotectores/metabolismo , Isomerasa de Peptidilprolil/genética , Fosfoproteínas/química , Fosfoproteínas/metabolismo , Fosforilación , Fosfoserina/metabolismo , Fosfotreonina/metabolismo , Placa Amiloide/metabolismo , Placa Amiloide/patología , Tauopatías/patología , Tauopatías/fisiopatología
14.
Anal Chim Acta ; 1133: 109-118, 2020 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-32993862

RESUMEN

Alzheimer's disease (AD) is a chronic neurodegenerative disease. Better imaging and early diagnosis of biomarkers of AD is extremely important for therapeutic interventions. The amyloid cascade hypothesis and its revised version identify insoluble ß-amyloid deposition as a good diagnostic biomarker for AD. Moreover, lipid droplets may also act as an auxiliary biomarker related to AD pathology based on recent studies. Herein, two quinoline-based AIE probes were designed and synthesized for the imaging of Aß plaques and lipid droplets. The probes exhibited remarkable turn-on fluorescence enhancements with the Aß aggregates. The lipid droplets-targeting probe FB exhibited high selectivity and binding affinity towards the Aß aggregates with a detection limit as low as 26.9 nM. Furthermore, FB was capable of readily imaging Aß plaques and lipid droplets at the cellular level and in brain sections of transgenic AD mice. The probe FB can serve as a promising tool for developing early diagnosis and innovative therapeutics of AD.


Asunto(s)
Enfermedad de Alzheimer , Enfermedades Neurodegenerativas , Enfermedad de Alzheimer/diagnóstico por imagen , Péptidos beta-Amiloides/metabolismo , Animales , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Colorantes Fluorescentes , Gotas Lipídicas/metabolismo , Ratones , Ratones Transgénicos , Placa Amiloide/diagnóstico por imagen
15.
J Neurochem ; 109(2): 476-84, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19200347

RESUMEN

Truncated tau is widely detected in Alzheimer's disease brain, and caspase-3 has been considered as a major executioner for tau truncation at aspartate421 (D421), according to its capability of cleaving recombinant tau in vitro. Here we investigated the relationship between D421 truncated tau and caspase-3 in two transgenic mouse models for tauopathies. In adult transgenic mice, activated caspase-3 could not be detected in neurons containing truncated tau, with the exception of a few glia-like cells or neurons in postnatal mice. Caspase-3 expression exhibited a dramatic decrease at the early development stage, and kept at constantly low levels during adult stages in both wild type and transgenic mice. On the other hand, co-incubating brain homogenates from adult tau transgenic mice and ethanol-treated postnatal mice promoted tau truncation at D421, which was mildly reduced by caspase inhibitor, but completely suppressed by phosphatase inhibitor, indicating that hyperphosphorylated tau becomes a poor substrate for truncation at D421. Taken together, our study shows that insufficient caspase-3 expression and hyperphosphorylated status of tau in the adult transgenic mouse brain restrict caspase-3 as an efficient enzyme for tau truncation in vivo. Clearly, there is a caspase-3 independent mechanism responsible for tau truncation at D421 in these models.


Asunto(s)
Ácido Aspártico/metabolismo , Caspasa 3/fisiología , Tauopatías/enzimología , Proteínas tau/metabolismo , Animales , Ácido Aspártico/genética , Caspasa 3/química , Modelos Animales de Enfermedad , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Tauopatías/genética , Proteínas tau/química , Proteínas tau/genética
16.
Acta Neuropathol ; 117(6): 687-97, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19190923

RESUMEN

In addition to tau hyperphosphorylation, tau truncation is also detected in Alzheimer's disease (AD) patients. In the brain of AD transgenic mouse models, the pathological details of truncated tau are not well characterized. In this study, we analyzed spatial relationships among tau truncation, tau phosphorylation and neurodegeneration or tangle formation in a tau(P301L) single transgenic mouse model and a triple transgenic mouse model that produces both amyloid plaques, and neurofibrillary tangles. During development of tau pathology, the spatial relationship between hyperphosphorylation and truncation of tau exhibited a shift from colocalization at low densities of hyperphosphorylated tau to partial dissociation at high densities. Importantly, we detected a few neurons that contained abundant truncated tau but were lacking hyperphosphorylation, and these neurons exhibited remarkable nuclear condensation. In the case of colocalization, truncated tau was commonly associated with high immunoreactivity of hyperphosphorylated tau and dense Gallyas silver staining. Taken together, our study shows that tau truncation appears after tau hyperphosphorylation in the brain of two transgenic mouse models, and that accumulation of truncated tau, in the absence or the presence of phosphorylated tau, is closely associated with a subset of neurons undergoing degeneration or containing neurofibrillary tangles.


Asunto(s)
Enfermedad de Alzheimer/genética , Encéfalo/fisiopatología , Enfermedades Neurodegenerativas/genética , Ovillos Neurofibrilares/genética , Proteínas tau/genética , Envejecimiento , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/fisiopatología , Precursor de Proteína beta-Amiloide/genética , Animales , Encéfalo/patología , Núcleo Celular/patología , Núcleo Celular/fisiología , Modelos Animales de Enfermedad , Femenino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Degeneración Nerviosa/genética , Degeneración Nerviosa/fisiopatología , Enfermedades Neurodegenerativas/patología , Enfermedades Neurodegenerativas/fisiopatología , Ovillos Neurofibrilares/fisiología , Neuronas/patología , Neuronas/fisiología , Fosforilación , Presenilina-1/genética , Nexinas de Proteasas , Receptores de Superficie Celular/genética , Proteínas tau/química , Proteínas tau/metabolismo
17.
J Mater Chem B ; 7(36): 5535-5540, 2019 09 18.
Artículo en Inglés | MEDLINE | ID: mdl-31451829

RESUMEN

Two quinoline-malononitrile-based NIR fluorescent probes with good water-solubility have been developed for detecting and imaging of Aß aggregates in Alzheimer's disease. In vitro studies demonstrated that both probes exhibited high affinity to Aß aggregates with an increase of fluorescence intensity due to the intramolecular charge transfer effect. Moreover, the probes could particularly image Aß plaques in brain sections of triple transgenic AD mice.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Péptidos beta-Amiloides/química , Colorantes Fluorescentes/química , Agua/química , Animales , Rayos Infrarrojos , Ratones , Ratones Transgénicos , Estructura Molecular , Tamaño de la Partícula , Agregado de Proteínas , Teoría Cuántica , Solubilidad , Propiedades de Superficie
19.
Neurosci Lett ; 447(2-3): 109-14, 2008 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-18852026

RESUMEN

The effect of general anesthetics on the developing brain is receiving growing attention. Nonetheless, there remains a paucity of evidence regarding the effect of sevoflurane, a widely used anesthetic in pediatric anesthesia. This study was designed to investigate the effect of sevoflurane on nerve cell apoptosis in the developing brain. Techniques to detect cell apoptosis included immunohistochemistry of cleaved caspase-3 and single-strand DNA, as well as electron microscopy. Elevated cleaved caspase-3 was also validated semi-quantitatively by immunoblotting assay. Mouse pups (day 7 postnatal) were subjected to sevoflurane inhalation. Twelve hours later, dramatically increased cleaved caspase-3 and single-strand DNA immunoreactivity were detected in the pup brains. Immunoblotting assay of cleaved caspase-3 revealed a significant increase after anesthetic exposure. Electron microscopy disclosed typical apoptotic morphology of the degenerative nerve cells. Blood glucose levels in the anesthetized group were not different from those of the control group, indicating that the neuronal apoptosis observed in the anesthetized group was not the result of hypoglycemia. Our results indicate that subanesthetic concentration of sevoflurane can trigger neuronal apoptosis in the postnatal mouse brain.


Asunto(s)
Apoptosis/efectos de los fármacos , Encéfalo , Éteres Metílicos/farmacología , Neuronas/efectos de los fármacos , Anestésicos por Inhalación/farmacología , Animales , Animales Recién Nacidos , Encéfalo/citología , Encéfalo/efectos de los fármacos , Encéfalo/crecimiento & desarrollo , Caspasa 3/metabolismo , ADN de Cadena Simple/metabolismo , Relación Dosis-Respuesta a Droga , Femenino , Indoles , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica de Transmisión/métodos , Neuronas/metabolismo , Neuronas/ultraestructura , Embarazo , Sevoflurano
20.
Chem Sci ; 8(12): 8279-8284, 2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-29619173

RESUMEN

Alzheimer's disease (AD) is the most prevalent but still incurable neurodegenerative form of dementia. Early diagnosis and intervention are crucial for delaying the onset and progression of the disease. We herein report a novel fluoro-substituted cyanine, F-SLOH, which exhibits good Aß oligomer selectivity with a high binding affinity, attributed to the synergistic effect of strong π-π stacking and intermolecular CH···O and CH···F interactions. The selectivity towards the Aß oligomers in the brain was ascertained by in vitro labelling on tissue sections and in vivo labelling through the systemic administration of F-SLOH in 7 month APP/PS1 double transgenic (Tg) and APP/PS1/Tau triple Tg mouse models. F-SLOH also shows remarkably effective inhibition on Aß aggregation and highly desirable neuroprotective effects against Aß-induced toxicities, including the inhibition of ROS production and Ca2+ influx. Its excellent blood-brain barrier (BBB) penetrability and low bio-toxicity further support its tremendous potential as a novel theranostic agent for both early diagnosis and therapy of AD.

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