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Liver cancer is a cunning malignancy with a high incidence and mortality rate among cancers worldwide. The NPC gene family members (NPCs: NPC1, NPC2, and NPC1L1) are closely linked to the development of multiple cancers, but their role in liver cancer remains unclear. As a result, we must investigate their functions in liver hepatocellular carcinoma (LIHC). NPCs were significantly differentially expressed between normal and LIHC tissues, with a high mutation frequency in LIHC. The ROC curve analysis revealed that NPC1/NPC2 had high diagnostic and prognostic values in LIHC. NPC1 expression was also found to be negatively correlated with its methylation level. The differentially expressed genes between high and low NPC1 expression groups in LIHC were mainly related to channel activity, transporter complexes, and plasma membrane adhesion molecules. Additionally, NPC1 expression was significantly associated with multiple immune cells and immunization checkpoints. It was hypothesized that a TUG1/SNHG4-miR-148a-3p-NPC1 regulatory axis is associated with hepatocarcinogenesis. Finally, the protein expression of NPC1 in LIHC tissues and paraneoplastic tissues was detected, and NPC1-knockdown HepG2 cells (NPC1KO) inhibited the proliferation, migration, and invasion. This study helped to identify new prognostic markers and potential immunotherapeutic targets for LIHC and revealed the molecular mechanisms underlying NPC1 regulation in LIHC. The NPCs play a key role in the prognosis and diagnosis of LIHC and may be an important indicator for LIHC prognosis and diagnosis; NPC1 might be a potential therapeutic target in LIHC.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , Prognóstico , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , MultiômicaRESUMO
Alterations in formaldehyde (FA) homeostasis are associated with the pathology of Alzheimer's disease (AD). In vivo tracking of FA flux is important for understanding the underlying molecular mechanisms, but is challenging due to the lack of sensitive probes favoring a selective, rapid, and reversible response toward FA. In this study, we re-engineered the promiscuous and irreversible phenylhydrazines to make them selective and reversible toward FA by tuning their nucleophilicity. This effort resulted in PFM309, a selective (selectivity coefficient KFA,methylglyoxal = 0.06), rapid (t1/2 = 32 s at [FA] = 200 µM), and reversible fluorogenic probe (K = 6.24 mM-1) that tracks the FA flux in both live cells and live mice. In vivo tracking of the FA flux was realized by PFM309 imaging, which revealed the gradual accumulation of FA in the live mice brain during normal aging and its further increase in AD mice. We further identified the age-dependent loss of catabolism enzymes ALDH2 and ADH5 as the primary mechanism responsible for formaldehyde excess. Activating ALDH2 with the small molecular activator Alda1 significantly protected neurovascular cells from formaldehyde overload and consequently from impairment during AD progress both in vitro and in vivo. These findings revealed PFM309 as a robust tool to study AD pathology and highlight ALDH2 as a potential target for AD drug development.
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Doença de Alzheimer , Envelhecimento , Aldeído-Desidrogenase Mitocondrial/metabolismo , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Animais , Formaldeído/metabolismo , CamundongosRESUMO
We experimentally investigate image reconstruction through a scattering medium under white-light illumination. To solve the inverse problem of noninvasive scattering imaging, a modified iterative algorithm is employed with an interpretable constraint on the optical transfer function (OTF). As a result, a sparse and real object can be retrieved whether it is illuminated with a narrowband or broadband light. Compared with the well-known speckle correlation technique (SCT), the proposed method requires no restrictions on the speckle autocorrelation and shows a potential advantage in scattering imaging.
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A speckle image formed by scattering lights can be decoded by recently invented techniques, owing to the optical memory effect, thereby enabling the observation of a hidden object behind a thin scattering medium. However, the range of three-dimensional OME is typically small; therefore, both the field of view and depth of field are limited. We propose a method that can significantly and simultaneously improve both values for a specific scenario, where one object moves around the other position-fixed object. The effectiveness of the proposed scheme is demonstrated through a set of experiments.
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Non-line-of-sight (NLOS) imaging has received considerable attentions for its ability to recover occluded objects from an indirect view. Various NLOS imaging techniques have been demonstrated recently. Here, we propose a white-light NLOS imaging method that is equipped only with an ordinary camera, and not necessary to operate under active coherent illumination as in other existing NLOS systems. The central idea is to incorporate speckle correlation-based model into a deep neural network (DNN), and form a two-step DNN strategy that endeavors to learn the optimization of the scattered pattern autocorrelation and object image reconstruction, respectively. Optical experiments are carried out to demonstrate the proposed method.
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The shape of two objects hidden behind a thin scattering medium is retrieved by the presented method. One of the two objects keeps stationary, while the other one is supposed to be gradually moving, and the Euclidean distance between them is always beyond the range of the 3D optical memory effect. We capture two speckle patterns to image the two isolated objects by using a developed speckle-differential-based strategy and the traditional speckle autocorrelation technique. The feasibility of our method is demonstrated by theoretical analysis and a set of experiments.
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Random Phase Encoding (RPE) techniques for image encryption have drawn increasing attention during the past decades. We demonstrate in this contribution that the RPE-based optical cryptosystems are vulnerable to the chosen-plaintext attack (CPA) with deep learning strategy. A deep neural network (DNN) model is employed and trained to learn the working mechanism of optical cryptosystems, and finally obtaining a certain optimized DNN that acts as a decryption system. Numerical simulations were carried out to verify its feasibility and reliability of not only the classical Double RPE (DRPE) scheme but also the security-enhanced Tripe RPE (TRPE) scheme. The results further indicate the possibility of reconstructing images (plaintexts) outside the original data set.
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A compressive optical steganography based on single-pixel imaging (SPI) is proposed. The SPI system, which employs a digital light projector to illuminate the host image with modulated patterns, is similar to a wireless broadcast system. Therefore, it is suitable for covert communication naturally. By leveraging the compressive sensing technique and a generalized phase retrieval algorithm, the secret message is sparse-sampled and then encoded into the illumination patterns, which are projected onto the host image in an SPI architecture. The resulting reflected light signals travel in the free space as a broadcast system, and the signals would be captured by the authorized receivers and the potential eavesdroppers. By implementing an inverse Fourier transform, a stegoimage will be received, which is almost the same as the host image. However, only the authorized receivers, who possess the secret key, could extract the desired data from the stegoimage and then reconstruct the secret message by using a convex optimization algorithm. Because the secret message is sparse-sampled before embedding, the imperceptibility is well preserved while the capacity also be kept in a high level. A series of simulation and experimental results verifies the validity and feasibility of the proposed method.
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Speckle correlation imaging (SCI) has been considered one of the most promising techniques for computational imaging through a scattering medium. However, the image quality is not always acceptable in conventional SCI, especially when a complex object is involved. In this work, a modified phase retrieval algorithm is introduced to significantly improve the imaging quality of SCI. In the proposed scheme, nonzero-pixel constraints, rather than the real and nonnegative constraints, are employed as the object domain constraints of the iterative algorithm in the image reconstruction process. Experimental results are presented to show the performance enhancement of this scheme, inclusive of less iterations, better image quality, and higher reliability, in comparison with the conventional SCI method.
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Accumulating evidence suggests that formation of peroxynitrite (ONOO(-)) in the cerebral vasculature contributes to the progression of ischemic damage, while the underlying molecular mechanisms remain elusive. To fully understand ONOO(-) biology, efficient tools that can realize the real-time tracing of endogenous ONOO(-) fluxes are indispensable. While a few ONOO(-) fluorescent probes have been reported, direct visualization of ONOO(-) fluxes in the cerebral vasculature of live mice remains a challenge. Herein, we present a fluorescent switch-on probe (NP3) for ONOO(-) imaging. NP3 exhibits good specificity, fast response, and high sensitivity toward ONOO(-) both in vitro and in vivo. Moreover, NP3 is two-photon excitable and readily blood-brain barrier penetrable. These desired photophysical and pharmacokinetic properties endow NP3 with the capability to monitor brain vascular ONOO(-) generation after injury with excellent temporal and spatial resolution. As a proof of concept, NP3 has enabled the direct visualization of neurovascular ONOO(-) formation in ischemia progression in live mouse brain by use of two-photon laser scanning microscopy. Due to these favorable properties, NP3 holds great promise for visualizing endogenous peroxynitrite fluxes in a variety of pathophysiological progressions in vitro and in vivo.
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Traumatismo Cerebrovascular/metabolismo , Células Endoteliais/metabolismo , Corantes Fluorescentes/química , Ácido Peroxinitroso/metabolismo , Animais , Traumatismo Cerebrovascular/patologia , Células Endoteliais/química , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/farmacocinética , Camundongos , Estrutura Molecular , Ácido Peroxinitroso/químicaRESUMO
We demonstrate in this paper that the traditional double random phase encoding (DRPE) technique is vulnerable to ciphertext-only attack (COA). In this method, an unauthorized user (or say attacker) is assumed to be able to retrieve the corresponding plaintext from the only ciphertext under some certain condition. The proposed scheme mainly relies on a hybrid iterative phase retrieval (HIPR) algorithm, which combines various phase retrieval algorithms. With an estimation of the number of nonzero pixels (NNP) in the original plaintext, an attacker could recover the plaintext in a large extent. The simulation results show that this method is feasible and validate.
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Lower global cognitive function scores are a common symptom of autism spectrum disorders (ASDs). This study investigates the effects of melatonin on hippocampal serine/threonine kinase signaling in an experimental ASD model. We found that chronic melatonin (1.0 or 5.0 mg/kg/day, 28 days) treatment significantly rescued valproic acid (VPA, 600 mg/kg)-induced decreases in CaMKII (Thr286), NMDAR1 (Ser896), and PKA (Thr197) phosphorylation in the hippocampus without affecting total protein levels. Compared with control rats, the immunostaining of pyramidal neurons in the hippocampus revealed a decrease in immunolabeling intensity for phospho-CaMKII (Thr286) in the hippocampus of VPA-treated rats, which was ameliorated by chronic melatonin treatment. Consistent with the elevation of CaMKII/PKA/PKC phosphorylation observed in melatonin-treated rat, long-term potentiation (LTP) was enhanced after chronic melatonin (5.0 mg/kg) treatment, as reflected by extracellular field potential slopes that increased from 56 to 60 min (133.4 ± 3.9% of the baseline, P < 0.01 versus VPA-treated rats) following high-frequency stimulation (HFS) in hippocampal slices. Accordingly, melatonin treatment also significantly improved social behavioral deficits at postnatal day 50 in VPA-treated rats. Taken together, the increased phosphorylation of CaMKII/PKA/PKC signaling might contribute to the beneficial effects of melatonin on autism symptoms.
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Transtorno Autístico , Comportamento Animal/efeitos dos fármacos , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/enzimologia , Melatonina/farmacologia , Análise de Variância , Animais , Antioxidantes/farmacologia , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/análise , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/química , Modelos Animais de Doenças , Feminino , Hipocampo/química , Imuno-Histoquímica , Masculino , Fosforilação/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Ácido Valproico/farmacologiaRESUMO
The present study was designed to investigate the role of autophagy-lysosome signaling in the brain after application of nanoparticles. Here, lipid nanoparticles (LNs) induced elevations of Atg5, P62, LC3 and cathepsin B in mice brain. The transmission electron microscopy revealed a dramatic elevation of lysosome vacuoles colocalized with LNs cluster inside the neurons in mice brain. Immunoblot data revealed abnormal expression of cathepsin B in brain cortex following LNs injection, whereas its expression was further elevated in Atg5(+/-) mice. The importance of Atg5 in the LNs-induced autophagy-lysosome cascade was further supported by our finding that neurovascular response was exaggerated in Atg5(+/-) mice. In addition, the siRNA knockdown of Atg5 significantly blunted the increasing of LC3 and P62 in LNs-treated Neuro-2a cells. Taken together, we propose that LNs induce autophagy-lysosome signaling and neurovascular response at least partially via an Atg5-dependent pathway. FROM THE CLINICAL EDITOR: These authors investigated autophagy-lysosome signaling in the mouse brain after application of lipid nanoparticles and report that these nanoparticles induce autophagy-lysosome signaling and neurovascular response at least partially via an Atg5-dependent pathway.
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Encéfalo/metabolismo , Catepsina B/metabolismo , Lipídeos/química , Lisossomos/metabolismo , Proteínas Associadas aos Microtúbulos/deficiência , Nanopartículas/química , Animais , Proteína 5 Relacionada à Autofagia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Proteínas Associadas aos Microtúbulos/genéticaRESUMO
BACKGROUND: Due to changes in lifestyle and dietary habits, the global population with obesity is increasing gradually, resulting in a significant rise in the number of individuals having obesity. Obesity is caused by an imbalance between energy intake and consumption, leading to excessive fat accumulation, which interferes with normal human metabolism. It is also associated with cardiovascular disease, metabolic syndrome, male reproductive endocrine regulation disorders, systemic and local inflammatory reactions, excessive oxidative stress, and apoptosis. All these factors can damage the internal environment for sperm generation and maturation, resulting in male sexual dysfunction, a decline in sperm quality, and lower fertility. This study analyzes the trends and priorities of the effects of obesity on male reproductive disorders from a bibliometric perspective. METHODS: This study uses the Web of Science as the statistical source, covering all time spans. Tools like Web of Science, VOSviewer, and CiteSpace are used to analyze countries, institutions, authors, journals, and keywords in the field. Total publications, total citations, and average number of citations are selected for statistics. RESULTS: The results show that the research on the impact of obesity on male reproductive function can be roughly divided into three stages: the initial stage, the slow development stage, and the rapid development stage. Our statistical scope includes 463 highly relevant articles that we have screened. We found that the journal with the most publications in this field is Andrologia, and the institution with the highest total citations is the University of Utah. The most influential countries, institutions, and authors in this field are the United States, the University of Utah, and Carrell, Douglas. Currently, research related to the impact of obesity on male reproduction focuses mainly on three aspects: biochemistry, molecular biology, and reproductive biology. The keyword explosion results indicate that sperm, obesity, and male reproduction are at the forefront and trends of future research in this field. There has been a shift from basic biochemical and molecular research to research on molecular mechanisms relying on omics technologies. However, we have observed that the number of papers published in 2022 is lower than in 2021, indicating a growth interruption during this period. Considering that this deviation may be due to the impact of the COVID-19 pandemic, it may hinder the progress of certain experiments in 2022. In recent years, China has rapidly developed research in this field. However, the average citation rate is relatively low, indicating the need for Chinese scholars to improve the quality of their articles further. Based on our research and in the context of global obesity, men are at risk of increased infertility. Addressing this issue relies on our continued research into the mechanisms of obesity-related male reproductive disorders. Over the past forty-three years, with the contributions of scientists worldwide, research in this field has flourished. CONCLUSION: The impact of obesity on male reproductive disorders has been extensively studied. Currently, research in this field primarily focuses on male sperm function, sperm quality, and the effects or mechanisms of cells on male reproduction. Future trends in this field should concentrate on the relationship between male fertility and energy metabolism, as well as the endocrine function of adipose tissue. This study comprehensively analyzes the current research status and global trends in obesity and male reproductive disorders. We also discuss the future developments in this field, making it easier for researchers to understand its developmental history, current status, and trends, providing valuable reference for effective exploration in this area.
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Bibliometria , Infertilidade Masculina , Obesidade , Masculino , Humanos , Obesidade/epidemiologia , Obesidade/metabolismo , Obesidade/fisiopatologia , Infertilidade Masculina/epidemiologia , Infertilidade Masculina/fisiopatologia , Reprodução/fisiologiaRESUMO
This study introduces an efficient RPA-PfAgo detection system for the MTHFR C677T polymorphism, proposing a potential strategy to simplify the genotyping process. By optimizing recombinase polymerase amplification (RPA) with Pyrococcus furiosus Argonaute (PfAgo) nucleases, we achieved DNA amplification at a constant temperature. The assay was fine-tuned through meticulous primer and guide DNA selection, with optimal conditions established at 2.0 µL of MgAc, a reaction temperature of 42 °C, and a 10-minute reaction time for RPA. Further optimization of the PfAgo cleavage assay revealed the ideal concentrations of MnCl2, guide DNA, molecular beacon probes, the PfAgo enzyme, and the RPA product to maximize sensitivity and specificity. Clinical validation of 20 samples showed 100% concordance with Sanger sequencing, confirming the method's precision. The RPA-PfAgo system is a promising tool for on-site genotyping, with broad applications in personalized medicine and disease prevention.
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Técnicas de Genotipagem , Metilenotetra-Hidrofolato Redutase (NADPH2) , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Técnicas de Genotipagem/métodos , Polimorfismo de Nucleotídeo Único , Pyrococcus furiosus/genética , Pyrococcus furiosus/enzimologia , Genótipo , Técnicas de Amplificação de Ácido Nucleico/métodos , Proteínas Argonautas/genética , Recombinases/metabolismo , Recombinases/genéticaRESUMO
BACKGROUND: Oocyte quality is critical for the mammalian reproduction due to its necessity on fertilization and early development. During aging, the declined oocytes showing with organelle dysfunction and oxidative stress lead to infertility. AMP-activated protein kinase (AMPK) is a serine/threonine protein kinase which is important for energy homeostasis for metabolism. Little is known about the potential relationship between AMPK with oocyte aging. RESULTS: In present study we reported that AMPK was related with low quality of oocytes under post ovulatory aging and the potential mechanism. We showed the altered AMPK level during aging and inhibition of AMPK activity induced mouse oocyte maturation defect. Further analysis indicated that similar with its upstream regulator PKD1, AMPK could reduce ROS level to avoid oxidative stress in oocytes, and this might be due to its regulation on mitochondria function, since loss of AMPK activity induced abnormal distribution, reduced ATP production and mtDNA copy number of mitochondria. Besides, we also found that the ER and Golgi apparatus distribution was aberrant after AMPK inhibition, and enhanced lysosome function was also observed. CONCLUSIONS: Taken together, these data indicated that AMPK is important for the organelle function to reduce oxidative stress during oocyte meiotic maturation.
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Proteínas Quinases Ativadas por AMP , Oócitos , Estresse Oxidativo , Animais , Feminino , Camundongos , Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Senescência Celular , Mitocôndrias/metabolismo , Oócitos/metabolismo , Organelas/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
A ciphertext-only attack (COA) on a joint transform correlator (JTC) encryption system is proposed. From the perspective view of optical cryptanalysis, we find out that the issue to be solved in the COA scheme could be transferred into a phase retrieval problem with single intensity measurement. And in this paper, the hybrid input-output (HIO) algorithm is employed to handle this issue with the help of an inartificial signal domain support and a given frequency domain constraint. Meanwhile, we provide a set of numerical simulations to demonstrate the validity and feasibility of the presented method.
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Clinical epidemiology has indicated that the endothelial injury is a potential contributor to the pathogenesis of ischemic neurovascular damage. In this report, we assessed S-nitrosylation and nitration of Keap1 to identify downstream nitric oxide redox signaling targets into endothelial cells during ischemia. Here, oxygen-glucose deprivation (OGD) exposure initiates the nuclear import of Keap1 in endothelial cells, which interacted with nuclear-localized Nrf2, as demonstrated through co-immunoprecipitation and immunocytochemical assay. Paralleling the ischemia-induced nuclear import of Keap1, increased nitrotyrosine immunoreactivity in endothelial cells was also observed. Consistently, the addition of peroxynitrite provoked nuclear import of Keap1 and a concomitant Nrf2 nuclear import in the endothelial cells. Importantly, pharmacological inhibition of nitrosative stress by melatonin partially inhibited the OGD-induced constitutive nuclear import of Keap1 and subsequently disturbance of Nrf2/Keap1 signaling. Moreover, the effect of melatonin on nitration and S-nitrosylation of keap1 was examined in endothelial cells with 6 hr OGD exposure. Here, we demonstrated that OGD induced tyrosine nitration of Keap1, which was blocked by melatonin treatment, while there were no significant changes in S-nitrosylation of Keap1. The specific amino acid residues of Keap1 involved in tyrosine nitration were identified as Y473 by mass spectrometry. Moreover, the protective role of melatonin against damage to endothelial tight junction integrity was addressed by ZO-1 expression, paralleled with the restored heme oxygenase-1 levels during OGD. Together, our results emphasize that upon nitrosative stress, the protective effect of melatonin on endothelial cells is likely mediated at least in part by inhibition of ischemia-evoked protein nitration of Keap1, hence contributing to relieve the disturbance of Nrf2/Keap1 antioxidative signaling.
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Células Endoteliais/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Isquemia/metabolismo , Melatonina/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Análise de Variância , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Linhagem Celular , Células Endoteliais/metabolismo , Glucose/metabolismo , Histocitoquímica , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch , Microscopia de Fluorescência , Fator 2 Relacionado a NF-E2/metabolismo , Nitratos/metabolismo , Oxigênio/metabolismo , Estresse Fisiológico/fisiologia , Tirosina/análogos & derivados , Tirosina/metabolismoRESUMO
AIMS: Cerebrovascular impairment contributes to the pathogenesis of Alzheimer's disease (AD). However, it still lacks effective intervention in clinical practice. Here, we investigated the efficacy of electroacupuncture (EA) in cerebrovascular repair in 3xTg-AD mice and its mechanism. METHODS: 3xTg-AD mice were employed to evaluate the protective effect of EA at ST36 acupoint (EAST36). Behavioral tests were performed to assess neurological disorders. Laser speckle contrast imaging, immunostaining, and Western blot were applied to determine EAST36-boosted cerebrovascular repair. The mechanism was explored in 3xTg mice and endothelial cell cultures by melatonin signaling modulation. RESULTS: EAST36 at 20/100 Hz effectively alleviated the olfactory impairment and anxiety behavior and boosted cerebrovascular repair in AD mice. EAST36 attenuated cerebral microvascular degeneration in AD mice by modulating endothelial cell viability and injury. Consequently, the Aß deposits and neural damage in AD mice were reversed after EAST36. Mechanistically, we revealed that EAST36 restored melatonin levels in AD mice. Melatonin supplement mimicked the EAST36 effect on cerebrovascular protection in AD mice and endothelial cell cultures. Importantly, blockage of melatonin signaling by antagonist blunted EAST36-induced cerebrovascular recovery and subsequent neurological improvement. CONCLUSIONS: These findings provided strong evidence to support EAST36 as a potential nonpharmacological therapy against cerebrovascular impairment in AD. Further study is necessary to better understand how EAST36 treatment drives melatonin signaling.
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Doença de Alzheimer , Eletroacupuntura , Melatonina , Camundongos , Animais , Doença de Alzheimer/terapia , Doença de Alzheimer/tratamento farmacológico , Melatonina/uso terapêutico , Eletroacupuntura/métodos , Modelos Animais de Doenças , Camundongos TransgênicosRESUMO
BACKGROUND: The cerebral microvascular occlusion elicits microvascular injury which mimics the different degrees of stroke severity observed in patients, but the mechanisms underlying these embolic injuries are far from understood. The Fas ligand (FasL)-Fas system has been implicated in a number of pathogenic states. Here, we examined the contribution of microglia-derived FasL to brain inflammatory injury, with a focus on the potential to suppress the FasL increase by inhibition of the P2X(7)-FasL signaling with pharmacological or genetic approaches during ischemia. METHODS: The cerebral microvascular occlusion was induced by microsphere injection in experimental animals. Morphological changes in microglial cells were studied immunohistochemically. The biochemical analyses were used to examine the intracellular changes of P2X(7)/FasL signaling. The BV-2 cells and primary microglia from mice genetically deficient in P2X(7) were used to further establish a linkage between microglia activation and FasL overproduction. RESULTS: The FasL expression was continuously elevated and was spatiotemporally related to microglia activation following microsphere embolism. Notably, P2X(7) expression concomitantly increased in microglia and presented a distribution pattern that was similar to that of FasL in ED1-positive cells at pathological process of microsphere embolism. Interestingly, FasL generation in cultured microglia cells subjected to oxygen-glucose deprivation-treated neuron-conditioned medium was prevented by the silencing of P2X(7). Furthermore, FasL induced the migration of BV-2 microglia, whereas the neutralization of FasL with a blocking antibody was highly effective in inhibiting ischemia-induced microglial mobility. Similar results were observed in primary microglia from wild-type mice or mice genetically deficient in P2X(7). Finally, the degrees of FasL overproduction and neuronal death were consistently reduced in P2X(7)(-/-) mice compared with wild-type littermates following microsphere embolism insult. CONCLUSION: FasL functions as a key component of an immunoreactive response loop by recruiting microglia to the lesion sites through a P2X(7)-dependent mechanism. The specific modulation of P2X(7)/FasL signaling and aberrant microglial activation could provide therapeutic benefits in acute and subacute phase of cerebral microembolic injury.