Resveratrol and Sir2 Reverse Sleep and Memory Defects Induced by Amyloid Precursor Protein / 神经科学通报·英文版

Resveratrol (RES), a natural polyphenolic phytochemical, has been suggested as a putative anti-aging molecule for the prevention and treatment of Alzheimer's disease (AD) by the activation of sirtuin 1 (Sirt1/Sir2). In this study, we tested the effects of RES and Sirt1/Sir2 on sleep and courtship memory in a Drosophila model by overexpression of amyloid precursor protein (APP), whose duplications and mutations cause familial AD. We found a mild but significant transcriptional increase of Drosophila Sir2 (dSir2) by RES supplementation for up to 17 days in APP flies, but not for 7 days. RES and dSir2 almost completely reversed the sleep and memory deficits in APP flies. We further demonstrated that dSir2 acts as a sleep promotor in Drosophila neurons. Interestingly, RES increased sleep in the absence of dSir2 in dSir2-null mutants, and RES further enhanced sleep when dSir2 was either overexpressed or knocked down in APP flies. Finally, we showed that Aβ aggregates in APP flies were reduced by RES and dSir2, probably via inhibiting Drosophila β-secretase (dBACE). Our data suggest that RES rescues the APP-induced behavioral deficits and Aβ burden largely, but not exclusively, via dSir2.

Disrupted Maturation of Prefrontal Layer 5 Neuronal Circuits in an Alzheimer's Mouse Model of Amyloid Deposition / 神经科学通报·英文版

Mutations in genes encoding amyloid precursor protein (APP) and presenilins (PSs) cause familial forms of Alzheimer's disease (AD), a neurodegenerative disorder strongly associated with aging. It is currently unknown whether and how AD risks affect early brain development, and to what extent subtle synaptic pathology may occur prior to overt hallmark AD pathology. Transgenic mutant APP/PS1 over-expression mouse lines are key tools for studying the molecular mechanisms of AD pathogenesis. Among these lines, the 5XFAD mice rapidly develop key features of AD pathology and have proven utility in studying amyloid plaque formation and amyloid β (Aβ)-induced neurodegeneration. We reasoned that transgenic mutant APP/PS1 over-expression in 5XFAD mice may lead to neurodevelopmental defects in early cortical neurons, and performed detailed synaptic physiological characterization of layer 5 (L5) neurons from the prefrontal cortex (PFC) of 5XFAD and wild-type littermate controls. L5 PFC neurons from 5XFAD mice show early APP/Aβ immunolabeling. Whole-cell patch-clamp recording at an early post-weaning age (P22-30) revealed functional impairments; although 5XFAD PFC-L5 neurons exhibited similar membrane properties, they were intrinsically less excitable. In addition, these neurons received smaller amplitude and frequency of miniature excitatory synaptic inputs. These functional disturbances were further corroborated by decreased dendritic spine density and spine head volumes that indicated impaired synapse maturation. Slice biotinylation followed by Western blot analysis of PFC-L5 tissue revealed that 5XFAD mice showed reduced synaptic AMPA receptor subunit GluA1 and decreased synaptic NMDA receptor subunit GluN2A. Consistent with this, patch-clamp recording of the evoked L23>L5 synaptic responses revealed a reduced AMPA/NMDA receptor current ratio, and an increased level of AMPAR-lacking silent synapses. These results suggest that transgenic mutant forms of APP/PS1 overexpression in 5XFAD mice leads to early developmental defects of cortical circuits, which could contribute to the age-dependent synaptic pathology and neurodegeneration later in life.

Electroacupuncture Improves Blood-Brain Barrier and Hippocampal Neuroinflammation in SAMP8 Mice by Inhibiting HMGB1/TLR4 and RAGE/NADPH Signaling Pathways / 中国结合医学杂志

OBJECTIVE@#To investigate the molecular mechanisms underlying the beneficial effect of electroacupuncture (EA) in experimental models of Alzheimer's disease (AD) in vivo.@*METHODS@#Senescence-accelerated mouse prone 8 (SAMP8) mice were used as AD models and received EA at Yingxiang (LI 20, bilateral) and Yintang (GV 29) points for 20 days. For certain experiments, SAMP8 mice were injected intravenously with human fibrin (2 mg). The Morris water maze test was used to assess cognitive and memory abilities. The changes of tight junctions of blood-brain barrier (BBB) in mice were observed by transmission electron microscope. The expressions of fibrin, amyloid- β (Aβ), and ionized calcium-binding adapter molecule 1 (IBa-1) in mouse hippocampus (CA1/CA3) were detected by reverse transcription-quantitative polymerase chain reaction (qRT-PCR), Western blot or immunohistochemical staining. The expression of fibrin in mouse plasma was detected by enzyme-linked immunosorbent assay. The expressions of tight junction proteins zonula occludens-1 and claudin-5 in hippocampus were detected by qRT-PCR and immunofluorescence staining. Apoptosis of hippocampal neurons was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining.@*RESULTS@#Fibrin was time-dependently deposited in the hippocampus of SAMP8 mice and this was inhibited by EA treatment (P<0.05 or P<0.01). Furthermore, EA treatment suppressed the accumulation of Aβ in the hippocampus of SAMP8 mice (P<0.01), which was reversed by fibrin injection (P<0.05 or P<0.01). EA improved SAMP8 mice cognitive impairment and BBB permeability (P<0.05 or P<0.01). Moreover, EA decreased reactive oxygen species levels and neuroinflammation in the hippocampus of SAMP8 mice, which was reversed by fibrin injection (P<0.05 or P<0.01). Mechanistically, EA inhibited the promoting effect of fibrin on the high mobility group box protein 1 (HMGB1)/toll-like receptor 4 (TLR4) and receptor for advanced glycation end products (RAGE)/nicotinamide adenine dinucleotide phosphate (NADPH) signaling pathways (P<0.01).@*CONCLUSION@#EA may potentially improve cognitive impairment in AD via inhibition of fibrin/A β deposition and deactivation of the HMGB1/TLR4 and RAGE/NADPH signaling pathways.

Therapeutic Mechanism of Kai Xin San on Alzheimer's Disease Based on Network Pharmacology and Experimental Validation / 中国结合医学杂志

OBJECTIVE@#To explore the specific pharmacological molecular mechanisms of Kai Xin San (KXS) on treating Alzheimer's disease (AD) based on network pharmacology and experimental validation.@*METHODS@#The chemical compounds of KXS and their corresponding targets were screened using the Encyclopedia of Traditional Chinese Medicine (ETCM) database. AD-related target proteins were obtained from MalaCards database and DisGeNET databases. Key compounds and targets were identified from the compound-target-disease network and protein-protein interaction (PPI) network analysis. Functional enrichment analysis predicted the potential key signaling pathways involved in the treatment of AD with KXS. The binding affinities between key ingredients and targets were further verified using molecular docking. Finally, the predicted key signaling pathway was validated experimentally. Positioning navigation and space search experiments were conducted to evaluate the cognitive improvement effect of KXS on AD rats. Western blot was used to further examine and investigate the expression of the key target proteins related to the predicted pathway.@*RESULTS@#In total, 38 active compounds and 469 corresponding targets of KXS were screened, and 264 target proteins associated with AD were identified. The compound-target-disease and PPI networks identified key active ingredients and protein targets. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis suggested a potential effect of KXS in the treatment of AD via the amyloid beta (A β)-glycogen synthase kinase-3 beta (GSK3 β)-Tau pathway. Molecular docking revealed a high binding affinity between the key ingredients and targets. In vivo, KXS treatment significantly improved cognitive deficits in AD rats induced by Aβ1-42, decreased the levels of Aβ, p-GSK3β, p-Tau and cyclin-dependent kinase 5, and increased the expressions of protein phosphatase 1 alpha (PP1A) and PP2A (P<0.05 or P<0.01).@*CONCLUSION@#KXS exerted neuroprotective effects by regulating the Aβ -GSK3β-Tau signaling pathway, which provides novel insights into the therapeutic mechanism of KXS and a feasible pharmacological strategy for the treatment of AD.

Visual analysis of research on traditional Chinese medicine treatment of Alzheimer's disease in recent ten years / 中国中药杂志

This study employed bibliometrics tools to review the studies of traditional Chinese medicine(TCM) treatment of Alzheimer's disease(AD) in recent ten years, aiming to explore the research status, hotspots, and future trends in this field at home and abroad. The relevant literature published from January 1, 2012 to August 15, 2022 was retrieved from Web of Science and CNKI. CiteSpace 6.1R2 and VOSviewer 1.6.15 were used for the visual analysis of authors, countries, institutions, keywords, journals, etc. A total of 2 254 Chinese articles and 545 English articles were included. The annual number of articles published showed a rising trend with fluctuations. The country with the largest number of relevant articles published and the largest centrality was China. SUN Guo-jie and WANG Qi were the authors publishing the most Chinese articles and English articles, respectively. Hubei University of Chinese Medicine and Beijing University of Chinese Medicine published the most articles in Chinese and English, respectively. Journal of Ethnopharmacology and Neuroscience Letters published the articles with the highest cited frequency and the highest centrality. According to the keywords, the research on TCM treatment of AD mainly focused on the mechanism of action and treatment methods. Metabolomics, intestinal flora, oxidative stress, tau hyperphosphorylation, β-amyloid(Aβ), inflammatory cytokines, and autophagy were the focuses of the research on mechanism of action. Acupuncture, clinical effect, kidney deficiency and phlegm stasis, and dredging governor vessel to revitalize mind were the hotspots of clinical research. This research field is still in the stage of exploration and development. Exchanges and cooperation among institutions should be encouraged to carry out more high-quality basic research on TCM treatment of AD, obtain high-level evidence, and clarify the pathogenesis and prescription mechanism.

Elevated Levels of Naturally-Occurring Autoantibodies Against the Extracellular Domain of p75NTR Aggravate the Pathology of Alzheimer's Disease / 神经科学通报·英文版

The extracellular domain (p75ECD) of p75 neurotrophin receptor (p75NTR) antagonizes Aβ neurotoxicity and promotes Aβ clearance in Alzheimer's disease (AD). The impaired shedding of p75ECD is a key pathological process in AD, but its regulatory mechanism is largely unknown. This study was designed to investigate the presence and alterations of naturally-occurring autoantibodies against p75ECD (p75ECD-NAbs) in AD patients and their effects on AD pathology. We found that the cerebrospinal fluid (CSF) level of p75ECD-NAbs was increased in AD, and negatively associated with the CSF levels of p75ECD. Transgenic AD mice actively immunized with p75ECD showed a lower level of p75ECD and more severe AD pathology in the brain, as well as worse cognitive functions than the control groups, which were immunized with Re-p75ECD (the reverse sequence of p75ECD) and phosphate-buffered saline, respectively. These findings demonstrate the impact of p75ECD-NAbs on p75NTR/p75ECD imbalance, providing a novel insight into the role of autoimmunity and p75NTR in AD.

Proteína precursora del beta-amiloide (ß-App) y daño axonal difuso tras un traumatismo craneoencefálico: un punto de vista forense / Beta-amiloid precursos protein (ß-App) and diffuse axonal damage after head injuries: a forensic point of view

Resumen La proteína precursora del β- Amiloide (β-APP) es una glicoproteína de membrana y un componente habitual de las neuronas. Tiene funciones en el crecimiento y la adhesión celular tras un traumatismo. Es transportada mediante transporte rápido axonal anterógrado y se acumula dentro de las neuronas cuando se daña citoesqueleto. Este proceso es activo, es decir consume energía. El β-APP no es específico de los traumatismos. Se acumula en cualquier circunstancia en la que se dañen los axones, tal como la hipoxia, alteraciones metabólicas, y cualquier otra causa de edema cerebral y aumento de la presión intracraneal que puedan conducir a un daño axonal difuso (DAI) En el presente estudio estudiamos la expresión de esta proteína en casos de traumatismo cráneo-encefálico con diferente evolución cronológica El daño del citoesqueleto producido por la proteólisis, junto con la alteración de las quinasas y las fosfatasas, aumentan la permeabilidad de la membrana, lo que provoca la entrada de calcio en la célula que, a su vez, activa la calmodulina que hace que los neurofilamentos se compacten, los microtúbulos desaparezcan y se rompa la espectrina. Esta disrupción del citoesqueleto tiene como consecuencia que las sustancias que se transportan a su través, se acumulen, sobre todo en las zonas afectadas por el DAI. Al final de todo este proceso, los axones se rompen, lo que se conoce como axotomía secundaria. El estudio de la acumulación del β-APP es útil para valorar la extensión del DAI y para determinar el tiempo de supervivencia tras el traumatismo o cualquier otro daño cerebral.

Abstract β-Amyloid Precursor Protein (β-APP) is a membrane glycoprotein and a common component of neurons. It is involved in adhesion and cell growth processes after traumatic events. It is carried by anterograde fast axonal transport, and it accumulates inside neurons when the cytoskeleton is damaged. This is a vital biochemical process that consumes energy. β-APP is not specific of traumatic events. It accumulates in any case of axonal damage, whatever its cause may be, like hypoxia, metabolic disorders, and any other circumstances that lead to brain swelling and intracranial pressure rising and in consequence to Diffuse Axonal Injury (DAI). In this study we review the expression of this protein in cases of traumatic brain injury with different chronological evolution. The damage of cytoskeleton due to proteolysis in addition to the disturbance of kinases and phosphatases increase the permeability of the membrane. Calcium gets into the cell and activates calmodulin, thus neurofilaments compact, microtubules disappear and spectrin breaks. This disruption of the cytoskeleton has as consequence that the transported substances accumulate in the most affected areas by DAI. At the end of this process axon breaks, which is known as secondary axotomy. The study of the accumulation of β-APP is useful to assess the extent of DAI and to determine the time elapsed after trauma or another insult to CNS.

Accuracy of the brief cognitive screening battery for diagnosing Alzheimer's disease defined by cerebrospinal fluid biomarkers and AT(N) classification: a case-control study / Acurácia da bateria breve de rastreio cognitivo no diagnóstico da doença de Alzheimer definida por biomarcadores no líquido cefalorraquidiano e classificação pelo sistema AT(N): estudo caso-controle

ABSTRACT Background: Validation of cognitive instruments for detection of Alzheimer's disease (AD) based on correlation with diagnostic biomarkers allows more reliable identification of the disease. Objectives: To investigate the accuracy of the Brief Cognitive Screening Battery (BCSB) in the differential diagnosis between AD, non-AD cognitive impairment (both defined by cerebrospinal fluid [CSF] biomarkers) and healthy cognition, and to correlate CSF biomarker results with cognitive performance. Methods: Overall, 117 individuals were evaluated: 45 patients with mild cognitive impairment (MCI) or mild dementia within the AD continuum defined by the AT(N) classification [A+T+/-(N)+/]; 27 non-AD patients with MCI or mild dementia [A-T+/-(N)+/-]; and 45 cognitively healthy individuals without CSF biomarker results. All participants underwent evaluation using the BCSB. Results: The total BCSB and delayed recall (DR) scores of the BCSB memory test showed high diagnostic accuracy, as indicated by areas under the ROC curve (AUC): 0.89 and 0.87, respectively, for discrimination between AD and non-AD versus cognitively healthy controls. Similarly, total BCSB and DR displayed high accuracy (AUC-ROC curves of 0.89 and 0.91, respectively) for differentiation between AD and controls. BCSB tests displayed low accuracy for differentiation between AD and non-AD. The CSF levels of biomarkers correlated significantly, though weakly, with DR. Conclusions: Total BCSB and DR scores presented good accuracy for differentiation between patients with a biological AD diagnosis and cognitively healthy individuals, but low accuracy for differentiating AD from non-AD patients.

RESUMO Antecedentes: A validação de testes cognitivos para identificação da doença de Alzheimer (DA) definida por biomarcadores aumenta a confiabilidade diagnóstica. Objetivos: Investigar a acurácia da Bateria Breve de Rastreio Cognitivo (BBRC) no diagnóstico diferencial entre DA, comprometimento cognitivo não-DA (ambos diagnósticos definidos por biomarcadores no líquido cefalorraquidiano-LCR) e indivíduos cognitivamente saudáveis, e investigar correlações entre desempenho nos testes e concentrações dos biomarcadores no LCR. Métodos: No total, 117 indivíduos foram avaliados. Quarenta e cinco pacientes com comprometimento cognitivo leve (CCL) ou demência leve com diagnóstico do continuum de DA definido pela classificação AT(N) [A+T+/-(N)+/-], 27 pacientes com CCL ou demência leve não-DA [A-T+/-(N)+/-], e 45 controles cognitivamente saudáveis sem estudo de biomarcadores no LCR. Os participantes foram submetidos à BBRC. Resultados: O escore total da BBRC e a evocação tardia (ET) no teste de memória da BBRC apresentaram elevada acurácia diagnóstica na diferenciação entre DA e não-DA versus controles, indicada pelas áreas sob a curva ROC (AUC) de 0,89 e 0,87, respectivamente. De modo semelhante, o escore total da BBRC e a ET mostraram elevadas acurácias (AUC-ROC de 0,89 e 0,91, respectivamente) para o diagnóstico diferencial entre DA e controles. A acurácia da BBRC foi baixa na diferenciação entre DA e não-DA. Os níveis dos biomarcadores no LCR se correlacionaram de forma significativa, embora fraca, com ET. Conclusões: Os escores totais da BCSB e a ET apresentaram boa acurácia na diferenciação entre pacientes com diagnóstico biológico de DA e controles cognitivamente saudáveis, mas baixa acurácia para diferenciar DA de não-DA.

Effects of TYROBP Deficiency on Neuroinflammation of a Alzheimer's Disease Mouse Model Carrying a PSEN1 p.G378E Mutation / 中国医学科学杂志(英文版)

Objective To study the effects of TYRO protein kinase-binding protein (TYROBP) deficiency on learning behavior, glia activation and pro-inflammatory cycokines, and Tau phosphorylation of a new Alzheimer's disease (AD) mouse model carrying a PSEN1 p.G378E mutation.Methods A new AD mouse model carrying PSEN1 p.G378E mutation was built based on our previously found AD family which might be ascribed to the PSEN1 mutation, and then crossed with TYROBP deficient mice to produce the heterozygous hybrid mice (PSEN1G378E/WT; Tyrobp+/-) and the homozygous hybrid mice (PSEN1G378E/G378E; Tyrobp-/-). Water maze test was used to detect spatial learning and memory ability of mice. After the mice were sacrificed, the hippocampus was excised for further analysis. Immunofluorescence was used to identify the cell that expresses TYROBP and the number of microglia and astrocyte. Western blot was used to detect the expression levels of Tau and phosphorylated Tau (p-Tau), and ELISA to measure the levels of pro-inflammatory cytokines. Results Our results showed that TYROBP specifically expressed in the microglia of mouse hippocampus. Absence of TYROBP in PSEN1G378E mutation mouse model prevented the deterioration of learning behavior, decreased the numbers of microglia and astrocytes, and the levels of interleukin-6, interleukin-1β and tumor necrosis factor-α in the hippocampus (all P < 0.05). The ratios of AT8/Tau5, PHF1/Tau5, pT181/Tau5, pT231/Tau5 and p-ERK/ERK were all higher in homozygous hybrid mice (PSEN1G378E/G378E; Tyrobp-/- mice) compared with PSEN1G378E/G378E mice (all P < 0.05). Conclusions TYROBP deficiency might play a protective role in the modulation of neuroinflammation of AD. However, the relationship between neuroinflammation processes involving microglia and astrocyte activation, and release of pro-inflammatory cytokines, and p-Tau pathology needs further study.

Potential neuroprotective of trans-resveratrol a promising agent tempeh and soybean seed coats-derived against beta-amyloid neurotoxicity on primary culture of nerve cells induced by 2-methoxyethanol / Potencial neuroprotetor do agente trans-resveratrol em cascas de sementes de soja e tempê derivadas da neurotoxicidade beta-amiloide na cultura primária de células nervosas induzidas pelo 2-metoxietanol

Resveratrol, a natural polyphenol found in tempeh, has not been investigated especially in vitro as a neuroprotective agent against 2-methoxyethanol (2-ME)-induced beta-amyloid cytotoxicity. Beta amyloid peptides (Aß) could initiate neurotoxic events and neuron-inflammatory response via microglial activation. However, it remains unknown whether the neurotoxic effect of beta-amyloid and/or associated with the potential of 2-ME to induce neurotoxic effects on primary culture of nerve cells induced by 2-ME. This study investigated potential neuroprotective of trans-resveratrol a promising agent tempeh and soybean seed coats-derived against betaamyloid cytotoxicity on primary culture of nerve cells induced by 2-methoxyethanol. Biotium and MTT assays were used to analyze neurons, which were isolated from the cerebral cortex of fetal mice at gestation day 19 (GD-19). A standard solution of 2-methoxyethanol was dosed at 10 µL. The cultured cells were randomly divided into the following groups: (1) 2-ME group + resveratrol standard, (2) 2-ME group + resveratrol isolated from tempeh, (3) 2-ME group + resveratrol isolated from soybean seed coats, and (4) the control group, without the addition of either 2-ME or resveratrol. Exposure of the primary cortical neuron cells to beta-amyloid monoclonal antibody pre-incubated for 24 h with 10 µL of 4.2 µg/mL resveratrol and 7.5 mmol/l 2-methoxy-ethanol additions. Here, we report that the addition of 2-ME and resveratrol (standard and isolated from tempeh) of cell culture at concentrations of 1.4, 2.8 and 4.2 µg/mL showed that the majority of neurons grew well. In contrast, after exposure to 2-ME and Beta-amyloid, showed that glial activated. These findings demonstrate a role for resveratrol in neuroprotective-neurorescuing action.

O resveratrol, um polifenol natural encontrado em tempê, não foi investigado apenas in vitro como agente neuroprotetor contra a citotoxicidade beta-amiloide induzida por 2-metoxietanol (2-ME). Os peptídeos betaamiloides (Aß) podem iniciar eventos neurotóxicos e resposta inflamatória dos neurônios via ativação microglial. No entanto, permanece desconhecido se o efeito neurotóxico do peptídeo beta-amiloide associado ao potencial do 2-ME causa efeitos neurotóxicos na cultura primária de células nervosas induzidas pelo 2-ME. Este estudo investigou o potencial neuroprotetor do agente trans-resveratrol em cascas de sementes de soja e tempê derivadas da citotoxicidade beta-amiloide na cultura primária de células nervosas induzidas pelo 2-metoxietanol. Ensaios de biotium e MTT foram utilizados para analisar os neurônios isolados do córtex cerebral de camundongos fetais no dia da gestação 19 (GD-19). As células cultivadas foram divididas aleatoriamente nos seguintes grupos: (1) grupo 2-ME + padrão de resveratrol; (2) grupo 2-ME + resveratrol isolado de tempê; (3) grupo 2-ME + resveratrol isolado de cascas de sementes de soja; e (4) grupo controle, sem a adição de 2-ME ou resveratrol. Houve exposição das células primárias dos neurônios corticais ao anticorpo monoclonal beta-amiloide pré-incubado por 24 horas, com 10 µL de 4,2 µg/mL de resveratrol, e adições de 7,5 mmol/l de 2-metoxietanol. A adição de 2-ME e resveratrol (padrão e isolado do tempê) da cultura de células nas concentrações de 1,4, 2,8 e 4,2 µg/mL mostrou que a maioria dos neurônios cresceu bem. Por outro lado, após a exposição ao 2-ME e beta-amiloide, a glia foi ativada. Esses achados demonstram um papel do resveratrol na ação neuroprotetora e de neurorresgate.

Chinese Herbal Medicine Adjusting Brain Microenvironment via Mediating Central Nervous System Lymphatic Drainage in Alzheimer's Disease / 中国结合医学杂志

Due to its complex pathogenesis and lack of effective therapeutic methods, Alzheimer's disease (AD) has become a severe public health problem worldwide. Recent studies have discovered the function of central nervous system lymphatic drainage, which provides a new strategy for the treatment of AD. Chinese herbal medicine (CHM) has been considered as a cure for AD for hundreds of years in China, and its effect on scavenging β-amyloid protein in the brain of AD patients has been confirmed. In this review, the mechanism of central nervous system lymphatic drainage and the regulatory functions of CHM on correlation factors were briefly summarized. The advances in our understanding regarding the treatment of AD via regulating the central lymphatic system with CHM will promote the clinical application of CHM in AD patients and the discovery of new therapeutic drugs.

Polysaccharide Krestin Prevents Alzheimer's Disease-type Pathology and Cognitive Deficits by Enhancing Monocyte Amyloid-β Processing / 神经科学通报·英文版

Deficits in the clearance of amyloid β protein (Aβ) by the peripheral system play a critical role in the pathogenesis of sporadic Alzheimer's disease (AD). Impaired uptake of Aβ by dysfunctional monocytes is deemed to be one of the major mechanisms underlying deficient peripheral Aβ clearance in AD. In the current study, flow cytometry and biochemical and behavioral techniques were applied to investigate the effects of polysaccharide krestin (PSK) on AD-related pathology in vitro and in vivo. We found that PSK, widely used in therapy for various cancers, has the potential to enhance Aβ uptake and intracellular processing by human monocytes in vitro. After administration of PSK by intraperitoneal injection, APP/PS1 mice performed better in behavioral tests, along with reduced Aβ deposition, neuroinflammation, neuronal loss, and tau hyperphosphorylation. These results suggest that PSK holds promise as a preventive agent for AD by strengthening the Aβ clearance by blood monocytes and alleviating AD-like pathology.

Ginsenoside Rg_1 protects PC12 cells against Aβ-induced injury through promotion of mitophagy by PINK1/parkin activation / 中国中药杂志

Amyloid β-protein(Aβ) deposition in the brain is directly responsible for neuronal mitochondrial damage of Alzheimer's disease(AD) patients. Mitophagy, which removes damaged mitochondria, is a vital mode of neuron protection. Ginsenoside Rg_1(Rg_1), with neuroprotective effect, has displayed promising potential for AD treatment. However, the mechanism underlying the neuroprotective effect of Rg_1 has not been fully elucidated. The present study investigated the effects of ginsenoside Rg_(1 )on the autophagy of PC12 cells injured by Aβ_(25-35) to gain insight into the neuroprotective mechanism of Rg_1. The autophagy inducer rapamycin and the autophagy inhi-bitor chloroquine were used to verify the correlation between the neuroprotective effect of Rg_1 and autophagy. The results showed that Rg_1 enhanced the viability and increased the mitochondrial membrane potential of Aβ-injured PC12 cells, while these changes were blocked by chloroquine. Furthermore, Rg_(1 )treatment increased the LC3Ⅱ/Ⅰ protein ratio, promoted the depletion of p62 protein, up-regulated the protein levels of PINK1 and parkin, and reduced the amount of autophagy adaptor OPTN, which indicated the enhancement of autophagy. After the silencing of PINK1, a key regulatory site of mitophagy, Rg_1 could not increase the expression of PINK1 and parkin or the amount of NDP52, whereas it can still increase the LC3Ⅱ/Ⅰ protein ratio and promote the depletion of OPTN protein which indicated the enhancement of autophagy. Collectively, the results of this study imply that Rg_1 can promote autophagy of PC12 cells injured by Aβ, and may reduce Aβ-induced mitochondrial damage by promoting PINK1-dependent mitophagy, which may be one of the key mechanisms of its neuroprotective effect.

Time dependent expression profiling of PTK2B and its relationship with Aβ, Tau and LRP-1 in hippocampus and blood of APPswe/PS1dE9 double-transgenic mouse / 中国应用生理学杂志

Objective: To uncover the time-dependent expression pattern of ptk2b gene and ptk2b-encoded protein, protein tyrosine kinase 2 beta(PTK2B), in the brain tissues of transgenic animal models of Alzheimer's disease (AD) and its relationship with the levels of Aβ1-42, phosphorylation of Tau (p-Tau) and low density lipoprotein receptor-related protein-1(LRP-1) in blood and brain tissues. Methods: In this study, 5-, 10- and 15-month-old APPswe/PS1dE9 double-transgenic mice harboring the genotype of AD confirmed by the gene test were divided into the 5-, 10- and 15-month-old experiment groups, and simultaneously, age-matched C57BL/6J mice were placed into the corresponding control groups, with 8 mice in each group. All mice were subjected to the Morris Water Maze for test of cognitive and behavioral ability. Expression profiles of PTK2B, Aβ1-42, p-Tau/Tau and LRP-1 in the hippocampus or blood of mice were quantified by using the immunohistochemistry staining, Western blot or enzyme-linked immunosorbent assay (ELISA), while the mRNA expression of ptk2b in the hippocampus was quantified by using the real-time quantitative polymerase chain reaction (qRT-PCR). Results: Results of experiment groups demonstrated that as mice aged, the expression levels of PTK2B, ptk2b mRNA, Aβ1-42 and p-Tau/Tau in the hippocampus were increased, and the expression of LRP-1 was decreased gradually. While in the blood, the level of Aβ1-42 was decreased, and the cognitive and behavioral ability was decreased in an age-dependent manner (all P＜ 0.05). However, comparisons among the control groups, only the age-dependent downregulation of LRP-1 were observed in hippocampus(P＜0.05), but other indicators had no significant differences (P＞0.05). Conclusion: In the hippocampus of APP/PS1 double-transgenic mice, the expressions of PTK2B, Aβ1-42 and p-Tau/Tau are upregulated, LRP-1 is downregulated, while cognitive and behavioral ability is decreased, and such changes are presented in a time-dependent manner.

circBIRC6 contributes to the development of non-small cell lung cancer via regulating microRNA-217/amyloid beta precursor protein binding protein 2 axis / 中华医学杂志(英文版)

BACKGROUND@#Circular RNAs (circRNAs) are considered to be important regulators in cancer biology. In this study, we focused on the effect of circRNA baculoviral inhibitor of apoptosis protein (IAP) repeat containing 6 (circBIRC6) on non-small cell lung cancer (NSCLC) progression.@*METHODS@#The NSCLC and adjacent non-tumor tissues were collected at Shanghai Ninth People's Hospital. Quantitative real-time polymerase chain reaction was conducted for assessing the levels of circBIRC6, amyloid beta precursor protein binding protein 2 (APPBP2) messenger RNA (mRNA), baculoviral IAP repeat containing 6 mRNA (BIRC6), and microRNA-217 (miR-217). Western blot assay was adopted for measuring the protein levels of APPBP2, E-cadherin, N-cadherin, and vimentin. Colony formation assay, transwell assay, and flow cytometry analysis were utilized for evaluating cell colony formation, metastasis, and apoptosis. Dualluciferase reporter assay and RNA immunoprecipitation assay were carried out to determine the interaction between miR-217 and circBIRC6 and APPBP2 in NSCLC tissues. The murine xenograft model assay was used to investigate the function of circBIRC6 in tumor formation in vivo. Differences were analyzed via Student's t test or one-way analysis of variance. Pearson's correlation coefficient analysis was used to analyze linear correlation.@*RESULTS@#CircBIRC6 was overexpressed in NSCLC tissues and cells. Knockdown of circBIRC6 repressed the colony formation and metastasis and facilitated apoptosis of NSCLC cells in vitro and restrained tumorigenesis in vivo. Mechanically, circBIRC6 functioned as miR-217 sponge to promote APPBP2 expression in NSCLC cells. MiR-217 inhibition rescued circBIRC6 knockdown-mediated effects on NSCLC cell colony formation, metastasis, and apoptosis. Overexpression of miR-217 inhibited the malignant phenotypes of NSCLC cells, while the effects were abrogated by elevating APPBP2.@*CONCLUSIONS@#CircBIRC6 aggravated NSCLC cell progression by elevating APPBP2 via sponging miR-217, which might provide a fresh perspective on NSCLC therapy.

Chronic hypoperfusion due to intracranial large artery stenosis is not associated with cerebral β-amyloid deposition and brain atrophy / 中华医学杂志(英文版)

BACKGROUND@#Insufficient cerebral perfusion is suggested to play a role in the development of Alzheimer disease (AD). However, there is a lack of direct evidence indicating whether hypoperfusion causes or aggravates AD pathology. We investigated the effect of chronic cerebral hypoperfusion on AD-related pathology in humans.@*METHODS@#We enrolled a group of cognitively normal patients (median age: 64 years) with unilateral chronic cerebral hypoperfusion. Regions of interest with the most pronounced hypoperfusion changes were chosen in the hypoperfused region and were then mirrored in the contralateral hemisphere to create a control region with normal perfusion. 11C-Pittsburgh compound-positron emission tomography standard uptake ratios and brain atrophy indices were calculated from the computed tomography images of each patient.@*RESULTS@#The median age of the 10 participants, consisting of 4 males and 6 females, was 64 years (47-76 years). We found that there were no differences in standard uptake ratios of the cortex (volume of interest [VOI]: P = 0.721, region of interest [ROI]: P = 0.241) and grey/white ratio (VOI: P = 0.333, ROI: P = 0.445) and brain atrophy indices (Bicaudate, Bifrontal, Evans, Cella, Cella media, and Ventricular index, P > 0.05) between the hypoperfused regions and contralateral normally perfused regions in patients with unilateral chronic cerebral hypoperfusion.@*CONCLUSION@#Our findings suggest that chronic hypoperfusion due to large vessel stenosis may not directly induce cerebral β-amyloid deposition and neurodegeneration in humans.

Age-related episodic memory decline and the role of amyloid-ß: a systematic review / Declínio da memória episódica relacionado à idade e o papel da beta-amiloide: uma revisão sistemática

ABSTRACT Aging has been associated with the functional decline of episodic memory (EM). Unanswered questions are whether the decline of EM occurs even during healthy aging and whether this decline is related to amyloid-β (Aβ) deposition in the hippocampus. Objective: The main purpose of this study was to investigate data on the relationship between the age-related EM decline and Aβ deposition. Methods: We searched the Cochrane, MEDLINE, Scopus, and Web of Science databases and reference lists of retrieved articles that were published in the past 10 years. The initial literature search identified 517 studies. After screening the title, abstract, key words, and reference lists, 56 studies met the inclusion criteria. Results: The overall results revealed that increases in Aβ are related to lower hippocampal volume and worse performance on EM tests. The results of this systematic review revealed that high levels of Aβ may be related to EM deficits and the progression to Alzheimer's disease. Conclusions: We discussed the strengths and pitfalls of various tests and techniques used for investigating EM and Aβ deposition, methodological issues, and potential directions for future research.

RESUMO O envelhecimento tem sido associado a um declínio funcional da memória episódica (ME). Algo ainda sem resposta é se o declínio da ME ocorre mesmo no envelhecimento saudável e se esse declínio pode estar relacionado à deposição de Aβ no hipocampo. Objetivo: Nosso objetivo principal foi investigar os dados sobre a relação entre a memória episódica e a deposição de Aβ no envelhecimento saudável. Métodos: Nós buscamos nas bases de dados Cochrane, MEDLINE, Scopus, Web of Science e nas listas de referências dos estudos dos últimos 10 anos. A busca inicial nas bases de dados identificou 517 estudos. Após a triagem de título, resumos, palavras-chave e referências, 56 estudos atenderam aos critérios de inclusão. Resultados: O resultado geral revelou que o aumento de Aβ estava relacionado ao menor volume do hipocampo e pior desempenho em testes de ME. Em resumo, os resultados da presente revisão sistemática revelaram que altos níveis de Aβ podem estar relacionados ao declínio de ME e conversão progressiva para a Doença de Alzheimer. Conclusões: Aqui, discutimos os pontos fortes e as limitações dos testes e técnicas para investigar a deposição ME e Aβ, bem como questões metodológicas e direções futuras.

Investigation of anti-Alzheimer's activity of aqueous extract of areca nuts (Areca catechu L): in vitro and in vivo studies / Investigación de la actividad anti-Alzheimer del extracto acuoso de nueces de areca (Areca catechu L): estudios in vitro e in vivo

Alzheimer's disease (AD) is an age-related neurodegenerative disorder. Sever cognitive and memory impairments, huge increase in the prevalence of the disease, and lacking definite cure have absorbed worldwide efforts to develop therapeutic approaches. Since many drugs have failed in the clinical trials due to multifactorial nature of AD, symptomatic treatments are still in the center attention and now, nootropic medicinal plants have been found as versatile ameliorators to reverse memory disorders. In this work, anti-Alzheimer's activity of aqueous extract of areca nuts (Areca catechu L.) was investigated via in vitro and in vivo studies. It depicted good amyloid ß (Aß) aggregation inhibitory activity, 82% at 100 µg/mL. In addition, it inhibited beta-secretase 1 (BACE1) with IC50 value of 19.03 µg/mL. Evaluation of neuroprotectivity of the aqueous extract of the plant against H2O2-induced cell death in PC12 neurons revealed 84.5% protection at 1 µg/mL. It should be noted that according to our results obtained from Morris Water Maze (MWM) test, the extract reversed scopolamine-induced memory deficit in rats at concentrations of 1.5 and 3 mg/kg.

La enfermedad de Alzheimer (EA) es un trastorno neurodegenerativo relacionado con la edad. Los severos deterioros cognitivos y de la memoria, el enorme aumento de la prevalencia de la enfermedad y la falta de una cura definitiva han absorbido los esfuerzos mundiales para desarrollar enfoques terapéuticos. Dado que muchos fármacos han fallado en los ensayos clínicos debido a la naturaleza multifactorial de la EA, los tratamientos sintomáticos siguen siendo el centro de atención y ahora, las plantas medicinales nootrópicas se han encontrado como mejoradores versátiles para revertir los trastornos de la memoria. En este trabajo, se investigó la actividad anti-Alzheimer del extracto acuoso de nueces de areca (Areca catechu L.) mediante estudios in vitro e in vivo. Representaba una buena actividad inhibidora de la agregación de amiloide ß (Aß), 82% a 100 µg/mL. Además, inhibió la beta-secretasa 1 (BACE1) con un valor de CI50 de 19,03 µg/mL. La evaluación de la neuroprotección del extracto acuoso de la planta contra la muerte celular inducida por H2O2 en neuronas PC12 reveló una protección del 84,5% a 1 µg/mL. Cabe señalar que, de acuerdo con nuestros resultados obtenidos de la prueba Morris Water Maze (MWM), el extracto revirtió el déficit de memoria inducido por escopolamina en ratas a concentraciones de 1,5 y 3 mg/kg.

Azeliragon ameliorates Alzheimer's disease via the Janus tyrosine kinase and signal transducer and activator of transcription signaling pathway

OBJECTIVES: TTP488, an antagonist of the receptor for advanced glycation end-products, was evaluated as a potential treatment for patients with mild-to-moderate Alzheimer's disease (AD). However, the mechanism underlying the protective action of TTP488 against AD has not yet been fully explored. METHODS: Healthy male rats were exposed to aberrant amyloid β (Aβ) 1-42. Lipopolysaccharide (LPS) and the NOD-like receptor family pyrin domain containing 1 (NLRP1) overexpression lentivirus were injected to activate the NLRP1 inflammasome and exacerbate AD. TTP488 was administered to reverse AD injury. Finally, tofacitinib and fludarabine were used to inhibit the activity of Janus tyrosine kinase (JAK) and signal transducer and activator of transcription (STAT) to prove the relationship between the JAK/STAT signaling pathway and TTP488. RESULTS: LPS and NLRP1 overexpression significantly increased the NLRP1 levels, reduced neurological function, and aggravated neuronal damage, as demonstrated by the impact latency time of, time spent by, and length of the platform covered by, the mice in the Morris water maze assay, Nissl staining, and immunofluorescence staining in rats with AD. CONCLUSIONS: TTP488 administration successfully reduced AD injury and reversed the aforementioned processes. Additionally, tofacitinib and fludarabine administration could further reverse AD injury after the TTP488 intervention. These results suggest a new potential mechanism underlying the TTP488-mediated alleviation of AD injury.