Osthole reduced Aβ synthesis by up-regulatingmiRNA-107 in neurons transfected with APP595/596 gene / 中国药理学通报

Aim To investigate the neuroprotective effects of osthole(Ost)on the primary cultured cortical neurons transfected with APP595/596 gene and its underlying mechanism.Methods Neonatal mouse cortical neurons were transfected with APP595/596 gene to establish AD cell models for the further study.Then,the cell viability was detected by CCK-8 assay,and the leakage of lactate dehydrogenase(LDH)was assayed by LDH kit to evaluate the injury degree.Transferase-mediated nick end labeling(TUNEL)was used to evaluate the cell apoptosis.The expression of β-amyloid peptide(Aβ)and β-site APP cleaving enzyme 1(BACE1)was measured by immunofluorescence,while the miRNA-107 was measured by RT-PCR.Results Compared to model group,Ost could significantly improve the neurons viability,decrease the LDH release and prevent the apoptosis.Ost also inhibited the expression of Aβ and BACE1 at protein level,while enhanced the expression of miRNA-107 at gene level.Conclusion Ost plays a neuroprotective role in neurons transfected with APP595/596 gene in part through up-regulating miRNA-107.

The effects of resveratrol on the express of inflammatory factors of human umbilical vein endothelial cells induced by Aβ1 -42 / 重庆医学

Objective To explore the effects of resveratrol on the express of inflammatory factors (IL‐1 ,IL‐6 ,TNF‐α)of hu‐man umbilical vein endothelial cells(HUVEC) induced by Aβ1 -42 .Methods HUVEC were stimulated with Aβ1 -42 5 × 101 μmol/L , last 24 h and administrated with resveratrol 160 ,80 ,40 ,20 μg/L ,HUVEC viability were detected by CCK‐8 ;the concentration of IL‐1 ,IL‐6 and TNF‐α were detected by ELISA .Results Compared with model group ,160 ,80 ,40 ,20 μg/L resveratrol could in‐crease HUVEC survival rate ,reduced HUVEC damage by Aβ1 -42 ,inhibited the concentration of IL‐1 ,IL‐6 and TNF‐α(P<0 .05) . Conclusion Resveratrol over 20 μg/L could reduce the release of IL‐1 ,IL‐6 and TNF‐αof HUVEC inducing by Aβ1 -42 .

Protective effects of Acanthopanax divaricatus extract in mouse models of Alzheimer's disease

BACKGROUND: Acanthopanax divaricatus var. albeofructus (ADA) extract has been reported to have anti-oxidant, immunomodulatory, and anti-mutagenic activity. MATERIALS/METHODS: We investigated the effects of ADA extract on two mouse models of Alzheimer's disease (AD); intracerebroventricular injection of beta-amyloid peptide (Abeta) and amyloid precursor protein/presenilin 1 (APP/PS1)-transgenic mice. RESULTS: Intra-gastric administration of ADA stem extract (0.25 g/kg, every 12 hrs started from one day prior to injection of Abeta1-42 until evaluation) effectively blocked Abeta1-42-induced impairment in passive avoidance performance, and Abeta1-42-induced increase in immunoreactivities of glial fibrillary acidic protein and interleukin (IL)-1alpha in the hippocampus. In addition, it alleviated the Abeta1-42-induced decrease in acetylcholine and increase in malondialdehyde levels in the cortex. In APP/PS1-transgenic mice, chronic oral administration of ADA stem extract (0.1 or 0.5 g/kg/day for six months from the age of six to 12 months) resulted in significantly enhanced performance of the novel-object recognition task, and reduced amyloid deposition and IL-1beta in the brain. CONCLUSIONS: The results of this study suggest that ADA stem extract may be useful for prevention and treatment of AD.

Protective effects of Acanthopanax divaricatus extract in mouse models of Alzheimer's disease

BACKGROUND: Acanthopanax divaricatus var. albeofructus (ADA) extract has been reported to have anti-oxidant, immunomodulatory, and anti-mutagenic activity. MATERIALS/METHODS: We investigated the effects of ADA extract on two mouse models of Alzheimer's disease (AD); intracerebroventricular injection of beta-amyloid peptide (Abeta) and amyloid precursor protein/presenilin 1 (APP/PS1)-transgenic mice. RESULTS: Intra-gastric administration of ADA stem extract (0.25 g/kg, every 12 hrs started from one day prior to injection of Abeta1-42 until evaluation) effectively blocked Abeta1-42-induced impairment in passive avoidance performance, and Abeta1-42-induced increase in immunoreactivities of glial fibrillary acidic protein and interleukin (IL)-1alpha in the hippocampus. In addition, it alleviated the Abeta1-42-induced decrease in acetylcholine and increase in malondialdehyde levels in the cortex. In APP/PS1-transgenic mice, chronic oral administration of ADA stem extract (0.1 or 0.5 g/kg/day for six months from the age of six to 12 months) resulted in significantly enhanced performance of the novel-object recognition task, and reduced amyloid deposition and IL-1beta in the brain. CONCLUSIONS: The results of this study suggest that ADA stem extract may be useful for prevention and treatment of AD.

Effects of Flavonoid Compounds on beta-amyloid-peptide-induced Neuronal Death in Cultured Mouse Cortical Neurons / 전남의대학술지

Excessive accumulation of beta-amyloid peptide (Abeta) is one of the major mechanisms responsible for neuronal death in Alzheimer's disease. Flavonoids, primarily antioxidants, are a group of polyphenolic compounds synthesized in plant cells. The present study aimed to identify flavonoid compounds that could inhibit Abeta-induced neuronal death by examining the effects of various flavonoids on the neurotoxicity of Abeta fragment 25-35 (Abeta25-35) in mouse cortical cultures. Abeta25-35 induced concentration- and exposure-time-dependent neuronal death. Neuronal death induced by 20 microM Abeta25-35 was significantly inhibited by treatment with either Trolox or ascorbic acid. Among 10 flavonoid compounds tested [apigenin, baicalein, catechin, epicatechin, epigallocatechin gallate (EGCG), kaempferol, luteolin, myricetin, quercetin, and rutin], all except apigenin showed strong 1,1-diphenyl-2-pycrylhydrazyl (DPPH) scavenging activity under cell-free conditions. The flavonoid compounds except apigenin at a concentration of 30 microM also significantly inhibited neuronal death induced by 20 microM Abeta25-35 at the end of 24 hours of exposure. Epicatechin, EGCG, luteolin, and myricetin showed more potent and persistent neuroprotective action than did the other compounds. These results demonstrated that oxidative stress was involved in Abeta-induced neuronal death, and antioxidative flavonoid compounds, especially epicatechin, EGCG, luteolin, and myricetin, could inhibit neuronal death. These findings suggest that these four compounds may be developed as neuroprotective agents against Alzheimer's disease.

Effects of Flavonoid Compounds on beta-amyloid-peptide-induced Neuronal Death in Cultured Mouse Cortical Neurons / 전남의대학술지

Excessive accumulation of beta-amyloid peptide (Abeta) is one of the major mechanisms responsible for neuronal death in Alzheimer's disease. Flavonoids, primarily antioxidants, are a group of polyphenolic compounds synthesized in plant cells. The present study aimed to identify flavonoid compounds that could inhibit Abeta-induced neuronal death by examining the effects of various flavonoids on the neurotoxicity of Abeta fragment 25-35 (Abeta25-35) in mouse cortical cultures. Abeta25-35 induced concentration- and exposure-time-dependent neuronal death. Neuronal death induced by 20 microM Abeta25-35 was significantly inhibited by treatment with either Trolox or ascorbic acid. Among 10 flavonoid compounds tested [apigenin, baicalein, catechin, epicatechin, epigallocatechin gallate (EGCG), kaempferol, luteolin, myricetin, quercetin, and rutin], all except apigenin showed strong 1,1-diphenyl-2-pycrylhydrazyl (DPPH) scavenging activity under cell-free conditions. The flavonoid compounds except apigenin at a concentration of 30 microM also significantly inhibited neuronal death induced by 20 microM Abeta25-35 at the end of 24 hours of exposure. Epicatechin, EGCG, luteolin, and myricetin showed more potent and persistent neuroprotective action than did the other compounds. These results demonstrated that oxidative stress was involved in Abeta-induced neuronal death, and antioxidative flavonoid compounds, especially epicatechin, EGCG, luteolin, and myricetin, could inhibit neuronal death. These findings suggest that these four compounds may be developed as neuroprotective agents against Alzheimer's disease.

Aspectos da fisiopatologia da doença de Alzheimer esporádica / Pathophysiological features of sporadic Alzheimer's disease

A doença de Alzheimer (DA) é a forma de demência degenerativa esporádica mais comum. Caracteristicamente ocorre expressiva perda neuronal progressiva em locais específicos nas pessoas atingidas. O distúrbio degenerativo progressivo se caracteriza pela perda de sinapses, de neurônios cerebrais e por depósitos de fibrilas de peptídeos de beta-amilóide extraneuronais, constituindo as placas senis e a presença de agregados intraneuronais da proteína tau, formando os emaranhados neurofibrilares. Fatores genéticos, metabólicos, neuroinflamação, alterações mitocondriais, distúrbios vasculares e processos oxidativos estão envolvidos no desencadear e manutenção de várias doenças neurodegenerativas, incluindo a DA. Todas essas alterações participam no processo fisiopatológico da doença. O objetivo desta revisão é mostrar a associação das várias causas subjacentes ao processo fisiopatológico da DA, com vistas ao desenvolvimento de marcadores biológicos e estratégias terapêuticas.

Alzheimer's disease (AD) is the most common form of sporadic degenerative dementia. Characteristically there is an expressive neuronal loss in specific sites in the affected persons. The progressive degenerative disorder is characterized by synaptic loss, of brain neurons, and by extraneuronal deposition of beta-amyloid fibrils, constituting the senile plaques, and the presence of intraneuronal aggregates of tau protein, forming the neurofibrillary tangles. Genetic factors, metabolic, neuroinflammation, mitochondrial disturbances, vascular disorders and oxidative processes are involved in the onset and maintenance of several neurodegenerative disorders, including AD. All these disturbances participate in the pathophysiological process of the disease. The aim of this review is to show the association of the varied causes underlying the pathophysiological process of AD, having in view the development of biological markers and therapeutic strategies.

INTERACCIÓN DE LA GLUTAMINA SINTETASA (GS) Y EL PÉPTIDO β -AMILOIDE COMO UNA ESTRATEGIA DE PURIFICACIÓN [title language="en"]INTERACTION OF GLUTAMINE SYNTHETASE (GS) AND AMYLOID β-PEPTIDE AS A PURIFICATION STRATEGY / INTERAÇÃO DA GLUTAMINA SINTETASE (GS) E PÉPTIDO β AMILÓIDE COMO UMA ESTRATÉGIA DE PURIFICAÇÃO

La enfermedad de Alzheimer (EA) es la forma de demencia más común en la edad adulta. Se manifiesta con la pérdida progresiva de la memoria a medida que las neuronas en la corteza cerebral y el hipocampo mueren. En todas las formas de EA se evidencia aumento de la expresión de diferentes proteínas, así como la presencia de agregados insolubles de péptido-β-amiloide (PBA). La glutamina sintetasa (GS) es una enzima clave en el metabolismo del glutamato y en la detoxificación de amonio (NH4+). Previamente se ha reportado una posible interacción GS-PBA que puede estar asociada con EA. En este trabajo se realizó la purificación de la enzima cerebral de rata a partir de un extracto sometido a precipitación fraccionada con (NH4)2SO4 del 20-60 % de saturación y posteriormente a través de cromatografías sucesivas de filtración en gel, intercambio iónico y afinidad. El peso molecular del complejo fue calculado en 137 kDa por el orden de elución en la columna de filtración. Se identificó interacción de la enzima con PBA 1-40, lográndose la purificación de una sola banda de 45 kDa, correspondiente a la forma monomérica de la GS. En este trabajo se presenta un nuevo método de purificación de la enzima y se demuestra la interacción de GS con el PBA. Se propone que esta interacción GS-PBA puede ser uno de los procesos que se presentan en la enfermedad al explicar la reducción de la actividad de la enzima en paciente con EA, ya que podría alterar el ciclo glutamato-glutamina y generar cambios en el entorno celular que favorecen excitotoxicidad por glutamato típica de los procesos de neurodegeneración.

Alzheimer's disease (AD) is the most common form of dementia in adulthood; it is manifested by the progressive loss of memory since neurons in both cerebral cortex and hippocampus die. In all the forms of AD is observed the increased expression of different proteins, as well as the presence of insoluble aggregates of β-amyloid peptide (BAP). Glutamine synthetase (GS) is a key enzyme in the metabolism of glutamate and in the detoxification of ammonium (NH4+). A possible interaction GS-PBA has been previously reported and it can be associated with AD. In this work we performed the purification of the enzyme from rat brain extract subjected to fractional precipitation 20-60 % saturation with (NH4)2SO4, and thereafter through successive chromatographies of gel filtration, ion exchange and affinity. The molecular weight of the complex was calculated at 137 kDa by the order of elution in the column filtration. The interaction of the enzyme with 1-40 PBA was identified, achieving the purification of a single band of 45 kDa corresponding to the monomeric form of the GS. In this paper we present a new method of the enzyme purification and we demonstrated the interaction of GS with the PBA. We propose this interaction GS-PBA can be one of the processes that occur in the disease and it could explain the reduction in enzyme activity in patients with AD, since it might alter the glutamate-glutamine cycle and generate changes in the cellular environment which favor glutamate excitotoxicity typical of neurodegeneration processes.

A doença do Alzhéimer (DA) é a forma mais comum de demência na idade adulta, que se manifesta pela perda progressiva da memória, já que os neurónios em córtex cerebral e hipocampo morrem. Em todas as formas de AD é observado o aumento da expressão de proteínas diferentes, bem como a presença de agregados insolúveis de β-amilóide péptido (BAP). Glutamina sintetase (GS) é uma enzima chave no metabolismo do glutamato e na desintoxicação de amónio (NH4+). Uma possível interacção GS-PBA foi relatada anteriormente e pode ser associada com o AD. Neste trabalho, foi realizada a purificação da enzima a partir do extrato do cérebro de rato e foi submetido a precipitação fraccionada com (NH4)2SO4 de 20- 60 % de saturação e, subsequentemente, através de cromatografias sucessivas de filtração em em gel, permuta iónica e de afinidade. O peso molecular do complexo foi calculado em 137 kDa por ordem de eluição na filtração de coluna. A interacção da enzima com 1-40 PBA foi identificada, alcançando a purificação de uma única banda de 45 kDa correspondente à forma monomérica do GS. Neste artigo, apresentamos um novo método de purificação da enzima e demonstramos a interação da GS com o PBA. Propomos que esta interacção GS-PBA pode ser um dos processos que ocorrem na doença e pode explicar a redução na actividade da enzima nos pacientes com o AD, uma vez que poderia alterar o ciclo de glutamatoglutamina e gerar alterações no ambiente celular que favorecem a excitotoxicidade típica do glutamato nos processos de neurodegeneração.

Estrés oxidativo, péptido beta-amiloide y enfermedad de Alzheimer / Oxidative stress, beta-amyloide peptide and Alzheimer's disease

La enfermedad de Alzheimer es la causa más común de demencia en la población de edad avanzada. Una de las características histopatológicas de esta enfermedad es la formación de placas seniles, cuyo componente proteínico es el péptido β-amiloide (Aβ) en su forma insoluble. Este péptido se produce normalmente en forma monomérica soluble y circula en concentraciones bajas en el líquido cefalorraquídeo y sangre. En concentraciones fisiológicas actúa como factor neurotrófico y neuroprotector, sin embargo con el envejecimiento y sobre todo en la enfermedad de Alzheimer se acumula, forma fibrillas insolubles y causa neurotoxicidad. La toxicidad del Aβ se ha asociado a la generación de radicales libres que causan peroxidación de lípidos y oxidación de proteínas entre otros daños. Se ha planteado que el Aβ pueda reconocer a receptores específicos que median a su vez neurotoxicidad. Entre estos se encuentra el receptor scavenger o pepenador que se expresa en la microglia y es capaz de internalizar agregados de este péptido. Independientemente de la vía de entrada del péptido a la célula, éste genera un estado de estrés oxidativo que eventualmente desencadena la muerte celular. Estudios recientes desarrollados en nuestro laboratorio muestran que el proceso de traducción de proteínas que intervienen en el proceso de endocitosis mediada por un receptor puede ser afectado por una condición de estrés oxidativo. Este es el caso de la β-adaptina, proteína clave en la formación del pozo cubierto.

Alzheimer's disease, the leading cause of dementia in the elderly is characterized by the presence in the brain of senile plaques formed of insoluble fibrillar deposits of beta-amyloid peptide. This peptide is normally produced in a monomeric soluble form and it is present in low concentrations in the blood and spinal fluid. At physiological concentrations, this peptide is a neurotrophic and neuroprotector factor; nevertheless, with aging and particularly in Alzheimer's disease this peptide accumulates, favors the formation of insoluble fibrils and causes neurotoxicity. beta-Amyloid peptide toxicity has been associated with the generation of free radicals that in turn promote lipid peroxidation and protein oxidation. Through the recognition of specific receptors such as the scavenger receptor, the beta-amyloid peptide becomes internalized in the form of aggregates. Independently of the way the peptide enters the cell, it generates oxidative stress that eventually triggers a state of neurotoxicity and cell death. Recent studies in our laboratory have shown the effect caused by an extracellular oxidative stress upon the internalization of the scavenger receptor. We have also demonstrated that the process of protein translation of molecules implicated in the mechanism of endocytosis through the scavenger receptor, such as the case of beta-adaptin, is arrested in microglial cells treated with beta-amyloid.

The dementia models induced by intracerebroventricular infusion of ?-Amyloid peptide in mice / 中国药理学通报

Aim To establish the dementia mice models induced by intracerebroventricular infusion of ?-Amyloid peptide and related measuring index. Methods The mice models were made by intracerebroventricular infusion of long fragment of soluble?-Amyloid peptide with micropump, intracerebroventricular injection of long soluble?-Amyloid peptide fragment and short insoluble ?-Amyloid peptide fragment,and intracerebroventricular injection of ?-Amyloid peptide combining with transforming growth factor. Results Compared with normal control, the learning and memory ability was decreased in all above model mice. the ChAT activity in both hippocampus and cortex of model mice decreased, the hippocampal neuron were depleted and the content of apoptosis associated protein Bal-2?BAX and p53 were increased. Conclusions All above mice models could be choose as the dementia models which were simulating the pathological charactoristics of the Alzheimer's disease.

Pharmacological Treatment Strategies for Alzheimer's Disease

Alzheimer's disease(AD) is one of the most common causes of mental deterioration in elderly individuals, accounting for around 45~60% of the overall cases of dementia over 65 years of age. Although there is presently no "cure" for AD, a large number of potential therapeutic interventions have emerged to correct cholinergic dysfunctions. Currently, cholinergic therapy, particularly cholinesterase inhibition, represents the most realistic approach to the symptomatic treatment of AD. Modest efficacy for mild to moderate AD has been shown in well-designed clinical trials for tacrine, donepezil, rivastigmine, and galantimine. Among other treatment options, estrogen replacement therapy in postmenopausal women is under active investigation, but recent studies showed somewhat disappointing results. Epidemiological and clinical data suggest that nonsteroidal anti-inflammatory drugs are beneficial in the treatment and prevention of AD. But prednisone and COX-2 inhibitor, celecoxib showed no clinical benefit in recent studies. Alpha-tocopherol and gingko biloba showed some beneficial effect in delaying the progression of AD and enhancing cognitive functions. Immunization with beta amyloid peptide was considered to be the only method to prevent and halt disease progression in patients with AD. Recently, phase II clinical trial using synthetic beta amyloid peptide (AN-1792) was discontinued because some patients showed neuro-inflammation which may be caused by autoimmune responses.

Effect of beta-amyloid Peptide on Fine Structure of Cardiac Myocytes in Culture / 대한해부학회지

Several predetermined concentrations of beta-amyloid peptide, (betaA) were administered to the rat cardiac myocyte cultures for three days to determine the effects of betaA. Stainings with congo red and crystal violet were used to evaluate the deposition of betaA in the cardiac myocytes and MTT assay was used to elucidate the cytotoxic effects of betaA by anlaysis of cell viability. Beating rates and morphological changes were investigated with inverted microscope and TEM was used to study the fine structures. Administration of 0.5 microgram/ml of betaA to cardiac myocytes induced the reduction of beating rate, however, it did neither affect the viability nor fine structures. No significant differences in cell viability or fine structures were noted in the experimental groups which were exposed to 5 microgram/ml or higher concentration of betaA. Deposition of betaA was confirmed in the cytoplasm of betaA treated cardiac myocytes with congo red and crystal violet amyloid stains. The viability of cardiac myocytes exposed to betaA was found to be reduced significantly (19%) compared to control cultures with the MTT assay. Cardiac myocytes treated with betaA presented a reduced cytoplasmic area that appeared very condensed under inverted microscope. Mitochondrial abnormalities in betaA treated cardiac myocytes included their significant enlargement, vacuolization, disorganization or paucity of cristae, paracrystalline inclusion, and accumulation of amorphous material in mitochondrial space. Mitochondrial abnormalities were present sometimes in betaA treated cardiac myocytes without disorganization of myofibils or degeneration of other cell organelles. To understand the mechanism involved in amyloid deposit and its role in pathogenesis of the diseases such as Alzheimer and inclusion body myositis (IBM), a need for in vitro model is imperative. This model of betaA treated cultured cardiac myocytes represent a amyloidosis model, and it offers several advantages for future studies of betaA to help elucidate the pathogenesis of amyloid diseases. For example, cardiac myocytes can be easily accessible, and since cardiac myocytes can be cultured for quite a long time, it is possible to study morphological and physiological changes consequent to amyloid deposits.

ACTIVATION OF caspase-3 DURING APOPTOSIS OF RAT CORTICAL NEURONS INDUCED BY ?-AP_(1-40) / 解剖学报

Objective To investigate the effects of caspase\|3 on ? ?? 1 40 induced apoptosis in rat cortical neurons. Methods Apoptosis was induced by 40?mg\5L -1 ?\|AP 1 40 .The apoptotic neurons were observed by TUNEL staining and DNA gel electrophoresis.The activity and mRNA expression of caspase\|3 was measured by fluorescent spectrofluorometer and RT\|PCR.The cleaved caspase\|3 was detected with immunocytochemistry. Results After treatment with ?\|AP 1\|40 ,the rat cortical neurons showed DNA fragmentation.The expression of caspase\|3 mRNA ratio to ? actin was 0^78,0^85 and 0^39 respectively after treatment for 12,24 and 48?h.Caspase\|3 activity was 133 24?7 47,192 16?11 03,88 87?4 24 MFI\5?g protein -1 \5h -1 .The cleaved caspase\|3 was observed within cytoplasm.Specific inhibitor of caspase\|3 Ac\|DEVD\|CHO inhibited caspase\|3 activation and blocked cortical neurons apoptosis markedly.Conclusion\ Caspase\|3 might be an executor during ? AP 1 40 induced apoptosis in rat cortical neurons.[