3-磷酸甘油醛脱氢酶与神经元凋亡

综述了 3-磷酸甘油醛脱氢酶 ( glyceraldehyde- 3- phosphate dehydrogenase,GAPDH)的基因表达、酶活性及亚细胞定位等三个方面与神经元凋亡的关系的研究新进展 ,并列举了一些 GAPDH参与神经退行性疾病的临床证据。

Impact of miRNAs on cardiovascular aging

Aging is a multidimensional process that leads to an increased risk of developing severe diseases, such as cancer and cardiovascular, neurodegenerative, and immunological diseases. Recently, small non-coding RNAs known as microRNAs （miRNAs） have been shown to regulate gene expression, which contributes to many physiological and pathophysiological processes in humans. Increasing evidence suggests that changes in miRNA expression profiles contribute to cellular senescence, aging and aging-related diseases. However, only a few miRNAs whose functions have been elucidated have been associated with aging and/or aging-related diseases. This article reviews the currently available findings regarding the roles of aging-related miRNAs, with a focus on cardiac and cardiovascular aging.

PrP 106-126 Altered PrP mRNA Gene Expression in Mouse Microglia BV-2 Cells

Prion diseases are infectious and fatal neurodegenerative diseases.The pathogenic agent is an abnormal prion protein aggregate.Microglial activation in the centre nervous system is a characteristic feature of prion disease.In this study,we examined the effect of PrP 106-126 on PrP mRNA gene expression in Mouse microglia cells BV-2 by real-time quantitative PCR.PrP mRNA expression level was found to be significantly increased after 18 h exposure of BV-2 cells to PrP 106-126,with 3-fold increase after 18 h and 4.5-fold increase after 24 h and BV-2 cells proliferating occurred correspondingly.Our results provide the first in vitro evidence of the increase of PrP mRNA levels in microglial cells exposed to PrP 106-126,and indicate that microglial cells might play a critical role in prion pathogenesis.

Neuroprotective effect of fucoxanthin on β-amyloid-induced cell death

Alzheimer＇s disease （AD） is one of the most common cognitive disorders of the elderly. Fucoxanthin is a carotenoid that is found in common edible seaweed, and it is considered as a major active compound of marine algae with cancer-preventing, antioxidant and anti-inflammatory properties. In this study, we investigated the ability of fucoxanthin to protect against the β-amyloid protein （Aβ）-induced neurotoxicity in primary cortical cultured neurons and PC12 cells. Neuroprotective effects of fucoxanthin were determined by measuring cell viability and nuclei double-staining with Hoechst 33342 and propidium iodide following Aβ treatment with or without fucoxanthin. Moreover, we also evaluated its potential mechanism on antioxidation by detecting the total antioxidant capacity （T-AOC）, level of lipid peroxidation malondialdehyde （MDA） and activity of superoxide dismutase （SOD）. We found that exposure of cortical cultured neurons or PC12 cells to Aβ resulted in neuronal cell death, whereas pre-treatment with fucoxanthin reduced Aβ-induced cell death. The data on the T-AOC, MDA level and SOD activity showed that Aβ treatment resulted in decreases in T-AOC and SOD activity and an increase in MDA level. After fucoxanthin administration, the results of T-AOC, MDA level and SOD activity showed an opposite trend, indicating that T-AOC was increased and MDA level was reduced. These results suggested that fucoxanthin prevented Aβ-induced neurotoxicity through attenuating oxidative stress induced by Aβ. Therefore, fucoxanthin might be useful as a potential preventive or theraoeutic agent for AD.

MicroRNAs in neural cell development and brain diseases

MicroRNAs play important roles in post-transcriptional regulation of gene expression by inhibiting protein translation and/or promoting mRNA degradation.Importantly,biogenesis of microRNAs displays specific temporal and spatial profiles in distinct cell and tissue types and hence affects a broad spectrum of biological functions in normal cell growth and tumor development.Recent discoveries have revealed sophisticated mechanisms that control microRNA production and homeostasis in response to developmental and extracellular signals.Moreover,a link between dysregulation of microRNAs and human brain disorders has become increasingly evident.In this review,we focus on recent advances in understanding the regulation of microRNA biogenesis and function in neuronal and glial development in the mammalian brain,and dysregulation of the microRNA pathway in neurodevelopmental and neurodegenerative diseases.

Tea and human health: biomedical functions of tea active components and current issues

Originating in China, tea and tea planting have spread throughout the world since the middle of the Tang dynasty. Now people from 160 countries in the world are accustomed to tea drinking. A brief history of tea＇s medicinal role in China and its spread to the world are introduced. The effectiveness of tea active components and tea drinking on major human diseases, including cancer, metabolic syndrome, cardiovascular disease, and neurodegenerative diseases, is discussed. Also presented are some related issues, such as the bioavailability of tea active components, the new formulations of tea polyphenols, and the safety for consumers of dietary supplements containing tea polyphenols.

O-GlcNAcylation, a sweet link to the pathology of diseases

O-linked N-acetylglucosamine(O-GlcNAc)is a dynamic post-translational modification occurring on myriad proteins in the cell nucleus,cytoplasm,and mitochondria.The donor sugar for O-Glc NAcylation,uridine-diphosphate N-acetylglucosamine(UDP-Glc NAc),is synthesized from glucose through the hexosamine biosynthetic pathway(HBP).The recycling of O-GlcNAc on proteins is mediated by two enzymes in cells—O-GlcNAc transferase(OGT)and O-Glc NAcase(OGA),which catalyze the addition and removal of O-GlcNAc,respectively.O-GlcNAcylation is involved in a number of important cell processes including transcription,translation,metabolism,signal transduction,and apoptosis.Deregulation of O-GlcNAcylation has been reported to be associated with various human diseases such as cancer,diabetes,neurodegenerative diseases,and cardiovascular diseases.A better understanding of the roles of O-GlcNAcylation in physiopathological processes would help to uncover novel avenues for therapeutic intervention.The aim of this review is to discuss the recent updates on the mechanisms and impacts of O-GlcNAcylation on these diseases,and its potential as a new clinical target.

Nitric oxide in neurodegeneration:potential benefits of non-steroidal anti-inflammatories

The cellular messenger nitric oxide（NO） has been linked to neurodegenerative disorders due to the increased expression of the enzymes that catalyze its synthesis in postmortem tissues derived from sufferers of these diseases.Nitrated proteins have also been detected in these samples,revealing that NO is biologically active in regions damaged during neurodegeneration.Modulation of NO levels has been reported not only in the neurons of the central nervous system,but also in the glial cells（microglia and astroglia） activated during the neuroinflammatory response.Neuroinflammation has been found in some neurodegenerative conditions,and inhibition of these neuroinflammatory signals has been shown to delay the progress of such disorders.Thus NO and the pathways triggering its release are emerging as an important research focus in the search for strategies to prevent,halt or cure neurodegenerative diseases.

Targeting Wnt signaling at the neuroimmune interface for dopaminergic neuroprotectionJrepair in Parkinson＇s disease

During the past three decades, the Wingless-type MMTV integration site （Wnt） signaling cascade has emerged as an essential system regulating multiple processes in developing and adult brain. Accumulating evidence points to a dysregulation of Wnt signaling in major neurodegenerative pathologies including Parkinson＇s disease （PD）, a common neurodegenerative disorder characterized by the pro- gressive loss of midbrain dopaminergic （mDA） neurons and deregulated activation of astrocytes and microglia. This review highlights the emerging link between Wnt signaling and key inflammatory pathways during mDA neuron damage/repair in PD progression. In particular, we summarize recent evidence documenting that aging and neurotoxicant exposure strongly antagonize Wnt/β-catenin signaling in mDA neurons and subventricular zone （SVZ） neuroprogenitors via astrocyte-microglial interactions. Dysregulation of the crosstalk between Wnt/β-catenin signaling and anti-oxidant/anti-inflammatory pathways delineate novel mechanisms driving the decline of SVZ plasticity with age and the limited nigrostriatal dopaminergic self-repair in PD. These findings hold a promise in devetoping therapies that target Wnt/β-catenin signaling to enhance endogenous restoration and neuronal outcome in age-dependent diseases, such as PD.

Presenilins as endoplasmic reticulum calcium leak channels and Alzheimer's disease pathogenesis

Alzheimer disease(AD) is the most common neurodegenerative disorder worldwide and is at present,incurable.The accumulation of toxic amyloid-beta(Aβ) peptide aggregates in AD brain is thought to trigger the extensive synaptic loss and neurodegeneration linked to cognitive decline,an idea that underlies the'amyloid hypothesis'of AD etiology in both the familal(FAD) and sporadic forms of the disease.Genetic mutations causing FAD also result in the dysregulation of neuronal calcium(Ca2+) handling and may contribute to AD pathogenesis,an idea termed the'calcium hypothesis'of AD.Mutations in presenilin proteins account for majority of FAD cases.Presenilins function as catalytic subunit ofγ-secretase involved in generation of Aβ peptide Recently,we discovered that presenilns function as low-conductance,passive ER Ca2+ leak channels,independent of γ-secretase activity.We further discovered that many FAD mutations in presenilins result in loss of ER Ca2+ leak function activity and Ca2+ overload in the ER.These results provided potential explanation for abnormal Ca2+ signaling observed in FAD cells with mutations in presenilns.Our latest work on studies of ER Ca2+ leak channel function of presenilins and implications of these findings for understanding AD pathogenesis are discussed in this article.

Alzheimer's disease and gut microbiota

Alzheimer＇s disease （AD） is a most common neurodegenerative disorder, which associates with impaired cognition. Gut microbiota can modulate host brain function and behavior via microbiota-gut-brain axis, including cognitive behavior. Germ-free animals, antibiotics, probiotics intervention and diet can induce alterations of gut microbiota and gut physiology and also host cognitive behavior, increasing or decreasing risks of AD. The increased permeability of intestine and blood-brain barrier induced by gut rnicrobiota disturbance will increase the incidence of neurodegeneration disorders. Gut microbial metabolites and their effects on host neurochemical changes may increase or decrease the risk of AD. Pathogenic microbes infection will also increase the risk of AD, and meanwhile, the onset of AD support the ＂hygiene hypothesis＂. All the results suggest that AD may begin in the gut, and is closely related to the imbalance of gut microbiota. Modulation of gut microbiota through personalized diet or beneficial microbiota intervention will probably become a new treatment for AD.

Human endogenous retrovirus W env increases nitric oxide production and enhances the migration ability of microglia by regulating the expression of inducible nitric oxide synthase

Human endogenous retrovirus W env(HERV-W env) plays a critical role in many neuropsychological diseases such as schizophrenia and multiple sclerosis(MS). These diseases are accompanied by immunological reactions in the central nervous system(CNS). Microglia are important immunocytes in brain inflammation that can produce a gasotransmitter – nitric oxide(NO). NO not only plays a role in the function of neuronal cells but also participates in the pathogenesis of various neuropsychological diseases. In this study, we reported increased NO production in CHME-5 microglia cells after they were transfected with HERV-W env. Moreover, HERV-W env increased the expression and function of human inducible nitric oxide synthase(hi NOS) and enhanced the promoter activity of hi NOS. Microglial migration was also enhanced. These data revealed that HERV-W env might contribute to increase NO production and microglial migration ability in neuropsychological disorders by regulating the expression of inducible NOS. Results from this study might lead to the identification of novel targets for the treatment of neuropsychological diseases, including neuroinflammatory diseases, stroke, and neurodegenerative diseases.