Have you heard of NG2 cells or NG2 glia or polydendro- cytes~. These are new names for the precursor cells that used to be referred to as oligodendrocyte precursor cells （OPCs）, which become the oligodendrocytes tha...Have you heard of NG2 cells or NG2 glia or polydendro- cytes~. These are new names for the precursor cells that used to be referred to as oligodendrocyte precursor cells （OPCs）, which become the oligodendrocytes that myelinate central nervous system （CNS） axons. Evidence suggests, however, that they have other functions, besides differentiating into oligodendrocytes. Most notably, the OPCs/NG2 cells are uni- formly distributed in grey matter as well as in white matter, which matches poorly with the distribution of myelinating oligodendrocytes. Furthermore, not every NG2 cell is fated to become an oligodendrocyte. Hence the term OPC can be fairly applied only when discussing the role of these cells in the oligodendrocyte lineage.展开更多
Synaptic dysfunction and abnormal processing of amyloid precursor protein(APP) are early pathological features in Alzheimer’s disease(AD). Recently, noncoding RNAs such as micro RNAs(mi RNAs) and circular RNAs(circ R...Synaptic dysfunction and abnormal processing of amyloid precursor protein(APP) are early pathological features in Alzheimer’s disease(AD). Recently, noncoding RNAs such as micro RNAs(mi RNAs) and circular RNAs(circ RNAs) have been reported to contribute to the pathogenesis of AD. We found an age-dependent elevation of mi R-138 in APP/PS1(presenilin-1) mice. Mi R-138 inhibited the expression of ADAM10 [a disintegrin and metalloproteinase domain-containing protein 10], promoted amyloid beta(Ab) production, and induced synaptic and learning/memory deficits in APP/PS1 mice, while its suppression alleviated the AD-like phenotype in these mice. Overexpression of sirtuin 1(Sirt1), a target of mi R-138, ameliorated the mi R-138-induced inhibition of ADAM10 and elevation of Ab in vitro. The circ RNA HDAC9(circ HDAC9) was predicted to contain a mi R-138 binding site in several databases. Its expression was inversely correlated with mi R-138 in both Ab-oligomertreated N2 a cells and APP/PS1 mice, and it co-localized with mi R-138 in the cytoplasm of N2 a cells. Circ HDAC9 acted as a mi R-138 sponge, decreasing mi R-138 expression, and reversing the Sirt1 suppression and excessive Ab production induced by mi R-138 in vitro. Moreover,circ HDAC9 was decreased in the serum of both AD patients and individuals with mild cognitive impairment.These results suggest that the circ HDAC9/mi R-138/Sirt1 pathway mediates synaptic function and APP processing in AD, providing a potential therapeutic target for its treatment.展开更多
Synapses are specialized structures that mediate information flow between neurons and target cells,and thus are the basis for neuronal system to execute various functions,including learning and memory.There are around...Synapses are specialized structures that mediate information flow between neurons and target cells,and thus are the basis for neuronal system to execute various functions,including learning and memory.There are around 1011 neurons in the human brain,with each neuron receiving thousands of synaptic inputs,either excitatory or inhibitory.A synapse is an asymmetric structure that is composed of pre-synaptic axon terminals,synaptic cleft,and postsynaptic compartments.Synapse formation involves a number of cell adhesion molecules,extracellular factors,and intracellular signaling or structural proteins.After the establishment of synaptic connections,synapses undergo structural or functional changes,known as synaptic plasticity which is believed to be regulated by neuronal activity and a variety of secreted factors.This review summarizes recent progress in the field of synapse development,with particular emphasis on the work carried out in China during the past 10 years(1999-2009).展开更多
基金supported by NIH NS079631,Shriners Hospitals for Children and Craig H.Neilsen Foundation
文摘Have you heard of NG2 cells or NG2 glia or polydendro- cytes~. These are new names for the precursor cells that used to be referred to as oligodendrocyte precursor cells （OPCs）, which become the oligodendrocytes that myelinate central nervous system （CNS） axons. Evidence suggests, however, that they have other functions, besides differentiating into oligodendrocytes. Most notably, the OPCs/NG2 cells are uni- formly distributed in grey matter as well as in white matter, which matches poorly with the distribution of myelinating oligodendrocytes. Furthermore, not every NG2 cell is fated to become an oligodendrocyte. Hence the term OPC can be fairly applied only when discussing the role of these cells in the oligodendrocyte lineage.
基金supported by the National Natural Science Foundation of China (81500925)
文摘Synaptic dysfunction and abnormal processing of amyloid precursor protein(APP) are early pathological features in Alzheimer’s disease(AD). Recently, noncoding RNAs such as micro RNAs(mi RNAs) and circular RNAs(circ RNAs) have been reported to contribute to the pathogenesis of AD. We found an age-dependent elevation of mi R-138 in APP/PS1(presenilin-1) mice. Mi R-138 inhibited the expression of ADAM10 [a disintegrin and metalloproteinase domain-containing protein 10], promoted amyloid beta(Ab) production, and induced synaptic and learning/memory deficits in APP/PS1 mice, while its suppression alleviated the AD-like phenotype in these mice. Overexpression of sirtuin 1(Sirt1), a target of mi R-138, ameliorated the mi R-138-induced inhibition of ADAM10 and elevation of Ab in vitro. The circ RNA HDAC9(circ HDAC9) was predicted to contain a mi R-138 binding site in several databases. Its expression was inversely correlated with mi R-138 in both Ab-oligomertreated N2 a cells and APP/PS1 mice, and it co-localized with mi R-138 in the cytoplasm of N2 a cells. Circ HDAC9 acted as a mi R-138 sponge, decreasing mi R-138 expression, and reversing the Sirt1 suppression and excessive Ab production induced by mi R-138 in vitro. Moreover,circ HDAC9 was decreased in the serum of both AD patients and individuals with mild cognitive impairment.These results suggest that the circ HDAC9/mi R-138/Sirt1 pathway mediates synaptic function and APP processing in AD, providing a potential therapeutic target for its treatment.
文摘Synapses are specialized structures that mediate information flow between neurons and target cells,and thus are the basis for neuronal system to execute various functions,including learning and memory.There are around 1011 neurons in the human brain,with each neuron receiving thousands of synaptic inputs,either excitatory or inhibitory.A synapse is an asymmetric structure that is composed of pre-synaptic axon terminals,synaptic cleft,and postsynaptic compartments.Synapse formation involves a number of cell adhesion molecules,extracellular factors,and intracellular signaling or structural proteins.After the establishment of synaptic connections,synapses undergo structural or functional changes,known as synaptic plasticity which is believed to be regulated by neuronal activity and a variety of secreted factors.This review summarizes recent progress in the field of synapse development,with particular emphasis on the work carried out in China during the past 10 years(1999-2009).
