Our previous findings have demonstrated that autophagy regulation can alleviate the decline of learning and memory by eliminating deposition of extracellular beta-amyloid peptide （Aβ） in the brain after stroke, but...Our previous findings have demonstrated that autophagy regulation can alleviate the decline of learning and memory by eliminating deposition of extracellular beta-amyloid peptide （Aβ） in the brain after stroke, but the exact mechanism is unclear. It is presumed that the regulation of beta-site APP-deaving enzyme 1 （BACE1）, the rate-limiting enzyme in metabolism of Aβ, would be a key site. Neuro-2a/amyloid precursor protein 695 （APP695） cell models of cerebral isch- emia were established by oxygen-glucose deprivation to investigate the effects of Rapamycin （an autophagy inducer） or 3-methyladenine （an autophagy inhibitor） on the expression of BACE1. Either oxygen-glucose deprivation or Rapamycin down-regulated the expression of BACE1 while 3-methyladenine up-regulated BACE1 expression. These results confirm that oxygen-glucose deprivation down-regulates BACE1 expression in Neuro-2a/APP695 cells through the introduction of autophagy.展开更多
While the peripheral nervous system has the capacity to regenerate following a nerve injury,it is often at a slow rate and results in unsatisfactory recovery,leaving patients with reduced function.Many regeneration as...While the peripheral nervous system has the capacity to regenerate following a nerve injury,it is often at a slow rate and results in unsatisfactory recovery,leaving patients with reduced function.Many regeneration associated genes have been identified over the years,which may shed some insight into how we can manipulate this intrinsic regenerative ability to enhance repair following peripheral nerve injuries.Our lab has identified the membrane bound protease beta-site amyloid precursor protein-cleaving enzyme 1（BACE1）,or beta secretase,as a potential negative regulator of peripheral nerve regeneration.When beta secretase activity levels are abolished via a null mutation in mice,peripheral regeneration is enhanced following a sciatic nerve crush injury.Conversely,when activity levels are greatly increased by overexpressing beta secretase in mice,nerve regeneration and functional recovery are impaired after a sciatic nerve crush injury.In addition to our work,many substrates of beta secretase have been found to be involved in regulating neurite outgrowth and some have even been identified as regeneration associated genes.In this review,we set out to discuss BACE1 and its substrates with respect to axonal regeneration and speculate on the possibility of utilizing BACE1 inhibitors to enhance regeneration following acute nerve injury and potential uses in peripheral neuropathies.展开更多
The deposition of amyloid-beta is a pathological hallmark of Alzheimer＇s disease, Amyloid-beta is derived from amyloid precursor protein through sequential proteolytic cleavages by β-secretase （beta-site amyloid pr...The deposition of amyloid-beta is a pathological hallmark of Alzheimer＇s disease, Amyloid-beta is derived from amyloid precursor protein through sequential proteolytic cleavages by β-secretase （beta-site amyloid precursor protein-cleaving enzyme 1） and r-secretase. To further elucidate the roles of beta-site amyloid precursor protein-cleaving enzyme 1 in the development of AIzheimer＇s disease, a yeast two-hybrid system was used to screen a human embryonic brain cDNA library for proteins directly interacting with the intracellular domain of beta-site amyloid precursor protein-cleaving enzyme 1. A potential beta-site amyloid precursor protein-cleaving enzyme 1- interacting protein identified from the positive clones was divalent cation tolerance protein. Immunoprecipitation studies in the neuroblastoma cell line N2a showed that exogenous divalent cation tolerance protein interacts with endogenous beta-site amyloid precursor protein-cleaving enzyme 1. The overexpression of divalent cation tolerance protein did not affect beta-site amyloid precursor protein-cleaving enzyme 1 protein levels, but led to increased amyloid precursor protein levels in N2a/APP695 cells, with a concomitant reduction in the processing product amyloid precursor protein C-terminal fragment, indicating that divalent cation tolerance protein inhibits the processing of amyloid precursor protein. Our experimental findings suggest that divalent cation tolerance protein negatively regulates the function of beta-site amyloid precursor protein-cleaving enzyme 1. Thus, divalent cation tolerance protein could play a protective role in Alzheimer＇s disease.展开更多
基金supported by the National Natural Science Foundation of China,No.31171014,31371065a grant from Shanghai Municipal Health Bureau,China,No.20134125a grant from Shanghai Pudong District Health Bureau of China,No.PDZz2013-10
文摘Our previous findings have demonstrated that autophagy regulation can alleviate the decline of learning and memory by eliminating deposition of extracellular beta-amyloid peptide （Aβ） in the brain after stroke, but the exact mechanism is unclear. It is presumed that the regulation of beta-site APP-deaving enzyme 1 （BACE1）, the rate-limiting enzyme in metabolism of Aβ, would be a key site. Neuro-2a/amyloid precursor protein 695 （APP695） cell models of cerebral isch- emia were established by oxygen-glucose deprivation to investigate the effects of Rapamycin （an autophagy inducer） or 3-methyladenine （an autophagy inhibitor） on the expression of BACE1. Either oxygen-glucose deprivation or Rapamycin down-regulated the expression of BACE1 while 3-methyladenine up-regulated BACE1 expression. These results confirm that oxygen-glucose deprivation down-regulates BACE1 expression in Neuro-2a/APP695 cells through the introduction of autophagy.
基金supported by the Muscular Dystrophy Association and R01NS079339 from the National Institutes of Neurological Disease and Stroke of the National Institutes of Health
文摘While the peripheral nervous system has the capacity to regenerate following a nerve injury,it is often at a slow rate and results in unsatisfactory recovery,leaving patients with reduced function.Many regeneration associated genes have been identified over the years,which may shed some insight into how we can manipulate this intrinsic regenerative ability to enhance repair following peripheral nerve injuries.Our lab has identified the membrane bound protease beta-site amyloid precursor protein-cleaving enzyme 1（BACE1）,or beta secretase,as a potential negative regulator of peripheral nerve regeneration.When beta secretase activity levels are abolished via a null mutation in mice,peripheral regeneration is enhanced following a sciatic nerve crush injury.Conversely,when activity levels are greatly increased by overexpressing beta secretase in mice,nerve regeneration and functional recovery are impaired after a sciatic nerve crush injury.In addition to our work,many substrates of beta secretase have been found to be involved in regulating neurite outgrowth and some have even been identified as regeneration associated genes.In this review,we set out to discuss BACE1 and its substrates with respect to axonal regeneration and speculate on the possibility of utilizing BACE1 inhibitors to enhance regeneration following acute nerve injury and potential uses in peripheral neuropathies.
基金supported by the National Natural Science Foundation of China, No. 81171192XMU Basic Training Program of Undergraduate, No. CXB2011019Visiting Scholar Fellowship of Key Laboratory of Ministry of Education for Cell Biology and Tumor Cell Engineering of Xiamen University, No. 201101
文摘The deposition of amyloid-beta is a pathological hallmark of Alzheimer＇s disease, Amyloid-beta is derived from amyloid precursor protein through sequential proteolytic cleavages by β-secretase （beta-site amyloid precursor protein-cleaving enzyme 1） and r-secretase. To further elucidate the roles of beta-site amyloid precursor protein-cleaving enzyme 1 in the development of AIzheimer＇s disease, a yeast two-hybrid system was used to screen a human embryonic brain cDNA library for proteins directly interacting with the intracellular domain of beta-site amyloid precursor protein-cleaving enzyme 1. A potential beta-site amyloid precursor protein-cleaving enzyme 1- interacting protein identified from the positive clones was divalent cation tolerance protein. Immunoprecipitation studies in the neuroblastoma cell line N2a showed that exogenous divalent cation tolerance protein interacts with endogenous beta-site amyloid precursor protein-cleaving enzyme 1. The overexpression of divalent cation tolerance protein did not affect beta-site amyloid precursor protein-cleaving enzyme 1 protein levels, but led to increased amyloid precursor protein levels in N2a/APP695 cells, with a concomitant reduction in the processing product amyloid precursor protein C-terminal fragment, indicating that divalent cation tolerance protein inhibits the processing of amyloid precursor protein. Our experimental findings suggest that divalent cation tolerance protein negatively regulates the function of beta-site amyloid precursor protein-cleaving enzyme 1. Thus, divalent cation tolerance protein could play a protective role in Alzheimer＇s disease.
