scholarly journals Viral proteins E1B19K and p35 protect sympathetic neurons from cell death induced by NGF deprivation.

1995 ◽  
Vol 128 (1) ◽  
pp. 201-208 ◽  
Author(s):  
I Martinou ◽  
P A Fernandez ◽  
M Missotten ◽  
E White ◽  
B Allet ◽  
...  
Keyword(s):  
Cell Death ◽  
Molecular Mechanisms ◽  
Sympathetic Neurons ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Viral Proteins ◽  
Lymphoid Cells ◽  
Expression Vectors ◽  
Cervical Ganglia ◽  
Adenoviral Proteins

To study molecular mechanisms underlying neuronal cell death, we have used sympathetic neurons from superior cervical ganglia which undergo programmed cell death when deprived of nerve growth factor. These neurons have been microinjected with expression vectors containing cDNAs encoding selected proteins to test their regulatory influence over cell death. Using this procedure, we have shown previously that sympathetic neurons can be protected from NGF deprivation by the protooncogene Bcl-2. We now report that the E1B19K protein from adenovirus and the p35 protein from baculovirus also rescue neurons. Other adenoviral proteins, E1A and E1B55K, have no effect on neuronal survival. E1B55K, known to block apoptosis mediated by p53 in proliferative cells, failed to rescue sympathetic neurons suggesting that p53 is not involved in neuronal death induced by NGF deprivation. E1B19K and p35 were also coinjected with Bcl-Xs which blocks Bcl-2 function in lymphoid cells. Although Bcl-Xs blocked the ability of Bcl-2 to rescue neurons, it had no effect on survival that was dependent upon expression of E1B19K or p35.

scholarly journals Aurintricarboxylic acid rescues PC12 cells and sympathetic neurons from cell death caused by nerve growth factor deprivation: correlation with suppression of endonuclease activity.

1991 ◽  
Vol 115 (2) ◽  
pp. 461-471 ◽  
Author(s):  
A Batistatou ◽  
L A Greene
Keyword(s):  
Cell Death ◽  
Nerve Growth Factor ◽  
Pc12 Cells ◽  
Sympathetic Neurons ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Endonuclease Activity ◽  
Term Survival ◽  
Serum Free

Past studies have shown that serum-free cultures of PC12 cells are a useful model system for studying the neuronal cell death which occurs after neurotrophic factor deprivation. In this experimental paradigm, nerve growth factor (NGF) rescues the cells from death. It is reported here that serum-deprived PC12 cells manifest an endonuclease activity that leads to internucleosomal cleavage of their cellular DNA. This activity is detected within 3 h of serum withdrawal and several hours before any morphological sign of cell degeneration or death. NGF and serum, which promote survival of the cells, inhibit the DNA fragmentation. Aurintricarboxylic acid (ATA), a general inhibitor of nucleases in vitro, suppresses the endonuclease activity and promotes long-term survival of PC12 cells in serum-free cultures. This effect appears to be independent of macromolecular synthesis. In addition, ATA promotes long-term survival of cultured sympathetic neurons after NGF withdrawal. ATA neither promotes nor maintains neurite outgrowth. It is hypothesized that the activation of an endogenous endonuclease could be responsible for neuronal cell death after neurotrophic factor deprivation and that growth factors could promote survival by leading to inhibition of constitutively present endonucleases.

scholarly journals Delta-secretase-cleaved Tau antagonizes TrkB neurotrophic signalings, mediating Alzheimer’s disease pathologies

2019 ◽  
Vol 116 (18) ◽  
pp. 9094-9102 ◽  
Author(s):  
Jie Xiang ◽  
Zhi-Hao Wang ◽  
Eun Hee Ahn ◽  
Xia Liu ◽  
Shan-Ping Yu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cell Death ◽  
Molecular Mechanisms ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Trophic Factor ◽  
Tau Pathology ◽  
Trkb Receptors ◽  
Repeat Domain

BDNF, an essential trophic factor implicated in synaptic plasticity and neuronal survival, is reduced in Alzheimer’s disease (AD). BDNF deficiency’s association with Tau pathology in AD is well documented. However, the molecular mechanisms accounting for these events remain incompletely understood. Here we show that BDNF deprivation triggers Tau proteolytic cleavage by activating δ-secretase [i.e., asparagine endopeptidase (AEP)], and the resultant Tau N368 fragment binds TrkB receptors and blocks its neurotrophic signals, inducing neuronal cell death. Knockout of BDNF or TrkB receptors provokes δ-secretase activation via reducing T322 phosphorylation by Akt and subsequent Tau N368 cleavage, inducing AD-like pathology and cognitive dysfunction, which can be restored by expression of uncleavable Tau N255A/N368A mutant. Blocking the Tau N368–TrkB complex using Tau repeat-domain 1 peptide reverses this pathology. Thus, our findings support that BDNF reduction mediates Tau pathology via activating δ-secretase in AD.

Bax promotes neuronal cell death and is downregulated during the development of the nervous system

Development ◽  
1997 ◽  
Vol 124 (6) ◽  
pp. 1239-1249 ◽  
Author(s):  
K. Vekrellis ◽  
M.J. McCarthy ◽  
A. Watson ◽  
J. Whitfield ◽  
L.L. Rubin ◽  
...  
Keyword(s):  
Cell Death ◽  
Cerebral Cortex ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Expression Vector ◽  
Sympathetic Neurons ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Nerve Growth ◽  
Cultured Sympathetic Neurons

The Bcl-2 and Bcl-x proteins suppress programmed cell death, whereas Bax promotes apoptosis. We investigated the pattern of expression of Bcl-2, Bax and Bcl-x during neuronal differentiation and development. All three proteins were widely expressed in neonatal rats but, in the adult, Bax levels were 20- to 140-fold lower in the cerebral cortex, cerebellum and heart muscle, whereas Bcl-x was not downregulated in any of the tissues examined. In the cerebral cortex and cerebellum, the decrease in Bax levels occurred after the period of developmental cell death. Further, microinjection of a Bax expression vector into cultured sympathetic neurons, which depend on nerve growth factor for survival, induced apoptosis in the presence of survival factor and increased the rate of cell death after nerve growth factor withdrawal. This effect could be blocked by co-injection of an expression vector for Bcl-xL or for the baculovirus p35 protein, an inhibitor of caspases (ICE-like proteases). These results suggest that, during development, the sensitivity of neurons to signals that induce apoptosis may be regulated by modulating Bax levels and that Bax-induced death requires caspase activity.

Molecular Mechanisms of Neuronal Cell Death: Implications for Nuclear Factors Responding to cAMP and Phorbol Esters

2002 ◽  
Vol 21 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Sheela Vyas ◽  
Nicole Faucon Biguet ◽  
Patrick P. Michel ◽  
Lucia Monaco ◽  
Nicholas S. Foulkes ◽  
...  
Keyword(s):  
Cell Death ◽  
Molecular Mechanisms ◽  
Phorbol Esters ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Nuclear Factors

scholarly journals RIPK1 or RIPK3 deletion prevents progressive neuronal cell death and improves memory function after traumatic brain injury

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Antonia Clarissa Wehn ◽  
Igor Khalin ◽  
Marco Duering ◽  
Farida Hellal ◽  
Carsten Culmsee ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Cell Death ◽  
Brain Injury ◽  
Brain Damage ◽  
Molecular Mechanisms ◽  
Memory Function ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Interacting Protein ◽  
Deficient Mice

AbstractTraumatic brain injury (TBI) causes acute and subacute tissue damage, but is also associated with chronic inflammation and progressive loss of brain tissue months and years after the initial event. The trigger and the subsequent molecular mechanisms causing chronic brain injury after TBI are not well understood. The aim of the current study was therefore to investigate the hypothesis that necroptosis, a form a programmed cell death mediated by the interaction of Receptor Interacting Protein Kinases (RIPK) 1 and 3, is involved in this process. Neuron-specific RIPK1- or RIPK3-deficient mice and their wild-type littermates were subjected to experimental TBI by controlled cortical impact. Posttraumatic brain damage and functional outcome were assessed longitudinally by repetitive magnetic resonance imaging (MRI) and behavioral tests (beam walk, Barnes maze, and tail suspension), respectively, for up to three months after injury. Thereafter, brains were investigated by immunohistochemistry for the necroptotic marker phosphorylated mixed lineage kinase like protein(pMLKL) and activation of astrocytes and microglia. WT mice showed progressive chronic brain damage in cortex and hippocampus and increased levels of pMLKL after TBI. Chronic brain damage occurred almost exclusively in areas with iron deposits and was significantly reduced in RIPK1- or RIPK3-deficient mice by up to 80%. Neuroprotection was accompanied by a reduction of astrocyte and microglia activation and improved memory function. The data of the current study suggest that progressive chronic brain damage and cognitive decline after TBI depend on the expression of RIPK1/3 in neurons. Hence, inhibition of necroptosis signaling may represent a novel therapeutic target for the prevention of chronic post-traumatic brain damage.

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