scholarly journals Neuronal Mitophagy: Friend or Foe?

2021 ◽  
Vol 8 ◽  
Author(s):  
Christina Doxaki ◽  
Konstantinos Palikaras
Keyword(s):  
Cell Death ◽  
Molecular Mechanisms ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Mitochondrial Content ◽  
Mitochondrial Homeostasis ◽  
Neuronal Homeostasis ◽  
Age Related ◽  
Health And Disease ◽  
Mitochondrial Number

Maintenance of neuronal homeostasis is a challenging task, due to unique cellular organization and bioenergetic demands of post-mitotic neurons. It is increasingly appreciated that impairment of mitochondrial homeostasis represents an early sign of neuronal dysfunction that is common in both age-related neurodegenerative as well as in neurodevelopmental disorders. Mitochondrial selective autophagy, known as mitophagy, regulates mitochondrial number ensuring cellular adaptation in response to several intracellular and environmental stimuli. Mounting evidence underlines that deregulation of mitophagy levels has an instructive role in the process of neurodegeneration. Although mitophagy induction mediates the elimination of damaged mitochondria and confers neuroprotection, uncontrolled runaway mitophagy could reduce mitochondrial content overstressing the remaining organelles and eventually triggering neuronal cell death. Unveiling the molecular mechanisms of neuronal mitophagy and its intricate role in neuronal survival and cell death, will assist in the development of novel mitophagy modulators to promote cellular and organismal homeostasis in health and disease.

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 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.

scholarly journals Deregulation of the Egfr/Ras Signaling Pathway Induces Age-related Brain Degeneration in the Drosophila Mutantvap

2003 ◽  
Vol 14 (1) ◽  
pp. 241-250 ◽  
Author(s):  
José A. Botella ◽  
Doris Kretzschmar ◽  
Claudia Kiermayer ◽  
Pascale Feldmann ◽  
David A. Hughes ◽  
...  
Keyword(s):  
Cell Death ◽  
Signaling Pathway ◽  
Egf Receptor ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Ras Signaling ◽  
Age Related ◽  
Receptor Signaling Pathway ◽  
Brain Degeneration

Ras signaling has been shown to play an important role in promoting cell survival in many different tissues. Here we show that upregulation of Ras activity in adult Drosophila neurons induces neuronal cell death, as evident from the phenotype of vacuolar peduncle (vap) mutants defective in theDrosophila RasGAP gene, which encodes a Ras GTPase-activating protein. These mutants show age-related brain degeneration that is dependent on activation of the EGF receptor signaling pathway in adult neurons, leading to autophagic cell death (cell death type 2). These results provide the first evidence for a requirement of Egf receptor activity in differentiated adultDrosophila neurons and show that a delicate balance of Ras activity is essential for the survival of adult neurons.

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
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