scholarly journals Novel pathophysiological mechanisms in dominant optic atrophy beyond the mitochondrial dynamics equilibrium

2017 ◽  
Vol 95 ◽  
Author(s):  
G. Lenaers ◽  
M. Charif ◽  
P. Amati-Bonneau ◽  
J. Chao de la Barca ◽  
V. Procaccio ◽  
...  
Author(s):  
Marta Zaninello ◽  
Konstantinos Palikaras ◽  
Aggeliki Sotiriou ◽  
Nektarios Tavernarakis ◽  
Luca Scorrano

AbstractMitochondrial dysfunction and mitophagy are often hallmarks of neurodegenerative diseases such as autosomal dominant optic atrophy (ADOA) caused by mutations in the key mitochondrial dynamics protein optic atrophy 1 (Opa1). However, the second messengers linking mitochondrial dysfunction to initiation of mitophagy remain poorly characterized. Here, we show in mammalian and nematode neurons that Opa1 mutations trigger Ca2+-dependent mitophagy. Deletion or expression of mutated Opa1 in mouse retinal ganglion cells and Caenorhabditis elegans motor neurons lead to mitochondrial dysfunction, increased cytosolic Ca2+ levels, and decreased axonal mitochondrial density. Chelation of Ca2+ restores mitochondrial density in neuronal processes, neuronal function, and viability. Mechanistically, sustained Ca2+ levels activate calcineurin and AMPK, placed in the same genetic pathway regulating axonal mitochondrial density. Our data reveal that mitophagy in ADOA depends on Ca2+-calcineurin-AMPK signaling cascade.


2021 ◽  
Vol 12 ◽  
Author(s):  
Valentina Del Dotto ◽  
Valerio Carelli

In the year 2000, the discovery of OPA1 mutations as causative for dominant optic atrophy (DOA) was pivotal to rapidly expand the field of mitochondrial dynamics and describe the complex machinery governing this pathway, with a multitude of other genes and encoded proteins involved in neurodegenerative disorders of the optic nerve. OPA1 turned out to be a much more complex protein than initially envisaged, connecting multiple pathways beyond its strict role in mitochondrial fusion, such as sensing of OXPHOS needs and mitochondrial DNA maintenance. As a consequence, an increasing need to investigate OPA1 functions at multiple levels has imposed the development of multiple tools and models that are here reviewed. Translational mitochondrial medicine, with the ultimate objective of translating basic science necessary to understand pathogenic mechanisms into therapeutic strategies, requires disease modeling at multiple levels: from the simplest, like in yeast, to cell models, including the increasing use of reprogrammed stem cells (iPSCs) from patients, to animal models. In the present review, we thoroughly examine and provide the state of the art of all these approaches.


2016 ◽  
Vol 3 (6) ◽  
pp. 408-421 ◽  
Author(s):  
Aurélie M. C. Millet ◽  
Ambre M. Bertholet ◽  
Marlène Daloyau ◽  
Pascal Reynier ◽  
Anne Galinier ◽  
...  

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Weiwei Zou ◽  
Qixin Chen ◽  
Jesse Slone ◽  
Li Yang ◽  
Xiaoting Lou ◽  
...  

AbstractSLC25A46 mutations have been found to lead to mitochondrial hyper-fusion and reduced mitochondrial respiratory function, which results in optic atrophy, cerebellar atrophy, and other clinical symptoms of mitochondrial disease. However, it is generally believed that mitochondrial fusion is attributable to increased mitochondrial oxidative phosphorylation (OXPHOS), which is inconsistent with the decreased OXPHOS of highly-fused mitochondria observed in previous studies. In this paper, we have used the live-cell nanoscope to observe and quantify the structure of mitochondrial cristae, and the behavior of mitochondria and lysosomes in patient-derived SLC25A46 mutant fibroblasts. The results show that the cristae have been markedly damaged in the mutant fibroblasts, but there is no corresponding increase in mitophagy. This study suggests that severely damaged mitochondrial cristae might be the predominant cause of reduced OXPHOS in SLC25A46 mutant fibroblasts. This study demonstrates the utility of nanoscope-based imaging for realizing the sub-mitochondrial morphology, mitophagy and mitochondrial dynamics in living cells, which may be particularly valuable for the quick evaluation of pathogenesis of mitochondrial morphological abnormalities.


2016 ◽  
Vol 27 (6) ◽  
pp. 475-480 ◽  
Author(s):  
Bo Y. Chun ◽  
Joseph F. Rizzo

Cell Calcium ◽  
2015 ◽  
Vol 57 (1) ◽  
pp. 49-55 ◽  
Author(s):  
László Fülöp ◽  
Anikó Rajki ◽  
Erika Maka ◽  
Mária Judit Molnár ◽  
András Spät

1991 ◽  
Vol 11 (5) ◽  
pp. 237-240
Author(s):  
M. P. Waterschoot ◽  
J. M. Guerit ◽  
M. Gersdorff ◽  
E. C. Laterre

2012 ◽  
Vol 68 (2) ◽  
pp. 108-110 ◽  
Author(s):  
X. Ayrignac ◽  
C. Liauzun ◽  
G. Lenaers ◽  
D. Renard ◽  
P. Amati-Bonneau ◽  
...  

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