scholarly journals Effect of the mitochondrial unfolded protein response on hypoxic death and mitochondrial protein aggregation

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Junyi Yan ◽  
Chun-Ling Sun ◽  
Seokyung Shin ◽  
Marc Van Gilst ◽  
C. Michael Crowder

AbstractMitochondria are the main oxygen consumers in cells and as such are the primary organelle affected by hypoxia. All hypoxia pathology presumably derives from the initial mitochondrial dysfunction. An early event in hypoxic pathology in C. elegans is disruption of mitochondrial proteostasis with induction of the mitochondrial unfolded protein response (UPRmt) and mitochondrial protein aggregation. Here in C. elegans, we screen through RNAis and mutants that confer either strong resistance to hypoxic cell death or strong induction of the UPRmt to determine the relationship between hypoxic cell death, UPRmt activation, and hypoxia-induced mitochondrial protein aggregation (HIMPA). We find that resistance to hypoxic cell death invariantly mitigated HIMPA. We also find that UPRmt activation invariantly mitigated HIMPA. However, UPRmt activation was neither necessary nor sufficient for resistance to hypoxic death and vice versa. We conclude that UPRmt is not necessarily hypoxia protective against cell death but does protect from mitochondrial protein aggregation, one of the early hypoxic pathologies in C. elegans.

2007 ◽  
Vol 13 (4) ◽  
pp. 467-480 ◽  
Author(s):  
Cole M. Haynes ◽  
Kseniya Petrova ◽  
Cristina Benedetti ◽  
Yun Yang ◽  
David Ron

2019 ◽  
Author(s):  
Sungjin Kim ◽  
Derek Sieburth

AbstractThe mitochondrial unfolded protein response (UPRmt) is an evolutionarily conserved adaptive response that functions to maintain mitochondrial homeostasis following mitochondrial damage. In C. elegans, the nervous system plays a central role in responding to mitochondrial stress by releasing endocrine signals that act upon distal tissues to activate the UPRmt. The mechanisms by which mitochondrial stress is sensed by neurons and transmitted to distal tissues is not fully understood. Here, we identify a role for the conserved follicle-stimulating hormone G protein coupled receptor (GPCR), FSHR-1, in promoting UPRmt activation. Genetic deficiency of fshr-1 severely attenuates UPRmt activation and organism-wide survival in response to mitochondrial stress. FSHR-1 functions in a common genetic pathway with SPHK-1/sphingosine kinase to promote UPRmt activation, and FSHR-1 regulates the mitochondrial association of SPHK-1 in the intestine. Through tissue-specific rescue assays, we show that FSHR-1 functions in neurons to activate the UPRmt, to promote mitochondrial association of SPHK-1 in the intestine, and to promote organism-wide survival in response to mitochondrial stress. We propose that FSHR-1 functions cell non-autonomously in neurons to activate UPRmt upstream of SPHK-1 signaling in the intestine.


2018 ◽  
Vol 115 (41) ◽  
pp. E9678-E9686 ◽  
Author(s):  
Jianwen Deng ◽  
Peng Wang ◽  
Xiaoping Chen ◽  
Haipeng Cheng ◽  
Jianghong Liu ◽  
...  

FUS (fused in sarcoma) proteinopathy is a group of neurodegenerative diseases characterized by the formation of inclusion bodies containing the FUS protein, including frontotemporal lobar degeneration and amyotrophic lateral sclerosis. Previous studies show that mitochondrial damage is an important aspect of FUS proteinopathy. However, the molecular mechanisms by which FUS induces mitochondrial damage remain to be elucidated. Our biochemical and genetic experiments demonstrate that FUS interacts with the catalytic subunit of mitochondrial ATP synthase (ATP5B), disrupts the formation of ATP synthase complexes, and inhibits mitochondrial ATP synthesis. FUS expression activates the mitochondrial unfolded protein response (UPRmt). Importantly, down-regulating expression of ATP5B or UPRmt genes in FUS transgenic flies ameliorates neurodegenerative phenotypes. Our data show that mitochondrial impairment is a critical early event in FUS proteinopathy, and provide insights into the pathogenic mechanism of FUS-induced neurodegeneration.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Priyanka Joshi ◽  
Michele Perni ◽  
Ryan Limbocker ◽  
Benedetta Mannini ◽  
Sam Casford ◽  
...  

AbstractAge-related changes in cellular metabolism can affect brain homeostasis, creating conditions that are permissive to the onset and progression of neurodegenerative disorders such as Alzheimer’s and Parkinson’s diseases. Although the roles of metabolites have been extensively studied with regard to cellular signaling pathways, their effects on protein aggregation remain relatively unexplored. By computationally analysing the Human Metabolome Database, we identified two endogenous metabolites, carnosine and kynurenic acid, that inhibit the aggregation of the amyloid beta peptide (Aβ) and rescue a C. elegans model of Alzheimer’s disease. We found that these metabolites act by triggering a cytosolic unfolded protein response through the transcription factor HSF-1 and downstream chaperones HSP40/J-proteins DNJ-12 and DNJ-19. These results help rationalise previous observations regarding the possible anti-ageing benefits of these metabolites by providing a mechanism for their action. Taken together, our findings provide a link between metabolite homeostasis and protein homeostasis, which could inspire preventative interventions against neurodegenerative disorders.


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