Close

Sub-lethal apoptotic stress enables mtDNA release during senescence and drives the SASP

James Chapman, Hanna Salmonowicz, Stella Victorelli, Maria Grazia Vizioli, Helene Martini, Joel S. Riley, Catherine Cloix, Jair Machado Espindola Netto, Diana Jurk, Anthony B. Lagnado, Lilian Sales Gomez, Joshua N. Farr, Dominik Saul, Becca Reed, Laura C. Greaves, Zhixun Dou, Derek A Mann, Claudio Akio Masuda, Sundeep Khosla, Haiming Dai, Scott H Kaufmann, Nathan LeBrasseur, Viktor I. Korolchuk, Xue Lei, Peter D. Adams, Alva Sainz, Gerald S. Shadel, Stephen W.G. Tait, João F. Passo

Posted on: 19 July 2022

Preprint posted on 10 March 2022

Stop leaky mitochondria and increase healthspan

Selected by Roberto Amadio

Categories: biochemistry, cell biology

 

Background

External stressors and ageing push cells to undergo senescence. Senescent cells irreversibly stop their growth to limit transformation, but also start to secrete inflammatory mediators to help resolving the originating stressor by removing senescent cells from the body (Coppé et al., 2008). During aging or in pathological conditions, the body loses its capacity to clear senescent cell and as consequence the senescence-associated secretory phenotype (SASP) increases, leading to pathologic inflammation. Mitochondrial dysfunction is central in senescence and targeting damaged mitochondria in senescent cells could potentially inhibit the SASP, whilst keeping the tumor-suppressor roles of senescent cells (Correia‐Melo et al. 2016).

In this work, Chapman, Salmonowicz, Victorelli and colleagues found that a limited fraction of mitochondria in senescent cells undergo permeabilization of the outer membrane through the oligomerization of BAX-BAK and release of mtDNA. This process resembles what happens to mitochondria during apoptosis; but senescent-inducing stressors are not enough to trigger cell death, because only few mitochondria lose their integrity. Oligomerization of BAX-BAK proteins in the outer membrane of mitochondria induces the release of mtDNA, but in senescent cells, caspases activation is not enough to kept immunologically silent cytosolic mtDNA, as instead happens during apoptosis. Therefore, mtDNA activates the cGAS-STING cytosolic DNA sensing pathway, leading to the SASP.

 

Key findings of this preprint

  1. Peripheral mitochondria are more permeable in senescent cells

Using 3D SIM super-resolution microscopy and complementary biochemical experiments, the authors discover that  the outer membrane protein TOM20 and the cytochrome c are not properly colocalized in a subset of peripheral mitochondria of senescent cells. Cytochrome c is generally released from mitochondria to the cytosol through BAX-BAK pores during apoptosis. Indeed, increased levels of cytosolic cytochrome c and BAX-BAK oligomers can be detected in senescent but not in proliferative fibroblasts by western blot.

 

  1. mtDNA is released in senescence

Airyscan confocal microscopy of dsDNA and TOM20 was used to quantify the number of DNA spots present into the cytoplasm of different fibroblastic cell lines during replicative conditions or in senescence. Senescent cells were observed to carry more cytosolic DNA and q-PCR with specific primers confirmed the source of this DNA as mitochondrial and not nuclear.

 

  1. miMOMP drives SASP

To probe whether mitochondrial outer membrane permeabilization (MOMP) occurring in a minority of mitochondria (miMOMP) could orchestrate by itself the SASP, the authors genetically delete by CRISPR-Cas9 both BAX and BAK and measured different hallmark of senescence, including cytokine secretion, proliferation, LMNB1 loss and DNA damage.

Of these, only cytosolic mtDNA and cytokine secretion were restored by BAX-BAK deletion, while proliferation markers (Ki-67), LMNB1 loss and DNA damage markers (γH2AX) were not rescued. To further confirm that BAX-BAK-mediated mtDNA leakage contributes to the SASP in senescent cell, the author also proved that other mechanisms of mtDNA leakage (i.e. formation of the mitochondrial permeability transition pore) were not concomitantly present in senescent cells; nor that BAX-BAK deletion generates confounding factors such as compromised oxidative phosphorylation and ROS production.

 

  1. Caspase activation following miMOMP is not able to block the SASP

During apoptosis, secretion of inflammatory mediators is blunted by concomitant activation of caspases that cleave cGAS (Ning et al., 2019). However, senescence-driven activation of caspases downstream miMOMP appeared to be not sufficient to suppress the SASP. Indeed, deleting a critical activator of caspases (APAF1), did not alter the SASP induced by irradiation. If caspases activity is not sufficient to prevent inflammatory activation, then cGAS and STING are likely to participate in the SASP, as previously suggested (Yang et al., 2017).

 

  1. Investigating cGAS-STING in senescence

As a tabula rasa to investigate involvement of cGAS-STING in the SASP, the authors wanted to generate cells completely lacking mitochondria, to study the effect of mtDNA sensing in senescent cells without any confounding factor. To this end, cells were stably transfected with a component of mitochondria disposal machinery (mitophagy) and mitochondria depolarization was triggered by the decoupler of the respiratory chain compound carbonyl cyanide m-chlorophenyl hydrazone (CCCP) to induce mitophagy and deplete cells from mitochondria. mtDNA reintroduction by transfection was sufficient to recapitulate the SASP phenotype. Moreover, TFAM deficient cells, that show increased cytosolic mtDNA, were confirmed to have an inflammatory phenotype which promotes senescence. Thus, mtDNA in the cytosol can accelerate senescence.

 

  1. BAX inhibition improves healthspan in aged mice

As a proof of concept, the authors treated aged mice with a BAX inhibitor, known to prevent apoptosis and block mtDNA release. Notably, musculoskeletal parameters and healthspan were improved in treated mice, without affecting lifespan.

In conclusion, this paper characterized miMOMP in senescence and linked mtDNA and cGAS-STING functions in aging. Moreover, it shows that cGAS-driven SASP is a major rate limiting factor to healthy aging in mice.

Why I chose this preprint

cGAS-STING is a hot topic, but its physiological involvement in senescence and aging is still debated. This paper, with cool microscopy and clever experiments, add an important piece of evidence to the cGAS-STING field of research and clarify the link between this cytosolic DNA sensing pathway and the SASP in senescence.

 

Questions to the authors

·  Why miMOMP is more frequently detected in peripheral mitochondria of senescent cells

·  Could the tested BAX inhibitor be used also in humans? Are there any trial with those kinds of small molecules to improve healthspan in humans?

 

References

·  Coppé, J.-P. et al. Senescence-Associated Secretory Phenotypes Reveal Cell-Nonautonomous Functions of Oncogenic RAS and the p53 Tumor Suppressor. PLOS Biology 6, e301, doi:10.1371/journal.pbio.0060301 (2008).

·  Correia‐Melo, C. et al. Mitochondria are required for pro‐ageing features of the senescent phenotype. The EMBO Journal 35, 724, doi:10.15252/embj.201592862 (2016).

·  X. Ning, Y. Wang, M. Jing, M. Sha, M. Lv, P. Gao, R. Zhang, X. Huang, J. M. Feng, Z. Jiang, Apoptotic Caspases Suppress Type I Interferon Production via the Cleavage of cGAS, MAVS, and IRF3. Mol. Cell. 74, 19-31.e7 (2019).

·  H. Yang, H. Wang, J. Ren, Q. Chen, Z. J. Chen, cGAS is essential for cellular senescence. PNAS (2017), doi:10.1073/pnas.1705499114.

 

Tags: ageing, cgas, inflammation, mtdna, sasp, senescence, sting

doi: https://doi.org/10.1242/prelights.32397

Read preprint (No Ratings Yet)

Have your say

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Sign up to customise the site to your preferences and to receive alerts

Register here

Also in the biochemistry category:

Triglyceride metabolism controls inflammation and APOE4-associated disease states in microglia

Roxan A. Stephenson, Kory R. Johnson, Linling Cheng, et al.

Selected by 22 August 2024

Gustavo Stelzer, Marcus Oliveira

Biochemistry

Impaired 26S proteasome causes learning and memory deficiency and induces neuroinflammation mediated by NF-κB in mice

Christa C. Huber, Eduardo Callegari, Maria Paez, et al.

Selected by 22 August 2024

Gustavo Stelzer, Marcus Oliveira

Biochemistry

Notch3 is a genetic modifier of NODAL signalling for patterning asymmetry during mouse heart looping

Tobias Holm Bønnelykke, Marie-Amandine Chabry, Emeline Perthame, et al.

Selected by 06 June 2024

Bhaval Parmar

Developmental Biology

Also in the cell biology category:

The RNA binding protein HNRNPA2B1 regulates RNA abundance and motor protein activity in neurites

Joelle Lo, Katherine F. Vaeth, Gurprit Bhardwaj, et al.

Selected by 24 September 2024

Felipe Del Valle Batalla

Neuroscience

Pharyngeal neuronal mechanisms governing sour taste perception in Drosophila melanogaster

Bhanu Shrestha, Jiun Sang, Suman Rimal, et al.

Selected by 23 September 2024

Matthew Davies

Cell Biology

Feedback regulation by the RhoA-specific GEF ARHGEF17 regulates actomyosin network disassembly

Vasundhara Rao, Benjamin Grädel, Lucien Hinderling, et al.

Selected by 18 September 2024

Vibha SINGH

Cell Biology

preLists in the biochemistry category:

BSCB-Biochemical Society 2024 Cell Migration meeting

This preList features preprints that were discussed and presented during the BSCB-Biochemical Society 2024 Cell Migration meeting in Birmingham, UK in April 2024. Kindly put together by Sara Morais da Silva, Reviews Editor at Journal of Cell Science.

 



List by Reinier Prosee

Peer Review in Biomedical Sciences

Communication of scientific knowledge has changed dramatically in recent decades and the public perception of scientific discoveries depends on the peer review process of articles published in scientific journals. Preprints are key vehicles for the dissemination of scientific discoveries, but they are still not properly recognized by the scientific community since peer review is very limited. On the other hand, peer review is very heterogeneous and a fundamental aspect to improve it is to train young scientists on how to think critically and how to evaluate scientific knowledge in a professional way. Thus, this course aims to: i) train students on how to perform peer review of scientific manuscripts in a professional manner; ii) develop students' critical thinking; iii) contribute to the appreciation of preprints as important vehicles for the dissemination of scientific knowledge without restrictions; iv) contribute to the development of students' curricula, as their opinions will be published and indexed on the preLights platform. The evaluations will be based on qualitative analyses of the oral presentations of preprints in the field of biomedical sciences deposited in the bioRxiv server, of the critical reports written by the students, as well as of the participation of the students during the preprints discussions.

 



List by Marcus Oliveira et al.

CellBio 2022 – An ASCB/EMBO Meeting

This preLists features preprints that were discussed and presented during the CellBio 2022 meeting in Washington, DC in December 2022.

 



List by Nadja Hümpfer et al.

20th “Genetics Workshops in Hungary”, Szeged (25th, September)

In this annual conference, Hungarian geneticists, biochemists and biotechnologists presented their works. Link: http://group.szbk.u-szeged.hu/minikonf/archive/prg2021.pdf

 



List by Nándor Lipták

Fibroblasts

The advances in fibroblast biology preList explores the recent discoveries and preprints of the fibroblast world. Get ready to immerse yourself with this list created for fibroblasts aficionados and lovers, and beyond. Here, my goal is to include preprints of fibroblast biology, heterogeneity, fate, extracellular matrix, behavior, topography, single-cell atlases, spatial transcriptomics, and their matrix!

 



List by Osvaldo Contreras

ASCB EMBO Annual Meeting 2019

A collection of preprints presented at the 2019 ASCB EMBO Meeting in Washington, DC (December 7-11)

 



List by Madhuja Samaddar et al.

EMBL Seeing is Believing – Imaging the Molecular Processes of Life

Preprints discussed at the 2019 edition of Seeing is Believing, at EMBL Heidelberg from the 9th-12th October 2019

 



List by Dey Lab

Cellular metabolism

A curated list of preprints related to cellular metabolism at Biorxiv by Pablo Ranea Robles from the Prelights community. Special interest on lipid metabolism, peroxisomes and mitochondria.

 



List by Pablo Ranea Robles

MitoList

This list of preprints is focused on work expanding our knowledge on mitochondria in any organism, tissue or cell type, from the normal biology to the pathology.

 



List by Sandra Franco Iborra

Also in the cell biology category:

BSCB-Biochemical Society 2024 Cell Migration meeting

This preList features preprints that were discussed and presented during the BSCB-Biochemical Society 2024 Cell Migration meeting in Birmingham, UK in April 2024. Kindly put together by Sara Morais da Silva, Reviews Editor at Journal of Cell Science.

 



List by Reinier Prosee

‘In preprints’ from Development 2022-2023

A list of the preprints featured in Development's 'In preprints' articles between 2022-2023

 



List by Alex Eve, Katherine Brown

preLights peer support – preprints of interest

This is a preprint repository to organise the preprints and preLights covered through the 'preLights peer support' initiative.

 



List by preLights peer support

The Society for Developmental Biology 82nd Annual Meeting

This preList is made up of the preprints discussed during the Society for Developmental Biology 82nd Annual Meeting that took place in Chicago in July 2023.

 



List by Joyce Yu, Katherine Brown

CSHL 87th Symposium: Stem Cells

Preprints mentioned by speakers at the #CSHLsymp23

 



List by Alex Eve

Journal of Cell Science meeting ‘Imaging Cell Dynamics’

This preList highlights the preprints discussed at the JCS meeting 'Imaging Cell Dynamics'. The meeting was held from 14 - 17 May 2023 in Lisbon, Portugal and was organised by Erika Holzbaur, Jennifer Lippincott-Schwartz, Rob Parton and Michael Way.

 



List by Helen Zenner

9th International Symposium on the Biology of Vertebrate Sex Determination

This preList contains preprints discussed during the 9th International Symposium on the Biology of Vertebrate Sex Determination. This conference was held in Kona, Hawaii from April 17th to 21st 2023.

 



List by Martin Estermann

Alumni picks – preLights 5th Birthday

This preList contains preprints that were picked and highlighted by preLights Alumni - an initiative that was set up to mark preLights 5th birthday. More entries will follow throughout February and March 2023.

 



List by Sergio Menchero et al.

CellBio 2022 – An ASCB/EMBO Meeting

This preLists features preprints that were discussed and presented during the CellBio 2022 meeting in Washington, DC in December 2022.

 



List by Nadja Hümpfer et al.

Fibroblasts

The advances in fibroblast biology preList explores the recent discoveries and preprints of the fibroblast world. Get ready to immerse yourself with this list created for fibroblasts aficionados and lovers, and beyond. Here, my goal is to include preprints of fibroblast biology, heterogeneity, fate, extracellular matrix, behavior, topography, single-cell atlases, spatial transcriptomics, and their matrix!

 



List by Osvaldo Contreras

EMBL Synthetic Morphogenesis: From Gene Circuits to Tissue Architecture (2021)

A list of preprints mentioned at the #EESmorphoG virtual meeting in 2021.

 



List by Alex Eve

FENS 2020

A collection of preprints presented during the virtual meeting of the Federation of European Neuroscience Societies (FENS) in 2020

 



List by Ana Dorrego-Rivas

Planar Cell Polarity – PCP

This preList contains preprints about the latest findings on Planar Cell Polarity (PCP) in various model organisms at the molecular, cellular and tissue levels.

 



List by Ana Dorrego-Rivas

BioMalPar XVI: Biology and Pathology of the Malaria Parasite

[under construction] Preprints presented at the (fully virtual) EMBL BioMalPar XVI, 17-18 May 2020 #emblmalaria

 



List by Dey Lab, Samantha Seah

1

Cell Polarity

Recent research from the field of cell polarity is summarized in this list of preprints. It comprises of studies focusing on various forms of cell polarity ranging from epithelial polarity, planar cell polarity to front-to-rear polarity.

 



List by Yamini Ravichandran

TAGC 2020

Preprints recently presented at the virtual Allied Genetics Conference, April 22-26, 2020. #TAGC20

 



List by Maiko Kitaoka et al.

3D Gastruloids

A curated list of preprints related to Gastruloids (in vitro models of early development obtained by 3D aggregation of embryonic cells). Updated until July 2021.

 



List by Paul Gerald L. Sanchez and Stefano Vianello

ECFG15 – Fungal biology

Preprints presented at 15th European Conference on Fungal Genetics 17-20 February 2020 Rome

 



List by Hiral Shah

ASCB EMBO Annual Meeting 2019

A collection of preprints presented at the 2019 ASCB EMBO Meeting in Washington, DC (December 7-11)

 



List by Madhuja Samaddar et al.

EMBL Seeing is Believing – Imaging the Molecular Processes of Life

Preprints discussed at the 2019 edition of Seeing is Believing, at EMBL Heidelberg from the 9th-12th October 2019

 



List by Dey Lab

Autophagy

Preprints on autophagy and lysosomal degradation and its role in neurodegeneration and disease. Includes molecular mechanisms, upstream signalling and regulation as well as studies on pharmaceutical interventions to upregulate the process.

 



List by Sandra Malmgren Hill

Lung Disease and Regeneration

This preprint list compiles highlights from the field of lung biology.

 



List by Rob Hynds

Cellular metabolism

A curated list of preprints related to cellular metabolism at Biorxiv by Pablo Ranea Robles from the Prelights community. Special interest on lipid metabolism, peroxisomes and mitochondria.

 



List by Pablo Ranea Robles

BSCB/BSDB Annual Meeting 2019

Preprints presented at the BSCB/BSDB Annual Meeting 2019

 



List by Dey Lab

Biophysical Society Annual Meeting 2019

Few of the preprints that were discussed in the recent BPS annual meeting at Baltimore, USA

 



List by Joseph Jose Thottacherry

ASCB/EMBO Annual Meeting 2018

This list relates to preprints that were discussed at the recent ASCB conference.

 



List by Dey Lab, Amanda Haage
Close