1. Developmental Biology

Autophagic cell death is dependent on lysosomal membrane permeability through Bax and Bak

  1. Jason Karch
  2. Tobias G Schips
  3. Bryan D Maliken
  4. Matthew J Brody
  5. Michelle A Sargent
  6. Onur Kanisciak
  7. Jeffery D Molkentin  Is a corresponding author
  1. University of Cincinnati, United States
https://doi.org/10.7554/eLife.30543
Share this article
Cite this article
  1. Jason Karch
  2. Tobias G Schips
  3. Bryan D Maliken
  4. Matthew J Brody
  5. Michelle A Sargent
  6. Onur Kanisciak
  7. Jeffery D Molkentin
(2017)
Autophagic cell death is dependent on lysosomal membrane permeability through Bax and Bak
eLife 6:e30543.
https://doi.org/10.7554/eLife.30543
  2. Download BibTeX
  3. Download .RIS

Abstract

Cells deficient in the pro-death Bcl-2 family members Bax and Bak are known to be resistant to apoptotic cell death, and in a previous eLIFE paper, Karch et al., 2013 showed that these 2 effectors are also needed for mitochondrial-dependent cellular necrosis. Here we show that mouse embryonic fibroblasts deficient in Bax/Bak1 are resistant to the third major form of cell death associated with autophagy through a mechanism involving lysosome permeability. Indeed, specifically targeting Bax only to the lysosome restores autophagic cell death in Bax/Bak1 null cells. Moreover, a monomeric-only mutant form of Bax is sufficient to increase lysosomal membrane permeability and restore autophagic cell death in Bax/Bak1 double-deleted mouse embryonic fibroblasts. Finally, increasing lysosomal permeability through a lysomotropic detergent in cells devoid of Bax/Bak1 restores autophagic cell death, collectively indicting that Bax/Bak integrate all major forms of cell death through direct effects on membrane permeability of multiple intracellular organelles.

Article and author information

Author details

  1. Jason Karch

    Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, United States
    Competing interests
    The authors declare that no competing interests exist.

  2. Tobias G Schips

    Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, United States
    Competing interests
    The authors declare that no competing interests exist.

  3. Bryan D Maliken

    Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, United States
    Competing interests
    The authors declare that no competing interests exist.

  4. Matthew J Brody

    Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, United States
    Competing interests
    The authors declare that no competing interests exist.

  5. Michelle A Sargent

    Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, United States
    Competing interests
    The authors declare that no competing interests exist.

  6. Onur Kanisciak

    Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, United States
    Competing interests
    The authors declare that no competing interests exist.

  7. Jeffery D Molkentin

    Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, United States
    For correspondence
    jeff.Molkentin@cchmc.org
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-3558-6529

Funding

National Institutes of Health (R01HL132831)

  • Jeffery D Molkentin

Howard Hughes Medical Institute (Molkentin)

  • Jeffery D Molkentin

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Copyright

© 2017, Karch et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 5,318
    views
  • 867
    downloads
  • 73
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Jason Karch
  2. Tobias G Schips
  3. Bryan D Maliken
  4. Matthew J Brody
  5. Michelle A Sargent
  6. Onur Kanisciak
  7. Jeffery D Molkentin
(2017)
Autophagic cell death is dependent on lysosomal membrane permeability through Bax and Bak
eLife 6:e30543.
https://doi.org/10.7554/eLife.30543

Share this article

https://doi.org/10.7554/eLife.30543

Categories and tags

Research organism

Further reading

    1. Cell Biology

    Bax and Bak function as the outer membrane component of the mitochondrial permeability pore in regulating necrotic cell death in mice

    Jason Karch, Jennifer Q Kwong ... Jeffery D Molkentin
    Research Article

    A critical event in ischemia-based cell death is the opening of the mitochondrial permeability transition pore (MPTP). However, the molecular identity of the components of the MPTP remains unknown. Here, we determined that the Bcl-2 family members Bax and Bak, which are central regulators of apoptotic cell death, are also required for mitochondrial pore-dependent necrotic cell death by facilitating outer membrane permeability of the MPTP. Loss of Bax/Bak reduced outer mitochondrial membrane permeability and conductance without altering inner membrane MPTP function, resulting in resistance to mitochondrial calcium overload and necrotic cell death. Reconstitution with mutants of Bax that cannot oligomerize and form apoptotic pores, but still enhance outer membrane permeability, permitted MPTP-dependent mitochondrial swelling and restored necrotic cell death. Our data predict that the MPTP is an inner membrane regulated process, although in the absence of Bax/Bak the outer membrane resists swelling and prevents organelle rupture to prevent cell death.

    1. Developmental Biology

    Apical constriction requires patterned apical surface remodeling to synchronize cellular deformation

    Satoshi Yamashita, Shuji Ishihara, François Graner
    Research Article

    Apical constriction is a basic mechanism for epithelial morphogenesis, making columnar cells into wedge shape and bending a flat cell sheet. It has long been thought that an apically localized myosin generates a contractile force and drives the cell deformation. However, when we tested the increased apical surface contractility in a cellular Potts model simulation, the constriction increased pressure inside the cell and pushed its lateral surface outward, making the cells adopt a drop shape instead of the expected wedge shape. To keep the lateral surface straight, we considered an alternative model in which the cell shape was determined by cell membrane elasticity and endocytosis, and the increased pressure is balanced among the cells. The cellular Potts model simulation succeeded in reproducing the apical constriction, and it also suggested that a too strong apical surface tension might prevent the tissue invagination.

    1. Cancer Biology
    2. Developmental Biology

    Oncogenic and teratogenic effects of Trp53Y217C, an inflammation-prone mouse model of the human hotspot mutant TP53Y220C

    Sara Jaber, Eliana Eldawra ... Franck Toledo
    Research Article

    Missense ‘hotspot’ mutations localized in six p53 codons account for 20% of TP53 mutations in human cancers. Hotspot p53 mutants have lost the tumor suppressive functions of the wildtype protein, but whether and how they may gain additional functions promoting tumorigenesis remain controversial. Here, we generated Trp53Y217C, a mouse model of the human hotspot mutant TP53Y220C. DNA damage responses were lost in Trp53Y217C/Y217C (Trp53YC/YC) cells, and Trp53YC/YC fibroblasts exhibited increased chromosome instability compared to Trp53-/- cells. Furthermore, Trp53YC/YC male mice died earlier than Trp53-/- males, with more aggressive thymic lymphomas. This correlated with an increased expression of inflammation-related genes in Trp53YC/YC thymic cells compared to Trp53-/- cells. Surprisingly, we recovered only one Trp53YC/YC female for 22 Trp53YC/YC males at weaning, a skewed distribution explained by a high frequency of Trp53YC/YC female embryos with exencephaly and the death of most Trp53YC/YC female neonates. Strikingly, however, when we treated pregnant females with the anti-inflammatory drug supformin (LCC-12), we observed a fivefold increase in the proportion of viable Trp53YC/YC weaned females in their progeny. Together, these data suggest that the p53Y217C mutation not only abrogates wildtype p53 functions but also promotes inflammation, with oncogenic effects in males and teratogenic effects in females.