Methods to dissect mitochondrial membrane permeabilization in the course of apoptosis.
In several paradigms of cell death, mitochondrial membrane permeabilization (MMP) delimits the frontier between life and death. Mitochondria control the intrinsic pathway of apoptosis and participate in the extrinsic pathway. Moreover, they have been implicated in nonapoptotic cell death modalities. Irrespective of its initiation at the inner or the outer mitochondrial membrane (IM and OM, respectively), MMP culminates in the functional (dissipation of the mitochondrial transmembrane potential, shutdown of ATP synthesis, redox imbalance) and structural (reorganization of cristae, release of toxic intermembrane space proteins into the cytosol) collapse of mitochondria. This has a profound impact on cellular metabolism, activates caspase-dependent and -independent executioner mechanisms, and finally results in the demise of the cell. However, the partial and/or temporary permeabilization of one or both mitochondrial membranes is not always a prelude to cell death. This chapter proposes a method and several guidelines to discriminate between IM and OM permeabilization and to identify MMP that does indeed precede cell death. This approach relies on the integration of currently available techniques and may be easily introduced in the laboratory routine for a more precise detection of cell death.
Galluzzi
Lorenzo
L
INSERM, U848, Institut Gustave Roussy, and Université Paris-Sud 11, Villejuif, France.
Vitale
Ilio
I
Kepp
Oliver
O
Séror
Claire
C
Hangen
Emilie
E
Perfettini
Jean-Luc
JL
Modjtahedi
Nazanine
N
Kroemer
Guido
G
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001692:Biological Transport; D005455:Fluorescent Antibody Technique; D006801:Humans; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000378:metabolism / Q000502:physiology*; D033681:Mitochondrial Membrane Transport Proteins / Q000378:metabolism / Q000502:physiology; D051336:Mitochondrial Membranes / Q000378:metabolism*; D000083162:Mitochondrial Permeability Transition Pore; D010539:Permeability
D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore