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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Mitochondrial Swelling and Incipient Outer Membrane Rupture in Preapoptotic and Apoptotic Cells

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Author(s):
Sesso, A. [1] ; Belizario, J. E. [2] ; Marques, M. M. [3] ; Higuchi, M. L. [4] ; Schumacher, R. I. [5] ; Colquhoun, A. [6] ; Ito, E. [1] ; Kawakami, J. [4]
Total Authors: 8
Affiliation:
[1] Univ Sao Paulo, Setor Biol Estrutural, Lab Imunopatol, Inst Trop Med, BR-05403000 Sao Paulo - Brazil
[2] Univ Sao Paulo, Dept Farmacol, Inst Ciencias Biomed, BR-05403000 Sao Paulo - Brazil
[3] Univ Sao Paulo, Dept Dent, Fac Odontol, BR-05403000 Sao Paulo - Brazil
[4] Univ Sao Paulo, Lab Anat Patol, Inst Coracao, BR-05403000 Sao Paulo - Brazil
[5] Univ Sao Paulo, Dept Bioquim, Inst Quim, BR-05403000 Sao Paulo - Brazil
[6] Univ Sao Paulo, Dept Histol, Inst Ciencias Biomed, BR-05403000 Sao Paulo - Brazil
Total Affiliations: 6
Document type: Journal article
Source: Anatomical Record-Advances in Integrative Anatomy and Evolutionary Biology; v. 295, n. 10, p. 1647-1659, OCT 2012.
Web of Science Citations: 26
Abstract

Outer mitochondrial membrane (OMM) rupture was first noted in isolated mitochondria in which the inner mitochondrial membrane (IMM) had lost its selective permeability. This phenomenon referred to as mitochondrial permeability transition (MPT) refers to a permeabilized inner membrane that originates a large swelling in the mitochondrial matrix, which distends the outer membrane until it ruptures. Here, we have expanded previous electron microscopic observations that in apoptotic cells, OMM rupture is not caused by a membrane stretching promoted by a markedly swollen matrix. It is shown that the widths of the ruptured regions of the OMM vary from 6 to 250 nm. Independent of the perforation size, herniation of the mitochondrial matrix appeared to have resulted in pushing the IMM through the perforation. A large, long focal herniation of the mitochondrial matrix, covered with the IMM, was associated with a rupture of the OMM that was as small as 6 nm. Contextually, the collapse of the selective permeability of the IMM may precede or follow the release of the mitochondrial proteins of the intermembrane space into the cytoplasm. When the MPT is a late event, exit of the intermembrane space proteins to the cytoplasm is unimpeded and occurs through channels that transverse the outer membrane, because so far, the inner membrane is impermeable. No channel within the outer membrane can expose to the cytoplasm a permeable inner membrane, because it would serve as a conduit for local herniation of the mitochondrial matrix. Anat Rec, 2012. (c) 2012 Wiley Periodicals, Inc. (AU)