A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Electron Microscopic Analysis of a Spherical Mitochondrial Structure
Tekijät: Ding WX, Li M, Biazik JM, Morgan DG, Guo FL, Ni HM, Goheen M, Eskelinen EL, Yin XM
Kustantaja: AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
Julkaisuvuosi: 2012
Tietokannassa oleva lehden nimi: JOURNAL OF BIOLOGICAL CHEMISTRY
Lehden akronyymi: J BIOL CHEM
Vuosikerta: 287
Numero: 50
Aloitussivu: 42373
Lopetussivu: 42378
Sivujen määrä: 6
ISSN: 0021-9258
DOI: https://doi.org/10.1074/jbc.M112.413674
Tiivistelmä
Mitochondria undergo dynamic structural alterations to meet changing needs and to maintain homeostasis. We report here a novel mitochondrial structure. Conventional transmission electron microscopic examination of murine embryonic fibroblasts treated with carbonyl cyanide m-chlorophenylhydrazone (CCCP), a mitochondrial uncoupler, found that more than half of the mitochondria presented a ring-shaped or C-shaped morphology. Many of these mitochondria seemed to have engulfed various cytosolic components. Serial sections through individual mitochondria indicated that they formed a ball-like structure with an internal lumen surrounded by the membranes and containing cytosolic materials. Notably, the lumen was connected to the external cytoplasm through a small opening. Electron tomographic reconstruction of the mitochondrial spheroids demonstrated the membrane topology and confirmed the vesicular configuration of this mitochondrial structure. The outside periphery and the lumen were defined by the outer membranes, which were lined with the inner membranes. Matrix and cristae were retained but distributed unevenly with less being kept near the luminal opening. Mitochondrial spheroids seem to form in response to oxidative mitochondrial damage independently of mitophagy. The structural features of the mitochondrial spheroids thus represent a novel mitochondrial dynamics.
Mitochondria undergo dynamic structural alterations to meet changing needs and to maintain homeostasis. We report here a novel mitochondrial structure. Conventional transmission electron microscopic examination of murine embryonic fibroblasts treated with carbonyl cyanide m-chlorophenylhydrazone (CCCP), a mitochondrial uncoupler, found that more than half of the mitochondria presented a ring-shaped or C-shaped morphology. Many of these mitochondria seemed to have engulfed various cytosolic components. Serial sections through individual mitochondria indicated that they formed a ball-like structure with an internal lumen surrounded by the membranes and containing cytosolic materials. Notably, the lumen was connected to the external cytoplasm through a small opening. Electron tomographic reconstruction of the mitochondrial spheroids demonstrated the membrane topology and confirmed the vesicular configuration of this mitochondrial structure. The outside periphery and the lumen were defined by the outer membranes, which were lined with the inner membranes. Matrix and cristae were retained but distributed unevenly with less being kept near the luminal opening. Mitochondrial spheroids seem to form in response to oxidative mitochondrial damage independently of mitophagy. The structural features of the mitochondrial spheroids thus represent a novel mitochondrial dynamics.
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