title: Subcellular heterogeneity of mitochondrial membrane potential: relationship with organelle distribution and intercellular contacts in normal, hypoxic and apoptotic cells.
abstract: The subcellular heterogeneity of mitochondrial membrane potential (mDelta psi) was investigated in confluent and sub-confluent cultures of four cell types (human astrocytes, HEp-2, MDCK and Vero cells) in normal growth conditions, hypoxia and apoptosis. The distribution of high-polarized mitochondria, detected by the potential-sensitive probe JC-1, was found to depend on: (1) the proximity to the cell edge; (2) the local absence of cell-cell contacts; and (3) the local absence of acidic vesicles. Both hypoxia and apoptosis produced a general mDelta psi increase with different redistributions of high-polarized mitochondria. Hypoxic cells maintained high-polarized mitochondria for over 24 hours, until cells underwent necrosis. On the other hand, apoptotic cells showed an unexpected convergence of high-polarized mitochondria into an extremely packed mass at one side of the nucleus, in a stage preceding nuclear condensation, but correlated to the retraction of cell-cell contacts.
authors: Departments of Cytomorphology and Medical Sciences, University of Cagliari, Italy. gdiaz@unica.it
authors: G
authors: G
authors: Diaz
authors: M D
authors: MD
authors: Setzu
authors: A
authors: A
authors: Zucca
authors: R
authors: R
authors: Isola
authors: A
authors: A
authors: Diana
authors: R
authors: R
authors: Murru
authors: V
authors: V
authors: Sogos
authors: F
authors: F
authors: Gremo
mesh_terms: D000818:Animals; D017209:Apoptosis; D001253:Astrocytes / Q000378:metabolism; D002166:Camptothecin / Q000494:pharmacology; D002460:Cell Line; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology; D006801:Humans; D000860:Hypoxia; D007425:Intracellular Membranes / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology*; D008928:Mitochondria / Q000502:physiology*; D015388:Organelles / Q000502:physiology*; D012965:Sodium Chloride / Q000378:metabolism; D014709:Vero Cells
chemical_list: D004791:Enzyme Inhibitors; D018698:Glutamic Acid; D012965:Sodium Chloride; D002166:Camptothecin