Altered mitochondrial structure and motion dynamics in living cells with energy metabolism defects revealed by real time microscope imaging.
Using the real time microscope (RTM), a system applying new developments in light microscopy, we documented the spatial and temporal dynamics of mitochondrial behavior in human cultured skin fibroblasts. Without the use of stains or probes, we resolved fibroblast mitochondria as dark slender filaments of approximately 0.2 m wide and up to 10 m long, as well as a few smaller ovoid forms. In the living cell, the three most common mitochondrial movements were: (1) small oscillatory movements; (2) larger movements including filament extension, retraction, and branching as well as combinations of these actions; and (3) whole transit movements of single mitochondrial filaments. Skin fibroblasts from patients with mitochondrial complex I deficiency and normal fibroblasts during incubation with rotenone, or antimycin A, contained higher proportions of mitochondria in the swollen filamentous forms, nodal filaments, and ovoid forms rather than the slender filamentous forms in normal cells. Interestingly, decreased motility was observed with the more ovoid mitochondrial forms compared to the filamentous forms. We conclude that mitochondrial morphology and dynamic motion are strongly associated with changes in mitochondrial energy metabolism. Images documenting our observations are presented both at single time points and as QuickTime videos.
Pham
Nhu-An
NA
Richardson Technologies Inc. at The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.
Richardson
Tim
T
Cameron
Jessie
J
Chue
Bruno
B
Robinson
Brian H
BH
D002460:Cell Line; D002465:Cell Movement; D004272:DNA, Mitochondrial / Q000235:genetics; D004734:Energy Metabolism / Q000502:physiology*; D005347:Fibroblasts / Q000378:metabolism; D005456:Fluorescent Dyes; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008853:Microscopy / Q000379:methods; D008928:Mitochondria / Q000378:metabolism* / Q000648:ultrastructure*; D028361:Mitochondrial Diseases / Q000473:pathology; D009068:Movement; D009245:NADH Dehydrogenase / Q000378:metabolism; D017384:Sequence Deletion; D012867:Skin / Q000378:metabolism
D004272:DNA, Mitochondrial; D005456:Fluorescent Dyes; D009245:NADH Dehydrogenase