Mitochondrial Morphology and Fundamental Parameters of the Mitochondrial Respiratory Chain Are Altered in Caenorhabditis elegans Strains Deficient in Mitochondrial Dynamics and Homeostasis Processes

• Published in: PloS one Vol. 10; no. 6; p. e0130940
• Main Authors: Luz, Anthony L, Rooney, John P, Kubik, Laura L, Gonzalez, Claudia P, Song, Dong Hoon, Meyer, Joel N
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 24.06.2015; Public Library of Science (PLoS)
• Subjects: 2,4-Dinitrophenol - pharmacology; Adenosine Triphosphate - metabolism; Analysis; Animals; Apoptosis; Aspect ratio; ATP; Caenorhabditis elegans; Caenorhabditis elegans - genetics; Caenorhabditis elegans - metabolism; Caenorhabditis elegans Proteins - genetics; Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone - pharmacology; Carbonyls; Chain dynamics; Cyanides; Cytochrome; Cytochrome b; Cytochrome oxidase; Cytochrome-c oxidase; Dicyclohexylcarbodiimide; Dicyclohexylcarbodiimide - pharmacology; Dynamins - deficiency; Dynamins - genetics; Electron Transport; Electron transport chain; Electron Transport Complex III - deficiency; Electron Transport Complex III - genetics; GTP Phosphohydrolases - deficiency; GTP Phosphohydrolases - genetics; Homeostasis; Inhibitors; Kinases; Mitochondria; Mitochondria - drug effects; Mitochondria - metabolism; Mitochondria - ultrastructure; Mitochondria, Muscle - drug effects; Mitochondria, Muscle - metabolism; Mitochondria, Muscle - ultrastructure; Mitochondrial DNA; Morphology; Mutation; Nematodes; Oligomycin; Oligomycins - pharmacology; Oxygen; Oxygen Consumption; Parameters; Pharmacology; Protein-Serine-Threonine Kinases - deficiency; Protein-Serine-Threonine Kinases - genetics; Protons; Respiration; Respiratory function; Roundworms; Sodium; Sodium azide; Sodium Azide - pharmacology; Strains (organisms); Ubiquitin-Protein Ligases - deficiency; Ubiquitin-Protein Ligases - genetics; North Carolina; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0130940

Mitochondrial dysfunction has been linked to myriad human diseases and toxicant exposures, highlighting the need for assays capable of rapidly assessing mitochondrial health in vivo. Here, using the Seahorse XFe24 Analyzer and the pharmacological inhibitors dicyclohexylcarbodiimide and oligomycin (ATP-synthase inhibitors), carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (mitochondrial uncoupler) and sodium azide (cytochrome c oxidase inhibitor), we measured the fundamental parameters of mitochondrial respiratory chain function: basal oxygen consumption, ATP-linked respiration, maximal respiratory capacity, spare respiratory capacity and proton leak in the model organism Caenhorhabditis elegans. Since mutations in mitochondrial homeostasis genes cause mitochondrial dysfunction and have been linked to human disease, we measured mitochondrial respiratory function in mitochondrial fission (drp-1)-, fusion (fzo-1)-, mitophagy (pdr-1, pink-1)-, and electron transport chain complex III (isp-1)-deficient C. elegans. All showed altered function, but the nature of the alterations varied between the tested strains. We report increased basal oxygen consumption in drp-1; reduced maximal respiration in drp-1, fzo-1, and isp-1; reduced spare respiratory capacity in drp-1 and fzo-1; reduced proton leak in fzo-1 and isp-1; and increased proton leak in pink-1 nematodes. As mitochondrial morphology can play a role in mitochondrial energetics, we also quantified the mitochondrial aspect ratio for each mutant strain using a novel method, and for the first time report increased aspect ratios in pdr-1- and pink-1-deficient nematodes.