title: Multi-parametric analysis and modeling of relationships between mitochondrial morphology and apoptosis.
abstract: Mitochondria exist as a network of interconnected organelles undergoing constant fission and fusion. Current approaches to study mitochondrial morphology are limited by low data sampling coupled with manual identification and classification of complex morphological phenotypes. Here we propose an integrated mechanistic and data-driven modeling approach to analyze heterogeneous, quantified datasets and infer relations between mitochondrial morphology and apoptotic events. We initially performed high-content, multi-parametric measurements of mitochondrial morphological, apoptotic, and energetic states by high-resolution imaging of human breast carcinoma MCF-7 cells. Subsequently, decision tree-based analysis was used to automatically classify networked, fragmented, and swollen mitochondrial subpopulations, at the single-cell level and within cell populations. Our results revealed subtle but significant differences in morphology class distributions in response to various apoptotic stimuli. Furthermore, key mitochondrial functional parameters including mitochondrial membrane potential and Bax activation, were measured under matched conditions. Data-driven fuzzy logic modeling was used to explore the non-linear relationships between mitochondrial morphology and apoptotic signaling, combining morphological and functional data as a single model. Modeling results are in accordance with previous studies, where Bax regulates mitochondrial fragmentation, and mitochondrial morphology influences mitochondrial membrane potential. In summary, we established and validated a platform for mitochondrial morphological and functional analysis that can be readily extended with additional datasets. We further discuss the benefits of a flexible systematic approach for elucidating specific and general relationships between mitochondrial morphology and apoptosis.
authors.affiliation: Division of Theoretical Bioinformatics, German Cancer Research Center and Institute of Pharmacy and Molecular Biotechnology, Bioquant, University of Heidelberg, Heidelberg, Germany.
authors.forename: Yara
authors.initials: Y
authors.lastname: Reis
authors.forename: Marti
authors.initials: M
authors.lastname: Bernardo-Faura
authors.forename: Daniela
authors.initials: D
authors.lastname: Richter
authors.forename: Thomas
authors.initials: T
authors.lastname: Wolf
authors.forename: Benedikt
authors.initials: B
authors.lastname: Brors
authors.forename: Anne
authors.initials: A
authors.lastname: Hamacher-Brady
authors.forename: Roland
authors.initials: R
authors.lastname: Eils
authors.forename: Nathan R
authors.initials: NR
authors.lastname: Brady
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002166:Camptothecin / Q000494:pharmacology; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D045744:Cell Line, Tumor; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism; D017143:Fuzzy Logic; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D009840:Oligomycins / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D019284:Thapsigargin / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D024101:Mitochondrial Proteins; D009840:Oligomycins; D014409:Tumor Necrosis Factor-alpha; D051028:bcl-2-Associated X Protein; D049452:Green Fluorescent Proteins; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D019284:Thapsigargin; D003576:Electron Transport Complex IV; D002166:Camptothecin