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Updated: Apr 17, 2026
Analyzing Mitochondrial Transport and Morphology in Human Induced Pluripotent Stem Cell-Derived Neurons in Hereditary Spastic Paraplegia
Published on: February 9, 2020
Automated detection of whole-cell mitochondrial motility and its dependence on cytoarchitectural integrity
Judith Kandel1, Philip Chou1, David M Eckmann2,3,4
1Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, 19104.
Abstract:
Current methodologies used for mitochondrial motility analysis tend to either overlook individual mitochondrial tracks or analyze only peripheral mitochondria instead of mitochondria in all regions of the cell. Furthermore, motility analysis of an individual mitochondrion is usually quantified by establishing an arbitrary threshold for "directed" motion. In this work, we created a custom, publicly available computational algorithm based on a previously published approach (Giedt et al., 2012. Ann Biomed Eng 40:1903-1916) in order to characterize the distribution of mitochondrial movements at the whole-cell level, while still preserving information about single mitochondria. Our technique is easy to use, robust, and computationally inexpensive. Images are first pre-processed for increased resolution, and then individual mitochondria are tracked based on object connectivity in space and time. When our method is applied to microscopy fields encompassing entire cells, we reveal that the mitochondrial net distances in fibroblasts follow a lognormal distribution within a given cell or group of cells. The ability to model whole-cell mitochondrial motility as a lognormal distribution provides a new quantitative paradigm for comparing mitochondrial motility in naïve and treated cells. We further demonstrate that microtubule and microfilament depolymerization shift the lognormal distribution in directions which indicate decreased and increased mitochondrial movement, respectively. These findings advance earlier work on neuronal axons (Morris and Hollenbeck, 1993. J Cell Sci 104:917-927) by relating them to a different cell type, applying them on a global scale, and automating measurement of mitochondrial motility in general.
Insights
This study introduces a new computational algorithm to analyze mitochondrial movement across entire cells, revealing a lognormal distribution of mitochondrial net distances in fibroblasts. This method offers a novel way to compare mitochondrial motility in different cellular conditions.
Area of Science:
- Cell Biology
- Computational Biology
- Biophysics
Background:
- Current mitochondrial motility analysis methods are limited, often focusing on peripheral mitochondria or arbitrary motion thresholds.
- Analyzing mitochondrial dynamics at a whole-cell level while retaining single-mitochondrion data is crucial for understanding cellular function.
Purpose of the Study:
- To develop and validate a custom, publicly available computational algorithm for comprehensive mitochondrial motility analysis.
- To characterize the distribution of mitochondrial movements at the whole-cell level in fibroblasts.
- To establish a new quantitative paradigm for comparing mitochondrial motility in various cellular states.
Main Methods:
- Developed a custom computational algorithm based on object connectivity for tracking individual mitochondria in space and time.
- Applied image pre-processing for enhanced resolution.
- Utilized the algorithm on microscopy images of entire fibroblasts to analyze mitochondrial movement patterns.
Main Results:
- Mitochondrial net distances in fibroblasts follow a lognormal distribution when analyzed at the whole-cell level.
- Microtubule and microfilament depolymerization significantly alter this lognormal distribution, indicating decreased and increased mitochondrial movement, respectively.
- The developed method is computationally inexpensive, robust, and easy to use.
Conclusions:
- The lognormal distribution model provides a novel quantitative framework for assessing mitochondrial motility.
- This approach advances the understanding of mitochondrial dynamics beyond previous studies by applying it to fibroblasts and enabling whole-cell analysis.
- The findings highlight the impact of cytoskeletal integrity on mitochondrial movement and offer a tool for studying cellular responses to various treatments.
