Related Experiment Video
Updated: Jun 23, 2025
Measuring Single-Cell Mitochondrial DNA Copy Number and Heteroplasmy Using Digital Droplet Polymerase Chain Reaction
Published on: July 12, 2022
Nanobiopsy investigation of the subcellular mtDNA heteroplasmy in human tissues
Alexander Bury1,2,3,4, Angela Pyle5, Amy E Vincent6,7
1Wellcome Centre for Mitochondrial Research, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK.
Abstract:
Mitochondrial function is critical to continued cellular vitality and is an important contributor to a growing number of human diseases. Mitochondrial dysfunction is typically heterogeneous, mediated through the clonal expansion of mitochondrial DNA (mtDNA) variants in a subset of cells in a given tissue. To date, our understanding of the dynamics of clonal expansion of mtDNA variants has been technically limited to the single cell-level. Here, we report the use of nanobiopsy for subcellular sampling from human tissues, combined with next-generation sequencing to assess subcellular mtDNA mutation load in human tissue from mitochondrial disease patients. The ability to map mitochondrial mutation loads within individual cells of diseased tissue samples will further our understanding of mitochondrial genetic diseases.
Insights
Researchers developed nanobiopsy to analyze mitochondrial DNA (mtDNA) mutation loads in individual cells. This technique enhances understanding of heterogeneous mitochondrial diseases caused by mtDNA variants and their clonal expansion in human tissues.
Area of Science:
- Cellular Biology
- Genetics
- Human Pathology
Background:
- Mitochondrial function is vital for cellular health and implicated in numerous human diseases.
- Mitochondrial dysfunction often arises from heterogeneous mitochondrial DNA (mtDNA) variants that clonally expand within specific cell populations.
- Current methods for studying mtDNA variant clonal expansion are limited to single-cell analyses.
Purpose of the Study:
- To introduce and validate nanobiopsy coupled with next-generation sequencing for assessing subcellular mtDNA mutation load.
- To investigate the dynamics of mtDNA variant clonal expansion at a subcellular level in human tissues.
- To improve the understanding of genetic mechanisms underlying mitochondrial diseases.
Main Methods:
- Development and application of nanobiopsy for precise subcellular sampling from human tissue.
- Utilizing next-generation sequencing (NGS) to quantify mtDNA mutation load within individual cells.
- Analysis of human tissue samples from patients diagnosed with mitochondrial diseases.
Main Results:
- Demonstrated the feasibility of nanobiopsy for subcellular sampling and mtDNA mutation load assessment.
- Provided a method to map mtDNA mutation heterogeneity within individual cells of diseased tissues.
- Established a new technical capability for studying clonal expansion of mtDNA variants.
Conclusions:
- Nanobiopsy combined with NGS offers a powerful approach to analyze subcellular mtDNA mutation loads.
- This technique significantly advances the study of mitochondrial genetic diseases by enabling single-cell level analysis of mtDNA variants.
- Mapping intracellular mutation loads will deepen insights into the pathogenesis and progression of mitochondrial disorders.
