Oxidative Stress, Mitochondrial DNA Damage and Human Disease: Learn how mitochondria repair their genome and how to measure mtDNA repair using quantitative PCR
Ben Van Houten, PhD
Department of Pharmacology and Chemical Biology
University of Pittsburgh Cancer Institute
Hillman Cancer Center
Webinar Abstract:
Mitochondria contain their own genome, which in human cells is 16,569 bp, and encodes 22 tRNA, 2 ribosomal RNA and 13 polypeptides all of which are essential for electron transport and ATP generation through oxidative phosphorylation.
Mitochondrial DNA (mtDNA) mutations are associated with a wide variety of human disorders including aging, cancer, and neurodegenerative diseases. Much of the DNA repair machinery that is available to fix damage in the nuclear genome is not imported into the mitochondria. Thus, mitochondria have limited DNA repair capacity and certain forms of DNA damage such as UV induce photoproducts and adducts from environmental carcinogens.
MtDNA by virtue of its close proximity to the electron transport chain suffers increased oxidative damage than nuclear DNA and mitochondria have a robust DNA repair system for the removal of oxidized bases through a repair pathway called base excision repair. All of these enzymes are encoded in the nucleus and imported into the mitochondria.
Our group has developed a quantitative PCR assay for the measurement of mtDNA damage and repair. Using this assay we have been able to show that hydrogen peroxide induces 3-10 fold more damage in mtDNA than nuclear DNA in many cell types from several different species. This damage is rapidly repaired, but protracted exposures causes persistent mtDNA damage, loss of mitochondrial membrane potential and cell death. Thus, mtDNA damage is a good biomarker of chronic oxidative stress.
Join us for this 45-minute webinar as we discuss:
- Mitochondrial base excision repair
- How to measure mtDNA repair using quantitative PCR
- The link between persistent mtDNA, mitochondrial dysfunction and human disease
Assay:
Energy Expenditure: Glycolytic Flux
Mitochondrial Function: BOFA with 2-DG
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