Posted on 26 January 2020
Previous research had shown that blood of healthy individuals contains up to 50,000 times more mitochondrial DNA than nuclear DNA. But mitochondria are the proverbial ‘power-generating units’ of our cells. Their key role is cellular energy generation, signalling inside the cell, and playing a key role in deciding when a cell should commit suicide for the greater good in a process known as apoptosis. Therefore no one quite understood why there is such significant amounts of mitochondrial components free-floating around in our bloodstream.
This recent research led by Inserm researcher Alain R. Thierry at the Montpellier Cancer Research Institute (Inserm/Université de Montpellier/Montpellier Cancer Institute) after a seven-year & 100-people study has now found complete and fully-functioning mitochondria in blood plasma. They estimated that there are between 200,000 and 3.7 million cell-free intact mitochondria per mL of blood plasma. This further complicates our understanding of the role and functioning of mitochondria in aging and health.
When we consider the sheer number of extracellular mitochondria found in the blood, we have to ask why such a discovery had not been made before.Alain R. Thierry at the Montpellier Cancer Research Institute
Our team has built up expertise in the specific and sensitive detection of DNA in the blood, by working on the fragmentation of extracellular DNA derived from the mitochondria in particular.Alain R. Thierry at the Montpellier Cancer Research Institute
But what is the role of these extracellular mitochondria? The researchers hypothesize that these circulating mitochondria could be a unique and yet undiscovered communication between the cells. Such intercellular communication may be involved in inflammation, and other processes of aging.
In addition to its importance to our knowledge of physiology, this discovery could lead to improvements in the diagnosis, monitoring and treatment of certain diseases.Alain R. Thierry at the Montpellier Cancer Research Institute
In fact, the research team is now devoting its attention to evaluating the extracellular mitochondria as biomarkers in non-invasive prenatal diagnosis, and cancer.
1) Blood contains circulating cell‐free respiratory competent mitochondria: https://doi.org/10.1096/fj.201901917RR