Blood contains circulating cell‐free respiratory competent mitochondria, 2020, Dache et al

[Andy]

Mitochondria are considered as the power‐generating units of the cell due to their key role in energy metabolism and cell signaling. However, mitochondrial components could be found in the extracellular space, as fragments or encapsulated in vesicles. In addition, this intact organelle has been recently reported to be released by platelets exclusively in specific conditions.

Here, we demonstrate for the first time, that blood preparation with resting platelets, contains whole functional mitochondria in normal physiological state. Likewise, we show, that normal and tumor cultured cells are able to secrete their mitochondria. Using serial centrifugation or filtration followed by polymerase chain reaction‐based methods, and Whole Genome Sequencing, we detect extracellular full‐length mitochondrial DNA in particles over 0.22 µm holding specific mitochondrial membrane proteins.

We identify these particles as intact cell‐free mitochondria using fluorescence‐activated cell sorting analysis, fluorescence microscopy, and transmission electron microscopy. Oxygen consumption analysis revealed that these mitochondria are respiratory competent. In view of previously described mitochondrial potential in intercellular transfer, this discovery could greatly widen the scope of cell‐cell communication biology. Further steps should be developed to investigate the potential role of mitochondria as a signaling organelle outside the cell and to determine whether these circulating units could be relevant for early detection and prognosis of various diseases.

Open access at https://onlinelibrary.wiley.com/doi/full/10.1096/fj.201901917RR

 

[ladycatlover]

Gosh, there's a turn up for the books! While I don't understand how mitochondria work (other than at an incredibly simplistic understanding) this sounds to me like something that's really exciting.

 

[mariovitali]

Merged thread

Researchers at the Montpellier Cancer Research Institute (IRCM) have discovered a new component in blood that has never been detected there before. Mitochondria are normally found inside cells, but the team has now discovered them floating around on their own in the bloodstream.

Often referred to as the power houses of cells, mitochondria are organelles that play a key role in metabolizing energy and cell signaling. Occasionally they are found outside of cells, but usually only as fragments within platelets.

But after a seven-year study, an IRCM team has now found complete and fully-functioning mitochondria in blood plasma, contained inside highly-stable structures. Using electron microscopy, the researchers analyzed plasma samples from about 100 people, and found up to 3.7 million of these mitochondria-containing structures per milliliter of plasma.

and

The discovery means that this extracellular mitochondria must be playing some kind of biological role. The team hypothesizes that it may be helping to induce immune and inflammatory responses, and helping cells communicate with each other.

https://newatlas.com/biology/unexpected-new-component-discovered-bloodstream/


Original study :

https://onlinelibrary.wiley.com/doi/epdf/10.1096/fj.201901917RR

 

[mariovitali]

Also from the study :

To sum up, we report here that blood contains intact cellfree full-length mitochondrial DNA in dense and biologically stable structures over 0.22 µm in diameter and that these structures have specific mitochondrial proteins, double membranes and a morphology resembling that of mitochondria. We further demonstrate that these structurally intact cell-free mitochondria in the blood circulation are respiratory competent. We estimate that there are between 200 000 and 3.7 million cell-free intact mitochondria per mL

 

[Patient4Life]

I wonder if this is what Dr. Davis has found in the blood when they were analyzing ME/CFS patients. He said it was larger than cytokines. I don't know if they had any healthy controls as it seems they would have found this in them also.

Well, hopefully someone can let Dr. Davis know.

 

[Andy]

Or perhaps we lack this, or maybe in us it doesn't do its job as well, or it might work too well. Although I would imagine he's aware of it I'll highlight this paper to Karl Morten, see what he makes of it.