Biological complexity: mitochondria controlling stem cells (Introduction)

by David Turell , Friday, September 02, 2022, 20:06 (603 days ago) @ David Turell

New discovery in muscles:

https://phys.org/news/2022-09-reveals-starring-role-shape-shifting-mitochondria.html

"Mitochondria are remarkable shape-shifting organelles that have long been understood as the powerhouses inside our cells. But relatively little is known about how the constant fission and fusion of these tiny energy generators impacts stem cell function and tissue regeneration.

"Now, compelling new research from Dr. Mireille Khacho's lab at the University of Ottawa Faculty of Medicine reveals a starring role for mitochondrial dynamics within adult muscle stem cells—those unique and primitive cells that serve as the body's raw material for muscle renewal and repair.

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"In essence, her lab suggests a wide-ranging repertoire for mitochondria. Not only do they act as internal sensors and communicators, but their fragmentation plays a big part in overall stem cell maintenance and functioning. Through a series of manipulations with a unique mouse model, the researchers showed that the essential mitochondrial shaping protein OPA1 regulates the dormant state of adult muscle stem cells. And the chronic loss of this protein and persistent fragmentation leads to severe muscle stem cell defects.

"Dr. Khacho's team says the findings show for the first time that the protein OPA1—one of the main regulators of mitochondrial fusion—is essential for muscle stem cell maintenance and function. They pieced together a connection between the depletion of stem cells and mitochondria becoming imbalanced and dysfunctional.

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"The tiny structure's role is somewhat counterintuitive. Generally, fragmentation of mitochondria is a destructive phenomenon for cells in tissues, Dr. Khacho explains. But in their experiments with adult muscle stem cells, her team found that their fragmentation also serves as a physiological mechanism that activates signaling to the nucleus. It does this by increasing levels of an antioxidant peptide called glutathione. Even more intriguing is that they uncovered a new function for this peptide: it acts as a signaling molecule that mediates the crosstalk between mitochondria and the nucleus."

Comment: another example of extreme complexity. Counterintuitive? No, just an example of God's designs at work.