I hope everything is going well and things are running smooth as we get into the New Year.
As promised today I’m writing about mitochondria, one of my favorite topics.
I remember when I was interviewing for my postdoc. I had trained in molecular virology and wanted to continue that road, but my mentor shared his interest on mitochondrial biology and explained me his new project on mitochondrial transcription. Suddenly I realized that had navigated grad school without thinking a lot about mitochondria and probably the last time I thought about them was in school (well, maybe not, I’ve thought about them when exercising but that’s another story). Have you ever thought about your mitochondria?
We all probably remember the cell from our science classes in high school. We might remember that at the center of the stage we have the nucleus, which main functions are encoding genetic information and ensure that information is expressed and maintained as well as inherited by daughter cells after cellular division. We may also remember that surrounding the nucleus and in the cell soup there are other ‘organelles’ with various functions, including mitochondria. Here is a typical representation of the cell anatomy, typically what we might have learned in high school. Mitochondria (plural, singular mitochondrion) are represented in yellow.
Figure 1: Schematic of an animal cell. Source Wikimedia Commons.
Eventually I became fascinated with these power factories and since I took the postdoctoral position to study mitochondrial transcription I had the opportunity to think and learn a lot more about mitochondria. Of course I learned that we don’t have only 1 or 2 per cell but many more!!! Look at this picture now…
Figure 2: HeLa cells stained with DAPI (blue) and Mitotracker (red). Personal collection.
In blue we can see the nucleus, and in red (stained with Mitotracker, a marker specific for mitochondria) we can see how mitochondria really look, there are thousands per cell, connected forming tubules, like a network; there are plenty surrounding the nucleus, but they extend to the edges of the cell. Isn’t that amazing!? And gorgeous!!!
As you can see these organelles essential for life are quite remarkable. Mitochondria main (but not only) role is to produce 90 % of the energy we require for every biochemical reaction that keeps us functioning, our heart beating, our muscles and nerves moving us around, our digestive system capturing the nutrients we ingest with food (when we actually ingest real food, more to come ;-), and so on. We require energy and we are ‘engineered’ and have evolved to produce it.
Many human chronic diseases have a connection with mitochondrial dysfunction, including muscular dystrophies, heart disease, metabolic diseases, neurodegenerative disorders, cancer, and aging. This connection has led the leaders in the field of mitochondrial medicine to propose these diseases are actually energetic diseases (Wallace, J Clin Invest. 2013;123(4):1405–1412. doi:10.1172/JCI61398). The idea is that environmental factors (such as energy resources, energy demands and toxins) and genetic variations influence the function of mitochondria and can lead to mitochondrial damage and progressive bioenergetics decline which in turn affects cell homeostasis and ultimately organ function. This is a fascinating field that promise to keep us exited for years to come!!!
So this week I invite to start thinking about this. Are you taking good care of yourself and your mitochondria? I hope so!
In the meanwhile, I hope you are enjoying the beginning of the year, working on the New Year’s resolutions and feeling energized!
Have a great week,