Mitochondria Inspire a Lifestyle

Abstract

Tucked inside our cells, we animals (and plants, and fungi) carry mitochondria, minuscule descendants of bacteria that invaded our common ancestor two billion years ago. This unplanned breakthrough endowed our ancestors with a convenient, portable source of energy, enabling them to progress towards more ambitious forms of life. Mitochondria still manufacture most of our energy; we have evolved to invest it to grow and produce offspring, and to last long enough to make it all happen. Yet because the continuous generation of energy is inevitably linked to that of toxic free radicals, mitochondria give us life and give us death. Stripping away clutter and minutiae, here we present a big-picture perspective of how mitochondria work, how they are passed on virtually only by mothers, and how they shape the lifestyles of species and individuals. We discuss why restricting food prolongs lifespan, why reproducing shortens it, and why moving about protects us from free radicals despite increasing their production. We show that our immune cells use special mitochondria to keep control over our gut microbes. And we lay out how the fabrication of energy and free radicals sets the internal clocks that command our everyday rhythms-waking, eating, sleeping. Mitochondria run the show.

Mental health, mitochondria, and the battle of the sexes

“…This resembles what happens to the offspring of female rats fed a protein-deficient diet starting before pregnancy [60]. The manufacture of SAM requires, besides methionine, the energy-carrying molecule ATP-which again is primarily delivered by mitochondria [18].…”

“…The larger impact of Alzheimer's disease on word recall in women appears related to impaired glucose metabolism: diabetes or insulin resistance-signs of such an impaired metabolism-worsen verbal fluency in women but not in men [17]. Metabolism falls within the purview of mitochondria, former bacteria residing in our cells that supply most of our energy (for a nontechnical review see [18]), and mitochondria cannot do their job if they do not receive enough fuel. Indeed, women who are undernourished due to anorexia nervosa are not as good as other women at using cues from voices, body postures, or facial expressions to read other people's emotions or intentions-or at putting themselves in somebody else's shoes (for a meta-analysis, see [19]).…”

Mitochondria-Microbiota Interaction in Neurodegeneration

“…Moreover, mitochondria release free radicals – chemicals that are corrosive to their host but also to their own mitochondrial DNA. As a result, over time, more and more of these mitochondria become dysfunctional ( Lane, 2015 ; Kramer and Bressan, 2019 ) and eventually unable to detoxify the amyloids ( Sivanesan et al, 2020 ).…”

“…Mitochondria are not only important for the maintenance of protective barriers but also for the proper functioning of the immune system ( Cardoso and Empadinhas, 2018 ; Munoz-Pinto et al, 2021 ). Each mitochondrion features an outer membrane that separates it from the rest of the cell, and an inner membrane that contains its machinery for energy production ( Kramer and Bressan, 2019 ). Curiously, the inner membrane of the mitochondria that reside in a particular type of white blood cells produces much less energy than it is capable of Konjar et al (2018) .…”

“…Aside from the fact that they consume resources, inflammation and free-radical production should thus not be brought to bear more than strictly needed ( Konjar et al, 2018 ). This, then, might be why mitochondria behave like gate keepers; they hold their guard dogs (immune cells) on a tight leash when all is fine and set them loose only when bad characters (pathogens) come charging in Kramer and Bressan (2019) .…”