We feel pain (nociception), internal sensations (interoception), and even our immune system (immunoception)
How does the brain monitor our energy status?
In this preprint, we propose that the brain feels the balance of energy demand (burn rate) and energy transformation capacity (mitochondrial OxPhos capacity) via mitoception
Cellular studies, animal models, clinical, and human studies suggest that the cytokine GDF15 is the main signal of mitoception
Preprint by Cynthia Liu and colleagues
@torwager @LFeldmanBarrett @Danbelsky @Dr_Epel @cohenaginglab
Every tissue expresses GDF15 at some level, whereas the receptor is only or mostly at appreciable levels in the brainstem
Perfect for body-to-brain signaling
Not all cells express GDF15
Some cells may be more competent "metaboceptors" -- metabolic receptors -- than other cells
Many different stressors can trigger GDF15. They appear to converge on "reductive stress", a consequence of energy resistance that activates the integrated stress response
Other than the integrated stress response, there are multiple mechanisms responsible for sending energy supply and abundance - both at the cell and organism level
We propose metaboception as a two-part interoceptive axis, with a dual output that change behaviors to save energy, and mobilize energy to rescue the energy gap within cells
Beyond nausea, which @StephenORahilly and colleagues showed in pregnancy is driven by GDF15, chronically elevated GDF probably does not feel good
Most surprising to us were the robust associations between elevated GDF15 and states of mind including fatigue, depression, anxiety, social isolation, and other negative psychosocial factors
More research required on that front
• • •
Missing some Tweet in this thread? You can try to
force a refresh
Comments welcome!
Thanks to @drmichaellevin and others for commenting and helping improving the model
In physical/mechanical systems, excessive resistance and dissipative loss drive information loss
In biological systems, the Energy Resistance Principle (ERP) predicts that elevated energy resistance (éR) is similarly the main driver of the cellular hallmarks of aging and disease
Exciting to be able to finally put a number on how well, or not so well -- with how much resistance? -- a cell/organ/person can flow energy
The cytokine/metaboline GDF15 is likely the best éR marker we have
Multiple mechanisms allow cells to share mitochondria
There are possibly some tissues and cell types that preferentially act as mitochondrial "donors", whereas other tissues may be better "acceptors"
This new field builds on a long history of important discovery that contributed to blur cellular boundaries, portraying the organism increasingly clearly as a dynamic cell collective
Of all metabolic, chemical, and possibly other ways in which mitochondria influence cellular functions and behaviors, changing the sequence of the nuclear genome may be one of the most "stable" mark
mtDNA insertions are called Numts (nuclear mtDNA insertions)
The process is called "Numtogenesis", and happens more frequently in cancer cells and believed to contribute to nuclear genome instability: doi.org/10.1016/j.semc…