Mitochondrial signal transduction (2022)
Mitochondria are explored here not just as the cell’s “powerhouse” but as dynamic signaling hubs that move within and sometimes between cells, influence immune responses, and may shape processes like aging, metabolism, and brain function. Commenters highlight emerging research on mitochondrial involvement in extracellular vesicles, neurological diseases, and endurance training, as well as experimental approaches to modulating their function through diet, drugs, or light therapy. Alongside the biology, there is a critical debate over the usefulness and limits of comparing cellular systems to computers, with concerns that such metaphors can both illuminate and mislead our understanding.
Role of Mitochondria Beyond “Powerhouse”
- Commenters emphasize mitochondria as dynamic organelles involved in signaling, immunity, stress responses, and neuronal function, not just ATP production.
- Some object to calling them a “microprocessor” or “processor,” seeing that as overly reductive or misleading.
- Others note they participate in analog, graded signal transduction rather than clean digital on/off logic.
Extracellular Mitochondria and Vesicles
- One participant with lab experience describes free mitochondria and mitochondria-containing extracellular vesicles (EVs) as surprisingly abundant under some culture conditions.
- They report experimental difficulty, sensitivity to small condition changes, and high variability in measurements.
- EVs are described as essential for normal physiology but also involved in pathology; therefore, not simply “aging villains” but fundamental machinery that can malfunction.
- Free mitochondria outside cells are said to provoke strong inflammatory responses, raising safety concerns about ideas like “mitochondria injections.”
Computational and Machine Analogies
- Repeated debate over computer metaphors for cells, brains, and mitochondria.
- Some argue analogies (e.g., brain as computer, mitochondria as processor) are useful teaching tools; others say they are vacuous or misleading if not predictive.
- There is concern that “everything is computation” rhetoric can encourage over-trust in algorithms and shallow cross-domain expertise.
- Several comments explore when analogies are legitimate models versus oversimplified “phibs” that break down outside narrow conditions.
Exercise, Metabolism, and Disease Links
- Commenters discuss increased mitochondrial numbers with endurance exercise and reduced sugar intake, tying this to improved ATP production and athletic performance.
- Mitochondrial function is linked (by commenters) to conditions like epilepsy, migraine, and broader mental health issues, with ketones and fasting suggested as potential modulators.
- Some speculate on mitochondrial dysfunction as a root factor in neurological and psychiatric diseases, while acknowledging this remains a developing research area.
Aging, Inheritance, and Modulation
- The mitochondrial theory of aging via reactive oxygen damage is mentioned, alongside questions about how maternally inherited mitochondria avoid cumulative damage.
- One explanation offered is that mitochondria passed to offspring come from specially protected maternal cells.
- Low-level laser therapy and dietary “mitochondrial modulators” are referenced, but their effectiveness and mechanisms are treated cautiously or as unclear.