The Prospect of Regenerating Limbs
https://theness.com/neurologicablog/the-prospect-of-regenerating-limbs/
Regeneration is a staple of science fiction because it’s powerful and not impossible. People are exploring several routes: cyborg replacements; organ or limb transplants from others; regrowth from the recipient’s own tissue; and stem-cell therapies that prompt rebuilding. Each option is under study and promising in glimpses, but none is ready for prime time. A newer idea adds a genetic twist: trigger natural regeneration in the body itself. Among natural models, axolotls stand out—they can regrow limbs, parts of the heart, spinal cord, and even parts of the brain. They do this by forming a blastoma of pluripotent cells at the injury site that rebuilds tissue in weeks. Zebrafish and mice show similar, though more limited, regenerative abilities. A recent cross-species study found shared SP6 and SP8 transcription factors in axolotl, zebrafish, and mice. Knocking out SP6 or SP8 impairs digit regeneration in mice; removing SP8 also hinders axolotls, hinting at a conserved toolkit. Adding zebrafish FGF8 partially restored regeneration in SP6/SP8-deficient mice. Humans carry SP6 and SP8, but scar formation, immune response, oxygen dynamics, and a cancer-risk trade-off keep full regeneration at a distance.
