A groundbreaking study published in Nature on May 21, 2025, by scientists at IMBA, sheds light on limb regeneration in axolotls. The research identifies Hand2 as a crucial factor that instructs cells on which part of the limb to regenerate, opening new avenues for tissue engineering and regenerative medicine.
Axolotls, native to a lake near Mexico City, possess the remarkable ability to regrow entire limbs. The study reveals that Hand2, expressed on the posterior side of the limb, functions as a positional cue. This cue enables cells to 'remember' their location and regenerate the correct structures following an injury.
Key Findings:
Hand2 activates the Shh signal, essential for cells to regenerate specific limb parts.
Cells can be reprogrammed to alter their identity, potentially transforming cells in different body parts.
The Hand2-Shh signaling circuit is also present in humans, suggesting possibilities for unlocking regenerative capabilities.
This discovery paves the way for advancements in tissue and organoid engineering. By manipulating Hand2 expression, scientists may be able to direct cells to initiate limb formation, potentially leading to limb regrowth in mammals.
Leo Otsuki, the study's first author, emphasizes the importance of converting cells remaining after an injury and changing their function for regenerative therapies. Elly Tanaka adds that these advances hold great promise for regenerative medicine.