Immunity and Wound Healing: Regeneration or Repair?

Tissue injury triggers a highly complex and dynamic process of healing, involving several coordinated molecular and cellular events to achieve the pre-damage integrity and homeostasis. The response can occur in the form of regeneration or repair. Regeneration is variable and results in full replacement of any part of the body (in some invertebrates), complex structures (eg, limbs), internal organs (eg, liver), or lost/damaged tissue so that the original architecture and function are completely restored. In contrast, repair involves fibrotic reactions leading to scar formation that often impair tissue functionality. The capacity to perfectly regrow lost appendages or injured tissues varies widely among animal species. It shows a general gradual loss during ontogenesis and, although the mechanisms underlying regenerative ability have been largely investigated, the reasons for the variable potentials remain unclear……