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Updated: Sep 27, 2025

Establishment of a Robust and Reproducible Model of Radiation-Induced Skin and Muscle Fibrosis
Published on: August 31, 2022
Immunohistochemistry indicates that persistent inflammation determines failure of tail, limb and finger regeneration
1Comparative Histolab Padova, Dipartimento di Biologia, University of Bologna, via Selmi 3, 40126 Bologna, Italy.
Background:
The presence of white blood inflammatory cells in injured tissues and their effect on the process of organ regeneration in lizards has been assessed on tail, limb and digits.
Methods:
The present immunohistochemical survey analyzes the occurrence of CD68-labeled cells in lizard organs uncapable of regenerating tissues that exhibit strong inflammatory activity.
Results:
This marker mainly identifies macrophages and mast cells present in large number within tissues of injured limbs and digits. Also a high inflammation is associated with amputated tails that do not regenerate, derived from cauterization or infection of tissues of the tail stump. In the healing limbs and fingers at 12-20 days post-amputation, numerous CD68-labeled cells, most likely macrophages, are seen among superficial connective tissues and injured muscles and bones. These cells likely stimulate and give rise to scarring tissues and no regeneration of limb and fingers occurs. In the cauterized or in the infected tail stump a strong accumulation of CD68-positive mast cells and macrophages is observed, where they likely evoke epidermal coagulation, formation of scarring connective tissue, and loss of regeneration.
Conclusions:
The present observations provide further cytological evidence that support the notion that a strong and lasting inflammatory condition impedes organ regeneration in specifically lizards and, more generally other vertebrates as well.

