Self-Control of Inflammation during Tail Regeneration of Lizards.

Bingqiang He,Honghua Song,Yongjun Wang

doi:10.3390/jdb9040048

Abstract

Lizards can spontaneously regenerate their lost tail without evoking excessive inflammation at the damaged site. In contrast, tissue/organ injury of its mammalian counterparts results in wound healing with a formation of a fibrotic scar due to uncontrolled activation of inflammatory responses. Unveiling the mechanism of self-limited inflammation occurring in the regeneration of a lizard tail will provide clues for a therapeutic alternative to tissue injury. The present review provides an overview of aspects of rapid wound healing and roles of antibacterial peptides, effects of leukocytes on the tail regeneration, self-blocking of the inflammatory activation in leukocytes, as well as inflammatory resistance of blastemal cells or immature somatic cells during lizard tail regeneration. These mechanistic insights of self-control of inflammation during lizard tail regeneration may lead in the future to the development of therapeutic strategies to fight injury-induced inflammation.

Highlights

Several adult vertebrates can spontaneously regenerate their lost appendages in high fidelity, while such regenerative capacity is evolutionarily absent in mammals
Experiments on both lizards and amphibian models have clearly demonstrated that infiltration of macrophages to the damaged sites is essential for successful appendage regeneration [43,44]
The natural evolution of lizards has endowed them with the powerful capacity of regenerating damaged tails by avoiding infection and inflammation

Summary

Introduction

Several adult vertebrates can spontaneously regenerate their lost appendages in high fidelity, while such regenerative capacity is evolutionarily absent in mammals. Appendage amputation of adult mammals often heals the wounding by the formation of a fibrotic scar [1,2,3,4,5]. The observation of the appendage regenerating process in vertebrates reveals that epimorphic regeneration shares conserved histological events, including re-epithelization of the wound, formation of the blastema and growth of the different tissues [6,7,8,9]. To avoid possible infection at diverse ecology and/or the endogenous activation of inflammation that will result in the failure of the regeneration, the lizards are obliged to employ an efficient molecular or genetic mechanism to rapidly control excessive activation of inflammatory response following tail amputation. We will introduce several aspects that lizards have evolved to circumvent inflammation during the spontaneous tail regeneration, which may provide a promising therapeutic alternative to mammalian traumatic inflammation

Rapid Wound Healing and Protection of Antibacterial Peptides

Infiltration of Leukocytes to the Wounded Tail

Self-Blocking of the Proinflammatory Signal Pathway in Leukocytes

Crosstalk between Inflammation and Blastemal Cells or Immature Somatic Cells

Conclusions