Senescent Cells Induce Dedifferentiation in Salamander Regeneration

Regeneration from injury is an intricate dance of many different cell types: stem cells, somatic cells, cells that become senescent, and innate immune cells such as macrophages. This is true of every higher species, but what is the meaningful difference between species capable of regenerating entire limbs and internal organs, such as salamanders, and species that scar and exhibit only partial regeneration of lost tissue, such as near all mammals? In recent years, researchers have discovered that senescent cells and macrophages behave differently in injured tissues in species capable of proficient regeneration. Clearance of senescent cells is unusually efficient in salamanders, for example. A characteristic of proficient tissue regeneration is a recapitulation of embryonic development, in which cells dedifferentiate to form a blastema in order to rebuild the structure of lost tissue. In today's open access paper, researchers find that salamander senescent cells produce signaling that encourages this dedifferentiation in muscle tissue during limb regeneration. Similar research in zebrafish, another highly regenerative species, has shown that senescent cells are necessary for regeneration of retinal tissues. While the senescence-associated secretory phenotype (SASP) produced by senescent cells is clearly different from species to species, identifying specific signal differences that may be involved in proficient regeneration, as here, is very much a work in progress. ...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs