Högskolan i Skövde

Spinal cord injury (SCI) is a severe CNS injury with irreversible recovery of functions in mammalian species and consequent detrimental of social and psychological condition. It accounts for major economic resources in healthcare and current therapies of engrafting transplantation of in vitro neural cultures do not lead to functional recovery. Senescence has been shown as a dormant state where cells secrete several factors into the environment before they become phagocytized and cleared. These senescence-associated secretory phenotype (SASP) factors have been shown as crucial in the development and regeneration processes, and therefore new studies are taking place to understand if inducing the cellular senescence program is therapeutically beneficial at lesion sites. Here, we analysed the regeneration of the caudal fin of the zebrafish, which is a vertebrate model capable of regenerating tissue leading to full recovery. By quantifying proportion of senescent cells through several time points of caudal fin regeneration, through SA-β-gal staining, we assessed if there are differences between normal non-injured tissue and the regenerating and full regenerated tissue. It was revealed that the number of senescent cells increase during the regeneration process, but they become effectively cleared upon the fin is almost full regenerated. Although this confirms that there is in fact a development-programmed senescence (DPS) during regeneration, the proportion of cells after regeneration was lower than the non-injured tissue, which may be interest for the study of age-related senescence.