Expression analysis of Hsp90α and cytokines in zebrafish caudal fin regeneration

Zebrafish (Danio rerio) is an ideal model organism for exploring the ability and mechanism of tissue regeneration in the vertebrate. However, the specific cellular and molecular mechanism of caudal fin regeneration in zebrafish remains largely unclear. Therefore, we first confirmed the crucial period of fin regeneration in adult zebrafish by morphological and histological analysis. Then we performed RNA-Seq analysis of the caudal fin regeneration at three key stages, which provided some clues for exploring the mechanism of caudal fin regeneration. Moreover, we also determined the expressions of inflammatory cytokines IL-1 beta, IL-6, IL-8, IL-10, TGF-beta, and the immune-related pathway JAK2 alpha and STAT1b in the caudal fin of zebrafish following fin amputation by quantitative real time PCR (qPCR). Particularly, Hsp90 alpha expression at mRNA and protein level determined by qPCR and Western blotting, respectively, and whole-mount in situ hybridization of Hsp90 alpha were also performed in this study. The results showed that inflammatory cytokines were mainly expressed in the early period of caudal fin regeneration (1-3 days post amputation, dpa), indicating that fish immune system was involved in the fin regeneration. Furthermore, the high expression of Hsp90 alpha in the vicinity of blastema and blood vessels of the regenerating fin suggests that Hsp90 alpha may play a role in the initiation and promotion of caudal fin regeneration. Overall, our results provide a framework for further understanding the cellular and molecular mechanism in caudal fin regeneration.

Automated summary

Zebrafish is an ideal model organism for studying tissue regeneration, and this study focused on the cellular and molecular mechanisms of caudal fin regeneration. By analyzing gene expressions and protein levels at different stages of regeneration, the study suggested the involvement of the fish immune system and the potential role of Hsp90 alpha in initiating and promoting fin regeneration.