Heparan sulfate proteoglycan expression in the regenerating zebrafish fin.

Background: Heparan sulfate proteoglycan (HSPG) expression is found in many animal tissues and regulates growth factor signaling such as of Fibroblast growth factors (Fgf), Wingless/Int (Wnt) and Hedgehog (HH). Glypicans, which are GPI (glycosylphosphatidylinositol)‐anchored proteins, and transmembrane‐anchored syndecans represent two major HSPG protein families whose involvement in development and disease has been demonstrated. Their participation in regenerative processes both of the central nervous system and of regenerating limbs is well documented. However, whether HSPG are expressed in regenerating zebrafish fins, is currently unknown. Results: Here, we carried out a systematic screen of glypican and syndecan mRNA expression in regenerating zebrafish fins during the outgrowth phase. We find that 8 of the 10 zebrafish glypicans and the three known zebrafish syndecans show specific expression at 3 days post amputation. Expression is found in different domains of the regenerate, including the distal and lateral basal layers of the wound epidermis, the distal most blastema and more proximal blastema regions. Conclusions: HSPG expression is prevalent in regenerating zebrafish fins. Further research is needed to delineate the function of glypican and syndecan action during zebrafish fin regeneration. Key Findings: A systematic screen on HSPG expression in regenerating zebrafish fins during the outgrowth phase was carried outMost HSPG are expressed in regenerating zebrafish finsHSPG expression is found in the wound epidermis, and different parts of the regeneration blastemaThe prevalence of HSPG expression suggests a functional contribution to fin regeneration [ABSTRACT FROM AUTHOR]