Dynamic remodeling of the extra cellular matrix during zebrafish fin regeneration

• Expression of key components of the ECM changes during regeneration and is associated with skeletal growth and patterning.
• A transitional matrix is up-regulated during fin regeneration.
• ECM remodeling is conserved during tissue repair and regeneration.

Extracellular matrix plays a dynamic role during the process of wound healing, embryogenesis and tissue regeneration. Caudal fin regeneration in zebrafish is an excellent model to study tissue and skeletal regeneration. We have analyzed the expression pattern of some of the well characterized ECM proteins during the process of caudal fin regeneration in zebrafish. Our results show that a transitional matrix analogous to the one formed during newt skeletal and heart muscle regeneration is synthesized during fin regeneration. Here we demonstrate that a provisional matrix rich in hyaluronic acid, tenascin C, and fibronectin is synthesized following amputation. Additionally, we observed that the link protein Hapln1a dependent ECM, consisting of Hapln1a, hyaluronan and proteoglycan aggrecan, is upregulated during fin regeneration. Laminin, the protein characteristic of differentiated tissues, showed only modest change in the expression pattern. Our findings on zebrafish fin regeneration implicates that changes in the extracellular milieu represent an evolutionarily conserved mechanism that proceeds during tissue regeneration, yet with distinct players depending on the type of tissue that is involved.