Protein expression pattern and analysis of differentially expressed peptides during various stages of tail regeneration in Hemidactylus flaviviridis.

Epimorphic regeneration is a process allowing the animal to regain its lost structure which depends on the resident pluripotent stem cells as well as de-differentiation of existing cells to form multi-potent stem cells. Many studies have been done to understand the appendage regeneration mechanism. The animal model used since decades is an urodele amphibian the axolotl. However, this ability is also seen in some members of reptiles, mainly lizards which on autotomy of tail regain the same by forming a replica of its lost tail. Lizards being closer to mammals are of greater interest and cannot be neglected. Hence, a stage specific protein profiling was undertaken in order to find the peptides playing a major role in epimorphosis. 2-DGE being basic tool for creating a protein profile was used. With advent of newer modern technology, label-free analysis which uses MS/MS was also performed. The study reports the peptides involved in apoptosis, inflammation and ECM remodelling across the stages of lizard tail regeneration for the first time. Apart from these peptides, structural protein, enzymes involved in metabolism have also been highlighted in the current study to give a bigger picture of the processes and the specific peptides required for tail regeneration.

Inhibition of BMP signaling reduces MMP-2 and MMP-9 expression and obstructs wound healing in regenerating fin of teleost fish Poecilia latipinna.

The tail fin of teleost fish responds to amputation by expressing few putative factors that promote scar-free wound healing, which paves the way for restoration of the lost part. Among the factors playing a role in this initial response, bone morphogenetic proteins (BMPs) are crucial. In the current study, we have analyzed the effect of BMP inhibition on wound healing in sailfin molly Poecilia latipinna. The study involved histological assessment of wound epithelium formation, an expression profile of proteins, and gelatinase activity as well as expression in response to BMP signal inhibition. LDN193189, a pharmacological inhibitor of BMP receptor, was administered to experimental fish. Our observations include incomplete wound healing and a significant reduction in the expression of a number of proteins as a result of LDN treatment at 24 h post-amputation. A pronounced effect was also seen on the gelatinases MMP-9 and MMP-2, which showed significantly reduced activities on a zymogram. Reduced expression of these MMPs after inhibitor treatment was also confirmed by western blot and real-time PCR analyses. In view of these results, we confirm that BMP signaling has a definitive role in the early stages of fin regeneration in P. latipinna. The effect of BMP inhibition is especially seen on the expression of MMP-9 and MMP-2, which are very important effectors of tissue remodeling immediately following amputation.