Zebrafish ProVEGF-C expression, proteolytic processing and inhibitory effect of unprocessed ProVEGF-C during fin regeneration.
BACKGROUND
In zebrafish, vascular endothelial growth factor-C precursor (proVEGF-C) processing occurs within the dibasic motif HSIIRR(214) suggesting the involvement of one or more basic amino acid-specific proprotein convertases (PCs) in this process. In the present study, we examined zebrafish proVEGF-C expression and processing and the effect of unprocessed proVEGF-C on caudal fin regeneration.


RESULTS
Cell transfection assays revealed that the cleavage of proVEGF-C, mainly mediated by the proprotein convertases Furin and PC5 and to a less degree by PACE4 and PC7, is abolished by PCs inhibitors or by mutation of its cleavage site (HSIIRR(214) into HSIISS(214)). In vitro, unprocessed proVEGF-C failed to activate its signaling proteins Akt and ERK and to induce cell proliferation. In vivo, following caudal fin amputation, the induction of VEGF-C, Furin and PC5 expression occurs as early as 2 days post-amputation (dpa) with a maximum levels at 4-7 dpa. Using immunofluorescence staining we localized high expression of VEGF-C and the convertases Furin and PC5 surrounding the apical growth zone of the regenerating fin. While expression of wild-type proVEGF-C in this area had no effect, unprocessed proVEGF-C inhibited fin regeneration.


CONCLUSIONS
Taken together, these data indicate that zebrafish fin regeneration is associated with up-regulation of VEGF-C and the convertases Furin and PC5 and highlight the inhibitory effect of unprocessed proVEGF-C on fin regeneration.
Khatib
Abdel-Majid
AM
INSERM, UMRS940, Equipe Avenir. Institut de Génétique Moléculaire, Hôpital St-Louis, Université Paris 7, Paris, France.
Lahlil
Rachid
R
Scamuffa
Nathalie
N
Akimenko
Marie-Andrée
MA
Ernest
Sylvain
S
Lomri
Abdderahim
A
Lalou
Claude
C
Seidah
Nabil G
NG
Villoutreix
Bruno O
BO
Calvo
Fabien
F
Siegfried
Geraldine
G
D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D015153:Blotting, Western; D049109:Cell Proliferation; D002478:Cells, Cultured; D045683:Furin / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D045702:Proprotein Convertase 5 / Q000235:genetics / Q000378:metabolism; D012038:Regeneration / Q000235:genetics / Q000502:physiology*; D014443:Tyrosine / Q000378:metabolism; D042582:Vascular Endothelial Growth Factor C / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
D042582:Vascular Endothelial Growth Factor C; D029961:Zebrafish Proteins; D014443:Tyrosine; D045702:Proprotein Convertase 5; D045683:Furin