Arteriogenesis is associated with an induction of the cardiac ankyrin repeat protein (carp).

OBJECTIVE Collateral artery growth (arteriogenesis) can be induced in rabbit and mice by occlusion of the femoral artery. We aimed to identify genes that are differentially expressed during arteriogenesis. METHODS 24 h after femoral ligation or sham operation collateral arteries were isolated from New Zealand white rabbits, mRNAs were extracted and amplified using the SMART technique. cDNAs were subjected to suppression subtractive hybridization. The differential expression was confirmed by Northern blot, Real time PCR and Western blot. Additionally, the gene expression was modulated in vivo by application of cytokines via osmotic minipumps. RESULTS We found the cardiac ankyrin repeat protein (carp) mRNA to be upregulated at 24 h and already at 6 h and 12 h after surgery as shown by Northern blot hybridization and real time PCR. The carp mRNA was also increased in our mouse model of arteriogenesis. Western blot results on nuclear extracts of rabbit collaterals 24 h after surgery indicated that carp, which we showed to be expressed in endothelial cells and smooth muscle cells of collateral arteries by immunohistochemistry, was also upregulated on the protein level. We infused MCP-1, TGF-beta1 or doxorubicin for 24 h in rabbits and found that only TGF-beta1 led to an additional increase of carp mRNA. Overexpression of carp in cos-1 cells resulted in a 3.7-fold increase of the immediate early gene egr-1. CONCLUSIONS Our results implicate that carp is associated with the initiation and regulation of arteriogenesis.