Recombinant adeno-associated virus-based gene transfer of cathelicidin induces therapeutic neovascularization preferentially via potent collateral growth.
Therapeutic neovascularization is a concept well validated in animal models, however, without clear-cut success in clinical studies. To achieve prolonged transgene expression, recombinant adeno-associated virus (rAAV) was used in a chronic ischemic hind-limb model and the human antimicrobial peptide cathelicidin (LL-37/hCAP-18) was used as proangiogenic factor. Seven days after femoral artery excision, 0.5 x 10(11) rAAV particles encoding for green fluorescent protein (rAAV.GFP), cathelicidin (rAAV.cath), or vascular endothelial growth factor A (rAAV.VEGF-A) were retroinfused into the anterior tibial vein of rabbits (n = 5 per group). In addition, one rAAV.cath-treated group obtained a constant infusion with the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin into the ischemic tissue starting on day 7. On day 7 and day 35 angiography of both hind limbs was performed for collateral quantification and frame count score (cinedensitometry). Capillary-to-muscle fiber ratios were obtained on day 35. Compared with controls, application of rAAV.cath induced a gain of perfusion (153 +/- 12 vs. 107 + 9% of day 7 controls) via increased collateral growth (length index, 161 +/- 14 vs. 97 +/- 9%, controls), but no significant capillary growth (1.16 +/- 0.09 vs. 0.99 +/- 0.08, controls). Wortmannin application completely abolished the effects of rAAV.cath, indicating the involvement of the PI3K signal pathway. In conclusion, rAAV-mediated cathelicidin expression is capable of inducing functionally relevant neovascularization, preferentially by collateral growth. The rAAV-based vectors as long-expressing vector expression systems and cathelicidin as proangiogenic factor provide a promising new combination in the treatment of peripheral artery disease.
Pinkenburg
Olaf
O
Division of Pulmonology, Department of Internal Medicine, Hospital of the University of Marburg, Philipps Universität Marburg, Marburg, Germany.
Pfosser
Achim
A
Hinkel
Rabea
R
Böttcher
Martina
M
Dinges
Claudia
C
Lebherz
Corinna
C
Sultana
Shahana
S
Enssle
Jörg
J
El-Aouni
Chiraz
C
Büning
Hildegard
H
Boekstegers
Peter
P
Bals
Robert
R
Kupatt
Christian
C
D000818:Animals; D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D000229:Dependovirus / Q000235:genetics*; D004195:Disease Models, Animal; D018014:Gene Transfer Techniques; D006614:Hindlimb / Q000098:blood supply; D006801:Humans; D007511:Ischemia / Q000628:therapy*; D018919:Neovascularization, Physiologic / Q000235:genetics*; D011817:Rabbits; D011994:Recombinant Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins; D011994:Recombinant Proteins; D042461:Vascular Endothelial Growth Factor A