AAV-Mediated Expression of AP-1-Neutralizing RNA Decoy Oligonucleotides Attenuates Transplant Vasculopathy in Mouse Aortic Allografts

Abstract

Transplant vasculopathy (TV), characterized by obstructive lesions in affected vessels, represents one of the long-term complications of cardiac transplantation. Activation of the transcription factor activator protein-1 (AP-1) is implicated in smooth muscle cell (SMC) phenotypic switch from contractile to synthetic function, increasing the migration and proliferation rate of these cells. We hypothesize that adeno-associated virus (AAV)-mediated delivery of an RNA hairpin AP-1 decoy oligonucleotide (dON) might effectively ameliorate TV severity in a mouse aortic allograft model. Aortic allografts from DBA/2 mice ex vivo transduced with modified AAV9-SLR carrying a targeting peptide within the capsid surface were transplanted into the infrarenal aorta of C57BL/6 mice. Cyclosporine A (10 mg/kg BW) was administered daily. AP-1 dONs were intracellularly expressed in the graft tissue as small hairpin RNA proved by fluorescent in situ hybridization. Explantation after 30 days and histomorphometric evaluation revealed that AP-1 dON treatment significantly reduced intima-to-media ratio by 41.5% (p < 0.05) in the grafts. In addition, expression of adhesion molecules, cytokines, as well as numbers of proliferative SMCs, matrix metalloproteinase-9-positive cells, and inflammatory cell infiltration were significantly decreased in treated aortic grafts. Our findings demonstrate the feasibility, efficacy, and specificity of the anti-AP-1 RNA dON approach for the treatment of allograft vasculopathy in an animal model. Moreover, the AAV-based approach in general provides the possibility to achieve a prolonged delivery of nucleic-acids-based therapeutics in to the blood vessel wall.

Navigating toward gene therapy in Marfan syndrome: A hope for halting aortic aneurysm

“… 7 This lab has a long-standing and ongoing tradition of using AAVs for potential therapeutic proposes. 8 , 9 , 10 The Marfan syndrome model chosen for the study is the fibrillin-1 hypomorphic mgR/mgR mouse, whose aortic aneurysm quickly evolves, usually ending in aortic dissection. Cultured Marfan aortic smooth muscle cells (SMCs) and aortic tissue showed a significant reduction in Regnase-1 protein levels.…”

Harnessing the Therapeutic Potential of Decoys in Non-Atherosclerotic Cardiovascular Diseases: State of the Art

“…AP-1 is a transcription factor involved in the transcriptional regulation of genes implicated in cell proliferation and extracellular matrix production in response to inflammatory cytokines and oxidative stress [ 42 ].…”

“…Ex-plantation after 30 days and evaluation showed that AP-1 decoy oligonucleotide therapy reduced the intima-to-media ratio in the grafts by 41.5 percent. Additionally, in treated grafts, expression of cytokines and adhesion molecules were greatly decreased, as were MMP-9-positive cells, SMCs, and inflammatory cell infiltration [ 42 ].…”