Thorac Cardiovasc Surg 2013; 61 - OP217
DOI: 10.1055/s-0032-1332456

Adenoviral gene therapy for reduction of Elastolysis causes severe inflammation in Fibrillin-1 deficient Marfan mice (mgR/mgR)

P Seppelt 1, S Schwill 1, M Zaradzki 1, R Arif 1, A Weber 1, PN Robinson 2, 3, A Wagner 4, S Ensminger 5, M Karck 1, K Kallenbach 1
  • 1University Hospital Heidelberg, Department of Cardiac Surgery, Heidelberg, Germany
  • 2Charité-Universitätsmedizin Berlin, Institute for Medical Genetics and Human Genetics, Berlin, Germany
  • 3Max-Planck Institute for Molecular Genetics, Berlin, Germany
  • 4University of Heidelberg, Institute of Physiology and Pathophysiology, Heidelberg, Germany
  • 5Herz- und Diabeteszentrum NRW, Klinik für Thorax- und Kardiovaskularchirurgie, Bad Oeynhausen, Germany

Objectives: On molecular level Marfan patients show lysis of aortic elastin layers caused by the proteolytic activity of matrix-metalloproteinases (MMP). Overexpression of Tissue Inhibitor of Matrix Metalloproteinases-1 (TIMP-1) may reduce elastolysis of the media and stabilize the vascular wall. In this study we present the first adenoviral mediated gene transfer of TIMP-1 in Fibrillin-1 deficient mice (mgR/mgR).

Methods: Overall 14 wild-type and 21 homozygous mgR/mgR mice (female C57BL/6, 6 – 9 weeks) underwent heterotopic infrarenal transplantation of the thoracic aorta. Aortic grafts of 7 mgR/mgR and 7 wild-type mice were treated immediately after harvest by adenoviral vector coding for TIMP-1 (Ad.TIMP-1, 5 × 109pfu/ml) for 30 minutes. Seven mgR/mgR control mice were treated by vector coding for ß -Galactosidase (Ad.ß -Gal, 5 × 109pfu/ml). 7 homozygous and 7 wild-type grafts did not receive any treatment. Evaluation of graft transduction was performed by immunohistochemistry against TIMP-1, ß-Galactosidase staining and gelatin in situ zymography (ISZ) 30 days after operation. Inflammation, Neointimal Index (NI) and elastin breaks were examined by histologic standard staining.

Results: Sufficient transduction of aortic grafts could be proven by Immunohistochemistry, ß-Galactosidase-staining and gelatin ISZ. Untreated wild-type and homozygous grafts showed no signs of inflammation. As expected homozygous grafts presented significant more elastolysis compared to wild-type (p = 0.01). Ad.ß-Gal. and Ad.TIMP-1 treated homozygous grafts showed severe cellular inflammation and intima hyperplasia (NI: 0.23; 0.43), in contrast to wild-type not reacting with Ad.TIMP-1 contact (NI: 0.00). Elastolysis in homozygous grafts was severely increased due to vector induced inflammation. Ad.TIMP-1 induced more intima hyperplasia than Ad.ß-Gal. (p = 0.038). Decreased expression of CD31 and EphrinB2 after Ad.TIMP-1 transfection indicates endothelial dysfunction in homozygous grafts.

Conclusions: Fibrillin-1 deficient aortic grafts showed severe Inflammation after adenoviral gene therapy. We suggest that endothelial dysfunction in Marfan syndrome enables Adenovirus to target basolateral Coxsackie B and Adenovirus Receptor. Further investigations need to examine the coherence between Fibrillin-1 deficiency, endothelial dysfunction and viral contact.