https://doi.org/10.1007/s00392-025-02625-4
1Universitätsklinikum Heidelberg Klinik für Herzchirurgie Heidelberg, Deutschland; 2Universitätsklinikum Schleswig-Holstein Molekulare Kardiologie Kiel, Deutschland; 3Universitätsklinikum Heidelberg Apotheke Heidelberg, Deutschland; 4Universität Heidelberg Herz- und Kreislaufphysiologie Heidelberg, Deutschland; 5Universitätsklinikum Schleswig-Holstein Klinik für Innere Medizin V mit dem Schwerpunkt Angiologie Kiel, Deutschland
Objectives: Marfan syndrome (MFS) is characterized by increased expression of matrix metalloproteinases (MMP) in smooth muscle cells (SMCs) associated with medial elastolysis and aortic aneurysm formation predominantly in the ascending aorta. Long-term overexpression of MMP antagonist tissue inhibitor of metalloproteinases 1 (TIMP-1) via adeno-associated virus transfer (AAV-TIMP-1) comprises a potential treatment option for MFS. Therefore, we aim to provide a causal therapy for the aortopathy of MFS using locally applied gene therapy in a minimal-invasive murine model.
Methods: Through a lateral mini-thoracotomy, AAV-TIMP-1 and AAV-enhanced green fluorescent protein (AAV-EGFP) vectors were circumferentially applied around the adventitia of the ascending aorta in adult male mgR/mgR Marfan mice. Thirty days postoperatively, the ascending aorta was harvested and prepared for cryostat sections. Subsequently, Van Giesson differential staining was carried out to assess the elastic fibers in the aortic media.
Additionally, aortic cryosections were used for endothelial marker CD31, tight junction proteins ZO-1 and Occludin IF-stainings to measure endothelial dysfunction. In situzymography was performed with aortic sections to evaluate MMP activity.
Results: AAV-TIMP-1-treated mice exhibited significantly reduced elastic fiber degradation compared to the AAV-EGFP control group (Islands of Damage = 3.00±2.61 vs 16.90±10.20; p<0.01). Evaluation of tight junction integrity through tight junction-proteins ZO-1 and occludin staining showed a severe reduction of these proteins in Marfan mice treated with AAV-EGFP (Mean grey value ZO-1 = 11.80±3.68%; Occludin = 14.14±3.02) compared to the AAV-TIMP-1-treated mice (mean grey value ZO-1 = 20.92±3.27%; occludin = 25.91±6.74) not only in the endothelial layer, but also in the aortic media (p<0.01). Furthermore, in situzymography showed a significant reduction of MMP activity in AAV-TIMP1-treated mice (mean grey value = 19.51± 3.80) compared to AAV-EGFP-treated mice (mean grey value = 27.75±3.90; p <0.01).
Conclusion: Local administration of AAV-TIMP-1 effectively reduces elastic fiber degradation and MMP activity and prevents endothelial dysfunction in the ascending aorta of fibrillin-1 deficient Marfan mice. Thus, the local overexpression of MMP inhibitors via gene therapy may represent a promising treatment option for the aortic complications of Marfan syndrome.