AAV8-mediated mouse/human PROC expression rescues thrombophilia in hereditary protein C-deficient mice

Hereditary protein C (PC) deficiency, which is caused by PROC gene mutations, increases the risk of venous thromboembolism and offers limited treatment options. In this study, we developed adeno-associated virus serotype 8 (AAV8) vectors carrying either murine PC (AAV8-mPROC) or human PC (AAV8-hPROC) transgenes. These vectors were delivered through tail vein injection into PROC knockout mice. The highest dose of AAV8-mPROC (6.00E + 12 vg/kg) resulted in PC activity and antigen levels reaching 200.7% and 190.1%, respectively, which were maintained at 171.8% and 165.2%, respectively, by week 48. Similarly, the highest dose of AAV8-hPROC (8.00E + 12 vg/kg) resulted in 295.4% PC activity and 3.72 μg/ml human protein C antigen, which were maintained at 195.1% and 1.13 μg/ml, respectively, by week 48. In the vein thrombosis model, AAV8-mPROC and AAV8-hPROC significantly reduced the thrombus weight from 12.11 ± 3.39 mg to 7.19 ± 2.28 mg and 6.81 ± 2.28 mg, respectively. In the pulmonary embolism model, the proportion of embolized vessels decreased from 88.53% to approximately 60.62% in the AAV8-mPROC group and 62.33% in the AAV8-hPROC group. Our study has established a preclinical foundation for the safe and effective application of AAV vector-based gene therapy in treating inherited PC deficiency.