Methods and Results: Antigenically APCs were immunomagnetically sorted from saphenous vein leftovers of patients undergoing coronary artery surgery and antigenically characterized for purity. Unlike bone marrow-derived mesenchymal stromal cells (BM-MSCs), APCs were resistant to osteochondrogenic induction by high phosphate (HP), as assessed by cytochemistry and expression of osteogenic markers. MiR-132 is natively expressed by APCs, with copy numbers being enhanced by HP stimulation. In silico bioinformatic analysis, followed by luciferase assays in HEK293 cells and miR-132 titration using agomiR and antagomiR in APCs, demonstrated that several osteochondrogenic genes were negatively regulated by miR-132. Among these, the glycolytic marker GLUT1 was downregulated in HP-stimulated APCs. In contrast to BM-APCs, APCs showed no increase in glycolysis under HP. Interestingly, incubation with APC-derived conditioned medium conferred swine cardiac valves with resistance to osteogenic transformation by HP; whereas, conditioned media from miR-132-knocked-down APCs failed to prevent the expression of these markers. Finally, we demonstrated the feasibility of using APCs to engineer bovine pericardium patches. APCs proliferate in the patch and secrete factors able to attract aortic endothelial cells under HP.
Conclusions: Human APCs are resistant to calcification compared with BM-MSCs and convey the anti-calcific phenotype to heart valves through miR-132. These findings may open new important avenues for prosthetic valve cellularization.
|Journal||European Journal of Heart Failure|
|Publication status||Submitted - 10 Jul 2020|
- Bristol Heart Institute