Human adventitial pericytes provide a unique source of anti-calcific cells for cardiac valve engineering: Role of microRNA-132-3p

• Published in: Free radical biology & medicine 2021-03, Vol.165, p.137-151
• Main Authors: Jover, Eva, Fagnano, Marco, Cathery, William, Slater, Sadie, Pisanu, Emanuela, Gu, Yue, Avolio, Elisa, Bruno, Domenico, Baz-Lopez, Daniel, Faulkner, Ashton, Carrabba, Michele, Angelini, Gianni, Madeddu, Paolo
• Format: Article
• Language: English
• Subjects: Aortic Valve; Calcification; Cell Differentiation; Cells, Cultured; Endothelial Cells; HEK293 Cells; Humans; Mesenchymal stromal cells; microRNAs; MicroRNAs - genetics; Osteogenesis - genetics; Pericytes; Prosthetic valve; Tissue engineering; Valvular heart disease
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2021.01.029

Tissue engineering aims to improve the longevity of prosthetic heart valves. However, the optimal cell source has yet to be determined. This study aimed to establish a mechanistic rationale supporting the suitability of human adventitial pericytes (APCs). APCs were immunomagnetically sorted from saphenous vein leftovers of patients undergoing coronary artery bypass graft surgery and antigenically characterized for purity. Unlike bone marrow-derived mesenchymal stromal cells (BM-MSCs), APCs were resistant to calcification and delayed osteochondrogenic differentiation upon high phosphate (HP) induction, as assessed by cytochemistry and expression of osteogenic markers. Moreover, glycolysis was activated during osteogenic differentiation of BM-MSCs, whereas APCs showed no increase in glycolysis upon HP challenge. The microRNA-132-3p (miR-132), a known inhibitor of osteogenesis, was found constitutively expressed by APCs and upregulated following HP stimulation. The anti-calcific role of miR-132 was further corroborated by in silico analysis, luciferase assays in HEK293 cells, and transfecting APCs with miR-132 agomir and antagomir, followed by assessment of osteochondrogenic markers. Interestingly, treatment of swine cardiac valves with APC-derived conditioned medium conferred them with resistance to HP-induced osteogenesis, with this effect being negated when using the medium of miR-132-silenced APCs. Additionally, as an initial bioengineering step, APCs were successfully engrafted onto pericardium sheets, where they proliferated and promoted aortic endothelial cells attraction, a process mimicking valve endothelialization. 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. [Display omitted] •Calcific valvular heart disease is the third most common form of adult cardiovascular disease.•Tissue engineering may provide living-like valve substitutes by exogenously implanted cells which are yet to be determined.•In this study, adventitial pericytes are resistant to calcification compared with mesenchymal stem cells.•Adventitial pericytes convey the anti-calcific phenotype to heart valves through miR-132.•Adventitial pericytes have promising properties, thus opening new avenues for prosthetic valve engineering.