Bristol Medical School (Translational Health Sciences), Bristol Heart Institute, University of Bristol, Bristol, United Kingdom; Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), IdiSNA, Pamplona, Spain.
Bristol Medical School (Translational Health Sciences), Bristol Heart Institute, University of Bristol, Bristol, United Kingdom.
Free Radic Biol Med. 2021 Mar;165:137-151. doi: 10.1016/j.freeradbiomed.2021.01.029. Epub 2021 Jan 23.
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.
组织工程旨在提高人工心脏瓣膜的耐久性。然而，最佳的细胞来源尚未确定。本研究旨在建立一个支持人血管外膜周细胞（APCs）适用性的机制基础。
从行冠状动脉旁路移植术患者的大隐静脉残余物中免疫磁珠分选 APCs，并进行纯度的抗原鉴定。与骨髓间充质基质细胞（BM-MSCs）不同，APCs 在高磷（HP）诱导下具有抗钙化和延迟成骨-软骨分化的特性，通过细胞化学和成骨标志物的表达来评估。此外，在 BM-MSCs 的成骨分化过程中糖酵解被激活，而 APCs 在受到 HP 挑战时糖酵解没有增加。微 RNA-132-3p（miR-132）是一种已知的成骨抑制剂，被发现 APCs 持续表达，并在受到 HP 刺激后上调。miR-132 的抗钙化作用进一步通过计算机分析、HEK293 细胞的荧光素酶测定以及用 miR-132 激动剂和拮抗剂转染 APCs 并评估成骨标志物来证实。有趣的是，用 APC 衍生的条件培养基处理猪心瓣膜可使它们具有抗 HP 诱导的成骨作用，而当使用 miR-132 沉默的 APC 的培养基时，这种作用被否定。此外，作为初始的生物工程步骤，APCs 成功地植入心包片上，在那里它们增殖并促进主动脉内皮细胞的吸引，这一过程模拟了瓣膜内皮化。
与 BM-MSCs 相比，人 APCs 具有抗钙化特性，并通过 miR-132 传递抗钙化表型至心脏瓣膜。这些发现可能为人工心脏瓣膜的细胞化开辟新的重要途径。
