Department of Oral and Maxillofacial Surgery, University Hospital Tübingen, 72076 Tübingen, Germany.
Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
Cells. 2022 Mar 14;11(6):988. doi: 10.3390/cells11060988.
Induced pluripotent stem cell (iPSC) derived mesenchymal stem cells (iMSCs) represent a promising source of progenitor cells for approaches in the field of bone regeneration. Bone formation is a multi-step process in which osteogenesis and angiogenesis are both involved. Many reports show that the secretome of mesenchymal stromal stem cells (MSCs) influences the microenvironment upon injury, promoting cytoprotection, angiogenesis, and tissue repair of the damaged area. However, the effects of iPSC-derived MSCs secretome on angiogenesis have seldom been investigated. In the present study, the angiogenic properties of IFN-γ pre-conditioned iMSC secretomes were analyzed. We detected a higher expression of the pro-angiogenic genes and proteins of iMSCs and their secretome under IFN-γ and hypoxic stimulation (IFN-H). Tube formation and wound healing assays revealed a higher angiogenic potential of HUVECs in the presence of IFN-γ conditioned iMSC secretome. Sprouting assays demonstrated that within Coll/HA scaffolds, HUVECs spheroids formed significantly more and longer sprouts in the presence of IFN-γ conditioned iMSC secretome. Through gene expression analyses, pro-angiogenic genes (FLT-1, KDR, MET, TIMP-1, HIF-1α, IL-8, and VCAM-1) in HUVECs showed a significant up-regulation and down-regulation of two anti-angiogenic genes (TIMP-4 and IGFBP-1) compared to the data obtained in the other groups. Our results demonstrate that the iMSC secretome, pre-conditioned under inflammatory and hypoxic conditions, induced the highest angiogenic properties of HUVECs. We conclude that pre-activated iMSCs enhance their efficacy and represent a suitable cell source for collagen/hydroxyapatite with angiogenic properties.
诱导多能干细胞（iPSC）衍生的间充质干细胞（iMSC）代表了一种有前途的祖细胞来源，可用于骨再生领域的方法。骨形成是一个多步骤的过程，涉及成骨和血管生成。许多报告表明，间充质基质干细胞（MSC）的分泌组影响损伤后的微环境，促进细胞保护、血管生成和受损区域的组织修复。然而，iPSC 衍生的 MSC 分泌组对血管生成的影响很少被研究。在本研究中，分析了 IFN-γ 预处理 iMSC 分泌组的血管生成特性。我们检测到 iMSC 及其分泌组在 IFN-γ 和低氧刺激（IFN-H）下，促血管生成基因和蛋白的表达更高。管形成和伤口愈合试验显示，在 IFN-γ 条件化 iMSC 分泌组存在的情况下，HUVEC 的血管生成潜力更高。发芽试验表明，在 Coll/HA 支架内，HUVEC 球体在 IFN-γ 条件化 iMSC 分泌组存在的情况下形成更多和更长的芽。通过基因表达分析，与其他组相比，HUVEC 中的促血管生成基因（FLT-1、KDR、MET、TIMP-1、HIF-1α、IL-8 和 VCAM-1）表达显著上调，而两种抗血管生成基因（TIMP-4 和 IGFBP-1）表达显著下调。我们的结果表明，在炎症和低氧条件下预处理的 iMSC 分泌组诱导了 HUVEC 最高的血管生成特性。我们得出结论，预激活的 iMSC 增强了它们的疗效，代表了具有血管生成特性的胶原/羟基磷灰石的合适细胞来源。
