Pre-Conditioning with IFN-γ and Hypoxia Enhances the Angiogenic Potential of iPSC-Derived MSC Secretome.

Suya Wang,António José Salgado,Siegmar Reinert,Dorothea Alexander,Wanjing Cen,Felix Umrath

doi:10.3390/cells11060988

Suya Wang, António José Salgado + Show 4 more

Open Access

https://doi.org/10.3390/cells11060988

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Abstract

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.

Highlights

The reconstruction of large tissue defects is one of the main challenges in the field of oral and maxillofacial surgery
To characterize the response of induced mesenchymal stem cell-like cells (iMSCs) to IFN-γ stimulation, the expression of histocompatibility leukocyte antigen (HLA)-I and HLA-II surface markers was analyzed via flow cytometry. iMSCs derived from three donors expressed high levels of HLA-I, under both hypoxic and normoxic conditions (Figure 2A)
We suggest that TIMP-4 inhibition in the Human umbilical vein endothelial cells (HUVECs) group cultivated with the pre-conditioned (IFN-γ and hypoxia) iMSCs secretome was based on its anti-angiogenic effect

Summary

Introduction

The reconstruction of large tissue defects is one of the main challenges in the field of oral and maxillofacial surgery. In order to overcome these drawbacks, tissue engineering with stem cells, signal molecules, and scaffolds has attracted attention in the area of regenerative medicine [3,4]. This therapeutic procedure benefits from the regenerative capacity of the human body through the application of adult stem cells in combination with optimized synthetic materials [5]. As oxygen and nutrient supply is essential for survival within the graft, the use of suitable cells to promote angiogenesis and to recruit endothelial cells has gained in importance. The secretome of MSCs influences the microenvironment upon injury, promoting cytoprotection, angiogenesis, and tissue repair at the damaged area [14]

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