Extracellular Matrix can Recover the Downregulation of Adhesion Molecules after Cell Detachment and Enhance Endothelial Cell Engraftment.

Ningning He,Zhongchao Han,Guowei Feng,Zongjin Li,Wei Du,Zuoxiang He,Yang Xu,Yuebing Wang,Lu Liang,Deling Kong,Joseph C Wu,Zhen Cheng,Xin Qi,Yan Fan

doi:10.1038/srep10902

Abstract

The low cell engraftment after transplantation limits the successful application of stem cell therapy and the exact pathway leading to acute donor cell death following transplantation is still unknown. Here we investigated if processes involved in cell preparation could initiate downregulation of adhesion-related survival signals, and further affect cell engraftment after transplantation. Human embryonic stem cell-derived endothelial cells (hESC-ECs) were suspended in PBS or Matrigel and kept at 4 °C. Quantitative RT-PCR analysis was used to test the adhesion and apoptosis genes’ expression of hESC-ECs. We demonstrated that cell detachment can cause downregulation of cell adhesion and extracellular matrix (ECM) molecules, but no obvious cell anoikis, a form of apoptosis after cell detachment, was observed. The downregulation of adhesion and ECM molecules could be regained in the presence of Matrigel. Finally, we transplanted hESC-ECs into a mouse myocardial ischemia model. When transplanted with Matrigel, the long-term engraftment of hESC-ECs was increased through promoting angiogenesis and inhibiting apoptosis, and this was confirmed by bioluminescence imaging. In conclusion, ECM could rescue the functional genes expression after cell detached from culture dish, and this finding highlights the importance of increasing stem cell engraftment by mimicking stem cell niches through ECM application.

Highlights

The low cell engraftment after transplantation limits the successful application of stem cell therapy and the exact pathway leading to acute donor cell death following transplantation is still unknown
In order to define the changes of adhesion molecules expression after cell detachment, we performed RT-PCR assays using PCR Array (Human Extracellular Matrix and Adhesion Molecules RT2 ProfilerTM PCR Array, 84 genes total) on (i) human embryonic stem cells (hESCs)-ECs suspension in phosphate-buffered saline (PBS), (ii) hESC-ECs suspension in Matrigel, and (iii) cultured hESC-ECs as positive controls (n = 4/group)
We found that a set of extracellular matrix (ECM) and adhesion molecules-specific genes was markedly downregulated in hESC-ECs suspended in PBS versus cultured hESC-ECs or hESC-ECs suspended in Matrigel

Summary

Introduction

The low cell engraftment after transplantation limits the successful application of stem cell therapy and the exact pathway leading to acute donor cell death following transplantation is still unknown. Traditional stem cell preparations for experimental or clinical transplantation involve enzymatically dispersed cells suspended in phosphate-buffered saline (PBS), stored for minutes to hours on ice at 4 °C During this period, important adhesion-related survival signals could be absent and a pathway of cell death called “anoikis” (Greek: state of homelessness), a form of apoptosis, will be initiated[9,10,11]. The strategy to seed stem cells on synthetic structures that are designed to mimic the extracellular matrix (ECM) before transplantation provides a scaffold for cell anchorage, and a supportive niche for engraftment or accelerating stem cell differentiation Those materials may reduce the number of stem cells needed for effective tissue reconstitution, as well as promote stem cell self-renewal[7,14,15]. Engineered microenvironments with ECM have been increasingly successful in controlling stem cell fate by emulating the key regulatory signals such as survival, growth, differentiation, and migration[17,18,19]

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Conclusion