Effectiveness of endothelial progenitor cell culture under microgravity for improved angiogenic potential

Hiroko Hagiwara,Shigeyuki Kanazawa,Akira Higashibata,Shiho Ogawa,Rica Tanaka,Hiroshi Mizuno

doi:10.1038/s41598-018-32073-2

Hiroko Hagiwara, Shigeyuki Kanazawa + Show 4 more

Open Access

https://doi.org/10.1038/s41598-018-32073-2

Copy DOI

Abstract

Endothelial progenitor cell (EPC) transplantation is beneficial for ischemic diseases such as critical limb ischemia and ischemic heart disease. The scarcity of functional EPCs in adults is a limiting factor for EPC transplantation therapy. The quality and quantity culture (QQc) system is an effective ex vivo method for enhancing the number and angiogenic potential of EPCs. Further, microgravity environments have been shown to enhance the functional potential of stem cells. We therefore hypothesized that cells cultured with QQc under microgravity may have enhanced functionality. We cultured human peripheral blood mononuclear cells using QQc under normal (E), microgravity (MG), or microgravity followed by normal (ME) conditions and found that ME resulted in the most significant increase in CD34+ and double positive Dil-Ac-LDL-FITC-Ulex-Lectin cells, both EPC markers. Furthermore, angiogenic potential was determined by an EPC-colony forming assay. While numbers of primitive EPC-colony forming units (pEPC-CFU) did not change, numbers of definitive EPC-CFU colonies increased most under ME conditions. Gene-expression profiling also identified increases in angiogenic factors, including vascular endothelial growth factor, under MG and ME conditions. Thus, QQc along with ME conditions could be an efficient system for significantly enhancing the number and angiogenic potential of EPCs.

Highlights

Endothelial progenitor cells (EPCs) are responsible for vasculogenesis in embryos and adults
The quality and quantity culture (QQc) system resulted in an increase in the expression of genes that are involved in angiogenesis, such as vascular endothelial growth factor (VEGF), insulin-like growth factor 1 (IGF-1), and matrix metallopeptidase-9 (MMP-9)[4]
Our results showed that peripheral blood mononuclear cells (PBMNCs) cultured with the QQc method under a microgravity environment resulted in a significant increase in CD34+ cell numbers

Summary

Introduction

Endothelial progenitor cells (EPCs) are responsible for vasculogenesis in embryos and adults. Aging, diabetes, hyperlipidemia, and cardiovascular disease all contribute to the declines in both the number and functionality of EPCs10–12 To overcome this problem, several conditions for the ex vivo cultivation and expansion of EPCs have been developed; these techniques yield insufficient cell numbers and angiogenic potential[13]. Another study cultivated human umbilical vein endothelial cells (HUVEC) under a microgravity environment and found accelerated neovascularization that resulted from increased lumen-formation[19] Based on these findings, we hypothesized that the QQc method may be more effective for EPC expansion ex vivo under microgravity conditions, compared to normal gravity conditions. Our study is the first to show that the QQc method combined with microgravity conditions is a superior method for EPC expansion

Methods

Results

Discussion

Conclusion