Cell-Surface MMP-9 Protein Is a Novel Functional Marker to Identify and Separate Proangiogenic Cells from Early Endothelial Progenitor Cells Derived from CD133+ Cells

Abstract

To develop cell therapies for ischemic diseases, endothelial progenitor cells (EPCs) have been expected to play a pivotal role in vascular regeneration. It is desirable to use a molecular marker that is related to the function of the cells. Here, a quantitative polymerase chain reaction array revealed that early EPCs derived from CD133 1 cells exhibited significant expression of MMP-9. Some populations of early EPCs expressed MMP-9 on the cell surface and others did not. We also attempted to separate the proangiogenic fraction from early EPCs derived from CD133 1 cells using a functional cell surface marker, and we then analyzed the MMP-9 1 and MMP-9 2 cell fractions. The MMP-9 1 cells not only revealed higher invasion ability but also produced a high amount of IL-8. Moreover, the stimulative effect of MMP-9 1 cells on angiogenesis in vitro and in vivo was prohibited by anti-IL-8 antibody. These data indicate that MMP-9 is one of the useful cell surface markers for the separation of angiogenic cells. Our treatment of early EPCs with hyaluronidase caused not only a downregulation of cell-surface MMP-9 but also a decrease in invasion ability, indicating that membrane-bound MMP-9, which is one of the useful markers for early EPCs, plays an important role in angiogenesis. STEM CELLS 2016;34:1251-1262 SIGNIFICANCE STATEMENTAngiogenic cell therapy is thought to be one of the promising strategies for the treatment of ischemic diseases. CD133-positive cells have been reported to be useful for vascular regeneration by releasing angiogenic factors. It is not known, however, that what population of cultured CD133 1 cells is functionally important for vascularization. In this study, we separated both MMP-9 1 cells and MMP-9 2 cells from cultured CD133 1 cells as a cell surface marker and conducted functional characterization of these cells. As results, MMP-9 1 cells from CD133 1 cells had a strong angiogenic ability.

The impact of bone marrow-derived mesenchymal stem cells on neovascularisation in rats with brain injury

“…CD34 is a surface marker of haematopoietic stem cells or mature endothelial cells [6]. However, endothelial progenitor cells (EPCs) only account for a small fraction of all CD34-positive cells in the bone marrow or peripheral blood; CD133 is a surface marker of neuroepithelial stem cells [8]. With the differentiation and mature of EPCs, the expression of CD133 gradually decreased, and mature vascular endothelial cells showed no expression of CD133, making it a good molecular marker for identifying mature endothelial cells from EPCs.…”

Occludin as a functional marker of vascular endothelial cells on tube‐forming activity

“…We previously characterized early EPCs derived from CD133 + cells and developed a method for the expansion of these cells (Kanayasu‐Toyoda, Yamaguchi, Oshizawa, & Hayakawa, ; Kanayasu‐Toyoda, Ishii‐Watabe, Suzuki, Oshizawa, & Yamaguchi, ). We also discovered that cell‐surface matrix metalloproteinase‐9 protein is a novel functional marker that can be used to identify and separate pro‐angiogenic cells from early EPCs derived from CD133 + cells (Kanayasu‐Toyoda et al, ). Our results and other reports suggest that even though early EPCs express endothelial markers, they lack tube‐formation ability in vitro.…”

Endothelial Progenitors: A Consensus Statement on Nomenclature

“…We do not support the use of the term EPCs because of its intrinsic ambiguity. In particular, EPCs should not be used to name cells such as MACs/CACs because these cells are not endothelial nor progenitor cells , but myeloid cells, albeit with potent pro‐angiogenic, vasoreparative functionality , through a paracrine mechanism . It is important to highlight that MACs do not give rise to endothelial cells, but remain true to their hematopoietic nature .…”