Endothelial progenitor cells as a possible component of stem cell niche to promote self-renewal of mesenchymal stem cells

Abstract

Stem cells dwell at the "stem cell niche" to accomplish a series of biological processes. The composition of the niche should be determined because the insufficient understanding of this feature limits the development in the study of stem cells. We showed in our study on mesenchymal stem cells (MSCs) that the MSCs first neighbored to CD31(+) cells, which proved to be endothelial progenitor cells (EPCs), and formed a group of cell colony before they exerted their biological functions. It was further proved that EPCs have close interactions with MSCs and promoted the self-renewal of the MSCs in vitro and in vivo. Together with these achievements, we hypothesized that EPCs may be a possible biological component of the MSC stem cell niche and affect the biological processes of MSCs.

Combination of low-energy shock-wave therapy and bone marrow mesenchymal stem cell transplantation to improve the erectile function of diabetic rats

“…MSCs were located around the capillaries in a variety of tissues,31 and the vasculature played an instructive role in the stem cell niche;16 in particular, CD31 + cells, which proved to be EPCs, might be an important component of the BMSC niche 32. CD31 expressed on vascular endothelial cells has been considered an angiogenesis cell marker of diabetic ED rats 93334.…”

E‐cadherin‐mediated contact of endothelial progenitor cells with mesenchymal stem cells through β‐catenin signaling

“…Our previous studies demonstrated that MSCs and EPCs adhere to each other in the BM cavity and in in vitro cultures (Zhang et al, 2014). An adhesion assay and fluorescence observations were performed to detect whether E-cad plays a role in the cohesion between MSCs and EPCs.…”

“…We previously reported that MSCs and EPCs adhere to each other in the BM cavity and in in vitro cultures (Zhang et al, 2014) and that this adhesion has important physiological significance. Cell proliferation is promoted when MSCs and EPCs are co-cultured and is beneficial to angiogenesis, tissue repair, and regeneration; the adhesion of MSCs and EPCs can promote the self-renewal of MSCs, which improves the biological function of osteoblasts, chondrocytes, and adipocytes (Wu et al, 2010;Zhang et al, 2014;Qiu et al, 2015). However, the adhesion mechanisms involved between MSCs and EPCs are poorly understood.…”

“…Endothelial progenitor cells (EPCs) are the precursors of endothelial cells present in the bone marrow; EPCs are a group of stem cell progenitors with a specific surface marker that have the ability to regenerate tissues and blood vessels (Bauersachs and Thum, 2007;Cao et al, 2011). We previously reported that MSCs and EPCs adhere to each other in the BM cavity and in in vitro cultures (Zhang et al, 2014) and that this adhesion has important physiological significance. Cell proliferation is promoted when MSCs and EPCs are co-cultured and is beneficial to angiogenesis, tissue repair, and regeneration; the adhesion of MSCs and EPCs can promote the self-renewal of MSCs, which improves the biological function of osteoblasts, chondrocytes, and adipocytes (Wu et al, 2010;Zhang et al, 2014;Qiu et al, 2015).…”

Suppressing angiogenesis regulates the irradiation‐induced stimulation on osteoclastogenesis in vitro

“…Changes in EPCs are associated with a wide variety of diseases including cardiovascular disorders, diabetic vasculopathies, and progression of angiogenesis in tumor microenvironments (Chen, Zhang, Tao, Wang, & Zhu, ; Ergun, Hohn, Kilic, Singer, & Tilki, ; Fadini, ; Güven, Shepherd, Bach, Capoccia, & Link, ). In tissue engineered bone (TEB), it has been shown that the composite implantation of bone marrow mesenchymal stem cells (BMSCs) with EPCs greatly facilitated TEB healing of bone fracture (Keramaris et al, ; Usami et al, ), which may because apart from contribution to neovascularization and preventing bone necrosis induced by absence of oxygen and nutrition, EPCs also promoted the self‐renewal and osteogenic differentiation of BMSCs (Fedorovich, Haverslag, Dhert, & Alblas, ; Zhang et al, ). Thus, attention should be paid to the effects of irradiation on EPCs.…”