Mesenchymal Stem Cells Support Migration, Extracellular Matrix Invasion, Proliferation, and Survival of Endothelial Cells In Vitro

Abstract

We investigated effects of the paracrine factors secreted by human mesenchymal stem cells (hMSCs) on endothelial cell migration, extracellular matrix invasion, proliferation, and survival in vitro. Human mesenchymal stem cells were cultured as a monolayer or as three-dimensional aggregates in hanging drops (hMSC spheroids). We performed analysis of paracrine factors in medium conditioned by a monolayer of hMSCs and hMSC spheroids. Concentrations of vascular endothelial growth factor (VEGF), basic fibroblast growth factor, angiogenin, procathepsin B, interleukin (IL)-11, and bone morphogenic protein 2 were increased 5-20 times in medium conditioned by hMSC spheroids, whereas concentrations of IL-6, IL-8, and monocyte hemoattractant protein-1 were not increased. Concentrations of VEGF and angiogenin in medium conditioned by hMSC spheroids showed a weak dependence on the presence of serum, which allows serum-free conditioned medium with elevated concentrations of angiogenic cytokines to be obtained. Medium conditioned by hMSC spheroids was more effective in stimulation of umbilical vein endothelial cell proliferation, migration, and basement membrane invasion than medium conditioned by a monolayer of hMSCs. This medium also promotes endothelial cell survival in vitro. We suggest that culturing of hMSCs as three-dimensional cellular aggregates provides a method to concentrate proangiogenic factors secreted by hMSCs and allows for reduction of serum concentration in conditioned medium. Our data support the hypothesis that hMSCs serve as trophic mediators for endothelial cells.

Device and application development for haematopoietic stem and progenitor cell (HSPC) and mesenchymal stromal cell (MSC) 3D spheroid cultures

“…While there were differences in gene expression patterns, these did not generally overlap with previous reports that had conducted similar gene expression surveys [327,328]. This lack of consistency between our current study and previous reports suggested that there were higher order variables that dominated over the influences driven by 2D versus 3D cell culture geometry.…”

“…In Table 2.2, a number of differentially expressed genes were contrasted from the current study (red heading) and those reported by Potapova et al [327] (green heading), against those reported to be significantly up--regulated by Bartosh et al [328] (blue heading).…”

“…Using microarrays to compare gene expression in 3D MSC spheroids versus 2D MSC adherent cultures, one study reported that more than one--thousand genes were up--regulated and over one--thousand genes were down--regulated [327], while another study found over two--hundred genes up--regulated and over two--hundred genes down--regulated [328]. Genes up--regulated in MSC spheroid cultures were primarily associated with proangiogenic factors [327] and anti--inflammatory properties [328].…”

“…Previous studies using microarrays have reported that gene expression profiles were changed when MSC were cultured as 3D spheroids, compared to 2D adherent monolayers [327,328]. In these previous studies, the hanging drop technique was used to produce relatively large MSC spheroids (formed from 25--250×10 3 cells per spheroid) and cultured in serum--containing medium in a 20 % O 2 atmosphere.…”

“…A number of studies have reported that culture of MSC in 3D spheroids, rather than in 2D adherent culture, resulted in characteristics that may be useful to tissue engineering applications and regenerative medicine. These characteristics include the maintenance of differentiation potential toward the mesodermal lineages (osteogenic, adipogenic [325,335,336], and chondrogenic [337]), which could serve as tissue building blocks, and the increased secretion of proangiogenic factors such as vascular endothelial growth factor (VEGF) [327] and anti--inflammatory molecules such as tumour necrosis factor--α (TNF--α)--stimulated gene/protein--6 (TSG--6) [328, 338--340].…”