Coculture of Vascular Endothelial Cells and Adipose-Derived Stem Cells as a Source for Bone Engineering

Abstract

The interaction between vascular endothelial cells (VECs) and osteoblasts (OBs) is the focus of this recent research. Vascular endothelial cells secrete bone morphogenetic protein, which promotes OB differentiation and stimulates OBs and their precursor cells to secrete vascular endothelial growth factor. Vascular endothelial growth factor is important in angiogenesis and angiopoiesis. Cloning studies have shown that adipose-derived stem cells (ADSCs) have the potential to differentiate into fat, bone, cartilage, and skeletal and smooth muscle cells, among others. Adipose-derived stem cells can express multiple growth factors, including vascular endothelial growth factor and hepatocyte growth factor. Our study examined the influence of coculturing VECs and ADSCs on osteogenic differentiation. Cord blood-derived VECs and ADSCs were isolated from rats and characterized with immunofluorescence staining and morphological observation. Coculture of third-generation ADSCs and VECs was induced for 6 weeks. Cell growth was analyzed using a modified MTT assay. Alkaline phosphatase (ALP) and osteocalcin (OC) was analyzed using immunofluorescence staining. When ADSCs and VECs were cocultured, the absorbance of cells gradually increased, reaching a peak on day 12. The highest absorbance was seen in a coculture system with a ratio of ADSCs and VECs of 1:1. The secretion of ALP and OC gradually increased in these cells and was significantly higher than controls (P < 0.01). Coculturing of ADSCs and VECs at a 1:1 ratio gave the highest secretion of ALP and OC at every time point, and was significantly higher than other groups (P < 0.01). Our results indicated that ADSCs can be induced to osteogenic differentiation by VECs in vitro, suggesting a coculture system of VECs and ADSC as a novel source of cells for bone engineering.

Osteogenic Differentiation of Mesenchymal Stem Cells by Mimicking the Cellular Niche of the Endochondral Template

“…9,[11][12][13][14][15][16][17]22,29,[63][64][65][66][67] The main rationale behind the use of these supplements is to provide signaling proteins or enzymes to activate mineral production by MSCs. Previous in vitro 2D studies have shown that the direct coculture of MSCs with endothelial cells [36][37][38][39] or chondrocytes 68 can provide the necessary factors to induce early markers of osteogenic differentiation (ALP expression) without the need for these supplements. A recent 2D study found that indirect coculture of MSCs with osteocytes led to increased calcium deposition compared with MSCs cocultured with osteoblasts.…”

“…The anatomical location of MSCs and vascular endothelial cells suggests that these two cell types are in direct cell-cell interaction and experience juxtacrine or paracrine signaling within the stem cell niche during endochondral ossification. Previous in vitro studies have shown that direct coculture of MSCs or osteoblasts with endothelial cells can upregulate production of the early osteogenic marker ALP, [36][37][38][39] without the presence of osteogenic supplements. Other studies have investigated whether coculture of MSCs and endothelial cells can increase ALP production in three-dimensional (3D) polymer scaffolds 40,41 or 3D cellular aggregates, [42][43][44][45] but the majority of these studies were conducted in the presence of osteogenic growth supplements.…”

Cell interactions between human progenitor-derived endothelial cells and human mesenchymal stem cells in a three-dimensional macroporous polysaccharide-based scaffold promote osteogenesis

“…In 3-D matrices, a number of studies using co-cultures of two lineages have been published, with cell lines from different sources (human and murine), including differentiated cells mixed with undifferentiated cells (MSCs or progenitors). Among the cell culture models used to develop these hybrid constructs, human umbilical vein endothelial cells (HUVEC) [22], human outgrowth endothelial cells (OEC) [23], human microcapillary endothelial cells [24] and endothelial progenitor cells from cord blood have been used for co-cultures with human bone-derived cells [25], osteoblast-like MG63 cells [26], primary human osteoblast cells [27], human osteoprogenitor cells from bone marrow [28], MSCs from adipose tissue [29] or bone marrow [30]. However, combining differentiated cells with undifferentiated cells arising from different sources (mouse, human) in co-culture assay does not mimic the physiological situation that occurs in a clinical situation of bone repair.…”

A Glycosaminoglycan Based, Modular Tissue Scaffold System for Rapid Assembly of Perfusable, High Cell Density, Engineered Tissues

“…Many studies have demonstrated functional relationships between endothelium and adjacent cell types [45]–[49], [50], [51]. Designing tissue assembly approaches that allow critical paracrine interactions is mandatory for achieving in vivo-like performance of engineered tissues.…”