Confirmation of endothelial differentiation.

<p>White arrows indicate vWF-positive cells (Scale bar: 50 μm).</p

Changes, and the Relevance Thereof, in Mitochondrial Morphology during Differentiation into Endothelial Cells

<div><p>The roles of mitochondria in various physiological functions of vascular endothelial cells have been investigated extensively. Morphological studies in relation to physiological functions have been performed. However, there have been few reports of morphological investigations related to stem cell differentiation. This was the first morphological study of mitochondria in relation to endothelial differentiation and focused on quantitative analysis of changes in mitochondrial morphology, number, area, and length during differentiation of human mesenchymal stem cells (hMSCs) into endothelial-like cells. To induce differentiation, we engaged vascular endothelial growth factors and flow-induced shear stress. Cells were classified according to the expression of von Willebrand factor as hMSCs, differentiating cells, and almost fully differentiated cells. Based on imaging analysis, we investigated changes in mitochondrial number, area, and length. In addition, mitochondrial networks were quantified on a single-mitochondrion basis by introducing a branch form factor. The data indicated that the mitochondrial number, area per cell, and length were decreased with differentiation. The mitochondrial morphology became simpler with progression of differentiation. These findings could be explained in view of energy level during differentiation; a higher level of energy is needed during differentiation, with larger numbers of mitochondria with branches. Application of this method to differentiation into other lineages will explain the energy levels required to control stem cell differentiation.</p></div

Changes, and the Relevance Thereof, in Mitochondrial Morphology during Differentiation into Endothelial Cells - Fig 2

<p>Branch form factor (A) Definition of branch form factor (B) Classification of branch form factor with complexity (C) Mitochondrial morphology in a cell (D) Sample calculation of BFF after skeletonization.</p

Flow system for inducing shear stress.

<p>Flow system for inducing shear stress.</p

Chondrogenic hMSCs in alginate beads in an NMR tube.

<p>Chondrogenic hMSCs in alginate beads in an NMR tube.</p

Rearranged branch form factor with endothelial differentiation regardless of culturing time.

<p>Rearranged branch form factor with endothelial differentiation regardless of culturing time.</p

Changes in levels of non-fatty acid metabolites during chondrogenesis.

<p>Changes in levels of non-fatty acid metabolites during chondrogenesis.</p

NMR spectrum of alginate beads without cells.

<p>NMR spectrum of alginate beads without cells.</p

Variation of cell density per alginate bead during chondrogenesis.

<p>Variation of cell density per alginate bead during chondrogenesis.</p

3D perspective of NMR spectra of chondrogenic hMSCs cultured on alginate beads.

<p>3D perspective of NMR spectra of chondrogenic hMSCs cultured on alginate beads.</p