Exposure of Induced Pluripotent Stem Cell-Derived Vascular Endothelial and Smooth Muscle Cells in Coculture to Hemodynamics Induces Primary Vascular Cell-Like Phenotypes

Abstract

Human induced pluripotent stem cells (iPSCs) can be differentiated into vascular endothelial (iEC) and smooth muscle (iSMC) cells. However, because iECs and iSMCs are not derived from an intact blood vessel, they represent an immature phenotype. Hemodynamics and heterotypic cell:cell communication play important roles in vascular cell phenotypic modulation. Here we tested the hypothesis that hemodynamic exposure of iECs in coculture with iSMCs induces an in vivo‐like phenotype. iECs and iSMCs were cocultured under vascular region‐specific blood flow hemodynamics, and compared to hemodynamic cocultures of blood vessel‐derived endothelial (pEC) and smooth muscle (pSMC) cells. Hemodynamic flow‐induced gene expression positively correlated between pECs and iECs as well as pSMCs and iSMCs. While endothelial nitric oxide synthase 3 protein was lower in iECs than pECs, iECs were functionally mature as seen by acetylated‐low‐density lipoprotein (LDL) uptake. SMC contractile protein markers were also positively correlated between pSMCs and iSMCs. Exposure of iECs and pECs to atheroprone hemodynamics with oxidized‐LDL induced an inflammatory response in both. Dysfunction of the transforming growth factor β (TGFβ) pathway is seen in several vascular diseases, and iECs and iSMCs exhibited a transcriptomic prolife similar to pECs and pSMCs, respectively, in their responses to LY2109761‐mediated transforming growth factor β receptor I/II (TGFβRI/II) inhibition. Although there are differences between ECs and SMCs derived from iPSCs versus blood vessels, hemodynamic coculture restores a high degree of similarity in their responses to pathological stimuli associated with vascular diseases. Thus, iPSC‐derived vascular cells exposed to hemodynamics may provide a viable system for modeling rare vascular diseases and testing new therapeutic approaches. Stem Cells Translational Medicine 2017;6:1673–1683

iPSCs-based generation of vascular cells: reprogramming approaches and applications

“…Jiao et al used the Cheung protocol to successfully differentiate human iPSCs reprogrammed from human peripheral blood cells (PBMCs) to paraxial mesoderm- and subsequently to paraxial-derived SMC [ 96 – 98 ]. Furthermore, the successful generation of human iPSC neural crest-derived SMC was reported using the Cheung protocol [ 99 ]. Herein, the initial differentiation stage (day 0–5 or day 0–7) begins with the induction of three intermediate lineages: neuroectoderm (NE), lateral plate mesoderm (LM) and paraxial mesoderm (PM) [ 95 ].…”

“…The growth and reactivity of SMC were influenced and controlled by the underlying endothelial cells that comprise a permeable tissue layer, which controls the interaction of the vessel wall with circulating blood components, and regulates the vascular response to hemodynamic forces. Collado et al speculated that iPSC-derived endothelial cells and SMC represent an immature phenotype because these cells were not derived from an intact blood vessel [ 99 ]. Because hemodynamics and heterotypic cell–cell communication play important roles in vascular cell phenotypic modulation the authors co-cultured iPSC-derived endothelial cells and SMC under vascular region-specific blood flow hemodynamics, and compared these hemodynamic co-cultures with adult blood vessel-derived endothelial and SMC.…”

Induced Pluripotent Stem Cell–Derived Endothelial Cells

“…17 They express endothelial nitric oxide synthase and have the ability to endocytose fluorescent-acetylated low-density lipoprotein. 17,31 Immunologically, iPSC-ECs have responses to inflammatory markers that resemble the behavior of primary ECs, suggesting that iPSC-ECs can be used to model and study the inflammatory state. For example, when iPSC-ECs were exposed to proinflammatory stimuli, such as IL-1b, TNF-a, and lipopolysaccharide, they expressed intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and E-selectin.…”

“…33 Endothelial nitric oxide synthase 3 protein was lower in iPSC-ECs compared with human aortic endothelial cells. 31 Given the heterogeneity of iPSC-ECs and differentiation protocols, it is difficult to generalize these findings for all iPSC-EC cell lines.…”

Induced Pluripotent Stem Cell–Derived Endothelial Cells in Insulin Resistance and Metabolic Syndrome

“…Some studies have proposed that there are limited differences between primary endothelial cells and iPSC-ECs 39, 48 while others have found larger differences that may affect functionality and the long-term stability of the endothelial identity in iPSC-EC. In particular, a phenotypic shift has been observed in long-term culture of iPSC-ECs, resembling the endothelial-to-mesenchymal transition that happens during normal embryonic development 49, 50 .…”