Closing the Mitochondrial Permeability Transition Pore in hiPSC-Derived Endothelial Cells Induces Glycocalyx Formation and Functional Maturation

Abstract

Human induced pluripotent stem cells (hiPSCs) are used to study organogenesis and model disease as well as being developed for regenerative medicine. Endothelial cells are among the many cell types differentiated from hiPSCs, but their maturation and stabilization fall short of that in adult endothelium. We examined whether shear stress alone or in combination with pericyte co-culture would induce flow alignment and maturation of hiPSC-derived endothelial cells (hiPSC-ECs) but found no effects comparable with those in primary microvascular ECs. In addition, hiPSC-ECs lacked a luminal glycocalyx, critical for vasculature homeostasis, shear stress sensing, and signaling. We noted, however, that hiPSC-ECs have dysfunctional mitochondrial permeability transition pores, resulting in reduced mitochondrial function and increased reactive oxygen species. Closure of these pores by cyclosporine A improved EC mitochondrial function but also restored the glycocalyx such that alignment to flow took place. These results indicated that mitochondrial maturation is required for proper hiPSC-EC functionality.

Development and Application of Endothelial Cells Derived From Pluripotent Stem Cells in Microphysiological Systems Models

“…Differences are observed between iPSC-derived ECs and primary ECs. RNA sequencing has shown that while iPSC-ECs show differing expression patterns from stem cells ( 54 ), they also do not cluster with primary ECs ( 55 ). Key endothelial markers and flow-sensitive genes, such as NOS3, are expressed, but often at lower levels than found in primary ECs ( 54 ).…”

“…Key endothelial markers and flow-sensitive genes, such as NOS3, are expressed, but often at lower levels than found in primary ECs ( 54 ). Metabolic genes also have significantly different expression in iPS-derived ECs compared to primary ECs ( 55 ). Pluripotent markers such as Oct4 and Klf4 ( 54 ) have been detected in iPS-derived ECs which signifies some immaturity.…”

Roles of Reactive Oxygen Species in Cardiac Differentiation, Reprogramming, and Regenerative Therapies

“…mPTP inhibition by cyclosporine-A increased ROS generation, but addition of antioxidants rather than prooxidant can enhance cardiomyogenesis [ 75 ]. Prolonged closure of mPTP with cyclosporine-A in human iPSC-derived endothelial cells resulted in more mature mitochondria, prevention of ROS leakage, and functional improvements [ 76 ]. These studies suggested that the redox signaling is a cardiogenic regulatory factor lying the downstream of mPTP inhibition.…”

“…Oxidative Medicine and Cellular Longevity A in human iPSC-derived endothelial cells resulted in more mature mitochondria, prevention of ROS leakage, and functional improvements [76]. These studies suggested that the redox signaling is a cardiogenic regulatory factor lying the downstream of mPTP inhibition.…”

Engineered tissues and strategies to overcome challenges in drug development

“…Recent research has identified influential parameters and strategies that regulate and promote hPSC-derived cell maturation. For example, cellular metabolism can regulate the phenotype of hPSC-derived cells, and glycolysis-to-oxidative phosphorylation mitochondrial switching enhances the maturity of hPSC-derived endothelial cells [ 178 ]. Similar metabolic switching via inhibition of hypoxia-inducible factor 1-alpha and its downstream target lactate dehydrogenase A mediated maturation of hPSC-derived cardiomyocytes [ 179 ], suggesting that cellular metabolism may be an important manipulatable factor for regulating the biological relevance of hPSC-derived cells for drug development.…”