RETRACTED: In Vitro Modeling of Blood-Brain Barrier with Human iPSC-Derived Endothelial Cells, Pericytes, Neurons, and Astrocytes via Notch Signaling

Abstract

SummaryThe blood-brain barrier (BBB) is composed of four cell populations, brain endothelial cells (BECs), pericytes, neurons, and astrocytes. Its role is to precisely regulate the microenvironment of the brain through selective substance crossing. Here we generated an in vitro model of the BBB by differentiating human induced pluripotent stem cells (hiPSCs) into all four populations. When the four hiPSC-derived populations were co-cultured, endothelial cells (ECs) were endowed with features consistent with BECs, including a high expression of nutrient transporters (CAT3, MFSD2A) and efflux transporters (ABCA1, BCRP, PGP, MRP5), and strong barrier function based on tight junctions. Neuron-derived Dll1, which activates Notch signaling in ECs, was essential for the BEC specification. We performed in vitro BBB permeability tests and assessed ten clinical drugs by nanoLC-MS/MS, finding a good correlation with the BBB permeability reported in previous cases. This technology should be useful for research on human BBB physiology, pathology, and drug development.

Paving the Way Toward Complex Blood-Brain Barrier Models Using Pluripotent Stem Cells

“…3F). Unfortunately, TEER values of only 100 Ocm 2 were achieved [71], which might potentially be increased by the further addition of pericytes and neurons into the transwell system. The beneficial effect of pericytes was also found in a systematic comparison of different multicellular models, in which hiPSC-BMECs were cocultured with hiPSC-derived or primary neuronal cells and pericytes [38].…”

“…The group previously characterized that cyclic AMP efficiently supports the differentiation of hiPSC toward ECs [72][73][74][75]. However, as in the other studies, co-culture with pericytes, astrocytes, and neurons is still necessary to induce BMEC hallmarks [71]. Strikingly, for their co-culture, they used hiPSC-derived neurons, astrocytes, and pericytes.…”

“…The second laboratory published an interesting approach, deriving all four cell types of the BBB from hiPSC (Fig. 3F) [71]. The group previously characterized that cyclic AMP efficiently supports the differentiation of hiPSC toward ECs [72][73][74][75].…”

“…Second, the co-differentiation experiments with NPCs [42,43], the isogenic co-culture model [76], and the fully PSC-derived model [71] showed that, in principle, all BBB cell types can be made from the same stem cell source. Third, the obtained BMECs showed extremely high TEER values that have never been generated with any other BMEC source.…”

Establishment of a Human iPSC- and Nanofiber-Based Microphysiological Blood–Brain Barrier System

“…10,12 Primary brain ECs isolated from human brain tissue were monocultured or co/tricultured with pericytes on one side of the insert membrane and astrocytes (sometimes with neurons) on the other side. 13–16 One trend is the utilization of human pluripotent or adult stem cells instead of primary cells or cells immortalized by the introduction of genes that deregulate the cell cycle because of the limitations that primary cells have, such as low availability and reproducibility, and that immortalized human cells are unable to form strong barrier properties because of the loss of important phenotypes, such as tight junctions. 17–19 Human pluripotent stem cells, especially human induced pluripotent stem cells (hiPSCs), are a promising stem cell source and have enormous potential for the development of human BBB in vitro models.…”