Establishment of a Human Blood-Brain Barrier Co-culture Model Mimicking the Neurovascular Unit Using Induced Pluri- and Multipotent Stem Cells

Abstract

SummaryIn vitro models of the human blood-brain barrier (BBB) are highly desirable for drug development. This study aims to analyze a set of ten different BBB culture models based on primary cells, human induced pluripotent stem cells (hiPSCs), and multipotent fetal neural stem cells (fNSCs). We systematically investigated the impact of astrocytes, pericytes, and NSCs on hiPSC-derived BBB endothelial cell function and gene expression. The quadruple culture models, based on these four cell types, achieved BBB characteristics including transendothelial electrical resistance (TEER) up to 2,500 Ω cm2 and distinct upregulation of typical BBB genes. A complex in vivo-like tight junction (TJ) network was detected by freeze-fracture and transmission electron microscopy. Treatment with claudin-specific TJ modulators caused TEER decrease, confirming the relevant role of claudin subtypes for paracellular tightness. Drug permeability tests with reference substances were performed and confirmed the suitability of the models for drug transport studies.

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

“…astrocytes, and hiPSC-NSCs [38]. This study further supports the beneficial effects of pericytes on BBB tightness.…”

“…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].…”

“…This approach yielded a differentiation efficiency of an impressive 93% and a TEER of 2,000 Ocm 2 [58]. Another study by Appelt-Menzel et al reproduced the differentiation of BMECs with the Lippmann protocol and retrieved TEER values of a maximum of 2,500 Ocm 2 in a co-culture model with NSCs, astrocytes, and pericytes [38]. Importantly, FFEM revealed that the TJ proteins showed a similar morphology as reported on brain ECs in vivo, showing that morphologically relevant BMECs can be retrieved from hiPSCs [38].…”

“…For example, PSC-derived BMECs have been reported to respond more physiologically to hypoxia than the hCMEC/D3 cell line [77]. Most importantly, however, is that a combination of co-culturing with varying (primary) cell sources appears to be a significant advantage of improving hiPSC-derived BMEC BBB tightness [38].…”

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

“…53,54 Normally, A β clearance and degradation are regulated by several mechanisms, such as A β protease degradation, low-density lipoprotein receptor-related protein 1 binding, the efflux by transport of A β across the BBB into the blood circulation, and the uptake and phagocytosis of by glia cells. 53,55,56 To verify the A β clearance capacity of the BBB model, we tricultured and engineered the BBB model consisting of hiPSC-ECs and hiPSC-Astro with hiPSC–NPCs (Figure 6A). The hiPSC–NPCs were induced for neuronal differentiation for 14 days before triculture.…”