Memantine transport by a proton-coupled organic cation antiporter in hCMEC/D3 cells, an in vitro human blood-brain barrier model

Generation of Brain Microvascular Endothelial-Like Cells from Human Induced Pluripotent Stem Cells by Co-Culture with C6 Glioma Cells

“…In addition, we found an elevation of the expression level of genes involved in influx and efflux transporters in iPS-ECs by co-culture with C6 cells (Fig 2). The TEER values (~55 Ω cm 2 ) in iPSEC-C6 were largely identical to those in hCMEC/D3 cells (30~40 Ω cm 2 ) [5], which are immortalized human BMECs that have been widely utilized as cell sources for human in vitro BBB models [19,20]. Our results, therefore, indicate that iPS-ECs would be maturated into BMEC-like cells by co-culture with C6 cells.…”

Cocktail-Dosing Microdialysis Study to Simultaneously Assess Delivery of Multiple Organic–Cationic Drugs to the Brain

“…18 As shown in Figure 1, no appreciable drugedrug interaction was seen in cellular uptake under conditions where each drug concentration was 1 mM (except for diphenhydramine: 3 mM) and the sum of the concentrations was 7:mM. Taking into account that the K m values are around 15-100 mM, 12,14,[17][18][19][20] it was expected that drugedrug interactions at the transporter would not occur under these conditions. Indeed, the K p,uu values determined by cocktail-dosing brain microdialysis study were consistent with those of each single-dosing study under conditions where the sum of the C p,u was less than 7 mM (Table 1).…”

“…Proton-coupled organic cation antiport system accepts substrates with K m values around 15-100 mM and is inhibited by many cationic drugs at relatively high concentrations. 12,14,[17][18][19][20] Therefore, to examine the possibility of drugedrug interaction during the BBB transport, we carried out an in vitro uptake study using hCMEC/D3 cells. It has been shown that functional expression of the proton-coupled organic cation antiport system in hCMEC/D3 cells is similar to that in rat BBB model cells, in terms of oxycodone and diphenhydramine uptakes.…”

“…12,14,[17][18][19][20] Though the molecular entity of this antiport system has not yet been identified, it can generate high unbound drug concentration gradients in the brain across the BBB. This is important, because CNS drugs with K p,uu greater than 1 are not only desirable in terms of good efficacy in the brain, but also exhibit reduced peripheral side effects (i.e., the unbound drug concentration in the plasma is lower than that in the brain).…”

“…For this purpose, we focused on the proton-coupled organic cation antiport system, and selected oxycodone, diphenhydramine, tramadol, memantine, and pyrilamine as model drugs. 12,14,17,18,20 Further, in cocktail dosing studies, it is important to avoid drugedrug interactions among candidates sharing the same influx transport system at the BBB, and therefore, we checked drugedrug interactions in hCMEC/D3 cells, an in vitro BBB model, 21 because these cells are known to express the proton-coupled organic cation antiport system. 18 The K p,uu values for these drugs were evaluated and compared under single-dosing and cocktail-dosing conditions.…”