Abstract:BackgroundDue to their ability to limitlessly proliferate and specialize into almost any cell type, human induced pluripotent stem cells (iPSCs) offer an unprecedented opportunity to generate human brain microvascular endothelial cells (BMECs), which compose the blood–brain barrier (BBB), for research purposes. Unfortunately, the time, expense, and expertise required to differentiate iPSCs to purified BMECs precludes their widespread use. Here, we report the use of a defined medium that accelerates the differe… Show more
“…However, one of the studies reported a significant decrease in discontinuous junctions [27]. Other iPSCderived BBB models have reported an increase in permeability of rhodamine 123 of 40%-50% after treatment with P-gp inhibitors [26,27], which is slightly higher than the 28% observed in our model. Similar to our results, these studies do not show changes in P-gp efflux activity between monoculture and coculture.…”
Section: Discussioncontrasting
confidence: 79%
“…In terms of functionally restricting permeability iPSC‐EC1 in coculture showed highest performance with high TEER, low NaF permeability, and functional efflux, comparable to other models using similar protocols to derive EC . However, the measured TEER values are lower than some of the highest reported values for iPSC‐derived ECs , and previous reports demonstrate that different iPSC lines give different maximum TEER . iPSC‐EC2 showed substantially lower TEER and higher NaF than iPSC‐EC1, however, in the same range as hCMEC/D3 and other models using similar protocols to derive EC for BBB models .…”
Cell-based models of the blood-brain barrier (BBB) are important for increasing the knowledge of BBB formation, degradation and brain exposure of drug substances. Human models are preferred over animal models because of interspecies differences in BBB structure and function. However, access to human primary BBB tissue is limited and has shown degeneration of BBB functions in vitro. Human induced pluripotent stem cells (iPSCs) can be used to generate relevant cell types to model the BBB with human tissue. We generated a human iPSC-derived model of the BBB that includes endothelial cells in coculture with pericytes, astrocytes and neurons. Evaluation of barrier properties showed that the endothelial cells in our coculture model have high transendothelial electrical resistance, functional efflux and ability to discriminate between CNS permeable and non-permeable substances. Whole genome expression profiling revealed transcriptional changes that occur in coculture, including upregulation of tight junction proteins, such as claudins and neurotransmitter transporters. Pathway analysis implicated changes in the WNT, TNF, and PI3K-Akt pathways upon coculture. Our data suggest that coculture of iPSC-derived endothelial cells promotes barrier formation on a functional and transcriptional level. The information about gene expression changes in coculture can be used to further improve iPSC-derived BBB models through selective pathway manipulation. Stem Cells 2018.
“…However, one of the studies reported a significant decrease in discontinuous junctions [27]. Other iPSCderived BBB models have reported an increase in permeability of rhodamine 123 of 40%-50% after treatment with P-gp inhibitors [26,27], which is slightly higher than the 28% observed in our model. Similar to our results, these studies do not show changes in P-gp efflux activity between monoculture and coculture.…”
Section: Discussioncontrasting
confidence: 79%
“…In terms of functionally restricting permeability iPSC‐EC1 in coculture showed highest performance with high TEER, low NaF permeability, and functional efflux, comparable to other models using similar protocols to derive EC . However, the measured TEER values are lower than some of the highest reported values for iPSC‐derived ECs , and previous reports demonstrate that different iPSC lines give different maximum TEER . iPSC‐EC2 showed substantially lower TEER and higher NaF than iPSC‐EC1, however, in the same range as hCMEC/D3 and other models using similar protocols to derive EC for BBB models .…”
Cell-based models of the blood-brain barrier (BBB) are important for increasing the knowledge of BBB formation, degradation and brain exposure of drug substances. Human models are preferred over animal models because of interspecies differences in BBB structure and function. However, access to human primary BBB tissue is limited and has shown degeneration of BBB functions in vitro. Human induced pluripotent stem cells (iPSCs) can be used to generate relevant cell types to model the BBB with human tissue. We generated a human iPSC-derived model of the BBB that includes endothelial cells in coculture with pericytes, astrocytes and neurons. Evaluation of barrier properties showed that the endothelial cells in our coculture model have high transendothelial electrical resistance, functional efflux and ability to discriminate between CNS permeable and non-permeable substances. Whole genome expression profiling revealed transcriptional changes that occur in coculture, including upregulation of tight junction proteins, such as claudins and neurotransmitter transporters. Pathway analysis implicated changes in the WNT, TNF, and PI3K-Akt pathways upon coculture. Our data suggest that coculture of iPSC-derived endothelial cells promotes barrier formation on a functional and transcriptional level. The information about gene expression changes in coculture can be used to further improve iPSC-derived BBB models through selective pathway manipulation. Stem Cells 2018.
“…Previous publications have extensively validated the iBBB cells produced by this differentiation protocol (Hollmann et al, 2017;Lippmann et al, 2012); to determine that the 22q11.2 deletion did not affect the differentiation process, we confirmed similar expression levels in vasculature-specific molecules by flow cytometry (Supplementary Figure 2), and in junctional proteins by immunofluorescence (Supplementary Figure 1A) and western blot (Figure 2A).…”
Section: Differentiation Of Ipscs Into Blood-brain Barrier Endotheliumsupporting
confidence: 78%
“…HiPSCs were differentiated into BBB-like endothelium following the protocol previously published (Hollmann et al, 2017;Lippmann et al, 2012). In brief, HiPSCs were plated onto Matrigel (Corning 354230) coated 6 well TC-treated plated (Falcon 353046) at 100,000 cells/well in Stem MACs iPS-Brew XF media.…”
Section: Differentiation Of Ipscs Into Blood-brain Barrier Endotheliummentioning
confidence: 99%
“…To evaluate the effect of the 22qDS deletion on barrier function, we obtained HiPSCs from 5 22qDS+SZ patients and 5 paired age-and sex-matched HCs. iBBB endothelial cells were derived from these HiPSCs using a differentiation protocol as previously described ( Figure 1A) (Hollmann et al, 2017;Lippmann et al, 2012). To interrogate the barrier function of the iBBB monolayers, we assessed their transendothelial electrical resistance (TEER) by repeatedly sampled resistance of the monolayers over the course of 72 hours.…”
Section: Barrier Function Is Impaired In the 22qds Bbbmentioning
Neuroimmune dysregulation is implicated in neuropsychiatric disorders including schizophrenia (SZ).As the blood brain barrier (BBB) is the immunological interface between the brain and the periphery, we investigated whether the BBB is intrinsically compromised in the most common genetic risk factor for SZ, the hemizygous deletion of chromosome 22q11.2 (22qDS). BBB-like endothelium (iBBB) differentiated from human 22qDS+SZ-induced pluripotent stem cells exhibited impaired barrier integrity, a phenotype substantiated in a mouse model of 22qDS. The proinflammatory intercellular adhesion molecule-1 (ICAM-1) was upregulated in 22qDS+SZ iBBB and 22qDS mice, indicating compromise of the BBB immune privilege. This immune imbalance resulted in increased migration/activation of leukocytes crossing the 22qDS+SZ iBBB. Finally, we found heightened astrocyte activation in murine and human 22qDS, suggesting that the BBB promotes astrocyte-mediated neuroinflammation. Overall, the barrier-promoting and immune privilege properties of the 22qDS BBB are compromised, and this might increase the risk for neuropsychiatric disease. 4
Reorganization of host red blood cells by the malaria parasite Plasmodium falciparum enables their sequestration via attachment to the microvasculature. This artificially increases the dwelling time of the infected red blood cells within inner organs such as the brain, which can lead to cerebral malaria. Cerebral malaria is the deadliest complication patients infected with P. falciparum can experience and still remains a major public health concern despite effective antimalarial therapies. Here, the current understanding of the effect of P. falciparum cytoadherence and their secreted proteins on structural features of the human blood-brain barrier and their involvement in the pathogenesis of cerebral malaria are highlighted. Advanced 2D and 3D in vitro models are further assessed to study this devastating interaction between parasite and host. A better understanding of the molecular mechanisms leading to neuronal and cognitive deficits in cerebral malaria will be pivotal in devising new strategies to treat and prevent blood-brain barrier dysfunction and subsequent neurological damage in patients with cerebral malaria.
MalariaMalaria is an ancient mosquito-borne disease caused by protozoan parasites of the genus Plasmodium. According to the latest World Malaria Report published by the World Health
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