Nikolakopoulou, P. | bioRxiv Science

bioRxiv2021

Generation of star-shaped human induced astrocytes with a mature inflammatory phenotype for CNS disease modeling

Generating astrocytes from induced pluripotent stem cells has been hampered by either prolonged differentiation -spanning over two months -or by shorter protocols that generate immature astrocytes, devoid of salient inflammation-associated astrocytic traits pivotal for CNS neuropathological modeling. We directed human neural stem cells derived from induced pluripotent stem cells to astrocytic commitment and maturity by orchestrating an astrocytic-tuned culturing environment. In under 28 days, the generated cells express canonical and mature astrocytic markers, denoted by the expression of AQP4 and, remarkably, the expression and functionality of glutamate transporter EAAT2. We also show that this protocol generates astrocytes that encompass traits critical in CNS disease modeling, such as glutathione synthesis and secretion, upregulation of ICAM-1 and a cytokine secretion profile which is on par with primary astrocytes. This protocol generates a multifaceted astrocytic model suitable for CNS in vitro disease modeling and personalized medicine through brain-on-chip technologies.

neuroscience↗

bioRxiv2021

Continuous monitoring reveals protective effects of N-acetylcysteine amide on an isogenic microphysiological model of the neurovascular unit

Microphysiological systems mimic the in-vivo cellular ensemble and microenvironment with the goal of providing more human-like models for biopharmaceutical research. We report the first such model of the blood-brain barrier (BBB-on-chip) featuring both isogenic human induced pluripotent stem cell (hiPSC)-derived cells and continuous barrier integrity monitoring with <2-minute temporal resolution. We showcase its capabilities in the first microphysiological study of nitrosative stress and antioxidant prophylaxis. Relying on off-stoichiometry thiol-ene epoxy (OSTE+) for fabrication greatly facilitates assembly and sensor integration compared to the prevalent polydimethylsiloxane devices. The integrated cell-substrate endothelial resistance monitoring allows us to capture formation and breakdown of our blood-brain barrier model, consisting of co-cultured hiPSC-derived endothelial-like and astrocyte-like cells. We observe clear cellular disruption when exposing the BBB-on-chip to the nitrosative stressor linsidomine, and report on the barrier permeability and barrier-protective effects of the antioxidant N-acetylcysteine amide. Using metabolomic network analysis, we further find drug-induced changes consistent with prior literature regarding, e.g., cysteine and glutathione involvement. A model like ours opens new possibilities for drug screening studies and personalized medicine, relying solely on isogenic human-derived cells and providing high-resolution temporal readouts that can help in pharmacodynamic studies.

bioengineering↗