Neuroinflammatory astrocytes generated from cord blood-derived human induced pluripotent stem cells

Abstract

Background Astrocytes respond to central nervous system (CNS) injury and disease by transforming to a reactive astrogliosis cell state that can contribute to either CNS dysfunction or repair. Neuroinflammation is a powerful driver of a harmful A1 astrogliosis phenotype associated with in vitro neurotoxicity and histopathology in human neurodegenerative diseases. Here we report a protocol for the rapid development of a human cell culture model of neuroinflammatory astrogliosis using induced pluripotent stem cells (iPSCs). Methods Using RNA sequencing and in vitro cell assays, we measured transcriptional and cellular effects of chronic exposure of human iPSC-derived astrocytes to the cytokines TNFα (tumor necrosis factor alpha) or IL-1β (interleukin-1 beta). Results We show TNFα and IL-1β induce pro-inflammatory gene signatures but by widely different magnitudes. TNFα treatment results in 606 differential expressed genes, the suppression of glutamate-uptake, and increased phagocytic activity in astrocyte cultures. In contrast, IL-1β effects are attenuated to 33 differential expressed genes and no significant effects on glutamate-uptake or increased phagocytic activity. Conclusion Our approach demonstrates a rapid tool for modeling neuroinflammatory human astrocytic responses in nervous system trauma and disease. In particular, we reveal a model for robust TNFα-induced human astrogliosis suitable for the study of neurotoxic A1 astrocytes.

Short and long TNF‐alpha exposure recapitulates canonical astrogliosis events in human‐induced pluripotent stem cells‐derived astrocytes

“…Once released by microglia, this cytokine participates in the induction of neurotoxic dysfunctional phenotype A1 (Liddelow et al, ). According to these recent reports, long‐term exposure to TNF‐α impaired glutamate uptake by iPSC‐derived astrocytes (Hyvarinen et al, ; Zhou et al, ), Here, we show that this impairment can occur just after short‐term exposure to TNF‐α as well. Of note, as astrogliosis progresses due to long‐term TNF‐α exposure, impairment of aspartate uptake confirmed their dysfunctionality indeed.…”

“…Recent evidences have shown that extracellular glutamate stimulates glutamate release from astrocytes in order to coordinate neuronal activity, pointing to an emerging role for astrocytes in modulating both glutamate uptake and release and extending their therapeutic potential (Mahmoud, Gharagozloo, Simard, & Gris, ). Recent advances in the characterization of A1/A2 astrocytes have contributed to understand the dual effects of reactive astrocytes (Liddelow et al, ), even though the reproducibility of these phenotypes has been challenged in vitro (Hyvarinen et al, ; Zhou et al, ). However, TNF‐alpha is one of main factors involved in the signaling of both phenotypes.…”

The role of the TNFα-mediated astrocyte signaling pathway in epilepsy

“…When glutamate reaches pathological levels, it can have toxic effects and cause damage to synapses [38]. Zhou et al have found that TNFα inhibits glutamate uptake through the NF-κB signaling pathway and enhances the phagocytosis of astrocytes in human NCRM-1 astrocytes [39]. In recent years, autoimmune encephalitis, which is associated with epileptic seizures, has been studied at a greater level.…”

The Age of Brain Organoids: Tailoring Cell Identity and Functionality for Normal Brain Development and Disease Modeling

“…Astrocytes actively participate in synaptic pruning during development and are essential players in synapse formation and maturity of neural networks (Chung et al, 2013). Despite some intrinsic limitations that include maintaining long-term cultures, we and others have generated astrocytes directly from iPSCs and explored their functional properties (Zhou et al, 2019;Trindade et al, 2020). In brain organoid models, radial glia and astrocytes have been previously described.…”