Cortical Spheroid Model for Studying the Effects of Ischemic Brain Injury

Stroke is a devastating neurological disorder and a leading cause of death and long-term disability. Despite many decades of research, there are still very few therapeutic options for patients suffering from stroke or its consequences. This is partially due to the limitations of current research models, including traditional in vitro models which lack the three-dimensional (3D) architecture and cellular make-up of the in vivo brain. 3D spheroids derived from primary postnatal rat cortex provide an in vivo-relevant model containing a similar cellular composition to the native cortex and a cell-synthesized extracellular matrix. These spheroids are costeffective, highly reproducible, and can be produced in a high-throughput manner, making this model an ideal candidate for screening potential therapeutics. To study the cellular and molecular mechanisms of stroke in this model, spheroids were deprived of glucose, oxygen, or both oxygen and glucose for 24 hours. Both oxygen and oxygen-glucose deprived spheroids demonstrated many of the hallmarks of stroke, including a decrease in metabolism, an increase in neural dysfunction, and an increase in reactive astrocytes. Pretreatment of spheroids with the antioxidant agent N-acetylcysteine (NAC) mitigated the decrease in ATP seen after 24 hours of oxygen-glucose deprivation. Together, these results show the utility of our 3D cortical spheroid model for studying ischemic injury and its potential for screening stroke therapeutics. Significance StatementThose who survive after suffering a stroke often have long-term cognitive or physical disabilities. There is currently only one available therapeutic, tissue plasminogen activator (tPA), and it must be administered within a few hours after the onset of stroke. As stroke prevalence increases with our aging population, there is a growing need for therapies to mitigate or reverse the resulting brain damage. Three-dimensional (3D) culture systems have the potential to screen novel therapeutics more reliably than traditional in vitro models. Here we present a novel 3D cortical spheroid ischemia model which replicates many of the characteristics of stroke and has the potential to be an effective tool in therapeutic development.