Tuning a bioengineered hydrogel for studying astrocyte reactivity in glioblastoma.

Astrocytes play many essential roles in the central nervous system (CNS) and are altered significantly in disease. These reactive astrocytes contribute to neuroinflammation and disease progression in many pathologies, including glioblastoma (GB), an aggressive form of brain cancer. Current in vitro platforms do not allow for accurate modeling of reactive astrocytes. In this study, we sought to engineer a simple bioengineered hydrogel platform that would support the growth of primary human astrocytes and allow for accurate analysis of various reactive states. After validating this platform using morphological analysis and qPCR, we then used the platform to begin investigating how astrocytes respond to GB derived extracellular vesicles (EVs) and soluble factors (SF). These studies reveal that EVs and SFs induce distinct astrocytic states. In future studies, this platform can be used to study how astrocytes transform the tumor microenvironment in GB and other diseases of the CNS. STATEMENT OF SIGNIFICANCE: Recent work has shown that astrocytes help maintain brain homeostasis and may contribute to disease progression in diseases such as glioblastoma (GB), a deadly primary brain cancer. In vitro models allow researchers to study basic mechanisms of astrocyte biology in healthy and diseased conditions, however current in vitro systems do not accurately mimic the native brain microenvironment. In this study, we show that our hydrogel system supports primary human astrocyte culture with an accurate phenotype and allows us to study how astrocytes change in response to a variety of inflammatory signals in GB. This platform could be used further investigate astrocyte behavior and possible therapeutics that target reactive astrocytes in GB and other brain diseases.