Small-molecule screen reveals pathways that regulate C4 secretion in stem cell-derived astrocytes
Francesca Rapino, Ted Natoli, Francesco Limone, Erin O’Connor, Jack Blank, Matthew Tegtmeyer, William Chen, Erika M. Norabuena, Juhi G. Narula, Dane Z. Hazelbaker, Gabriella Angelini, Lindy E. Barrett, Alison O’Neil, Ursula K. Beattie, Jessica M. Thanos, Heather de Rivera, Steven D. Sheridan, Roy H. Perlis, Steven A. McCarroll, Beth Stevens, Aravind Subramanian, Ralda Nehme, Lee L. Rubin
Abstract
In the brain, the complement system plays a crucial role in the immune response and in synaptic elimination during normal development and disease. Here, we sought to identify pathways that modulate the production of complement component 4 (C4), recently associated with an increased risk of schizophrenia. To design a disease-relevant assay, we first developed a rapid and robust 3D protocol capable of producing large numbers of astrocytes from pluripotent cells. Transcriptional profiling of these astrocytes confirmed the homogeneity of this population of dorsal fetal-like astrocytes. Using a novel ELISA-based small-molecule screen, we identified epigenetic regulators, as well as inhibitors of intracellular signaling pathways, able to modulate C4 secretion from astrocytes. We then built a connectivity map to predict and validate additional key regulatory pathways, including one involving c-Jun-kinase. This work provides a foundation for developing therapies for CNS diseases involving the complement cascade.