Ferroptosis in post-hemorrhagic hydrocephalus following severe neonatal intraventricular hemorrhage (IVH) - defining the role of iron in choroid plexus and ependymal cell death

/ABSTRACT Post-hemorrhagic hydrocephalus following severe intraventricular hemorrhage (IVH) is the most severe consequence of premature birth. There are no treatments available to prevent hydrocephalus after IVH has occurred. The long-term objective of this research is to advance therapies for the prevention of hydrocephalus in preterm severe IVH. To address this unmet need, we need a better understanding of the cellular mechanisms leading to hydrocephalus following severe IVH. We propose that ferroptosis-driven ependymal and choroid plexus epithelial cell death is a critical mechanism for developing post-hemorrhagic hydrocephalus in infants with severe neonatal IVH. This work is novel both conceptually and in its approach. We will utilize a novel, highly specific biomarker of ferroptosis, 3R dimer of the transferrin receptor 1, to characterize ferroptosis. We will employ our novel rat pup model of IVH that recapitulates the severity of the human hydrocephalus disease state more realistically that prior animal models. Finally, we will take a novel approach of utilizing a genetic defect in DMT1 in the Belgrade (b/b) rat to manipulate an intrinsic disease mechanism to understand its role in an extrinsic etiology (IVH). To test the hypothesis that ferroptosis is the mechanism of cell death in the ventricular ependyma and choroid plexus following severe IVH and leading to hydrocephalus, our experiments will address the following AIMS: (1) Test if ferroptosis mediates ependymal and choroid plexus cell death after severe neonatal IVH in post-hemorrhagic hydrocephalus. We will test if 3R dimer formation is higher in [1.1] rat pups with severe IVH and hydrocephalus than in controls, and [1.2] CSF of human infants with hydrocephalus following severe IVH, compared to control (non-IVH) and resolved IVH (without hydrocephalus). (2) Test if divalent metal cation-1 (DMT-1) mediates ependymal and choroidal cell iron uptake following severe IVH, thereby increasing ferroptosis and post-hemorrhagic hydrocephalus. We will test if [2.1] ependymal and choroid plexus 3R dimer formation and [2.2] rates of hydrocephalus in DMT-1 deficient Belgrade (b/b) rats are reduced compared to wildtype rats following IVH induction, reflecting decreased ferroptosis in the DMT-1 deficient rat. (3) Test if intracerebroventricular (ICV) iron chelation with deferiprone prevents post- hemorrhagic hydrocephalus by inhibiting cellular iron uptake and ferroptosis-mediated ependymal and choroid plexus cell death. We will test if ICV deferiprone decreases [3.1] ependymal and choroid plexus 3R dimer formation and [3.2] hydrocephalus in IVH rat pups compared to controls. Project Number: 1R01NS144825-01A1 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of Neurological Disorders and Stroke (NINDS) | Principal Investigator: KELLY MAHANEY | Institution: STANFORD UNIVERSITY, STANFORD, CA | Award Amount: $432,647 | Activity Code: R01 | Study Section: Developmental Brain Disorders Study Section[DBD] View on NIH RePORTER: https://reporter.nih.gov/project-details/11368897