PROJECT SUMMARY
Perinatal white matter injury (WMI) is a common sequela of neonatal brain injury. One of the leading causes
of neonatal brain injury and morbidity in premature infants is post-hemorrhagic hydrocephalus (PHH). PHH is
triggered by germinal matrix and/or intraventricular hemorrhage (IVH) that results in accumulation of
cerebrospinal fluid (CSF) in the brain ventricles. This accumulation of CSF can cause compression of
surrounding brain tissue and injury to the developing white matter. Specifically, in PHH the degree of
ventricular dilation is correlated with severity of WMI as measured by decreased myelination and increased
axonal injury, cellularity, and cytoplasmic vacuolation. Myelination in the central nervous system (CNS) has
been previously identified as dependent upon Autotaxin (ATX), which can be sourced via the CSF. The
choroid plexus (ChP) is the tissue which controls the amount and composition of the CSF and therefore helps
instruct the developing nervous system. Here, we examine expression and availability of ChP-secreted ATX
influencing white matter development and myelination of the mouse CNS and hypothesize this may be an
important signaling axis which could be therapeutically harnessed to treat WMI associated with PHH. The
Lehtinen Lab's single nucleus sequencing data demonstrates ATX expression across all epithelial cell
clusters, thereby suggesting the epithelial cells may secrete ATX into the CSF. In preliminary studies we
confirm that the ChP secretes ATX and show that ATX abundance in the ChP and CSF increase throughout
development, with a particularly noticeable upregulation in the critical postnatal window associated with
myelination of the CNS in mouse. In Aim 1, I will determine the effect of ChP-specific ATX modulation on
myelination using advanced in vivo mouse manipulation techniques to selectively delete or overexpress ATX
in the ChP. In Aim 2, I will further explore role for ATX in the pathophysiological mechanisms of WMI using
the lab's translationally relevant mouse model of neonatal PHH following IVH. The results of these studies
will inform our understanding of the mechanisms of hemorrhage induced WMI and will help guide rational
intervention strategies for treatment, thereby improving quality of life for patients and caregivers. The
proposed research will take place at Boston Children's Hospital under the guidance of Dr. Maria Lehtinen, an
expert in the field of choroid plexus and CSF biology, and will provide training in ChP in vivo manipulation
techniques, glial biology, exposure to clinical experience, and in the design of translationally relevant
preclinical studies. We will routinely consult with collaborators and mentors who are experts on both white
matter development and the neurologic sequelae associated with PHH of prematurity. The results from this
proposal will result in first-authored publications and a large body of support for a K99/R00 application, with
the goal of launching an independent academic career.