TOP 79 - Translational insights from regional brain evaluation of a novel therapeutic approach in neonatal hypoxic-ischemic encephalopathy

Publication Number: 3811.TOP 79

Dania Jacubovich, Eastern Virginia Medical School, Norfolk, VA, United States; Meghana Kunam, Eastern Virginia Medical School, Norfolk, VA, United States; Aliyah Mohammed, Children’s Hospital of the King’s Daughters, Norfolk, VA, United States; Andreea Necula, Eastern Virginia Medical School, Norfolk, VA, United States; Haree Pallera, Children's Hospital of The King's Daughters / Eastern Virginia Medical School, Norfolk, VA, United States; Angela Saadat, eastern virginia medical school, Norfolk, VA, United States; Tushar Shah, Childrens hospital of the kings daughters, Norfolk, VA, United States

Background: Neonatal hypoxic-ischemic encephalopathy (HIE) remains a major cause of mortality and long-term neurodevelopmental impairment. Currently, therapeutic hypothermia (TH) is the only approved treatment for HIE. We have previously demonstrated sexual dimorphism in the outcomes of treated and untreated HIE. Most preclinical and clinical studies rely on global outcome measures that may obscure region-specific vulnerabilities and therapeutic effects. Precise regional quantification of tissue loss and neuroinflammation is therefore critical to delineate the spatial heterogeneity of HIE pathology, and can enable the development of sex-specific, region-targeted neuroprotective strategies for neonatal HIE.
Complement is an innate immune defense with important roles in normal development. In diseases of reperfusion injury such as neonatal HIE, complement pathways are key contributors to excessive inflammation and injury. Complement proteins C3a and C5a are central to all complement pathways. C3a plays a paradoxical role in neuroinflammation and can be anti-inflammatory in acute phases of injury. C5a facilitates inflammation by binding C5aR1, and PMX205 is a small molecule inhibitor of this interaction. We have developed a novel therapeutic cocktail of PMX205+ C3a (CT) that synergizes with TH. We have shown that overall, TH treated demonstrated more improvement in female rats, CT demonstrated more improvement in male outcomes, and combining CT+TH showed additive improvement in both sexes

Objective: In this study, we employ region-specific volumetric and histopathological analyses to quantify differential patterns of injury and tissue loss in neonatal rats treated with our novel therapeutic cocktail, with the goal of informing the design of sex-specific therapeutic approaches for HIE.

Design/Methods: Injury was induced in P10-P12 rat pups by Vannucci’s method. Following, subsets of rats received no treatment (NT), CT, TH or combination CT and TH. Control animals received sham surgery. Structural injury was assessed and compared between treatment groups at 2-3 days post-injury (dpi) in the cortex, hippocampus, and thalamic regions of the brain. Lesion area was measured from whole and coronal brain images with ImageJ software. Cellular, inflammatory, and injury markers such as NeuN, GFAP, Iba1, TUNEL, and MPO were assessed by IHC. Differences will be stratified by sex and compared between groups. Data will be analyzed with JMP statistical software. Histopathological measures will also be correlated with functional outcomes that have already been measured.