Classical complement pathway inhibition reduces brain damage in a hypoxic ischemic encephalopathy animal model

PLoS One. 2021 Sep 30;16(9):e0257960. doi: 10.1371/journal.pone.0257960. eCollection 2021.

Abstract

Perinatal hypoxic ischemic encephalopathy (HIE) remains a major contributor of infant death and long-term disability worldwide. The role played by the complement system in this ischemia-reperfusion injury remains poorly understood. In order to better understand the role of complement activation and other modifiable mechanisms of injury in HIE, we tested the dual-targeting anti-inflammatory peptide, RLS-0071 in an animal model of HIE. Using the well-established HIE rat pup model we measured the effects of RLS-0071 during the acute stages of the brain injury and on long-term neurocognitive outcomes. Rat pups subject to hypoxia-ischemia insult received one of 4 interventions including normothermia, hypothermia and RLS-0071 with and without hypothermia. We measured histopathological effects, brain C1q levels and neuroimaging at day 1 and 21 after the injury. A subset of animals was followed into adolescence and evaluated for neurocognitive function. On histological evaluation, RLS-0071 showed neuronal protection in combination with hypothermia (P = 0.048) in addition to reducing C1q levels in the brain at 1hr (P = 0.01) and at 8 hr in combination with hypothermia (P = 0.005). MRI neuroimaging demonstrated that RLS-0071 in combination with hypothermia reduced lesion volume at 24 hours (P<0.05) as well as decreased T2 signal at day 21 in combination with hypothermia (P<0.01). RLS-0071 alone or in combination with hypothermia improved both short-term and long-term memory. These findings suggest that modulation by RLS-0071 can potentially decrease brain damage resulting from HIE.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / drug effects*
  • Brain / metabolism
  • Brain / pathology
  • Combined Modality Therapy
  • Complement C1q / antagonists & inhibitors*
  • Complement C1q / metabolism
  • Complement Inactivating Agents / pharmacology*
  • Complement Inactivating Agents / therapeutic use
  • Complement Pathway, Classical / drug effects*
  • Disease Models, Animal
  • Hypothermia, Induced
  • Hypoxia-Ischemia, Brain / drug therapy
  • Hypoxia-Ischemia, Brain / metabolism
  • Hypoxia-Ischemia, Brain / pathology
  • Hypoxia-Ischemia, Brain / therapy*
  • Maze Learning / drug effects
  • Maze Learning / physiology
  • Motor Skills / drug effects
  • Motor Skills / physiology
  • Rats
  • Recognition, Psychology / drug effects
  • Recognition, Psychology / physiology
  • Treatment Outcome

Substances

  • Complement Inactivating Agents
  • Complement C1q

Grants and funding

The funder provided support in the form of salaries for authors [PK,PH,KC, NK], but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.