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Updated: May 16, 2025
Modeling Encephalopathy of Prematurity Using Prenatal Hypoxia-ischemia with Intra-amniotic Lipopolysaccharide in Rats
Published on: November 20, 2015
The Anti-inflammatory Peptide RLS-0071 Reduces Immune Cell Recruitment and Oxidative Damage in a Neonatal Rat Model
Kaitlyn G Jackson1, Alana C Sampson2, Kenji M Cunnion2,3,4,5
1Department of Microbiology, Eastern Virginia Medical School, Norfolk, Virginia.
Insights
Perinatal hypoxic-ischemic encephalopathy (HIE) is a severe condition with no drug treatments. A novel peptide, RLS-0071, demonstrated neuroprotective effects comparable to therapeutic hypothermia in a neonatal rat model of HIE.
Area of Science:
- Neuroscience
- Immunology
- Neonatal Medicine
Background:
- Perinatal hypoxic-ischemic encephalopathy (HIE) causes infant mortality and neurological damage.
- Neuroinflammation and oxidative stress from immune cells exacerbate HIE-induced neuronal injury.
- Current treatments for HIE are limited, with therapeutic hypothermia (TH) being the sole effective option.
Purpose of the Study:
- To investigate the efficacy of a novel anti-inflammatory peptide, RLS-0071 (pegtarazimod), in modulating neuroinflammation in a neonatal rat model of HIE.
- To test the hypothesis that RLS-0071 can reduce neuronal loss and oxidative damage in HIE.
Main Methods:
- Utilized the Vannucci rat pup model to induce hypoxic-ischemic brain injury.
- Administered RLS-0071, therapeutic hypothermia (TH), or normothermia as interventions.
- Assessed histopathological changes, including neuronal survival (NeuN staining), microglial recruitment (Iba1 staining), and oxidative damage (MPO staining) at 24 and 48 hours post-insult.
Main Results:
- RLS-0071 treatment resulted in increased neuron survival at 48 hours compared to TH.
- Both RLS-0071 and TH significantly reduced microglial cell recruitment (Iba1) and myeloperoxidase (MPO) activity compared to normothermia controls.
- RLS-0071 demonstrated comparable efficacy to TH in reducing immune cell infiltration and oxidative damage.
Conclusions:
- RLS-0071 effectively decreases immune cell recruitment and oxidative damage in a neonatal HIE model.
- RLS-0071 shows potential as a novel pharmacotherapeutic agent for HIE, possibly offering an orthogonal treatment strategy.
- These findings highlight RLS-0071 as a promising candidate for treating HIE, addressing a significant unmet medical need.
Abstract:
Perinatal hypoxic-ischemic encephalopathy (HIE) is a major contributor to infant death and neurological injury worldwide. Both neuroglia and infiltrating peripheral immune cells contribute to inflammation and oxidative stress, which leads to neuronal loss and cerebral tissue necrosis in neonates with HIE. To date, there are no approved pharmacological interventions to treat inflammatory responses in infants affected by HIE. Therapeutic hypothermia (TH) remains the only effective treatment option. Therefore, novel pharmacotherapeutics that interrupt immune-mediated brain inflammation in HIE represent a promising target for intervention. To meet this unmet need, this study tested the hypothesis that a novel anti-inflammatory peptide, RLS-0071 (pegtarazimod), could modulate neuroinflammation in a neonatal rat model of HIE.RLS-0071 was evaluated in the acute stages of hypoxic-ischemic injury utilizing the well-established Vannucci rat pup model of HIE. Rat pups subject to hypoxia-ischemic brain insult received three interventions: normothermia, hypothermia, and RLS-0071. Histopathological effects were assessed via fluorescence microscopy of the hypoxic-ischemic induced cerebral infarct in the cortex at 24 and 48 hours after controlled oxygen deprivation.Increased surviving neurons were seen at 48 hours for RLS-0071 treatment compared with hypothermia treatment as assessed by neuronal nuclear protein (NeuN) staining. Ionized calcium-binding adaptor molecule 1 (Iba1)-positive microglial recruitment was reduced by fourfold in RLS-0071 treatment or hypothermia-treated rats between 24 and 48 hours, compared to normothermia controls. Likewise, myeloperoxidase (MPO) staining showed a twofold decrease in RLS-0071 or hypothermia-treated rats between 24 and 48 hours compared to normothermia controls.Our findings suggest that RLS-0071 decreases immune cell recruitment and oxidative damage to levels comparable to TH in an animal model of HIE. · No pharmacologic interventions for HIE currently exist.. · TH is the current standard of care.. · RLS-0071 increases neuron survival and lowers microglial cell influx in a HIE rat model.. · RLS-0071 limits oxidative damage in a HIE rat model.. · RLS-0071 may provide an orthogonal treatment for HIE..
