Repression of the Glucocorticoid Receptor Increases Hypoxic-Ischemic Brain Injury in the Male Neonatal Rat
Hypoxic-ischemic encephalopathy (HIE) resulting from asphyxia is the most common cause of neonatal brain damage and results in significant neurological sequelae, including cerebral palsy. The current therapeutic interventions are extremely limited in improving neonatal outcomes. The present study te...
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doaj-6aa73827539746b6a3e4d86137ca406a2020-11-25T02:34:58ZengMDPI AGInternational Journal of Molecular Sciences1422-00672019-07-012014349310.3390/ijms20143493ijms20143493Repression of the Glucocorticoid Receptor Increases Hypoxic-Ischemic Brain Injury in the Male Neonatal RatKatherine R. Knox-Concepcion0Johnny D. Figueroa1Richard E. Hartman2Yong Li3Lubo Zhang4Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USACenter for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA 92350, USADepartment of Psychology, Loma Linda University, Loma Linda, CA 92350, USALawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USALawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USAHypoxic-ischemic encephalopathy (HIE) resulting from asphyxia is the most common cause of neonatal brain damage and results in significant neurological sequelae, including cerebral palsy. The current therapeutic interventions are extremely limited in improving neonatal outcomes. The present study tests the hypothesis that the suppression of endogenous glucocorticoid receptors (GRs) in the brain increases hypoxic-ischemic (HI) induced neonatal brain injury and worsens neurobehavioral outcomes through the promotion of increased inflammation. A mild HI treatment of P9 rat pups with ligation of the right common carotid artery followed by the treatment of 8% O<sub>2</sub> for 60 min produced more significant brain injury with larger infarct size in female than male pups. Intracerebroventricular injection of GR siRNAs significantly reduced GR protein and mRNA abundance in the neonatal brain. Knockdown of endogenous brain GRs significantly increased brain infarct size after HI injury in male, but not female, rat pups. Moreover, GR repression resulted in a significant increase in inflammatory cytokines TNF-α and IL-10 at 6 h after HI injury in male pups. Male pups treated with GR siRNAs showed a significantly worsened reflex response and exhibited significant gait disturbances. The present study demonstrates that endogenous brain GRs play an important role in protecting the neonatal brain from HI induced injury in male pups, and suggests a potential role of glucocorticoids in sex differential treatment of HIE in the neonate.https://www.mdpi.com/1422-0067/20/14/3493glucocorticoidglucocorticoid receptorneuroprotectionRice–Vannuccineonatalhypoxic-ischemicencephalopathybrainneuroinflammationfunctional outcomes |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Katherine R. Knox-Concepcion Johnny D. Figueroa Richard E. Hartman Yong Li Lubo Zhang |
spellingShingle |
Katherine R. Knox-Concepcion Johnny D. Figueroa Richard E. Hartman Yong Li Lubo Zhang Repression of the Glucocorticoid Receptor Increases Hypoxic-Ischemic Brain Injury in the Male Neonatal Rat International Journal of Molecular Sciences glucocorticoid glucocorticoid receptor neuroprotection Rice–Vannucci neonatal hypoxic-ischemic encephalopathy brain neuroinflammation functional outcomes |
author_facet |
Katherine R. Knox-Concepcion Johnny D. Figueroa Richard E. Hartman Yong Li Lubo Zhang |
author_sort |
Katherine R. Knox-Concepcion |
title |
Repression of the Glucocorticoid Receptor Increases Hypoxic-Ischemic Brain Injury in the Male Neonatal Rat |
title_short |
Repression of the Glucocorticoid Receptor Increases Hypoxic-Ischemic Brain Injury in the Male Neonatal Rat |
title_full |
Repression of the Glucocorticoid Receptor Increases Hypoxic-Ischemic Brain Injury in the Male Neonatal Rat |
title_fullStr |
Repression of the Glucocorticoid Receptor Increases Hypoxic-Ischemic Brain Injury in the Male Neonatal Rat |
title_full_unstemmed |
Repression of the Glucocorticoid Receptor Increases Hypoxic-Ischemic Brain Injury in the Male Neonatal Rat |
title_sort |
repression of the glucocorticoid receptor increases hypoxic-ischemic brain injury in the male neonatal rat |
publisher |
MDPI AG |
series |
International Journal of Molecular Sciences |
issn |
1422-0067 |
publishDate |
2019-07-01 |
description |
Hypoxic-ischemic encephalopathy (HIE) resulting from asphyxia is the most common cause of neonatal brain damage and results in significant neurological sequelae, including cerebral palsy. The current therapeutic interventions are extremely limited in improving neonatal outcomes. The present study tests the hypothesis that the suppression of endogenous glucocorticoid receptors (GRs) in the brain increases hypoxic-ischemic (HI) induced neonatal brain injury and worsens neurobehavioral outcomes through the promotion of increased inflammation. A mild HI treatment of P9 rat pups with ligation of the right common carotid artery followed by the treatment of 8% O<sub>2</sub> for 60 min produced more significant brain injury with larger infarct size in female than male pups. Intracerebroventricular injection of GR siRNAs significantly reduced GR protein and mRNA abundance in the neonatal brain. Knockdown of endogenous brain GRs significantly increased brain infarct size after HI injury in male, but not female, rat pups. Moreover, GR repression resulted in a significant increase in inflammatory cytokines TNF-α and IL-10 at 6 h after HI injury in male pups. Male pups treated with GR siRNAs showed a significantly worsened reflex response and exhibited significant gait disturbances. The present study demonstrates that endogenous brain GRs play an important role in protecting the neonatal brain from HI induced injury in male pups, and suggests a potential role of glucocorticoids in sex differential treatment of HIE in the neonate. |
topic |
glucocorticoid glucocorticoid receptor neuroprotection Rice–Vannucci neonatal hypoxic-ischemic encephalopathy brain neuroinflammation functional outcomes |
url |
https://www.mdpi.com/1422-0067/20/14/3493 |
work_keys_str_mv |
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