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Updated: Aug 3, 2025
The Hypoxic Ischemic Encephalopathy Model of Perinatal Ischemia
Published on: November 19, 2008
Inter-Alpha Inhibitor Proteins Modify the Microvasculature after Exposure to Hypoxia-Ischemia and Hypoxia in Neonatal
Francesco Girolamo1, Yow-Pin Lim2,3, Daniela Virgintino1
1Department of Translational Biomedicines and Neuroscience (DiBraiN), University of Bari School of Medicine, 70124 Bari, Italy.
Insights
Inter-alpha inhibitor proteins (IAIPs) impact neonatal brain microvasculature following hypoxia-ischemia (HI) and hypoxia (H) injury. These effects show sex-related differences, influencing laminin content and angiogenic responses.
Area of Science:
- Neonatal neuroscience
- Vascular biology
- Neuroprotection
Background:
- Neonatal brain injury from hypoxia-ischemia (HI) and hypoxia (H) is a significant concern.
- Inter-alpha inhibitor proteins (IAIPs) are known to reduce neonatal brain injury post-HI.
- The specific impact of IAIPs on the developing brain microvasculature after HI has not been previously investigated.
Purpose of the Study:
- To investigate the effects of human IAIPs (hIAIPs) on the brain microvasculature in neonatal rats exposed to HI or H.
- To determine if hIAIPs modulate key microvascular parameters including laminin staining, vessel length, and tunneling nanotube (TNT) density.
- To explore potential sex-related differences in the response to hIAIP treatment.
Main Methods:
- Neonatal rats (postnatal day 7) were subjected to sham treatment or HI (right carotid artery ligation and 8% oxygen for 90 min).
- hIAIPs (30 mg/kg) or placebo were administered at 0, 24, and 48 hours post-HI/H.
- Brains were analyzed 72 hours post-HI/H using laminin immunohistochemistry to quantify laminin-stained area, cumulative microvessel length, and TNT density.
Main Results:
- hIAIPs significantly affected the percentage of laminin-stained area following HI/H.
- Cumulative microvessel length was influenced by hIAIPs after H, but not after HI.
- TNT density was altered by hIAIPs in female rats but not in male rats, indicating sex-specific effects.
Conclusions:
- hIAIPs modify the microvasculature in neonatal rats following HI and H exposure, impacting laminin content and angiogenic processes.
- The study reveals sex-related differential effects of hIAIPs on the neonatal brain microvasculature.
- These findings suggest IAIPs as a potential therapeutic agent with sex-specific implications for neonatal brain injury.
Abstract:
Microvasculature develops during early brain development. Hypoxia-ischemia (HI) and hypoxia (H) predispose to brain injury in neonates. Inter-alpha inhibitor proteins (IAIPs) attenuate injury to the neonatal brain after exposure to HI. However, the effects of IAIPs on the brain microvasculature after exposure to HI have not been examined in neonates. Postnatal day-7 rats were exposed to sham treatment or right carotid artery ligation and 8% oxygen for 90 min. HI comprises hypoxia (H) and ischemia to the right hemisphere (HI-right) and hypoxia to the whole body, including the left hemisphere (H-left). Human IAIPs (hIAIPs, 30 mg/kg) or placebo were injected immediately, 24 and 48 h after HI/H. The brains were analyzed 72 h after HI/H to determine the effects of hIAIPs on the microvasculature by laminin immunohistochemistry and calculation of (1) the percentage area stained by laminin, (2) cumulative microvessel length, and (3) density of tunneling nanotubes (TNTs), which are sensitive indicators of the earliest phases of neo-vascularization/collateralization. hIAIPs mainly affected the percent of the laminin-stained area after HI/H, cumulative vessel length after H but not HI, and TNT density in females but not males. hIAIPs modify the effects of HI/H on the microvasculature after brain injury in neonatal rats and exhibit sex-related differential effects. Our findings suggest that treatment with hIAIPs after exposure to H and HI in neonatal rats affects the laminin content of the vessel basal lamina and angiogenic responses in a sex-related fashion.
