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Updated: Aug 21, 2026
Modeling Posthemorrhagic Hydrocephalus of Prematurity in Rats
Published on: March 28, 2025
Transforming growth factor-betas in a rat model of neonatal posthaemorrhagic hydrocephalus
S Cherian1, M Thoresen, I A Silver
1Department of Clinical Science (South Bristol), University of Bristol, Bristol, UK.
Insights
Transforming growth factor-betas (TGF-betas) and extracellular matrix deposition may contribute to posthaemorrhagic ventricular dilatation (PHVD) in premature infants. This study explored TGF-beta roles in a neonatal rat model of PHVD.
Area of Science:
- Neonatal Neurology
- Developmental Biology
- Molecular Pathology
Background:
- Posthaemorrhagic ventricular dilatation (PHVD) frequently complicates intraventricular hemorrhage in premature infants.
- Transforming growth factor-betas (TGF-betas) are polypeptides known for their potent desmoplastic properties.
- The precise mechanisms underlying PHVD development and maintenance remain incompletely understood.
Purpose of the Study:
- To investigate the role of TGF-betas in the etiology of PHVD.
- To utilize a newly developed neonatal rat model to study PHVD.
- To examine the expression of TGF-beta isoforms, MAP kinases, and extracellular matrix proteins in this model.
Main Methods:
- Neonatal rats received intraventricular injections of either citrated rat blood or artificial cerebrospinal fluid (ACSF).
- Immunohistochemistry was performed to assess the expression of TGF-beta1, -beta2, -beta3, phosphorylated p44/42 MAP kinases, and extracellular matrix proteins (laminin, vitronectin, fibronectin).
- Brains were analyzed 14 days post-injection.
Main Results:
- Ventricular dilatation occurred in a significant percentage of animals following both blood and ACSF injections.
- Periventricular TGF-beta1 and -beta2 immunoreactivity increased in injected animals, with higher levels in those with hydrocephalus.
- TGF-beta3 immunoreactivity was elevated specifically in hydrocephalic rats, and extracellular matrix protein deposition accompanied TGF-beta expression.
Conclusions:
- TGF-beta expression, particularly TGF-beta1 and -beta2, is upregulated following ventricular distension, irrespective of the injectant.
- Elevated TGF-beta3 and extracellular matrix deposition correlate with hydrocephalus development in this neonatal rat model.
- These findings suggest that TGF-betas and extracellular matrix remodeling may play a role in the pathogenesis and persistence of hydrocephalus after neonatal intraventricular hemorrhage.
Abstract:
Posthaemorrhagic ventricular dilatation (PHVD) is a common complication of intraventricular haemorrhage in premature infants. The aim of this study was to investigate the role of transforming growth factor-betas (TGF-betas), a family of polypeptides with potent desmoplastic properties, in the aetiology of PHVD in a newly developed neonatal rat model of this disorder. Pups were injected with citrated rat blood or artificial cerebrospinal fluid (ACSF) into alternate lateral ventricles on postnatal days 7 and 8. The brains were perfusion-fixed 14 days later and immunohistochemistry was performed for TGF-beta1, -beta2 and -beta3, p44/42 mitogen-activated protein (MAP) kinases, and the extracellular matrix proteins laminin, vitronectin and fibronectin. Ventricular dilatation occurred in 58.3% of animals injected with blood and 36.7% of those injected with ACSF. Periventricular immunoreactivity for TGF-beta1 and -beta2 increased in injected animals irrespective of the presence or absence of ventricular dilatation, although the levels of both isoforms tended to be higher in animals with hydrocephalus. TGF-beta3 immunoreactivity was elevated in hydrocephalic rats only. The immunolabelling for phosphorylated p44/42 MAP kinases rose in a pattern similar to that for TGF-beta1 and -beta2. Expression of TGF-betas was accompanied by deposition of the extracellular matrix proteins fibronectin, laminin and vitronectin. The changes caused by injection of ACSF were the same as those caused by injection of blood. Our results raise the possibility that expression of TGF-betas, together with extracellular matrix protein deposition, may be involved in the development and/or maintenance of hydrocephalus after ventricular distension due to haemorrhage in the neonate.
