Regulation of Choroid Plexus Bicarbonate Transporters Following Intraventricular Hemorrhage in Mice

Laura Øllegaard Johnsen1, Rasmus Herløw1, Rasmus West Knopper2

  • 1Department of Biomedicine, Aarhus University, Aarhus, Denmark.

PubMed

Insights

Two mouse models of intraventricular hemorrhage were studied. Both models caused ventricular enlargement, but through distinct molecular pathways, indicating a milder pathophysiology in mice.

Area of Science:

  • Neuroscience
  • Physiology
  • Biochemistry

Background:

  • Posthemorrhagic hydrocephalus, a complication of intraventricular hemorrhage, causes enlarged brain ventricles and increased intracranial pressure due to cerebrospinal fluid (CSF) accumulation.
  • Understanding the pathophysiology of this condition is crucial for developing effective treatments.

Purpose of the Study:

  • To investigate two mouse models of intraventricular hemorrhage (IVH): lysed red blood cell (LRBC) injection and autologous full blood injection.
  • To analyze the molecular and biochemical responses, CSF secretion, and ventricular volume changes in these models.

Main Methods:

  • Ventriculo-cisternal perfusion and magnetic resonance imaging (MRI) were used to assess CSF secretion and ventricular volume.
  • Immunoblotting, RT-qPCR, flame photometry, and blood-gas measurements were employed for molecular and biochemical analyses.

Main Results:

  • LRBC injection transiently altered choroid plexus bicarbonate transporter (Ncbe) expression.
  • Full blood injection transiently increased mRNA levels of NBCn1 and Ncbe without altering protein expression.
  • Both models demonstrated increased CSF volume (70-73%) and ventricular enlargement (30% in LRBC model) without affecting CSF secretion rate.

Conclusions:

  • Both LRBC and full-blood injections induce ventricular enlargement in mice, mediated by different molecular responses.
  • Murine models of IVH exhibit a milder form of pathophysiology compared to other species, as sustained CSF hypersecretion was not replicated.