Volume 7 Supplement 1

54th Annual Meeting of the Society for Research into Hydrocephalus and Spina Bifida

Open Access

Acetazolamide affects Aquaporin 1 expression of cultured choroid plexus cells

  • Jogi V Pattisapu1Email author,
  • Pouya Ameli1,
  • Meenu Madan1,
  • Amin Yu1,
  • Srinu Chigurupathi1 and
  • Sic L Chan1
Cerebrospinal Fluid Research20107(Suppl 1):S33

https://doi.org/10.1186/1743-8454-7-S1-S33

Published: 15 December 2010

Background

Acetazolamide (AZA), the only drug generally approved for hydrocephalus, is effective in only 25-30% of patients, and its effect on basal fluid flow in choroid plexus (CP) is unknown. The drug reversibly inhibits Aquaporin 4 (AQP4), the most highly expressed ‘water pore’ in the brain, and it is postulated that it reduces CSF production by modulating the expression and/or function of AQP1 (mostly found in the apical membrane of CP). In this study, we sought to elucidate the direct effect of AZA on basal fluid flow in CP.

Materials and methods

CP tissues were harvested from 10-day Sprague-Dawley rat pups. CP cultures were grown to confluence in Transwell permeable supports and tested using: a) Kir 7.1 immunocytochemistry to confirm CP cell morphology; b) Lucifer Yellow assay and trans-epithelial electrical resistance (TEER) to determine level of confluence; c) fluid assays using TRITC-labeled Dextran to assay the direction and extent of fluid flow through the monolayers; d) expression of AQP1 protein by immunoblotting and immunocytochemistry.

Results

Immunblotting and immunocytochemical analyses showed that AQP1 protein level decreases rapidly with 10 um AZA treatment. The reduction of AQP1 protein was transient as its level returned to baseline 12 hours after AZA exposure. Transwell fluid assay indicated that the early loss of AQP protein is correlated with decreased basal fluid flow in CP.

Conclusions

The observed effect of AZA on AQP1 protein level suggests that AZA can directly modulate basal fluid flow in CP. The AZA induced effect in CP resulted in an initial fluid flow into the basolateral side of the transwells, with subsequent flow into the apical side of the CP membranes. Our results indicate that modulating AQP1 function via effectively targeted pharmaceuticals could potentially yield new treatments for hydrocephalus.

Declarations

Completing interest

The authors have no conflict of interest to declare.

Authors’ Affiliations

(1)
Burnett School of Biomedical Sciences, University of Central Florida College of Medicine Bldg 20

Copyright

© Pattisapu et al; licensee BioMed Central Ltd. 2010

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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