Pregnancy‐induced up‐regulation of aquaporin‐4 protein in brain and its role in eclampsia
- 1 December 2004
- journal article
- review article
- Published by Wiley in The FASEB Journal
- Vol. 19 (2), 170-175
- https://doi.org/10.1096/fj.04-1901hyp
Abstract
Neurologic complications of eclampsia are thought to be similar to hypertensive encephalopathy in which an acute, excessive elevation in blood pressure causes blood-brain barrier (BBB) disruption and edema formation. Because women who develop eclampsia are in general normotensive and asymptomatic prior to pregnancy, we hypothesized that pregnancy alone predisposes the brain to edema formation by up-regulation of aquaporin 4 (AQP4), a water channel in the brain that has been shown to positively correlate with edema formation. To test this hypothesis, we compared localization (immunohistochemistry), mRNA (RT-PCR), and protein levels (Western analysis) of AQP4 in brains from Sprague Dawley rats that were nonpregnant (NP, proestrous), mid-pregnant (MP, days 9–10), late-pregnant (LP, days 19–20), and postpartum (PP, days 3–4). AQP4 mRNA was detected in the brains of all the animals and was localized primarily around the brain parenchymal blood vessels, strongly implicating its role in BBB function. Western analysis revealed that the major AQP4 band at ∼32 kDa was significantly elevated in MP, LP, and PP animals compared with NP by 9-, 22-, and 17-fold, respectively. These results suggest that pregnancy and the postpartum state up-regulate AQP4 protein located around the intraparenchymal blood vessels, a consequence that could promote edema formation when blood pressure is acutely and excessively elevated, as during eclampsia.—Quick, A. M., Cipolla, M. J. Pregnancy-induced up-regulation of aquaporin-4 protein in brain and its role in eclampsia.Keywords
Funding Information
- National Institutes of Health (P20 RR16435)
- Totman Medical Research Trust, University of Vermont
This publication has 32 references indexed in Scilit:
- Alpha syntrophin deletion removes the perivascular but not the endothelial pool of aquaporin‐4 at the blood‐brain barrier and delays the development of brain edema in an experimental model of acute hyponatremiaThe FASEB Journal, 2004
- The molecular basis of water transport in the brainNature Reviews Neuroscience, 2003
- Aquaporin water channels and endothelial cell function*Journal of Anatomy, 2002
- Physiological importance of aquaporin water channelsAnnals of Medicine, 2002
- Immunolocalization of AQP9 in Liver, Epididymis, Testis, Spleen, and BrainBiochemical and Biophysical Research Communications, 2000
- Heterotetrameric Composition of Aquaporin-4 Water ChannelsBiochemistry, 1999
- Differential Upregulation of Aquaporin-4 mRNA Expression in Reactive Astrocytes after Brain Injury: Potential Role in Brain EdemaNeurobiology of Disease, 1999
- Upregulation of aquaporin 2 water channel expression in pregnant rats.JCI Insight, 1998
- Requirement of Human Renal Water Channel Aquaporin-2 for Vasopressin-dependent Concentration of UrineScience, 1994
- Astrocytes induce blood–brain barrier properties in endothelial cellsNature, 1987