TY - JOUR
T1 - Fluid-percussion brain injury induces changes in aquaporin channel expression
AU - Oliva, A. A.
AU - Kang, Y.
AU - Truettner, J. S.
AU - Sanchez-Molano, J.
AU - Furones, C.
AU - Yool, A. J.
AU - Atkins, C. M.
N1 - Funding Information:
This work was supported by The Miami Project to Cure Paralysis , The Buoniconti Fund to Cure Paralysis , and the Channel 7 Children's Research Foundation , Australia. We thank Dr. C. Falo for scientific input, Dr. G. Flynn for providing AqB013, and Drs. Helen Bramlett and Michael Norenberg for critical reading of the manuscript.
PY - 2011/4/28
Y1 - 2011/4/28
N2 - Edema, the accumulation of excess fluid, is a major pathological change in the brain that contributes significantly to pathology and mortality after moderate to severe brain injury. Edema is regulated by aquaporin (AQP) channels which transport water across cellular membranes. Six AQPs are found in the brain (1, 3, 4, 5, 8, and 9), and previous studies have found that AQP4 is regulated after traumatic brain injury (TBI). To further understand how AQPs contribute to brain edema, we investigated whether expression of AQP1, 3, and 9 are also regulated after TBI. Adult male Sprague Dawley rats received moderate parasagittal fluid-percussion brain injury (FPI) or sham surgery. After induction of FPI, the injured, ipsilateral parietal cortex and hippocampus were dissected and analyzed by Western blotting. We observed a small decrease in AQP3 and 4 levels at 7 days after FPI in the ipsilateral, parietal cortex. Both AQP1 and 9 significantly increased within 30 min post-injury and remained elevated for up to 6 h in the ipsilateral, parietal cortex. Aqp1 and 9 mRNA levels were also significantly increased at 30 min post-FPI. Administration of an AQP1 and 4 antagonist, AqB013, non-significantly increased brain water content in sham, non-injured animals, and did not prevent edema formation 24 h after trauma in either the parietal cortex or hippocampus. These results indicate that Aqp1 and 9 mRNA and protein levels increase after moderate parasagittal FPI and that an inhibitor of AQP1 and 4 does not decrease edema after moderate parasagittal FPI.
AB - Edema, the accumulation of excess fluid, is a major pathological change in the brain that contributes significantly to pathology and mortality after moderate to severe brain injury. Edema is regulated by aquaporin (AQP) channels which transport water across cellular membranes. Six AQPs are found in the brain (1, 3, 4, 5, 8, and 9), and previous studies have found that AQP4 is regulated after traumatic brain injury (TBI). To further understand how AQPs contribute to brain edema, we investigated whether expression of AQP1, 3, and 9 are also regulated after TBI. Adult male Sprague Dawley rats received moderate parasagittal fluid-percussion brain injury (FPI) or sham surgery. After induction of FPI, the injured, ipsilateral parietal cortex and hippocampus were dissected and analyzed by Western blotting. We observed a small decrease in AQP3 and 4 levels at 7 days after FPI in the ipsilateral, parietal cortex. Both AQP1 and 9 significantly increased within 30 min post-injury and remained elevated for up to 6 h in the ipsilateral, parietal cortex. Aqp1 and 9 mRNA levels were also significantly increased at 30 min post-FPI. Administration of an AQP1 and 4 antagonist, AqB013, non-significantly increased brain water content in sham, non-injured animals, and did not prevent edema formation 24 h after trauma in either the parietal cortex or hippocampus. These results indicate that Aqp1 and 9 mRNA and protein levels increase after moderate parasagittal FPI and that an inhibitor of AQP1 and 4 does not decrease edema after moderate parasagittal FPI.
KW - Aquaporin
KW - Edema
KW - Fluid-percussion
KW - Traumatic brain injury
KW - Water channel
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U2 - 10.1016/j.neuroscience.2011.02.020
DO - 10.1016/j.neuroscience.2011.02.020
M3 - Article
C2 - 21329742
AN - SCOPUS:79953173197
VL - 180
SP - 272
EP - 279
JO - Neuroscience
JF - Neuroscience
SN - 0306-4522
ER -