Roles of aquaporins and matrix metalloproteinases in mouse brain edema formation induced by subacute exposure to 1,2-dichloroethane.

The aim of this study was to explore the effects of 1,2-dichloroethane (1,2-DCE) on expression of aquaporins (AQPs) and matrix metalloproteinases (MMPs) in the process of brain edema formation. Two parts were included in this study, establishment of animal model of brain edema, and mechanism of brain edema induced by subacute exposure to 1,2-DCE. In part one, mice were exposed to 0, 1.1, 1.2 or 1.3g/m(3) 1,2-DCE, 3.5h per day for 3days. Pathological analysis and water content detection in the brain were examined. In part two, mice were exposed to 1.2g/m(3) 1,2-DCE, 3.5h per day for 1, 2 or 3days, named group D, E and F, respectively. Expression of AQP4, MMP2 and MMP9 in the brain was determined by immunochemical staining, western blot and real time PCR. According to the results of part one, the 1.2g/m(3) dose was chosen for part two, a follow-up time-course study. In part two, protein expression of MMP2 and MMP9 in group F, and AQP4 in group E and F significantly increased compared to the control. Similarly, mRNA levels of AQP4 in group F, and MMP9 in group E and F significantly increased. Our results suggested that exposure to 1,2-DCE might up-regulate the expression of AQP4 protein and MMP9 mRNA at the early phase of brain edema, and AQP4 may play an important role in the brain edema formation.