INTRODUCTION: 3% Sodium Chloride (NaCl) treatment has been shown to reduce brain edema and inhibited brain aquaporin 4 (AQP4) expression in bacterial meningitis induced by Escherichia coli. Lipopolysaccharide (LPS) is the main pathogenic component of Escherichia coli. We aimed to explore the effect of 3% NaCl in mouse brain edema induced by LPS, as well as to elucidate the potential mechanisms of action.METHODS: 3% NaCl was used to treat cerebral edema induced by LPS in mice in vivo. Measurements of brain water content, interleukin-1 beta (IL-1beta), tumor necrosis factor alfa (TNFalpha), immunoglobulin G (IgG), AQP4 mRNA and protein in brain tissues were performed. IL-1beta, 3% NaCl and Calphostin C (a specifi... More
INTRODUCTION: 3% Sodium Chloride (NaCl) treatment has been shown to reduce brain edema and inhibited brain aquaporin 4 (AQP4) expression in bacterial meningitis induced by Escherichia coli. Lipopolysaccharide (LPS) is the main pathogenic component of Escherichia coli. We aimed to explore the effect of 3% NaCl in mouse brain edema induced by LPS, as well as to elucidate the potential mechanisms of action.METHODS: 3% NaCl was used to treat cerebral edema induced by LPS in mice in vivo. Measurements of brain water content, interleukin-1 beta (IL-1beta), tumor necrosis factor alfa (TNFalpha), immunoglobulin G (IgG), AQP4 mRNA and protein in brain tissues were performed. IL-1beta, 3% NaCl and Calphostin C (a specific inhibitor of protein kinase C) were used to treat the primary astrocytes in vitro. Measurements of AQP4 mRNA and protein in astrocytes were performed. Differences in various groups were determined by one-way analysis of variance.RESULTS: 3% NaCl attenuated the increase of brain water content, IL-1beta, TNFalpha, IgG, AQP4 mRNA and protein in brain tissues induced by LPS. 3% NaCl inhibited the increase of AQP4 mRNA and protein in astrocytes induced by IL-1beta in vitro. Calphostin C blocked the decrease of AQP4 mRNA and protein in astrocytes induced by 3% NaCl in vitro.CONCLUSIONS: Osmotherapy with 3% NaCl ameliorated LPS-induced cerebral edema in vivo. In addition to its osmotic force, 3% NaCl exerted anti-edema effects possibly through down-regulating the expression of proinflammatory cytokines (IL-1beta and TNFalpha) and inhibiting the expression of AQP4 induced by proinflammatory cytokine. 3% NaCl attenuated the expression of AQP4 through activation of protein kinase C in astrocytes.
