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Gene interference regulates aquaporin-4 expression in swollen tissue of rats with cerebral ischemic edema: Correlation with variation in apparent diffusion coefficient.

Hu H, Lu H, He Z, Han X, Chen J, Tu R - Neural Regen Res (2012)

Bottom Line: In the RNA interference group, during 0.25-6 hours after injection of siRNA- aquaporin-4 solution, the relative apparent diffusion coefficient slightly fluctuated and aquaporin-4 expression was upregulated; during 0.5-4 hours, the relative apparent diffusion coefficient was significantly higher, while aquaporin-4 expression was significantly lower when compared with the control group, and intracellular edema was markedly reduced; at 0.25 and 6 hours, the relative apparent diffusion coefficient and aquaporin-4 expression were similar when compared with the control group; obvious angioedema remained at 6 hours.Pearson's correlation test results showed that aquaporin-4 expression was negatively correlated with the apparent diffusion coefficient (r = -0.806, P < 0.01).These findings suggest that upregulated aquaporin-4 expression is likely to be the main molecular mechanism of intracellular edema and may be the molecular basis for decreased relative apparent diffusion coefficient.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Affiliated Haikou Hospital of Xiangya School of Medicine, Central South University (Haikou Municipal People's Hospital), Haikou 570208, Hainan Province, China.

ABSTRACT
To investigate the effects of mRNA interference on aquaporin-4 expression in swollen tissue of rats with ischemic cerebral edema, and diagnose the significance of diffusion-weighted MRI, we injected 5 μL shRNA- aquaporin-4 (control group) or siRNA- aquaporin-4 solution (1:800) (RNA interference group) into the rat right basal ganglia immediately before occlusion of the middle cerebral artery. At 0.25 hours after occlusion of the middle cerebral artery, diffusion-weighted MRI displayed a high signal; within 2 hours, the relative apparent diffusion coefficient decreased markedly, aquaporin-4 expression increased rapidly, and intracellular edema was obviously aggravated; at 4 and 6 hours, the relative apparent diffusion coefficient slowly returned to control levels, aquaporin-4 expression slightly increased, and angioedema was observed. In the RNA interference group, during 0.25-6 hours after injection of siRNA- aquaporin-4 solution, the relative apparent diffusion coefficient slightly fluctuated and aquaporin-4 expression was upregulated; during 0.5-4 hours, the relative apparent diffusion coefficient was significantly higher, while aquaporin-4 expression was significantly lower when compared with the control group, and intracellular edema was markedly reduced; at 0.25 and 6 hours, the relative apparent diffusion coefficient and aquaporin-4 expression were similar when compared with the control group; obvious angioedema remained at 6 hours. Pearson's correlation test results showed that aquaporin-4 expression was negatively correlated with the apparent diffusion coefficient (r = -0.806, P < 0.01). These findings suggest that upregulated aquaporin-4 expression is likely to be the main molecular mechanism of intracellular edema and may be the molecular basis for decreased relative apparent diffusion coefficient. Aquaporin-4 gene interference can effectively inhibit the upregulation of aquaporin-4 expression during the stage of intracellular edema with time-effectiveness. Moreover, diffusion-weighted MRI can accurately detect intracellular edema.

No MeSH data available.


Related in: MedlinePlus

Aquaporin-4 (AQP4) mRNA expression in rat right basal ganglia tissue (infarct site).Data are expressed as mean ± SD of six rats at each time point. Repeated-measures analysis of variance was used.There was no significant difference in AQP4 mRNA expression between the control group and ischemia group (P > 0.05), as well as between the control group and RNA interference (RNAi) group at 0.25 hours and 6 hours (P > 0.05).AQP4 mRNA expression was significantly higher in the control group than in the RNA interference group during 0.5–4 hours (P < 0.05).
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Figure 7: Aquaporin-4 (AQP4) mRNA expression in rat right basal ganglia tissue (infarct site).Data are expressed as mean ± SD of six rats at each time point. Repeated-measures analysis of variance was used.There was no significant difference in AQP4 mRNA expression between the control group and ischemia group (P > 0.05), as well as between the control group and RNA interference (RNAi) group at 0.25 hours and 6 hours (P > 0.05).AQP4 mRNA expression was significantly higher in the control group than in the RNA interference group during 0.5–4 hours (P < 0.05).

Mentions: Real-time PCR showed that there was no significant difference in aquaporin-4 mRNA expression between the control and ischemia groups (P > 0.05). In the control group, aquaporin-4 mRNA expression increased quickly within 2 hours and slowly during 4–6 hours. In the RNA interference group, aquaporin-4 mRNA expression was significantly up regulated during 0.25–4 hours. Aquaporin-4 mRNA expression significantly decreased in the RNA interference group compared with the control group during 0.5–4 hours (P < 0.05; Figure 7).


Gene interference regulates aquaporin-4 expression in swollen tissue of rats with cerebral ischemic edema: Correlation with variation in apparent diffusion coefficient.

Hu H, Lu H, He Z, Han X, Chen J, Tu R - Neural Regen Res (2012)

Aquaporin-4 (AQP4) mRNA expression in rat right basal ganglia tissue (infarct site).Data are expressed as mean ± SD of six rats at each time point. Repeated-measures analysis of variance was used.There was no significant difference in AQP4 mRNA expression between the control group and ischemia group (P > 0.05), as well as between the control group and RNA interference (RNAi) group at 0.25 hours and 6 hours (P > 0.05).AQP4 mRNA expression was significantly higher in the control group than in the RNA interference group during 0.5–4 hours (P < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4308770&req=5

Figure 7: Aquaporin-4 (AQP4) mRNA expression in rat right basal ganglia tissue (infarct site).Data are expressed as mean ± SD of six rats at each time point. Repeated-measures analysis of variance was used.There was no significant difference in AQP4 mRNA expression between the control group and ischemia group (P > 0.05), as well as between the control group and RNA interference (RNAi) group at 0.25 hours and 6 hours (P > 0.05).AQP4 mRNA expression was significantly higher in the control group than in the RNA interference group during 0.5–4 hours (P < 0.05).
Mentions: Real-time PCR showed that there was no significant difference in aquaporin-4 mRNA expression between the control and ischemia groups (P > 0.05). In the control group, aquaporin-4 mRNA expression increased quickly within 2 hours and slowly during 4–6 hours. In the RNA interference group, aquaporin-4 mRNA expression was significantly up regulated during 0.25–4 hours. Aquaporin-4 mRNA expression significantly decreased in the RNA interference group compared with the control group during 0.5–4 hours (P < 0.05; Figure 7).

Bottom Line: In the RNA interference group, during 0.25-6 hours after injection of siRNA- aquaporin-4 solution, the relative apparent diffusion coefficient slightly fluctuated and aquaporin-4 expression was upregulated; during 0.5-4 hours, the relative apparent diffusion coefficient was significantly higher, while aquaporin-4 expression was significantly lower when compared with the control group, and intracellular edema was markedly reduced; at 0.25 and 6 hours, the relative apparent diffusion coefficient and aquaporin-4 expression were similar when compared with the control group; obvious angioedema remained at 6 hours.Pearson's correlation test results showed that aquaporin-4 expression was negatively correlated with the apparent diffusion coefficient (r = -0.806, P < 0.01).These findings suggest that upregulated aquaporin-4 expression is likely to be the main molecular mechanism of intracellular edema and may be the molecular basis for decreased relative apparent diffusion coefficient.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Affiliated Haikou Hospital of Xiangya School of Medicine, Central South University (Haikou Municipal People's Hospital), Haikou 570208, Hainan Province, China.

ABSTRACT
To investigate the effects of mRNA interference on aquaporin-4 expression in swollen tissue of rats with ischemic cerebral edema, and diagnose the significance of diffusion-weighted MRI, we injected 5 μL shRNA- aquaporin-4 (control group) or siRNA- aquaporin-4 solution (1:800) (RNA interference group) into the rat right basal ganglia immediately before occlusion of the middle cerebral artery. At 0.25 hours after occlusion of the middle cerebral artery, diffusion-weighted MRI displayed a high signal; within 2 hours, the relative apparent diffusion coefficient decreased markedly, aquaporin-4 expression increased rapidly, and intracellular edema was obviously aggravated; at 4 and 6 hours, the relative apparent diffusion coefficient slowly returned to control levels, aquaporin-4 expression slightly increased, and angioedema was observed. In the RNA interference group, during 0.25-6 hours after injection of siRNA- aquaporin-4 solution, the relative apparent diffusion coefficient slightly fluctuated and aquaporin-4 expression was upregulated; during 0.5-4 hours, the relative apparent diffusion coefficient was significantly higher, while aquaporin-4 expression was significantly lower when compared with the control group, and intracellular edema was markedly reduced; at 0.25 and 6 hours, the relative apparent diffusion coefficient and aquaporin-4 expression were similar when compared with the control group; obvious angioedema remained at 6 hours. Pearson's correlation test results showed that aquaporin-4 expression was negatively correlated with the apparent diffusion coefficient (r = -0.806, P < 0.01). These findings suggest that upregulated aquaporin-4 expression is likely to be the main molecular mechanism of intracellular edema and may be the molecular basis for decreased relative apparent diffusion coefficient. Aquaporin-4 gene interference can effectively inhibit the upregulation of aquaporin-4 expression during the stage of intracellular edema with time-effectiveness. Moreover, diffusion-weighted MRI can accurately detect intracellular edema.

No MeSH data available.


Related in: MedlinePlus