Objective      To study the expression of aquaglyceroporin genes (AQP3

AQP7 and AQP9) in a sodium oleate-induced hepatocyte steatosis model and its significance.       Methods      Routinely cultured human HepG2 cells were used as controls

and steatosis of HepG2 cells was induced with sodium oleate to establish a nonalcoholic hepatocyte steatosis model. Hepatocyte steatosis and triglyceride level in hepatocytes were measured with oil red O staining. Expression of AQP3

AQP7 and AQP9 was detected by RT-PCR and Western blotting respectively at 0

12

24 and 48 h.       Results      Oil red O staining showed that hepatocyte steatosis occurred 12 h after HepG2 cells were treated with sodium oleate and aggravated with the stimulating time. The triglyceride level in hepatocytes was significantly higher at 48 h (79.76±0.75) than at 0 h (P0.05). The expression level of AQP3 mRNA was lower at 12 and 48 h (0.39±0.08) in model group than in control group (P0.05). The expression level of AQP7 mRNA was slightly higher in model group than in control group (P0.05). The expression level of AQP9 mRNA was higher at 12 h in model group (1.59±0.11) than in control group (P0.05). The expression level of AQP3 protein was lower at 12

24 (0.016±0.002) and 48 h (0.012±0.001) in model group than in control group (P0.05). No significant difference was found in expression of AQP7 protein between model group and control group (P0.05). The expression level of AQP9 protein was higher at 12

24 (0.050±0.002) and 48 h (0.079±0.002) than in control group (P0.05).       Conclusion      The expression of AQP3 is down-regulated while that of AQP9 is up-regulated in hepatocyte steatosis model

indicating that different types of aquaglyceroporins may be involved in hepatocyte steatosis via different mechanisms.