Objective      To construct a recombinant plasmid of human aquaglyceroporin 9 (AQP9)

to examine its expression in liver cell L-02 and to detect its effect on cellular models of nonalcoholic fatty liver disease (NAFLD).       Methods      Total mRNA was extracted from human hepatic tissues

and human AQP9 gene was amplified by RT-PCR. AQP9 gene was then inserted into pEGFP-N1 to construct recombinant plasmid pEGFP-N1-AQP9

which was transfected into L-02 cells. The transfection was detected by fluorescent microscopy

and the expression of AQP9 gene was detected by RT-PCR and Western blotting. The effect of AQP9 on NAFLD cellular models was examined by oil red O staining and the determination of triglycerides (TG)

free fatty acids (FFAs) and glycerol contents.       Results      Recombinant plasmid pEGFP-N1-AQP9 was successfully constructed

and AQP9 expression could be detected after L-02 cells were transfected with pEGFP-N1-AQP9. The oil red O staining showed that the intracellular lipid contents were significantly higher in the oleic acid/pEGFP-N1-AQP9 group than in the oleic acid group (P0.01). The intracellular TG

FFAs and glycerol contents in the oleic acid/pEGFP-N1-AQP9 group were 5.435±0.337

2.016±0.144 and 1.485±0.113 mmol/L

respectively

while those in the oleic acid group were 3.218±0.220

1.538±0.193 and 1.024±0.148 mmol/L

respectively. It indicated that the upregulation of AQP9 could aggravate the degree of steatosis.       Conclusion      AQP9 abnormal upregulation can lead to or aggravate NAFLD.