KHK gene knockdown prevents the fructose-induced increases in cellular pyruvate and ATP level as well as dopamine release from the N2a cells. Representative immunofluorescence images showing distribution of KHK in the N2a cells (A) on day 7 after the lentiviral transfection of small hairpin RNA of KHK (KHK shRNA) or control shRNA; as well as changes in KHK mRNA (B), cellular pyruvate (C) and ATP contents (D), and dopamine levels in the culture medium (E), detected at 72 hours after the administration of different concentrations of fructose (0, 12.5, 25, or 50 μM) to the culture medium of the KHK shRNA or control shRNA-transfected N2a cells. Values are mean ± SEM of quadruplicate analyses. *P < 0.05 versus control (0 μM fructose) group and #P < 0.05 versus CONTROL shRNA group in the post hoc Tukey’s multiple range tests. WT, wild type N2a cells. 4’,6-diamidino-2-phenylindole (DAPI) was used to identify nucleus in the cultured cells.