Abstract: Objective To observe the impact of sphingosine kinase (SPK), catalysatee of sphingosine 1-phosphate (S1P), on the glucose metabolism of the LO2 liver cell insulin resistance model. Methods LO2 cells were induced with insulin to establish insulin resistance, and the MTT staining method to detect impacts of insulin on LO2 cells proliferation; the glucose-hexokinase method to detect remnant glucose concentration variations in the media stimulated with insulin of varying concentrations, and S1P’s impact on blood glucose absorption of cells in the insulin resistance model; the oil red O staining method to detect the extent of steatosis, and the fluorescence double staining method to identify the changes of mitochondrial ROS in LO2 cells; and Western blot method to detect SPK1 protein expression. Results Compared with the control group, insulin concentrations of 10, 100, and 1000 nmol/L insulin had no significant impact on glucose uptake capacity (P>0.05). Following a 48-h induction with 1000 nmol/L insulin, with decreased insulin sensitivity index and establishment of the insulin resistance model. Compared with the control group, liquid droplets area in the model group was found with an increase, and mitochondrial ROS was found with a significant increase. At the same time, the expression of SPK1 protein also showed a trend of increase. S1P, when added in the model group, could significantly promote cellular uptake of glucose. Conclusion The LO2 liver cell model of insulin resistance was established with insulin induction. S1P may be able to promote glucose metabolism, prompting S1P may serve as a new target spot for screening hypoglycemic drugs for type-II diabetes patients.

Key words: SPK/S1P pathway, L02 cell, Insulin resistance, glucose metabolism