Change in the activity of glucosylceramide synthase in human hepatoma cell line with hepatitis B virus infection in vitro / 临床肝胆病杂志

ABSTRACT

ObjectiveTo investigate the change in the activity of glucosylceramide synthase, the key enzyme in glycosphingolipid metabolism and synthesis, in Huh7 cells infected by hepatitis B virus (HBV) in vitro. MethodsBlood samples were collected from nine previously untreated patients with acute hepatitis B who attended Department of Infectious Diseases, The First Hospital of Lanzhou University, from June to August, 2019, and the blood samples collected from seven healthy individuals who underwent physical examination were established as control. Huh7 cells were inoculated with the high-copy HBV particles (＞9.9×107 IU/ml) in the serum of patients with HBV infection (infection group), and Huh7 cells co-cultured with the serum of healthy individuals were established as control group. The expression levels of HBsAg and HBV DNA in the cytoplasm of HBV-infected Huh7 cells were measured, and the correlation between GCS activity and virus was analyzed. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups, and a Pearson correlation analysis was performed. ResultsCompared with the control group, the infection group had a significant reduction in the number of cells, an increase in cell volume, and cell membrane fragmentation. The infection group had a significant increase in the expression of HBsAg in cytoplasm at 4 hours, 8 hours, 2 days, and 5 days after infection (P＜0.05); the expression level of HBV DNA tended to increase significantly from 4 hours after infection to 8 hours, 2 days, and 5 days after infection (16.67±11.55 IU/ml vs 112.01±25.94 IU/ml/328.01±10350 IU/ml/101.60±49.84 IU/ml, P＜0.001), with the highest level at 2 days after infection. During HBV infection, the activity of GCS gradually increased with the increase in viral replication from 4 hours after infection (126.21±9.59 IU/ml) and reached a peak at 2 days after infection (226.53±36.27 IU/ml), with a significant difference between the infection group and the control group at 2 days after infection (226.53±36.27 IU/ml vs 136.50±1544 IU/ml, t=3.956, P=0.016 7). The activity of GCS was positively correlated with HBV DNA level (r=0.576 8, P=0047 1). ConclusionHuh7 cells are successfully infected with the high-copy HBV particles in the serum of patients with HBV infection, which mimics the characteristics of HBV infection in vitro to a certain degree. The activity of GCS may be associated with HBV infection, suggesting that glycosphingolipid synthesis and metabolism may be closely associated with HBV.