Differential proteomic screening of plasma exosomes before and after magnesium isoglycyrrhizinate treatment in chronic hepatitis B

Abstract

Objective: To screen the differential proteomic of plasma exosomes before and after magnesium isoglycyrrhizinate (MgIG) treatment in chronic hepatitis B patients. Methods: Plasma samples were collected from 36 cases with chronic hepatitis B before and after MgIG treatment (2 ml/case). Plasma exosomes were extracted by ultracentrifugation. Exosomal particles concentration and inner diameter were detected by Nanosight NS300 particle size analyzer. Three cases of plasma exosomes were randomly selected before and after MgIG treatment. Proteins were extracted after lysis and digested with trypsin. Label-free differential proteomics analysis was performed by liquid chromatography-tandem mass spectrometry to screen out differential proteins that changed more than 1.5 times. Enzyme linked immunosorbent assay (ELISA) was used to verify the quantitative differential protein expression (n = 30). Measurement data were compared by paired sample t-test. Results: The average particle concentration of the extracted exosomes was 2.2×10(9)/ml, and the average size was (107 ± 52) nm, which was consistent with the theoretical value of plasma exosome size, proving that the plasma exosomes were successfully extracted. Proteomics results showed that before and after MgIG treatment in chronic hepatitis B patients, a total of 153 differentially expressed proteins were screened, including 85 up-regulated and 68 down-regulated proteins. Enzyme-linked immunosorbent assay results showed that compared with the MgIG before and after treatment group of chronic hepatitis B patients, the differences in the concentrations of hepatocyte growth factor activator and hepatocyte growth factor like protein in plasma exosomes were statistically significant (P < 0.05). Hepatocyte growth factor activator concentration in the plasma exosomes before and after MgIG treatment group was (45.9 ± 9.4) μg/ml and (13.9 ± 2.0) μg/ml, respectively, and it was down-regulated by about 3 times. Hepatocyte growth factor-like protein concentration in the plasma exosomes before and after MgIG treatment group was (23.4 ± 4.9) μg/ml and (13.8 ± 2.2) μg/ml, respectively, and it was down-regulated by about 2 times. Enzyme-linked immunosorbent assay results had consistency with the proteomics results. Conclusion: This study successfully screened the differential proteomic of plasma exosomes before and after MgIG treatment in chronic hepatitis B, and provided experimental basis for studying the molecular mechanism of MgIG treatment for chronic hepatitis B.