Effects of dengue type 2 virus on the apoptosis and autophagy of primary HHSECs and the expres-sion of related genes / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the effects of dengue type 2 virus(DENV-2)on the apopto-sis and autophagy of primary human hepatic sinusoidal endothelial cells(HHSECs)and the expression of ICAM-1 and Beclin-1 at mRNA level and to analyze the possible pathogenic mechanism of DENV-2. Meth-ods Immunohistochemistry(IHC)and flow cytometry analysis(FCM)were performed to identify HHSECs by detecting factor Ⅷ and CD31. The DENV-2 strain was identified by using PCR and HindⅢ. The 50%tissue culture infective dose(TCID50 )of DENV-2 was calculated after infecting C6 / 36 cells with DENV-2. Dynamic changes of DENV-2 NS1 were measured by real-time PCR after infecting HHSECs with DENV-2. CCK-8 was used to dynamically detect the cytotoxicity of DENV-2 to HHSECs. The transcriptional levers of Beclin-1 and ICAM-1 in DENV-2-infected HHSECs were detected by real-time PCR. FCM was performed to analyze the apoptosis of HHSECs and the expression of LC3B and ICAM-1. Results The cells in the exper-imental group were stained brown by DAB and the positive expression rate of CD31 reached 87. 1% . The TICD50 of DENV-2 to C6 / 36 cells was 10-6. 845 / 0. 1 ml. Compared with the uninfected cells,partial se-quences of NS1 gene were expressed in DENV-2-infected HHSECs. DENV-2 suppressed the cell activities of HHSECs. The suppression rates of DENV-2 to HHSECs at 12 h,24 h,36 h and 48 h were respectively (10. 90±1. 24)% ,(16. 40±0. 42)% ,(17. 00±0. 46)% and(29. 60±0. 26)%(P﹤0. 05). The tran-scriptional levels of Beclin-1 and ICAM-1 in HHSECs were significantly increased at the time point of 24 h after DENV-2 infection,the 2-△△Ct values of which were 46. 77±2. 55 and 40. 97±4. 91,respectively. The expression of LC3B and ICAM-1 in DENV-2-infected HHSECs were increased,the peaks of which were reached at 24 h(14. 7% )and 36 h(35. 5% ),respectively. The apoptosis of DENV-2-infected HHSECs was remarkably enhanced at 12 h with an apoptosis rate of 13. 17% . Conclusion HHSECs was susceptible to DENV-2. DENV-2 induced the upregulation of ICAM-1 and the activation of HHSECs. Moreover,autoph-agy and apoptosis of HHSECs could also be induced by DENV-2.