Human cytomegalovirus infection-induced autophagy was associated with the biological behavioral changes of human umbilical vein endothelial cell (HUVEC)

Abstract

In this study, we investigated the enacted role of autophagy in biological behavioral changes of human umbilical vein endothelial cell (HUVEC) infected with human cytomegalovirus (HCMV). It was found that in HCMV-infected cells, the number of punctuate structures increased from 24 h to 48 h p.i. while decreased at 60 h p.i. by GFP-LC3 tranfecting, Monodansylcadaverine (MDC), acridine orange (AO) staining, which suggested that autophagy was induced at early stage, but it was inhibited at later stage in responding to HCMV infection. By real-time qPCR assay, it was revealed that mTOR autophagy pathway inhibitor rapamycin could promote HCMV proliferation in HUVEC cells. After the treatment of autophagy promoting agent, autophagy inhibitor, and mTOR signaling pathway inhibitor in HCMV-infected HUVECs showed similar results to the above findings by Western Blotting assay. Moreover, invasion assay showed that HCMV infection promoted HUVEC cell migration, and ELISA assay showed that HCMV infection increased the expression of adhesion molecules of HUVEC cells. In conclusion, HCMV infection induced autophagy in a time-dependent manner in HUVECs with the involvement of mTOR signaling pathway. The autophagy of HUVEC may enhance its cell invasiveness and the expression of ICAM-1 and VCAM-1. Thus, HCMV infection-induced autophagy was associated with the biological behavioral changes of HUVECs.