Human Cytomegalovirus Can Induce Alteration of β-Actin mRNA and Microfilaments as Well as Induce Apoptosis in Mesenchymal Stem Cells.

Mesenchymal stem cells (MSCs) is a very important cell system in bone marrow stromal and human cytomegalovirus (CMV) infection is one of the most common complications following stem cells transplantation. Our studies were to investigate the cytoskeleton change as well as the apoptosis induction effects of CMV infection on MSCs. In our study, MSCs were infected by 100,10,1 TCID₅₀ of CMV. After 48h of culture with DMEM supplemented with 10% (v/v) fetal calf serum, MSCs shapes were observed with microscope. CMV particles and ultra structure in the cells were detected with transmission electron microscope. RT-PCR assay was used to detect the mRNA expression of CMV immediate early (IE) gene,β-actin gene and GAPDH genes. Flow Cytometry was used to detect the apoptotic cells. After the infection of CMV, shape of MSCs changed, turning from thin shuttle shape to round and thick ball shape, even escaping from wall. Cell shape changed more dominantly as the CMV titer increased. With transmission electron microscope, CMV particles and typical cellular apoptotic character as well as the ruptured- Microfilaments could be seen in the cells infected by CMV. MSCs infected by CMV could express IE mRNA and the expression of β-actin mRNA decreased in a time- and titer- dependent manner compared with the uninfected cells whose expression of GAPDH mRNA did not change much. With Flow Cytometry, it was found there were more apoptotic and necrosis cells in the cells infected by CMV. These results indicate that CMV can not only infect MSCs and destroy the cytoskeleton in the cells but also can induce apoptosis of the cells, much more attention of CMV infection on MSCs should be paid after stem cells transplantation.