Human cytomegalovirus infection perturbs neural progenitor cell fate via the expression of viral microRNAs

Congenital human cytomegalovirus (HCMV) infection is the leading infectious cause of birth defects, including neurodevelopmental disorders. HCMV infection mainly targets neural progenitor cells (NPCs) in fetal brains, inducing abnormal differentiation by altering key regulatory pathways. HCMV expresses a series of viral miRNAs during infection, but their roles, particularly in NPCs, are not fully understood. In this study, we characterized expression profiles of both cellular and viral miRNAs in HCMV-infected NPCs by microarray analysis during early infection time points and investigated the primary effects of these miRNAs on regulating NPC fate. While expression of most cellular miRNAs was unaffected by HCMV infection, one cellular miRNA was upregulated and six were downregulated from 2 to 24 h post infection. Moreover, of 17 HCMV miRNAs evaluated, six were differentially expressed in HCMV-infected NPCs during early infection time points. Primary human NPCs were mock-infected (mock) or infected with HCMV Towne strain at a multiplicity of infection (MOI) of 3 and investigated at early time points of 2, 4, 12 and 24 hpi. RNA samples were subjected to microarray analysis using miRNA microarray chips designed to detect both cellular and HCMV miRNAs based on the miRBase database annotation.